diff options
Diffstat (limited to 'lib/libbe/be.c')
| -rw-r--r-- | lib/libbe/be.c | 1345 |
1 files changed, 1345 insertions, 0 deletions
diff --git a/lib/libbe/be.c b/lib/libbe/be.c new file mode 100644 index 000000000000..613235d5e908 --- /dev/null +++ b/lib/libbe/be.c @@ -0,0 +1,1345 @@ +/* + * Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in> + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include <sys/param.h> +#include <sys/module.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <sys/ucred.h> +#include <sys/queue.h> +#include <sys/zfs_context.h> +#include <sys/mntent.h> +#include <sys/zfs_ioctl.h> + +#include <libzutil.h> +#include <ctype.h> +#include <libgen.h> +#include <libzfs_core.h> +#include <libzfs_impl.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <unistd.h> +#include <libzfsbootenv.h> + +#include "be.h" +#include "be_impl.h" + +struct promote_entry { + char name[BE_MAXPATHLEN]; + SLIST_ENTRY(promote_entry) link; +}; + +struct be_destroy_data { + libbe_handle_t *lbh; + char target_name[BE_MAXPATHLEN]; + char *snapname; + SLIST_HEAD(, promote_entry) promotelist; +}; + +#if SOON +static int be_create_child_noent(libbe_handle_t *lbh, const char *active, + const char *child_path); +static int be_create_child_cloned(libbe_handle_t *lbh, const char *active); +#endif + +/* Arbitrary... should tune */ +#define BE_SNAP_SERIAL_MAX 1024 + +/* + * Iterator function for locating the rootfs amongst the children of the + * zfs_be_root set by loader(8). data is expected to be a libbe_handle_t *. + */ +static int +be_locate_rootfs(libbe_handle_t *lbh) +{ + struct statfs sfs; + struct mnttab entry; + zfs_handle_t *zfs; + + /* + * Check first if root is ZFS; if not, we'll bail on rootfs capture. + * Unfortunately needed because zfs_path_to_zhandle will emit to + * stderr if / isn't actually a ZFS filesystem, which we'd like + * to avoid. + */ + if (statfs("/", &sfs) == 0) { + statfs2mnttab(&sfs, &entry); + if (strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0) + return (1); + } else + return (1); + zfs = zfs_path_to_zhandle(lbh->lzh, "/", ZFS_TYPE_FILESYSTEM); + if (zfs == NULL) + return (1); + + strlcpy(lbh->rootfs, zfs_get_name(zfs), sizeof(lbh->rootfs)); + zfs_close(zfs); + return (0); +} + +/* + * Initializes the libbe context to operate in the root boot environment + * dataset, for example, zroot/ROOT. + */ +libbe_handle_t * +libbe_init(const char *root) +{ + char altroot[MAXPATHLEN]; + libbe_handle_t *lbh; + char *poolname, *pos; + int pnamelen; + + lbh = NULL; + poolname = pos = NULL; + + /* + * If the zfs kmod's not loaded then the later libzfs_init() will load + * the module for us, but that's not desirable for a couple reasons. If + * the module's not loaded, there's no pool imported and we're going to + * fail anyways. We also don't really want libbe consumers to have that + * kind of side-effect (module loading) in the general case. + */ + if (modfind("zfs") < 0) + goto err; + + if ((lbh = calloc(1, sizeof(libbe_handle_t))) == NULL) + goto err; + + if ((lbh->lzh = libzfs_init()) == NULL) + goto err; + + /* + * Grab rootfs, we'll work backwards from there if an optional BE root + * has not been passed in. + */ + if (be_locate_rootfs(lbh) != 0) { + if (root == NULL) + goto err; + *lbh->rootfs = '\0'; + } + if (root == NULL) { + /* Strip off the final slash from rootfs to get the be root */ + strlcpy(lbh->root, lbh->rootfs, sizeof(lbh->root)); + pos = strrchr(lbh->root, '/'); + if (pos == NULL) + goto err; + *pos = '\0'; + } else + strlcpy(lbh->root, root, sizeof(lbh->root)); + + if ((pos = strchr(lbh->root, '/')) == NULL) + goto err; + + pnamelen = pos - lbh->root; + poolname = malloc(pnamelen + 1); + if (poolname == NULL) + goto err; + + strlcpy(poolname, lbh->root, pnamelen + 1); + if ((lbh->active_phandle = zpool_open(lbh->lzh, poolname)) == NULL) + goto err; + free(poolname); + poolname = NULL; + + if (zpool_get_prop(lbh->active_phandle, ZPOOL_PROP_BOOTFS, lbh->bootfs, + sizeof(lbh->bootfs), NULL, true) != 0) + goto err; + + if (zpool_get_prop(lbh->active_phandle, ZPOOL_PROP_ALTROOT, + altroot, sizeof(altroot), NULL, true) == 0 && + strcmp(altroot, "-") != 0) + lbh->altroot_len = strlen(altroot); + + (void) lzbe_get_boot_device(zpool_get_name(lbh->active_phandle), + &lbh->bootonce); + + return (lbh); +err: + if (lbh != NULL) { + if (lbh->active_phandle != NULL) + zpool_close(lbh->active_phandle); + if (lbh->lzh != NULL) + libzfs_fini(lbh->lzh); + free(lbh); + } + free(poolname); + return (NULL); +} + + +/* + * Free memory