/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
*/
#include <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_impl.h>
#include <sys/dmu_tx.h>
#include <sys/arc.h>
#include <sys/zio.h>
#include <sys/zap.h>
#include <sys/zfeature.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);
ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
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_referenced_bytes += used;
ds->ds_phys->ds_compressed_bytes += compressed;
ds->ds_phys->ds_uncompressed_bytes += uncompressed;
ds->ds_phys->ds_unique_bytes += used;
mutex_exit(&ds->ds_lock);
dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
compressed, uncompressed, tx);
dsl_dir_transfer_space(ds->ds_dir, used - delta,
DD_USED_REFRSRV, DD_USED_HEAD, tx);
mutex_exit(&ds->ds_dir->dd_lock);
}
int
dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
boolean_t async)
{
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_referenced_bytes, >=, used);
ds->ds_phys->ds_referenced_bytes -= used;
ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
ds->ds_phys->ds_compressed_bytes -= compressed;
ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
mutex_exit(&ds->ds_lock);
return (used);
}
uint64_t
dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
{
uint64_t trysnap = 0;
if (ds == NULL)
return (0);
/*
* The snapshot creation could fail, but that would cause an
* incorrect FALSE return, which would only result in an
* overestimation of the amount of space that an operation would
* consume, which is OK.
*
* There's also a small window where we could miss a pending
* snapshot, because we could set the sync task in the quiescing
* phase. So this should only be used as a guess.
*/
if (ds->ds_trysnap_txg >
spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
trysnap = ds->ds_trysnap_txg;
return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
}
boolean_t
dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
uint64_t blk_birth)
{
if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
return (B_FALSE);
ddt_prefetch(dsl_dataset_get_spa(ds), bp);
return (B_TRUE);
}
/* ARGSUSED */
static void
dsl_dataset_evict(dmu_buf_t *db, void *dsv)
{
dsl_dataset_t *ds = dsv;
ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
unique_remove(ds->ds_fsid_guid);
if (ds->ds_objset != NULL)
dmu_objset_evict(ds->ds_objset);
if (ds->ds_prev) {
dsl_dataset_drop_ref(ds->ds_prev, ds);
ds->ds_prev = NULL;
}
bplist_destroy(&ds->ds_pending_deadlist);
if (db != NULL) {
dsl_deadlist_close(&ds->ds_deadlist);
} else {
ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
ASSERT(!ds->ds_deadlist.dl_oldfmt);
}
if (ds->ds_dir)
dsl_dir_close(ds->ds_dir, ds);
ASSERT(!list_link_active(&ds->ds_synced_link));
mutex_destroy(&ds->ds_lock);
mutex_destroy(&ds->ds_recvlock);
mutex_destroy(&ds->ds_opening_lock);
rw_destroy(&ds->ds_rwlock);
cv_destroy(&ds->ds_exclusive_cv);
kmem_free(ds, sizeof (dsl_dataset_t));
}
static int
dsl_dataset_get_snapname(dsl_dataset_t *ds)
{
dsl_dataset_phys_t *headphys;
int err;
dmu_buf_t *headdbuf;
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
if (ds->ds_snapname[0])
return (0);
if (ds->ds_phys->ds_next_snap_obj == 0)
return (0);
err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
FTAG, &headdbuf);
if (err)
return (err);
headphys = headdbuf->db_data;
err = zap_value_search(dp->dp_meta_objset,
headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
dmu_buf_rele(headdbuf, FTAG);
return (err);
}
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);
mutex_init(&ds->ds_sendstream_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);
list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
offsetof(dmu_sendarg_t, dsa_link));
if (err == 0) {
err = dsl_dir_open_obj(dp,
ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
}
if (err) {
mutex_destroy(&ds->ds_lock);
mutex_destroy(&ds->ds_recvlock);
mutex_destroy(&ds->ds_opening_lock);
rw_destroy(&ds->ds_rwlock);
cv_destroy(&ds->ds_exclusive_cv);
bplist_destroy(&ds->ds_pending_deadlist);
dsl_deadlist_close(&ds->ds_deadlist);
kmem_free(ds, sizeof (dsl_dataset_t));
dmu_buf_rele(dbuf, tag);
return (err);
}
if (!dsl_dataset_is_snapshot(ds)) {
ds->ds_snapname[0] = '\0';
if (ds->ds_phys->ds_prev_snap_obj) {
err = dsl_dataset_get_ref(dp,
ds->ds_phys->ds_prev_snap_obj,
ds, &ds->ds_prev);
}
} else {
if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
err = dsl_dataset_get_snapname(ds);
if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
err = zap_count(
ds->ds_dir->dd_pool->dp_meta_objset,
ds->ds_phys->ds_userrefs_obj,
&ds->ds_userrefs);
}
}
if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
/*
* In sync context, we're called with either no lock
* or with the write lock. If we're not syncing,
* we're always called with the read lock held.
*/
boolean_t need_lock =
!RW_WRITE_HELD(&dp->dp_config_rwlock) &&
dsl_pool_sync_context(dp);
if (need_lock)
rw_enter(&dp->dp_config_rwlock, RW_READER);
err = dsl_prop_get_ds(ds,
"refreservation", sizeof (uint64_t), 1,
&ds->ds_reserved, NULL);
if (err == 0) {
err = dsl_prop_get_ds(ds,
"refquota", sizeof (uint64_t), 1,
&ds->ds_quota, NULL);
}
if (need_lock)
rw_exit(&dp->dp_config_rwlock);
} else {
ds->ds_reserved = ds->ds_quota = 0;
}
if (err == 0) {
winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
dsl_dataset_evict);
}
if (err || winner) {
bplist_destroy(&ds->ds_pending_deadlist);
dsl_deadlist_close(&ds->ds_deadlist);
if (ds->ds_prev)
dsl_dataset_drop_ref(ds->ds_prev, ds);
dsl_dir_close(ds->ds_dir, ds);
mutex_destroy(&ds->ds_lock);
mutex_destroy(&ds->ds_recvlock);
mutex_destroy(&ds->ds_opening_lock);
rw_destroy(&ds->ds_rwlock);
cv_destroy(&ds->ds_exclusive_cv);
kmem_free(ds, sizeof (dsl_dataset_t));
if (err) {
dmu_buf_rele(dbuf, tag);
return (err);
}
ds = winner;
} else {
ds->ds_fsid_guid =
unique_insert(ds->ds_phys->ds_fsid_guid);
}
}
ASSERT3P(ds->ds_dbuf, ==, dbuf);
ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
mutex_enter(&ds->ds_lock);
if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
mutex_exit(&ds->ds_lock);
dmu_buf_rele(ds->ds_dbuf, tag);
return (ENOENT);
}
mutex_exit(&ds->ds_lock);
*dsp = ds;
return (0);
}
static int
dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
/*
* In syncing context we don't want the rwlock lock: there
* may be an existing writer waiting for sync phase to
* finish. We don't need to worry about such writers, since
* sync phase is single-threaded, so the writer can't be
* doing anything while we are active.
