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mirror_zfs/module/zfs/dsl_scan.c
ka7 4e33ba4c38 Fix spelling 
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Haakan T Johansson <f96hajo@chalmers.se>
Closes #5547 
Closes #5543
2017-01-03 11:31:18 -06:00

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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) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011, 2016 by Delphix. All rights reserved.
* Copyright 2016 Gary Mills
*/
#include <sys/dsl_scan.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_prop.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_synctask.h>
#include <sys/dnode.h>
#include <sys/dmu_tx.h>
#include <sys/dmu_objset.h>
#include <sys/arc.h>
#include <sys/zap.h>
#include <sys/zio.h>
#include <sys/zfs_context.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_znode.h>
#include <sys/spa_impl.h>
#include <sys/vdev_impl.h>
#include <sys/zil_impl.h>
#include <sys/zio_checksum.h>
#include <sys/ddt.h>
#include <sys/sa.h>
#include <sys/sa_impl.h>
#include <sys/zfeature.h>
#include <sys/abd.h>
#ifdef _KERNEL
#include <sys/zfs_vfsops.h>
#endif
typedef int (scan_cb_t)(dsl_pool_t *, const blkptr_t *,
const zbookmark_phys_t *);
static scan_cb_t dsl_scan_scrub_cb;
static void dsl_scan_cancel_sync(void *, dmu_tx_t *);
static void dsl_scan_sync_state(dsl_scan_t *, dmu_tx_t *);
static boolean_t dsl_scan_restarting(dsl_scan_t *, dmu_tx_t *);
int zfs_top_maxinflight = 32; /* maximum I/Os per top-level */
int zfs_resilver_delay = 2; /* number of ticks to delay resilver */
int zfs_scrub_delay = 4; /* number of ticks to delay scrub */
int zfs_scan_idle = 50; /* idle window in clock ticks */
int zfs_scan_min_time_ms = 1000; /* min millisecs to scrub per txg */
int zfs_free_min_time_ms = 1000; /* min millisecs to free per txg */
int zfs_resilver_min_time_ms = 3000; /* min millisecs to resilver per txg */
int zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */
int zfs_no_scrub_prefetch = B_FALSE; /* set to disable scrub prefetch */
enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE;
int dsl_scan_delay_completion = B_FALSE; /* set to delay scan completion */
/* max number of blocks to free in a single TXG */
unsigned long zfs_free_max_blocks = 100000;
#define DSL_SCAN_IS_SCRUB_RESILVER(scn) \
((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \
(scn)->scn_phys.scn_func == POOL_SCAN_RESILVER)
/*
* Enable/disable the processing of the free_bpobj object.
*/
int zfs_free_bpobj_enabled = 1;
/* the order has to match pool_scan_type */
static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = {
NULL,
dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */
dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */
};
int
dsl_scan_init(dsl_pool_t *dp, uint64_t txg)
{
int err;
dsl_scan_t *scn;
spa_t *spa = dp->dp_spa;
uint64_t f;
scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP);
scn->scn_dp = dp;
/*
* It's possible that we're resuming a scan after a reboot so
* make sure that the scan_async_destroying flag is initialized
* appropriately.
*/
ASSERT(!scn->scn_async_destroying);
scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa,
SPA_FEATURE_ASYNC_DESTROY);
err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
"scrub_func", sizeof (uint64_t), 1, &f);
if (err == 0) {
/*
* There was an old-style scrub in progress. Restart a
* new-style scrub from the beginning.
*/
scn->scn_restart_txg = txg;
zfs_dbgmsg("old-style scrub was in progress; "
"restarting new-style scrub in txg %llu",
scn->scn_restart_txg);
/*
* Load the queue obj from the old location so that it
* can be freed by dsl_scan_done().
*/
(void) zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
"scrub_queue", sizeof (uint64_t), 1,
&scn->scn_phys.scn_queue_obj);
} else {
err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS,
&scn->scn_phys);
/*
* Detect if the pool contains the signature of #2094. If it
* does properly update the scn->scn_phys structure and notify
* the administrator by setting an errata for the pool.
*/
if (err == EOVERFLOW) {
uint64_t zaptmp[SCAN_PHYS_NUMINTS + 1];
VERIFY3S(SCAN_PHYS_NUMINTS, ==, 24);
VERIFY3S(offsetof(dsl_scan_phys_t, scn_flags), ==,
(23 * sizeof (uint64_t)));
err = zap_lookup(dp->dp_meta_objset,
DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SCAN,
sizeof (uint64_t), SCAN_PHYS_NUMINTS + 1, &zaptmp);
if (err == 0) {
uint64_t overflow = zaptmp[SCAN_PHYS_NUMINTS];
if (overflow & ~DSL_SCAN_FLAGS_MASK ||
scn->scn_async_destroying) {
spa->spa_errata =
ZPOOL_ERRATA_ZOL_2094_ASYNC_DESTROY;
return (EOVERFLOW);
}
bcopy(zaptmp, &scn->scn_phys,
SCAN_PHYS_NUMINTS * sizeof (uint64_t));
scn->scn_phys.scn_flags = overflow;
/* Required scrub already in progress. */
if (scn->scn_phys.scn_state == DSS_FINISHED ||
scn->scn_phys.scn_state == DSS_CANCELED)
spa->spa_errata =
ZPOOL_ERRATA_ZOL_2094_SCRUB;
}
}
if (err == ENOENT)
return (0);
else if (err)
return (err);
if (scn->scn_phys.scn_state == DSS_SCANNING &&
spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) {
/*
* A new-type scrub was in progress on an old
* pool, and the pool was accessed by old
* software. Restart from the beginning, since
* the old software may have changed the pool in
* the meantime.
*/
scn->scn_restart_txg = txg;
zfs_dbgmsg("new-style scrub was modified "
"by old software; restarting in txg %llu",
scn->scn_restart_txg);
}
}
spa_scan_stat_init(spa);
return (0);
}
void
dsl_scan_fini(dsl_pool_t *dp)
{
if (dp->dp_scan) {
kmem_free(dp->dp_scan, sizeof (dsl_scan_t));
dp->dp_scan = NULL;
}
}
/* ARGSUSED */
static int
dsl_scan_setup_check(void *arg, dmu_tx_t *tx)
{
dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
if (scn->scn_phys.scn_state == DSS_SCANNING)
return (SET_ERROR(EBUSY));
return (0);
}
static void
dsl_scan_setup_sync(void *arg, dmu_tx_t *tx)
{
dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
pool_scan_func_t *funcp = arg;
dmu_object_type_t ot = 0;
dsl_pool_t *dp = scn->scn_dp;
spa_t *spa = dp->dp_spa;
ASSERT(scn->scn_phys.scn_state != DSS_SCANNING);
ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS);
bzero(&scn->scn_phys, sizeof (scn->scn_phys));
scn->scn_phys.scn_func = *funcp;
scn->scn_phys.scn_state = DSS_SCANNING;
scn->scn_phys.scn_min_txg = 0;
scn->scn_phys.scn_max_txg = tx->tx_txg;
scn->scn_phys.scn_ddt_class_max = DDT_CLASSES - 1; /* the entire DDT */
scn->scn_phys.scn_start_time = gethrestime_sec();
scn->scn_phys.scn_errors = 0;
scn->scn_phys.scn_to_examine = spa->spa_root_vdev->vdev_stat.vs_alloc;
scn->scn_restart_txg = 0;
scn->scn_done_txg = 0;
spa_scan_stat_init(spa);
if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) {
scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max;
/* rewrite all disk labels */
vdev_config_dirty(spa->spa_root_vdev);
if (vdev_resilver_needed(spa->spa_root_vdev,
&scn->scn_phys.scn_min_txg, &scn->scn_phys.scn_max_txg)) {
spa_event_notify(spa, NULL, ESC_ZFS_RESILVER_START);
} else {
spa_event_notify(spa, NULL, ESC_ZFS_SCRUB_START);
}
spa->spa_scrub_started = B_TRUE;
/*
* If this is an incremental scrub, limit the DDT scrub phase
* to just the auto-ditto class (for correctness); the rest
* of the scrub should go faster using top-down pruning.