allocated by libbe_init() + */ +void +libbe_close(libbe_handle_t *lbh) +{ + + if (lbh->active_phandle != NULL) + zpool_close(lbh->active_phandle); + libzfs_fini(lbh->lzh); + + free(lbh->bootonce); + free(lbh); +} + +/* + * Proxy through to libzfs for the moment. + */ +void +be_nicenum(uint64_t num, char *buf, size_t buflen) +{ + + zfs_nicenum(num, buf, buflen); +} + +static bool +be_should_promote_clones(zfs_handle_t *zfs_hdl, struct be_destroy_data *bdd) +{ + char *atpos; + + if (zfs_get_type(zfs_hdl) != ZFS_TYPE_SNAPSHOT) + return (false); + + /* + * If we're deleting a snapshot, we need to make sure we only promote + * clones that are derived from one of the snapshots we're deleting, + * rather than that of a snapshot we're not touching. This keeps stuff + * in a consistent state, making sure that we don't error out unless + * we really need to. + */ + if (bdd->snapname == NULL) + return (true); + + atpos = strchr(zfs_get_name(zfs_hdl), '@'); + return (strcmp(atpos + 1, bdd->snapname) == 0); +} + +/* + * This is executed from be_promote_dependent_clones via zfs_iter_dependents, + * It checks if the dependent type is a snapshot then attempts to find any + * clones associated with it. Any clones not related to the destroy target are + * added to the promote list. + */ +static int +be_dependent_clone_cb(zfs_handle_t *zfs_hdl, void *data) +{ + int err; + bool found; + const char *name; + struct nvlist *nvl; + struct nvpair *nvp; + struct be_destroy_data *bdd; + struct promote_entry *entry, *newentry; + + nvp = NULL; + err = 0; + bdd = (struct be_destroy_data *)data; + + if (be_should_promote_clones(zfs_hdl, bdd) && + (nvl = zfs_get_clones_nvl(zfs_hdl)) != NULL) { + while ((nvp = nvlist_next_nvpair(nvl, nvp)) != NULL) { + name = nvpair_name(nvp); + + /* + * Skip if the clone is equal to, or a child of, the + * destroy target. + */ + if (strncmp(name, bdd->target_name, + strlen(bdd->target_name)) == 0 || + strstr(name, bdd->target_name) == name) { + continue; + } + + found = false; + SLIST_FOREACH(entry, &bdd->promotelist, link) { + if (strcmp(entry->name, name) == 0) { + found = true; + break; + } + } + + if (found) + continue; + + newentry = malloc(sizeof(struct promote_entry)); + if (newentry == NULL) { + err = ENOMEM; + break; + } + +#define BE_COPY_NAME(entry, src) \ + strlcpy((entry)->name, (src), sizeof((entry)->name)) + if (BE_COPY_NAME(newentry, name) >= + sizeof(newentry->name)) { + /* Shouldn't happen. */ + free(newentry); + err = ENAMETOOLONG; + break; + } +#undef BE_COPY_NAME + + /* + * We're building up a SLIST here to make sure both that + * we get the order right and so that we don't + * inadvertently observe the wrong state by promoting + * datasets while we're still walking the tree. The + * latter can lead to situations where we promote a BE + * then effectively demote it again. + */ + SLIST_INSERT_HEAD(&bdd->promotelist, newentry, link); + } + nvlist_free(nvl); + } + zfs_close(zfs_hdl); + return (err); +} + +/* + * This is called before a destroy, so that any datasets(environments) that are + * dependent on this one get promoted before destroying the target. + */ +static int +be_promote_dependent_clones(zfs_handle_t *zfs_hdl, struct be_destroy_data *bdd) +{ + int err; + zfs_handle_t *clone; + struct promote_entry *entry; + + snprintf(bdd->target_name, BE_MAXPATHLEN, "%s/", zfs_get_name(zfs_hdl)); + err = zfs_iter_dependents(zfs_hdl, true, be_dependent_clone_cb, bdd); + + /* + * Drain the list and walk away from it if we're only deleting a + * snapshot. + */ + if (bdd->snapname != NULL && !SLIST_EMPTY(&bdd->promotelist)) + err = BE_ERR_HASCLONES; + while (!SLIST_EMPTY(&bdd->promotelist)) { + entry = SLIST_FIRST(&bdd->promotelist); + SLIST_REMOVE_HEAD(&bdd->promotelist, link); + +#define ZFS_GRAB_CLONE() \ + zfs_open(bdd->lbh->lzh, entry->name, ZFS_TYPE_FILESYSTEM) + /* + * Just skip this part on error, we still want to clean up the + * promotion list after the first error. We'll then preserve it + * all the way back. + */ + if (err == 0 && (clone = ZFS_GRAB_CLONE()) != NULL) { + err = zfs_promote(clone); + if (err != 0) + err = BE_ERR_DESTROYMNT; + zfs_close(clone); + } +#undef ZFS_GRAB_CLONE + free(entry); + } + + return (err); +} + +static int +be_destroy_cb(zfs_handle_t *zfs_hdl, void *data) +{ + char path[BE_MAXPATHLEN]; + struct be_destroy_data *bdd; + zfs_handle_t *snap; + int err; + + bdd = (struct be_destroy_data *)data; + if (bdd->snapname == NULL) { + err = zfs_iter_children(zfs_hdl, be_destroy_cb, data); + if (err != 0) + return (err); + return (zfs_destroy(zfs_hdl, false)); + } + /* If we're dealing with snapshots instead, delete that one alone */ + err = zfs_iter_filesystems(zfs_hdl, be_destroy_cb, data); + if (err != 0) + return (err); + /* + * This part is intentionally glossing over any potential errors, + * because there's a lot less potential for errors when we're cleaning + * up snapshots rather than a full deep BE. The primary error case + * here being if the snapshot doesn't exist in the first place, which + * the caller will likely deem insignificant as long as it doesn't + * exist after the call. Thus, such a missing snapshot shouldn't jam + * up the destruction. + */ + snprintf(path, sizeof(path), "%s@%s", zfs_get_name(zfs_hdl), + bdd->snapname); + if (!zfs_dataset_exists(bdd->lbh->lzh, path, ZFS_TYPE_SNAPSHOT)) + return (0); + snap = zfs_open(bdd->lbh->lzh, path, ZFS_TYPE_SNAPSHOT); + if (snap != NULL) + zfs_destroy(snap, false); + return (0); +} + +#define BE_DESTROY_WANTORIGIN (BE_DESTROY_ORIGIN | BE_DESTROY_AUTOORIGIN) +/* + * Destroy the boot environment or snapshot specified by the name + * parameter. Options are or'd together with the possible values: + * BE_DESTROY_FORCE : forces operation on mounted datasets + * BE_DESTROY_ORIGIN: destroy the origin snapshot as well + */ +static int +be_destroy_internal(libbe_handle_t *lbh, const char *name, int options, + bool odestroyer) +{ + struct be_destroy_data bdd; + char origin[BE_MAXPATHLEN], path[BE_MAXPATHLEN]; + zfs_handle_t *fs; + char *snapdelim; + int err, force, mounted; + size_t rootlen; + + bdd.lbh = lbh; + bdd.snapname = NULL; + SLIST_INIT(&bdd.promotelist); + force = options & BE_DESTROY_FORCE; + *origin = '\0'; + + be_root_concat(lbh, name, path); + + if ((snapdelim = strchr(path, '@')) == NULL) { + if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_FILESYSTEM)) + return (set_error(lbh, BE_ERR_NOENT)); + + if (strcmp(path, lbh->rootfs) == 0 || + strcmp(path, lbh->bootfs) == 0) + return (set_error(lbh, BE_ERR_DESTROYACT)); + + fs = zfs_open(lbh->lzh, path, ZFS_TYPE_FILESYSTEM); + if (fs == NULL) + return (set_error(lbh, BE_ERR_ZFSOPEN)); + + /* Don't destroy a mounted dataset unless force is specified */ + if ((mounted = zfs_is_mounted(fs, NULL)) != 0) { + if (force) { + zfs_unmount(fs, NULL, 0); + } else { + free(bdd.snapname); + return (set_error(lbh, BE_ERR_DESTROYMNT)); + } + } + + /* Handle destroying bootonce */ + if (lbh->bootonce != NULL && + strcmp(path, lbh->bootonce) == 0) + (void) lzbe_set_boot_device( + zpool_get_name(lbh->active_phandle), lzbe_add, NULL); + } else { + /* + * If we're initially destroying a snapshot, origin options do + * not make sense. If we're destroying the origin snapshot of + * a BE, we want to maintain the options in case we need to + * fake success after failing to promote. + */ + if (!odestroyer) + options &= ~BE_DESTROY_WANTORIGIN; + if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_SNAPSHOT)) + return (set_error(lbh, BE_ERR_NOENT)); + + bdd.snapname = strdup(snapdelim + 1); + if (bdd.snapname == NULL) + return (set_error(lbh, BE_ERR_NOMEM)); + *snapdelim = '\0'; + fs = zfs_open(lbh->lzh, path, ZFS_TYPE_DATASET); + if (fs == NULL) { + free(bdd.snapname); + return (set_error(lbh, BE_ERR_ZFSOPEN)); + } + } + + /* + * Whether we're destroying a BE or a single snapshot, we need to walk + * the tree of what we're going to destroy and promote everything in our + * path so that we can make it happen. + */ + if ((err = be_promote_dependent_clones(fs, &bdd)) != 0) { + free(bdd.snapname); + + /* + * If we're just destroying the origin of some other dataset + * we were invoked to destroy, then we just ignore + * BE_ERR_HASCLONES and return success unless the caller wanted + * to force the issue. + */ + if (odestroyer && err == BE_ERR_HASCLONES && + (options & BE_DESTROY_AUTOORIGIN) != 0) + return (0); + return (set_error(lbh, err)); + } + + /* + * This was deferred until after we promote all of the derivatives so + * that we grab the new origin after everything's settled down. + */ + if ((options & BE_DESTROY_WANTORIGIN) != 0 && + zfs_prop_get(fs, ZFS_PROP_ORIGIN, origin, sizeof(origin), + NULL, NULL, 0, 1) != 0 && + (options & BE_DESTROY_ORIGIN) != 0) + return (set_error(lbh, BE_ERR_NOORIGIN)); + + /* + * If the caller wants auto-origin destruction and the origin + * name matches one of our automatically created snapshot names + * (i.e. strftime("%F-%T") with a serial at the end), then + * we'll set the DESTROY_ORIGIN flag and nuke it + * be_is_auto_snapshot_name is exported