4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
26 #include <sys/dsl_scan.h>
27 #include <sys/dsl_pool.h>
28 #include <sys/dsl_dataset.h>
29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_dir.h>
31 #include <sys/dsl_synctask.h>
32 #include <sys/dnode.h>
33 #include <sys/dmu_tx.h>
34 #include <sys/dmu_objset.h>
38 #include <sys/zfs_context.h>
39 #include <sys/fs/zfs.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/spa_impl.h>
42 #include <sys/vdev_impl.h>
43 #include <sys/zil_impl.h>
44 #include <sys/zio_checksum.h>
47 #include <sys/sa_impl.h>
48 #include <sys/zfeature.h>
50 #include <sys/zfs_vfsops.h>
53 typedef int (scan_cb_t)(dsl_pool_t *, const blkptr_t *,
54 const zbookmark_phys_t *);
56 static scan_cb_t dsl_scan_scrub_cb;
57 static void dsl_scan_cancel_sync(void *, dmu_tx_t *);
58 static void dsl_scan_sync_state(dsl_scan_t *, dmu_tx_t *tx);
60 unsigned int zfs_top_maxinflight = 32; /* maximum I/Os per top-level */
61 unsigned int zfs_resilver_delay = 2; /* number of ticks to delay resilver */
62 unsigned int zfs_scrub_delay = 4; /* number of ticks to delay scrub */
63 unsigned int zfs_scan_idle = 50; /* idle window in clock ticks */
65 unsigned int zfs_scan_min_time_ms = 1000; /* min millisecs to scrub per txg */
66 unsigned int zfs_free_min_time_ms = 1000; /* min millisecs to free per txg */
67 unsigned int zfs_resilver_min_time_ms = 3000; /* min millisecs to resilver
69 boolean_t zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */
70 boolean_t zfs_no_scrub_prefetch = B_FALSE; /* set to disable scrub prefetch */
72 SYSCTL_DECL(_vfs_zfs);
73 TUNABLE_INT("vfs.zfs.top_maxinflight", &zfs_top_maxinflight);
74 SYSCTL_UINT(_vfs_zfs, OID_AUTO, top_maxinflight, CTLFLAG_RW,
75 &zfs_top_maxinflight, 0, "Maximum I/Os per top-level vdev");
76 TUNABLE_INT("vfs.zfs.resilver_delay", &zfs_resilver_delay);
77 SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_delay, CTLFLAG_RW,
78 &zfs_resilver_delay, 0, "Number of ticks to delay resilver");
79 TUNABLE_INT("vfs.zfs.scrub_delay", &zfs_scrub_delay);
80 SYSCTL_UINT(_vfs_zfs, OID_AUTO, scrub_delay, CTLFLAG_RW,
81 &zfs_scrub_delay, 0, "Number of ticks to delay scrub");
82 TUNABLE_INT("vfs.zfs.scan_idle", &zfs_scan_idle);
83 SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_idle, CTLFLAG_RW,
84 &zfs_scan_idle, 0, "Idle scan window in clock ticks");
85 TUNABLE_INT("vfs.zfs.scan_min_time_ms", &zfs_scan_min_time_ms);
86 SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_min_time_ms, CTLFLAG_RW,
87 &zfs_scan_min_time_ms, 0, "Min millisecs to scrub per txg");
88 TUNABLE_INT("vfs.zfs.free_min_time_ms", &zfs_free_min_time_ms);
89 SYSCTL_UINT(_vfs_zfs, OID_AUTO, free_min_time_ms, CTLFLAG_RW,
90 &zfs_free_min_time_ms, 0, "Min millisecs to free per txg");
91 TUNABLE_INT("vfs.zfs.resilver_min_time_ms", &zfs_resilver_min_time_ms);
92 SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_min_time_ms, CTLFLAG_RW,
93 &zfs_resilver_min_time_ms, 0, "Min millisecs to resilver per txg");
94 TUNABLE_INT("vfs.zfs.no_scrub_io", &zfs_no_scrub_io);
95 SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_io, CTLFLAG_RW,
96 &zfs_no_scrub_io, 0, "Disable scrub I/O");
97 TUNABLE_INT("vfs.zfs.no_scrub_prefetch", &zfs_no_scrub_prefetch);
98 SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_prefetch, CTLFLAG_RW,
99 &zfs_no_scrub_prefetch, 0, "Disable scrub prefetching");
101 enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE;
102 /* max number of blocks to free in a single TXG */
103 uint64_t zfs_free_max_blocks = UINT64_MAX;
104 SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, free_max_blocks, CTLFLAG_RWTUN,
105 &zfs_free_max_blocks, 0, "Maximum number of blocks to free in one TXG");
108 #define DSL_SCAN_IS_SCRUB_RESILVER(scn) \
109 ((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \
110 (scn)->scn_phys.scn_func == POOL_SCAN_RESILVER)
112 extern int zfs_txg_timeout;
114 /* the order has to match pool_scan_type */
115 static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = {
117 dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */
118 dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */
122 dsl_scan_init(dsl_pool_t *dp, uint64_t txg)
126 spa_t *spa = dp->dp_spa;
129 scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP);
133 * It's possible that we're resuming a scan after a reboot so
134 * make sure that the scan_async_destroying flag is initialized
137 ASSERT(!scn->scn_async_destroying);
138 scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa,
139 SPA_FEATURE_ASYNC_DESTROY);
141 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
142 "scrub_func", sizeof (uint64_t), 1, &f);
145 * There was an old-style scrub in progress. Restart a
146 * new-style scrub from the beginning.
148 scn->scn_restart_txg = txg;
149 zfs_dbgmsg("old-style scrub was in progress; "
150 "restarting new-style scrub in txg %llu",
151 scn->scn_restart_txg);
154 * Load the queue obj from the old location so that it
155 * can be freed by dsl_scan_done().
