29 files changed, 394 insertions, 78 deletions

diff --git a/sys/contrib/openzfs/META b/sys/contrib/openzfs/META
index 0953cc51922f..9ffe90458dbd 100644
--- a/sys/contrib/openzfs/META
+++ b/sys/contrib/openzfs/META
@@ -6,5 +6,5 @@ Release:       rc4
 Release-Tags:  relext
 License:       CDDL
 Author:        OpenZFS
-Linux-Maximum: 6.4
+Linux-Maximum: 6.5
 Linux-Minimum: 3.10
diff --git a/sys/contrib/openzfs/cmd/zed/agents/zfs_mod.c b/sys/contrib/openzfs/cmd/zed/agents/zfs_mod.c
index a8d084bb4bd3..2f040ff7582c 100644
--- a/sys/contrib/openzfs/cmd/zed/agents/zfs_mod.c
+++ b/sys/contrib/openzfs/cmd/zed/agents/zfs_mod.c
@@ -372,6 +372,7 @@ zfs_process_add(zpool_handle_t *zhp, nvlist_t *vdev, boolean_t labeled)
 	/* Only autoreplace bad disks */
 	if ((vs->vs_state != VDEV_STATE_DEGRADED) &&
 	    (vs->vs_state != VDEV_STATE_FAULTED) &&
+	    (vs->vs_state != VDEV_STATE_REMOVED) &&
 	    (vs->vs_state != VDEV_STATE_CANT_OPEN)) {
 		zed_log_msg(LOG_INFO, "  not autoreplacing since disk isn't in "
 		    "a bad state (currently %llu)", vs->vs_state);
diff --git a/sys/contrib/openzfs/cmd/zed/zed.d/statechange-led.sh b/sys/contrib/openzfs/cmd/zed/zed.d/statechange-led.sh
index 46bfc1b866f1..40cb61f17307 100755
--- a/sys/contrib/openzfs/cmd/zed/zed.d/statechange-led.sh
+++ b/sys/contrib/openzfs/cmd/zed/zed.d/statechange-led.sh
@@ -121,7 +121,7 @@ state_to_val()
 {
 	state="$1"
 	case "$state" in
-		FAULTED|DEGRADED|UNAVAIL)
+		FAULTED|DEGRADED|UNAVAIL|REMOVED)
 			echo 1
 			;;
 		ONLINE)
diff --git a/sys/contrib/openzfs/config/kernel-blkdev.m4 b/sys/contrib/openzfs/config/kernel-blkdev.m4
index 887acee670ba..e04a2bd2c3b6 100644
--- a/sys/contrib/openzfs/config/kernel-blkdev.m4
+++ b/sys/contrib/openzfs/config/kernel-blkdev.m4
@@ -16,12 +16,63 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_GET_BY_PATH], [
 	])
 ])
 
+dnl #
+dnl # 6.5.x API change,
+dnl # blkdev_get_by_path() takes 4 args
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_GET_BY_PATH_4ARG], [
+	ZFS_LINUX_TEST_SRC([blkdev_get_by_path_4arg], [
+		#include <linux/fs.h>
+		#include <linux/blkdev.h>
+	], [
+		struct block_device *bdev __attribute__ ((unused)) = NULL;
+		const char *path = "path";
+		fmode_t mode = 0;
+		void *holder = NULL;
+		struct blk_holder_ops h;
+
+		bdev = blkdev_get_by_path(path, mode, holder, &h);
+	])
+])
+
 AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_GET_BY_PATH], [
-	AC_MSG_CHECKING([whether blkdev_get_by_path() exists])
+	AC_MSG_CHECKING([whether blkdev_get_by_path() exists and takes 3 args])
 	ZFS_LINUX_TEST_RESULT([blkdev_get_by_path], [
 		AC_MSG_RESULT(yes)
 	], [
-		ZFS_LINUX_TEST_ERROR([blkdev_get_by_path()])
+		AC_MSG_RESULT(no)
+		AC_MSG_CHECKING([whether blkdev_get_by_path() exists and takes 4 args])
+		ZFS_LINUX_TEST_RESULT([blkdev_get_by_path_4arg], [
+			AC_DEFINE(HAVE_BLKDEV_GET_BY_PATH_4ARG, 1,
+				[blkdev_get_by_path() exists and takes 4 args])
+			AC_MSG_RESULT(yes)
+		], [
+			ZFS_LINUX_TEST_ERROR([blkdev_get_by_path()])
+		])
+	])
+])
+
+dnl #
+dnl # 6.5.x API change
+dnl # blk_mode_t was added as a type to supercede some places where fmode_t
+dnl # is used
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_BLK_MODE_T], [
+	ZFS_LINUX_TEST_SRC([blk_mode_t], [
+		#include <linux/fs.h>
+		#include <linux/blkdev.h>
+	], [
+		blk_mode_t m __attribute((unused)) = (blk_mode_t)0;
+	])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_BLK_MODE_T], [
+	AC_MSG_CHECKING([whether blk_mode_t is defined])
+	ZFS_LINUX_TEST_RESULT([blk_mode_t], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BLK_MODE_T, 1, [blk_mode_t is defined])
+	], [
+		AC_MSG_RESULT(no)
 	])
 ])
 
@@ -41,12 +92,35 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_PUT], [
 	])
 ])
 