from libbe(3) so that + * the caller can determine if it needs to warn about the origin + * not being destroyed or not. + */ + if ((options & BE_DESTROY_AUTOORIGIN) != 0 && *origin != '\0' && + be_is_auto_snapshot_name(lbh, origin)) + options |= BE_DESTROY_ORIGIN; + + err = be_destroy_cb(fs, &bdd); + zfs_close(fs); + free(bdd.snapname); + if (err != 0) { + /* Children are still present or the mount is referenced */ + if (err == EBUSY) + return (set_error(lbh, BE_ERR_DESTROYMNT)); + return (set_error(lbh, BE_ERR_UNKNOWN)); + } + + if ((options & BE_DESTROY_ORIGIN) == 0) + return (0); + + /* The origin can't possibly be shorter than the BE root */ + rootlen = strlen(lbh->root); + if (*origin == '\0' || strlen(origin) <= rootlen + 1) + return (set_error(lbh, BE_ERR_INVORIGIN)); + + /* + * We'll be chopping off the BE root and running this back through + * be_destroy, so that we properly handle the origin snapshot whether + * it be that of a deep BE or not. + */ + if (strncmp(origin, lbh->root, rootlen) != 0 || origin[rootlen] != '/') + return (0); + + return (be_destroy_internal(lbh, origin + rootlen + 1, + options & ~BE_DESTROY_ORIGIN, true)); +} + +int +be_destroy(libbe_handle_t *lbh, const char *name, int options) +{ + + /* + * The consumer must not set both BE_DESTROY_AUTOORIGIN and + * BE_DESTROY_ORIGIN. Internally, we'll set the latter from the former. + * The latter should imply that we must succeed at destroying the + * origin, or complain otherwise. + */ + if ((options & BE_DESTROY_WANTORIGIN) == BE_DESTROY_WANTORIGIN) + return (set_error(lbh, BE_ERR_UNKNOWN)); + return (be_destroy_internal(lbh, name, options, false)); +} + +static void +be_setup_snapshot_name(libbe_handle_t *lbh, char *buf, size_t buflen) +{ + time_t rawtime; + int len, serial; + + time(&rawtime); + len = strlen(buf); + len += strftime(buf + len, buflen - len, "@%F-%T", localtime(&rawtime)); + /* No room for serial... caller will do its best */ + if (buflen - len < 2) + return; + + for (serial = 0; serial < BE_SNAP_SERIAL_MAX; ++serial) { + snprintf(buf + len, buflen - len, "-%d", serial); + if (!zfs_dataset_exists(lbh->lzh, buf, ZFS_TYPE_SNAPSHOT)) + return; + } +} + +bool +be_is_auto_snapshot_name(libbe_handle_t *lbh __unused, const char *name) +{ + const char *snap; + int day, hour, minute, month, second, serial, year; + + if ((snap = strchr(name, '@')) == NULL) + return (false); + ++snap; + /* We'll grab the individual components and do some light validation. */ + if (sscanf(snap, "%d-%d-%d-%d:%d:%d-%d", &year, &month, &day, &hour, + &minute, &second, &serial) != 7) + return (false); + return (year >= 1970) && (month >= 1 && month <= 12) && + (day >= 1 && day <= 31) && (hour >= 0 && hour <= 23) && + (minute >= 0 && minute <= 59) && (second >= 0 && second <= 60) && + serial >= 0; +} + +int +be_snapshot(libbe_handle_t *lbh, const char *source, const char *snap_name, + bool recursive, char *result) +{ + char buf[BE_MAXPATHLEN]; + int err; + + be_root_concat(lbh, source, buf); + + if ((err = be_exists(lbh, buf)) != 0) + return (set_error(lbh, err)); + + if (snap_name != NULL) { + if (strlcat(buf, "@", sizeof(buf)) >= sizeof(buf)) + return (set_error(lbh, BE_ERR_INVALIDNAME)); + + if (strlcat(buf, snap_name, sizeof(buf)) >= sizeof(buf)) + return (set_error(lbh, BE_ERR_INVALIDNAME)); + + if (result != NULL) + snprintf(result, BE_MAXPATHLEN, "%s@%s", source, + snap_name); + } else { + be_setup_snapshot_name(lbh, buf, sizeof(buf)); + + if (result != NULL && strlcpy(result, strrchr(buf, '/') + 1, + sizeof(buf)) >= sizeof(buf)) + return (set_error(lbh, BE_ERR_INVALIDNAME)); + } + if ((err = zfs_snapshot(lbh->lzh, buf, recursive, NULL)) != 0) { + switch (err) { + case EZFS_INVALIDNAME: + return (set_error(lbh, BE_ERR_INVALIDNAME)); + + default: + /* + * The other errors that zfs_ioc_snapshot might return + * shouldn't happen if we've set things up properly, so + * we'll gloss over them and call it UNKNOWN as it will + * require further triage. + */ + if (errno == ENOTSUP) + return (set_error(lbh, BE_ERR_NOPOOL)); + return (set_error(lbh, BE_ERR_UNKNOWN)); + } + } + + return (BE_ERR_SUCCESS); +} + + +/* + * Create the boot environment specified by the name parameter + */ +int +be_create(libbe_handle_t *lbh, const char *name) +{ + int err; + + err = be_create_from_existing(lbh, name, be_active_path(lbh)); + + return (set_error(lbh, err)); +} + +static int +be_deep_clone_prop(int prop, void *cb) +{ + int err; + struct libbe_dccb *dccb; + zprop_source_t src; + char pval[BE_MAXPATHLEN]; + char