/* * 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 2015 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2014, 2022 by Delphix. All rights reserved. * Copyright 2016 Igor Kozhukhov * Copyright 2017 RackTop Systems. * Copyright (c) 2018 Datto Inc. * Copyright 2018 OmniOS Community Edition (OmniOSce) Association. */ /* * Routines to manage ZFS mounts. We separate all the nasty routines that have * to deal with the OS. The following functions are the main entry points -- * they are used by mount and unmount and when changing a filesystem's * mountpoint. * * zfs_is_mounted() * zfs_mount() * zfs_mount_at() * zfs_unmount() * zfs_unmountall() * * This file also contains the functions used to manage sharing filesystems: * * zfs_is_shared() * zfs_share() * zfs_unshare() * zfs_unshareall() * zfs_commit_shares() * * The following functions are available for pool consumers, and will * mount/unmount and share/unshare all datasets within pool: * * zpool_enable_datasets() * zpool_disable_datasets() */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "libzfs_impl.h" #include #include #include #define MAXISALEN 257 /* based on sysinfo(2) man page */ static int mount_tp_nthr = 512; /* tpool threads for multi-threaded mounting */ static void zfs_mount_task(void *); static const proto_table_t proto_table[SA_PROTOCOL_COUNT] = { [SA_PROTOCOL_NFS] = {ZFS_PROP_SHARENFS, EZFS_SHARENFSFAILED, EZFS_UNSHARENFSFAILED}, [SA_PROTOCOL_SMB] = {ZFS_PROP_SHARESMB, EZFS_SHARESMBFAILED, EZFS_UNSHARESMBFAILED}, }; static const enum sa_protocol share_all_proto[SA_PROTOCOL_COUNT + 1] = { SA_PROTOCOL_NFS, SA_PROTOCOL_SMB, SA_NO_PROTOCOL }; static boolean_t dir_is_empty_stat(const char *dirname) { struct stat st; /* * We only want to return false if the given path is a non empty * directory, all other errors are handled elsewhere. */ if (stat(dirname, &st) < 0 || !S_ISDIR(st.st_mode)) { return (B_TRUE); } /* * An empty directory will still have two entries in it, one * entry for each of "." and "..". */ if (st.st_size > 2) { return (B_FALSE); } return (B_TRUE); } static boolean_t dir_is_empty_readdir(const char *dirname) { DIR *dirp; struct dirent64 *dp; int dirfd; if ((dirfd = openat(AT_FDCWD, dirname, O_RDONLY | O_NDELAY | O_LARGEFILE | O_CLOEXEC, 0)) < 0) { return (B_TRUE); } if ((dirp = fdopendir(dirfd)) == NULL) { (void) close(dirfd); return (B_TRUE); } while ((dp = readdir64(dirp)) != NULL) { if (strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0) continue; (void) closedir(dirp); return (B_FALSE); } (void) closedir(dirp); return (B_TRUE); } /* * Returns true if the specified directory is empty. If we can't open the * directory at all, return true so that the mount can fail with a more * informative error message. */ static boolean_t dir_is_empty(const char *dirname) { struct statfs64 st; /* * If the statvfs call fails or the filesystem is not a ZFS * filesystem, fall back to the slow path which uses readdir. */ if ((statfs64(dirname, &st) != 0) || (st.f_type != ZFS_SUPER_MAGIC)) { return (dir_is_empty_readdir(dirname)); } /* * At this point, we know the provided path is on a ZFS * filesystem, so we can use stat instead of readdir to * determine if the directory is empty or not. We try to avoid * using readdir because that requires opening "dirname"; this * open file descriptor can potentially end up in a child * process if there's a concurrent fork, thus preventing the * zfs_mount() from otherwise succeeding (the open file * descriptor inherited by the child process will cause the * parent's mount to fail with EBUSY). The performance * implications of replacing the open, read, and close with a * single stat is nice; but is not the main motivation for the * added complexity. */ return (dir_is_empty_stat(dirname)); } /* * Checks to see if the mount is active. If the filesystem is mounted, we fill * in 'where' with the current mountpoint, and return 1. Otherwise, we return * 0. */ boolean_t is_mounted(libzfs_handle_t *zfs_hdl, const char *special, char **where) { struct mnttab entry; if (libzfs_mnttab_find(zfs_hdl, special, &entry) != 0) return (B_FALSE); if (where != NULL) *where = zfs_strdup(zfs_hdl, entry.mnt_mountp); return (B_TRUE); } boolean_t zfs_is_mounted(zfs_handle_t *zhp, char **where) { return (is_mounted(zhp->zfs_hdl, zfs_get_name(zhp), where)); } /* * Checks any higher order concerns about whether the given