+dnl #
+dnl # 6.5.x API change.
+dnl # blkdev_put() takes (void* holder) as arg 2
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV_PUT_HOLDER], [
+	ZFS_LINUX_TEST_SRC([blkdev_put_holder], [
+		#include <linux/fs.h>
+		#include <linux/blkdev.h>
+	], [
+		struct block_device *bdev = NULL;
+		void *holder = NULL;
+
+		blkdev_put(bdev, holder);
+	])
+])
+
 AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_PUT], [
 	AC_MSG_CHECKING([whether blkdev_put() exists])
 	ZFS_LINUX_TEST_RESULT([blkdev_put], [
 		AC_MSG_RESULT(yes)
 	], [
-		ZFS_LINUX_TEST_ERROR([blkdev_put()])
+		AC_MSG_CHECKING([whether blkdev_put() accepts void* as arg 2])
+		ZFS_LINUX_TEST_RESULT([blkdev_put_holder], [
+			AC_MSG_RESULT(yes)
+			AC_DEFINE(HAVE_BLKDEV_PUT_HOLDER, 1,
+				[blkdev_put() accepts void* as arg 2])
+		], [
+			ZFS_LINUX_TEST_ERROR([blkdev_put()])
+		])
 	])
 ])
 
@@ -495,7 +569,9 @@ AC_DEFUN([ZFS_AC_KERNEL_BLKDEV_BLK_STS_RESV_CONFLICT], [
 
 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_PUT
+	ZFS_AC_KERNEL_SRC_BLKDEV_PUT_HOLDER
 	ZFS_AC_KERNEL_SRC_BLKDEV_REREAD_PART
 	ZFS_AC_KERNEL_SRC_BLKDEV_INVALIDATE_BDEV
 	ZFS_AC_KERNEL_SRC_BLKDEV_LOOKUP_BDEV
@@ -510,6 +586,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLKDEV], [
 	ZFS_AC_KERNEL_SRC_BLKDEV_PART_TO_DEV
 	ZFS_AC_KERNEL_SRC_BLKDEV_DISK_CHECK_MEDIA_CHANGE
 	ZFS_AC_KERNEL_SRC_BLKDEV_BLK_STS_RESV_CONFLICT
+	ZFS_AC_KERNEL_SRC_BLKDEV_BLK_MODE_T
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_BLKDEV], [
@@ -530,4 +607,5 @@ AC_DEFUN([ZFS_AC_KERNEL_BLKDEV], [
 	ZFS_AC_KERNEL_BLKDEV_PART_TO_DEV
 	ZFS_AC_KERNEL_BLKDEV_DISK_CHECK_MEDIA_CHANGE
 	ZFS_AC_KERNEL_BLKDEV_BLK_STS_RESV_CONFLICT
+	ZFS_AC_KERNEL_BLKDEV_BLK_MODE_T
 ])
diff --git a/sys/contrib/openzfs/config/kernel-block-device-operations.m4 b/sys/contrib/openzfs/config/kernel-block-device-operations.m4
index 84e39dc8a2f6..d13c1337b1fb 100644
--- a/sys/contrib/openzfs/config/kernel-block-device-operations.m4
+++ b/sys/contrib/openzfs/config/kernel-block-device-operations.m4
@@ -49,12 +49,42 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID], [
 	], [], [])
 ])
 
+dnl #
+dnl # 5.9.x API change
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS_RELEASE_1ARG], [
+	ZFS_LINUX_TEST_SRC([block_device_operations_release_void_1arg], [
+		#include <linux/blkdev.h>
+
+		void blk_release(struct gendisk *g) {
+			(void) g;
+			return;
+		}
+
+		static const struct block_device_operations
+		    bops __attribute__ ((unused)) = {
+			.open		= NULL,
+			.release	= blk_release,
+			.ioctl		= NULL,
+			.compat_ioctl	= NULL,
+		};
+	], [], [])
+])
+
 AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID], [
-	AC_MSG_CHECKING([whether bops->release() is void])
+	AC_MSG_CHECKING([whether bops->release() is void and takes 2 args])
 	ZFS_LINUX_TEST_RESULT([block_device_operations_release_void], [
 		AC_MSG_RESULT(yes)
 	],[
-		ZFS_LINUX_TEST_ERROR([bops->release()])
+		AC_MSG_RESULT(no)
+		AC_MSG_CHECKING([whether bops->release() is void and takes 1 arg])
+		ZFS_LINUX_TEST_RESULT([block_device_operations_release_void_1arg], [
+			AC_MSG_RESULT(yes)
+			AC_DEFINE([HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_1ARG], [1],
+				[Define if release() in block_device_operations takes 1 arg])
+		],[
+			ZFS_LINUX_TEST_ERROR([bops->release()])
+		])
 	])
 ])
 
@@ -92,6 +122,7 @@ AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_REVALIDATE_DISK], [
 AC_DEFUN([ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS], [
 	ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
 	ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
+	ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS_RELEASE_1ARG
 	ZFS_AC_KERNEL_SRC_BLOCK_DEVICE_OPERATIONS_REVALIDATE_DISK
 ])
 
