/* * 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, 2017 by Delphix. All rights reserved. * Copyright 2016 Igor Kozhukhov * Copyright 2017 RackTop Systems. * Copyright (c) 2018 Datto Inc. */ /* * 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_unmount() * zfs_unmountall() * * This file also contains the functions used to manage sharing filesystems via * NFS and iSCSI: * * zfs_is_shared() * zfs_share() * zfs_unshare() * * zfs_is_shared_nfs() * zfs_is_shared_smb() * zfs_share_proto() * zfs_shareall(); * zfs_unshare_nfs() * zfs_unshare_smb() * zfs_unshareall_nfs() * zfs_unshareall_smb() * zfs_unshareall() * zfs_unshareall_bypath() * * 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 int zfs_share_proto(zfs_handle_t *, zfs_share_proto_t *); zfs_share_type_t zfs_is_shared_proto(zfs_handle_t *, char **, zfs_share_proto_t); /* * The share protocols table must be in the same order as the zfs_share_proto_t * enum in libzfs_impl.h */ typedef struct { zfs_prop_t p_prop; char *p_name; int p_share_err; int p_unshare_err; } proto_table_t; proto_table_t proto_table[PROTO_END] = { {ZFS_PROP_SHARENFS, "nfs", EZFS_SHARENFSFAILED, EZFS_UNSHARENFSFAILED}, {ZFS_PROP_SHARESMB, "smb", EZFS_SHARESMBFAILED, EZFS_UNSHARESMBFAILED}, }; zfs_share_proto_t nfs_only[] = { PROTO_NFS, PROTO_END }; zfs_share_proto_t smb_only[] = { PROTO_SMB, PROTO_END }; zfs_share_proto_t share_all_proto[] = { PROTO_NFS, PROTO_SMB, PROTO_END }; /* * Search the sharetab for the given mountpoint and protocol, returning * a zfs_share_type_t value. */ static zfs_share_type_t is_shared(libzfs_handle_t *hdl, const char *mountpoint, zfs_share_proto_t proto) { char buf[MAXPATHLEN], *tab; char *ptr; if (hdl->libzfs_sharetab == NULL) return (SHARED_NOT_SHARED); /* Reopen ZFS_SHARETAB to prevent reading stale data from open file */ if (freopen(ZFS_SHARETAB, "r", hdl->libzfs_sharetab) == NULL) return (SHARED_NOT_SHARED); (void) fseek(hdl->libzfs_sharetab, 0, SEEK_SET); while (fgets(buf, sizeof (buf), hdl->libzfs_sharetab) != NULL) { /* the mountpoint is the first entry on each line */ if ((tab = strchr(buf, '\t')) == NULL) continue; *tab = '\0'; if (strcmp(buf, mountpoint) == 0) { /* * the protocol field is the third field * skip over second field */ ptr = ++tab; if ((tab = strchr(ptr, '\t')) == NULL) continue; ptr = ++tab; if ((tab = strchr(ptr, '\t')) == NULL) continue; *tab = '\0'; if (strcmp(ptr, proto_table[proto].p_name) == 0) { switch (proto) { case PROTO_NFS: return (SHARED_NFS); case PROTO_SMB: return (SHARED_SMB); default: return (0); } } } } return (SHARED_NOT_SHARED); } 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)); } /* * 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) { 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_prop_get_int(zhp, ZFS_PROP_ZONED) && getzoneid() == GLOBAL_ZONEID) 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 do_mount(const char *src, const char *mntpt, char *opts) { char *argv[9] = { "/bin/mount", "--no-canonicalize", "-t", MNTTYPE_ZFS, "-o", opts, (char *)src, (char *)mntpt, (char *)NULL }; int rc; /* Return only the most critical mount error */ rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE); if (rc) { if (rc & MOUNT_FILEIO) return (EIO); if (rc & MOUNT_USER) return (EINTR); if (rc & MOUNT_SOFTWARE) return (EPIPE); if (rc & MOUNT_BUSY) return (EBUSY); if (rc & MOUNT_SYSERR) return (EAGAIN); if (rc & MOUNT_USAGE) return (EINVAL); return (ENXIO); /* Generic error */ } return (0); } static int do_unmount(const char *mntpt, int 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); } static