diff options
Diffstat (limited to 'lib/libzfs/os/linux/libzfs_mount_os.c')
| -rw-r--r-- | lib/libzfs/os/linux/libzfs_mount_os.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/lib/libzfs/os/linux/libzfs_mount_os.c b/lib/libzfs/os/linux/libzfs_mount_os.c new file mode 100644 index 0000000000000..92052f28ffe77 --- /dev/null +++ b/lib/libzfs/os/linux/libzfs_mount_os.c @@ -0,0 +1,411 @@ +/* + * 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 http://www.opensolaris.org/os/licensing. + * 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 2015 Nexenta Systems, Inc. All rights reserved. + * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2014, 2020 by Delphix. All rights reserved. + * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com> + * Copyright 2017 RackTop Systems. + * Copyright (c) 2018 Datto Inc. + * Copyright 2018 OmniOS Community Edition (OmniOSce) Association. + */ + +#include <dirent.h> +#include <dlfcn.h> +#include <errno.h> +#include <fcntl.h> +#include <libgen.h> +#include <libintl.h> +#include <stdio.h> +#include <stdlib.h> +#include <strings.h> +#include <unistd.h> +#include <zone.h> +#include <sys/mntent.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <sys/vfs.h> +#include <sys/dsl_crypt.h> +#include <libzfs.h> + +#include "libzfs_impl.h" +#include <thread_pool.h> + +#define ZS_COMMENT 0x00000000 /* comment */ +#define ZS_ZFSUTIL 0x00000001 /* caller is zfs(8) */ + +typedef struct option_map { + const char *name; + unsigned long mntmask; + unsigned long zfsmask; +} option_map_t; + +static const option_map_t option_map[] = { + /* Canonicalized filesystem independent options from mount(8) */ + { MNTOPT_NOAUTO, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_DEFAULTS, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_NODEVICES, MS_NODEV, ZS_COMMENT }, + { MNTOPT_DEVICES, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_DIRSYNC, MS_DIRSYNC, ZS_COMMENT }, + { MNTOPT_NOEXEC, MS_NOEXEC, ZS_COMMENT }, + { MNTOPT_EXEC, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_GROUP, MS_GROUP, ZS_COMMENT }, + { MNTOPT_NETDEV, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_NOFAIL, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_NOSUID, MS_NOSUID, ZS_COMMENT }, + { MNTOPT_SUID, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_OWNER, MS_OWNER, ZS_COMMENT }, + { MNTOPT_REMOUNT, MS_REMOUNT, ZS_COMMENT }, + { MNTOPT_RO, MS_RDONLY, ZS_COMMENT }, + { MNTOPT_RW, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_SYNC, MS_SYNCHRONOUS, ZS_COMMENT }, + { MNTOPT_USER, MS_USERS, ZS_COMMENT }, + { MNTOPT_USERS, MS_USERS, ZS_COMMENT }, + /* acl flags passed with util-linux-2.24 mount command */ + { MNTOPT_ACL, MS_POSIXACL, ZS_COMMENT }, + { MNTOPT_NOACL, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_POSIXACL, MS_POSIXACL, ZS_COMMENT }, +#ifdef MS_NOATIME + { MNTOPT_NOATIME, MS_NOATIME, ZS_COMMENT }, + { MNTOPT_ATIME, MS_COMMENT, ZS_COMMENT }, +#endif +#ifdef MS_NODIRATIME + { MNTOPT_NODIRATIME, MS_NODIRATIME, ZS_COMMENT }, + { MNTOPT_DIRATIME, MS_COMMENT, ZS_COMMENT }, +#endif +#ifdef MS_RELATIME + { MNTOPT_RELATIME, MS_RELATIME, ZS_COMMENT }, + { MNTOPT_NORELATIME, MS_COMMENT, ZS_COMMENT }, +#endif +#ifdef MS_STRICTATIME + { MNTOPT_STRICTATIME, MS_STRICTATIME, ZS_COMMENT }, + { MNTOPT_NOSTRICTATIME, MS_COMMENT, ZS_COMMENT }, +#endif +#ifdef MS_LAZYTIME + { MNTOPT_LAZYTIME, MS_LAZYTIME, ZS_COMMENT }, +#endif + { MNTOPT_CONTEXT, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_FSCONTEXT, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_DEFCONTEXT, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_ROOTCONTEXT, MS_COMMENT, ZS_COMMENT }, +#ifdef MS_I_VERSION + { MNTOPT_IVERSION, MS_I_VERSION, ZS_COMMENT }, +#endif +#ifdef MS_MANDLOCK + { MNTOPT_NBMAND, MS_MANDLOCK, ZS_COMMENT }, + { MNTOPT_NONBMAND, MS_COMMENT, ZS_COMMENT }, +#endif + /* Valid options not found in mount(8) */ + { MNTOPT_BIND, MS_BIND, ZS_COMMENT }, +#ifdef MS_REC + { MNTOPT_RBIND, MS_BIND|MS_REC, ZS_COMMENT }, +#endif + { MNTOPT_COMMENT, MS_COMMENT, ZS_COMMENT }, +#ifdef MS_NOSUB + { MNTOPT_NOSUB, MS_NOSUB, ZS_COMMENT }, +#endif +#ifdef MS_SILENT + { MNTOPT_QUIET, MS_SILENT, ZS_COMMENT }, +#endif + /* Custom zfs options */ + { MNTOPT_XATTR, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_NOXATTR, MS_COMMENT, ZS_COMMENT }, + { MNTOPT_ZFSUTIL, MS_COMMENT, ZS_ZFSUTIL }, + { NULL, 0, 0 } }; + +/* + * Break the mount option in to a name/value pair. The name is + * validated against the option map and mount flags set accordingly. + */ +static int +parse_option(char *mntopt, unsigned long *mntflags, + unsigned long *zfsflags, int sloppy) +{ + const option_map_t *opt; + char *ptr, *name, *value = NULL; + int error = 0; + + name = strdup(mntopt); + if (name == NULL) + return (ENOMEM); + + for (ptr = name; ptr && *ptr; ptr++) { + if (*ptr == '=') { + *ptr = '\0'; + value = ptr+1; + VERIFY3P(value, !=, NULL); + break; + } + } + + for (opt = option_map; opt->name != NULL; opt++) { + if (strncmp(name, opt->name, strlen(name)) == 0) { + *mntflags |= opt->mntmask; + *zfsflags |= opt->zfsmask; + error = 0; + goto out; + } + } + + if (!sloppy) + error = ENOENT; +out: + /* If required further process on the value may be done here */ + free(name); + return (error); +} + +/* + * Translate the mount option string in to MS_* mount flags for the + * kernel vfs. When sloppy is non-zero unknown options will be ignored + * otherwise they are considered fatal are copied in to badopt. + */ +int +zfs_parse_mount_options(char *mntopts, unsigned long *mntflags, + unsigned long *zfsflags, int sloppy, char *badopt, char *mtabopt) +{ + int error = 0, quote = 0, flag = 0, count = 0; + char *ptr, *opt, *opts; + + opts = strdup(mntopts); + if (opts == NULL) + return (ENOMEM); + + *mntflags = 0; + opt = NULL; + + /* + * Scan through all mount options which must be comma delimited. + * We must be careful to notice regions which are double quoted + * and skip commas in these regions. Each option is then checked + * to determine if it is a known option. + */ + for (ptr = opts; ptr && !flag; ptr++) { + if (opt == NULL) + opt = ptr; + + if (*ptr == '"') + quote = !quote; + + if (quote) + continue; + + if (*ptr == '\0') + flag = 1; + + if ((*ptr == ',') || (*ptr == '\0')) { + *ptr = '\0'; + + error = parse_option(opt, mntflags, zfsflags, sloppy); + if (error) { + strcpy(badopt, opt); + goto out; + + } + + if (!(*mntflags & MS_REMOUNT) && + !(*zfsflags & ZS_ZFSUTIL) && + mtabopt != NULL) { + if (count > 0) + strlcat(mtabopt, ",", MNT_LINE_MAX); + + strlcat(mtabopt, opt, MNT_LINE_MAX); + count++; + } + + opt = NULL; + } + } + +out: + free(opts); + return (error); +} + +static void +append_mntopt(const char *name, const char *val, char *mntopts, + char *mtabopt, boolean_t quote) +{ + char tmp[MNT_LINE_MAX]; + + snprintf(tmp, MNT_LINE_MAX, quote ? ",%s=\"%s\"" : ",%s=%s", name, val); + + if (mntopts) + strlcat(mntopts, tmp, MNT_LINE_MAX); + + if (mtabopt) + strlcat(mtabopt, tmp, MNT_LINE_MAX); +} + +static void +zfs_selinux_setcontext(zfs_handle_t *zhp, zfs_prop_t zpt, const char *name, + char *mntopts, char *mtabopt) +{ + char context[ZFS_MAXPROPLEN]; + + if (zfs_prop_get(zhp, zpt, context, sizeof (context), + NULL, NULL, 0, B_FALSE) == 0) { + if (strcmp(context, "none") != 0) + append_mntopt(name, context, mntopts, mtabopt, B_TRUE); + } +} + +void +zfs_adjust_mount_options(zfs_handle_t *zhp, const char *mntpoint, + char *mntopts, char *mtabopt) +{ + char prop[ZFS_MAXPROPLEN]; + + /* + * Checks to see if the ZFS_PROP_SELINUX_CONTEXT exists + * if it does, create a tmp variable in