zfs: merge openzfs/zfs@256659204 (zfs-2.2-release) into stable/14

OpenZFS release 2.2.4

Notable upstream pull request merges:
 #15076 fdd97e009 Refactor dmu_prefetch()
 #15225 5972bb856 Use ASSERT0P() to check that a pointer is NULL
 #15381 7ea833100 ZIL: Detect single-threaded workloads
 #15515 8b1a132de ZIO: Optimize zio_flush()
 #15225 d6da6cbd7 Clean up existing VERIFY*() macros
 #15225 5dda8c091 Add VERIFY0P() and ASSERT0P() macros
 #15436 61f3638a3 Add prefetch property
 #15509 6f323353d Add ashift validation when adding devices to a pool
 #15539 ea3f7c12a Extend import_progress kstat with a notes field
 #15635 25ea8ce94 ZIL: Improve next log block size prediction
 #15784 16c223eec Do no use .cfi_negate_ra_state within the assembly on
                  Arm64
 #15839 706307445 vdev probe to slow disk can stall mmp write checker
 #15879 86b39b41a zpool: Fix locale-specific time
 #15927 fa5de0c5c Update resume token at object receive
 #15941 fdd8c0aea BRT: Skip duplicate BRT prefetches
 #15942 889152ce4 Give better message from 'zpool get' with invalid pool
                  name
 #15950 3e91a9c52 BRT: Skip getting length in brt_entry_lookup()
 #15951 19bf54b76 ZAP: Massively switch to _by_dnode() interfaces
 #15954 f7c1db636 BRT: Change brt_pending_tree sorting order
 #15955 457e62d7c BRT: Relax brt_pending_apply() locking
 #15967 c94f73007 BRT: Make BRT block sizes configurable
 #15976 dced953b6 ZAP: Some cleanups/micro-optimizations
 #15983 531572b59 Fix panics when truncating/deleting files
 #15992 5fc134ff2 zvol: use multiple taskq
 #16007 2ea370a4e BRT: Fix holes cloning
 #16008 67995229a zpool: Fix option string, adding -e and fixing order
 #16015 8a5604713 Add support for zfs mount -R <filesystem>
 #16022 026fe7964 Speculative prefetch for reordered requests
 #16040 575872cc3 L2ARC: Relax locking during write
 #16042 d5fb6abd3 Improve dbuf_read() error reporting
 #16051 5d859a2e2 xdr: header cleanup
 #16052 602b5dca7 Fix read errors race after block cloning
 #16057 97d7228f4 Remove db_state DB_NOFILL checks from syncing context
 #16072 f4ce02ae4 Small fix to prefetch ranges aggregation
 #16074 97889c037 return NULL at end of send_progress_thread
 #16086 7aaf6ce9d Add the BTI elf note to the AArch64 SHA2 assembly
 #16094 4d17e200d Add zfetch stats in arcstats
 #16128 3d4d61988 Fix updating the zvol_htable when renaming a zvol
 #16141 b3b37b84e Fix arcstats for FreeBSD after zfetch support

Obtained from:	OpenZFS
OpenZFS commit:	2566592045780e7be7afc899c2496b1ae3af4f4d
OpenZFS tag:	zfs-2.2.4

158 files changed, 4808 insertions, 1646 deletions

diff --git a/cddl/lib/libnvpair/Makefile b/cddl/lib/libnvpair/Makefile
index fb80d7c22ea5..a93ffcbd00de 100644
--- a/cddl/lib/libnvpair/Makefile
+++ b/cddl/lib/libnvpair/Makefile
@@ -27,6 +27,4 @@ CFLAGS+= -I${SRCTOP}/cddl/compat/opensolaris/include
 CFLAGS+= -include ${SRCTOP}/sys/contrib/openzfs/include/os/freebsd/spl/sys/ccompile.h
 CFLAGS+= -DHAVE_ISSETUGID  -DHAVE_CONFIG_H -DHAVE_XDR_BYTESREC
 
-
-CFLAGS.nvpair.c+= -UHAVE_RPC_TYPES
 .include <bsd.lib.mk>
diff --git a/sys/contrib/openzfs/.mailmap b/sys/contrib/openzfs/.mailmap
index 46ef016b93f8..32bdb5209613 100644
--- a/sys/contrib/openzfs/.mailmap
+++ b/sys/contrib/openzfs/.mailmap
@@ -30,6 +30,7 @@ Andreas Dilger <adilger@dilger.ca>
 Andrew Walker <awalker@ixsystems.com>
 Benedikt Neuffer <github@itfriend.de>
 Chengfei Zhu <chengfeix.zhu@intel.com>
+ChenHao Lu <18302010006@fudan.edu.cn>
 Chris Lindee <chris.lindee+github@gmail.com>
 Colm Buckley <colm@tuatha.org>
 Crag Wang <crag0715@gmail.com>
@@ -43,6 +44,7 @@ Glenn Washburn <development@efficientek.com>
 Gordan Bobic <gordan.bobic@gmail.com>
 Gregory Bartholomew <gregory.lee.bartholomew@gmail.com>
 hedong zhang <h_d_zhang@163.com>
+Ilkka Sovanto <github@ilkka.kapsi.fi>
 InsanePrawn <Insane.Prawny@gmail.com>
 Jason Cohen <jwittlincohen@gmail.com>
 Jason Harmening <jason.harmening@gmail.com>
@@ -57,6 +59,7 @@ KernelOfTruth <kerneloftruth@gmail.com>
 Liu Hua <liu.hua130@zte.com.cn>
 Liu Qing <winglq@gmail.com>
 loli10K <ezomori.nozomu@gmail.com>
+Mart Frauenlob <allkind@fastest.cc>
 Matthias Blankertz <matthias@blankertz.org>
 Michael Gmelin <grembo@FreeBSD.org>
 Olivier Mazouffre <olivier.mazouffre@ims-bordeaux.fr>
@@ -73,6 +76,9 @@ WHR <msl0000023508@gmail.com>
 Yanping Gao <yanping.gao@xtaotech.com>
 Youzhong Yang <youzhong@gmail.com>
 
+# Signed-off-by: overriding Author:
+Yuxin Wang <yuxinwang9999@gmail.com> <Bi11gates9999@gmail.com>
+
 # Commits from strange places, long ago
 Brian Behlendorf <behlendorf1@llnl.gov> <behlendo@7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c>
 Brian Behlendorf <behlendorf1@llnl.gov> <behlendo@fedora-17-amd64.(none)>
@@ -102,12 +108,15 @@ Brandon Thetford <brandon@dodecatec.com> <dodexahedron@users.noreply.github.com>
 buzzingwires <buzzingwires@outlook.com> <131118055+buzzingwires@users.noreply.github.com>
 Cedric Maunoury <cedric.maunoury@gmail.com> <38213715+cedricmaunoury@users.noreply.github.com>
 Charles Suh <charles.suh@gmail.com> <charlessuh@users.noreply.github.com>
+Chris Peredun <chris.peredun@ixsystems.com> <126915832+chrisperedun@users.noreply.github.com>
 Dacian Reece-Stremtan <dacianstremtan@gmail.com> <35844628+dacianstremtan@users.noreply.github.com>
 Damian Szuberski <szuberskidamian@gmail.com> <30863496+szubersk@users.noreply.github.com>
 Daniel Hiepler <d-git@coderdu.de> <32984777+heeplr@users.noreply.github.com>
 Daniel Kobras <d.kobras@science-computing.de> <sckobras@users.noreply.github.com>
 Daniel Reichelt <hacking@nachtgeist.net> <nachtgeist@users.noreply.github.com>
 David Quigley <david.quigley@intel.com> <dpquigl@users.noreply.github.com>
+Dennis R. Friedrichsen <dennis.r.friedrichsen@gmail.com> <31087738+dennisfriedrichsen@users.noreply.github.com>
+Dex Wood <slash2314@gmail.com> <slash2314@users.noreply.github.com>
 DHE <git@dehacked.net> <DeHackEd@users.noreply.github.com>
 Dmitri John Ledkov <dimitri.ledkov@canonical.com> <19779+xnox@users.noreply.github.com>
 Dries Michiels <driesm.michiels@gmail.com> <32487486+driesmp@users.noreply.github.com>
@@ -128,6 +137,7 @@ Harry Mallon <hjmallon@gmail.com> <1816667+hjmallon@users.noreply.github.com>
 Hiếu Lê <leorize+oss@disroot.org> <alaviss@users.noreply.github.com>
 Jake Howard <git@theorangeone.net> <RealOrangeOne@users.noreply.github.com>
 James Cowgill <james.cowgill@mips.com> <jcowgill@users.noreply.github.com>
+Jaron Kent-Dobias <jaron@kent-dobias.com> <kentdobias@users.noreply.github.com>
 Jason King <jason.king@joyent.com> <jasonbking@users.noreply.github.com>
 Jeff Dike <jdike@akamai.com> <52420226+jdike@users.noreply.github.com>
 Jitendra Patidar <jitendra.patidar@nutanix.com> <53164267+jsai20@users.noreply.github.com>
@@ -137,7 +147,9 @@ John L. Hammond <john.hammond@intel.com> <35266395+jhammond-intel@users.noreply.
 John-Mark Gurney <jmg@funkthat.com> <jmgurney@users.noreply.github.com>
 John Ramsden <johnramsden@riseup.net> <johnramsden@users.noreply.github.com>
 Jonathon Fernyhough <jonathon@m2x.dev> <559369+jonathonf@users.noreply.github.com>
+Jose Luis Duran <jlduran@gmail.com> <jlduran@users.noreply.github.com>
 Justin Hibbits <chmeeedalf@gmail.com> <chmeeedalf@users.noreply.github.com>
+Kevin Greene <kevin.greene@delphix.com> <104801862+kxgreene@users.noreply.github.com>
 Kevin Jin <lostking2008@hotmail.com> <33590050+jxdking@users.noreply.github.com>
 Kevin P. Fleming <kevin@km6g.us> <kpfleming@users.noreply.github.com>
 Krzysztof Piecuch <piecuch@kpiecuch.pl> <3964215+pikrzysztof@users.noreply.github.com>
@@ -148,9 +160,11 @@ Lorenz Hüdepohl <dev@stellardeath.org> <lhuedepohl@users.noreply.github.com>
 Luís Henriques <henrix@camandro.org> <73643340+lumigch@users.noreply.github.com>
 Marcin Skarbek <git@skarbek.name> <mskarbek@users.noreply.github.com>
 Matt Fiddaman <github@m.fiddaman.uk> <81489167+matt-fidd@users.noreply.github.com>
+Maxim Filimonov <che@bein.link> <part1zano@users.noreply.github.com>
 Max Zettlmeißl <max@zettlmeissl.de> <6818198+maxz@users.noreply.github.com>
 Michael Niewöhner <foss@mniewoehner.de> <c0d3z3r0@users.noreply.github.com>
 Michael Zhivich <mzhivich@akamai.com> <33133421+mzhivich@users.noreply.github.com>
+MigeljanImeri <ImeriMigel@gmail.com> <78048439+MigeljanImeri@users.noreply.github.com>
 Mo Zhou <cdluminate@gmail.com> <5723047+cdluminate@users.noreply.github.com>
 Nick Mattis <nickm970@gmail.com> <nmattis@users.noreply.github.com>
 omni <omni+vagant@hack.org> <79493359+omnivagant@users.noreply.github.com>
@@ -164,6 +178,7 @@ Ping Huang <huangping@smartx.com> <101400146+hpingfs@users.noreply.github.com>
 Piotr P. Stefaniak <pstef@freebsd.org> <pstef@users.noreply.github.com>
 Richard Allen <belperite@gmail.com> <33836503+belperite@users.noreply.github.com>
 Rich Ercolani <rincebrain@gmail.com> <214141+rincebrain@users.noreply.github.com>
+Rick Macklem <rmacklem@uoguelph.ca> <64620010+rmacklem@users.noreply.github.com>
 Rob Wing <rob.wing@klarasystems.com> <98866084+rob-wing@users.noreply.github.com>
 Roman Strashkin <roman.strashkin@nexenta.com> <Ramzec@users.noreply.github.com>
 Ryan Hirasaki <ryanhirasaki@gmail.com> <4690732+RyanHir@users.noreply.github.com>
@@ -174,6 +189,8 @@ Scott Colby <scott@scolby.com> <scolby33@users.noreply.github.com>
 Sean Eric Fagan <kithrup@mac.com> <kithrup@users.noreply.github.com>
 Spencer Kinny <spencerkinny1995@gmail.com> <30333052+Spencer-Kinny@users.noreply.github.com>
 Srikanth N S <srikanth.nagasubbaraoseetharaman@hpe.com> <75025422+nssrikanth@users.noreply.github.com>
+Stefan Lendl <s.lendl@proxmox.com> <1321542+stfl@users.noreply.github.com>
+Thomas Bertschinger <bertschinger@lanl.gov> <101425190+bertschinger@users.noreply.github.com>
 Thomas Geppert <geppi@digitx.de> <geppi@users.noreply.github.com>
 Tim Crawford <tcrawford@datto.com> <crawfxrd@users.noreply.github.com>
 Tom Matthews <tom@axiom-partners.com> <tomtastic@users.noreply.github.com>
@@ -181,6 +198,7 @@ Tony Perkins <tperkins@datto.com> <62951051+tony-zfs@users.noreply.github.com>
 Torsten Wörtwein <twoertwein@gmail.com> <twoertwein@users.noreply.github.com>
 Tulsi Jain <tulsi.jain@delphix.com> <TulsiJain@users.noreply.github.com>
 Václav Skála <skala@vshosting.cz> <33496485+vaclavskala@users.noreply.github.com>
+Vaibhav Bhanawat <vaibhav.bhanawat@delphix.com> <88050553+vaibhav-delphix@users.noreply.github.com>
 Violet Purcell <vimproved@inventati.org> <66446404+vimproved@users.noreply.github.com>
 Vipin Kumar Verma <vipin.verma@hpe.com> <75025470+vermavipinkumar@users.noreply.github.com>
 Wolfgang Bumiller <w.bumiller@proxmox.com> <Blub@users.noreply.github.com>
diff --git a/sys/contrib/openzfs/AUTHORS b/sys/contrib/openzfs/AUTHORS
index be1efb87b34c..d7d55f42d2e7 100644
--- a/sys/contrib/openzfs/AUTHORS
+++ b/sys/contrib/openzfs/AUTHORS
@@ -88,9 +88,11 @@ CONTRIBUTORS:
     Bassu <bassu@phi9.com>
     Ben Allen <bsallen@alcf.anl.gov>
     Ben Cordero <bencord0@condi.me>
+    Benda Xu <orv@debian.org>
     Benedikt Neuffer <github@itfriend.de>
     Benjamin Albrecht <git@albrecht.io>
     Benjamin Gentil <benjgentil.pro@gmail.com>
+    Benjamin Sherman <benjamin@holyarmy.org>
     Ben McGough <bmcgough@fredhutch.org>
     Ben Rubson <ben.rubson@gmail.com>
     Ben Wolsieffer <benwolsieffer@gmail.com>
@@ -111,6 +113,7 @@ CONTRIBUTORS:
     bzzz77 <bzzz.tomas@gmail.com>
     cable2999 <cable2999@users.noreply.github.com>
     Caleb James DeLisle <calebdelisle@lavabit.com>
+    Cameron Harr <harr1@llnl.gov>
     Cao Xuewen <cao.xuewen@zte.com.cn>
     Carlo Landmeter <clandmeter@gmail.com>
     Carlos Alberto Lopez Perez <clopez@igalia.com>
@@ -120,12 +123,15 @@ CONTRIBUTORS:
     Chen Can <chen.can2@zte.com.cn>
     Chengfei Zhu <chengfeix.zhu@intel.com>
     Chen Haiquan <oc@yunify.com>
+    ChenHao Lu <18302010006@fudan.edu.cn>
     Chip Parker <aparker@enthought.com>
     Chris Burroughs <chris.burroughs@gmail.com>
+    Chris Davidson <christopher.davidson@gmail.com>
     Chris Dunlap <cdunlap@llnl.gov>
     Chris Dunlop <chris@onthe.net.au>
     Chris Lindee <chris.lindee+github@gmail.com>
     Chris McDonough <chrism@plope.com>
+    Chris Peredun <chris.peredun@ixsystems.com>
     Chris Siden <chris.siden@delphix.com>
     Chris Siebenmann <cks.github@cs.toronto.edu>
     Christer Ekholm <che@chrekh.se>
@@ -144,6 +150,7 @@ CONTRIBUTORS:
     Clint Armstrong <clint@clintarmstrong.net>
     Coleman Kane <ckane@colemankane.org>
     Colin Ian King <colin.king@canonical.com>
+    Colin Percival <cperciva@tarsnap.com>
     Colm Buckley <colm@tuatha.org>
     Crag Wang <crag0715@gmail.com>
     Craig Loomis <cloomis@astro.princeton.edu>
@@ -156,6 +163,7 @@ CONTRIBUTORS:
     Damiano Albani <damiano.albani@gmail.com>
     Damian Szuberski <szuberskidamian@gmail.com>
     Damian Wojsław <damian@wojslaw.pl>
+    Daniel Berlin <dberlin@dberlin.org>
     Daniel Hiepler <d-git@coderdu.de>
     Daniel Hoffman <dj.hoffman@delphix.com>
     Daniel Kobras <d.kobras@science-computing.de>
@@ -176,8 +184,10 @@ CONTRIBUTORS:
     David Quigley <david.quigley@intel.com>
     Debabrata Banerjee <dbanerje@akamai.com>
     D. Ebdrup <debdrup@freebsd.org>
+    Dennis R. Friedrichsen <dennis.r.friedrichsen@gmail.com>
     Denys Rtveliashvili <denys@rtveliashvili.name>
     Derek Dai <daiderek@gmail.com>
+    Dex Wood <slash2314@gmail.com>
     DHE <git@dehacked.net>
     Didier Roche <didrocks@ubuntu.com>
     Dimitri John Ledkov <xnox@ubuntu.com>
@@ -235,9 +245,11 @@ CONTRIBUTORS:
     Gionatan Danti <g.danti@assyoma.it>
     Giuseppe Di Natale <guss80@gmail.com>
     Glenn Washburn <development@efficientek.com>
+    gofaster <felix.gofaster@gmail.com>
     Gordan Bobic <gordan@redsleeve.org>
     Gordon Bergling <gbergling@googlemail.com>
     Gordon Ross <gwr@nexenta.com>
+    Gordon Tetlow <gordon@freebsd.org>
     Graham Christensen <graham@grahamc.com>
     Graham Perrin <grahamperrin@gmail.com>
     Gregor Kopka <gregor@kopka.net>
@@ -265,6 +277,7 @@ CONTRIBUTORS:
     Igor Kozhukhov <ikozhukhov@gmail.com>
     Igor Lvovsky <ilvovsky@gmail.com>
     ilbsmart <wgqimut@gmail.com>
+    Ilkka Sovanto <github@ilkka.kapsi.fi>
     illiliti <illiliti@protonmail.com>
     ilovezfs <ilovezfs@icloud.com>
     InsanePrawn <Insane.Prawny@gmail.com>
@@ -280,9 +293,11 @@ CONTRIBUTORS:
     Jan Engelhardt <jengelh@inai.de>
     Jan Kryl <jan.kryl@nexenta.com>
     Jan Sanislo <oystr@cs.washington.edu>
+    Jaron Kent-Dobias <jaron@kent-dobias.com>
     Jason Cohen <jwittlincohen@gmail.com>
     Jason Harmening <jason.harmening@gmail.com>
     Jason King <jason.brian.king@gmail.com>
+    Jason Lee <jasonlee@lanl.gov>
     Jason Zaman <jasonzaman@gmail.com>
     Javen Wu <wu.javen@gmail.com>
     Jean-Baptiste Lallement <jean-baptiste@ubuntu.com>
@@ -313,6 +328,7 @@ CONTRIBUTORS:
     Jonathon Fernyhough <jonathon@m2x.dev>
     Jorgen Lundman <lundman@lundman.net>
     Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
+    Jose Luis Duran <jlduran@gmail.com>
     Josh Soref <jsoref@users.noreply.github.com>
     Joshua M. Clulow <josh@sysmgr.org>
     José Luis Salvador Rufo <salvador.joseluis@gmail.com>
@@ -336,8 +352,10 @@ CONTRIBUTORS:
     Kash Pande <kash@tripleback.net>
     Kay Pedersen <christianpe96@gmail.com>
     Keith M Wesolowski <wesolows@foobazco.org>
+    Kent Ross <k@mad.cash>
     KernelOfTruth <kerneloftruth@gmail.com>
     Kevin Bowling <kevin.bowling@kev009.com>
+    Kevin Greene <kevin.greene@delphix.com>
     Kevin Jin <lostking2008@hotmail.com>
     Kevin P. Fleming <kevin@km6g.us>
     Kevin Tanguy <kevin.tanguy@ovh.net>
@@ -389,6 +407,7 @@ CONTRIBUTORS:
     Mark Shellenbaum <Mark.Shellenbaum@Oracle.COM>
     marku89 <mar42@kola.li>
     Mark Wright <markwright@internode.on.net>
+    Mart Frauenlob <allkind@fastest.cc>
     Martin Matuska <mm@FreeBSD.org>
     Martin Rüegg <martin.rueegg@metaworx.ch>
     Massimo Maggi <me@massimo-maggi.eu>
@@ -405,6 +424,7 @@ CONTRIBUTORS:
     Matus Kral <matuskral@me.com>
     Mauricio Faria de Oliveira <mfo@canonical.com>
     Max Grossman <max.grossman@delphix.com>
+    Maxim Filimonov <che@bein.link>
     Maximilian Mehnert <maximilian.mehnert@gmx.de>
     Max Zettlmeißl <max@zettlmeissl.de>
     Md Islam <mdnahian@outlook.com>
@@ -417,6 +437,7 @@ CONTRIBUTORS:
     Michael Niewöhner <foss@mniewoehner.de>
     Michael Zhivich <mzhivich@akamai.com>
     Michal Vasilek <michal@vasilek.cz>
+    MigeljanImeri <ImeriMigel@gmail.com>
     Mike Gerdts <mike.gerdts@joyent.com>
     Mike Harsch <mike@harschsystems.com>
     Mike Leddy <mike.leddy@gmail.com>
@@ -448,6 +469,7 @@ CONTRIBUTORS:
     Olaf Faaland <faaland1@llnl.gov>
     Oleg Drokin <green@linuxhacker.ru>
     Oleg Stepura <oleg@stepura.com>
+    Olivier Certner <olce.freebsd@certner.fr>
     Olivier Mazouffre <olivier.mazouffre@ims-bordeaux.fr>
     omni <omni+vagant@hack.org>
     Orivej Desh <orivej@gmx.fr>
@@ -479,6 +501,7 @@ CONTRIBUTORS:
     Prasad Joshi <prasadjoshi124@gmail.com>
     privb0x23 <privb0x23@users.noreply.github.com>
     P.SCH <p88@yahoo.com>
+    Quartz <yyhran@163.com>
     Quentin Zdanis <zdanisq@gmail.com>
     Rafael Kitover <rkitover@gmail.com>
     RageLtMan <sempervictus@users.noreply.github.com>
@@ -491,11 +514,15 @@ CONTRIBUTORS:
     Riccardo Schirone <rschirone91@gmail.com>
     Richard Allen <belperite@gmail.com>
     Richard Elling <Richard.Elling@RichardElling.com>
+    Richard Kojedzinszky <richard@kojedz.in>
     Richard Laager <rlaager@wiktel.com>
     Richard Lowe <richlowe@richlowe.net>
     Richard Sharpe <rsharpe@samba.org>
     Richard Yao <ryao@gentoo.org>
     Rich Ercolani <rincebrain@gmail.com>
+    Rick Macklem <rmacklem@uoguelph.ca>
+    rilysh <nightquick@proton.me>
+    Robert Evans <evansr@google.com>
     Robert Novak <sailnfool@gmail.com>
     Roberto Ricci <ricci@disroot.org>
     Rob Norris <robn@despairlabs.com>
@@ -509,7 +536,9 @@ CONTRIBUTORS:
     Ryan Lahfa <masterancpp@gmail.com>
     Ryan Libby <rlibby@FreeBSD.org>
     Ryan Moeller <freqlabs@FreeBSD.org>
+    Sam Atkinson <samatk@amazon.com>
     Sam Hathaway <github.com@munkynet.org>
+    Sam James <sam@gentoo.org>
     Sam Lunt <samuel.j.lunt@gmail.com>
     Samuel VERSCHELDE <stormi-github@ylix.fr>
     Samuel Wycliffe <samuelwycliffe@gmail.com>
@@ -530,6 +559,8 @@ CONTRIBUTORS:
     Shaan Nobee <sniper111@gmail.com>
     Shampavman <sham.pavman@nexenta.com>
     Shaun Tancheff <shaun@aeonazure.com>
+    Shawn Bayern <sbayern@law.fsu.edu>
+    Shengqi Chen <harry-chen@outlook.com>
     Shen Yan <shenyanxxxy@qq.com>
     Simon Guest <simon.guest@tesujimath.org>
     Simon Klinkert <simon.klinkert@gmail.com>
@@ -537,6 +568,7 @@ CONTRIBUTORS:
     Spencer Kinny <spencerkinny1995@gmail.com>
     Srikanth N S <srikanth.nagasubbaraoseetharaman@hpe.com>
     Stanislav Seletskiy <s.seletskiy@gmail.com>
+    Stefan Lendl <s.lendl@proxmox.com>
     Steffen Müthing <steffen.muething@iwr.uni-heidelberg.de>
     Stephen Blinick <stephen.blinick@delphix.com>
     sterlingjensen <sterlingjensen@users.noreply.github.com>
@@ -557,6 +589,7 @@ CONTRIBUTORS:
     Teodor Spæren <teodor_spaeren@riseup.net>
     TerraTech <TerraTech@users.noreply.github.com>
     Thijs Cramer <thijs.cramer@gmail.com>
+    Thomas Bertschinger <bertschinger@lanl.gov>
     Thomas Geppert <geppi@digitx.de>
     Thomas Lamprecht <guggentom@hotmail.de>
     Till Maas <opensource@till.name>
@@ -586,6 +619,7 @@ CONTRIBUTORS:
     Turbo Fredriksson <turbo@bayour.com>
     Tyler J. Stachecki <stachecki.tyler@gmail.com>
     Umer Saleem <usaleem@ixsystems.com>
+    Vaibhav Bhanawat <vaibhav.bhanawat@delphix.com>
     Valmiky Arquissandas <kayvlim@gmail.com>
     Val Packett <val@packett.cool>
     Vince van Oosten <techhazard@codeforyouand.me>
@@ -614,6 +648,7 @@ CONTRIBUTORS:
     yuina822 <ayuichi@club.kyutech.ac.jp>
     YunQiang Su <syq@debian.org>
     Yuri Pankov <yuri.pankov@gmail.com>
+    Yuxin Wang <yuxinwang9999@gmail.com>
     Yuxuan Shui <yshuiv7@gmail.com>
     Zachary Bedell <zac@thebedells.org>
     Zach Dykstra <dykstra.zachary@gmail.com>
diff --git a/sys/contrib/openzfs/META b/sys/contrib/openzfs/META
index d64414e32225..383fa37fd42a 100644
--- a/sys/contrib/openzfs/META
+++ b/sys/contrib/openzfs/META
@@ -1,10 +1,10 @@
 Meta:          1
 Name:          zfs
 Branch:        1.0
-Version:       2.2.3
+Version:       2.2.4
 Release:       1
 Release-Tags:  relext
 License:       CDDL
 Author:        OpenZFS
-Linux-Maximum: 6.7
+Linux-Maximum: 6.8
 Linux-Minimum: 3.10
diff --git a/sys/contrib/openzfs/cmd/arc_summary b/sys/contrib/openzfs/cmd/arc_summary
index 9c69ec4f8ccc..100fb1987a8b 100755
--- a/sys/contrib/openzfs/cmd/arc_summary
+++ b/sys/contrib/openzfs/cmd/arc_summary
@@ -793,18 +793,27 @@ def section_dmu(kstats_dict):
 
     zfetch_stats = isolate_section('zfetchstats', kstats_dict)
 
-    zfetch_access_total = int(zfetch_stats['hits'])+int(zfetch_stats['misses'])
+    zfetch_access_total = int(zfetch_stats['hits']) +\
+        int(zfetch_stats['future']) + int(zfetch_stats['stride']) +\
+        int(zfetch_stats['past']) + int(zfetch_stats['misses'])
 
     prt_1('DMU predictive prefetcher calls:', f_hits(zfetch_access_total))
     prt_i2('Stream hits:',
            f_perc(zfetch_stats['hits'], zfetch_access_total),
            f_hits(zfetch_stats['hits']))
+    future = int(zfetch_stats['future']) + int(zfetch_stats['stride'])
+    prt_i2('Hits ahead of stream:', f_perc(future, zfetch_access_total),
+           f_hits(future))
+    prt_i2('Hits behind stream:',
+           f_perc(zfetch_stats['past'], zfetch_access_total),
+           f_hits(zfetch_stats['past']))
     prt_i2('Stream misses:',
            f_perc(zfetch_stats['misses'], zfetch_access_total),
            f_hits(zfetch_stats['misses']))
     prt_i2('Streams limit reached:',
            f_perc(zfetch_stats['max_streams'], zfetch_stats['misses']),
            f_hits(zfetch_stats['max_streams']))
+    prt_i1('Stream strides:', f_hits(zfetch_stats['stride']))
     prt_i1('Prefetches issued', f_hits(zfetch_stats['io_issued']))
     print()
 
diff --git a/sys/contrib/openzfs/cmd/arcstat.in b/sys/contrib/openzfs/cmd/arcstat.in
index 8df1c62f7e86..c4f10a1d6d3b 100755
--- a/sys/contrib/openzfs/cmd/arcstat.in
+++ b/sys/contrib/openzfs/cmd/arcstat.in
@@ -157,6 +157,16 @@ cols = {
     "free":       [5, 1024, "ARC free memory"],
     "avail":      [5, 1024, "ARC available memory"],
     "waste":      [5, 1024, "Wasted memory due to round up to pagesize"],
+    "ztotal":     [6, 1000, "zfetch total prefetcher calls per second"],
+    "zhits":      [5, 1000, "zfetch stream hits per second"],
+    "zahead":     [6, 1000, "zfetch hits ahead of streams per second"],
+    "zpast":      [5, 1000, "zfetch hits behind streams per second"],
+    "zmisses":    [7, 1000, "zfetch stream misses per second"],
+    "zmax":       [4, 1000, "zfetch limit reached per second"],
+    "zfuture":    [7, 1000, "zfetch stream future per second"],
+    "zstride":    [7, 1000, "zfetch stream strides per second"],
+    "zissued":    [7, 1000, "zfetch prefetches issued per second"],
+    "zactive":    [7, 1000, "zfetch prefetches active per second"],
 }
 
 v = {}
@@ -164,6 +174,8 @@ hdr = ["time", "read", "ddread", "ddh%", "dmread", "dmh%", "pread", "ph%",
        "size", "c", "avail"]
 xhdr = ["time", "mfu", "mru", "mfug", "mrug", "unc", "eskip", "mtxmis",
         "dread", "pread", "read"]
+zhdr = ["time", "ztotal", "zhits", "zahead", "zpast", "zmisses", "zmax",
+        "zfuture", "zstride", "zissued", "zactive"]
 sint = 1               # Default interval is 1 second
 count = 1              # Default count is 1
 hdr_intr = 20          # Print header every 20 lines of output
@@ -188,6 +200,8 @@ if sys.platform.startswith('freebsd'):
 
         k = [ctl for ctl in sysctl.filter('kstat.zfs.misc.arcstats')
              if ctl.type != sysctl.CTLTYPE_NODE]
+        k += [ctl for ctl in sysctl.filter('kstat.zfs.misc.zfetchstats')
+             if ctl.type != sysctl.CTLTYPE_NODE]
 
         if not k:
             sys.exit(1)
@@ -199,19 +213,28 @@ if sys.platform.startswith('freebsd'):
                 continue
 
             name, value = s.name, s.value
-            # Trims 'kstat.zfs.misc.arcstats' from the name
-            kstat[name[24:]] = int(value)
+
+            if "arcstats" in name:
+                # Trims 'kstat.zfs.misc.arcstats' from the name
+                kstat[name[24:]] = int(value)
+            else:
+                kstat["zfetch_" + name[27:]] = int(value)
 
 elif sys.platform.startswith('linux'):
     def kstat_update():
         global kstat
 
-        k = [line.strip() for line in open('/proc/spl/kstat/zfs/arcstats')]
+        k1 = [line.strip() for line in open('/proc/spl/kstat/zfs/arcstats')]
 
-        if not k:
+        k2 = ["zfetch_" + line.strip() for line in
+             open('/proc/spl/kstat/zfs/zfetchstats')]
+
+        if k1 is None or k2 is None:
             sys.exit(1)
 
-        del k[0:2]
+        del k1[0:2]
+        del k2[0:2]
+        k = k1 + k2
         kstat = {}
 
         for s in k:
@@ -239,6 +262,7 @@ def usage():
     sys.stderr.write("\t -v : List all possible field headers and definitions"
                      "\n")
     sys.stderr.write("\t -x : Print extended stats\n")
+    sys.stderr.write("\t -z : Print zfetch stats\n")
     sys.stderr.write("\t -f : Specify specific fields to print (see -v)\n")
     sys.stderr.write("\t -o : Redirect output to the specified file\n")
     sys.stderr.write("\t -s : Override default field separator with custom "
@@ -357,6 +381,7 @@ def init():
     global count
     global hdr
     global xhdr
+    global zhdr
     global opfile
     global sep
     global out
@@ -368,15 +393,17 @@ def init():
     xflag = False
     hflag = False
     vflag = False
+    zflag = False
     i = 1
 
     try:
         opts, args = getopt.getopt(
             sys.argv[1:],
-            "axo:hvs:f:p",
+            "axzo:hvs:f:p",
             [
                 "all",
                 "extended",
+                "zfetch",
                 "outfile",
                 "help",
                 "verbose",
@@ -410,13 +437,15 @@ def init():
             i += 1
         if opt in ('-p', '--parsable'):
             pretty_print = False
+        if opt in ('-z', '--zfetch'):
+            zflag = True
         i += 1
 
     argv = sys.argv[i:]
     sint = int(argv[0]) if argv else sint
     count = int(argv[1]) if len(argv) > 1 else (0 if len(argv) > 0 else 1)
 
-    if hflag or (xflag and desired_cols):
+    if hflag or (xflag and zflag) or ((zflag or xflag) and desired_cols):
         usage()
 
     if vflag:
@@ -425,6 +454,9 @@ def init():
     if xflag:
         hdr = xhdr
 
+    if zflag:
+        hdr = zhdr
+
     update_hdr_intr()
 
     # check if L2ARC exists
@@ -569,6 +601,17 @@ def calculate():
     v["el2mru"] = d["evict_l2_eligible_mru"] // sint
     v["el2inel"] = d["evict_l2_ineligible"] // sint
     v["mtxmis"] = d["mutex_miss"] // sint
+    v["ztotal"] = (d["zfetch_hits"] + d["zfetch_future"] + d["zfetch_stride"] +
+                   d["zfetch_past"] + d["zfetch_misses"]) // sint
+    v["zhits"] = d["zfetch_hits"] // sint
+    v["zahead"] = (d["zfetch_future"] + d["zfetch_stride"]) // sint
+    v["zpast"] = d["zfetch_past"] // sint
+    v["zmisses"] = d["zfetch_misses"] // sint
+    v["zmax"] = d["zfetch_max_streams"] // sint
+    v["zfuture"] = d["zfetch_future"] // sint
+    v["zstride"] = d["zfetch_stride"] // sint
+    v["zissued"] = d["zfetch_io_issued"] // sint
+    v["zactive"] = d["zfetch_io_active"] // sint
 
     if l2exist:
         v["l2hits"] = d["l2_hits"] // sint
diff --git a/sys/contrib/openzfs/cmd/zed/agents/fmd_api.c b/sys/contrib/openzfs/cmd/zed/agents/fmd_api.c
index 4a6cfbf8c05c..fe43e2ab971e 100644
--- a/sys/contrib/openzfs/cmd/zed/agents/fmd_api.c
+++ b/sys/contrib/openzfs/cmd/zed/agents/fmd_api.c
@@ -22,6 +22,7 @@
  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  *
  * Copyright (c) 2016, Intel Corporation.
+ * Copyright (c) 2023, Klara Inc.
  */
 
 /*
@@ -231,28 +232,6 @@ fmd_prop_get_int32(fmd_hdl_t *hdl, const char *name)
 	if (strcmp(name, "spare_on_remove") == 0)
 		return (1);
 
-	if (strcmp(name, "io_N") == 0 || strcmp(name, "checksum_N") == 0)
-		return (10);	/* N = 10 events */
-
-	return (0);
-}
-
-int64_t
-fmd_prop_get_int64(fmd_hdl_t *hdl, const char *name)
-{
-	(void) hdl;
-
-	/*
-	 * These can be looked up in mp->modinfo->fmdi_props
-	 * For now we just hard code for phase 2. In the
-	 * future, there can be a ZED based override.
-	 */
-	if (strcmp(name, "remove_timeout") == 0)
-		return (15ULL * 1000ULL * 1000ULL * 1000ULL);	/* 15 sec */
-
-	if (strcmp(name, "io_T") == 0 || strcmp(name, "checksum_T") == 0)
-		return (1000ULL * 1000ULL * 1000ULL * 600ULL);	/* 10 min */
-
 	return (0);
 }
 
@@ -535,20 +514,31 @@ fmd_serd_exists(fmd_hdl_t *hdl, const char *name)
 	return (fmd_serd_eng_lookup(&mp->mod_serds, name) != NULL);
 }
 
-void
-fmd_serd_reset(fmd_hdl_t *hdl, const char *name)
+int
+fmd_serd_active(fmd_hdl_t *hdl, const char *name)
 {
 	fmd_module_t *mp = (fmd_module_t *)hdl;
 	fmd_serd_eng_t *sgp;
 
 	if ((sgp = fmd_serd_eng_lookup(&mp->mod_serds, name)) == NULL) {
 		zed_log_msg(LOG_ERR, "serd engine '%s' does not exist", name);
-		return;
+		return (0);
 	}
+	return (fmd_serd_eng_fired(sgp) || !fmd_serd_eng_empty(sgp));
+}
 
-	fmd_serd_eng_reset(sgp);
+void
+fmd_serd_reset(fmd_hdl_t *hdl, const char *name)
+{
+	fmd_module_t *mp = (fmd_module_t *)hdl;
+	fmd_serd_eng_t *sgp;
 
-	fmd_hdl_debug(hdl, "serd_reset %s", name);
+	if ((sgp = fmd_serd_eng_lookup(&mp->mod_serds, name)) == NULL) {
+		zed_log_msg(LOG_ERR, "serd engine '%s' does not exist", name);
+	} else {
+		fmd_serd_eng_reset(sgp);
+		fmd_hdl_debug(hdl, "serd_reset %s", name);
+	}
 }
 
 int
@@ -556,16 +546,21 @@ fmd_serd_record(fmd_hdl_t *hdl, const char *name, fmd_event_t *ep)
 {
 	fmd_module_t *mp = (fmd_module_t *)hdl;
 	fmd_serd_eng_t *sgp;
-	int err;
 
 	if ((sgp = fmd_serd_eng_lookup(&mp->mod_serds, name)) == NULL) {
 		zed_log_msg(LOG_ERR, "failed to add record to SERD engine '%s'",
 		    name);
 		return (0);
 	}
-	err = fmd_serd_eng_record(sgp, ep->ev_hrt);
+	return (fmd_serd_eng_record(sgp, ep->ev_hrt));
+}
+
+void
+fmd_serd_gc(fmd_hdl_t *hdl)
+{
+	fmd_module_t *mp = (fmd_module_t *)hdl;
 
-	return (err);
+	fmd_serd_hash_apply(&mp->mod_serds, fmd_serd_eng_gc, NULL);
 }
 
 /* FMD Timers */
@@ -579,7 +574,7 @@ _timer_notify(union sigval sv)
 	const fmd_hdl_ops_t *ops = mp->mod_info->fmdi_ops;
 	struct itimerspec its;
 
-	fmd_hdl_debug(hdl, "timer fired (%p)", ftp->ft_tid);
+	fmd_hdl_debug(hdl, "%s timer fired (%p)", mp->mod_name, ftp->ft_tid);
 
 	/* disarm the timer */
 	memset(&its, 0, sizeof (struct itimerspec));
diff --git a/sys/contrib/openzfs/cmd/zed/agents/fmd_api.h b/sys/contrib/openzfs/cmd/zed/agents/fmd_api.h
index b940d0d395ec..8471feecf33f 100644
--- a/sys/contrib/openzfs/cmd/zed/agents/fmd_api.h
+++ b/sys/contrib/openzfs/cmd/zed/agents/fmd_api.h
@@ -151,7 +151,6 @@ extern void fmd_hdl_vdebug(fmd_hdl_t *, const char *, va_list);
 extern void fmd_hdl_debug(fmd_hdl_t *, const char *, ...);
 
 extern int32_t fmd_prop_get_int32(fmd_hdl_t *, const char *);
-extern int64_t fmd_prop_get_int64(fmd_hdl_t *, const char *);
 
 #define	FMD_STAT_NOALLOC	0x0	/* fmd should use caller's memory */
 #define	FMD_STAT_ALLOC		0x1	/* fmd should allocate stats memory */
@@ -195,10 +194,12 @@ extern size_t fmd_buf_size(fmd_hdl_t *, fmd_case_t *, const char *);
 extern void fmd_serd_create(fmd_hdl_t *, const char *, uint_t, hrtime_t);
 extern void fmd_serd_destroy(fmd_hdl_t *, const char *);
 extern int fmd_serd_exists(fmd_hdl_t *, const char *);
+extern int fmd_serd_active(fmd_hdl_t *, const char *);
 extern void fmd_serd_reset(fmd_hdl_t *, const char *);
 extern int fmd_serd_record(fmd_hdl_t *, const char *, fmd_event_t *);
 extern int fmd_serd_fired(fmd_hdl_t *, const char *);
 extern int fmd_serd_empty(fmd_hdl_t *, const char *);
+extern void fmd_serd_gc(fmd_hdl_t *);
 
 extern id_t fmd_timer_install(fmd_hdl_t *, void *, fmd_event_t *, hrtime_t);
 extern void fmd_timer_remove(fmd_hdl_t *, id_t);
diff --git a/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.c b/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.c
index 0bb2c535f094..f942e62b3f48 100644
--- a/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.c
+++ b/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.c
@@ -310,8 +310,9 @@ fmd_serd_eng_reset(fmd_serd_eng_t *sgp)
 }
 
 void
-fmd_serd_eng_gc(fmd_serd_eng_t *sgp)
+fmd_serd_eng_gc(fmd_serd_eng_t *sgp, void *arg)
 {
+	(void) arg;
 	fmd_serd_elem_t *sep, *nep;
 	hrtime_t hrt;
 
diff --git a/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.h b/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.h
index 25b6888e61f2..80ff9a3b25b8 100644
--- a/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.h
+++ b/sys/contrib/openzfs/cmd/zed/agents/fmd_serd.h
@@ -77,7 +77,7 @@ extern int fmd_serd_eng_fired(fmd_serd_eng_t *);
 extern int fmd_serd_eng_empty(fmd_serd_eng_t *);
 
 extern void fmd_serd_eng_reset(fmd_serd_eng_t *);
-extern void fmd_serd_eng_gc(fmd_serd_eng_t *);
+extern void fmd_serd_eng_gc(fmd_serd_eng_t *, void *);
 
 #ifdef	__cplusplus
 }
diff --git a/sys/contrib/openzfs/cmd/zed/agents/zfs_diagnosis.c b/sys/contrib/openzfs/cmd/zed/agents/zfs_diagnosis.c
index f6ba334a3ba3..e0ad00800add 100644
--- a/sys/contrib/openzfs/cmd/zed/agents/zfs_diagnosis.c
+++ b/sys/contrib/openzfs/cmd/zed/agents/zfs_diagnosis.c
@@ -23,6 +23,7 @@
  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2016, Intel Corporation.
+ * Copyright (c) 2023, Klara Inc.
  */
 
 #include <stddef.h>
@@ -47,11 +48,16 @@
 #define	DEFAULT_CHECKSUM_T	600	/* seconds */
 #define	DEFAULT_IO_N		10	/* events */
 #define	DEFAULT_IO_T		600	/* seconds */
+#define	DEFAULT_SLOW_IO_N	10	/* events */
+#define	DEFAULT_SLOW_IO_T	30	/* seconds */
+
+#define	CASE_GC_TIMEOUT_SECS	43200	/* 12 hours */
 
 /*
- * Our serd engines are named 'zfs_<pool_guid>_<vdev_guid>_{checksum,io}'.  This
- * #define reserves enough space for two 64-bit hex values plus the length of
- * the longest string.
+ * Our serd engines are named in the following format:
+ *     'zfs_<pool_guid>_<vdev_guid>_{checksum,io,slow_io}'
+ * This #define reserves enough space for two 64-bit hex values plus the
+ * length of the longest string.
  */
 #define	MAX_SERDLEN	(16 * 2 + sizeof ("zfs___checksum"))
 
@@ -68,6 +74,7 @@ typedef struct zfs_case_data {
 	int		zc_pool_state;
 	char		zc_serd_checksum[MAX_SERDLEN];
 	char		zc_serd_io[MAX_SERDLEN];
+	char		zc_serd_slow_io[MAX_SERDLEN];
 	int		zc_has_remove_timer;
 } zfs_case_data_t;
 
@@ -114,7 +121,8 @@ zfs_de_stats_t zfs_stats = {
 	{ "resource_drops", FMD_TYPE_UINT64, "resource related ereports" }
 };
 
-static hrtime_t zfs_remove_timeout;
+/* wait 15 seconds after a removal */
+static hrtime_t zfs_remove_timeout = SEC2NSEC(15);
 
 uu_list_pool_t *zfs_case_pool;
 uu_list_t *zfs_cases;
@@ -124,6 +132,8 @@ uu_list_t *zfs_cases;
 #define	ZFS_MAKE_EREPORT(type)	\
     FM_EREPORT_CLASS "." ZFS_ERROR_CLASS "." type
 
+static void zfs_purge_cases(fmd_hdl_t *hdl);
+
 /*
  * Write out the persistent representation of an active case.
  */
@@ -171,6 +181,42 @@ zfs_case_unserialize(fmd_hdl_t *hdl, fmd_case_t *cp)
 }
 
 /*
+ * count other unique slow-io cases in a pool
+ */
+static uint_t
+zfs_other_slow_cases(fmd_hdl_t *hdl, const zfs_case_data_t *zfs_case)
+{
+	zfs_case_t *zcp;
+	uint_t cases = 0;
+	static hrtime_t next_check = 0;
+
+	/*
+	 * Note that plumbing in some external GC would require adding locking,
+	 * since most of this module code is not thread safe and assumes there
+	 * is only one thread running against the module. So we perform GC here
+	 * inline periodically so that future delay induced faults will be
+	 * possible once the issue causing multiple vdev delays is resolved.
+	 */
+	if (gethrestime_sec() > next_check) {
+		/* Periodically purge old SERD entries and stale cases */
+		fmd_serd_gc(hdl);
+		zfs_purge_cases(hdl);
+		next_check = gethrestime_sec() + CASE_GC_TIMEOUT_SECS;
+	}
+
+	for (zcp = uu_list_first(zfs_cases); zcp != NULL;
+	    zcp = uu_list_next(zfs_cases, zcp)) {
+		if (zcp->zc_data.zc_pool_guid == zfs_case->zc_pool_guid &&
+		    zcp->zc_data.zc_vdev_guid != zfs_case->zc_vdev_guid &&
+		    zcp->zc_data.zc_serd_slow_io[0] != '\0' &&
+		    fmd_serd_active(hdl, zcp->zc_data.zc_serd_slow_io)) {
+			cases++;
+		}
+	}
+	return (cases);
+}
+
+/*
  * Iterate over any active cases.  If any cases are associated with a pool or
  * vdev which is no longer present on the system, close the associated case.
  */
@@ -376,6 +422,14 @@ zfs_serd_name(char *buf, uint64_t pool_guid, uint64_t vdev_guid,
 	    (long long unsigned int)vdev_guid, type);
 }
 
+static void
+zfs_case_retire(fmd_hdl_t *hdl, zfs_case_t *zcp)
+{
+	fmd_hdl_debug(hdl, "retiring case");
+
+	fmd_case_close(hdl, zcp->zc_case);
+}
+
 /*
  * Solve a given ZFS case.  This first checks to make sure the diagnosis is
  * still valid, as well as cleaning up any pending timer associated with the
@@ -632,9 +686,7 @@ zfs_fm_recv(fmd_hdl_t *hdl, fmd_event_t *ep, nvlist_t *nvl, const char *class)
 		if (strcmp(class,
 		    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_DATA)) == 0 ||
 		    strcmp(class,
-		    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE)) == 0 ||
-		    strcmp(class,
-		    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_DELAY)) == 0) {
+		    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE)) == 0) {
 			zfs_stats.resource_drops.fmds_value.ui64++;
 			return;
 		}
@@ -702,6 +754,9 @@ zfs_fm_recv(fmd_hdl_t *hdl, fmd_event_t *ep, nvlist_t *nvl, const char *class)
 			if (zcp->zc_data.zc_serd_checksum[0] != '\0')
 				fmd_serd_reset(hdl,
 				    zcp->zc_data.zc_serd_checksum);
+			if (zcp->zc_data.zc_serd_slow_io[0] != '\0')
+				fmd_serd_reset(hdl,
+				    zcp->zc_data.zc_serd_slow_io);
 		} else if (fmd_nvl_class_match(hdl, nvl,
 		    ZFS_MAKE_RSRC(FM_RESOURCE_STATECHANGE))) {
 			uint64_t state = 0;
@@ -730,7 +785,11 @@ zfs_fm_recv(fmd_hdl_t *hdl, fmd_event_t *ep, nvlist_t *nvl, const char *class)
 	if (fmd_case_solved(hdl, zcp->zc_case))
 		return;
 
-	fmd_hdl_debug(hdl, "error event '%s'", class);
+	if (vdev_guid)
+		fmd_hdl_debug(hdl, "error event '%s', vdev %llu", class,
+		    vdev_guid);
+	else
+		fmd_hdl_debug(hdl, "error event '%s'", class);
 
 	/*
 	 * Determine if we should solve the case and generate a fault.  We solve
@@ -779,6 +838,8 @@ zfs_fm_recv(fmd_hdl_t *hdl, fmd_event_t *ep, nvlist_t *nvl, const char *class)
 	    fmd_nvl_class_match(hdl, nvl,
 	    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_IO_FAILURE)) ||
 	    fmd_nvl_class_match(hdl, nvl,
+	    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_DELAY)) ||
+	    fmd_nvl_class_match(hdl, nvl,
 	    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_PROBE_FAILURE))) {
 		const char *failmode = NULL;
 		boolean_t checkremove = B_FALSE;
@@ -815,6 +876,51 @@ zfs_fm_recv(fmd_hdl_t *hdl, fmd_event_t *ep, nvlist_t *nvl, const char *class)
 			if (fmd_serd_record(hdl, zcp->zc_data.zc_serd_io, ep))
 				checkremove = B_TRUE;
 		} else if (fmd_nvl_class_match(hdl, nvl,
+		    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_DELAY))) {
+			uint64_t slow_io_n, slow_io_t;
+
+			/*
+			 * Create a slow io SERD engine when the VDEV has the
+			 * 'vdev_slow_io_n' and 'vdev_slow_io_n' properties.
+			 */
+			if (zcp->zc_data.zc_serd_slow_io[0] == '\0' &&
+			    nvlist_lookup_uint64(nvl,
+			    FM_EREPORT_PAYLOAD_ZFS_VDEV_SLOW_IO_N,
+			    &slow_io_n) == 0 &&
+			    nvlist_lookup_uint64(nvl,
+			    FM_EREPORT_PAYLOAD_ZFS_VDEV_SLOW_IO_T,
+			    &slow_io_t) == 0) {
+				zfs_serd_name(zcp->zc_data.zc_serd_slow_io,
+				    pool_guid, vdev_guid, "slow_io");
+				fmd_serd_create(hdl,
+				    zcp->zc_data.zc_serd_slow_io,
+				    slow_io_n,
+				    SEC2NSEC(slow_io_t));
+				zfs_case_serialize(zcp);
+			}
+			/* Pass event to SERD engine and see if this triggers */
+			if (zcp->zc_data.zc_serd_slow_io[0] != '\0' &&
+			    fmd_serd_record(hdl, zcp->zc_data.zc_serd_slow_io,
+			    ep)) {
+				/*
+				 * Ignore a slow io diagnosis when other
+				 * VDEVs in the pool show signs of being slow.
+				 */
+				if (zfs_other_slow_cases(hdl, &zcp->zc_data)) {
+					zfs_case_retire(hdl, zcp);
+					fmd_hdl_debug(hdl, "pool %llu has "
+					    "multiple slow io cases -- skip "
+					    "degrading vdev %llu",
+					    (u_longlong_t)
+					    zcp->zc_data.zc_pool_guid,
+					    (u_longlong_t)
+					    zcp->zc_data.zc_vdev_guid);
+				} else {
+					zfs_case_solve(hdl, zcp,
+					    "fault.fs.zfs.vdev.slow_io");
+				}
+			}
+		} else if (fmd_nvl_class_match(hdl, nvl,
 		    ZFS_MAKE_EREPORT(FM_EREPORT_ZFS_CHECKSUM))) {
 			/*
 			 * We ignore ereports for checksum errors generated by
@@ -924,6 +1030,8 @@ zfs_fm_close(fmd_hdl_t *hdl, fmd_case_t *cs)
 		fmd_serd_destroy(hdl, zcp->zc_data.zc_serd_checksum);
 	if (zcp->zc_data.zc_serd_io[0] != '\0')
 		fmd_serd_destroy(hdl, zcp->zc_data.zc_serd_io);
+	if (zcp->zc_data.zc_serd_slow_io[0] != '\0')
+		fmd_serd_destroy(hdl, zcp->zc_data.zc_serd_slow_io);
 	if (zcp->zc_data.zc_has_remove_timer)
 		fmd_timer_remove(hdl, zcp->zc_remove_timer);
 
@@ -932,30 +1040,15 @@ zfs_fm_close(fmd_hdl_t *hdl, fmd_case_t *cs)
 	fmd_hdl_free(hdl, zcp, sizeof (zfs_case_t));
 }
 
-/*
- * We use the fmd gc entry point to look for old cases that no longer apply.
- * This allows us to keep our set of case data small in a long running system.
- */
-static void
-zfs_fm_gc(fmd_hdl_t *hdl)
-{
-	zfs_purge_cases(hdl);
-}
-
 static const fmd_hdl_ops_t fmd_ops = {
 	zfs_fm_recv,	/* fmdo_recv */
 	zfs_fm_timeout,	/* fmdo_timeout */
 	zfs_fm_close,	/* fmdo_close */
 	NULL,		/* fmdo_stats */
-	zfs_fm_gc,	/* fmdo_gc */
+	NULL,	/* fmdo_gc */
 };
 
 static const fmd_prop_t fmd_props[] = {
-	{ "checksum_N", FMD_TYPE_UINT32, "10" },
-	{ "checksum_T", FMD_TYPE_TIME, "10min" },
-	{ "io_N", FMD_TYPE_UINT32, "10" },
-	{ "io_T", FMD_TYPE_TIME, "10min" },
-	{ "remove_timeout", FMD_TYPE_TIME, "15sec" },
 	{ NULL, 0, NULL }
 };
 
@@ -996,8 +1089,6 @@ _zfs_diagnosis_init(fmd_hdl_t *hdl)
 
 	(void) fmd_stat_create(hdl, FMD_STAT_NOALLOC, sizeof (zfs_stats) /
 	    sizeof (fmd_stat_t), (fmd_stat_t *)&zfs_stats);
-
-	zfs_remove_timeout = fmd_prop_get_int64(hdl, "remove_timeout");
 }
 
 void
diff --git a/sys/contrib/openzfs/cmd/zed/agents/zfs_retire.c b/sys/contrib/openzfs/cmd/zed/agents/zfs_retire.c
index a0e377a4a0c8..1ef5c631a438 100644
--- a/sys/contrib/openzfs/cmd/zed/agents/zfs_retire.c
+++ b/sys/contrib/openzfs/cmd/zed/agents/zfs_retire.c
@@ -524,6 +524,9 @@ zfs_retire_recv(fmd_hdl_t *hdl, fmd_event_t *ep, nvlist_t *nvl,
 		    "fault.fs.zfs.vdev.checksum")) {
 			degrade_device = B_TRUE;
 		} else if (fmd_nvl_class_match(hdl, fault,
+		    "fault.fs.zfs.vdev.slow_io")) {
+			degrade_device = B_TRUE;
+		} else if (fmd_nvl_class_match(hdl, fault,
 		    "fault.fs.zfs.device")) {
 			fault_device = B_FALSE;
 		} else if (fmd_nvl_class_match(hdl, fault, "fault.io.*")) {
diff --git a/sys/contrib/openzfs/cmd/zfs/zfs_main.c b/sys/contrib/openzfs/cmd/zfs/zfs_main.c
index f7e07b8199d3..a5dbf3f5a2b1 100644
--- a/sys/contrib/openzfs/cmd/zfs/zfs_main.c
+++ b/sys/contrib/openzfs/cmd/zfs/zfs_main.c
@@ -309,7 +309,8 @@ get_usage(zfs_help_t idx)
 		    "[filesystem|volume|snapshot] ...\n"));
 	case HELP_MOUNT:
 		return (gettext("\tmount\n"
-		    "\tmount [-flvO] [-o opts] <-a | filesystem>\n"));
+		    "\tmount [-flvO] [-o opts] <-a|-R filesystem|"
+		    "filesystem>\n"));
 	case HELP_PROMOTE:
 		return (gettext("\tpromote <clone-filesystem>\n"));
 	case HELP_RECEIVE:
@@ -6750,6 +6751,8 @@ zfs_do_holds(int argc, char **argv)
 #define	MOUNT_TIME 1		/* seconds */
 
 typedef struct get_all_state {
+	char		**ga_datasets;
+	int		ga_count;
 	boolean_t	ga_verbose;
 	get_all_cb_t	*ga_cbp;
 } get_all_state_t;
@@ -6796,19 +6799,35 @@ get_one_dataset(zfs_handle_t *zhp, void *data)
 	return (0);
 }
 
-static void
-get_all_datasets(get_all_cb_t *cbp, boolean_t verbose)
+static int
+get_recursive_datasets(zfs_handle_t *zhp, void *data)
 {
-	get_all_state_t state = {
-	    .ga_verbose = verbose,
-	    .ga_cbp = cbp
-	};
+	get_all_state_t *state = data;
+	int len = strlen(zfs_get_name(zhp));
+	for (int i = 0; i < state->ga_count; ++i) {
+		if (strcmp(state->ga_datasets[i], zfs_get_name(zhp)) == 0)
+			return (get_one_dataset(zhp, data));
+		else if ((strncmp(state->ga_datasets[i], zfs_get_name(zhp),
+		    len) == 0) && state->ga_datasets[i][len] == '/') {
+			(void) zfs_iter_filesystems_v2(zhp, 0,
+			    get_recursive_datasets, data);
+		}
+	}
+	zfs_close(zhp);
+	return (0);
+}
 
-	if (verbose)
+static void
+get_all_datasets(get_all_state_t *state)
+{
+	if (state->ga_verbose)
 		set_progress_header(gettext("Reading ZFS config"));
-	(void) zfs_iter_root(g_zfs, get_one_dataset, &state);
+	if (state->ga_datasets == NULL)
+		(void) zfs_iter_root(g_zfs, get_one_dataset, state);
+	else
+		(void) zfs_iter_root(g_zfs, get_recursive_datasets, state);
 
-	if (verbose)
+	if (state->ga_verbose)
 		finish_progress(gettext("done."));
 }
 
@@ -7154,18 +7173,22 @@ static int
 share_mount(int op, int argc, char **argv)
 {
 	int do_all = 0;
+	int recursive = 0;
 	boolean_t verbose = B_FALSE;
 	int c, ret = 0;
 	char *options = NULL;
 	int flags = 0;
 
 	/* check options */
-	while ((c = getopt(argc, argv, op == OP_MOUNT ? ":alvo:Of" : "al"))
+	while ((c = getopt(argc, argv, op == OP_MOUNT ? ":aRlvo:Of" : "al"))
 	    != -1) {
 		switch (c) {
 		case 'a':
 			do_all = 1;
 			break;
+		case 'R':
+			recursive = 1;
+			break;
 		case 'v':
 			verbose = B_TRUE;
 			break;
@@ -7207,7 +7230,7 @@ share_mount(int op, int argc, char **argv)
 	argv += optind;
 
 	/* check number of arguments */
-	if (do_all) {
+	if (do_all || recursive) {
 		enum sa_protocol protocol = SA_NO_PROTOCOL;
 
 		if (op == OP_SHARE && argc > 0) {
@@ -7216,14 +7239,38 @@ share_mount(int op, int argc, char **argv)
 			argv++;
 		}
 
-		if (argc != 0) {
+		if (argc != 0 && do_all) {
 			(void) fprintf(stderr, gettext("too many arguments\n"));
 			usage(B_FALSE);
 		}
 
+		if (argc == 0 && recursive) {
+			(void) fprintf(stderr,
+			    gettext("no dataset provided\n"));
+			usage(B_FALSE);
+		}
+
 		start_progress_timer();
 		get_all_cb_t cb = { 0 };
-		get_all_datasets(&cb, verbose);
+		get_all_state_t state = { 0 };
+		if (argc == 0) {
+			state.ga_datasets = NULL;
+			state.ga_count = -1;
+		} else {
+			zfs_handle_t *zhp;
+			for (int i = 0; i < argc; i++) {
+				zhp = zfs_open(g_zfs, argv[i],
+				    ZFS_TYPE_FILESYSTEM);
+				if (zhp == NULL)
+					usage(B_FALSE);
+				zfs_close(zhp);
+			}
+			state.ga_datasets = argv;
+			state.ga_count = argc;
+		}
+		state.ga_verbose = verbose;
+		state.ga_cbp = &cb;
+		get_all_datasets(&state);
 
 		if (cb.cb_used == 0) {
 			free(options);
diff --git a/sys/contrib/openzfs/cmd/zinject/zinject.c b/sys/contrib/openzfs/cmd/zinject/zinject.c
index f1262ed772de..a11b6d0b7fac 100644
--- a/sys/contrib/openzfs/cmd/zinject/zinject.c
+++ b/sys/contrib/openzfs/cmd/zinject/zinject.c
@@ -1083,6 +1083,22 @@ main(int argc, char **argv)
 			libzfs_fini(g_zfs);
 			return (1);
 		}
+
+		if (record.zi_nlanes) {
+			switch (io_type) {
+			case ZIO_TYPE_READ:
+			case ZIO_TYPE_WRITE:
+			case ZIO_TYPES:
+				break;
+			default:
+				(void) fprintf(stderr, "I/O type for a delay "
+				    "must be 'read' or 'write'\n");
+				usage();
+				libzfs_fini(g_zfs);
+				return (1);
+			}
+		}
+
 		if (!error)
 			error = ENXIO;
 
diff --git a/sys/contrib/openzfs/cmd/zpool/os/linux/zpool_vdev_os.c b/sys/contrib/openzfs/cmd/zpool/os/linux/zpool_vdev_os.c
index 006a3a7d8e01..f194d28c55a9 100644
--- a/sys/contrib/openzfs/cmd/zpool/os/linux/zpool_vdev_os.c
+++ b/sys/contrib/openzfs/cmd/zpool/os/linux/zpool_vdev_os.c
@@ -438,7 +438,7 @@ static char *zpool_sysfs_gets(char *path)
 		return (NULL);
 	}
 
-	buf = calloc(sizeof (*buf), statbuf.st_size + 1);
+	buf = calloc(statbuf.st_size + 1, sizeof (*buf));
 	if (buf == NULL) {
 		close(fd);
 		return (NULL);
@@ -458,7 +458,7 @@ static char *zpool_sysfs_gets(char *path)
 	}
 
 	/* Remove trailing newline */
-	if (buf[count - 1] == '\n')
+	if (count > 0 && buf[count - 1] == '\n')
 		buf[count - 1] = 0;
 
 	close(fd);
diff --git a/sys/contrib/openzfs/cmd/zpool/zpool_main.c b/sys/contrib/openzfs/cmd/zpool/zpool_main.c
index 69bf9649acf6..ed0b8d7a12d7 100644
--- a/sys/contrib/openzfs/cmd/zpool/zpool_main.c
+++ b/sys/contrib/openzfs/cmd/zpool/zpool_main.c
@@ -22,7 +22,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
- * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright (c) 2012 by Frederik Wessels. All rights reserved.
  * Copyright (c) 2012 by Cyril Plisko. All rights reserved.
  * Copyright (c) 2013 by Prasad Joshi (sTec). All rights reserved.
@@ -131,6 +131,13 @@ static int zpool_do_help(int argc, char **argv);
 static zpool_compat_status_t zpool_do_load_compat(
     const char *, boolean_t *);
 
+enum zpool_options {
+	ZPOOL_OPTION_POWER = 1024,
+	ZPOOL_OPTION_ALLOW_INUSE,
+	ZPOOL_OPTION_ALLOW_REPLICATION_MISMATCH,
+	ZPOOL_OPTION_ALLOW_ASHIFT_MISMATCH
+};
+
 /*
  * These libumem hooks provide a reasonable set of defaults for the allocator's
  * debugging facilities.
@@ -347,7 +354,7 @@ get_usage(zpool_help_t idx)
 {
 	switch (idx) {
 	case HELP_ADD:
-		return (gettext("\tadd [-fgLnP] [-o property=value] "
+		return (gettext("\tadd [-afgLnP] [-o property=value] "
 		    "<pool> <vdev> ...\n"));
 	case HELP_ATTACH:
 		return (gettext("\tattach [-fsw] [-o property=value] "
@@ -413,7 +420,7 @@ get_usage(zpool_help_t idx)
 		    "[<device> ...]\n"));
 	case HELP_STATUS:
 		return (gettext("\tstatus [--power] [-c [script1,script2,...]] "
-		    "[-igLpPstvxD]  [-T d|u] [pool] ... \n"
+		    "[-DegiLpPstvx] [-T d|u] [pool] ...\n"
 		    "\t    [interval [count]]\n"));
 	case HELP_UPGRADE:
 		return (gettext("\tupgrade\n"
@@ -1009,8 +1016,9 @@ add_prop_list_default(const char *propname, const char *propval,
 }
 
 /*
- * zpool add [-fgLnP] [-o property=value] <pool> <vdev> ...
+ * zpool add [-afgLnP] [-o property=value] <pool> <vdev> ...
  *
+ *	-a	Disable the ashift validation checks
  *	-f	Force addition of devices, even if they appear in use
  *	-g	Display guid for individual vdev name.
  *	-L	Follow links when resolving vdev path name.
@@ -1026,8 +1034,11 @@ add_prop_list_default(const char *propname, const char *propval,
 int
 zpool_do_add(int argc, char **argv)
 {
-	boolean_t force = B_FALSE;
+	boolean_t check_replication = B_TRUE;
+	boolean_t check_inuse = B_TRUE;
 	boolean_t dryrun = B_FALSE;
+	boolean_t check_ashift = B_TRUE;
+	boolean_t force = B_FALSE;
 	int name_flags = 0;
 	int c;
 	nvlist_t *nvroot;
@@ -1038,8 +1049,18 @@ zpool_do_add(int argc, char **argv)
 	nvlist_t *props = NULL;
 	char *propval;
 
+	struct option long_options[] = {
+		{"allow-in-use", no_argument, NULL, ZPOOL_OPTION_ALLOW_INUSE},
+		{"allow-replication-mismatch", no_argument, NULL,
+		    ZPOOL_OPTION_ALLOW_REPLICATION_MISMATCH},
+		{"allow-ashift-mismatch", no_argument, NULL,
+		    ZPOOL_OPTION_ALLOW_ASHIFT_MISMATCH},
+		{0, 0, 0, 0}
+	};
+
 	/* check options */
-	while ((c = getopt(argc, argv, "fgLno:P")) != -1) {
+	while ((c = getopt_long(argc, argv, "fgLno:P", long_options, NULL))
+	    != -1) {
 		switch (c) {
 		case 'f':
 			force = B_TRUE;
@@ -1069,6 +1090,15 @@ zpool_do_add(int argc, char **argv)
 		case 'P':
 			name_flags |= VDEV_NAME_PATH;
 			break;
+		case ZPOOL_OPTION_ALLOW_INUSE:
+			check_inuse = B_FALSE;
+			break;
+		case ZPOOL_OPTION_ALLOW_REPLICATION_MISMATCH:
+			check_replication = B_FALSE;
+			break;
+		case ZPOOL_OPTION_ALLOW_ASHIFT_MISMATCH:
+			check_ashift = B_FALSE;
+			break;
 		case '?':
 			(void) fprintf(stderr, gettext("invalid option '%c'\n"),
 			    optopt);
@@ -1089,6 +1119,19 @@ zpool_do_add(int argc, char **argv)
 		usage(B_FALSE);
 	}
 
+	if (force) {
+		if (!check_inuse || !check_replication || !check_ashift) {
+			(void) fprintf(stderr, gettext("'-f' option is not "
+			    "allowed with '--allow-replication-mismatch', "
+			    "'--allow-ashift-mismatch', or "
+			    "'--allow-in-use'\n"));
+			usage(B_FALSE);
+		}
+		check_inuse = B_FALSE;
+		check_replication = B_FALSE;
+		check_ashift = B_FALSE;
+	}
+
 	poolname = argv[0];
 
 	argc--;
@@ -1119,8 +1162,8 @@ zpool_do_add(int argc, char **argv)
 	}
 
 	/* pass off to make_root_vdev for processing */
-	nvroot = make_root_vdev(zhp, props, force, !force, B_FALSE, dryrun,
-	    argc, argv);
+	nvroot = make_root_vdev(zhp, props, !check_inuse,
+	    check_replication, B_FALSE, dryrun, argc, argv);
 	if (nvroot == NULL) {
 		zpool_close(zhp);
 		return (1);
@@ -1224,7 +1267,7 @@ zpool_do_add(int argc, char **argv)
 
 		ret = 0;
 	} else {
-		ret = (zpool_add(zhp, nvroot) != 0);
+		ret = (zpool_add(zhp, nvroot, check_ashift) != 0);
 	}
 
 	nvlist_free(props);
@@ -2246,7 +2289,6 @@ print_status_initialize(vdev_stat_t *vs, boolean_t verbose)
 		    !vs->vs_scan_removing) {
 			char zbuf[1024];
 			char tbuf[256];
-			struct tm zaction_ts;
 
 			time_t t = vs->vs_initialize_action_time;
 			int initialize_pct = 100;
@@ -2256,8 +2298,8 @@ print_status_initialize(vdev_stat_t *vs, boolean_t verbose)
 				    100 / (vs->vs_initialize_bytes_est + 1));
 			}
 
