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-rw-r--r--uts/common/fs/zfs/dsl_dataset.c4030
1 files changed, 4030 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/dsl_dataset.c b/uts/common/fs/zfs/dsl_dataset.c
new file mode 100644
index 000000000000..59ac4a60947a
--- /dev/null
+++ b/uts/common/fs/zfs/dsl_dataset.c
@@ -0,0 +1,4030 @@
+/*
+ * 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.
+ */
+
+#include <sys/dmu_objset.h>
+#include <sys/dsl_dataset.h>
+#include <sys/dsl_dir.h>
+#include <sys/dsl_prop.h>
+#include <sys/dsl_synctask.h>
+#include <sys/dmu_traverse.h>
+#include <sys/dmu_tx.h>
+#include <sys/arc.h>
+#include <sys/zio.h>
+#include <sys/zap.h>
+#include <sys/unique.h>
+#include <sys/zfs_context.h>
+#include <sys/zfs_ioctl.h>
+#include <sys/spa.h>
+#include <sys/zfs_znode.h>
+#include <sys/zfs_onexit.h>
+#include <sys/zvol.h>
+#include <sys/dsl_scan.h>
+#include <sys/dsl_deadlist.h>
+
+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 = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
+ int compressed = BP_GET_PSIZE(bp);
+ int uncompressed = BP_GET_UCSIZE(bp);
+ int64_t delta;
+
+ 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);
+ ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
+ if (ds == NULL) {
+ /*
+ * Account for the meta-objset space in its placeholder
+ * dsl_dir.
+ */
+ ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
+ dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
+ used, compressed, uncompressed, tx);
+ dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
+ 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_used_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)
+{
+ if (BP_IS_HOLE(bp))
+ return (0);
+
+ ASSERT(dmu_tx_is_syncing(tx));
+ ASSERT(bp->blk_birth <= tx->tx_txg);
+
+ int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
+ int compressed = BP_GET_PSIZE(bp);
+ int uncompressed = BP_GET_UCSIZE(bp);
+
+ ASSERT(used > 0);
+ if (ds == NULL) {
+ /*
+ * Account for the meta-objset space in its placeholder
+ * dataset.
+ */
+ dsl_free(tx->tx_pool, tx->tx_txg, bp);
+
+ dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
+ -used, -compressed, -uncompressed, tx);
+ dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
+ 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_used_bytes, >=, used);
+ ds->ds_phys->ds_used_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);
+}
+
+static 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;
+
+ ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
+ ds->ds_dbuf = dbuf;
+ ds->ds_object = dsobj;
+ ds->ds_phys = dbuf->db_data;
+
+ 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);
+ rw_init(&ds->ds_rwlock, 0, 0, 0);
+ 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);
+
+ 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_used_bytes =
+ origin->ds_phys->ds_used_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);
+}
+
+struct destroyarg {
+ dsl_sync_task_group_t *dstg;
+ char *snapname;
+ char *failed;
+ boolean_t defer;
+};
+
+static int
+dsl_snapshot_destroy_one(const char *name, void *arg)
+{
+ struct destroyarg *da = arg;
+ dsl_dataset_t *ds;
+ int err;
+ char *dsname;
+
+ dsname = kmem_asprintf("%s@%s", name, da->snapname);
+ err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds);
+ strfree(dsname);
+ if (err == 0) {
+ struct dsl_ds_destroyarg *dsda;
+
+ dsl_dataset_make_exclusive(ds, da->dstg);
+ dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP);
+ dsda->ds = ds;
+ dsda->defer = da->defer;
+ dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check,
+ dsl_dataset_destroy_sync, dsda, da->dstg, 0);
+ } else if (err == ENOENT) {
+ err = 0;
+ } else {
+ (void) strcpy(da->failed, name);
+ }
+ return (err);
+}
+
+/*
+ * Destroy 'snapname' in all descendants of 'fsname'.
+ */
+#pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy
+int
+dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer)
+{
+ int err;
+ struct destroyarg da;
+ dsl_sync_task_t *dst;
+ spa_t *spa;
+
+ err = spa_open(fsname, &spa, FTAG);
+ if (err)
+ return (err);
+ da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
+ da.snapname = snapname;
+ da.failed = fsname;
+ da.defer = defer;
+
+ err = dmu_objset_find(fsname,
+ dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN);
+
+ if (err == 0)
+ err = dsl_sync_task_group_wait(da.dstg);
+
+ for (dst = list_head(&da.dstg->dstg_tasks); dst;
+ dst = list_next(&da.dstg->dstg_tasks, dst)) {
+ struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
+ dsl_dataset_t *ds = dsda->ds;
+
+ /*
+ * Return the file system name that triggered the error
+ */
+ if (dst->dst_err) {
+ dsl_dataset_name(ds, fsname);
+ *strchr(fsname, '@') = '\0';
+ }
+ ASSERT3P(dsda->rm_origin, ==, NULL);
+ dsl_dataset_disown(ds, da.dstg);
+ kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
+ }
+
+ dsl_sync_task_group_destroy(da.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 };
+ dsl_dataset_t dummy_ds = { 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;
+ dummy_ds.ds_dir = dd;
+ dummy_ds.ds_object = ds->ds_object;
+
+ /*
+ * 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 the objects in open context, so that we won't
+ * have too much to do in 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;
+
+ /*
+ * Only the ZIL knows how to free log blocks.