dataset is * mountable, false otherwise. zfs_is_mountable_internal specifically assumes * that the caller has verified the sanity of mounting the dataset at * its mountpoint to the extent the caller wants. */ static boolean_t zfs_is_mountable_internal(zfs_handle_t *zhp) { if (zfs_prop_get_int(zhp, ZFS_PROP_ZONED) && getzoneid() == GLOBAL_ZONEID) return (B_FALSE); return (B_TRUE); } /* * Returns true if the given dataset is mountable, false otherwise. Returns the * mountpoint in 'buf'. */ static boolean_t zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen, zprop_source_t *source, int flags) { char sourceloc[MAXNAMELEN]; zprop_source_t sourcetype; if (!zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type, B_FALSE)) return (B_FALSE); verify(zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, buf, buflen, &sourcetype, sourceloc, sizeof (sourceloc), B_FALSE) == 0); if (strcmp(buf, ZFS_MOUNTPOINT_NONE) == 0 || strcmp(buf, ZFS_MOUNTPOINT_LEGACY) == 0) return (B_FALSE); if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_OFF) return (B_FALSE); if (!zfs_is_mountable_internal(zhp)) return (B_FALSE); if (zfs_prop_get_int(zhp, ZFS_PROP_REDACTED) && !(flags & MS_FORCE)) return (B_FALSE); if (source) *source = sourcetype; return (B_TRUE); } /* * 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. * * In the long term a shared library called libmount is under development * which provides a common API to address the locking and errno issues. * Once the standard mount utility has been updated to use this library * we can add an autoconf check to conditionally use it. * * http://www.kernel.org/pub/linux/utils/util-linux/libmount-docs/index.html */ static int zfs_add_option(zfs_handle_t *zhp, char *options, int len, zfs_prop_t prop, const char *on, const char *off) { const char *source; uint64_t value; /* Skip adding duplicate default options */ if ((strstr(options, on) != NULL) || (strstr(options, off) != NULL)) return (0); /* * zfs_prop_get_int() is not used to ensure our mount options * are not influenced by the current /proc/self/mounts contents. */ value = getprop_uint64(zhp, prop, &source); (void) strlcat(options, ",", len); (void) strlcat(options, value ? on : off, len); return (0); } static int zfs_add_options(zfs_handle_t *zhp, char *options, int len) { int error = 0; error = zfs_add_option(zhp, options, len, ZFS_PROP_ATIME, MNTOPT_ATIME, MNTOPT_NOATIME); /* * don't add relatime/strictatime when atime=off, otherwise strictatime * will force atime=on */ if (strstr(options, MNTOPT_NOATIME) == NULL) { error = zfs_add_option(zhp, options, len, ZFS_PROP_RELATIME, MNTOPT_RELATIME, MNTOPT_STRICTATIME); } error = error ? error : zfs_add_option(zhp, options, len, ZFS_PROP_DEVICES, MNTOPT_DEVICES, MNTOPT_NODEVICES); error = error ? error : zfs_add_option(zhp, options, len, ZFS_PROP_EXEC, MNTOPT_EXEC, MNTOPT_NOEXEC); error = error ? error : zfs_add_option(zhp, options, len, ZFS_PROP_READONLY, MNTOPT_RO, MNTOPT_RW); error = error ? error : zfs_add_option(zhp, options, len, ZFS_PROP_SETUID, MNTOPT_SETUID, MNTOPT_NOSETUID); error = error ? error : zfs_add_option(zhp, options, len, ZFS_PROP_NBMAND, MNTOPT_NBMAND, MNTOPT_NONBMAND); return (error); } int zfs_mount(zfs_handle_t *zhp, const char *options, int flags) { char mountpoint[ZFS_MAXPROPLEN]; if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL, flags)) return (0); return (zfs_mount_at(zhp, options, flags, mountpoint)); } /* * Mount the given filesystem. */ int zfs_mount_at(zfs_handle_t *zhp, const char *options, int flags, const char *mountpoint) { struct stat buf; char mntopts[MNT_LINE_MAX]; char overlay[ZFS_MAXPROPLEN]; char prop_encroot[MAXNAMELEN]; boolean_t is_encroot; zfs_handle_t *encroot_hp = zhp; libzfs_handle_t *hdl = zhp->zfs_hdl; uint64_t keystatus; int remount = 0, rc; if (options == NULL) { (void) strlcpy(mntopts, MNTOPT_DEFAULTS, sizeof (mntopts)); } else { (void) strlcpy(mntopts, options, sizeof (mntopts)); } if (strstr(mntopts, MNTOPT_REMOUNT) != NULL) remount = 1; /* Potentially duplicates some checks if invoked by zfs_mount(). */ if (!zfs_is_mountable_internal(zhp)) return (0); /* * If the pool is imported read-only then all mounts must be read-only */ if (zpool_get_prop_int(zhp->zpool_hdl, ZPOOL_PROP_READONLY, NULL)) (void) strlcat(mntopts, "," MNTOPT_RO, sizeof (mntopts)); /* * Append default mount options which apply to the mount