157 (void) zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
158 "scrub_queue", sizeof (uint64_t), 1,
159 &scn->scn_phys.scn_queue_obj);
161 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
162 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS,
169 if (scn->scn_phys.scn_state == DSS_SCANNING &&
170 spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) {
172 * A new-type scrub was in progress on an old
173 * pool, and the pool was accessed by old
174 * software. Restart from the beginning, since
175 * the old software may have changed the pool in
178 scn->scn_restart_txg = txg;
179 zfs_dbgmsg("new-style scrub was modified "
180 "by old software; restarting in txg %llu",
181 scn->scn_restart_txg);
185 spa_scan_stat_init(spa);
190 dsl_scan_fini(dsl_pool_t *dp)
193 kmem_free(dp->dp_scan, sizeof (dsl_scan_t));
200 dsl_scan_setup_check(void *arg, dmu_tx_t *tx)
202 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
204 if (scn->scn_phys.scn_state == DSS_SCANNING)
205 return (SET_ERROR(EBUSY));
211 dsl_scan_setup_sync(void *arg, dmu_tx_t *tx)
213 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
214 pool_scan_func_t *funcp = arg;
215 dmu_object_type_t ot = 0;
216 dsl_pool_t *dp = scn->scn_dp;
217 spa_t *spa = dp->dp_spa;
219 ASSERT(scn->scn_phys.scn_state != DSS_SCANNING);
220 ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS);
221 bzero(&scn->scn_phys, sizeof (scn->scn_phys));
222 scn->scn_phys.scn_func = *funcp;
223 scn->scn_phys.scn_state = DSS_SCANNING;
224 scn->scn_phys.scn_min_txg = 0;
225 scn->scn_phys.scn_max_txg = tx->tx_txg;
226 scn->scn_phys.scn_ddt_class_max = DDT_CLASSES - 1; /* the entire DDT */
227 scn->scn_phys.scn_start_time = gethrestime_sec();
228 scn->scn_phys.scn_errors = 0;
229 scn->scn_phys.scn_to_examine = spa->spa_root_vdev->vdev_stat.vs_alloc;
230 scn->scn_restart_txg = 0;
231 scn->scn_done_txg = 0;
232 spa_scan_stat_init(spa);
234 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) {
235 scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max;
237 /* rewrite all disk labels */
238 vdev_config_dirty(spa->spa_root_vdev);
240 if (vdev_resilver_needed(spa->spa_root_vdev,
241 &scn->scn_phys.scn_min_txg, &scn->scn_phys.scn_max_txg)) {
242 spa_event_notify(spa, NULL, ESC_ZFS_RESILVER_START);
244 spa_event_notify(spa, NULL, ESC_ZFS_SCRUB_START);
247 spa->spa_scrub_started = B_TRUE;
249 * If this is an incremental scrub, limit the DDT scrub phase
250 * to just the auto-ditto class (for correctness); the rest
251 * of the scrub should go faster using top-down pruning.
253 if (scn->scn_phys.scn_min_txg > TXG_INITIAL)
254 scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO;
258 /* back to the generic stuff */
260 if (dp->dp_blkstats == NULL) {
262 kmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP);
264 bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
266 if (spa_version(spa) < SPA_VERSION_DSL_SCRUB)
267 ot = DMU_OT_ZAP_OTHER;
269 scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset,
270 ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx);
272 dsl_scan_sync_state(scn, tx);
274 spa_history_log_internal(spa, "scan setup", tx,
275 "func=%u mintxg=%llu maxtxg=%llu",
276 *funcp, scn->scn_phys.scn_min_txg, scn->scn_phys.scn_max_txg);
281 dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx)
283 static const char *old_names[] = {
285 "scrub_ddt_bookmark",
286 "scrub_ddt_class_max",
295 dsl_pool_t *dp = scn->scn_dp;
296 spa_t *spa = dp->dp_spa;
299 /* Remove any remnants of an old-style scrub. */
300 for (i = 0; old_names[i]; i++) {
301 (void) zap_remove(dp->dp_meta_objset,
302 DMU_POOL_DIRECTORY_OBJECT, old_names[i], tx);
305 if (scn->scn_phys.scn_queue_obj != 0) {
306 VERIFY(0 == dmu_object_free(dp->dp_meta_objset,
307 scn->scn_phys.scn_queue_obj, tx));
308 scn->scn_phys.scn_queue_obj = 0;
312 * If we were "restarted" from a stopped state, don't bother
313 * with anything else.
315 if (scn->scn_phys.scn_state != DSS_SCANNING)
319 scn->scn_phys.scn_state = DSS_FINISHED;
321 scn->scn_phys.scn_state = DSS_CANCELED;
323 spa_history_log_internal(spa, "scan done", tx,
324 "complete=%u", complete);
326 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) {
327 mutex_enter(&spa->spa_scrub_lock);
328 while (spa->spa_scrub_inflight > 0) {
329 cv_wait(&spa->spa_scrub_io_cv,
330 &spa->spa_scrub_lock);
332 mutex_exit(&spa->spa_scrub_lock);
333 spa->spa_scrub_started = B_FALSE;
334 spa->spa_scrub_active = B_FALSE;
337 * If the scrub/resilver completed, update all DTLs to
338 * reflect this. Whether it succeeded or not, vacate
339 * all temporary scrub DTLs.
341 vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg,
342 complete ? scn->scn_phys.scn_max_txg : 0, B_TRUE);
344 spa_event_notify(spa, NULL, scn->scn_phys.scn_min_txg ?
345 ESC_ZFS_RESILVER_FINISH : ESC_ZFS_SCRUB_FINISH);
347 spa_errlog_rotate(spa);
350 * We may have finished replacing a device.
351 * Let the async thread assess this and handle the detach.