*/
if (scn->scn_phys.scn_min_txg > TXG_INITIAL)
scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO;
}
/* back to the generic stuff */
if (dp->dp_blkstats == NULL) {
dp->dp_blkstats =
vmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP);
}
bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
if (spa_version(spa) < SPA_VERSION_DSL_SCRUB)
ot = DMU_OT_ZAP_OTHER;
scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset,
ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx);
dsl_scan_sync_state(scn, tx);
spa_history_log_internal(spa, "scan setup", tx,
"func=%u mintxg=%llu maxtxg=%llu",
*funcp, scn->scn_phys.scn_min_txg, scn->scn_phys.scn_max_txg);
}
/* ARGSUSED */
static void
dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx)
{
static const char *old_names[] = {
"scrub_bookmark",
"scrub_ddt_bookmark",
"scrub_ddt_class_max",
"scrub_queue",
"scrub_min_txg",
"scrub_max_txg",
"scrub_func",
"scrub_errors",
NULL
};
dsl_pool_t *dp = scn->scn_dp;
spa_t *spa = dp->dp_spa;
int i;
/* Remove any remnants of an old-style scrub. */
for (i = 0; old_names[i]; i++) {
(void) zap_remove(dp->dp_meta_objset,
DMU_POOL_DIRECTORY_OBJECT, old_names[i], tx);
}
if (scn->scn_phys.scn_queue_obj != 0) {
VERIFY(0 == dmu_object_free(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, tx));
scn->scn_phys.scn_queue_obj = 0;
}
/*
* If we were "restarted" from a stopped state, don't bother
* with anything else.
*/
if (scn->scn_phys.scn_state != DSS_SCANNING)
return;
if (complete)
scn->scn_phys.scn_state = DSS_FINISHED;
else
scn->scn_phys.scn_state = DSS_CANCELED;
if (dsl_scan_restarting(scn, tx))
spa_history_log_internal(spa, "scan aborted, restarting", tx,
"errors=%llu", spa_get_errlog_size(spa));
else if (!complete)
spa_history_log_internal(spa, "scan cancelled", tx,
"errors=%llu", spa_get_errlog_size(spa));
else
spa_history_log_internal(spa, "scan done", tx,
"errors=%llu", spa_get_errlog_size(spa));
if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) {
mutex_enter(&spa->spa_scrub_lock);
while (spa->spa_scrub_inflight > 0) {
cv_wait(&spa->spa_scrub_io_cv,
&spa->spa_scrub_lock);
}
mutex_exit(&spa->spa_scrub_lock);
spa->spa_scrub_started = B_FALSE;
spa->spa_scrub_active = B_FALSE;
/*
* If the scrub/resilver completed, update all DTLs to
* reflect this. Whether it succeeded or not, vacate
* all temporary scrub DTLs.
*/
vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg,
complete ? scn->scn_phys.scn_max_txg : 0, B_TRUE);
if (complete) {
spa_event_notify(spa, NULL, scn->scn_phys.scn_min_txg ?
ESC_ZFS_RESILVER_FINISH : ESC_ZFS_SCRUB_FINISH);
}
spa_errlog_rotate(spa);
/*
* We may have finished replacing a device.
* Let the async thread assess this and handle the detach.
*/
spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
}
scn->scn_phys.scn_end_time = gethrestime_sec();
if (spa->spa_errata == ZPOOL_ERRATA_ZOL_2094_SCRUB)
spa->spa_errata = 0;
}
/* ARGSUSED */
static int
dsl_scan_cancel_check(void *arg, dmu_tx_t *tx)
{
dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
if (scn->scn_phys.scn_state != DSS_SCANNING)
return (SET_ERROR(ENOENT));
return (0);
}
/* ARGSUSED */
static void
dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx)
{
dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
dsl_scan_done(scn, B_FALSE, tx);
dsl_scan_sync_state(scn, tx);
}
int
dsl_scan_cancel(dsl_pool_t *dp)
{
return (dsl_sync_task(spa_name(dp->dp_spa), dsl_scan_cancel_check,
dsl_scan_cancel_sync, NULL, 3, ZFS_SPACE_CHECK_RESERVED));
}
static void dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb,
dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn,
dmu_objset_type_t ostype, dmu_tx_t *tx);
inline __attribute__((always_inline)) static void dsl_scan_visitdnode(
dsl_scan_t *, dsl_dataset_t *ds, dmu_objset_type_t ostype,
dnode_phys_t *dnp, uint64_t object, dmu_tx_t *tx);
void
dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp)
{
zio_free(dp->dp_spa, txg, bp);
}
void
dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp)
{
ASSERT(dsl_pool_sync_context(dp));
zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, pio->io_flags));
}
static uint64_t
dsl_scan_ds_maxtxg(dsl_dataset_t *ds)
{
uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg;
if (ds->ds_is_snapshot)
return (MIN(smt, dsl_dataset_phys(ds)->ds_creation_txg));
return (smt);
}
static void
dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx)
{
VERIFY0(zap_update(scn->scn_dp->dp_meta_objset,
DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS,
&scn->scn_phys, tx));
}
extern int zfs_vdev_async_write_active_min_dirty_percent;
static boolean_t
dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_phys_t *zb)
{
uint64_t elapsed_nanosecs;
int mintime;
int dirty_pct;
/* we never skip user/group accounting objects */
if (zb && (int64_t)zb->zb_object < 0)
return (B_FALSE);
if (scn->scn_pausing)
return (B_TRUE); /* we're already pausing */
if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark))
return (B_FALSE); /* we're resuming */
/* We only know how to resume from level-0 blocks. */
if (zb && zb->zb_level != 0)
return (B_FALSE);
/*
* We pause if:
* - we have scanned for the maximum time: an entire txg
* timeout (default 5 sec)
* or
* - we have scanned for at least the minimum time (default 1 sec
* for scrub, 3 sec for resilver), and either we have sufficient
* dirty data that we are starting to write more quickly
* (default 30%), or someone is explicitly waiting for this txg
* to complete.
* or
* - the spa is shutting down because this pool is being exported
* or the machine is rebooting.
*/
mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ?
zfs_resilver_min_time_ms : zfs_scan_min_time_ms;
elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time;
dirty_pct = scn->scn_dp->dp_dirty_total * 100 / zfs_dirty_data_max;
if (elapsed_nanosecs / NANOSEC >= zfs_txg_timeout ||
(NSEC2MSEC(elapsed_nanosecs) > mintime &&
(txg_sync_waiting(scn->scn_dp) ||
dirty_pct >= zfs_vdev_async_write_active_min_dirty_percent)) ||
spa_shutting_down(scn->scn_dp->dp_spa)) {
if (zb) {
dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n",
(longlong_t)zb->zb_objset,
(longlong_t)zb->zb_object,
(longlong_t)zb->zb_level,
(longlong_t)zb->zb_blkid);
scn->scn_phys.scn_bookmark = *zb;
}
dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n",
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor);
scn->scn_pausing = B_TRUE;
return (B_TRUE);
}
return (B_FALSE);
}
typedef struct zil_scan_arg {
dsl_pool_t *zsa_dp;
zil_header_t *zsa_zh;
} zil_scan_arg_t;
/* ARGSUSED */
static int
dsl_scan_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
{
zil_scan_arg_t *zsa = arg;
dsl_pool_t *dp = zsa->zsa_dp;
dsl_scan_t *scn = dp->dp_scan;
zil_header_t *zh = zsa->zsa_zh;
zbookmark_phys_t zb;
if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg)
return (0);
/*
* One block ("stubby") can be allocated a long time ago; we
* want to visit that one because it has been allocated
* (on-disk) even if it hasn't been claimed (even though for
* scrub there's nothing to do to it).