*/
if (dsl_pool_sync_context(dp)) {
ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
return (0);
}
/*
* Normal users will hold the ds_rwlock as a READER until they
* are finished (i.e., call dsl_dataset_rele()). "Owners" will
* drop their READER lock after they set the ds_owner field.
*
* If the dataset is being destroyed, the destroy thread will
* obtain a WRITER lock for exclusive access after it's done its
* open-context work and then change the ds_owner to
* dsl_reaper once destruction is assured. So threads
* may block here temporarily, until the "destructability" of
* the dataset is determined.
*/
ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
mutex_enter(&ds->ds_lock);
while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
rw_exit(&dp->dp_config_rwlock);
cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
if (DSL_DATASET_IS_DESTROYED(ds)) {
mutex_exit(&ds->ds_lock);
dsl_dataset_drop_ref(ds, tag);
rw_enter(&dp->dp_config_rwlock, RW_READER);
return (ENOENT);
}
/*
* The dp_config_rwlock lives above the ds_lock. And
* we need to check DSL_DATASET_IS_DESTROYED() while
* holding the ds_lock, so we have to drop and reacquire
* the ds_lock here.
*/
mutex_exit(&ds->ds_lock);
rw_enter(&dp->dp_config_rwlock, RW_READER);
mutex_enter(&ds->ds_lock);
}
mutex_exit(&ds->ds_lock);
return (0);
}
int
dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
dsl_dataset_t **dsp)
{
int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
if (err)
return (err);
return (dsl_dataset_hold_ref(*dsp, tag));
}
int
dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
void *tag, dsl_dataset_t **dsp)
{
int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
if (err)
return (err);
if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
dsl_dataset_rele(*dsp, tag);
*dsp = NULL;
return (EBUSY);
}
return (0);
}
int
dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
{
dsl_dir_t *dd;
dsl_pool_t *dp;
const char *snapname;
uint64_t obj;
int err = 0;
err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
if (err)
return (err);
dp = dd->dd_pool;
obj = dd->dd_phys->dd_head_dataset_obj;
rw_enter(&dp->dp_config_rwlock, RW_READER);
if (obj)
err = dsl_dataset_get_ref(dp, obj, tag, dsp);
else
err = ENOENT;
if (err)
goto out;
err = dsl_dataset_hold_ref(*dsp, tag);
/* we may be looking for a snapshot */
if (err == 0 && snapname != NULL) {
dsl_dataset_t *ds = NULL;
if (*snapname++ != '@') {
dsl_dataset_rele(*dsp, tag);
err = ENOENT;
goto out;
}
dprintf("looking for snapshot '%s'\n", snapname);
err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
if (err == 0)
err = dsl_dataset_get_ref(dp, obj, tag, &ds);
dsl_dataset_rele(*dsp, tag);
ASSERT3U((err == 0), ==, (ds != NULL));
if (ds) {
mutex_enter(&ds->ds_lock);
if (ds->ds_snapname[0] == 0)
(void) strlcpy(ds->ds_snapname, snapname,
sizeof (ds->ds_snapname));
mutex_exit(&ds->ds_lock);
err = dsl_dataset_hold_ref(ds, tag);
*dsp = err ? NULL : ds;
}
}
out:
rw_exit(&dp->dp_config_rwlock);
dsl_dir_close(dd, FTAG);
return (err);
}
int
dsl_dataset_own(const char *name, boolean_t inconsistentok,
void *tag, dsl_dataset_t **dsp)
{
int err = dsl_dataset_hold(name, tag, dsp);
if (err)
return (err);
if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
dsl_dataset_rele(*dsp, tag);
return (EBUSY);
}
return (0);
}
void
dsl_dataset_name(dsl_dataset_t *ds, char *name)
{
if (ds == NULL) {
(void) strcpy(name, "mos");
} else {
dsl_dir_name(ds->ds_dir, name);
VERIFY(0 == dsl_dataset_get_snapname(ds));
if (ds->ds_snapname[0]) {
(void) strcat(name, "@");
/*
* We use a "recursive" mutex so that we
* can call dprintf_ds() with ds_lock held.