353 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
356 scn->scn_phys.scn_end_time = gethrestime_sec();
361 dsl_scan_cancel_check(void *arg, dmu_tx_t *tx)
363 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
365 if (scn->scn_phys.scn_state != DSS_SCANNING)
366 return (SET_ERROR(ENOENT));
372 dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx)
374 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
376 dsl_scan_done(scn, B_FALSE, tx);
377 dsl_scan_sync_state(scn, tx);
381 dsl_scan_cancel(dsl_pool_t *dp)
383 return (dsl_sync_task(spa_name(dp->dp_spa), dsl_scan_cancel_check,
384 dsl_scan_cancel_sync, NULL, 3, ZFS_SPACE_CHECK_RESERVED));
387 static void dsl_scan_visitbp(blkptr_t *bp,
388 const zbookmark_phys_t *zb, dnode_phys_t *dnp, arc_buf_t *pbuf,
389 dsl_dataset_t *ds, dsl_scan_t *scn, dmu_objset_type_t ostype,
391 static void dsl_scan_visitdnode(dsl_scan_t *, dsl_dataset_t *ds,
392 dmu_objset_type_t ostype,
393 dnode_phys_t *dnp, arc_buf_t *buf, uint64_t object, dmu_tx_t *tx);
396 dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp)
398 zio_free(dp->dp_spa, txg, bp);
402 dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp)
404 ASSERT(dsl_pool_sync_context(dp));
405 zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, BP_GET_PSIZE(bpp),
410 dsl_scan_ds_maxtxg(dsl_dataset_t *ds)
412 uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg;
413 if (dsl_dataset_is_snapshot(ds))
414 return (MIN(smt, ds->ds_phys->ds_creation_txg));
419 dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx)
421 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset,
422 DMU_POOL_DIRECTORY_OBJECT,
423 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS,
424 &scn->scn_phys, tx));
428 dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_phys_t *zb)
430 uint64_t elapsed_nanosecs;
431 unsigned int mintime;
433 /* we never skip user/group accounting objects */
434 if (zb && (int64_t)zb->zb_object < 0)
437 if (scn->scn_pausing)
438 return (B_TRUE); /* we're already pausing */
440 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark))
441 return (B_FALSE); /* we're resuming */
443 /* We only know how to resume from level-0 blocks. */
444 if (zb && zb->zb_level != 0)
447 mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ?
448 zfs_resilver_min_time_ms : zfs_scan_min_time_ms;
449 elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time;
450 if (elapsed_nanosecs / NANOSEC > zfs_txg_timeout ||
451 (NSEC2MSEC(elapsed_nanosecs) > mintime &&
452 txg_sync_waiting(scn->scn_dp)) ||
453 spa_shutting_down(scn->scn_dp->dp_spa)) {
455 dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n",
456 (longlong_t)zb->zb_objset,
457 (longlong_t)zb->zb_object,
458 (longlong_t)zb->zb_level,
459 (longlong_t)zb->zb_blkid);
460 scn->scn_phys.scn_bookmark = *zb;
462 dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n",
463 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class,
464 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type,
465 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum,
466 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor);
467 scn->scn_pausing = B_TRUE;
473 typedef struct zil_scan_arg {
475 zil_header_t *zsa_zh;
480 dsl_scan_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
482 zil_scan_arg_t *zsa = arg;
483 dsl_pool_t *dp = zsa->zsa_dp;
484 dsl_scan_t *scn = dp->dp_scan;
485 zil_header_t *zh = zsa->zsa_zh;
488 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg)
492 * One block ("stubby") can be allocated a long time ago; we
493 * want to visit that one because it has been allocated
494 * (on-disk) even if it hasn't been claimed (even though for
495 * scrub there's nothing to do to it).
497 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa))
500 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET],
501 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
503 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb));
509 dsl_scan_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
511 if (lrc->lrc_txtype == TX_WRITE) {
512 zil_scan_arg_t *zsa = arg;
513 dsl_pool_t *dp = zsa->zsa_dp;
514 dsl_scan_t *scn = dp->dp_scan;
515 zil_header_t *zh = zsa->zsa_zh;
516 lr_write_t *lr = (lr_write_t *)lrc;
517 blkptr_t *bp = &lr->lr_blkptr;
520 if (BP_IS_HOLE(bp) ||
521 bp->blk_birth <= scn->scn_phys.scn_cur_min_txg)
525 * birth can be < claim_txg if this record's txg is
526 * already txg sync'ed (but this log block contains
527 * other records that are not synced)
529 if (claim_txg == 0 || bp->blk_birth < claim_txg)
532 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET],
533 lr->lr_foid, ZB_ZIL_LEVEL,
534 lr->lr_offset / BP_GET_LSIZE(bp));
536 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb));
542 dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh)
544 uint64_t claim_txg = zh->zh_claim_txg;
545 zil_scan_arg_t zsa = { dp, zh };
549 * We only want to visit blocks that have been claimed but not yet
550 * replayed (or, in read-only mode, blocks that *would* be claimed).
552 if (claim_txg == 0 && spa_writeable(dp->dp_spa))
555 zilog = zil_alloc(dp->dp_meta_objset, zh);
557 (void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa,
565 dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp,
566 uint64_t objset, uint64_t object, uint64_t blkid)
568 zbookmark_phys_t czb;
569 uint32_t flags = ARC_NOWAIT | ARC_PREFETCH;
571 if (zfs_no_scrub_prefetch)
574 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_min_txg ||
575 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE))
578 SET_BOOKMARK(&czb, objset, object, BP_GET_LEVEL(bp), blkid);
580 (void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp,
581 NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
582 ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb);
586 dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp,
587 const zbookmark_phys_t *zb)
590 * We never skip over user/group accounting objects (obj<0)
592 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) &&
593 (int64_t)zb->zb_object >= 0) {
595 * If we already visited this bp & everything below (in
596 * a prior txg sync), don't bother doing it again.
598 if (zbookmark_is_before(dnp, zb, &scn->scn_phys.scn_bookmark))
602 * If we found the block we're trying to resume from, or
603 * we went past it to a different object, zero it out to
604 * indicate that it's OK to start checking for pausing
607 if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 ||
608 zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) {
609 dprintf("resuming at %llx/%llx/%llx/%llx\n",
610 (longlong_t)zb->zb_objset,
611 (longlong_t)zb->zb_object,
612 (longlong_t)zb->zb_level,
613 (longlong_t)zb->zb_blkid);
614 bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb));
621 * Return nonzero on i/o error.
622 * Return new buf to write out in *bufp.