*/
if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa))
return (0);
SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET],
ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb));
return (0);
}
/* ARGSUSED */
static int
dsl_scan_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
{
if (lrc->lrc_txtype == TX_WRITE) {
zil_scan_arg_t *zsa = arg;
dsl_pool_t *dp = zsa->zsa_dp;
dsl_scan_t *scn = dp->dp_scan;
zil_header_t *zh = zsa->zsa_zh;
lr_write_t *lr = (lr_write_t *)lrc;
blkptr_t *bp = &lr->lr_blkptr;
zbookmark_phys_t zb;
if (BP_IS_HOLE(bp) ||
bp->blk_birth <= scn->scn_phys.scn_cur_min_txg)
return (0);
/*
* birth can be < claim_txg if this record's txg is
* already txg sync'ed (but this log block contains
* other records that are not synced)
*/
if (claim_txg == 0 || bp->blk_birth < claim_txg)
return (0);
SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET],
lr->lr_foid, ZB_ZIL_LEVEL,
lr->lr_offset / BP_GET_LSIZE(bp));
VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb));
}
return (0);
}
static void
dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh)
{
uint64_t claim_txg = zh->zh_claim_txg;
zil_scan_arg_t zsa = { dp, zh };
zilog_t *zilog;
/*
* We only want to visit blocks that have been claimed but not yet
* replayed (or, in read-only mode, blocks that *would* be claimed).
*/
if (claim_txg == 0 && spa_writeable(dp->dp_spa))
return;
zilog = zil_alloc(dp->dp_meta_objset, zh);
(void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa,
claim_txg);
zil_free(zilog);
}
/* ARGSUSED */
static void
dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp,
uint64_t objset, uint64_t object, uint64_t blkid)
{
zbookmark_phys_t czb;
arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
if (zfs_no_scrub_prefetch)
return;
if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_min_txg ||
(BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE))
return;
SET_BOOKMARK(&czb, objset, object, BP_GET_LEVEL(bp), blkid);
(void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp,
NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb);
}
static boolean_t
dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp,
const zbookmark_phys_t *zb)
{
/*
* We never skip over user/group accounting objects (obj<0)
*/
if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) &&
(int64_t)zb->zb_object >= 0) {
/*
* If we already visited this bp & everything below (in
* a prior txg sync), don't bother doing it again.
*/
if (zbookmark_subtree_completed(dnp, zb,
&scn->scn_phys.scn_bookmark))
return (B_TRUE);
/*
* If we found the block we're trying to resume from, or
* we went past it to a different object, zero it out to
* indicate that it's OK to start checking for pausing
* again.
*/
if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 ||
zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) {
dprintf("resuming at %llx/%llx/%llx/%llx\n",
(longlong_t)zb->zb_objset,
(longlong_t)zb->zb_object,
(longlong_t)zb->zb_level,
(longlong_t)zb->zb_blkid);
bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb));
}
}
return (B_FALSE);
}
/*
* Return nonzero on i/o error.
* Return new buf to write out in *bufp.
*/
inline __attribute__((always_inline)) static int
dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
dnode_phys_t *dnp, const blkptr_t *bp,
const zbookmark_phys_t *zb, dmu_tx_t *tx)
{
dsl_pool_t *dp = scn->scn_dp;
int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD;
int err;
if (BP_GET_LEVEL(bp) > 0) {
arc_flags_t flags = ARC_FLAG_WAIT;
int i;
blkptr_t *cbp;
int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
arc_buf_t *buf;
err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err) {
scn->scn_phys.scn_errors++;
return (err);
}
for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) {
dsl_scan_prefetch(scn, buf, cbp, zb->zb_objset,
zb->zb_object, zb->zb_blkid * epb + i);
}
for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) {
zbookmark_phys_t czb;
SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
zb->zb_level - 1,
zb->zb_blkid * epb + i);
dsl_scan_visitbp(cbp, &czb, dnp,
ds, scn, ostype, tx);
}
arc_buf_destroy(buf, &buf);
} else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
arc_flags_t flags = ARC_FLAG_WAIT;
dnode_phys_t *cdnp;
int i, j;
int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
arc_buf_t *buf;
err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err) {
scn->scn_phys.scn_errors++;
return (err);
}
for (i = 0, cdnp = buf->b_data; i < epb;
i += cdnp->dn_extra_slots + 1,
cdnp += cdnp->dn_extra_slots + 1) {
for (j = 0; j < cdnp->dn_nblkptr; j++) {
blkptr_t *cbp = &cdnp->dn_blkptr[j];
dsl_scan_prefetch(scn, buf, cbp,
zb->zb_objset, zb->zb_blkid * epb + i, j);
}
}
for (i = 0, cdnp = buf->b_data; i < epb;
i += cdnp->dn_extra_slots + 1,
cdnp += cdnp->dn_extra_slots + 1) {
dsl_scan_visitdnode(scn, ds, ostype,
cdnp, zb->zb_blkid * epb + i, tx);
}
arc_buf_destroy(buf, &buf);
} else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
arc_flags_t flags = ARC_FLAG_WAIT;
objset_phys_t *osp;
arc_buf_t *buf;
err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err) {
scn->scn_phys.scn_errors++;
return (err);
}
osp = buf->b_data;
dsl_scan_visitdnode(scn, ds, osp->os_type,
&osp->os_meta_dnode, DMU_META_DNODE_OBJECT, tx);
if (OBJSET_BUF_HAS_USERUSED(buf)) {
/*
* We also always visit user/group accounting
* objects, and never skip them, even if we are
* pausing. This is necessary so that the space
* deltas from this txg get integrated.
*/
dsl_scan_visitdnode(scn, ds, osp->os_type,
&osp->os_groupused_dnode,
DMU_GROUPUSED_OBJECT, tx);
dsl_scan_visitdnode(scn, ds, osp->os_type,
&osp->os_userused_dnode,
DMU_USERUSED_OBJECT, tx);
}
arc_buf_destroy(buf, &buf);
}
return (0);
}
inline __attribute__((always_inline)) static void
dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds,
dmu_objset_type_t ostype, dnode_phys_t *dnp,
uint64_t object, dmu_tx_t *tx)
{
int j;
for (j = 0; j < dnp->dn_nblkptr; j++) {
zbookmark_phys_t czb;
SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object,
dnp->dn_nlevels - 1, j);
dsl_scan_visitbp(&dnp->dn_blkptr[j],
&czb, dnp, ds, scn, ostype, tx);
}
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
zbookmark_phys_t czb;
SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object,
0, DMU_SPILL_BLKID);
dsl_scan_visitbp(DN_SPILL_BLKPTR(dnp),
&czb, dnp, ds, scn, ostype, tx);
}
}
/*
* The arguments are in this order because mdb can only print the
* first 5; we want them to be useful.