*/
if (!MUTEX_HELD(&ds->ds_lock)) {
mutex_enter(&ds->ds_lock);
(void) strcat(name, ds->ds_snapname);
mutex_exit(&ds->ds_lock);
} else {
(void) strcat(name, ds->ds_snapname);
}
}
}
}
static int
dsl_dataset_namelen(dsl_dataset_t *ds)
{
int result;
if (ds == NULL) {
result = 3; /* "mos" */
} else {
result = dsl_dir_namelen(ds->ds_dir);
VERIFY(0 == dsl_dataset_get_snapname(ds));
if (ds->ds_snapname[0]) {
++result; /* adding one for the @-sign */
if (!MUTEX_HELD(&ds->ds_lock)) {
mutex_enter(&ds->ds_lock);
result += strlen(ds->ds_snapname);
mutex_exit(&ds->ds_lock);
} else {
result += strlen(ds->ds_snapname);
}
}
}
return (result);
}
void
dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
{
dmu_buf_rele(ds->ds_dbuf, tag);
}
void
dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
{
if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
rw_exit(&ds->ds_rwlock);
}
dsl_dataset_drop_ref(ds, tag);
}
void
dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
{
ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
(DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
mutex_enter(&ds->ds_lock);
ds->ds_owner = NULL;
if (RW_WRITE_HELD(&ds->ds_rwlock)) {
rw_exit(&ds->ds_rwlock);
cv_broadcast(&ds->ds_exclusive_cv);
}
mutex_exit(&ds->ds_lock);
if (ds->ds_dbuf)
dsl_dataset_drop_ref(ds, tag);
else
dsl_dataset_evict(NULL, ds);
}
boolean_t
dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
{
boolean_t gotit = FALSE;
mutex_enter(&ds->ds_lock);
if (ds->ds_owner == NULL &&
(!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
ds->ds_owner = tag;
if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
rw_exit(&ds->ds_rwlock);
gotit = TRUE;
}
mutex_exit(&ds->ds_lock);
return (gotit);
}
void
dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
{
ASSERT3P(owner, ==, ds->ds_owner);
if (!RW_WRITE_HELD(&ds->ds_rwlock))
rw_enter(&ds->ds_rwlock, RW_WRITER);
}
uint64_t
dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
uint64_t flags, dmu_tx_t *tx)
{
dsl_pool_t *dp = dd->dd_pool;
dmu_buf_t *dbuf;
dsl_dataset_phys_t *dsphys;
uint64_t dsobj;
objset_t *mos = dp->dp_meta_objset;
if (origin == NULL)
origin = dp->dp_origin_snap;
ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
ASSERT(dmu_tx_is_syncing(tx));
ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
dmu_buf_will_dirty(dbuf, tx);
dsphys = dbuf->db_data;
bzero(dsphys, sizeof (dsl_dataset_phys_t));
dsphys->ds_dir_obj = dd->dd_object;
dsphys->ds_flags = flags;
dsphys->ds_fsid_guid = unique_create();
(void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
sizeof (dsphys->ds_guid));
dsphys->ds_snapnames_zapobj =
zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
DMU_OT_NONE, 0, tx);
dsphys->ds_creation_time = gethrestime_sec();
dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
if (origin == NULL) {
dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
} else {
dsl_dataset_t *ohds;
dsphys->ds_prev_snap_obj = origin->ds_object;
dsphys->ds_prev_snap_txg =
origin->ds_phys->ds_creation_txg;
dsphys->ds_referenced_bytes =
origin->ds_phys->ds_referenced_bytes;
dsphys->ds_compressed_bytes =
origin->ds_phys->ds_compressed_bytes;
dsphys->ds_uncompressed_bytes =
origin->ds_phys->ds_uncompressed_bytes;
dsphys->ds_bp = origin->ds_phys->ds_bp;
dsphys->ds_flags |= origin->ds_phys->ds_flags;
dmu_buf_will_dirty(origin->ds_dbuf, tx);
origin->ds_phys->ds_num_children++;
VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
dsl_dataset_rele(ohds, FTAG);
if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
if (origin->ds_phys->ds_next_clones_obj == 0) {
origin->ds_phys->ds_next_clones_obj =
zap_create(mos,
DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
}
VERIFY(0 == zap_add_int(mos,
origin->ds_phys->ds_next_clones_obj,
dsobj, tx));
}
dmu_buf_will_dirty(dd->dd_dbuf, tx);
dd->dd_phys->dd_origin_obj = origin->ds_object;
if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
if (origin->ds_dir->dd_phys->dd_clones == 0) {
dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
origin->ds_dir->dd_phys->dd_clones =
zap_create(mos,
DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
}
VERIFY3U(0, ==, zap_add_int(mos,
origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
}
}
if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
dmu_buf_rele(dbuf, FTAG);
dmu_buf_will_dirty(dd->dd_dbuf, tx);
dd->dd_phys->dd_head_dataset_obj = dsobj;
return (dsobj);
}
uint64_t
dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
{
dsl_pool_t *dp = pdd->dd_pool;
uint64_t dsobj, ddobj;
dsl_dir_t *dd;
ASSERT(lastname[0] != '@');
ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
dsl_deleg_set_create_perms(dd, tx, cr);
dsl_dir_close(dd, FTAG);
/*
* If we are creating a clone, make sure we zero out any stale
* data from the origin snapshots zil header.
*/
if (origin != NULL) {
dsl_dataset_t *ds;
objset_t *os;
VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
bzero(&os->os_zil_header, sizeof (os->os_zil_header));
dsl_dataset_dirty(ds, tx);
dsl_dataset_rele(ds, FTAG);
}
return (dsobj);
}
/*
* The snapshots must all be in the same pool.
*/
int
dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, char *failed)
{
int err;
dsl_sync_task_t *dst;
spa_t *spa;
nvpair_t *pair;
dsl_sync_task_group_t *dstg;
pair = nvlist_next_nvpair(snaps, NULL);
if (pair == NULL)
return (0);
err = spa_open(nvpair_name(pair), &spa, FTAG);
if (err)
return (err);
dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
pair = nvlist_next_nvpair(snaps, pair)) {
dsl_dataset_t *ds;
err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds);
if (err == 0) {
struct dsl_ds_destroyarg *dsda;
dsl_dataset_make_exclusive(ds, dstg);
dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg),
KM_SLEEP);
dsda->ds = ds;
dsda->defer = defer;
dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
dsl_dataset_destroy_sync, dsda, dstg, 0);
} else if (err == ENOENT) {
err = 0;
} else {
(void) strcpy(failed, nvpair_name(pair));
break;
}
}
if (err == 0)
err = dsl_sync_task_group_wait(dstg);
for (dst = list_head(&dstg->dstg_tasks); dst;
dst = list_next(&dstg->dstg_tasks, dst)) {
struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
dsl_dataset_t *ds = dsda->ds;
/*
* Return the file system name that triggered the error
*/
if (dst->dst_err) {
dsl_dataset_name(ds, failed);
}
ASSERT3P(dsda->rm_origin, ==, NULL);
dsl_dataset_disown(ds, dstg);
kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
}
dsl_sync_task_group_destroy(dstg);
spa_close(spa, FTAG);
return (err);
}
static boolean_t
dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
{
boolean_t might_destroy = B_FALSE;
mutex_enter(&ds->ds_lock);
if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
DS_IS_DEFER_DESTROY(ds))
might_destroy = B_TRUE;
mutex_exit(&ds->ds_lock);
return (might_destroy);
}
/*
* If we're removing a clone, and these three conditions are true:
* 1) the clone's origin has no other children
* 2) the clone's origin has no user references
* 3) the clone's origin has been marked for deferred destruction
* Then, prepare to remove the origin as part of this sync task group.