625 dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype,
626 dnode_phys_t *dnp, const blkptr_t *bp,
627 const zbookmark_phys_t *zb, dmu_tx_t *tx, arc_buf_t **bufp)
629 dsl_pool_t *dp = scn->scn_dp;
630 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD;
633 if (BP_GET_LEVEL(bp) > 0) {
634 uint32_t flags = ARC_WAIT;
637 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
639 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp,
640 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
642 scn->scn_phys.scn_errors++;
645 for (i = 0, cbp = (*bufp)->b_data; i < epb; i++, cbp++) {
646 dsl_scan_prefetch(scn, *bufp, cbp, zb->zb_objset,
647 zb->zb_object, zb->zb_blkid * epb + i);
649 for (i = 0, cbp = (*bufp)->b_data; i < epb; i++, cbp++) {
650 zbookmark_phys_t czb;
652 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
654 zb->zb_blkid * epb + i);
655 dsl_scan_visitbp(cbp, &czb, dnp,
656 *bufp, ds, scn, ostype, tx);
658 } else if (BP_GET_TYPE(bp) == DMU_OT_USERGROUP_USED) {
659 uint32_t flags = ARC_WAIT;
661 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp,
662 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
664 scn->scn_phys.scn_errors++;
667 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
668 uint32_t flags = ARC_WAIT;
671 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
673 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp,
674 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
676 scn->scn_phys.scn_errors++;
679 for (i = 0, cdnp = (*bufp)->b_data; i < epb; i++, cdnp++) {
680 for (j = 0; j < cdnp->dn_nblkptr; j++) {
681 blkptr_t *cbp = &cdnp->dn_blkptr[j];
682 dsl_scan_prefetch(scn, *bufp, cbp,
683 zb->zb_objset, zb->zb_blkid * epb + i, j);
686 for (i = 0, cdnp = (*bufp)->b_data; i < epb; i++, cdnp++) {
687 dsl_scan_visitdnode(scn, ds, ostype,
688 cdnp, *bufp, zb->zb_blkid * epb + i, tx);
691 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
692 uint32_t flags = ARC_WAIT;
695 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp,
696 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
698 scn->scn_phys.scn_errors++;
702 osp = (*bufp)->b_data;
704 dsl_scan_visitdnode(scn, ds, osp->os_type,
705 &osp->os_meta_dnode, *bufp, DMU_META_DNODE_OBJECT, tx);
707 if (OBJSET_BUF_HAS_USERUSED(*bufp)) {
709 * We also always visit user/group accounting
710 * objects, and never skip them, even if we are
711 * pausing. This is necessary so that the space
712 * deltas from this txg get integrated.
714 dsl_scan_visitdnode(scn, ds, osp->os_type,
715 &osp->os_groupused_dnode, *bufp,
716 DMU_GROUPUSED_OBJECT, tx);
717 dsl_scan_visitdnode(scn, ds, osp->os_type,
718 &osp->os_userused_dnode, *bufp,
719 DMU_USERUSED_OBJECT, tx);
727 dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds,
728 dmu_objset_type_t ostype, dnode_phys_t *dnp, arc_buf_t *buf,
729 uint64_t object, dmu_tx_t *tx)
733 for (j = 0; j < dnp->dn_nblkptr; j++) {
734 zbookmark_phys_t czb;
736 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object,
737 dnp->dn_nlevels - 1, j);
738 dsl_scan_visitbp(&dnp->dn_blkptr[j],
739 &czb, dnp, buf, ds, scn, ostype, tx);
742 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
743 zbookmark_phys_t czb;
744 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object,
746 dsl_scan_visitbp(&dnp->dn_spill,
747 &czb, dnp, buf, ds, scn, ostype, tx);
752 * The arguments are in this order because mdb can only print the
753 * first 5; we want them to be useful.
756 dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb,
757 dnode_phys_t *dnp, arc_buf_t *pbuf,
758 dsl_dataset_t *ds, dsl_scan_t *scn, dmu_objset_type_t ostype,
761 dsl_pool_t *dp = scn->scn_dp;
762 arc_buf_t *buf = NULL;
763 blkptr_t bp_toread = *bp;
765 /* ASSERT(pbuf == NULL || arc_released(pbuf)); */
767 if (dsl_scan_check_pause(scn, zb))
770 if (dsl_scan_check_resume(scn, dnp, zb))
776 scn->scn_visited_this_txg++;
779 "visiting ds=%p/%llu zb=%llx/%llx/%llx/%llx buf=%p bp=%p",
780 ds, ds ? ds->ds_object : 0,
781 zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid,
784 if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg)
787 if (dsl_scan_recurse(scn, ds, ostype, dnp, &bp_toread, zb, tx,
792 * If dsl_scan_ddt() has aready visited this block, it will have
793 * already done any translations or scrubbing, so don't call the
796 if (ddt_class_contains(dp->dp_spa,
797 scn->scn_phys.scn_ddt_class_max, bp)) {
803 * If this block is from the future (after cur_max_txg), then we
804 * are doing this on behalf of a deleted snapshot, and we will
805 * revisit the future block on the next pass of this dataset.
806 * Don't scan it now unless we need to because something
807 * under it was modified.
