/* * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2012 by Delphix. All rights reserved. * Copyright (c) 2012, Joyent, Inc. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static char *dsl_reaper = "the grim reaper"; static dsl_checkfunc_t dsl_dataset_destroy_begin_check; static dsl_syncfunc_t dsl_dataset_destroy_begin_sync; static dsl_syncfunc_t dsl_dataset_set_reservation_sync; #define SWITCH64(x, y) \ { \ uint64_t __tmp = (x); \ (x) = (y); \ (y) = __tmp; \ } #define DS_REF_MAX (1ULL << 62) #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper) /* * Figure out how much of this delta should be propogated to the dsl_dir * layer. If there's a refreservation, that space has already been * partially accounted for in our ancestors. */ static int64_t parent_delta(dsl_dataset_t *ds, int64_t delta) { uint64_t old_bytes, new_bytes; if (ds->ds_reserved == 0) return (delta); old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved); ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta)); return (new_bytes - old_bytes); } void dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx) { int used, compressed, uncompressed; int64_t delta; used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); compressed = BP_GET_PSIZE(bp); uncompressed = BP_GET_UCSIZE(bp); dprintf_bp(bp, "ds=%p", ds); ASSERT(dmu_tx_is_syncing(tx)); /* It could have been compressed away to nothing */ if (BP_IS_HOLE(bp)) return; ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE); ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp))); if (ds == NULL) { dsl_pool_mos_diduse_space(tx->tx_pool, used, compressed, uncompressed); return; } dmu_buf_will_dirty(ds->ds_dbuf, tx); mutex_enter(&ds->ds_dir->dd_lock); mutex_enter(&ds->ds_lock); delta = parent_delta(ds, used); ds->ds_phys->ds_referenced_bytes += used; ds->ds_phys->ds_compressed_bytes += compressed; ds->ds_phys->ds_uncompressed_bytes += uncompressed; ds->ds_phys->ds_unique_bytes += used; mutex_exit(&ds->ds_lock); dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, compressed, uncompressed, tx); dsl_dir_transfer_space(ds->ds_dir, used - delta, DD_USED_REFRSRV, DD_USED_HEAD, tx); mutex_exit(&ds->ds_dir->dd_lock); } int dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, boolean_t async) { int used, compressed, uncompressed; if (BP_IS_HOLE(bp)) return (0); ASSERT(dmu_tx_is_syncing(tx)); ASSERT(bp->blk_birth <= tx->tx_txg); used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); compressed = BP_GET_PSIZE(bp); uncompressed = BP_GET_UCSIZE(bp); ASSERT(used > 0); if (ds == NULL) { dsl_free(tx->tx_pool, tx->tx_txg, bp); dsl_pool_mos_diduse_space(tx->tx_pool, -used, -compressed, -uncompressed); return (used); } ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); ASSERT(!dsl_dataset_is_snapshot(ds)); dmu_buf_will_dirty(ds->ds_dbuf, tx); if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { int64_t delta; dprintf_bp(bp, "freeing ds=%llu", ds->ds_object); dsl_free(tx->tx_pool, tx->tx_txg, bp); mutex_enter(&ds->ds_dir->dd_lock); mutex_enter(&ds->ds_lock); ASSERT(ds->ds_phys->ds_unique_bytes >= used || !DS_UNIQUE_IS_ACCURATE(ds)); delta = parent_delta(ds, -used); ds->ds_phys->ds_unique_bytes -= used; mutex_exit(&ds->ds_lock); dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, -compressed, -uncompressed, tx); dsl_dir_transfer_space(ds->ds_dir, -used - delta, DD_USED_REFRSRV, DD_USED_HEAD, tx); mutex_exit(&ds->ds_dir->dd_lock); } else { dprintf_bp(bp, "putting on dead list: %s", ""); if (async) { /* * We are here as part of zio's write done callback, * which means we're a zio interrupt thread. We can't * call dsl_deadlist_insert() now because it may block * waiting for I/O. Instead, put bp on the deferred * queue and let dsl_pool_sync() finish the job. */ bplist_append(&ds->ds_pending_deadlist, bp); } else { dsl_deadlist_insert(&ds->ds_deadlist, bp, tx); } ASSERT3U(ds->ds_prev->ds_object, ==, ds->ds_phys->ds_prev_snap_obj); ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object && bp->blk_birth > ds->ds_prev->ds_phys->ds_prev_snap_txg) { dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); mutex_enter(&ds->ds_prev->ds_lock); ds->ds_prev->ds_phys->ds_unique_bytes += used; mutex_exit(&ds->ds_prev->ds_lock); } if (bp->blk_birth > ds->ds_dir->dd_origin_txg) { dsl_dir_transfer_space(ds->ds_dir, used, DD_USED_HEAD, DD_USED_SNAP, tx); } } mutex_enter(&ds->ds_lock); ASSERT3U(ds->ds_phys->ds_referenced_bytes, >=, used); ds->ds_phys->ds_referenced_bytes -= used; ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); ds->ds_phys->ds_compressed_bytes -= compressed; ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); ds->ds_phys->ds_uncompressed_bytes -= uncompressed; mutex_exit(&ds->ds_lock); return (used); } uint64_t dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) { uint64_t trysnap = 0; if (ds == NULL) return (0); /* * The snapshot creation could fail, but that would cause an * incorrect FALSE return, which would only result in an * overestimation of the amount of space that an operation would * consume, which is OK. * * There's also a small window where we could miss a pending * snapshot, because we could set the sync task in the quiescing * phase. So this should only be used as a guess. */ if (ds->ds_trysnap_txg > spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) trysnap = ds->ds_trysnap_txg; return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); } boolean_t dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp, uint64_t blk_birth) { if (blk_birth <= dsl_dataset_prev_snap_txg(ds)) return (B_FALSE); ddt_prefetch(dsl_dataset_get_spa(ds), bp); return (B_TRUE); } /* ARGSUSED */ static void dsl_dataset_evict(dmu_buf_t *db, void *dsv) { dsl_dataset_t *ds = dsv; ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); unique_remove(ds->ds_fsid_guid); if (ds->ds_objset != NULL) dmu_objset_evict(ds->ds_objset); if (ds->ds_prev) { dsl_dataset_drop_ref(ds->ds_prev, ds); ds->ds_prev = NULL; } bplist_destroy(&ds->ds_pending_deadlist); if (db != NULL) { dsl_deadlist_close(&ds->ds_deadlist); } else { ASSERT(ds->ds_deadlist.dl_dbuf == NULL); ASSERT(!ds->ds_deadlist.dl_oldfmt); } if (ds->ds_dir) dsl_dir_close(ds->ds_dir, ds); ASSERT(!list_link_active(&ds->ds_synced_link)); mutex_destroy(&ds->ds_lock); mutex_destroy(&ds->ds_recvlock); mutex_destroy(&ds->ds_opening_lock); rw_destroy(&ds->ds_rwlock); cv_destroy(&ds->ds_exclusive_cv); kmem_free(ds, sizeof (dsl_dataset_t)); } static int dsl_dataset_get_snapname(dsl_dataset_t *ds) { dsl_dataset_phys_t *headphys; int err; dmu_buf_t *headdbuf; dsl_pool_t *dp = ds->ds_dir->dd_pool; objset_t *mos = dp->dp_meta_objset; if (ds->ds_snapname[0]) return (0); if (ds->ds_phys->ds_next_snap_obj == 0) return (0); err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &headdbuf); if (err) return (err); headphys = headdbuf->db_data; err = zap_value_search(dp->dp_meta_objset, headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); dmu_buf_rele(headdbuf, FTAG); return (err); } int dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) { objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; matchtype_t mt; int err; if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) mt = MT_FIRST; else mt = MT_EXACT; err = zap_lookup_norm(mos, snapobj, name, 8, 1, value, mt, NULL, 0, NULL); if (err == ENOTSUP && mt == MT_FIRST) err = zap_lookup(mos, snapobj, name, 8, 1, value); return (err); } static int dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) { objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; matchtype_t mt; int err; dsl_dir_snap_cmtime_update(ds->ds_dir); if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) mt = MT_FIRST; else mt = MT_EXACT; err = zap_remove_norm(mos, snapobj, name, mt, tx); if (err == ENOTSUP && mt == MT_FIRST) err = zap_remove(mos, snapobj, name, tx); return (err); } static int dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, dsl_dataset_t **dsp) { objset_t *mos = dp->dp_meta_objset; dmu_buf_t *dbuf; dsl_dataset_t *ds; int err; dmu_object_info_t doi; ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || dsl_pool_sync_context(dp)); err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); if (err) return (err); /* Make sure dsobj has the correct object type. */ dmu_object_info_from_db(dbuf, &doi); if (doi.doi_type != DMU_OT_DSL_DATASET) return (EINVAL); ds = dmu_buf_get_user(dbuf); if (ds == NULL) { dsl_dataset_t *winner = NULL; ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_PUSHPAGE); ds->ds_dbuf = dbuf; ds->ds_object = dsobj; ds->ds_phys = dbuf->db_data; list_link_init(&ds->ds_synced_link); mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL); rw_init(&ds->ds_rwlock, NULL, RW_DEFAULT, NULL); cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); bplist_create(&ds->ds_pending_deadlist); dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t), offsetof(dmu_sendarg_t, dsa_link)); if (err == 0) { err = dsl_dir_open_obj(dp, ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); } if (err) { mutex_destroy(&ds->ds_lock); mutex_destroy(&ds->ds_recvlock); mutex_destroy(&ds->ds_opening_lock); rw_destroy(&ds->ds_rwlock); cv_destroy(&ds->ds_exclusive_cv); bplist_destroy(&ds->ds_pending_deadlist); dsl_deadlist_close(&ds->ds_deadlist); kmem_free(ds, sizeof (dsl_dataset_t)); dmu_buf_rele(dbuf, tag); return (err); } if (!dsl_dataset_is_snapshot(ds)) { ds->ds_snapname[0] = '\0'; if (ds->ds_phys->ds_prev_snap_obj) { err = dsl_dataset_get_ref(dp, ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev); } } else { if (zfs_flags & ZFS_DEBUG_SNAPNAMES) err = dsl_dataset_get_snapname(ds); if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { err = zap_count( ds->ds_dir->dd_pool->dp_meta_objset, ds->ds_phys->ds_userrefs_obj, &ds->ds_userrefs); } } if (err == 0 && !dsl_dataset_is_snapshot(ds)) { /* * In sync context, we're called with either no lock * or with the write lock. If we're not syncing, * we're always called with the read lock held. */ boolean_t need_lock = !RW_WRITE_HELD(&dp->dp_config_rwlock) && dsl_pool_sync_context(dp); if (need_lock) rw_enter(&dp->dp_config_rwlock, RW_READER); err = dsl_prop_get_ds(ds, "refreservation", sizeof (uint64_t), 1, &ds->ds_reserved, NULL); if (err == 0) { err = dsl_prop_get_ds(ds, "refquota", sizeof (uint64_t), 1, &ds->ds_quota, NULL); } if (need_lock) rw_exit(&dp->dp_config_rwlock); } else { ds->ds_reserved = ds->ds_quota = 0; } if (err == 0) { winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, dsl_dataset_evict); } if (err || winner) { bplist_destroy(&ds->ds_pending_deadlist); dsl_deadlist_close(&ds->ds_deadlist); if (ds->ds_prev) dsl_dataset_drop_ref(ds->ds_prev, ds); dsl_dir_close(ds->ds_dir, ds); mutex_destroy(&ds->ds_lock); mutex_destroy(&ds->ds_recvlock); mutex_destroy(&ds->ds_opening_lock); rw_destroy(&ds->ds_rwlock); cv_destroy(&ds->ds_exclusive_cv); kmem_free(ds, sizeof (dsl_dataset_t)); if (err) { dmu_buf_rele(dbuf, tag); return (err); } ds = winner; } else { ds->ds_fsid_guid = unique_insert(ds->ds_phys->ds_fsid_guid); } } ASSERT3P(ds->ds_dbuf, ==, dbuf); ASSERT3P(ds->ds_phys, ==, dbuf->db_data); ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); mutex_enter(&ds->ds_lock); if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { mutex_exit(&ds->ds_lock); dmu_buf_rele(ds->ds_dbuf, tag); return (ENOENT); } mutex_exit(&ds->ds_lock); *dsp = ds; return (0); } static int dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) { dsl_pool_t *dp = ds->ds_dir->dd_pool; /* * In syncing context we don't want the rwlock lock: there * may be an existing writer waiting for sync phase to * finish. We don't need to worry about such writers, since * sync phase is single-threaded, so the writer can't be * doing anything while we are active. */ if (dsl_pool_sync_context(dp)) { ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); return (0); } /* * Normal users will hold the ds_rwlock as a READER until they * are finished (i.e., call dsl_dataset_rele()). "Owners" will * drop their READER lock after they set the ds_owner field. * * If the dataset is being destroyed, the destroy thread will * obtain a WRITER lock for exclusive access after it's done its * open-context work and then change the ds_owner to * dsl_reaper once destruction is assured. So threads * may block here temporarily, until the "destructability" of * the dataset is determined. */ ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); mutex_enter(&ds->ds_lock); while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { rw_exit(&dp->dp_config_rwlock); cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); if (DSL_DATASET_IS_DESTROYED(ds)) { mutex_exit(&ds->ds_lock); dsl_dataset_drop_ref(ds, tag); rw_enter(&dp->dp_config_rwlock, RW_READER); return (ENOENT); } /* * The dp_config_rwlock lives above the ds_lock. And * we need to check DSL_DATASET_IS_DESTROYED() while * holding the ds_lock, so we have to drop and reacquire * the ds_lock here. */ mutex_exit(&ds->ds_lock); rw_enter(&dp->dp_config_rwlock, RW_READER); mutex_enter(&ds->ds_lock); } mutex_exit(&ds->ds_lock); return (0); } int dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, dsl_dataset_t **dsp) { int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); if (err) return (err); return (dsl_dataset_hold_ref(*dsp, tag)); } int dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, void *tag, dsl_dataset_t **dsp) { int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); if (err) return (err); if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { dsl_dataset_rele(*dsp, tag); *dsp = NULL; return (EBUSY); } return (0); } int dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) { dsl_dir_t *dd; dsl_pool_t *dp; const char *snapname; uint64_t obj; int err = 0; err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); if (err) return (err); dp = dd->dd_pool; obj = dd->dd_phys->dd_head_dataset_obj; rw_enter(&dp->dp_config_rwlock, RW_READER); if (obj) err = dsl_dataset_get_ref(dp, obj, tag, dsp); else err = ENOENT; if (err) goto out; err = dsl_dataset_hold_ref(*dsp, tag); /* we may be looking for a snapshot */ if (err == 0 && snapname != NULL) { dsl_dataset_t *ds = NULL; if (*snapname++ != '@') { dsl_dataset_rele(*dsp, tag); err = ENOENT; goto out; } dprintf("looking for snapshot '%s'\n", snapname); err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); if (err == 0) err = dsl_dataset_get_ref(dp, obj, tag, &ds); dsl_dataset_rele(*dsp, tag); ASSERT3U((err == 0), ==, (ds != NULL)); if (ds) { mutex_enter(&ds->ds_lock); if (ds->ds_snapname[0] == 0) (void) strlcpy(ds->ds_snapname, snapname, sizeof (ds->ds_snapname)); mutex_exit(&ds->ds_lock); err = dsl_dataset_hold_ref(ds, tag); *dsp = err ? NULL : ds; } } out: rw_exit(&dp->dp_config_rwlock); dsl_dir_close(dd, FTAG); return (err); } int dsl_dataset_own(const char *name, boolean_t inconsistentok, void *tag, dsl_dataset_t **dsp) { int err = dsl_dataset_hold(name, tag, dsp); if (err) return (err); if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { dsl_dataset_rele(*dsp, tag); return (EBUSY); } return (0); } void dsl_dataset_name(dsl_dataset_t *ds, char *name) { if (ds == NULL) { (void) strcpy(name, "mos"); } else { dsl_dir_name(ds->ds_dir, name); VERIFY(0 == dsl_dataset_get_snapname(ds)); if (ds->ds_snapname[0]) { (void) strcat(name, "@"); /* * We use a "recursive" mutex so that we * can call dprintf_ds() with ds_lock held. */ if (!MUTEX_HELD(&ds->ds_lock)) { mutex_enter(&ds->ds_lock); (void) strcat(name, ds->ds_snapname); mutex_exit(&ds->ds_lock); } else { (void) strcat(name, ds->ds_snapname); } } } } static int dsl_dataset_namelen(dsl_dataset_t *ds) { int result; if (ds == NULL) { result = 3; /* "mos" */ } else { result = dsl_dir_namelen(ds->ds_dir); VERIFY(0 == dsl_dataset_get_snapname(ds)); if (ds->ds_snapname[0]) { ++result; /* adding one for the @-sign */ if (!MUTEX_HELD(&ds->ds_lock)) { mutex_enter(&ds->ds_lock); result += strlen(ds->ds_snapname); mutex_exit(&ds->ds_lock); } else { result += strlen(ds->ds_snapname); } } } return (result); } void dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) { dmu_buf_rele(ds->ds_dbuf, tag); } void dsl_dataset_rele(dsl_dataset_t *ds, void *tag) { if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { rw_exit(&ds->ds_rwlock); } dsl_dataset_drop_ref(ds, tag); } void dsl_dataset_disown(dsl_dataset_t *ds, void *tag) { ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); mutex_enter(&ds->ds_lock); ds->ds_owner = NULL; if (RW_WRITE_HELD(&ds->ds_rwlock)) { rw_exit(&ds->ds_rwlock); cv_broadcast(&ds->ds_exclusive_cv); } mutex_exit(&ds->ds_lock); if (ds->ds_dbuf) dsl_dataset_drop_ref(ds, tag); else dsl_dataset_evict(NULL, ds); } boolean_t dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) { boolean_t gotit = FALSE; mutex_enter(&ds->ds_lock); if (ds->ds_owner == NULL && (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { ds->ds_owner = tag; if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) rw_exit(&ds->ds_rwlock); gotit = TRUE; } mutex_exit(&ds->ds_lock); return (gotit); } void dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) { ASSERT3P(owner, ==, ds->ds_owner); if (!RW_WRITE_HELD(&ds->ds_rwlock)) rw_enter(&ds->ds_rwlock, RW_WRITER); } uint64_t dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, uint64_t flags, dmu_tx_t *tx) { dsl_pool_t *dp = dd->dd_pool; dmu_buf_t *dbuf; dsl_dataset_phys_t *dsphys; uint64_t dsobj; objset_t *mos = dp->dp_meta_objset; if (origin == NULL) origin = dp->dp_origin_snap; ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); ASSERT(dmu_tx_is_syncing(tx)); ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); dmu_buf_will_dirty(dbuf, tx); dsphys = dbuf->db_data; bzero(dsphys, sizeof (dsl_dataset_phys_t)); dsphys->ds_dir_obj = dd->dd_object; dsphys->ds_flags = flags; dsphys->ds_fsid_guid = unique_create(); (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, sizeof (dsphys->ds_guid)); dsphys->ds_snapnames_zapobj = zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, DMU_OT_NONE, 0, tx); dsphys->ds_creation_time = gethrestime_sec(); dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; if (origin == NULL) { dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx); } else { dsl_dataset_t *ohds; dsphys->ds_prev_snap_obj = origin->ds_object; dsphys->ds_prev_snap_txg = origin->ds_phys->ds_creation_txg; dsphys->ds_referenced_bytes = origin->ds_phys->ds_referenced_bytes; dsphys->ds_compressed_bytes = origin->ds_phys->ds_compressed_bytes; dsphys->ds_uncompressed_bytes = origin->ds_phys->ds_uncompressed_bytes; dsphys->ds_bp = origin->ds_phys->ds_bp; dsphys->ds_flags |= origin->ds_phys->ds_flags; dmu_buf_will_dirty(origin->ds_dbuf, tx); origin->ds_phys->ds_num_children++; VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds)); dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist, dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx); dsl_dataset_rele(ohds, FTAG); if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { if (origin->ds_phys->ds_next_clones_obj == 0) { origin->ds_phys->ds_next_clones_obj = zap_create(mos, DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); } VERIFY(0 == zap_add_int(mos, origin->ds_phys->ds_next_clones_obj, dsobj, tx)); } dmu_buf_will_dirty(dd->dd_dbuf, tx); dd->dd_phys->dd_origin_obj = origin->ds_object; if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { if (origin->ds_dir->dd_phys->dd_clones == 0) { dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); origin->ds_dir->dd_phys->dd_clones = zap_create(mos, DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); } VERIFY3U(0, ==, zap_add_int(mos, origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); } } if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; dmu_buf_rele(dbuf, FTAG); dmu_buf_will_dirty(dd->dd_dbuf, tx); dd->dd_phys->dd_head_dataset_obj = dsobj; return (dsobj); } uint64_t dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) { dsl_pool_t *dp = pdd->dd_pool; uint64_t dsobj, ddobj; dsl_dir_t *dd; ASSERT(lastname[0] != '@'); ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); dsl_deleg_set_create_perms(dd, tx, cr); dsl_dir_close(dd, FTAG); /* * If we are creating a clone, make sure we zero out any stale * data from the origin snapshots zil header. */ if (origin != NULL) { dsl_dataset_t *ds; objset_t *os; VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); bzero(&os->os_zil_header, sizeof (os->os_zil_header)); dsl_dataset_dirty(ds, tx); dsl_dataset_rele(ds, FTAG); } return (dsobj); } /* * The snapshots must all be in the same pool. */ int dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, nvlist_t *errlist) { int err; dsl_sync_task_t *dst; spa_t *spa; nvpair_t *pair; dsl_sync_task_group_t *dstg; pair = nvlist_next_nvpair(snaps, NULL); if (pair == NULL) return (0); err = spa_open(nvpair_name(pair), &spa, FTAG); if (err) return (err); dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL; pair = nvlist_next_nvpair(snaps, pair)) { dsl_dataset_t *ds; err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds); if (err == 0) { struct dsl_ds_destroyarg *dsda; dsl_dataset_make_exclusive(ds, dstg); dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP); dsda->ds = ds; dsda->defer = defer; dsl_sync_task_create(dstg, dsl_dataset_destroy_check, dsl_dataset_destroy_sync, dsda, dstg, 0); } else if (err == ENOENT) { err = 0; } else { fnvlist_add_int32(errlist, nvpair_name(pair), err); break; } } if (err == 0) err = dsl_sync_task_group_wait(dstg); for (dst = list_head(&dstg->dstg_tasks); dst; dst = list_next(&dstg->dstg_tasks, dst)) { struct dsl_ds_destroyarg *dsda = dst->dst_arg1; dsl_dataset_t *ds = dsda->ds; /* * Return the snapshots that triggered the error. */ if (dst->dst_err != 0) { char name[ZFS_MAXNAMELEN]; dsl_dataset_name(ds, name); fnvlist_add_int32(errlist, name, dst->dst_err); } ASSERT3P(dsda->rm_origin, ==, NULL); dsl_dataset_disown(ds, dstg); kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); } dsl_sync_task_group_destroy(dstg); spa_close(spa, FTAG); return (err); } static boolean_t dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) { boolean_t might_destroy = B_FALSE; mutex_enter(&ds->ds_lock); if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && DS_IS_DEFER_DESTROY(ds)) might_destroy = B_TRUE; mutex_exit(&ds->ds_lock); return (might_destroy); } /* * If we're removing a clone, and these three conditions are true: * 1) the clone's origin has no other children * 2) the clone's origin has no user references * 3) the clone's origin has been marked for deferred destruction * Then, prepare to remove the origin as part of this sync task group. */ static int dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) { dsl_dataset_t *ds = dsda->ds; dsl_dataset_t *origin = ds->ds_prev; if (dsl_dataset_might_destroy_origin(origin)) { char *name; int namelen; int error; namelen = dsl_dataset_namelen(origin) + 1; name = kmem_alloc(namelen, KM_SLEEP); dsl_dataset_name(origin, name); #ifdef _KERNEL error = zfs_unmount_snap(name, NULL); if (error) { kmem_free(name, namelen); return (error); } #endif error = dsl_dataset_own(name, B_TRUE, tag, &origin); kmem_free(name, namelen); if (error) return (error); dsda->rm_origin = origin; dsl_dataset_make_exclusive(origin, tag); } return (0); } /* * ds must be opened as OWNER. On return (whether successful or not), * ds will be closed and caller can no longer dereference it. */ int dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) { int err; dsl_sync_task_group_t *dstg; objset_t *os; dsl_dir_t *dd; uint64_t obj; struct dsl_ds_destroyarg dsda = { 0 }; dsda.ds = ds; if (dsl_dataset_is_snapshot(ds)) { /* Destroying a snapshot is simpler */ dsl_dataset_make_exclusive(ds, tag); dsda.defer = defer; err = dsl_sync_task_do(ds->ds_dir->dd_pool, dsl_dataset_destroy_check, dsl_dataset_destroy_sync, &dsda, tag, 0); ASSERT3P(dsda.rm_origin, ==, NULL); goto out; } else if (defer) { err = EINVAL; goto out; } dd = ds->ds_dir; if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds), &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) { /* * Check for errors and mark this ds as inconsistent, in * case we crash while freeing the objects. */ err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, dsl_dataset_destroy_begin_sync, ds, NULL, 0); if (err) goto out; err = dmu_objset_from_ds(ds, &os); if (err) goto out; /* * Remove all objects while in the open context so that * there is less work to do in the syncing context. */ for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, ds->ds_phys->ds_prev_snap_txg)) { /* * Ignore errors, if there is not enough disk space * we will deal with it in dsl_dataset_destroy_sync(). */ (void) dmu_free_object(os, obj); } if (err != ESRCH) goto out; /* * Sync out all in-flight IO. */ txg_wait_synced(dd->dd_pool, 0); /* * If we managed to free all the objects in open * context, the user space accounting should be zero. */ if (ds->ds_phys->ds_bp.blk_fill == 0 && dmu_objset_userused_enabled(os)) { ASSERTV(uint64_t count); ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || count == 0); ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || count == 0); } } rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); rw_exit(&dd->dd_pool->dp_config_rwlock); if (err) goto out; /* * Blow away the dsl_dir + head dataset. */ dsl_dataset_make_exclusive(ds, tag); /* * If we're removing a clone, we might also need to remove its * origin. */ do { dsda.need_prep = B_FALSE; if (dsl_dir_is_clone(dd)) { err = dsl_dataset_origin_rm_prep(&dsda, tag); if (err) { dsl_dir_close(dd, FTAG); goto out; } } dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); dsl_sync_task_create(dstg, dsl_dataset_destroy_check, dsl_dataset_destroy_sync, &dsda, tag, 0); dsl_sync_task_create(dstg, dsl_dir_destroy_check, dsl_dir_destroy_sync, dd, FTAG, 0); err = dsl_sync_task_group_wait(dstg); dsl_sync_task_group_destroy(dstg); /* * We could be racing against 'zfs release' or 'zfs destroy -d' * on the origin snap, in which case we can get EBUSY if we * needed to destroy the origin snap but were not ready to * do so. */ if (dsda.need_prep) { ASSERT(err == EBUSY); ASSERT(dsl_dir_is_clone(dd)); ASSERT(dsda.rm_origin == NULL); } } while (dsda.need_prep); if (dsda.rm_origin != NULL) dsl_dataset_disown(dsda.rm_origin, tag); /* if