source[BE_MAXPATHLEN]; + char *val; + + dccb = cb; + /* Skip some properties we don't want to touch */ + switch (prop) { + /* + * libzfs insists on these being naturally inherited in the + * cloning process. + */ + case ZFS_PROP_KEYFORMAT: + case ZFS_PROP_KEYLOCATION: + case ZFS_PROP_ENCRYPTION: + case ZFS_PROP_PBKDF2_ITERS: + + /* FALLTHROUGH */ + case ZFS_PROP_CANMOUNT: /* Forced by libbe */ + return (ZPROP_CONT); + } + + /* Don't copy readonly properties */ + if (zfs_prop_readonly(prop)) + return (ZPROP_CONT); + + if ((err = zfs_prop_get(dccb->zhp, prop, (char *)&pval, + sizeof(pval), &src, (char *)&source, sizeof(source), false))) + /* Just continue if we fail to read a property */ + return (ZPROP_CONT); + + /* + * Only copy locally defined or received properties. This continues + * to avoid temporary/default/local properties intentionally without + * breaking received datasets. + */ + if (src != ZPROP_SRC_LOCAL && src != ZPROP_SRC_RECEIVED) + return (ZPROP_CONT); + + /* Augment mountpoint with altroot, if needed */ + val = pval; + if (prop == ZFS_PROP_MOUNTPOINT) + val = be_mountpoint_augmented(dccb->lbh, val); + + nvlist_add_string(dccb->props, zfs_prop_to_name(prop), val); + + return (ZPROP_CONT); +} + +/* + * Return the corresponding boot environment path for a given + * dataset path, the constructed path is placed in 'result'. + * + * example: say our new boot environment name is 'bootenv' and + * the dataset path is 'zroot/ROOT/default/data/set'. + * + * result should produce: 'zroot/ROOT/bootenv/data/set' + */ +static int +be_get_path(struct libbe_deep_clone *ldc, const char *dspath, char *result, int result_size) +{ + char *pos; + char *child_dataset; + + /* match the root path for the boot environments */ + pos = strstr(dspath, ldc->lbh->root); + + /* no match, different pools? */ + if (pos == NULL) + return (BE_ERR_BADPATH); + + /* root path of the new boot environment */ + snprintf(result, result_size, "%s/%s", ldc->lbh->root, ldc->bename); + + /* gets us to the parent dataset, the +1 consumes a trailing slash */ + pos += strlen(ldc->lbh->root) + 1; + + /* skip the parent dataset */ + if ((child_dataset = strchr(pos, '/')) != NULL) + strlcat(result, child_dataset, result_size); + + return (BE_ERR_SUCCESS); +} + +static int +be_clone_cb(zfs_handle_t *ds, void *data) +{ + int err; + char be_path[BE_MAXPATHLEN]; + char snap_path[BE_MAXPATHLEN]; + const char *dspath; + zfs_handle_t *snap_hdl; + nvlist_t *props; + struct libbe_deep_clone *ldc; + struct libbe_dccb dccb; + + ldc = (struct libbe_deep_clone *)data; + dspath = zfs_get_name(ds); + + snprintf(snap_path, sizeof(snap_path), "%s@%s", dspath, ldc->snapname); + + /* construct the boot environment path from the dataset we're cloning */ + if (be_get_path(ldc, dspath, be_path, sizeof(be_path)) != BE_ERR_SUCCESS) + return (BE_ERR_UNKNOWN); + + /* the dataset to be created (i.e. the boot environment) already exists */ + if (zfs_dataset_exists(ldc->lbh->lzh, be_path, ZFS_TYPE_DATASET)) + return (BE_ERR_EXISTS); + + /* no snapshot found for this dataset, silently skip it */ + if (!zfs_dataset_exists(ldc->lbh->lzh, snap_path, ZFS_TYPE_SNAPSHOT)) + return (0); + + if ((snap_hdl = + zfs_open(ldc->lbh->lzh, snap_path, ZFS_TYPE_SNAPSHOT)) == NULL) + return (BE_ERR_ZFSOPEN); + + nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP); + nvlist_add_string(props, "canmount", "noauto"); + + dccb.lbh = ldc->lbh; + dccb.zhp = ds; + dccb.props = props; + if (zprop_iter(be_deep_clone_prop, &dccb, B_FALSE, B_FALSE, + ZFS_TYPE_FILESYSTEM) == ZPROP_INVAL) + return (-1); + + if ((err = zfs_clone(snap_hdl, be_path, props)) != 0) + return (BE_ERR_ZFSCLONE); + + nvlist_free(props); + zfs_close(snap_hdl); + + if (ldc->depth_limit == -1 || ldc->depth < ldc->depth_limit) { + ldc->depth++; + err = zfs_iter_filesystems(ds, be_clone_cb, ldc); + ldc->depth--; + } + + return (err); +} + +/* + * Create a boot environment with a given name from a given snapshot. + * Snapshots can be in the format 'zroot/ROOT/default@snapshot' or + * 'default@snapshot'. In the latter case, 'default@snapshot' will be prepended + * with the root path that libbe was initailized with. +*/ +static int +be_clone(libbe_handle_t *lbh, const char *bename, const char *snapshot, int depth) +{ + int err; + char snap_path[BE_MAXPATHLEN]; + char *parentname, *snapname; + zfs_handle_t *parent_hdl; + struct libbe_deep_clone ldc; + + /* ensure the boot environment name is valid */ + if ((err = be_validate_name(lbh, bename)) != 0) + return (set_error(lbh, err)); + + /* + * prepend