point. * This is done because under Linux (unlike Solaris) multiple mount * points may reference a single super block. This means that just * given a super block there is no back reference to update the per * mount point options. */ rc = zfs_add_options(zhp, mntopts, sizeof (mntopts)); if (rc) { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "default options unavailable")); return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint)); } /* * If the filesystem is encrypted the key must be loaded in order to * mount. If the key isn't loaded, the MS_CRYPT flag decides whether * or not we attempt to load the keys. Note: we must call * zfs_refresh_properties() here since some callers of this function * (most notably zpool_enable_datasets()) may implicitly load our key * by loading the parent's key first. */ if (zfs_prop_get_int(zhp, ZFS_PROP_ENCRYPTION) != ZIO_CRYPT_OFF) { zfs_refresh_properties(zhp); keystatus = zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS); /* * If the key is unavailable and MS_CRYPT is set give the * user a chance to enter the key. Otherwise just fail * immediately. */ if (keystatus == ZFS_KEYSTATUS_UNAVAILABLE) { if (flags & MS_CRYPT) { rc = zfs_crypto_get_encryption_root(zhp, &is_encroot, prop_encroot); if (rc) { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "Failed to get encryption root for " "'%s'."), zfs_get_name(zhp)); return (rc); } if (!is_encroot) { encroot_hp = zfs_open(hdl, prop_encroot, ZFS_TYPE_DATASET); if (encroot_hp == NULL) return (hdl->libzfs_error); } rc = zfs_crypto_load_key(encroot_hp, B_FALSE, NULL); if (!is_encroot) zfs_close(encroot_hp); if (rc) return (rc); } else { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "encryption key not loaded")); return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint)); } } } /* * Append zfsutil option so the mount helper allow the mount */ strlcat(mntopts, "," MNTOPT_ZFSUTIL, sizeof (mntopts)); /* Create the directory if it doesn't already exist */ if (lstat(mountpoint, &buf) != 0) { if (mkdirp(mountpoint, 0755) != 0) { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "failed to create mountpoint: %s"), strerror(errno)); return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint)); } } /* * Overlay mounts are enabled by default but may be disabled * via the 'overlay' property. The -O flag remains for compatibility. */ if (!(flags & MS_OVERLAY)) { if (zfs_prop_get(zhp, ZFS_PROP_OVERLAY, overlay, sizeof (overlay), NULL, NULL, 0, B_FALSE) == 0) { if (strcmp(overlay, "on") == 0) { flags |= MS_OVERLAY; } } } /* * Determine if the mountpoint is empty. If so, refuse to perform the * mount. We don't perform this check if 'remount' is * specified or if overlay option (-O) is given */ if ((flags & MS_OVERLAY) == 0 && !remount && !dir_is_empty(mountpoint)) { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "directory is not empty")); return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint)); } /* perform the mount */ rc = do_mount(zhp, mountpoint, mntopts, flags); if (rc) { /* * Generic errors are nasty, but there are just way too many * from mount(), and they're well-understood. We pick a few * common ones to improve upon. */ if (rc == EBUSY) { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "mountpoint or dataset is busy")); } else if (rc == EPERM) { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "Insufficient privileges")); } else if (rc == ENOTSUP) { int spa_version; VERIFY(zfs_spa_version(zhp, &spa_version) == 0); zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "Can't mount a version %llu " "file system on a version %d pool. Pool must be" " upgraded to mount this file system."), (u_longlong_t)zfs_prop_get_int(zhp, ZFS_PROP_VERSION), spa_version); } else { zfs_error_aux(hdl, "%s", strerror(rc)); } return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), zhp->zfs_name)); } /* remove the mounted entry before re-adding on remount */ if (remount) libzfs_mnttab_remove(hdl, zhp->zfs_name); /* add the mounted entry into our cache */ libzfs_mnttab_add(hdl, zfs_get_name(zhp), mountpoint, mntopts); return (0); } /* * Unmount a single filesystem. */ static int unmount_one(zfs_handle_t *zhp, const char *mountpoint, int flags) { int error; error = do_unmount(zhp, mountpoint, flags); if (error != 0) { int libzfs_err; switch (error) { case EBUSY: libzfs_err = EZFS_BUSY; break; case