+ */
+ zil_destroy(dmu_objset_zil(os), B_FALSE);
+
+ /*
+ * 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)) {
+ 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, &dummy_ds, 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);
+ }
+}
+
+/*
+ * 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_used_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_used_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, arc_buf_t *pbuf,
+ 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;
+ dsl_pool_t *dp = ds->ds_dir->dd_pool;
+
+ /* 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(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
+ "dataset = %llu", ds->ds_object);
+}
+
+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;
+ uint64_t count;
+ int err;
+
+ 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) {
+ VERIFY3U(err, ==, 0);
+ }
+ 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));
+ VERIFY3U(zio_wait(poa.pio), ==, 0);
+ 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);
+}
+
+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;
+ 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;
+ return;
+ }
+
+ /* 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);
+ ASSERT3U(ds->ds_reserved, ==, 0);
+ }
+
+ 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);
+ dsl_dir_dirty(tx->tx_pool->dp_free_dir, 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;
+
+ /*
+ * 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. */
+ dsl_dataset_t *hds;
+ 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 {
+ /*
+ * 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.)
+ */
+ struct killarg ka;
+
+ dsl_deadlist_close(&ds->ds_deadlist);
+ dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
+ ds->ds_phys->ds_deadlist_obj = 0;
+
+ /*
+ * 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);
+ ASSERT3U(err, ==, 0);
+ ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
+ ds->ds_phys->ds_unique_bytes == 0);
+
+ 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);
+ ASSERT3U(err, ==, 0);
+ 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);
+ spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
+ "dataset = %llu", ds->ds_object);
+
+ if (ds->ds_phys->ds_next_clones_obj != 0) {
+ 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);
+
+ /*
+ * Propogate 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(void *arg1, void *arg2, dmu_tx_t *tx)
+{
+ dsl_dataset_t *ds = arg1;
+ const char *snapname = arg2;
+ 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 name 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(void *arg1, void *arg2, dmu_tx_t *tx)
+{
+ dsl_dataset_t *ds = arg1;
+ const char *snapname = arg2;
+ 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_used_bytes = ds->ds_phys->ds_used_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(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
+ "dataset = %llu", dsobj);
+}
+
+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;
+
+ dsl_dir_dirty(ds->ds_dir, tx);
+ dmu_objset_sync(ds->ds_objset, zio, tx);
+}
+
+void
+dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
+{
+ uint64_t refd, avail, uobjs, aobjs;
+
+ 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_next_snap_obj) {
+ /*
+ * This is a snapshot; override the dd's space used with
+ * our unique space and compression ratio.
+ */
+ dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
+ ds->ds_phys->ds_unique_bytes);
+ dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO,
+ ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
+ (ds->ds_phys->ds_uncompressed_bytes * 100 /
+ ds->ds_phys->ds_compressed_bytes));
+ }
+}
+
+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;
+ if (ds->ds_phys->ds_next_snap_obj) {
+ 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;
+ }
+
+ /* clone origin is really a dsl_dir thing... */
+ 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);
+ } else {
+ stat->dds_origin[0] = '\0';
+ }
+ 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_used_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)
+{
+ 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);
+ ASSERT3U(err, ==, 0);
+ 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);
+ ASSERT3U(err, ==, 0);
+
+ spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
+ "dataset = %llu", ds->ds_object);
+ 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 boolean_t snaplist_unstable(list_t *l);
+
+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_used_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_used_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);
+ }
+
+ ASSERT3U(dsl_prop_numcb(ds), ==, 0);
+ }
+
+ /*
+ * 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(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
+ "dataset = %llu", hds->ds_object);
+
+ 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 = { 0 };
+ struct promotenode *snap;
+ int err;
+
+ 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_used_bytes + cdl_used -
+ (csa->ohds->ds_phys->ds_used_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_used_bytes,
+ csa->cds->ds_phys->ds_used_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);
+}
+
+/*
+ * 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_used_bytes + inflight >= ds->ds_quota) {
+ if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
+ error = ERESTART;
+ else
+ error = EDQUOT;
+ }
+ 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_used_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(LOG_DS_REFQUOTA,
+ ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ",
+ (longlong_t)ds->ds_quota, ds->ds_object);
+ }
+}
+
+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, &quota);
+
+ 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(LOG_DS_REFRESERV,
+ ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu",
+ (longlong_t)effective_value, ds->ds_object);
+}
+
+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;
+ 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;
+ 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(LOG_DS_USER_HOLD,
+ dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
+ (int)ha->temphold, ds->ds_object);
+}
+
+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 dsobj = ds->ds_object;
+ 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);
+ }
+
+ spa_history_log_internal(LOG_DS_USER_RELEASE,
+ dp->dp_spa, tx, "<%s> %lld dataset = %llu",
+ ra->htag, (longlong_t)refs, dsobj);
+}
+
+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 fuction 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);
+}