freebsd-dev/module/zfs/dsl_destroy.c

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/*
* 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) 2013 by Delphix. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/dsl_userhold.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_synctask.h>
#include <sys/dmu_tx.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_dir.h>
#include <sys/dmu_traverse.h>
#include <sys/dsl_scan.h>
#include <sys/dmu_objset.h>
#include <sys/zap.h>
#include <sys/zfeature.h>
#include <sys/zfs_ioctl.h>
#include <sys/dsl_deleg.h>
typedef struct dmu_snapshots_destroy_arg {
nvlist_t *dsda_snaps;
nvlist_t *dsda_successful_snaps;
boolean_t dsda_defer;
nvlist_t *dsda_errlist;
} dmu_snapshots_destroy_arg_t;
int
dsl_destroy_snapshot_check_impl(dsl_dataset_t *ds, boolean_t defer)
{
if (!dsl_dataset_is_snapshot(ds))
return (SET_ERROR(EINVAL));
if (dsl_dataset_long_held(ds))
return (SET_ERROR(EBUSY));
/*
* Only allow deferred destroy on pools that support it.
* NOTE: deferred destroy is only supported on snapshots.
*/
if (defer) {
if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
SPA_VERSION_USERREFS)
return (SET_ERROR(ENOTSUP));
return (0);
}
/*
* If this snapshot has an elevated user reference count,
* we can't destroy it yet.
*/
if (ds->ds_userrefs > 0)
return (SET_ERROR(EBUSY));
/*
* Can't delete a branch point.
*/
if (ds->ds_phys->ds_num_children > 1)
return (SET_ERROR(EEXIST));
return (0);
}
static int
dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx)
{
dmu_snapshots_destroy_arg_t *dsda = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvpair_t *pair;
int error = 0;
if (!dmu_tx_is_syncing(tx))
return (0);
for (pair = nvlist_next_nvpair(dsda->dsda_snaps, NULL);
pair != NULL; pair = nvlist_next_nvpair(dsda->dsda_snaps, pair)) {
dsl_dataset_t *ds;
error = dsl_dataset_hold(dp, nvpair_name(pair),
FTAG, &ds);
/*
* If the snapshot does not exist, silently ignore it
* (it's "already destroyed").
*/
if (error == ENOENT)
continue;
if (error == 0) {
error = dsl_destroy_snapshot_check_impl(ds,
dsda->dsda_defer);
dsl_dataset_rele(ds, FTAG);
}
if (error == 0) {
fnvlist_add_boolean(dsda->dsda_successful_snaps,
nvpair_name(pair));
} else {
fnvlist_add_int32(dsda->dsda_errlist,
nvpair_name(pair), error);
}
}
pair = nvlist_next_nvpair(dsda->dsda_errlist, NULL);
if (pair != NULL)
return (fnvpair_value_int32(pair));
return (0);
}
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;
uint64_t deadlist_obj;
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);
VERIFY0(bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
process_old_cb, &poa, tx));
VERIFY0(zio_wait(poa.pio));
ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
/* change snapused */
dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
-poa.used, -poa.comp, -poa.uncomp, tx);
/* swap next's deadlist to our deadlist */
dsl_deadlist_close(&ds->ds_deadlist);
dsl_deadlist_close(&ds_next->ds_deadlist);
deadlist_obj = ds->ds_phys->ds_deadlist_obj;
ds->ds_phys->ds_deadlist_obj = ds_next->ds_phys->ds_deadlist_obj;
ds_next->ds_phys->ds_deadlist_obj = 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 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;
Reduce the stack usage of dsl_dataset_remove_clones_key dataset_remove_clones_key does recursion, so if the recursion goes deep it can overrun the linux kernel stack size of 8KB. I have seen this happen in the actual deployment, and subsequently confirmed it by running a test workload on a custom-built kernel that uses 32KB stack. See the following stack trace as an example of the case where it would have run over the 8KB stack kernel: Depth Size Location (42 entries) ----- ---- -------- 0) 11192 72 __kmalloc+0x2e/0x240 1) 11120 144 kmem_alloc_debug+0x20e/0x500 2) 10976 72 dbuf_hold_impl+0x4a/0xa0 3) 10904 120 dbuf_prefetch+0xd3/0x280 4) 10784 80 dmu_zfetch_dofetch.isra.5+0x10f/0x180 5) 10704 240 dmu_zfetch+0x5f7/0x10e0 6) 10464 168 dbuf_read+0x71e/0x8f0 7) 10296 104 dnode_hold_impl+0x1ee/0x620 8) 10192 16 dnode_hold+0x19/0x20 9) 10176 88 dmu_buf_hold+0x42/0x1b0 10) 10088 144 zap_lockdir+0x48/0x730 11) 9944 128 zap_cursor_retrieve+0x1c4/0x2f0 12) 9816 392 dsl_dataset_remove_clones_key.isra.14+0xab/0x190 13) 9424 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 14) 9032 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 15) 8640 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 16) 8248 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 17) 7856 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 18) 7464 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 19) 7072 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 20) 6680 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 21) 6288 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 22) 5896 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 23) 5504 