EIO: libzfs_err = EZFS_IO; break; case ENOENT: libzfs_err = EZFS_NOENT; break; case ENOMEM: libzfs_err = EZFS_NOMEM; break; case EPERM: libzfs_err = EZFS_PERM; break; default: libzfs_err = EZFS_UMOUNTFAILED; } if (zhp) { return (zfs_error_fmt(zhp->zfs_hdl, libzfs_err, dgettext(TEXT_DOMAIN, "cannot unmount '%s'"), mountpoint)); } else { return (-1); } } return (0); } /* * Unmount the given filesystem. */ int zfs_unmount(zfs_handle_t *zhp, const char *mountpoint, int flags) { libzfs_handle_t *hdl = zhp->zfs_hdl; struct mnttab entry; char *mntpt = NULL; boolean_t encroot, unmounted = B_FALSE; /* check to see if we need to unmount the filesystem */ if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) && libzfs_mnttab_find(hdl, zhp->zfs_name, &entry) == 0)) { /* * mountpoint may have come from a call to * getmnt/getmntany if it isn't NULL. If it is NULL, * we know it comes from libzfs_mnttab_find which can * then get freed later. We strdup it to play it safe. */ if (mountpoint == NULL) mntpt = zfs_strdup(hdl, entry.mnt_mountp); else mntpt = zfs_strdup(hdl, mountpoint); /* * Unshare and unmount the filesystem */ if (zfs_unshare(zhp, mntpt, share_all_proto) != 0) { free(mntpt); return (-1); } zfs_commit_shares(NULL); if (unmount_one(zhp, mntpt, flags) != 0) { free(mntpt); (void) zfs_share(zhp, NULL); zfs_commit_shares(NULL); return (-1); } libzfs_mnttab_remove(hdl, zhp->zfs_name); free(mntpt); unmounted = B_TRUE; } /* * If the MS_CRYPT flag is provided we must ensure we attempt to * unload the dataset's key regardless of whether we did any work * to unmount it. We only do this for encryption roots. */ if ((flags & MS_CRYPT) != 0 && zfs_prop_get_int(zhp, ZFS_PROP_ENCRYPTION) != ZIO_CRYPT_OFF) { zfs_refresh_properties(zhp); if (zfs_crypto_get_encryption_root(zhp, &encroot, NULL) != 0 && unmounted) { (void) zfs_mount(zhp, NULL, 0); return (-1); } if (encroot && zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS) == ZFS_KEYSTATUS_AVAILABLE && zfs_crypto_unload_key(zhp) != 0) { (void) zfs_mount(zhp, NULL, 0); return (-1); } } zpool_disable_volume_os(zhp->zfs_name); return (0); } /* * Unmount this filesystem and any children inheriting the mountpoint property. * To do this, just act like we're changing the mountpoint property, but don't * remount the filesystems afterwards. */ int zfs_unmountall(zfs_handle_t *zhp, int flags) { prop_changelist_t *clp; int ret; clp = changelist_gather(zhp, ZFS_PROP_MOUNTPOINT, CL_GATHER_ITER_MOUNTED, flags); if (clp == NULL) return (-1); ret = changelist_prefix(clp); changelist_free(clp); return (ret); } /* * Unshare a filesystem by mountpoint. */ static int unshare_one(libzfs_handle_t *hdl, const char *name, const char *mountpoint, enum sa_protocol proto) { int err = sa_disable_share(mountpoint, proto); if (err != SA_OK) return (zfs_error_fmt(hdl, proto_table[proto].p_unshare_err, dgettext(TEXT_DOMAIN, "cannot unshare '%s': %s"), name, sa_errorstr(err))); return (0); } /* * Share the given filesystem according to the options in the specified * protocol specific properties (sharenfs, sharesmb). We rely * on "libshare" to do the dirty work for us. */ int zfs_share(zfs_handle_t *zhp, const enum sa_protocol *proto) { char mountpoint[ZFS_MAXPROPLEN]; char shareopts[ZFS_MAXPROPLEN]; char sourcestr[ZFS_MAXPROPLEN]; const enum sa_protocol *curr_proto; zprop_source_t sourcetype; int err = 0; if (proto == NULL) proto = share_all_proto; if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL, 0)) return (0); for (curr_proto = proto; *curr_proto != SA_NO_PROTOCOL; curr_proto++) { /* * Return success if there are no share options. */ if (zfs_prop_get(zhp, proto_table[*curr_proto].p_prop, shareopts, sizeof (shareopts), &sourcetype, sourcestr, ZFS_MAXPROPLEN, B_FALSE) != 0 || strcmp(shareopts, "off") == 0) continue; /* * If the 'zoned' property is set, then zfs_is_mountable() * will have already bailed out if we are in the global zone. * But local zones cannot be NFS servers, so we ignore it for * local zones as well. */ if (zfs_prop_get_int(zhp, ZFS_PROP_ZONED)) continue; err = sa_enable_share(zfs_get_name(zhp), mountpoint, shareopts, *curr_proto); if (err != SA_OK) { return (zfs_error_fmt(zhp->zfs_hdl, proto_table[*curr_proto].p_share_err, dgettext(TEXT_DOMAIN, "cannot share '%s: %s'"), zfs_get_name(zhp), sa_errorstr(err))); } } return (0); } /* * Check to see if the filesystem is currently