it is successful, dsl_dir_destroy_sync will close the dd */ if (err) dsl_dir_close(dd, FTAG); out: dsl_dataset_disown(ds, tag); return (err); } blkptr_t * dsl_dataset_get_blkptr(dsl_dataset_t *ds) { return (&ds->ds_phys->ds_bp); } void dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) { ASSERT(dmu_tx_is_syncing(tx)); /* If it's the meta-objset, set dp_meta_rootbp */ if (ds == NULL) { tx->tx_pool->dp_meta_rootbp = *bp; } else { dmu_buf_will_dirty(ds->ds_dbuf, tx); ds->ds_phys->ds_bp = *bp; } } spa_t * dsl_dataset_get_spa(dsl_dataset_t *ds) { return (ds->ds_dir->dd_pool->dp_spa); } void dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) { dsl_pool_t *dp; if (ds == NULL) /* this is the meta-objset */ return; ASSERT(ds->ds_objset != NULL); if (ds->ds_phys->ds_next_snap_obj != 0) panic("dirtying snapshot!"); dp = ds->ds_dir->dd_pool; if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { /* up the hold count until we can be written out */ dmu_buf_add_ref(ds->ds_dbuf, ds); } } boolean_t dsl_dataset_is_dirty(dsl_dataset_t *ds) { int t; for (t = 0; t < TXG_SIZE; t++) { if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets, ds, t)) return (B_TRUE); } return (B_FALSE); } /* * The unique space in the head dataset can be calculated by subtracting * the space used in the most recent snapshot, that is still being used * in this file system, from the space currently in use. To figure out * the space in the most recent snapshot still in use, we need to take * the total space used in the snapshot and subtract out the space that * has been freed up since the snapshot was taken. */ static void dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) { uint64_t mrs_used; uint64_t dlused, dlcomp, dluncomp; ASSERT(!dsl_dataset_is_snapshot(ds)); if (ds->ds_phys->ds_prev_snap_obj != 0) mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes; else mrs_used = 0; dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); ASSERT3U(dlused, <=, mrs_used); ds->ds_phys->ds_unique_bytes = ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused); if (spa_version(ds->ds_dir->dd_pool->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; } struct killarg { dsl_dataset_t *ds; dmu_tx_t *tx; }; /* ARGSUSED */ static int kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) { struct killarg *ka = arg; dmu_tx_t *tx = ka->tx; if (bp == NULL) return (0); if (zb->zb_level == ZB_ZIL_LEVEL) { ASSERT(zilog != NULL); /* * It's a block in the intent log. It has no * accounting, so just free it. */ dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); } else { ASSERT(zilog == NULL); ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); } return (0); } /* ARGSUSED */ static int dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; uint64_t count; int err; /* * Can't delete a head dataset if there are snapshots of it. * (Except if the only snapshots are from the branch we cloned * from.) */ if (ds->ds_prev != NULL && ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) return (EBUSY); /* * This is really a dsl_dir thing, but check it here so that * we'll be less likely to leave this dataset inconsistent & * nearly destroyed. */ err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); if (err) return (err); if (count != 0) return (EEXIST); return (0); } /* ARGSUSED */ static void dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; /* Mark it as inconsistent on-disk, in case we crash */ dmu_buf_will_dirty(ds->ds_dbuf, tx); ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; spa_history_log_internal_ds(ds, "destroy begin", tx, ""); } static int dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, dmu_tx_t *tx) { dsl_dataset_t *ds = dsda->ds; dsl_dataset_t *ds_prev = ds->ds_prev; if (dsl_dataset_might_destroy_origin(ds_prev)) { struct dsl_ds_destroyarg ndsda = {0}; /* * If we're not prepared to remove the origin, don't remove * the clone either. */ if (dsda->rm_origin == NULL) { dsda->need_prep = B_TRUE; return (EBUSY); } ndsda.ds = ds_prev; ndsda.is_origin_rm = B_TRUE; return (dsl_dataset_destroy_check(&ndsda, tag, tx)); } /* * If we're not going to remove the origin after all, * undo the open context setup. */ if (dsda->rm_origin != NULL) { dsl_dataset_disown(dsda->rm_origin, tag); dsda->rm_origin = NULL; } return (0); } /* * If you add new checks here, you may need to add * additional checks to the "temporary" case in * snapshot_check() in dmu_objset.c. */ /* ARGSUSED */ int dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) { struct dsl_ds_destroyarg *dsda = arg1; dsl_dataset_t *ds = dsda->ds; /* we have an owner hold, so noone else can destroy us */ ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); /* * Only allow deferred destroy on pools that support it. * NOTE: deferred destroy is only supported on snapshots. */ if (dsda->defer) { if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) return (ENOTSUP); ASSERT(dsl_dataset_is_snapshot(ds)); return (0); } /* * Can't delete a head dataset if there are snapshots of it. * (Except if the only snapshots are from the branch we cloned * from.) */ if (ds->ds_prev != NULL && ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) return (EBUSY); /* * If we made changes this txg, traverse_dsl_dataset won't find * them. Try again. */ if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) return (EAGAIN); if (dsl_dataset_is_snapshot(ds)) { /* * If this snapshot has an elevated user reference count, * we can't destroy it yet. */ if (ds->ds_userrefs > 0 && !dsda->releasing) return (EBUSY); mutex_enter(&ds->ds_lock); /* * Can't delete a branch point. However, if we're destroying * a clone and removing its origin due to it having a user * hold count of 0 and having been marked for deferred destroy, * it's OK for the origin to have a single clone. */ if (ds->ds_phys->ds_num_children > (dsda->is_origin_rm ? 2 : 1)) { mutex_exit(&ds->ds_lock); return (EEXIST); } mutex_exit(&ds->ds_lock); } else if (dsl_dir_is_clone(ds->ds_dir)) { return (dsl_dataset_origin_check(dsda, arg2, tx)); } /* XXX we should do some i/o error checking... */ return (0); } struct refsarg { kmutex_t lock; boolean_t gone; kcondvar_t cv; }; /* ARGSUSED */ static void dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) { struct refsarg *arg = argv; mutex_enter(&arg->lock); arg->gone = TRUE; cv_signal(&arg->cv); mutex_exit(&arg->lock); } static void dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) { struct refsarg arg; mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); arg.gone = FALSE; (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, dsl_dataset_refs_gone); dmu_buf_rele(ds->ds_dbuf, tag); mutex_enter(&arg.lock); while (!arg.gone) cv_wait(&arg.cv, &arg.lock); ASSERT(arg.gone); mutex_exit(&arg.lock); ds->ds_dbuf = NULL; ds->ds_phys = NULL; mutex_destroy(&arg.lock); cv_destroy(&arg.cv); } static void remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) { objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; int err; ASSERTV(uint64_t count); ASSERT(ds->ds_phys->ds_num_children >= 2); err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); /* * The err should not be ENOENT, but a bug in a previous version * of the code could cause upgrade_clones_cb() to not set * ds_next_snap_obj when it should, leading to a missing entry. * If we knew that the pool was created after * SPA_VERSION_NEXT_CLONES, we could assert that it isn't * ENOENT. However, at least we can check that we don't have * too many entries in the next_clones_obj even after failing to * remove this one. */ if (err != ENOENT) { VERIFY0(err); } ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, &count)); ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); } static void dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) { objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; zap_cursor_t zc; zap_attribute_t za; /* * If it is the old version, dd_clones doesn't exist so we can't * find the clones, but deadlist_remove_key() is a no-op so it * doesn't matter. */ if (ds->ds_dir->dd_phys->dd_clones == 0) return; for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); zap_cursor_retrieve(&zc, &za) == 0; zap_cursor_advance(&zc)) { dsl_dataset_t *clone; VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool, za.za_first_integer, FTAG, &clone)); if (clone->ds_dir->dd_origin_txg > mintxg) { dsl_deadlist_remove_key(&clone->ds_deadlist, mintxg, tx); dsl_dataset_remove_clones_key(clone, mintxg, tx); } dsl_dataset_rele(clone, FTAG); } zap_cursor_fini(&zc); } struct process_old_arg { dsl_dataset_t *ds; dsl_dataset_t *ds_prev; boolean_t after_branch_point; zio_t *pio; uint64_t used, comp, uncomp; }; static int process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) { struct process_old_arg *poa = arg; dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); if (poa->ds_prev && !poa->after_branch_point && bp->blk_birth > poa->ds_prev->ds_phys->ds_prev_snap_txg) { poa->ds_prev->ds_phys->ds_unique_bytes += bp_get_dsize_sync(dp->dp_spa, bp); } } else { poa->used += bp_get_dsize_sync(dp->dp_spa, bp); poa->comp += BP_GET_PSIZE(bp); poa->uncomp += BP_GET_UCSIZE(bp); dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); } return (0); } static void process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) { struct process_old_arg poa = { 0 }; dsl_pool_t *dp = ds->ds_dir->dd_pool; objset_t *mos = dp->dp_meta_objset; ASSERT(ds->ds_deadlist.dl_oldfmt); ASSERT(ds_next->ds_deadlist.dl_oldfmt); poa.ds = ds; poa.ds_prev = ds_prev; poa.after_branch_point = after_branch_point; poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, process_old_cb, &poa, tx)); VERIFY0(zio_wait(poa.pio)); ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); /* change snapused */ dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, -poa.used, -poa.comp, -poa.uncomp, tx); /* swap next's deadlist to our deadlist */ dsl_deadlist_close(&ds->ds_deadlist); dsl_deadlist_close(&ds_next->ds_deadlist); SWITCH64(ds_next->ds_phys->ds_deadlist_obj, ds->ds_phys->ds_deadlist_obj); dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); dsl_deadlist_open(&ds_next->ds_deadlist, mos, ds_next->ds_phys->ds_deadlist_obj); } static int old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx) { int err; struct killarg ka; /* * Free everything that we point to (that's born after * the previous snapshot, if we are a clone) * * NB: this should be very quick, because we already * freed all the objects in open context. */ ka.ds = ds; ka.tx = tx; err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST, kill_blkptr, &ka); ASSERT0(err); ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0); return (err); } void dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx) { struct dsl_ds_destroyarg *dsda = arg1; dsl_dataset_t *ds = dsda->ds; int err = 0; int after_branch_point = FALSE; dsl_pool_t *dp = ds->ds_dir->dd_pool; objset_t *mos = dp->dp_meta_objset; dsl_dataset_t *ds_prev = NULL; boolean_t wont_destroy; uint64_t obj; wont_destroy = (dsda->defer && (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)); ASSERT(ds->ds_owner || wont_destroy); ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); ASSERT(ds->ds_prev == NULL || ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); if (wont_destroy) { ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); dmu_buf_will_dirty(ds->ds_dbuf, tx); ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; spa_history_log_internal_ds(ds, "defer_destroy", tx, ""); return; } /* We need to log before removing it from the namespace. */ spa_history_log_internal_ds(ds, "destroy", tx, ""); /* signal any waiters that this dataset is going away */ mutex_enter(&ds->ds_lock); ds->ds_owner = dsl_reaper; cv_broadcast(&ds->ds_exclusive_cv); mutex_exit(&ds->ds_lock); /* Remove our reservation */ if (ds->ds_reserved != 0) { dsl_prop_setarg_t psa; uint64_t value = 0; dsl_prop_setarg_init_uint64(&psa, "refreservation", (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), &value); psa.psa_effective_value = 0; /* predict default value */ dsl_dataset_set_reservation_sync(ds, &psa, tx); ASSERT0(ds->ds_reserved); } ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); dsl_scan_ds_destroyed(ds, tx); obj = ds->ds_object; if (ds->ds_phys->ds_prev_snap_obj != 0) { if (ds->ds_prev) { ds_prev = ds->ds_prev; } else { VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); } after_branch_point = (ds_prev->ds_phys->ds_next_snap_obj != obj); dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); if (after_branch_point && ds_prev->ds_phys->ds_next_clones_obj != 0) { remove_from_next_clones(ds_prev, obj, tx); if (ds->ds_phys->ds_next_snap_obj != 0) { VERIFY(0 == zap_add_int(mos, ds_prev->ds_phys->ds_next_clones_obj, ds->ds_phys->ds_next_snap_obj, tx)); } } if (after_branch_point && ds->ds_phys->ds_next_snap_obj == 0) { /* This clone is toast. */ ASSERT(ds_prev->ds_phys->ds_num_children > 1); ds_prev->ds_phys->ds_num_children--; /* * If the clone's origin has no other clones, no * user holds, and has been marked for deferred * deletion, then we should have done the necessary * destroy setup for it. */ if (ds_prev->ds_phys->ds_num_children == 1 && ds_prev->ds_userrefs == 0 && DS_IS_DEFER_DESTROY(ds_prev)) { ASSERT3P(dsda->rm_origin, !