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 24) 5112 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 25) 4720 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 26) 4328 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 27) 3936 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 28) 3544 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 29) 3152 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 30) 2760 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 31) 2368 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 32) 1976 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 33) 1584 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 34) 1192 232 dsl_dataset_destroy_sync+0x311/0xf60 35) 960 72 dsl_sync_task_group_sync+0x12f/0x230 36) 888 168 dsl_pool_sync+0x48b/0x5c0 37) 720 184 spa_sync+0x417/0xb00 38) 536 184 txg_sync_thread+0x325/0x5b0 39) 352 48 thread_generic_wrapper+0x7a/0x90 40) 304 128 kthread+0xc0/0xd0 41) 176 176 ret_from_fork+0x7c/0xb0 This change reduces the stack usage in dsl_dataset_remove_clones_key by allocating structures in heap, not in stack. This is not a fundamental fix, as one can create an arbitrary large data set that runs over any fixed size stack, but this will make the problem far less likely. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Kohsuke Kawaguchi <kk@kohsuke.org> Closes #1726
2013-09-25 22:14:47 +00:00
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 dsl_deadlist_remove_key() is a no-op so it
* doesn't matter.
*/
if (ds->ds_dir->dd_phys->dd_clones == 0)
return;
Reduce the stack usage of dsl_dataset_remove_clones_key dataset_remove_clones_key does recursion, so if the recursion goes deep it can overrun the linux kernel stack size of 8KB. I have seen this happen in the actual deployment, and subsequently confirmed it by running a test workload on a custom-built kernel that uses 32KB stack. See the following stack trace as an example of the case where it would have run over the 8KB stack kernel: Depth Size Location (42 entries) ----- ---- -------- 0) 11192 72 __kmalloc+0x2e/0x240 1) 11120 144 kmem_alloc_debug+0x20e/0x500 2) 10976 72 dbuf_hold_impl+0x4a/0xa0 3) 10904 120 dbuf_prefetch+0xd3/0x280 4) 10784 80 dmu_zfetch_dofetch.isra.5+0x10f/0x180 5) 10704 240 dmu_zfetch+0x5f7/0x10e0 6) 10464 168 dbuf_read+0x71e/0x8f0 7) 10296 104 dnode_hold_impl+0x1ee/0x620 8) 10192 16 dnode_hold+0x19/0x20 9) 10176 88 dmu_buf_hold+0x42/0x1b0 10) 10088 144 zap_lockdir+0x48/0x730 11) 9944 128 zap_cursor_retrieve+0x1c4/0x2f0 12) 9816 392 dsl_dataset_remove_clones_key.isra.14+0xab/0x190 13) 9424 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 14) 9032 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 15) 8640 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 16) 8248 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 17) 7856 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 18) 7464 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 19) 7072 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 20) 6680 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 21) 6288 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 22) 5896 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 23) 5504 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 24) 5112 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 25) 4720 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 26) 4328 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 27) 3936 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 28) 3544 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 29) 3152 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 30) 2760 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 31) 2368 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 32) 1976 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 33) 1584 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 34) 1192 232 dsl_dataset_destroy_sync+0x311/0xf60 35) 960 72 dsl_sync_task_group_sync+0x12f/0x230 36) 888 168 dsl_pool_sync+0x48b/0x5c0 37) 720 184 spa_sync+0x417/0xb00 38) 536 184 txg_sync_thread+0x325/0x5b0 39) 352 48 thread_generic_wrapper+0x7a/0x90 40) 304 128 kthread+0xc0/0xd0 41) 176 176 ret_from_fork+0x7c/0xb0 This change reduces the stack usage in dsl_dataset_remove_clones_key by allocating structures in heap, not in stack. This is not a fundamental fix, as one can create an arbitrary large data set that runs over any fixed size stack, but this will make the problem far less likely. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Kohsuke Kawaguchi <kk@kohsuke.org> Closes #1726
2013-09-25 22:14:47 +00:00
zc = kmem_alloc(sizeof (zap_cursor_t), KM_PUSHPAGE);
za = kmem_alloc(sizeof (zap_attribute_t), KM_PUSHPAGE);
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;
VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