-			(void) localtime_r(&t, &zaction_ts);
-			(void) strftime(tbuf, sizeof (tbuf), "%c", &zaction_ts);
+			(void) ctime_r(&t, tbuf);
+			tbuf[24] = 0;
 
 			switch (vs->vs_initialize_state) {
 			case VDEV_INITIALIZE_SUSPENDED:
@@ -2297,7 +2339,6 @@ print_status_trim(vdev_stat_t *vs, boolean_t verbose)
 		    !vs->vs_scan_removing) {
 			char zbuf[1024];
 			char tbuf[256];
-			struct tm zaction_ts;
 
 			time_t t = vs->vs_trim_action_time;
 			int trim_pct = 100;
@@ -2306,8 +2347,8 @@ print_status_trim(vdev_stat_t *vs, boolean_t verbose)
 				    100 / (vs->vs_trim_bytes_est + 1));
 			}
 
-			(void) localtime_r(&t, &zaction_ts);
-			(void) strftime(tbuf, sizeof (tbuf), "%c", &zaction_ts);
+			(void) ctime_r(&t, tbuf);
+			tbuf[24] = 0;
 
 			switch (vs->vs_trim_state) {
 			case VDEV_TRIM_SUSPENDED:
@@ -2569,7 +2610,13 @@ print_status_config(zpool_handle_t *zhp, status_cbdata_t *cb, const char *name,
 			break;
 
 		case VDEV_AUX_ERR_EXCEEDED:
-			(void) printf(gettext("too many errors"));
+			if (vs->vs_read_errors + vs->vs_write_errors +
+			    vs->vs_checksum_errors == 0 && children == 0 &&
+			    vs->vs_slow_ios > 0) {
+				(void) printf(gettext("too many slow I/Os"));
+			} else {
+				(void) printf(gettext("too many errors"));
+			}
 			break;
 
 		case VDEV_AUX_IO_FAILURE:
@@ -3396,10 +3443,10 @@ do_import(nvlist_t *config, const char *newname, const char *mntopts,
 		ms_status = zpool_enable_datasets(zhp, mntopts, 0);
 		if (ms_status == EZFS_SHAREFAILED) {
 			(void) fprintf(stderr, gettext("Import was "
-			    "successful, but unable to share some datasets"));
+			    "successful, but unable to share some datasets\n"));
 		} else if (ms_status == EZFS_MOUNTFAILED) {
 			(void) fprintf(stderr, gettext("Import was "
-			    "successful, but unable to mount some datasets"));
+			    "successful, but unable to mount some datasets\n"));
 		}
 	}
 
@@ -7064,7 +7111,6 @@ zpool_do_split(int argc, char **argv)
 	return (ret);
 }
 
-#define	POWER_OPT 1024
 
 /*
  * zpool online [--power] <pool> <device> ...
@@ -7082,7 +7128,7 @@ zpool_do_online(int argc, char **argv)
 	int flags = 0;
 	boolean_t is_power_on = B_FALSE;
 	struct option long_options[] = {
-		{"power", no_argument, NULL, POWER_OPT},
+		{"power", no_argument, NULL, ZPOOL_OPTION_POWER},
 		{0, 0, 0, 0}
 	};
 
@@ -7092,7 +7138,7 @@ zpool_do_online(int argc, char **argv)
 		case 'e':
 			flags |= ZFS_ONLINE_EXPAND;
 			break;
-		case POWER_OPT:
+		case ZPOOL_OPTION_POWER:
 			is_power_on = B_TRUE;
 			break;
 		case '?':
@@ -7205,7 +7251,7 @@ zpool_do_offline(int argc, char **argv)
 	boolean_t is_power_off = B_FALSE;
 
 	struct option long_options[] = {
-		{"power", no_argument, NULL, POWER_OPT},
+		{"power", no_argument, NULL, ZPOOL_OPTION_POWER},
 		{0, 0, 0, 0}
 	};
 
@@ -7218,7 +7264,7 @@ zpool_do_offline(int argc, char **argv)
 		case 't':
 			istmp = B_TRUE;
 			break;
-		case POWER_OPT:
+		case ZPOOL_OPTION_POWER:
 			is_power_off = B_TRUE;
 			break;
 		case '?':
@@ -7318,7 +7364,7 @@ zpool_do_clear(int argc, char **argv)
 	char *pool, *device;
 
 	struct option long_options[] = {
-		{"power", no_argument, NULL, POWER_OPT},
+		{"power", no_argument, NULL, ZPOOL_OPTION_POWER},
 		{0, 0, 0, 0}
 	};
 
@@ -7335,7 +7381,7 @@ zpool_do_clear(int argc, char **argv)
 		case 'X':
 			xtreme_rewind = B_TRUE;
 			break;
-		case POWER_OPT:
+		case ZPOOL_OPTION_POWER:
 			is_power_on = B_TRUE;
 			break;
 		case '?':
@@ -8864,7 +8910,7 @@ status_callback(zpool_handle_t *zhp, void *data)
 		printf_color(ANSI_BOLD, gettext("action: "));
 		printf_color(ANSI_YELLOW, gettext("Make sure the pool's devices"
 		    " are connected, then reboot your system and\n\timport the "
-		    "pool.\n"));
+		    "pool or run 'zpool clear' to resume the pool.\n"));
 		break;
 
 	case ZPOOL_STATUS_IO_FAILURE_WAIT:
@@ -9064,22 +9110,22 @@ status_callback(zpool_handle_t *zhp, void *data)
 }
 
 /*
- * zpool status [-c [script1,script2,...]] [-igLpPstvx] [--power] [-T d|u] ...
+ * zpool status [-c [script1,script2,...]] [-DegiLpPstvx] [--power] [-T d|u] ...
  *              [pool] [interval [count]]
  *
  *	-c CMD	For each vdev, run command CMD
+ *	-D	Display dedup status (undocumented)
  *	-e	Display only unhealthy vdevs
- *	-i	Display vdev initialization status.
  *	-g	Display guid for individual vdev name.
+ *	-i	Display vdev initialization status.
  *	-L	Follow links when resolving vdev path name.
  *	-p	Display values in parsable (exact) format.
  *	-P	Display full path for vdev name.
  *	-s	Display slow IOs column.
- *	-v	Display complete error logs
- *	-x	Display only pools with potential problems
- *	-D	Display dedup status (undocumented)
  *	-t	Display vdev TRIM status.
  *	-T	Display a timestamp in date(1) or Unix format
+ *	-v	Display complete error logs
+ *	-x	Display only pools with potential problems
  *	--power	Display vdev enclosure slot power status
  *
  * Describes the health status of all pools or some subset.
@@ -9095,12 +9141,12 @@ zpool_do_status(int argc, char **argv)
 	char *cmd = NULL;
 
 	struct option long_options[] = {
-		{"power", no_argument, NULL, POWER_OPT},
+		{"power", no_argument, NULL, ZPOOL_OPTION_POWER},
 		{0, 0, 0, 0}
 	};
 
 	/* check options */
-	while ((c = getopt_long(argc, argv, "c:eigLpPsvxDtT:", long_options,
+	while ((c = getopt_long(argc, argv, "c:DegiLpPstT:vx", long_options,
 	    NULL)) != -1) {
 		switch (c) {
 		case 'c':
@@ -9127,15 +9173,18 @@ zpool_do_status(int argc, char **argv)
 			}
 			cmd = optarg;
 			break;
+		case 'D':
+			cb.cb_dedup_stats = B_TRUE;
+			break;
 		case 'e':
 			cb.cb_print_unhealthy = B_TRUE;
 			break;
-		case 'i':
-			cb.cb_print_vdev_init = B_TRUE;
-			break;
 		case 'g':
 			cb.cb_name_flags |= VDEV_NAME_GUID;
 			break;
+		case 'i':
+			cb.cb_print_vdev_init = B_TRUE;
+			break;
 		case 'L':
 			cb.cb_name_flags |= VDEV_NAME_FOLLOW_LINKS;
 			break;
@@ -9148,22 +9197,19 @@ zpool_do_status(int argc, char **argv)
 		case 's':
 			cb.cb_print_slow_ios = B_TRUE;
 			break;
-		case 'v':
-			cb.cb_verbose = B_TRUE;
-			break;
-		case 'x':
-			cb.cb_explain = B_TRUE;
-			break;
-		case 'D':
-			cb.cb_dedup_stats = B_TRUE;
-			break;
 		case 't':
 			cb.cb_print_vdev_trim = B_TRUE;
 			break;
 		case 'T':
 			get_timestamp_arg(*optarg);
 			break;
-		case POWER_OPT:
+		case 'v':
+			cb.cb_verbose = B_TRUE;
+			break;
+		case 'x':
+			cb.cb_explain = B_TRUE;
+			break;
+		case ZPOOL_OPTION_POWER:
 			cb.cb_print_power = B_TRUE;
 			break;
 		case '?':
@@ -9202,7 +9248,6 @@ zpool_do_status(int argc, char **argv)
 
 		if (cb.vcdl != NULL)
 			free_vdev_cmd_data_list(cb.vcdl);
-
 		if (argc == 0 && cb.cb_count == 0)
 			(void) fprintf(stderr, gettext("no pools available\n"));
 		else if (cb.cb_explain && cb.cb_first && cb.cb_allpools)
@@ -10638,11 +10683,10 @@ found:
 		}
 	} else {
 		/*
-		 * The first arg isn't a pool name,
+		 * The first arg isn't the name of a valid pool.
 		 */
-		fprintf(stderr, gettext("missing pool name.\n"));
-		fprintf(stderr, "\n");
-		usage(B_FALSE);
+		fprintf(stderr, gettext("Cannot get properties of %s: "
+		    "no such pool available.\n"), argv[0]);
 		return (1);
 	}
 
diff --git a/sys/contrib/openzfs/cmd/ztest.c b/sys/contrib/openzfs/cmd/ztest.c
index 8cfbdfe1c2e2..34744d12b592 100644
--- a/sys/contrib/openzfs/cmd/ztest.c
+++ b/sys/contrib/openzfs/cmd/ztest.c
@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
@@ -3270,7 +3270,7 @@ ztest_vdev_add_remove(ztest_ds_t *zd, uint64_t id)
 		    "log" : NULL, ztest_opts.zo_raid_children, zs->zs_mirrors,
 		    1);
 
-		error = spa_vdev_add(spa, nvroot);
+		error = spa_vdev_add(spa, nvroot, B_FALSE);
 		fnvlist_free(nvroot);
 
 		switch (error) {
@@ -3332,7 +3332,7 @@ ztest_vdev_class_add(ztest_ds_t *zd, uint64_t id)
 	nvroot = make_vdev_root(NULL, NULL, NULL, ztest_opts.zo_vdev_size, 0,
 	    class, ztest_opts.zo_raid_children, zs->zs_mirrors, 1);
 
-	error = spa_vdev_add(spa, nvroot);
+	error = spa_vdev_add(spa, nvroot, B_FALSE);
 	fnvlist_free(nvroot);
 
 	if (error == ENOSPC)
@@ -3439,7 +3439,7 @@ ztest_vdev_aux_add_remove(ztest_ds_t *zd, uint64_t id)
 		 */
 		nvlist_t *nvroot = make_vdev_root(NULL, aux, NULL,
 		    (ztest_opts.zo_vdev_size * 5) / 4, 0, NULL, 0, 0, 1);
-		error = spa_vdev_add(spa, nvroot);
+		error = spa_vdev_add(spa, nvroot, B_FALSE);
 
 		switch (error) {
 		case 0:
diff --git a/sys/contrib/openzfs/config/Substfiles.am b/sys/contrib/openzfs/config/Substfiles.am
index 38e870b2f501..2459637abe6e 100644
--- a/sys/contrib/openzfs/config/Substfiles.am
+++ b/sys/contrib/openzfs/config/Substfiles.am
@@ -18,6 +18,7 @@ subst_sed_cmd = \
 	-e 's|@ASAN_ENABLED[@]|$(ASAN_ENABLED)|g' \
 	-e 's|@DEFAULT_INIT_NFS_SERVER[@]|$(DEFAULT_INIT_NFS_SERVER)|g' \
 	-e 's|@DEFAULT_INIT_SHELL[@]|$(DEFAULT_INIT_SHELL)|g' \
+	-e 's|@IS_SYSV_RC[@]|$(IS_SYSV_RC)|g' \
 	-e 's|@LIBFETCH_DYNAMIC[@]|$(LIBFETCH_DYNAMIC)|g' \
 	-e 's|@LIBFETCH_SONAME[@]|$(LIBFETCH_SONAME)|g' \
 	-e 's|@PYTHON[@]|$(PYTHON)|g' \
@@ -43,4 +44,4 @@ SUBSTFILES =
 CLEANFILES += $(SUBSTFILES)
 dist_noinst_DATA += $(SUBSTFILES:=.in)
 
-$(call SUBST,%,)
+$(SUBSTFILES): $(call SUBST,%,)
diff --git a/sys/contrib/openzfs/config/always-pyzfs.m4 b/sys/contrib/openzfs/config/always-pyzfs.m4
index 9b123b1b2db1..98c1cc230205 100644
--- a/sys/contrib/openzfs/config/always-pyzfs.m4
+++ b/sys/contrib/openzfs/config/always-pyzfs.m4
@@ -80,10 +80,11 @@ AC_DEFUN([ZFS_AC_CONFIG_ALWAYS_PYZFS], [
 			[AC_MSG_ERROR("Python $PYTHON_VERSION unknown")]
 		)
 
-		AX_PYTHON_DEVEL([$PYTHON_REQUIRED_VERSION], [
-			AS_IF([test "x$enable_pyzfs" = xyes], [
-				AC_MSG_ERROR("Python $PYTHON_REQUIRED_VERSION development library is not installed")
-			], [test "x$enable_pyzfs" != xno], [
+		AS_IF([test "x$enable_pyzfs" = xyes], [
+			AX_PYTHON_DEVEL([$PYTHON_REQUIRED_VERSION])
+		], [
+			AX_PYTHON_DEVEL([$PYTHON_REQUIRED_VERSION], [true])
+			AS_IF([test "x$ax_python_devel_found" = xno], [
 				enable_pyzfs=no
 			])
 		])
diff --git a/sys/contrib/openzfs/config/ax_python_devel.m4 b/sys/contrib/openzfs/config/ax_python_devel.m4
index f6d4b01444d6..1f480db6d233 100644
--- a/sys/contrib/openzfs/config/ax_python_devel.m4
+++ b/sys/contrib/openzfs/config/ax_python_devel.m4
@@ -4,18 +4,13 @@
 #
 # SYNOPSIS
 #
-#   AX_PYTHON_DEVEL([version], [action-if-not-found])
+#   AX_PYTHON_DEVEL([version[,optional]])
 #
 # DESCRIPTION
 #
 #   Note: Defines as a precious variable "PYTHON_VERSION". Don't override it
 #   in your configure.ac.
 #
-#   Note: this is a slightly modified version of the original AX_PYTHON_DEVEL
-#   macro which accepts an additional [action-if-not-found] argument. This
-#   allow to detect if Python development is available without aborting the
-#   configure phase with an hard error in case it is not.
-#
 #   This macro checks for Python and tries to get the include path to
 #   'Python.h'. It provides the $(PYTHON_CPPFLAGS) and $(PYTHON_LIBS) output
 #   variables. It also exports $(PYTHON_EXTRA_LIBS) and
@@ -28,6 +23,11 @@
 #   version number. Don't use "PYTHON_VERSION" for this: that environment
 #   variable is declared as precious and thus reserved for the end-user.
 #
+#   By default this will fail if it does not detect a development version of
+#   python.  If you want it to continue, set optional to true, like
+#   AX_PYTHON_DEVEL([], [true]).  The ax_python_devel_found variable will be
+#   "no" if it fails.
+#
 #   This macro should work for all versions of Python >= 2.1.0. As an end
 #   user, you can disable the check for the python version by setting the
 #   PYTHON_NOVERSIONCHECK environment variable to something else than the
@@ -45,7 +45,6 @@
 #   Copyright (c) 2009 Matteo Settenvini <matteo@member.fsf.org>
 #   Copyright (c) 2009 Horst Knorr <hk_classes@knoda.org>
 #   Copyright (c) 2013 Daniel Mullner <muellner@math.stanford.edu>
-#   Copyright (c) 2018 loli10K <ezomori.nozomu@gmail.com>
 #
 #   This program is free software: you can redistribute it and/or modify it
 #   under the terms of the GNU General Public License as published by the
@@ -73,10 +72,18 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 21
+#serial 36
 
 AU_ALIAS([AC_PYTHON_DEVEL], [AX_PYTHON_DEVEL])
 AC_DEFUN([AX_PYTHON_DEVEL],[
+	# Get whether it's optional
+	if test -z "$2"; then
+	   ax_python_devel_optional=false
+	else
+	   ax_python_devel_optional=$2
+	fi
+	ax_python_devel_found=yes
+
 	#
 	# Allow the use of a (user set) custom python version
 	#
@@ -87,23 +94,26 @@ AC_DEFUN([AX_PYTHON_DEVEL],[
 
 	AC_PATH_PROG([PYTHON],[python[$PYTHON_VERSION]])
 	if test -z "$PYTHON"; then
-		m4_ifvaln([$2],[$2],[
-			AC_MSG_ERROR([Cannot find python$PYTHON_VERSION in your system path])
-			PYTHON_VERSION=""
-		])
+	   AC_MSG_WARN([Cannot find python$PYTHON_VERSION in your system path])
+	   if ! $ax_python_devel_optional; then
+	      AC_MSG_ERROR([Giving up, python development not available])
+	   fi
+	   ax_python_devel_found=no
+	   PYTHON_VERSION=""
 	fi
 
-	#
-	# Check for a version of Python >= 2.1.0
-	#
-	AC_MSG_CHECKING([for a version of Python >= '2.1.0'])
-	ac_supports_python_ver=`$PYTHON -c "import sys; \
+	if test $ax_python_devel_found = yes; then
+	   #
+	   # Check for a version of Python >= 2.1.0
+	   #
+	   AC_MSG_CHECKING([for a version of Python >= '2.1.0'])
+	   ac_supports_python_ver=`$PYTHON -c "import sys; \
 		ver = sys.version.split ()[[0]]; \
 		print (ver >= '2.1.0')"`
-	if test "$ac_supports_python_ver" != "True"; then
+	   if test "$ac_supports_python_ver" != "True"; then
 		if test -z "$PYTHON_NOVERSIONCHECK"; then
 			AC_MSG_RESULT([no])
-			AC_MSG_FAILURE([
+			AC_MSG_WARN([
 This version of the AC@&t@_PYTHON_DEVEL macro
 doesn't work properly with versions of Python before
 2.1.0. You may need to re-run configure, setting the
@@ -112,20 +122,27 @@ PYTHON_EXTRA_LIBS and PYTHON_EXTRA_LDFLAGS by hand.
 Moreover, to disable this check, set PYTHON_NOVERSIONCHECK
 to something else than an empty string.
 ])
+			if ! $ax_python_devel_optional; then
+			   AC_MSG_FAILURE([Giving up])
+			fi
+			ax_python_devel_found=no
+			PYTHON_VERSION=""
 		else
 			AC_MSG_RESULT([skip at user request])
 		fi
-	else
+	   else
 		AC_MSG_RESULT([yes])
+	   fi
 	fi
 
-	#
-	# If the macro parameter ``version'' is set, honour it.
-	# A Python shim class, VPy, is used to implement correct version comparisons via
-	# string expressions, since e.g. a naive textual ">= 2.7.3" won't work for
-	# Python 2.7.10 (the ".1" being evaluated as less than ".3").
-	#
-	if test -n "$1"; then
+	if test $ax_python_devel_found = yes; then
+	   #
+	   # If the macro parameter ``version'' is set, honour it.
+	   # A Python shim class, VPy, is used to implement correct version comparisons via
+	   # string expressions, since e.g. a naive textual ">= 2.7.3" won't work for
+	   # Python 2.7.10 (the ".1" being evaluated as less than ".3").
+	   #
+	   if test -n "$1"; then
 		AC_MSG_CHECKING([for a version of Python $1])
                 cat << EOF > ax_python_devel_vpy.py
 class VPy:
@@ -133,7 +150,7 @@ class VPy:
         return tuple(map(int, s.strip().replace("rc", ".").split(".")))
     def __init__(self):
         import sys
-        self.vpy = tuple(sys.version_info)
+        self.vpy = tuple(sys.version_info)[[:3]]
     def __eq__(self, s):
         return self.vpy == self.vtup(s)
     def __ne__(self, s):
@@ -155,25 +172,69 @@ EOF
 			AC_MSG_RESULT([yes])
 		else
 			AC_MSG_RESULT([no])
-			AC_MSG_ERROR([this package requires Python $1.
+			AC_MSG_WARN([this package requires Python $1.
 If you have it installed, but it isn't the default Python
 interpreter in your system path, please pass the PYTHON_VERSION
 variable to configure. See ``configure --help'' for reference.
 ])
+			if ! $ax_python_devel_optional; then
+			   AC_MSG_ERROR([Giving up])
+			fi
+			ax_python_devel_found=no
 			PYTHON_VERSION=""
 		fi
+	   fi
 	fi
 
-	#
-	# Check for Python include path
-	#
-	#
-	AC_MSG_CHECKING([for Python include path])
-	if test -z "$PYTHON_CPPFLAGS"; then
-		python_path=`$PYTHON -c "import sysconfig; \
-			print (sysconfig.get_path('include'));"`
-		plat_python_path=`$PYTHON -c "import sysconfig; \
-			print (sysconfig.get_path('platinclude'));"`
+	if test $ax_python_devel_found = yes; then
+	   #
+	   # Check if you have distutils, else fail
+	   #
+	   AC_MSG_CHECKING([for the sysconfig Python package])
+	   ac_sysconfig_result=`$PYTHON -c "import sysconfig" 2>&1`
+	   if test $? -eq 0; then
+		AC_MSG_RESULT([yes])
+		IMPORT_SYSCONFIG="import sysconfig"
+	   else
+		AC_MSG_RESULT([no])
+
+		AC_MSG_CHECKING([for the distutils Python package])
+		ac_sysconfig_result=`$PYTHON -c "from distutils import sysconfig" 2>&1`
+		if test $? -eq 0; then
+			AC_MSG_RESULT([yes])
+			IMPORT_SYSCONFIG="from distutils import sysconfig"
+		else
+			AC_MSG_WARN([cannot import Python module "distutils".
+Please check your Python installation. The error was:
+$ac_sysconfig_result])
+			if ! $ax_python_devel_optional; then
+			   AC_MSG_ERROR([Giving up])
+			fi
+			ax_python_devel_found=no
+			PYTHON_VERSION=""
+		fi
+	   fi
+	fi
+
+	if test $ax_python_devel_found = yes; then
+	   #
+	   # Check for Python include path
+	   #
+	   AC_MSG_CHECKING([for Python include path])
+	   if test -z "$PYTHON_CPPFLAGS"; then
+		if test "$IMPORT_SYSCONFIG" = "import sysconfig"; then
+			# sysconfig module has different functions
+			python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+				print (sysconfig.get_path ('include'));"`
+			plat_python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+				print (sysconfig.get_path ('platinclude'));"`
+		else
+			# old distutils way
+			python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+				print (sysconfig.get_python_inc ());"`
+			plat_python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+				print (sysconfig.get_python_inc (plat_specific=1));"`
+		fi
 		if test -n "${python_path}"; then
 			if test "${plat_python_path}" != "${python_path}"; then
 				python_path="-I$python_path -I$plat_python_path"
@@ -182,15 +243,15 @@ variable to configure. See ``configure --help'' for reference.
 			fi
 		fi
 		PYTHON_CPPFLAGS=$python_path
-	fi
-	AC_MSG_RESULT([$PYTHON_CPPFLAGS])
-	AC_SUBST([PYTHON_CPPFLAGS])
+	   fi
+	   AC_MSG_RESULT([$PYTHON_CPPFLAGS])
+	   AC_SUBST([PYTHON_CPPFLAGS])
 
-	#
-	# Check for Python library path
-	#
-	AC_MSG_CHECKING([for Python library path])
-	if test -z "$PYTHON_LIBS"; then
+	   #
+	   # Check for Python library path
+	   #
+	   AC_MSG_CHECKING([for Python library path])
+	   if test -z "$PYTHON_LIBS"; then
 		# (makes two attempts to ensure we've got a version number
 		# from the interpreter)
 		ac_python_version=`cat<<EOD | $PYTHON -
@@ -208,7 +269,7 @@ EOD`
 				ac_python_version=$PYTHON_VERSION
 			else
 				ac_python_version=`$PYTHON -c "import sys; \
-					print ('.'.join(sys.version.split('.')[[:2]]))"`
+					print ("%d.%d" % sys.version_info[[:2]])"`
 			fi
 		fi
 
@@ -220,7 +281,7 @@ EOD`
 		ac_python_libdir=`cat<<EOD | $PYTHON -
 
 # There should be only one
-import sysconfig
+$IMPORT_SYSCONFIG
 e = sysconfig.get_config_var('LIBDIR')
 if e is not None:
 	print (e)
@@ -229,7 +290,7 @@ EOD`
 		# Now, for the library:
 		ac_python_library=`cat<<EOD | $PYTHON -
 
-import sysconfig
+$IMPORT_SYSCONFIG
 c = sysconfig.get_config_vars()
 if 'LDVERSION' in c:
 	print ('python'+c[['LDVERSION']])
@@ -249,88 +310,140 @@ EOD`
 		else
 			# old way: use libpython from python_configdir
 			ac_python_libdir=`$PYTHON -c \
-			  "import sysconfig; \
+			  "from sysconfig import get_python_lib as f; \
 			  import os; \
-			  print (os.path.join(sysconfig.get_path('platstdlib'), 'config'));"`
+			  print (os.path.join(f(plat_specific=1, standard_lib=1), 'config'));"`
 			PYTHON_LIBS="-L$ac_python_libdir -lpython$ac_python_version"
 		fi
 
 		if test -z "PYTHON_LIBS"; then
-			m4_ifvaln([$2],[$2],[
-				AC_MSG_ERROR([
+			AC_MSG_WARN([
   Cannot determine location of your Python DSO. Please check it was installed with
   dynamic libraries enabled, or try setting PYTHON_LIBS by hand.
-				])
 			])
+			if ! $ax_python_devel_optional; then
+			   AC_MSG_ERROR([Giving up])
+			fi
+			ax_python_devel_found=no
+			PYTHON_VERSION=""
 		fi
+	   fi
 	fi
-	AC_MSG_RESULT([$PYTHON_LIBS])
-	AC_SUBST([PYTHON_LIBS])
 
-	#
-	# Check for site packages
-	#
-	AC_MSG_CHECKING([for Python site-packages path])
-	if test -z "$PYTHON_SITE_PKG"; then
-		PYTHON_SITE_PKG=`$PYTHON -c "import distutils.sysconfig; \
-			print (distutils.sysconfig.get_python_lib(0,0));" 2>/dev/null || \
-			$PYTHON -c "import sysconfig; \
-			print (sysconfig.get_path('purelib'));"`
-	fi
-	AC_MSG_RESULT([$PYTHON_SITE_PKG])
-	AC_SUBST([PYTHON_SITE_PKG])
+	if test $ax_python_devel_found = yes; then
+	   AC_MSG_RESULT([$PYTHON_LIBS])
+	   AC_SUBST([PYTHON_LIBS])
 
-	#
-	# libraries which must be linked in when embedding
-	#
-	AC_MSG_CHECKING(python extra libraries)
-	if test -z "$PYTHON_EXTRA_LIBS"; then
-	   PYTHON_EXTRA_LIBS=`$PYTHON -c "import sysconfig; \
+	   #
+	   # Check for site packages
+	   #
+	   AC_MSG_CHECKING([for Python site-packages path])
+	   if test -z "$PYTHON_SITE_PKG"; then
+		if test "$IMPORT_SYSCONFIG" = "import sysconfig"; then
+			PYTHON_SITE_PKG=`$PYTHON -c "
+$IMPORT_SYSCONFIG;
+if hasattr(sysconfig, 'get_default_scheme'):
+    scheme = sysconfig.get_default_scheme()
+else:
+    scheme = sysconfig._get_default_scheme()
+if scheme == 'posix_local':
+    # Debian's default scheme installs to /usr/local/ but we want to find headers in /usr/
+    scheme = 'posix_prefix'
+prefix = '$prefix'
+if prefix == 'NONE':
+    prefix = '$ac_default_prefix'
+sitedir = sysconfig.get_path('purelib', scheme, vars={'base': prefix})
+print(sitedir)"`
+		else
+			# distutils.sysconfig way
+			PYTHON_SITE_PKG=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+				print (sysconfig.get_python_lib(0,0));"`
+		fi
+	   fi
+	   AC_MSG_RESULT([$PYTHON_SITE_PKG])
+	   AC_SUBST([PYTHON_SITE_PKG])
+
+	   #
+	   # Check for platform-specific site packages
+	   #
+	   AC_MSG_CHECKING([for Python platform specific site-packages path])
+	   if test -z "$PYTHON_PLATFORM_SITE_PKG"; then
+		if test "$IMPORT_SYSCONFIG" = "import sysconfig"; then
+			PYTHON_PLATFORM_SITE_PKG=`$PYTHON -c "
+$IMPORT_SYSCONFIG;
+if hasattr(sysconfig, 'get_default_scheme'):
+    scheme = sysconfig.get_default_scheme()
+else:
+    scheme = sysconfig._get_default_scheme()
+if scheme == 'posix_local':
+    # Debian's default scheme installs to /usr/local/ but we want to find headers in /usr/
+    scheme = 'posix_prefix'
+prefix = '$prefix'
+if prefix == 'NONE':
+    prefix = '$ac_default_prefix'
+sitedir = sysconfig.get_path('platlib', scheme, vars={'platbase': prefix})
+print(sitedir)"`
+		else
+			# distutils.sysconfig way
+			PYTHON_PLATFORM_SITE_PKG=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+				print (sysconfig.get_python_lib(1,0));"`
+		fi
+	   fi
+	   AC_MSG_RESULT([$PYTHON_PLATFORM_SITE_PKG])
+	   AC_SUBST([PYTHON_PLATFORM_SITE_PKG])
+
+	   #
+	   # libraries which must be linked in when embedding
+	   #
+	   AC_MSG_CHECKING(python extra libraries)
+	   if test -z "$PYTHON_EXTRA_LIBS"; then
+	      PYTHON_EXTRA_LIBS=`$PYTHON -c "$IMPORT_SYSCONFIG; \
                 conf = sysconfig.get_config_var; \
                 print (conf('LIBS') + ' ' + conf('SYSLIBS'))"`
-	fi
-	AC_MSG_RESULT([$PYTHON_EXTRA_LIBS])
-	AC_SUBST(PYTHON_EXTRA_LIBS)
+	   fi
+	   AC_MSG_RESULT([$PYTHON_EXTRA_LIBS])
+	   AC_SUBST(PYTHON_EXTRA_LIBS)
 
-	#
-	# linking flags needed when embedding
-	#
-	AC_MSG_CHECKING(python extra linking flags)
-	if test -z "$PYTHON_EXTRA_LDFLAGS"; then
-		PYTHON_EXTRA_LDFLAGS=`$PYTHON -c "import sysconfig; \
+	   #
+	   # linking flags needed when embedding
+	   #
+	   AC_MSG_CHECKING(python extra linking flags)
+	   if test -z "$PYTHON_EXTRA_LDFLAGS"; then
+		PYTHON_EXTRA_LDFLAGS=`$PYTHON -c "$IMPORT_SYSCONFIG; \
 			conf = sysconfig.get_config_var; \
 			print (conf('LINKFORSHARED'))"`
-	fi
-	AC_MSG_RESULT([$PYTHON_EXTRA_LDFLAGS])
-	AC_SUBST(PYTHON_EXTRA_LDFLAGS)
+		# Hack for macos, it sticks this in here.
+		PYTHON_EXTRA_LDFLAGS=`echo $PYTHON_EXTRA_LDFLAGS | sed 's/CoreFoundation.*$/CoreFoundation/'`
+	   fi
+	   AC_MSG_RESULT([$PYTHON_EXTRA_LDFLAGS])
+	   AC_SUBST(PYTHON_EXTRA_LDFLAGS)
 
-	#
-	# final check to see if everything compiles alright
-	#
-	AC_MSG_CHECKING([consistency of all components of python development environment])
-	# save current global flags
-	ac_save_LIBS="$LIBS"
-	ac_save_LDFLAGS="$LDFLAGS"
-	ac_save_CPPFLAGS="$CPPFLAGS"
-	LIBS="$ac_save_LIBS $PYTHON_LIBS $PYTHON_EXTRA_LIBS $PYTHON_EXTRA_LIBS"
-	LDFLAGS="$ac_save_LDFLAGS $PYTHON_EXTRA_LDFLAGS"
-	CPPFLAGS="$ac_save_CPPFLAGS $PYTHON_CPPFLAGS"
-	AC_LANG_PUSH([C])
-	AC_LINK_IFELSE([
+	   #
+	   # final check to see if everything compiles alright
+	   #
+	   AC_MSG_CHECKING([consistency of all components of python development environment])
+	   # save current global flags
+	   ac_save_LIBS="$LIBS"
+	   ac_save_LDFLAGS="$LDFLAGS"
+	   ac_save_CPPFLAGS="$CPPFLAGS"
+	   LIBS="$ac_save_LIBS $PYTHON_LIBS $PYTHON_EXTRA_LIBS"
+	   LDFLAGS="$ac_save_LDFLAGS $PYTHON_EXTRA_LDFLAGS"
+	   CPPFLAGS="$ac_save_CPPFLAGS $PYTHON_CPPFLAGS"
+	   AC_LANG_PUSH([C])
+	   AC_LINK_IFELSE([
 		AC_LANG_PROGRAM([[#include <Python.h>]],
 				[[Py_Initialize();]])
 		],[pythonexists=yes],[pythonexists=no])
-	AC_LANG_POP([C])
-	# turn back to default flags
-	CPPFLAGS="$ac_save_CPPFLAGS"
-	LIBS="$ac_save_LIBS"
-	LDFLAGS="$ac_save_LDFLAGS"
+	   AC_LANG_POP([C])
+	   # turn back to default flags
+	   CPPFLAGS="$ac_save_CPPFLAGS"
+	   LIBS="$ac_save_LIBS"
+	   LDFLAGS="$ac_save_LDFLAGS"
 
-	AC_MSG_RESULT([$pythonexists])
+	   AC_MSG_RESULT([$pythonexists])
 
-        if test ! "x$pythonexists" = "xyes"; then
-		m4_ifvaln([$2],[$2],[
-			AC_MSG_FAILURE([
+	   if test ! "x$pythonexists" = "xyes"; then
+	      AC_MSG_WARN([
   Could not link test program to Python. Maybe the main Python library has been
   installed in some non-standard library path. If so, pass it to configure,
   via the LIBS environment variable.
@@ -340,9 +453,13 @@ EOD`
    You probably have to install the development version of the Python package
    for your distribution.  The exact name of this package varies among them.
   ============================================================================
-	   ])
-			PYTHON_VERSION=""
-		])
+	      ])
+	      if ! $ax_python_devel_optional; then
+		 AC_MSG_ERROR([Giving up])
+	      fi
+	      ax_python_devel_found=no
+	      PYTHON_VERSION=""
+	   fi
 	fi
 
 	#
diff --git a/sys/contrib/openzfs/config/kernel-blk-queue.m4 b/sys/contrib/openzfs/config/kernel-blk-queue.m4
index bb5903b313eb..15dbe1c7dff0 100644
--- a/sys/contrib/openzfs/config/kernel-blk-queue.m4
+++ b/sys/contrib/openzfs/config/kernel-blk-queue.m4
@@ -377,6 +377,14 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLK_MQ], [
 		(void) blk_mq_alloc_tag_set(&tag_set);
 		return BLK_STS_OK;
 	], [])
+	ZFS_LINUX_TEST_SRC([blk_mq_rq_hctx], [
+		#include <linux/blk-mq.h>
+		#include <linux/blkdev.h>
+	], [
+		struct request rq = {0};
+		struct blk_mq_hw_ctx *hctx = NULL;
+		rq.mq_hctx = hctx;
+	], [])
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_BLK_MQ], [
@@ -384,6 +392,13 @@ AC_DEFUN([ZFS_AC_KERNEL_BLK_MQ], [
 	ZFS_LINUX_TEST_RESULT([blk_mq], [
 		AC_MSG_RESULT(yes)
 		AC_DEFINE(HAVE_BLK_MQ, 1, [block multiqueue is available])
+		AC_MSG_CHECKING([whether block multiqueue hardware context is cached in struct request])
+		ZFS_LINUX_TEST_RESULT([blk_mq_rq_hctx], [
+			AC_MSG_RESULT(yes)
+			AC_DEFINE(HAVE_BLK_MQ_RQ_HCTX, 1, [block multiqueue hardware context is cached in struct request])
+		], [
+			AC_MSG_RESULT(no)
+		])
 	], [
 		AC_MSG_RESULT(no)
 	])
diff --git a/sys/contrib/openzfs/config/kernel-blkdev.m4 b/sys/contrib/openzfs/config/kernel-blkdev.m4
index c5a353ca9203..b6ce1e1cf083 100644
--- a/sys/contrib/openzfs/config/kernel-blkdev.m4
+++ b/sys/contrib/openzfs/config/kernel-blkdev.m4
@@ -54,6 +54,26 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_BDEV_OPEN_BY_PATH], [
 	])
 ])
 
+dnl #
+dnl # 6.9.x API change
+dnl # bdev_file_open_by_path() replaced bdev_open_by_path(),
+dnl # and returns struct file*
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_BDEV_FILE_OPEN_BY_PATH], [
+	ZFS_LINUX_TEST_SRC([bdev_file_open_by_path], [
+		#include <linux/fs.h>
+		#include <linux/blkdev.h>
+	], [
+		struct file *file __attribute__ ((unused)) = NULL;
+		const char *path = "path";
+		fmode_t mode = 0;
+		void *holder = NULL;
+		struct blk_holder_ops h;
+
+		file = bdev_file_open_by_path(path, mode, holder, &h);
+	])
+])
+
 AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_GET_BY_PATH], [
 	AC_MSG_CHECKING([whether blkdev_get_by_path() exists and takes 3 args])
 	ZFS_LINUX_TEST_RESULT([blkdev_get_by_path], [
@@ -73,7 +93,16 @@ AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_GET_BY_PATH], [
 					[bdev_open_by_path() exists])
 				AC_MSG_RESULT(yes)
 			], [
-				ZFS_LINUX_TEST_ERROR([blkdev_get_by_path()])
+				AC_MSG_RESULT(no)
+				AC_MSG_CHECKING([whether bdev_file_open_by_path() exists])
+				ZFS_LINUX_TEST_RESULT([bdev_file_open_by_path], [
+					AC_DEFINE(HAVE_BDEV_FILE_OPEN_BY_PATH, 1,
+						[bdev_file_open_by_path() exists])
+					AC_MSG_RESULT(yes)
+				], [
+					AC_MSG_RESULT(no)
+					ZFS_LINUX_TEST_ERROR([blkdev_get_by_path()])
+				])
 			])
 		])
 	])
@@ -149,10 +178,19 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_BDEV_RELEASE], [
 	])
 ])
 
+dnl #
+dnl # 6.9.x API change
+dnl #
+dnl # bdev_release() now private, but because bdev_file_open_by_path() returns
+dnl # struct file*, we can just use fput(). So the blkdev_put test no longer
+dnl # fails if not found.
+dnl #
+
 AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_PUT], [
 	AC_MSG_CHECKING([whether blkdev_put() exists])
 	ZFS_LINUX_TEST_RESULT([blkdev_put], [
 		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BLKDEV_PUT, 1, [blkdev_put() exists])
 	], [
 		AC_MSG_RESULT(no)
 		AC_MSG_CHECKING([whether blkdev_put() accepts void* as arg 2])
@@ -168,7 +206,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_PUT], [
 				AC_DEFINE(HAVE_BDEV_RELEASE, 1,
 					[bdev_release() exists])
 			], [
-				ZFS_LINUX_TEST_ERROR([blkdev_put()])
+				AC_MSG_RESULT(no)
 			])
 		])
 	])
@@ -523,12 +561,29 @@ AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_BDEVNAME], [
 ])
 
 dnl #
-dnl # 5.19 API: blkdev_issue_secure_erase()
-dnl # 4.7  API: __blkdev_issue_discard(..., BLKDEV_DISCARD_SECURE)
-dnl # 3.10 API: blkdev_issue_discard(..., BLKDEV_DISCARD_SECURE)
+dnl # TRIM support: discard and secure erase. We make use of asynchronous
+dnl #               functions when available.
 dnl #
-AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_ISSUE_SECURE_ERASE], [
-	ZFS_LINUX_TEST_SRC([blkdev_issue_secure_erase], [
+dnl # 3.10:
+dnl #   sync discard:  blkdev_issue_discard(..., 0)
+dnl #   sync erase:    blkdev_issue_discard(..., BLKDEV_DISCARD_SECURE)
+dnl #   async discard: [not available]
+dnl #   async erase:   [not available]
+dnl #
+dnl # 4.7:
+dnl #   sync discard:  blkdev_issue_discard(..., 0)
+dnl #   sync erase:    blkdev_issue_discard(..., BLKDEV_DISCARD_SECURE)
+dnl #   async discard: __blkdev_issue_discard(..., 0)
+dnl #   async erase:   __blkdev_issue_discard(..., BLKDEV_DISCARD_SECURE)
+dnl #
+dnl # 5.19:
+dnl #   sync discard:  blkdev_issue_discard(...)
+dnl #   sync erase:    blkdev_issue_secure_erase(...)
+dnl #   async discard: __blkdev_issue_discard(...)
+dnl #   async erase:   [not available]
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_ISSUE_DISCARD], [
+	ZFS_LINUX_TEST_SRC([blkdev_issue_discard_noflags], [
 		#include <linux/blkdev.h>
 	],[
 		struct block_device *bdev = NULL;
@@ -536,10 +591,33 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_ISSUE_SECURE_ERASE], [
 		sector_t nr_sects = 0;
 		int error __attribute__ ((unused));
 
-		error = blkdev_issue_secure_erase(bdev,
+		error = blkdev_issue_discard(bdev,
 		    sector, nr_sects, GFP_KERNEL);
 	])
+	ZFS_LINUX_TEST_SRC([blkdev_issue_discard_flags], [
+		#include <linux/blkdev.h>
+	],[
+		struct block_device *bdev = NULL;
+		sector_t sector = 0;
+		sector_t nr_sects = 0;
+		unsigned long flags = 0;
+		int error __attribute__ ((unused));
 
+		error = blkdev_issue_discard(bdev,
+		    sector, nr_sects, GFP_KERNEL, flags);
+	])
+	ZFS_LINUX_TEST_SRC([blkdev_issue_discard_async_noflags], [
+		#include <linux/blkdev.h>
+	],[
+		struct block_device *bdev = NULL;
+		sector_t sector = 0;
+		sector_t nr_sects = 0;
+		struct bio *biop = NULL;
+		int error __attribute__ ((unused));
+
+		error = __blkdev_issue_discard(bdev,
+		    sector, nr_sects, GFP_KERNEL, &biop);
+	])
 	ZFS_LINUX_TEST_SRC([blkdev_issue_discard_async_flags], [
 		#include <linux/blkdev.h>
 	],[
@@ -553,22 +631,52 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_ISSUE_SECURE_ERASE], [
 		error = __blkdev_issue_discard(bdev,
 		    sector, nr_sects, GFP_KERNEL, flags, &biop);
 	])
-
-	ZFS_LINUX_TEST_SRC([blkdev_issue_discard_flags], [
+	ZFS_LINUX_TEST_SRC([blkdev_issue_secure_erase], [
 		#include <linux/blkdev.h>
 	],[
 		struct block_device *bdev = NULL;
 		sector_t sector = 0;
 		sector_t nr_sects = 0;
-		unsigned long flags = 0;
 		int error __attribute__ ((unused));
 
-		error = blkdev_issue_discard(bdev,
-		    sector, nr_sects, GFP_KERNEL, flags);
+		error = blkdev_issue_secure_erase(bdev,
+		    sector, nr_sects, GFP_KERNEL);
 	])
 ])
 
-AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_ISSUE_SECURE_ERASE], [
+AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_ISSUE_DISCARD], [
+	AC_MSG_CHECKING([whether blkdev_issue_discard() is available])
+	ZFS_LINUX_TEST_RESULT([blkdev_issue_discard_noflags], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BLKDEV_ISSUE_DISCARD_NOFLAGS, 1,
+		    [blkdev_issue_discard() is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
+	AC_MSG_CHECKING([whether blkdev_issue_discard(flags) is available])
+	ZFS_LINUX_TEST_RESULT([blkdev_issue_discard_flags], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BLKDEV_ISSUE_DISCARD_FLAGS, 1,
+		    [blkdev_issue_discard(flags) is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
+	AC_MSG_CHECKING([whether __blkdev_issue_discard() is available])
+	ZFS_LINUX_TEST_RESULT([blkdev_issue_discard_async_noflags], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_NOFLAGS, 1,
+		    [__blkdev_issue_discard() is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
+	AC_MSG_CHECKING([whether __blkdev_issue_discard(flags) is available])
+	ZFS_LINUX_TEST_RESULT([blkdev_issue_discard_async_flags], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_FLAGS, 1,
+		    [__blkdev_issue_discard(flags) is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
 	AC_MSG_CHECKING([whether blkdev_issue_secure_erase() is available])
 	ZFS_LINUX_TEST_RESULT([blkdev_issue_secure_erase], [
 		AC_MSG_RESULT(yes)
@@ -576,24 +684,6 @@ AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_ISSUE_SECURE_ERASE], [
 		    [blkdev_issue_secure_erase() is available])
 	],[
 		AC_MSG_RESULT(no)
-
-		AC_MSG_CHECKING([whether __blkdev_issue_discard() is available])
-		ZFS_LINUX_TEST_RESULT([blkdev_issue_discard_async_flags], [
-			AC_MSG_RESULT(yes)
-			AC_DEFINE(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC, 1,
-			    [__blkdev_issue_discard() is available])
-		],[
-			AC_MSG_RESULT(no)
-
-			AC_MSG_CHECKING([whether blkdev_issue_discard() is available])
-			ZFS_LINUX_TEST_RESULT([blkdev_issue_discard_flags], [
-				AC_MSG_RESULT(yes)
-				AC_DEFINE(HAVE_BLKDEV_ISSUE_DISCARD, 1,
-					[blkdev_issue_discard() is available])
-			],[
-				ZFS_LINUX_TEST_ERROR([blkdev_issue_discard()])
-			])
-		])
 	])
 ])
 
@@ -645,6 +735,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV], [
 	ZFS_AC_KERNEL_SRC_BLKDEV_GET_BY_PATH
 	ZFS_AC_KERNEL_SRC_BLKDEV_GET_BY_PATH_4ARG
 	ZFS_AC_KERNEL_SRC_BLKDEV_BDEV_OPEN_BY_PATH
+	ZFS_AC_KERNEL_SRC_BDEV_FILE_OPEN_BY_PATH
 	ZFS_AC_KERNEL_SRC_BLKDEV_PUT
 	ZFS_AC_KERNEL_SRC_BLKDEV_PUT_HOLDER
 	ZFS_AC_KERNEL_SRC_BLKDEV_BDEV_RELEASE
@@ -657,7 +748,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV], [
 	ZFS_AC_KERNEL_SRC_BLKDEV_BDEV_CHECK_MEDIA_CHANGE
 	ZFS_AC_KERNEL_SRC_BLKDEV_BDEV_WHOLE
 	ZFS_AC_KERNEL_SRC_BLKDEV_BDEVNAME
-	ZFS_AC_KERNEL_SRC_BLKDEV_ISSUE_SECURE_ERASE
+	ZFS_AC_KERNEL_SRC_BLKDEV_ISSUE_DISCARD
 	ZFS_AC_KERNEL_SRC_BLKDEV_BDEV_KOBJ
 	ZFS_AC_KERNEL_SRC_BLKDEV_PART_TO_DEV
 	ZFS_AC_KERNEL_SRC_BLKDEV_DISK_CHECK_MEDIA_CHANGE
@@ -678,7 +769,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BLKDEV], [
 	ZFS_AC_KERNEL_BLKDEV_BDEV_WHOLE
 	ZFS_AC_KERNEL_BLKDEV_BDEVNAME
 	ZFS_AC_KERNEL_BLKDEV_GET_ERESTARTSYS
-	ZFS_AC_KERNEL_BLKDEV_ISSUE_SECURE_ERASE
+	ZFS_AC_KERNEL_BLKDEV_ISSUE_DISCARD
 	ZFS_AC_KERNEL_BLKDEV_BDEV_KOBJ
 	ZFS_AC_KERNEL_BLKDEV_PART_TO_DEV
 	ZFS_AC_KERNEL_BLKDEV_DISK_CHECK_MEDIA_CHANGE
diff --git a/sys/contrib/openzfs/config/kernel-filemap.m4 b/sys/contrib/openzfs/config/kernel-filemap.m4
index 745928168f92..0b7da828d299 100644
--- a/sys/contrib/openzfs/config/kernel-filemap.m4
+++ b/sys/contrib/openzfs/config/kernel-filemap.m4
@@ -4,6 +4,7 @@ dnl #
 AC_DEFUN([ZFS_AC_KERNEL_SRC_FILEMAP], [
 	ZFS_LINUX_TEST_SRC([filemap_range_has_page], [
 		#include <linux/fs.h>
+		#include <linux/pagemap.h>
 	],[
 		struct address_space *mapping = NULL;
 		loff_t lstart = 0;
diff --git a/sys/contrib/openzfs/config/kernel-make-request-fn.m4 b/sys/contrib/openzfs/config/kernel-make-request-fn.m4
index 4d20dd45c4a1..9813ad2fb3f3 100644
--- a/sys/contrib/openzfs/config/kernel-make-request-fn.m4
+++ b/sys/contrib/openzfs/config/kernel-make-request-fn.m4
@@ -50,6 +50,14 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_MAKE_REQUEST_FN], [
 		disk = blk_alloc_disk(NUMA_NO_NODE);
 	])
 
+	ZFS_LINUX_TEST_SRC([blk_alloc_disk_2arg], [
+		#include <linux/blkdev.h>
+	],[
+		struct queue_limits *lim = NULL;
+		struct gendisk *disk  __attribute__ ((unused));
+		disk = blk_alloc_disk(lim, NUMA_NO_NODE);
+	])
+
 	ZFS_LINUX_TEST_SRC([blk_cleanup_disk], [
 		#include <linux/blkdev.h>
 	],[
@@ -96,6 +104,31 @@ AC_DEFUN([ZFS_AC_KERNEL_MAKE_REQUEST_FN], [
 		], [
 			AC_MSG_RESULT(no)
 		])
+
+		dnl #
+		dnl # Linux 6.9 API Change:
+		dnl # blk_alloc_queue() takes a nullable queue_limits arg.
+		dnl #
+		AC_MSG_CHECKING([whether blk_alloc_disk() exists and takes 2 args])
+		ZFS_LINUX_TEST_RESULT([blk_alloc_disk_2arg], [
+			AC_MSG_RESULT(yes)
+			AC_DEFINE([HAVE_BLK_ALLOC_DISK_2ARG], 1, [blk_alloc_disk() exists and takes 2 args])
+
+			dnl #
+			dnl # 5.20 API change,
+			dnl # Removed blk_cleanup_disk(), put_disk() should be used.
+			dnl #
+			AC_MSG_CHECKING([whether blk_cleanup_disk() exists])
+			ZFS_LINUX_TEST_RESULT([blk_cleanup_disk], [
+				AC_MSG_RESULT(yes)
+				AC_DEFINE([HAVE_BLK_CLEANUP_DISK], 1,
+				    [blk_cleanup_disk() exists])
+			], [
+				AC_MSG_RESULT(no)
+			])
+		], [
+			AC_MSG_RESULT(no)
+		])
 	],[
 		AC_MSG_RESULT(no)
 
diff --git a/sys/contrib/openzfs/config/kernel-mm-page-size.m4 b/sys/contrib/openzfs/config/kernel-mm-page-size.m4
new file mode 100644
index 000000000000..d5ebd926986a
--- /dev/null
+++ b/sys/contrib/openzfs/config/kernel-mm-page-size.m4
@@ -0,0 +1,17 @@
+AC_DEFUN([ZFS_AC_KERNEL_SRC_MM_PAGE_SIZE], [
+	ZFS_LINUX_TEST_SRC([page_size], [
+		#include <linux/mm.h>
+	],[
+		unsigned long s;
+		s = page_size(NULL);
+	])
+])
+AC_DEFUN([ZFS_AC_KERNEL_MM_PAGE_SIZE], [
+	AC_MSG_CHECKING([whether page_size() is available])
+	ZFS_LINUX_TEST_RESULT([page_size], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_MM_PAGE_SIZE, 1, [page_size() is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
+])
diff --git a/sys/contrib/openzfs/config/kernel-vfs-file_range.m4 b/sys/contrib/openzfs/config/kernel-vfs-file_range.m4
index cc96404d8bbe..8a5cbe2eeeed 100644
--- a/sys/contrib/openzfs/config/kernel-vfs-file_range.m4
+++ b/sys/contrib/openzfs/config/kernel-vfs-file_range.m4
@@ -16,6 +16,9 @@ dnl #
 dnl # 5.3: VFS copy_file_range() expected to do its own fallback,
 dnl #      generic_copy_file_range() added to support it
 dnl #
+dnl # 6.8: generic_copy_file_range() removed, replaced by
+dnl #      splice_copy_file_range()
+dnl #
 AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_COPY_FILE_RANGE], [
 	ZFS_LINUX_TEST_SRC([vfs_copy_file_range], [
 		#include <linux/fs.h>
@@ -72,6 +75,30 @@ AC_DEFUN([ZFS_AC_KERNEL_VFS_GENERIC_COPY_FILE_RANGE], [
 	])
 ])
 
+AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_SPLICE_COPY_FILE_RANGE], [
+	ZFS_LINUX_TEST_SRC([splice_copy_file_range], [
+		#include <linux/splice.h>
+	], [
+		struct file *src_file __attribute__ ((unused)) = NULL;
+		loff_t src_off __attribute__ ((unused)) = 0;
+		struct file *dst_file __attribute__ ((unused)) = NULL;
+		loff_t dst_off __attribute__ ((unused)) = 0;
+		size_t len __attribute__ ((unused)) = 0;
+		splice_copy_file_range(src_file, src_off, dst_file, dst_off,
+		    len);
+	])
+])
+AC_DEFUN([ZFS_AC_KERNEL_VFS_SPLICE_COPY_FILE_RANGE], [
+	AC_MSG_CHECKING([whether splice_copy_file_range() is available])
+	ZFS_LINUX_TEST_RESULT([splice_copy_file_range], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_VFS_SPLICE_COPY_FILE_RANGE, 1,
+		    [splice_copy_file_range() is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
+])
+
 AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_CLONE_FILE_RANGE], [
 	ZFS_LINUX_TEST_SRC([vfs_clone_file_range], [
 		#include <linux/fs.h>
diff --git a/sys/contrib/openzfs/config/kernel.m4 b/sys/contrib/openzfs/config/kernel.m4
index e3f8645774c5..548905ccd04d 100644
--- a/sys/contrib/openzfs/config/kernel.m4
+++ b/sys/contrib/openzfs/config/kernel.m4
@@ -118,6 +118,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_VFS_IOV_ITER
 	ZFS_AC_KERNEL_SRC_VFS_COPY_FILE_RANGE
 	ZFS_AC_KERNEL_SRC_VFS_GENERIC_COPY_FILE_RANGE
+	ZFS_AC_KERNEL_SRC_VFS_SPLICE_COPY_FILE_RANGE
 	ZFS_AC_KERNEL_SRC_VFS_REMAP_FILE_RANGE
 	ZFS_AC_KERNEL_SRC_VFS_CLONE_FILE_RANGE
 	ZFS_AC_KERNEL_SRC_VFS_DEDUPE_FILE_RANGE
@@ -166,6 +167,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_REGISTER_SYSCTL_TABLE
 	ZFS_AC_KERNEL_SRC_COPY_SPLICE_READ
 	ZFS_AC_KERNEL_SRC_SYNC_BDEV
+	ZFS_AC_KERNEL_SRC_MM_PAGE_SIZE
 	case "$host_cpu" in
 		powerpc*)
 			ZFS_AC_KERNEL_SRC_CPU_HAS_FEATURE
@@ -266,6 +268,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_VFS_IOV_ITER
 	ZFS_AC_KERNEL_VFS_COPY_FILE_RANGE
 	ZFS_AC_KERNEL_VFS_GENERIC_COPY_FILE_RANGE
+	ZFS_AC_KERNEL_VFS_SPLICE_COPY_FILE_RANGE
 	ZFS_AC_KERNEL_VFS_REMAP_FILE_RANGE
 	ZFS_AC_KERNEL_VFS_CLONE_FILE_RANGE
 	ZFS_AC_KERNEL_VFS_DEDUPE_FILE_RANGE
@@ -314,6 +317,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_REGISTER_SYSCTL_TABLE
 	ZFS_AC_KERNEL_COPY_SPLICE_READ
 	ZFS_AC_KERNEL_SYNC_BDEV
+	ZFS_AC_KERNEL_MM_PAGE_SIZE
 	case "$host_cpu" in
 		powerpc*)
 			ZFS_AC_KERNEL_CPU_HAS_FEATURE
diff --git a/sys/contrib/openzfs/config/zfs-build.m4 b/sys/contrib/openzfs/config/zfs-build.m4
index 5f36569fe25b..bb5a85d815d1 100644
--- a/sys/contrib/openzfs/config/zfs-build.m4
+++ b/sys/contrib/openzfs/config/zfs-build.m4
@@ -578,13 +578,15 @@ AC_DEFUN([ZFS_AC_DEFAULT_PACKAGE], [
 
 	AC_MSG_CHECKING([default shell])
 	case "$VENDOR" in
-		gentoo)     DEFAULT_INIT_SHELL="/sbin/openrc-run";;
-		alpine)     DEFAULT_INIT_SHELL="/sbin/openrc-run";;
-		*)          DEFAULT_INIT_SHELL="/bin/sh"         ;;
+		gentoo|alpine)	DEFAULT_INIT_SHELL=/sbin/openrc-run
+				IS_SYSV_RC=false	;;
+		*)		DEFAULT_INIT_SHELL=/bin/sh
+				IS_SYSV_RC=true		;;
 	esac
 
 	AC_MSG_RESULT([$DEFAULT_INIT_SHELL])
 	AC_SUBST(DEFAULT_INIT_SHELL)
+	AC_SUBST(IS_SYSV_RC)
 
 	AC_MSG_CHECKING([default nfs server init script])
 	AS_IF([test "$VENDOR" = "debian"],
diff --git a/sys/contrib/openzfs/contrib/debian/control b/sys/contrib/openzfs/contrib/debian/control
index 98beb900d0fa..e56fbf0f1c93 100644
--- a/sys/contrib/openzfs/contrib/debian/control
+++ b/sys/contrib/openzfs/contrib/debian/control
@@ -189,7 +189,7 @@ Depends: dkms (>> 2.1.1.2-5),
          file,
          libc6-dev | libc-dev,
          lsb-release,
-         python3-distutils | libpython3-stdlib (<< 3.6.4),
+         python3 (>> 3.12) | python3-distutils | libpython3-stdlib (<< 3.6.4),
          ${misc:Depends},
          ${perl:Depends}
 Recommends: openzfs-zfs-zed, openzfs-zfsutils (>= ${source:Version}), ${linux:Recommends}
diff --git a/sys/contrib/openzfs/etc/init.d/README.md b/sys/contrib/openzfs/etc/init.d/README.md
index 2de05042ce63..da780fdc1222 100644
--- a/sys/contrib/openzfs/etc/init.d/README.md
+++ b/sys/contrib/openzfs/etc/init.d/README.md
@@ -7,11 +7,7 @@ DESCRIPTION
 
   They have been tested successfully on:
 
-    * Debian GNU/Linux Wheezy
-    * Debian GNU/Linux Jessie
-    * Ubuntu Trusty
-    * CentOS 6.0
-    * CentOS 6.6
+    * Debian GNU/Linux Bookworm
     * Gentoo
 
 SUPPORT
diff --git a/sys/contrib/openzfs/etc/init.d/zfs-import.in b/sys/contrib/openzfs/etc/init.d/zfs-import.in
index a9a0604f81ac..ff169eb96d86 100755
--- a/sys/contrib/openzfs/etc/init.d/zfs-import.in
+++ b/sys/contrib/openzfs/etc/init.d/zfs-import.in
@@ -307,7 +307,7 @@ do_start()
 
 # ----------------------------------------------------
 
-if [ ! -e /sbin/openrc-run ]
+if @IS_SYSV_RC@
 then
 	case "$1" in
 		start)
diff --git a/sys/contrib/openzfs/etc/init.d/zfs-load-key.in b/sys/contrib/openzfs/etc/init.d/zfs-load-key.in
index 53c7766b793a..27dfeeb0bcc5 100755
--- a/sys/contrib/openzfs/etc/init.d/zfs-load-key.in
+++ b/sys/contrib/openzfs/etc/init.d/zfs-load-key.in
@@ -104,7 +104,7 @@ do_stop()
 
 # ----------------------------------------------------
 
-if [ ! -e /sbin/openrc-run ]
+if @IS_SYSV_RC@
 then
 	case "$1" in
 		start)
diff --git a/sys/contrib/openzfs/etc/init.d/zfs-mount.in b/sys/contrib/openzfs/etc/init.d/zfs-mount.in
index a0825f19fcdd..6a3ca5f86908 100755
--- a/sys/contrib/openzfs/etc/init.d/zfs-mount.in
+++ b/sys/contrib/openzfs/etc/init.d/zfs-mount.in
@@ -114,7 +114,7 @@ do_stop()
 
 # ----------------------------------------------------
 
-if [ ! -e /sbin/openrc-run ]
+if @IS_SYSV_RC@
 then
 	case "$1" in
 		start)
diff --git a/sys/contrib/openzfs/etc/init.d/zfs-share.in b/sys/contrib/openzfs/etc/init.d/zfs-share.in
index 88978071cbf6..06c59c620b75 100755
--- a/sys/contrib/openzfs/etc/init.d/zfs-share.in
+++ b/sys/contrib/openzfs/etc/init.d/zfs-share.in
@@ -57,7 +57,8 @@ do_stop()
 
 # ----------------------------------------------------
 
-if [ ! -e /sbin/openrc-run ]; then
+if @IS_SYSV_RC@
+then
 	case "$1" in
 		start)
 			do_start
diff --git a/sys/contrib/openzfs/etc/init.d/zfs-zed.in b/sys/contrib/openzfs/etc/init.d/zfs-zed.in
index e9cf8867403c..3d40600cea5d 100755
--- a/sys/contrib/openzfs/etc/init.d/zfs-zed.in
+++ b/sys/contrib/openzfs/etc/init.d/zfs-zed.in
@@ -93,7 +93,8 @@ do_reload()
 
 # ----------------------------------------------------
 
-if [ ! -e /sbin/openrc-run ]; then
+if @IS_SYSV_RC@
+then
 	case "$1" in
 		start)
 			do_start
diff --git a/sys/contrib/openzfs/include/libzfs.h b/sys/contrib/openzfs/include/libzfs.h
index 770c5e1f201c..2823b8845827 100644
--- a/sys/contrib/openzfs/include/libzfs.h
+++ b/sys/contrib/openzfs/include/libzfs.h
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2022 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright Joyent, Inc.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  * Copyright (c) 2016, Intel Corporation.
@@ -157,6 +157,8 @@ typedef enum zfs_error {
 	EZFS_CKSUM,		/* insufficient replicas */
 	EZFS_RESUME_EXISTS,	/* Resume on existing dataset without force */
 	EZFS_SHAREFAILED,	/* filesystem share failed */
+	EZFS_RAIDZ_EXPAND_IN_PROGRESS,	/* a raidz is currently expanding */
+	EZFS_ASHIFT_MISMATCH,   /* can't add vdevs with different ashifts */
 	EZFS_UNKNOWN
 } zfs_error_t;
 
@@ -260,7 +262,7 @@ _LIBZFS_H boolean_t zpool_skip_pool(const char *);
 _LIBZFS_H int zpool_create(libzfs_handle_t *, const char *, nvlist_t *,
     nvlist_t *, nvlist_t *);
 _LIBZFS_H int zpool_destroy(zpool_handle_t *, const char *);
-_LIBZFS_H int zpool_add(zpool_handle_t *, nvlist_t *);
+_LIBZFS_H int zpool_add(zpool_handle_t *, nvlist_t *, boolean_t check_ashift);
 
 typedef struct splitflags {
 	/* do not split, but return the config that would be split off */
diff --git a/sys/contrib/openzfs/include/os/freebsd/Makefile.am b/sys/contrib/openzfs/include/os/freebsd/Makefile.am
index 9819e534b7f6..d4103c2f062a 100644
--- a/sys/contrib/openzfs/include/os/freebsd/Makefile.am
+++ b/sys/contrib/openzfs/include/os/freebsd/Makefile.am
@@ -4,8 +4,6 @@ noinst_HEADERS = \
 	\
 	%D%/spl/acl/acl_common.h \
 	\
-	%D%/spl/rpc/xdr.h \
-	\
 	%D%/spl/sys/ia32/asm_linkage.h \
 	\
 	%D%/spl/sys/acl.h \
@@ -80,7 +78,9 @@ noinst_HEADERS = \
 	%D%/spl/sys/zmod.h \
 	%D%/spl/sys/zone.h \
 	\
+	%D%/zfs/sys/arc_os.h \
 	%D%/zfs/sys/freebsd_crypto.h \
+	%D%/zfs/sys/freebsd_event.h \
 	%D%/zfs/sys/vdev_os.h \
 	%D%/zfs/sys/zfs_bootenv_os.h \
 	%D%/zfs/sys/zfs_context_os.h \
diff --git a/sys/contrib/openzfs/include/os/freebsd/spl/rpc/xdr.h b/sys/contrib/openzfs/include/os/freebsd/spl/rpc/xdr.h
deleted file mode 100644
index c98466e9d16a..000000000000
--- a/sys/contrib/openzfs/include/os/freebsd/spl/rpc/xdr.h
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
- * unrestricted use provided that this legend is included on all tape
- * media and as a part of the software program in whole or part.  Users
- * may copy or modify Sun RPC without charge, but are not authorized
- * to license or distribute it to anyone else except as part of a product or
- * program developed by the user.
- *
- * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
- * WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
- *
- * Sun RPC is provided with no support and without any obligation on the
- * part of Sun Microsystems, Inc. to assist in its use, correction,
- * modification or enhancement.
- *
- * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
- * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
- * OR ANY PART THEREOF.
- *
- * In no event will Sun Microsystems, Inc. be liable for any lost revenue
- * or profits or other special, indirect and consequential damages, even if
- * Sun has been advised of the possibility of such damages.
- *
- * Sun Microsystems, Inc.
- * 2550 Garcia Avenue
- * Mountain View, California  94043
- */
-
-#ifndef	_OPENSOLARIS_RPC_XDR_H_
-#define	_OPENSOLARIS_RPC_XDR_H_
-
-#include <rpc/types.h>
-#include_next <rpc/xdr.h>
-
-#if !defined(_KERNEL) && !defined(_STANDALONE)
-
-#include <assert.h>
-
-/*
- * Taken from sys/xdr/xdr_mem.c.
- *
- * FreeBSD's userland XDR doesn't implement control method (only the kernel),
- * but OpenSolaris nvpair still depend on it, so we have to implement it here.
- */
-static __inline bool_t
-xdrmem_control(XDR *xdrs, int request, void *info)
-{
-	xdr_bytesrec *xptr;
-
-	switch (request) {
-	case XDR_GET_BYTES_AVAIL:
-		xptr = (xdr_bytesrec *)info;
-		xptr->xc_is_last_record = TRUE;
-		xptr->xc_num_avail = xdrs->x_handy;
-		return (TRUE);
-	default:
-		assert(!"unexpected request");
-	}
-	return (FALSE);
-}
-
-#undef XDR_CONTROL
-#define	XDR_CONTROL(xdrs, req, op)					\
-	(((xdrs)->x_ops->x_control == NULL) ?				\
-	    xdrmem_control((xdrs), (req), (op)) :			\
-	    (*(xdrs)->x_ops->x_control)(xdrs, req, op))
-
-#endif	/* !_KERNEL && !_STANDALONE */
-
-#endif	/* !_OPENSOLARIS_RPC_XDR_H_ */
diff --git a/sys/contrib/openzfs/include/os/freebsd/spl/sys/debug.h b/sys/contrib/openzfs/include/os/freebsd/spl/sys/debug.h
index 3e67cf0e9a7d..785fcf62dd16 100644
--- a/sys/contrib/openzfs/include/os/freebsd/spl/sys/debug.h
+++ b/sys/contrib/openzfs/include/os/freebsd/spl/sys/debug.h
@@ -39,12 +39,14 @@
  * ASSERT3U()	- Assert unsigned X OP Y is true, if not panic.
  * ASSERT3P()	- Assert pointer X OP Y is true, if not panic.
  * ASSERT0()	- Assert value is zero, if not panic.
+ * ASSERT0P()	- Assert pointer is null, if not panic.
  * VERIFY()	- Verify X is true, if not panic.
  * VERIFY3B()	- Verify boolean X OP Y is true, if not panic.
  * VERIFY3S()	- Verify signed X OP Y is true, if not panic.
  * VERIFY3U()	- Verify unsigned X OP Y is true, if not panic.
  * VERIFY3P()	- Verify pointer X OP Y is true, if not panic.
  * VERIFY0()	- Verify value is zero, if not panic.
+ * VERIFY0P()	- Verify pointer is null, if not panic.
  */
 
 #ifndef _SPL_DEBUG_H
@@ -89,8 +91,8 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
 		    "failed (%d " #OP " %d)\n",				\
-		    (boolean_t)(_verify3_left),				\
-		    (boolean_t)(_verify3_right));			\
+		    (boolean_t)_verify3_left,				\
+		    (boolean_t)_verify3_right);				\
 	} while (0)
 