diff --git a/sys/contrib/openzfs/config/kernel-filemap-splice-read.m4 b/sys/contrib/openzfs/config/kernel-filemap-splice-read.m4
new file mode 100644
index 000000000000..4c83b31d738a
--- /dev/null
+++ b/sys/contrib/openzfs/config/kernel-filemap-splice-read.m4
@@ -0,0 +1,25 @@
+AC_DEFUN([ZFS_AC_KERNEL_SRC_COPY_SPLICE_READ], [
+	dnl #
+	dnl # Kernel 6.5 - generic_file_splice_read was removed in favor
+	dnl # of copy_splice_read for the .splice_read member of the
+	dnl # file_operations struct.
+	dnl #
+	ZFS_LINUX_TEST_SRC([has_copy_splice_read], [
+		#include <linux/fs.h>
+
+		struct file_operations fops __attribute__((unused)) = {
+			.splice_read = copy_splice_read,
+		};
+	],[])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_COPY_SPLICE_READ], [
+	AC_MSG_CHECKING([whether copy_splice_read() exists])
+	ZFS_LINUX_TEST_RESULT([has_copy_splice_read], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_COPY_SPLICE_READ, 1,
+		    [copy_splice_read exists])
+	],[
+		AC_MSG_RESULT(no)
+	])
+])
diff --git a/sys/contrib/openzfs/config/kernel-register_sysctl_table.m4 b/sys/contrib/openzfs/config/kernel-register_sysctl_table.m4
new file mode 100644
index 000000000000..a5e934f56d29
--- /dev/null
+++ b/sys/contrib/openzfs/config/kernel-register_sysctl_table.m4
@@ -0,0 +1,27 @@
+dnl #
+dnl # Linux 6.5 removes register_sysctl_table
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_REGISTER_SYSCTL_TABLE], [
+	ZFS_LINUX_TEST_SRC([has_register_sysctl_table], [
+		#include <linux/sysctl.h>
+
+		static struct ctl_table dummy_table[] = {
+			{}
+		};
+
+    ],[
+		struct ctl_table_header *h
+			__attribute((unused)) = register_sysctl_table(dummy_table);
+    ])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_REGISTER_SYSCTL_TABLE], [
+	AC_MSG_CHECKING([whether register_sysctl_table exists])
+	ZFS_LINUX_TEST_RESULT([has_register_sysctl_table], [
+		AC_MSG_RESULT([yes])
+		AC_DEFINE(HAVE_REGISTER_SYSCTL_TABLE, 1,
+			[register_sysctl_table exists])
+	],[
+		AC_MSG_RESULT([no])
+	])
+])
diff --git a/sys/contrib/openzfs/config/kernel-vfs-iov_iter.m4 b/sys/contrib/openzfs/config/kernel-vfs-iov_iter.m4
index e0617faab02c..ff560ff3eef0 100644
--- a/sys/contrib/openzfs/config/kernel-vfs-iov_iter.m4
+++ b/sys/contrib/openzfs/config/kernel-vfs-iov_iter.m4
@@ -6,8 +6,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_IOV_ITER], [
 		#include <linux/fs.h>
 		#include <linux/uio.h>
 	],[
-		int type __attribute__ ((unused)) =
-		    ITER_IOVEC | ITER_KVEC | ITER_BVEC | ITER_PIPE;
+		int type __attribute__ ((unused)) = ITER_KVEC;
 	])
 
 	ZFS_LINUX_TEST_SRC([iov_iter_advance], [
@@ -93,6 +92,14 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_IOV_ITER], [
 		struct iov_iter iter = { 0 };
 		__attribute__((unused)) enum iter_type i = iov_iter_type(&iter);
 	])
+
+	ZFS_LINUX_TEST_SRC([iter_iov], [
+		#include <linux/fs.h>
+		#include <linux/uio.h>
+	],[
+		struct iov_iter iter = { 0 };
+		__attribute__((unused)) const struct iovec *iov = iter_iov(&iter);
+	])
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_VFS_IOV_ITER], [
@@ -201,4 +208,19 @@ AC_DEFUN([ZFS_AC_KERNEL_VFS_IOV_ITER], [
 		AC_DEFINE(HAVE_VFS_IOV_ITER, 1,
 		    [All required iov_iter interfaces are available])
 	])
+
+	dnl #
+	dnl # Kernel 6.5 introduces the iter_iov() function that returns the
+	dnl # __iov member of an iov_iter*. The iov member was renamed to this
+	dnl # __iov member, and is intended to be accessed via the helper
+	dnl # function now.
+	dnl #
+	AC_MSG_CHECKING([whether iter_iov() is available])
+	ZFS_LINUX_TEST_RESULT([iter_iov], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_ITER_IOV, 1,
+		    [iter_iov() is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
 ])
diff --git a/sys/contrib/openzfs/config/kernel.m4 b/sys/contrib/openzfs/config/kernel.m4
index 1487fa2e7793..df194ec72207 100644
--- a/sys/contrib/openzfs/config/kernel.m4
+++ b/sys/contrib/openzfs/config/kernel.m4
@@ -160,6 +160,8 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_FILEMAP
 	ZFS_AC_KERNEL_SRC_WRITEPAGE_T
 	ZFS_AC_KERNEL_SRC_RECLAIMED
+	ZFS_AC_KERNEL_SRC_REGISTER_SYSCTL_TABLE
+	ZFS_AC_KERNEL_SRC_COPY_SPLICE_READ
 	case "$host_cpu" in
 		powerpc*)
 			ZFS_AC_KERNEL_SRC_CPU_HAS_FEATURE
@@ -299,6 +301,8 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_FILEMAP
 	ZFS_AC_KERNEL_WRITEPAGE_T
 	ZFS_AC_KERNEL_RECLAIMED
+	ZFS_AC_KERNEL_REGISTER_SYSCTL_TABLE
+	ZFS_AC_KERNEL_COPY_SPLICE_READ
 	case "$host_cpu" in
 		powerpc*)
 			ZFS_AC_KERNEL_CPU_HAS_FEATURE
diff --git a/sys/contrib/openzfs/include/os/freebsd/zfs/sys/zfs_vfsops_os.h b/sys/contrib/openzfs/include/os/freebsd/zfs/sys/zfs_vfsops_os.h
index 5948e44daab1..56a0ac96ac19 100644
--- a/sys/contrib/openzfs/include/os/freebsd/zfs/sys/zfs_vfsops_os.h
+++ b/sys/contrib/openzfs/include/os/freebsd/zfs/sys/zfs_vfsops_os.h
@@ -93,7 +93,6 @@ struct zfsvfs {
 	zfs_teardown_lock_t z_teardown_lock;
 	zfs_teardown_inactive_lock_t z_teardown_inactive_lock;
 	list_t		z_all_znodes;	/* all vnodes in the fs */
-	uint64_t	z_nr_znodes;	/* number of znodes in the fs */
 	kmutex_t	z_znodes_lock;	/* lock for z_all_znodes */
 	struct zfsctl_root	*z_ctldir;	/* .zfs directory pointer */
 	boolean_t	z_show_ctldir;	/* expose .zfs in the root dir */
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 e0f20ba32008..f111e648ccf7 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
@@ -347,6 +347,7 @@ zfs_check_media_change(struct block_device *bdev)
 #define	vdev_bdev_reread_part(bdev)	zfs_check_media_change(bdev)
 #elif defined(HAVE_DISK_CHECK_MEDIA_CHANGE)
 #define	vdev_bdev_reread_part(bdev)	disk_check_media_change(bdev->bd_disk)
+#define	zfs_check_media_change(bdev)	disk_check_media_change(bdev->bd_disk)
 #else
 /*
  * This is encountered if check_disk_change() and bdev_check_media_change()
@@ -397,6 +398,12 @@ vdev_lookup_bdev(const char *path, dev_t *dev)
 #endif
 }
 
