/* * 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 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" /* * Routines to manage ZFS mounts. We separate all the nasty routines that have * to deal with the OS. The main entry points are: * * zfs_is_mounted() * zfs_mount() * zfs_unmount() * zfs_unmountall() * * These functions are used by mount and unmount, and when changing a * filesystem's mountpoint. This file also contains the functions used to * manage sharing filesystems via NFS: * * zfs_is_shared() * zfs_share() * zfs_unshare() * zfs_unshareall() * * The following functions are available for pool consumers, and will * mount/unmount (and share/unshare) all datasets within pool: * * zpool_mount_datasets() * zpool_unmount_datasets() */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "libzfs_impl.h" /* * Search the sharetab for the given mountpoint, returning true if it is found. */ static boolean_t is_shared(libzfs_handle_t *hdl, const char *mountpoint) { char buf[MAXPATHLEN], *tab; if (hdl->libzfs_sharetab == NULL) return (0); (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) { *tab = '\0'; if (strcmp(buf, mountpoint) == 0) return (B_TRUE); } } return (B_FALSE); } /* * 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) { DIR *dirp; struct dirent64 *dp; if ((dirp = opendir(dirname)) == NULL) 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); } /* * 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 zfs_is_mounted(zfs_handle_t *zhp, char **where) { struct mnttab search = { 0 }, entry; /* * Search for the entry in /etc/mnttab. We don't bother getting the * mountpoint, as we can just search for the special device. This will * also let us find mounts when the mountpoint is 'legacy'. */ search.mnt_special = (char *)zfs_get_name(zhp); search.mnt_fstype = MNTTYPE_ZFS; rewind(zhp->zfs_hdl->libzfs_mnttab); if (getmntany(zhp->zfs_hdl->libzfs_mnttab, &entry, &search) != 0) return (B_FALSE); if (where != NULL) *where = zfs_strdup(zhp->zfs_hdl, entry.mnt_mountp); 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, zfs_source_t *source) { char sourceloc[ZFS_MAXNAMELEN]; zfs_source_t sourcetype; if (!zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type)) 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)) 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); } /* * 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]; libzfs_handle_t *hdl = zhp->zfs_hdl; if (options == NULL) mntopts[0] = '\0'; else (void) strlcpy(mntopts, options, sizeof (mntopts)); if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL)) return (0); /* 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(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint)); } } /* * Determine if the mountpoint is empty. If so, refuse to perform the * mount. We don't perform this check if MS_OVERLAY is specified, which * would defeat the point. We also avoid this check if 'remount' is * specified. */ if ((flags & MS_OVERLAY) == 0 && strstr(mntopts, MNTOPT_REMOUNT) == NULL && !dir_is_empty(mountpoint)) { zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "directory is not empty")); return (zfs_error(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint)); } /* perform the mount */ if (mount(zfs_get_name(zhp), mountpoint, MS_OPTIONSTR | flags, MNTTYPE_ZFS, NULL, 0, mntopts, sizeof (mntopts)) != 0) { /* * 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 (errno == EBUSY) zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "mountpoint or dataset is busy")); else zfs_error_aux(hdl, strerror(errno)); return (zfs_error(hdl, EZFS_MOUNTFAILED, dgettext(TEXT_DOMAIN, "cannot mount '%s'"), zhp->zfs_name)); } return (0); } /* * Unmount a single filesystem. */ static int unmount_one(libzfs_handle_t *hdl, const char *mountpoint, int flags) { if (umount2(mountpoint, flags) != 0) { zfs_error_aux(hdl, strerror(errno)); return (zfs_error(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) { struct mnttab search = { 0 }, entry; /* check to see if need to unmount the filesystem */ search.mnt_special = zhp->zfs_name; search.mnt_fstype = MNTTYPE_ZFS; rewind(zhp->zfs_hdl->libzfs_mnttab); if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) && getmntany(zhp->zfs_hdl->libzfs_mnttab, &entry, &search) == 0)) { if (mountpoint == NULL) mountpoint = entry.mnt_mountp; /* * Unshare and unmount the filesystem */ if (zfs_unshare(zhp, mountpoint) != 0 || unmount_one(zhp->zfs_hdl, mountpoint, flags) != 0) return (-1); } 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, flags); if (clp == NULL) return (-1); ret = changelist_prefix(clp); changelist_free(clp); return (ret); } /* * Check to see if the filesystem is currently shared. */ boolean_t zfs_is_shared(zfs_handle_t *zhp, char **where) { char *mountpoint; if (!zfs_is_mounted(zhp, &mountpoint)) return (B_FALSE); if (is_shared(zhp->zfs_hdl, mountpoint)) { if (where != NULL) *where = mountpoint; else free(mountpoint); return (B_TRUE); } else { free(mountpoint); return (B_FALSE); } } /* * Share the given filesystem according to the options in 'sharenfs'. We rely * on share(1M) to the dirty work for us. */ int zfs_share(zfs_handle_t *zhp) { char mountpoint[ZFS_MAXPROPLEN]; char shareopts[ZFS_MAXPROPLEN]; char buf[MAXPATHLEN]; FILE *fp; libzfs_handle_t *hdl = zhp->zfs_hdl; if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL)) return (0); /* return success if there are no share options */ if (zfs_prop_get(zhp, ZFS_PROP_SHARENFS, shareopts, sizeof (shareopts), NULL, NULL, 0, B_FALSE) != 0 || strcmp(shareopts, "off") == 0) return (0); /* * 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)) return (0); /* * Invoke the share(1M) command. We always do this, even if it's * currently shared, as the options may have changed. */ if (strcmp(shareopts, "on") == 0) (void) snprintf(buf, sizeof (buf), "/usr/sbin/share " "-F nfs \"%s\" 2>&1", mountpoint); else (void) snprintf(buf, sizeof (buf), "/usr/sbin/share " "-F nfs -o \"%s\" \"%s\" 2>&1", shareopts, mountpoint); if ((fp = popen(buf, "r")) == NULL) return (zfs_error(hdl, EZFS_SHAREFAILED, dgettext(TEXT_DOMAIN, "cannot share '%s'"), zfs_get_name(zhp))); /* * share(1M) should only produce output if there is some kind * of error. All output begins with "share_nfs: ", so we trim * this off to get to the real error. */ if (fgets(buf, sizeof (buf), fp) != NULL) { char *colon = strchr(buf, ':'); while (buf[strlen(buf) - 1] == '\n') buf[strlen(buf) - 1] = '\0'; if (colon != NULL) zfs_error_aux(hdl, colon + 2); (void) zfs_error(hdl, EZFS_SHAREFAILED, dgettext(TEXT_DOMAIN, "cannot share '%s'"), zfs_get_name(zhp)); verify(pclose(fp) != 0); return (-1); } verify(pclose(fp) == 0); return (0); } /* * Unshare a filesystem by mountpoint. */ static int unshare_one(libzfs_handle_t *hdl, const char *name, const char *mountpoint) { char buf[MAXPATHLEN]; FILE *fp; (void) snprintf(buf, sizeof (buf), "/usr/sbin/unshare \"%s\" 2>&1", mountpoint); if ((fp = popen(buf, "r")) == NULL) return (zfs_error(hdl, EZFS_UNSHAREFAILED, dgettext(TEXT_DOMAIN, "cannot unshare '%s'"), name)); /* * unshare(1M) should only produce output if there is * some kind of error. All output begins with "unshare * nfs: ", so we trim this off to get to the real error. */ if (fgets(buf, sizeof (buf), fp) != NULL) { char *colon = strchr(buf, ':'); while (buf[strlen(buf) - 1] == '\n') buf[strlen(buf) - 1] = '\0'; if (colon != NULL) zfs_error_aux(hdl, colon + 2); verify(pclose(fp) != 0); return (zfs_error(hdl, EZFS_UNSHAREFAILED, dgettext(TEXT_DOMAIN, "cannot unshare '%s'"), name)); } verify(pclose(fp) == 0); return (0); } /* * Unshare the given filesystem. */ int zfs_unshare(zfs_handle_t *zhp, const char *mountpoint) { struct mnttab search = { 0 }, entry; /* check to see if need to unmount