 #define	VERIFY3S(LEFT, OP, RIGHT)	do {				\
@@ -100,8 +102,8 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
 		    "failed (%lld " #OP " %lld)\n",			\
-		    (long long) (_verify3_left),			\
-		    (long long) (_verify3_right));			\
+		    (long long)_verify3_left,				\
+		    (long long)_verify3_right);				\
 	} while (0)
 
 #define	VERIFY3U(LEFT, OP, RIGHT)	do {				\
@@ -111,8 +113,8 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
 		    "failed (%llu " #OP " %llu)\n",			\
-		    (unsigned long long) (_verify3_left),		\
-		    (unsigned long long) (_verify3_right));		\
+		    (unsigned long long)_verify3_left,			\
+		    (unsigned long long)_verify3_right);		\
 	} while (0)
 
 #define	VERIFY3P(LEFT, OP, RIGHT)	do {				\
@@ -121,19 +123,27 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		if (unlikely(!(_verify3_left OP _verify3_right)))	\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
-		    "failed (%px " #OP " %px)\n",			\
-		    (void *) (_verify3_left),				\
-		    (void *) (_verify3_right));				\
+		    "failed (%p " #OP " %p)\n",				\
+		    (void *)_verify3_left,				\
+		    (void *)_verify3_right);				\
 	} while (0)
 
 #define	VERIFY0(RIGHT)	do {						\
-		const int64_t _verify3_left = (int64_t)(0);		\
-		const int64_t _verify3_right = (int64_t)(RIGHT);	\
-		if (unlikely(!(_verify3_left == _verify3_right)))	\
+		const int64_t _verify0_right = (int64_t)(RIGHT);	\
+		if (unlikely(!(0 == _verify0_right)))			\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
-		    "VERIFY0(0 == " #RIGHT ") "				\
+		    "VERIFY0(" #RIGHT ") "				\
 		    "failed (0 == %lld)\n",				\
-		    (long long) (_verify3_right));			\
+		    (long long)_verify0_right);				\
+	} while (0)
+
+#define	VERIFY0P(RIGHT)	do {						\
+		const uintptr_t _verify0_right = (uintptr_t)(RIGHT);	\
+		if (unlikely(!(0 == _verify0_right)))			\
+		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
+		    "VERIFY0P(" #RIGHT ") "				\
+		    "failed (NULL == %p)\n",				\
+		    (void *)_verify0_right);				\
 	} while (0)
 
 /*
@@ -151,6 +161,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3P(x, y, z)						\
 	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
 #define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	ASSERT0P(x)		((void) sizeof ((uintptr_t)(x)))
 #define	IMPLY(A, B)							\
 	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
 #define	EQUIV(A, B)		\
@@ -166,6 +177,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
+#define	ASSERT0P	VERIFY0P
 #define	ASSERT		VERIFY
 #define	IMPLY(A, B) \
 	((void)(likely((!(A)) || (B)) ||				\
diff --git a/sys/contrib/openzfs/include/os/linux/Makefile.am b/sys/contrib/openzfs/include/os/linux/Makefile.am
index 3830d198dfff..332569efe361 100644
--- a/sys/contrib/openzfs/include/os/linux/Makefile.am
+++ b/sys/contrib/openzfs/include/os/linux/Makefile.am
@@ -5,6 +5,7 @@ kernel_linux_HEADERS = \
 	%D%/kernel/linux/compiler_compat.h \
 	%D%/kernel/linux/dcache_compat.h \
 	%D%/kernel/linux/kmap_compat.h \
+	%D%/kernel/linux/mm_compat.h \
 	%D%/kernel/linux/mod_compat.h \
 	%D%/kernel/linux/page_compat.h \
 	%D%/kernel/linux/percpu_compat.h \
@@ -46,6 +47,7 @@ kernel_sys_HEADERS = \
 
 kernel_spl_rpcdir = $(kerneldir)/spl/rpc
 kernel_spl_rpc_HEADERS = \
+	%D%/spl/rpc/types.h \
 	%D%/spl/rpc/xdr.h
 
 kernel_spl_sysdir = $(kerneldir)/spl/sys
diff --git a/sys/contrib/openzfs/include/os/linux/kernel/linux/blkdev_compat.h b/sys/contrib/openzfs/include/os/linux/kernel/linux/blkdev_compat.h
index f111e648ccf7..b0f398354e4f 100644
--- a/sys/contrib/openzfs/include/os/linux/kernel/linux/blkdev_compat.h
+++ b/sys/contrib/openzfs/include/os/linux/kernel/linux/blkdev_compat.h
@@ -563,9 +563,11 @@ static inline boolean_t
 bdev_discard_supported(struct block_device *bdev)
 {
 #if defined(HAVE_BDEV_MAX_DISCARD_SECTORS)
-	return (!!bdev_max_discard_sectors(bdev));
+	return (bdev_max_discard_sectors(bdev) > 0 &&
+	    bdev_discard_granularity(bdev) > 0);
 #elif defined(HAVE_BLK_QUEUE_DISCARD)
-	return (!!blk_queue_discard(bdev_get_queue(bdev)));
+	return (blk_queue_discard(bdev_get_queue(bdev)) > 0 &&
+	    bdev_get_queue(bdev)->limits.discard_granularity > 0);
 #else
 #error "Unsupported kernel"
 #endif
diff --git a/sys/contrib/openzfs/include/os/linux/kernel/linux/mm_compat.h b/sys/contrib/openzfs/include/os/linux/kernel/linux/mm_compat.h
new file mode 100644
index 000000000000..40056c68d6dd
--- /dev/null
+++ b/sys/contrib/openzfs/include/os/linux/kernel/linux/mm_compat.h
@@ -0,0 +1,36 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2023, 2024, Klara Inc.
+ */
+
+#ifndef _ZFS_MM_COMPAT_H
+#define	_ZFS_MM_COMPAT_H
+
+#include <linux/mm.h>
+
+/* 5.4 introduced page_size(). Older kernels can use a trivial macro instead */
+#ifndef HAVE_MM_PAGE_SIZE
+#define	page_size(p) ((unsigned long)(PAGE_SIZE << compound_order(p)))
+#endif
+
+#endif /* _ZFS_MM_COMPAT_H */
diff --git a/sys/contrib/openzfs/include/os/linux/kernel/linux/mod_compat.h b/sys/contrib/openzfs/include/os/linux/kernel/linux/mod_compat.h
index 8e20a9613539..039865b703ef 100644
--- a/sys/contrib/openzfs/include/os/linux/kernel/linux/mod_compat.h
+++ b/sys/contrib/openzfs/include/os/linux/kernel/linux/mod_compat.h
@@ -68,6 +68,7 @@ enum scope_prefix_types {
 	zfs_trim,
 	zfs_txg,
 	zfs_vdev,
+	zfs_vdev_disk,
 	zfs_vdev_file,
 	zfs_vdev_mirror,
 	zfs_vnops,
diff --git a/sys/contrib/openzfs/include/os/linux/spl/rpc/types.h b/sys/contrib/openzfs/include/os/linux/spl/rpc/types.h
new file mode 100644
index 000000000000..5bbb4f2dec46
--- /dev/null
+++ b/sys/contrib/openzfs/include/os/linux/spl/rpc/types.h
@@ -0,0 +1,30 @@
+/*
+ *  Copyright (c) 2008 Sun Microsystems, Inc.
+ *  Written by Ricardo Correia <Ricardo.M.Correia@Sun.COM>
+ *
+ *  This file is part of the SPL, Solaris Porting Layer.
+ *
+ *  The SPL is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  The SPL is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _SPL_RPC_TYPES_H
+#define	_SPL_RPC_TYPES_H
+
+#include <sys/types.h>
+
+/* Just enough to support rpc/xdr.h */
+
+typedef int bool_t;
+
+#endif /* SPL_RPC_TYPES_H */
diff --git a/sys/contrib/openzfs/include/os/linux/spl/rpc/xdr.h b/sys/contrib/openzfs/include/os/linux/spl/rpc/xdr.h
index b00f3542fcdf..5b621fa9c863 100644
--- a/sys/contrib/openzfs/include/os/linux/spl/rpc/xdr.h
+++ b/sys/contrib/openzfs/include/os/linux/spl/rpc/xdr.h
@@ -23,8 +23,6 @@
 
 #include <sys/types.h>
 
-typedef int bool_t;
-
 /*
  * XDR enums and types.
  */
diff --git a/sys/contrib/openzfs/include/os/linux/spl/sys/debug.h b/sys/contrib/openzfs/include/os/linux/spl/sys/debug.h
index 007238574fe1..288193ad21c5 100644
--- a/sys/contrib/openzfs/include/os/linux/spl/sys/debug.h
+++ b/sys/contrib/openzfs/include/os/linux/spl/sys/debug.h
@@ -34,12 +34,14 @@
  * ASSERT3U()	- Assert unsigned X OP Y is true, if not panic.
  * ASSERT3P()	- Assert pointer X OP Y is true, if not panic.
  * ASSERT0()	- Assert value is zero, if not panic.
+ * ASSERT0P()	- Assert pointer is null, if not panic.
  * VERIFY()	- Verify X is true, if not panic.
  * VERIFY3B()	- Verify boolean X OP Y is true, if not panic.
  * VERIFY3S()	- Verify signed X OP Y is true, if not panic.
  * VERIFY3U()	- Verify unsigned X OP Y is true, if not panic.
  * VERIFY3P()	- Verify pointer X OP Y is true, if not panic.
  * VERIFY0()	- Verify value is zero, if not panic.
+ * VERIFY0P()	- Verify pointer is null, if not panic.
  */
 
 #ifndef _SPL_DEBUG_H
@@ -93,8 +95,8 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
 		    "failed (%d " #OP " %d)\n",				\
-		    (boolean_t)(_verify3_left),				\
-		    (boolean_t)(_verify3_right));			\
+		    (boolean_t)_verify3_left,				\
+		    (boolean_t)_verify3_right);				\
 	} while (0)
 
 #define	VERIFY3S(LEFT, OP, RIGHT)	do {				\
@@ -104,8 +106,8 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
 		    "failed (%lld " #OP " %lld)\n",			\
-		    (long long)(_verify3_left),				\
-		    (long long)(_verify3_right));			\
+		    (long long)_verify3_left,				\
+		    (long long)_verify3_right);				\
 	} while (0)
 
 #define	VERIFY3U(LEFT, OP, RIGHT)	do {				\
@@ -115,8 +117,8 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
 		    "failed (%llu " #OP " %llu)\n",			\
-		    (unsigned long long)(_verify3_left),		\
-		    (unsigned long long)(_verify3_right));		\
+		    (unsigned long long)_verify3_left,			\
+		    (unsigned long long)_verify3_right);		\
 	} while (0)
 
 #define	VERIFY3P(LEFT, OP, RIGHT)	do {				\
@@ -126,18 +128,26 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
 		    "VERIFY3(" #LEFT " "  #OP " "  #RIGHT ") "		\
 		    "failed (%px " #OP " %px)\n",			\
-		    (void *) (_verify3_left),				\
-		    (void *) (_verify3_right));				\
+		    (void *)_verify3_left,				\
+		    (void *)_verify3_right);				\
 	} while (0)
 
 #define	VERIFY0(RIGHT)	do {						\
-		const int64_t _verify3_left = (int64_t)(0);		\
-		const int64_t _verify3_right = (int64_t)(RIGHT);	\
-		if (unlikely(!(_verify3_left == _verify3_right)))	\
+		const int64_t _verify0_right = (int64_t)(RIGHT);	\
+		if (unlikely(!(0 == _verify0_right)))			\
 		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
-		    "VERIFY0(0 == " #RIGHT ") "				\
+		    "VERIFY0(" #RIGHT ") "				\
 		    "failed (0 == %lld)\n",				\
-		    (long long) (_verify3_right));			\
+		    (long long)_verify0_right);				\
+	} while (0)
+
+#define	VERIFY0P(RIGHT)	do {						\
+		const uintptr_t _verify0_right = (uintptr_t)(RIGHT);	\
+		if (unlikely(!(0 == _verify0_right)))			\
+		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
+		    "VERIFY0P(" #RIGHT ") "				\
+		    "failed (NULL == %px)\n",				\
+		    (void *)_verify0_right);				\
 	} while (0)
 
 #define	VERIFY_IMPLY(A, B) \
@@ -165,6 +175,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3P(x, y, z)						\
 	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
 #define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	ASSERT0P(x)		((void) sizeof ((uintptr_t)(x)))
 #define	IMPLY(A, B)							\
 	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
 #define	EQUIV(A, B)		\
@@ -180,6 +191,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
+#define	ASSERT0P	VERIFY0P
 #define	ASSERT		VERIFY
 #define	IMPLY		VERIFY_IMPLY
 #define	EQUIV		VERIFY_EQUIV
diff --git a/sys/contrib/openzfs/include/os/linux/spl/sys/taskq.h b/sys/contrib/openzfs/include/os/linux/spl/sys/taskq.h
index 6c1b4377a98a..6c0dbbefda7f 100644
--- a/sys/contrib/openzfs/include/os/linux/spl/sys/taskq.h
+++ b/sys/contrib/openzfs/include/os/linux/spl/sys/taskq.h
@@ -104,7 +104,7 @@ typedef struct taskq {
 	/* list node for the cpu hotplug callback */
 	struct hlist_node	tq_hp_cb_node;
 	boolean_t		tq_hp_support;
-	unsigned long		lastshouldstop; /* when to purge dynamic */
+	unsigned long		lastspawnstop;	/* when to purge dynamic */
 } taskq_t;
 
 typedef struct taskq_ent {
diff --git a/sys/contrib/openzfs/include/os/linux/zfs/sys/trace_zil.h b/sys/contrib/openzfs/include/os/linux/zfs/sys/trace_zil.h
index afa1a274e43c..ae1caa3ac473 100644
--- a/sys/contrib/openzfs/include/os/linux/zfs/sys/trace_zil.h
+++ b/sys/contrib/openzfs/include/os/linux/zfs/sys/trace_zil.h
@@ -51,7 +51,9 @@
 		__field(uint64_t,	zl_parse_lr_seq)		    \
 		__field(uint64_t,	zl_parse_blk_count)		    \
 		__field(uint64_t,	zl_parse_lr_count)		    \
-		__field(uint64_t,	zl_cur_used)			    \
+		__field(uint64_t,	zl_cur_size)			    \
+		__field(uint64_t,	zl_cur_left)			    \
+		__field(uint64_t,	zl_cur_max)			    \
 		__field(clock_t,	zl_replay_time)			    \
 		__field(uint64_t,	zl_replay_blks)
 
@@ -72,7 +74,9 @@
 		__entry->zl_parse_lr_seq	= zilog->zl_parse_lr_seq;   \
 		__entry->zl_parse_blk_count	= zilog->zl_parse_blk_count;\
 		__entry->zl_parse_lr_count	= zilog->zl_parse_lr_count; \
-		__entry->zl_cur_used	= zilog->zl_cur_used;		    \
+		__entry->zl_cur_size	= zilog->zl_cur_size;		    \
+		__entry->zl_cur_left	= zilog->zl_cur_left;		    \
+		__entry->zl_cur_max	= zilog->zl_cur_max;		    \
 		__entry->zl_replay_time	= zilog->zl_replay_time;	    \
 		__entry->zl_replay_blks	= zilog->zl_replay_blks;
 
@@ -82,7 +86,8 @@
 	"replay %u stop_sync %u logbias %u sync %u "			    \
 	"parse_error %u parse_blk_seq %llu parse_lr_seq %llu "		    \
 	"parse_blk_count %llu parse_lr_count %llu "			    \
-	"cur_used %llu replay_time %lu replay_blks %llu }"
+	"cur_size %llu cur_left %llu cur_max %llu replay_time %lu "	    \
+	"replay_blks %llu }"
 
 #define	ZILOG_TP_PRINTK_ARGS						    \
 	    __entry->zl_lr_seq, __entry->zl_commit_lr_seq,		    \
@@ -92,7 +97,8 @@
 	    __entry->zl_stop_sync, __entry->zl_logbias, __entry->zl_sync,   \
 	    __entry->zl_parse_error, __entry->zl_parse_blk_seq,		    \
 	    __entry->zl_parse_lr_seq, __entry->zl_parse_blk_count,	    \
-	    __entry->zl_parse_lr_count, __entry->zl_cur_used,		    \
+	    __entry->zl_parse_lr_count, __entry->zl_cur_size,		    \
+	    __entry->zl_cur_left, __entry->zl_cur_max,			    \
 	    __entry->zl_replay_time, __entry->zl_replay_blks
 
 #define	ITX_TP_STRUCT_ENTRY						    \
diff --git a/sys/contrib/openzfs/include/sys/abd.h b/sys/contrib/openzfs/include/sys/abd.h
index 750f9986c1da..bee38b831bc0 100644
--- a/sys/contrib/openzfs/include/sys/abd.h
+++ b/sys/contrib/openzfs/include/sys/abd.h
@@ -79,6 +79,9 @@ typedef struct abd {
 
 typedef int abd_iter_func_t(void *buf, size_t len, void *priv);
 typedef int abd_iter_func2_t(void *bufa, void *bufb, size_t len, void *priv);
+#if defined(__linux__) && defined(_KERNEL)
+typedef int abd_iter_page_func_t(struct page *, size_t, size_t, void *);
+#endif
 
 extern int zfs_abd_scatter_enabled;
 
@@ -125,6 +128,10 @@ void abd_release_ownership_of_buf(abd_t *);
 int abd_iterate_func(abd_t *, size_t, size_t, abd_iter_func_t *, void *);
 int abd_iterate_func2(abd_t *, abd_t *, size_t, size_t, size_t,
     abd_iter_func2_t *, void *);
+#if defined(__linux__) && defined(_KERNEL)
+int abd_iterate_page_func(abd_t *, size_t, size_t, abd_iter_page_func_t *,
+    void *);
+#endif
 void abd_copy_off(abd_t *, abd_t *, size_t, size_t, size_t);
 void abd_copy_from_buf_off(abd_t *, const void *, size_t, size_t);
 void abd_copy_to_buf_off(void *, abd_t *, size_t, size_t);
@@ -213,6 +220,8 @@ void abd_fini(void);
 
 /*
  * Linux ABD bio functions
+ * Note: these are only needed to support vdev_classic. See comment in
+ * vdev_disk.c.
  */
 #if defined(__linux__) && defined(_KERNEL)
 unsigned int abd_bio_map_off(struct bio *, abd_t *, unsigned int, size_t);
diff --git a/sys/contrib/openzfs/include/sys/abd_impl.h b/sys/contrib/openzfs/include/sys/abd_impl.h
index 40546d4af137..f88ea25e245d 100644
--- a/sys/contrib/openzfs/include/sys/abd_impl.h
+++ b/sys/contrib/openzfs/include/sys/abd_impl.h
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
  * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
+ * Copyright (c) 2023, 2024, Klara Inc.
  */
 
 #ifndef _ABD_IMPL_H
@@ -38,12 +39,30 @@ typedef enum abd_stats_op {
 	ABDSTAT_DECR  /* Decrease abdstat values */
 } abd_stats_op_t;
 
-struct scatterlist; /* forward declaration */
+/* forward declarations */
+struct scatterlist;
+struct page;
 
 struct abd_iter {
 	/* public interface */
-	void		*iter_mapaddr;	/* addr corresponding to iter_pos */
-	size_t		iter_mapsize;	/* length of data valid at mapaddr */
+	union {
+		/* for abd_iter_map()/abd_iter_unmap() */
+		struct {
+			/* addr corresponding to iter_pos */
+			void		*iter_mapaddr;
+			/* length of data valid at mapaddr */
+			size_t		iter_mapsize;
+		};
+		/* for abd_iter_page() */
+		struct {
+			/* current page */
+			struct page	*iter_page;
+			/* offset of data in page */
+			size_t		iter_page_doff;
+			/* size of data in page */
+			size_t		iter_page_dsize;
+		};
+	};
 
 	/* private */
 	abd_t		*iter_abd;	/* ABD being iterated through */
@@ -78,6 +97,7 @@ boolean_t abd_iter_at_end(struct abd_iter *);
 void abd_iter_advance(struct abd_iter *, size_t);
 void abd_iter_map(struct abd_iter *);
 void abd_iter_unmap(struct abd_iter *);
+void abd_iter_page(struct abd_iter *);
 
 /*
  * Helper macros
diff --git a/sys/contrib/openzfs/include/sys/dmu.h b/sys/contrib/openzfs/include/sys/dmu.h
index 06b4dc27dfea..26b329b53f05 100644
--- a/sys/contrib/openzfs/include/sys/dmu.h
+++ b/sys/contrib/openzfs/include/sys/dmu.h
@@ -739,8 +739,6 @@ void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
 void *dmu_buf_get_user(dmu_buf_t *db);
 
 objset_t *dmu_buf_get_objset(dmu_buf_t *db);
-dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db);
-void dmu_buf_dnode_exit(dmu_buf_t *db);
 
 /* Block until any in-progress dmu buf user evictions complete. */
 void dmu_buf_user_evict_wait(void);
@@ -889,6 +887,9 @@ extern uint_t zfs_max_recordsize;
  */
 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
 	uint64_t len, enum zio_priority pri);
+void dmu_prefetch_by_dnode(dnode_t *dn, int64_t level, uint64_t offset,
+	uint64_t len, enum zio_priority pri);
+void dmu_prefetch_dnode(objset_t *os, uint64_t object, enum zio_priority pri);
 
 typedef struct dmu_object_info {
 	/* All sizes are in bytes unless otherwise indicated. */
diff --git a/sys/contrib/openzfs/include/sys/dmu_objset.h b/sys/contrib/openzfs/include/sys/dmu_objset.h
index 9f6e0fdd601b..a9123e862af7 100644
--- a/sys/contrib/openzfs/include/sys/dmu_objset.h
+++ b/sys/contrib/openzfs/include/sys/dmu_objset.h
@@ -132,6 +132,7 @@ struct objset {
 	zfs_logbias_op_t os_logbias;
 	zfs_cache_type_t os_primary_cache;
 	zfs_cache_type_t os_secondary_cache;
+	zfs_prefetch_type_t os_prefetch;
 	zfs_sync_type_t os_sync;
 	zfs_redundant_metadata_type_t os_redundant_metadata;
 	uint64_t os_recordsize;
diff --git a/sys/contrib/openzfs/include/sys/dmu_zfetch.h b/sys/contrib/openzfs/include/sys/dmu_zfetch.h
index f00e13cf03a6..322472fb1ae2 100644
--- a/sys/contrib/openzfs/include/sys/dmu_zfetch.h
+++ b/sys/contrib/openzfs/include/sys/dmu_zfetch.h
@@ -45,18 +45,24 @@ typedef struct zfetch {
 	int		zf_numstreams;	/* number of zstream_t's */
 } zfetch_t;
 
+typedef struct zsrange {
+	uint16_t	start;
+	uint16_t	end;
+} zsrange_t;
+
+#define	ZFETCH_RANGES	9		/* Fits zstream_t into 128 bytes */
+
 typedef struct zstream {
+	list_node_t	zs_node;	/* link for zf_stream */
 	uint64_t	zs_blkid;	/* expect next access at this blkid */
+	uint_t		zs_atime;	/* time last prefetch issued */
+	zsrange_t	zs_ranges[ZFETCH_RANGES]; /* ranges from future */
 	unsigned int	zs_pf_dist;	/* data prefetch distance in bytes */
 	unsigned int	zs_ipf_dist;	/* L1 prefetch distance in bytes */
 	uint64_t	zs_pf_start;	/* first data block to prefetch */
 	uint64_t	zs_pf_end;	/* data block to prefetch up to */
 	uint64_t	zs_ipf_start;	/* first data block to prefetch L1 */
 	uint64_t	zs_ipf_end;	/* data block to prefetch L1 up to */
-
-	list_node_t	zs_node;	/* link for zf_stream */
-	hrtime_t	zs_atime;	/* time last prefetch issued */
-	zfetch_t	*zs_fetch;	/* parent fetch */
 	boolean_t	zs_missed;	/* stream saw cache misses */
 	boolean_t	zs_more;	/* need more distant prefetch */
 	zfs_refcount_t	zs_callers;	/* number of pending callers */
@@ -74,7 +80,7 @@ void		dmu_zfetch_init(zfetch_t *, struct dnode *);
 void		dmu_zfetch_fini(zfetch_t *);
 zstream_t	*dmu_zfetch_prepare(zfetch_t *, uint64_t, uint64_t, boolean_t,
     boolean_t);
-void		dmu_zfetch_run(zstream_t *, boolean_t, boolean_t);
+void		dmu_zfetch_run(zfetch_t *, zstream_t *, boolean_t, boolean_t);
 void		dmu_zfetch(zfetch_t *, uint64_t, uint64_t, boolean_t, boolean_t,
     boolean_t);
 
diff --git a/sys/contrib/openzfs/include/sys/fm/fs/zfs.h b/sys/contrib/openzfs/include/sys/fm/fs/zfs.h
index fb9e8649221e..c746600cd2d5 100644
--- a/sys/contrib/openzfs/include/sys/fm/fs/zfs.h
+++ b/sys/contrib/openzfs/include/sys/fm/fs/zfs.h
@@ -82,6 +82,8 @@ extern "C" {
 #define	FM_EREPORT_PAYLOAD_ZFS_VDEV_CKSUM_T	"vdev_cksum_t"
 #define	FM_EREPORT_PAYLOAD_ZFS_VDEV_IO_N	"vdev_io_n"
 #define	FM_EREPORT_PAYLOAD_ZFS_VDEV_IO_T	"vdev_io_t"
+#define	FM_EREPORT_PAYLOAD_ZFS_VDEV_SLOW_IO_N	"vdev_slow_io_n"
+#define	FM_EREPORT_PAYLOAD_ZFS_VDEV_SLOW_IO_T	"vdev_slow_io_t"
 #define	FM_EREPORT_PAYLOAD_ZFS_VDEV_DELAYS	"vdev_delays"
 #define	FM_EREPORT_PAYLOAD_ZFS_PARENT_GUID	"parent_guid"
 #define	FM_EREPORT_PAYLOAD_ZFS_PARENT_TYPE	"parent_type"
diff --git a/sys/contrib/openzfs/include/sys/fs/zfs.h b/sys/contrib/openzfs/include/sys/fs/zfs.h
index bc940e8a7929..4329e4e86f2d 100644
--- a/sys/contrib/openzfs/include/sys/fs/zfs.h
+++ b/sys/contrib/openzfs/include/sys/fs/zfs.h
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2013, 2017 Joyent, Inc. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
@@ -191,6 +191,7 @@ typedef enum {
 	ZFS_PROP_REDACTED,
 	ZFS_PROP_REDACT_SNAPS,
 	ZFS_PROP_SNAPSHOTS_CHANGED,
+	ZFS_PROP_PREFETCH,
 	ZFS_NUM_PROPS
 } zfs_prop_t;
 
@@ -363,6 +364,9 @@ typedef enum {
 	VDEV_PROP_CHECKSUM_T,
 	VDEV_PROP_IO_N,
 	VDEV_PROP_IO_T,
+	VDEV_PROP_RAIDZ_EXPANDING,
+	VDEV_PROP_SLOW_IO_N,
+	VDEV_PROP_SLOW_IO_T,
 	VDEV_NUM_PROPS
 } vdev_prop_t;
 
@@ -543,6 +547,12 @@ typedef enum zfs_key_location {
 	ZFS_KEYLOCATION_LOCATIONS
 } zfs_keylocation_t;
 
+typedef enum {
+	ZFS_PREFETCH_NONE = 0,
+	ZFS_PREFETCH_METADATA = 1,
+	ZFS_PREFETCH_ALL = 2
+} zfs_prefetch_type_t;
+
 #define	DEFAULT_PBKDF2_ITERATIONS 350000
 #define	MIN_PBKDF2_ITERATIONS 100000
 
@@ -1569,6 +1579,8 @@ typedef enum {
 	ZFS_ERR_NOT_USER_NAMESPACE,
 	ZFS_ERR_RESUME_EXISTS,
 	ZFS_ERR_CRYPTO_NOTSUP,
+	ZFS_ERR_RAIDZ_EXPAND_IN_PROGRESS,
+	ZFS_ERR_ASHIFT_MISMATCH,
 } zfs_errno_t;
 
 /*
diff --git a/sys/contrib/openzfs/include/sys/multilist.h b/sys/contrib/openzfs/include/sys/multilist.h
index 26f37c37ab38..e7de86f2379b 100644
--- a/sys/contrib/openzfs/include/sys/multilist.h
+++ b/sys/contrib/openzfs/include/sys/multilist.h
@@ -82,12 +82,15 @@ int  multilist_is_empty(multilist_t *);
 unsigned int multilist_get_num_sublists(multilist_t *);
 unsigned int multilist_get_random_index(multilist_t *);
 
-multilist_sublist_t *multilist_sublist_lock(multilist_t *, unsigned int);
+void multilist_sublist_lock(multilist_sublist_t *);
+multilist_sublist_t *multilist_sublist_lock_idx(multilist_t *, unsigned int);
 multilist_sublist_t *multilist_sublist_lock_obj(multilist_t *, void *);
 void multilist_sublist_unlock(multilist_sublist_t *);
 
 void multilist_sublist_insert_head(multilist_sublist_t *, void *);
 void multilist_sublist_insert_tail(multilist_sublist_t *, void *);
+void multilist_sublist_insert_after(multilist_sublist_t *, void *, void *);
+void multilist_sublist_insert_before(multilist_sublist_t *, void *, void *);
 void multilist_sublist_move_forward(multilist_sublist_t *mls, void *obj);
 void multilist_sublist_remove(multilist_sublist_t *, void *);
 int  multilist_sublist_is_empty(multilist_sublist_t *);
diff --git a/sys/contrib/openzfs/include/sys/spa.h b/sys/contrib/openzfs/include/sys/spa.h
index 87ddbd90e170..6611141b9569 100644
--- a/sys/contrib/openzfs/include/sys/spa.h
+++ b/sys/contrib/openzfs/include/sys/spa.h
@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2021 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  * Copyright 2013 Saso Kiselkov. All rights reserved.
@@ -769,7 +769,7 @@ extern int bpobj_enqueue_free_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx);
 
 #define	SPA_ASYNC_CONFIG_UPDATE			0x01
 #define	SPA_ASYNC_REMOVE			0x02
-#define	SPA_ASYNC_PROBE				0x04
+#define	SPA_ASYNC_FAULT_VDEV			0x04
 #define	SPA_ASYNC_RESILVER_DONE			0x08
 #define	SPA_ASYNC_RESILVER			0x10
 #define	SPA_ASYNC_AUTOEXPAND			0x20
@@ -784,7 +784,7 @@ extern int bpobj_enqueue_free_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx);
 #define	SPA_ASYNC_DETACH_SPARE			0x4000
 
 /* device manipulation */
-extern int spa_vdev_add(spa_t *spa, nvlist_t *nvroot);
+extern int spa_vdev_add(spa_t *spa, nvlist_t *nvroot, boolean_t ashift_check);
 extern int spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot,
     int replacing, int rebuild);
 extern int spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid,
@@ -966,6 +966,10 @@ extern int spa_import_progress_set_max_txg(uint64_t pool_guid,
     uint64_t max_txg);
 extern int spa_import_progress_set_state(uint64_t pool_guid,
     spa_load_state_t spa_load_state);
+extern void spa_import_progress_set_notes(spa_t *spa,
+    const char *fmt, ...) __printflike(2, 3);
+extern void spa_import_progress_set_notes_nolog(spa_t *spa,
+    const char *fmt, ...) __printflike(2, 3);
 
 /* Pool configuration locks */
 extern int spa_config_tryenter(spa_t *spa, int locks, const void *tag,
@@ -1109,6 +1113,8 @@ extern uint32_t spa_get_hostid(spa_t *spa);
 extern void spa_activate_allocation_classes(spa_t *, dmu_tx_t *);
 extern boolean_t spa_livelist_delete_check(spa_t *spa);
 
+extern boolean_t spa_mmp_remote_host_activity(spa_t *spa);
+
 extern spa_mode_t spa_mode(spa_t *spa);
 extern uint64_t zfs_strtonum(const char *str, char **nptr);
 
diff --git a/sys/contrib/openzfs/include/sys/uberblock_impl.h b/sys/contrib/openzfs/include/sys/uberblock_impl.h
index 03bcfa8f4dd1..13fce9c29e2d 100644
--- a/sys/contrib/openzfs/include/sys/uberblock_impl.h
+++ b/sys/contrib/openzfs/include/sys/uberblock_impl.h
@@ -50,20 +50,20 @@ extern "C" {
 #define	MMP_SEQ_VALID_BIT	0x02
 #define	MMP_FAIL_INT_VALID_BIT	0x04
 
-#define	MMP_VALID(ubp)		(ubp->ub_magic == UBERBLOCK_MAGIC && \
-				    ubp->ub_mmp_magic == MMP_MAGIC)
-#define	MMP_INTERVAL_VALID(ubp)	(MMP_VALID(ubp) && (ubp->ub_mmp_config & \
+#define	MMP_VALID(ubp)		((ubp)->ub_magic == UBERBLOCK_MAGIC && \
+				    (ubp)->ub_mmp_magic == MMP_MAGIC)
+#define	MMP_INTERVAL_VALID(ubp)	(MMP_VALID(ubp) && ((ubp)->ub_mmp_config & \
 				    MMP_INTERVAL_VALID_BIT))
-#define	MMP_SEQ_VALID(ubp)	(MMP_VALID(ubp) && (ubp->ub_mmp_config & \
+#define	MMP_SEQ_VALID(ubp)	(MMP_VALID(ubp) && ((ubp)->ub_mmp_config & \
 				    MMP_SEQ_VALID_BIT))
-#define	MMP_FAIL_INT_VALID(ubp)	(MMP_VALID(ubp) && (ubp->ub_mmp_config & \
+#define	MMP_FAIL_INT_VALID(ubp)	(MMP_VALID(ubp) && ((ubp)->ub_mmp_config & \
 				    MMP_FAIL_INT_VALID_BIT))
 
-#define	MMP_INTERVAL(ubp)	((ubp->ub_mmp_config & 0x00000000FFFFFF00) \
+#define	MMP_INTERVAL(ubp)	(((ubp)->ub_mmp_config & 0x00000000FFFFFF00) \
 				    >> 8)
-#define	MMP_SEQ(ubp)		((ubp->ub_mmp_config & 0x0000FFFF00000000) \
+#define	MMP_SEQ(ubp)		(((ubp)->ub_mmp_config & 0x0000FFFF00000000) \
 				    >> 32)
-#define	MMP_FAIL_INT(ubp)	((ubp->ub_mmp_config & 0xFFFF000000000000) \
+#define	MMP_FAIL_INT(ubp)	(((ubp)->ub_mmp_config & 0xFFFF000000000000) \
 				    >> 48)
 
 #define	MMP_INTERVAL_SET(write) \
diff --git a/sys/contrib/openzfs/include/sys/vdev_impl.h b/sys/contrib/openzfs/include/sys/vdev_impl.h
index 3f2312c23438..8c6ab316fa18 100644
--- a/sys/contrib/openzfs/include/sys/vdev_impl.h
+++ b/sys/contrib/openzfs/include/sys/vdev_impl.h
@@ -22,6 +22,7 @@
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
  * Copyright (c) 2017, Intel Corporation.
+ * Copyright (c) 2023, Klara Inc.
  */
 
 #ifndef _SYS_VDEV_IMPL_H
@@ -273,7 +274,7 @@ struct vdev {
 	txg_list_t	vdev_dtl_list;	/* per-txg dirty DTL lists	*/
 	txg_node_t	vdev_txg_node;	/* per-txg dirty vdev linkage	*/
 	boolean_t	vdev_remove_wanted; /* async remove wanted?	*/
-	boolean_t	vdev_probe_wanted; /* async probe wanted?	*/
+	boolean_t	vdev_fault_wanted; /* async faulted wanted?	*/
 	list_node_t	vdev_config_dirty_node; /* config dirty list	*/
 	list_node_t	vdev_state_dirty_node; /* state dirty list	*/
 	uint64_t	vdev_deflate_ratio; /* deflation ratio (x512)	*/
@@ -453,12 +454,14 @@ struct vdev {
 	zfs_ratelimit_t vdev_checksum_rl;
 
 	/*
-	 * Checksum and IO thresholds for tuning ZED
+	 * Vdev properties for tuning ZED or zfsd
 	 */
 	uint64_t	vdev_checksum_n;
 	uint64_t	vdev_checksum_t;
 	uint64_t	vdev_io_n;
 	uint64_t	vdev_io_t;
+	uint64_t	vdev_slow_io_n;
+	uint64_t	vdev_slow_io_t;
 };
 
 #define	VDEV_PAD_SIZE		(8 << 10)
diff --git a/sys/contrib/openzfs/include/sys/zap.h b/sys/contrib/openzfs/include/sys/zap.h
index 308a7c7284d7..96ddcc324b65 100644
--- a/sys/contrib/openzfs/include/sys/zap.h
+++ b/sys/contrib/openzfs/include/sys/zap.h
@@ -253,6 +253,9 @@ int zap_add_by_dnode(dnode_t *dn, const char *key,
 int zap_add_uint64(objset_t *ds, uint64_t zapobj, const uint64_t *key,
     int key_numints, int integer_size, uint64_t num_integers,
     const void *val, dmu_tx_t *tx);
+int zap_add_uint64_by_dnode(dnode_t *dn, const uint64_t *key,
+    int key_numints, int integer_size, uint64_t num_integers,
+    const void *val, dmu_tx_t *tx);
 
 /*
  * Set the attribute with the given name to the given value.  If an
@@ -267,6 +270,9 @@ int zap_update(objset_t *ds, uint64_t zapobj, const char *name,
 int zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
     int key_numints,
     int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx);
+int zap_update_uint64_by_dnode(dnode_t *dn, const uint64_t *key,
+    int key_numints,
+    int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx);
 
 /*
  * Get the length (in integers) and the integer size of the specified
@@ -292,6 +298,8 @@ int zap_remove_norm(objset_t *ds, uint64_t zapobj, const char *name,
 int zap_remove_by_dnode(dnode_t *dn, const char *name, dmu_tx_t *tx);
 int zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
     int key_numints, dmu_tx_t *tx);
+int zap_remove_uint64_by_dnode(dnode_t *dn, const uint64_t *key,
+    int key_numints, dmu_tx_t *tx);
 
 /*
  * Returns (in *count) the number of attributes in the specified zap
diff --git a/sys/contrib/openzfs/include/sys/zap_impl.h b/sys/contrib/openzfs/include/sys/zap_impl.h
index 74853f5faceb..2959aa9b2ca4 100644
--- a/sys/contrib/openzfs/include/sys/zap_impl.h
+++ b/sys/contrib/openzfs/include/sys/zap_impl.h
@@ -145,6 +145,7 @@ typedef struct zap {
 	dmu_buf_user_t zap_dbu;
 	objset_t *zap_objset;
 	uint64_t zap_object;
+	dnode_t *zap_dnode;
 	struct dmu_buf *zap_dbuf;
 	krwlock_t zap_rwlock;
 	boolean_t zap_ismicro;
diff --git a/sys/contrib/openzfs/include/sys/zap_leaf.h b/sys/contrib/openzfs/include/sys/zap_leaf.h
index ebc67c2bf465..e54456d3472b 100644
--- a/sys/contrib/openzfs/include/sys/zap_leaf.h
+++ b/sys/contrib/openzfs/include/sys/zap_leaf.h
@@ -47,7 +47,7 @@ struct zap_stats;
  * entries - header space (2*chunksize)
  */
 #define	ZAP_LEAF_NUMCHUNKS_BS(bs) \
-	(((1<<(bs)) - 2*ZAP_LEAF_HASH_NUMENTRIES_BS(bs)) / \
+	(((1U << (bs)) - 2 * ZAP_LEAF_HASH_NUMENTRIES_BS(bs)) / \
 	ZAP_LEAF_CHUNKSIZE - 2)
 
 #define	ZAP_LEAF_NUMCHUNKS(l) (ZAP_LEAF_NUMCHUNKS_BS(((l)->l_bs)))
@@ -80,7 +80,7 @@ struct zap_stats;
  * chunks per entry (3).
  */
 #define	ZAP_LEAF_HASH_SHIFT_BS(bs) ((bs) - 5)
-#define	ZAP_LEAF_HASH_NUMENTRIES_BS(bs) (1 << ZAP_LEAF_HASH_SHIFT_BS(bs))
+#define	ZAP_LEAF_HASH_NUMENTRIES_BS(bs) (1U << ZAP_LEAF_HASH_SHIFT_BS(bs))
 #define	ZAP_LEAF_HASH_SHIFT(l) (ZAP_LEAF_HASH_SHIFT_BS(((l)->l_bs)))
 #define	ZAP_LEAF_HASH_NUMENTRIES(l) (ZAP_LEAF_HASH_NUMENTRIES_BS(((l)->l_bs)))
 
@@ -132,7 +132,7 @@ typedef struct zap_leaf_phys {
 	 * with the ZAP_LEAF_CHUNK() macro.
 	 */
 
-	uint16_t l_hash[1];
+	uint16_t l_hash[];
 } zap_leaf_phys_t;
 
 typedef union zap_leaf_chunk {
@@ -163,7 +163,7 @@ typedef struct zap_leaf {
 	dmu_buf_user_t l_dbu;
 	krwlock_t l_rwlock;
 	uint64_t l_blkid;		/* 1<<ZAP_BLOCK_SHIFT byte block off */
-	int l_bs;			/* block size shift */
+	uint_t l_bs;			/* block size shift */
 	dmu_buf_t *l_dbuf;
 } zap_leaf_t;
 
@@ -243,7 +243,7 @@ extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh,
  */
 
 extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort);
-extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, int len);
+extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, size_t len);
 extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort);
 extern void zap_leaf_stats(struct zap *zap, zap_leaf_t *l,
     struct zap_stats *zs);
diff --git a/sys/contrib/openzfs/include/sys/zil_impl.h b/sys/contrib/openzfs/include/sys/zil_impl.h
index f780ad3d61bc..9a34bafc1c77 100644
--- a/sys/contrib/openzfs/include/sys/zil_impl.h
+++ b/sys/contrib/openzfs/include/sys/zil_impl.h
@@ -181,7 +181,7 @@ typedef struct zil_vdev_node {
 	avl_node_t	zv_node;	/* AVL tree linkage */
 } zil_vdev_node_t;
 
-#define	ZIL_PREV_BLKS 16
+#define	ZIL_BURSTS 8
 
 /*
  * Stable storage intent log management structure.  One per dataset.
@@ -216,14 +216,18 @@ struct zilog {
 	uint64_t	zl_parse_lr_count; /* number of log records parsed */
 	itxg_t		zl_itxg[TXG_SIZE]; /* intent log txg chains */
 	list_t		zl_itx_commit_list; /* itx list to be committed */
-	uint64_t	zl_cur_used;	/* current commit log size used */
+	uint64_t	zl_cur_size;	/* current burst full size */
+	uint64_t	zl_cur_left;	/* current burst remaining size */
+	uint64_t	zl_cur_max;	/* biggest record in current burst */
 	list_t		zl_lwb_list;	/* in-flight log write list */
 	avl_tree_t	zl_bp_tree;	/* track bps during log parse */
 	clock_t		zl_replay_time;	/* lbolt of when replay started */
 	uint64_t	zl_replay_blks;	/* number of log blocks replayed */
 	zil_header_t	zl_old_header;	/* debugging aid */
-	uint_t		zl_prev_blks[ZIL_PREV_BLKS]; /* size - sector rounded */
+	uint_t		zl_parallel;	/* workload is multi-threaded */
 	uint_t		zl_prev_rotor;	/* rotor for zl_prev[] */
+	uint_t		zl_prev_opt[ZIL_BURSTS]; /* optimal block size */
+	uint_t		zl_prev_min[ZIL_BURSTS]; /* minimal first block size */
 	txg_node_t	zl_dirty_link;	/* protected by dp_dirty_zilogs list */
 	uint64_t	zl_dirty_max_txg; /* highest txg used to dirty zilog */
 
diff --git a/sys/contrib/openzfs/lib/libspl/include/assert.h b/sys/contrib/openzfs/lib/libspl/include/assert.h
index af4957dfbaa6..57f5719c1ac1 100644
--- a/sys/contrib/openzfs/lib/libspl/include/assert.h
+++ b/sys/contrib/openzfs/lib/libspl/include/assert.h
@@ -110,8 +110,8 @@ do {									\
 	const uintptr_t __right = (uintptr_t)(RIGHT);			\
 	if (!(__left OP __right))					\
 		libspl_assertf(__FILE__, __FUNCTION__, __LINE__,	\
-		    "%s %s %s (0x%llx %s 0x%llx)", #LEFT, #OP, #RIGHT,	\
-		    (u_longlong_t)__left, #OP, (u_longlong_t)__right);	\
+		    "%s %s %s (%p %s %p)", #LEFT, #OP, #RIGHT,		\
+		    (void *)__left, #OP, (void *)__right);		\
 } while (0)
 
 #define	VERIFY0(LEFT)							\
@@ -123,6 +123,15 @@ do {									\
 		    (u_longlong_t)__left);				\
 } while (0)
 
+#define	VERIFY0P(LEFT)							\
+do {									\
+	const uintptr_t __left = (uintptr_t)(LEFT);			\
+	if (!(__left == 0))						\
+		libspl_assertf(__FILE__, __FUNCTION__, __LINE__,	\
+		    "%s == 0 (%p == 0)", #LEFT,				\
+		    (void *)__left);					\
+} while (0)
+
 #ifdef assert
 #undef assert
 #endif
@@ -137,6 +146,7 @@ do {									\
 #define	ASSERT3P(x, y, z)						\
 	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
 #define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	ASSERT0P(x)		((void) sizeof ((uintptr_t)(x)))
 #define	ASSERT(x)		((void) sizeof ((uintptr_t)(x)))
 #define	assert(x)		((void) sizeof ((uintptr_t)(x)))
 #define	IMPLY(A, B)							\
@@ -149,6 +159,7 @@ do {									\
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
+#define	ASSERT0P	VERIFY0P
 #define	ASSERT		VERIFY
 #define	assert		VERIFY
 #define	IMPLY(A, B) \
diff --git a/sys/contrib/openzfs/lib/libuutil/uu_list.c b/sys/contrib/openzfs/lib/libuutil/uu_list.c
index 0ca6f05205e9..aa8b129cc22a 100644
--- a/sys/contrib/openzfs/lib/libuutil/uu_list.c
+++ b/sys/contrib/openzfs/lib/libuutil/uu_list.c
@@ -505,14 +505,20 @@ uu_list_walk(uu_list_t *lp, uu_walk_fn_t *func, void *private, uint32_t flags)
 	}
 
 	if (lp->ul_debug || robust) {
-		uu_list_walk_t my_walk;
+		uu_list_walk_t *my_walk;
 		void *e;
 
-		list_walk_init(&my_walk, lp, flags);
+		my_walk = uu_zalloc(sizeof (*my_walk));
+		if (my_walk == NULL)
+			return (-1);
+
+		list_walk_init(my_walk, lp, flags);
 		while (status == UU_WALK_NEXT &&
-		    (e = uu_list_walk_next(&my_walk)) != NULL)
+		    (e = uu_list_walk_next(my_walk)) != NULL)
 			status = (*func)(e, private);
-		list_walk_fini(&my_walk);
+		list_walk_fini(my_walk);
+
+		uu_free(my_walk);
 	} else {
 		if (!reverse) {
 			for (np = lp->ul_null_node.uln_next;
diff --git a/sys/contrib/openzfs/lib/libzfs/libzfs.abi b/sys/contrib/openzfs/lib/libzfs/libzfs.abi
index 9bb8f6a47de1..8bedfe72294c 100644
--- a/sys/contrib/openzfs/lib/libzfs/libzfs.abi
+++ b/sys/contrib/openzfs/lib/libzfs/libzfs.abi
@@ -1112,14 +1112,11 @@
         <var-decl name='prev' type-id='b03eadb4' visibility='default'/>
       </data-member>
     </class-decl>
-    <class-decl name='list' size-in-bits='256' is-struct='yes' visibility='default' id='e824dae9'>
+    <class-decl name='list' size-in-bits='192' is-struct='yes' visibility='default' id='e824dae9'>
       <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='list_size' type-id='b59d7dce' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='64'>
         <var-decl name='list_offset' type-id='b59d7dce' visibility='default'/>
       </data-member>
-      <data-member access='public' layout-offset-in-bits='128'>
+      <data-member access='public' layout-offset-in-bits='64'>
         <var-decl name='list_head' type-id='b0b5e45e' visibility='default'/>
       </data-member>
     </class-decl>
@@ -1870,7 +1867,8 @@
       <enumerator name='ZFS_PROP_REDACTED' value='93'/>
       <enumerator name='ZFS_PROP_REDACT_SNAPS' value='94'/>
       <enumerator name='ZFS_PROP_SNAPSHOTS_CHANGED' value='95'/>
-      <enumerator name='ZFS_NUM_PROPS' value='96'/>
+      <enumerator name='ZFS_PROP_PREFETCH' value='96'/>
+      <enumerator name='ZFS_NUM_PROPS' value='97'/>
     </enum-decl>
     <typedef-decl name='zfs_prop_t' type-id='4b000d60' id='58603c44'/>
     <enum-decl name='zprop_source_t' naming-typedef-id='a2256d42' id='5903f80e'>
@@ -2878,6 +2876,9 @@
     </function-type>
   </abi-instr>
   <abi-instr address-size='64' path='lib/libzfs/libzfs_crypto.c' language='LANG_C99'>
+    <array-type-def dimensions='1' type-id='38b51b3c' size-in-bits='832' id='02b72c00'>
+      <subrange length='13' type-id='7359adad' id='487fded1'/>
+    </array-type-def>
     <array-type-def dimensions='1' type-id='fb7c6451' size-in-bits='256' id='64177143'>
       <subrange length='32' type-id='7359adad' id='ae5bde82'/>
     </array-type-def>
@@ -2890,6 +2891,10 @@
     <class-decl name='_IO_codecvt' is-struct='yes' visibility='default' is-declaration-only='yes' id='a4036571'/>
     <class-decl name='_IO_marker' is-struct='yes' visibility='default' is-declaration-only='yes' id='010ae0b9'/>
     <class-decl name='_IO_wide_data' is-struct='yes' visibility='default' is-declaration-only='yes' id='79bd3751'/>
+    <class-decl name='__locale_data' is-struct='yes' visibility='default' is-declaration-only='yes' id='23de8b96'/>
+    <array-type-def dimensions='1' type-id='80f4b756' size-in-bits='832' id='39e6f84a'>
+      <subrange length='13' type-id='7359adad' id='487fded1'/>
+    </array-type-def>
     <array-type-def dimensions='1' type-id='95e97e5e' size-in-bits='896' id='47394ee0'>
       <subrange length='28' type-id='7359adad' id='3db583d7'/>
     </array-type-def>
@@ -3010,6 +3015,24 @@
     <typedef-decl name='__clock_t' type-id='bd54fe1a' id='4d66c6d7'/>
     <typedef-decl name='__ssize_t' type-id='bd54fe1a' id='41060289'/>
     <typedef-decl name='FILE' type-id='ec1ed955' id='aa12d1ba'/>
+    <class-decl name='__locale_struct' size-in-bits='1856' is-struct='yes' visibility='default' id='90cc1ce3'>
+      <data-member access='public' layout-offset-in-bits='0'>
+        <var-decl name='__locales' type-id='02b72c00' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='832'>
+        <var-decl name='__ctype_b' type-id='31347b7a' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='896'>
+        <var-decl name='__ctype_tolower' type-id='6d60f45d' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='960'>
+        <var-decl name='__ctype_toupper' type-id='6d60f45d' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='1024'>
+        <var-decl name='__names' type-id='39e6f84a' visibility='default'/>
+      </data-member>
+    </class-decl>
+    <typedef-decl name='__locale_t' type-id='f01e1813' id='b7ac9b5f'/>
     <class-decl name='__sigset_t' size-in-bits='1024' is-struct='yes' naming-typedef-id='b9c97942' visibility='default' id='2616147f'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='__val' type-id='d2baa450' visibility='default'/>
@@ -3025,6 +3048,7 @@
       </data-member>
     </union-decl>
     <typedef-decl name='__sigval_t' type-id='a094b870' id='eabacd01'/>
+    <typedef-decl name='locale_t' type-id='b7ac9b5f' id='973a4f8d'/>
     <class-decl name='siginfo_t' size-in-bits='1024' is-struct='yes' naming-typedef-id='cb681f62' visibility='default' id='d8149419'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='si_signo' type-id='95e97e5e' visibility='default'/>
@@ -3260,9 +3284,13 @@
     <pointer-type-def type-id='bb4788fa' size-in-bits='64' id='cecf4ea7'/>
     <pointer-type-def type-id='010ae0b9' size-in-bits='64' id='e4c6fa61'/>
     <pointer-type-def type-id='79bd3751' size-in-bits='64' id='c65a1f29'/>
+    <pointer-type-def type-id='23de8b96' size-in-bits='64' id='38b51b3c'/>
+    <pointer-type-def type-id='90cc1ce3' size-in-bits='64' id='f01e1813'/>
     <qualified-type-def type-id='9b23c9ad' restrict='yes' id='8c85230f'/>
     <qualified-type-def type-id='80f4b756' restrict='yes' id='9d26089a'/>
     <pointer-type-def type-id='80f4b756' size-in-bits='64' id='7d3cd834'/>
+    <qualified-type-def type-id='95e97e5e' const='yes' id='2448a865'/>
+    <pointer-type-def type-id='2448a865' size-in-bits='64' id='6d60f45d'/>
     <qualified-type-def type-id='aca3bac8' const='yes' id='2498fd78'/>
     <pointer-type-def type-id='2498fd78' size-in-bits='64' id='eed6c816'/>
     <qualified-type-def type-id='eed6c816' restrict='yes' id='a431a9da'/>
@@ -3295,6 +3323,7 @@
     <class-decl name='_IO_codecvt' is-struct='yes' visibility='default' is-declaration-only='yes' id='a4036571'/>
     <class-decl name='_IO_marker' is-struct='yes' visibility='default' is-declaration-only='yes' id='010ae0b9'/>
     <class-decl name='_IO_wide_data' is-struct='yes' visibility='default' is-declaration-only='yes' id='79bd3751'/>
+    <class-decl name='__locale_data' is-struct='yes' visibility='default' is-declaration-only='yes' id='23de8b96'/>
     <function-decl name='zpool_get_prop_int' mangled-name='zpool_get_prop_int' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_get_prop_int'>
       <parameter type-id='4c81de99'/>
       <parameter type-id='5d0c23fb'/>
@@ -3399,6 +3428,10 @@
     <function-decl name='dlerror' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='26a90f95'/>
     </function-decl>
+    <function-decl name='uselocale' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='973a4f8d'/>
+      <return type-id='973a4f8d'/>
+    </function-decl>
     <function-decl name='PKCS5_PBKDF2_HMAC_SHA1' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <parameter type-id='95e97e5e'/>
@@ -3482,8 +3515,9 @@
       <parameter type-id='80f4b756'/>
       <return type-id='26a90f95'/>
     </function-decl>
-    <function-decl name='strerror' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='strerror_l' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
+      <parameter type-id='973a4f8d'/>
       <return type-id='26a90f95'/>
     </function-decl>
     <function-decl name='tcgetattr' visibility='default' binding='global' size-in-bits='64'>
@@ -3840,12 +3874,18 @@
     <qualified-type-def type-id='9c313c2d' const='yes' id='c3b7ba7d'/>
     <pointer-type-def type-id='c3b7ba7d' size-in-bits='64' id='713a56f5'/>
     <pointer-type-def type-id='01a1b934' size-in-bits='64' id='566b3f52'/>
+    <qualified-type-def type-id='566b3f52' restrict='yes' id='c878edd6'/>
+    <pointer-type-def type-id='566b3f52' size-in-bits='64' id='82d4e9e8'/>
+    <qualified-type-def type-id='82d4e9e8' restrict='yes' id='aa19c230'/>
     <pointer-type-def type-id='7e291ce6' size-in-bits='64' id='ca64ff60'/>
     <pointer-type-def type-id='9da381c4' size-in-bits='64' id='cb785ebf'/>
     <pointer-type-def type-id='1b055409' size-in-bits='64' id='9d424d31'/>
     <pointer-type-def type-id='8e0af06e' size-in-bits='64' id='053457bd'/>
     <pointer-type-def type-id='857bb57e' size-in-bits='64' id='75be733c'/>
     <pointer-type-def type-id='a63d15a3' size-in-bits='64' id='a195f4a3'/>
+    <qualified-type-def type-id='a195f4a3' restrict='yes' id='33518961'/>
+    <pointer-type-def type-id='a195f4a3' size-in-bits='64' id='e80ff3ab'/>
+    <qualified-type-def type-id='e80ff3ab' restrict='yes' id='8f2c7109'/>
     <pointer-type-def type-id='eae6431d' size-in-bits='64' id='0d41d328'/>
     <pointer-type-def type-id='7a6844eb' size-in-bits='64' id='18c91f9e'/>
     <pointer-type-def type-id='dddf6ca2' size-in-bits='64' id='d915a820'/>
@@ -4278,9 +4318,13 @@
       <parameter type-id='9d424d31'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='getgrnam' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <return type-id='566b3f52'/>
+    <function-decl name='getgrnam_r' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='9d26089a'/>
+      <parameter type-id='c878edd6'/>
+      <parameter type-id='266fe297'/>
+      <parameter type-id='b59d7dce'/>
+      <parameter type-id='aa19c230'/>
+      <return type-id='95e97e5e'/>
     </function-decl>
     <function-decl name='hasmntopt' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='48bea5ec'/>
@@ -4304,9 +4348,13 @@
       <parameter type-id='18c91f9e'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='getpwnam' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <return type-id='a195f4a3'/>
+    <function-decl name='getpwnam_r' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='9d26089a'/>
+      <parameter type-id='33518961'/>
+      <parameter type-id='266fe297'/>
+      <parameter type-id='b59d7dce'/>
+      <parameter type-id='8f2c7109'/>
+      <return type-id='95e97e5e'/>
     </function-decl>
     <function-decl name='strtol' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='9d26089a'/>
@@ -5671,7 +5719,10 @@
       <enumerator name='VDEV_PROP_CHECKSUM_T' value='43'/>
       <enumerator name='VDEV_PROP_IO_N' value='44'/>
       <enumerator name='VDEV_PROP_IO_T' value='45'/>
-      <enumerator name='VDEV_NUM_PROPS' value='46'/>
+      <enumerator name='VDEV_PROP_RAIDZ_EXPANDING' value='46'/>
+      <enumerator name='VDEV_PROP_SLOW_IO_N' value='47'/>
+      <enumerator name='VDEV_PROP_SLOW_IO_T' value='48'/>
+      <enumerator name='VDEV_NUM_PROPS' value='49'/>
     </enum-decl>
     <typedef-decl name='vdev_prop_t' type-id='1573bec8' id='5aa5c90c'/>
     <class-decl name='zpool_load_policy' size-in-bits='256' is-struct='yes' visibility='default' id='2f65b36f'>
@@ -6242,6 +6293,7 @@
     <function-decl name='zpool_add' mangled-name='zpool_add' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_add'>
       <parameter type-id='4c81de99' name='zhp'/>
       <parameter type-id='5ce45b60' name='nvroot'/>
+      <parameter type-id='c19b74c3' name='ashift_check'/>
       <return type-id='95e97e5e'/>
     </function-decl>
     <function-decl name='zpool_export' mangled-name='zpool_export' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_export'>
@@ -6693,7 +6745,7 @@
       <enumerator name='LZC_SEND_FLAG_RAW' value='8'/>
       <enumerator name='LZC_SEND_FLAG_SAVED' value='16'/>
     </enum-decl>
-    <class-decl name='ddt_key' size-in-bits='320' is-struct='yes' visibility='default' id='e0a4a1cb'>
+    <class-decl name='ddt_key_t' size-in-bits='320' is-struct='yes' naming-typedef-id='67f6d2cf' visibility='default' id='5fae1718'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='ddk_cksum' type-id='39730d0b' visibility='default'/>
       </data-member>
@@ -6701,7 +6753,7 @@
         <var-decl name='ddk_prop' type-id='9c313c2d' visibility='default'/>
       </data-member>
     </class-decl>
-    <typedef-decl name='ddt_key_t' type-id='e0a4a1cb' id='67f6d2cf'/>
+    <typedef-decl name='ddt_key_t' type-id='5fae1718' id='67f6d2cf'/>
     <enum-decl name='dmu_object_type' id='04b3b0b9'>
       <underlying-type type-id='9cac1fee'/>
       <enumerator name='DMU_OT_NONE' value='0'/>
diff --git a/sys/contrib/openzfs/lib/libzfs/libzfs_pool.c b/sys/contrib/openzfs/lib/libzfs/libzfs_pool.c
index 2f9ccbc2ab57..e95b361da866 100644
--- a/sys/contrib/openzfs/lib/libzfs/libzfs_pool.c
+++ b/sys/contrib/openzfs/lib/libzfs/libzfs_pool.c
@@ -22,7 +22,7 @@
 /*
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
  * Copyright (c) 2018 Datto Inc.
  * Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
@@ -1724,7 +1724,7 @@ zpool_discard_checkpoint(zpool_handle_t *zhp)
  * necessary verification to ensure that the vdev specification is well-formed.
  */
 int
-zpool_add(zpool_handle_t *zhp, nvlist_t *nvroot)
+zpool_add(zpool_handle_t *zhp, nvlist_t *nvroot, boolean_t check_ashift)
 {
 	zfs_cmd_t zc = {"\0"};
 	int ret;
@@ -1756,6 +1756,7 @@ zpool_add(zpool_handle_t *zhp, nvlist_t *nvroot)
 
 	zcmd_write_conf_nvlist(hdl, &zc, nvroot);
 	(void) strlcpy(zc.zc_name, zhp->zpool_name, sizeof (zc.zc_name));
+	zc.zc_flags = check_ashift;
 
 	if (zfs_ioctl(hdl, ZFS_IOC_VDEV_ADD, &zc) != 0) {
 		switch (errno) {
@@ -1899,7 +1900,8 @@ zpool_rewind_exclaim(libzfs_handle_t *hdl, const char *name, boolean_t dryrun,
 	(void) nvlist_lookup_int64(nv, ZPOOL_CONFIG_REWIND_TIME, &loss);
 
 	if (localtime_r((time_t *)&rewindto, &t) != NULL &&
-	    strftime(timestr, 128, "%c", &t) != 0) {
+	    ctime_r((time_t *)&rewindto, timestr) != NULL) {
+		timestr[24] = 0;
 		if (dryrun) {
 			(void) printf(dgettext(TEXT_DOMAIN,
 			    "Would be able to return %s "
@@ -1961,7 +1963,8 @@ zpool_explain_recover(libzfs_handle_t *hdl, const char *name, int reason,
 	    "Recovery is possible, but will result in some data loss.\n"));
 
 	if (localtime_r((time_t *)&rewindto, &t) != NULL &&
-	    strftime(timestr, 128, "%c", &t) != 0) {
+	    ctime_r((time_t *)&rewindto, timestr) != NULL) {
+		timestr[24] = 0;
 		(void) printf(dgettext(TEXT_DOMAIN,
 		    "\tReturning the pool to its state as of %s\n"
 		    "\tshould correct the problem.  "),
@@ -5224,6 +5227,8 @@ zpool_get_vdev_prop_value(nvlist_t *nvprop, vdev_prop_t prop, char *prop_name,
 		case VDEV_PROP_CHECKSUM_T:
 		case VDEV_PROP_IO_N:
 		case VDEV_PROP_IO_T:
+		case VDEV_PROP_SLOW_IO_N:
+		case VDEV_PROP_SLOW_IO_T:
 			if (intval == UINT64_MAX) {
 				(void) strlcpy(buf, "-", len);
 			} else {
diff --git a/sys/contrib/openzfs/lib/libzfs/libzfs_sendrecv.c b/sys/contrib/openzfs/lib/libzfs/libzfs_sendrecv.c
index e9bc78aa8d39..143aecb9459f 100644
--- a/sys/contrib/openzfs/lib/libzfs/libzfs_sendrecv.c
+++ b/sys/contrib/openzfs/lib/libzfs/libzfs_sendrecv.c
@@ -1053,6 +1053,7 @@ send_progress_thread(void *arg)
 		}
 	}
 	pthread_cleanup_pop(B_TRUE);
+	return (NULL);
 }
 
 static boolean_t
diff --git a/sys/contrib/openzfs/lib/libzfs/libzfs_util.c b/sys/contrib/openzfs/lib/libzfs/libzfs_util.c
index fdd1975fa677..60e9262f6b71 100644
--- a/sys/contrib/openzfs/lib/libzfs/libzfs_util.c
+++ b/sys/contrib/openzfs/lib/libzfs/libzfs_util.c
@@ -22,7 +22,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2020 Joyent, Inc. All rights reserved.
- * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
  * Copyright (c) 2017 Datto Inc.
  * Copyright (c) 2020 The FreeBSD Foundation
@@ -317,6 +317,9 @@ libzfs_error_description(libzfs_handle_t *hdl)
 	case EZFS_RESUME_EXISTS:
 		return (dgettext(TEXT_DOMAIN, "Resuming recv on existing "
 		    "dataset without force"));
+	case EZFS_ASHIFT_MISMATCH:
+		return (dgettext(TEXT_DOMAIN, "adding devices with "
+		    "different physical sector sizes is not allowed"));
 	case EZFS_UNKNOWN:
 		return (dgettext(TEXT_DOMAIN, "unknown error"));
 	default:
@@ -763,6 +766,9 @@ zpool_standard_error_fmt(libzfs_handle_t *hdl, int error, const char *fmt, ...)
 	case ZFS_ERR_IOC_ARG_BADTYPE:
 		zfs_verror(hdl, EZFS_IOC_NOTSUPPORTED, fmt, ap);
 		break;
+	case ZFS_ERR_ASHIFT_MISMATCH:
+		zfs_verror(hdl, EZFS_ASHIFT_MISMATCH, fmt, ap);
+		break;
 	default:
 		zfs_error_aux(hdl, "%s", strerror(error));
 		zfs_verror(hdl, EZFS_UNKNOWN, fmt, ap);
@@ -1699,7 +1705,9 @@ zprop_parse_value(libzfs_handle_t *hdl, nvpair_t *elem, int prop,
 		    (prop == VDEV_PROP_CHECKSUM_N ||
 		    prop == VDEV_PROP_CHECKSUM_T ||
 		    prop == VDEV_PROP_IO_N ||
-		    prop == VDEV_PROP_IO_T)) {
+		    prop == VDEV_PROP_IO_T ||
+		    prop == VDEV_PROP_SLOW_IO_N ||
+		    prop == VDEV_PROP_SLOW_IO_T)) {
 			*ivalp = UINT64_MAX;
 		}
 
diff --git a/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_pool_os.c b/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_pool_os.c
index 401151b1afb5..86eef3255bc2 100644
--- a/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_pool_os.c
+++ b/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_pool_os.c
@@ -273,6 +273,16 @@ zpool_label_disk(libzfs_handle_t *hdl, zpool_handle_t *zhp, const char *name)
 	vtoc->efi_parts[0].p_start = start_block;
 	vtoc->efi_parts[0].p_size = slice_size;
 