*/
static int
dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
{
dsl_dataset_t *ds = dsda->ds;
dsl_dataset_t *origin = ds->ds_prev;
if (dsl_dataset_might_destroy_origin(origin)) {
char *name;
int namelen;
int error;
namelen = dsl_dataset_namelen(origin) + 1;
name = kmem_alloc(namelen, KM_SLEEP);
dsl_dataset_name(origin, name);
#ifdef _KERNEL
error = zfs_unmount_snap(name, NULL);
if (error) {
kmem_free(name, namelen);
return (error);
}
#endif
error = dsl_dataset_own(name, B_TRUE, tag, &origin);
kmem_free(name, namelen);
if (error)
return (error);
dsda->rm_origin = origin;
dsl_dataset_make_exclusive(origin, tag);
}
return (0);
}
/*
* ds must be opened as OWNER. On return (whether successful or not),
* ds will be closed and caller can no longer dereference it.
*/
int
dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
{
int err;
dsl_sync_task_group_t *dstg;
objset_t *os;
dsl_dir_t *dd;
uint64_t obj;
struct dsl_ds_destroyarg dsda = { 0 };
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;
/*
* If async destruction is not enabled try to remove all objects
* while in the open context so that there is less work to do in
* the syncing context.
*/
if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds),
&spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
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_referenced_bytes;
else
mrs_used = 0;
dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
ASSERT3U(dlused, <=, mrs_used);
ds->ds_phys->ds_unique_bytes =
ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused);
if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
SPA_VERSION_UNIQUE_ACCURATE)
ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
}
struct killarg {
dsl_dataset_t *ds;
dmu_tx_t *tx;
};
/* ARGSUSED */
static int
kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 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);
}
static int
old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx)
{
int err;
struct killarg ka;
/*
* Free everything that we point to (that's born after
* the previous snapshot, if we are a clone)
*
* NB: this should be very quick, because we already
* freed all the objects in open context.
*/
ka.ds = ds;
ka.tx = tx;
err = traverse_dataset(ds,
ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST,
kill_blkptr, &ka);
ASSERT3U(err, ==, 0);
ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0);
return (err);
}
void
dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
{
struct dsl_ds_destroyarg *dsda = arg1;
dsl_dataset_t *ds = dsda->ds;
int err;
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);
/* 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 {
zfeature_info_t *async_destroy =
&spa_feature_table[SPA_FEATURE_ASYNC_DESTROY];
/*
* There's no next snapshot, so this is a head dataset.
* Destroy the deadlist. Unless it's a clone, the
* deadlist should be empty. (If it's a clone, it's
* safe to ignore the deadlist contents.)
*/
dsl_deadlist_close(&ds->ds_deadlist);
dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
ds->ds_phys->ds_deadlist_obj = 0;
if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) {
err = old_synchronous_dataset_destroy(ds, tx);
} else {
/*
* Move the bptree into the pool's list of trees to
* clean up and update space accounting information.
*/
uint64_t used, comp, uncomp;
ASSERT(err == 0 || err == EBUSY);
if (!spa_feature_is_active(dp->dp_spa, async_destroy)) {
spa_feature_incr(dp->dp_spa, async_destroy, tx);
dp->dp_bptree_obj = bptree_alloc(
dp->dp_meta_objset, tx);
VERIFY(zap_add(dp->dp_meta_objset,
DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
&dp->dp_bptree_obj, tx) == 0);
}
used = ds->ds_dir->dd_phys->dd_used_bytes;
comp = ds->ds_dir->dd_phys->dd_compressed_bytes;
uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes;
ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
ds->ds_phys->ds_unique_bytes == used);
bptree_add(dp->dp_meta_objset, dp->dp_bptree_obj,
&ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg,
used, comp, uncomp, tx);
dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
-used, -comp, -uncomp, tx);
dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
used, comp, uncomp, tx);
}
if (ds->ds_prev != NULL) {
if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
VERIFY3U(0, ==, zap_remove_int(mos,
ds->ds_prev->ds_dir->dd_phys->dd_clones,
ds->ds_object, tx));
}
dsl_dataset_rele(ds->ds_prev, ds);
ds->ds_prev = ds_prev = NULL;
}
}
/*
* This must be done after the dsl_traverse(), because it will
* re-open the objset.