809 if (BP_PHYSICAL_BIRTH(bp) <= scn->scn_phys.scn_cur_max_txg) {
810 scan_funcs[scn->scn_phys.scn_func](dp, bp, zb);
813 (void) arc_buf_remove_ref(buf, &buf);
817 dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp,
822 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
823 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
824 dsl_scan_visitbp(bp, &zb, NULL, NULL,
825 ds, scn, DMU_OST_NONE, tx);
827 dprintf_ds(ds, "finished scan%s", "");
831 dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx)
833 dsl_pool_t *dp = ds->ds_dir->dd_pool;
834 dsl_scan_t *scn = dp->dp_scan;
837 if (scn->scn_phys.scn_state != DSS_SCANNING)
840 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) {
841 if (dsl_dataset_is_snapshot(ds)) {
842 /* Note, scn_cur_{min,max}_txg stays the same. */
843 scn->scn_phys.scn_bookmark.zb_objset =
844 ds->ds_phys->ds_next_snap_obj;
845 zfs_dbgmsg("destroying ds %llu; currently traversing; "
846 "reset zb_objset to %llu",
847 (u_longlong_t)ds->ds_object,
848 (u_longlong_t)ds->ds_phys->ds_next_snap_obj);
849 scn->scn_phys.scn_flags |= DSF_VISIT_DS_AGAIN;
851 SET_BOOKMARK(&scn->scn_phys.scn_bookmark,
852 ZB_DESTROYED_OBJSET, 0, 0, 0);
853 zfs_dbgmsg("destroying ds %llu; currently traversing; "
854 "reset bookmark to -1,0,0,0",
855 (u_longlong_t)ds->ds_object);
857 } else if (zap_lookup_int_key(dp->dp_meta_objset,
858 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) {
859 ASSERT3U(ds->ds_phys->ds_num_children, <=, 1);
860 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
861 scn->scn_phys.scn_queue_obj, ds->ds_object, tx));
862 if (dsl_dataset_is_snapshot(ds)) {
864 * We keep the same mintxg; it could be >
865 * ds_creation_txg if the previous snapshot was
868 VERIFY(zap_add_int_key(dp->dp_meta_objset,
869 scn->scn_phys.scn_queue_obj,
870 ds->ds_phys->ds_next_snap_obj, mintxg, tx) == 0);
871 zfs_dbgmsg("destroying ds %llu; in queue; "
872 "replacing with %llu",
873 (u_longlong_t)ds->ds_object,
874 (u_longlong_t)ds->ds_phys->ds_next_snap_obj);
876 zfs_dbgmsg("destroying ds %llu; in queue; removing",
877 (u_longlong_t)ds->ds_object);
880 zfs_dbgmsg("destroying ds %llu; ignoring",
881 (u_longlong_t)ds->ds_object);
885 * dsl_scan_sync() should be called after this, and should sync
886 * out our changed state, but just to be safe, do it here.
888 dsl_scan_sync_state(scn, tx);
892 dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx)
894 dsl_pool_t *dp = ds->ds_dir->dd_pool;
895 dsl_scan_t *scn = dp->dp_scan;
898 if (scn->scn_phys.scn_state != DSS_SCANNING)
901 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0);
903 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) {
904 scn->scn_phys.scn_bookmark.zb_objset =
905 ds->ds_phys->ds_prev_snap_obj;
906 zfs_dbgmsg("snapshotting ds %llu; currently traversing; "
907 "reset zb_objset to %llu",
908 (u_longlong_t)ds->ds_object,
909 (u_longlong_t)ds->ds_phys->ds_prev_snap_obj);
910 } else if (zap_lookup_int_key(dp->dp_meta_objset,
911 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) {
912 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
913 scn->scn_phys.scn_queue_obj, ds->ds_object, tx));
914 VERIFY(zap_add_int_key(dp->dp_meta_objset,
915 scn->scn_phys.scn_queue_obj,
916 ds->ds_phys->ds_prev_snap_obj, mintxg, tx) == 0);
917 zfs_dbgmsg("snapshotting ds %llu; in queue; "
918 "replacing with %llu",
919 (u_longlong_t)ds->ds_object,
920 (u_longlong_t)ds->ds_phys->ds_prev_snap_obj);
922 dsl_scan_sync_state(scn, tx);
926 dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx)
928 dsl_pool_t *dp = ds1->ds_dir->dd_pool;
929 dsl_scan_t *scn = dp->dp_scan;
932 if (scn->scn_phys.scn_state != DSS_SCANNING)
935 if (scn->scn_phys.scn_bookmark.zb_objset == ds1->ds_object) {
936 scn->scn_phys.scn_bookmark.zb_objset = ds2->ds_object;
937 zfs_dbgmsg("clone_swap ds %llu; currently traversing; "
938 "reset zb_objset to %llu",
939 (u_longlong_t)ds1->ds_object,
940 (u_longlong_t)ds2->ds_object);
941 } else if (scn->scn_phys.scn_bookmark.zb_objset == ds2->ds_object) {
942 scn->scn_phys.scn_bookmark.zb_objset = ds1->ds_object;
943 zfs_dbgmsg("clone_swap ds %llu; currently traversing; "
944 "reset zb_objset to %llu",
945 (u_longlong_t)ds2->ds_object,
946 (u_longlong_t)ds1->ds_object);
949 if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj,
950 ds1->ds_object, &mintxg) == 0) {
953 ASSERT3U(mintxg, ==, ds1->ds_phys->ds_prev_snap_txg);
954 ASSERT3U(mintxg, ==, ds2->ds_phys->ds_prev_snap_txg);
955 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
956 scn->scn_phys.scn_queue_obj, ds1->ds_object, tx));
957 err = zap_add_int_key(dp->dp_meta_objset,
958 scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg, tx);
959 VERIFY(err == 0 || err == EEXIST);
961 /* Both were there to begin with */
962 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset,
963 scn->scn_phys.scn_queue_obj,
964 ds1->ds_object, mintxg, tx));
966 zfs_dbgmsg("clone_swap ds %llu; in queue; "
967 "replacing with %llu",
968 (u_longlong_t)ds1->ds_object,
969 (u_longlong_t)ds2->ds_object);
970 } else if (zap_lookup_int_key(dp->dp_meta_objset,
971 scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg) == 0) {
972 ASSERT3U(mintxg, ==, ds1->ds_phys->ds_prev_snap_txg);
973 ASSERT3U(mintxg, ==, ds2->ds_phys->ds_prev_snap_txg);
974 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
975 scn->scn_phys.scn_queue_obj, ds2->ds_object, tx));
976 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset,
977 scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg, tx));
978 zfs_dbgmsg("clone_swap ds %llu; in queue; "
979 "replacing with %llu",
980 (u_longlong_t)ds2->ds_object,
981 (u_longlong_t)ds1->ds_object);
984 dsl_scan_sync_state(scn, tx);
987 struct enqueue_clones_arg {
994 enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
996 struct enqueue_clones_arg *eca = arg;
999 dsl_scan_t *scn = dp->dp_scan;
1001 if (hds->ds_dir->dd_phys->dd_origin_obj != eca->originobj)
1004 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
1008 while (ds->ds_phys->ds_prev_snap_obj != eca->originobj) {
1009 dsl_dataset_t *prev;
1010 err = dsl_dataset_hold_obj(dp,
1011 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
1013 dsl_dataset_rele(ds, FTAG);
1018 VERIFY(zap_add_int_key(dp->dp_meta_objset,
1019 scn->scn_phys.scn_queue_obj, ds->ds_object,
1020 ds->ds_phys->ds_prev_snap_txg, eca->tx) == 0);
1021 dsl_dataset_rele(ds, FTAG);
1026 dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx)
1028 dsl_pool_t *dp = scn->scn_dp;
1032 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
1034 if (dmu_objset_from_ds(ds, &os))
1038 * Only the ZIL in the head (non-snapshot) is valid. Even though
1039 * snapshots can have ZIL block pointers (which may be the same
1040 * BP as in the head), they must be ignored. So we traverse the
1041 * ZIL here, rather than in scan_recurse(), because the regular
1042 * snapshot block-sharing rules don't apply to it.
