From: Andriy Gapon Date: Thu, 27 Jul 2017 12:58:52 +0000 (+0300) Subject: OpenZFS 8520 - lzc_rollback X-Git-Tag: zfs-0.8.0-rc1~342 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=13342832252c43a0b372b41cb6319377d160bc15;p=zfs OpenZFS 8520 - lzc_rollback 8520 lzc_rollback_to should support rolling back to origin 7198 libzfs should gracefully handle EINVAL from lzc_rollback lzc_rollback_to() should support rolling back to a clone's origin. The current checks in zfs_ioc_rollback() would not allow that because the origin snapshot belongs to a different filesystem. The overly restrictive check was in introduced in 7600, but it was not a regression as none of the existing tools provided a way to rollback to the origin. Authored by: Andriy Gapon Reviewed by: Matthew Ahrens Approved by: Dan McDonald Ported-by: Brian Behlendorf OpenZFS-issue: https://www.illumos.org/issues/8520 OpenZFS-issue: https://www.illumos.org/issues/7198 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/78a5a1a25a Closes #7150 --- diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c index a0e8e7fb6..3d4718025 100644 --- a/lib/libzfs/libzfs_dataset.c +++ b/lib/libzfs/libzfs_dataset.c @@ -4211,17 +4211,31 @@ zfs_rollback(zfs_handle_t *zhp, zfs_handle_t *snap, boolean_t force) * a new snapshot is created before this request is processed. */ err = lzc_rollback_to(zhp->zfs_name, snap->zfs_name); - if (err == EXDEV) { - zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, - "'%s' is not the latest snapshot"), snap->zfs_name); - (void) zfs_error_fmt(zhp->zfs_hdl, EZFS_BUSY, - dgettext(TEXT_DOMAIN, "cannot rollback '%s'"), - zhp->zfs_name); - return (err); - } else if (err != 0) { - (void) zfs_standard_error_fmt(zhp->zfs_hdl, errno, + if (err != 0) { + char errbuf[1024]; + + (void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN, "cannot rollback '%s'"), zhp->zfs_name); + switch (err) { + case EEXIST: + zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, + "there is a snapshot or bookmark more recent " + "than '%s'"), snap->zfs_name); + (void) zfs_error(zhp->zfs_hdl, EZFS_EXISTS, errbuf); + break; + case ESRCH: + zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN, + "'%s' is not found among snapshots of '%s'"), + snap->zfs_name, zhp->zfs_name); + (void) zfs_error(zhp->zfs_hdl, EZFS_NOENT, errbuf); + break; + case EINVAL: + (void) zfs_error(zhp->zfs_hdl, EZFS_BADTYPE, errbuf); + break; + default: + (void) zfs_standard_error(zhp->zfs_hdl, err, errbuf); + } return (err); } diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c index 0bfc4cd7a..86f088889 100644 --- a/module/zfs/dsl_dataset.c +++ b/module/zfs/dsl_dataset.c @@ -2541,7 +2541,7 @@ dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx) /* must have a most recent snapshot */ if (dsl_dataset_phys(ds)->ds_prev_snap_txg < TXG_INITIAL) { dsl_dataset_rele(ds, FTAG); - return (SET_ERROR(EINVAL)); + return (SET_ERROR(ESRCH)); } /* @@ -2561,11 +2561,46 @@ dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx) * the latest snapshot is it. */ if (ddra->ddra_tosnap != NULL) { - char namebuf[ZFS_MAX_DATASET_NAME_LEN]; + dsl_dataset_t *snapds; + + /* Check if the target snapshot exists at all. */ + error = dsl_dataset_hold(dp, ddra->ddra_tosnap, FTAG, &snapds); + if (error != 0) { + /* + * ESRCH is used to signal that the target snapshot does + * not exist, while ENOENT is used to report that + * the rolled back dataset does not exist. + * ESRCH is also used to cover other cases where the + * target snapshot is not related to the dataset being + * rolled back such as being in a different pool. + */ + if (error == ENOENT || error == EXDEV) + error = SET_ERROR(ESRCH); + dsl_dataset_rele(ds, FTAG); + return (error); + } + ASSERT(snapds->ds_is_snapshot); - dsl_dataset_name(ds->ds_prev, namebuf); - if (strcmp(namebuf, ddra->ddra_tosnap) != 0) - return (SET_ERROR(EXDEV)); + /* Check if the snapshot is the latest snapshot indeed. */ + if (snapds != ds->ds_prev) { + /* + * Distinguish between the case where the only problem + * is intervening snapshots (EEXIST) vs the snapshot + * not being a valid target for rollback (ESRCH). + */ + if (snapds->ds_dir == ds->ds_dir || + (dsl_dir_is_clone(ds->ds_dir) && + dsl_dir_phys(ds->ds_dir)->dd_origin_obj == + snapds->ds_object)) { + error = SET_ERROR(EEXIST); + } else { + error = SET_ERROR(ESRCH); + } + dsl_dataset_rele(snapds, FTAG); + dsl_dataset_rele(ds, FTAG); + return (error); + } + dsl_dataset_rele(snapds, FTAG); } /* must not have any bookmarks after the most recent snapshot */ @@ -2574,8 +2609,10 @@ dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx) nvlist_t *bookmarks = fnvlist_alloc(); error = dsl_get_bookmarks_impl(ds, proprequest, bookmarks); fnvlist_free(proprequest); - if (error != 0) + if (error != 0) { + dsl_dataset_rele(ds, FTAG); return (error); + } for (nvpair_t *pair = nvlist_next_nvpair(bookmarks, NULL); pair != NULL; pair = nvlist_next_nvpair(bookmarks, pair)) { nvlist_t *valuenv = diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c index cc7155a78..fcd2fca12 100644 --- a/module/zfs/zfs_ioctl.c +++ b/module/zfs/zfs_ioctl.c @@ -3773,11 +3773,14 @@ zfs_ioc_rollback(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl) (void) nvlist_lookup_string(innvl, "target", &target); if (target != NULL) { - int fslen = strlen(fsname); + const char *cp = strchr(target, '@'); - if (strncmp(fsname, target, fslen) != 0) - return (SET_ERROR(EINVAL)); - if (target[fslen] != '@') + /* + * The snap name must contain an @, and the part after it must + * contain only valid characters. + */ + if (cp == NULL || + zfs_component_namecheck(cp + 1, NULL, NULL) != 0) return (SET_ERROR(EINVAL)); }