Reduce the stack usage of dsl_dataset_remove_clones_key dataset_remove_clones_key does recursion, so if the recursion goes deep it can overrun the linux kernel stack size of 8KB. I have seen this happen in the actual deployment, and subsequently confirmed it by running a test workload on a custom-built kernel that uses 32KB stack. See the following stack trace as an example of the case where it would have run over the 8KB stack kernel: Depth Size Location (42 entries) ----- ---- -------- 0) 11192 72 __kmalloc+0x2e/0x240 1) 11120 144 kmem_alloc_debug+0x20e/0x500 2) 10976 72 dbuf_hold_impl+0x4a/0xa0 3) 10904 120 dbuf_prefetch+0xd3/0x280 4) 10784 80 dmu_zfetch_dofetch.isra.5+0x10f/0x180 5) 10704 240 dmu_zfetch+0x5f7/0x10e0 6) 10464 168 dbuf_read+0x71e/0x8f0 7) 10296 104 dnode_hold_impl+0x1ee/0x620 8) 10192 16 dnode_hold+0x19/0x20 9) 10176 88 dmu_buf_hold+0x42/0x1b0 10) 10088 144 zap_lockdir+0x48/0x730 11) 9944 128 zap_cursor_retrieve+0x1c4/0x2f0 12) 9816 392 dsl_dataset_remove_clones_key.isra.14+0xab/0x190 13) 9424 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 14) 9032 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 15) 8640 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 16) 8248 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 17) 7856 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 18) 7464 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 19) 7072 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 20) 6680 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 21) 6288 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 22) 5896 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 23) 5504 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 24) 5112 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 25) 4720 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 26) 4328 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 27) 3936 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 28) 3544 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 29) 3152 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 30) 2760 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 31) 2368 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 32) 1976 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 33) 1584 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 34) 1192 232 dsl_dataset_destroy_sync+0x311/0xf60 35) 960 72 dsl_sync_task_group_sync+0x12f/0x230 36) 888 168 dsl_pool_sync+0x48b/0x5c0 37) 720 184 spa_sync+0x417/0xb00 38) 536 184 txg_sync_thread+0x325/0x5b0 39) 352 48 thread_generic_wrapper+0x7a/0x90 40) 304 128 kthread+0xc0/0xd0 41) 176 176 ret_from_fork+0x7c/0xb0 This change reduces the stack usage in dsl_dataset_remove_clones_key by allocating structures in heap, not in stack. This is not a fundamental fix, as one can create an arbitrary large data set that runs over any fixed size stack, but this will make the problem far less likely. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Kohsuke Kawaguchi <kk@kohsuke.org> Closes #1726
2013-09-25 22:14:47 +00:00
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);
}
Reduce the stack usage of dsl_dataset_remove_clones_key dataset_remove_clones_key does recursion, so if the recursion goes deep it can overrun the linux kernel stack size of 8KB. I have seen this happen in the actual deployment, and subsequently confirmed it by running a test workload on a custom-built kernel that uses 32KB stack. See the following stack trace as an example of the case where it would have run over the 8KB stack kernel: Depth Size Location (42 entries) ----- ---- -------- 0) 11192 72 __kmalloc+0x2e/0x240 1) 11120 144 kmem_alloc_debug+0x20e/0x500 2) 10976 72 dbuf_hold_impl+0x4a/0xa0 3) 10904 120 dbuf_prefetch+0xd3/0x280 4) 10784 80 dmu_zfetch_dofetch.isra.5+0x10f/0x180 5) 10704 240 dmu_zfetch+0x5f7/0x10e0 6) 10464 168 dbuf_read+0x71e/0x8f0 7) 10296 104 dnode_hold_impl+0x1ee/0x620 8) 10192 16 dnode_hold+0x19/0x20 9) 10176 88 dmu_buf_hold+0x42/0x1b0 10) 10088 144 zap_lockdir+0x48/0x730 11) 9944 128 zap_cursor_retrieve+0x1c4/0x2f0 12) 9816 392 dsl_dataset_remove_clones_key.isra.14+0xab/0x190 13) 9424 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 14) 9032 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 15) 8640 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 16) 8248 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 17) 7856 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 18) 7464 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 19) 7072 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 20) 6680 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 21) 6288 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 22) 5896 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 23) 5504 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 24) 5112 