+	if (vtoc->efi_parts[0].p_size * vtoc->efi_lbasize < SPA_MINDEVSIZE) {
+		(void) close(fd);
+		efi_free(vtoc);
+
+		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "cannot "
+		    "label '%s': partition would be less than the minimum "
+		    "device size (64M)"), path);
+		return (zfs_error(hdl, EZFS_LABELFAILED, errbuf));
+	}
+
 	/*
 	 * Why we use V_USR: V_BACKUP confuses users, and is considered
 	 * disposable by some EFI utilities (since EFI doesn't have a backup
diff --git a/sys/contrib/openzfs/man/Makefile.am b/sys/contrib/openzfs/man/Makefile.am
index 45156571eec3..43bb014ddd32 100644
--- a/sys/contrib/openzfs/man/Makefile.am
+++ b/sys/contrib/openzfs/man/Makefile.am
@@ -62,7 +62,6 @@ dist_man_MANS = \
 	%D%/man8/zfs-userspace.8 \
 	%D%/man8/zfs-wait.8 \
 	%D%/man8/zfs_ids_to_path.8 \
-	%D%/man8/zfs_prepare_disk.8 \
 	%D%/man8/zgenhostid.8 \
 	%D%/man8/zinject.8 \
 	%D%/man8/zpool.8 \
@@ -115,7 +114,8 @@ endif
 
 nodist_man_MANS = \
 	%D%/man8/zed.8 \
-	%D%/man8/zfs-mount-generator.8
+	%D%/man8/zfs-mount-generator.8 \
+	%D%/man8/zfs_prepare_disk.8
 
 dist_noinst_DATA += $(dist_noinst_man_MANS) $(dist_man_MANS)
 
diff --git a/sys/contrib/openzfs/man/man4/spl.4 b/sys/contrib/openzfs/man/man4/spl.4
index 414a92394858..5cc12764e18c 100644
--- a/sys/contrib/openzfs/man/man4/spl.4
+++ b/sys/contrib/openzfs/man/man4/spl.4
@@ -186,18 +186,8 @@ reading it could cause a lock-up if the list grow too large
 without limiting the output.
 "(truncated)" will be shown if the list is larger than the limit.
 .
-.It Sy spl_taskq_thread_timeout_ms Ns = Ns Sy 10000 Pq uint
-(Linux-only)
-How long a taskq has to have had no work before we tear it down.
-Previously, we would tear down a dynamic taskq worker as soon
-as we noticed it had no work, but it was observed that this led
-to a lot of churn in tearing down things we then immediately
-spawned anew.
-In practice, it seems any nonzero value will remove the vast
-majority of this churn, while the nontrivially larger value
-was chosen to help filter out the little remaining churn on
-a mostly idle system.
-Setting this value to
-.Sy 0
-will revert to the previous behavior.
+.It Sy spl_taskq_thread_timeout_ms Ns = Ns Sy 5000 Pq uint
+Minimum idle threads exit interval for dynamic taskqs.
+Smaller values allow idle threads exit more often and potentially be
+respawned again on demand, causing more churn.
 .El
diff --git a/sys/contrib/openzfs/man/man4/zfs.4 b/sys/contrib/openzfs/man/man4/zfs.4
index 352990e02daf..1191cc962492 100644
--- a/sys/contrib/openzfs/man/man4/zfs.4
+++ b/sys/contrib/openzfs/man/man4/zfs.4
@@ -2,6 +2,7 @@
 .\" Copyright (c) 2013 by Turbo Fredriksson <turbo@bayour.com>. All rights reserved.
 .\" Copyright (c) 2019, 2021 by Delphix. All rights reserved.
 .\" Copyright (c) 2019 Datto Inc.
+.\" Copyright (c) 2023, 2024 Klara, Inc.
 .\" The contents of this file are subject to the terms of the Common Development
 .\" and Distribution License (the "License").  You may not use this file except
 .\" in compliance with the License. You can obtain a copy of the license at
@@ -15,7 +16,7 @@
 .\" own identifying information:
 .\" Portions Copyright [yyyy] [name of copyright owner]
 .\"
-.Dd July 21, 2023
+.Dd January 9, 2024
 .Dt ZFS 4
 .Os
 .
@@ -244,12 +245,25 @@ For blocks that could be forced to be a gang block (due to
 .Sy metaslab_force_ganging ) ,
 force this many of them to be gang blocks.
 .
-.It Sy zfs_ddt_zap_default_bs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
+.It Sy brt_zap_prefetch Ns = Ns Sy 1 Ns | Ns 0 Pq int
+Controls prefetching BRT records for blocks which are going to be cloned.
+.
+.It Sy brt_zap_default_bs Ns = Ns Sy 12 Po 4 KiB Pc Pq int
+Default BRT ZAP data block size as a power of 2. Note that changing this after
+creating a BRT on the pool will not affect existing BRTs, only newly created
+ones.
+.
+.It Sy brt_zap_default_ibs Ns = Ns Sy 12 Po 4 KiB Pc Pq int
+Default BRT ZAP indirect block size as a power of 2. Note that changing this
+after creating a BRT on the pool will not affect existing BRTs, only newly
+created ones.
+.
+.It Sy ddt_zap_default_bs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
 Default DDT ZAP data block size as a power of 2. Note that changing this after
 creating a DDT on the pool will not affect existing DDTs, only newly created
 ones.
 .
-.It Sy zfs_ddt_zap_default_ibs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
+.It Sy ddt_zap_default_ibs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
 Default DDT ZAP indirect block size as a power of 2. Note that changing this
 after creating a DDT on the pool will not affect existing DDTs, only newly
 created ones.
@@ -530,6 +544,10 @@ However, this is limited by
 Maximum micro ZAP size.
 A micro ZAP is upgraded to a fat ZAP, once it grows beyond the specified size.
 .
+.It Sy zfetch_hole_shift Ns = Ns Sy 2 Pq uint
+Log2 fraction of holes in speculative prefetch stream allowed for it to
+proceed.
+.
 .It Sy zfetch_min_distance Ns = Ns Sy 4194304 Ns B Po 4 MiB Pc Pq uint
 Min bytes to prefetch per stream.
 Prefetch distance starts from the demand access size and quickly grows to
@@ -544,6 +562,13 @@ Max bytes to prefetch per stream.
 .It Sy zfetch_max_idistance Ns = Ns Sy 67108864 Ns B Po 64 MiB Pc Pq uint
 Max bytes to prefetch indirects for per stream.
 .
+.It Sy zfetch_max_reorder Ns = Ns Sy 16777216 Ns B Po 16 MiB Pc Pq uint
+Requests within this byte distance from the current prefetch stream position
+are considered parts of the stream, reordered due to parallel processing.
+Such requests do not advance the stream position immediately unless
+.Sy zfetch_hole_shift
+fill threshold is reached, but saved to fill holes in the stream later.
+.
 .It Sy zfetch_max_streams Ns = Ns Sy 8 Pq uint
 Max number of streams per zfetch (prefetch streams per file).
 .
@@ -798,7 +823,7 @@ Note that this should not be set below the ZED thresholds
 (currently 10 checksums over 10 seconds)
 or else the daemon may not trigger any action.
 .
-.It Sy zfs_commit_timeout_pct Ns = Ns Sy 5 Ns % Pq uint
+.It Sy zfs_commit_timeout_pct Ns = Ns Sy 10 Ns % Pq uint
 This controls the amount of time that a ZIL block (lwb) will remain "open"
 when it isn't "full", and it has a thread waiting for it to be committed to
 stable storage.
@@ -1345,6 +1370,42 @@ _
 	4	Driver	No driver retries on driver errors.
 .TE
 .
+.It Sy zfs_vdev_disk_max_segs Ns = Ns Sy 0 Pq uint
+Maximum number of segments to add to a BIO (min 4).
+If this is higher than the maximum allowed by the device queue or the kernel
+itself, it will be clamped.
+Setting it to zero will cause the kernel's ideal size to be used.
+This parameter only applies on Linux.
+This parameter is ignored if
+.Sy zfs_vdev_disk_classic Ns = Ns Sy 1 .
+.
+.It Sy zfs_vdev_disk_classic Ns = Ns 0 Ns | Ns Sy 1 Pq uint
+Controls the method used to submit IO to the Linux block layer
+(default
+.Sy 1 "classic" Ns
+)
+.Pp
+If set to 1, the "classic" method is used.
+This is the method that has been in use since the earliest versions of
+ZFS-on-Linux.
+It has known issues with highly fragmented IO requests and is less efficient on
+many workloads, but it well known and well understood.
+.Pp
+If set to 0, the "new" method is used.
+This method is available since 2.2.4 and should resolve all known issues and be
+far more efficient, but has not had as much testing.
+In the 2.2.x series, this parameter defaults to 1, to use the "classic" method.
+.Pp
+It is not recommended that you change it except on advice from the OpenZFS
+developers.
+If you do change it, please also open a bug report describing why you did so,
+including the workload involved and any error messages.
+.Pp
+This parameter and the "classic" submission method will be removed in a future
+release of OpenZFS once we have total confidence in the new method.
+.Pp
+This parameter only applies on Linux, and can only be set at module load time.
+.
 .It Sy zfs_expire_snapshot Ns = Ns Sy 300 Ns s Pq int
 Time before expiring
 .Pa .zfs/snapshot .
@@ -2169,13 +2230,6 @@ This sets the maximum number of write bytes logged via WR_COPIED.
 It tunes a tradeoff between additional memory copy and possibly worse log
 space efficiency vs additional range lock/unlock.
 .
-.It Sy zil_min_commit_timeout Ns = Ns Sy 5000 Pq u64
-This sets the minimum delay in nanoseconds ZIL care to delay block commit,
-waiting for more records.
-If ZIL writes are too fast, kernel may not be able sleep for so short interval,
-increasing log latency above allowed by
-.Sy zfs_commit_timeout_pct .
-.
 .It Sy zil_nocacheflush Ns = Ns Sy 0 Ns | Ns 1 Pq int
 Disable the cache flush commands that are normally sent to disk by
 the ZIL after an LWB write has completed.
@@ -2333,6 +2387,13 @@ The number of requests which can be handled concurrently is controlled by
 is ignored when running on a kernel that supports block multiqueue
 .Pq Li blk-mq .
 .
+.It Sy zvol_num_taskqs Ns = Ns Sy 0 Pq uint
+Number of zvol taskqs.
+If
+.Sy 0
+(the default) then scaling is done internally to prefer 6 threads per taskq.
+This only applies on Linux.
+.
 .It Sy zvol_threads Ns = Ns Sy 0 Pq uint
 The number of system wide threads to use for processing zvol block IOs.
 If
diff --git a/sys/contrib/openzfs/man/man7/vdevprops.7 b/sys/contrib/openzfs/man/man7/vdevprops.7
index 6eebfa0060de..5ec37df179de 100644
--- a/sys/contrib/openzfs/man/man7/vdevprops.7
+++ b/sys/contrib/openzfs/man/man7/vdevprops.7
@@ -44,7 +44,7 @@ section, below.
 Every vdev has a set of properties that export statistics about the vdev
 as well as control various behaviors.
 Properties are not inherited from top-level vdevs, with the exception of
-checksum_n, checksum_t, io_n, and io_t.
+checksum_n, checksum_t, io_n, io_t, slow_io_n, and slow_io_t.
 .Pp
 The values of numeric properties can be specified using human-readable suffixes
 .Po for example,
@@ -117,7 +117,7 @@ If this device is currently being removed from the pool
 .Pp
 The following native properties can be used to change the behavior of a vdev.
 .Bl -tag -width "allocating"
-.It Sy checksum_n , checksum_t , io_n , io_t
+.It Sy checksum_n , checksum_t , io_n , io_t , slow_io_n , slow_io_t
 Tune the fault management daemon by specifying checksum/io thresholds of <N>
 errors in <T> seconds, respectively.
 These properties can be set on leaf and top-level vdevs.
@@ -127,7 +127,13 @@ If the property is only set on the top-level vdev, this value will be used.
 The value of these properties do not persist across vdev replacement.
 For this reason, it is advisable to set the property on the top-level vdev -
 not on the leaf vdev itself.
-The default values are 10 errors in 600 seconds.
+The default values for
+.Sy OpenZFS on Linux
+are 10 errors in 600 seconds.
+For
+.Sy OpenZFS on FreeBSD
+defaults see
+.Xr zfsd 8 .
 .It Sy comment
 A text comment up to 8192 characters long
 .It Sy bootsize
diff --git a/sys/contrib/openzfs/man/man7/zfsprops.7 b/sys/contrib/openzfs/man/man7/zfsprops.7
index e3674b1f8a8d..59f6404379af 100644
--- a/sys/contrib/openzfs/man/man7/zfsprops.7
+++ b/sys/contrib/openzfs/man/man7/zfsprops.7
@@ -1613,6 +1613,23 @@ If this property is set to
 then only metadata is cached.
 The default value is
 .Sy all .
+.It Sy prefetch Ns = Ns Sy all Ns | Ns Sy none Ns | Ns Sy metadata
+Controls what speculative prefetch does.
+If this property is set to
+.Sy all ,
+then both user data and metadata are prefetched.
+If this property is set to
+.Sy none ,
+then neither user data nor metadata are prefetched.
+If this property is set to
+.Sy metadata ,
+then only metadata are prefetched.
+The default value is
+.Sy all .
+.Pp
+Please note that the module parameter zfs_disable_prefetch=1 can
+be used to totally disable speculative prefetch, bypassing anything
+this property does.
 .It Sy setuid Ns = Ns Sy on Ns | Ns Sy off
 Controls whether the setuid bit is respected for the file system.
 The default value is
diff --git a/sys/contrib/openzfs/man/man7/zpoolconcepts.7 b/sys/contrib/openzfs/man/man7/zpoolconcepts.7
index 98f3ee7cd660..18dfca6dc8ac 100644
--- a/sys/contrib/openzfs/man/man7/zpoolconcepts.7
+++ b/sys/contrib/openzfs/man/man7/zpoolconcepts.7
@@ -260,8 +260,8 @@ sufficient replicas exist to continue functioning.
 The underlying conditions are as follows:
 .Bl -bullet -compact
 .It
-The number of checksum errors exceeds acceptable levels and the device is
-degraded as an indication that something may be wrong.
+The number of checksum errors or slow I/Os exceeds acceptable levels and the
+device is degraded as an indication that something may be wrong.
 ZFS continues to use the device as necessary.
 .It
 The number of I/O errors exceeds acceptable levels.
diff --git a/sys/contrib/openzfs/man/man8/zfs-mount.8 b/sys/contrib/openzfs/man/man8/zfs-mount.8
index 35aa187cf063..20dbe4d0e648 100644
--- a/sys/contrib/openzfs/man/man8/zfs-mount.8
+++ b/sys/contrib/openzfs/man/man8/zfs-mount.8
@@ -43,7 +43,7 @@
 .Cm mount
 .Op Fl Oflv
 .Op Fl o Ar options
-.Fl a Ns | Ns Ar filesystem
+.Fl a Ns | Ns Fl R Ar filesystem Ns | Ns Ar filesystem
 .Nm zfs
 .Cm unmount
 .Op Fl fu
@@ -61,7 +61,7 @@ Displays all ZFS file systems currently mounted.
 .Cm mount
 .Op Fl Oflv
 .Op Fl o Ar options
-.Fl a Ns | Ns Ar filesystem
+.Fl a Ns | Ns Fl R Ar filesystem Ns | Ns Ar filesystem
 .Xc
 Mount ZFS filesystem on a path described by its
 .Sy mountpoint
@@ -83,6 +83,8 @@ for more information.
 .It Fl a
 Mount all available ZFS file systems.
 Invoked automatically as part of the boot process if configured.
+.It Fl R
+Mount the specified filesystems along with all their children.
 .It Ar filesystem
 Mount the specified filesystem.
 .It Fl o Ar options
diff --git a/sys/contrib/openzfs/man/man8/zinject.8 b/sys/contrib/openzfs/man/man8/zinject.8
index 4f0bbae81212..b692f12130a8 100644
--- a/sys/contrib/openzfs/man/man8/zinject.8
+++ b/sys/contrib/openzfs/man/man8/zinject.8
@@ -69,6 +69,7 @@ Force a vdev into the DEGRADED or FAULTED state.
 .Nm zinject
 .Fl d Ar vdev
 .Fl D Ar latency : Ns Ar lanes
+.Op Fl T Ar read|write
 .Ar pool
 .Xc
 Add an artificial delay to I/O requests on a particular
diff --git a/sys/contrib/openzfs/man/man8/zpool-add.8 b/sys/contrib/openzfs/man/man8/zpool-add.8
index 8ccdcccc7b06..60b35f1a511a 100644
--- a/sys/contrib/openzfs/man/man8/zpool-add.8
+++ b/sys/contrib/openzfs/man/man8/zpool-add.8
@@ -24,8 +24,9 @@
 .\" Copyright (c) 2018 George Melikov. All Rights Reserved.
 .\" Copyright 2017 Nexenta Systems, Inc.
 .\" Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
+.\" Copyright (c) 2024 by Delphix. All Rights Reserved.
 .\"
-.Dd March 16, 2022
+.Dd March 8, 2024
 .Dt ZPOOL-ADD 8
 .Os
 .
@@ -36,6 +37,7 @@
 .Nm zpool
 .Cm add
 .Op Fl fgLnP
+.Op Fl -allow-in-use -allow-replication-mismatch -allow-ashift-mismatch
 .Oo Fl o Ar property Ns = Ns Ar value Oc
 .Ar pool vdev Ns …
 .
@@ -56,7 +58,8 @@ subcommand.
 .It Fl f
 Forces use of
 .Ar vdev Ns s ,
-even if they appear in use or specify a conflicting replication level.
+even if they appear in use, have conflicting ashift values, or specify
+a conflicting replication level.
 Not all devices can be overridden in this manner.
 .It Fl g
 Display
@@ -91,6 +94,17 @@ See the
 manual page for a list of valid properties that can be set.
 The only property supported at the moment is
 .Sy ashift .
+.It Fl -allow-ashift-mismatch
+Disable the ashift validation which allows mismatched ashift values in the
+pool.
+Adding top-level
+.Ar vdev Ns s
+with different sector sizes will prohibit future device removal operations, see
+.Xr zpool-remove 8 .
+.It Fl -allow-in-use
+Allow vdevs to be added even if they might be in use in another pool.
+.It Fl -allow-replication-mismatch
+Allow vdevs with conflicting replication levels to be added to the pool.
 .El
 .
 .Sh EXAMPLES
diff --git a/sys/contrib/openzfs/man/man8/zpool-clear.8 b/sys/contrib/openzfs/man/man8/zpool-clear.8
index c61ecae483ac..3e448be87fc2 100644
--- a/sys/contrib/openzfs/man/man8/zpool-clear.8
+++ b/sys/contrib/openzfs/man/man8/zpool-clear.8
@@ -50,9 +50,10 @@ If the pool was suspended it will be brought back online provided the
 devices can be accessed.
 Pools with
 .Sy multihost
-enabled which have been suspended cannot be resumed.
-While the pool was suspended, it may have been imported on
-another host, and resuming I/O could result in pool damage.
+enabled which have been suspended cannot be resumed when there is evidence
+that the pool was imported by another host.
+The same checks performed during an import will be applied before the clear
+proceeds.
 .Bl -tag -width Ds
 .It Fl -power
 Power on the devices's slot in the storage enclosure and wait for the device
diff --git a/sys/contrib/openzfs/man/man8/zpool-status.8 b/sys/contrib/openzfs/man/man8/zpool-status.8
index 24ad6e643cae..bbe7a45aa0c6 100644
--- a/sys/contrib/openzfs/man/man8/zpool-status.8
+++ b/sys/contrib/openzfs/man/man8/zpool-status.8
@@ -36,7 +36,7 @@
 .Sh SYNOPSIS
 .Nm zpool
 .Cm status
-.Op Fl DeigLpPstvx
+.Op Fl DegiLpPstvx
 .Op Fl T Sy u Ns | Ns Sy d
 .Op Fl c Op Ar SCRIPT1 Ns Oo , Ns Ar SCRIPT2 Oc Ns …
 .Oo Ar pool Oc Ns …
@@ -69,14 +69,20 @@ See the
 option of
 .Nm zpool Cm iostat
 for complete details.
+.It Fl D
+Display a histogram of deduplication statistics, showing the allocated
+.Pq physically present on disk
+and referenced
+.Pq logically referenced in the pool
+block counts and sizes by reference count.
 .It Fl e
 Only show unhealthy vdevs (not-ONLINE or with errors).
-.It Fl i
-Display vdev initialization status.
 .It Fl g
 Display vdev GUIDs instead of the normal device names
 These GUIDs can be used in place of device names for the zpool
 detach/offline/remove/replace commands.
+.It Fl i
+Display vdev initialization status.
 .It Fl L
 Display real paths for vdevs resolving all symbolic links.
 This can be used to look up the current block device name regardless of the
@@ -90,12 +96,6 @@ the path.
 This can be used in conjunction with the
 .Fl L
 flag.
-.It Fl D
-Display a histogram of deduplication statistics, showing the allocated
-.Pq physically present on disk
-and referenced
-.Pq logically referenced in the pool
-block counts and sizes by reference count.
 .It Fl s
 Display the number of leaf vdev slow I/O operations.
 This is the number of I/O operations that didn't complete in
diff --git a/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse2.S b/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse2.S
index dc2719d142db..e66bb4bc7f26 100644
--- a/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse2.S
+++ b/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse2.S
@@ -32,6 +32,14 @@
  */
 
 #if defined(__aarch64__)
+
+/* make gcc <= 9 happy */
+#if LD_VERSION >= 233010000
+#define CFI_NEGATE_RA_STATE .cfi_negate_ra_state
+#else
+#define CFI_NEGATE_RA_STATE
+#endif
+
 	.text
 	.section	.note.gnu.property,"a",@note
 	.p2align	3
@@ -51,7 +59,7 @@
 zfs_blake3_compress_in_place_sse2:
 	.cfi_startproc
 	hint	#25
-	.cfi_negate_ra_state
+	CFI_NEGATE_RA_STATE
 	sub	sp, sp, #96
 	stp	x29, x30, [sp, #64]
 	add	x29, sp, #64
@@ -555,7 +563,7 @@ compress_pre:
 zfs_blake3_compress_xof_sse2:
 	.cfi_startproc
 	hint	#25
-	.cfi_negate_ra_state
+	CFI_NEGATE_RA_STATE
 	sub	sp, sp, #96
 	stp	x29, x30, [sp, #64]
 	add	x29, sp, #64
@@ -608,7 +616,7 @@ zfs_blake3_compress_xof_sse2:
 zfs_blake3_hash_many_sse2:
 	.cfi_startproc
 	hint	#25
-	.cfi_negate_ra_state
+	CFI_NEGATE_RA_STATE
 	stp	d15, d14, [sp, #-160]!
 	stp	d13, d12, [sp, #16]
 	stp	d11, d10, [sp, #32]
diff --git a/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse41.S b/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse41.S
index c4c2dfc5bcde..b9fb28dfcf03 100644
--- a/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse41.S
+++ b/sys/contrib/openzfs/module/icp/asm-aarch64/blake3/b3_aarch64_sse41.S
@@ -32,6 +32,14 @@
  */
 
 #if defined(__aarch64__)
+
+/* make gcc <= 9 happy */
+#if LD_VERSION >= 233010000
+#define CFI_NEGATE_RA_STATE .cfi_negate_ra_state
+#else
+#define CFI_NEGATE_RA_STATE
+#endif
+
 	.text
 	.section	.note.gnu.property,"a",@note
 	.p2align	3
@@ -51,7 +59,7 @@
 zfs_blake3_compress_in_place_sse41:
 	.cfi_startproc
 	hint	#25
-	.cfi_negate_ra_state
+	CFI_NEGATE_RA_STATE
 	sub	sp, sp, #96
 	stp	x29, x30, [sp, #64]
 	add	x29, sp, #64
@@ -565,7 +573,7 @@ compress_pre:
 zfs_blake3_compress_xof_sse41:
 	.cfi_startproc
 	hint	#25
-	.cfi_negate_ra_state
+	CFI_NEGATE_RA_STATE
 	sub	sp, sp, #96
 	stp	x29, x30, [sp, #64]
 	add	x29, sp, #64
diff --git a/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha256-armv8.S b/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha256-armv8.S
index 7ae486e4e229..4dcdd3b65d0b 100644
--- a/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha256-armv8.S
+++ b/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha256-armv8.S
@@ -21,6 +21,16 @@
 
 #if defined(__aarch64__)
 
+	.section	.note.gnu.property,"a",@note
+	.p2align	3
+	.word	4
+	.word	16
+	.word	5
+	.asciz	"GNU"
+	.word	3221225472
+	.word	4
+	.word	3
+	.word	0
 .text
 
 .align	6
diff --git a/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha512-armv8.S b/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha512-armv8.S
index 9c61eeee4d7b..f6c8f7742912 100644
--- a/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha512-armv8.S
+++ b/sys/contrib/openzfs/module/icp/asm-aarch64/sha2/sha512-armv8.S
@@ -21,6 +21,16 @@
 
 #if defined(__aarch64__)
 
+	.section	.note.gnu.property,"a",@note
+	.p2align	3
+	.word	4
+	.word	16
+	.word	5
+	.asciz	"GNU"
+	.word	3221225472
+	.word	4
+	.word	3
+	.word	0
 .text
 
 .align	6
diff --git a/sys/contrib/openzfs/module/nvpair/nvpair.c b/sys/contrib/openzfs/module/nvpair/nvpair.c
index d9449e47e87a..887f7d32df4a 100644
--- a/sys/contrib/openzfs/module/nvpair/nvpair.c
+++ b/sys/contrib/openzfs/module/nvpair/nvpair.c
@@ -41,6 +41,7 @@
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/string.h>
+#include <rpc/types.h>
 #include <rpc/xdr.h>
 #include <sys/mod.h>
 
diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/abd_os.c b/sys/contrib/openzfs/module/os/freebsd/zfs/abd_os.c
index 58a37df62b69..3b812271f98b 100644
--- a/sys/contrib/openzfs/module/os/freebsd/zfs/abd_os.c
+++ b/sys/contrib/openzfs/module/os/freebsd/zfs/abd_os.c
@@ -417,10 +417,8 @@ abd_iter_init(struct abd_iter *aiter, abd_t *abd)
 {
 	ASSERT(!abd_is_gang(abd));
 	abd_verify(abd);
+	memset(aiter, 0, sizeof (struct abd_iter));
 	aiter->iter_abd = abd;
-	aiter->iter_pos = 0;
-	aiter->iter_mapaddr = NULL;
-	aiter->iter_mapsize = 0;
 }
 
 /*
diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
index 93bbfa8e3ef2..617e3bbbca48 100644
--- a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
+++ b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
@@ -1869,10 +1869,8 @@ zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
 
 		ASSERT3S(outcount, <=, bufsize);
 
-		/* Prefetch znode */
 		if (prefetch)
-			dmu_prefetch(os, objnum, 0, 0, 0,
-			    ZIO_PRIORITY_SYNC_READ);
+			dmu_prefetch_dnode(os, objnum, ZIO_PRIORITY_SYNC_READ);
 
 		/*
 		 * Move to the next entry, fill in the previous offset.
diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/zvol_os.c b/sys/contrib/openzfs/module/os/freebsd/zfs/zvol_os.c
index b6edac434dea..7c418f26fc14 100644
--- a/sys/contrib/openzfs/module/os/freebsd/zfs/zvol_os.c
+++ b/sys/contrib/openzfs/module/os/freebsd/zfs/zvol_os.c
@@ -1273,7 +1273,7 @@ zvol_os_rename_minor(zvol_state_t *zv, const char *newname)
 	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
 
 	/* Move to a new hashtable entry.  */
-	zv->zv_hash = zvol_name_hash(zv->zv_name);
+	zv->zv_hash = zvol_name_hash(newname);
 	hlist_del(&zv->zv_hlink);
 	hlist_add_head(&zv->zv_hlink, ZVOL_HT_HEAD(zv->zv_hash));
 
diff --git a/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c b/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c
index d18f935b167c..0e44aa1fcd38 100644
--- a/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c
+++ b/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c
@@ -36,12 +36,12 @@ static int spl_taskq_thread_bind = 0;
 module_param(spl_taskq_thread_bind, int, 0644);
 MODULE_PARM_DESC(spl_taskq_thread_bind, "Bind taskq thread to CPU by default");
 
-static uint_t spl_taskq_thread_timeout_ms = 10000;
+static uint_t spl_taskq_thread_timeout_ms = 5000;
 /* BEGIN CSTYLED */
 module_param(spl_taskq_thread_timeout_ms, uint, 0644);
 /* END CSTYLED */
 MODULE_PARM_DESC(spl_taskq_thread_timeout_ms,
-	"Time to require a dynamic thread be idle before it gets cleaned up");
+	"Minimum idle threads exit interval for dynamic taskqs");
 
 static int spl_taskq_thread_dynamic = 1;
 module_param(spl_taskq_thread_dynamic, int, 0444);
@@ -594,8 +594,7 @@ taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t flags)
 	ASSERT(tq->tq_nactive <= tq->tq_nthreads);
 	if ((flags & TQ_NOQUEUE) && (tq->tq_nactive == tq->tq_nthreads)) {
 		/* Dynamic taskq may be able to spawn another thread */
-		if (!(tq->tq_flags & TASKQ_DYNAMIC) ||
-		    taskq_thread_spawn(tq) == 0)
+		if (taskq_thread_spawn(tq) == 0)
 			goto out;
 	}
 
@@ -629,11 +628,11 @@ taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t flags)
 	spin_unlock(&t->tqent_lock);
 
 	wake_up(&tq->tq_work_waitq);
-out:
+
 	/* Spawn additional taskq threads if required. */
 	if (!(flags & TQ_NOQUEUE) && tq->tq_nactive == tq->tq_nthreads)
 		(void) taskq_thread_spawn(tq);
-
+out:
 	spin_unlock_irqrestore(&tq->tq_lock, irqflags);
 	return (rc);
 }
@@ -676,10 +675,11 @@ taskq_dispatch_delay(taskq_t *tq, task_func_t func, void *arg,
 	ASSERT(!(t->tqent_flags & TQENT_FLAG_PREALLOC));
 
 	spin_unlock(&t->tqent_lock);
-out:
+
 	/* Spawn additional taskq threads if required. */
 	if (tq->tq_nactive == tq->tq_nthreads)
 		(void) taskq_thread_spawn(tq);
+out:
 	spin_unlock_irqrestore(&tq->tq_lock, irqflags);
 	return (rc);
 }
@@ -704,9 +704,8 @@ taskq_dispatch_ent(taskq_t *tq, task_func_t func, void *arg, uint_t flags,
 
 	if ((flags & TQ_NOQUEUE) && (tq->tq_nactive == tq->tq_nthreads)) {
 		/* Dynamic taskq may be able to spawn another thread */
-		if (!(tq->tq_flags & TASKQ_DYNAMIC) ||
-		    taskq_thread_spawn(tq) == 0)
-			goto out2;
+		if (taskq_thread_spawn(tq) == 0)
+			goto out;
 		flags |= TQ_FRONT;
 	}
 
@@ -742,11 +741,11 @@ taskq_dispatch_ent(taskq_t *tq, task_func_t func, void *arg, uint_t flags,
 	spin_unlock(&t->tqent_lock);
 
 	wake_up(&tq->tq_work_waitq);
-out:
+
 	/* Spawn additional taskq threads if required. */
 	if (tq->tq_nactive == tq->tq_nthreads)
 		(void) taskq_thread_spawn(tq);
-out2:
+out:
 	spin_unlock_irqrestore(&tq->tq_lock, irqflags);
 }
 EXPORT_SYMBOL(taskq_dispatch_ent);
@@ -825,6 +824,7 @@ taskq_thread_spawn(taskq_t *tq)
 	if (!(tq->tq_flags & TASKQ_DYNAMIC))
 		return (0);
 
+	tq->lastspawnstop = jiffies;
 	if ((tq->tq_nthreads + tq->tq_nspawn < tq->tq_maxthreads) &&
 	    (tq->tq_flags & TASKQ_ACTIVE)) {
 		spawning = (++tq->tq_nspawn);
@@ -836,9 +836,9 @@ taskq_thread_spawn(taskq_t *tq)
 }
 
 /*
- * Threads in a dynamic taskq should only exit once it has been completely
- * drained and no other threads are actively servicing tasks.  This prevents
- * threads from being created and destroyed more than is required.
+ * Threads in a dynamic taskq may exit once there is no more work to do.
+ * To prevent threads from being created and destroyed too often limit
+ * the exit rate to one per spl_taskq_thread_timeout_ms.
  *
  * The first thread is the thread list is treated as the primary thread.
  * There is nothing special about the primary thread but in order to avoid
@@ -847,44 +847,22 @@ taskq_thread_spawn(taskq_t *tq)
 static int
 taskq_thread_should_stop(taskq_t *tq, taskq_thread_t *tqt)
 {
-	if (!(tq->tq_flags & TASKQ_DYNAMIC))
+	ASSERT(!taskq_next_ent(tq));
+	if (!(tq->tq_flags & TASKQ_DYNAMIC) || !spl_taskq_thread_dynamic)
 		return (0);
-
+	if (!(tq->tq_flags & TASKQ_ACTIVE))
+		return (1);
 	if (list_first_entry(&(tq->tq_thread_list), taskq_thread_t,
 	    tqt_thread_list) == tqt)
 		return (0);
-
-	int no_work =
-	    ((tq->tq_nspawn == 0) &&	/* No threads are being spawned */
-	    (tq->tq_nactive == 0) &&	/* No threads are handling tasks */
-	    (tq->tq_nthreads > 1) &&	/* More than 1 thread is running */
-	    (!taskq_next_ent(tq)) &&	/* There are no pending tasks */
-	    (spl_taskq_thread_dynamic)); /* Dynamic taskqs are allowed */
-
-	/*
-	 * If we would have said stop before, let's instead wait a bit, maybe
-	 * we'll see more work come our way soon...
-	 */
-	if (no_work) {
-		/* if it's 0, we want the old behavior. */
-		/* if the taskq is being torn down, we also want to go away. */
-		if (spl_taskq_thread_timeout_ms == 0 ||
-		    !(tq->tq_flags & TASKQ_ACTIVE))
-			return (1);
-		unsigned long lasttime = tq->lastshouldstop;
-		if (lasttime > 0) {
-			if (time_after(jiffies, lasttime +
-			    msecs_to_jiffies(spl_taskq_thread_timeout_ms)))
-				return (1);
-			else
-				return (0);
-		} else {
-			tq->lastshouldstop = jiffies;
-		}
-	} else {
-		tq->lastshouldstop = 0;
-	}
-	return (0);
+	ASSERT3U(tq->tq_nthreads, >, 1);
+	if (tq->tq_nspawn != 0)
+		return (0);
+	if (time_before(jiffies, tq->lastspawnstop +
+	    msecs_to_jiffies(spl_taskq_thread_timeout_ms)))
+		return (0);
+	tq->lastspawnstop = jiffies;
+	return (1);
 }
 
 static int
@@ -935,10 +913,8 @@ taskq_thread(void *args)
 		if (list_empty(&tq->tq_pend_list) &&
 		    list_empty(&tq->tq_prio_list)) {
 
-			if (taskq_thread_should_stop(tq, tqt)) {
-				wake_up_all(&tq->tq_wait_waitq);
+			if (taskq_thread_should_stop(tq, tqt))
 				break;
-			}
 
 			add_wait_queue_exclusive(&tq->tq_work_waitq, &wait);
 			spin_unlock_irqrestore(&tq->tq_lock, flags);
@@ -1013,9 +989,6 @@ taskq_thread(void *args)
 			tqt->tqt_id = TASKQID_INVALID;
 			tqt->tqt_flags = 0;
 			wake_up_all(&tq->tq_wait_waitq);
-		} else {
-			if (taskq_thread_should_stop(tq, tqt))
-				break;
 		}
 
 		set_current_state(TASK_INTERRUPTIBLE);
@@ -1122,7 +1095,7 @@ taskq_create(const char *name, int threads_arg, pri_t pri,
 	tq->tq_flags = (flags | TASKQ_ACTIVE);
 	tq->tq_next_id = TASKQID_INITIAL;
 	tq->tq_lowest_id = TASKQID_INITIAL;
-	tq->lastshouldstop = 0;
+	tq->lastspawnstop = jiffies;
 	INIT_LIST_HEAD(&tq->tq_free_list);
 	INIT_LIST_HEAD(&tq->tq_pend_list);
 	INIT_LIST_HEAD(&tq->tq_prio_list);
diff --git a/sys/contrib/openzfs/module/os/linux/spl/spl-xdr.c b/sys/contrib/openzfs/module/os/linux/spl/spl-xdr.c
index 6b77524181db..e1773da5d173 100644
--- a/sys/contrib/openzfs/module/os/linux/spl/spl-xdr.c
+++ b/sys/contrib/openzfs/module/os/linux/spl/spl-xdr.c
@@ -25,6 +25,7 @@
 #include <sys/debug.h>
 #include <sys/types.h>
 #include <sys/sysmacros.h>
+#include <rpc/types.h>
 #include <rpc/xdr.h>
 
 /*
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/abd_os.c b/sys/contrib/openzfs/module/os/linux/zfs/abd_os.c
index 24390fbbf125..d3255dcbc0f7 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/abd_os.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/abd_os.c
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
  * Copyright (c) 2019 by Delphix. All rights reserved.
+ * Copyright (c) 2023, 2024, Klara Inc.
  */
 
 /*
@@ -59,7 +60,9 @@
 #include <sys/zfs_znode.h>
 #ifdef _KERNEL
 #include <linux/kmap_compat.h>
+#include <linux/mm_compat.h>
 #include <linux/scatterlist.h>
+#include <linux/version.h>
 #endif
 
 #ifdef _KERNEL
@@ -895,14 +898,9 @@ abd_iter_init(struct abd_iter *aiter, abd_t *abd)
 {
 	ASSERT(!abd_is_gang(abd));
 	abd_verify(abd);
+	memset(aiter, 0, sizeof (struct abd_iter));
 	aiter->iter_abd = abd;
-	aiter->iter_mapaddr = NULL;
-	aiter->iter_mapsize = 0;
-	aiter->iter_pos = 0;
-	if (abd_is_linear(abd)) {
-		aiter->iter_offset = 0;
-		aiter->iter_sg = NULL;
-	} else {
+	if (!abd_is_linear(abd)) {
 		aiter->iter_offset = ABD_SCATTER(abd).abd_offset;
 		aiter->iter_sg = ABD_SCATTER(abd).abd_sgl;
 	}
@@ -915,6 +913,7 @@ abd_iter_init(struct abd_iter *aiter, abd_t *abd)
 boolean_t
 abd_iter_at_end(struct abd_iter *aiter)
 {
+	ASSERT3U(aiter->iter_pos, <=, aiter->iter_abd->abd_size);
 	return (aiter->iter_pos == aiter->iter_abd->abd_size);
 }
 
@@ -926,8 +925,15 @@ abd_iter_at_end(struct abd_iter *aiter)
 void
 abd_iter_advance(struct abd_iter *aiter, size_t amount)
 {
+	/*
+	 * Ensure that last chunk is not in use. abd_iterate_*() must clear
+	 * this state (directly or abd_iter_unmap()) before advancing.
+	 */
 	ASSERT3P(aiter->iter_mapaddr, ==, NULL);
 	ASSERT0(aiter->iter_mapsize);
+	ASSERT3P(aiter->iter_page, ==, NULL);
+	ASSERT0(aiter->iter_page_doff);
+	ASSERT0(aiter->iter_page_dsize);
 
 	/* There's nothing left to advance to, so do nothing */
 	if (abd_iter_at_end(aiter))
@@ -1010,6 +1016,106 @@ abd_cache_reap_now(void)
 
 #if defined(_KERNEL)
 /*
+ * Yield the next page struct and data offset and size within it, without
+ * mapping it into the address space.
+ */
+void
+abd_iter_page(struct abd_iter *aiter)
+{
+	if (abd_iter_at_end(aiter)) {
+		aiter->iter_page = NULL;
+		aiter->iter_page_doff = 0;
+		aiter->iter_page_dsize = 0;
+		return;
+	}
+
+	struct page *page;
+	size_t doff, dsize;
+
+	if (abd_is_linear(aiter->iter_abd)) {
+		ASSERT3U(aiter->iter_pos, ==, aiter->iter_offset);
+
+		/* memory address at iter_pos */
+		void *paddr = ABD_LINEAR_BUF(aiter->iter_abd) + aiter->iter_pos;
+
+		/* struct page for address */
+		page = is_vmalloc_addr(paddr) ?
+		    vmalloc_to_page(paddr) : virt_to_page(paddr);
+
+		/* offset of address within the page */
+		doff = offset_in_page(paddr);
+
+		/* total data remaining in abd from this position */
+		dsize = aiter->iter_abd->abd_size - aiter->iter_offset;
+	} else {
+		ASSERT(!abd_is_gang(aiter->iter_abd));
+
+		/* current scatter page */
+		page = sg_page(aiter->iter_sg);
+
+		/* position within page */
+		doff = aiter->iter_offset;
+
+		/* remaining data in scatterlist */
+		dsize = MIN(aiter->iter_sg->length - aiter->iter_offset,
+		    aiter->iter_abd->abd_size - aiter->iter_pos);
+	}
+	ASSERT(page);
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)
+	if (PageTail(page)) {
+		/*
+		 * This page is part of a "compound page", which is a group of
+		 * pages that can be referenced from a single struct page *.
+		 * Its organised as a "head" page, followed by a series of
+		 * "tail" pages.
+		 *
+		 * In OpenZFS, compound pages are allocated using the
+		 * __GFP_COMP flag, which we get from scatter ABDs and SPL
+		 * vmalloc slabs (ie >16K allocations). So a great many of the
+		 * IO buffers we get are going to be of this type.
+		 *
+		 * The tail pages are just regular PAGE_SIZE pages, and can be
+		 * safely used as-is. However, the head page has length
+		 * covering itself and all the tail pages. If this ABD chunk
+		 * spans multiple pages, then we can use the head page and a
+		 * >PAGE_SIZE length, which is far more efficient.
+		 *
+		 * To do this, we need to adjust the offset to be counted from
+		 * the head page. struct page for compound pages are stored
+		 * contiguously, so we can just adjust by a simple offset.
+		 *
+		 * Before kernel 4.5, compound page heads were refcounted
+		 * separately, such that moving back to the head page would
+		 * require us to take a reference to it and releasing it once
+		 * we're completely finished with it. In practice, that means
+		 * when our caller is done with the ABD, which we have no
+		 * insight into from here. Rather than contort this API to
+		 * track head page references on such ancient kernels, we just
+		 * compile this block out and use the tail pages directly. This
+		 * is slightly less efficient, but makes everything far
+		 * simpler.
+		 */
+		struct page *head = compound_head(page);
+		doff += ((page - head) * PAGESIZE);
+		page = head;
+	}
+#endif
+
+	/* final page and position within it */
+	aiter->iter_page = page;
+	aiter->iter_page_doff = doff;
+
+	/* amount of data in the chunk, up to the end of the page */
+	aiter->iter_page_dsize = MIN(dsize, page_size(page) - doff);
+}
+
+/*
+ * Note: ABD BIO functions only needed to support vdev_classic. See comments in
+ * vdev_disk.c.
+ */
+
+/*
  * bio_nr_pages for ABD.
  * @off is the offset in @abd
  */
@@ -1163,4 +1269,5 @@ MODULE_PARM_DESC(zfs_abd_scatter_min_size,
 module_param(zfs_abd_scatter_max_order, uint, 0644);
 MODULE_PARM_DESC(zfs_abd_scatter_max_order,
 	"Maximum order allocation used for a scatter ABD.");
-#endif
+
+#endif /* _KERNEL */
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/vdev_disk.c b/sys/contrib/openzfs/module/os/linux/zfs/vdev_disk.c
index b0bda5fa2012..943e534ef5b0 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/vdev_disk.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/vdev_disk.c
@@ -24,6 +24,7 @@
  * Rewritten for Linux by Brian Behlendorf <behlendorf1@llnl.gov>.
  * LLNL-CODE-403049.
  * Copyright (c) 2012, 2019 by Delphix. All rights reserved.
+ * Copyright (c) 2023, 2024, Klara Inc.
  */
 
 #include <sys/zfs_context.h>
@@ -44,15 +45,25 @@
 /*
  * Linux 6.8.x uses a bdev_handle as an instance/refcount for an underlying
  * block_device. Since it carries the block_device inside, its convenient to
- * just use the handle as a proxy. For pre-6.8, we just emulate this with
- * a cast, since we don't need any of the other fields inside the handle.
+ * just use the handle as a proxy.
+ *
+ * Linux 6.9.x uses a file for the same purpose.
+ *
+ * For pre-6.8, we just emulate this with a cast, since we don't need any of
+ * the other fields inside the handle.
  */
-#ifdef HAVE_BDEV_OPEN_BY_PATH
+#if defined(HAVE_BDEV_OPEN_BY_PATH)
 typedef struct bdev_handle zfs_bdev_handle_t;
 #define	BDH_BDEV(bdh)		((bdh)->bdev)
 #define	BDH_IS_ERR(bdh)		(IS_ERR(bdh))
 #define	BDH_PTR_ERR(bdh)	(PTR_ERR(bdh))
 #define	BDH_ERR_PTR(err)	(ERR_PTR(err))
+#elif defined(HAVE_BDEV_FILE_OPEN_BY_PATH)
+typedef struct file zfs_bdev_handle_t;
+#define	BDH_BDEV(bdh)		(file_bdev(bdh))
+#define	BDH_IS_ERR(bdh)		(IS_ERR(bdh))
+#define	BDH_PTR_ERR(bdh)	(PTR_ERR(bdh))
+#define	BDH_ERR_PTR(err)	(ERR_PTR(err))
 #else
 typedef void zfs_bdev_handle_t;
 #define	BDH_BDEV(bdh)		((struct block_device *)bdh)
@@ -67,6 +78,13 @@ typedef struct vdev_disk {
 } vdev_disk_t;
 
 /*
+ * Maximum number of segments to add to a bio (min 4). If this is higher than
+ * the maximum allowed by the device queue or the kernel itself, it will be
+ * clamped. Setting it to zero will cause the kernel's ideal size to be used.
+ */
+uint_t zfs_vdev_disk_max_segs = 0;
+
+/*
  * Unique identifier for the exclusive vdev holder.
  */
 static void *zfs_vdev_holder = VDEV_HOLDER;
@@ -84,54 +102,46 @@ static uint_t zfs_vdev_open_timeout_ms = 1000;
 #define	EFI_MIN_RESV_SIZE	(16 * 1024)
 
 /*
- * Virtual device vector for disks.
- */
-typedef struct dio_request {
-	zio_t			*dr_zio;	/* Parent ZIO */
-	atomic_t		dr_ref;		/* References */
-	int			dr_error;	/* Bio error */
-	int			dr_bio_count;	/* Count of bio's */
-	struct bio		*dr_bio[];	/* Attached bio's */
-} dio_request_t;
-
-/*
  * BIO request failfast mask.
  */
 
 static unsigned int zfs_vdev_failfast_mask = 1;
 
+/*
+ * Convert SPA mode flags into bdev open mode flags.
+ */
 #ifdef HAVE_BLK_MODE_T
-static blk_mode_t
+typedef blk_mode_t vdev_bdev_mode_t;
+#define	VDEV_BDEV_MODE_READ	BLK_OPEN_READ
+#define	VDEV_BDEV_MODE_WRITE	BLK_OPEN_WRITE
+#define	VDEV_BDEV_MODE_EXCL	BLK_OPEN_EXCL
+#define	VDEV_BDEV_MODE_MASK	(BLK_OPEN_READ|BLK_OPEN_WRITE|BLK_OPEN_EXCL)
 #else
-static fmode_t
+typedef fmode_t vdev_bdev_mode_t;
+#define	VDEV_BDEV_MODE_READ	FMODE_READ
+#define	VDEV_BDEV_MODE_WRITE	FMODE_WRITE
+#define	VDEV_BDEV_MODE_EXCL	FMODE_EXCL
+#define	VDEV_BDEV_MODE_MASK	(FMODE_READ|FMODE_WRITE|FMODE_EXCL)
 #endif
-vdev_bdev_mode(spa_mode_t spa_mode, boolean_t exclusive)
-{
-#ifdef HAVE_BLK_MODE_T
-	blk_mode_t mode = 0;
 
-	if (spa_mode & SPA_MODE_READ)
-		mode |= BLK_OPEN_READ;
-
-	if (spa_mode & SPA_MODE_WRITE)
-		mode |= BLK_OPEN_WRITE;
+static vdev_bdev_mode_t
+vdev_bdev_mode(spa_mode_t smode)
+{
+	ASSERT3U(smode, !=, SPA_MODE_UNINIT);
+	ASSERT0(smode & ~(SPA_MODE_READ|SPA_MODE_WRITE));
 
-	if (exclusive)
-		mode |= BLK_OPEN_EXCL;
-#else
-	fmode_t mode = 0;
+	vdev_bdev_mode_t bmode = VDEV_BDEV_MODE_EXCL;
 
-	if (spa_mode & SPA_MODE_READ)
-		mode |= FMODE_READ;
+	if (smode & SPA_MODE_READ)
+		bmode |= VDEV_BDEV_MODE_READ;
 
-	if (spa_mode & SPA_MODE_WRITE)
-		mode |= FMODE_WRITE;
+	if (smode & SPA_MODE_WRITE)
+		bmode |= VDEV_BDEV_MODE_WRITE;
 
-	if (exclusive)
-		mode |= FMODE_EXCL;
-#endif
+	ASSERT(bmode & VDEV_BDEV_MODE_MASK);
+	ASSERT0(bmode & ~VDEV_BDEV_MODE_MASK);
 
-	return (mode);
+	return (bmode);
 }
 
 /*
@@ -238,30 +248,32 @@ vdev_disk_kobj_evt_post(vdev_t *v)
 }
 
 static zfs_bdev_handle_t *
-vdev_blkdev_get_by_path(const char *path, spa_mode_t mode, void *holder)
+vdev_blkdev_get_by_path(const char *path, spa_mode_t smode, void *holder)
 {
-#if defined(HAVE_BDEV_OPEN_BY_PATH)
-	return (bdev_open_by_path(path,
-	    vdev_bdev_mode(mode, B_TRUE), holder, NULL));
+	vdev_bdev_mode_t bmode = vdev_bdev_mode(smode);
+
+#if defined(HAVE_BDEV_FILE_OPEN_BY_PATH)
+	return (bdev_file_open_by_path(path, bmode, holder, NULL));
+#elif defined(HAVE_BDEV_OPEN_BY_PATH)
+	return (bdev_open_by_path(path, bmode, holder, NULL));
 #elif defined(HAVE_BLKDEV_GET_BY_PATH_4ARG)
-	return (blkdev_get_by_path(path,
-	    vdev_bdev_mode(mode, B_TRUE), holder, NULL));
+	return (blkdev_get_by_path(path, bmode, holder, NULL));
 #else
-	return (blkdev_get_by_path(path,
-	    vdev_bdev_mode(mode, B_TRUE), holder));
+	return (blkdev_get_by_path(path, bmode, holder));
 #endif
 }
 
 static void
-vdev_blkdev_put(zfs_bdev_handle_t *bdh, spa_mode_t mode, void *holder)
+vdev_blkdev_put(zfs_bdev_handle_t *bdh, spa_mode_t smode, void *holder)
 {
 #if defined(HAVE_BDEV_RELEASE)
 	return (bdev_release(bdh));
 #elif defined(HAVE_BLKDEV_PUT_HOLDER)
 	return (blkdev_put(BDH_BDEV(bdh), holder));
+#elif defined(HAVE_BLKDEV_PUT)
+	return (blkdev_put(BDH_BDEV(bdh), vdev_bdev_mode(smode)));
 #else
-	return (blkdev_put(BDH_BDEV(bdh),
-	    vdev_bdev_mode(mode, B_TRUE)));
+	fput(bdh);
 #endif
 }
 
@@ -270,11 +282,7 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
     uint64_t *logical_ashift, uint64_t *physical_ashift)
 {
 	zfs_bdev_handle_t *bdh;
-#ifdef HAVE_BLK_MODE_T
-	blk_mode_t mode = vdev_bdev_mode(spa_mode(v->vdev_spa), B_FALSE);
-#else
-	fmode_t mode = vdev_bdev_mode(spa_mode(v->vdev_spa), B_FALSE);
-#endif
+	spa_mode_t smode = spa_mode(v->vdev_spa);
 	hrtime_t timeout = MSEC2NSEC(zfs_vdev_open_timeout_ms);
 	vdev_disk_t *vd;
 
@@ -325,16 +333,16 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 					reread_part = B_TRUE;
 			}
 
-			vdev_blkdev_put(bdh, mode, zfs_vdev_holder);
+			vdev_blkdev_put(bdh, smode, zfs_vdev_holder);
 		}
 
 		if (reread_part) {
-			bdh = vdev_blkdev_get_by_path(disk_name, mode,
+			bdh = vdev_blkdev_get_by_path(disk_name, smode,
 			    zfs_vdev_holder);
 			if (!BDH_IS_ERR(bdh)) {
 				int error =
 				    vdev_bdev_reread_part(BDH_BDEV(bdh));
-				vdev_blkdev_put(bdh, mode, zfs_vdev_holder);
+				vdev_blkdev_put(bdh, smode, zfs_vdev_holder);
 				if (error == 0) {
 					timeout = MSEC2NSEC(
 					    zfs_vdev_open_timeout_ms * 2);
@@ -379,7 +387,7 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 	hrtime_t start = gethrtime();
 	bdh = BDH_ERR_PTR(-ENXIO);
 	while (BDH_IS_ERR(bdh) && ((gethrtime() - start) < timeout)) {
-		bdh = vdev_blkdev_get_by_path(v->vdev_path, mode,
+		bdh = vdev_blkdev_get_by_path(v->vdev_path, smode,
 		    zfs_vdev_holder);
 		if (unlikely(BDH_PTR_ERR(bdh) == -ENOENT)) {
 			/*
@@ -457,95 +465,15 @@ vdev_disk_close(vdev_t *v)
 	if (v->vdev_reopening || vd == NULL)
 		return;
 
-	if (vd->vd_bdh != NULL) {
+	if (vd->vd_bdh != NULL)
 		vdev_blkdev_put(vd->vd_bdh, spa_mode(v->vdev_spa),
 		    zfs_vdev_holder);
-	}
 
 	rw_destroy(&vd->vd_lock);
 	kmem_free(vd, sizeof (vdev_disk_t));
 	v->vdev_tsd = NULL;
 }
 
-static dio_request_t *
-vdev_disk_dio_alloc(int bio_count)
-{
-	dio_request_t *dr = kmem_zalloc(sizeof (dio_request_t) +
-	    sizeof (struct bio *) * bio_count, KM_SLEEP);
-	atomic_set(&dr->dr_ref, 0);
-	dr->dr_bio_count = bio_count;
-	dr->dr_error = 0;
-
-	for (int i = 0; i < dr->dr_bio_count; i++)
-		dr->dr_bio[i] = NULL;
-
-	return (dr);
-}
-
-static void
-vdev_disk_dio_free(dio_request_t *dr)
-{
-	int i;
-
-	for (i = 0; i < dr->dr_bio_count; i++)
-		if (dr->dr_bio[i])
-			bio_put(dr->dr_bio[i]);
-
-	kmem_free(dr, sizeof (dio_request_t) +
-	    sizeof (struct bio *) * dr->dr_bio_count);
-}
-
-static void
-vdev_disk_dio_get(dio_request_t *dr)
-{
-	atomic_inc(&dr->dr_ref);
-}
-
-static void
-vdev_disk_dio_put(dio_request_t *dr)
-{
-	int rc = atomic_dec_return(&dr->dr_ref);
-
-	/*
-	 * Free the dio_request when the last reference is dropped and
-	 * ensure zio_interpret is called only once with the correct zio
-	 */
-	if (rc == 0) {
-		zio_t *zio = dr->dr_zio;
-		int error = dr->dr_error;
-
-		vdev_disk_dio_free(dr);
-
-		if (zio) {
-			zio->io_error = error;
-			ASSERT3S(zio->io_error, >=, 0);
-			if (zio->io_error)
-				vdev_disk_error(zio);
-
-			zio_delay_interrupt(zio);
-		}
-	}
-}
-
-BIO_END_IO_PROTO(vdev_disk_physio_completion, bio, error)
-{
-	dio_request_t *dr = bio->bi_private;
-
-	if (dr->dr_error == 0) {
-#ifdef HAVE_1ARG_BIO_END_IO_T
-		dr->dr_error = BIO_END_IO_ERROR(bio);
-#else
-		if (error)
-			dr->dr_error = -(error);
-		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
-			dr->dr_error = EIO;
-#endif
-	}
-
-	/* Drop reference acquired by __vdev_disk_physio */
-	vdev_disk_dio_put(dr);
-}
-
 static inline void
 vdev_submit_bio_impl(struct bio *bio)
 {
@@ -697,8 +625,463 @@ vdev_bio_alloc(struct block_device *bdev, gfp_t gfp_mask,
 	return (bio);
 }
 
+static inline uint_t
+vdev_bio_max_segs(struct block_device *bdev)
+{
+	/*
+	 * Smallest of the device max segs and the tuneable max segs. Minimum
+	 * 4, so there's room to finish split pages if they come up.
+	 */
+	const uint_t dev_max_segs = queue_max_segments(bdev_get_queue(bdev));
+	const uint_t tune_max_segs = (zfs_vdev_disk_max_segs > 0) ?
+	    MAX(4, zfs_vdev_disk_max_segs) : dev_max_segs;
+	const uint_t max_segs = MIN(tune_max_segs, dev_max_segs);
+
+#ifdef HAVE_BIO_MAX_SEGS
+	return (bio_max_segs(max_segs));
+#else
+	return (MIN(max_segs, BIO_MAX_PAGES));
+#endif
+}
+
+static inline uint_t
+vdev_bio_max_bytes(struct block_device *bdev)
+{
+	return (queue_max_sectors(bdev_get_queue(bdev)) << 9);
+}
+
+
+/*
+ * Virtual block IO object (VBIO)
+ *
+ * Linux block IO (BIO) objects have a limit on how many data segments (pages)
+ * they can hold. Depending on how they're allocated and structured, a large
+ * ZIO can require more than one BIO to be submitted to the kernel, which then
+ * all have to complete before we can return the completed ZIO back to ZFS.
+ *
+ * A VBIO is a wrapper around multiple BIOs, carrying everything needed to
+ * translate a ZIO down into the kernel block layer and back again.
+ *
+ * Note that these are only used for data ZIOs (read/write). Meta-operations
+ * (flush/trim) don't need multiple BIOs and so can just make the call
+ * directly.
+ */
+typedef struct {
+	zio_t		*vbio_zio;	/* parent zio */
+
+	struct block_device *vbio_bdev;	/* blockdev to submit bios to */
+
+	abd_t		*vbio_abd;	/* abd carrying borrowed linear buf */
+
+	uint_t		vbio_max_segs;	/* max segs per bio */
+
+	uint_t		vbio_max_bytes;	/* max bytes per bio */
+	uint_t		vbio_lbs_mask;	/* logical block size mask */
+
+	uint64_t	vbio_offset;	/* start offset of next bio */
+
+	struct bio	*vbio_bio;	/* pointer to the current bio */
+	int		vbio_flags;	/* bio flags */
+} vbio_t;
+
+static vbio_t *
+vbio_alloc(zio_t *zio, struct block_device *bdev, int flags)
+{
+	vbio_t *vbio = kmem_zalloc(sizeof (vbio_t), KM_SLEEP);
+
+	vbio->vbio_zio = zio;
+	vbio->vbio_bdev = bdev;
+	vbio->vbio_abd = NULL;
+	vbio->vbio_max_segs = vdev_bio_max_segs(bdev);
+	vbio->vbio_max_bytes = vdev_bio_max_bytes(bdev);
+	vbio->vbio_lbs_mask = ~(bdev_logical_block_size(bdev)-1);
+	vbio->vbio_offset = zio->io_offset;
+	vbio->vbio_bio = NULL;
+	vbio->vbio_flags = flags;
+
+	return (vbio);
+}
+
+BIO_END_IO_PROTO(vbio_completion, bio, error);
+
+static int
+vbio_add_page(vbio_t *vbio, struct page *page, uint_t size, uint_t offset)
+{
+	struct bio *bio = vbio->vbio_bio;
+	uint_t ssize;
+
+	while (size > 0) {
+		if (bio == NULL) {
+			/* New BIO, allocate and set up */
+			bio = vdev_bio_alloc(vbio->vbio_bdev, GFP_NOIO,
+			    vbio->vbio_max_segs);
+			VERIFY(bio);
+
+			BIO_BI_SECTOR(bio) = vbio->vbio_offset >> 9;
+			bio_set_op_attrs(bio,
+			    vbio->vbio_zio->io_type == ZIO_TYPE_WRITE ?
+			    WRITE : READ, vbio->vbio_flags);
+
+			if (vbio->vbio_bio) {
+				bio_chain(vbio->vbio_bio, bio);
+				vdev_submit_bio(vbio->vbio_bio);
+			}
+			vbio->vbio_bio = bio;
+		}
+
+		/*
+		 * Only load as much of the current page data as will fit in
+		 * the space left in the BIO, respecting lbs alignment. Older
+		 * kernels will error if we try to overfill the BIO, while
+		 * newer ones will accept it and split the BIO. This ensures
+		 * everything works on older kernels, and avoids an additional
+		 * overhead on the new.
+		 */
+		ssize = MIN(size, (vbio->vbio_max_bytes - BIO_BI_SIZE(bio)) &
+		    vbio->vbio_lbs_mask);
+		if (ssize > 0 &&
+		    bio_add_page(bio, page, ssize, offset) == ssize) {
+			/* Accepted, adjust and load any remaining. */
+			size -= ssize;
+			offset += ssize;
+			continue;
+		}
+
+		/* No room, set up for a new BIO and loop */
+		vbio->vbio_offset += BIO_BI_SIZE(bio);
+
+		/* Signal new BIO allocation wanted */
+		bio = NULL;
+	}
+
+	return (0);
+}
+
+/* Iterator callback to submit ABD pages to the vbio. */
+static int
+vbio_fill_cb(struct page *page, size_t off, size_t len, void *priv)
+{
+	vbio_t *vbio = priv;
+	return (vbio_add_page(vbio, page, len, off));
+}
+
+/* Create some BIOs, fill them with data and submit them */
+static void
+vbio_submit(vbio_t *vbio, abd_t *abd, uint64_t size)
+{
+	/*
+	 * We plug so we can submit the BIOs as we go and only unplug them when
+	 * they are fully created and submitted. This is important; if we don't
+	 * plug, then the kernel may start executing earlier BIOs while we're
+	 * still creating and executing later ones, and if the device goes
+	 * away while that's happening, older kernels can get confused and
+	 * trample memory.
+	 */
+	struct blk_plug plug;
+	blk_start_plug(&plug);
+
+	(void) abd_iterate_page_func(abd, 0, size, vbio_fill_cb, vbio);
+	ASSERT(vbio->vbio_bio);
+
+	vbio->vbio_bio->bi_end_io = vbio_completion;
+	vbio->vbio_bio->bi_private = vbio;
+
+	/*
+	 * Once submitted, vbio_bio now owns vbio (through bi_private) and we
+	 * can't touch it again. The bio may complete and vbio_completion() be
+	 * called and free the vbio before this task is run again, so we must
+	 * consider it invalid from this point.
+	 */
+	vdev_submit_bio(vbio->vbio_bio);
+
+	blk_finish_plug(&plug);
+}
+
+/* IO completion callback */
+BIO_END_IO_PROTO(vbio_completion, bio, error)
+{
+	vbio_t *vbio = bio->bi_private;
+	zio_t *zio = vbio->vbio_zio;
+
+	ASSERT(zio);
+
+	/* Capture and log any errors */
+#ifdef HAVE_1ARG_BIO_END_IO_T
+	zio->io_error = BIO_END_IO_ERROR(bio);
+#else
+	zio->io_error = 0;
+	if (error)
+		zio->io_error = -(error);
+	else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+		zio->io_error = EIO;
+#endif
+	ASSERT3U(zio->io_error, >=, 0);
+
+	if (zio->io_error)
+		vdev_disk_error(zio);
+
+	/* Return the BIO to the kernel */
+	bio_put(bio);
+
+	/*
+	 * If we copied the ABD before issuing it, clean up and return the copy
+	 * to the ADB, with changes if appropriate.
+	 */
+	if (vbio->vbio_abd != NULL) {
+		void *buf = abd_to_buf(vbio->vbio_abd);
+		abd_free(vbio->vbio_abd);
+		vbio->vbio_abd = NULL;
+
+		if (zio->io_type == ZIO_TYPE_READ)
+			abd_return_buf_copy(zio->io_abd, buf, zio->io_size);
+		else
+			abd_return_buf(zio->io_abd, buf, zio->io_size);
+	}
+
+	/* Final cleanup */
+	kmem_free(vbio, sizeof (vbio_t));
+
+	/* All done, submit for processing */
+	zio_delay_interrupt(zio);
+}
+
+/*
+ * Iterator callback to count ABD pages and check their size & alignment.
+ *
+ * On Linux, each BIO segment can take a page pointer, and an offset+length of
+ * the data within that page. A page can be arbitrarily large ("compound"
+ * pages) but we still have to ensure the data portion is correctly sized and
+ * aligned to the logical block size, to ensure that if the kernel wants to
+ * split the BIO, the two halves will still be properly aligned.
+ */
+typedef struct {
+	uint_t  bmask;
+	uint_t  npages;
+	uint_t  end;
+} vdev_disk_check_pages_t;
+
+static int
+vdev_disk_check_pages_cb(struct page *page, size_t off, size_t len, void *priv)
+{
+	vdev_disk_check_pages_t *s = priv;
+
+	/*
+	 * If we didn't finish on a block size boundary last time, then there
+	 * would be a gap if we tried to use this ABD as-is, so abort.
+	 */
+	if (s->end != 0)
+		return (1);
+
+	/*
+	 * Note if we're taking less than a full block, so we can check it
+	 * above on the next call.
+	 */
+	s->end = (off+len) & s->bmask;
+
+	/* All blocks after the first must start on a block size boundary. */
+	if (s->npages != 0 && (off & s->bmask) != 0)
+		return (1);
+
+	s->npages++;
+	return (0);
+}
+
+/*
+ * Check if we can submit the pages in this ABD to the kernel as-is. Returns
+ * the number of pages, or 0 if it can't be submitted like this.
+ */
+static boolean_t
+vdev_disk_check_pages(abd_t *abd, uint64_t size, struct block_device *bdev)
+{
+	vdev_disk_check_pages_t s = {
+	    .bmask = bdev_logical_block_size(bdev)-1,
+	    .npages = 0,
+	    .end = 0,
+	};
+
+	if (abd_iterate_page_func(abd, 0, size, vdev_disk_check_pages_cb, &s))
+		return (B_FALSE);
+
+	return (B_TRUE);
+}
+
+static int
+vdev_disk_io_rw(zio_t *zio)
+{
+	vdev_t *v = zio->io_vd;
+	vdev_disk_t *vd = v->vdev_tsd;
+	struct block_device *bdev = BDH_BDEV(vd->vd_bdh);
+	int flags = 0;
+
+	/*
+	 * Accessing outside the block device is never allowed.
+	 */
+	if (zio->io_offset + zio->io_size > bdev->bd_inode->i_size) {
+		vdev_dbgmsg(zio->io_vd,
+		    "Illegal access %llu size %llu, device size %llu",
+		    (u_longlong_t)zio->io_offset,
+		    (u_longlong_t)zio->io_size,
+		    (u_longlong_t)i_size_read(bdev->bd_inode));
+		return (SET_ERROR(EIO));
+	}
+
+	if (!(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)) &&
+	    v->vdev_failfast == B_TRUE) {
+		bio_set_flags_failfast(bdev, &flags, zfs_vdev_failfast_mask & 1,
+		    zfs_vdev_failfast_mask & 2, zfs_vdev_failfast_mask & 4);
+	}
+
+	/*
+	 * Check alignment of the incoming ABD. If any part of it would require
+	 * submitting a page that is not aligned to the logical block size,
+	 * then we take a copy into a linear buffer and submit that instead.
+	 * This should be impossible on a 512b LBS, and fairly rare on 4K,
+	 * usually requiring abnormally-small data blocks (eg gang blocks)
+	 * mixed into the same ABD as larger ones (eg aggregated).
+	 */
+	abd_t *abd = zio->io_abd;
+	if (!vdev_disk_check_pages(abd, zio->io_size, bdev)) {
+		void *buf;
+		if (zio->io_type == ZIO_TYPE_READ)
+			buf = abd_borrow_buf(zio->io_abd, zio->io_size);
+		else
+			buf = abd_borrow_buf_copy(zio->io_abd, zio->io_size);
+
+		/*
+		 * Wrap the copy in an abd_t, so we can use the same iterators
+		 * to count and fill the vbio later.
+		 */
+		abd = abd_get_from_buf(buf, zio->io_size);
+
+		/*
+		 * False here would mean the borrowed copy has an invalid
+		 * alignment too, which would mean we've somehow been passed a
+		 * linear ABD with an interior page that has a non-zero offset
+		 * or a size not a multiple of PAGE_SIZE. This is not possible.
+		 * It would mean either zio_buf_alloc() or its underlying
+		 * allocators have done something extremely strange, or our
+		 * math in vdev_disk_check_pages() is wrong. In either case,
+		 * something in seriously wrong and its not safe to continue.
+		 */
+		VERIFY(vdev_disk_check_pages(abd, zio->io_size, bdev));
+	}
+
+	/* Allocate vbio, with a pointer to the borrowed ABD if necessary */
+	vbio_t *vbio = vbio_alloc(zio, bdev, flags);
+	if (abd != zio->io_abd)
+		vbio->vbio_abd = abd;
+
+	/* Fill it with data pages and submit it to the kernel */
+	vbio_submit(vbio, abd, zio->io_size);
+	return (0);
+}
+
+/* ========== */
+
+/*
+ * This is the classic, battle-tested BIO submission code. Until we're totally
+ * sure that the new code is safe and correct in all cases, this will remain
+ * available.
+ *
+ * It is enabled by setting zfs_vdev_disk_classic=1 at module load time. It is
+ * enabled (=1) by default since 2.2.4, and disabled by default (=0) on master.
+ *
+ * These functions have been renamed to vdev_classic_* to make it clear what
+ * they belong to, but their implementations are unchanged.
+ */
+
+/*
+ * Virtual device vector for disks.
+ */
+typedef struct dio_request {
+	zio_t			*dr_zio;	/* Parent ZIO */
+	atomic_t		dr_ref;		/* References */
+	int			dr_error;	/* Bio error */
+	int			dr_bio_count;	/* Count of bio's */
+	struct bio		*dr_bio[];	/* Attached bio's */
+} dio_request_t;
+
+static dio_request_t *
+vdev_classic_dio_alloc(int bio_count)
+{
+	dio_request_t *dr = kmem_zalloc(sizeof (dio_request_t) +
+	    sizeof (struct bio *) * bio_count, KM_SLEEP);
+	atomic_set(&dr->dr_ref, 0);
+	dr->dr_bio_count = bio_count;
+	dr->dr_error = 0;
+
+	for (int i = 0; i < dr->dr_bio_count; i++)
+		dr->dr_bio[i] = NULL;
+
+	return (dr);
+}
+
+static void
+vdev_classic_dio_free(dio_request_t *dr)
+{
+	int i;
+
+	for (i = 0; i < dr->dr_bio_count; i++)
+		if (dr->dr_bio[i])
+			bio_put(dr->dr_bio[i]);
+
+	kmem_free(dr, sizeof (dio_request_t) +
+	    sizeof (struct bio *) * dr->dr_bio_count);
+}
+
+static void
+vdev_classic_dio_get(dio_request_t *dr)
+{
+	atomic_inc(&dr->dr_ref);
+}
+
+static void
+vdev_classic_dio_put(dio_request_t *dr)
+{
+	int rc = atomic_dec_return(&dr->dr_ref);
+
+	/*
+	 * Free the dio_request when the last reference is dropped and
+	 * ensure zio_interpret is called only once with the correct zio
+	 */
+	if (rc == 0) {
+		zio_t *zio = dr->dr_zio;
+		int error = dr->dr_error;
+
+		vdev_classic_dio_free(dr);
+
+		if (zio) {
+			zio->io_error = error;
+			ASSERT3S(zio->io_error, >=, 0);
+			if (zio->io_error)
+				vdev_disk_error(zio);
+
+			zio_delay_interrupt(zio);
+		}
+	}
+}
+
+BIO_END_IO_PROTO(vdev_classic_physio_completion, bio, error)
+{
+	dio_request_t *dr = bio->bi_private;
+
+	if (dr->dr_error == 0) {
+#ifdef HAVE_1ARG_BIO_END_IO_T
+		dr->dr_error = BIO_END_IO_ERROR(bio);
+#else
+		if (error)
+			dr->dr_error = -(error);
+		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+			dr->dr_error = EIO;
+#endif
+	}
+
+	/* Drop reference acquired by vdev_classic_physio */
+	vdev_classic_dio_put(dr);
+}
+
 static inline unsigned int
-vdev_bio_max_segs(zio_t *zio, int bio_size, uint64_t abd_offset)
+vdev_classic_bio_max_segs(zio_t *zio, int bio_size, uint64_t abd_offset)
 {
 	unsigned long nr_segs = abd_nr_pages_off(zio->io_abd,
 	    bio_size, abd_offset);
@@ -711,9 +1094,16 @@ vdev_bio_max_segs(zio_t *zio, int bio_size, uint64_t abd_offset)
 }
 
 static int
-__vdev_disk_physio(struct block_device *bdev, zio_t *zio,
-    size_t io_size, uint64_t io_offset, int rw, int flags)
+vdev_classic_physio(zio_t *zio)
 {
+	vdev_t *v = zio->io_vd;
+	vdev_disk_t *vd = v->vdev_tsd;
+	struct block_device *bdev = BDH_BDEV(vd->vd_bdh);
+	size_t io_size = zio->io_size;
+	uint64_t io_offset = zio->io_offset;
+	int rw = zio->io_type == ZIO_TYPE_READ ? READ : WRITE;
+	int flags = 0;
+
 	dio_request_t *dr;
 	uint64_t abd_offset;
 	uint64_t bio_offset;
@@ -736,7 +1126,7 @@ __vdev_disk_physio(struct block_device *bdev, zio_t *zio,
 	}
 
 retry:
-	dr = vdev_disk_dio_alloc(bio_count);
+	dr = vdev_classic_dio_alloc(bio_count);
 
 	if (!(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)) &&
 	    zio->io_vd->vdev_failfast == B_TRUE) {
@@ -771,23 +1161,23 @@ retry:
 		 * this should be rare - see the comment above.
 		 */
 		if (dr->dr_bio_count == i) {
-			vdev_disk_dio_free(dr);
+			vdev_classic_dio_free(dr);
 			bio_count *= 2;
 			goto retry;
 		}
 