the boot environment root path if we're + * given a partial snapshot name. + */ + if ((err = be_root_concat(lbh, snapshot, snap_path)) != 0) + return (set_error(lbh, err)); + + /* ensure the snapshot exists */ + if ((err = be_validate_snap(lbh, snap_path)) != 0) + return (set_error(lbh, err)); + + /* get a copy of the snapshot path so we can disect it */ + if ((parentname = strdup(snap_path)) == NULL) + return (set_error(lbh, BE_ERR_UNKNOWN)); + + /* split dataset name from snapshot name */ + snapname = strchr(parentname, '@'); + if (snapname == NULL) { + free(parentname); + return (set_error(lbh, BE_ERR_UNKNOWN)); + } + *snapname = '\0'; + snapname++; + + /* set-up the boot environment */ + ldc.lbh = lbh; + ldc.bename = bename; + ldc.snapname = snapname; + ldc.depth = 0; + ldc.depth_limit = depth; + + /* the boot environment will be cloned from this dataset */ + parent_hdl = zfs_open(lbh->lzh, parentname, ZFS_TYPE_DATASET); + + /* create the boot environment */ + err = be_clone_cb(parent_hdl, &ldc); + + free(parentname); + return (set_error(lbh, err)); +} + +/* + * Create a boot environment from pre-existing snapshot, specifying a depth. + */ +int be_create_depth(libbe_handle_t *lbh, const char *bename, + const char *snap, int depth) +{ + return (be_clone(lbh, bename, snap, depth)); +} + +/* + * Create the boot environment from pre-existing snapshot + */ +int +be_create_from_existing_snap(libbe_handle_t *lbh, const char *bename, + const char *snap) +{ + return (be_clone(lbh, bename, snap, -1)); +} + + +/* + * Create a boot environment from an existing boot environment + */ +int +be_create_from_existing(libbe_handle_t *lbh, const char *bename, const char *old) +{ + int err; + char snap[BE_MAXPATHLEN]; + + if ((err = be_snapshot(lbh, old, NULL, true, snap)) != 0) + return (set_error(lbh, err)); + + err = be_clone(lbh, bename, snap, -1); + + return (set_error(lbh, err)); +} + + +/* + * Verifies that a snapshot has a valid name, exists, and has a mountpoint of + * '/'. Returns BE_ERR_SUCCESS (0), upon success, or the relevant BE_ERR_* upon + * failure. Does not set the internal library error state. + */ +int +be_validate_snap(libbe_handle_t *lbh, const char *snap_name) +{ + + if (strlen(snap_name) >= BE_MAXPATHLEN) + return (BE_ERR_PATHLEN); + + if (!zfs_name_valid(snap_name, ZFS_TYPE_SNAPSHOT)) + return (BE_ERR_INVALIDNAME); + + if (!zfs_dataset_exists(lbh->lzh, snap_name, + ZFS_TYPE_SNAPSHOT)) + return (BE_ERR_NOENT); + + return (BE_ERR_SUCCESS); +} + + +/* + * Idempotently appends the name argument to the root boot environment path + * and copies the resulting string into the result buffer (which is assumed + * to be at least BE_MAXPATHLEN characters long. Returns BE_ERR_SUCCESS upon + * success, BE_ERR_PATHLEN if the resulting path is longer than BE_MAXPATHLEN, + * or BE_ERR_INVALIDNAME if the name is a path that does not begin with + * zfs_be_root. Does not set internal library error state. + */ +int +be_root_concat(libbe_handle_t *lbh, const char *name, char *result) +{ + size_t name_len, root_len; + + name_len = strlen(name); + root_len = strlen(lbh->root); + + /* Act idempotently; return be name if it is already a full path */ + if (strrchr(name, '/') != NULL) { + if (strstr(name, lbh->root) != name) + return (BE_ERR_INVALIDNAME); + + if (name_len >= BE_MAXPATHLEN) + return (BE_ERR_PATHLEN); + + strlcpy(result, name, BE_MAXPATHLEN); + return (BE_ERR_SUCCESS); + } else if (name_len + root_len + 1 < BE_MAXPATHLEN) { + snprintf(result, BE_MAXPATHLEN, "%s/%s", lbh->root, + name); + return (BE_ERR_SUCCESS); + } + + return (BE_ERR_PATHLEN); +} + + +/* + * Verifies the validity of a boot environment name (A-Za-z0-9-_.). Returns + * BE_ERR_SUCCESS (0) if name is valid, otherwise returns BE_ERR_INVALIDNAME + * or BE_ERR_PATHLEN. + * Does not set internal library error state. + */ +int +be_validate_name(libbe_handle_t *lbh, const char *name) +{ + + /* + * Impose the additional restriction that the entire dataset name must + * not exceed the maximum length of a dataset, i.e. MAXNAMELEN. + */ + if (strlen(lbh->root) + 1 + strlen(name) > MAXNAMELEN) + return (BE_ERR_PATHLEN); + + if (!zfs_name_valid(name, ZFS_TYPE_DATASET)) + return (BE_ERR_INVALIDNAME); + + /* + * ZFS allows spaces in boot environment names, but the kernel can't + * handle booting from such a dataset right now. vfs.root.mountfrom + * is defined to be a space-separated list, and there's no protocol for + * escaping whitespace in the path component of a dev:path spec. So + * while loader can