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 25) 4720 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 26) 4328 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 27) 3936 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 28) 3544 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 29) 3152 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 30) 2760 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 31) 2368 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 32) 1976 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 33) 1584 392 dsl_dataset_remove_clones_key.isra.14+0x10c/0x190 34) 1192 232 dsl_dataset_destroy_sync+0x311/0xf60 35) 960 72 dsl_sync_task_group_sync+0x12f/0x230 36) 888 168 dsl_pool_sync+0x48b/0x5c0 37) 720 184 spa_sync+0x417/0xb00 38) 536 184 txg_sync_thread+0x325/0x5b0 39) 352 48 thread_generic_wrapper+0x7a/0x90 40) 304 128 kthread+0xc0/0xd0 41) 176 176 ret_from_fork+0x7c/0xb0 This change reduces the stack usage in dsl_dataset_remove_clones_key by allocating structures in heap, not in stack. This is not a fundamental fix, as one can create an arbitrary large data set that runs over any fixed size stack, but this will make the problem far less likely. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Kohsuke Kawaguchi <kk@kohsuke.org> Closes #1726
2013-09-25 22:14:47 +00:00
zap_cursor_fini(zc);
kmem_free(za, sizeof (zap_attribute_t));
kmem_free(zc, sizeof (zap_cursor_t));
}
void
dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx)
{
#ifdef ZFS_DEBUG
int err;
#endif
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;
uint64_t obj, old_unique, used = 0, comp = 0, uncomp = 0;
dsl_dataset_t *ds_next, *ds_head, *hds;
ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
ASSERT(refcount_is_zero(&ds->ds_longholds));
if (defer &&
(ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)) {
ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
spa_history_log_internal_ds(ds, "defer_destroy", tx, "");
return;
}
ASSERT3U(ds->ds_phys->ds_num_children, <=, 1);
/* We need to log before removing it from the namespace. */
spa_history_log_internal_ds(ds, "destroy", tx, "");
dsl_scan_ds_destroyed(ds, tx);
obj = ds->ds_object;
if (ds->ds_phys->ds_prev_snap_obj != 0) {
ASSERT3P(ds->ds_prev, ==, NULL);
VERIFY0(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) {
dsl_dataset_remove_from_next_clones(ds_prev, obj, tx);
if (ds->ds_phys->ds_next_snap_obj != 0) {
VERIFY0(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_prev->ds_phys->ds_next_snap_obj =
ds->ds_phys->ds_next_snap_obj;
}
}
VERIFY0(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);
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_phys->ds_deadlist_obj = 0;
/* 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).
*/
VERIFY0(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. */
VERIFY0(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_rele(ds_next->ds_prev, ds_next);
ds_next->ds_prev = NULL;
if (ds_prev) {
VERIFY0(dsl_dataset_hold_obj(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 unconsumed 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);
/*
* 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;
}
/* remove from snapshot namespace */
ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
VERIFY0(dsl_dataset_hold_obj(dp,
ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
VERIFY0(dsl_dataset_get_snapname(ds));
#ifdef ZFS_DEBUG
{
uint64_t val;
err = dsl_dataset_snap_lookup(ds_head,
ds->ds_snapname, &val);
ASSERT0(err);
ASSERT3U(val, ==, obj);
}
#endif
VERIFY0(dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx));
dsl_dataset_rele(ds_head, FTAG);
if (ds_prev != NULL)
dsl_dataset_rele(ds_prev, FTAG);
spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
if (ds->ds_phys->ds_next_clones_obj != 0) {
ASSERTV(uint64_t count);
ASSERT0(zap_count(mos,
ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
VERIFY0(dmu_object_free(mos,
ds->ds_phys->ds_next_clones_obj, tx));
}
if (ds->ds_phys->ds_props_obj != 0)
VERIFY0(zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
if (ds->ds_phys->ds_userrefs_obj != 0)
VERIFY0(zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
dsl_dir_rele(ds->ds_dir, ds);
ds->ds_dir = NULL;
VERIFY0(dmu_object_free(mos, obj, tx));
}
static void
dsl_destroy_snapshot_sync(void *arg, dmu_tx_t *tx)
{
dmu_snapshots_destroy_arg_t *dsda = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvpair_t *pair;
for (pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, NULL);
pair != NULL;
pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, pair)) {
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
dsl_destroy_snapshot_sync_impl(ds, dsda->dsda_defer, tx);
dsl_dataset_rele(ds, FTAG);
}
}
/*
* The semantics of this function are described in the comment above
* lzc_destroy_snaps(). To summarize:
*
* The snapshots must all be in the same pool.