int zfs_add_option(zfs_handle_t *zhp, char *options, int len, zfs_prop_t prop, char *on, char *off) { 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); } /* * Mount the given filesystem. */ int zfs_mount(zfs_handle_t *zhp, const char *options, int flags) { struct stat buf; char mountpoint[ZFS_MAXPROPLEN]; char mntopts[MNT_LINE_MAX]; char overlay[ZFS_MAXPROPLEN]; 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; /* * 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)); if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL)) return (0); /* * 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_load_key(zhp, B_FALSE, NULL); 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")); return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint)); } } /* * Overlay mounts are disabled by default but may be enabled * via the 'overlay' property or the 'zfs mount -O' option. */ 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(zfs_get_name(zhp), mountpoint, mntopts); 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) { char buf[256]; int spa_version; VERIFY(zfs_spa_version(zhp, &spa_version) == 0); (void) snprintf(buf, sizeof (buf), dgettext(TEXT_DOMAIN, "Can't mount a version %lld " "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); zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, buf)); } else { zfs_error_aux(hdl, 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(libzfs_handle_t *hdl, const char *mountpoint, int flags) { int error; error = do_unmount(mountpoint, flags); if (error != 0) { return (zfs_error_fmt(hdl, EZFS_UMOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot unmount '%s'"), mountpoint)); } 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; /* 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_proto(zhp, mntpt, share_all_proto) != 0) { free(mntpt); return (-1); } if (unmount_one(hdl, mntpt, flags) != 0) { free(mntpt); (void) zfs_shareall(zhp); return (-1); } libzfs_mnttab_remove(hdl, zhp->zfs_name); free(mntpt); } 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, 0); if (clp == NULL) return (-1); ret = changelist_prefix(clp); changelist_free(clp); return (ret); } boolean_t zfs_is_shared(zfs_handle_t *zhp) { zfs_share_type_t rc = 0; zfs_share_proto_t *curr_proto; if (ZFS_IS_VOLUME(zhp)) return (B_FALSE); for (curr_proto = share_all_proto; *curr_proto != PROTO_END; curr_proto++) rc |= zfs_is_shared_proto(zhp, NULL, *curr_proto); return (rc ? B_TRUE : B_FALSE); } int zfs_share(zfs_handle_t *zhp) { assert(!ZFS_IS_VOLUME(zhp)); return (zfs_share_proto(zhp, share_all_proto)); } int zfs_unshare(zfs_handle_t *zhp) { assert(!ZFS_IS_VOLUME(zhp)); return (zfs_unshareall(zhp)); } /* * Check to see if the filesystem is currently shared. */ zfs_share_type_t zfs_is_shared_proto(zfs_handle_t *zhp, char **where, zfs_share_proto_t proto) { char *mountpoint; zfs_share_type_t rc; if (!zfs_is_mounted(zhp, &mountpoint)) return (SHARED_NOT_SHARED); if ((rc = is_shared(zhp->zfs_hdl, mountpoint, proto)) != SHARED_NOT_SHARED) { if (where != NULL) *where = mountpoint; else free(mountpoint); return (rc); } else { free(mountpoint); return (SHARED_NOT_SHARED); } } boolean_t zfs_is_shared_nfs(zfs_handle_t *zhp, char **where) { return (zfs_is_shared_proto(zhp, where, PROTO_NFS) != SHARED_NOT_SHARED); } boolean_t zfs_is_shared_smb(zfs_handle_t *zhp, char **where) { return (zfs_is_shared_proto(zhp, where, PROTO_SMB) != SHARED_NOT_SHARED); } /* * zfs_init_libshare(zhandle, service) * * Initialize the libshare API if it hasn't already been initialized. * In all cases