case it's needed + * checks to see if the selinux context is set to the default + * if it is, allow the setting of the other context properties + * this is needed because the 'context' property overrides others + * if it is not the default, set the 'context' property + */ + if (zfs_prop_get(zhp, ZFS_PROP_SELINUX_CONTEXT, prop, sizeof (prop), + NULL, NULL, 0, B_FALSE) == 0) { + if (strcmp(prop, "none") == 0) { + zfs_selinux_setcontext(zhp, ZFS_PROP_SELINUX_FSCONTEXT, + MNTOPT_FSCONTEXT, mntopts, mtabopt); + zfs_selinux_setcontext(zhp, ZFS_PROP_SELINUX_DEFCONTEXT, + MNTOPT_DEFCONTEXT, mntopts, mtabopt); + zfs_selinux_setcontext(zhp, + ZFS_PROP_SELINUX_ROOTCONTEXT, MNTOPT_ROOTCONTEXT, + mntopts, mtabopt); + } else { + append_mntopt(MNTOPT_CONTEXT, prop, + mntopts, mtabopt, B_TRUE); + } + } + + /* A hint used to determine an auto-mounted snapshot mount point */ + append_mntopt(MNTOPT_MNTPOINT, mntpoint, mntopts, NULL, B_FALSE); +} + +/* + * By default the filesystem by preparing the mount options (i.e. parsing + * some flags from the "opts" parameter into the "flags" parameter) and then + * directly calling the system call mount(2). We don't need the mount utility + * or update /etc/mtab, because this is a symlink on all modern systems. + * + * If the environment variable ZFS_MOUNT_HELPER is set, we fall back to the + * previous behavior: + * The filesystem is mounted by invoking the system mount utility rather + * than by the system call mount(2). This ensures that the /etc/mtab + * file is correctly locked for the update. Performing our own locking + * and /etc/mtab update requires making an unsafe assumption about how + * the mount utility performs its locking. Unfortunately, this also means + * in the case of a mount failure we do not have the exact errno. We must + * make due with return value from the mount process. + */ +int +do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts, int flags) +{ + const char *src = zfs_get_name(zhp); + int error = 0; + + if (!libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) { + char badopt[MNT_LINE_MAX] = {0}; + unsigned long mntflags = flags, zfsflags; + char myopts[MNT_LINE_MAX] = {0}; + + if (zfs_parse_mount_options(opts, &mntflags, + &zfsflags, 0, badopt, NULL)) { + return (EINVAL); + } + strlcat(myopts, opts, MNT_LINE_MAX); + zfs_adjust_mount_options(zhp, mntpt, myopts, NULL); + if (mount(src, mntpt, MNTTYPE_ZFS, mntflags, myopts)) { + return (errno); + } + } else { + char *argv[9] = { + "/bin/mount", + "--no-canonicalize", + "-t", MNTTYPE_ZFS, + "-o", opts, + (char *)src, + (char *)mntpt, + (char *)NULL }; + + /* Return only the most critical mount error */ + error = libzfs_run_process(argv[0], argv, + STDOUT_VERBOSE|STDERR_VERBOSE); + if (error) { + if (error & MOUNT_FILEIO) { + error = EIO; + } else if (error & MOUNT_USER) { + error = EINTR; + } else if (error & MOUNT_SOFTWARE) { + error = EPIPE; + } else if (error & MOUNT_BUSY) { + error = EBUSY; + } else if (error & MOUNT_SYSERR) { + error = EAGAIN; + } else if (error & MOUNT_USAGE) { + error = EINVAL; + } else + error = ENXIO; /* Generic error */ + } + } + + return (error); +} + +int +do_unmount(const char *mntpt, int flags) +{ + if (!libzfs_envvar_is_set("ZFS_MOUNT_HELPER")) { + return (umount2(mntpt, flags)); + } + + char force_opt[] = "-f"; + char lazy_opt[] = "-l"; + char *argv[7] = { + "/bin/umount", + "-t", MNTTYPE_ZFS, + NULL, NULL, NULL, NULL }; + int rc, count = 3; + + if (flags & MS_FORCE) { + argv[count] = force_opt; + count++; + } + + if (flags & MS_DETACH) { + argv[count] = lazy_opt; + count++; + } + + argv[count] = (char *)mntpt; + rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE); + + return (rc ? EINVAL : 0); +} + +int +zfs_mount_delegation_check(void) +{ + return ((geteuid() != 0) ? EACCES : 0); +} |