*
* Snapshots that don't exist will be silently ignored (considered to be
* "already deleted").
*
* On success, all snaps will be destroyed and this will return 0.
* On failure, no snaps will be destroyed, the errlist will be filled in,
* and this will return an errno.
*/
int
dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t defer,
nvlist_t *errlist)
{
dmu_snapshots_destroy_arg_t dsda;
int error;
nvpair_t *pair;
pair = nvlist_next_nvpair(snaps, NULL);
if (pair == NULL)
return (0);
dsda.dsda_snaps = snaps;
VERIFY0(nvlist_alloc(&dsda.dsda_successful_snaps,
NV_UNIQUE_NAME, KM_PUSHPAGE));
dsda.dsda_defer = defer;
dsda.dsda_errlist = errlist;
error = dsl_sync_task(nvpair_name(pair),
dsl_destroy_snapshot_check, dsl_destroy_snapshot_sync,
&dsda, 0);
fnvlist_free(dsda.dsda_successful_snaps);
return (error);
}
int
dsl_destroy_snapshot(const char *name, boolean_t defer)
{
int error;
nvlist_t *nvl;
nvlist_t *errlist;
VERIFY0(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_PUSHPAGE));
VERIFY0(nvlist_alloc(&errlist, NV_UNIQUE_NAME, KM_PUSHPAGE));
fnvlist_add_boolean(nvl, name);
error = dsl_destroy_snapshots_nvl(nvl, defer, errlist);
fnvlist_free(errlist);
fnvlist_free(nvl);
return (error);
}
struct killarg {
dsl_dataset_t *ds;
dmu_tx_t *tx;
};
/* ARGSUSED */
static int
kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
{
struct killarg *ka = arg;
dmu_tx_t *tx = ka->tx;
if (bp == NULL)
return (0);
if (zb->zb_level == ZB_ZIL_LEVEL) {
ASSERT(zilog != NULL);
/*
* It's a block in the intent log. It has no
* accounting, so just free it.
*/
dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
} else {
ASSERT(zilog == NULL);
ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
(void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
}
return (0);
}
static void
old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx)
{
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;
VERIFY0(traverse_dataset(ds,
ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST,
kill_blkptr, &ka));
ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0);
}
typedef struct dsl_destroy_head_arg {
const char *ddha_name;
} dsl_destroy_head_arg_t;
int
dsl_destroy_head_check_impl(dsl_dataset_t *ds, int expected_holds)
{
int error;
uint64_t count;
objset_t *mos;
if (dsl_dataset_is_snapshot(ds))
return (SET_ERROR(EINVAL));
if (refcount_count(&ds->ds_longholds) != expected_holds)
return (SET_ERROR(EBUSY));
mos = ds->ds_dir->dd_pool->dp_meta_objset;
/*
* 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 (SET_ERROR(EBUSY));
/*
* Can't delete if there are children of this fs.
*/
error = zap_count(mos,
ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
if (error != 0)
return (error);
if (count != 0)
return (SET_ERROR(EEXIST));
if (dsl_dir_is_clone(ds->ds_dir) && DS_IS_DEFER_DESTROY(ds->ds_prev) &&
ds->ds_prev->ds_phys->ds_num_children == 2 &&
ds->ds_prev->ds_userrefs == 0) {
/* We need to remove the origin snapshot as well. */
if (!refcount_is_zero(&ds->ds_prev->ds_longholds))
return (SET_ERROR(EBUSY));
}
return (0);
}
static int
dsl_destroy_head_check(void *arg, dmu_tx_t *tx)
{
dsl_destroy_head_arg_t *ddha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
dsl_dataset_t *ds;
int error;
error = dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds);
if (error != 0)
return (error);
error = dsl_destroy_head_check_impl(ds, 0);
dsl_dataset_rele(ds, FTAG);
return (error);
}
static void
dsl_dir_destroy_sync(uint64_t ddobj, dmu_tx_t *tx)
{
dsl_dir_t *dd;
dsl_pool_t *dp = dmu_tx_pool(tx);
objset_t *mos = dp->dp_meta_objset;
dd_used_t t;
ASSERT(RRW_WRITE_HELD(&dmu_tx_pool(tx)->dp_config_rwlock));
VERIFY0(dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd));
ASSERT0(dd->dd_phys->dd_head_dataset_obj);
/*
* Remove our reservation. The impl() routine avoids setting the
* actual property, which would require the (already destroyed) ds.