shared. */ boolean_t zfs_is_shared(zfs_handle_t *zhp, char **where, const enum sa_protocol *proto) { char *mountpoint; if (proto == NULL) proto = share_all_proto; if (ZFS_IS_VOLUME(zhp)) return (B_FALSE); if (!zfs_is_mounted(zhp, &mountpoint)) return (B_FALSE); for (const enum sa_protocol *p = proto; *p != SA_NO_PROTOCOL; ++p) if (sa_is_shared(mountpoint, *p)) { if (where != NULL) *where = mountpoint; else free(mountpoint); return (B_TRUE); } free(mountpoint); return (B_FALSE); } void zfs_commit_shares(const enum sa_protocol *proto) { if (proto == NULL) proto = share_all_proto; for (const enum sa_protocol *p = proto; *p != SA_NO_PROTOCOL; ++p) sa_commit_shares(*p); } void zfs_truncate_shares(const enum sa_protocol *proto) { if (proto == NULL) proto = share_all_proto; for (const enum sa_protocol *p = proto; *p != SA_NO_PROTOCOL; ++p) sa_truncate_shares(*p); } /* * Unshare the given filesystem. */ int zfs_unshare(zfs_handle_t *zhp, const char *mountpoint, const enum sa_protocol *proto) { libzfs_handle_t *hdl = zhp->zfs_hdl; struct mnttab entry; if (proto == NULL) proto = share_all_proto; if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) && libzfs_mnttab_find(hdl, zfs_get_name(zhp), &entry) == 0)) { /* check to see if need to unmount the filesystem */ const char *mntpt = mountpoint ?: entry.mnt_mountp; for (const enum sa_protocol *curr_proto = proto; *curr_proto != SA_NO_PROTOCOL; curr_proto++) if (sa_is_shared(mntpt, *curr_proto) && unshare_one(hdl, zhp->zfs_name, mntpt, *curr_proto) != 0) return (-1); } return (0); } /* * Same as zfs_unmountall(), but for NFS and SMB unshares. */ int zfs_unshareall(zfs_handle_t *zhp, const enum sa_protocol *proto) { prop_changelist_t *clp; int ret; if (proto == NULL) proto = share_all_proto; clp = changelist_gather(zhp, ZFS_PROP_SHARENFS, 0, 0); if (clp == NULL) return (-1); ret = changelist_unshare(clp, proto); changelist_free(clp); return (ret); } /* * Remove the mountpoint associated with the current dataset, if necessary. * We only remove the underlying directory if: * * - The mountpoint is not 'none' or 'legacy' * - The mountpoint is non-empty * - The mountpoint is the default or inherited * - The 'zoned' property is set, or we're in a local zone * * Any other directories we leave alone. */ void remove_mountpoint(zfs_handle_t *zhp) { char mountpoint[ZFS_MAXPROPLEN]; zprop_source_t source; if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), &source, 0)) return; if (source == ZPROP_SRC_DEFAULT || source == ZPROP_SRC_INHERITED) { /* * Try to remove the directory, silently ignoring any errors. * The filesystem may have since been removed or moved around, * and this error isn't really useful to the administrator in * any way. */ (void) rmdir(mountpoint); } } /* * Add the given zfs handle to the cb_handles array, dynamically reallocating * the array if it is out of space. */ void libzfs_add_handle(get_all_cb_t *cbp, zfs_handle_t *zhp) { if (cbp->cb_alloc == cbp->cb_used) { size_t newsz; zfs_handle_t **newhandles; newsz = cbp->cb_alloc != 0 ? cbp->cb_alloc * 2 : 64; newhandles = zfs_realloc(zhp->zfs_hdl, cbp->cb_handles, cbp->cb_alloc * sizeof (zfs_handle_t *), newsz * sizeof (zfs_handle_t *)); cbp->cb_handles = newhandles; cbp->cb_alloc = newsz; } cbp->cb_handles[cbp->cb_used++] = zhp; } /* * Recursive helper function used during file system enumeration */ static int zfs_iter_cb(zfs_handle_t *zhp, void *data) { get_all_cb_t *cbp = data; if (!(zfs_get_type(zhp) & ZFS_TYPE_FILESYSTEM)) { zfs_close(zhp); return (0); } if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_NOAUTO) { zfs_close(zhp); return (0); } if (zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS) == ZFS_KEYSTATUS_UNAVAILABLE) { zfs_close(zhp); return (0); } /* * If this filesystem is inconsistent and has a receive resume * token, we can not mount it. */ if (zfs_prop_get_int(zhp, ZFS_PROP_INCONSISTENT) && zfs_prop_get(zhp, ZFS_PROP_RECEIVE_RESUME_TOKEN, NULL, 0, NULL, NULL, 0, B_TRUE) == 0) { zfs_close(zhp); return (0); } libzfs_add_handle(cbp, zhp); if (zfs_iter_filesystems(zhp, 0, zfs_iter_cb, cbp) != 0) { zfs_close(zhp); return (-1); } return (0); } /* * Sort comparator that compares two mountpoint paths. We sort these paths so * that subdirectories immediately follow their parents. This means that we * effectively treat the '/' character as the lowest value non-nul char. * Since filesystems