handle this situation alright, it can't safely pass + * it on to mountroot. + */ + if (strchr(name, ' ') != NULL) + return (BE_ERR_INVALIDNAME); + + return (BE_ERR_SUCCESS); +} + + +/* + * usage + */ +int +be_rename(libbe_handle_t *lbh, const char *old, const char *new) +{ + char full_old[BE_MAXPATHLEN]; + char full_new[BE_MAXPATHLEN]; + zfs_handle_t *zfs_hdl; + int err; + + /* + * be_validate_name is documented not to set error state, so we should + * do so here. + */ + if ((err = be_validate_name(lbh, new)) != 0) + return (set_error(lbh, err)); + if ((err = be_root_concat(lbh, old, full_old)) != 0) + return (set_error(lbh, err)); + if ((err = be_root_concat(lbh, new, full_new)) != 0) + return (set_error(lbh, err)); + + if (!zfs_dataset_exists(lbh->lzh, full_old, ZFS_TYPE_DATASET)) + return (set_error(lbh, BE_ERR_NOENT)); + + if (zfs_dataset_exists(lbh->lzh, full_new, ZFS_TYPE_DATASET)) + return (set_error(lbh, BE_ERR_EXISTS)); + + if ((zfs_hdl = zfs_open(lbh->lzh, full_old, + ZFS_TYPE_FILESYSTEM)) == NULL) + return (set_error(lbh, BE_ERR_ZFSOPEN)); + + /* recurse, nounmount, forceunmount */ + struct renameflags flags = { + .nounmount = 1, + }; + err = zfs_rename(zfs_hdl, full_new, flags); + if (err != 0) + goto error; + + /* handle renaming bootonce */ + if (lbh->bootonce != NULL && + strcmp(full_old, lbh->bootonce) == 0) + err = be_activate(lbh, new, true); + +error: + zfs_close(zfs_hdl); + return (set_error(lbh, err)); +} + + +int +be_export(libbe_handle_t *lbh, const char *bootenv, int fd) +{ + char snap_name[BE_MAXPATHLEN]; + char buf[BE_MAXPATHLEN]; + zfs_handle_t *zfs; + sendflags_t flags = { 0 }; + int err; + + if ((err = be_snapshot(lbh, bootenv, NULL, true, snap_name)) != 0) + /* Use the error set by be_snapshot */ + return (err); + + be_root_concat(lbh, snap_name, buf); + + if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_DATASET)) == NULL) + return (set_error(lbh, BE_ERR_ZFSOPEN)); + + err = zfs_send_one(zfs, NULL, fd, &flags, /* redactbook */ NULL); + zfs_close(zfs); + + return (err); +} + + +int +be_import(libbe_handle_t *lbh, const char *bootenv, int fd) +{ + char buf[BE_MAXPATHLEN]; + nvlist_t *props; + zfs_handle_t *zfs; + recvflags_t flags = { .nomount = 1 }; + int err; + + be_root_concat(lbh, bootenv, buf); + + if ((err = zfs_receive(lbh->lzh, buf, NULL, &flags, fd, NULL)) != 0) { + switch (err) { + case EINVAL: + return (set_error(lbh, BE_ERR_NOORIGIN)); + case ENOENT: + return (set_error(lbh, BE_ERR_NOENT)); + case EIO: + return (set_error(lbh, BE_ERR_IO)); + default: + return (set_error(lbh, BE_ERR_UNKNOWN)); + } + } + + if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_FILESYSTEM)) == NULL) + return (set_error(lbh, BE_ERR_ZFSOPEN)); + + nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP); + nvlist_add_string(props, "canmount", "noauto"); + nvlist_add_string(props, "mountpoint", "none"); + + err = zfs_prop_set_list(zfs, props); + nvlist_free(props); + + zfs_close(zfs); + + if (err != 0) + return (set_error(lbh, BE_ERR_UNKNOWN)); + + return (0); +} + +#if SOON +static int +be_create_child_noent(libbe_handle_t *lbh, const char *active, + const char *child_path) +{ + nvlist_t *props; + zfs_handle_t *zfs; + int err; + + nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP); + nvlist_add_string(props, "canmount", "noauto"); + nvlist_add_string(props, "mountpoint", child_path); + + /* Create */ + if ((err = zfs_create(lbh->lzh, active, ZFS_TYPE_DATASET, + props)) != 0) { + switch (err) { + case EZFS_EXISTS: + return (set_error(lbh, BE_ERR_EXISTS)); + case EZFS_NOENT: + return (set_error(lbh, BE_ERR_NOENT)); + case EZFS_BADTYPE: + case EZFS_BADVERSION: + return (set_error(lbh, BE_ERR_NOPOOL)); + case EZFS_BADPROP: + default: + /* We set something up wrong, probably... */ + return (set_error(lbh, BE_ERR_UNKNOWN)); + } + } + nvlist_free(props); + + if ((zfs = zfs_open(lbh->lzh, active, ZFS_TYPE_DATASET)) == NULL) + return (set_error(lbh, BE_ERR_ZFSOPEN)); + + /* Set props */ + if ((err = zfs_prop_set(zfs, "canmount", "noauto")) != 0) { + zfs_close(zfs); + /* + * Similar to other cases, this shouldn't fail unless we've + * done something wrong. This is a new dataset that shouldn't + * have been mounted anywhere between creation and now. + */ + if (err == EZFS_NOMEM) + return (set_error(lbh, BE_ERR_NOMEM)); + return (set_error(lbh, BE_ERR_UNKNOWN)); + } + zfs_close(zfs); + return (BE_ERR_SUCCESS); +} + +static int +be_create_child_cloned(libbe_handle_t *lbh, const char *active) +{ + char buf[BE_MAXPATHLEN], tmp[BE_MAXPATHLEN]; + zfs_handle_t *zfs; + int err; + + /* XXX TODO ? */ + + /* + * Establish if the existing path is a zfs dataset or just + * the subdirectory of one + */ + strlcpy(tmp, "tmp/be_snap.XXXXX", sizeof(tmp)); + if (mktemp(tmp) == NULL) + return (set_error(lbh, BE_ERR_UNKNOWN)); + + be_root_concat(lbh, tmp, buf); + printf("Here %s?