1044 if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !dsl_dataset_is_snapshot(ds))
1045 dsl_scan_zil(dp, &os->os_zil_header);
1048 * Iterate over the bps in this ds.
1050 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1051 dsl_scan_visit_rootbp(scn, ds, &ds->ds_phys->ds_bp, tx);
1053 char *dsname = kmem_alloc(ZFS_MAXNAMELEN, KM_SLEEP);
1054 dsl_dataset_name(ds, dsname);
1055 zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; "
1057 (longlong_t)dsobj, dsname,
1058 (longlong_t)scn->scn_phys.scn_cur_min_txg,
1059 (longlong_t)scn->scn_phys.scn_cur_max_txg,
1060 (int)scn->scn_pausing);
1061 kmem_free(dsname, ZFS_MAXNAMELEN);
1063 if (scn->scn_pausing)
1067 * We've finished this pass over this dataset.
1071 * If we did not completely visit this dataset, do another pass.
1073 if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) {
1074 zfs_dbgmsg("incomplete pass; visiting again");
1075 scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN;
1076 VERIFY(zap_add_int_key(dp->dp_meta_objset,
1077 scn->scn_phys.scn_queue_obj, ds->ds_object,
1078 scn->scn_phys.scn_cur_max_txg, tx) == 0);
1083 * Add descendent datasets to work queue.
1085 if (ds->ds_phys->ds_next_snap_obj != 0) {
1086 VERIFY(zap_add_int_key(dp->dp_meta_objset,
1087 scn->scn_phys.scn_queue_obj, ds->ds_phys->ds_next_snap_obj,
1088 ds->ds_phys->ds_creation_txg, tx) == 0);
1090 if (ds->ds_phys->ds_num_children > 1) {
1091 boolean_t usenext = B_FALSE;
1092 if (ds->ds_phys->ds_next_clones_obj != 0) {
1095 * A bug in a previous version of the code could
1096 * cause upgrade_clones_cb() to not set
1097 * ds_next_snap_obj when it should, leading to a
1098 * missing entry. Therefore we can only use the
1099 * next_clones_obj when its count is correct.
1101 int err = zap_count(dp->dp_meta_objset,
1102 ds->ds_phys->ds_next_clones_obj, &count);
1104 count == ds->ds_phys->ds_num_children - 1)
1109 VERIFY0(zap_join_key(dp->dp_meta_objset,
1110 ds->ds_phys->ds_next_clones_obj,
1111 scn->scn_phys.scn_queue_obj,
1112 ds->ds_phys->ds_creation_txg, tx));
1114 struct enqueue_clones_arg eca;
1116 eca.originobj = ds->ds_object;
1118 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
1119 enqueue_clones_cb, &eca, DS_FIND_CHILDREN));
1124 dsl_dataset_rele(ds, FTAG);
1129 enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
1134 dsl_scan_t *scn = dp->dp_scan;
1136 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
1140 while (ds->ds_phys->ds_prev_snap_obj != 0) {
1141 dsl_dataset_t *prev;
1142 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
1145 dsl_dataset_rele(ds, FTAG);
1150 * If this is a clone, we don't need to worry about it for now.
1152 if (prev->ds_phys->ds_next_snap_obj != ds->ds_object) {
1153 dsl_dataset_rele(ds, FTAG);
1154 dsl_dataset_rele(prev, FTAG);
1157 dsl_dataset_rele(ds, FTAG);
1161 VERIFY(zap_add_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj,
1162 ds->ds_object, ds->ds_phys->ds_prev_snap_txg, tx) == 0);
1163 dsl_dataset_rele(ds, FTAG);
1168 * Scrub/dedup interaction.
1170 * If there are N references to a deduped block, we don't want to scrub it
1171 * N times -- ideally, we should scrub it exactly once.
1173 * We leverage the fact that the dde's replication class (enum ddt_class)
1174 * is ordered from highest replication class (DDT_CLASS_DITTO) to lowest
1175 * (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order.
1177 * To prevent excess scrubbing, the scrub begins by walking the DDT
1178 * to find all blocks with refcnt > 1, and scrubs each of these once.
1179 * Since there are two replication classes which contain blocks with
1180 * refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first.
1181 * Finally the top-down scrub begins, only visiting blocks with refcnt == 1.
1183 * There would be nothing more to say if a block's refcnt couldn't change
1184 * during a scrub, but of course it can so we must account for changes
1185 * in a block's replication class.
1187 * Here's an example of what can occur:
1189 * If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1
1190 * when visited during the top-down scrub phase, it will be scrubbed twice.
1191 * This negates our scrub optimization, but is otherwise harmless.
1193 * If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1
1194 * on each visit during the top-down scrub phase, it will never be scrubbed.