-		nr_vecs = vdev_bio_max_segs(zio, bio_size, abd_offset);
+		nr_vecs = vdev_classic_bio_max_segs(zio, bio_size, abd_offset);
 		dr->dr_bio[i] = vdev_bio_alloc(bdev, GFP_NOIO, nr_vecs);
 		if (unlikely(dr->dr_bio[i] == NULL)) {
-			vdev_disk_dio_free(dr);
+			vdev_classic_dio_free(dr);
 			return (SET_ERROR(ENOMEM));
 		}
 
-		/* Matching put called by vdev_disk_physio_completion */
-		vdev_disk_dio_get(dr);
+		/* Matching put called by vdev_classic_physio_completion */
+		vdev_classic_dio_get(dr);
 
 		BIO_BI_SECTOR(dr->dr_bio[i]) = bio_offset >> 9;
-		dr->dr_bio[i]->bi_end_io = vdev_disk_physio_completion;
+		dr->dr_bio[i]->bi_end_io = vdev_classic_physio_completion;
 		dr->dr_bio[i]->bi_private = dr;
 		bio_set_op_attrs(dr->dr_bio[i], rw, flags);
 
@@ -801,7 +1191,7 @@ retry:
 	}
 
 	/* Extra reference to protect dio_request during vdev_submit_bio */
-	vdev_disk_dio_get(dr);
+	vdev_classic_dio_get(dr);
 
 	if (dr->dr_bio_count > 1)
 		blk_start_plug(&plug);
@@ -815,11 +1205,13 @@ retry:
 	if (dr->dr_bio_count > 1)
 		blk_finish_plug(&plug);
 
-	vdev_disk_dio_put(dr);
+	vdev_classic_dio_put(dr);
 
 	return (error);
 }
 
+/* ========== */
+
 BIO_END_IO_PROTO(vdev_disk_io_flush_completion, bio, error)
 {
 	zio_t *zio = bio->bi_private;
@@ -862,8 +1254,6 @@ vdev_disk_io_flush(struct block_device *bdev, zio_t *zio)
 	return (0);
 }
 
-#if defined(HAVE_BLKDEV_ISSUE_SECURE_ERASE) || \
-	defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC)
 BIO_END_IO_PROTO(vdev_disk_discard_end_io, bio, error)
 {
 	zio_t *zio = bio->bi_private;
@@ -878,62 +1268,109 @@ BIO_END_IO_PROTO(vdev_disk_discard_end_io, bio, error)
 	zio_interrupt(zio);
 }
 
+/*
+ * Wrappers for the different secure erase and discard APIs. We use async
+ * when available; in this case, *biop is set to the last bio in the chain.
+ */
 static int
-vdev_issue_discard_trim(zio_t *zio, unsigned long flags)
+vdev_bdev_issue_secure_erase(zfs_bdev_handle_t *bdh, sector_t sector,
+    sector_t nsect, struct bio **biop)
 {
-	int ret;
-	struct bio *bio = NULL;
+	*biop = NULL;
+	int error;
 
-#if defined(BLKDEV_DISCARD_SECURE)
-	ret = - __blkdev_issue_discard(
-	    BDH_BDEV(((vdev_disk_t *)zio->io_vd->vdev_tsd)->vd_bdh),
-	    zio->io_offset >> 9, zio->io_size >> 9, GFP_NOFS, flags, &bio);
+#if defined(HAVE_BLKDEV_ISSUE_SECURE_ERASE)
+	error = blkdev_issue_secure_erase(BDH_BDEV(bdh),
+	    sector, nsect, GFP_NOFS);
+#elif defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_FLAGS)
+	error = __blkdev_issue_discard(BDH_BDEV(bdh),
+	    sector, nsect, GFP_NOFS, BLKDEV_DISCARD_SECURE, biop);
+#elif defined(HAVE_BLKDEV_ISSUE_DISCARD_FLAGS)
+	error = blkdev_issue_discard(BDH_BDEV(bdh),
+	    sector, nsect, GFP_NOFS, BLKDEV_DISCARD_SECURE);
 #else
-	(void) flags;
-	ret = - __blkdev_issue_discard(
-	    BDH_BDEV(((vdev_disk_t *)zio->io_vd->vdev_tsd)->vd_bdh),
-	    zio->io_offset >> 9, zio->io_size >> 9, GFP_NOFS, &bio);
+#error "unsupported kernel"
 #endif
-	if (!ret && bio) {
-		bio->bi_private = zio;
-		bio->bi_end_io = vdev_disk_discard_end_io;
-		vdev_submit_bio(bio);
-	}
-	return (ret);
+
+	return (error);
 }
+
+static int
+vdev_bdev_issue_discard(zfs_bdev_handle_t *bdh, sector_t sector,
+    sector_t nsect, struct bio **biop)
+{
+	*biop = NULL;
+	int error;
+
+#if defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_FLAGS)
+	error = __blkdev_issue_discard(BDH_BDEV(bdh),
+	    sector, nsect, GFP_NOFS, 0, biop);
+#elif defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_NOFLAGS)
+	error = __blkdev_issue_discard(BDH_BDEV(bdh),
+	    sector, nsect, GFP_NOFS, biop);
+#elif defined(HAVE_BLKDEV_ISSUE_DISCARD_FLAGS)
+	error = blkdev_issue_discard(BDH_BDEV(bdh),
+	    sector, nsect, GFP_NOFS, 0);
+#elif defined(HAVE_BLKDEV_ISSUE_DISCARD_NOFLAGS)
+	error = blkdev_issue_discard(BDH_BDEV(bdh),
+	    sector, nsect, GFP_NOFS);
+#else
+#error "unsupported kernel"
 #endif
 
+	return (error);
+}
+
+/*
+ * Entry point for TRIM ops. This calls the right wrapper for secure erase or
+ * discard, and then does the appropriate finishing work for error vs success
+ * and async vs sync.
+ */
 static int
 vdev_disk_io_trim(zio_t *zio)
 {
-	unsigned long trim_flags = 0;
-	if (zio->io_trim_flags & ZIO_TRIM_SECURE) {
-#if defined(HAVE_BLKDEV_ISSUE_SECURE_ERASE)
-		return (-blkdev_issue_secure_erase(
-		    BDH_BDEV(((vdev_disk_t *)zio->io_vd->vdev_tsd)->vd_bdh),
-		    zio->io_offset >> 9, zio->io_size >> 9, GFP_NOFS));
-#elif defined(BLKDEV_DISCARD_SECURE)
-		trim_flags |= BLKDEV_DISCARD_SECURE;
-#endif
+	int error;
+	struct bio *bio;
+
+	zfs_bdev_handle_t *bdh = ((vdev_disk_t *)zio->io_vd->vdev_tsd)->vd_bdh;
+	sector_t sector = zio->io_offset >> 9;
+	sector_t nsects = zio->io_size >> 9;
+
+	if (zio->io_trim_flags & ZIO_TRIM_SECURE)
+		error = vdev_bdev_issue_secure_erase(bdh, sector, nsects, &bio);
+	else
+		error = vdev_bdev_issue_discard(bdh, sector, nsects, &bio);
+
+	if (error != 0)
+		return (SET_ERROR(-error));
+
+	if (bio == NULL) {
+		/*
+		 * This was a synchronous op that completed successfully, so
+		 * return it to ZFS immediately.
+		 */
+		zio_interrupt(zio);
+	} else {
+		/*
+		 * This was an asynchronous op; set up completion callback and
+		 * issue it.
+		 */
+		bio->bi_private = zio;
+		bio->bi_end_io = vdev_disk_discard_end_io;
+		vdev_submit_bio(bio);
 	}
-#if defined(HAVE_BLKDEV_ISSUE_SECURE_ERASE) || \
-	defined(HAVE_BLKDEV_ISSUE_DISCARD_ASYNC)
-	return (vdev_issue_discard_trim(zio, trim_flags));
-#elif defined(HAVE_BLKDEV_ISSUE_DISCARD)
-	return (-blkdev_issue_discard(
-	    BDH_BDEV(((vdev_disk_t *)zio->io_vd->vdev_tsd)->vd_bdh),
-	    zio->io_offset >> 9, zio->io_size >> 9, GFP_NOFS, trim_flags));
-#else
-#error "Unsupported kernel"
-#endif
+
+	return (0);
 }
 
+int (*vdev_disk_io_rw_fn)(zio_t *zio) = NULL;
+
 static void
 vdev_disk_io_start(zio_t *zio)
 {
 	vdev_t *v = zio->io_vd;
 	vdev_disk_t *vd = v->vdev_tsd;
-	int rw, error;
+	int error;
 
 	/*
 	 * If the vdev is closed, it's likely in the REMOVED or FAULTED state.
@@ -996,42 +1433,44 @@ vdev_disk_io_start(zio_t *zio)
 		rw_exit(&vd->vd_lock);
 		zio_execute(zio);
 		return;
-	case ZIO_TYPE_WRITE:
-		rw = WRITE;
-		break;
-
-	case ZIO_TYPE_READ:
-		rw = READ;
-		break;
 
 	case ZIO_TYPE_TRIM:
-		zio->io_error = vdev_disk_io_trim(zio);
+		error = vdev_disk_io_trim(zio);
 		rw_exit(&vd->vd_lock);
-#if defined(HAVE_BLKDEV_ISSUE_SECURE_ERASE)
-		if (zio->io_trim_flags & ZIO_TRIM_SECURE)
+		if (error) {
+			zio->io_error = error;
+			zio_execute(zio);
+		}
+		return;
+
+	case ZIO_TYPE_READ:
+	case ZIO_TYPE_WRITE:
+		zio->io_target_timestamp = zio_handle_io_delay(zio);
+		error = vdev_disk_io_rw_fn(zio);
+		rw_exit(&vd->vd_lock);
+		if (error) {
+			zio->io_error = error;
 			zio_interrupt(zio);
-#elif defined(HAVE_BLKDEV_ISSUE_DISCARD)
-		zio_interrupt(zio);
-#endif
+		}
 		return;
 
 	default:
+		/*
+		 * Getting here means our parent vdev has made a very strange
+		 * request of us, and shouldn't happen. Assert here to force a
+		 * crash in dev builds, but in production return the IO
+		 * unhandled. The pool will likely suspend anyway but that's
+		 * nicer than crashing the kernel.
+		 */
+		ASSERT3S(zio->io_type, ==, -1);
+
 		rw_exit(&vd->vd_lock);
 		zio->io_error = SET_ERROR(ENOTSUP);
 		zio_interrupt(zio);
 		return;
 	}
 
-	zio->io_target_timestamp = zio_handle_io_delay(zio);
-	error = __vdev_disk_physio(BDH_BDEV(vd->vd_bdh), zio,
-	    zio->io_size, zio->io_offset, rw, 0);
-	rw_exit(&vd->vd_lock);
-
-	if (error) {
-		zio->io_error = error;
-		zio_interrupt(zio);
-		return;
-	}
+	__builtin_unreachable();
 }
 
 static void
@@ -1080,8 +1519,49 @@ vdev_disk_rele(vdev_t *vd)
 	/* XXX: Implement me as a vnode rele for the device */
 }
 
+/*
+ * BIO submission method. See comment above about vdev_classic.
+ * Set zfs_vdev_disk_classic=0 for new, =1 for classic
+ */
+static uint_t zfs_vdev_disk_classic = 1;	/* default classic */
+
+/* Set submission function from module parameter */
+static int
+vdev_disk_param_set_classic(const char *buf, zfs_kernel_param_t *kp)
+{
+	int err = param_set_uint(buf, kp);
+	if (err < 0)
+		return (SET_ERROR(err));
+
+	vdev_disk_io_rw_fn =
+	    zfs_vdev_disk_classic ? vdev_classic_physio : vdev_disk_io_rw;
+
+	printk(KERN_INFO "ZFS: forcing %s BIO submission\n",
+	    zfs_vdev_disk_classic ? "classic" : "new");
+
+	return (0);
+}
+
+/*
+ * At first use vdev use, set the submission function from the default value if
+ * it hasn't been set already.
+ */
+static int
+vdev_disk_init(spa_t *spa, nvlist_t *nv, void **tsd)
+{
+	(void) spa;
+	(void) nv;
+	(void) tsd;
+
+	if (vdev_disk_io_rw_fn == NULL)
+		vdev_disk_io_rw_fn = zfs_vdev_disk_classic ?
+		    vdev_classic_physio : vdev_disk_io_rw;
+
+	return (0);
+}
+
 vdev_ops_t vdev_disk_ops = {
-	.vdev_op_init = NULL,
+	.vdev_op_init = vdev_disk_init,
 	.vdev_op_fini = NULL,
 	.vdev_op_open = vdev_disk_open,
 	.vdev_op_close = vdev_disk_close,
@@ -1174,3 +1654,10 @@ ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, open_timeout_ms, UINT, ZMOD_RW,
 
 ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, failfast_mask, UINT, ZMOD_RW,
 	"Defines failfast mask: 1 - device, 2 - transport, 4 - driver");
+
+ZFS_MODULE_PARAM(zfs_vdev_disk, zfs_vdev_disk_, max_segs, UINT, ZMOD_RW,
+	"Maximum number of data segments to add to an IO request (min 4)");
+
+ZFS_MODULE_PARAM_CALL(zfs_vdev_disk, zfs_vdev_disk_, classic,
+    vdev_disk_param_set_classic, param_get_uint, ZMOD_RD,
+	"Use classic BIO submission method");
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zfs_vnops_os.c b/sys/contrib/openzfs/module/os/linux/zfs/zfs_vnops_os.c
index c06a75662bf7..be528f6e8176 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zfs_vnops_os.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zfs_vnops_os.c
@@ -1610,11 +1610,8 @@ zfs_readdir(struct inode *ip, zpl_dir_context_t *ctx, cred_t *cr)
 		if (done)
 			break;
 
-		/* Prefetch znode */
-		if (prefetch) {
-			dmu_prefetch(os, objnum, 0, 0, 0,
-			    ZIO_PRIORITY_SYNC_READ);
-		}
+		if (prefetch)
+			dmu_prefetch_dnode(os, objnum, ZIO_PRIORITY_SYNC_READ);
 
 		/*
 		 * Move to the next entry, fill in the previous offset.
@@ -3792,11 +3789,8 @@ zfs_putpage(struct inode *ip, struct page *pp, struct writeback_control *wbc,
 	dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
 	zfs_sa_upgrade_txholds(tx, zp);
 
-	err = dmu_tx_assign(tx, TXG_NOWAIT);
+	err = dmu_tx_assign(tx, TXG_WAIT);
 	if (err != 0) {
-		if (err == ERESTART)
-			dmu_tx_wait(tx);
-
 		dmu_tx_abort(tx);
 #ifdef HAVE_VFS_FILEMAP_DIRTY_FOLIO
 		filemap_dirty_folio(page_mapping(pp), page_folio(pp));
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zpl_file.c b/sys/contrib/openzfs/module/os/linux/zfs/zpl_file.c
index 3caa0fc6c214..9dec52215c7c 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zpl_file.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zpl_file.c
@@ -720,23 +720,23 @@ zpl_putpage(struct page *pp, struct writeback_control *wbc, void *data)
 {
 	boolean_t *for_sync = data;
 	fstrans_cookie_t cookie;
+	int ret;
 
 	ASSERT(PageLocked(pp));
 	ASSERT(!PageWriteback(pp));
 
 	cookie = spl_fstrans_mark();
-	(void) zfs_putpage(pp->mapping->host, pp, wbc, *for_sync);
+	ret = zfs_putpage(pp->mapping->host, pp, wbc, *for_sync);
 	spl_fstrans_unmark(cookie);
 
-	return (0);
+	return (ret);
 }
 
 #ifdef HAVE_WRITEPAGE_T_FOLIO
 static int
 zpl_putfolio(struct folio *pp, struct writeback_control *wbc, void *data)
 {
-	(void) zpl_putpage(&pp->page, wbc, data);
-	return (0);
+	return (zpl_putpage(&pp->page, wbc, data));
 }
 #endif
 
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zpl_file_range.c b/sys/contrib/openzfs/module/os/linux/zfs/zpl_file_range.c
index 3065d54fa9da..64728fdb1187 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zpl_file_range.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zpl_file_range.c
@@ -26,6 +26,9 @@
 #include <linux/compat.h>
 #endif
 #include <linux/fs.h>
+#ifdef HAVE_VFS_SPLICE_COPY_FILE_RANGE
+#include <linux/splice.h>
+#endif
 #include <sys/file.h>
 #include <sys/zfs_znode.h>
 #include <sys/zfs_vnops.h>
@@ -102,7 +105,7 @@ zpl_copy_file_range(struct file *src_file, loff_t src_off,
 	ret = zpl_clone_file_range_impl(src_file, src_off,
 	    dst_file, dst_off, len);
 
-#ifdef HAVE_VFS_GENERIC_COPY_FILE_RANGE
+#if defined(HAVE_VFS_GENERIC_COPY_FILE_RANGE)
 	/*
 	 * Since Linux 5.3 the filesystem driver is responsible for executing
 	 * an appropriate fallback, and a generic fallback function is provided.
@@ -111,6 +114,15 @@ zpl_copy_file_range(struct file *src_file, loff_t src_off,
 	    ret == -EAGAIN)
 		ret = generic_copy_file_range(src_file, src_off, dst_file,
 		    dst_off, len, flags);
+#elif defined(HAVE_VFS_SPLICE_COPY_FILE_RANGE)
+	/*
+	 * Since 6.8 the fallback function is called splice_copy_file_range
+	 * and has a slightly different signature.
+	 */
+	if (ret == -EOPNOTSUPP || ret == -EINVAL || ret == -EXDEV ||
+	    ret == -EAGAIN)
+		ret = splice_copy_file_range(src_file, src_off, dst_file,
+		    dst_off, len);
 #else
 	/*
 	 * Before Linux 5.3 the filesystem has to return -EOPNOTSUPP to signal
@@ -118,7 +130,7 @@ zpl_copy_file_range(struct file *src_file, loff_t src_off,
 	 */
 	if (ret == -EINVAL || ret == -EXDEV || ret == -EAGAIN)
 		ret = -EOPNOTSUPP;
-#endif /* HAVE_VFS_GENERIC_COPY_FILE_RANGE */
+#endif /* HAVE_VFS_GENERIC_COPY_FILE_RANGE || HAVE_VFS_SPLICE_COPY_FILE_RANGE */
 
 	return (ret);
 }
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zvol_os.c b/sys/contrib/openzfs/module/os/linux/zfs/zvol_os.c
index 8562e989738d..61c8db5d8178 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zvol_os.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zvol_os.c
@@ -37,6 +37,7 @@
 #include <sys/spa_impl.h>
 #include <sys/zvol.h>
 #include <sys/zvol_impl.h>
+#include <cityhash.h>
 
 #include <linux/blkdev_compat.h>
 #include <linux/task_io_accounting_ops.h>
@@ -53,6 +54,12 @@ static unsigned int zvol_request_sync = 0;
 static unsigned int zvol_prefetch_bytes = (128 * 1024);
 static unsigned long zvol_max_discard_blocks = 16384;
 
+/*
+ * Switch taskq at multiple of 512 MB offset. This can be set to a lower value
+ * to utilize more threads for small files but may affect prefetch hits.
+ */
+#define	ZVOL_TASKQ_OFFSET_SHIFT 29
+
 #ifndef HAVE_BLKDEV_GET_ERESTARTSYS
 static unsigned int zvol_open_timeout_ms = 1000;
 #endif
@@ -76,6 +83,8 @@ static boolean_t zvol_use_blk_mq = B_FALSE;
 static unsigned int zvol_blk_mq_blocks_per_thread = 8;
 #endif
 
+static unsigned int zvol_num_taskqs = 0;
+
 #ifndef	BLKDEV_DEFAULT_RQ
 /* BLKDEV_MAX_RQ was renamed to BLKDEV_DEFAULT_RQ in the 5.16 kernel */
 #define	BLKDEV_DEFAULT_RQ BLKDEV_MAX_RQ
@@ -114,7 +123,11 @@ struct zvol_state_os {
 	boolean_t use_blk_mq;
 };
 
-static taskq_t *zvol_taskq;
+typedef struct zv_taskq {
+	uint_t tqs_cnt;
+	taskq_t **tqs_taskq;
+} zv_taskq_t;
+static zv_taskq_t zvol_taskqs;
 static struct ida zvol_ida;
 
 typedef struct zv_request_stack {
@@ -532,6 +545,22 @@ zvol_request_impl(zvol_state_t *zv, struct bio *bio, struct request *rq,
 	}
 
 	zv_request_task_t *task;
+	zv_taskq_t *ztqs = &zvol_taskqs;
+	uint_t blk_mq_hw_queue = 0;
+	uint_t tq_idx;
+	uint_t taskq_hash;
+#ifdef HAVE_BLK_MQ
+	if (rq)
+#ifdef HAVE_BLK_MQ_RQ_HCTX
+		blk_mq_hw_queue = rq->mq_hctx->queue_num;
+#else
+		blk_mq_hw_queue =
+		    rq->q->queue_hw_ctx[rq->q->mq_map[rq->cpu]]->queue_num;
+#endif
+#endif
+	taskq_hash = cityhash4((uintptr_t)zv, offset >> ZVOL_TASKQ_OFFSET_SHIFT,
+	    blk_mq_hw_queue, 0);
+	tq_idx = taskq_hash % ztqs->tqs_cnt;
 
 	if (rw == WRITE) {
 		if (unlikely(zv->zv_flags & ZVOL_RDONLY)) {
@@ -601,7 +630,7 @@ zvol_request_impl(zvol_state_t *zv, struct bio *bio, struct request *rq,
 				zvol_discard(&zvr);
 			} else {
 				task = zv_request_task_create(zvr);
-				taskq_dispatch_ent(zvol_taskq,
+				taskq_dispatch_ent(ztqs->tqs_taskq[tq_idx],
 				    zvol_discard_task, task, 0, &task->ent);
 			}
 		} else {
@@ -609,7 +638,7 @@ zvol_request_impl(zvol_state_t *zv, struct bio *bio, struct request *rq,
 				zvol_write(&zvr);
 			} else {
 				task = zv_request_task_create(zvr);
-				taskq_dispatch_ent(zvol_taskq,
+				taskq_dispatch_ent(ztqs->tqs_taskq[tq_idx],
 				    zvol_write_task, task, 0, &task->ent);
 			}
 		}
@@ -631,7 +660,7 @@ zvol_request_impl(zvol_state_t *zv, struct bio *bio, struct request *rq,
 			zvol_read(&zvr);
 		} else {
 			task = zv_request_task_create(zvr);
-			taskq_dispatch_ent(zvol_taskq,
+			taskq_dispatch_ent(ztqs->tqs_taskq[tq_idx],
 			    zvol_read_task, task, 0, &task->ent);
 		}
 	}
@@ -1055,6 +1084,16 @@ zvol_alloc_non_blk_mq(struct zvol_state_os *zso)
 
 	zso->zvo_disk->minors = ZVOL_MINORS;
 	zso->zvo_queue = zso->zvo_disk->queue;
+#elif defined(HAVE_BLK_ALLOC_DISK_2ARG)
+	struct gendisk *disk = blk_alloc_disk(NULL, NUMA_NO_NODE);
+	if (IS_ERR(disk)) {
+		zso->zvo_disk = NULL;
+		return (1);
+	}
+
+	zso->zvo_disk = disk;
+	zso->zvo_disk->minors = ZVOL_MINORS;
+	zso->zvo_queue = zso->zvo_disk->queue;
 #else
 	zso->zvo_queue = blk_alloc_queue(NUMA_NO_NODE);
 	if (zso->zvo_queue == NULL)
@@ -1103,6 +1142,17 @@ zvol_alloc_blk_mq(zvol_state_t *zv)
 	}
 	zso->zvo_queue = zso->zvo_disk->queue;
 	zso->zvo_disk->minors = ZVOL_MINORS;
+#elif defined(HAVE_BLK_ALLOC_DISK_2ARG)
+	struct gendisk *disk = blk_mq_alloc_disk(&zso->tag_set, NULL, zv);
+	if (IS_ERR(disk)) {
+		zso->zvo_disk = NULL;
+		blk_mq_free_tag_set(&zso->tag_set);
+		return (1);
+	}
+
+	zso->zvo_disk = disk;
+	zso->zvo_queue = zso->zvo_disk->queue;
+	zso->zvo_disk->minors = ZVOL_MINORS;
 #else
 	zso->zvo_disk = alloc_disk(ZVOL_MINORS);
 	if (zso->zvo_disk == NULL) {
@@ -1256,7 +1306,7 @@ zvol_os_free(zvol_state_t *zv)
 
 	del_gendisk(zv->zv_zso->zvo_disk);
 #if defined(HAVE_SUBMIT_BIO_IN_BLOCK_DEVICE_OPERATIONS) && \
-	defined(HAVE_BLK_ALLOC_DISK)
+	(defined(HAVE_BLK_ALLOC_DISK) || defined(HAVE_BLK_ALLOC_DISK_2ARG))
 #if defined(HAVE_BLK_CLEANUP_DISK)
 	blk_cleanup_disk(zv->zv_zso->zvo_disk);
 #else
@@ -1313,6 +1363,13 @@ zvol_os_create_minor(const char *name)
 	if (idx < 0)
 		return (SET_ERROR(-idx));
 	minor = idx << ZVOL_MINOR_BITS;
+	if (MINOR(minor) != minor) {
+		/* too many partitions can cause an overflow */
+		zfs_dbgmsg("zvol: create minor overflow: %s, minor %u/%u",
+		    name, minor, MINOR(minor));
+		ida_simple_remove(&zvol_ida, idx);
+		return (SET_ERROR(EINVAL));
+	}
 
 	zv = zvol_find_by_name_hash(name, hash, RW_NONE);
 	if (zv) {
@@ -1507,7 +1564,7 @@ zvol_os_rename_minor(zvol_state_t *zv, const char *newname)
 	strlcpy(zv->zv_name, newname, sizeof (zv->zv_name));
 
 	/* move to new hashtable entry  */
-	zv->zv_hash = zvol_name_hash(zv->zv_name);
+	zv->zv_hash = zvol_name_hash(newname);
 	hlist_del(&zv->zv_hlink);
 	hlist_add_head(&zv->zv_hlink, ZVOL_HT_HEAD(zv->zv_hash));
 
@@ -1563,8 +1620,40 @@ zvol_init(void)
 		zvol_actual_threads = MIN(MAX(zvol_threads, 1), 1024);
 	}
 
+	/*
+	 * Use atleast 32 zvol_threads but for many core system,
+	 * prefer 6 threads per taskq, but no more taskqs
+	 * than threads in them on large systems.
+	 *
+	 *                 taskq   total
+	 * cpus    taskqs  threads threads
+	 * ------- ------- ------- -------
+	 * 1       1       32       32
+	 * 2       1       32       32
+	 * 4       1       32       32
+	 * 8       2       16       32
+	 * 16      3       11       33
+	 * 32      5       7        35
+	 * 64      8       8        64
+	 * 128     11      12       132
+	 * 256     16      16       256
+	 */
+	zv_taskq_t *ztqs = &zvol_taskqs;
+	uint_t num_tqs = MIN(num_online_cpus(), zvol_num_taskqs);
+	if (num_tqs == 0) {
+		num_tqs = 1 + num_online_cpus() / 6;
+		while (num_tqs * num_tqs > zvol_actual_threads)
+			num_tqs--;
+	}
+	uint_t per_tq_thread = zvol_actual_threads / num_tqs;
+	if (per_tq_thread * num_tqs < zvol_actual_threads)
+		per_tq_thread++;
+	ztqs->tqs_cnt = num_tqs;
+	ztqs->tqs_taskq = kmem_alloc(num_tqs * sizeof (taskq_t *), KM_SLEEP);
 	error = register_blkdev(zvol_major, ZVOL_DRIVER);
 	if (error) {
+		kmem_free(ztqs->tqs_taskq, ztqs->tqs_cnt * sizeof (taskq_t *));
+		ztqs->tqs_taskq = NULL;
 		printk(KERN_INFO "ZFS: register_blkdev() failed %d\n", error);
 		return (error);
 	}
@@ -1584,11 +1673,22 @@ zvol_init(void)
 		    1024);
 	}
 #endif
-	zvol_taskq = taskq_create(ZVOL_DRIVER, zvol_actual_threads, maxclsyspri,
-	    zvol_actual_threads, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
-	if (zvol_taskq == NULL) {
-		unregister_blkdev(zvol_major, ZVOL_DRIVER);
-		return (-ENOMEM);
+	for (uint_t i = 0; i < num_tqs; i++) {
+		char name[32];
+		(void) snprintf(name, sizeof (name), "%s_tq-%u",
+		    ZVOL_DRIVER, i);
+		ztqs->tqs_taskq[i] = taskq_create(name, per_tq_thread,
+		    maxclsyspri, per_tq_thread, INT_MAX,
+		    TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
+		if (ztqs->tqs_taskq[i] == NULL) {
+			for (int j = i - 1; j >= 0; j--)
+				taskq_destroy(ztqs->tqs_taskq[j]);
+			unregister_blkdev(zvol_major, ZVOL_DRIVER);
+			kmem_free(ztqs->tqs_taskq, ztqs->tqs_cnt *
+			    sizeof (taskq_t *));
+			ztqs->tqs_taskq = NULL;
+			return (-ENOMEM);
+		}
 	}
 
 	zvol_init_impl();
@@ -1599,9 +1699,22 @@ zvol_init(void)
 void
 zvol_fini(void)
 {
+	zv_taskq_t *ztqs = &zvol_taskqs;
 	zvol_fini_impl();
 	unregister_blkdev(zvol_major, ZVOL_DRIVER);
-	taskq_destroy(zvol_taskq);
+
+	if (ztqs->tqs_taskq == NULL) {
+		ASSERT3U(ztqs->tqs_cnt, ==, 0);
+	} else {
+		for (uint_t i = 0; i < ztqs->tqs_cnt; i++) {
+			ASSERT3P(ztqs->tqs_taskq[i], !=, NULL);
+			taskq_destroy(ztqs->tqs_taskq[i]);
+		}
+		kmem_free(ztqs->tqs_taskq, ztqs->tqs_cnt *
+		    sizeof (taskq_t *));
+		ztqs->tqs_taskq = NULL;
+	}
+
 	ida_destroy(&zvol_ida);
 }
 
@@ -1622,6 +1735,9 @@ MODULE_PARM_DESC(zvol_request_sync, "Synchronously handle bio requests");
 module_param(zvol_max_discard_blocks, ulong, 0444);
 MODULE_PARM_DESC(zvol_max_discard_blocks, "Max number of blocks to discard");
 
+module_param(zvol_num_taskqs, uint, 0444);
+MODULE_PARM_DESC(zvol_num_taskqs, "Number of zvol taskqs");
+
 module_param(zvol_prefetch_bytes, uint, 0644);
 MODULE_PARM_DESC(zvol_prefetch_bytes, "Prefetch N bytes at zvol start+end");
 
diff --git a/sys/contrib/openzfs/module/zcommon/zfs_prop.c b/sys/contrib/openzfs/module/zcommon/zfs_prop.c
index 3db6fd13f4ae..29764674a31b 100644
--- a/sys/contrib/openzfs/module/zcommon/zfs_prop.c
+++ b/sys/contrib/openzfs/module/zcommon/zfs_prop.c
@@ -345,6 +345,13 @@ zfs_prop_init(void)
 		{ NULL }
 	};
 
+	static const zprop_index_t prefetch_table[] = {
+		{ "none",	ZFS_PREFETCH_NONE },
+		{ "metadata",	ZFS_PREFETCH_METADATA },
+		{ "all",	ZFS_PREFETCH_ALL },
+		{ NULL }
+	};
+
 	static const zprop_index_t sync_table[] = {
 		{ "standard",	ZFS_SYNC_STANDARD },
 		{ "always",	ZFS_SYNC_ALWAYS },
@@ -453,6 +460,10 @@ zfs_prop_init(void)
 	    ZFS_CACHE_ALL, PROP_INHERIT,
 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT | ZFS_TYPE_VOLUME,
 	    "all | none | metadata", "SECONDARYCACHE", cache_table, sfeatures);
+	zprop_register_index(ZFS_PROP_PREFETCH, "prefetch",
+	    ZFS_PREFETCH_ALL, PROP_INHERIT,
+	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT | ZFS_TYPE_VOLUME,
+	    "none | metadata | all", "PREFETCH", prefetch_table, sfeatures);
 	zprop_register_index(ZFS_PROP_LOGBIAS, "logbias", ZFS_LOGBIAS_LATENCY,
 	    PROP_INHERIT, ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME,
 	    "latency | throughput", "LOGBIAS", logbias_table, sfeatures);
diff --git a/sys/contrib/openzfs/module/zcommon/zpool_prop.c b/sys/contrib/openzfs/module/zcommon/zpool_prop.c
index c4aca04a96bd..ff70c0e3c35b 100644
--- a/sys/contrib/openzfs/module/zcommon/zpool_prop.c
+++ b/sys/contrib/openzfs/module/zcommon/zpool_prop.c
@@ -431,6 +431,12 @@ vdev_prop_init(void)
 	zprop_register_number(VDEV_PROP_IO_T, "io_t", UINT64_MAX,
 	    PROP_DEFAULT, ZFS_TYPE_VDEV, "<seconds>", "IO_T", B_FALSE,
 	    sfeatures);
+	zprop_register_number(VDEV_PROP_SLOW_IO_N, "slow_io_n", UINT64_MAX,
+	    PROP_DEFAULT, ZFS_TYPE_VDEV, "<events>", "SLOW_IO_N", B_FALSE,
+	    sfeatures);
+	zprop_register_number(VDEV_PROP_SLOW_IO_T, "slow_io_t", UINT64_MAX,
+	    PROP_DEFAULT, ZFS_TYPE_VDEV, "<seconds>", "SLOW_IO_T", B_FALSE,
+	    sfeatures);
 
 	/* default index (boolean) properties */
 	zprop_register_index(VDEV_PROP_REMOVING, "removing", 0,
diff --git a/sys/contrib/openzfs/module/zfs/abd.c b/sys/contrib/openzfs/module/zfs/abd.c
index d982f201c930..3388e2357305 100644
--- a/sys/contrib/openzfs/module/zfs/abd.c
+++ b/sys/contrib/openzfs/module/zfs/abd.c
@@ -826,6 +826,48 @@ abd_iterate_func(abd_t *abd, size_t off, size_t size,
 	return (ret);
 }
 
+#if defined(__linux__) && defined(_KERNEL)
+int
+abd_iterate_page_func(abd_t *abd, size_t off, size_t size,
+    abd_iter_page_func_t *func, void *private)
+{
+	struct abd_iter aiter;
+	int ret = 0;
+
+	if (size == 0)
+		return (0);
+
+	abd_verify(abd);
+	ASSERT3U(off + size, <=, abd->abd_size);
+
+	abd_t *c_abd = abd_init_abd_iter(abd, &aiter, off);
+
+	while (size > 0) {
+		IMPLY(abd_is_gang(abd), c_abd != NULL);
+
+		abd_iter_page(&aiter);
+
+		size_t len = MIN(aiter.iter_page_dsize, size);
+		ASSERT3U(len, >, 0);
+
+		ret = func(aiter.iter_page, aiter.iter_page_doff,
+		    len, private);
+
+		aiter.iter_page = NULL;
+		aiter.iter_page_doff = 0;
+		aiter.iter_page_dsize = 0;
+
+		if (ret != 0)
+			break;
+
+		size -= len;
+		c_abd = abd_advance_abd_iter(abd, c_abd, &aiter, len);
+	}
+
+	return (ret);
+}
+#endif
+
 struct buf_arg {
 	void *arg_buf;
 };
diff --git a/sys/contrib/openzfs/module/zfs/arc.c b/sys/contrib/openzfs/module/zfs/arc.c
index 4db6c06148b1..1953640139b3 100644
--- a/sys/contrib/openzfs/module/zfs/arc.c
+++ b/sys/contrib/openzfs/module/zfs/arc.c
@@ -3872,7 +3872,7 @@ arc_evict_state_impl(multilist_t *ml, int idx, arc_buf_hdr_t *marker,
 
 	ASSERT3P(marker, !=, NULL);
 
-	mls = multilist_sublist_lock(ml, idx);
+	mls = multilist_sublist_lock_idx(ml, idx);
 
 	for (hdr = multilist_sublist_prev(mls, marker); likely(hdr != NULL);
 	    hdr = multilist_sublist_prev(mls, marker)) {
@@ -3984,6 +3984,26 @@ arc_evict_state_impl(multilist_t *ml, int idx, arc_buf_hdr_t *marker,
 	return (bytes_evicted);
 }
 
+static arc_buf_hdr_t *
+arc_state_alloc_marker(void)
+{
+	arc_buf_hdr_t *marker = kmem_cache_alloc(hdr_full_cache, KM_SLEEP);
+
+	/*
+	 * A b_spa of 0 is used to indicate that this header is
+	 * a marker. This fact is used in arc_evict_state_impl().
+	 */
+	marker->b_spa = 0;
+
+	return (marker);
+}
+
+static void
+arc_state_free_marker(arc_buf_hdr_t *marker)
+{
+	kmem_cache_free(hdr_full_cache, marker);
+}
+
 /*
  * Allocate an array of buffer headers used as placeholders during arc state
  * eviction.
@@ -3994,16 +4014,8 @@ arc_state_alloc_markers(int count)
 	arc_buf_hdr_t **markers;
 
 	markers = kmem_zalloc(sizeof (*markers) * count, KM_SLEEP);
-	for (int i = 0; i < count; i++) {
-		markers[i] = kmem_cache_alloc(hdr_full_cache, KM_SLEEP);
-
-		/*
-		 * A b_spa of 0 is used to indicate that this header is
-		 * a marker. This fact is used in arc_evict_state_impl().
-		 */
-		markers[i]->b_spa = 0;
-
-	}
+	for (int i = 0; i < count; i++)
+		markers[i] = arc_state_alloc_marker();
 	return (markers);
 }
 
@@ -4011,7 +4023,7 @@ static void
 arc_state_free_markers(arc_buf_hdr_t **markers, int count)
 {
 	for (int i = 0; i < count; i++)
-		kmem_cache_free(hdr_full_cache, markers[i]);
+		arc_state_free_marker(markers[i]);
 	kmem_free(markers, sizeof (*markers) * count);
 }
 
@@ -4055,7 +4067,7 @@ arc_evict_state(arc_state_t *state, arc_buf_contents_t type, uint64_t spa,
 	for (int i = 0; i < num_sublists; i++) {
 		multilist_sublist_t *mls;
 
-		mls = multilist_sublist_lock(ml, i);
+		mls = multilist_sublist_lock_idx(ml, i);
 		multilist_sublist_insert_tail(mls, markers[i]);
 		multilist_sublist_unlock(mls);
 	}
@@ -4120,7 +4132,7 @@ arc_evict_state(arc_state_t *state, arc_buf_contents_t type, uint64_t spa,
 	}
 
 	for (int i = 0; i < num_sublists; i++) {
-		multilist_sublist_t *mls = multilist_sublist_lock(ml, i);
+		multilist_sublist_t *mls = multilist_sublist_lock_idx(ml, i);
 		multilist_sublist_remove(mls, markers[i]);
 		multilist_sublist_unlock(mls);
 	}
@@ -8628,7 +8640,7 @@ l2arc_sublist_lock(int list_num)
 	 * sublists being selected.
 	 */
 	idx = multilist_get_random_index(ml);
-	return (multilist_sublist_lock(ml, idx));
+	return (multilist_sublist_lock_idx(ml, idx));
 }
 
 /*
@@ -9040,9 +9052,9 @@ l2arc_blk_fetch_done(zio_t *zio)
 static uint64_t
 l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 {
-	arc_buf_hdr_t 		*hdr, *hdr_prev, *head;
-	uint64_t 		write_asize, write_psize, write_lsize, headroom;
-	boolean_t		full;
+	arc_buf_hdr_t 		*hdr, *head, *marker;
+	uint64_t 		write_asize, write_psize, headroom;
+	boolean_t		full, from_head = !arc_warm;
 	l2arc_write_callback_t	*cb = NULL;
 	zio_t 			*pio, *wzio;
 	uint64_t 		guid = spa_load_guid(spa);
@@ -9051,10 +9063,11 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 	ASSERT3P(dev->l2ad_vdev, !=, NULL);
 
 	pio = NULL;
-	write_lsize = write_asize = write_psize = 0;
+	write_asize = write_psize = 0;
 	full = B_FALSE;
 	head = kmem_cache_alloc(hdr_l2only_cache, KM_PUSHPAGE);
 	arc_hdr_set_flags(head, ARC_FLAG_L2_WRITE_HEAD | ARC_FLAG_HAS_L2HDR);
+	marker = arc_state_alloc_marker();
 
 	/*
 	 * Copy buffers for L2ARC writing.
@@ -9069,40 +9082,34 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 				continue;
 		}
 
-		multilist_sublist_t *mls = l2arc_sublist_lock(pass);
 		uint64_t passed_sz = 0;
-
-		VERIFY3P(mls, !=, NULL);
+		headroom = target_sz * l2arc_headroom;
+		if (zfs_compressed_arc_enabled)
+			headroom = (headroom * l2arc_headroom_boost) / 100;
 
 		/*
-		 * L2ARC fast warmup.
-		 *
 		 * Until the ARC is warm and starts to evict, read from the
 		 * head of the ARC lists rather than the tail.
 		 */
-		if (arc_warm == B_FALSE)
+		multilist_sublist_t *mls = l2arc_sublist_lock(pass);
+		ASSERT3P(mls, !=, NULL);
+		if (from_head)
 			hdr = multilist_sublist_head(mls);
 		else
 			hdr = multilist_sublist_tail(mls);
 
-		headroom = target_sz * l2arc_headroom;
-		if (zfs_compressed_arc_enabled)
-			headroom = (headroom * l2arc_headroom_boost) / 100;
-
-		for (; hdr; hdr = hdr_prev) {
+		while (hdr != NULL) {
 			kmutex_t *hash_lock;
 			abd_t *to_write = NULL;
 
-			if (arc_warm == B_FALSE)
-				hdr_prev = multilist_sublist_next(mls, hdr);
-			else
-				hdr_prev = multilist_sublist_prev(mls, hdr);
-
 			hash_lock = HDR_LOCK(hdr);
 			if (!mutex_tryenter(hash_lock)) {
-				/*
-				 * Skip this buffer rather than waiting.
-				 */
+skip:
+				/* Skip this buffer rather than waiting. */
+				if (from_head)
+					hdr = multilist_sublist_next(mls, hdr);
+				else
+					hdr = multilist_sublist_prev(mls, hdr);
 				continue;
 			}
 
@@ -9117,11 +9124,10 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 
 			if (!l2arc_write_eligible(guid, hdr)) {
 				mutex_exit(hash_lock);
-				continue;
+				goto skip;
 			}
 
 			ASSERT(HDR_HAS_L1HDR(hdr));
-
 			ASSERT3U(HDR_GET_PSIZE(hdr), >, 0);
 			ASSERT3U(arc_hdr_size(hdr), >, 0);
 			ASSERT(hdr->b_l1hdr.b_pabd != NULL ||
@@ -9143,12 +9149,18 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 			}
 
 			/*
-			 * We rely on the L1 portion of the header below, so
-			 * it's invalid for this header to have been evicted out
-			 * of the ghost cache, prior to being written out. The
-			 * ARC_FLAG_L2_WRITING bit ensures this won't happen.
+			 * We should not sleep with sublist lock held or it
+			 * may block ARC eviction.  Insert a marker to save
+			 * the position and drop the lock.
 			 */
-			arc_hdr_set_flags(hdr, ARC_FLAG_L2_WRITING);
+			if (from_head) {
+				multilist_sublist_insert_after(mls, hdr,
+				    marker);
+			} else {
+				multilist_sublist_insert_before(mls, hdr,
+				    marker);
+			}
+			multilist_sublist_unlock(mls);
 
 			/*
 			 * If this header has b_rabd, we can use this since it
@@ -9179,32 +9191,45 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 				    &to_write);
 				if (ret != 0) {
 					arc_hdr_clear_flags(hdr,
-					    ARC_FLAG_L2_WRITING);
+					    ARC_FLAG_L2CACHE);
 					mutex_exit(hash_lock);
-					continue;
+					goto next;
 				}
 
 				l2arc_free_abd_on_write(to_write, asize, type);
 			}
 
+			hdr->b_l2hdr.b_dev = dev;
+			hdr->b_l2hdr.b_daddr = dev->l2ad_hand;
+			hdr->b_l2hdr.b_hits = 0;
+			hdr->b_l2hdr.b_arcs_state =
+			    hdr->b_l1hdr.b_state->arcs_state;
+			mutex_enter(&dev->l2ad_mtx);
 			if (pio == NULL) {
 				/*
 				 * Insert a dummy header on the buflist so
 				 * l2arc_write_done() can find where the
 				 * write buffers begin without searching.
 				 */
-				mutex_enter(&dev->l2ad_mtx);
 				list_insert_head(&dev->l2ad_buflist, head);
-				mutex_exit(&dev->l2ad_mtx);
+			}
+			list_insert_head(&dev->l2ad_buflist, hdr);
+			mutex_exit(&dev->l2ad_mtx);
+			arc_hdr_set_flags(hdr, ARC_FLAG_HAS_L2HDR |
+			    ARC_FLAG_L2_WRITING);
+
+			(void) zfs_refcount_add_many(&dev->l2ad_alloc,
+			    arc_hdr_size(hdr), hdr);
+			l2arc_hdr_arcstats_increment(hdr);
 
+			boolean_t commit = l2arc_log_blk_insert(dev, hdr);
+			mutex_exit(hash_lock);
+
+			if (pio == NULL) {
 				cb = kmem_alloc(
 				    sizeof (l2arc_write_callback_t), KM_SLEEP);
 				cb->l2wcb_dev = dev;
 				cb->l2wcb_head = head;
-				/*
-				 * Create a list to save allocated abd buffers
-				 * for l2arc_log_blk_commit().
-				 */
 				list_create(&cb->l2wcb_abd_list,
 				    sizeof (l2arc_lb_abd_buf_t),
 				    offsetof(l2arc_lb_abd_buf_t, node));
@@ -9212,54 +9237,34 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 				    ZIO_FLAG_CANFAIL);
 			}
 
-			hdr->b_l2hdr.b_dev = dev;
-			hdr->b_l2hdr.b_hits = 0;
-
-			hdr->b_l2hdr.b_daddr = dev->l2ad_hand;
-			hdr->b_l2hdr.b_arcs_state =
-			    hdr->b_l1hdr.b_state->arcs_state;
-			arc_hdr_set_flags(hdr, ARC_FLAG_HAS_L2HDR);
-
-			mutex_enter(&dev->l2ad_mtx);
-			list_insert_head(&dev->l2ad_buflist, hdr);
-			mutex_exit(&dev->l2ad_mtx);
-
-			(void) zfs_refcount_add_many(&dev->l2ad_alloc,
-			    arc_hdr_size(hdr), hdr);
-
 			wzio = zio_write_phys(pio, dev->l2ad_vdev,
-			    hdr->b_l2hdr.b_daddr, asize, to_write,
+			    dev->l2ad_hand, asize, to_write,
 			    ZIO_CHECKSUM_OFF, NULL, hdr,
 			    ZIO_PRIORITY_ASYNC_WRITE,
 			    ZIO_FLAG_CANFAIL, B_FALSE);
 
-			write_lsize += HDR_GET_LSIZE(hdr);
 			DTRACE_PROBE2(l2arc__write, vdev_t *, dev->l2ad_vdev,
 			    zio_t *, wzio);
+			zio_nowait(wzio);
 
 			write_psize += psize;
 			write_asize += asize;
 			dev->l2ad_hand += asize;
-			l2arc_hdr_arcstats_increment(hdr);
 			vdev_space_update(dev->l2ad_vdev, asize, 0, 0);
 
-			mutex_exit(hash_lock);
-
-			/*
-			 * Append buf info to current log and commit if full.
-			 * arcstat_l2_{size,asize} kstats are updated
-			 * internally.
-			 */
-			if (l2arc_log_blk_insert(dev, hdr)) {
-				/*
-				 * l2ad_hand will be adjusted in
-				 * l2arc_log_blk_commit().
-				 */
+			if (commit) {
+				/* l2ad_hand will be adjusted inside. */
 				write_asize +=
 				    l2arc_log_blk_commit(dev, pio, cb);
 			}
 
-			zio_nowait(wzio);
+next:
+			multilist_sublist_lock(mls);
+			if (from_head)
+				hdr = multilist_sublist_next(mls, marker);
+			else
+				hdr = multilist_sublist_prev(mls, marker);
+			multilist_sublist_remove(mls, marker);
 		}
 
 		multilist_sublist_unlock(mls);
@@ -9268,9 +9273,11 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
 			break;
 	}
 
+	arc_state_free_marker(marker);
+
 	/* No buffers selected for writing? */
 	if (pio == NULL) {
-		ASSERT0(write_lsize);
+		ASSERT0(write_psize);
 		ASSERT(!HDR_HAS_L1HDR(head));
 		kmem_cache_free(hdr_l2only_cache, head);
 
@@ -10598,7 +10605,7 @@ l2arc_log_blk_insert(l2arc_dev_t *dev, const arc_buf_hdr_t *hdr)
 	L2BLK_SET_TYPE((le)->le_prop, hdr->b_type);
 	L2BLK_SET_PROTECTED((le)->le_prop, !!(HDR_PROTECTED(hdr)));
 	L2BLK_SET_PREFETCH((le)->le_prop, !!(HDR_PREFETCH(hdr)));
-	L2BLK_SET_STATE((le)->le_prop, hdr->b_l1hdr.b_state->arcs_state);
+	L2BLK_SET_STATE((le)->le_prop, hdr->b_l2hdr.b_arcs_state);
 
 	dev->l2ad_log_blk_payload_asize += vdev_psize_to_asize(dev->l2ad_vdev,
 	    HDR_GET_PSIZE(hdr));
diff --git a/sys/contrib/openzfs/module/zfs/brt.c b/sys/contrib/openzfs/module/zfs/brt.c
index 225ddaca1e54..bf8fdf6ea4b4 100644
--- a/sys/contrib/openzfs/module/zfs/brt.c
+++ b/sys/contrib/openzfs/module/zfs/brt.c
@@ -248,7 +248,7 @@ static kmem_cache_t *brt_pending_entry_cache;
 /*
  * Enable/disable prefetching of BRT entries that we are going to modify.
  */
-int zfs_brt_prefetch = 1;
+static int brt_zap_prefetch = 1;
 
 #ifdef ZFS_DEBUG
 #define	BRT_DEBUG(...)	do {						\
@@ -260,8 +260,8 @@ int zfs_brt_prefetch = 1;
 #define	BRT_DEBUG(...)	do { } while (0)
 #endif
 
-int brt_zap_leaf_blockshift = 12;
-int brt_zap_indirect_blockshift = 12;
+static int brt_zap_default_bs = 12;
+static int brt_zap_default_ibs = 12;
 
 static kstat_t	*brt_ksp;
 
@@ -458,8 +458,7 @@ brt_vdev_create(brt_t *brt, brt_vdev_t *brtvd, dmu_tx_t *tx)
 
 	brtvd->bv_mos_entries = zap_create_flags(brt->brt_mos, 0,
 	    ZAP_FLAG_HASH64 | ZAP_FLAG_UINT64_KEY, DMU_OTN_ZAP_METADATA,
-	    brt_zap_leaf_blockshift, brt_zap_indirect_blockshift, DMU_OT_NONE,
-	    0, tx);
+	    brt_zap_default_bs, brt_zap_default_ibs, DMU_OT_NONE, 0, tx);
 	VERIFY(brtvd->bv_mos_entries != 0);
 	BRT_DEBUG("MOS entries created, object=%llu",
 	    (u_longlong_t)brtvd->bv_mos_entries);
@@ -901,7 +900,6 @@ static int
 brt_entry_lookup(brt_t *brt, brt_vdev_t *brtvd, brt_entry_t *bre)
 {
 	uint64_t mos_entries;
-	uint64_t one, physsize;
 	int error;
 
 	ASSERT(RW_LOCK_HELD(&brt->brt_lock));
@@ -919,21 +917,8 @@ brt_entry_lookup(brt_t *brt, brt_vdev_t *brtvd, brt_entry_t *bre)
 
 	brt_unlock(brt);
 
-	error = zap_length_uint64(brt->brt_mos, mos_entries, &bre->bre_offset,
-	    BRT_KEY_WORDS, &one, &physsize);
-	if (error == 0) {
-		ASSERT3U(one, ==, 1);
-		ASSERT3U(physsize, ==, sizeof (bre->bre_refcount));
-
-		error = zap_lookup_uint64(brt->brt_mos, mos_entries,
-		    &bre->bre_offset, BRT_KEY_WORDS, 1,
-		    sizeof (bre->bre_refcount), &bre->bre_refcount);
-		BRT_DEBUG("ZAP lookup: object=%llu vdev=%llu offset=%llu "
-		    "count=%llu error=%d", (u_longlong_t)mos_entries,
-		    (u_longlong_t)brtvd->bv_vdevid,
-		    (u_longlong_t)bre->bre_offset,
-		    error == 0 ? (u_longlong_t)bre->bre_refcount : 0, error);
-	}
+	error = zap_lookup_uint64(brt->brt_mos, mos_entries, &bre->bre_offset,
+	    BRT_KEY_WORDS, 1, sizeof (bre->bre_refcount), &bre->bre_refcount);
 
 	brt_wlock(brt);
 
@@ -955,52 +940,10 @@ brt_entry_prefetch(brt_t *brt, uint64_t vdevid, brt_entry_t *bre)
 	if (mos_entries == 0)
 		return;
 
-	BRT_DEBUG("ZAP prefetch: object=%llu vdev=%llu offset=%llu",
-	    (u_longlong_t)mos_entries, (u_longlong_t)vdevid,
-	    (u_longlong_t)bre->bre_offset);
 	(void) zap_prefetch_uint64(brt->brt_mos, mos_entries,
 	    (uint64_t *)&bre->bre_offset, BRT_KEY_WORDS);
 }
 
-static int
-brt_entry_update(brt_t *brt, brt_vdev_t *brtvd, brt_entry_t *bre, dmu_tx_t *tx)
-{
-	int error;
-
-	ASSERT(RW_LOCK_HELD(&brt->brt_lock));
-	ASSERT(brtvd->bv_mos_entries != 0);
-	ASSERT(bre->bre_refcount > 0);
-
-	error = zap_update_uint64(brt->brt_mos, brtvd->bv_mos_entries,
-	    (uint64_t *)&bre->bre_offset, BRT_KEY_WORDS, 1,
-	    sizeof (bre->bre_refcount), &bre->bre_refcount, tx);
-	BRT_DEBUG("ZAP update: object=%llu vdev=%llu offset=%llu count=%llu "
-	    "error=%d", (u_longlong_t)brtvd->bv_mos_entries,
-	    (u_longlong_t)brtvd->bv_vdevid, (u_longlong_t)bre->bre_offset,
-	    (u_longlong_t)bre->bre_refcount, error);
-
-	return (error);
-}
-
-static int
-brt_entry_remove(brt_t *brt, brt_vdev_t *brtvd, brt_entry_t *bre, dmu_tx_t *tx)
-{
-	int error;
-
-	ASSERT(RW_LOCK_HELD(&brt->brt_lock));
-	ASSERT(brtvd->bv_mos_entries != 0);
-	ASSERT0(bre->bre_refcount);
-
-	error = zap_remove_uint64(brt->brt_mos, brtvd->bv_mos_entries,
-	    (uint64_t *)&bre->bre_offset, BRT_KEY_WORDS, tx);
-	BRT_DEBUG("ZAP remove: object=%llu vdev=%llu offset=%llu count=%llu "
-	    "error=%d", (u_longlong_t)brtvd->bv_mos_entries,
-	    (u_longlong_t)brtvd->bv_vdevid, (u_longlong_t)bre->bre_offset,
-	    (u_longlong_t)bre->bre_refcount, error);
-
-	return (error);
-}
-
 /*
  * Return TRUE if we _can_ have BRT entry for this bp. It might be false
  * positive, but gives us quick answer if we should look into BRT, which
@@ -1405,7 +1348,7 @@ brt_prefetch(brt_t *brt, const blkptr_t *bp)
 
 	ASSERT(bp != NULL);
 
-	if (!zfs_brt_prefetch)
+	if (!brt_zap_prefetch)
 		return;
 
 	brt_entry_fill(bp, &bre, &vdevid);
@@ -1420,13 +1363,14 @@ brt_pending_entry_compare(const void *x1, const void *x2)
 	const blkptr_t *bp1 = &bpe1->bpe_bp, *bp2 = &bpe2->bpe_bp;
 	int cmp;
 
-	cmp = TREE_CMP(BP_PHYSICAL_BIRTH(bp1), BP_PHYSICAL_BIRTH(bp2));
+	cmp = TREE_CMP(DVA_GET_VDEV(&bp1->blk_dva[0]),
+	    DVA_GET_VDEV(&bp2->blk_dva[0]));
 	if (cmp == 0) {
-		cmp = TREE_CMP(DVA_GET_VDEV(&bp1->blk_dva[0]),
-		    DVA_GET_VDEV(&bp2->blk_dva[0]));
-		if (cmp == 0) {
-			cmp = TREE_CMP(DVA_GET_OFFSET(&bp1->blk_dva[0]),
-			    DVA_GET_OFFSET(&bp2->blk_dva[0]));
+		cmp = TREE_CMP(DVA_GET_OFFSET(&bp1->blk_dva[0]),
+		    DVA_GET_OFFSET(&bp2->blk_dva[0]));
+		if (unlikely(cmp == 0)) {
+			cmp = TREE_CMP(BP_PHYSICAL_BIRTH(bp1),
+			    BP_PHYSICAL_BIRTH(bp2));
 		}
 	}
 
@@ -1471,10 +1415,10 @@ brt_pending_add(spa_t *spa, const blkptr_t *bp, dmu_tx_t *tx)
 		kmem_cache_free(brt_pending_entry_cache, newbpe);
 	} else {
 		ASSERT(bpe == NULL);
-	}
 
-	/* Prefetch BRT entry, as we will need it in the syncing context. */
-	brt_prefetch(brt, bp);
+		/* Prefetch BRT entry for the syncing context. */
+		brt_prefetch(brt, bp);
+	}
 }
 
 void
@@ -1514,26 +1458,23 @@ brt_pending_remove(spa_t *spa, const blkptr_t *bp, dmu_tx_t *tx)
 void
 brt_pending_apply(spa_t *spa, uint64_t txg)
 {
-	brt_t *brt;
+	brt_t *brt = spa->spa_brt;
 	brt_pending_entry_t *bpe;
 	avl_tree_t *pending_tree;
-	kmutex_t *pending_lock;
 	void *c;
 
 	ASSERT3U(txg, !=, 0);
 
-	brt = spa->spa_brt;
+	/*
+	 * We are in syncing context, so no other brt_pending_tree accesses
+	 * are possible for the TXG. Don't need to acquire brt_pending_lock.
+	 */
 	pending_tree = &brt->brt_pending_tree[txg & TXG_MASK];
-	pending_lock = &brt->brt_pending_lock[txg & TXG_MASK];
-
-	mutex_enter(pending_lock);
 
 	c = NULL;
 	while ((bpe = avl_destroy_nodes(pending_tree, &c)) != NULL) {
 		boolean_t added_to_ddt;
 
-		mutex_exit(pending_lock);
-
 		for (int i = 0; i < bpe->bpe_count; i++) {
 			/*
 			 * If the block has DEDUP bit set, it means that it
@@ -1551,31 +1492,20 @@ brt_pending_apply(spa_t *spa, uint64_t txg)
 		}
 
 		kmem_cache_free(brt_pending_entry_cache, bpe);
-		mutex_enter(pending_lock);
 	}
-
-	mutex_exit(pending_lock);
 }
 
 static void
-brt_sync_entry(brt_t *brt, brt_vdev_t *brtvd, brt_entry_t *bre, dmu_tx_t *tx)
+brt_sync_entry(dnode_t *dn, brt_entry_t *bre, dmu_tx_t *tx)
 {
-
-	ASSERT(RW_WRITE_HELD(&brt->brt_lock));
-	ASSERT(brtvd->bv_mos_entries != 0);
-
 	if (bre->bre_refcount == 0) {
-		int error;
-
-		error = brt_entry_remove(brt, brtvd, bre, tx);
-		ASSERT(error == 0 || error == ENOENT);
-		/*
-		 * If error == ENOENT then zfs_clone_range() was done from a
-		 * removed (but opened) file (open(), unlink()).
-		 */
-		ASSERT(brt_entry_lookup(brt, brtvd, bre) == ENOENT);
+		int error = zap_remove_uint64_by_dnode(dn, &bre->bre_offset,
+		    BRT_KEY_WORDS, tx);
+		VERIFY(error == 0 || error == ENOENT);
 	} else {
-		VERIFY0(brt_entry_update(brt, brtvd, bre, tx));
+		VERIFY0(zap_update_uint64_by_dnode(dn, &bre->bre_offset,
+		    BRT_KEY_WORDS, 1, sizeof (bre->bre_refcount),
+		    &bre->bre_refcount, tx));
 	}
 }
 
@@ -1584,6 +1514,7 @@ brt_sync_table(brt_t *brt, dmu_tx_t *tx)
 {
 	brt_vdev_t *brtvd;
 	brt_entry_t *bre;
+	dnode_t *dn;
 	uint64_t vdevid;
 	void *c;
 
@@ -1607,14 +1538,19 @@ brt_sync_table(brt_t *brt, dmu_tx_t *tx)
 		if (brtvd->bv_mos_brtvdev == 0)
 			brt_vdev_create(brt, brtvd, tx);
 
+		VERIFY0(dnode_hold(brt->brt_mos, brtvd->bv_mos_entries,
+		    FTAG, &dn));
+
 		c = NULL;
 		while ((bre = avl_destroy_nodes(&brtvd->bv_tree, &c)) != NULL) {
-			brt_sync_entry(brt, brtvd, bre, tx);
+			brt_sync_entry(dn, bre, tx);
 			brt_entry_free(bre);
 			ASSERT(brt->brt_nentries > 0);
 			brt->brt_nentries--;
 		}
 
+		dnode_rele(dn, FTAG);
+
 		brt_vdev_sync(brt, brtvd, tx);
 
 		if (brtvd->bv_totalcount == 0)
@@ -1729,9 +1665,10 @@ brt_unload(spa_t *spa)
 }
 
 /* BEGIN CSTYLED */
-ZFS_MODULE_PARAM(zfs_brt, zfs_brt_, prefetch, INT, ZMOD_RW,
-    "Enable prefetching of BRT entries");
-#ifdef ZFS_BRT_DEBUG
-ZFS_MODULE_PARAM(zfs_brt, zfs_brt_, debug, INT, ZMOD_RW, "BRT debug");
-#endif
+ZFS_MODULE_PARAM(zfs_brt, , brt_zap_prefetch, INT, ZMOD_RW,
+	"Enable prefetching of BRT ZAP entries");
+ZFS_MODULE_PARAM(zfs_brt, , brt_zap_default_bs, UINT, ZMOD_RW,
+	"BRT ZAP leaf blockshift");
+ZFS_MODULE_PARAM(zfs_brt, , brt_zap_default_ibs, UINT, ZMOD_RW,
+	"BRT ZAP indirect blockshift");
 /* END CSTYLED */
diff --git a/sys/contrib/openzfs/module/zfs/dbuf.c b/sys/contrib/openzfs/module/zfs/dbuf.c
index 6e983093fb97..bb921af6d78a 100644
--- a/sys/contrib/openzfs/module/zfs/dbuf.c
+++ b/sys/contrib/openzfs/module/zfs/dbuf.c
@@ -754,7 +754,7 @@ static void
 dbuf_evict_one(void)
 {
 	int idx = multilist_get_random_index(&dbuf_caches[DB_DBUF_CACHE].cache);
-	multilist_sublist_t *mls = multilist_sublist_lock(
+	multilist_sublist_t *mls = multilist_sublist_lock_idx(
 	    &dbuf_caches[DB_DBUF_CACHE].cache, idx);
 
 	ASSERT(!MUTEX_HELD(&dbuf_evict_lock));
@@ -1542,17 +1542,14 @@ dbuf_read_verify_dnode_crypt(dmu_buf_impl_t *db, uint32_t flags)
  * returning.
  */
 static int
-dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
+dbuf_read_impl(dmu_buf_impl_t *db, dnode_t *dn, zio_t *zio, uint32_t flags,
     db_lock_type_t dblt, const void *tag)
 {
-	dnode_t *dn;
 	zbookmark_phys_t zb;
 	uint32_t aflags = ARC_FLAG_NOWAIT;
 	int err, zio_flags;
-	blkptr_t bp, *bpp;
+	blkptr_t bp, *bpp = NULL;
 
-	DB_DNODE_ENTER(db);
-	dn = DB_DNODE(db);
 	ASSERT(!zfs_refcount_is_zero(&db->db_holds));
 	ASSERT(MUTEX_HELD(&db->db_mtx));
 	ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
@@ -1565,29 +1562,28 @@ dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
 		goto early_unlock;
 	}
 
-	if (db->db_state == DB_UNCACHED) {
-		if (db->db_blkptr == NULL) {
-			bpp = NULL;
-		} else {
-			bp = *db->db_blkptr;
+	/*
+	 * If we have a pending block clone, we don't want to read the
+	 * underlying block, but the content of the block being cloned,
+	 * pointed by the dirty record, so we have the most recent data.
+	 * If there is no dirty record, then we hit a race in a sync
+	 * process when the dirty record is already removed, while the
+	 * dbuf is not yet destroyed. Such case is equivalent to uncached.
+	 */
+	if (db->db_state == DB_NOFILL) {
+		dbuf_dirty_record_t *dr = list_head(&db->db_dirty_records);
+		if (dr != NULL) {
+			if (!dr->dt.dl.dr_brtwrite) {
+				err = EIO;
+				goto early_unlock;
+			}
+			bp = dr->dt.dl.dr_overridden_by;
 			bpp = &bp;
 		}
-	} else {
-		dbuf_dirty_record_t *dr;
-
-		ASSERT3S(db->db_state, ==, DB_NOFILL);
+	}
 
-		/*
-		 * Block cloning: If we have a pending block clone,
-		 * we don't want to read the underlying block, but the content
-		 * of the block being cloned, so we have the most recent data.
-		 */
-		dr = list_head(&db->db_dirty_records);
-		if (dr == NULL || !dr->dt.dl.dr_brtwrite) {
-			err = EIO;
-			goto early_unlock;
-		}
-		bp = dr->dt.dl.dr_overridden_by;
+	if (bpp == NULL && db->db_blkptr != NULL) {
+		bp = *db->db_blkptr;
 		bpp = &bp;
 	}
 
@@ -1627,8 +1623,6 @@ dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
 	if (err != 0)
 		goto early_unlock;
 
-	DB_DNODE_EXIT(db);
-
 	db->db_state = DB_READ;
 	DTRACE_SET_STATE(db, "read issued");
 	mutex_exit(&db->db_mtx);
@@ -1653,12 +1647,11 @@ dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
 	 * parent's rwlock, which would be a lock ordering violation.
 	 */
 	dmu_buf_unlock_parent(db, dblt, tag);
-	(void) arc_read(zio, db->db_objset->os_spa, bpp,
+	return (arc_read(zio, db->db_objset->os_spa, bpp,
 	    dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ, zio_flags,
-	    &aflags, &zb);
-	return (err);
+	    &aflags, &zb));
+
 early_unlock:
-	DB_DNODE_EXIT(db);
 	mutex_exit(&db->db_mtx);
 	dmu_buf_unlock_parent(db, dblt, tag);
 	return (err);
@@ -1743,7 +1736,7 @@ dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg)
 }
 
 int
-dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
+dbuf_read(dmu_buf_impl_t *db, zio_t *pio, uint32_t flags)
 {
 	int err = 0;
 	boolean_t prefetch;
@@ -1759,7 +1752,7 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
 	dn = DB_DNODE(db);
 
 	prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
-	    (flags & DB_RF_NOPREFETCH) == 0 && dn != NULL;
+	    (flags & DB_RF_NOPREFETCH) == 0;
 
 	mutex_enter(&db->db_mtx);
 	if (flags & DB_RF_PARTIAL_FIRST)
@@ -1806,13 +1799,13 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
 
 		db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
 
-		if (zio == NULL && (db->db_state == DB_NOFILL ||
+		if (pio == NULL && (db->db_state == DB_NOFILL ||
 		    (db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)))) {
 			spa_t *spa = dn->dn_objset->os_spa;
-			zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
+			pio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
 			need_wait = B_TRUE;
 		}
-		err = dbuf_read_impl(db, zio, flags, dblt, FTAG);
+		err = dbuf_read_impl(db, dn, pio, flags, dblt, FTAG);
 		/*
 		 * dbuf_read_impl has dropped db_mtx and our parent's rwlock
 		 * for us
@@ -1833,9 +1826,10 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
 		 */
 		if (need_wait) {
 			if (err == 0)
-				err = zio_wait(zio);
+				err = zio_wait(pio);
 			else
-				VERIFY0(zio_wait(zio));
+				(void) zio_wait(pio);
+			pio = NULL;
 		}
 	} else {
 		/*
@@ -1862,7 +1856,7 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
 				ASSERT(db->db_state == DB_READ ||
 				    (flags & DB_RF_HAVESTRUCT) == 0);
 				DTRACE_PROBE2(blocked__read, dmu_buf_impl_t *,
-				    db, zio_t *, zio);
+				    db, zio_t *, pio);
 				cv_wait(&db->db_changed, &db->db_mtx);
 			}
 			if (db->db_state == DB_UNCACHED)
@@ -1871,6 +1865,13 @@ dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
 		}
 	}
 