*/
if (ds->ds_objset) {
dmu_objset_evict(ds->ds_objset);
ds->ds_objset = NULL;
}
if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
/* Erase the link in the dir */
dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
ASSERT(err == 0);
} else {
/* remove from snapshot namespace */
dsl_dataset_t *ds_head;
ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
VERIFY(0 == dsl_dataset_hold_obj(dp,
ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
VERIFY(0 == dsl_dataset_get_snapname(ds));
#ifdef ZFS_DEBUG
{
uint64_t val;
err = dsl_dataset_snap_lookup(ds_head,
ds->ds_snapname, &val);
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_referenced_bytes = ds->ds_phys->ds_referenced_bytes;
dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
dsphys->ds_flags = ds->ds_phys->ds_flags;
dsphys->ds_bp = ds->ds_phys->ds_bp;
dmu_buf_rele(dbuf, FTAG);
ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
if (ds->ds_prev) {
uint64_t next_clones_obj =
ds->ds_prev->ds_phys->ds_next_clones_obj;
ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
ds->ds_object ||
ds->ds_prev->ds_phys->ds_num_children > 1);
if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
ds->ds_prev->ds_phys->ds_creation_txg);
ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
} else if (next_clones_obj != 0) {
remove_from_next_clones(ds->ds_prev,
dsphys->ds_next_snap_obj, tx);
VERIFY3U(0, ==, zap_add_int(mos,
next_clones_obj, dsobj, tx));
}
}
/*
* If we have a reference-reservation on this dataset, we will
* need to increase the amount of refreservation being charged
* since our unique space is going to zero.
*/
if (ds->ds_reserved) {
int64_t delta;
ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
delta, 0, 0, tx);
}
dmu_buf_will_dirty(ds->ds_dbuf, tx);
zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
ds->ds_dir->dd_myname, snapname, dsobj,
ds->ds_phys->ds_prev_snap_txg);
ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
dsl_deadlist_close(&ds->ds_deadlist);
dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
dsl_deadlist_add_key(&ds->ds_deadlist,
ds->ds_phys->ds_prev_snap_txg, tx);
ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
ds->ds_phys->ds_prev_snap_obj = dsobj;
ds->ds_phys->ds_prev_snap_txg = crtxg;
ds->ds_phys->ds_unique_bytes = 0;
if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
snapname, 8, 1, &dsobj, tx);
ASSERT(err == 0);
if (ds->ds_prev)
dsl_dataset_drop_ref(ds->ds_prev, ds);
VERIFY(0 == dsl_dataset_get_ref(dp,
ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
dsl_scan_ds_snapshotted(ds, tx);
dsl_dir_snap_cmtime_update(ds->ds_dir);
spa_history_log_internal(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);
}
static void
get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
{
uint64_t count = 0;
objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
zap_cursor_t zc;
zap_attribute_t za;
nvlist_t *propval;
nvlist_t *val;
rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0);
/*
* There may me missing entries in ds_next_clones_obj
* due to a bug in a previous version of the code.
* Only trust it if it has the right number of entries.
*/
if (ds->ds_phys->ds_next_clones_obj != 0) {
ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
&count));
}
if (count != ds->ds_phys->ds_num_children - 1) {
goto fail;
}
for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
zap_cursor_retrieve(&zc, &za) == 0;
zap_cursor_advance(&zc)) {
dsl_dataset_t *clone;
char buf[ZFS_MAXNAMELEN];
/*
* Even though we hold the dp_config_rwlock, the dataset
* may fail to open, returning ENOENT. If there is a
* thread concurrently attempting to destroy this
* dataset, it will have the ds_rwlock held for
* RW_WRITER. Our call to dsl_dataset_hold_obj() ->
* dsl_dataset_hold_ref() will fail its
* rw_tryenter(&ds->ds_rwlock, RW_READER), drop the
* dp_config_rwlock, and wait for the destroy progress
* and signal ds_exclusive_cv. If the destroy was
* successful, we will see that
* DSL_DATASET_IS_DESTROYED(), and return ENOENT.
*/
if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
za.za_first_integer, FTAG, &clone) != 0)
continue;
dsl_dir_name(clone->ds_dir, buf);
VERIFY(nvlist_add_boolean(val, buf) == 0);
dsl_dataset_rele(clone, FTAG);
}
zap_cursor_fini(&zc);
VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0);
VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES),
propval) == 0);
fail:
nvlist_free(val);
nvlist_free(propval);
rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
}
void
dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
{
uint64_t refd, avail, uobjs, aobjs, ratio;
dsl_dir_stats(ds->ds_dir, nv);
dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
ds->ds_phys->ds_creation_time);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
ds->ds_phys->ds_creation_txg);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
ds->ds_quota);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
ds->ds_reserved);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
ds->ds_phys->ds_guid);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
ds->ds_phys->ds_unique_bytes);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
ds->ds_object);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
ds->ds_userrefs);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
if (ds->ds_phys->ds_prev_snap_obj != 0) {
uint64_t written, comp, uncomp;
dsl_pool_t *dp = ds->ds_dir->dd_pool;
dsl_dataset_t *prev;
rw_enter(&dp->dp_config_rwlock, RW_READER);
int err = dsl_dataset_hold_obj(dp,
ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
rw_exit(&dp->dp_config_rwlock);
if (err == 0) {
err = dsl_dataset_space_written(prev, ds, &written,
&comp, &uncomp);
dsl_dataset_rele(prev, FTAG);
if (err == 0) {
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
written);
}
}
}
ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
(ds->ds_phys->ds_uncompressed_bytes * 100 /
ds->ds_phys->ds_compressed_bytes);
dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
if (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, ratio);
get_clones_stat(ds, nv);
}
}
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_referenced_bytes;
*availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
*availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
if (ds->ds_quota != 0) {
/*
* Adjust available bytes according to refquota
*/
if (*refdbytesp < ds->ds_quota)
*availbytesp = MIN(*availbytesp,
ds->ds_quota - *refdbytesp);
else
*availbytesp = 0;
}
*usedobjsp = ds->ds_phys->ds_bp.blk_fill;
*availobjsp = DN_MAX_OBJECT - *usedobjsp;
}
boolean_t
dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
{
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_referenced_bytes;
pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
for (snap = list_head(&pa->shared_snaps); snap;
snap = list_next(&pa->shared_snaps, snap)) {
uint64_t val, dlused, dlcomp, dluncomp;
dsl_dataset_t *ds = snap->ds;
/* Check that the snapshot name does not conflict */
VERIFY(0 == dsl_dataset_get_snapname(ds));
err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
if (err == 0) {
err = EEXIST;
goto out;
}
if (err != ENOENT)
goto out;
/* The very first snapshot does not have a deadlist */
if (ds->ds_phys->ds_prev_snap_obj == 0)
continue;
dsl_deadlist_space(&ds->ds_deadlist,
&dlused, &dlcomp, &dluncomp);
pa->used += dlused;
pa->comp += dlcomp;
pa->uncomp += dluncomp;
}
/*
* If we are a clone of a clone then we never reached ORIGIN,
* so we need to subtract out the clone origin's used space.