1195 * To catch this, ddt_sync_entry() notifies the scrub code whenever a block's
1196 * reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to
1197 * DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1
1198 * while a scrub is in progress, it scrubs the block right then.
1201 dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx)
1203 ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark;
1204 ddt_entry_t dde = { 0 };
1208 while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) {
1211 if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max)
1213 dprintf("visiting ddb=%llu/%llu/%llu/%llx\n",
1214 (longlong_t)ddb->ddb_class,
1215 (longlong_t)ddb->ddb_type,
1216 (longlong_t)ddb->ddb_checksum,
1217 (longlong_t)ddb->ddb_cursor);
1219 /* There should be no pending changes to the dedup table */
1220 ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum];
1221 ASSERT(avl_first(&ddt->ddt_tree) == NULL);
1223 dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx);
1226 if (dsl_scan_check_pause(scn, NULL))
1230 zfs_dbgmsg("scanned %llu ddt entries with class_max = %u; pausing=%u",
1231 (longlong_t)n, (int)scn->scn_phys.scn_ddt_class_max,
1232 (int)scn->scn_pausing);
1234 ASSERT(error == 0 || error == ENOENT);
1235 ASSERT(error != ENOENT ||
1236 ddb->ddb_class > scn->scn_phys.scn_ddt_class_max);
1241 dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum,
1242 ddt_entry_t *dde, dmu_tx_t *tx)
1244 const ddt_key_t *ddk = &dde->dde_key;
1245 ddt_phys_t *ddp = dde->dde_phys;
1247 zbookmark_phys_t zb = { 0 };
1249 if (scn->scn_phys.scn_state != DSS_SCANNING)
1252 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
1253 if (ddp->ddp_phys_birth == 0 ||
1254 ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg)
1256 ddt_bp_create(checksum, ddk, ddp, &bp);
1258 scn->scn_visited_this_txg++;
1259 scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb);
1264 dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx)
1266 dsl_pool_t *dp = scn->scn_dp;
1270 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <=
1271 scn->scn_phys.scn_ddt_class_max) {
1272 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg;
1273 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg;
1274 dsl_scan_ddt(scn, tx);
1275 if (scn->scn_pausing)
1279 if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) {
1280 /* First do the MOS & ORIGIN */
1282 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg;
1283 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg;
1284 dsl_scan_visit_rootbp(scn, NULL,
1285 &dp->dp_meta_rootbp, tx);
1286 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
1287 if (scn->scn_pausing)
1290 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) {
1291 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
1292 enqueue_cb, tx, DS_FIND_CHILDREN));
1294 dsl_scan_visitds(scn,
1295 dp->dp_origin_snap->ds_object, tx);
1297 ASSERT(!scn->scn_pausing);
1298 } else if (scn->scn_phys.scn_bookmark.zb_objset !=
1299 ZB_DESTROYED_OBJSET) {
1301 * If we were paused, continue from here. Note if the
1302 * ds we were paused on was deleted, the zb_objset may
1303 * be -1, so we will skip this and find a new objset
1306 dsl_scan_visitds(scn, scn->scn_phys.scn_bookmark.zb_objset, tx);
1307 if (scn->scn_pausing)
1312 * In case we were paused right at the end of the ds, zero the
1313 * bookmark so we don't think that we're still trying to resume.
1315 bzero(&scn->scn_phys.scn_bookmark, sizeof (zbookmark_phys_t));
1317 /* keep pulling things out of the zap-object-as-queue */
1318 while (zap_cursor_init(&zc, dp->dp_meta_objset,
1319 scn->scn_phys.scn_queue_obj),
1320 zap_cursor_retrieve(&zc, &za) == 0) {
1324 dsobj = strtonum(za.za_name, NULL);
1325 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
1326 scn->scn_phys.scn_queue_obj, dsobj, tx));
1328 /* Set up min/max txg */
1329 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
1330 if (za.za_first_integer != 0) {
1331 scn->scn_phys.scn_cur_min_txg =
1332 MAX(scn->scn_phys.scn_min_txg,
1333 za.za_first_integer);
1335 scn->scn_phys.scn_cur_min_txg =
1336 MAX(scn->scn_phys.scn_min_txg,
1337 ds->ds_phys->ds_prev_snap_txg);
1339 scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds);
1340 dsl_dataset_rele(ds, FTAG);
1342 dsl_scan_visitds(scn, dsobj, tx);
1343 zap_cursor_fini(&zc);
1344 if (scn->scn_pausing)
1347 zap_cursor_fini(&zc);
1351 dsl_scan_free_should_pause(dsl_scan_t *scn)
1353 uint64_t elapsed_nanosecs;
1358 if (scn->scn_visited_this_txg >= zfs_free_max_blocks)
1361 elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time;
1362 return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout ||
1363 (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms &&
1364 txg_sync_waiting(scn->scn_dp)) ||
1365 spa_shutting_down(scn->scn_dp->dp_spa));
1369 dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1371 dsl_scan_t *scn = arg;
1373 if (!scn->scn_is_bptree ||
1374 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) {
1375 if (dsl_scan_free_should_pause(scn))
1376 return (SET_ERROR(ERESTART));
1379 zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa,
1380 dmu_tx_get_txg(tx), bp, BP_GET_PSIZE(bp), 0));
1381 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD,
1382 -bp_get_dsize_sync(scn->scn_dp->dp_spa, bp),
1383 -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx);
1384 scn->scn_visited_this_txg++;
1389 dsl_scan_active(dsl_scan_t *scn)
1391 spa_t *spa = scn->scn_dp->dp_spa;
1392 uint64_t used = 0, comp, uncomp;
1394 if (spa->spa_load_state != SPA_LOAD_NONE)
1396 if (spa_shutting_down(spa))
1398 if (scn->scn_phys.scn_state == DSS_SCANNING ||
1399 (scn->scn_async_destroying && !scn->scn_async_stalled))
1402 if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
1403 (void) bpobj_space(&scn->scn_dp->dp_free_bpobj,
1404 &used, &comp, &uncomp);
1410 dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx)
1412 dsl_scan_t *scn = dp->dp_scan;
1413 spa_t *spa = dp->dp_spa;
1417 * Check for scn_restart_txg before checking spa_load_state, so
1418 * that we can restart an old-style scan while the pool is being
1419 * imported (see dsl_scan_init).