+#if defined(HAVE_BLK_MODE_T)
+#define	blk_mode_is_open_write(flag)	((flag) & BLK_OPEN_WRITE)
+#else
+#define	blk_mode_is_open_write(flag)	((flag) & FMODE_WRITE)
+#endif
+
 /*
  * Kernels without bio_set_op_attrs use bi_rw for the bio flags.
  */
diff --git a/sys/contrib/openzfs/include/os/linux/spl/sys/uio.h b/sys/contrib/openzfs/include/os/linux/spl/sys/uio.h
index fe2b5c07a018..cce097e16fbc 100644
--- a/sys/contrib/openzfs/include/os/linux/spl/sys/uio.h
+++ b/sys/contrib/openzfs/include/os/linux/spl/sys/uio.h
@@ -173,4 +173,16 @@ zfs_uio_iov_iter_init(zfs_uio_t *uio, struct iov_iter *iter, offset_t offset,
 }
 #endif
 
+#if defined(HAVE_ITER_IOV)
+#define	zfs_uio_iter_iov(iter)	iter_iov((iter))
+#else
+#define	zfs_uio_iter_iov(iter)	(iter)->iov
+#endif
+
+#if defined(HAVE_IOV_ITER_TYPE)
+#define	zfs_uio_iov_iter_type(iter)	iov_iter_type((iter))
+#else
+#define	zfs_uio_iov_iter_type(iter)	(iter)->type
+#endif
+
 #endif /* SPL_UIO_H */
diff --git a/sys/contrib/openzfs/include/os/linux/zfs/sys/zfs_vfsops_os.h b/sys/contrib/openzfs/include/os/linux/zfs/sys/zfs_vfsops_os.h
index e320b8de4222..b4d5db21f5e5 100644
--- a/sys/contrib/openzfs/include/os/linux/zfs/sys/zfs_vfsops_os.h
+++ b/sys/contrib/openzfs/include/os/linux/zfs/sys/zfs_vfsops_os.h
@@ -105,7 +105,6 @@ struct zfsvfs {
 	rrmlock_t	z_teardown_lock;
 	krwlock_t	z_teardown_inactive_lock;
 	list_t		z_all_znodes;	/* all znodes in the fs */
-	uint64_t	z_nr_znodes;	/* number of znodes in the fs */
 	unsigned long	z_rollback_time; /* last online rollback time */
 	unsigned long	z_snap_defer_time; /* last snapshot unmount deferral */
 	kmutex_t	z_znodes_lock;	/* lock for z_all_znodes */
diff --git a/sys/contrib/openzfs/man/man7/zpoolconcepts.7 b/sys/contrib/openzfs/man/man7/zpoolconcepts.7
index db3fd4926236..98f3ee7cd660 100644
--- a/sys/contrib/openzfs/man/man7/zpoolconcepts.7
+++ b/sys/contrib/openzfs/man/man7/zpoolconcepts.7
@@ -203,11 +203,9 @@ For more information, see the
 section.
 .El
 .Pp
-Virtual devices cannot be nested, so a mirror or raidz virtual device can only
-contain files or disks.
-Mirrors of mirrors
-.Pq or other combinations
-are not allowed.
+Virtual devices cannot be nested arbitrarily.
+A mirror, raidz or draid virtual device can only be created with files or disks.
+Mirrors of mirrors or other such combinations are not allowed.
 .Pp
 A pool can have any number of virtual devices at the top of the configuration
 .Po known as
diff --git a/sys/contrib/openzfs/module/Makefile.in b/sys/contrib/openzfs/module/Makefile.in
index 5b71e1abf79e..9b34b3dfaec7 100644
--- a/sys/contrib/openzfs/module/Makefile.in
+++ b/sys/contrib/openzfs/module/Makefile.in
@@ -168,4 +168,4 @@ gen-zstd-symbols:
 	for obj in $(addprefix zstd/,$(ZSTD_UPSTREAM_OBJS)); do echo; echo "/* $${obj#zstd/}: */"; @OBJDUMP@ -t $$obj | awk '$$2 == "g" && !/ zfs_/ {print "#define\t" $$6 " zfs_" $$6}' | sort; done >> zstd/include/zstd_compat_wrapper.h
 
 check-zstd-symbols:
-	@OBJDUMP@ -t $(addprefix zstd/,$(ZSTD_UPSTREAM_OBJS)) | awk '/file format/ {print}  $$2 == "g" && !/ zfs_/ {++ret; print}  END {exit ret}'
+	@OBJDUMP@ -t $(addprefix zstd/,$(ZSTD_UPSTREAM_OBJS)) | awk '/file format/ {print}  $$2 == "g" && (!/ zfs_/ && !/ __pfx_zfs_/) {++ret; print}  END {exit ret}'
diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vfsops.c b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vfsops.c
index 49b97ae8f590..8969fd6a54bd 100644
--- a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vfsops.c
+++ b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vfsops.c
@@ -1158,7 +1158,6 @@ zfsvfs_free(zfsvfs_t *zfsvfs)
 