*/
dsl_dir_set_reservation_sync_impl(dd, 0, tx);
ASSERT0(dd->dd_phys->dd_used_bytes);
ASSERT0(dd->dd_phys->dd_reserved);
for (t = 0; t < DD_USED_NUM; t++)
ASSERT0(dd->dd_phys->dd_used_breakdown[t]);
VERIFY0(zap_destroy(mos, dd->dd_phys->dd_child_dir_zapobj, tx));
VERIFY0(zap_destroy(mos, dd->dd_phys->dd_props_zapobj, tx));
VERIFY0(dsl_deleg_destroy(mos, dd->dd_phys->dd_deleg_zapobj, tx));
VERIFY0(zap_remove(mos,
dd->dd_parent->dd_phys->dd_child_dir_zapobj, dd->dd_myname, tx));
dsl_dir_rele(dd, FTAG);
VERIFY0(dmu_object_free(mos, ddobj, tx));
}
void
dsl_destroy_head_sync_impl(dsl_dataset_t *ds, dmu_tx_t *tx)
{
dsl_pool_t *dp = dmu_tx_pool(tx);
objset_t *mos = dp->dp_meta_objset;
uint64_t obj, ddobj, prevobj = 0;
boolean_t rmorigin;
zfeature_info_t *async_destroy;
objset_t *os;
ASSERT3U(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);
ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
/* We need to log before removing it from the namespace. */
spa_history_log_internal_ds(ds, "destroy", tx, "");
rmorigin = (dsl_dir_is_clone(ds->ds_dir) &&
DS_IS_DEFER_DESTROY(ds->ds_prev) &&
ds->ds_prev->ds_phys->ds_num_children == 2 &&
ds->ds_prev->ds_userrefs == 0);
/* Remove our reservation */
if (ds->ds_reserved != 0) {
dsl_dataset_set_refreservation_sync_impl(ds,
(ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
0, tx);
ASSERT0(ds->ds_reserved);
}
dsl_scan_ds_destroyed(ds, tx);
obj = ds->ds_object;
if (ds->ds_phys->ds_prev_snap_obj != 0) {
/* This is a clone */
ASSERT(ds->ds_prev != NULL);
ASSERT3U(ds->ds_prev->ds_phys->ds_next_snap_obj, !=, obj);
ASSERT0(ds->ds_phys->ds_next_snap_obj);
dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
if (ds->ds_prev->ds_phys->ds_next_clones_obj != 0) {
dsl_dataset_remove_from_next_clones(ds->ds_prev,
obj, tx);
}
ASSERT3U(ds->ds_prev->ds_phys->ds_num_children, >, 1);
ds->ds_prev->ds_phys->ds_num_children--;
}
async_destroy =
&spa_feature_table[SPA_FEATURE_ASYNC_DESTROY];
/*
* 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);
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_phys->ds_deadlist_obj = 0;
VERIFY0(dmu_objset_from_ds(ds, &os));
if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) {
old_synchronous_dataset_destroy(ds, tx);
} else {
/*
* Move the bptree into the pool's list of trees to
* clean up and update space accounting information.