\n", buf); + if ((err = zfs_snapshot(lbh->lzh, buf, false, NULL)) != 0) { + switch (err) { + case EZFS_INVALIDNAME: + return (set_error(lbh, BE_ERR_INVALIDNAME)); + + default: + /* + * The other errors that zfs_ioc_snapshot might return + * shouldn't happen if we've set things up properly, so + * we'll gloss over them and call it UNKNOWN as it will + * require further triage. + */ + if (errno == ENOTSUP) + return (set_error(lbh, BE_ERR_NOPOOL)); + return (set_error(lbh, BE_ERR_UNKNOWN)); + } + } + + /* Clone */ + if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_SNAPSHOT)) == NULL) + return (BE_ERR_ZFSOPEN); + + if ((err = zfs_clone(zfs, active, NULL)) != 0) + /* XXX TODO correct error */ + return (set_error(lbh, BE_ERR_UNKNOWN)); + + /* set props */ + zfs_close(zfs); + return (BE_ERR_SUCCESS); +} + +int +be_add_child(libbe_handle_t *lbh, const char *child_path, bool cp_if_exists) +{ + struct stat sb; + char active[BE_MAXPATHLEN], buf[BE_MAXPATHLEN]; + nvlist_t *props; + const char *s; + + /* Require absolute paths */ + if (*child_path != '/') + return (set_error(lbh, BE_ERR_BADPATH)); + + strlcpy(active, be_active_path(lbh), BE_MAXPATHLEN); + strcpy(buf, active); + + /* Create non-mountable parent dataset(s) */ + s = child_path; + for (char *p; (p = strchr(s+1, '/')) != NULL; s = p) { + size_t len = p - s; + strncat(buf, s, len); + + nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP); + nvlist_add_string(props, "canmount", "off"); + nvlist_add_string(props, "mountpoint", "none"); + zfs_create(lbh->lzh, buf, ZFS_TYPE_DATASET, props); + nvlist_free(props); + } + + /* Path does not exist as a descendent of / yet */ + if (strlcat(active, child_path, BE_MAXPATHLEN) >= BE_MAXPATHLEN) + return (set_error(lbh, BE_ERR_PATHLEN)); + + if (stat(child_path, &sb) != 0) { + /* Verify that error is ENOENT */ + if (errno != ENOENT) + return (set_error(lbh, BE_ERR_UNKNOWN)); + return (be_create_child_noent(lbh, active, child_path)); + } else if (cp_if_exists) + /* Path is already a descendent of / and should be copied */ + return (be_create_child_cloned(lbh, active)); + return (set_error(lbh, BE_ERR_EXISTS)); +} +#endif /* SOON */ + +/* + * Deactivate old BE dataset; currently just sets canmount=noauto or + * resets boot once configuration. + */ +int +be_deactivate(libbe_handle_t *lbh, const char *ds, bool temporary) +{ + zfs_handle_t *zfs; + + if (temporary) { + return (lzbe_set_boot_device( + zpool_get_name(lbh->active_phandle), lzbe_add, NULL)); + } + + if ((zfs = zfs_open(lbh->lzh, ds, ZFS_TYPE_DATASET)) == NULL) + return (1); + if (zfs_prop_set(zfs, "canmount", "noauto") != 0) + return (1); + zfs_close(zfs); + return (0); +} + +static int +be_zfs_promote_cb(zfs_handle_t *zhp, void *data) +{ + char origin[BE_MAXPATHLEN]; + bool *found_origin = (bool *)data; + int err; + + if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, sizeof(origin), + NULL, NULL, 0, true) == 0) { + *found_origin = true; + err = zfs_promote(zhp); + if (err) + return (err); + } + + return (zfs_iter_filesystems(zhp, be_zfs_promote_cb, data)); +} + +static int +be_zfs_promote(zfs_handle_t *zhp, bool *found_origin) +{ + *found_origin = false; + return (be_zfs_promote_cb(zhp, (void *)found_origin)); +} + +int +be_activate(libbe_handle_t *lbh, const char *bootenv, bool temporary) +{ + char be_path[BE_MAXPATHLEN]; + zfs_handle_t *zhp; + int err; + bool found_origin; + + be_root_concat(lbh, bootenv, be_path); + + /* Note: be_exists fails if mountpoint is not / */ + if ((err = be_exists(lbh, be_path)) != 0) + return (set_error(lbh, err)); + + if (temporary) { + return (lzbe_set_boot_device( + zpool_get_name(lbh->active_phandle), lzbe_add, be_path)); + } else { + if (strncmp(lbh->bootfs, "-", 1) != 0 && + be_deactivate(lbh, lbh->bootfs, false) != 0) + return (-1); + + /* Obtain bootenv zpool */ + err = zpool_set_prop(lbh->active_phandle, "bootfs", be_path); + if (err) + return (-1); + + for (;;) { + zhp = zfs_open(lbh->lzh, be_path, ZFS_TYPE_FILESYSTEM); + if (zhp == NULL) + return (-1); + + err = be_zfs_promote(zhp, &found_origin); + + zfs_close(zhp); + if (!found_origin) + break; + if (err) + return (err); + } + + if (err) + return (-1); + } + + return (BE_ERR_SUCCESS); +} |