+	if (pio && err != 0) {
+		zio_t *zio = zio_null(pio, pio->io_spa, NULL, NULL, NULL,
+		    ZIO_FLAG_CANFAIL);
+		zio->io_error = err;
+		zio_nowait(zio);
+	}
+
 	return (err);
 }
 
@@ -2615,26 +2616,24 @@ dmu_buf_will_dirty_impl(dmu_buf_t *db_fake, int flags, dmu_tx_t *tx)
 	ASSERT(!zfs_refcount_is_zero(&db->db_holds));
 
 	/*
-	 * Quick check for dirtiness.  For already dirty blocks, this
-	 * reduces runtime of this function by >90%, and overall performance
-	 * by 50% for some workloads (e.g. file deletion with indirect blocks
-	 * cached).
+	 * Quick check for dirtiness to improve performance for some workloads
+	 * (e.g. file deletion with indirect blocks cached).
 	 */
 	mutex_enter(&db->db_mtx);
-
 	if (db->db_state == DB_CACHED || db->db_state == DB_NOFILL) {
-		dbuf_dirty_record_t *dr = dbuf_find_dirty_eq(db, tx->tx_txg);
 		/*
-		 * It's possible that it is already dirty but not cached,
+		 * It's possible that the dbuf is already dirty but not cached,
 		 * because there are some calls to dbuf_dirty() that don't
 		 * go through dmu_buf_will_dirty().
 		 */
+		dbuf_dirty_record_t *dr = dbuf_find_dirty_eq(db, tx->tx_txg);
 		if (dr != NULL) {
-			if (dr->dt.dl.dr_brtwrite) {
+			if (db->db_level == 0 &&
+			    dr->dt.dl.dr_brtwrite) {
 				/*
 				 * Block cloning: If we are dirtying a cloned
-				 * block, we cannot simply redirty it, because
-				 * this dr has no data associated with it.
+				 * level 0 block, we cannot simply redirty it,
+				 * because this dr has no associated data.
 				 * We will go through a full undirtying below,
 				 * before dirtying it again.
 				 */
@@ -2702,7 +2701,7 @@ dmu_buf_will_clone(dmu_buf_t *db_fake, dmu_tx_t *tx)
 	mutex_enter(&db->db_mtx);
 	DBUF_VERIFY(db);
 	VERIFY(!dbuf_undirty(db, tx));
-	ASSERT3P(dbuf_find_dirty_eq(db, tx->tx_txg), ==, NULL);
+	ASSERT0P(dbuf_find_dirty_eq(db, tx->tx_txg));
 	if (db->db_buf != NULL) {
 		arc_buf_destroy(db->db_buf, db);
 		db->db_buf = NULL;
@@ -4127,21 +4126,6 @@ dmu_buf_get_objset(dmu_buf_t *db)
 	return (dbi->db_objset);
 }
 
-dnode_t *
-dmu_buf_dnode_enter(dmu_buf_t *db)
-{
-	dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
-	DB_DNODE_ENTER(dbi);
-	return (DB_DNODE(dbi));
-}
-
-void
-dmu_buf_dnode_exit(dmu_buf_t *db)
-{
-	dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
-	DB_DNODE_EXIT(dbi);
-}
-
 static void
 dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
 {
@@ -4564,11 +4548,10 @@ dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
 	if (os->os_encrypted && dn->dn_object == DMU_META_DNODE_OBJECT)
 		dbuf_prepare_encrypted_dnode_leaf(dr);
 
-	if (db->db_state != DB_NOFILL &&
+	if (*datap != NULL && *datap == db->db_buf &&
 	    dn->dn_object != DMU_META_DNODE_OBJECT &&
 	    zfs_refcount_count(&db->db_holds) > 1 &&
-	    dr->dt.dl.dr_override_state != DR_OVERRIDDEN &&
-	    *datap == db->db_buf) {
+	    dr->dt.dl.dr_override_state != DR_OVERRIDDEN) {
 		/*
 		 * If this buffer is currently "in use" (i.e., there
 		 * are active holds and db_data still references it),
@@ -4853,11 +4836,9 @@ dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
 	if (db->db_level == 0) {
 		ASSERT(db->db_blkid != DMU_BONUS_BLKID);
 		ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
-		if (db->db_state != DB_NOFILL) {
-			if (dr->dt.dl.dr_data != NULL &&
-			    dr->dt.dl.dr_data != db->db_buf) {
-				arc_buf_destroy(dr->dt.dl.dr_data, db);
-			}
+		if (dr->dt.dl.dr_data != NULL &&
+		    dr->dt.dl.dr_data != db->db_buf) {
+			arc_buf_destroy(dr->dt.dl.dr_data, db);
 		}
 	} else {
 		ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
@@ -5056,21 +5037,18 @@ dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
 
 	os = dn->dn_objset;
 
-	if (db->db_state != DB_NOFILL) {
-		if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) {
-			/*
-			 * Private object buffers are released here rather
-			 * than in dbuf_dirty() since they are only modified
-			 * in the syncing context and we don't want the
-			 * overhead of making multiple copies of the data.
-			 */
-			if (BP_IS_HOLE(db->db_blkptr)) {
-				arc_buf_thaw(data);
-			} else {
-				dbuf_release_bp(db);
-			}
-			dbuf_remap(dn, db, tx);
-		}
+	if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) {
+		/*
+		 * Private object buffers are released here rather than in
+		 * dbuf_dirty() since they are only modified in the syncing
+		 * context and we don't want the overhead of making multiple
+		 * copies of the data.
+		 */
+		if (BP_IS_HOLE(db->db_blkptr))
+			arc_buf_thaw(data);
+		else
+			dbuf_release_bp(db);
+		dbuf_remap(dn, db, tx);
 	}
 
 	if (parent != dn->dn_dbuf) {
@@ -5106,7 +5084,7 @@ dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
 
 	if (db->db_blkid == DMU_SPILL_BLKID)
 		wp_flag = WP_SPILL;
-	wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0;
+	wp_flag |= (data == NULL) ? WP_NOFILL : 0;
 
 	dmu_write_policy(os, dn, db->db_level, wp_flag, &zp);
 
@@ -5138,7 +5116,7 @@ dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
 		    dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite,
 		    dr->dt.dl.dr_brtwrite);
 		mutex_exit(&db->db_mtx);
-	} else if (db->db_state == DB_NOFILL) {
+	} else if (data == NULL) {
 		ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF ||
 		    zp.zp_checksum == ZIO_CHECKSUM_NOPARITY);
 		dr->dr_zio = zio_write(pio, os->os_spa, txg,
diff --git a/sys/contrib/openzfs/module/zfs/dmu.c b/sys/contrib/openzfs/module/zfs/dmu.c
index 3215ab1c2a14..d8d5cfdbd230 100644
--- a/sys/contrib/openzfs/module/zfs/dmu.c
+++ b/sys/contrib/openzfs/module/zfs/dmu.c
@@ -569,8 +569,10 @@ dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
 	for (i = 0; i < nblks; i++) {
 		dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag);
 		if (db == NULL) {
-			if (zs)
-				dmu_zfetch_run(zs, missed, B_TRUE);
+			if (zs) {
+				dmu_zfetch_run(&dn->dn_zfetch, zs, missed,
+				    B_TRUE);
+			}
 			rw_exit(&dn->dn_struct_rwlock);
 			dmu_buf_rele_array(dbp, nblks, tag);
 			if (read)
@@ -606,7 +608,7 @@ dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
 		zfs_racct_write(length, nblks);
 
 	if (zs)
-		dmu_zfetch_run(zs, missed, B_TRUE);
+		dmu_zfetch_run(&dn->dn_zfetch, zs, missed, B_TRUE);
 	rw_exit(&dn->dn_struct_rwlock);
 
 	if (read) {
@@ -695,72 +697,99 @@ dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, const void *tag)
 }
 
 /*
- * Issue prefetch i/os for the given blocks.  If level is greater than 0, the
+ * Issue prefetch I/Os for the given blocks.  If level is greater than 0, the
  * indirect blocks prefetched will be those that point to the blocks containing
- * the data starting at offset, and continuing to offset + len.
+ * the data starting at offset, and continuing to offset + len.  If the range
+ * it too long, prefetch the first dmu_prefetch_max bytes as requested, while
+ * for the rest only a higher level, also fitting within dmu_prefetch_max.  It
+ * should primarily help random reads, since for long sequential reads there is
+ * a speculative prefetcher.
  *
  * Note that if the indirect blocks above the blocks being prefetched are not
- * in cache, they will be asynchronously read in.
+ * in cache, they will be asynchronously read in.  Dnode read by dnode_hold()
+ * is currently synchronous.
  */
 void
 dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
     uint64_t len, zio_priority_t pri)
 {
 	dnode_t *dn;
-	uint64_t blkid;
-	int nblks, err;
-
-	if (len == 0) {  /* they're interested in the bonus buffer */
-		dn = DMU_META_DNODE(os);
 
-		if (object == 0 || object >= DN_MAX_OBJECT)
-			return;
-
-		rw_enter(&dn->dn_struct_rwlock, RW_READER);
-		blkid = dbuf_whichblock(dn, level,
-		    object * sizeof (dnode_phys_t));
-		dbuf_prefetch(dn, level, blkid, pri, 0);
-		rw_exit(&dn->dn_struct_rwlock);
+	if (dmu_prefetch_max == 0 || len == 0) {
+		dmu_prefetch_dnode(os, object, pri);
 		return;
 	}
 
-	/*
-	 * See comment before the definition of dmu_prefetch_max.
-	 */
-	len = MIN(len, dmu_prefetch_max);
-
-	/*
-	 * XXX - Note, if the dnode for the requested object is not
-	 * already cached, we will do a *synchronous* read in the
-	 * dnode_hold() call.  The same is true for any indirects.
-	 */
-	err = dnode_hold(os, object, FTAG, &dn);
-	if (err != 0)
+	if (dnode_hold(os, object, FTAG, &dn) != 0)
 		return;
 
+	dmu_prefetch_by_dnode(dn, level, offset, len, pri);
+
+	dnode_rele(dn, FTAG);
+}
+
+void
+dmu_prefetch_by_dnode(dnode_t *dn, int64_t level, uint64_t offset,
+    uint64_t len, zio_priority_t pri)
+{
+	int64_t level2 = level;
+	uint64_t start, end, start2, end2;
+
 	/*
-	 * offset + len - 1 is the last byte we want to prefetch for, and offset
-	 * is the first.  Then dbuf_whichblk(dn, level, off + len - 1) is the
-	 * last block we want to prefetch, and dbuf_whichblock(dn, level,
-	 * offset)  is the first.  Then the number we need to prefetch is the
-	 * last - first + 1.
+	 * Depending on len we may do two prefetches: blocks [start, end) at
+	 * level, and following blocks [start2, end2) at higher level2.
 	 */
 	rw_enter(&dn->dn_struct_rwlock, RW_READER);
-	if (level > 0 || dn->dn_datablkshift != 0) {
-		nblks = dbuf_whichblock(dn, level, offset + len - 1) -
-		    dbuf_whichblock(dn, level, offset) + 1;
+	if (dn->dn_datablkshift != 0) {
+		/*
+		 * The object has multiple blocks.  Calculate the full range
+		 * of blocks [start, end2) and then split it into two parts,
+		 * so that the first [start, end) fits into dmu_prefetch_max.
+		 */
+		start = dbuf_whichblock(dn, level, offset);
+		end2 = dbuf_whichblock(dn, level, offset + len - 1) + 1;
+		uint8_t ibs = dn->dn_indblkshift;
+		uint8_t bs = (level == 0) ? dn->dn_datablkshift : ibs;
+		uint_t limit = P2ROUNDUP(dmu_prefetch_max, 1 << bs) >> bs;
+		start2 = end = MIN(end2, start + limit);
+
+		/*
+		 * Find level2 where [start2, end2) fits into dmu_prefetch_max.
+		 */
+		uint8_t ibps = ibs - SPA_BLKPTRSHIFT;
+		limit = P2ROUNDUP(dmu_prefetch_max, 1 << ibs) >> ibs;
+		do {
+			level2++;
+			start2 = P2ROUNDUP(start2, 1 << ibps) >> ibps;
+			end2 = P2ROUNDUP(end2, 1 << ibps) >> ibps;
+		} while (end2 - start2 > limit);
 	} else {
-		nblks = (offset < dn->dn_datablksz);
+		/* There is only one block.  Prefetch it or nothing. */
+		start = start2 = end2 = 0;
+		end = start + (level == 0 && offset < dn->dn_datablksz);
 	}
 
-	if (nblks != 0) {
-		blkid = dbuf_whichblock(dn, level, offset);
-		for (int i = 0; i < nblks; i++)
-			dbuf_prefetch(dn, level, blkid + i, pri, 0);
-	}
+	for (uint64_t i = start; i < end; i++)
+		dbuf_prefetch(dn, level, i, pri, 0);
+	for (uint64_t i = start2; i < end2; i++)
+		dbuf_prefetch(dn, level2, i, pri, 0);
 	rw_exit(&dn->dn_struct_rwlock);
+}
 
-	dnode_rele(dn, FTAG);
+/*
+ * Issue prefetch I/Os for the given object's dnode.
+ */
+void
+dmu_prefetch_dnode(objset_t *os, uint64_t object, zio_priority_t pri)
+{
+	if (object == 0 || object >= DN_MAX_OBJECT)
+		return;
+
+	dnode_t *dn = DMU_META_DNODE(os);
+	rw_enter(&dn->dn_struct_rwlock, RW_READER);
+	uint64_t blkid = dbuf_whichblock(dn, 0, object * sizeof (dnode_phys_t));
+	dbuf_prefetch(dn, 0, blkid, pri, 0);
+	rw_exit(&dn->dn_struct_rwlock);
 }
 
 /*
@@ -2238,11 +2267,13 @@ dmu_read_l0_bps(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
 
 		if (bp == NULL) {
 			/*
-			 * The block was created in this transaction group,
-			 * so it has no BP yet.
+			 * The file size was increased, but the block was never
+			 * written, otherwise we would either have the block
+			 * pointer or the dirty record and would not get here.
+			 * It is effectively a hole, so report it as such.
 			 */
-			error = SET_ERROR(EAGAIN);
-			goto out;
+			BP_ZERO(&bps[i]);
+			continue;
 		}
 		/*
 		 * Make sure we clone only data blocks.
@@ -2334,18 +2365,16 @@ dmu_brt_clone(objset_t *os, uint64_t object, uint64_t offset, uint64_t length,
 		ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
 		dl = &dr->dt.dl;
 		dl->dr_overridden_by = *bp;
-		dl->dr_brtwrite = B_TRUE;
-		dl->dr_override_state = DR_OVERRIDDEN;
-		if (BP_IS_HOLE(bp)) {
-			dl->dr_overridden_by.blk_birth = 0;
-			dl->dr_overridden_by.blk_phys_birth = 0;
-		} else {
-			dl->dr_overridden_by.blk_birth = dr->dr_txg;
+		if (!BP_IS_HOLE(bp) || bp->blk_birth != 0) {
 			if (!BP_IS_EMBEDDED(bp)) {
-				dl->dr_overridden_by.blk_phys_birth =
-				    BP_PHYSICAL_BIRTH(bp);
+				BP_SET_BIRTH(&dl->dr_overridden_by, dr->dr_txg,
+				    BP_PHYSICAL_BIRTH(bp));
+			} else {
+				dl->dr_overridden_by.blk_birth = dr->dr_txg;
 			}
 		}
+		dl->dr_brtwrite = B_TRUE;
+		dl->dr_override_state = DR_OVERRIDDEN;
 
 		mutex_exit(&db->db_mtx);
 
@@ -2544,6 +2573,8 @@ EXPORT_SYMBOL(dmu_bonus_hold_by_dnode);
 EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
 EXPORT_SYMBOL(dmu_buf_rele_array);
 EXPORT_SYMBOL(dmu_prefetch);
+EXPORT_SYMBOL(dmu_prefetch_by_dnode);
+EXPORT_SYMBOL(dmu_prefetch_dnode);
 EXPORT_SYMBOL(dmu_free_range);
 EXPORT_SYMBOL(dmu_free_long_range);
 EXPORT_SYMBOL(dmu_free_long_object);
diff --git a/sys/contrib/openzfs/module/zfs/dmu_objset.c b/sys/contrib/openzfs/module/zfs/dmu_objset.c
index d134d4958f7c..ef966d6703c9 100644
--- a/sys/contrib/openzfs/module/zfs/dmu_objset.c
+++ b/sys/contrib/openzfs/module/zfs/dmu_objset.c
@@ -264,6 +264,19 @@ secondary_cache_changed_cb(void *arg, uint64_t newval)
 }
 
 static void
+prefetch_changed_cb(void *arg, uint64_t newval)
+{
+	objset_t *os = arg;
+
+	/*
+	 * Inheritance should have been done by now.
+	 */
+	ASSERT(newval == ZFS_PREFETCH_ALL || newval == ZFS_PREFETCH_NONE ||
+	    newval == ZFS_PREFETCH_METADATA);
+	os->os_prefetch = newval;
+}
+
+static void
 sync_changed_cb(void *arg, uint64_t newval)
 {
 	objset_t *os = arg;
@@ -562,6 +575,11 @@ dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
 			    zfs_prop_to_name(ZFS_PROP_SECONDARYCACHE),
 			    secondary_cache_changed_cb, os);
 		}
+		if (err == 0) {
+			err = dsl_prop_register(ds,
+			    zfs_prop_to_name(ZFS_PROP_PREFETCH),
+			    prefetch_changed_cb, os);
+		}
 		if (!ds->ds_is_snapshot) {
 			if (err == 0) {
 				err = dsl_prop_register(ds,
@@ -635,6 +653,7 @@ dmu_objset_open_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
 		os->os_primary_cache = ZFS_CACHE_ALL;
 		os->os_secondary_cache = ZFS_CACHE_ALL;
 		os->os_dnodesize = DNODE_MIN_SIZE;
+		os->os_prefetch = ZFS_PREFETCH_ALL;
 	}
 
 	if (ds == NULL || !ds->ds_is_snapshot)
@@ -1633,7 +1652,7 @@ sync_dnodes_task(void *arg)
 	sync_dnodes_arg_t *sda = arg;
 
 	multilist_sublist_t *ms =
-	    multilist_sublist_lock(sda->sda_list, sda->sda_sublist_idx);
+	    multilist_sublist_lock_idx(sda->sda_list, sda->sda_sublist_idx);
 
 	dmu_objset_sync_dnodes(ms, sda->sda_tx);
 
@@ -1987,8 +2006,8 @@ userquota_updates_task(void *arg)
 	dnode_t *dn;
 	userquota_cache_t cache = { { 0 } };
 
-	multilist_sublist_t *list =
-	    multilist_sublist_lock(&os->os_synced_dnodes, uua->uua_sublist_idx);
+	multilist_sublist_t *list = multilist_sublist_lock_idx(
+	    &os->os_synced_dnodes, uua->uua_sublist_idx);
 
 	ASSERT(multilist_sublist_head(list) == NULL ||
 	    dmu_objset_userused_enabled(os));
@@ -2070,8 +2089,8 @@ dnode_rele_task(void *arg)
 	userquota_updates_arg_t *uua = arg;
 	objset_t *os = uua->uua_os;
 
-	multilist_sublist_t *list =
-	    multilist_sublist_lock(&os->os_synced_dnodes, uua->uua_sublist_idx);
+	multilist_sublist_t *list = multilist_sublist_lock_idx(
+	    &os->os_synced_dnodes, uua->uua_sublist_idx);
 
 	dnode_t *dn;
 	while ((dn = multilist_sublist_head(list)) != NULL) {
diff --git a/sys/contrib/openzfs/module/zfs/dmu_recv.c b/sys/contrib/openzfs/module/zfs/dmu_recv.c
index 54aa60259ea1..9f1c25f866f7 100644
--- a/sys/contrib/openzfs/module/zfs/dmu_recv.c
+++ b/sys/contrib/openzfs/module/zfs/dmu_recv.c
@@ -2110,6 +2110,16 @@ receive_object(struct receive_writer_arg *rwa, struct drr_object *drro,
 		dmu_buf_rele(db, FTAG);
 		dnode_rele(dn, FTAG);
 	}
+
+	/*
+	 * If the receive fails, we want the resume stream to start with the
+	 * same record that we last successfully received. There is no way to
+	 * request resume from the object record, but we can benefit from the
+	 * fact that sender always sends object record before anything else,
+	 * after which it will "resend" data at offset 0 and resume normally.
+	 */
+	save_resume_state(rwa, drro->drr_object, 0, tx);
+
 	dmu_tx_commit(tx);
 
 	return (0);
@@ -2343,7 +2353,6 @@ receive_process_write_record(struct receive_writer_arg *rwa,
 	if (rwa->heal) {
 		blkptr_t *bp;
 		dmu_buf_t *dbp;
-		dnode_t *dn;
 		int flags = DB_RF_CANFAIL;
 
 		if (rwa->raw)
@@ -2375,19 +2384,15 @@ receive_process_write_record(struct receive_writer_arg *rwa,
 			dmu_buf_rele(dbp, FTAG);
 			return (err);
 		}
-		dn = dmu_buf_dnode_enter(dbp);
 		/* Make sure the on-disk block and recv record sizes match */
-		if (drrw->drr_logical_size !=
-		    dn->dn_datablkszsec << SPA_MINBLOCKSHIFT) {
+		if (drrw->drr_logical_size != dbp->db_size) {
 			err = ENOTSUP;
-			dmu_buf_dnode_exit(dbp);
 			dmu_buf_rele(dbp, FTAG);
 			return (err);
 		}
 		/* Get the block pointer for the corrupted block */
 		bp = dmu_buf_get_blkptr(dbp);
 		err = do_corrective_recv(rwa, drrw, rrd, bp);
-		dmu_buf_dnode_exit(dbp);
 		dmu_buf_rele(dbp, FTAG);
 		return (err);
 	}
diff --git a/sys/contrib/openzfs/module/zfs/dmu_zfetch.c b/sys/contrib/openzfs/module/zfs/dmu_zfetch.c
index d0acaf502066..ed50f1889b59 100644
--- a/sys/contrib/openzfs/module/zfs/dmu_zfetch.c
+++ b/sys/contrib/openzfs/module/zfs/dmu_zfetch.c
@@ -65,9 +65,16 @@ unsigned int	zfetch_max_distance = 64 * 1024 * 1024;
 #endif
 /* max bytes to prefetch indirects for per stream (default 64MB) */
 unsigned int	zfetch_max_idistance = 64 * 1024 * 1024;
+/* max request reorder distance within a stream (default 16MB) */
+unsigned int	zfetch_max_reorder = 16 * 1024 * 1024;
+/* Max log2 fraction of holes in a stream */
+unsigned int	zfetch_hole_shift = 2;
 
 typedef struct zfetch_stats {
 	kstat_named_t zfetchstat_hits;
+	kstat_named_t zfetchstat_future;
+	kstat_named_t zfetchstat_stride;
+	kstat_named_t zfetchstat_past;
 	kstat_named_t zfetchstat_misses;
 	kstat_named_t zfetchstat_max_streams;
 	kstat_named_t zfetchstat_io_issued;
@@ -76,6 +83,9 @@ typedef struct zfetch_stats {
 
 static zfetch_stats_t zfetch_stats = {
 	{ "hits",			KSTAT_DATA_UINT64 },
+	{ "future",			KSTAT_DATA_UINT64 },
+	{ "stride",			KSTAT_DATA_UINT64 },
+	{ "past",			KSTAT_DATA_UINT64 },
 	{ "misses",			KSTAT_DATA_UINT64 },
 	{ "max_streams",		KSTAT_DATA_UINT64 },
 	{ "io_issued",			KSTAT_DATA_UINT64 },
@@ -84,6 +94,9 @@ static zfetch_stats_t zfetch_stats = {
 
 struct {
 	wmsum_t zfetchstat_hits;
+	wmsum_t zfetchstat_future;
+	wmsum_t zfetchstat_stride;
+	wmsum_t zfetchstat_past;
 	wmsum_t zfetchstat_misses;
 	wmsum_t zfetchstat_max_streams;
 	wmsum_t zfetchstat_io_issued;
@@ -107,6 +120,12 @@ zfetch_kstats_update(kstat_t *ksp, int rw)
 		return (EACCES);
 	zs->zfetchstat_hits.value.ui64 =
 	    wmsum_value(&zfetch_sums.zfetchstat_hits);
+	zs->zfetchstat_future.value.ui64 =
+	    wmsum_value(&zfetch_sums.zfetchstat_future);
+	zs->zfetchstat_stride.value.ui64 =
+	    wmsum_value(&zfetch_sums.zfetchstat_stride);
+	zs->zfetchstat_past.value.ui64 =
+	    wmsum_value(&zfetch_sums.zfetchstat_past);
 	zs->zfetchstat_misses.value.ui64 =
 	    wmsum_value(&zfetch_sums.zfetchstat_misses);
 	zs->zfetchstat_max_streams.value.ui64 =
@@ -122,6 +141,9 @@ void
 zfetch_init(void)
 {
 	wmsum_init(&zfetch_sums.zfetchstat_hits, 0);
+	wmsum_init(&zfetch_sums.zfetchstat_future, 0);
+	wmsum_init(&zfetch_sums.zfetchstat_stride, 0);
+	wmsum_init(&zfetch_sums.zfetchstat_past, 0);
 	wmsum_init(&zfetch_sums.zfetchstat_misses, 0);
 	wmsum_init(&zfetch_sums.zfetchstat_max_streams, 0);
 	wmsum_init(&zfetch_sums.zfetchstat_io_issued, 0);
@@ -147,6 +169,9 @@ zfetch_fini(void)
 	}
 
 	wmsum_fini(&zfetch_sums.zfetchstat_hits);
+	wmsum_fini(&zfetch_sums.zfetchstat_future);
+	wmsum_fini(&zfetch_sums.zfetchstat_stride);
+	wmsum_fini(&zfetch_sums.zfetchstat_past);
 	wmsum_fini(&zfetch_sums.zfetchstat_misses);
 	wmsum_fini(&zfetch_sums.zfetchstat_max_streams);
 	wmsum_fini(&zfetch_sums.zfetchstat_io_issued);
@@ -222,22 +247,22 @@ static void
 dmu_zfetch_stream_create(zfetch_t *zf, uint64_t blkid)
 {
 	zstream_t *zs, *zs_next, *zs_old = NULL;
-	hrtime_t now = gethrtime(), t;
+	uint_t now = gethrestime_sec(), t;
 
 	ASSERT(MUTEX_HELD(&zf->zf_lock));
 
 	/*
 	 * Delete too old streams, reusing the first found one.
 	 */
-	t = now - SEC2NSEC(zfetch_max_sec_reap);
+	t = now - zfetch_max_sec_reap;
 	for (zs = list_head(&zf->zf_stream); zs != NULL; zs = zs_next) {
 		zs_next = list_next(&zf->zf_stream, zs);
 		/*
 		 * Skip if still active.  1 -- zf_stream reference.
 		 */
-		if (zfs_refcount_count(&zs->zs_refs) != 1)
+		if ((int)(zs->zs_atime - t) >= 0)
 			continue;
-		if (zs->zs_atime > t)
+		if (zfs_refcount_count(&zs->zs_refs) != 1)
 			continue;
 		if (zs_old)
 			dmu_zfetch_stream_remove(zf, zs);
@@ -246,6 +271,7 @@ dmu_zfetch_stream_create(zfetch_t *zf, uint64_t blkid)
 	}
 	if (zs_old) {
 		zs = zs_old;
+		list_remove(&zf->zf_stream, zs);
 		goto reuse;
 	}
 
@@ -255,21 +281,23 @@ dmu_zfetch_stream_create(zfetch_t *zf, uint64_t blkid)
 	 * for all the streams to be non-overlapping.
 	 */
 	uint32_t max_streams = MAX(1, MIN(zfetch_max_streams,
-	    zf->zf_dnode->dn_maxblkid * zf->zf_dnode->dn_datablksz /
+	    (zf->zf_dnode->dn_maxblkid << zf->zf_dnode->dn_datablkshift) /
 	    zfetch_max_distance));
 	if (zf->zf_numstreams >= max_streams) {
-		t = now - SEC2NSEC(zfetch_min_sec_reap);
+		t = now - zfetch_min_sec_reap;
 		for (zs = list_head(&zf->zf_stream); zs != NULL;
 		    zs = list_next(&zf->zf_stream, zs)) {
-			if (zfs_refcount_count(&zs->zs_refs) != 1)
+			if ((int)(zs->zs_atime - t) >= 0)
 				continue;
-			if (zs->zs_atime > t)
+			if (zfs_refcount_count(&zs->zs_refs) != 1)
 				continue;
-			if (zs_old == NULL || zs->zs_atime < zs_old->zs_atime)
+			if (zs_old == NULL ||
+			    (int)(zs_old->zs_atime - zs->zs_atime) >= 0)
 				zs_old = zs;
 		}
 		if (zs_old) {
 			zs = zs_old;
+			list_remove(&zf->zf_stream, zs);
 			goto reuse;
 		}
 		ZFETCHSTAT_BUMP(zfetchstat_max_streams);
@@ -277,24 +305,24 @@ dmu_zfetch_stream_create(zfetch_t *zf, uint64_t blkid)
 	}
 
 	zs = kmem_zalloc(sizeof (*zs), KM_SLEEP);
-	zs->zs_fetch = zf;
 	zfs_refcount_create(&zs->zs_callers);
 	zfs_refcount_create(&zs->zs_refs);
 	/* One reference for zf_stream. */
 	zfs_refcount_add(&zs->zs_refs, NULL);
 	zf->zf_numstreams++;
-	list_insert_head(&zf->zf_stream, zs);
 
 reuse:
+	list_insert_head(&zf->zf_stream, zs);
 	zs->zs_blkid = blkid;
+	/* Allow immediate stream reuse until first hit. */
+	zs->zs_atime = now - zfetch_min_sec_reap;
+	memset(zs->zs_ranges, 0, sizeof (zs->zs_ranges));
 	zs->zs_pf_dist = 0;
+	zs->zs_ipf_dist = 0;
 	zs->zs_pf_start = blkid;
 	zs->zs_pf_end = blkid;
-	zs->zs_ipf_dist = 0;
 	zs->zs_ipf_start = blkid;
 	zs->zs_ipf_end = blkid;
-	/* Allow immediate stream reuse until first hit. */
-	zs->zs_atime = now - SEC2NSEC(zfetch_min_sec_reap);
 	zs->zs_missed = B_FALSE;
 	zs->zs_more = B_FALSE;
 }
@@ -312,6 +340,120 @@ dmu_zfetch_done(void *arg, uint64_t level, uint64_t blkid, boolean_t io_issued)
 }
 
 /*
+ * Process stream hit access for nblks blocks starting at zs_blkid.  Return
+ * number of blocks to proceed for after aggregation with future ranges.
+ */
+static uint64_t
+dmu_zfetch_hit(zstream_t *zs, uint64_t nblks)
+{
+	uint_t i, j;
+
+	/* Optimize sequential accesses (no future ranges). */
+	if (zs->zs_ranges[0].start == 0)
+		goto done;
+
+	/* Look for intersections with further ranges. */
+	for (i = 0; i < ZFETCH_RANGES; i++) {
+		zsrange_t *r = &zs->zs_ranges[i];
+		if (r->start == 0 || r->start > nblks)
+			break;
+		if (r->end >= nblks) {
+			nblks = r->end;
+			i++;
+			break;
+		}
+	}
+
+	/* Delete all found intersecting ranges, updates remaining. */
+	for (j = 0; i < ZFETCH_RANGES; i++, j++) {
+		if (zs->zs_ranges[i].start == 0)
+			break;
+		ASSERT3U(zs->zs_ranges[i].start, >, nblks);
+		ASSERT3U(zs->zs_ranges[i].end, >, nblks);
+		zs->zs_ranges[j].start = zs->zs_ranges[i].start - nblks;
+		zs->zs_ranges[j].end = zs->zs_ranges[i].end - nblks;
+	}
+	if (j < ZFETCH_RANGES) {
+		zs->zs_ranges[j].start = 0;
+		zs->zs_ranges[j].end = 0;
+	}
+
+done:
+	zs->zs_blkid += nblks;
+	return (nblks);
+}
+
+/*
+ * Process future stream access for nblks blocks starting at blkid.  Return
+ * number of blocks to proceed for if future ranges reach fill threshold.
+ */
+static uint64_t
+dmu_zfetch_future(zstream_t *zs, uint64_t blkid, uint64_t nblks)
+{
+	ASSERT3U(blkid, >, zs->zs_blkid);
+	blkid -= zs->zs_blkid;
+	ASSERT3U(blkid + nblks, <=, UINT16_MAX);
+
+	/* Search for first and last intersection or insert point. */
+	uint_t f = ZFETCH_RANGES, l = 0, i;
+	for (i = 0; i < ZFETCH_RANGES; i++) {
+		zsrange_t *r = &zs->zs_ranges[i];
+		if (r->start == 0 || r->start > blkid + nblks)
+			break;
+		if (r->end < blkid)
+			continue;
+		if (f > i)
+			f = i;
+		if (l < i)
+			l = i;
+	}
+	if (f <= l) {
+		/* Got some intersecting range, expand it if needed. */
+		if (zs->zs_ranges[f].start > blkid)
+			zs->zs_ranges[f].start = blkid;
+		zs->zs_ranges[f].end = MAX(zs->zs_ranges[l].end, blkid + nblks);
+		if (f < l) {
+			/* Got more than one intersection, remove others. */
+			for (f++, l++; l < ZFETCH_RANGES; f++, l++) {
+				zs->zs_ranges[f].start = zs->zs_ranges[l].start;
+				zs->zs_ranges[f].end = zs->zs_ranges[l].end;
+			}
+			zs->zs_ranges[f].start = 0;
+			zs->zs_ranges[f].end = 0;
+		}
+	} else if (i < ZFETCH_RANGES) {
+		/* Got no intersecting ranges, insert new one. */
+		for (l = ZFETCH_RANGES - 1; l > i; l--) {
+			zs->zs_ranges[l].start = zs->zs_ranges[l - 1].start;
+			zs->zs_ranges[l].end = zs->zs_ranges[l - 1].end;
+		}
+		zs->zs_ranges[i].start = blkid;
+		zs->zs_ranges[i].end = blkid + nblks;
+	} else {
+		/* No space left to insert.  Drop the range. */
+		return (0);
+	}
+
+	/* Check if with the new access addition we reached fill threshold. */
+	if (zfetch_hole_shift >= 16)
+		return (0);
+	uint_t hole = 0;
+	for (i = f = l = 0; i < ZFETCH_RANGES; i++) {
+		zsrange_t *r = &zs->zs_ranges[i];
+		if (r->start == 0)
+			break;
+		hole += r->start - f;
+		f = r->end;
+		if (hole <= r->end >> zfetch_hole_shift)
+			l = r->end;
+	}
+	if (l > 0)
+		return (dmu_zfetch_hit(zs, l));
+
+	return (0);
+}
+
+/*
  * This is the predictive prefetch entry point.  dmu_zfetch_prepare()
  * associates dnode access specified with blkid and nblks arguments with
  * prefetch stream, predicts further accesses based on that stats and returns
@@ -329,9 +471,14 @@ dmu_zfetch_prepare(zfetch_t *zf, uint64_t blkid, uint64_t nblks,
 {
 	zstream_t *zs;
 	spa_t *spa = zf->zf_dnode->dn_objset->os_spa;
+	zfs_prefetch_type_t os_prefetch = zf->zf_dnode->dn_objset->os_prefetch;
 
-	if (zfs_prefetch_disable)
+	if (zfs_prefetch_disable || os_prefetch == ZFS_PREFETCH_NONE)
 		return (NULL);
+
+	if (os_prefetch == ZFS_PREFETCH_METADATA)
+		fetch_data = B_FALSE;
+
 	/*
 	 * If we haven't yet loaded the indirect vdevs' mappings, we
 	 * can only read from blocks that we carefully ensure are on
@@ -365,53 +512,92 @@ dmu_zfetch_prepare(zfetch_t *zf, uint64_t blkid, uint64_t nblks,
 	mutex_enter(&zf->zf_lock);
 
 	/*
-	 * Find matching prefetch stream.  Depending on whether the accesses
+	 * Find perfect prefetch stream.  Depending on whether the accesses
 	 * are block-aligned, first block of the new access may either follow
 	 * the last block of the previous access, or be equal to it.
 	 */
+	unsigned int dbs = zf->zf_dnode->dn_datablkshift;
+	uint64_t end_blkid = blkid + nblks;
 	for (zs = list_head(&zf->zf_stream); zs != NULL;
 	    zs = list_next(&zf->zf_stream, zs)) {
 		if (blkid == zs->zs_blkid) {
-			break;
+			goto hit;
 		} else if (blkid + 1 == zs->zs_blkid) {
 			blkid++;
 			nblks--;
-			break;
+			goto hit;
 		}
 	}
 
 	/*
-	 * If the file is ending, remove the matching stream if found.
-	 * If not found then it is too late to create a new one now.
+	 * Find close enough prefetch stream.  Access crossing stream position
+	 * is a hit in its new part.  Access ahead of stream position considered
+	 * a hit for metadata prefetch, since we do not care about fill percent,
+	 * or stored for future otherwise.  Access behind stream position is
+	 * silently ignored, since we already skipped it reaching fill percent.
 	 */
-	uint64_t end_of_access_blkid = blkid + nblks;
-	if (end_of_access_blkid >= maxblkid) {
-		if (zs != NULL)
-			dmu_zfetch_stream_remove(zf, zs);
-		mutex_exit(&zf->zf_lock);
-		if (!have_lock)
-			rw_exit(&zf->zf_dnode->dn_struct_rwlock);
-		return (NULL);
+	uint_t max_reorder = MIN((zfetch_max_reorder >> dbs) + 1, UINT16_MAX);
+	uint_t t = gethrestime_sec() - zfetch_max_sec_reap;
+	for (zs = list_head(&zf->zf_stream); zs != NULL;
+	    zs = list_next(&zf->zf_stream, zs)) {
+		if (blkid > zs->zs_blkid) {
+			if (end_blkid <= zs->zs_blkid + max_reorder) {
+				if (!fetch_data) {
+					nblks = dmu_zfetch_hit(zs,
+					    end_blkid - zs->zs_blkid);
+					ZFETCHSTAT_BUMP(zfetchstat_stride);
+					goto future;
+				}
+				nblks = dmu_zfetch_future(zs, blkid, nblks);
+				if (nblks > 0)
+					ZFETCHSTAT_BUMP(zfetchstat_stride);
+				else
+					ZFETCHSTAT_BUMP(zfetchstat_future);
+				goto future;
+			}
+		} else if (end_blkid >= zs->zs_blkid) {
+			nblks -= zs->zs_blkid - blkid;
+			blkid += zs->zs_blkid - blkid;
+			goto hit;
+		} else if (end_blkid + max_reorder > zs->zs_blkid &&
+		    (int)(zs->zs_atime - t) >= 0) {
+			ZFETCHSTAT_BUMP(zfetchstat_past);
+			zs->zs_atime = gethrestime_sec();
+			goto out;
+		}
 	}
 
-	/* Exit if we already prefetched this block before. */
-	if (nblks == 0) {
-		mutex_exit(&zf->zf_lock);
-		if (!have_lock)
-			rw_exit(&zf->zf_dnode->dn_struct_rwlock);
-		return (NULL);
-	}
+	/*
+	 * This access is not part of any existing stream.  Create a new
+	 * stream for it unless we are at the end of file.
+	 */
+	if (end_blkid < maxblkid)
+		dmu_zfetch_stream_create(zf, end_blkid);
+	mutex_exit(&zf->zf_lock);
+	if (!have_lock)
+		rw_exit(&zf->zf_dnode->dn_struct_rwlock);
+	ZFETCHSTAT_BUMP(zfetchstat_misses);
+	return (NULL);
 
-	if (zs == NULL) {
-		/*
-		 * This access is not part of any existing stream.  Create
-		 * a new stream for it.
-		 */
-		dmu_zfetch_stream_create(zf, end_of_access_blkid);
+hit:
+	nblks = dmu_zfetch_hit(zs, nblks);
+	ZFETCHSTAT_BUMP(zfetchstat_hits);
+
+future:
+	zs->zs_atime = gethrestime_sec();
+
+	/* Exit if we already prefetched for this position before. */
+	if (nblks == 0)
+		goto out;
+
+	/* If the file is ending, remove the stream. */
+	end_blkid = zs->zs_blkid;
+	if (end_blkid >= maxblkid) {
+		dmu_zfetch_stream_remove(zf, zs);
+out:
 		mutex_exit(&zf->zf_lock);
 		if (!have_lock)
 			rw_exit(&zf->zf_dnode->dn_struct_rwlock);
-		ZFETCHSTAT_BUMP(zfetchstat_misses);
 		return (NULL);
 	}
 
@@ -427,7 +613,6 @@ dmu_zfetch_prepare(zfetch_t *zf, uint64_t blkid, uint64_t nblks,
 	 * than ~6% of ARC held by active prefetches.  It should help with
 	 * getting out of RAM on some badly mispredicted read patterns.
 	 */
-	unsigned int dbs = zf->zf_dnode->dn_datablkshift;
 	unsigned int nbytes = nblks << dbs;
 	unsigned int pf_nblks;
 	if (fetch_data) {
@@ -447,10 +632,10 @@ dmu_zfetch_prepare(zfetch_t *zf, uint64_t blkid, uint64_t nblks,
 	} else {
 		pf_nblks = 0;
 	}
-	if (zs->zs_pf_start < end_of_access_blkid)
-		zs->zs_pf_start = end_of_access_blkid;
-	if (zs->zs_pf_end < end_of_access_blkid + pf_nblks)
-		zs->zs_pf_end = end_of_access_blkid + pf_nblks;
+	if (zs->zs_pf_start < end_blkid)
+		zs->zs_pf_start = end_blkid;
+	if (zs->zs_pf_end < end_blkid + pf_nblks)
+		zs->zs_pf_end = end_blkid + pf_nblks;
 
 	/*
 	 * Do the same for indirects, starting where we will stop reading
@@ -468,9 +653,6 @@ dmu_zfetch_prepare(zfetch_t *zf, uint64_t blkid, uint64_t nblks,
 	if (zs->zs_ipf_end < zs->zs_pf_end + pf_nblks)
 		zs->zs_ipf_end = zs->zs_pf_end + pf_nblks;
 
-	zs->zs_blkid = end_of_access_blkid;
-	/* Protect the stream from reclamation. */
-	zs->zs_atime = gethrtime();
 	zfs_refcount_add(&zs->zs_refs, NULL);
 	/* Count concurrent callers. */
 	zfs_refcount_add(&zs->zs_callers, NULL);
@@ -478,15 +660,13 @@ dmu_zfetch_prepare(zfetch_t *zf, uint64_t blkid, uint64_t nblks,
 
 	if (!have_lock)
 		rw_exit(&zf->zf_dnode->dn_struct_rwlock);
-
-	ZFETCHSTAT_BUMP(zfetchstat_hits);
 	return (zs);
 }
 
 void
-dmu_zfetch_run(zstream_t *zs, boolean_t missed, boolean_t have_lock)
+dmu_zfetch_run(zfetch_t *zf, zstream_t *zs, boolean_t missed,
+    boolean_t have_lock)
 {
-	zfetch_t *zf = zs->zs_fetch;
 	int64_t pf_start, pf_end, ipf_start, ipf_end;
 	int epbs, issued;
 
@@ -562,7 +742,7 @@ dmu_zfetch(zfetch_t *zf, uint64_t blkid, uint64_t nblks, boolean_t fetch_data,
 
 	zs = dmu_zfetch_prepare(zf, blkid, nblks, fetch_data, have_lock);
 	if (zs)
-		dmu_zfetch_run(zs, missed, have_lock);
+		dmu_zfetch_run(zf, zs, missed, have_lock);
 }
 
 ZFS_MODULE_PARAM(zfs_prefetch, zfs_prefetch_, disable, INT, ZMOD_RW,
@@ -585,3 +765,9 @@ ZFS_MODULE_PARAM(zfs_prefetch, zfetch_, max_distance, UINT, ZMOD_RW,
 
 ZFS_MODULE_PARAM(zfs_prefetch, zfetch_, max_idistance, UINT, ZMOD_RW,
 	"Max bytes to prefetch indirects for per stream");
+
+ZFS_MODULE_PARAM(zfs_prefetch, zfetch_, max_reorder, UINT, ZMOD_RW,
+	"Max request reorder distance within a stream");
+
+ZFS_MODULE_PARAM(zfs_prefetch, zfetch_, hole_shift, UINT, ZMOD_RW,
+	"Max log2 fraction of holes in a stream");
diff --git a/sys/contrib/openzfs/module/zfs/dsl_deadlist.c b/sys/contrib/openzfs/module/zfs/dsl_deadlist.c
index ac30a370813f..e6c8d4be13b4 100644
--- a/sys/contrib/openzfs/module/zfs/dsl_deadlist.c
+++ b/sys/contrib/openzfs/module/zfs/dsl_deadlist.c
@@ -173,8 +173,8 @@ dsl_deadlist_load_tree(dsl_deadlist_t *dl)
 		 * in parallel.  Then open them all in a second pass.
 		 */
 		dle->dle_bpobj.bpo_object = za.za_first_integer;
-		dmu_prefetch(dl->dl_os, dle->dle_bpobj.bpo_object,
-		    0, 0, 0, ZIO_PRIORITY_SYNC_READ);
+		dmu_prefetch_dnode(dl->dl_os, dle->dle_bpobj.bpo_object,
+		    ZIO_PRIORITY_SYNC_READ);
 
 		avl_add(&dl->dl_tree, dle);
 	}
@@ -235,8 +235,8 @@ dsl_deadlist_load_cache(dsl_deadlist_t *dl)
 		 * in parallel.  Then open them all in a second pass.
 		 */
 		dlce->dlce_bpobj = za.za_first_integer;
-		dmu_prefetch(dl->dl_os, dlce->dlce_bpobj,
-		    0, 0, 0, ZIO_PRIORITY_SYNC_READ);
+		dmu_prefetch_dnode(dl->dl_os, dlce->dlce_bpobj,
+		    ZIO_PRIORITY_SYNC_READ);
 		avl_add(&dl->dl_cache, dlce);
 	}
 	VERIFY3U(error, ==, ENOENT);
diff --git a/sys/contrib/openzfs/module/zfs/metaslab.c b/sys/contrib/openzfs/module/zfs/metaslab.c
index 5809a832bcb0..dbfc00362ff8 100644
--- a/sys/contrib/openzfs/module/zfs/metaslab.c
+++ b/sys/contrib/openzfs/module/zfs/metaslab.c
@@ -641,7 +641,7 @@ metaslab_class_evict_old(metaslab_class_t *mc, uint64_t txg)
 {
 	multilist_t *ml = &mc->mc_metaslab_txg_list;
 	for (int i = 0; i < multilist_get_num_sublists(ml); i++) {
-		multilist_sublist_t *mls = multilist_sublist_lock(ml, i);
+		multilist_sublist_t *mls = multilist_sublist_lock_idx(ml, i);
 		metaslab_t *msp = multilist_sublist_head(mls);
 		multilist_sublist_unlock(mls);
 		while (msp != NULL) {
@@ -658,7 +658,7 @@ metaslab_class_evict_old(metaslab_class_t *mc, uint64_t txg)
 				i--;
 				break;
 			}
-			mls = multilist_sublist_lock(ml, i);
+			mls = multilist_sublist_lock_idx(ml, i);
 			metaslab_t *next_msp = multilist_sublist_next(mls, msp);
 			multilist_sublist_unlock(mls);
 			if (txg >
@@ -2190,12 +2190,12 @@ metaslab_potentially_evict(metaslab_class_t *mc)
 		unsigned int idx = multilist_get_random_index(
 		    &mc->mc_metaslab_txg_list);
 		multilist_sublist_t *mls =
-		    multilist_sublist_lock(&mc->mc_metaslab_txg_list, idx);
+		    multilist_sublist_lock_idx(&mc->mc_metaslab_txg_list, idx);
 		metaslab_t *msp = multilist_sublist_head(mls);
 		multilist_sublist_unlock(mls);
 		while (msp != NULL && allmem * zfs_metaslab_mem_limit / 100 <
 		    inuse * size) {
-			VERIFY3P(mls, ==, multilist_sublist_lock(
+			VERIFY3P(mls, ==, multilist_sublist_lock_idx(
 			    &mc->mc_metaslab_txg_list, idx));
 			ASSERT3U(idx, ==,
 			    metaslab_idx_func(&mc->mc_metaslab_txg_list, msp));
diff --git a/sys/contrib/openzfs/module/zfs/mmp.c b/sys/contrib/openzfs/module/zfs/mmp.c
index 25eea0752941..8144d8965085 100644
--- a/sys/contrib/openzfs/module/zfs/mmp.c
+++ b/sys/contrib/openzfs/module/zfs/mmp.c
@@ -663,12 +663,13 @@ mmp_thread(void *arg)
 		    (gethrtime() - mmp->mmp_last_write) > mmp_fail_ns) {
 			zfs_dbgmsg("MMP suspending pool '%s': gethrtime %llu "
 			    "mmp_last_write %llu mmp_interval %llu "
-			    "mmp_fail_intervals %llu mmp_fail_ns %llu",
+			    "mmp_fail_intervals %llu mmp_fail_ns %llu txg %llu",
 			    spa_name(spa), (u_longlong_t)gethrtime(),
 			    (u_longlong_t)mmp->mmp_last_write,
 			    (u_longlong_t)mmp_interval,
 			    (u_longlong_t)mmp_fail_intervals,
-			    (u_longlong_t)mmp_fail_ns);
+			    (u_longlong_t)mmp_fail_ns,
+			    (u_longlong_t)spa->spa_uberblock.ub_txg);
 			cmn_err(CE_WARN, "MMP writes to pool '%s' have not "
 			    "succeeded in over %llu ms; suspending pool. "
 			    "Hrtime %llu",
diff --git a/sys/contrib/openzfs/module/zfs/multilist.c b/sys/contrib/openzfs/module/zfs/multilist.c
index b1cdf1c5c5f4..3d3ef86e6839 100644
--- a/sys/contrib/openzfs/module/zfs/multilist.c
+++ b/sys/contrib/openzfs/module/zfs/multilist.c
@@ -277,9 +277,15 @@ multilist_get_random_index(multilist_t *ml)
 	return (random_in_range(ml->ml_num_sublists));
 }
 
+void
+multilist_sublist_lock(multilist_sublist_t *mls)
+{
+	mutex_enter(&mls->mls_lock);
+}
+
 /* Lock and return the sublist specified at the given index */
 multilist_sublist_t *
-multilist_sublist_lock(multilist_t *ml, unsigned int sublist_idx)
+multilist_sublist_lock_idx(multilist_t *ml, unsigned int sublist_idx)
 {
 	multilist_sublist_t *mls;
 
@@ -294,7 +300,7 @@ multilist_sublist_lock(multilist_t *ml, unsigned int sublist_idx)
 multilist_sublist_t *
 multilist_sublist_lock_obj(multilist_t *ml, void *obj)
 {
-	return (multilist_sublist_lock(ml, ml->ml_index_func(ml, obj)));
+	return (multilist_sublist_lock_idx(ml, ml->ml_index_func(ml, obj)));
 }
 
 void
@@ -327,6 +333,22 @@ multilist_sublist_insert_tail(multilist_sublist_t *mls, void *obj)
 	list_insert_tail(&mls->mls_list, obj);
 }
 
+/* please see comment above multilist_sublist_insert_head */
+void
+multilist_sublist_insert_after(multilist_sublist_t *mls, void *prev, void *obj)
+{
+	ASSERT(MUTEX_HELD(&mls->mls_lock));
+	list_insert_after(&mls->mls_list, prev, obj);
+}
+
+/* please see comment above multilist_sublist_insert_head */
+void
+multilist_sublist_insert_before(multilist_sublist_t *mls, void *next, void *obj)
+{
+	ASSERT(MUTEX_HELD(&mls->mls_lock));
+	list_insert_before(&mls->mls_list, next, obj);
+}
+
 /*
  * Move the object one element forward in the list.
  *
diff --git a/sys/contrib/openzfs/module/zfs/spa.c b/sys/contrib/openzfs/module/zfs/spa.c
index d7fe96cde6a4..251dd8a4d1c7 100644
--- a/sys/contrib/openzfs/module/zfs/spa.c
+++ b/sys/contrib/openzfs/module/zfs/spa.c
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright (c) 2018, Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  * Copyright 2013 Saso Kiselkov. All rights reserved.
@@ -3324,6 +3324,7 @@ spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type)
 	spa->spa_load_state = state;
 	(void) spa_import_progress_set_state(spa_guid(spa),
 	    spa_load_state(spa));
+	spa_import_progress_set_notes(spa, "spa_load()");
 
 	gethrestime(&spa->spa_loaded_ts);
 	error = spa_load_impl(spa, type, &ereport);
@@ -3541,18 +3542,23 @@ spa_activity_check_duration(spa_t *spa, uberblock_t *ub)
 }
 
 /*
- * Perform the import activity check.  If the user canceled the import or
- * we detected activity then fail.
+ * Remote host activity check.
+ *
+ * error results:
+ *          0 - no activity detected
+ *  EREMOTEIO - remote activity detected
+ *      EINTR - user canceled the operation
  */
 static int
-spa_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *config)
+spa_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *config,
+    boolean_t importing)
 {
 	uint64_t txg = ub->ub_txg;
 	uint64_t timestamp = ub->ub_timestamp;
 	uint64_t mmp_config = ub->ub_mmp_config;
 	uint16_t mmp_seq = MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0;
 	uint64_t import_delay;
-	hrtime_t import_expire;
+	hrtime_t import_expire, now;
 	nvlist_t *mmp_label = NULL;
 	vdev_t *rvd = spa->spa_root_vdev;
 	kcondvar_t cv;
@@ -3590,9 +3596,23 @@ spa_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *config)
 
 	import_expire = gethrtime() + import_delay;
 
-	while (gethrtime() < import_expire) {
-		(void) spa_import_progress_set_mmp_check(spa_guid(spa),
-		    NSEC2SEC(import_expire - gethrtime()));
+	if (importing) {
+		spa_import_progress_set_notes(spa, "Checking MMP activity, "
+		    "waiting %llu ms", (u_longlong_t)NSEC2MSEC(import_delay));
+	}
+
+	int iterations = 0;
+	while ((now = gethrtime()) < import_expire) {
+		if (importing && iterations++ % 30 == 0) {
+			spa_import_progress_set_notes(spa, "Checking MMP "
+			    "activity, %llu ms remaining",
+			    (u_longlong_t)NSEC2MSEC(import_expire - now));
+		}
+
+		if (importing) {
+			(void) spa_import_progress_set_mmp_check(spa_guid(spa),
+			    NSEC2SEC(import_expire - gethrtime()));
+		}
 
 		vdev_uberblock_load(rvd, ub, &mmp_label);
 
@@ -3674,6 +3694,61 @@ out:
 	return (error);
 }
 
+/*
+ * Called from zfs_ioc_clear for a pool that was suspended
+ * after failing mmp write checks.
+ */
+boolean_t
+spa_mmp_remote_host_activity(spa_t *spa)
+{
+	ASSERT(spa_multihost(spa) && spa_suspended(spa));
+
+	nvlist_t *best_label;
+	uberblock_t best_ub;
+
+	/*
+	 * Locate the best uberblock on disk
+	 */
+	vdev_uberblock_load(spa->spa_root_vdev, &best_ub, &best_label);
+	if (best_label) {
+		/*
+		 * confirm that the best hostid matches our hostid
+		 */
+		if (nvlist_exists(best_label, ZPOOL_CONFIG_HOSTID) &&
+		    spa_get_hostid(spa) !=
+		    fnvlist_lookup_uint64(best_label, ZPOOL_CONFIG_HOSTID)) {
+			nvlist_free(best_label);
+			return (B_TRUE);
+		}
+		nvlist_free(best_label);
+	} else {
+		return (B_TRUE);
+	}
+
+	if (!MMP_VALID(&best_ub) ||
+	    !MMP_FAIL_INT_VALID(&best_ub) ||
+	    MMP_FAIL_INT(&best_ub) == 0) {
+		return (B_TRUE);
+	}
+
+	if (best_ub.ub_txg != spa->spa_uberblock.ub_txg ||
+	    best_ub.ub_timestamp != spa->spa_uberblock.ub_timestamp) {
+		zfs_dbgmsg("txg mismatch detected during pool clear "
+		    "txg %llu ub_txg %llu timestamp %llu ub_timestamp %llu",
+		    (u_longlong_t)spa->spa_uberblock.ub_txg,
+		    (u_longlong_t)best_ub.ub_txg,
+		    (u_longlong_t)spa->spa_uberblock.ub_timestamp,
+		    (u_longlong_t)best_ub.ub_timestamp);
+		return (B_TRUE);
+	}
+
+	/*
+	 * Perform an activity check looking for any remote writer
+	 */
+	return (spa_activity_check(spa, &spa->spa_uberblock, spa->spa_config,
+	    B_FALSE) != 0);
+}
+
 static int
 spa_verify_host(spa_t *spa, nvlist_t *mos_config)
 {
@@ -3994,7 +4069,8 @@ spa_ld_select_uberblock(spa_t *spa, spa_import_type_t type)
 			return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
 		}
 
-		int error = spa_activity_check(spa, ub, spa->spa_config);
+		int error =
+		    spa_activity_check(spa, ub, spa->spa_config, B_TRUE);
 		if (error) {
 			nvlist_free(label);
 			return (error);
@@ -5204,6 +5280,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	/*
 	 * Retrieve the checkpoint txg if the pool has a checkpoint.
 	 */
+	spa_import_progress_set_notes(spa, "Loading checkpoint txg");
 	error = spa_ld_read_checkpoint_txg(spa);
 	if (error != 0)
 		return (error);
@@ -5216,6 +5293,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * initiated. Otherwise we could be reading from indirect vdevs before
 	 * we have loaded their mappings.
 	 */
+	spa_import_progress_set_notes(spa, "Loading indirect vdev metadata");
 	error = spa_ld_open_indirect_vdev_metadata(spa);
 	if (error != 0)
 		return (error);
@@ -5224,6 +5302,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * Retrieve the full list of active features from the MOS and check if
 	 * they are all supported.
 	 */
+	spa_import_progress_set_notes(spa, "Checking feature flags");
 	error = spa_ld_check_features(spa, &missing_feat_write);
 	if (error != 0)
 		return (error);
@@ -5232,6 +5311,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * Load several special directories from the MOS needed by the dsl_pool
 	 * layer.
 	 */
+	spa_import_progress_set_notes(spa, "Loading special MOS directories");
 	error = spa_ld_load_special_directories(spa);
 	if (error != 0)
 		return (error);
@@ -5239,6 +5319,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	/*
 	 * Retrieve pool properties from the MOS.
 	 */
+	spa_import_progress_set_notes(spa, "Loading properties");
 	error = spa_ld_get_props(spa);
 	if (error != 0)
 		return (error);
@@ -5247,6 +5328,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * Retrieve the list of auxiliary devices - cache devices and spares -
 	 * and open them.
 	 */
+	spa_import_progress_set_notes(spa, "Loading AUX vdevs");
 	error = spa_ld_open_aux_vdevs(spa, type);
 	if (error != 0)
 		return (error);
@@ -5255,14 +5337,17 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * Load the metadata for all vdevs. Also check if unopenable devices
 	 * should be autoreplaced.
 	 */
+	spa_import_progress_set_notes(spa, "Loading vdev metadata");
 	error = spa_ld_load_vdev_metadata(spa);
 	if (error != 0)
 		return (error);
 
+	spa_import_progress_set_notes(spa, "Loading dedup tables");
 	error = spa_ld_load_dedup_tables(spa);
 	if (error != 0)
 		return (error);
 
+	spa_import_progress_set_notes(spa, "Loading BRT");
 	error = spa_ld_load_brt(spa);
 	if (error != 0)
 		return (error);
@@ -5271,6 +5356,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * Verify the logs now to make sure we don't have any unexpected errors
 	 * when we claim log blocks later.
 	 */
+	spa_import_progress_set_notes(spa, "Verifying Log Devices");
 	error = spa_ld_verify_logs(spa, type, ereport);
 	if (error != 0)
 		return (error);
@@ -5292,6 +5378,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * state. When performing an extreme rewind, we verify the whole pool,
 	 * which can take a very long time.
 	 */
+	spa_import_progress_set_notes(spa, "Verifying pool data");
 	error = spa_ld_verify_pool_data(spa);
 	if (error != 0)
 		return (error);
@@ -5301,6 +5388,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * we write anything to the pool because we'd need to update the space
 	 * accounting using the deflated sizes.
 	 */
+	spa_import_progress_set_notes(spa, "Calculating deflated space");
 	spa_update_dspace(spa);
 
 	/*
@@ -5308,6 +5396,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 	 * pool. If we are importing the pool in read-write mode, a few
 	 * additional steps must be performed to finish the import.
 	 */
+	spa_import_progress_set_notes(spa, "Starting import");
 	if (spa_writeable(spa) && (spa->spa_load_state == SPA_LOAD_RECOVER ||
 	    spa->spa_load_max_txg == UINT64_MAX)) {
 		uint64_t config_cache_txg = spa->spa_config_txg;
@@ -5324,6 +5413,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 			    (u_longlong_t)spa->spa_uberblock.ub_checkpoint_txg);
 		}
 
+		spa_import_progress_set_notes(spa, "Claiming ZIL blocks");
 		/*
 		 * Traverse the ZIL and claim all blocks.
 		 */
@@ -5343,6 +5433,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 		 * will have been set for us by ZIL traversal operations
 		 * performed above.
 		 */
+		spa_import_progress_set_notes(spa, "Syncing ZIL claims");
 		txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
 
 		/*
@@ -5350,6 +5441,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 		 * next sync, we would update the config stored in vdev labels
 		 * and the cachefile (by default /etc/zfs/zpool.cache).
 		 */
+		spa_import_progress_set_notes(spa, "Updating configs");
 		spa_ld_check_for_config_update(spa, config_cache_txg,
 		    update_config_cache);
 
@@ -5358,6 +5450,7 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 		 * Then check all DTLs to see if anything needs resilvering.
 		 * The resilver will be deferred if a rebuild was started.
 		 */
+		spa_import_progress_set_notes(spa, "Starting resilvers");
 		if (vdev_rebuild_active(spa->spa_root_vdev)) {
 			vdev_rebuild_restart(spa);
 		} else if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
@@ -5371,6 +5464,8 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 		 */
 		spa_history_log_version(spa, "open", NULL);
 
+		spa_import_progress_set_notes(spa,
+		    "Restarting device removals");
 		spa_restart_removal(spa);
 		spa_spawn_aux_threads(spa);
 
@@ -5383,19 +5478,26 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
 		 * auxiliary threads above (from which the livelist
 		 * deletion zthr is part of).
 		 */
+		spa_import_progress_set_notes(spa,
+		    "Cleaning up inconsistent objsets");
 		(void) dmu_objset_find(spa_name(spa),
 		    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
 
 		/*
 		 * Clean up any stale temporary dataset userrefs.
 		 */
+		spa_import_progress_set_notes(spa,
+		    "Cleaning up temporary userrefs");
 		dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
 
 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
+		spa_import_progress_set_notes(spa, "Restarting initialize");
 		vdev_initialize_restart(spa->spa_root_vdev);
+		spa_import_progress_set_notes(spa, "Restarting TRIM");
 		vdev_trim_restart(spa->spa_root_vdev);
 		vdev_autotrim_restart(spa);
 		spa_config_exit(spa, SCL_CONFIG, FTAG);
+		spa_import_progress_set_notes(spa, "Finished importing");
 	}
 
 	spa_import_progress_remove(spa_guid(spa));
@@ -6978,7 +7080,7 @@ spa_draid_feature_incr(void *arg, dmu_tx_t *tx)
  * Add a device to a storage pool.
  */
 int
-spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
+spa_vdev_add(spa_t *spa, nvlist_t *nvroot, boolean_t check_ashift)
 {
 	uint64_t txg, ndraid = 0;
 	int error;
@@ -7069,6 +7171,16 @@ spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
 		}
 	}
 
+	if (check_ashift && spa->spa_max_ashift == spa->spa_min_ashift) {
+		for (int c = 0; c < vd->vdev_children; c++) {
+			tvd = vd->vdev_child[c];
+			if (tvd->vdev_ashift != spa->spa_max_ashift) {
+				return (spa_vdev_exit(spa, vd, txg,
+				    ZFS_ERR_ASHIFT_MISMATCH));
+			}
+		}
+	}
+
 	for (int c = 0; c < vd->vdev_children; c++) {
 		tvd = vd->vdev_child[c];
 		vdev_remove_child(vd, tvd);
@@ -8542,15 +8654,16 @@ spa_async_remove(spa_t *spa, vdev_t *vd)
 }
 
 static void
-spa_async_probe(spa_t *spa, vdev_t *vd)
+spa_async_fault_vdev(spa_t *spa, vdev_t *vd)
 {
-	if (vd->vdev_probe_wanted) {
-		vd->vdev_probe_wanted = B_FALSE;
-		vdev_reopen(vd);	/* vdev_open() does the actual probe */
+	if (vd->vdev_fault_wanted) {
+		vd->vdev_fault_wanted = B_FALSE;
+		vdev_set_state(vd, B_TRUE, VDEV_STATE_FAULTED,
+		    VDEV_AUX_ERR_EXCEEDED);
 	}
 
 	for (int c = 0; c < vd->vdev_children; c++)
-		spa_async_probe(spa, vd->vdev_child[c]);
+		spa_async_fault_vdev(spa, vd->vdev_child[c]);
 }
 
 static void
@@ -8638,11 +8751,11 @@ spa_async_thread(void *arg)
 	}
 
 	/*
-	 * See if any devices need to be probed.
+	 * See if any devices need to be marked faulted.
 	 */
-	if (tasks & SPA_ASYNC_PROBE) {
+	if (tasks & SPA_ASYNC_FAULT_VDEV) {
 		spa_vdev_state_enter(spa, SCL_NONE);
-		spa_async_probe(spa, spa->spa_root_vdev);
+		spa_async_fault_vdev(spa, spa->spa_root_vdev);
 		(void) spa_vdev_state_exit(spa, NULL, 0);
 	}
 
diff --git a/sys/contrib/openzfs/module/zfs/spa_log_spacemap.c b/sys/contrib/openzfs/module/zfs/spa_log_spacemap.c
index 2878e68c6e4b..873089a53e34 100644
--- a/sys/contrib/openzfs/module/zfs/spa_log_spacemap.c
+++ b/sys/contrib/openzfs/module/zfs/spa_log_spacemap.c
@@ -1147,12 +1147,13 @@ spa_ld_log_sm_data(spa_t *spa)
 	/* Prefetch log spacemaps dnodes. */
 	for (sls = avl_first(&spa->spa_sm_logs_by_txg); sls;
 	    sls = AVL_NEXT(&spa->spa_sm_logs_by_txg, sls)) {
-		dmu_prefetch(spa_meta_objset(spa), sls->sls_sm_obj,
-		    0, 0, 0, ZIO_PRIORITY_SYNC_READ);
+		dmu_prefetch_dnode(spa_meta_objset(spa), sls->sls_sm_obj,
+		    ZIO_PRIORITY_SYNC_READ);
 	}
 
 	uint_t pn = 0;
 	uint64_t ps = 0;
+	uint64_t nsm = 0;
 	psls = sls = avl_first(&spa->spa_sm_logs_by_txg);
 	while (sls != NULL) {
 		/* Prefetch log spacemaps up to 16 TXGs or MBs ahead. */
@@ -1185,6 +1186,10 @@ spa_ld_log_sm_data(spa_t *spa)
 		summary_add_data(spa, sls->sls_txg,
 		    sls->sls_mscount, 0, sls->sls_nblocks);
 
+		spa_import_progress_set_notes_nolog(spa,
+		    "Read %llu of %lu log space maps", (u_longlong_t)nsm,
+		    avl_numnodes(&spa->spa_sm_logs_by_txg));
+
 		struct spa_ld_log_sm_arg vla = {
 			.slls_spa = spa,
 			.slls_txg = sls->sls_txg
@@ -1200,6 +1205,7 @@ spa_ld_log_sm_data(spa_t *spa)
 
 		pn--;
 		ps -= space_map_length(sls->sls_sm);
+		nsm++;
 		space_map_close(sls->sls_sm);
 		sls->sls_sm = NULL;
 		sls = AVL_NEXT(&spa->spa_sm_logs_by_txg, sls);
@@ -1210,11 +1216,11 @@ spa_ld_log_sm_data(spa_t *spa)
 
 	hrtime_t read_logs_endtime = gethrtime();
 	spa_load_note(spa,
-	    "read %llu log space maps (%llu total blocks - blksz = %llu bytes) "
-	    "in %lld ms", (u_longlong_t)avl_numnodes(&spa->spa_sm_logs_by_txg),
+	    "Read %lu log space maps (%llu total blocks - blksz = %llu bytes) "
+	    "in %lld ms", avl_numnodes(&spa->spa_sm_logs_by_txg),
 	    (u_longlong_t)spa_log_sm_nblocks(spa),
 	    (u_longlong_t)zfs_log_sm_blksz,
-	    (longlong_t)((read_logs_endtime - read_logs_starttime) / 1000000));
+	    (longlong_t)NSEC2MSEC(read_logs_endtime - read_logs_starttime));
 
 out:
 	if (error != 0) {
diff --git a/sys/contrib/openzfs/module/zfs/spa_misc.c b/sys/contrib/openzfs/module/zfs/spa_misc.c
index 24f038ad7f4b..649fe2f634b5 100644
--- a/sys/contrib/openzfs/module/zfs/spa_misc.c
+++ b/sys/contrib/openzfs/module/zfs/spa_misc.c
@@ -417,6 +417,8 @@ spa_load_note(spa_t *spa, const char *fmt, ...)
 
 	zfs_dbgmsg("spa_load(%s, config %s): %s", spa->spa_name,
 	    spa->spa_trust_config ? "trusted" : "untrusted", buf);
+
+	spa_import_progress_set_notes_nolog(spa, "%s", buf);
 }
 