*/
static void
dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb,
dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn,
dmu_objset_type_t ostype, dmu_tx_t *tx)
{
dsl_pool_t *dp = scn->scn_dp;
blkptr_t *bp_toread;
bp_toread = kmem_alloc(sizeof (blkptr_t), KM_SLEEP);
*bp_toread = *bp;
/* ASSERT(pbuf == NULL || arc_released(pbuf)); */
if (dsl_scan_check_pause(scn, zb))
goto out;
if (dsl_scan_check_resume(scn, dnp, zb))
goto out;
if (BP_IS_HOLE(bp))
goto out;
scn->scn_visited_this_txg++;
/*
* This debugging is commented out to conserve stack space. This
* function is called recursively and the debugging addes several
* bytes to the stack for each call. It can be commented back in
* if required to debug an issue in dsl_scan_visitbp().
*
* dprintf_bp(bp,
* "visiting ds=%p/%llu zb=%llx/%llx/%llx/%llx bp=%p",
* ds, ds ? ds->ds_object : 0,
* zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid,
* bp);
*/
if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg)
goto out;
if (dsl_scan_recurse(scn, ds, ostype, dnp, bp_toread, zb, tx) != 0)
goto out;
/*
* If dsl_scan_ddt() has already visited this block, it will have
* already done any translations or scrubbing, so don't call the
* callback again.
*/
if (ddt_class_contains(dp->dp_spa,
scn->scn_phys.scn_ddt_class_max, bp)) {
goto out;
}
/*
* If this block is from the future (after cur_max_txg), then we
* are doing this on behalf of a deleted snapshot, and we will
* revisit the future block on the next pass of this dataset.
* Don't scan it now unless we need to because something
* under it was modified.
*/
if (BP_PHYSICAL_BIRTH(bp) <= scn->scn_phys.scn_cur_max_txg) {
scan_funcs[scn->scn_phys.scn_func](dp, bp, zb);
}
out:
kmem_free(bp_toread, sizeof (blkptr_t));
}
static void
dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp,
dmu_tx_t *tx)
{
zbookmark_phys_t zb;
SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
dsl_scan_visitbp(bp, &zb, NULL,
ds, scn, DMU_OST_NONE, tx);
dprintf_ds(ds, "finished scan%s", "");
}
void
dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
dsl_scan_t *scn = dp->dp_scan;
uint64_t mintxg;
if (scn->scn_phys.scn_state != DSS_SCANNING)
return;
if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) {
if (ds->ds_is_snapshot) {
/*
* Note:
* - scn_cur_{min,max}_txg stays the same.
* - Setting the flag is not really necessary if
* scn_cur_max_txg == scn_max_txg, because there
* is nothing after this snapshot that we care
* about. However, we set it anyway and then
* ignore it when we retraverse it in
* dsl_scan_visitds().
*/
scn->scn_phys.scn_bookmark.zb_objset =
dsl_dataset_phys(ds)->ds_next_snap_obj;
zfs_dbgmsg("destroying ds %llu; currently traversing; "
"reset zb_objset to %llu",
(u_longlong_t)ds->ds_object,
(u_longlong_t)dsl_dataset_phys(ds)->
ds_next_snap_obj);
scn->scn_phys.scn_flags |= DSF_VISIT_DS_AGAIN;
} else {
SET_BOOKMARK(&scn->scn_phys.scn_bookmark,
ZB_DESTROYED_OBJSET, 0, 0, 0);
zfs_dbgmsg("destroying ds %llu; currently traversing; "
"reset bookmark to -1,0,0,0",
(u_longlong_t)ds->ds_object);
}
} else if (zap_lookup_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) {
ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);
VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds->ds_object, tx));
if (ds->ds_is_snapshot) {
/*
* We keep the same mintxg; it could be >
* ds_creation_txg if the previous snapshot was
* deleted too.
*/
VERIFY(zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj,
dsl_dataset_phys(ds)->ds_next_snap_obj,
mintxg, tx) == 0);
zfs_dbgmsg("destroying ds %llu; in queue; "
"replacing with %llu",
(u_longlong_t)ds->ds_object,
(u_longlong_t)dsl_dataset_phys(ds)->
ds_next_snap_obj);
} else {
zfs_dbgmsg("destroying ds %llu; in queue; removing",
(u_longlong_t)ds->ds_object);
}
}
/*
* dsl_scan_sync() should be called after this, and should sync
* out our changed state, but just to be safe, do it here.
*/
dsl_scan_sync_state(scn, tx);
}
void
dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
dsl_scan_t *scn = dp->dp_scan;
uint64_t mintxg;
if (scn->scn_phys.scn_state != DSS_SCANNING)
return;
ASSERT(dsl_dataset_phys(ds)->ds_prev_snap_obj != 0);
if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) {
scn->scn_phys.scn_bookmark.zb_objset =
dsl_dataset_phys(ds)->ds_prev_snap_obj;
zfs_dbgmsg("snapshotting ds %llu; currently traversing; "
"reset zb_objset to %llu",
(u_longlong_t)ds->ds_object,
(u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj);
} else if (zap_lookup_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) {
VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds->ds_object, tx));
VERIFY(zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj,
dsl_dataset_phys(ds)->ds_prev_snap_obj, mintxg, tx) == 0);
zfs_dbgmsg("snapshotting ds %llu; in queue; "
"replacing with %llu",
(u_longlong_t)ds->ds_object,
(u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj);
}
dsl_scan_sync_state(scn, tx);
}
void
dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx)
{
dsl_pool_t *dp = ds1->ds_dir->dd_pool;
dsl_scan_t *scn = dp->dp_scan;
uint64_t mintxg;
if (scn->scn_phys.scn_state != DSS_SCANNING)
return;
if (scn->scn_phys.scn_bookmark.zb_objset == ds1->ds_object) {
scn->scn_phys.scn_bookmark.zb_objset = ds2->ds_object;
zfs_dbgmsg("clone_swap ds %llu; currently traversing; "
"reset zb_objset to %llu",
(u_longlong_t)ds1->ds_object,
(u_longlong_t)ds2->ds_object);
} else if (scn->scn_phys.scn_bookmark.zb_objset == ds2->ds_object) {
scn->scn_phys.scn_bookmark.zb_objset = ds1->ds_object;
zfs_dbgmsg("clone_swap ds %llu; currently traversing; "
"reset zb_objset to %llu",
(u_longlong_t)ds2->ds_object,
(u_longlong_t)ds1->ds_object);
}
if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj,
ds1->ds_object, &mintxg) == 0) {
int err;
ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg);
ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg);
VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds1->ds_object, tx));
err = zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg, tx);
VERIFY(err == 0 || err == EEXIST);
if (err == EEXIST) {
/* Both were there to begin with */
VERIFY(0 == zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj,
ds1->ds_object, mintxg, tx));
}
zfs_dbgmsg("clone_swap ds %llu; in queue; "
"replacing with %llu",
(u_longlong_t)ds1->ds_object,
(u_longlong_t)ds2->ds_object);
} else if (zap_lookup_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg) == 0) {
ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg);
ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg);
VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds2->ds_object, tx));
VERIFY(0 == zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg, tx));
zfs_dbgmsg("clone_swap ds %llu; in queue; "
"replacing with %llu",
(u_longlong_t)ds2->ds_object,
(u_longlong_t)ds1->ds_object);
}
dsl_scan_sync_state(scn, tx);
}
struct enqueue_clones_arg {
dmu_tx_t *tx;
uint64_t originobj;
};
/* ARGSUSED */
static int
enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
{
struct enqueue_clones_arg *eca = arg;
dsl_dataset_t *ds;
int err;
dsl_scan_t *scn = dp->dp_scan;
if (dsl_dir_phys(hds->ds_dir)->dd_origin_obj != eca->originobj)
return (0);
err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
if (err)
return (err);
while (dsl_dataset_phys(ds)->ds_prev_snap_obj != eca->originobj) {
dsl_dataset_t *prev;
err = dsl_dataset_hold_obj(dp,
dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev);
dsl_dataset_rele(ds, FTAG);
if (err)
return (err);
ds = prev;
}
VERIFY(zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds->ds_object,
dsl_dataset_phys(ds)->ds_prev_snap_txg, eca->tx) == 0);
dsl_dataset_rele(ds, FTAG);
return (0);
}
static void
dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx)
{
dsl_pool_t *dp = scn->scn_dp;
dsl_dataset_t *ds;
objset_t *os;
char *dsname;
VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
if (scn->scn_phys.scn_cur_min_txg >=
scn->scn_phys.scn_max_txg) {
/*
* This can happen if this snapshot was created after the
* scan started, and we already completed a previous snapshot
* that was created after the scan started. This snapshot
* only references blocks with:
*
* birth < our ds_creation_txg
* cur_min_txg is no less than ds_creation_txg.