 	mutex_destroy(&zfsvfs->z_znodes_lock);
 	mutex_destroy(&zfsvfs->z_lock);
-	ASSERT3U(zfsvfs->z_nr_znodes, ==, 0);
 	list_destroy(&zfsvfs->z_all_znodes);
 	ZFS_TEARDOWN_DESTROY(zfsvfs);
 	ZFS_TEARDOWN_INACTIVE_DESTROY(zfsvfs);
@@ -1562,12 +1561,11 @@ zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
 		 * may add the parents of dir-based xattrs to the taskq
 		 * so we want to wait for these.
 		 *
-		 * We can safely read z_nr_znodes without locking because the
-		 * VFS has already blocked operations which add to the
-		 * z_all_znodes list and thus increment z_nr_znodes.
+		 * We can safely check z_all_znodes for being empty because the
+		 * VFS has already blocked operations which add to it.
 		 */
 		int round = 0;
-		while (zfsvfs->z_nr_znodes > 0) {
+		while (!list_is_empty(&zfsvfs->z_all_znodes)) {
 			taskq_wait_outstanding(dsl_pool_zrele_taskq(
 			    dmu_objset_pool(zfsvfs->z_os)), 0);
 			if (++round > 1 && !unmounting)
diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_znode.c b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_znode.c
index c4f2b722ef4e..0d4c94555c6b 100644
--- a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_znode.c
+++ b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_znode.c
@@ -537,7 +537,6 @@ zfs_znode_alloc(zfsvfs_t *zfsvfs, dmu_buf_t *db, int blksz,
 
 	mutex_enter(&zfsvfs->z_znodes_lock);
 	list_insert_tail(&zfsvfs->z_all_znodes, zp);
-	zfsvfs->z_nr_znodes++;
 	zp->z_zfsvfs = zfsvfs;
 	mutex_exit(&zfsvfs->z_znodes_lock);
 
@@ -1286,7 +1285,6 @@ zfs_znode_free(znode_t *zp)
 	mutex_enter(&zfsvfs->z_znodes_lock);
 	POINTER_INVALIDATE(&zp->z_zfsvfs);
 	list_remove(&zfsvfs->z_all_znodes, zp);
-	zfsvfs->z_nr_znodes--;
 	mutex_exit(&zfsvfs->z_znodes_lock);
 
 #if __FreeBSD_version >= 1300139
diff --git a/sys/contrib/openzfs/module/os/linux/spl/spl-proc.c b/sys/contrib/openzfs/module/os/linux/spl/spl-proc.c
index 01f5619e1893..f0f929d3ce90 100644
--- a/sys/contrib/openzfs/module/os/linux/spl/spl-proc.c
+++ b/sys/contrib/openzfs/module/os/linux/spl/spl-proc.c
@@ -47,6 +47,10 @@ static unsigned long table_min = 0;
 static unsigned long table_max = ~0;
 
 static struct ctl_table_header *spl_header = NULL;
+#ifndef HAVE_REGISTER_SYSCTL_TABLE
+static struct ctl_table_header *spl_kmem = NULL;
+static struct ctl_table_header *spl_kstat = NULL;
+#endif
 static struct proc_dir_entry *proc_spl = NULL;
 static struct proc_dir_entry *proc_spl_kmem = NULL;
 static struct proc_dir_entry *proc_spl_kmem_slab = NULL;
@@ -624,6 +628,7 @@ static struct ctl_table spl_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dohostid,
 	},
+#ifdef HAVE_REGISTER_SYSCTL_TABLE
 	{
 		.procname	= "kmem",
 		.mode		= 0555,
@@ -634,9 +639,11 @@ static struct ctl_table spl_table[] = {
 		.mode		= 0555,
 		.child		= spl_kstat_table,
 	},
+#endif
 	{},
 };
 
+#ifdef HAVE_REGISTER_SYSCTL_TABLE
 static struct ctl_table spl_dir[] = {
 	{
 		.procname	= "spl",
@@ -648,21 +655,64 @@ static struct ctl_table spl_dir[] = {
 
 static struct ctl_table spl_root[] = {
 	{
-	.procname = "kernel",
-	.mode = 0555,
-	.child = spl_dir,
+		.procname	= "kernel",
+		.mode		= 0555,
+		.child		= spl_dir,
 	},
 	{}
 };
+#endif
+
+static void spl_proc_cleanup(void)
+{
+	remove_proc_entry("kstat", proc_spl);
+	remove_proc_entry("slab", proc_spl_kmem);
+	remove_proc_entry("kmem", proc_spl);
+	remove_proc_entry("taskq-all", proc_spl);
+	remove_proc_entry("taskq", proc_spl);
+	remove_proc_entry("spl", NULL);
+
+#ifndef HAVE_REGISTER_SYSCTL_TABLE
+	if (spl_kstat) {
+		unregister_sysctl_table(spl_kstat);
+		spl_kstat = NULL;
+	}
+	if (spl_kmem) {
+		unregister_sysctl_table(spl_kmem);
+		spl_kmem = NULL;
+	}
+#endif
+	if (spl_header) {
+		unregister_sysctl_table(spl_header);
+		spl_header = NULL;
+	}
+}
 
 int
 spl_proc_init(void)
 {
 	int rc = 0;
 