 /*
@@ -2172,6 +2174,7 @@ typedef struct spa_import_progress {
 	uint64_t		pool_guid;	/* unique id for updates */
 	char			*pool_name;
 	spa_load_state_t	spa_load_state;
+	char			*spa_load_notes;
 	uint64_t		mmp_sec_remaining;	/* MMP activity check */
 	uint64_t		spa_load_max_txg;	/* rewind txg */
 	procfs_list_node_t	smh_node;
@@ -2182,9 +2185,9 @@ spa_history_list_t *spa_import_progress_list = NULL;
 static int
 spa_import_progress_show_header(struct seq_file *f)
 {
-	seq_printf(f, "%-20s %-14s %-14s %-12s %s\n", "pool_guid",
+	seq_printf(f, "%-20s %-14s %-14s %-12s %-16s %s\n", "pool_guid",
 	    "load_state", "multihost_secs", "max_txg",
-	    "pool_name");
+	    "pool_name", "notes");
 	return (0);
 }
 
@@ -2193,11 +2196,12 @@ spa_import_progress_show(struct seq_file *f, void *data)
 {
 	spa_import_progress_t *sip = (spa_import_progress_t *)data;
 
-	seq_printf(f, "%-20llu %-14llu %-14llu %-12llu %s\n",
+	seq_printf(f, "%-20llu %-14llu %-14llu %-12llu %-16s %s\n",
 	    (u_longlong_t)sip->pool_guid, (u_longlong_t)sip->spa_load_state,
 	    (u_longlong_t)sip->mmp_sec_remaining,
 	    (u_longlong_t)sip->spa_load_max_txg,
-	    (sip->pool_name ? sip->pool_name : "-"));
+	    (sip->pool_name ? sip->pool_name : "-"),
+	    (sip->spa_load_notes ? sip->spa_load_notes : "-"));
 
 	return (0);
 }
@@ -2211,6 +2215,8 @@ spa_import_progress_truncate(spa_history_list_t *shl, unsigned int size)
 		sip = list_remove_head(&shl->procfs_list.pl_list);
 		if (sip->pool_name)
 			spa_strfree(sip->pool_name);
+		if (sip->spa_load_notes)
+			kmem_strfree(sip->spa_load_notes);
 		kmem_free(sip, sizeof (spa_import_progress_t));
 		shl->size--;
 	}
@@ -2266,6 +2272,10 @@ spa_import_progress_set_state(uint64_t pool_guid,
 	    sip = list_prev(&shl->procfs_list.pl_list, sip)) {
 		if (sip->pool_guid == pool_guid) {
 			sip->spa_load_state = load_state;
+			if (sip->spa_load_notes != NULL) {
+				kmem_strfree(sip->spa_load_notes);
+				sip->spa_load_notes = NULL;
+			}
 			error = 0;
 			break;
 		}
@@ -2275,6 +2285,59 @@ spa_import_progress_set_state(uint64_t pool_guid,
 	return (error);
 }
 
+static void
+spa_import_progress_set_notes_impl(spa_t *spa, boolean_t log_dbgmsg,
+    const char *fmt, va_list adx)
+{
+	spa_history_list_t *shl = spa_import_progress_list;
+	spa_import_progress_t *sip;
+	uint64_t pool_guid = spa_guid(spa);
+
+	if (shl->size == 0)
+		return;
+
+	char *notes = kmem_vasprintf(fmt, adx);
+
+	mutex_enter(&shl->procfs_list.pl_lock);
+	for (sip = list_tail(&shl->procfs_list.pl_list); sip != NULL;
+	    sip = list_prev(&shl->procfs_list.pl_list, sip)) {
+		if (sip->pool_guid == pool_guid) {
+			if (sip->spa_load_notes != NULL) {
+				kmem_strfree(sip->spa_load_notes);
+				sip->spa_load_notes = NULL;
+			}
+			sip->spa_load_notes = notes;
+			if (log_dbgmsg)
+				zfs_dbgmsg("'%s' %s", sip->pool_name, notes);
+			notes = NULL;
+			break;
+		}
+	}
+	mutex_exit(&shl->procfs_list.pl_lock);
+	if (notes != NULL)
+		kmem_strfree(notes);
+}
+
+void
+spa_import_progress_set_notes(spa_t *spa, const char *fmt, ...)
+{
+	va_list adx;
+
+	va_start(adx, fmt);
+	spa_import_progress_set_notes_impl(spa, B_TRUE, fmt, adx);
+	va_end(adx);
+}
+
+void
+spa_import_progress_set_notes_nolog(spa_t *spa, const char *fmt, ...)
+{
+	va_list adx;
+
+	va_start(adx, fmt);
+	spa_import_progress_set_notes_impl(spa, B_FALSE, fmt, adx);
+	va_end(adx);
+}
+
 int
 spa_import_progress_set_max_txg(uint64_t pool_guid, uint64_t load_max_txg)
 {
@@ -2343,6 +2406,7 @@ spa_import_progress_add(spa_t *spa)
 		poolname = spa_name(spa);
 	sip->pool_name = spa_strdup(poolname);
 	sip->spa_load_state = spa_load_state(spa);
+	sip->spa_load_notes = NULL;
 
 	mutex_enter(&shl->procfs_list.pl_lock);
 	procfs_list_add(&shl->procfs_list, sip);
@@ -2362,6 +2426,8 @@ spa_import_progress_remove(uint64_t pool_guid)
 		if (sip->pool_guid == pool_guid) {
 			if (sip->pool_name)
 				spa_strfree(sip->pool_name);
+			if (sip->spa_load_notes)
+				spa_strfree(sip->spa_load_notes);
 			list_remove(&shl->procfs_list.pl_list, sip);
 			shl->size--;
 			kmem_free(sip, sizeof (spa_import_progress_t));
diff --git a/sys/contrib/openzfs/module/zfs/txg.c b/sys/contrib/openzfs/module/zfs/txg.c
index a67c043446f5..5ce6be69be14 100644
--- a/sys/contrib/openzfs/module/zfs/txg.c
+++ b/sys/contrib/openzfs/module/zfs/txg.c
@@ -551,6 +551,15 @@ txg_sync_thread(void *arg)
 		}
 
 		/*
+		 * When we're suspended, nothing should be changing and for
+		 * MMP we don't want to bump anything that would make it
+		 * harder to detect if another host is changing it when
+		 * resuming after a MMP suspend.
+		 */
+		if (spa_suspended(spa))
+			continue;
+
+		/*
 		 * Wait until the quiesce thread hands off a txg to us,
 		 * prompting it to do so if necessary.
 		 */
diff --git a/sys/contrib/openzfs/module/zfs/vdev.c b/sys/contrib/openzfs/module/zfs/vdev.c
index e1ca1aecc900..981da4e986c4 100644
--- a/sys/contrib/openzfs/module/zfs/vdev.c
+++ b/sys/contrib/openzfs/module/zfs/vdev.c
@@ -676,6 +676,8 @@ vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid, vdev_ops_t *ops)
 	vd->vdev_checksum_t = vdev_prop_default_numeric(VDEV_PROP_CHECKSUM_T);
 	vd->vdev_io_n = vdev_prop_default_numeric(VDEV_PROP_IO_N);
 	vd->vdev_io_t = vdev_prop_default_numeric(VDEV_PROP_IO_T);
+	vd->vdev_slow_io_n = vdev_prop_default_numeric(VDEV_PROP_SLOW_IO_N);
+	vd->vdev_slow_io_t = vdev_prop_default_numeric(VDEV_PROP_SLOW_IO_T);
 
 	list_link_init(&vd->vdev_config_dirty_node);
 	list_link_init(&vd->vdev_state_dirty_node);
@@ -1659,6 +1661,7 @@ vdev_metaslab_fini(vdev_t *vd)
 typedef struct vdev_probe_stats {
 	boolean_t	vps_readable;
 	boolean_t	vps_writeable;
+	boolean_t	vps_zio_done_probe;
 	int		vps_flags;
 } vdev_probe_stats_t;
 
@@ -1702,6 +1705,17 @@ vdev_probe_done(zio_t *zio)
 			(void) zfs_ereport_post(FM_EREPORT_ZFS_PROBE_FAILURE,
 			    spa, vd, NULL, NULL, 0);
 			zio->io_error = SET_ERROR(ENXIO);
+
+			/*
+			 * If this probe was initiated from zio pipeline, then
+			 * change the state in a spa_async_request. Probes that
+			 * were initiated from a vdev_open can change the state
+			 * as part of the open call.
+			 */
+			if (vps->vps_zio_done_probe) {
+				vd->vdev_fault_wanted = B_TRUE;
+				spa_async_request(spa, SPA_ASYNC_FAULT_VDEV);
+			}
 		}
 
 		mutex_enter(&vd->vdev_probe_lock);
@@ -1752,6 +1766,7 @@ vdev_probe(vdev_t *vd, zio_t *zio)
 
 		vps->vps_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_PROBE |
 		    ZIO_FLAG_DONT_AGGREGATE | ZIO_FLAG_TRYHARD;
+		vps->vps_zio_done_probe = (zio != NULL);
 
 		if (spa_config_held(spa, SCL_ZIO, RW_WRITER)) {
 			/*
@@ -1778,15 +1793,6 @@ vdev_probe(vdev_t *vd, zio_t *zio)
 		vd->vdev_probe_zio = pio = zio_null(NULL, spa, vd,
 		    vdev_probe_done, vps,
 		    vps->vps_flags | ZIO_FLAG_DONT_PROPAGATE);
-
-		/*
-		 * We can't change the vdev state in this context, so we
-		 * kick off an async task to do it on our behalf.
-		 */
-		if (zio != NULL) {
-			vd->vdev_probe_wanted = B_TRUE;
-			spa_async_request(spa, SPA_ASYNC_PROBE);
-		}
 	}
 
 	if (zio != NULL)
@@ -3730,6 +3736,18 @@ vdev_load(vdev_t *vd)
 		if (error && error != ENOENT)
 			vdev_dbgmsg(vd, "vdev_load: zap_lookup(zap=%llu) "
 			    "failed [error=%d]", (u_longlong_t)zapobj, error);
+
+		error = vdev_prop_get_int(vd, VDEV_PROP_SLOW_IO_N,
+		    &vd->vdev_slow_io_n);
+		if (error && error != ENOENT)
+			vdev_dbgmsg(vd, "vdev_load: zap_lookup(zap=%llu) "
+			    "failed [error=%d]", (u_longlong_t)zapobj, error);
+
+		error = vdev_prop_get_int(vd, VDEV_PROP_SLOW_IO_T,
+		    &vd->vdev_slow_io_t);
+		if (error && error != ENOENT)
+			vdev_dbgmsg(vd, "vdev_load: zap_lookup(zap=%llu) "
+			    "failed [error=%d]", (u_longlong_t)zapobj, error);
 	}
 
 	/*
@@ -5934,6 +5952,20 @@ vdev_prop_set(vdev_t *vd, nvlist_t *innvl, nvlist_t *outnvl)
 			}
 			vd->vdev_io_t = intval;
 			break;
+		case VDEV_PROP_SLOW_IO_N:
+			if (nvpair_value_uint64(elem, &intval) != 0) {
+				error = EINVAL;
+				break;
+			}
+			vd->vdev_slow_io_n = intval;
+			break;
+		case VDEV_PROP_SLOW_IO_T:
+			if (nvpair_value_uint64(elem, &intval) != 0) {
+				error = EINVAL;
+				break;
+			}
+			vd->vdev_slow_io_t = intval;
+			break;
 		default:
 			/* Most processing is done in vdev_props_set_sync */
 			break;
@@ -6269,6 +6301,8 @@ vdev_prop_get(vdev_t *vd, nvlist_t *innvl, nvlist_t *outnvl)
 			case VDEV_PROP_CHECKSUM_T:
 			case VDEV_PROP_IO_N:
 			case VDEV_PROP_IO_T:
+			case VDEV_PROP_SLOW_IO_N:
+			case VDEV_PROP_SLOW_IO_T:
 				err = vdev_prop_get_int(vd, prop, &intval);
 				if (err && err != ENOENT)
 					break;
diff --git a/sys/contrib/openzfs/module/zfs/vdev_label.c b/sys/contrib/openzfs/module/zfs/vdev_label.c
index 737d8b33e188..5c0e750c4614 100644
--- a/sys/contrib/openzfs/module/zfs/vdev_label.c
+++ b/sys/contrib/openzfs/module/zfs/vdev_label.c
@@ -1982,6 +1982,7 @@ retry:
 	/*
 	 * If this isn't a resync due to I/O errors,
 	 * and nothing changed in this transaction group,
+	 * and multihost protection isn't enabled,
 	 * and the vdev configuration hasn't changed,
 	 * then there's nothing to do.
 	 */
@@ -1989,7 +1990,8 @@ retry:
 		boolean_t changed = uberblock_update(ub, spa->spa_root_vdev,
 		    txg, spa->spa_mmp.mmp_delay);
 
-		if (!changed && list_is_empty(&spa->spa_config_dirty_list))
+		if (!changed && list_is_empty(&spa->spa_config_dirty_list) &&
+		    !spa_multihost(spa))
 			return (0);
 	}
 
diff --git a/sys/contrib/openzfs/module/zfs/vdev_raidz.c b/sys/contrib/openzfs/module/zfs/vdev_raidz.c
index 3445fa9d35d5..34ef57a3548d 100644
--- a/sys/contrib/openzfs/module/zfs/vdev_raidz.c
+++ b/sys/contrib/openzfs/module/zfs/vdev_raidz.c
@@ -1283,8 +1283,9 @@ vdev_raidz_matrix_reconstruct(raidz_row_t *rr, int n, int nmissing,
 static void
 vdev_raidz_reconstruct_general(raidz_row_t *rr, int *tgts, int ntgts)
 {
-	int n, i, c, t, tt;
-	int nmissing_rows;
+	int i, c, t, tt;
+	unsigned int n;
+	unsigned int nmissing_rows;
 	int missing_rows[VDEV_RAIDZ_MAXPARITY];
 	int parity_map[VDEV_RAIDZ_MAXPARITY];
 	uint8_t *p, *pp;
diff --git a/sys/contrib/openzfs/module/zfs/zap.c b/sys/contrib/openzfs/module/zfs/zap.c
index dde05d7005c2..da86defb445c 100644
--- a/sys/contrib/openzfs/module/zfs/zap.c
+++ b/sys/contrib/openzfs/module/zfs/zap.c
@@ -133,7 +133,7 @@ fzap_upgrade(zap_t *zap, dmu_tx_t *tx, zap_flags_t flags)
 	 * set up block 1 - the first leaf
 	 */
 	dmu_buf_t *db;
-	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
+	VERIFY0(dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    1<<FZAP_BLOCK_SHIFT(zap), FTAG, &db, DMU_READ_NO_PREFETCH));
 	dmu_buf_will_dirty(db, tx);
 
@@ -182,7 +182,7 @@ zap_table_grow(zap_t *zap, zap_table_phys_t *tbl,
 		newblk = zap_allocate_blocks(zap, tbl->zt_numblks * 2);
 		tbl->zt_nextblk = newblk;
 		ASSERT0(tbl->zt_blks_copied);
-		dmu_prefetch(zap->zap_objset, zap->zap_object, 0,
+		dmu_prefetch_by_dnode(zap->zap_dnode, 0,
 		    tbl->zt_blk << bs, tbl->zt_numblks << bs,
 		    ZIO_PRIORITY_SYNC_READ);
 	}
@@ -193,21 +193,21 @@ zap_table_grow(zap_t *zap, zap_table_phys_t *tbl,
 
 	uint64_t b = tbl->zt_blks_copied;
 	dmu_buf_t *db_old;
-	int err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
+	int err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    (tbl->zt_blk + b) << bs, FTAG, &db_old, DMU_READ_NO_PREFETCH);
 	if (err != 0)
 		return (err);
 
 	/* first half of entries in old[b] go to new[2*b+0] */
 	dmu_buf_t *db_new;
-	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
+	VERIFY0(dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    (newblk + 2*b+0) << bs, FTAG, &db_new, DMU_READ_NO_PREFETCH));
 	dmu_buf_will_dirty(db_new, tx);
 	transfer_func(db_old->db_data, db_new->db_data, hepb);
 	dmu_buf_rele(db_new, FTAG);
 
 	/* second half of entries in old[b] go to new[2*b+1] */
-	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
+	VERIFY0(dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    (newblk + 2*b+1) << bs, FTAG, &db_new, DMU_READ_NO_PREFETCH));
 	dmu_buf_will_dirty(db_new, tx);
 	transfer_func((uint64_t *)db_old->db_data + hepb,
@@ -255,7 +255,7 @@ zap_table_store(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t val,
 	uint64_t off = idx & ((1<<(bs-3))-1);
 
 	dmu_buf_t *db;
-	int err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
+	int err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    (tbl->zt_blk + blk) << bs, FTAG, &db, DMU_READ_NO_PREFETCH);
 	if (err != 0)
 		return (err);
@@ -267,7 +267,7 @@ zap_table_store(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t val,
 		uint64_t off2 = idx2 & ((1<<(bs-3))-1);
 		dmu_buf_t *db2;
 
-		err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
+		err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 		    (tbl->zt_nextblk + blk2) << bs, FTAG, &db2,
 		    DMU_READ_NO_PREFETCH);
 		if (err != 0) {
@@ -296,16 +296,9 @@ zap_table_load(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t *valp)
 	uint64_t blk = idx >> (bs-3);
 	uint64_t off = idx & ((1<<(bs-3))-1);
 
-	/*
-	 * Note: this is equivalent to dmu_buf_hold(), but we use
-	 * _dnode_enter / _by_dnode because it's faster because we don't
-	 * have to hold the dnode.
-	 */
-	dnode_t *dn = dmu_buf_dnode_enter(zap->zap_dbuf);
 	dmu_buf_t *db;
-	int err = dmu_buf_hold_by_dnode(dn,
+	int err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    (tbl->zt_blk + blk) << bs, FTAG, &db, DMU_READ_NO_PREFETCH);
-	dmu_buf_dnode_exit(zap->zap_dbuf);
 	if (err != 0)
 		return (err);
 	*valp = ((uint64_t *)db->db_data)[off];
@@ -319,11 +312,9 @@ zap_table_load(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t *valp)
 		 */
 		blk = (idx*2) >> (bs-3);
 
-		dn = dmu_buf_dnode_enter(zap->zap_dbuf);
-		err = dmu_buf_hold_by_dnode(dn,
+		err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 		    (tbl->zt_nextblk + blk) << bs, FTAG, &db,
 		    DMU_READ_NO_PREFETCH);
-		dmu_buf_dnode_exit(zap->zap_dbuf);
 		if (err == 0)
 			dmu_buf_rele(db, FTAG);
 	}
@@ -368,7 +359,7 @@ zap_grow_ptrtbl(zap_t *zap, dmu_tx_t *tx)
 
 		uint64_t newblk = zap_allocate_blocks(zap, 1);
 		dmu_buf_t *db_new;
-		int err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
+		int err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 		    newblk << FZAP_BLOCK_SHIFT(zap), FTAG, &db_new,
 		    DMU_READ_NO_PREFETCH);
 		if (err != 0)
@@ -433,7 +424,7 @@ zap_create_leaf(zap_t *zap, dmu_tx_t *tx)
 	l->l_blkid = zap_allocate_blocks(zap, 1);
 	l->l_dbuf = NULL;
 
-	VERIFY0(dmu_buf_hold(zap->zap_objset, zap->zap_object,
+	VERIFY0(dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    l->l_blkid << FZAP_BLOCK_SHIFT(zap), NULL, &l->l_dbuf,
 	    DMU_READ_NO_PREFETCH));
 	dmu_buf_init_user(&l->l_dbu, zap_leaf_evict_sync, NULL, &l->l_dbuf);
@@ -533,10 +524,8 @@ zap_get_leaf_byblk(zap_t *zap, uint64_t blkid, dmu_tx_t *tx, krw_t lt,
 		return (SET_ERROR(ENOENT));
 
 	int bs = FZAP_BLOCK_SHIFT(zap);
-	dnode_t *dn = dmu_buf_dnode_enter(zap->zap_dbuf);
-	int err = dmu_buf_hold_by_dnode(dn,
+	int err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 	    blkid << bs, NULL, &db, DMU_READ_NO_PREFETCH);
-	dmu_buf_dnode_exit(zap->zap_dbuf);
 	if (err != 0)
 		return (err);
 
@@ -985,7 +974,7 @@ fzap_prefetch(zap_name_t *zn)
 	if (zap_idx_to_blk(zap, idx, &blk) != 0)
 		return;
 	int bs = FZAP_BLOCK_SHIFT(zap);
-	dmu_prefetch(zap->zap_objset, zap->zap_object, 0, blk << bs, 1 << bs,
+	dmu_prefetch_by_dnode(zap->zap_dnode, 0, blk << bs, 1 << bs,
 	    ZIO_PRIORITY_SYNC_READ);
 }
 
@@ -1228,7 +1217,7 @@ fzap_cursor_retrieve(zap_t *zap, zap_cursor_t *zc, zap_attribute_t *za)
 	 */
 	if (zc->zc_hash == 0 && zap_iterate_prefetch &&
 	    zc->zc_prefetch && zap_f_phys(zap)->zap_freeblk > 2) {
-		dmu_prefetch(zc->zc_objset, zc->zc_zapobj, 0, 0,
+		dmu_prefetch_by_dnode(zap->zap_dnode, 0, 0,
 		    zap_f_phys(zap)->zap_freeblk << FZAP_BLOCK_SHIFT(zap),
 		    ZIO_PRIORITY_ASYNC_READ);
 	}
@@ -1356,7 +1345,7 @@ fzap_get_stats(zap_t *zap, zap_stats_t *zs)
 		zap_stats_ptrtbl(zap, &ZAP_EMBEDDED_PTRTBL_ENT(zap, 0),
 		    1 << ZAP_EMBEDDED_PTRTBL_SHIFT(zap), zs);
 	} else {
-		dmu_prefetch(zap->zap_objset, zap->zap_object, 0,
+		dmu_prefetch_by_dnode(zap->zap_dnode, 0,
 		    zap_f_phys(zap)->zap_ptrtbl.zt_blk << bs,
 		    zap_f_phys(zap)->zap_ptrtbl.zt_numblks << bs,
 		    ZIO_PRIORITY_SYNC_READ);
@@ -1366,7 +1355,7 @@ fzap_get_stats(zap_t *zap, zap_stats_t *zs)
 			dmu_buf_t *db;
 			int err;
 
-			err = dmu_buf_hold(zap->zap_objset, zap->zap_object,
+			err = dmu_buf_hold_by_dnode(zap->zap_dnode,
 			    (zap_f_phys(zap)->zap_ptrtbl.zt_blk + b) << bs,
 			    FTAG, &db, DMU_READ_NO_PREFETCH);
 			if (err == 0) {
diff --git a/sys/contrib/openzfs/module/zfs/zap_leaf.c b/sys/contrib/openzfs/module/zfs/zap_leaf.c
index e6afb1c58c95..032aca92695e 100644
--- a/sys/contrib/openzfs/module/zfs/zap_leaf.c
+++ b/sys/contrib/openzfs/module/zfs/zap_leaf.c
@@ -41,7 +41,8 @@
 #include <sys/zap_leaf.h>
 #include <sys/arc.h>
 
-static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);
+static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, struct zap_leaf_entry *le,
+    uint16_t entry);
 
 #define	CHAIN_END 0xffff /* end of the chunk chain */
 
@@ -53,16 +54,6 @@ static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);
 #define	LEAF_HASH_ENTPTR(l, h)	(&zap_leaf_phys(l)->l_hash[LEAF_HASH(l, h)])
 
 static void
-zap_memset(void *a, int c, size_t n)
-{
-	char *cp = a;
-	char *cpend = cp + n;
-
-	while (cp < cpend)
-		*cp++ = c;
-}
-
-static void
 stv(int len, void *addr, uint64_t value)
 {
 	switch (len) {
@@ -79,7 +70,7 @@ stv(int len, void *addr, uint64_t value)
 		*(uint64_t *)addr = value;
 		return;
 	default:
-		cmn_err(CE_PANIC, "bad int len %d", len);
+		PANIC("bad int len %d", len);
 	}
 }
 
@@ -96,13 +87,13 @@ ldv(int len, const void *addr)
 	case 8:
 		return (*(uint64_t *)addr);
 	default:
-		cmn_err(CE_PANIC, "bad int len %d", len);
+		PANIC("bad int len %d", len);
 	}
 	return (0xFEEDFACEDEADBEEFULL);
 }
 
 void
-zap_leaf_byteswap(zap_leaf_phys_t *buf, int size)
+zap_leaf_byteswap(zap_leaf_phys_t *buf, size_t size)
 {
 	zap_leaf_t l;
 	dmu_buf_t l_dbuf;
@@ -119,10 +110,10 @@ zap_leaf_byteswap(zap_leaf_phys_t *buf, int size)
 	buf->l_hdr.lh_prefix_len =	BSWAP_16(buf->l_hdr.lh_prefix_len);
 	buf->l_hdr.lh_freelist =	BSWAP_16(buf->l_hdr.lh_freelist);
 
-	for (int i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
+	for (uint_t i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
 		buf->l_hash[i] = BSWAP_16(buf->l_hash[i]);
 
-	for (int i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
+	for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
 		zap_leaf_chunk_t *lc = &ZAP_LEAF_CHUNK(&l, i);
 		struct zap_leaf_entry *le;
 
@@ -160,11 +151,11 @@ void
 zap_leaf_init(zap_leaf_t *l, boolean_t sort)
 {
 	l->l_bs = highbit64(l->l_dbuf->db_size) - 1;
-	zap_memset(&zap_leaf_phys(l)->l_hdr, 0,
+	memset(&zap_leaf_phys(l)->l_hdr, 0,
 	    sizeof (struct zap_leaf_header));
-	zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
+	memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
 	    2*ZAP_LEAF_HASH_NUMENTRIES(l));
-	for (int i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
+	for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
 		ZAP_LEAF_CHUNK(l, i).l_free.lf_type = ZAP_CHUNK_FREE;
 		ZAP_LEAF_CHUNK(l, i).l_free.lf_next = i+1;
 	}
@@ -185,7 +176,7 @@ zap_leaf_chunk_alloc(zap_leaf_t *l)
 {
 	ASSERT(zap_leaf_phys(l)->l_hdr.lh_nfree > 0);
 
-	int chunk = zap_leaf_phys(l)->l_hdr.lh_freelist;
+	uint_t chunk = zap_leaf_phys(l)->l_hdr.lh_freelist;
 	ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 	ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_free.lf_type, ==, ZAP_CHUNK_FREE);
 
@@ -223,28 +214,29 @@ zap_leaf_array_create(zap_leaf_t *l, const char *buf,
 {
 	uint16_t chunk_head;
 	uint16_t *chunkp = &chunk_head;
-	int byten = 0;
+	int byten = integer_size;
 	uint64_t value = 0;
 	int shift = (integer_size - 1) * 8;
 	int len = num_integers;
 
 	ASSERT3U(num_integers * integer_size, <=, ZAP_MAXVALUELEN);
 
+	if (len > 0)
+		value = ldv(integer_size, buf);
 	while (len > 0) {
 		uint16_t chunk = zap_leaf_chunk_alloc(l);
 		struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
 
 		la->la_type = ZAP_CHUNK_ARRAY;
 		for (int i = 0; i < ZAP_LEAF_ARRAY_BYTES; i++) {
-			if (byten == 0)
-				value = ldv(integer_size, buf);
 			la->la_array[i] = value >> shift;
 			value <<= 8;
-			if (++byten == integer_size) {
-				byten = 0;
-				buf += integer_size;
+			if (--byten == 0) {
 				if (--len == 0)
 					break;
+				byten = integer_size;
+				buf += integer_size;
+				value = ldv(integer_size, buf);
 			}
 		}
 
@@ -264,7 +256,7 @@ zap_leaf_array_free(zap_leaf_t *l, uint16_t *chunkp)
 	*chunkp = CHAIN_END;
 
 	while (chunk != CHAIN_END) {
-		int nextchunk = ZAP_LEAF_CHUNK(l, chunk).l_array.la_next;
+		uint_t nextchunk = ZAP_LEAF_CHUNK(l, chunk).l_array.la_next;
 		ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_array.la_type, ==,
 		    ZAP_CHUNK_ARRAY);
 		zap_leaf_chunk_free(l, chunk);
@@ -333,7 +325,7 @@ zap_leaf_array_read(zap_leaf_t *l, uint16_t chunk,
 
 static boolean_t
 zap_leaf_array_match(zap_leaf_t *l, zap_name_t *zn,
-    int chunk, int array_numints)
+    uint_t chunk, int array_numints)
 {
 	int bseen = 0;
 
@@ -562,7 +554,7 @@ zap_entry_create(zap_leaf_t *l, zap_name_t *zn, uint32_t cd,
 
 	uint64_t valuelen = integer_size * num_integers;
 
-	int numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(zn->zn_key_orig_numints *
+	uint_t numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(zn->zn_key_orig_numints *
 	    zn->zn_key_intlen) + ZAP_LEAF_ARRAY_NCHUNKS(valuelen);
 	if (numchunks > ZAP_LEAF_NUMCHUNKS(l))
 		return (SET_ERROR(E2BIG));
@@ -624,7 +616,7 @@ zap_entry_create(zap_leaf_t *l, zap_name_t *zn, uint32_t cd,
 
 	/* link it into the hash chain */
 	/* XXX if we did the search above, we could just use that */
-	uint16_t *chunkp = zap_leaf_rehash_entry(l, chunk);
+	uint16_t *chunkp = zap_leaf_rehash_entry(l, le, chunk);
 
 	zap_leaf_phys(l)->l_hdr.lh_nentries++;
 
@@ -687,9 +679,8 @@ zap_entry_normalization_conflict(zap_entry_handle_t *zeh, zap_name_t *zn,
  */
 
 static uint16_t *
-zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry)
+zap_leaf_rehash_entry(zap_leaf_t *l, struct zap_leaf_entry *le, uint16_t entry)
 {
-	struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
 	struct zap_leaf_entry *le2;
 	uint16_t *chunkp;
 
@@ -722,7 +713,7 @@ zap_leaf_transfer_array(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
 		    &ZAP_LEAF_CHUNK(nl, nchunk).l_array;
 		struct zap_leaf_array *la =
 		    &ZAP_LEAF_CHUNK(l, chunk).l_array;
-		int nextchunk = la->la_next;
+		uint_t nextchunk = la->la_next;
 
 		ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 		ASSERT3U(nchunk, <, ZAP_LEAF_NUMCHUNKS(l));
@@ -739,7 +730,7 @@ zap_leaf_transfer_array(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
 }
 
 static void
-zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
+zap_leaf_transfer_entry(zap_leaf_t *l, uint_t entry, zap_leaf_t *nl)
 {
 	struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
 	ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
@@ -748,7 +739,7 @@ zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
 	struct zap_leaf_entry *nle = ZAP_LEAF_ENTRY(nl, chunk);
 	*nle = *le; /* structure assignment */
 
-	(void) zap_leaf_rehash_entry(nl, chunk);
+	(void) zap_leaf_rehash_entry(nl, nle, chunk);
 
 	nle->le_name_chunk = zap_leaf_transfer_array(l, le->le_name_chunk, nl);
 	nle->le_value_chunk =
@@ -766,7 +757,7 @@ zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
 void
 zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
 {
-	int bit = 64 - 1 - zap_leaf_phys(l)->l_hdr.lh_prefix_len;
+	uint_t bit = 64 - 1 - zap_leaf_phys(l)->l_hdr.lh_prefix_len;
 
 	/* set new prefix and prefix_len */
 	zap_leaf_phys(l)->l_hdr.lh_prefix <<= 1;
@@ -777,7 +768,7 @@ zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
 	    zap_leaf_phys(l)->l_hdr.lh_prefix_len;
 
 	/* break existing hash chains */
-	zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
+	memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
 	    2*ZAP_LEAF_HASH_NUMENTRIES(l));
 
 	if (sort)
@@ -792,7 +783,7 @@ zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
 	 * but this accesses memory more sequentially, and when we're
 	 * called, the block is usually pretty full.
 	 */
-	for (int i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
+	for (uint_t i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
 		struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, i);
 		if (le->le_type != ZAP_CHUNK_ENTRY)
 			continue;
@@ -800,14 +791,14 @@ zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
 		if (le->le_hash & (1ULL << bit))
 			zap_leaf_transfer_entry(l, i, nl);
 		else
-			(void) zap_leaf_rehash_entry(l, i);
+			(void) zap_leaf_rehash_entry(l, le, i);
 	}
 }
 
 void
 zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
 {
-	int n = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
+	uint_t n = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
 	    zap_leaf_phys(l)->l_hdr.lh_prefix_len;
 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
 	zs->zs_leafs_with_2n_pointers[n]++;
@@ -823,9 +814,9 @@ zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
 	n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
 	zs->zs_blocks_n_tenths_full[n]++;
 
-	for (int i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
-		int nentries = 0;
-		int chunk = zap_leaf_phys(l)->l_hash[i];
+	for (uint_t i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
+		uint_t nentries = 0;
+		uint_t chunk = zap_leaf_phys(l)->l_hash[i];
 
 		while (chunk != CHAIN_END) {
 			struct zap_leaf_entry *le =
diff --git a/sys/contrib/openzfs/module/zfs/zap_micro.c b/sys/contrib/openzfs/module/zfs/zap_micro.c
index 085d9cd8b4b6..d806988af96d 100644
--- a/sys/contrib/openzfs/module/zfs/zap_micro.c
+++ b/sys/contrib/openzfs/module/zfs/zap_micro.c
@@ -415,7 +415,7 @@ mze_destroy(zap_t *zap)
 }
 
 static zap_t *
-mzap_open(objset_t *os, uint64_t obj, dmu_buf_t *db)
+mzap_open(dmu_buf_t *db)
 {
 	zap_t *winner;
 	uint64_t *zap_hdr = (uint64_t *)db->db_data;
@@ -427,8 +427,8 @@ mzap_open(objset_t *os, uint64_t obj, dmu_buf_t *db)
 	zap_t *zap = kmem_zalloc(sizeof (zap_t), KM_SLEEP);
 	rw_init(&zap->zap_rwlock, NULL, RW_DEFAULT, NULL);
 	rw_enter(&zap->zap_rwlock, RW_WRITER);
-	zap->zap_objset = os;
-	zap->zap_object = obj;
+	zap->zap_objset = dmu_buf_get_objset(db);
+	zap->zap_object = db->db_object;
 	zap->zap_dbuf = db;
 
 	if (zap_block_type != ZBT_MICRO) {
@@ -518,7 +518,7 @@ handle_winner:
  * have the specified tag.
  */
 static int
-zap_lockdir_impl(dmu_buf_t *db, const void *tag, dmu_tx_t *tx,
+zap_lockdir_impl(dnode_t *dn, dmu_buf_t *db, const void *tag, dmu_tx_t *tx,
     krw_t lti, boolean_t fatreader, boolean_t adding, zap_t **zapp)
 {
 	ASSERT0(db->db_offset);
@@ -528,13 +528,13 @@ zap_lockdir_impl(dmu_buf_t *db, const void *tag, dmu_tx_t *tx,
 
 	*zapp = NULL;
 
-	dmu_object_info_from_db(db, &doi);
+	dmu_object_info_from_dnode(dn, &doi);
 	if (DMU_OT_BYTESWAP(doi.doi_type) != DMU_BSWAP_ZAP)
 		return (SET_ERROR(EINVAL));
 
 	zap_t *zap = dmu_buf_get_user(db);
 	if (zap == NULL) {
-		zap = mzap_open(os, obj, db);
+		zap = mzap_open(db);
 		if (zap == NULL) {
 			/*
 			 * mzap_open() didn't like what it saw on-disk.
@@ -563,6 +563,7 @@ zap_lockdir_impl(dmu_buf_t *db, const void *tag, dmu_tx_t *tx,
 	}
 
 	zap->zap_objset = os;
+	zap->zap_dnode = dn;
 
 	if (lt == RW_WRITER)
 		dmu_buf_will_dirty(db, tx);
@@ -598,23 +599,16 @@ zap_lockdir_by_dnode(dnode_t *dn, dmu_tx_t *tx,
     zap_t **zapp)
 {
 	dmu_buf_t *db;
+	int err;
 
-	int err = dmu_buf_hold_by_dnode(dn, 0, tag, &db, DMU_READ_NO_PREFETCH);
-	if (err != 0) {
+	err = dmu_buf_hold_by_dnode(dn, 0, tag, &db, DMU_READ_NO_PREFETCH);
+	if (err != 0)
 		return (err);
-	}
-#ifdef ZFS_DEBUG
-	{
-		dmu_object_info_t doi;
-		dmu_object_info_from_db(db, &doi);
-		ASSERT3U(DMU_OT_BYTESWAP(doi.doi_type), ==, DMU_BSWAP_ZAP);
-	}
-#endif
-
-	err = zap_lockdir_impl(db, tag, tx, lti, fatreader, adding, zapp);
-	if (err != 0) {
+	err = zap_lockdir_impl(dn, db, tag, tx, lti, fatreader, adding, zapp);
+	if (err != 0)
 		dmu_buf_rele(db, tag);
-	}
+	else
+		VERIFY(dnode_add_ref(dn, tag));
 	return (err);
 }
 
@@ -623,21 +617,23 @@ zap_lockdir(objset_t *os, uint64_t obj, dmu_tx_t *tx,
     krw_t lti, boolean_t fatreader, boolean_t adding, const void *tag,
     zap_t **zapp)
 {
+	dnode_t *dn;
 	dmu_buf_t *db;
+	int err;
 
-	int err = dmu_buf_hold(os, obj, 0, tag, &db, DMU_READ_NO_PREFETCH);
+	err = dnode_hold(os, obj, tag, &dn);
 	if (err != 0)
 		return (err);
-#ifdef ZFS_DEBUG
-	{
-		dmu_object_info_t doi;
-		dmu_object_info_from_db(db, &doi);
-		ASSERT3U(DMU_OT_BYTESWAP(doi.doi_type), ==, DMU_BSWAP_ZAP);
+	err = dmu_buf_hold_by_dnode(dn, 0, tag, &db, DMU_READ_NO_PREFETCH);
+	if (err != 0) {
+		dnode_rele(dn, tag);
+		return (err);
 	}
-#endif
-	err = zap_lockdir_impl(db, tag, tx, lti, fatreader, adding, zapp);
-	if (err != 0)
+	err = zap_lockdir_impl(dn, db, tag, tx, lti, fatreader, adding, zapp);
+	if (err != 0) {
 		dmu_buf_rele(db, tag);
+		dnode_rele(dn, tag);
+	}
 	return (err);
 }
 
@@ -645,6 +641,7 @@ void
 zap_unlockdir(zap_t *zap, const void *tag)
 {
 	rw_exit(&zap->zap_rwlock);
+	dnode_rele(zap->zap_dnode, tag);
 	dmu_buf_rele(zap->zap_dbuf, tag);
 }
 
@@ -730,7 +727,8 @@ mzap_create_impl(dnode_t *dn, int normflags, zap_flags_t flags, dmu_tx_t *tx)
 	if (flags != 0) {
 		zap_t *zap;
 		/* Only fat zap supports flags; upgrade immediately. */
-		VERIFY0(zap_lockdir_impl(db, FTAG, tx, RW_WRITER,
+		VERIFY(dnode_add_ref(dn, FTAG));
+		VERIFY0(zap_lockdir_impl(dn, db, FTAG, tx, RW_WRITER,
 		    B_FALSE, B_FALSE, &zap));
 		VERIFY0(mzap_upgrade(&zap, FTAG, tx, flags));
 		zap_unlockdir(zap, FTAG);
@@ -1325,6 +1323,26 @@ zap_add_by_dnode(dnode_t *dn, const char *key,
 	return (err);
 }
 
+static int
+zap_add_uint64_impl(zap_t *zap, const uint64_t *key,
+    int key_numints, int integer_size, uint64_t num_integers,
+    const void *val, dmu_tx_t *tx, const void *tag)
+{
+	int err;
+
+	zap_name_t *zn = zap_name_alloc_uint64(zap, key, key_numints);
+	if (zn == NULL) {
+		zap_unlockdir(zap, tag);
+		return (SET_ERROR(ENOTSUP));
+	}
+	err = fzap_add(zn, integer_size, num_integers, val, tag, tx);
+	zap = zn->zn_zap;	/* fzap_add() may change zap */
+	zap_name_free(zn);
+	if (zap != NULL)	/* may be NULL if fzap_add() failed */
+		zap_unlockdir(zap, tag);
+	return (err);
+}
+
 int
 zap_add_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
     int key_numints, int integer_size, uint64_t num_integers,
@@ -1336,16 +1354,26 @@ zap_add_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
 	    zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, FTAG, &zap);
 	if (err != 0)
 		return (err);
-	zap_name_t *zn = zap_name_alloc_uint64(zap, key, key_numints);
-	if (zn == NULL) {
-		zap_unlockdir(zap, FTAG);
-		return (SET_ERROR(ENOTSUP));
-	}
-	err = fzap_add(zn, integer_size, num_integers, val, FTAG, tx);
-	zap = zn->zn_zap;	/* fzap_add() may change zap */
-	zap_name_free(zn);
-	if (zap != NULL)	/* may be NULL if fzap_add() failed */
-		zap_unlockdir(zap, FTAG);
+	err = zap_add_uint64_impl(zap, key, key_numints,
+	    integer_size, num_integers, val, tx, FTAG);
+	/* zap_add_uint64_impl() calls zap_unlockdir() */
+	return (err);
+}
+
+int
+zap_add_uint64_by_dnode(dnode_t *dn, const uint64_t *key,
+    int key_numints, int integer_size, uint64_t num_integers,
+    const void *val, dmu_tx_t *tx)
+{
+	zap_t *zap;
+
+	int err =
+	    zap_lockdir_by_dnode(dn, tx, RW_WRITER, TRUE, TRUE, FTAG, &zap);
+	if (err != 0)
+		return (err);
+	err = zap_add_uint64_impl(zap, key, key_numints,
+	    integer_size, num_integers, val, tx, FTAG);
+	/* zap_add_uint64_impl() calls zap_unlockdir() */
 	return (err);
 }
 
@@ -1396,27 +1424,56 @@ zap_update(objset_t *os, uint64_t zapobj, const char *name,
 	return (err);
 }
 
-int
-zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
-    int key_numints,
-    int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx)
+static int
+zap_update_uint64_impl(zap_t *zap, const uint64_t *key, int key_numints,
+    int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx,
+    const void *tag)
 {
-	zap_t *zap;
+	int err;
 
-	int err =
-	    zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, FTAG, &zap);
-	if (err != 0)
-		return (err);
 	zap_name_t *zn = zap_name_alloc_uint64(zap, key, key_numints);
 	if (zn == NULL) {
-		zap_unlockdir(zap, FTAG);
+		zap_unlockdir(zap, tag);
 		return (SET_ERROR(ENOTSUP));
 	}
-	err = fzap_update(zn, integer_size, num_integers, val, FTAG, tx);
+	err = fzap_update(zn, integer_size, num_integers, val, tag, tx);
 	zap = zn->zn_zap;	/* fzap_update() may change zap */
 	zap_name_free(zn);
 	if (zap != NULL)	/* may be NULL if fzap_upgrade() failed */
-		zap_unlockdir(zap, FTAG);
+		zap_unlockdir(zap, tag);
+	return (err);
+}
+
+int
+zap_update_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
+    int key_numints, int integer_size, uint64_t num_integers, const void *val,
+    dmu_tx_t *tx)
+{
+	zap_t *zap;
+
+	int err =
+	    zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, TRUE, FTAG, &zap);
+	if (err != 0)
+		return (err);
+	err = zap_update_uint64_impl(zap, key, key_numints,
+	    integer_size, num_integers, val, tx, FTAG);
+	/* zap_update_uint64_impl() calls zap_unlockdir() */
+	return (err);
+}
+
+int
+zap_update_uint64_by_dnode(dnode_t *dn, const uint64_t *key, int key_numints,
+    int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx)
+{
+	zap_t *zap;
+
+	int err =
+	    zap_lockdir_by_dnode(dn, tx, RW_WRITER, TRUE, TRUE, FTAG, &zap);
+	if (err != 0)
+		return (err);
+	err = zap_update_uint64_impl(zap, key, key_numints,
+	    integer_size, num_integers, val, tx, FTAG);
+	/* zap_update_uint64_impl() calls zap_unlockdir() */
 	return (err);
 }
 
@@ -1481,6 +1538,23 @@ zap_remove_by_dnode(dnode_t *dn, const char *name, dmu_tx_t *tx)
 	return (err);
 }
 
+static int
+zap_remove_uint64_impl(zap_t *zap, const uint64_t *key, int key_numints,
+    dmu_tx_t *tx, const void *tag)
+{
+	int err;
+
+	zap_name_t *zn = zap_name_alloc_uint64(zap, key, key_numints);
+	if (zn == NULL) {
+		zap_unlockdir(zap, tag);
+		return (SET_ERROR(ENOTSUP));
+	}
+	err = fzap_remove(zn, tx);
+	zap_name_free(zn);
+	zap_unlockdir(zap, tag);
+	return (err);
+}
+
 int
 zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
     int key_numints, dmu_tx_t *tx)
@@ -1491,14 +1565,23 @@ zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
 	    zap_lockdir(os, zapobj, tx, RW_WRITER, TRUE, FALSE, FTAG, &zap);
 	if (err != 0)
 		return (err);
-	zap_name_t *zn = zap_name_alloc_uint64(zap, key, key_numints);
-	if (zn == NULL) {
-		zap_unlockdir(zap, FTAG);
-		return (SET_ERROR(ENOTSUP));
-	}
-	err = fzap_remove(zn, tx);
-	zap_name_free(zn);
-	zap_unlockdir(zap, FTAG);
+	err = zap_remove_uint64_impl(zap, key, key_numints, tx, FTAG);
+	/* zap_remove_uint64_impl() calls zap_unlockdir() */
+	return (err);
+}
+
+int
+zap_remove_uint64_by_dnode(dnode_t *dn, const uint64_t *key, int key_numints,
+    dmu_tx_t *tx)
+{
+	zap_t *zap;
+
+	int err =
+	    zap_lockdir_by_dnode(dn, tx, RW_WRITER, TRUE, FALSE, FTAG, &zap);
+	if (err != 0)
+		return (err);
+	err = zap_remove_uint64_impl(zap, key, key_numints, tx, FTAG);
+	/* zap_remove_uint64_impl() calls zap_unlockdir() */
 	return (err);
 }
 
@@ -1704,14 +1787,17 @@ EXPORT_SYMBOL(zap_prefetch_uint64);
 EXPORT_SYMBOL(zap_add);
 EXPORT_SYMBOL(zap_add_by_dnode);
 EXPORT_SYMBOL(zap_add_uint64);
+EXPORT_SYMBOL(zap_add_uint64_by_dnode);
 EXPORT_SYMBOL(zap_update);
 EXPORT_SYMBOL(zap_update_uint64);
+EXPORT_SYMBOL(zap_update_uint64_by_dnode);
 EXPORT_SYMBOL(zap_length);
 EXPORT_SYMBOL(zap_length_uint64);
 EXPORT_SYMBOL(zap_remove);
 EXPORT_SYMBOL(zap_remove_by_dnode);
 EXPORT_SYMBOL(zap_remove_norm);
 EXPORT_SYMBOL(zap_remove_uint64);
+EXPORT_SYMBOL(zap_remove_uint64_by_dnode);
 EXPORT_SYMBOL(zap_count);
 EXPORT_SYMBOL(zap_value_search);
 EXPORT_SYMBOL(zap_join);
diff --git a/sys/contrib/openzfs/module/zfs/zfs_fm.c b/sys/contrib/openzfs/module/zfs/zfs_fm.c
index c4eb74e873db..481af2ba826b 100644
--- a/sys/contrib/openzfs/module/zfs/zfs_fm.c
+++ b/sys/contrib/openzfs/module/zfs/zfs_fm.c
@@ -222,6 +222,12 @@ vdev_prop_get_inherited(vdev_t *vd, vdev_prop_t prop)
 		case VDEV_PROP_IO_T:
 			propval = vd->vdev_io_t;
 			break;
+		case VDEV_PROP_SLOW_IO_N:
+			propval = vd->vdev_slow_io_n;
+			break;
+		case VDEV_PROP_SLOW_IO_T:
+			propval = vd->vdev_slow_io_t;
+			break;
 		default:
 			propval = propdef;
 			break;
@@ -741,6 +747,26 @@ zfs_ereport_start(nvlist_t **ereport_out, nvlist_t **detector_out,
 			    NULL);
 	}
 
+	if (vd != NULL && strcmp(subclass, FM_EREPORT_ZFS_DELAY) == 0) {
+		uint64_t slow_io_n, slow_io_t;
+
+		slow_io_n = vdev_prop_get_inherited(vd, VDEV_PROP_SLOW_IO_N);
+		if (slow_io_n != vdev_prop_default_numeric(VDEV_PROP_SLOW_IO_N))
+			fm_payload_set(ereport,
+			    FM_EREPORT_PAYLOAD_ZFS_VDEV_SLOW_IO_N,
+			    DATA_TYPE_UINT64,
+			    slow_io_n,
+			    NULL);
+
+		slow_io_t = vdev_prop_get_inherited(vd, VDEV_PROP_SLOW_IO_T);
+		if (slow_io_t != vdev_prop_default_numeric(VDEV_PROP_SLOW_IO_T))
+			fm_payload_set(ereport,
+			    FM_EREPORT_PAYLOAD_ZFS_VDEV_SLOW_IO_T,
+			    DATA_TYPE_UINT64,
+			    slow_io_t,
+			    NULL);
+	}
+
 	mutex_exit(&spa->spa_errlist_lock);
 
 	*ereport_out = ereport;
diff --git a/sys/contrib/openzfs/module/zfs/zfs_ioctl.c b/sys/contrib/openzfs/module/zfs/zfs_ioctl.c
index 2738385e260b..b07837113293 100644
--- a/sys/contrib/openzfs/module/zfs/zfs_ioctl.c
+++ b/sys/contrib/openzfs/module/zfs/zfs_ioctl.c
@@ -27,7 +27,7 @@
  * Copyright (c) 2014, 2016 Joyent, Inc. All rights reserved.
  * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2014, Joyent, Inc. All rights reserved.
- * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
@@ -1887,7 +1887,7 @@ zfs_ioc_vdev_add(zfs_cmd_t *zc)
 	error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
 	    zc->zc_iflags, &config);
 	if (error == 0) {
-		error = spa_vdev_add(spa, config);
+		error = spa_vdev_add(spa, config, zc->zc_flags);
 		nvlist_free(config);
 	}
 	spa_close(spa, FTAG);
@@ -5800,10 +5800,13 @@ zfs_ioc_clear(zfs_cmd_t *zc)
 
 	/*
 	 * If multihost is enabled, resuming I/O is unsafe as another
-	 * host may have imported the pool.
+	 * host may have imported the pool. Check for remote activity.
 	 */
-	if (spa_multihost(spa) && spa_suspended(spa))
-		return (SET_ERROR(EINVAL));
+	if (spa_multihost(spa) && spa_suspended(spa) &&
+	    spa_mmp_remote_host_activity(spa)) {
+		spa_close(spa, FTAG);
+		return (SET_ERROR(EREMOTEIO));
+	}
 
 	spa_vdev_state_enter(spa, SCL_NONE);
 
diff --git a/sys/contrib/openzfs/module/zfs/zfs_vnops.c b/sys/contrib/openzfs/module/zfs/zfs_vnops.c
index 2b37834d5c56..7020f88ecf93 100644
--- a/sys/contrib/openzfs/module/zfs/zfs_vnops.c
+++ b/sys/contrib/openzfs/module/zfs/zfs_vnops.c
@@ -130,7 +130,7 @@ zfs_holey_common(znode_t *zp, ulong_t cmd, loff_t *off)
 
 	/* Flush any mmap()'d data to disk */
 	if (zn_has_cached_data(zp, 0, file_sz - 1))
-		zn_flush_cached_data(zp, B_FALSE);
+		zn_flush_cached_data(zp, B_TRUE);
 
 	lr = zfs_rangelock_enter(&zp->z_rangelock, 0, UINT64_MAX, RL_READER);
 	error = dmu_offset_next(ZTOZSB(zp)->z_os, zp->z_id, hole, &noff);
@@ -1193,6 +1193,10 @@ zfs_clone_range(znode_t *inzp, uint64_t *inoffp, znode_t *outzp,
 		}
 	}
 
+	/* Flush any mmap()'d data to disk */
+	if (zn_has_cached_data(inzp, inoff, inoff + len - 1))
+		zn_flush_cached_data(inzp, B_TRUE);
+
 	/*
 	 * Maintain predictable lock order.
 	 */
diff --git a/sys/contrib/openzfs/module/zfs/zil.c b/sys/contrib/openzfs/module/zfs/zil.c
index 5642f082bdb8..9b5d866a8c22 100644
--- a/sys/contrib/openzfs/module/zfs/zil.c
+++ b/sys/contrib/openzfs/module/zfs/zil.c
@@ -91,15 +91,7 @@
  * committed to stable storage. Please refer to the zil_commit_waiter()
  * function (and the comments within it) for more details.
  */
-static uint_t zfs_commit_timeout_pct = 5;
-
-/*
- * Minimal time we care to delay commit waiting for more ZIL records.
- * At least FreeBSD kernel can't sleep for less than 2us at its best.
- * So requests to sleep for less then 5us is a waste of CPU time with
- * a risk of significant log latency increase due to oversleep.
- */
-static uint64_t zil_min_commit_timeout = 5000;
+static uint_t zfs_commit_timeout_pct = 10;
 
 /*
  * See zil.h for more information about these fields.
@@ -152,6 +144,7 @@ static kmem_cache_t *zil_zcw_cache;
 
 static void zil_lwb_commit(zilog_t *zilog, lwb_t *lwb, itx_t *itx);
 static itx_t *zil_itx_clone(itx_t *oitx);
+static uint64_t zil_max_waste_space(zilog_t *zilog);
 
 static int
 zil_bp_compare(const void *x1, const void *x2)
@@ -1630,7 +1623,7 @@ zil_lwb_write_done(zio_t *zio)
 
 	while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
 		vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
-		if (vd != NULL && !vd->vdev_nowritecache) {
+		if (vd != NULL) {
 			/*
 			 * The "ZIO_FLAG_DONT_PROPAGATE" is currently
 			 * always used within "zio_flush". This means,
@@ -1719,24 +1712,6 @@ zil_lwb_write_open(zilog_t *zilog, lwb_t *lwb)
 }
 
 /*
- * Define a limited set of intent log block sizes.
- *
- * These must be a multiple of 4KB. Note only the amount used (again
- * aligned to 4KB) actually gets written. However, we can't always just
- * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted.
- */
-static const struct {
-	uint64_t	limit;
-	uint64_t	blksz;
-} zil_block_buckets[] = {
-	{ 4096,		4096 },			/* non TX_WRITE */
-	{ 8192 + 4096,	8192 + 4096 },		/* database */
-	{ 32768 + 4096,	32768 + 4096 },		/* NFS writes */
-	{ 65536 + 4096,	65536 + 4096 },		/* 64KB writes */
-	{ UINT64_MAX,	SPA_OLD_MAXBLOCKSIZE},	/* > 128KB writes */
-};
-
-/*
  * Maximum block size used by the ZIL.  This is picked up when the ZIL is
  * initialized.  Otherwise this should not be used directly; see
  * zl_max_block_size instead.
@@ -1744,13 +1719,98 @@ static const struct {
 static uint_t zil_maxblocksize = SPA_OLD_MAXBLOCKSIZE;
 
 /*
+ * Plan splitting of the provided burst size between several blocks.
+ */
+static uint_t
+zil_lwb_plan(zilog_t *zilog, uint64_t size, uint_t *minsize)
+{
+	uint_t md = zilog->zl_max_block_size - sizeof (zil_chain_t);
+
+	if (size <= md) {
+		/*
+		 * Small bursts are written as-is in one block.
+		 */
+		*minsize = size;
+		return (size);
+	} else if (size > 8 * md) {
+		/*
+		 * Big bursts use maximum blocks.  The first block size
+		 * is hard to predict, but it does not really matter.
+		 */
+		*minsize = 0;
+		return (md);
+	}
+
+	/*
+	 * Medium bursts try to divide evenly to better utilize several SLOG
+	 * VDEVs.  The first block size we predict assuming the worst case of
+	 * maxing out others.  Fall back to using maximum blocks if due to
+	 * large records or wasted space we can not predict anything better.
+	 */
+	uint_t s = size;
+	uint_t n = DIV_ROUND_UP(s, md - sizeof (lr_write_t));
+	uint_t chunk = DIV_ROUND_UP(s, n);
+	uint_t waste = zil_max_waste_space(zilog);
+	waste = MAX(waste, zilog->zl_cur_max);
+	if (chunk <= md - waste) {
+		*minsize = MAX(s - (md - waste) * (n - 1), waste);
+		return (chunk);
+	} else {
+		*minsize = 0;
+		return (md);
+	}
+}
+
+/*
+ * Try to predict next block size based on previous history.  Make prediction
+ * sufficient for 7 of 8 previous bursts.  Don't try to save if the saving is
+ * less then 50%, extra writes may cost more, but we don't want single spike
+ * to badly affect our predictions.
+ */
+static uint_t
+zil_lwb_predict(zilog_t *zilog)
+{
+	uint_t m, o;
+
+	/* If we are in the middle of a burst, take it into account also. */
+	if (zilog->zl_cur_size > 0) {
+		o = zil_lwb_plan(zilog, zilog->zl_cur_size, &m);
+	} else {
+		o = UINT_MAX;
+		m = 0;
+	}
+
+	/* Find minimum optimal size.  We don't need to go below that. */
+	for (int i = 0; i < ZIL_BURSTS; i++)
+		o = MIN(o, zilog->zl_prev_opt[i]);
+
+	/* Find two biggest minimal first block sizes above the optimal. */
+	uint_t m1 = MAX(m, o), m2 = o;
+	for (int i = 0; i < ZIL_BURSTS; i++) {
+		m = zilog->zl_prev_min[i];
+		if (m >= m1) {
+			m2 = m1;
+			m1 = m;
+		} else if (m > m2) {
+			m2 = m;
+		}
+	}
+
+	/*
+	 * If second minimum size gives 50% saving -- use it.  It may cost us
+	 * one additional write later, but the space saving is just too big.
+	 */
+	return ((m1 < m2 * 2) ? m1 : m2);
+}
+
+/*
  * Close the log block for being issued and allocate the next one.
  * Has to be called under zl_issuer_lock to chain more lwbs.
  */
 static lwb_t *
 zil_lwb_write_close(zilog_t *zilog, lwb_t *lwb, lwb_state_t state)
 {
-	int i;
+	uint64_t blksz, plan, plan2;
 
 	ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock));
 	ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED);
@@ -1765,34 +1825,40 @@ zil_lwb_write_close(zilog_t *zilog, lwb_t *lwb, lwb_state_t state)
 		return (NULL);
 
 	/*
-	 * Log blocks are pre-allocated. Here we select the size of the next
-	 * block, based on size used in the last block.
-	 * - first find the smallest bucket that will fit the block from a
-	 *   limited set of block sizes. This is because it's faster to write
-	 *   blocks allocated from the same metaslab as they are adjacent or
-	 *   close.
-	 * - next find the maximum from the new suggested size and an array of
-	 *   previous sizes. This lessens a picket fence effect of wrongly
-	 *   guessing the size if we have a stream of say 2k, 64k, 2k, 64k
-	 *   requests.
-	 *
-	 * Note we only write what is used, but we can't just allocate
-	 * the maximum block size because we can exhaust the available
-	 * pool log space.
+	 * Log blocks are pre-allocated.  Here we select the size of the next
+	 * block, based on what's left of this burst and the previous history.
+	 * While we try to only write used part of the block, we can't just
+	 * always allocate the maximum block size because we can exhaust all
+	 * available pool log space, so we try to be reasonable.
 	 */
-	uint64_t zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t);
-	for (i = 0; zil_blksz > zil_block_buckets[i].limit; i++)
-		continue;
-	zil_blksz = MIN(zil_block_buckets[i].blksz, zilog->zl_max_block_size);
-	zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz;
-	for (i = 0; i < ZIL_PREV_BLKS; i++)
-		zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]);
-	DTRACE_PROBE3(zil__block__size, zilog_t *, zilog,
-	    uint64_t, zil_blksz,
-	    uint64_t, zilog->zl_prev_blks[zilog->zl_prev_rotor]);
-	zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1);
-
-	return (zil_alloc_lwb(zilog, zil_blksz, NULL, 0, 0, state));
+	if (zilog->zl_cur_left > 0) {
+		/*
+		 * We are in the middle of a burst and know how much is left.
+		 * But if workload is multi-threaded there may be more soon.
+		 * Try to predict what can it be and plan for the worst case.
+		 */
+		uint_t m;
+		plan = zil_lwb_plan(zilog, zilog->zl_cur_left, &m);
+		if (zilog->zl_parallel) {
+			plan2 = zil_lwb_plan(zilog, zilog->zl_cur_left +
+			    zil_lwb_predict(zilog), &m);
+			if (plan < plan2)
+				plan = plan2;
+		}
+	} else {
+		/*
+		 * The previous burst is done and we can only predict what
+		 * will come next.
+		 */
+		plan = zil_lwb_predict(zilog);
+	}
+	blksz = plan + sizeof (zil_chain_t);
+	blksz = P2ROUNDUP_TYPED(blksz, ZIL_MIN_BLKSZ, uint64_t);
+	blksz = MIN(blksz, zilog->zl_max_block_size);
+	DTRACE_PROBE3(zil__block__size, zilog_t *, zilog, uint64_t, blksz,
+	    uint64_t, plan);
+
+	return (zil_alloc_lwb(zilog, blksz, NULL, 0, 0, state));
 }
 
 /*
@@ -1843,7 +1909,7 @@ next_lwb:
 	int wsz = lwb->lwb_sz;
 	if (lwb->lwb_error == 0) {
 		abd_t *lwb_abd = abd_get_from_buf(lwb->lwb_buf, lwb->lwb_sz);
-		if (!lwb->lwb_slog || zilog->zl_cur_used <= zil_slog_bulk)
+		if (!lwb->lwb_slog || zilog->zl_cur_size <= zil_slog_bulk)
 			prio = ZIO_PRIORITY_SYNC_WRITE;
 		else
 			prio = ZIO_PRIORITY_ASYNC_WRITE;
@@ -2004,6 +2070,42 @@ zil_max_copied_data(zilog_t *zilog)
 	return (MIN(max_data, zil_maxcopied));
 }
 
+static uint64_t
+zil_itx_record_size(itx_t *itx)
+{
+	lr_t *lr = &itx->itx_lr;
+
+	if (lr->lrc_txtype == TX_COMMIT)
+		return (0);
+	ASSERT3U(lr->lrc_reclen, >=, sizeof (lr_t));
+	return (lr->lrc_reclen);
+}
+
+static uint64_t
+zil_itx_data_size(itx_t *itx)
+{
+	lr_t *lr = &itx->itx_lr;
+	lr_write_t *lrw = (lr_write_t *)lr;
+
+	if (lr->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) {
+		ASSERT3U(lr->lrc_reclen, ==, sizeof (lr_write_t));
+		return (P2ROUNDUP_TYPED(lrw->lr_length, sizeof (uint64_t),
+		    uint64_t));
+	}
+	return (0);
+}
+
+static uint64_t
+zil_itx_full_size(itx_t *itx)
+{
+	lr_t *lr = &itx->itx_lr;
+
+	if (lr->lrc_txtype == TX_COMMIT)
+		return (0);
+	ASSERT3U(lr->lrc_reclen, >=, sizeof (lr_t));
+	return (lr->lrc_reclen + zil_itx_data_size(itx));
+}
+
 /*
  * Estimate space needed in the lwb for the itx.  Allocate more lwbs or
  * split the itx as needed, but don't touch the actual transaction data.
@@ -2046,16 +2148,9 @@ zil_lwb_assign(zilog_t *zilog, lwb_t *lwb, itx_t *itx, list_t *ilwbs)
 	}
 
 	reclen = lr->lrc_reclen;
-	if (lr->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) {
-		ASSERT3U(reclen, ==, sizeof (lr_write_t));
-		dlen = P2ROUNDUP_TYPED(
-		    lrw->lr_length, sizeof (uint64_t), uint64_t);
-	} else {
-		ASSERT3U(reclen, >=, sizeof (lr_t));
-		dlen = 0;
-	}
+	ASSERT3U(reclen, >=, sizeof (lr_t));
 	ASSERT3U(reclen, <=, zil_max_log_data(zilog, 0));
-	zilog->zl_cur_used += (reclen + dlen);
+	dlen = zil_itx_data_size(itx);
 
 cont:
 	/*
@@ -2096,6 +2191,7 @@ cont:
 		clrw->lr_length = dnow;
 		lrw->lr_offset += dnow;
 		lrw->lr_length -= dnow;
+		zilog->zl_cur_left -= dnow;
 	} else {
 		citx = itx;
 		clr = lr;
@@ -2117,10 +2213,8 @@ cont:
 	list_insert_tail(&lwb->lwb_itxs, citx);
 
 	dlen -= dnow;
-	if (dlen > 0) {
-		zilog->zl_cur_used += reclen;
+	if (dlen > 0)
 		goto cont;
-	}
 
 	if (lr->lrc_txtype == TX_WRITE &&
 	    lr->lrc_txg > spa_freeze_txg(zilog->zl_spa))
@@ -2147,13 +2241,8 @@ zil_lwb_commit(zilog_t *zilog, lwb_t *lwb, itx_t *itx)
 	if (lr->lrc_txtype == TX_COMMIT)
 		return;
 
-	if (lr->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) {
-		dlen = P2ROUNDUP_TYPED(
-		    lrw->lr_length, sizeof (uint64_t), uint64_t);
-	} else {
-		dlen = 0;
-	}
 	reclen = lr->lrc_reclen;
+	dlen = zil_itx_data_size(itx);
 	ASSERT3U(reclen + dlen, <=, lwb->lwb_nused - lwb->lwb_nfilled);
 
 	lr_buf = lwb->lwb_buf + lwb->lwb_nfilled;
@@ -2584,6 +2673,7 @@ zil_get_commit_list(zilog_t *zilog)
 		ASSERT(zilog_is_dirty_in_txg(zilog, txg) ||
 		    spa_freeze_txg(zilog->zl_spa) != UINT64_MAX);
 		list_t *sync_list = &itxg->itxg_itxs->i_sync_list;
+		itx_t *itx = NULL;
 		if (unlikely(zilog->zl_suspend > 0)) {
 			/*
 			 * ZIL was just suspended, but we lost the race.
@@ -2593,10 +2683,20 @@ zil_get_commit_list(zilog_t *zilog)
 			if (!list_is_empty(sync_list))
 				wtxg = MAX(wtxg, txg);
 		} else {
+			itx = list_head(sync_list);
 			list_move_tail(commit_list, sync_list);
 		}
 
 		mutex_exit(&itxg->itxg_lock);
+
+		while (itx != NULL) {
+			uint64_t s = zil_itx_full_size(itx);
+			zilog->zl_cur_size += s;
+			zilog->zl_cur_left += s;
+			s = zil_itx_record_size(itx);
+			zilog->zl_cur_max = MAX(zilog->zl_cur_max, s);
+			itx = list_next(commit_list, itx);
+		}
 	}
 	return (wtxg);
 }
@@ -2732,6 +2832,26 @@ zil_commit_writer_stall(zilog_t *zilog)
 	ASSERT(list_is_empty(&zilog->zl_lwb_list));
 }
 
+static void
+zil_burst_done(zilog_t *zilog)
+{
+	if (!list_is_empty(&zilog->zl_itx_commit_list) ||
+	    zilog->zl_cur_size == 0)
+		return;
+
+	if (zilog->zl_parallel)
+		zilog->zl_parallel--;
+
+	uint_t r = (zilog->zl_prev_rotor + 1) & (ZIL_BURSTS - 1);
+	zilog->zl_prev_rotor = r;
+	zilog->zl_prev_opt[r] = zil_lwb_plan(zilog, zilog->zl_cur_size,
+	    &zilog->zl_prev_min[r]);
+
+	zilog->zl_cur_size = 0;
+	zilog->zl_cur_max = 0;
+	zilog->zl_cur_left = 0;
+}
+
 /*
  * This function will traverse the commit list, creating new lwbs as
  * needed, and committing the itxs from the commit list to these newly
@@ -2746,7 +2866,6 @@ zil_process_commit_list(zilog_t *zilog, zil_commit_waiter_t *zcw, list_t *ilwbs)
 	list_t nolwb_waiters;
 	lwb_t *lwb, *plwb;
 	itx_t *itx;
-	boolean_t first = B_TRUE;
 
 	ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock));
 