=, NULL); } else { ASSERT3P(dsda->rm_origin, ==, NULL); } } else if (!after_branch_point) { ds_prev->ds_phys->ds_next_snap_obj = ds->ds_phys->ds_next_snap_obj; } } if (dsl_dataset_is_snapshot(ds)) { dsl_dataset_t *ds_next; uint64_t old_unique; uint64_t used = 0, comp = 0, uncomp = 0; VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); old_unique = ds_next->ds_phys->ds_unique_bytes; dmu_buf_will_dirty(ds_next->ds_dbuf, tx); ds_next->ds_phys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; ds_next->ds_phys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); if (ds_next->ds_deadlist.dl_oldfmt) { process_old_deadlist(ds, ds_prev, ds_next, after_branch_point, tx); } else { /* Adjust prev's unique space. */ if (ds_prev && !after_branch_point) { dsl_deadlist_space_range(&ds_next->ds_deadlist, ds_prev->ds_phys->ds_prev_snap_txg, ds->ds_phys->ds_prev_snap_txg, &used, &comp, &uncomp); ds_prev->ds_phys->ds_unique_bytes += used; } /* Adjust snapused. */ dsl_deadlist_space_range(&ds_next->ds_deadlist, ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &used, &comp, &uncomp); dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, -used, -comp, -uncomp, tx); /* Move blocks to be freed to pool's free list. */ dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, tx); dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD, used, comp, uncomp, tx); /* Merge our deadlist into next's and free it. */ dsl_deadlist_merge(&ds_next->ds_deadlist, ds->ds_phys->ds_deadlist_obj, tx); } dsl_deadlist_close(&ds->ds_deadlist); dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); /* Collapse range in clone heads */ dsl_dataset_remove_clones_key(ds, ds->ds_phys->ds_creation_txg, tx); if (dsl_dataset_is_snapshot(ds_next)) { dsl_dataset_t *ds_nextnext; dsl_dataset_t *hds; /* * Update next's unique to include blocks which * were previously shared by only this snapshot * and it. Those blocks will be born after the * prev snap and before this snap, and will have * died after the next snap and before the one * after that (ie. be on the snap after next's * deadlist). */ VERIFY(0 == dsl_dataset_hold_obj(dp, ds_next->ds_phys->ds_next_snap_obj, FTAG, &ds_nextnext)); dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, ds->ds_phys->ds_prev_snap_txg, ds->ds_phys->ds_creation_txg, &used, &comp, &uncomp); ds_next->ds_phys->ds_unique_bytes += used; dsl_dataset_rele(ds_nextnext, FTAG); ASSERT3P(ds_next->ds_prev, ==, NULL); /* Collapse range in this head. */ VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &hds)); dsl_deadlist_remove_key(&hds->ds_deadlist, ds->ds_phys->ds_creation_txg, tx); dsl_dataset_rele(hds, FTAG); } else { ASSERT3P(ds_next->ds_prev, ==, ds); dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); ds_next->ds_prev = NULL; if (ds_prev) { VERIFY(0 == dsl_dataset_get_ref(dp, ds->ds_phys->ds_prev_snap_obj, ds_next, &ds_next->ds_prev)); } dsl_dataset_recalc_head_uniq(ds_next); /* * Reduce the amount of our unconsmed refreservation * being charged to our parent by the amount of * new unique data we have gained. */ if (old_unique < ds_next->ds_reserved) { int64_t mrsdelta; uint64_t new_unique = ds_next->ds_phys->ds_unique_bytes; ASSERT(old_unique <= new_unique); mrsdelta = MIN(new_unique - old_unique, ds_next->ds_reserved - old_unique); dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); } } dsl_dataset_rele(ds_next, FTAG); } else { zfeature_info_t *async_destroy = &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY]; objset_t *os; /* * There's no next snapshot, so this is a head dataset. * Destroy the deadlist. Unless it's a clone, the * deadlist should be empty. (If it's a clone, it's * safe to ignore the deadlist contents.) */ dsl_deadlist_close(&ds->ds_deadlist); dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); ds->ds_phys->ds_deadlist_obj = 0; VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) { err = old_synchronous_dataset_destroy(ds, tx); } else { /* * Move the bptree into the pool's list of trees to * clean up and update space accounting information. */ uint64_t used, comp, uncomp; zil_destroy_sync(dmu_objset_zil(os), tx); if (!spa_feature_is_active(dp->dp_spa, async_destroy)) { spa_feature_incr(dp->dp_spa, async_destroy, tx); dp->dp_bptree_obj = bptree_alloc(mos, tx); VERIFY(zap_add(mos, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1, &dp->dp_bptree_obj, tx) == 0); } used = ds->ds_dir->dd_phys->dd_used_bytes; comp = ds->ds_dir->dd_phys->dd_compressed_bytes; uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes; ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == used); bptree_add(mos, dp->dp_bptree_obj, &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg, used, comp, uncomp, tx); dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, -used, -comp, -uncomp, tx); dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, used, comp, uncomp, tx); } if (ds->ds_prev != NULL) { if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { VERIFY3U(0, ==, zap_remove_int(mos, ds->ds_prev->ds_dir->dd_phys->dd_clones, ds->ds_object, tx)); } dsl_dataset_rele(ds->ds_prev, ds); ds->ds_prev = ds_prev = NULL; } } /* * This must be done after the dsl_traverse(), because it will * re-open the objset. */ if (ds->ds_objset) { dmu_objset_evict(ds->ds_objset); ds->ds_objset = NULL; } if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { /* Erase the link in the dir */ dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); ASSERT(err == 0); } else { /* remove from snapshot namespace */ dsl_dataset_t *ds_head; ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); VERIFY(0 == dsl_dataset_get_snapname(ds)); #ifdef ZFS_DEBUG { uint64_t val; err = dsl_dataset_snap_lookup(ds_head, ds->ds_snapname, &val); ASSERT0(err); ASSERT3U(val, ==, obj); } #endif err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); ASSERT(err == 0); dsl_dataset_rele(ds_head, FTAG); } if (ds_prev && ds->ds_prev != ds_prev) dsl_dataset_rele(ds_prev, FTAG); spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); if (ds->ds_phys->ds_next_clones_obj != 0) { ASSERTV(uint64_t count); ASSERT(0 == zap_count(mos, ds->ds_phys->ds_next_clones_obj, &count) && count == 0); VERIFY(0 == dmu_object_free(mos, ds->ds_phys->ds_next_clones_obj, tx)); } if (ds->ds_phys->ds_props_obj != 0) VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); if (ds->ds_phys->ds_userrefs_obj != 0) VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); dsl_dir_close(ds->ds_dir, ds); ds->ds_dir = NULL; dsl_dataset_drain_refs(ds, tag); VERIFY(0 == dmu_object_free(mos, obj, tx)); if (dsda->rm_origin) { /* * Remove the origin of the clone we just destroyed. */ struct dsl_ds_destroyarg ndsda = {0}; ndsda.ds = dsda->rm_origin; dsl_dataset_destroy_sync(&ndsda, tag, tx); } } static int dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) { uint64_t asize; if (!dmu_tx_is_syncing(tx)) return (0); /* * If there's an fs-only reservation, any blocks that might become * owned by the snapshot dataset must be accommodated by space * outside of the reservation. */ ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds)); asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) return (ENOSPC); /* * Propagate any reserved space for this snapshot to other * snapshot checks in this sync group. */ if (asize > 0) dsl_dir_willuse_space(ds->ds_dir, asize, tx); return (0); } int dsl_dataset_snapshot_check(dsl_dataset_t *ds, const char *snapname, dmu_tx_t *tx) { int err; uint64_t value; /* * We don't allow multiple snapshots of the same txg. If there * is already one, try again. */ if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) return (EAGAIN); /* * Check for conflicting snapshot name. */ err = dsl_dataset_snap_lookup(ds, snapname, &value); if (err == 0) return (EEXIST); if (err != ENOENT) return (err); /* * Check that the dataset's name is not too long. Name consists * of the dataset's length + 1 for the @-sign + snapshot name's length */ if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) return (ENAMETOOLONG); err = dsl_dataset_snapshot_reserve_space(ds, tx); if (err) return (err); ds->ds_trysnap_txg = tx->tx_txg; return (0); } void dsl_dataset_snapshot_sync(dsl_dataset_t *ds, const char *snapname, dmu_tx_t *tx) { dsl_pool_t *dp = ds->ds_dir->dd_pool; dmu_buf_t *dbuf; dsl_dataset_phys_t *dsphys; uint64_t dsobj, crtxg; objset_t *mos = dp->dp_meta_objset; int err; ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); /* * The origin's ds_creation_txg has to be < TXG_INITIAL */ if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) crtxg = 1; else crtxg = tx->tx_txg; dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); dmu_buf_will_dirty(dbuf, tx); dsphys = dbuf->db_data; bzero(dsphys, sizeof (dsl_dataset_phys_t)); dsphys->ds_dir_obj = ds->ds_dir->dd_object; dsphys->ds_fsid_guid = unique_create(); (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, sizeof (dsphys->ds_guid)); dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; dsphys->ds_next_snap_obj = ds->ds_object; dsphys->ds_num_children = 1; dsphys->ds_creation_time = gethrestime_sec(); dsphys->ds_creation_txg = crtxg; dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes; dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; dsphys->ds_flags = ds->ds_phys->ds_flags; dsphys->ds_bp = ds->ds_phys->ds_bp; dmu_buf_rele(dbuf, FTAG); ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); if (ds->ds_prev) { uint64_t next_clones_obj = ds->ds_prev->ds_phys->ds_next_clones_obj; ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object || ds->ds_prev->ds_phys->ds_num_children > 1); if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, ds->ds_prev->ds_phys->ds_creation_txg); ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; } else if (next_clones_obj != 0) { remove_from_next_clones(ds->ds_prev, dsphys->ds_next_snap_obj, tx); VERIFY3U(0, ==, zap_add_int(mos, next_clones_obj, dsobj, tx)); } } /* * If we have a reference-reservation on this dataset, we will * need to increase the amount of refreservation being charged * since our unique space is going to zero. */ if (ds->ds_reserved) { int64_t delta; ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); } dmu_buf_will_dirty(ds->ds_dbuf, tx); zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu", ds->ds_dir->dd_myname, snapname, dsobj, ds->ds_phys->ds_prev_snap_txg); ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist, UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx); dsl_deadlist_close(&ds->ds_deadlist); dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); dsl_deadlist_add_key(&ds->ds_deadlist, ds->ds_phys->ds_prev_snap_txg, tx); ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); ds->ds_phys->ds_prev_snap_obj = dsobj; ds->ds_phys->ds_prev_snap_txg = crtxg; ds->ds_phys->ds_unique_bytes = 0; if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, snapname, 8, 1, &dsobj, tx); ASSERT(err == 0); if (ds->ds_prev) dsl_dataset_drop_ref(ds->ds_prev, ds); VERIFY(0 == dsl_dataset_get_ref(dp, ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); dsl_scan_ds_snapshotted(ds, tx); dsl_dir_snap_cmtime_update(ds->ds_dir); spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, ""); } void dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) { ASSERT(dmu_tx_is_syncing(tx)); ASSERT(ds->ds_objset != NULL); ASSERT(ds->ds_phys->ds_next_snap_obj == 0); /* * in case we had to change ds_fsid_guid when we opened it, * sync it out now. */ dmu_buf_will_dirty(ds->ds_dbuf, tx); ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; dmu_objset_sync(ds->ds_objset, zio, tx); } static void get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv) { uint64_t count = 0; objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; zap_cursor_t zc; zap_attribute_t za; nvlist_t *propval; nvlist_t *val; rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0); VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0); /* * There may me missing entries in ds_next_clones_obj * due to a bug in a previous version of the code. * Only trust it if it has the right number of entries. */ if (ds->ds_phys->ds_next_clones_obj != 0) { ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, &count)); } if (count != ds->ds_phys->ds_num_children - 1) { goto fail; } for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj); zap_cursor_retrieve(&zc, &za) == 0; zap_cursor_advance(&zc)) { dsl_dataset_t *clone; char buf[ZFS_MAXNAMELEN]; /* * Even though we hold the dp_config_rwlock, the dataset * may fail to open, returning ENOENT. If there is a * thread concurrently attempting to destroy this * dataset, it will have the ds_rwlock held for * RW_WRITER. Our call to dsl_dataset_hold_obj() -> * dsl_dataset_hold_ref() will fail its * rw_tryenter(&ds->ds_rwlock, RW_READER), drop the * dp_config_rwlock, and wait for the destroy progress * and signal ds_exclusive_cv. If the destroy was * successful, we will see that * DSL_DATASET_IS_DESTROYED(), and return ENOENT. */ if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool, za.za_first_integer, FTAG, &clone) != 0) continue; dsl_dir_name(clone->ds_dir, buf); VERIFY(nvlist_add_boolean(val, buf) == 0); dsl_dataset_rele(clone, FTAG); } zap_cursor_fini(&zc); VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0); VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), propval) == 0); fail: nvlist_free(val); nvlist_free(propval); rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); } void dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) { uint64_t refd, avail, uobjs, aobjs, ratio; ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 : (ds->ds_phys->ds_uncompressed_bytes * 100 / ds->ds_phys->ds_compressed_bytes); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio); if (dsl_dataset_is_snapshot(ds)) { dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, ds->ds_phys->ds_unique_bytes); get_clones_stat(ds, nv); } else { dsl_dir_stats(ds->ds_dir, nv); } dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, ds->ds_phys->ds_creation_time); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, ds->ds_phys->ds_creation_txg); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, ds->ds_quota); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, ds->ds_reserved); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, ds->ds_phys->ds_guid); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, ds->ds_phys->ds_unique_bytes); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, ds->ds_object); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, ds->ds_userrefs); dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, DS_IS_DEFER_DESTROY(ds) ? 