from non-global zones can have the same mountpoint * as other filesystems, the comparator sorts global zone filesystems to * the top of the list. This means that the global zone will traverse the * filesystem list in the correct order and can stop when it sees the * first zoned filesystem. In a non-global zone, only the delegated * filesystems are seen. * * An example sorted list using this comparator would look like: * * /foo * /foo/bar * /foo/bar/baz * /foo/baz * /foo.bar * /foo (NGZ1) * /foo (NGZ2) * * The mounting code depends on this ordering to deterministically iterate * over filesystems in order to spawn parallel mount tasks. */ static int mountpoint_cmp(const void *arga, const void *argb) { zfs_handle_t *const *zap = arga; zfs_handle_t *za = *zap; zfs_handle_t *const *zbp = argb; zfs_handle_t *zb = *zbp; char mounta[MAXPATHLEN]; char mountb[MAXPATHLEN]; const char *a = mounta; const char *b = mountb; boolean_t gota, gotb; uint64_t zoneda, zonedb; zoneda = zfs_prop_get_int(za, ZFS_PROP_ZONED); zonedb = zfs_prop_get_int(zb, ZFS_PROP_ZONED); if (zoneda && !zonedb) return (1); if (!zoneda && zonedb) return (-1); gota = (zfs_get_type(za) == ZFS_TYPE_FILESYSTEM); if (gota) { verify(zfs_prop_get(za, ZFS_PROP_MOUNTPOINT, mounta, sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0); } gotb = (zfs_get_type(zb) == ZFS_TYPE_FILESYSTEM); if (gotb) { verify(zfs_prop_get(zb, ZFS_PROP_MOUNTPOINT, mountb, sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0); } if (gota && gotb) { while (*a != '\0' && (*a == *b)) { a++; b++; } if (*a == *b) return (0); if (*a == '\0') return (-1); if (*b == '\0') return (1); if (*a == '/') return (-1); if (*b == '/') return (1); return (*a < *b ? -1 : *a > *b); } if (gota) return (-1); if (gotb) return (1); /* * If neither filesystem has a mountpoint, revert to sorting by * dataset name. */ return (strcmp(zfs_get_name(za), zfs_get_name(zb))); } /* * Return true if path2 is a child of path1 or path2 equals path1 or * path1 is "/" (path2 is always a child of "/"). */ static boolean_t libzfs_path_contains(const char *path1, const char *path2) { return (strcmp(path1, path2) == 0 || strcmp(path1, "/") == 0 || (strstr(path2, path1) == path2 && path2[strlen(path1)] == '/')); } /* * Given a mountpoint specified by idx in the handles array, find the first * non-descendent of that mountpoint and return its index. Descendant paths * start with the parent's path. This function relies on the ordering * enforced by mountpoint_cmp(). */ static int non_descendant_idx(zfs_handle_t **handles, size_t num_handles, int idx) { char parent[ZFS_MAXPROPLEN]; char child[ZFS_MAXPROPLEN]; int i; verify(zfs_prop_get(handles[idx], ZFS_PROP_MOUNTPOINT, parent, sizeof (parent), NULL, NULL, 0, B_FALSE) == 0); for (i = idx + 1; i < num_handles; i++) { verify(zfs_prop_get(handles[i], ZFS_PROP_MOUNTPOINT, child, sizeof (child), NULL, NULL, 0, B_FALSE) == 0); if (!libzfs_path_contains(parent, child)) break; } return (i); } typedef struct mnt_param { libzfs_handle_t *mnt_hdl; tpool_t *mnt_tp; zfs_handle_t **mnt_zhps; /* filesystems to mount */ size_t mnt_num_handles; int mnt_idx; /* Index of selected entry to mount */ zfs_iter_f mnt_func; void *mnt_data; } mnt_param_t; /* * Allocate and populate the parameter struct for mount function, and * schedule mounting of the entry selected by idx. */ static void zfs_dispatch_mount(libzfs_handle_t *hdl, zfs_handle_t **handles, size_t num_handles, int idx, zfs_iter_f func, void *data, tpool_t *tp) { mnt_param_t *mnt_param = zfs_alloc(hdl, sizeof (mnt_param_t)); mnt_param->mnt_hdl = hdl; mnt_param->mnt_tp = tp; mnt_param->mnt_zhps = handles; mnt_param->mnt_num_handles = num_handles; mnt_param->mnt_idx = idx; mnt_param->mnt_func = func; mnt_param->mnt_data = data; (void) tpool_dispatch(tp, zfs_mount_task, (void*)mnt_param); } /* * This is the structure used to keep state of mounting or sharing operations * during a call to zpool_enable_datasets(). */ typedef struct mount_state { /* * ms_mntstatus is set to -1 if any mount fails. While multiple threads * could update this variable concurrently, no synchronization is * needed as it's only ever set to -1. */ int ms_mntstatus; int ms_mntflags; const char *ms_mntopts; } mount_state_t; static int zfs_mount_one(zfs_handle_t *zhp, void *arg) { mount_state_t *ms = arg; int ret = 0; /* * don't attempt to mount encrypted datasets