* We have already visited these blocks.
* or
* birth > scn_max_txg
* The scan requested not to visit these blocks.
*
* Subsequent snapshots (and clones) can reference our
* blocks, or blocks with even higher birth times.
* Therefore we do not need to visit them either,
* so we do not add them to the work queue.
*
* Note that checking for cur_min_txg >= cur_max_txg
* is not sufficient, because in that case we may need to
* visit subsequent snapshots. This happens when min_txg > 0,
* which raises cur_min_txg. In this case we will visit
* this dataset but skip all of its blocks, because the
* rootbp's birth time is < cur_min_txg. Then we will
* add the next snapshots/clones to the work queue.
*/
char *dsname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
dsl_dataset_name(ds, dsname);
zfs_dbgmsg("scanning dataset %llu (%s) is unnecessary because "
"cur_min_txg (%llu) >= max_txg (%llu)",
dsobj, dsname,
scn->scn_phys.scn_cur_min_txg,
scn->scn_phys.scn_max_txg);
kmem_free(dsname, MAXNAMELEN);
goto out;
}
if (dmu_objset_from_ds(ds, &os))
goto out;
/*
* Only the ZIL in the head (non-snapshot) is valid. Even though
* snapshots can have ZIL block pointers (which may be the same
* BP as in the head), they must be ignored. So we traverse the
* ZIL here, rather than in scan_recurse(), because the regular
* snapshot block-sharing rules don't apply to it.
*/
if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !ds->ds_is_snapshot)
dsl_scan_zil(dp, &os->os_zil_header);
/*
* Iterate over the bps in this ds.
*/
dmu_buf_will_dirty(ds->ds_dbuf, tx);
dsl_scan_visit_rootbp(scn, ds, &dsl_dataset_phys(ds)->ds_bp, tx);
dsname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
dsl_dataset_name(ds, dsname);
zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; "
"pausing=%u",
(longlong_t)dsobj, dsname,
(longlong_t)scn->scn_phys.scn_cur_min_txg,
(longlong_t)scn->scn_phys.scn_cur_max_txg,
(int)scn->scn_pausing);
kmem_free(dsname, ZFS_MAX_DATASET_NAME_LEN);
if (scn->scn_pausing)
goto out;
/*
* We've finished this pass over this dataset.
*/
/*
* If we did not completely visit this dataset, do another pass.
*/
if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) {
zfs_dbgmsg("incomplete pass; visiting again");
scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN;
VERIFY(zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, ds->ds_object,
scn->scn_phys.scn_cur_max_txg, tx) == 0);
goto out;
}
/*
* Add descendent datasets to work queue.
*/
if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) {
VERIFY(zap_add_int_key(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj,
dsl_dataset_phys(ds)->ds_next_snap_obj,
dsl_dataset_phys(ds)->ds_creation_txg, tx) == 0);
}
if (dsl_dataset_phys(ds)->ds_num_children > 1) {
boolean_t usenext = B_FALSE;
if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) {
uint64_t count;
/*
* 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. Therefore we can only use the
* next_clones_obj when its count is correct.
*/
int err = zap_count(dp->dp_meta_objset,
dsl_dataset_phys(ds)->ds_next_clones_obj, &count);
if (err == 0 &&
count == dsl_dataset_phys(ds)->ds_num_children - 1)
usenext = B_TRUE;
}
if (usenext) {
VERIFY0(zap_join_key(dp->dp_meta_objset,
dsl_dataset_phys(ds)->ds_next_clones_obj,
scn->scn_phys.scn_queue_obj,
dsl_dataset_phys(ds)->ds_creation_txg, tx));
} else {
struct enqueue_clones_arg eca;
eca.tx = tx;
eca.originobj = ds->ds_object;
VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
enqueue_clones_cb, &eca, DS_FIND_CHILDREN));
}
}
out:
dsl_dataset_rele(ds, FTAG);
}
/* ARGSUSED */
static int
enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
{
dmu_tx_t *tx = arg;
dsl_dataset_t *ds;
int err;
dsl_scan_t *scn = dp->dp_scan;
err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
if (err)
return (err);
while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
dsl_dataset_t *prev;
err = dsl_dataset_hold_obj(dp,
dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev);
if (err) {
dsl_dataset_rele(ds, FTAG);
return (err);
}
/*
* If this is a clone, we don't need to worry about it for now.
*/
if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object) {
dsl_dataset_rele(ds, FTAG);
dsl_dataset_rele(prev, FTAG);
return (0);
}
dsl_dataset_rele(ds, FTAG);
ds = prev;
}
VERIFY(zap_add_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj,
ds->ds_object, dsl_dataset_phys(ds)->ds_prev_snap_txg, tx) == 0);
dsl_dataset_rele(ds, FTAG);
return (0);
}
/*
* Scrub/dedup interaction.
*
* If there are N references to a deduped block, we don't want to scrub it
* N times -- ideally, we should scrub it exactly once.
*
* We leverage the fact that the dde's replication class (enum ddt_class)
* is ordered from highest replication class (DDT_CLASS_DITTO) to lowest
* (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order.
*
* To prevent excess scrubbing, the scrub begins by walking the DDT
* to find all blocks with refcnt > 1, and scrubs each of these once.
* Since there are two replication classes which contain blocks with
* refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first.
* Finally the top-down scrub begins, only visiting blocks with refcnt == 1.
*
* There would be nothing more to say if a block's refcnt couldn't change
* during a scrub, but of course it can so we must account for changes
* in a block's replication class.
*
* Here's an example of what can occur:
*
* If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1
* when visited during the top-down scrub phase, it will be scrubbed twice.
* This negates our scrub optimization, but is otherwise harmless.
*
* If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1
* on each visit during the top-down scrub phase, it will never be scrubbed.
* To catch this, ddt_sync_entry() notifies the scrub code whenever a block's
* reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to
* DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1
* while a scrub is in progress, it scrubs the block right then.