*/
uint64_t used, comp, uncomp;
zil_destroy_sync(dmu_objset_zil(os), tx);
if (!spa_feature_is_active(dp->dp_spa, async_destroy)) {
dsl_scan_t *scn = dp->dp_scan;
spa_feature_incr(dp->dp_spa, async_destroy, tx);
dp->dp_bptree_obj = bptree_alloc(mos, tx);
VERIFY0(zap_add(mos,
DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
&dp->dp_bptree_obj, tx));
ASSERT(!scn->scn_async_destroying);
scn->scn_async_destroying = B_TRUE;
}
used = ds->ds_dir->dd_phys->dd_used_bytes;
comp = ds->ds_dir->dd_phys->dd_compressed_bytes;
uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes;
ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
ds->ds_phys->ds_unique_bytes == used);
bptree_add(mos, dp->dp_bptree_obj,
&ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg,
used, comp, uncomp, tx);
dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
-used, -comp, -uncomp, tx);
dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
used, comp, uncomp, tx);
}
if (ds->ds_prev != NULL) {
if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
VERIFY0(zap_remove_int(mos,
ds->ds_prev->ds_dir->dd_phys->dd_clones,
ds->ds_object, tx));
}
prevobj = ds->ds_prev->ds_object;
dsl_dataset_rele(ds->ds_prev, ds);
ds->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;
}
/* 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;
ddobj = ds->ds_dir->dd_object;
ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
VERIFY0(zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx));
spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
ASSERT0(ds->ds_phys->ds_next_clones_obj);
ASSERT0(ds->ds_phys->ds_props_obj);
ASSERT0(ds->ds_phys->ds_userrefs_obj);
dsl_dir_rele(ds->ds_dir, ds);
ds->ds_dir = NULL;
VERIFY0(dmu_object_free(mos, obj, tx));
dsl_dir_destroy_sync(ddobj, tx);
if (rmorigin) {
dsl_dataset_t *prev;
VERIFY0(dsl_dataset_hold_obj(dp, prevobj, FTAG, &prev));
dsl_destroy_snapshot_sync_impl(prev, B_FALSE, tx);
dsl_dataset_rele(prev, FTAG);
}
}
static void
dsl_destroy_head_sync(void *arg, dmu_tx_t *tx)
{
dsl_destroy_head_arg_t *ddha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
dsl_destroy_head_sync_impl(ds, tx);
dsl_dataset_rele(ds, FTAG);
}
static void
dsl_destroy_head_begin_sync(void *arg, dmu_tx_t *tx)
{
dsl_destroy_head_arg_t *ddha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
/* Mark it as inconsistent on-disk, in case we crash */
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
spa_history_log_internal_ds(ds, "destroy begin", tx, "");
dsl_dataset_rele(ds, FTAG);
}
int
dsl_destroy_head(const char *name)
{
dsl_destroy_head_arg_t ddha;
int error;
spa_t *spa;
boolean_t isenabled;
#ifdef _KERNEL
zfs_destroy_unmount_origin(name);
#endif
error = spa_open(name, &spa, FTAG);
if (error != 0)
return (error);
isenabled = spa_feature_is_enabled(spa,
&spa_feature_table[SPA_FEATURE_ASYNC_DESTROY]);
spa_close(spa, FTAG);
ddha.ddha_name = name;
if (!isenabled) {
objset_t *os;
error = dsl_sync_task(name, dsl_destroy_head_check,
dsl_destroy_head_begin_sync, &ddha, 0);
if (error != 0)
return (error);
/*
* Head deletion is processed in one txg on old pools;
* remove the objects from open context so that the txg sync
* is not too long.
*/
error = dmu_objset_own(name, DMU_OST_ANY, B_FALSE, FTAG, &os);
if (error == 0) {
uint64_t obj;
uint64_t prev_snap_txg =
dmu_objset_ds(os)->ds_phys->ds_prev_snap_txg;
for (obj = 0; error == 0;
error = dmu_object_next(os, &obj, FALSE,
prev_snap_txg))
(void) dmu_free_long_object(os, obj);
/* sync out all frees */
txg_wait_synced(dmu_objset_pool(os), 0);
dmu_objset_disown(os, FTAG);
}
}
return (dsl_sync_task(name, dsl_destroy_head_check,
dsl_destroy_head_sync, &ddha, 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)
{
objset_t *os;
if (dmu_objset_hold(dsname, FTAG, &os) == 0) {
boolean_t inconsistent = DS_IS_INCONSISTENT(dmu_objset_ds(os));
dmu_objset_rele(os, FTAG);
if (inconsistent)
(void) dsl_destroy_head(dsname);
}
return (0);
}
#if defined(_KERNEL) && defined(HAVE_SPL)
EXPORT_SYMBOL(dsl_destroy_head);
EXPORT_SYMBOL(dsl_destroy_head_sync_impl);
EXPORT_SYMBOL(dsl_dataset_user_hold_check_one);
EXPORT_SYMBOL(dsl_destroy_snapshot_sync_impl);
EXPORT_SYMBOL(dsl_destroy_inconsistent);
EXPORT_SYMBOL(dsl_dataset_user_release_tmp);
EXPORT_SYMBOL(dsl_destroy_head_check_impl);
#endif