*/
if (pa->origin_origin) {
pa->used -= pa->origin_origin->ds_phys->ds_referenced_bytes;
pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
}
/* Check that there is enough space here */
err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
pa->used);
if (err)
return (err);
/*
* Compute the amounts of space that will be used by snapshots
* after the promotion (for both origin and clone). For each,
* it is the amount of space that will be on all of their
* deadlists (that was not born before their new origin).
*/
if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
uint64_t space;
/*
* Note, typically this will not be a clone of a clone,
* so dd_origin_txg will be < TXG_INITIAL, so
* these snaplist_space() -> dsl_deadlist_space_range()
* calls will be fast because they do not have to
* iterate over all bps.
*/
snap = list_head(&pa->origin_snaps);
err = snaplist_space(&pa->shared_snaps,
snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
if (err)
return (err);
err = snaplist_space(&pa->clone_snaps,
snap->ds->ds_dir->dd_origin_txg, &space);
if (err)
return (err);
pa->cloneusedsnap += space;
}
if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
err = snaplist_space(&pa->origin_snaps,
origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
if (err)
return (err);
}
return (0);
out:
pa->err_ds = snap->ds->ds_snapname;
return (err);
}
static void
dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dataset_t *hds = arg1;
struct promotearg *pa = arg2;
struct promotenode *snap = list_head(&pa->shared_snaps);
dsl_dataset_t *origin_ds = snap->ds;
dsl_dataset_t *origin_head;
dsl_dir_t *dd = hds->ds_dir;
dsl_pool_t *dp = hds->ds_dir->dd_pool;
dsl_dir_t *odd = NULL;
uint64_t oldnext_obj;
int64_t delta;
ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
snap = list_head(&pa->origin_snaps);
origin_head = snap->ds;
/*
* We need to explicitly open odd, since origin_ds's dd will be
* changing.
*/
VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
NULL, FTAG, &odd));
/* change origin's next snap */
dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
snap = list_tail(&pa->clone_snaps);
ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
/* change the origin's next clone */
if (origin_ds->ds_phys->ds_next_clones_obj) {
remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
origin_ds->ds_phys->ds_next_clones_obj,
oldnext_obj, tx));
}
/* change origin */
dmu_buf_will_dirty(dd->dd_dbuf, tx);
ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
dmu_buf_will_dirty(odd->dd_dbuf, tx);
odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
origin_head->ds_dir->dd_origin_txg =
origin_ds->ds_phys->ds_creation_txg;
/* change dd_clone entries */
if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
odd->dd_phys->dd_clones, hds->ds_object, tx));
VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
pa->origin_origin->ds_dir->dd_phys->dd_clones,
hds->ds_object, tx));
VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
pa->origin_origin->ds_dir->dd_phys->dd_clones,
origin_head->ds_object, tx));
if (dd->dd_phys->dd_clones == 0) {
dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
}
VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
dd->dd_phys->dd_clones, origin_head->ds_object, tx));
}
/* move snapshots to this dir */
for (snap = list_head(&pa->shared_snaps); snap;
snap = list_next(&pa->shared_snaps, snap)) {
dsl_dataset_t *ds = snap->ds;
/* unregister props as dsl_dir is changing */
if (ds->ds_objset) {
dmu_objset_evict(ds->ds_objset);
ds->ds_objset = NULL;
}
/* move snap name entry */
VERIFY(0 == dsl_dataset_get_snapname(ds));
VERIFY(0 == dsl_dataset_snap_remove(origin_head,
ds->ds_snapname, tx));
VERIFY(0 == zap_add(dp->dp_meta_objset,
hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
8, 1, &ds->ds_object, tx));
/* change containing dsl_dir */
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
ds->ds_phys->ds_dir_obj = dd->dd_object;
ASSERT3P(ds->ds_dir, ==, odd);
dsl_dir_close(ds->ds_dir, ds);
VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
NULL, ds, &ds->ds_dir));
/* move any clone references */
if (ds->ds_phys->ds_next_clones_obj &&
spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
zap_cursor_t zc;
zap_attribute_t za;
for (zap_cursor_init(&zc, dp->dp_meta_objset,
ds->ds_phys->ds_next_clones_obj);
zap_cursor_retrieve(&zc, &za) == 0;
zap_cursor_advance(&zc)) {
dsl_dataset_t *cnds;
uint64_t o;
if (za.za_first_integer == oldnext_obj) {
/*
* We've already moved the
* origin's reference.
*/
continue;
}
VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
za.za_first_integer, FTAG, &cnds));
o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
VERIFY3U(zap_remove_int(dp->dp_meta_objset,
odd->dd_phys->dd_clones, o, tx), ==, 0);
VERIFY3U(zap_add_int(dp->dp_meta_objset,
dd->dd_phys->dd_clones, o, tx), ==, 0);
dsl_dataset_rele(cnds, FTAG);
}
zap_cursor_fini(&zc);
}
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_referenced_bytes + cdl_used -
(csa->ohds->ds_phys->ds_referenced_bytes + odl_used);
dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
(csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
cdl_uncomp -
(csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
dused, dcomp, duncomp, tx);
dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
-dused, -dcomp, -duncomp, tx);
/*
* The difference in the space used by snapshots is the
* difference in snapshot space due to the head's
* deadlist (since that's the only thing that's
* changing that affects the snapused).