+#ifdef HAVE_REGISTER_SYSCTL_TABLE
 	spl_header = register_sysctl_table(spl_root);
 	if (spl_header == NULL)
 		return (-EUNATCH);
+#else
+	spl_header = register_sysctl("kernel/spl", spl_table);
+	if (spl_header == NULL)
+		return (-EUNATCH);
+
+	spl_kmem = register_sysctl("kernel/spl/kmem", spl_kmem_table);
+	if (spl_kmem == NULL) {
+		rc = -EUNATCH;
+		goto out;
+	}
+	spl_kstat = register_sysctl("kernel/spl/kstat", spl_kstat_table);
+	if (spl_kstat == NULL) {
+		rc = -EUNATCH;
+		goto out;
+	}
+#endif
 
 	proc_spl = proc_mkdir("spl", NULL);
 	if (proc_spl == NULL) {
@@ -703,15 +753,8 @@ spl_proc_init(void)
 		goto out;
 	}
 out:
-	if (rc) {
-		remove_proc_entry("kstat", proc_spl);
-		remove_proc_entry("slab", proc_spl_kmem);
-		remove_proc_entry("kmem", proc_spl);
-		remove_proc_entry("taskq-all", proc_spl);
-		remove_proc_entry("taskq", proc_spl);
-		remove_proc_entry("spl", NULL);
-		unregister_sysctl_table(spl_header);
-	}
+	if (rc)
+		spl_proc_cleanup();
 
 	return (rc);
 }
@@ -719,13 +762,5 @@ out:
 void
 spl_proc_fini(void)
 {
-	remove_proc_entry("kstat", proc_spl);
-	remove_proc_entry("slab", proc_spl_kmem);
-	remove_proc_entry("kmem", proc_spl);
-	remove_proc_entry("taskq-all", proc_spl);
-	remove_proc_entry("taskq", proc_spl);
-	remove_proc_entry("spl", NULL);
-
-	ASSERT(spl_header != NULL);
-	unregister_sysctl_table(spl_header);
+	spl_proc_cleanup();
 }
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 925ee9d9fe9c..48ac55f07034 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/vdev_disk.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/vdev_disk.c
@@ -80,9 +80,22 @@ typedef struct dio_request {
 
 static unsigned int zfs_vdev_failfast_mask = 1;
 
+#ifdef HAVE_BLK_MODE_T
+static blk_mode_t
+#else
 static fmode_t
+#endif
 vdev_bdev_mode(spa_mode_t spa_mode)
 {
+#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;
+#else
 	fmode_t mode = 0;
 
 	if (spa_mode & SPA_MODE_READ)
@@ -90,6 +103,7 @@ vdev_bdev_mode(spa_mode_t spa_mode)
 
 	if (spa_mode & SPA_MODE_WRITE)
 		mode |= FMODE_WRITE;
+#endif
 
 	return (mode);
 }
@@ -197,12 +211,47 @@ vdev_disk_kobj_evt_post(vdev_t *v)
 	}
 }
 
+#if !defined(HAVE_BLKDEV_GET_BY_PATH_4ARG)
+/*
+ * Define a dummy struct blk_holder_ops for kernel versions
+ * prior to 6.5.
+ */
+struct blk_holder_ops {};
+#endif
+
+static struct block_device *
+vdev_blkdev_get_by_path(const char *path, spa_mode_t mode, void *holder,
+    const struct blk_holder_ops *hops)
+{
+#ifdef HAVE_BLKDEV_GET_BY_PATH_4ARG
+	return (blkdev_get_by_path(path,
+	    vdev_bdev_mode(mode) | BLK_OPEN_EXCL, holder, hops));
+#else
+	return (blkdev_get_by_path(path,
+	    vdev_bdev_mode(mode) | FMODE_EXCL, holder));
+#endif
+}
+
+static void
+vdev_blkdev_put(struct block_device *bdev, spa_mode_t mode, void *holder)
+{
+#ifdef HAVE_BLKDEV_PUT_HOLDER
+	return (blkdev_put(bdev, holder));
+#else
+	return (blkdev_put(bdev, vdev_bdev_mode(mode) | FMODE_EXCL));
+#endif
+}
+
 static int
 vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
     uint64_t *logical_ashift, uint64_t *physical_ashift)
 {
 	struct block_device *bdev;
+#ifdef HAVE_BLK_MODE_T
+	blk_mode_t mode = vdev_bdev_mode(spa_mode(v->vdev_spa));
+#else
 	fmode_t mode = vdev_bdev_mode(spa_mode(v->vdev_spa));
+#endif
 	hrtime_t timeout = MSEC2NSEC(zfs_vdev_open_timeout_ms);
 	vdev_disk_t *vd;
 
@@ -252,15 +301,15 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 					reread_part = B_TRUE;
 			}
 
-			blkdev_put(bdev, mode | FMODE_EXCL);
+			vdev_blkdev_put(bdev, mode, zfs_vdev_holder);
 		}
 
 		if (reread_part) {
-			bdev = blkdev_get_by_path(disk_name, mode | FMODE_EXCL,
-			    zfs_vdev_holder);
+			bdev = vdev_blkdev_get_by_path(disk_name, mode,
+			    zfs_vdev_holder, NULL);
 			if (!IS_ERR(bdev)) {
 				int error = vdev_bdev_reread_part(bdev);
-				blkdev_put(bdev, mode | FMODE_EXCL);
+				vdev_blkdev_put(bdev, mode, zfs_vdev_holder);
 				if (error == 0) {
 					timeout = MSEC2NSEC(
 					    zfs_vdev_open_timeout_ms * 2);
@@ -305,8 +354,8 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
 	hrtime_t start = gethrtime();
 	bdev = ERR_PTR(-ENXIO);
 	while (IS_ERR(bdev) && ((gethrtime() - start) < timeout)) {
-		bdev = blkdev_get_by_path(v->vdev_path, mode | FMODE_EXCL,
-		    zfs_vdev_holder);
+		bdev = vdev_blkdev_get_by_path(v->vdev_path, mode,
+		    zfs_vdev_holder, NULL);
 		if (unlikely(PTR_ERR(bdev) == -ENOENT)) {
 			/*
 			 * There is no point of waiting since device is removed
@@ -382,8 +431,8 @@ vdev_disk_close(vdev_t *v)
 		return;
 
 	if (vd->vd_bdev != NULL) {
-		blkdev_put(vd->vd_bdev,
-		    vdev_bdev_mode(spa_mode(v->vdev_spa)) | FMODE_EXCL);
+		vdev_blkdev_put(vd->vd_bdev, spa_mode(v->vdev_spa),
+		    zfs_vdev_holder);
 	}
 
 	rw_destroy(&vd->vd_lock);
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zfs_ctldir.c b/sys/contrib/openzfs/module/os/linux/zfs/zfs_ctldir.c
index c45a3eb5a4eb..02cb379ea840 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zfs_ctldir.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zfs_ctldir.c
@@ -537,7 +537,6 @@ zfsctl_inode_alloc(zfsvfs_t *zfsvfs, uint64_t id,
 
 	mutex_enter(&zfsvfs->z_znodes_lock);
 	list_insert_tail(&zfsvfs->z_all_znodes, zp);
-	zfsvfs->z_nr_znodes++;
 	membar_producer();
 	mutex_exit(&zfsvfs->z_znodes_lock);
 