1 : 0); if (ds->ds_phys->ds_prev_snap_obj != 0) { uint64_t written, comp, uncomp; dsl_pool_t *dp = ds->ds_dir->dd_pool; dsl_dataset_t *prev; int err; rw_enter(&dp->dp_config_rwlock, RW_READER); err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj, FTAG, &prev); rw_exit(&dp->dp_config_rwlock); if (err == 0) { err = dsl_dataset_space_written(prev, ds, &written, &comp, &uncomp); dsl_dataset_rele(prev, FTAG); if (err == 0) { dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN, written); } } } } void dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) { stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; stat->dds_guid = ds->ds_phys->ds_guid; stat->dds_origin[0] = '\0'; if (dsl_dataset_is_snapshot(ds)) { stat->dds_is_snapshot = B_TRUE; stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; } else { stat->dds_is_snapshot = B_FALSE; stat->dds_num_clones = 0; rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); if (dsl_dir_is_clone(ds->ds_dir)) { dsl_dataset_t *ods; VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); dsl_dataset_name(ods, stat->dds_origin); dsl_dataset_drop_ref(ods, FTAG); } rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); } } uint64_t dsl_dataset_fsid_guid(dsl_dataset_t *ds) { return (ds->ds_fsid_guid); } void dsl_dataset_space(dsl_dataset_t *ds, uint64_t *refdbytesp, uint64_t *availbytesp, uint64_t *usedobjsp, uint64_t *availobjsp) { *refdbytesp = ds->ds_phys->ds_referenced_bytes; *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; if (ds->ds_quota != 0) { /* * Adjust available bytes according to refquota */ if (*refdbytesp < ds->ds_quota) *availbytesp = MIN(*availbytesp, ds->ds_quota - *refdbytesp); else *availbytesp = 0; } *usedobjsp = ds->ds_phys->ds_bp.blk_fill; *availobjsp = DN_MAX_OBJECT - *usedobjsp; } boolean_t dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) { ASSERTV(dsl_pool_t *dp = ds->ds_dir->dd_pool); ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || dsl_pool_sync_context(dp)); if (ds->ds_prev == NULL) return (B_FALSE); if (ds->ds_phys->ds_bp.blk_birth > ds->ds_prev->ds_phys->ds_creation_txg) { objset_t *os, *os_prev; /* * It may be that only the ZIL differs, because it was * reset in the head. Don't count that as being * modified. */ if (dmu_objset_from_ds(ds, &os) != 0) return (B_TRUE); if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0) return (B_TRUE); return (bcmp(&os->os_phys->os_meta_dnode, &os_prev->os_phys->os_meta_dnode, sizeof (os->os_phys->os_meta_dnode)) != 0); } return (B_FALSE); } /* ARGSUSED */ static int dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; char *newsnapname = arg2; dsl_dir_t *dd = ds->ds_dir; dsl_dataset_t *hds; uint64_t val; int err; err = dsl_dataset_hold_obj(dd->dd_pool, dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); if (err) return (err); /* new name better not be in use */ err = dsl_dataset_snap_lookup(hds, newsnapname, &val); dsl_dataset_rele(hds, FTAG); if (err == 0) err = EEXIST; else if (err == ENOENT) err = 0; /* dataset name + 1 for the "@" + the new snapshot name must fit */ if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) err = ENAMETOOLONG; return (err); } static void dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; const char *newsnapname = arg2; dsl_dir_t *dd = ds->ds_dir; objset_t *mos = dd->dd_pool->dp_meta_objset; dsl_dataset_t *hds; int err; ASSERT(ds->ds_phys->ds_next_snap_obj != 0); VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); VERIFY(0 == dsl_dataset_get_snapname(ds)); err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); ASSERT0(err); mutex_enter(&ds->ds_lock); (void) strcpy(ds->ds_snapname, newsnapname); mutex_exit(&ds->ds_lock); err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 8, 1, &ds->ds_object, tx); ASSERT0(err); spa_history_log_internal_ds(ds, "rename", tx, "-> @%s", newsnapname); dsl_dataset_rele(hds, FTAG); } struct renamesnaparg { dsl_sync_task_group_t *dstg; char failed[MAXPATHLEN]; char *oldsnap; char *newsnap; }; static int dsl_snapshot_rename_one(const char *name, void *arg) { struct renamesnaparg *ra = arg; dsl_dataset_t *ds = NULL; char *snapname; int err; snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); /* * For recursive snapshot renames the parent won't be changing * so we just pass name for both the to/from argument. */ err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); if (err != 0) { strfree(snapname); return (err == ENOENT ? 0 : err); } #ifdef _KERNEL /* * For all filesystems undergoing rename, we'll need to unmount it. */ (void) zfs_unmount_snap(snapname, NULL); #endif err = dsl_dataset_hold(snapname, ra->dstg, &ds); strfree(snapname); if (err != 0) return (err == ENOENT ? 0 : err); dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); return (0); } static int dsl_recursive_rename(char *oldname, const char *newname) { int err; struct renamesnaparg *ra; dsl_sync_task_t *dst; spa_t *spa; char *cp, *fsname = spa_strdup(oldname); int len = strlen(oldname) + 1; /* truncate the snapshot name to get the fsname */ cp = strchr(fsname, '@'); *cp = '\0'; err = spa_open(fsname, &spa, FTAG); if (err) { kmem_free(fsname, len); return (err); } ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); ra->oldsnap = strchr(oldname, '@') + 1; ra->newsnap = strchr(newname, '@') + 1; *ra->failed = '\0'; err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, DS_FIND_CHILDREN); kmem_free(fsname, len); if (err == 0) { err = dsl_sync_task_group_wait(ra->dstg); } for (dst = list_head(&ra->dstg->dstg_tasks); dst; dst = list_next(&ra->dstg->dstg_tasks, dst)) { dsl_dataset_t *ds = dst->dst_arg1; if (dst->dst_err) { dsl_dir_name(ds->ds_dir, ra->failed); (void) strlcat(ra->failed, "@", sizeof (ra->failed)); (void) strlcat(ra->failed, ra->newsnap, sizeof (ra->failed)); } dsl_dataset_rele(ds, ra->dstg); } if (err) (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); dsl_sync_task_group_destroy(ra->dstg); kmem_free(ra, sizeof (struct renamesnaparg)); spa_close(spa, FTAG); return (err); } static int dsl_valid_rename(const char *oldname, void *arg) { int delta = *(int *)arg; if (strlen(oldname) + delta >= MAXNAMELEN) return (ENAMETOOLONG); return (0); } #pragma weak dmu_objset_rename = dsl_dataset_rename int dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) { dsl_dir_t *dd; dsl_dataset_t *ds; const char *tail; int err; err = dsl_dir_open(oldname, FTAG, &dd, &tail); if (err) return (err); if (tail == NULL) { int delta = strlen(newname) - strlen(oldname); /* if we're growing, validate child name lengths */ if (delta > 0) err = dmu_objset_find(oldname, dsl_valid_rename, &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); if (err == 0) err = dsl_dir_rename(dd, newname); dsl_dir_close(dd, FTAG); return (err); } if (tail[0] != '@') { /* the name ended in a nonexistent component */ dsl_dir_close(dd, FTAG); return (ENOENT); } dsl_dir_close(dd, FTAG); /* new name must be snapshot in same filesystem */ tail = strchr(newname, '@'); if (tail == NULL) return (EINVAL); tail++; if (strncmp(oldname, newname, tail - newname) != 0) return (EXDEV); if (recursive) { err = dsl_recursive_rename(oldname, newname); } else { err = dsl_dataset_hold(oldname, FTAG, &ds); if (err) return (err); err = dsl_sync_task_do(ds->ds_dir->dd_pool, dsl_dataset_snapshot_rename_check, dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); dsl_dataset_rele(ds, FTAG); } return (err); } struct promotenode { list_node_t link; dsl_dataset_t *ds; }; struct promotearg { list_t shared_snaps, origin_snaps, clone_snaps; dsl_dataset_t *origin_origin; uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; char *err_ds; }; static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); static int dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *hds = arg1; struct promotearg *pa = arg2; struct promotenode *snap = list_head(&pa->shared_snaps); dsl_dataset_t *origin_ds = snap->ds; int err; uint64_t unused; /* Check that it is a real clone */ if (!dsl_dir_is_clone(hds->ds_dir)) return (EINVAL); /* Since this is so expensive, don't do the preliminary check */ if (!dmu_tx_is_syncing(tx)) return (0); if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) return (EXDEV); /* compute origin's new unique space */ snap = list_tail(&pa->clone_snaps); ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); dsl_deadlist_space_range(&snap->ds->ds_deadlist, origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &pa->unique, &unused, &unused); /* * Walk the snapshots that we are moving * * Compute space to transfer. Consider the incremental changes * to used for each snapshot: * (my used) = (prev's used) + (blocks born) - (blocks killed) * So each snapshot gave birth to: * (blocks born) = (my used) - (prev's used) + (blocks killed) * So a sequence would look like: * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) * Which simplifies to: * uN + kN + kN-1 + ... + k1 + k0 * Note however, if we stop before we reach the ORIGIN we get: * uN + kN + kN-1 + ... + kM - uM-1 */ pa->used = origin_ds->ds_phys->ds_referenced_bytes; pa->comp = origin_ds->ds_phys->ds_compressed_bytes; pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; for (snap = list_head(&pa->shared_snaps); snap; snap = list_next(&pa->shared_snaps, snap)) { uint64_t val, dlused, dlcomp, dluncomp; dsl_dataset_t *ds = snap->ds; /* Check that the snapshot name does not conflict */ VERIFY(0 == dsl_dataset_get_snapname(ds)); err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); if (err == 0) { err = EEXIST; goto out; } if (err != ENOENT) goto out; /* The very first snapshot does not have a deadlist */ if (ds->ds_phys->ds_prev_snap_obj == 0) continue; dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); pa->used += dlused; pa->comp += dlcomp; pa->uncomp += dluncomp; } /* * If we are a clone of a clone then we never reached ORIGIN, * so we need to subtract out the clone origin's used space. */ if (pa->origin_origin) { pa->used -= pa->origin_origin->ds_phys->ds_referenced_bytes; pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; } /* Check that there is enough space here */ err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, pa->used); if (err) return (err); /* * Compute the amounts of space that will be used by snapshots * after the promotion (for both origin and clone). For each, * it is the amount of space that will be on all of their * deadlists (that was not born before their new origin). */ if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { uint64_t space; /* * Note, typically this will not be a clone of a clone, * so dd_origin_txg will be < TXG_INITIAL, so * these snaplist_space() -> dsl_deadlist_space_range() * calls will be fast because they do not have to * iterate over all bps. */ snap = list_head(&pa->origin_snaps); err = snaplist_space(&pa->shared_snaps, snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap); if (err) return (err); err = snaplist_space(&pa->clone_snaps, snap->ds->ds_dir->dd_origin_txg, &space); if (err) return (err); pa->cloneusedsnap += space; } if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { err = snaplist_space(&pa->origin_snaps, origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); if (err) return (err); } return (0); out: pa->err_ds = snap->ds->ds_snapname; return (err); } static void dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *hds = arg1; struct promotearg *pa = arg2; struct promotenode *snap = list_head(&pa->shared_snaps); dsl_dataset_t *origin_ds = snap->ds; dsl_dataset_t *origin_head; dsl_dir_t *dd = hds->ds_dir; dsl_pool_t *dp = hds->ds_dir->dd_pool; dsl_dir_t *odd = NULL; uint64_t oldnext_obj; int64_t delta; ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); snap = list_head(&pa->origin_snaps); origin_head = snap->ds; /* * We need to explicitly open odd, since origin_ds's dd will be * changing. */ VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, NULL, FTAG, &odd)); /* change origin's next snap */ dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; snap = list_tail(&pa->clone_snaps); ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; /* change the origin's next clone */ if (origin_ds->ds_phys->ds_next_clones_obj) { remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, origin_ds->ds_phys->ds_next_clones_obj, oldnext_obj, tx)); } /* change origin */ dmu_buf_will_dirty(dd->dd_dbuf, tx); ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg; dmu_buf_will_dirty(odd->dd_dbuf, tx); odd->dd_phys->dd_origin_obj = origin_ds->ds_object; origin_head->ds_dir->dd_origin_txg = origin_ds->ds_phys->ds_creation_txg; /* change dd_clone entries */ if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, odd->dd_phys->dd_clones, hds->ds_object, tx)); VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, pa->origin_origin->ds_dir->dd_phys->dd_clones, hds->ds_object, tx)); VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, pa->origin_origin->ds_dir->dd_phys->dd_clones, origin_head->ds_object, tx)); if (dd->dd_phys->dd_clones == 0) { dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset, DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); } VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, dd->dd_phys->dd_clones, origin_head->ds_object, tx)); } /* move snapshots to this dir */ for (snap = list_head(&pa->shared_snaps); snap; snap = list_next(&pa->shared_snaps, snap)) { dsl_dataset_t *ds = snap->ds; /* unregister props as dsl_dir is changing */ if (ds->ds_objset) { dmu_objset_evict(ds->ds_objset); ds->ds_objset = NULL; } /* move snap name entry */ VERIFY(0 == dsl_dataset_get_snapname(ds)); VERIFY(0 == dsl_dataset_snap_remove(origin_head, ds->ds_snapname, tx)); VERIFY(0 == zap_add(dp->dp_meta_objset, hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 8, 1, &ds->ds_object, tx)); /* change containing dsl_dir */ dmu_buf_will_dirty(ds->ds_dbuf, tx); ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); ds->ds_phys->ds_dir_obj = dd->dd_object; ASSERT3P(ds->ds_dir, ==, odd); dsl_dir_close(ds->ds_dir, ds); VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, NULL, ds, &ds->ds_dir)); /* move any clone references */ if (ds->ds_phys->ds_next_clones_obj && spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { zap_cursor_t zc; zap_attribute_t za; for (zap_cursor_init(&zc, dp->dp_meta_objset, ds->ds_phys->ds_next_clones_obj); zap_cursor_retrieve(&zc, &za) == 0; zap_cursor_advance(&zc)) { dsl_dataset_t *cnds; uint64_t o; if (za.za_first_integer == oldnext_obj) { /* * We've already moved the * origin's reference. */ continue; } VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, za.za_first_integer, FTAG, &cnds)); o = cnds->ds_dir->dd_phys->dd_head_dataset_obj; VERIFY3U(zap_remove_int(dp->dp_meta_objset, odd->dd_phys->dd_clones, o, tx), ==, 0); VERIFY3U(zap_add_int(dp->dp_meta_objset, dd->dd_phys->dd_clones, o, tx), ==, 0); dsl_dataset_rele(cnds, FTAG); } zap_cursor_fini(&zc); } ASSERT0(dsl_prop_numcb(ds)); } /* * Change space accounting. * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either * both be valid, or both be 0 (resulting in delta == 0). This * is true for each of {clone,origin} independently. */ delta = pa->cloneusedsnap - dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; ASSERT3S(delta, >=, 0); ASSERT3U(pa->used, >=, delta); dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); dsl_dir_diduse_space(dd, DD_USED_HEAD, pa->used - delta, pa->comp, pa->uncomp, tx); delta = pa->originusedsnap - odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; ASSERT3S(delta, <=, 0); ASSERT3U(pa->used, >=, -delta); dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); dsl_dir_diduse_space(odd, DD_USED_HEAD, -pa->used - delta, -pa->comp, -pa->uncomp, tx); origin_ds->ds_phys->ds_unique_bytes = pa->unique; /* log history record */ spa_history_log_internal_ds(hds, "promote", tx, ""); dsl_dir_close(odd, FTAG); } static char *snaplist_tag = "snaplist"; /* * Make a list of dsl_dataset_t's for the snapshots between first_obj * (exclusive) and last_obj (inclusive). The list will be in reverse * order (last_obj will be the list_head()). If first_obj == 0, do all * snapshots back to this dataset's origin. */ static int snaplist_make(dsl_pool_t *dp, boolean_t own, uint64_t first_obj, uint64_t last_obj, list_t *l) { uint64_t obj = last_obj; ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); list_create(l, sizeof (struct promotenode), offsetof(struct promotenode, link)); while (obj != first_obj) { dsl_dataset_t *ds; struct promotenode *snap; int err; if (own) { err = dsl_dataset_own_obj(dp, obj, 0, snaplist_tag, &ds); if (err == 0) dsl_dataset_make_exclusive(ds, snaplist_tag); } else { err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); } if (err == ENOENT) { /* lost race with snapshot destroy */ struct promotenode *last = list_tail(l); ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); obj = last->ds->ds_phys->ds_prev_snap_obj; continue; } else if (err) { return (err); } if (first_obj == 0) first_obj = ds->ds_dir->dd_phys->dd_origin_obj; snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); snap->ds = ds; list_insert_tail(l, snap); obj = ds->ds_phys->ds_prev_snap_obj; } return (0); } static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) { struct promotenode *snap; *spacep = 0; for (snap = list_head(l); snap; snap = list_next(l, snap)) { uint64_t used, comp, uncomp; dsl_deadlist_space_range(&snap->ds->ds_deadlist, mintxg, UINT64_MAX, &used, &comp, &uncomp); *spacep += used; } return (0); } static void snaplist_destroy(list_t *l, boolean_t own) { struct promotenode *snap; if (!l || !list_link_active(&l->list_head)) return; while ((snap = list_tail(l)) != NULL) { list_remove(l, snap); if (own) dsl_dataset_disown(snap->ds, snaplist_tag); else dsl_dataset_rele(snap->ds, snaplist_tag); kmem_free(snap, sizeof (struct promotenode)); } list_destroy(l); } /* * Promote a clone. Nomenclature note: * "clone" or "cds": the original clone which is being promoted * "origin" or "ods": the snapshot which is originally clone's origin * "origin head" or "ohds": the dataset which is the head * (filesystem/volume) for the origin * "origin origin": the origin of the origin's filesystem (typically * NULL, indicating that the clone is not a clone of a clone). */ int dsl_dataset_promote(const char *name, char *conflsnap) { dsl_dataset_t *ds; dsl_dir_t *dd; dsl_pool_t *dp; dmu_object_info_t doi; struct promotearg pa; struct promotenode *snap; int err; bzero(&pa, sizeof(struct promotearg)); err = dsl_dataset_hold(name, FTAG, &ds); if (err) return (err); dd = ds->ds_dir; dp = dd->dd_pool; err = dmu_object_info(dp->dp_meta_objset, ds->ds_phys->ds_snapnames_zapobj, &doi); if (err) { dsl_dataset_rele(ds, FTAG); return (err); } if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { dsl_dataset_rele(ds, FTAG); return (EINVAL); } /* * We are going to inherit all the snapshots taken before our * origin (i.e., our new origin will be our parent's origin). * Take ownership of them so that we can rename them into our * namespace. */ rw_enter(&dp->dp_config_rwlock, RW_READER); err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, &pa.shared_snaps); if (err != 0) goto out; err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); if (err != 0) goto out; snap = list_head(&pa.shared_snaps); ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); if (err != 0) goto out; if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) { err = dsl_dataset_hold_obj(dp, snap->ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &pa.origin_origin); if (err != 0) goto out; } out: rw_exit(&dp->dp_config_rwlock); /* * Add in 128x the snapnames zapobj size, since we will be moving * a bunch of snapnames to the promoted ds, and dirtying their * bonus buffers. */ if (err == 0) { err = dsl_sync_task_do(dp, dsl_dataset_promote_check, dsl_dataset_promote_sync, ds, &pa, 2 + 2 * doi.doi_physical_blocks_512); if (err && pa.err_ds && conflsnap) (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); } snaplist_destroy(&pa.shared_snaps, B_TRUE); snaplist_destroy(&pa.clone_snaps, B_FALSE); snaplist_destroy(&pa.origin_snaps, B_FALSE); if (pa.origin_origin) dsl_dataset_rele(pa.origin_origin, FTAG); dsl_dataset_rele(ds, FTAG); return (err); } struct cloneswaparg { dsl_dataset_t *cds; /* clone dataset */ dsl_dataset_t *ohds; /* origin's head dataset */ boolean_t force; int64_t unused_refres_delta; /* change in unconsumed refreservation */ }; /* ARGSUSED */ static int dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) { struct cloneswaparg *csa = arg1; /* they should both be heads */ if (dsl_dataset_is_snapshot(csa->cds) || dsl_dataset_is_snapshot(csa->ohds)) return (EINVAL); /* the branch point should be just before them */ if (csa->cds->ds_prev != csa->ohds->ds_prev) return (EINVAL); /* cds should be the clone (unless they are unrelated) */ if (csa->cds->ds_prev != NULL && csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && csa->ohds->ds_object != csa->cds->ds_prev->ds_phys->ds_next_snap_obj) return (EINVAL); /* the clone should be a child of the origin */ if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) return (EINVAL); /* ohds shouldn't be modified unless 'force' */ if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) return (ETXTBSY); /* adjust amount of any unconsumed refreservation */ csa->unused_refres_delta = (int64_t)MIN(csa->ohds->ds_reserved, csa->ohds->ds_phys->ds_unique_bytes) - (int64_t)MIN(csa->ohds->ds_reserved, csa->cds->ds_phys->ds_unique_bytes); if (csa->unused_refres_delta > 0 && csa->unused_refres_delta > dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) return (ENOSPC); if (csa->ohds->ds_quota != 0 && csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) return (EDQUOT); return (0); } /* ARGSUSED */ static void dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx) { struct cloneswaparg *csa = arg1; dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; ASSERT(csa->cds->ds_reserved == 0); ASSERT(csa->ohds->ds_quota == 0 || csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); if (csa->cds->ds_objset != NULL) { dmu_objset_evict(csa->cds->ds_objset); csa->cds->ds_objset = NULL; } if (csa->ohds->ds_objset != NULL) { dmu_objset_evict(csa->ohds->ds_objset); csa->ohds->ds_objset = NULL; } /* * Reset origin's unique bytes, if it exists. */ if (csa->cds->ds_prev) { dsl_dataset_t *origin = csa->cds->ds_prev; uint64_t comp, uncomp; dmu_buf_will_dirty(origin->ds_dbuf, tx); dsl_deadlist_space_range(&csa->cds->ds_deadlist, origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, &origin->ds_phys->ds_unique_bytes, &comp, &uncomp); } /* swap blkptrs */ { blkptr_t tmp; tmp = csa->ohds->ds_phys->ds_bp; csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; csa->cds->ds_phys->ds_bp = tmp; } /* set dd_*_bytes */ { int64_t dused, dcomp, duncomp; uint64_t cdl_used, cdl_comp, cdl_uncomp; uint64_t odl_used, odl_comp, odl_uncomp; ASSERT3U(csa->cds->ds_dir->dd_phys-> dd_used_breakdown[DD_USED_SNAP], ==, 0); dsl_deadlist_space(&csa->cds->ds_deadlist, &cdl_used, &cdl_comp, &cdl_uncomp); dsl_deadlist_space(&csa->ohds->ds_deadlist, &odl_used, &odl_comp, &odl_uncomp); dused = csa->cds->ds_phys->ds_referenced_bytes + cdl_used - (csa->ohds->ds_phys->ds_referenced_bytes + odl_used); dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + cdl_uncomp - (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, dused, dcomp, duncomp, tx); dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, -dused, -dcomp, -duncomp, tx); /* * The difference in the space used by snapshots is the * difference in snapshot space due to the head's * deadlist (since that's the only thing that's * changing that affects the snapused). */ dsl_deadlist_space_range(&csa->cds->ds_deadlist, csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, &cdl_used, &cdl_comp, &cdl_uncomp); dsl_deadlist_space_range(&csa->ohds->ds_deadlist, csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, &odl_used, &odl_comp, &odl_uncomp); dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, DD_USED_HEAD, DD_USED_SNAP, tx); } /* swap ds_*_bytes */ SWITCH64(csa->ohds->ds_phys->ds_referenced_bytes, csa->cds->ds_phys->ds_referenced_bytes); SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, csa->cds->ds_phys->ds_compressed_bytes); SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, csa->cds->ds_phys->ds_uncompressed_bytes); SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, csa->cds->ds_phys->ds_unique_bytes); /* apply any parent delta for change in unconsumed refreservation */ dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, csa->unused_refres_delta, 0, 0, tx); /* * Swap deadlists. */ dsl_deadlist_close(&csa->cds->ds_deadlist); dsl_deadlist_close(&csa->ohds->ds_deadlist); SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, csa->cds->ds_phys->ds_deadlist_obj); dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, csa->cds->ds_phys->ds_deadlist_obj); dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, csa->ohds->ds_phys->ds_deadlist_obj); dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx); spa_history_log_internal_ds(csa->cds, "clone swap", tx, "parent=%s", csa->ohds->ds_dir->dd_myname); } /* * Swap 'clone' with its origin head datasets. Used at the end of "zfs * recv" into an existing fs to swizzle the file system to the new * version, and by "zfs rollback". Can also be used to swap two * independent head datasets if neither has any snapshots. */ int dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, boolean_t force) { struct cloneswaparg csa; int error; ASSERT(clone->ds_owner); ASSERT(origin_head->ds_owner); retry: /* * Need exclusive access for the swap. If we're swapping these * datasets back after an error, we already hold the locks. */ if (!RW_WRITE_HELD(&clone->ds_rwlock)) rw_enter(&clone->ds_rwlock, RW_WRITER); if (!RW_WRITE_HELD(&origin_head->ds_rwlock) && !