@@ -2772,9 +2891,22 @@ zil_process_commit_list(zilog_t *zilog, zil_commit_waiter_t *zcw, list_t *ilwbs)
 		zil_commit_activate_saxattr_feature(zilog);
 		ASSERT(lwb->lwb_state == LWB_STATE_NEW ||
 		    lwb->lwb_state == LWB_STATE_OPENED);
-		first = (lwb->lwb_state == LWB_STATE_NEW) &&
-		    ((plwb = list_prev(&zilog->zl_lwb_list, lwb)) == NULL ||
-		    plwb->lwb_state == LWB_STATE_FLUSH_DONE);
+
+		/*
+		 * If the lwb is still opened, it means the workload is really
+		 * multi-threaded and we won the chance of write aggregation.
+		 * If it is not opened yet, but previous lwb is still not
+		 * flushed, it still means the workload is multi-threaded, but
+		 * there was too much time between the commits to aggregate, so
+		 * we try aggregation next times, but without too much hopes.
+		 */
+		if (lwb->lwb_state == LWB_STATE_OPENED) {
+			zilog->zl_parallel = ZIL_BURSTS;
+		} else if ((plwb = list_prev(&zilog->zl_lwb_list, lwb))
+		    != NULL && plwb->lwb_state != LWB_STATE_FLUSH_DONE) {
+			zilog->zl_parallel = MAX(zilog->zl_parallel,
+			    ZIL_BURSTS / 2);
+		}
 	}
 
 	while ((itx = list_remove_head(&zilog->zl_itx_commit_list)) != NULL) {
@@ -2849,7 +2981,9 @@ zil_process_commit_list(zilog_t *zilog, zil_commit_waiter_t *zcw, list_t *ilwbs)
 					 * Our lwb is done, leave the rest of
 					 * itx list to somebody else who care.
 					 */
-					first = B_FALSE;
+					zilog->zl_parallel = ZIL_BURSTS;
+					zilog->zl_cur_left -=
+					    zil_itx_full_size(itx);
 					break;
 				}
 			} else {
@@ -2859,8 +2993,10 @@ zil_process_commit_list(zilog_t *zilog, zil_commit_waiter_t *zcw, list_t *ilwbs)
 				}
 				list_insert_tail(&nolwb_itxs, itx);
 			}
+			zilog->zl_cur_left -= zil_itx_full_size(itx);
 		} else {
 			ASSERT3S(lrc->lrc_txtype, !=, TX_COMMIT);
+			zilog->zl_cur_left -= zil_itx_full_size(itx);
 			zil_itx_destroy(itx);
 		}
 	}
@@ -2941,28 +3077,15 @@ zil_process_commit_list(zilog_t *zilog, zil_commit_waiter_t *zcw, list_t *ilwbs)
 		 * try and pack as many itxs into as few lwbs as
 		 * possible, without significantly impacting the latency
 		 * of each individual itx.
-		 *
-		 * If we had no already running or open LWBs, it can be
-		 * the workload is single-threaded.  And if the ZIL write
-		 * latency is very small or if the LWB is almost full, it
-		 * may be cheaper to bypass the delay.
 		 */
-		if (lwb->lwb_state == LWB_STATE_OPENED && first) {
-			hrtime_t sleep = zilog->zl_last_lwb_latency *
-			    zfs_commit_timeout_pct / 100;
-			if (sleep < zil_min_commit_timeout ||
-			    lwb->lwb_nmax - lwb->lwb_nused <
-			    lwb->lwb_nmax / 8) {
-				list_insert_tail(ilwbs, lwb);
-				lwb = zil_lwb_write_close(zilog, lwb,
-				    LWB_STATE_NEW);
-				zilog->zl_cur_used = 0;
-				if (lwb == NULL) {
-					while ((lwb = list_remove_head(ilwbs))
-					    != NULL)
-						zil_lwb_write_issue(zilog, lwb);
-					zil_commit_writer_stall(zilog);
-				}
+		if (lwb->lwb_state == LWB_STATE_OPENED && !zilog->zl_parallel) {
+			zil_burst_done(zilog);
+			list_insert_tail(ilwbs, lwb);
+			lwb = zil_lwb_write_close(zilog, lwb, LWB_STATE_NEW);
+			if (lwb == NULL) {
+				while ((lwb = list_remove_head(ilwbs)) != NULL)
+					zil_lwb_write_issue(zilog, lwb);
+				zil_commit_writer_stall(zilog);
 			}
 		}
 	}
@@ -3116,24 +3239,11 @@ zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw)
 	 * since we've reached the commit waiter's timeout and it still
 	 * hasn't been issued.
 	 */
+	zil_burst_done(zilog);
 	lwb_t *nlwb = zil_lwb_write_close(zilog, lwb, LWB_STATE_NEW);
 
 	ASSERT3S(lwb->lwb_state, ==, LWB_STATE_CLOSED);
 
-	/*
-	 * Since the lwb's zio hadn't been issued by the time this thread
-	 * reached its timeout, we reset the zilog's "zl_cur_used" field
-	 * to influence the zil block size selection algorithm.
-	 *
-	 * By having to issue the lwb's zio here, it means the size of the
-	 * lwb was too large, given the incoming throughput of itxs.  By
-	 * setting "zl_cur_used" to zero, we communicate this fact to the
-	 * block size selection algorithm, so it can take this information
-	 * into account, and potentially select a smaller size for the
-	 * next lwb block that is allocated.
-	 */
-	zilog->zl_cur_used = 0;
-
 	if (nlwb == NULL) {
 		/*
 		 * When zil_lwb_write_close() returns NULL, this
@@ -3728,7 +3838,9 @@ zil_alloc(objset_t *os, zil_header_t *zh_phys)
 	zilog->zl_dirty_max_txg = 0;
 	zilog->zl_last_lwb_opened = NULL;
 	zilog->zl_last_lwb_latency = 0;
-	zilog->zl_max_block_size = zil_maxblocksize;
+	zilog->zl_max_block_size = MIN(MAX(P2ALIGN_TYPED(zil_maxblocksize,
+	    ZIL_MIN_BLKSZ, uint64_t), ZIL_MIN_BLKSZ),
+	    spa_maxblocksize(dmu_objset_spa(os)));
 
 	mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
 	mutex_init(&zilog->zl_issuer_lock, NULL, MUTEX_DEFAULT, NULL);
@@ -3748,6 +3860,11 @@ zil_alloc(objset_t *os, zil_header_t *zh_phys)
 	cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
 	cv_init(&zilog->zl_lwb_io_cv, NULL, CV_DEFAULT, NULL);
 
+	for (int i = 0; i < ZIL_BURSTS; i++) {
+		zilog->zl_prev_opt[i] = zilog->zl_max_block_size -
+		    sizeof (zil_chain_t);
+	}
+
 	return (zilog);
 }
 
@@ -4250,9 +4367,6 @@ EXPORT_SYMBOL(zil_kstat_values_update);
 ZFS_MODULE_PARAM(zfs, zfs_, commit_timeout_pct, UINT, ZMOD_RW,
 	"ZIL block open timeout percentage");
 
-ZFS_MODULE_PARAM(zfs_zil, zil_, min_commit_timeout, U64, ZMOD_RW,
-	"Minimum delay we care for ZIL block commit");
-
 ZFS_MODULE_PARAM(zfs_zil, zil_, replay_disable, INT, ZMOD_RW,
 	"Disable intent logging replay");
 
diff --git a/sys/contrib/openzfs/module/zfs/zio.c b/sys/contrib/openzfs/module/zfs/zio.c
index d8eb075eef54..046e6d64c1a9 100644
--- a/sys/contrib/openzfs/module/zfs/zio.c
+++ b/sys/contrib/openzfs/module/zfs/zio.c
@@ -1435,23 +1435,10 @@ zio_t *
 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
     zio_done_func_t *done, void *private, zio_flag_t flags)
 {
-	zio_t *zio;
-	int c;
-
-	if (vd->vdev_children == 0) {
-		zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
-		    ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
-		    ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
-
-		zio->io_cmd = cmd;
-	} else {
-		zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
-
-		for (c = 0; c < vd->vdev_children; c++)
-			zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
-			    done, private, flags));
-	}
-
+	zio_t *zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
+	    ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
+	    ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
+	zio->io_cmd = cmd;
 	return (zio);
 }
 
@@ -1622,11 +1609,18 @@ zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size,
 }
 
 void
-zio_flush(zio_t *zio, vdev_t *vd)
+zio_flush(zio_t *pio, vdev_t *vd)
 {
-	zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
-	    NULL, NULL,
-	    ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
+	if (vd->vdev_nowritecache)
+		return;
+	if (vd->vdev_children == 0) {
+		zio_nowait(zio_ioctl(pio, vd->vdev_spa, vd,
+		    DKIOCFLUSHWRITECACHE, NULL, NULL, ZIO_FLAG_CANFAIL |
+		    ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
+	} else {
+		for (uint64_t c = 0; c < vd->vdev_children; c++)
+			zio_flush(pio, vd->vdev_child[c]);
+	}
 }
 
 void
@@ -2509,8 +2503,10 @@ zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason)
 		    "failure and the failure mode property for this pool "
 		    "is set to panic.", spa_name(spa));
 
-	cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable I/O "
-	    "failure and has been suspended.\n", spa_name(spa));
+	if (reason != ZIO_SUSPEND_MMP) {
+		cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable "
+		    "I/O failure and has been suspended.\n", spa_name(spa));
+	}
 
 	(void) zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL,
 	    NULL, NULL, 0);
diff --git a/sys/contrib/openzfs/module/zfs/zio_inject.c b/sys/contrib/openzfs/module/zfs/zio_inject.c
index 3598351c499d..66ad72fb88e9 100644
--- a/sys/contrib/openzfs/module/zfs/zio_inject.c
+++ b/sys/contrib/openzfs/module/zfs/zio_inject.c
@@ -605,6 +605,12 @@ zio_handle_io_delay(zio_t *zio)
 		if (vd->vdev_guid != handler->zi_record.zi_guid)
 			continue;
 
+		/* also match on I/O type (e.g., -T read) */
+		if (handler->zi_record.zi_iotype != ZIO_TYPES &&
+		    handler->zi_record.zi_iotype != zio->io_type) {
+			continue;
+		}
+
 		/*
 		 * Defensive; should never happen as the array allocation
 		 * occurs prior to inserting this handler on the list.
diff --git a/sys/contrib/openzfs/module/zfs/zvol.c b/sys/contrib/openzfs/module/zfs/zvol.c
index 20ea71f23376..89b523ddd903 100644
--- a/sys/contrib/openzfs/module/zfs/zvol.c
+++ b/sys/contrib/openzfs/module/zfs/zvol.c
@@ -931,7 +931,7 @@ zvol_prefetch_minors_impl(void *arg)
 	job->error = dmu_objset_own(dsname, DMU_OST_ZVOL, B_TRUE, B_TRUE,
 	    FTAG, &os);
 	if (job->error == 0) {
-		dmu_prefetch(os, ZVOL_OBJ, 0, 0, 0, ZIO_PRIORITY_SYNC_READ);
+		dmu_prefetch_dnode(os, ZVOL_OBJ, ZIO_PRIORITY_SYNC_READ);
 		dmu_objset_disown(os, B_TRUE, FTAG);
 	}
 }
diff --git a/sys/contrib/openzfs/rpm/redhat/zfs-kmod.spec.in b/sys/contrib/openzfs/rpm/redhat/zfs-kmod.spec.in
index 9c836786baea..876c198c64de 100644
--- a/sys/contrib/openzfs/rpm/redhat/zfs-kmod.spec.in
+++ b/sys/contrib/openzfs/rpm/redhat/zfs-kmod.spec.in
@@ -17,7 +17,7 @@ BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 # by generating a preamble text file which kmodtool can append to the spec file.
 %(/bin/echo -e "\
 Requires:       @PACKAGE@ = %{version}\n\
-Conflicts:      @PACKAGE@-dkms)
+Conflicts:      @PACKAGE@-dkms" > %{_sourcedir}/kmod-preamble)
 
 # LDFLAGS are not sanitized by arch/*/Makefile for these architectures.
 %ifarch ppc ppc64 ppc64le aarch64
diff --git a/sys/contrib/openzfs/tests/runfiles/common.run b/sys/contrib/openzfs/tests/runfiles/common.run
index 7331244515f6..3e1a3aeb6cbe 100644
--- a/sys/contrib/openzfs/tests/runfiles/common.run
+++ b/sys/contrib/openzfs/tests/runfiles/common.run
@@ -246,7 +246,7 @@ tests = ['zfs_mount_001_pos', 'zfs_mount_002_pos', 'zfs_mount_003_pos',
     'zfs_mount_009_neg', 'zfs_mount_010_neg', 'zfs_mount_011_neg',
     'zfs_mount_012_pos', 'zfs_mount_all_001_pos', 'zfs_mount_encrypted',
     'zfs_mount_remount', 'zfs_mount_all_fail', 'zfs_mount_all_mountpoints',
-    'zfs_mount_test_race']
+    'zfs_mount_test_race', 'zfs_mount_recursive']
 tags = ['functional', 'cli_root', 'zfs_mount']
 
 [tests/functional/cli_root/zfs_program]
@@ -372,7 +372,8 @@ tags = ['functional', 'cli_root', 'zpool']
 tests = ['zpool_add_001_pos', 'zpool_add_002_pos', 'zpool_add_003_pos',
     'zpool_add_004_pos', 'zpool_add_006_pos', 'zpool_add_007_neg',
     'zpool_add_008_neg', 'zpool_add_009_neg', 'zpool_add_010_pos',
-    'add-o_ashift', 'add_prop_ashift', 'zpool_add_dryrun_output']
+    'add-o_ashift', 'add_prop_ashift', 'zpool_add_dryrun_output',
+    'zpool_add--allow-ashift-mismatch']
 tags = ['functional', 'cli_root', 'zpool_add']
 
 [tests/functional/cli_root/zpool_attach]
@@ -458,7 +459,8 @@ tests = ['zpool_import_001_pos', 'zpool_import_002_pos',
     'import_devices_missing', 'import_log_missing',
     'import_paths_changed',
     'import_rewind_config_changed',
-    'import_rewind_device_replaced']
+    'import_rewind_device_replaced',
+    'zpool_import_status']
 tags = ['functional', 'cli_root', 'zpool_import']
 timeout = 1200
 
diff --git a/sys/contrib/openzfs/tests/runfiles/linux.run b/sys/contrib/openzfs/tests/runfiles/linux.run
index 6a4cd3fe691c..92ce09ec6fcb 100644
--- a/sys/contrib/openzfs/tests/runfiles/linux.run
+++ b/sys/contrib/openzfs/tests/runfiles/linux.run
@@ -104,7 +104,8 @@ tags = ['functional', 'devices']
 
 [tests/functional/events:Linux]
 tests = ['events_001_pos', 'events_002_pos', 'zed_rc_filter', 'zed_fd_spill',
-    'zed_cksum_reported', 'zed_cksum_config', 'zed_io_config']
+    'zed_cksum_reported', 'zed_cksum_config', 'zed_io_config',
+    'zed_slow_io', 'zed_slow_io_many_vdevs']
 tags = ['functional', 'events']
 
 [tests/functional/fadvise:Linux]
@@ -145,7 +146,7 @@ tags = ['functional', 'mmap']
 tests = ['mmp_on_thread', 'mmp_on_uberblocks', 'mmp_on_off', 'mmp_interval',
     'mmp_active_import', 'mmp_inactive_import', 'mmp_exported_import',
     'mmp_write_uberblocks', 'mmp_reset_interval', 'multihost_history',
-    'mmp_on_zdb', 'mmp_write_distribution', 'mmp_hostid']
+    'mmp_on_zdb', 'mmp_write_distribution', 'mmp_hostid', 'mmp_write_slow_disk']
 tags = ['functional', 'mmp']
 
 [tests/functional/mount:Linux]
diff --git a/sys/contrib/openzfs/tests/runfiles/sanity.run b/sys/contrib/openzfs/tests/runfiles/sanity.run
index ab41c05b8473..695d3697a602 100644
--- a/sys/contrib/openzfs/tests/runfiles/sanity.run
+++ b/sys/contrib/openzfs/tests/runfiles/sanity.run
@@ -155,7 +155,8 @@ tests = ['zfs_mount_001_pos', 'zfs_mount_002_pos', 'zfs_mount_003_pos',
     'zfs_mount_004_pos', 'zfs_mount_005_pos', 'zfs_mount_007_pos',
     'zfs_mount_009_neg', 'zfs_mount_010_neg', 'zfs_mount_011_neg',
     'zfs_mount_012_pos', 'zfs_mount_encrypted', 'zfs_mount_remount',
-    'zfs_mount_all_fail', 'zfs_mount_all_mountpoints', 'zfs_mount_test_race']
+    'zfs_mount_all_fail', 'zfs_mount_all_mountpoints',
+    'zfs_mount_test_race', 'zfs_mount_recursive']
 tags = ['functional', 'cli_root', 'zfs_mount']
 
 [tests/functional/cli_root/zfs_program]
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/Makefile.am b/sys/contrib/openzfs/tests/zfs-tests/tests/Makefile.am
index e2824ee065e8..cc66d762f3c2 100644
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/Makefile.am
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/Makefile.am
@@ -769,6 +769,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/cli_root/zfs_mount/zfs_mount_all_fail.ksh \
 	functional/cli_root/zfs_mount/zfs_mount_all_mountpoints.ksh \
 	functional/cli_root/zfs_mount/zfs_mount_encrypted.ksh \
+	functional/cli_root/zfs_mount/zfs_mount_recursive.ksh \
 	functional/cli_root/zfs_mount/zfs_mount_remount.ksh \
 	functional/cli_root/zfs_mount/zfs_mount_test_race.ksh \
 	functional/cli_root/zfs_mount/zfs_multi_mount.ksh \
@@ -988,6 +989,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/cli_root/zpool_add/add_prop_ashift.ksh \
 	functional/cli_root/zpool_add/cleanup.ksh \
 	functional/cli_root/zpool_add/setup.ksh \
+	functional/cli_root/zpool_add/zpool_add--allow-ashift-mismatch.ksh \
 	functional/cli_root/zpool_add/zpool_add_001_pos.ksh \
 	functional/cli_root/zpool_add/zpool_add_002_pos.ksh \
 	functional/cli_root/zpool_add/zpool_add_003_pos.ksh \
@@ -1446,6 +1448,8 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/events/zed_fd_spill.ksh \
 	functional/events/zed_io_config.ksh \
 	functional/events/zed_rc_filter.ksh \
+	functional/events/zed_slow_io.ksh \
+	functional/events/zed_slow_io_many_vdevs.ksh \
 	functional/exec/cleanup.ksh \
 	functional/exec/exec_001_pos.ksh \
 	functional/exec/exec_002_neg.ksh \
@@ -1584,6 +1588,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/mmp/mmp_on_zdb.ksh \
 	functional/mmp/mmp_reset_interval.ksh \
 	functional/mmp/mmp_write_distribution.ksh \
+	functional/mmp/mmp_write_slow_disk.ksh \
 	functional/mmp/mmp_write_uberblocks.ksh \
 	functional/mmp/multihost_history.ksh \
 	functional/mmp/setup.ksh \
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_common.kshlib b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_common.kshlib
index 3b8eaea5bb54..84b92b4dcdc9 100644
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_common.kshlib
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_common.kshlib
@@ -97,20 +97,19 @@ function verify_pool_prop_eq
 
 function verify_pool_props
 {
-    typeset -r dsize=$1
-    typeset -r ratio=$2
+    typeset -r oused=$1
+    typeset -r osaved=$2
+    typeset dsize=$3
+    typeset ratio=$4
 
     if [[ $dsize -eq 0 ]]; then
-        verify_pool_prop_eq bcloneused 0
-        verify_pool_prop_eq bclonesaved 0
-        verify_pool_prop_eq bcloneratio 1.00
-    else
-        if [[ $ratio -eq 1 ]]; then
-            verify_pool_prop_eq bcloneused 0
-        else
-            verify_pool_prop_eq bcloneused $dsize
-        fi
-        verify_pool_prop_eq bclonesaved $((dsize*(ratio-1)))
+        ratio=1
+    elif [[ $ratio -eq 1 ]]; then
+        dsize=0
+    fi
+    verify_pool_prop_eq bcloneused $(($oused+$dsize))
+    verify_pool_prop_eq bclonesaved $(($osaved+dsize*(ratio-1)))
+    if [[ $oused -eq 0 ]]; then
         verify_pool_prop_eq bcloneratio "${ratio}.00"
     fi
 }
@@ -124,16 +123,22 @@ function bclone_test
     typeset -r srcdir=$4
     typeset -r dstdir=$5
     typeset dsize
+    typeset oused
+    typeset osaved
 
     typeset -r original="${srcdir}/original"
     typeset -r clone="${dstdir}/clone"
 
     log_note "Testing file copy with datatype $datatype, file size $filesize, embedded $embedded"
 
+    # Save current block cloning stats for later use.
+    sync_pool $TESTPOOL
+    oused=$(get_pool_prop bcloneused $TESTPOOL)
+    osaved=$(get_pool_prop bclonesaved $TESTPOOL)
+
     # Create a test file with known content.
     case $datatype in
         random|text)
-            sync_pool $TESTPOOL
             if [[ $datatype = "random" ]]; then
                 dd if=/dev/urandom of=$original bs=$filesize count=1 2>/dev/null
             else
@@ -146,13 +151,13 @@ function bclone_test
             sync_pool $TESTPOOL
             # It is hard to predict block sizes that will be used,
             # so just do one clone and take it from bcloneused.
-            filesize=$(zpool get -Hp -o value bcloneused $TESTPOOL)
+            dsize=$(get_pool_prop bcloneused $TESTPOOL)
+            dsize=$(($dsize-$oused))
             if [[ $embedded = "false" ]]; then
-                log_must test $filesize -gt 0
+                log_must test $dsize -gt 0
             fi
             rm -f "${clone}-tmp"
             sync_pool $TESTPOOL
-            dsize=$filesize
             ;;
         hole)
             log_must truncate_test -s $filesize -f $original
@@ -217,7 +222,7 @@ function bclone_test
     test_file_integrity $original_checksum "${clone}4" $filesize
     test_file_integrity $original_checksum "${clone}5" $filesize
 
-    verify_pool_props $dsize 7
+    verify_pool_props $oused $osaved $dsize 7
 
     # Clear cache and test after fresh import.
     log_must zpool export $TESTPOOL
@@ -240,7 +245,7 @@ function bclone_test
 
     sync_pool $TESTPOOL
 
-    verify_pool_props $dsize 11
+    verify_pool_props $oused $osaved $dsize 11
 
     log_must zpool export $TESTPOOL
     log_must zpool import $TESTPOOL
@@ -268,7 +273,7 @@ function bclone_test
     test_file_integrity $original_checksum "${clone}8" $filesize
     test_file_integrity $original_checksum "${clone}9" $filesize
 
-    verify_pool_props $dsize 6
+    verify_pool_props $oused $osaved $dsize 6
 
     rm -f "${clone}0" "${clone}2" "${clone}4" "${clone}8" "${clone}9"
 
@@ -276,11 +281,11 @@ function bclone_test
 
     test_file_integrity $original_checksum "${clone}6" $filesize
 
-    verify_pool_props $dsize 1
+    verify_pool_props $oused $osaved $dsize 1
 
     rm -f "${clone}6"
 
     sync_pool $TESTPOOL
 
-    verify_pool_props $dsize 1
+    verify_pool_props $oused $osaved $dsize 1
 }
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_corner_cases.kshlib b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_corner_cases.kshlib
index ddfbfc999c4e..aeb8efe91715 100644
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_corner_cases.kshlib
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/bclone/bclone_corner_cases.kshlib
@@ -66,7 +66,7 @@ function bclone_corner_cases_init
     export SECOND_HALF_ORIG0_CHECKSUM=$(second_half_checksum $ORIG0)
     export SECOND_HALF_ORIG1_CHECKSUM=$(second_half_checksum $ORIG1)
     export SECOND_HALF_ORIG2_CHECKSUM=$(second_half_checksum $ORIG2)
-    export ZEROS_CHECKSUM=$(dd if=/dev/zero bs=$HALFRECORDSIZE count=1 | sha256digest)
+    export ZEROS_CHECKSUM=$(dd if=/dev/zero bs=$HALFRECORDSIZE count=1 2>/dev/null | sha256digest)
     export FIRST_HALF_CHECKSUM=""
     export SECOND_HALF_CHECKSUM=""
 }
@@ -210,6 +210,8 @@ function bclone_corner_cases_test
     typeset -r dstdir=$2
     typeset limit=$3
     typeset -i count=0
+    typeset oused
+    typeset osaved
 
     if [[ $srcdir != "count" ]]; then
         if [[ -n "$limit" ]]; then
@@ -217,6 +219,11 @@ function bclone_corner_cases_test
             limit=$(random_int_between 1 $total_count $((limit*2)) | sort -nu | head -n $limit | xargs)
         fi
         bclone_corner_cases_init $srcdir $dstdir
+
+        # Save current block cloning stats for later use.
+        sync_pool $TESTPOOL
+        oused=$(get_pool_prop bcloneused $TESTPOOL)
+        osaved=$(get_pool_prop bclonesaved $TESTPOOL)
     fi
 
     #
@@ -285,21 +292,24 @@ function bclone_corner_cases_test
                                     overwrite_clone "$second_overwrite"
 
                                     if checksum_compare $read_after; then
-                                        log_note "existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / read_after: $read_after"
+                                        log_note "existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / second_overwrite: $second_overwrite / read_after: $read_after"
                                     else
-                                        log_fail "FAIL: existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / read_after: $read_after"
+                                        log_fail "FAIL: existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / second_overwrite: $second_overwrite / read_after: $read_after"
                                     fi
 
                                     log_must zpool export $TESTPOOL
                                     log_must zpool import $TESTPOOL
 
                                     if checksum_compare "yes"; then
-                                        log_note "existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / read_after: $read_after / read_next_txg"
+                                        log_note "existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / second_overwrite: $second_overwrite / read_after: $read_after / read_next_txg"
                                     else
-                                        log_fail "FAIL: existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / read_after: $read_after / read_next_txg"
+                                        log_fail "FAIL: existing: $existing / cached: $cached / first_clone: $first_clone / first_overwrite: $first_overwrite / read_before: $read_before / second_clone: $second_clone / second_overwrite: $second_overwrite / read_after: $read_after / read_next_txg"
                                     fi
 
                                     rm -f "$CLONE"
+                                    sync_pool $TESTPOOL
+                                    verify_pool_prop_eq bcloneused $oused
+                                    verify_pool_prop_eq bclonesaved $osaved
                                 done
                             done
                         done
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount.cfg b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount.cfg
index 06d25faf0356..739baf16086a 100644
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount.cfg
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount.cfg
@@ -31,6 +31,7 @@
 export mountcmd=mount
 export mountforce="$mountcmd -f"
 export mountall="$mountcmd -a"
+export mountrecursive="$mountcmd -R"
 
 export unmountcmd=unmount
 export unmountforce="$unmountcmd -f"
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount_recursive.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount_recursive.ksh
new file mode 100755
index 000000000000..0e5cc5d6955e
--- /dev/null
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zfs_mount/zfs_mount_recursive.ksh
@@ -0,0 +1,146 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2024, iXsystems Inc. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/cli_root/zfs_mount/zfs_mount.kshlib
+
+#
+# DESCRIPTION:
+# Verify zfs mount -R <filesystems/s> functionality.
+#
+# STRATEGY:
+# 1. Create nested datasets
+# 2. Unmount all datasets
+# 3. Recusrively mount root datasets, this should mount all datasets
+#    present in a pool
+# 4. Unmount all datasets
+# 5. Recusrsively mount child datasets with children. This should mount
+#    child datasets, but not the root dataset or parent datasets
+# 6. Unmount all datasets
+# 7. Mount root dataset recursively again and confirm all child
+#    datasets are mounted.
+#
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must datasetexists $TESTPOOL/$TESTFS1 && \
+		destroy_dataset $TESTPOOL/$TESTFS1 -R
+	log_must datasetexists $TESTPOOL/$TESTFS2 && \
+		destroy_dataset $TESTPOOL/$TESTFS2 -R
+	log_must datasetexists $TESTPOOL/$TESTFS3 && \
+		destroy_dataset $TESTPOOL/$TESTFS3 -R
+}
+
+function setup_all
+{
+	log_must datasetexists $TESTPOOL/$TESTFS || zfs create $TESTPOOL/$TESTFS
+	log_must zfs create $TESTPOOL/$TESTFS1
+	log_must zfs create $TESTPOOL/$TESTFS2
+	log_must zfs create $TESTPOOL/$TESTFS3
+	log_must zfs create $TESTPOOL/$TESTFS2/child1
+	log_must zfs create $TESTPOOL/$TESTFS2/child2
+	log_must zfs create $TESTPOOL/$TESTFS2/child3
+	log_must zfs create $TESTPOOL/$TESTFS2/child2/subchild
+	log_must zfs create $TESTPOOL/$TESTFS3/child
+}
+
+log_assert "Verify that 'zfs $mountrecursive' successfully, " \
+	"mounts the dataset along with all its children."
+
+log_onexit cleanup
+
+log_must setup_all
+
+log_must zfs $unmountall
+
+log_must zfs $mountrecursive $TESTPOOL
+
+log_must mounted $TESTPOOL
+log_must mounted $TESTPOOL/$TESTFS
+log_must mounted $TESTPOOL/$TESTFS1
+log_must mounted $TESTPOOL/$TESTFS2
+log_must mounted $TESTPOOL/$TESTFS3
+log_must mounted $TESTPOOL/$TESTFS2/child1
+log_must mounted $TESTPOOL/$TESTFS2/child2
+log_must mounted $TESTPOOL/$TESTFS2/child3
+log_must mounted $TESTPOOL/$TESTFS2/child2/subchild
+log_must mounted $TESTPOOL/$TESTFS3/child
+
+log_must zfs $unmountall
+
+log_mustnot mounted $TESTPOOL
+log_mustnot mounted $TESTPOOL/$TESTFS
+log_mustnot mounted $TESTPOOL/$TESTFS1
+log_mustnot mounted $TESTPOOL/$TESTFS2
+log_mustnot mounted $TESTPOOL/$TESTFS3
+log_mustnot mounted $TESTPOOL/$TESTFS2/child1
+log_mustnot mounted $TESTPOOL/$TESTFS2/child2
+log_mustnot mounted $TESTPOOL/$TESTFS2/child3
+log_mustnot mounted $TESTPOOL/$TESTFS2/child2/subchild
+log_mustnot mounted $TESTPOOL/$TESTFS3/child
+
+log_must zfs $mountrecursive $TESTPOOL/$TESTFS2 $TESTPOOL/$TESTFS3
+
+log_mustnot mounted $TESTPOOL
+log_mustnot mounted $TESTPOOL/$TESTFS
+log_mustnot mounted $TESTPOOL/$TESTFS1
+log_must mounted $TESTPOOL/$TESTFS2
+log_must mounted $TESTPOOL/$TESTFS3
+log_must mounted $TESTPOOL/$TESTFS2/child1
+log_must mounted $TESTPOOL/$TESTFS2/child2
+log_must mounted $TESTPOOL/$TESTFS2/child3
+log_must mounted $TESTPOOL/$TESTFS2/child2/subchild
+log_must mounted $TESTPOOL/$TESTFS3/child
+
+log_must zfs $unmountall
+
+log_mustnot mounted $TESTPOOL
+log_mustnot mounted $TESTPOOL/$TESTFS
+log_mustnot mounted $TESTPOOL/$TESTFS1
+log_mustnot mounted $TESTPOOL/$TESTFS2
+log_mustnot mounted $TESTPOOL/$TESTFS3
+log_mustnot mounted $TESTPOOL/$TESTFS2/child1
+log_mustnot mounted $TESTPOOL/$TESTFS2/child2
+log_mustnot mounted $TESTPOOL/$TESTFS2/child3
+log_mustnot mounted $TESTPOOL/$TESTFS2/child2/subchild
+log_mustnot mounted $TESTPOOL/$TESTFS3/child
+
+log_must zfs $mountrecursive $TESTPOOL/$TESTFS2/child2
+
+log_must mounted $TESTPOOL/$TESTFS2/child2
+log_must mounted $TESTPOOL/$TESTFS2/child2/subchild
+log_mustnot mounted $TESTPOOL
+log_mustnot mounted $TESTPOOL/$TESTFS
+log_mustnot mounted $TESTPOOL/$TESTFS1
+log_mustnot mounted $TESTPOOL/$TESTFS2
+log_mustnot mounted $TESTPOOL/$TESTFS3
+log_mustnot mounted $TESTPOOL/$TESTFS2/child1
+log_mustnot mounted $TESTPOOL/$TESTFS2/child3
+log_mustnot mounted $TESTPOOL/$TESTFS3/child
+
+log_pass "'zfs $mountrecursive' behaves as expected."
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add-o_ashift.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add-o_ashift.ksh
index 7ecaf849e44b..51871934dd22 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add-o_ashift.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add-o_ashift.ksh
@@ -22,7 +22,7 @@
 
 #
 # Copyright 2017, loli10K. All rights reserved.
-# Copyright (c) 2020 by Delphix. All rights reserved.
+# Copyright (c) 2020, 2024 by Delphix. All rights reserved.
 #
 
 . $STF_SUITE/include/libtest.shlib
@@ -60,12 +60,23 @@ log_must mkfile $SIZE $disk2
 logical_ashift=$(get_tunable VDEV_FILE_LOGICAL_ASHIFT)
 orig_ashift=$(get_tunable VDEV_FILE_PHYSICAL_ASHIFT)
 max_auto_ashift=$(get_tunable VDEV_MAX_AUTO_ASHIFT)
+opt=""
 
 typeset ashifts=("9" "10" "11" "12" "13" "14" "15" "16")
 for ashift in ${ashifts[@]}
 do
+	#
+	# Need to add the --allow-ashift-mismatch option to disable the
+	# ashift mismatch checks in zpool add.
+	#
+	if [[ $ashift -eq $orig_ashift ]]; then
+		opt=""
+	else
+		opt="--allow-ashift-mismatch"
+	fi
+
 	log_must zpool create $TESTPOOL $disk1
-	log_must zpool add -o ashift=$ashift $TESTPOOL $disk2
+	log_must zpool add $opt -o ashift=$ashift $TESTPOOL $disk2
 	log_must verify_ashift $disk2 $ashift
 
 	# clean things for the next run
@@ -78,7 +89,7 @@ do
 	#
 	log_must zpool create $TESTPOOL $disk1
 	log_must set_tunable32 VDEV_FILE_PHYSICAL_ASHIFT $ashift
-	log_must zpool add $TESTPOOL $disk2
+	log_must zpool add $opt $TESTPOOL $disk2
 	exp=$(( (ashift <= max_auto_ashift) ? ashift : logical_ashift ))
 	log_must verify_ashift $disk2 $exp
 
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add_prop_ashift.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add_prop_ashift.ksh
index 228f62232aae..6a3283d0618f 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add_prop_ashift.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/add_prop_ashift.ksh
@@ -22,7 +22,7 @@
 
 #
 # Copyright 2017, loli10K. All rights reserved.
-# Copyright (c) 2020 by Delphix. All rights reserved.
+# Copyright (c) 2020, 2024 by Delphix. All rights reserved.
 #
 
 . $STF_SUITE/include/libtest.shlib
@@ -68,8 +68,13 @@ log_must set_tunable32 VDEV_FILE_PHYSICAL_ASHIFT 16
 typeset ashifts=("9" "10" "11" "12" "13" "14" "15" "16")
 for ashift in ${ashifts[@]}
 do
+	if [ $ashift -eq $orig_ashift ];then
+		opt=""
+	else
+		opt="--allow-ashift-mismatch"
+	fi
 	log_must zpool create -o ashift=$ashift $TESTPOOL $disk1
-	log_must zpool add $TESTPOOL $disk2
+	log_must zpool add $opt $TESTPOOL $disk2
 	log_must verify_ashift $disk2 $ashift
 
 	# clean things for the next run
@@ -82,8 +87,13 @@ for ashift in ${ashifts[@]}
 do
 	for cmdval in ${ashifts[@]}
 	do
+		if [ $ashift -eq $cmdval ];then
+			opt=""
+		else
+			opt="--allow-ashift-mismatch"
+		fi
 		log_must zpool create -o ashift=$ashift $TESTPOOL $disk1
-		log_must zpool add -o ashift=$cmdval $TESTPOOL $disk2
+		log_must zpool add $opt -o ashift=$cmdval $TESTPOOL $disk2
 		log_must verify_ashift $disk2 $cmdval
 
 		# clean things for the next run
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add--allow-ashift-mismatch.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add--allow-ashift-mismatch.ksh
new file mode 100755
index 000000000000..e69de29bb2d1
--- /dev/null
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add--allow-ashift-mismatch.ksh
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_002_pos.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_002_pos.ksh
index c5c06f76340b..afee34a33469 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_002_pos.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_002_pos.ksh
@@ -65,4 +65,15 @@ log_mustnot vdevs_in_pool $TESTPOOL $DISK2
 log_must zpool add -f $TESTPOOL $DISK2
 log_must vdevs_in_pool $TESTPOOL $DISK2
 
+log_must zpool destroy $TESTPOOL
+
+create_pool $TESTPOOL mirror $DISK0 $DISK1
+log_must poolexists $TESTPOOL
+
+log_mustnot zpool add $TESTPOOL $DISK2
+log_mustnot vdevs_in_pool $TESTPOOL $DISK2
+
+log_must zpool add --allow-replication-mismatch $TESTPOOL $DISK2
+log_must vdevs_in_pool $TESTPOOL $DISK2
+
 log_pass "'zpool add -f <pool> <vdev> ...' executes successfully."
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_004_pos.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_004_pos.ksh
index 646edc1a4557..cecda56ab125 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_004_pos.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_004_pos.ksh
@@ -70,7 +70,7 @@ if is_freebsd; then
 	recursive=$(get_tunable VOL_RECURSIVE)
 	log_must set_tunable64 VOL_RECURSIVE 1
 fi
-log_must zpool add $TESTPOOL $ZVOL_DEVDIR/$TESTPOOL1/$TESTVOL
+log_must zpool add --allow-ashift-mismatch $TESTPOOL $ZVOL_DEVDIR/$TESTPOOL1/$TESTVOL
 
 log_must vdevs_in_pool "$TESTPOOL" "$ZVOL_DEVDIR/$TESTPOOL1/$TESTVOL"
 
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_005_pos.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_005_pos.ksh
index 4990ef9d29b0..0e9d9f5f030f 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_005_pos.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_005_pos.ksh
@@ -75,7 +75,9 @@ log_must poolexists $TESTPOOL1
 
 unset NOINUSE_CHECK
 log_mustnot zpool add -f $TESTPOOL $DISK1
+log_mustnot zpool add --allow-in-use $TESTPOOL $DISK1
 log_mustnot zpool add -f $TESTPOOL $mnttab_dev
+log_mustnot zpool add --allow-in-use $TESTPOOL $mnttab_dev
 if is_linux; then
        log_mustnot zpool add $TESTPOOL $vfstab_dev
 else
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_009_neg.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_009_neg.ksh
index d7f3a900e8fd..a13a27160e76 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_009_neg.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_009_neg.ksh
@@ -64,7 +64,9 @@ log_mustnot zpool add -f $TESTPOOL $DISK0
 for type in "" "mirror" "raidz" "draid" "spare" "log" "dedup" "special" "cache"
 do
 	log_mustnot zpool add -f $TESTPOOL $type $DISK0 $DISK1
+	log_mustnot zpool add --allow-in-use $TESTPOOL $type $DISK0 $DISK1
 	log_mustnot zpool add -f $TESTPOOL $type $DISK1 $DISK1
+	log_mustnot zpool add --allow-in-use $TESTPOOL $type $DISK1 $DISK1
 done
 
 log_pass "'zpool add' get fail as expected if vdevs are the same or vdev is " \
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_010_pos.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_010_pos.ksh
index b8b25db1b9f9..22860e9caf1d 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_010_pos.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add_010_pos.ksh
@@ -138,7 +138,7 @@ function zpool_create_forced_add
 		while ((j < ${#add_args[@]})); do
 			log_must zpool create $TESTPOOL1 ${create_args[$i]}
 			log_mustnot zpool add $TESTPOOL1 ${add_args[$j]}
-			log_must zpool add -f $TESTPOOL1 ${add_args[$j]}
+			log_must zpool add --allow-replication-mismatch $TESTPOOL1 ${add_args[$j]}
 			log_must zpool destroy -f $TESTPOOL1
 
 			((j += 1))
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_get/vdev_get.cfg b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_get/vdev_get.cfg
index 71a64d4fae7a..c3b9efd6464a 100644
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_get/vdev_get.cfg
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_get/vdev_get.cfg
@@ -70,4 +70,6 @@ typeset -a properties=(
     checksum_t
     io_n
     io_t
+    slow_io_n
+    slow_io_t
 )
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_status.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_status.ksh
new file mode 100755
index 000000000000..c96961bf6419
--- /dev/null
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_status.ksh
@@ -0,0 +1,132 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2023 Klara, Inc.
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/cli_root/zpool_import/zpool_import.cfg
+
+#
+# DESCRIPTION:
+# 	During a pool import, the 'import_progress' kstat contains details
+# 	on the import progress.
+#
+# STRATEGY:
+#	1. Create test pool with several devices
+#	2. Generate some ZIL records and spacemap logs
+#	3. Export the pool
+#	4. Import the pool in the background and monitor the kstat content
+#	5. Check the zfs debug messages for import progress
+#
+
+verify_runnable "global"
+
+function cleanup
+{
+	log_must set_tunable64 KEEP_LOG_SPACEMAPS_AT_EXPORT 0
+	log_must set_tunable64 METASLAB_DEBUG_LOAD 0
+
+	destroy_pool $TESTPOOL1
+}
+
+log_assert "During a pool import, the 'import_progress' kstat contains " \
+	"notes on the progress"
+
+log_onexit cleanup
+
+log_must zpool create $TESTPOOL1 $VDEV0 $VDEV1 $VDEV2
+typeset guid=$(zpool get -H -o value guid $TESTPOOL1)
+
+log_must zfs create -o recordsize=8k $TESTPOOL1/fs
+#
+# This dd command works around an issue where ZIL records aren't created
+# after freezing the pool unless a ZIL header already exists. Create a file
+# synchronously to force ZFS to write one out.
+#
+log_must dd if=/dev/zero of=/$TESTPOOL1/fs/sync conv=fsync bs=1 count=1
+
+#
+# Overwrite some blocks to populate spacemap logs
+#
+log_must dd if=/dev/urandom of=/$TESTPOOL1/fs/00 bs=1M count=200
+sync_all_pools
+log_must dd if=/dev/urandom of=/$TESTPOOL1/fs/00 bs=1M count=200
+sync_all_pools
+
+#
+# Freeze the pool to retain intent log records
+#
+log_must zpool freeze $TESTPOOL1
+
+# fill_fs [destdir] [dirnum] [filenum] [bytes] [num_writes] [data]
+log_must fill_fs /$TESTPOOL1/fs 1 2000 100 1024 R
+
+log_must zpool list -v $TESTPOOL1
+
+#
+# Unmount filesystem and export the pool
+#
+# At this stage the zfs intent log contains
+# a set of records to replay.
+#
+log_must zfs unmount /$TESTPOOL1/fs
+
+log_must set_tunable64 KEEP_LOG_SPACEMAPS_AT_EXPORT 1
+log_must zpool export $TESTPOOL1
+
+log_must set_tunable64 METASLAB_DEBUG_LOAD 1
+log_note "Starting zpool import in background at" $(date +'%H:%M:%S')
+zpool import -d $DEVICE_DIR -f $guid &
+pid=$!
+
+#
+# capture progress until import is finished
+#
+log_note waiting for pid $pid to exit
+kstat import_progress
+while [[ -d /proc/"$pid" ]]; do
+	line=$(kstat import_progress | grep -v pool_guid)
+	if [[ -n $line ]]; then
+		echo $line
+	fi
+	if [[ -f /$TESTPOOL1/fs/00 ]]; then
+		break;
+	fi
+	sleep 0.0001
+done
+log_note "zpool import completed at" $(date +'%H:%M:%S')
+
+entries=$(kstat dbgmsg | grep "spa_import_progress_set_notes_impl(): 'testpool1'" | wc -l)
+log_note "found $entries progress notes in dbgmsg"
+log_must test $entries -gt 20
+
+log_must zpool status $TESTPOOL1
+
+log_pass "During a pool import, the 'import_progress' kstat contains " \
+	"notes on the progress"
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cp_files/cp_files_002_pos.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cp_files/cp_files_002_pos.ksh
index 60817449ab03..4db968ffae05 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cp_files/cp_files_002_pos.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cp_files/cp_files_002_pos.ksh
@@ -76,7 +76,7 @@ log_onexit cleanup
 
 SRC_FILE=src.data
 DST_FILE=dst.data
-SRC_SIZE=$(($RANDOM % 2048))
+SRC_SIZE=$((1024 + $RANDOM % 1024))
 
 # A smaller recordsize is used merely to speed up the test.
 RECORDSIZE=4096
@@ -120,7 +120,7 @@ for mode in "never" "auto" "always"; do
 	# Overwrite a random range of an existing file and immediately copy it.
 	sync_pool $TESTPOOL
 	log_must dd if=/dev/urandom of=$SRC_FILE bs=$((RECORDSIZE / 2)) \
-            seek=$(($RANDOM % $SRC_SIZE)) count=$(($RANDOM % 16)) conv=notrunc
+            seek=$(($RANDOM % $SRC_SIZE)) count=$((1 + $RANDOM % 16)) conv=notrunc
 	if [[ "$mode" == "always" ]]; then
 		log_mustnot cp --reflink=$mode $SRC_FILE $DST_FILE
 		log_must ls -l $CP_TESTDIR
@@ -152,7 +152,7 @@ for mode in "never" "auto" "always"; do
 
 	# Overwrite a random range of an existing file and immediately copy it.
 	log_must dd if=/dev/urandom of=$SRC_FILE bs=$((RECORDSIZE / 2)) \
-            seek=$(($RANDOM % $SRC_SIZE)) count=$(($RANDOM % 16)) conv=notrunc
+            seek=$(($RANDOM % $SRC_SIZE)) count=$((1 + $RANDOM % 16)) conv=notrunc
 	log_must cp --reflink=$mode $SRC_FILE $DST_FILE
 	verify_copy $SRC_FILE $DST_FILE
 	log_must rm -f $SRC_FILE $DST_FILE
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/cleanup.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/cleanup.ksh
index ef6e098cf42a..669b8ae99456 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/cleanup.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/cleanup.ksh
@@ -26,8 +26,10 @@
 
 . $STF_SUITE/include/libtest.shlib
 
+zed_stop
+
 zed_cleanup all-debug.sh all-syslog.sh all-dumpfds
 
-zed_stop
+zed_events_drain
 
 default_cleanup
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/zed_slow_io.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/zed_slow_io.ksh
new file mode 100755
index 000000000000..d9fabb2c3bc9
--- /dev/null
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/zed_slow_io.ksh
@@ -0,0 +1,205 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2023, Klara Inc.
+#
+
+# DESCRIPTION:
+#	Verify that vdev properties, slow_io_n and slow_io_t, work with ZED.
+#
+# STRATEGY:
+#	1. Create a pool with single vdev
+#	2. Set slow_io_n/slow_io_t to non-default values
+#	3. Inject slow io errors
+#	4. Verify that ZED degrades vdev
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+TESTDIR="$TEST_BASE_DIR/zed_slow_io"
+VDEV="$TEST_BASE_DIR/vdevfile.$$"
+TESTPOOL="slow_io_pool"
+FILEPATH="$TESTDIR/slow_io.testfile"
+
+OLD_SLOW_IO=$(get_tunable ZIO_SLOW_IO_MS)
+OLD_SLOW_IO_EVENTS=$(get_tunable SLOW_IO_EVENTS_PER_SECOND)
+
+verify_runnable "both"
+
+function do_setup
+{
+	log_must truncate -s 1G $VDEV
+	default_setup_noexit $VDEV
+	zed_events_drain
+	log_must zfs set compression=off $TESTPOOL
+	log_must zfs set primarycache=none $TESTPOOL
+	log_must zfs set prefetch=none $TESTPOOL
+	log_must zfs set recordsize=512 $TESTPOOL
+	for i in {1..10}; do
+		dd if=/dev/urandom of=${FILEPATH}$i bs=512 count=1 2>/dev/null
+	done
+	zpool sync
+}
+
+# intermediate cleanup
+function do_clean
+{
+	log_must zinject -c all
+	log_must zpool destroy $TESTPOOL
+	log_must rm -f $VDEV
+}
+
+# final cleanup
+function cleanup
+{
+	log_must zinject -c all
+
+	# if pool still exists then something failed so log additional info
+	if poolexists $TESTPOOL ; then
+		log_note "$(zpool status -s $TESTPOOL)"
+		echo "=================== zed log search ==================="
+		grep "Diagnosis Engine" $ZEDLET_DIR/zed.log
+		destroy_pool $TESTPOOL
+	fi
+	log_must zed_stop
+
+	log_must rm -f $VDEV
+
+	log_must set_tunable64 ZIO_SLOW_IO_MS $OLD_SLOW_IO
+	log_must set_tunable64 SLOW_IO_EVENTS_PER_SECOND $OLD_SLOW_IO_EVENTS
+}
+
+function start_slow_io
+{
+	zpool sync
+	log_must set_tunable64 ZIO_SLOW_IO_MS 10
+	log_must set_tunable64 SLOW_IO_EVENTS_PER_SECOND 1000
+
+	log_must zinject -d $VDEV -D10:1 -T read $TESTPOOL
+	zpool sync
+}
+
+function stop_slow_io
+{
+	log_must set_tunable64 ZIO_SLOW_IO_MS $OLD_SLOW_IO
+	log_must set_tunable64 SLOW_IO_EVENTS_PER_SECOND $OLD_SLOW_IO_EVENTS
+
+	log_must zinject -c all
+}
+
+# Test default ZED settings:
+#    inject 10 events over 2.5 seconds, should not degrade.
+function default_degrade
+{
+	do_setup
+
+	start_slow_io
+	for i in {1..10}; do
+		dd if=${FILEPATH}$i of=/dev/null count=1 bs=512 2>/dev/null
+		sleep 0.25
+	done
+	stop_slow_io
+	log_note "$(zpool status -s $TESTPOOL)"
+
+	# give slow ZED a chance to process the delay events
+	sleep 18
+	log_note "$(zpool status -s $TESTPOOL)"
+
+	degrades=$(grep "zpool_vdev_degrade" $ZEDLET_DIR/zed.log | wc -l)
+	log_note $degrades vdev degrades in ZED log
+	[ $degrades -eq "0" ] || \
+		log_fail "expecting no degrade events, found $degrades"
+
+	do_clean
+}
+
+# change slow_io_n, slow_io_t to 5 events in 60 seconds
+# fire more than 5 events, should degrade
+function slow_io_degrade
+{
+	do_setup
+
+	zpool set slow_io_n=5 $TESTPOOL $VDEV
+	zpool set slow_io_t=60 $TESTPOOL $VDEV
+
+	start_slow_io
+	for i in {1..16}; do
+		dd if=${FILEPATH}$i of=/dev/null count=1 bs=512 2>/dev/null
+		sleep 0.5
+	done
+	stop_slow_io
+	zpool sync
+
+	#
+	# wait up to 60 seconds for kernel to produce at least 5 delay events
+	#
+	typeset -i i=0
+	typeset -i events=0
+	while [[ $i -lt 60 ]]; do
+		events=$(zpool events | grep "ereport\.fs\.zfs.delay" | wc -l)
+		[[ $events -ge "5" ]] && break
+		i=$((i+1))
+		sleep 1
+	done
+	log_note "$events delay events found"
+
+	if [[ $events -ge "5" ]]; then
+		log_must wait_vdev_state $TESTPOOL $VDEV "DEGRADED" 10
+	fi
+
+	do_clean
+}
+
+# change slow_io_n, slow_io_t to 10 events in 1 second
+# inject events spaced 0.5 seconds apart, should not degrade
+function slow_io_no_degrade
+{
+	do_setup
+
+	zpool set slow_io_n=10 $TESTPOOL $VDEV
+	zpool set slow_io_t=1 $TESTPOOL $VDEV
+
+	start_slow_io
+	for i in {1..16}; do
+		dd if=${FILEPATH}$i of=/dev/null count=1 bs=512 2>/dev/null
+		sleep 0.5
+	done
+	stop_slow_io
+	zpool sync
+
+	log_mustnot wait_vdev_state $TESTPOOL $VDEV "DEGRADED" 45
+
+	do_clean
+}
+
+log_assert "Test ZED slow io configurability"
+log_onexit cleanup
+
+log_must zed_events_drain
+log_must zed_start
+
+default_degrade
+slow_io_degrade
+slow_io_no_degrade
+
+log_pass "Test ZED slow io configurability"
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/zed_slow_io_many_vdevs.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/zed_slow_io_many_vdevs.ksh
new file mode 100755
index 000000000000..3357ae2e3510
--- /dev/null
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/events/zed_slow_io_many_vdevs.ksh
@@ -0,0 +1,177 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2023, Klara Inc.
+#
+
+# DESCRIPTION:
+#	Verify that delay events from multiple vdevs doesnt degrade
+#
+# STRATEGY:
+#	1. Create a pool with a 3 disk raidz vdev
+#	2. Inject slow io errors
+#	3. Verify that ZED detects slow I/Os but doesn't degrade any vdevs
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+TESTDIR="$TEST_BASE_DIR/zed_slow_io"
+VDEV1="$TEST_BASE_DIR/vdevfile1.$$"
+VDEV2="$TEST_BASE_DIR/vdevfile2.$$"
+VDEV3="$TEST_BASE_DIR/vdevfile3.$$"
+VDEV4="$TEST_BASE_DIR/vdevfile4.$$"
+VDEVS="$VDEV1 $VDEV2 $VDEV3 $VDEV4"
+TESTPOOL="slow_io_pool"
+FILEPATH="$TESTDIR/slow_io.testfile"
+
+OLD_SLOW_IO=$(get_tunable ZIO_SLOW_IO_MS)
+OLD_SLOW_IO_EVENTS=$(get_tunable SLOW_IO_EVENTS_PER_SECOND)
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must zinject -c all
+
+	# if pool still exists then something failed so log additional info
+	if poolexists $TESTPOOL ; then
+		log_note "$(zpool status -s $TESTPOOL)"
+		echo "=================== zed log search ==================="
+		grep "Diagnosis Engine" $ZEDLET_DIR/zed.log
+		destroy_pool $TESTPOOL
+	fi
+	log_must zed_stop
+
+	log_must rm -f $VDEVS
+	log_must set_tunable64 ZIO_SLOW_IO_MS $OLD_SLOW_IO
+	log_must set_tunable64 SLOW_IO_EVENTS_PER_SECOND $OLD_SLOW_IO_EVENTS
+}
+
+function start_slow_io
+{
+	for vdev in $VDEVS
+	do
+		log_must zpool set slow_io_n=4 $TESTPOOL $vdev
+		log_must zpool set slow_io_t=60 $TESTPOOL $vdev
+	done
+	zpool sync
+
+	log_must set_tunable64 ZIO_SLOW_IO_MS 10
+	log_must set_tunable64 SLOW_IO_EVENTS_PER_SECOND 1000
+
+	for vdev in $VDEVS
+	do
+		log_must zinject -d $vdev -D10:1 $TESTPOOL
+	done
+	zpool sync
+}
+
+function stop_slow_io
+{
+	log_must set_tunable64 ZIO_SLOW_IO_MS $OLD_SLOW_IO
+	log_must set_tunable64 SLOW_IO_EVENTS_PER_SECOND $OLD_SLOW_IO_EVENTS
+
+	log_must zinject -c all
+}
+
+function multiple_slow_vdevs_test
+{
+	log_must truncate -s 1G $VDEVS
+	default_raidz_setup_noexit $VDEVS
+
+	log_must zpool events -c
+	log_must zfs set compression=off $TESTPOOL
+	log_must zfs set primarycache=none $TESTPOOL
+	log_must zfs set recordsize=4K $TESTPOOL
+
+	log_must dd if=/dev/urandom of=$FILEPATH bs=1M count=20
+	zpool sync
+
+	#
+	# Read the file with slow io injected on the disks
+	# This will cause multiple errors on each disk to trip ZED SERD
+	#
+	#   pool: slow_io_pool
+	#  state: ONLINE
+	# config:
+	#
+	#         NAME                           STATE  READ WRITE CKSUM  SLOW
+	#         slow_io_pool                   ONLINE    0     0     0     -
+	#           raidz1-0                     ONLINE    0     0     0     -
+	#             /var/tmp/vdevfile1.499278  ONLINE    0     0     0   113
+	#             /var/tmp/vdevfile2.499278  ONLINE    0     0     0   109
+	#             /var/tmp/vdevfile3.499278  ONLINE    0     0     0    96
+	#             /var/tmp/vdevfile4.499278  ONLINE    0     0     0   109
+	#
+	start_slow_io
+	dd if=$FILEPATH of=/dev/null bs=1M count=20 2>/dev/null
+	stop_slow_io
+
+	# count events available for processing
+	typeset -i i=0
+	typeset -i events=0
+	while [[ $i -lt 60 ]]; do
+		events=$(zpool events | grep "ereport\.fs\.zfs.delay" | wc -l)
+		[[ $events -ge "50" ]] && break
+		i=$((i+1))
+		sleep 1
+	done
+	log_note "$events delay events found"
+	if [[ $events -lt "50" ]]; then
+		log_note "bailing: not enough events to complete the test"
+		destroy_pool $TESTPOOL
+		return
+	fi
+
+	#
+	# give slow ZED a chance to process the delay events
+	#
+	typeset -i i=0
+	typeset -i skips=0
+	while [[ $i -lt 75 ]]; do
+		skips=$(grep "retiring case" \
+			$ZEDLET_DIR/zed.log | wc -l)
+		[[ $skips -gt "0" ]] && break
+		i=$((i+1))
+		sleep 1
+	done
+
+	log_note $skips degrade skips in ZED log after $i seconds
+	[ $skips -gt "0" ] || log_fail "expecting to see skips"
+
+	degrades=$(grep "zpool_vdev_degrade" $ZEDLET_DIR/zed.log | wc -l)
+	log_note $degrades vdev degrades in ZED log
+	[ $degrades -eq "0" ] || \
+		log_fail "expecting no degrade events, found $degrades"
+
+	destroy_pool $TESTPOOL
+}
+
+log_assert "Test ZED slow io across multiple vdevs"
+log_onexit cleanup
+
+log_must zed_events_drain
+log_must zed_start
+multiple_slow_vdevs_test
+
+log_pass "Test ZED slow io across multiple vdevs"
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/cleanup.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/cleanup.ksh
index 654343c0cf00..2959236b59a3 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/cleanup.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/cleanup.ksh
@@ -32,5 +32,6 @@ cleanup_devices $DISKS
 
 zed_stop
 zed_cleanup resilver_finish-start-scrub.sh
+zed_events_drain
 
 log_pass
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/setup.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/setup.ksh
index 62f1c8ab56cb..61b9206ec1a6 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/setup.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/fault/setup.ksh
@@ -28,6 +28,7 @@
 
 verify_runnable "global"
 
+zed_events_drain
 zed_setup resilver_finish-start-scrub.sh
 zed_start
 
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/mmp/mmp_write_slow_disk.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/mmp/mmp_write_slow_disk.ksh
new file mode 100755
index 000000000000..8b118684aa7f
--- /dev/null
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/mmp/mmp_write_slow_disk.ksh
@@ -0,0 +1,97 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2024, Klara Inc
+#
+
+# DESCRIPTION:
+#	Verify that long VDEV probes do not cause MMP checks to suspend pool
+#	Note: without PR-15839 fix, this test will suspend the pool.
+#
+#	A device that is returning unexpected errors will trigger a vdev_probe.
+#	When the device additionally has slow response times, the probe can hold
+#	the spa config lock as a writer for a long period of time such that the
+#	mmp uberblock updates stall when trying to acquire the spa config lock.
+#
+# STRATEGY:
+#	1. Create a pool with multiple leaf vdevs
+#	2. Enable multihost and multihost_history
+#	3. Delay for MMP writes to occur
+#	4. Verify that a long VDEV probe didn't cause MMP check to suspend pool
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/mmp/mmp.cfg
+. $STF_SUITE/tests/functional/mmp/mmp.kshlib
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must zinject -c all
+
+	if [[ $(zpool list -H -o health $MMP_POOL) == "SUSPENDED" ]]; then
+		log_must zpool clear $MMP_POOL
+		zpool get state $MMP_POOL $MMP_DIR/file.3
+		zpool events | grep ".fs.zfs." | grep -v "history_event"
+	fi
+
+	poolexists $MMP_POOL && destroy_pool $MMP_POOL
+	log_must rm -r $MMP_DIR
+	log_must mmp_clear_hostid
+}
+
+log_assert "A long VDEV probe doesn't cause a MMP check suspend"
+log_onexit cleanup
+
+MMP_HISTORY_URL=/proc/spl/kstat/zfs/$MMP_POOL/multihost
+
+# Create a multiple drive pool
+log_must zpool events -c
+log_must mkdir -p $MMP_DIR
+log_must truncate -s 128M $MMP_DIR/file.{0,1,2,3,4,5}
+log_must zpool create -f $MMP_POOL \
+	mirror $MMP_DIR/file.{0,1,2} \
+	mirror $MMP_DIR/file.{3,4,5}
+
+# Enable MMP
+log_must mmp_set_hostid $HOSTID1
+log_must zpool set multihost=on $MMP_POOL
+clear_mmp_history
+
+# Inject vdev write error along with a delay
+log_must zinject -f 33 -e io -L pad2 -T write -d $MMP_DIR/file.3 $MMP_POOL
+log_must zinject -f 50 -e io -L uber -T write -d $MMP_DIR/file.3 $MMP_POOL
+log_must zinject -D 2000:4 -T write -d $MMP_DIR/file.3 $MMP_POOL
+
+log_must dd if=/dev/urandom of=/$MMP_POOL/data bs=1M count=5
+sleep 10
+sync_pool $MMP_POOL
+
+# Confirm mmp writes to the non-slow disks have taken place
+for x in {0,1,2,4}; do
+	write_count=$(grep -c file.${x} $MMP_HISTORY_URL)
+	[[ $write_count -gt 0 ]] || log_fail "expecting mmp writes"
+done
+
+# Expect that the pool was not suspended
+log_must check_state $MMP_POOL "" "ONLINE"
+health=$(zpool list -H -o health $MMP_POOL)
+log_note "$MMP_POOL health is $health"
+[[ "$health" == "SUSPENDED" ]] && log_fail "$MMP_POOL $health unexpected"
+
+log_pass "A long VDEV probe doesn't cause a MMP check suspend"
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/user_namespace/user_namespace_004.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/user_namespace/user_namespace_004.ksh
index 37ef84b72377..e6ad25f23f93 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/user_namespace/user_namespace_004.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/user_namespace/user_namespace_004.ksh
@@ -44,8 +44,6 @@ user_ns_cleanup() {
 	log_must zfs destroy -r "$TESTPOOL/userns"
 }
 
-log_onexit user_ns_cleanup
-
 log_assert "Check zfs zone command handling of non-namespace files"
 
 # Pass if user namespaces are not supported.
@@ -54,6 +52,8 @@ if [ "$?" -ne "0" ]; then
 	log_unsupported "Failed to create user namespace"
 fi
 
+log_onexit user_ns_cleanup
+
 # Create the baseline datasets.
 log_must zfs create -o zoned=on "$TESTPOOL/userns"
 
diff --git a/sys/contrib/openzfs/udev/zvol_id.c b/sys/contrib/openzfs/udev/zvol_id.c
index 5960b978787a..609349594767 100644
--- a/sys/contrib/openzfs/udev/zvol_id.c
+++ b/sys/contrib/openzfs/udev/zvol_id.c
@@ -51,7 +51,7 @@ const char *__asan_default_options(void) {
 int
 main(int argc, const char *const *argv)
 {
-	if (argc != 2) {
+	if (argc != 2 || strncmp(argv[1], "/dev/zd", 7) != 0) {
 		fprintf(stderr, "usage: %s /dev/zdX\n", argv[0]);
 		return (1);
 	}
@@ -72,9 +72,10 @@ main(int argc, const char *const *argv)
 		return (1);
 	}
 
-	unsigned int dev_part = minor(sb.st_rdev) % ZVOL_MINORS;
-	if (dev_part != 0)
-		sprintf(zvol_name + strlen(zvol_name), "-part%u", dev_part);
+	const char *dev_part = strrchr(dev_name, 'p');
+	if (dev_part != NULL) {
+		sprintf(zvol_name + strlen(zvol_name), "-part%s", dev_part + 1);
+	}
 
 	for (size_t i = 0; i < strlen(zvol_name); ++i)
 		if (isblank(zvol_name[i]))
diff --git a/sys/modules/zfs/zfs_config.h b/sys/modules/zfs/zfs_config.h
index fe8580263185..35e6b4655832 100644
--- a/sys/modules/zfs/zfs_config.h
+++ b/sys/modules/zfs/zfs_config.h
@@ -93,6 +93,9 @@
 /* bdev_check_media_change() exists */
 /* #undef HAVE_BDEV_CHECK_MEDIA_CHANGE */
 
+/* bdev_file_open_by_path() exists */
+/* #undef HAVE_BDEV_FILE_OPEN_BY_PATH */
+
 /* bdev_*_io_acct() available */
 /* #undef HAVE_BDEV_IO_ACCT_63 */
 
@@ -159,15 +162,24 @@
 /* blkdev_get_by_path() handles ERESTARTSYS */
 /* #undef HAVE_BLKDEV_GET_ERESTARTSYS */
 
-/* blkdev_issue_discard() is available */
-/* #undef HAVE_BLKDEV_ISSUE_DISCARD */
+/* __blkdev_issue_discard(flags) is available */
+/* #undef HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_FLAGS */
 
 /* __blkdev_issue_discard() is available */
-/* #undef HAVE_BLKDEV_ISSUE_DISCARD_ASYNC */
+/* #undef HAVE_BLKDEV_ISSUE_DISCARD_ASYNC_NOFLAGS */
+
+/* blkdev_issue_discard(flags) is available */
+/* #undef HAVE_BLKDEV_ISSUE_DISCARD_FLAGS */
+
+/* blkdev_issue_discard() is available */
+/* #undef HAVE_BLKDEV_ISSUE_DISCARD_NOFLAGS */
 
 /* blkdev_issue_secure_erase() is available */
 /* #undef HAVE_BLKDEV_ISSUE_SECURE_ERASE */
 
+/* blkdev_put() exists */
+/* #undef HAVE_BLKDEV_PUT */
+
 /* blkdev_put() accepts void* as arg 2 */
 /* #undef HAVE_BLKDEV_PUT_HOLDER */
 
@@ -183,6 +195,9 @@
 /* blk_alloc_disk() exists */
 /* #undef HAVE_BLK_ALLOC_DISK */
 
+/* blk_alloc_disk() exists and takes 2 args */
+/* #undef HAVE_BLK_ALLOC_DISK_2ARG */
+
 /* blk_alloc_queue() expects request function */
 /* #undef HAVE_BLK_ALLOC_QUEUE_REQUEST_FN */
 
@@ -198,6 +213,9 @@
 /* block multiqueue is available */
 /* #undef HAVE_BLK_MQ */
 
+/* block multiqueue hardware context is cached in struct request */
+/* #undef HAVE_BLK_MQ_RQ_HCTX */
+
 /* blk queue backing_dev_info is dynamic */
 /* #undef HAVE_BLK_QUEUE_BDI_DYNAMIC */
 
@@ -550,7 +568,7 @@
 /* yes */
 /* #undef HAVE_IO_SCHEDULE_TIMEOUT */
 
-/* Define to 1 if you have the `issetugid' function. */
+/* Define to 1 if you have the 'issetugid' function. */
 #define HAVE_ISSETUGID 1
 
 /* iter_iov() is available */
@@ -658,9 +676,12 @@
 /* iops->mkdir() takes umode_t */
 /* #undef HAVE_MKDIR_UMODE_T */
 
-/* Define to 1 if you have the `mlockall' function. */
+/* Define to 1 if you have the 'mlockall' function. */
 #define HAVE_MLOCKALL 1
 
+/* page_size() is available */
+/* #undef HAVE_MM_PAGE_SIZE */
+
 /* lookup_bdev() wants mode arg */
 /* #undef HAVE_MODE_LOOKUP_BDEV */
 
@@ -861,10 +882,10 @@
 /* Define to 1 if you have the <string.h> header file. */
 #define HAVE_STRING_H 1
 
-/* Define to 1 if you have the `strlcat' function. */
+/* Define to 1 if you have the 'strlcat' function. */
 #define HAVE_STRLCAT 1
 
-/* Define to 1 if you have the `strlcpy' function. */
+/* Define to 1 if you have the 'strlcpy' function. */
 #define HAVE_STRLCPY 1
 
 /* submit_bio is member of struct block_device_operations */
@@ -912,7 +933,7 @@
 /* kernel has totalram_pages() */
 /* #undef HAVE_TOTALRAM_PAGES_FUNC */
 
-/* Define to 1 if you have the `udev_device_get_is_initialized' function. */
+/* Define to 1 if you have the 'udev_device_get_is_initialized' function. */
 /* #undef HAVE_UDEV_DEVICE_GET_IS_INITIALIZED */
 
 /* kernel has __kernel_fpu_* functions */
@@ -990,6 +1011,9 @@
 /* __set_page_dirty_nobuffers exists */
 /* #undef HAVE_VFS_SET_PAGE_DIRTY_NOBUFFERS */
 
+/* splice_copy_file_range() is available */
+/* #undef HAVE_VFS_SPLICE_COPY_FILE_RANGE */
+
 /* __vmalloc page flags exists */
 /* #undef HAVE_VMALLOC_PAGE_KERNEL */
 
@@ -1104,7 +1128,7 @@
 /* pde_data() is PDE_DATA() */
 /* #undef SPL_PDE_DATA */
 
-/* Define to 1 if all of the C90 standard headers exist (not just the ones
+/* Define to 1 if all of the C89 standard headers exist (not just the ones
    required in a freestanding environment). This macro is provided for
    backward compatibility; new code need not use it. */
 #define SYSTEM_FREEBSD 1
@@ -1152,7 +1176,7 @@
 /* #undef ZFS_IS_GPL_COMPATIBLE */
 
 /* Define the project alias string. */
-#define ZFS_META_ALIAS "zfs-2.2.3-FreeBSD_gc883088df"
+#define ZFS_META_ALIAS "zfs-2.2.4-FreeBSD_g256659204"
 
 /* Define the project author. */
 #define ZFS_META_AUTHOR "OpenZFS"
@@ -1161,7 +1185,7 @@
 /* #undef ZFS_META_DATA */
 
 /* Define the maximum compatible kernel version. */
-#define ZFS_META_KVER_MAX "6.7"
+#define ZFS_META_KVER_MAX "6.8"
 
 /* Define the minimum compatible kernel version. */
 #define ZFS_META_KVER_MIN "3.10"
@@ -1182,10 +1206,10 @@
 #define ZFS_META_NAME "zfs"
 
 /* Define the project release. */
-#define ZFS_META_RELEASE "FreeBSD_gc883088df"
+#define ZFS_META_RELEASE "FreeBSD_g256659204"
 
 /* Define the project version. */
-#define ZFS_META_VERSION "2.2.3"
+#define ZFS_META_VERSION "2.2.4"
 
 /* count is located in percpu_ref.data */
 /* #undef ZFS_PERCPU_REF_COUNT_IN_DATA */
diff --git a/sys/modules/zfs/zfs_gitrev.h b/sys/modules/zfs/zfs_gitrev.h
index 70b3c3310d8f..663c8a847fd9 100644
--- a/sys/modules/zfs/zfs_gitrev.h
+++ b/sys/modules/zfs/zfs_gitrev.h
@@ -1 +1 @@
-#define	ZFS_META_GITREV "zfs-2.2.3-0-gc883088df"
+#define	ZFS_META_GITREV "zfs-2.2.4-0-g256659204"