the filesystem */ search.mnt_special = (char *)zfs_get_name(zhp); search.mnt_fstype = MNTTYPE_ZFS; rewind(zhp->zfs_hdl->libzfs_mnttab); if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) && getmntany(zhp->zfs_hdl->libzfs_mnttab, &entry, &search) == 0)) { if (mountpoint == NULL) mountpoint = entry.mnt_mountp; if (is_shared(zhp->zfs_hdl, mountpoint) && unshare_one(zhp->zfs_hdl, zhp->zfs_name, mountpoint) != 0) return (-1); } return (0); } /* * Same as zfs_unmountall(), but for unshares. */ int zfs_unshareall(zfs_handle_t *zhp) { prop_changelist_t *clp; int ret; clp = changelist_gather(zhp, ZFS_PROP_SHARENFS, 0); if (clp == NULL) return (-1); ret = changelist_unshare(clp); 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]; zfs_source_t source; if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), &source)) return; if (source == ZFS_SRC_DEFAULT || source == ZFS_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); } } /* * Mount and share all datasets within the given pool. This assumes that no * datasets within the pool are currently mounted. Because users can create * complicated nested hierarchies of mountpoints, we first gather all the * datasets and mountpoints within the pool, and sort them by mountpoint. Once * we have the list of all filesystems, we iterate over them in order and mount * and/or share each one. */ typedef struct mount_cbdata { zfs_handle_t **cb_datasets; int cb_used; int cb_alloc; } mount_cbdata_t; static int mount_cb(zfs_handle_t *zhp, void *data) { mount_cbdata_t *cbp = data; if (zfs_get_type(zhp) != ZFS_TYPE_FILESYSTEM) { zfs_close(zhp); return (0); } if (cbp->cb_alloc == cbp->cb_used) { void *ptr; if ((ptr = zfs_realloc(zhp->zfs_hdl, cbp->cb_datasets, cbp->cb_alloc * sizeof (void *), cbp->cb_alloc * 2 * sizeof (void *))) == NULL) return (-1); cbp->cb_datasets = ptr; cbp->cb_alloc *= 2; } cbp->cb_datasets[cbp->cb_used++] = zhp; return (0); } static int dataset_compare(const void *a, const void *b) { zfs_handle_t **za = (zfs_handle_t **)a; zfs_handle_t **zb = (zfs_handle_t **)b; char mounta[MAXPATHLEN]; char mountb[MAXPATHLEN]; verify(zfs_prop_get(*za, ZFS_PROP_MOUNTPOINT, mounta, sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0); verify(zfs_prop_get(*zb, ZFS_PROP_MOUNTPOINT, mountb, sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0); return (strcmp(mounta, mountb)); } int zpool_mount_datasets(zpool_handle_t *zhp, const char *mntopts, int flags) { mount_cbdata_t cb = { 0 }; libzfs_handle_t *hdl = zhp->zpool_hdl; zfs_handle_t *zfsp; int i, ret = -1; /* * Gather all datasets within the pool. */ if ((cb.cb_datasets = zfs_alloc(hdl, 4 * sizeof (void *))) == NULL) return (-1); cb.cb_alloc = 4; if ((zfsp = zfs_open(hdl, zhp->zpool_name, ZFS_TYPE_ANY)) == NULL) goto out; cb.cb_datasets[0] = zfsp; cb.cb_used = 1; if (zfs_iter_children(zfsp, mount_cb, &cb) != 0) goto out; /* * Sort the datasets by mountpoint. */ qsort(cb.cb_datasets, cb.cb_used, sizeof (void *), dataset_compare); /* * And mount all the datasets. */ ret = 0; for (i = 0; i < cb.cb_used; i++) { if (zfs_mount(cb.cb_datasets[i], mntopts, flags) != 0 || zfs_share(cb.cb_datasets[i]) != 0) ret = -1; } out: for (i = 0; i < cb.cb_used; i++) zfs_close(cb.cb_datasets[i]); free(cb.cb_datasets); return (ret); } /* * 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 /etc/mnttab and * gather all the filesystems that are currently mounted. */ static int mountpoint_compare(const void *a, const void *b) { const char *mounta = *((char **)a); const char *mountb = *((char **)b); return (strcmp(mountb, mounta)); } int zpool_unmount_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); rewind(hdl->libzfs_mnttab); 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++) { if (is_shared(hdl, mountpoints[i]) && unshare_one(hdl, mountpoints[i], mountpoints[i]) != 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); }