with * unloaded keys */ if (zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS) == ZFS_KEYSTATUS_UNAVAILABLE) return (0); if (zfs_mount(zhp, ms->ms_mntopts, ms->ms_mntflags) != 0) ret = ms->ms_mntstatus = -1; return (ret); } static int zfs_share_one(zfs_handle_t *zhp, void *arg) { mount_state_t *ms = arg; int ret = 0; if (zfs_share(zhp, NULL) != 0) ret = ms->ms_mntstatus = -1; return (ret); } /* * Thread pool function to mount one file system. On completion, it finds and * schedules its children to be mounted. This depends on the sorting done in * zfs_foreach_mountpoint(). Note that the degenerate case (chain of entries * each descending from the previous) will have no parallelism since we always * have to wait for the parent to finish mounting before we can schedule * its children. */ static void zfs_mount_task(void *arg) { mnt_param_t *mp = arg; int idx = mp->mnt_idx; zfs_handle_t **handles = mp->mnt_zhps; size_t num_handles = mp->mnt_num_handles; char mountpoint[ZFS_MAXPROPLEN]; verify(zfs_prop_get(handles[idx], ZFS_PROP_MOUNTPOINT, mountpoint, sizeof (mountpoint), NULL, NULL, 0, B_FALSE) == 0); if (mp->mnt_func(handles[idx], mp->mnt_data) != 0) goto out; /* * We dispatch tasks to mount filesystems with mountpoints underneath * this one. We do this by dispatching the next filesystem with a * descendant mountpoint of the one we just mounted, then skip all of * its descendants, dispatch the next descendant mountpoint, and so on. * The non_descendant_idx() function skips over filesystems that are * descendants of the filesystem we just dispatched. */ for (int i = idx + 1; i < num_handles; i = non_descendant_idx(handles, num_handles, i)) { char child[ZFS_MAXPROPLEN]; verify(zfs_prop_get(handles[i], ZFS_PROP_MOUNTPOINT, child, sizeof (child), NULL, NULL, 0, B_FALSE) == 0); if (!libzfs_path_contains(mountpoint, child)) break; /* not a descendant, return */ zfs_dispatch_mount(mp->mnt_hdl, handles, num_handles, i, mp->mnt_func, mp->mnt_data, mp->mnt_tp); } out: free(mp); } /* * Issue the func callback for each ZFS handle contained in the handles * array. This function is used to mount all datasets, and so this function * guarantees that filesystems for parent mountpoints are called before their * children. As such, before issuing any callbacks, we first sort the array * of handles by mountpoint. * * Callbacks are issued in one of two ways: * * 1. Sequentially: If the parallel argument is B_FALSE or the ZFS_SERIAL_MOUNT * environment variable is set, then we issue callbacks sequentially. * * 2. In parallel: If the parallel argument is B_TRUE and the ZFS_SERIAL_MOUNT * environment variable is not set, then we use a tpool to dispatch threads * to mount filesystems in parallel. This function dispatches tasks to mount * the filesystems at the top-level mountpoints, and these tasks in turn * are responsible for recursively mounting filesystems in their children * mountpoints. */ void zfs_foreach_mountpoint(libzfs_handle_t *hdl, zfs_handle_t **handles, size_t num_handles, zfs_iter_f func, void *data, boolean_t parallel) { zoneid_t zoneid = getzoneid(); /* * The ZFS_SERIAL_MOUNT environment variable is an undocumented * variable that can be used as a convenience to do a/b comparison * of serial vs. parallel mounting. */ boolean_t serial_mount = !parallel || (getenv("ZFS_SERIAL_MOUNT") != NULL); /* * Sort the datasets by mountpoint. See mountpoint_cmp for details * of how these are sorted. */ qsort(handles, num_handles, sizeof (zfs_handle_t *), mountpoint_cmp); if (serial_mount) { for (int i = 0; i < num_handles; i++) { func(handles[i], data); } return; } /* * Issue the callback function for each dataset using a parallel * algorithm that uses a thread pool to manage threads. */ tpool_t *tp = tpool_create(1, mount_tp_nthr, 0, NULL); /* * There may be multiple "top level" mountpoints outside of the pool's * root mountpoint, e.g.: /foo /bar. Dispatch a mount task for each of * these. */ for (int i = 0; i < num_handles; i = non_descendant_idx(handles, num_handles, i)) { /* * Since the mountpoints have been sorted so that the zoned * filesystems are at the end, a zoned filesystem seen from * the global zone means that we're done. */ if (zoneid == GLOBAL_ZONEID && zfs_prop_get_int(handles[i], ZFS_PROP_ZONED)) break; zfs_dispatch_mount(hdl, handles, num_handles, i, func, data, tp); } tpool_wait(tp); /* wait for all scheduled