*/
dsl_deadlist_space_range(&csa->cds->ds_deadlist,
csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
&cdl_used, &cdl_comp, &cdl_uncomp);
dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
&odl_used, &odl_comp, &odl_uncomp);
dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
DD_USED_HEAD, DD_USED_SNAP, tx);
}
/* swap ds_*_bytes */
SWITCH64(csa->ohds->ds_phys->ds_referenced_bytes,
csa->cds->ds_phys->ds_referenced_bytes);
SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
csa->cds->ds_phys->ds_compressed_bytes);
SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
csa->cds->ds_phys->ds_uncompressed_bytes);
SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
csa->cds->ds_phys->ds_unique_bytes);
/* apply any parent delta for change in unconsumed refreservation */
dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
csa->unused_refres_delta, 0, 0, tx);
/*
* Swap deadlists.
*/
dsl_deadlist_close(&csa->cds->ds_deadlist);
dsl_deadlist_close(&csa->ohds->ds_deadlist);
SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
csa->cds->ds_phys->ds_deadlist_obj);
dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
csa->cds->ds_phys->ds_deadlist_obj);
dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
csa->ohds->ds_phys->ds_deadlist_obj);
dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
}
/*
* Swap 'clone' with its origin head datasets. Used at the end of "zfs
* recv" into an existing fs to swizzle the file system to the new
* version, and by "zfs rollback". Can also be used to swap two
* independent head datasets if neither has any snapshots.
*/
int
dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
boolean_t force)
{
struct cloneswaparg csa;
int error;
ASSERT(clone->ds_owner);
ASSERT(origin_head->ds_owner);
retry:
/*
* Need exclusive access for the swap. If we're swapping these
* datasets back after an error, we already hold the locks.
*/
if (!RW_WRITE_HELD(&clone->ds_rwlock))
rw_enter(&clone->ds_rwlock, RW_WRITER);
if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
rw_exit(&clone->ds_rwlock);
rw_enter(&origin_head->ds_rwlock, RW_WRITER);
if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
rw_exit(&origin_head->ds_rwlock);
goto retry;
}
}
csa.cds = clone;
csa.ohds = origin_head;
csa.force = force;
error = dsl_sync_task_do(clone->ds_dir->dd_pool,
dsl_dataset_clone_swap_check,
dsl_dataset_clone_swap_sync, &csa, NULL, 9);
return (error);
}
/*
* Given a pool name and a dataset object number in that pool,
* return the name of that dataset.
*/
int
dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
{
spa_t *spa;
dsl_pool_t *dp;
dsl_dataset_t *ds;
int error;
if ((error = spa_open(pname, &spa, FTAG)) != 0)
return (error);
dp = spa_get_dsl(spa);
rw_enter(&dp->dp_config_rwlock, RW_READER);
if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
dsl_dataset_name(ds, buf);
dsl_dataset_rele(ds, FTAG);
}
rw_exit(&dp->dp_config_rwlock);
spa_close(spa, FTAG);
return (error);
}
int
dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
{
int error = 0;
ASSERT3S(asize, >, 0);
/*
* *ref_rsrv is the portion of asize that will come from any
* unconsumed refreservation space.
*/
*ref_rsrv = 0;
mutex_enter(&ds->ds_lock);
/*
* Make a space adjustment for reserved bytes.
*/
if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
ASSERT3U(*used, >=,
ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
*used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
*ref_rsrv =
asize - MIN(asize, parent_delta(ds, asize + inflight));
}
if (!check_quota || ds->ds_quota == 0) {
mutex_exit(&ds->ds_lock);
return (0);
}
/*
* If they are requesting more space, and our current estimate
* is over quota, they get to try again unless the actual
* on-disk is over quota and there are no pending changes (which
* may free up space for us).
*/
if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) {
if (inflight > 0 ||
ds->ds_phys->ds_referenced_bytes < ds->ds_quota)
error = ERESTART;
else
error = EDQUOT;
}
mutex_exit(&ds->ds_lock);
return (error);
}
/* ARGSUSED */
static int
dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dataset_t *ds = arg1;
dsl_prop_setarg_t *psa = arg2;
int err;
if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
return (ENOTSUP);
if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
return (err);
if (psa->psa_effective_value == 0)
return (0);
if (psa->psa_effective_value < ds->ds_phys->ds_referenced_bytes ||
psa->psa_effective_value < ds->ds_reserved)
return (ENOSPC);
return (0);
}
extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
void
dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dataset_t *ds = arg1;
dsl_prop_setarg_t *psa = arg2;
uint64_t effective_value = psa->psa_effective_value;
dsl_prop_set_sync(ds, psa, tx);
DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
if (ds->ds_quota != effective_value) {
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_quota = effective_value;
spa_history_log_internal(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, "a);
err = dsl_dataset_hold(dsname, FTAG, &ds);
if (err)
return (err);
/*
* If someone removes a file, then tries to set the quota, we
* want to make sure the file freeing takes effect.
*/
txg_wait_open(ds->ds_dir->dd_pool, 0);
err = dsl_sync_task_do(ds->ds_dir->dd_pool,
dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
ds, &psa, 0);
dsl_dataset_rele(ds, FTAG);
return (err);
}
static int
dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dataset_t *ds = arg1;
dsl_prop_setarg_t *psa = arg2;
uint64_t effective_value;
uint64_t unique;
int err;
if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
SPA_VERSION_REFRESERVATION)
return (ENOTSUP);
if (dsl_dataset_is_snapshot(ds))
return (EINVAL);
if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
return (err);
effective_value = psa->psa_effective_value;
/*
* If we are doing the preliminary check in open context, the
* space estimates may be inaccurate.