it returns 0 if it succeeded and an error if not. The * service value is which part(s) of the API to initialize and is a * direct map to the libshare sa_init(service) interface. */ int zfs_init_libshare(libzfs_handle_t *zhandle, int service) { int ret = SA_OK; if (ret == SA_OK && zhandle->libzfs_shareflags & ZFSSHARE_MISS) { /* * We had a cache miss. Most likely it is a new ZFS * dataset that was just created. We want to make sure * so check timestamps to see if a different process * has updated any of the configuration. If there was * some non-ZFS change, we need to re-initialize the * internal cache. */ zhandle->libzfs_shareflags &= ~ZFSSHARE_MISS; if (sa_needs_refresh(zhandle->libzfs_sharehdl)) { zfs_uninit_libshare(zhandle); zhandle->libzfs_sharehdl = sa_init(service); } } if (ret == SA_OK && zhandle && zhandle->libzfs_sharehdl == NULL) zhandle->libzfs_sharehdl = sa_init(service); if (ret == SA_OK && zhandle->libzfs_sharehdl == NULL) ret = SA_NO_MEMORY; return (ret); } /* * zfs_uninit_libshare(zhandle) * * Uninitialize the libshare API if it hasn't already been * uninitialized. It is OK to call multiple times. */ void zfs_uninit_libshare(libzfs_handle_t *zhandle) { if (zhandle != NULL && zhandle->libzfs_sharehdl != NULL) { sa_fini(zhandle->libzfs_sharehdl); zhandle->libzfs_sharehdl = NULL; } } /* * zfs_parse_options(options, proto) * * Call the legacy parse interface to get the protocol specific * options using the NULL arg to indicate that this is a "parse" only. */ int zfs_parse_options(char *options, zfs_share_proto_t proto) { return (sa_parse_legacy_options(NULL, options, proto_table[proto].p_name)); } /* * 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. */ static int zfs_share_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto) { char mountpoint[ZFS_MAXPROPLEN]; char shareopts[ZFS_MAXPROPLEN]; char sourcestr[ZFS_MAXPROPLEN]; libzfs_handle_t *hdl = zhp->zfs_hdl; sa_share_t share; zfs_share_proto_t *curr_proto; zprop_source_t sourcetype; int ret; if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL)) return (0); for (curr_proto = proto; *curr_proto != PROTO_END; 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; ret = zfs_init_libshare(hdl, SA_INIT_SHARE_API); if (ret != SA_OK) { (void) zfs_error_fmt(hdl, EZFS_SHARENFSFAILED, dgettext(TEXT_DOMAIN, "cannot share '%s': %s"), zfs_get_name(zhp), sa_errorstr(ret)); return (-1); } /* * 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; share = sa_find_share(hdl->libzfs_sharehdl, mountpoint); if (share == NULL) { /* * This may be a new file system that was just * created so isn't in the internal cache * (second time through). Rather than * reloading the entire configuration, we can * assume ZFS has done the checking and it is * safe to add this to the internal * configuration. */ if (sa_zfs_process_share(hdl->libzfs_sharehdl, NULL, NULL, mountpoint, proto_table[*curr_proto].p_name, sourcetype, shareopts, sourcestr, zhp->zfs_name) != SA_OK) { (void) zfs_error_fmt(hdl, proto_table[*curr_proto].p_share_err, dgettext(TEXT_DOMAIN, "cannot share '%s'"), zfs_get_name(zhp)); return (-1); } hdl->libzfs_shareflags |= ZFSSHARE_MISS; share = sa_find_share(hdl->libzfs_sharehdl, mountpoint); } if (share != NULL) { int err; err = sa_enable_share(share, proto_table[*curr_proto].p_name); if (err != SA_OK) { (void) zfs_error_fmt(hdl, proto_table[*curr_proto].p_share_err, dgettext(TEXT_DOMAIN, "cannot share '%s'"), zfs_get_name(zhp)); return (-1); } } else { (void) zfs_error_fmt(hdl, proto_table[*curr_proto].p_share_err, dgettext(TEXT_DOMAIN, "cannot