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zfs_vfsops.c b/sys/contrib/openzfs/module/os/linux/zfs/zfs_vfsops.c
index 464c12e1108d..a1db5c57c18b 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zfs_vfsops.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zfs_vfsops.c
@@ -1330,12 +1330,11 @@ zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
 		 * may add the parents of dir-based xattrs to the taskq
 		 * so we want to wait for these.
 		 *
-		 * We can safely read z_nr_znodes without locking because the
-		 * VFS has already blocked operations which add to the
-		 * z_all_znodes list and thus increment z_nr_znodes.
+		 * We can safely check z_all_znodes for being empty because the
+		 * VFS has already blocked operations which add to it.
 		 */
 		int round = 0;
-		while (zfsvfs->z_nr_znodes > 0) {
+		while (!list_is_empty(&zfsvfs->z_all_znodes)) {
 			taskq_wait_outstanding(dsl_pool_zrele_taskq(
 			    dmu_objset_pool(zfsvfs->z_os)), 0);
 			if (++round > 1 && !unmounting)
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 234c4d5ef0e0..33baac9db06b 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
@@ -186,7 +186,7 @@ zfs_open(struct inode *ip, int mode, int flag, cred_t *cr)
 		return (error);
 
 	/* Honor ZFS_APPENDONLY file attribute */
-	if ((mode & FMODE_WRITE) && (zp->z_pflags & ZFS_APPENDONLY) &&
+	if (blk_mode_is_open_write(mode) && (zp->z_pflags & ZFS_APPENDONLY) &&
 	    ((flag & O_APPEND) == 0)) {
 		zfs_exit(zfsvfs, FTAG);
 		return (SET_ERROR(EPERM));
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zfs_znode.c b/sys/contrib/openzfs/module/os/linux/zfs/zfs_znode.c
index 335ae3460c58..52c8e51df659 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zfs_znode.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zfs_znode.c
@@ -390,7 +390,6 @@ zfs_inode_destroy(struct inode *ip)
 	mutex_enter(&zfsvfs->z_znodes_lock);
 	if (list_link_active(&zp->z_link_node)) {
 		list_remove(&zfsvfs->z_all_znodes, zp);
-		zfsvfs->z_nr_znodes--;
 	}
 	mutex_exit(&zfsvfs->z_znodes_lock);
 
@@ -641,7 +640,6 @@ zfs_znode_alloc(zfsvfs_t *zfsvfs, dmu_buf_t *db, int blksz,
 
 	mutex_enter(&zfsvfs->z_znodes_lock);
 	list_insert_tail(&zfsvfs->z_all_znodes, zp);
-	zfsvfs->z_nr_znodes++;
 	mutex_exit(&zfsvfs->z_znodes_lock);
 
 	if (links > 0)
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/zpl_ctldir.c b/sys/contrib/openzfs/module/os/linux/zfs/zpl_ctldir.c
index 68a7de78f471..7786444fea35 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zpl_ctldir.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zpl_ctldir.c
@@ -42,7 +42,7 @@
 static int
 zpl_common_open(struct inode *ip, struct file *filp)
 {
-	if (filp->f_mode & FMODE_WRITE)
+	if (blk_mode_is_open_write(filp->f_mode))
 		return (-EACCES);
 
 	return (generic_file_open(ip, filp));
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 73526db731c4..3caa0fc6c214 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zpl_file.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zpl_file.c
@@ -301,15 +301,10 @@ zpl_uio_init(zfs_uio_t *uio, struct kiocb *kiocb, struct iov_iter *to,
 #if defined(HAVE_VFS_IOV_ITER)
 	zfs_uio_iov_iter_init(uio, to, pos, count, skip);
 #else
-#ifdef HAVE_IOV_ITER_TYPE
-	zfs_uio_iovec_init(uio, to->iov, to->nr_segs, pos,
-	    iov_iter_type(to) & ITER_KVEC ? UIO_SYSSPACE : UIO_USERSPACE,
+	zfs_uio_iovec_init(uio, zfs_uio_iter_iov(to), to->nr_segs, pos,
+	    zfs_uio_iov_iter_type(to) & ITER_KVEC ?
+	    UIO_SYSSPACE : UIO_USERSPACE,
 	    count, skip);
-#else
-	zfs_uio_iovec_init(uio, to->iov, to->nr_segs, pos,
-	    to->type & ITER_KVEC ? UIO_SYSSPACE : UIO_USERSPACE,
-	    count, skip);
-#endif
 #endif
 }
 