*/
static void
dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx)
{
ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark;
ddt_entry_t dde;
int error;
uint64_t n = 0;
bzero(&dde, sizeof (ddt_entry_t));
while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) {
ddt_t *ddt;
if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max)
break;
dprintf("visiting ddb=%llu/%llu/%llu/%llx\n",
(longlong_t)ddb->ddb_class,
(longlong_t)ddb->ddb_type,
(longlong_t)ddb->ddb_checksum,
(longlong_t)ddb->ddb_cursor);
/* There should be no pending changes to the dedup table */
ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum];
ASSERT(avl_first(&ddt->ddt_tree) == NULL);
dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx);
n++;
if (dsl_scan_check_pause(scn, NULL))
break;
}
zfs_dbgmsg("scanned %llu ddt entries with class_max = %u; pausing=%u",
(longlong_t)n, (int)scn->scn_phys.scn_ddt_class_max,
(int)scn->scn_pausing);
ASSERT(error == 0 || error == ENOENT);
ASSERT(error != ENOENT ||
ddb->ddb_class > scn->scn_phys.scn_ddt_class_max);
}
/* ARGSUSED */
void
dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum,
ddt_entry_t *dde, dmu_tx_t *tx)
{
const ddt_key_t *ddk = &dde->dde_key;
ddt_phys_t *ddp = dde->dde_phys;
blkptr_t bp;
zbookmark_phys_t zb = { 0 };
int p;
if (scn->scn_phys.scn_state != DSS_SCANNING)
return;
for (p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
if (ddp->ddp_phys_birth == 0 ||
ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg)
continue;
ddt_bp_create(checksum, ddk, ddp, &bp);
scn->scn_visited_this_txg++;
scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb);
}
}
static void
dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx)
{
dsl_pool_t *dp = scn->scn_dp;
zap_cursor_t *zc;
zap_attribute_t *za;
if (scn->scn_phys.scn_ddt_bookmark.ddb_class <=
scn->scn_phys.scn_ddt_class_max) {
scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg;
scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg;
dsl_scan_ddt(scn, tx);
if (scn->scn_pausing)
return;
}
if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) {
/* First do the MOS & ORIGIN */
scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg;
scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg;
dsl_scan_visit_rootbp(scn, NULL,
&dp->dp_meta_rootbp, tx);
spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
if (scn->scn_pausing)
return;
if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) {
VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
enqueue_cb, tx, DS_FIND_CHILDREN));
} else {
dsl_scan_visitds(scn,
dp->dp_origin_snap->ds_object, tx);
}
ASSERT(!scn->scn_pausing);
} else if (scn->scn_phys.scn_bookmark.zb_objset !=
ZB_DESTROYED_OBJSET) {
/*
* If we were paused, continue from here. Note if the
* ds we were paused on was deleted, the zb_objset may
* be -1, so we will skip this and find a new objset
* below.
*/
dsl_scan_visitds(scn, scn->scn_phys.scn_bookmark.zb_objset, tx);
if (scn->scn_pausing)
return;
}
/*
* In case we were paused right at the end of the ds, zero the
* bookmark so we don't think that we're still trying to resume.
*/
bzero(&scn->scn_phys.scn_bookmark, sizeof (zbookmark_phys_t));
zc = kmem_alloc(sizeof (zap_cursor_t), KM_SLEEP);
za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
/* keep pulling things out of the zap-object-as-queue */
while (zap_cursor_init(zc, dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj),
zap_cursor_retrieve(zc, za) == 0) {
dsl_dataset_t *ds;
uint64_t dsobj;
dsobj = strtonum(za->za_name, NULL);
VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
scn->scn_phys.scn_queue_obj, dsobj, tx));
/* Set up min/max txg */
VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
if (za->za_first_integer != 0) {
scn->scn_phys.scn_cur_min_txg =
MAX(scn->scn_phys.scn_min_txg,
za->za_first_integer);
} else {
scn->scn_phys.scn_cur_min_txg =
MAX(scn->scn_phys.scn_min_txg,
dsl_dataset_phys(ds)->ds_prev_snap_txg);
}
scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds);
dsl_dataset_rele(ds, FTAG);
dsl_scan_visitds(scn, dsobj, tx);
zap_cursor_fini(zc);
if (scn->scn_pausing)
goto out;
}
zap_cursor_fini(zc);
out:
kmem_free(za, sizeof (zap_attribute_t));
kmem_free(zc, sizeof (zap_cursor_t));
}
static boolean_t
dsl_scan_free_should_pause(dsl_scan_t *scn)
{
uint64_t elapsed_nanosecs;
if (zfs_recover)
return (B_FALSE);
if (scn->scn_visited_this_txg >= zfs_free_max_blocks)
return (B_TRUE);
elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time;
return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout ||
(NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms &&
txg_sync_waiting(scn->scn_dp)) ||
spa_shutting_down(scn->scn_dp->dp_spa));
}
static int
dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
{
dsl_scan_t *scn = arg;
if (!scn->scn_is_bptree ||
(BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) {
if (dsl_scan_free_should_pause(scn))
return (SET_ERROR(ERESTART));
}
zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa,
dmu_tx_get_txg(tx), bp, 0));
dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD,
-bp_get_dsize_sync(scn->scn_dp->dp_spa, bp),
-BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx);
scn->scn_visited_this_txg++;
return (0);
}
boolean_t
dsl_scan_active(dsl_scan_t *scn)
{
spa_t *spa = scn->scn_dp->dp_spa;
uint64_t used = 0, comp, uncomp;
if (spa->spa_load_state != SPA_LOAD_NONE)
return (B_FALSE);
if (spa_shutting_down(spa))
return (B_FALSE);
if (scn->scn_phys.scn_state == DSS_SCANNING ||
(scn->scn_async_destroying && !scn->scn_async_stalled))
return (B_TRUE);
if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
(void) bpobj_space(&scn->scn_dp->dp_free_bpobj,
&used, &comp, &uncomp);
}
return (used != 0);
}
void
dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx)
{
dsl_scan_t *scn = dp->dp_scan;
spa_t *spa = dp->dp_spa;
int err = 0;
/*
* Check for scn_restart_txg before checking spa_load_state, so
* that we can restart an old-style scan while the pool is being
* imported (see dsl_scan_init).
*/
if (dsl_scan_restarting(scn, tx)) {
pool_scan_func_t func = POOL_SCAN_SCRUB;
dsl_scan_done(scn, B_FALSE, tx);
if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL))
func = POOL_SCAN_RESILVER;
zfs_dbgmsg("restarting scan func=%u txg=%llu",
func, tx->tx_txg);
dsl_scan_setup_sync(&func, tx);
}
/*
* Only process scans in sync pass 1.
*/
if (spa_sync_pass(dp->dp_spa) > 1)
return;
/*
* If the spa is shutting down, then stop scanning. This will
* ensure that the scan does not dirty any new data during the
* shutdown phase.
*/
if (spa_shutting_down(spa))
return;
/*
* If the scan is inactive due to a stalled async destroy, try again.
*/
if (!scn->scn_async_stalled && !dsl_scan_active(scn))
return;
scn->scn_visited_this_txg = 0;
scn->scn_pausing = B_FALSE;
scn->scn_sync_start_time = gethrtime();
spa->spa_scrub_active = B_TRUE;
/*
* First process the async destroys. If we pause, don't do
* any scrubbing or resilvering. This ensures that there are no
* async destroys while we are scanning, so the scan code doesn't
* have to worry about traversing it. It is also faster to free the
* blocks than to scrub them.