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { rw_exit(&clone->ds_rwlock); rw_enter(&origin_head->ds_rwlock, RW_WRITER); if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { rw_exit(&origin_head->ds_rwlock); goto retry; } } csa.cds = clone; csa.ohds = origin_head; csa.force = force; error = dsl_sync_task_do(clone->ds_dir->dd_pool, dsl_dataset_clone_swap_check, dsl_dataset_clone_swap_sync, &csa, NULL, 9); return (error); } /* * Given a pool name and a dataset object number in that pool, * return the name of that dataset. */ int dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) { spa_t *spa; dsl_pool_t *dp; dsl_dataset_t *ds; int error; if ((error = spa_open(pname, &spa, FTAG)) != 0) return (error); dp = spa_get_dsl(spa); rw_enter(&dp->dp_config_rwlock, RW_READER); if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { dsl_dataset_name(ds, buf); dsl_dataset_rele(ds, FTAG); } rw_exit(&dp->dp_config_rwlock); spa_close(spa, FTAG); return (error); } int dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) { int error = 0; ASSERT3S(asize, >, 0); /* * *ref_rsrv is the portion of asize that will come from any * unconsumed refreservation space. */ *ref_rsrv = 0; mutex_enter(&ds->ds_lock); /* * Make a space adjustment for reserved bytes. */ if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { ASSERT3U(*used, >=, ds->ds_reserved - ds->ds_phys->ds_unique_bytes); *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); *ref_rsrv = asize - MIN(asize, parent_delta(ds, asize + inflight)); } if (!check_quota || ds->ds_quota == 0) { mutex_exit(&ds->ds_lock); return (0); } /* * If they are requesting more space, and our current estimate * is over quota, they get to try again unless the actual * on-disk is over quota and there are no pending changes (which * may free up space for us). */ if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) { if (inflight > 0 || ds->ds_phys->ds_referenced_bytes < ds->ds_quota) error = ERESTART; else error = EDQUOT; DMU_TX_STAT_BUMP(dmu_tx_quota); } mutex_exit(&ds->ds_lock); return (error); } /* ARGSUSED */ static int dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; dsl_prop_setarg_t *psa = arg2; int err; if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) return (ENOTSUP); if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) return (err); if (psa->psa_effective_value == 0) return (0); if (psa->psa_effective_value < ds->ds_phys->ds_referenced_bytes || psa->psa_effective_value < ds->ds_reserved) return (ENOSPC); return (0); } extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *); void dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; dsl_prop_setarg_t *psa = arg2; uint64_t effective_value = psa->psa_effective_value; dsl_prop_set_sync(ds, psa, tx); DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); if (ds->ds_quota != effective_value) { dmu_buf_will_dirty(ds->ds_dbuf, tx); ds->ds_quota = effective_value; spa_history_log_internal_ds(ds, "set refquota", tx, "refquota=%lld", (longlong_t)ds->ds_quota); } } int dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) { dsl_dataset_t *ds; dsl_prop_setarg_t psa; int err; dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); err = dsl_dataset_hold(dsname, FTAG, &ds); if (err) return (err); /* * If someone removes a file, then tries to set the quota, we * want to make sure the file freeing takes effect. */ txg_wait_open(ds->ds_dir->dd_pool, 0); err = dsl_sync_task_do(ds->ds_dir->dd_pool, dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, ds, &psa, 0); dsl_dataset_rele(ds, FTAG); return (err); } static int dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; dsl_prop_setarg_t *psa = arg2; uint64_t effective_value; uint64_t unique; int err; if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFRESERVATION) return (ENOTSUP); if (dsl_dataset_is_snapshot(ds)) return (EINVAL); if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) return (err); effective_value = psa->psa_effective_value; /* * If we are doing the preliminary check in open context, the * space estimates may be inaccurate. */ if (!dmu_tx_is_syncing(tx)) return (0); mutex_enter(&ds->ds_lock); if (!DS_UNIQUE_IS_ACCURATE(ds)) dsl_dataset_recalc_head_uniq(ds); unique = ds->ds_phys->ds_unique_bytes; mutex_exit(&ds->ds_lock); if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { uint64_t delta = MAX(unique, effective_value) - MAX(unique, ds->ds_reserved); if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) return (ENOSPC); if (ds->ds_quota > 0 && effective_value > ds->ds_quota) return (ENOSPC); } return (0); } static void dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; dsl_prop_setarg_t *psa = arg2; uint64_t effective_value = psa->psa_effective_value; uint64_t unique; int64_t delta; dsl_prop_set_sync(ds, psa, tx); DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); dmu_buf_will_dirty(ds->ds_dbuf, tx); mutex_enter(&ds->ds_dir->dd_lock); mutex_enter(&ds->ds_lock); ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); unique = ds->ds_phys->ds_unique_bytes; delta = MAX(0, (int64_t)(effective_value - unique)) - MAX(0, (int64_t)(ds->ds_reserved - unique)); ds->ds_reserved = effective_value; mutex_exit(&ds->ds_lock); dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); mutex_exit(&ds->ds_dir->dd_lock); spa_history_log_internal_ds(ds, "set refreservation", tx, "refreservation=%lld", (longlong_t)effective_value); } int dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, uint64_t reservation) { dsl_dataset_t *ds; dsl_prop_setarg_t psa; int err; dsl_prop_setarg_init_uint64(&psa, "refreservation", source, &reservation); err = dsl_dataset_hold(dsname, FTAG, &ds); if (err) return (err); err = dsl_sync_task_do(ds->ds_dir->dd_pool, dsl_dataset_set_reservation_check, dsl_dataset_set_reservation_sync, ds, &psa, 0); dsl_dataset_rele(ds, FTAG); return (err); } typedef struct zfs_hold_cleanup_arg { dsl_pool_t *dp; uint64_t dsobj; char htag[MAXNAMELEN]; } zfs_hold_cleanup_arg_t; static void dsl_dataset_user_release_onexit(void *arg) { zfs_hold_cleanup_arg_t *ca = arg; (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag, B_TRUE); kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t)); } void dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag, minor_t minor) { zfs_hold_cleanup_arg_t *ca; ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP); ca->dp = ds->ds_dir->dd_pool; ca->dsobj = ds->ds_object; (void) strlcpy(ca->htag, htag, sizeof (ca->htag)); VERIFY3U(0, ==, zfs_onexit_add_cb(minor, dsl_dataset_user_release_onexit, ca, NULL)); } /* * If you add new checks here, you may need to add * additional checks to the "temporary" case in * snapshot_check() in dmu_objset.c. */ static int dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; struct dsl_ds_holdarg *ha = arg2; const char *htag = ha->htag; objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; int error = 0; if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) return (ENOTSUP); if (!dsl_dataset_is_snapshot(ds)) return (EINVAL); /* tags must be unique */ mutex_enter(&ds->ds_lock); if (ds->ds_phys->ds_userrefs_obj) { error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 8, 1, tx); if (error == 0) error = EEXIST; else if (error == ENOENT) error = 0; } mutex_exit(&ds->ds_lock); if (error == 0 && ha->temphold && strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) error = E2BIG; return (error); } void dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx) { dsl_dataset_t *ds = arg1; struct dsl_ds_holdarg *ha = arg2; const char *htag = ha->htag; dsl_pool_t *dp = ds->ds_dir->dd_pool; objset_t *mos = dp->dp_meta_objset; uint64_t now = gethrestime_sec(); uint64_t zapobj; mutex_enter(&ds->ds_lock); if (ds->ds_phys->ds_userrefs_obj == 0) { /* * This is the first user hold for this dataset. Create * the userrefs zap object. */ dmu_buf_will_dirty(ds->ds_dbuf, tx); zapobj = ds->ds_phys->ds_userrefs_obj = zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); } else { zapobj = ds->ds_phys->ds_userrefs_obj; } ds->ds_userrefs++; mutex_exit(&ds->ds_lock); VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); if (ha->temphold) { VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, htag, &now, tx)); } spa_history_log_internal_ds(ds, "hold", tx, "tag = %s temp = %d holds now = %llu", htag, (int)ha->temphold, ds->ds_userrefs); } static int dsl_dataset_user_hold_one(const char *dsname, void *arg) { struct dsl_ds_holdarg *ha = arg; dsl_dataset_t *ds; int error; char *name; /* alloc a buffer to hold dsname@snapname plus terminating NULL */ name = kmem_asprintf("%s@%s", dsname, ha->snapname); error = dsl_dataset_hold(name, ha->dstg, &ds); strfree(name); if (error == 0) { ha->gotone = B_TRUE; dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync, ds, ha, 0); } else if (error == ENOENT && ha->recursive) { error = 0; } else { (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); } return (error); } int dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag, boolean_t temphold) { struct dsl_ds_holdarg *ha; int error; ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); ha->htag = htag; ha->temphold = temphold; error = dsl_sync_task_do(ds->ds_dir->dd_pool, dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync, ds, ha, 0); kmem_free(ha, sizeof (struct dsl_ds_holdarg)); return (error); } int dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, boolean_t recursive, boolean_t temphold, int cleanup_fd) { struct dsl_ds_holdarg *ha; dsl_sync_task_t *dst; spa_t *spa; int error; minor_t minor = 0; if (cleanup_fd != -1) { /* Currently we only support cleanup-on-exit of tempholds. */ if (!temphold) return (EINVAL); error = zfs_onexit_fd_hold(cleanup_fd, &minor); if (error) return (error); } ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); error = spa_open(dsname, &spa, FTAG); if (error) { kmem_free(ha, sizeof (struct dsl_ds_holdarg)); if (cleanup_fd != -1) zfs_onexit_fd_rele(cleanup_fd); return (error); } ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); ha->htag = htag; ha->snapname = snapname; ha->recursive = recursive; ha->temphold = temphold; if (recursive) { error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, ha, DS_FIND_CHILDREN); } else { error = dsl_dataset_user_hold_one(dsname, ha); } if (error == 0) error = dsl_sync_task_group_wait(ha->dstg); for (dst = list_head(&ha->dstg->dstg_tasks); dst; dst = list_next(&ha->dstg->dstg_tasks, dst)) { dsl_dataset_t *ds = dst->dst_arg1; if (dst->dst_err) { dsl_dataset_name(ds, ha->failed); *strchr(ha->failed, '@') = '\0'; } else if (error == 0 && minor != 0 && temphold) { /* * If this hold is to be released upon process exit, * register that action now. */ dsl_register_onexit_hold_cleanup(ds, htag, minor); } dsl_dataset_rele(ds, ha->dstg); } if (error == 0 && recursive && !ha->gotone) error = ENOENT; if (error) (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); dsl_sync_task_group_destroy(ha->dstg); kmem_free(ha, sizeof (struct dsl_ds_holdarg)); spa_close(spa, FTAG); if (cleanup_fd != -1) zfs_onexit_fd_rele(cleanup_fd); return (error); } struct dsl_ds_releasearg { dsl_dataset_t *ds; const char *htag; boolean_t own; /* do we own or just hold ds? */ }; static int dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, boolean_t *might_destroy) { objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; uint64_t zapobj; uint64_t tmp; int error; *might_destroy = B_FALSE; mutex_enter(&ds->ds_lock); zapobj = ds->ds_phys->ds_userrefs_obj; if (zapobj == 0) { /* The tag can't possibly exist */ mutex_exit(&ds->ds_lock); return (ESRCH); } /* Make sure the tag exists */ error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); if (error) { mutex_exit(&ds->ds_lock); if (error == ENOENT) error = ESRCH; return (error); } if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && DS_IS_DEFER_DESTROY(ds)) *might_destroy = B_TRUE; mutex_exit(&ds->ds_lock); return (0); } static int dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) { struct dsl_ds_releasearg *ra = arg1; dsl_dataset_t *ds = ra->ds; boolean_t might_destroy; int error; if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) return (ENOTSUP); error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); if (error) return (error); if (might_destroy) { struct dsl_ds_destroyarg dsda = {0}; if (dmu_tx_is_syncing(tx)) { /* * If we're not prepared to remove the snapshot, * we can't allow the release to happen right now. */ if (!ra->own) return (EBUSY); } dsda.ds = ds; dsda.releasing = B_TRUE; return (dsl_dataset_destroy_check(&dsda, tag, tx)); } return (0); } static void dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx) { struct dsl_ds_releasearg *ra = arg1; dsl_dataset_t *ds = ra->ds; dsl_pool_t *dp = ds->ds_dir->dd_pool; objset_t *mos = dp->dp_meta_objset; uint64_t zapobj; uint64_t refs; int error; mutex_enter(&ds->ds_lock); ds->ds_userrefs--; refs = ds->ds_userrefs; mutex_exit(&ds->ds_lock); error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); VERIFY(error == 0 || error == ENOENT); zapobj = ds->ds_phys->ds_userrefs_obj; VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && DS_IS_DEFER_DESTROY(ds)) { struct dsl_ds_destroyarg dsda = {0}; ASSERT(ra->own); dsda.ds = ds; dsda.releasing = B_TRUE; /* We already did the destroy_check */ dsl_dataset_destroy_sync(&dsda, tag, tx); } } static int dsl_dataset_user_release_one(const char *dsname, void *arg) { struct dsl_ds_holdarg *ha = arg; struct dsl_ds_releasearg *ra; dsl_dataset_t *ds; int error; void *dtag = ha->dstg; char *name; boolean_t own = B_FALSE; boolean_t might_destroy; /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ name = kmem_asprintf("%s@%s", dsname, ha->snapname); error = dsl_dataset_hold(name, dtag, &ds); strfree(name); if (error == ENOENT && ha->recursive) return (0); (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); if (error) return (error); ha->gotone = B_TRUE; ASSERT(dsl_dataset_is_snapshot(ds)); error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); if (error) { dsl_dataset_rele(ds, dtag); return (error); } if (might_destroy) { #ifdef _KERNEL name = kmem_asprintf("%s@%s", dsname, ha->snapname); error = zfs_unmount_snap(name, NULL); strfree(name); if (error) { dsl_dataset_rele(ds, dtag); return (error); } #endif if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { dsl_dataset_rele(ds, dtag); return (EBUSY); } else { own = B_TRUE; dsl_dataset_make_exclusive(ds, dtag); } } ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); ra->ds = ds; ra->htag = ha->htag; ra->own = own; dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, dsl_dataset_user_release_sync, ra, dtag, 0); return (0); } int dsl_dataset_user_release(char *dsname, char *snapname, char *htag, boolean_t recursive) { struct dsl_ds_holdarg *ha; dsl_sync_task_t *dst; spa_t *spa; int error; top: ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); error = spa_open(dsname, &spa, FTAG); if (error) { kmem_free(ha, sizeof (struct dsl_ds_holdarg)); return (error); } ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); ha->htag = htag; ha->snapname = snapname; ha->recursive = recursive; if (recursive) { error = dmu_objset_find(dsname, dsl_dataset_user_release_one, ha, DS_FIND_CHILDREN); } else { error = dsl_dataset_user_release_one(dsname, ha); } if (error == 0) error = dsl_sync_task_group_wait(ha->dstg); for (dst = list_head(&ha->dstg->dstg_tasks); dst; dst = list_next(&ha->dstg->dstg_tasks, dst)) { struct dsl_ds_releasearg *ra = dst->dst_arg1; dsl_dataset_t *ds = ra->ds; if (dst->dst_err) dsl_dataset_name(ds, ha->failed); if (ra->own) dsl_dataset_disown(ds, ha->dstg); else dsl_dataset_rele(ds, ha->dstg); kmem_free(ra, sizeof (struct dsl_ds_releasearg)); } if (error == 0 && recursive && !ha->gotone) error = ENOENT; if (error && error != EBUSY) (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); dsl_sync_task_group_destroy(ha->dstg); kmem_free(ha, sizeof (struct dsl_ds_holdarg)); spa_close(spa, FTAG); /* * We can get EBUSY if we were racing with deferred destroy and * dsl_dataset_user_release_check() hadn't done the necessary * open context setup. We can also get EBUSY if we're racing * with destroy and that thread is the ds_owner. Either way * the busy condition should be transient, and we should retry * the release operation. */ if (error == EBUSY) goto top; return (error); } /* * Called at spa_load time (with retry == B_FALSE) to release a stale * temporary user hold. Also called by the onexit code (with retry == B_TRUE). */ int dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag, boolean_t retry) { dsl_dataset_t *ds; char *snap; char *name; int namelen; int error; do { rw_enter(&dp->dp_config_rwlock, RW_READER); error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); rw_exit(&dp->dp_config_rwlock); if (error) return (error); namelen = dsl_dataset_namelen(ds)+1; name = kmem_alloc(namelen, KM_SLEEP); dsl_dataset_name(ds, name); dsl_dataset_rele(ds, FTAG); snap = strchr(name, '@'); *snap = '\0'; ++snap; error = dsl_dataset_user_release(name, snap, htag, B_FALSE); kmem_free(name, namelen); /* * The object can't have been destroyed because we have a hold, * but it might have been renamed, resulting in ENOENT. Retry * if we've been requested to do so. * * It would be nice if we could use the dsobj all the way * through and avoid ENOENT entirely. But we might need to * unmount the snapshot, and there's currently no way to lookup * a vfsp using a ZFS object id. */ } while ((error == ENOENT) && retry); return (error); } int dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) { dsl_dataset_t *ds; int err; err = dsl_dataset_hold(dsname, FTAG, &ds); if (err) return (err); VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); if (ds->ds_phys->ds_userrefs_obj != 0) { zap_attribute_t *za; zap_cursor_t zc; za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, ds->ds_phys->ds_userrefs_obj); zap_cursor_retrieve(&zc, za) == 0; zap_cursor_advance(&zc)) { VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, za->za_first_integer)); } zap_cursor_fini(&zc); kmem_free(za, sizeof (zap_attribute_t)); } dsl_dataset_rele(ds, FTAG); return (0); } /* * Note, this function is used as the callback for dmu_objset_find(). We * always return 0 so that we will continue to find and process * inconsistent datasets, even if we encounter an error trying to * process one of them. */ /* ARGSUSED */ int dsl_destroy_inconsistent(const char *dsname, void *arg) { dsl_dataset_t *ds; if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { if (DS_IS_INCONSISTENT(ds)) (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); else dsl_dataset_disown(ds, FTAG); } return (0); } /* * Return (in *usedp) the amount of space written in new that is not * present in oldsnap. New may be a snapshot or the head. Old must be * a snapshot before new, in new's filesystem (or its origin). If not then * fail and return EINVAL. * * The written space is calculated by considering two components: First, we * ignore any freed space, and calculate the written as new's used space * minus old's used space. Next, we add in the amount of space that was freed * between the two snapshots, thus reducing new's used space relative to old's. * Specifically, this is the space that was born before old->ds_creation_txg, * and freed before new (ie. on new's deadlist or a previous deadlist). * * space freed [---------------------] * snapshots ---O-------O--------O-------O------ * oldsnap new */ int dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new, uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) { int err = 0; uint64_t snapobj; dsl_pool_t *dp = new->ds_dir->dd_pool; *usedp = 0; *usedp += new->ds_phys->ds_referenced_bytes; *usedp -= oldsnap->ds_phys->ds_referenced_bytes; *compp = 0; *compp += new->ds_phys->ds_compressed_bytes; *compp -= oldsnap->ds_phys->ds_compressed_bytes; *uncompp = 0; *uncompp += new->ds_phys->ds_uncompressed_bytes; *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes; rw_enter(&dp->dp_config_rwlock, RW_READER); snapobj = new->ds_object; while (snapobj != oldsnap->ds_object) { dsl_dataset_t *snap; uint64_t used, comp, uncomp; if (snapobj == new->ds_object) { snap = new; } else { err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap); if (err != 0) break; } if (snap->ds_phys->ds_prev_snap_txg == oldsnap->ds_phys->ds_creation_txg) { /* * The blocks in the deadlist can not be born after * ds_prev_snap_txg, so get the whole deadlist space, * which is more efficient (especially for old-format * deadlists). Unfortunately the deadlist code * doesn't have enough information to make this * optimization itself. */ dsl_deadlist_space(&snap->ds_deadlist, &used, &comp, &uncomp); } else { dsl_deadlist_space_range(&snap->ds_deadlist, 0, oldsnap->ds_phys->ds_creation_txg, &used, &comp, &uncomp); } *usedp += used; *compp += comp; *uncompp += uncomp; /* * If we get to the beginning of the chain of snapshots * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap * was not a snapshot of/before new. */ snapobj = snap->ds_phys->ds_prev_snap_obj; if (snap != new) dsl_dataset_rele(snap, FTAG); if (snapobj == 0) { err = EINVAL; break; } } rw_exit(&dp->dp_config_rwlock); return (err); } /* * Return (in *usedp) the amount of space that will be reclaimed if firstsnap, * lastsnap, and all snapshots in between are deleted. * * blocks that would be freed [---------------------------] * snapshots ---O-------O--------O-------O--------O * firstsnap lastsnap * * This is the set of blocks that were born after the snap before firstsnap, * (birth > firstsnap->prev_snap_txg) and died before the snap after the * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist). * We calculate this by iterating over the relevant deadlists (from the snap * after lastsnap, backward to the snap after firstsnap), summing up the * space on the deadlist that was born after the snap before firstsnap. */ int dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap, dsl_dataset_t *lastsnap, uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) { int err = 0; uint64_t snapobj; dsl_pool_t *dp = firstsnap->ds_dir->dd_pool; ASSERT(dsl_dataset_is_snapshot(firstsnap)); ASSERT(dsl_dataset_is_snapshot(lastsnap)); /* * Check that the snapshots are in the same dsl_dir, and firstsnap * is before lastsnap. */ if (firstsnap->ds_dir != lastsnap->ds_dir || firstsnap->ds_phys->ds_creation_txg > lastsnap->ds_phys->ds_creation_txg) return (EINVAL); *usedp = *compp = *uncompp = 0; rw_enter(&dp->dp_config_rwlock, RW_READER); snapobj = lastsnap->ds_phys->ds_next_snap_obj; while (snapobj != firstsnap->ds_object) { dsl_dataset_t *ds; uint64_t used, comp, uncomp; err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds); if (err != 0) break; dsl_deadlist_space_range(&ds->ds_deadlist, firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX, &used, &comp, &uncomp); *usedp += used; *compp += comp; *uncompp += uncomp; snapobj = ds->ds_phys->ds_prev_snap_obj; ASSERT3U(snapobj, !=, 0); dsl_dataset_rele(ds, FTAG); } rw_exit(&dp->dp_config_rwlock); return (err); } #if defined(_KERNEL) && defined(HAVE_SPL) EXPORT_SYMBOL(dmu_snapshots_destroy_nvl); EXPORT_SYMBOL(dsl_dataset_hold); EXPORT_SYMBOL(dsl_dataset_hold_obj); EXPORT_SYMBOL(dsl_dataset_own); EXPORT_SYMBOL(dsl_dataset_own_obj); EXPORT_SYMBOL(dsl_dataset_name); EXPORT_SYMBOL(dsl_dataset_rele); EXPORT_SYMBOL(dsl_dataset_disown); EXPORT_SYMBOL(dsl_dataset_drop_ref); EXPORT_SYMBOL(dsl_dataset_tryown); EXPORT_SYMBOL(dsl_dataset_make_exclusive); EXPORT_SYMBOL(dsl_dataset_create_sync); EXPORT_SYMBOL(dsl_dataset_create_sync_dd); EXPORT_SYMBOL(dsl_dataset_destroy); EXPORT_SYMBOL(dsl_dataset_destroy_check); EXPORT_SYMBOL(dsl_dataset_destroy_sync); EXPORT_SYMBOL(dsl_dataset_snapshot_check); EXPORT_SYMBOL(dsl_dataset_snapshot_sync); EXPORT_SYMBOL(dsl_dataset_rename); EXPORT_SYMBOL(dsl_dataset_promote); EXPORT_SYMBOL(dsl_dataset_clone_swap); EXPORT_SYMBOL(dsl_dataset_user_hold); EXPORT_SYMBOL(dsl_dataset_user_release); EXPORT_SYMBOL(dsl_dataset_user_release_tmp); EXPORT_SYMBOL(dsl_dataset_get_holds); EXPORT_SYMBOL(dsl_dataset_get_blkptr); EXPORT_SYMBOL(dsl_dataset_set_blkptr); EXPORT_SYMBOL(dsl_dataset_get_spa); EXPORT_SYMBOL(dsl_dataset_modified_since_lastsnap); EXPORT_SYMBOL(dsl_dataset_space_written); EXPORT_SYMBOL(dsl_dataset_space_wouldfree); EXPORT_SYMBOL(dsl_dataset_sync); EXPORT_SYMBOL(dsl_dataset_block_born); EXPORT_SYMBOL(dsl_dataset_block_kill); EXPORT_SYMBOL(dsl_dataset_block_freeable); EXPORT_SYMBOL(dsl_dataset_prev_snap_txg); EXPORT_SYMBOL(dsl_dataset_dirty); EXPORT_SYMBOL(dsl_dataset_stats); EXPORT_SYMBOL(dsl_dataset_fast_stat); EXPORT_SYMBOL(dsl_dataset_space); EXPORT_SYMBOL(dsl_dataset_fsid_guid); EXPORT_SYMBOL(dsl_dsobj_to_dsname); EXPORT_SYMBOL(dsl_dataset_check_quota); EXPORT_SYMBOL(dsl_dataset_set_quota); EXPORT_SYMBOL(dsl_dataset_set_quota_sync); EXPORT_SYMBOL(dsl_dataset_set_reservation); EXPORT_SYMBOL(dsl_destroy_inconsistent); #endif