share '%s'"), zfs_get_name(zhp)); return (-1); } } return (0); } int zfs_share_nfs(zfs_handle_t *zhp) { return (zfs_share_proto(zhp, nfs_only)); } int zfs_share_smb(zfs_handle_t *zhp) { return (zfs_share_proto(zhp, smb_only)); } int zfs_shareall(zfs_handle_t *zhp) { return (zfs_share_proto(zhp, share_all_proto)); } /* * Unshare a filesystem by mountpoint. */ static int unshare_one(libzfs_handle_t *hdl, const char *name, const char *mountpoint, zfs_share_proto_t proto) { sa_share_t share; int err; char *mntpt; /* * Mountpoint could get trashed if libshare calls getmntany * which it does during API initialization, so strdup the * value. */ mntpt = zfs_strdup(hdl, mountpoint); /* make sure libshare initialized */ if ((err = zfs_init_libshare(hdl, SA_INIT_SHARE_API)) != SA_OK) { free(mntpt); /* don't need the copy anymore */ return (zfs_error_fmt(hdl, proto_table[proto].p_unshare_err, dgettext(TEXT_DOMAIN, "cannot unshare '%s': %s"), name, sa_errorstr(err))); } share = sa_find_share(hdl->libzfs_sharehdl, mntpt); free(mntpt); /* don't need the copy anymore */ if (share != NULL) { err = sa_disable_share(share, proto_table[proto].p_name); 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))); } } else { return (zfs_error_fmt(hdl, proto_table[proto].p_unshare_err, dgettext(TEXT_DOMAIN, "cannot unshare '%s': not found"), name)); } return (0); } /* * Unshare the given filesystem. */ int zfs_unshare_proto(zfs_handle_t *zhp, const char *mountpoint, zfs_share_proto_t *proto) { libzfs_handle_t *hdl = zhp->zfs_hdl; struct mnttab entry; char *mntpt = NULL; /* check to see if need to unmount the filesystem */ if (mountpoint != NULL) mntpt = zfs_strdup(hdl, mountpoint); if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) && libzfs_mnttab_find(hdl, zfs_get_name(zhp), &entry) == 0)) { zfs_share_proto_t *curr_proto; if (mountpoint == NULL) mntpt = zfs_strdup(zhp->zfs_hdl, entry.mnt_mountp); for (curr_proto = proto; *curr_proto != PROTO_END; curr_proto++) { if (is_shared(hdl, mntpt, *curr_proto) && unshare_one(hdl, zhp->zfs_name, mntpt, *curr_proto) != 0) { if (mntpt != NULL) free(mntpt); return (-1); } } } if (mntpt != NULL) free(mntpt); return (0); } int zfs_unshare_nfs(zfs_handle_t *zhp, const char *mountpoint) { return (zfs_unshare_proto(zhp, mountpoint, nfs_only)); } int zfs_unshare_smb(zfs_handle_t *zhp, const char *mountpoint) { return (zfs_unshare_proto(zhp, mountpoint, smb_only)); } /* * Same as zfs_unmountall(), but for NFS and SMB unshares. */ int zfs_unshareall_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto) { prop_changelist_t *clp; int ret; clp = changelist_gather(zhp, ZFS_PROP_SHARENFS, 0, 0); if (clp == NULL) return (-1); ret = changelist_unshare(clp, proto); changelist_free(clp); return (ret); } int zfs_unshareall_nfs(zfs_handle_t *zhp) { return (zfs_unshareall_proto(zhp, nfs_only)); } int zfs_unshareall_smb(zfs_handle_t *zhp) { return (zfs_unshareall_proto(zhp, smb_only)); } int zfs_unshareall(zfs_handle_t *zhp) { return (zfs_unshareall_proto(zhp, share_all_proto)); } int zfs_unshareall_bypath(zfs_handle_t *zhp, const char *mountpoint) { return (zfs_unshare_proto(zhp, mountpoint, share_all_proto)); } int zfs_unshareall_bytype(zfs_handle_t *zhp, const char *mountpoint, const char *proto) { if (proto == NULL) return (zfs_unshare_proto(zhp, mountpoint, share_all_proto)); if (strcmp(proto, "nfs") == 0) return (zfs_unshare_proto(zhp, mountpoint, nfs_only)); else if (strcmp(proto, "smb") == 0) return (zfs_unshare_proto(zhp, mountpoint, smb_only)); else return (1); } /* * 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)) 