*/
if (!dmu_tx_is_syncing(tx))
return (0);
mutex_enter(&ds->ds_lock);
if (!DS_UNIQUE_IS_ACCURATE(ds))
dsl_dataset_recalc_head_uniq(ds);
unique = ds->ds_phys->ds_unique_bytes;
mutex_exit(&ds->ds_lock);
if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
uint64_t delta = MAX(unique, effective_value) -
MAX(unique, ds->ds_reserved);
if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
return (ENOSPC);
if (ds->ds_quota > 0 &&
effective_value > ds->ds_quota)
return (ENOSPC);
}
return (0);
}
static void
dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dataset_t *ds = arg1;
dsl_prop_setarg_t *psa = arg2;
uint64_t effective_value = psa->psa_effective_value;
uint64_t unique;
int64_t delta;
dsl_prop_set_sync(ds, psa, tx);
DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
dmu_buf_will_dirty(ds->ds_dbuf, tx);
mutex_enter(&ds->ds_dir->dd_lock);
mutex_enter(&ds->ds_lock);
ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
unique = ds->ds_phys->ds_unique_bytes;
delta = MAX(0, (int64_t)(effective_value - unique)) -
MAX(0, (int64_t)(ds->ds_reserved - unique));
ds->ds_reserved = effective_value;
mutex_exit(&ds->ds_lock);
dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
mutex_exit(&ds->ds_dir->dd_lock);
spa_history_log_internal(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 function is used as the callback for dmu_objset_find(). We
* always return 0 so that we will continue to find and process
* inconsistent datasets, even if we encounter an error trying to
* process one of them.
*/
/* ARGSUSED */
int
dsl_destroy_inconsistent(const char *dsname, void *arg)
{
dsl_dataset_t *ds;
if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
if (DS_IS_INCONSISTENT(ds))
(void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
else
dsl_dataset_disown(ds, FTAG);
}
return (0);
}
/*
* Return (in *usedp) the amount of space written in new that is not
* present in oldsnap. New may be a snapshot or the head. Old must be
* a snapshot before new, in new's filesystem (or its origin). If not then
* fail and return EINVAL.
*
* The written space is calculated by considering two components: First, we
* ignore any freed space, and calculate the written as new's used space
* minus old's used space. Next, we add in the amount of space that was freed
* between the two snapshots, thus reducing new's used space relative to old's.
* Specifically, this is the space that was born before old->ds_creation_txg,
* and freed before new (ie. on new's deadlist or a previous deadlist).
*
* space freed [---------------------]
* snapshots ---O-------O--------O-------O------
* oldsnap new
*/
int
dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
{
int err = 0;
uint64_t snapobj;
dsl_pool_t *dp = new->ds_dir->dd_pool;
*usedp = 0;
*usedp += new->ds_phys->ds_referenced_bytes;
*usedp -= oldsnap->ds_phys->ds_referenced_bytes;
*compp = 0;
*compp += new->ds_phys->ds_compressed_bytes;
*compp -= oldsnap->ds_phys->ds_compressed_bytes;
*uncompp = 0;
*uncompp += new->ds_phys->ds_uncompressed_bytes;
*uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
rw_enter(&dp->dp_config_rwlock, RW_READER);
snapobj = new->ds_object;
while (snapobj != oldsnap->ds_object) {
dsl_dataset_t *snap;
uint64_t used, comp, uncomp;
if (snapobj == new->ds_object) {
snap = new;
} else {
err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
if (err != 0)
break;
}
if (snap->ds_phys->ds_prev_snap_txg ==
oldsnap->ds_phys->ds_creation_txg) {
/*
* The blocks in the deadlist can not be born after
* ds_prev_snap_txg, so get the whole deadlist space,
* which is more efficient (especially for old-format
* deadlists). Unfortunately the deadlist code
* doesn't have enough information to make this
* optimization itself.
*/
dsl_deadlist_space(&snap->ds_deadlist,
&used, &comp, &uncomp);
} else {
dsl_deadlist_space_range(&snap->ds_deadlist,
0, oldsnap->ds_phys->ds_creation_txg,
&used, &comp, &uncomp);
}
*usedp += used;
*compp += comp;
*uncompp += uncomp;
/*
* If we get to the beginning of the chain of snapshots
* (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
* was not a snapshot of/before new.
*/
snapobj = snap->ds_phys->ds_prev_snap_obj;
if (snap != new)
dsl_dataset_rele(snap, FTAG);
if (snapobj == 0) {
err = EINVAL;
break;
}
}
rw_exit(&dp->dp_config_rwlock);
return (err);
}
/*
* Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
* lastsnap, and all snapshots in between are deleted.
*
* blocks that would be freed [---------------------------]
* snapshots ---O-------O--------O-------O--------O
* firstsnap lastsnap
*
* This is the set of blocks that were born after the snap before firstsnap,
* (birth > firstsnap->prev_snap_txg) and died before the snap after the
* last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
* We calculate this by iterating over the relevant deadlists (from the snap
* after lastsnap, backward to the snap after firstsnap), summing up the
* space on the deadlist that was born after the snap before firstsnap.
*/
int
dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
dsl_dataset_t *lastsnap,
uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
{
int err = 0;
uint64_t snapobj;
dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
ASSERT(dsl_dataset_is_snapshot(firstsnap));
ASSERT(dsl_dataset_is_snapshot(lastsnap));
/*
* Check that the snapshots are in the same dsl_dir, and firstsnap
* is before lastsnap.
*/
if (firstsnap->ds_dir != lastsnap->ds_dir ||
firstsnap->ds_phys->ds_creation_txg >
lastsnap->ds_phys->ds_creation_txg)
return (EINVAL);
*usedp = *compp = *uncompp = 0;
rw_enter(&dp->dp_config_rwlock, RW_READER);
snapobj = lastsnap->ds_phys->ds_next_snap_obj;
while (snapobj != firstsnap->ds_object) {
dsl_dataset_t *ds;
uint64_t used, comp, uncomp;
err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
if (err != 0)
break;
dsl_deadlist_space_range(&ds->ds_deadlist,
firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
&used, &comp, &uncomp);
*usedp += used;
*compp += comp;
*uncompp += uncomp;
snapobj = ds->ds_phys->ds_prev_snap_obj;
ASSERT3U(snapobj, !=, 0);
dsl_dataset_rele(ds, FTAG);
}
rw_exit(&dp->dp_config_rwlock);
return (err);
}