*/
if (zfs_free_bpobj_enabled &&
spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
scn->scn_is_bptree = B_FALSE;
scn->scn_zio_root = zio_root(dp->dp_spa, NULL,
NULL, ZIO_FLAG_MUSTSUCCEED);
err = bpobj_iterate(&dp->dp_free_bpobj,
dsl_scan_free_block_cb, scn, tx);
VERIFY3U(0, ==, zio_wait(scn->scn_zio_root));
if (err != 0 && err != ERESTART)
zfs_panic_recover("error %u from bpobj_iterate()", err);
}
if (err == 0 && spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) {
ASSERT(scn->scn_async_destroying);
scn->scn_is_bptree = B_TRUE;
scn->scn_zio_root = zio_root(dp->dp_spa, NULL,
NULL, ZIO_FLAG_MUSTSUCCEED);
err = bptree_iterate(dp->dp_meta_objset,
dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, scn, tx);
VERIFY0(zio_wait(scn->scn_zio_root));
if (err == EIO || err == ECKSUM) {
err = 0;
} else if (err != 0 && err != ERESTART) {
zfs_panic_recover("error %u from "
"traverse_dataset_destroyed()", err);
}
if (bptree_is_empty(dp->dp_meta_objset, dp->dp_bptree_obj)) {
/* finished; deactivate async destroy feature */
spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, tx);
ASSERT(!spa_feature_is_active(spa,
SPA_FEATURE_ASYNC_DESTROY));
VERIFY0(zap_remove(dp->dp_meta_objset,
DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_BPTREE_OBJ, tx));
VERIFY0(bptree_free(dp->dp_meta_objset,
dp->dp_bptree_obj, tx));
dp->dp_bptree_obj = 0;
scn->scn_async_destroying = B_FALSE;
scn->scn_async_stalled = B_FALSE;
} else {
/*
* If we didn't make progress, mark the async
* destroy as stalled, so that we will not initiate
* a spa_sync() on its behalf. Note that we only
* check this if we are not finished, because if the
* bptree had no blocks for us to visit, we can
* finish without "making progress".
*/
scn->scn_async_stalled =
(scn->scn_visited_this_txg == 0);
}
}
if (scn->scn_visited_this_txg) {
zfs_dbgmsg("freed %llu blocks in %llums from "
"free_bpobj/bptree txg %llu; err=%u",
(longlong_t)scn->scn_visited_this_txg,
(longlong_t)
NSEC2MSEC(gethrtime() - scn->scn_sync_start_time),
(longlong_t)tx->tx_txg, err);
scn->scn_visited_this_txg = 0;
/*
* Write out changes to the DDT that may be required as a
* result of the blocks freed. This ensures that the DDT
* is clean when a scrub/resilver runs.
*/
ddt_sync(spa, tx->tx_txg);
}
if (err != 0)
return;
if (dp->dp_free_dir != NULL && !scn->scn_async_destroying &&
zfs_free_leak_on_eio &&
(dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes != 0 ||
dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes != 0 ||
dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes != 0)) {
/*
* We have finished background destroying, but there is still
* some space left in the dp_free_dir. Transfer this leaked
* space to the dp_leak_dir.
*/
if (dp->dp_leak_dir == NULL) {
rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
(void) dsl_dir_create_sync(dp, dp->dp_root_dir,
LEAK_DIR_NAME, tx);
VERIFY0(dsl_pool_open_special_dir(dp,
LEAK_DIR_NAME, &dp->dp_leak_dir));
rrw_exit(&dp->dp_config_rwlock, FTAG);
}
dsl_dir_diduse_space(dp->dp_leak_dir, DD_USED_HEAD,
dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes,
dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes,
dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx);
dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
-dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes,
-dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes,
-dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx);
}
if (dp->dp_free_dir != NULL && !scn->scn_async_destroying) {
/* finished; verify that space accounting went to zero */
ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes);
ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes);
ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes);
}
if (scn->scn_phys.scn_state != DSS_SCANNING)
return;
if (scn->scn_done_txg == tx->tx_txg) {
ASSERT(!scn->scn_pausing);
/* finished with scan. */
zfs_dbgmsg("txg %llu scan complete", tx->tx_txg);
dsl_scan_done(scn, B_TRUE, tx);
ASSERT3U(spa->spa_scrub_inflight, ==, 0);
dsl_scan_sync_state(scn, tx);
return;
}
if (scn->scn_phys.scn_ddt_bookmark.ddb_class <=
scn->scn_phys.scn_ddt_class_max) {
zfs_dbgmsg("doing scan sync txg %llu; "
"ddt bm=%llu/%llu/%llu/%llx",
(longlong_t)tx->tx_txg,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum,
(longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor);
ASSERT(scn->scn_phys.scn_bookmark.zb_objset == 0);
ASSERT(scn->scn_phys.scn_bookmark.zb_object == 0);
ASSERT(scn->scn_phys.scn_bookmark.zb_level == 0);
ASSERT(scn->scn_phys.scn_bookmark.zb_blkid == 0);
} else {
zfs_dbgmsg("doing scan sync txg %llu; bm=%llu/%llu/%llu/%llu",
(longlong_t)tx->tx_txg,
(longlong_t)scn->scn_phys.scn_bookmark.zb_objset,
(longlong_t)scn->scn_phys.scn_bookmark.zb_object,
(longlong_t)scn->scn_phys.scn_bookmark.zb_level,
(longlong_t)scn->scn_phys.scn_bookmark.zb_blkid);
}
scn->scn_zio_root = zio_root(dp->dp_spa, NULL,
NULL, ZIO_FLAG_CANFAIL);
dsl_pool_config_enter(dp, FTAG);
dsl_scan_visit(scn, tx);
dsl_pool_config_exit(dp, FTAG);
(void) zio_wait(scn->scn_zio_root);
scn->scn_zio_root = NULL;
zfs_dbgmsg("visited %llu blocks in %llums",
(longlong_t)scn->scn_visited_this_txg,
(longlong_t)NSEC2MSEC(gethrtime() - scn->scn_sync_start_time));
if (!scn->scn_pausing) {
scn->scn_done_txg = tx->tx_txg + 1;
zfs_dbgmsg("txg %llu traversal complete, waiting till txg %llu",
tx->tx_txg, scn->scn_done_txg);
}
if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) {
mutex_enter(&spa->spa_scrub_lock);
while (spa->spa_scrub_inflight > 0) {
cv_wait(&spa->spa_scrub_io_cv,
&spa->spa_scrub_lock);
}
mutex_exit(&spa->spa_scrub_lock);
}
dsl_scan_sync_state(scn, tx);
}
/*
* This will start a new scan, or restart an existing one.
*/
void
dsl_resilver_restart(dsl_pool_t *dp, uint64_t txg)
{
if (txg == 0) {
dmu_tx_t *tx;
tx = dmu_tx_create_dd(dp->dp_mos_dir);
VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT));
txg = dmu_tx_get_txg(tx);
dp->dp_scan->scn_restart_txg = txg;
dmu_tx_commit(tx);
} else {
dp->dp_scan->scn_restart_txg = txg;
}
zfs_dbgmsg("restarting resilver txg=%llu", txg);
}
boolean_t
dsl_scan_resilvering(dsl_pool_t *dp)
{
return (dp->dp_scan->scn_phys.scn_state == DSS_SCANNING &&
dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER);
}
/*
* scrub consumers
*/
static void
count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp)
{
int i;
/*
* If we resume after a reboot, zab will be NULL; don't record
* incomplete stats in that case.