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, 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. An * example sorted list using this comparator would look like: * * /foo * /foo/bar * /foo/bar/baz * /foo/baz * /foo.bar * * The mounting code depends on this ordering to deterministically iterate * over filesystems in order to spawn parallel mount tasks. */ 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; 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. */ static boolean_t libzfs_path_contains(const char *path1, const char *path2) { return (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) != 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) return; /* * 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); } 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) { /* * 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)) { 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. */ #pragma weak zpool_mount_datasets = zpool_enable_datasets 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, 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; out: for (int i = 0; i < cb.cb_used; i++) zfs_close(cb.cb_handles[i]); free(cb.cb_handles); return (ret); } static int mountpoint_compare(const void *a, const void *b) { const char *mounta = *((char **)a); const char *mountb = *((char **)b); return (strcmp(mountb, mounta)); } /* alias for 2002/240 */ #pragma weak zpool_unmount_datasets = zpool_disable_datasets /* * 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; struct mnttab entry; size_t namelen; char **mountpoints = NULL; zfs_handle_t **datasets = NULL; libzfs_handle_t *hdl = zhp->zpool_hdl; int i; int ret = -1; int flags = (force ? MS_FORCE : 0); namelen = strlen(zhp->zpool_name); /* Reopen MNTTAB to prevent reading stale data from open file */ if (freopen(MNTTAB, "r", hdl->libzfs_mnttab) == NULL) return (ENOENT); used = alloc = 0; while (getmntent(hdl->libzfs_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) { if ((mountpoints = zfs_alloc(hdl, 8 * sizeof (void *))) == NULL) goto out; if ((datasets = zfs_alloc(hdl, 8 * sizeof (void *))) == NULL) goto out; alloc = 8; } else { void *ptr; if ((ptr = zfs_realloc(hdl, mountpoints, alloc * sizeof (void *), alloc * 2 * sizeof (void *))) == NULL) goto out; mountpoints = ptr; if ((ptr = zfs_realloc(hdl, datasets, alloc * sizeof (void *), alloc * 2 * sizeof (void *))) == NULL) goto out; datasets = ptr; alloc *= 2; } } if ((mountpoints[used] = zfs_strdup(hdl, entry.mnt_mountp)) == NULL) goto out; /* * 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. */ datasets[used] = make_dataset_handle(hdl, entry.mnt_special); used++; } /* * At this point, we have the entire list of filesystems, so sort it by * mountpoint. */ qsort(mountpoints, used, sizeof (char *), mountpoint_compare); /* * Walk through and first unshare everything. */ for (i = 0; i < used; i++) { zfs_share_proto_t *curr_proto; for (curr_proto = share_all_proto; *curr_proto != PROTO_END; curr_proto++) { if (is_shared(hdl, mountpoints[i], *curr_proto) && unshare_one(hdl, mountpoints[i], mountpoints[i], *curr_proto) != 0) goto out; } } /* * Now unmount everything, removing the underlying directories as * appropriate. */ for (i = 0; i < used; i++) { if (unmount_one(hdl, mountpoints[i], flags) != 0) goto out; } for (i = 0; i < used; i++) { if (datasets[i]) remove_mountpoint(datasets[i]); } ret = 0; out: for (i = 0; i < used; i++) { if (datasets[i]) zfs_close(datasets[i]); free(mountpoints[i]); } free(datasets); free(mountpoints); return (ret); }