@@ -1328,7 +1323,11 @@ const struct file_operations zpl_file_operations = {
 	.read_iter	= zpl_iter_read,
 	.write_iter	= zpl_iter_write,
 #ifdef HAVE_VFS_IOV_ITER
+#ifdef HAVE_COPY_SPLICE_READ
+	.splice_read	= copy_splice_read,
+#else
 	.splice_read	= generic_file_splice_read,
+#endif
 	.splice_write	= iter_file_splice_write,
 #endif
 #else
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 38bc8e2c4eeb..7a95b54bdf0d 100644
--- a/sys/contrib/openzfs/module/os/linux/zfs/zvol_os.c
+++ b/sys/contrib/openzfs/module/os/linux/zfs/zvol_os.c
@@ -671,7 +671,11 @@ zvol_request(struct request_queue *q, struct bio *bio)
 }
 
 static int
+#ifdef HAVE_BLK_MODE_T
+zvol_open(struct gendisk *disk, blk_mode_t flag)
+#else
 zvol_open(struct block_device *bdev, fmode_t flag)
+#endif
 {
 	zvol_state_t *zv;
 	int error = 0;
@@ -686,10 +690,14 @@ retry:
 	/*
 	 * Obtain a copy of private_data under the zvol_state_lock to make
 	 * sure that either the result of zvol free code path setting
-	 * bdev->bd_disk->private_data to NULL is observed, or zvol_os_free()
+	 * disk->private_data to NULL is observed, or zvol_os_free()
 	 * is not called on this zv because of the positive zv_open_count.
 	 */
+#ifdef HAVE_BLK_MODE_T
+	zv = disk->private_data;
+#else
 	zv = bdev->bd_disk->private_data;
+#endif
 	if (zv == NULL) {
 		rw_exit(&zvol_state_lock);
 		return (SET_ERROR(-ENXIO));
@@ -769,14 +777,15 @@ retry:
 			}
 		}
 
-		error = -zvol_first_open(zv, !(flag & FMODE_WRITE));
+		error = -zvol_first_open(zv, !(blk_mode_is_open_write(flag)));
 
 		if (drop_namespace)
 			mutex_exit(&spa_namespace_lock);
 	}
 
 	if (error == 0) {
-		if ((flag & FMODE_WRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
+		if ((blk_mode_is_open_write(flag)) &&
+		    (zv->zv_flags & ZVOL_RDONLY)) {
 			if (zv->zv_open_count == 0)
 				zvol_last_close(zv);
 
@@ -791,14 +800,25 @@ retry:
 		rw_exit(&zv->zv_suspend_lock);
 
 	if (error == 0)
+#ifdef HAVE_BLK_MODE_T
+		disk_check_media_change(disk);
+#else
 		zfs_check_media_change(bdev);
+#endif
 
 	return (error);
 }
 
 static void
-zvol_release(struct gendisk *disk, fmode_t mode)
+#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_1ARG
+zvol_release(struct gendisk *disk)
+#else
+zvol_release(struct gendisk *disk, fmode_t unused)
+#endif
 {
+#if !defined(HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_1ARG)
+	(void) unused;
+#endif
 	zvol_state_t *zv;
 	boolean_t drop_suspend = B_TRUE;
 
diff --git a/sys/contrib/openzfs/module/zfs/spa_errlog.c b/sys/contrib/openzfs/module/zfs/spa_errlog.c
index 2e5c22c11490..5dd08f597f33 100644
--- a/sys/contrib/openzfs/module/zfs/spa_errlog.c
+++ b/sys/contrib/openzfs/module/zfs/spa_errlog.c
@@ -930,12 +930,21 @@ spa_upgrade_errlog(spa_t *spa, dmu_tx_t *tx)
 	if (spa->spa_errlog_last != 0) {
 		sync_upgrade_errlog(spa, spa->spa_errlog_last, &newobj, tx);
 		spa->spa_errlog_last = newobj;
+
+		(void) zap_update(spa->spa_meta_objset,
+		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_ERRLOG_LAST,
+		    sizeof (uint64_t), 1, &spa->spa_errlog_last, tx);
 	}
 
 	if (spa->spa_errlog_scrub != 0) {
 		sync_upgrade_errlog(spa, spa->spa_errlog_scrub, &newobj, tx);
 		spa->spa_errlog_scrub = newobj;
+
+		(void) zap_update(spa->spa_meta_objset,
+		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_ERRLOG_SCRUB,
+		    sizeof (uint64_t), 1, &spa->spa_errlog_scrub, tx);
 	}
+
 	mutex_exit(&spa->spa_errlog_lock);
 }
 
diff --git a/sys/contrib/openzfs/module/zfs/zil.c b/sys/contrib/openzfs/module/zfs/zil.c
index b30676b42d88..9e9c9c22549d 100644
--- a/sys/contrib/openzfs/module/zfs/zil.c
+++ b/sys/contrib/openzfs/module/zfs/zil.c
@@ -1550,7 +1550,16 @@ zil_lwb_write_done(zio_t *zio)
 	lwb->lwb_state = LWB_STATE_WRITE_DONE;
 	lwb->lwb_child_zio = NULL;
 	lwb->lwb_write_zio = NULL;
+
+	/*
+	 * If nlwb is not yet issued, zil_lwb_set_zio_dependency() is not
+	 * called for it yet, and when it will be, it won't be able to make
+	 * its write ZIO a parent this ZIO.  In such case we can not defer
+	 * our flushes or below may be a race between the done callbacks.
+	 */
 	nlwb = list_next(&zilog->zl_lwb_list, lwb);
+	if (nlwb && nlwb->lwb_state != LWB_STATE_ISSUED)
+		nlwb = NULL;
 	mutex_exit(&zilog->zl_lock);
 
 	if (avl_numnodes(t) == 0)
diff --git a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh
index 0a4d24fa695a..cfa26f54b11f 100755
--- a/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh
+++ b/sys/contrib/openzfs/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh
@@ -204,11 +204,11 @@ function histo_check_test_pool
 	# 4096 blocksize count for asize.   For verification we stick
 	# to just lsize counts.
 	#
-	# The max_variance is hard-coded here at 12% to leave us some
-	# margin.  Testing has shown this normally to be in the range
-	# of 2%-8%, but it may be as large as 11%.
+	# Variances are expected since this test does not account for
+	# metadata. The hardcoded limit here is empirical and should
+	# not be construed as deterministic.
 	###################
-	let max_variance=12
+	let max_variance=15
 	let fail_value=0
 	let error_count=0
 	log_note "Comparisons for ${pool}"