*/
if (zab == NULL)
return;
for (i = 0; i < 4; i++) {
int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS;
int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL;
int equal;
zfs_blkstat_t *zb;
if (t & DMU_OT_NEWTYPE)
t = DMU_OT_OTHER;
zb = &zab->zab_type[l][t];
zb->zb_count++;
zb->zb_asize += BP_GET_ASIZE(bp);
zb->zb_lsize += BP_GET_LSIZE(bp);
zb->zb_psize += BP_GET_PSIZE(bp);
zb->zb_gangs += BP_COUNT_GANG(bp);
switch (BP_GET_NDVAS(bp)) {
case 2:
if (DVA_GET_VDEV(&bp->blk_dva[0]) ==
DVA_GET_VDEV(&bp->blk_dva[1]))
zb->zb_ditto_2_of_2_samevdev++;
break;
case 3:
equal = (DVA_GET_VDEV(&bp->blk_dva[0]) ==
DVA_GET_VDEV(&bp->blk_dva[1])) +
(DVA_GET_VDEV(&bp->blk_dva[0]) ==
DVA_GET_VDEV(&bp->blk_dva[2])) +
(DVA_GET_VDEV(&bp->blk_dva[1]) ==
DVA_GET_VDEV(&bp->blk_dva[2]));
if (equal == 1)
zb->zb_ditto_2_of_3_samevdev++;
else if (equal == 3)
zb->zb_ditto_3_of_3_samevdev++;
break;
}
}
}
static void
dsl_scan_scrub_done(zio_t *zio)
{
spa_t *spa = zio->io_spa;
abd_free(zio->io_abd);
mutex_enter(&spa->spa_scrub_lock);
spa->spa_scrub_inflight--;
cv_broadcast(&spa->spa_scrub_io_cv);
if (zio->io_error && (zio->io_error != ECKSUM ||
!(zio->io_flags & ZIO_FLAG_SPECULATIVE))) {
spa->spa_dsl_pool->dp_scan->scn_phys.scn_errors++;
}
mutex_exit(&spa->spa_scrub_lock);
}
static int
dsl_scan_scrub_cb(dsl_pool_t *dp,
const blkptr_t *bp, const zbookmark_phys_t *zb)
{
dsl_scan_t *scn = dp->dp_scan;
size_t size = BP_GET_PSIZE(bp);
spa_t *spa = dp->dp_spa;
uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp);
boolean_t needs_io = B_FALSE;
int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL;
int scan_delay = 0;
int d;
if (phys_birth <= scn->scn_phys.scn_min_txg ||
phys_birth >= scn->scn_phys.scn_max_txg)
return (0);
count_block(dp->dp_blkstats, bp);
if (BP_IS_EMBEDDED(bp))
return (0);
ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn));
if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) {
zio_flags |= ZIO_FLAG_SCRUB;
needs_io = B_TRUE;
scan_delay = zfs_scrub_delay;
} else {
ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER);
zio_flags |= ZIO_FLAG_RESILVER;
needs_io = B_FALSE;
scan_delay = zfs_resilver_delay;
}
/* If it's an intent log block, failure is expected. */
if (zb->zb_level == ZB_ZIL_LEVEL)
zio_flags |= ZIO_FLAG_SPECULATIVE;
for (d = 0; d < BP_GET_NDVAS(bp); d++) {
vdev_t *vd = vdev_lookup_top(spa,
DVA_GET_VDEV(&bp->blk_dva[d]));
/*
* Keep track of how much data we've examined so that
* zpool(1M) status can make useful progress reports.
*/
scn->scn_phys.scn_examined += DVA_GET_ASIZE(&bp->blk_dva[d]);
spa->spa_scan_pass_exam += DVA_GET_ASIZE(&bp->blk_dva[d]);
/* if it's a resilver, this may not be in the target range */
if (!needs_io) {
if (DVA_GET_GANG(&bp->blk_dva[d])) {
/*
* Gang members may be spread across multiple
* vdevs, so the best estimate we have is the
* scrub range, which has already been checked.
* XXX -- it would be better to change our
* allocation policy to ensure that all
* gang members reside on the same vdev.
*/
needs_io = B_TRUE;
} else {
needs_io = vdev_dtl_contains(vd, DTL_PARTIAL,
phys_birth, 1);
}
}
}
if (needs_io && !zfs_no_scrub_io) {
vdev_t *rvd = spa->spa_root_vdev;
uint64_t maxinflight = rvd->vdev_children * zfs_top_maxinflight;
mutex_enter(&spa->spa_scrub_lock);
while (spa->spa_scrub_inflight >= maxinflight)
cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
spa->spa_scrub_inflight++;
mutex_exit(&spa->spa_scrub_lock);
/*
* If we're seeing recent (zfs_scan_idle) "important" I/Os
* then throttle our workload to limit the impact of a scan.
*/
if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle)
delay(scan_delay);
zio_nowait(zio_read(NULL, spa, bp,
abd_alloc_for_io(size, B_FALSE), size, dsl_scan_scrub_done,
NULL, ZIO_PRIORITY_SCRUB, zio_flags, zb));
}
/* do not relocate this block */
return (0);
}
int
dsl_scan(dsl_pool_t *dp, pool_scan_func_t func)
{
spa_t *spa = dp->dp_spa;
/*
* Purge all vdev caches and probe all devices. We do this here
* rather than in sync context because this requires a writer lock
* on the spa_config lock, which we can't do from sync context. The
* spa_scrub_reopen flag indicates that vdev_open() should not
* attempt to start another scrub.
*/
spa_vdev_state_enter(spa, SCL_NONE);
spa->spa_scrub_reopen = B_TRUE;
vdev_reopen(spa->spa_root_vdev);
spa->spa_scrub_reopen = B_FALSE;
(void) spa_vdev_state_exit(spa, NULL, 0);
return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check,
dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_NONE));
}
static boolean_t
dsl_scan_restarting(dsl_scan_t *scn, dmu_tx_t *tx)
{
return (scn->scn_restart_txg != 0 &&
scn->scn_restart_txg <= tx->tx_txg);
}
#if defined(_KERNEL) && defined(HAVE_SPL)
module_param(zfs_top_maxinflight, int, 0644);
MODULE_PARM_DESC(zfs_top_maxinflight, "Max I/Os per top-level");
module_param(zfs_resilver_delay, int, 0644);
MODULE_PARM_DESC(zfs_resilver_delay, "Number of ticks to delay resilver");
module_param(zfs_scrub_delay, int, 0644);
MODULE_PARM_DESC(zfs_scrub_delay, "Number of ticks to delay scrub");
module_param(zfs_scan_idle, int, 0644);
MODULE_PARM_DESC(zfs_scan_idle, "Idle window in clock ticks");
module_param(zfs_scan_min_time_ms, int, 0644);
MODULE_PARM_DESC(zfs_scan_min_time_ms, "Min millisecs to scrub per txg");
module_param(zfs_free_min_time_ms, int, 0644);
MODULE_PARM_DESC(zfs_free_min_time_ms, "Min millisecs to free per txg");
module_param(zfs_resilver_min_time_ms, int, 0644);
MODULE_PARM_DESC(zfs_resilver_min_time_ms, "Min millisecs to resilver per txg");
module_param(zfs_no_scrub_io, int, 0644);
MODULE_PARM_DESC(zfs_no_scrub_io, "Set to disable scrub I/O");
module_param(zfs_no_scrub_prefetch, int, 0644);
MODULE_PARM_DESC(zfs_no_scrub_prefetch, "Set to disable scrub prefetching");
/* CSTYLED */
module_param(zfs_free_max_blocks, ulong, 0644);
MODULE_PARM_DESC(zfs_free_max_blocks, "Max number of blocks freed in one txg");
module_param(zfs_free_bpobj_enabled, int, 0644);
MODULE_PARM_DESC(zfs_free_bpobj_enabled, "Enable processing of the free_bpobj");
#endif
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