mounts to complete */ tpool_destroy(tp); } /* * Mount and share all datasets within the given pool. This assumes that no * datasets within the pool are currently mounted. */ int zpool_enable_datasets(zpool_handle_t *zhp, const char *mntopts, int flags) { get_all_cb_t cb = { 0 }; mount_state_t ms = { 0 }; zfs_handle_t *zfsp; int ret = 0; if ((zfsp = zfs_open(zhp->zpool_hdl, zhp->zpool_name, ZFS_TYPE_DATASET)) == NULL) goto out; /* * Gather all non-snapshot datasets within the pool. Start by adding * the root filesystem for this pool to the list, and then iterate * over all child filesystems. */ libzfs_add_handle(&cb, zfsp); if (zfs_iter_filesystems(zfsp, 0, zfs_iter_cb, &cb) != 0) goto out; /* * Mount all filesystems */ ms.ms_mntopts = mntopts; ms.ms_mntflags = flags; zfs_foreach_mountpoint(zhp->zpool_hdl, cb.cb_handles, cb.cb_used, zfs_mount_one, &ms, B_TRUE); if (ms.ms_mntstatus != 0) ret = ms.ms_mntstatus; /* * Share all filesystems that need to be shared. This needs to be * a separate pass because libshare is not mt-safe, and so we need * to share serially. */ ms.ms_mntstatus = 0; zfs_foreach_mountpoint(zhp->zpool_hdl, cb.cb_handles, cb.cb_used, zfs_share_one, &ms, B_FALSE); if (ms.ms_mntstatus != 0) ret = ms.ms_mntstatus; else zfs_commit_shares(NULL); out: for (int i = 0; i < cb.cb_used; i++) zfs_close(cb.cb_handles[i]); free(cb.cb_handles); return (ret); } struct sets_s { char *mountpoint; zfs_handle_t *dataset; }; static int mountpoint_compare(const void *a, const void *b) { const struct sets_s *mounta = (struct sets_s *)a; const struct sets_s *mountb = (struct sets_s *)b; return (strcmp(mountb->mountpoint, mounta->mountpoint)); } /* * Unshare and unmount all datasets within the given pool. We don't want to * rely on traversing the DSL to discover the filesystems within the pool, * because this may be expensive (if not all of them are mounted), and can fail * arbitrarily (on I/O error, for example). Instead, we walk /proc/self/mounts * and gather all the filesystems that are currently mounted. */ int zpool_disable_datasets(zpool_handle_t *zhp, boolean_t force) { int used, alloc; FILE *mnttab; struct mnttab entry; size_t namelen; struct sets_s *sets = NULL; libzfs_handle_t *hdl = zhp->zpool_hdl; int i; int ret = -1; int flags = (force ? MS_FORCE : 0); namelen = strlen(zhp->zpool_name); if ((mnttab = fopen(MNTTAB, "re")) == NULL) return (ENOENT); used = alloc = 0; while (getmntent(mnttab, &entry) == 0) { /* * Ignore non-ZFS entries. */ if (entry.mnt_fstype == NULL || strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0) continue; /* * Ignore filesystems not within this pool. */ if (entry.mnt_mountp == NULL || strncmp(entry.mnt_special, zhp->zpool_name, namelen) != 0 || (entry.mnt_special[namelen] != '/' && entry.mnt_special[namelen] != '\0')) continue; /* * At this point we've found a filesystem within our pool. Add * it to our growing list. */ if (used == alloc) { if (alloc == 0) { sets = zfs_alloc(hdl, 8 * sizeof (struct sets_s)); alloc = 8; } else { sets = zfs_realloc(hdl, sets, alloc * sizeof (struct sets_s), alloc * 2 * sizeof (struct sets_s)); alloc *= 2; } } sets[used].mountpoint = zfs_strdup(hdl, entry.mnt_mountp); /* * This is allowed to fail, in case there is some I/O error. It * is only used to determine if we need to remove the underlying * mountpoint, so failure is not fatal. */ sets[used].dataset = make_dataset_handle(hdl, entry.mnt_special); used++; } /* * At this point, we have the entire list of filesystems, so sort it by * mountpoint. */ if (used != 0) qsort(sets, used, sizeof (struct sets_s), mountpoint_compare); /* * Walk through and first unshare everything. */ for (i = 0; i < used; i++) { for (enum sa_protocol p = 0; p < SA_PROTOCOL_COUNT; ++p) { if (sa_is_shared(sets[i].mountpoint, p) && unshare_one(hdl, sets[i].mountpoint, sets[i].mountpoint, p) != 0) goto out; } } zfs_commit_shares(NULL); /* * Now unmount everything, removing the underlying directories as * appropriate. */ for (i = 0; i < used; i++) { if (unmount_one(sets[i].dataset, sets[i].mountpoint, flags) != 0) goto out; } for (i = 0; i < used; i++) { if (sets[i].dataset) remove_mountpoint(sets[i].dataset); } zpool_disable_datasets_os(zhp, force); ret = 0; out: (void) fclose(mnttab); for (i = 0; i < used; i++) { if (sets[i].dataset) zfs_close(sets[i].dataset); free(sets[i].mountpoint); } free(sets); return (ret); }