1421 if (scn->scn_restart_txg != 0 &&
1422 scn->scn_restart_txg <= tx->tx_txg) {
1423 pool_scan_func_t func = POOL_SCAN_SCRUB;
1424 dsl_scan_done(scn, B_FALSE, tx);
1425 if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL))
1426 func = POOL_SCAN_RESILVER;
1427 zfs_dbgmsg("restarting scan func=%u txg=%llu",
1429 dsl_scan_setup_sync(&func, tx);
1433 * If the scan is inactive due to a stalled async destroy, try again.
1435 if ((!scn->scn_async_stalled && !dsl_scan_active(scn)) ||
1436 spa_sync_pass(dp->dp_spa) > 1)
1439 scn->scn_visited_this_txg = 0;
1440 scn->scn_pausing = B_FALSE;
1441 scn->scn_sync_start_time = gethrtime();
1442 spa->spa_scrub_active = B_TRUE;
1445 * First process the async destroys. If we pause, don't do
1446 * any scrubbing or resilvering. This ensures that there are no
1447 * async destroys while we are scanning, so the scan code doesn't
1448 * have to worry about traversing it. It is also faster to free the
1449 * blocks than to scrub them.
1451 if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
1452 scn->scn_is_bptree = B_FALSE;
1453 scn->scn_zio_root = zio_root(dp->dp_spa, NULL,
1454 NULL, ZIO_FLAG_MUSTSUCCEED);
1455 err = bpobj_iterate(&dp->dp_free_bpobj,
1456 dsl_scan_free_block_cb, scn, tx);
1457 VERIFY3U(0, ==, zio_wait(scn->scn_zio_root));
1459 if (err != 0 && err != ERESTART)
1460 zfs_panic_recover("error %u from bpobj_iterate()", err);
1463 if (err == 0 && spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) {
1464 ASSERT(scn->scn_async_destroying);
1465 scn->scn_is_bptree = B_TRUE;
1466 scn->scn_zio_root = zio_root(dp->dp_spa, NULL,
1467 NULL, ZIO_FLAG_MUSTSUCCEED);
1468 err = bptree_iterate(dp->dp_meta_objset,
1469 dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, scn, tx);
1470 VERIFY0(zio_wait(scn->scn_zio_root));
1472 if (err == EIO || err == ECKSUM) {
1474 } else if (err != 0 && err != ERESTART) {
1475 zfs_panic_recover("error %u from "
1476 "traverse_dataset_destroyed()", err);
1480 * If we didn't make progress, mark the async destroy as
1481 * stalled, so that we will not initiate a spa_sync() on
1484 scn->scn_async_stalled = (scn->scn_visited_this_txg == 0);
1486 if (bptree_is_empty(dp->dp_meta_objset, dp->dp_bptree_obj)) {
1487 /* finished; deactivate async destroy feature */
1488 spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, tx);
1489 ASSERT(!spa_feature_is_active(spa,
1490 SPA_FEATURE_ASYNC_DESTROY));
1491 VERIFY0(zap_remove(dp->dp_meta_objset,
1492 DMU_POOL_DIRECTORY_OBJECT,
1493 DMU_POOL_BPTREE_OBJ, tx));
1494 VERIFY0(bptree_free(dp->dp_meta_objset,
1495 dp->dp_bptree_obj, tx));
1496 dp->dp_bptree_obj = 0;
1497 scn->scn_async_destroying = B_FALSE;
1500 if (scn->scn_visited_this_txg) {
1501 zfs_dbgmsg("freed %llu blocks in %llums from "
1502 "free_bpobj/bptree txg %llu; err=%u",
1503 (longlong_t)scn->scn_visited_this_txg,
1505 NSEC2MSEC(gethrtime() - scn->scn_sync_start_time),
1506 (longlong_t)tx->tx_txg, err);
1507 scn->scn_visited_this_txg = 0;
1510 * Write out changes to the DDT that may be required as a
1511 * result of the blocks freed. This ensures that the DDT
1512 * is clean when a scrub/resilver runs.
1514 ddt_sync(spa, tx->tx_txg);
1518 if (!scn->scn_async_destroying && zfs_free_leak_on_eio &&
1519 (dp->dp_free_dir->dd_phys->dd_used_bytes != 0 ||
1520 dp->dp_free_dir->dd_phys->dd_compressed_bytes != 0 ||
1521 dp->dp_free_dir->dd_phys->dd_uncompressed_bytes != 0)) {
1523 * We have finished background destroying, but there is still
1524 * some space left in the dp_free_dir. Transfer this leaked
1525 * space to the dp_leak_dir.
1527 if (dp->dp_leak_dir == NULL) {
1528 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
1529 (void) dsl_dir_create_sync(dp, dp->dp_root_dir,
1531 VERIFY0(dsl_pool_open_special_dir(dp,
1532 LEAK_DIR_NAME, &dp->dp_leak_dir));
1533 rrw_exit(&dp->dp_config_rwlock, FTAG);
1535 dsl_dir_diduse_space(dp->dp_leak_dir, DD_USED_HEAD,
1536 dp->dp_free_dir->dd_phys->dd_used_bytes,
1537 dp->dp_free_dir->dd_phys->dd_compressed_bytes,
1538 dp->dp_free_dir->dd_phys->dd_uncompressed_bytes, tx);
1539 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
1540 -dp->dp_free_dir->dd_phys->dd_used_bytes,
1541 -dp->dp_free_dir->dd_phys->dd_compressed_bytes,
1542 -dp->dp_free_dir->dd_phys->dd_uncompressed_bytes, tx);
1544 if (!scn->scn_async_destroying) {
1545 /* finished; verify that space accounting went to zero */
1546 ASSERT0(dp->dp_free_dir->dd_phys->dd_used_bytes);
1547 ASSERT0(dp->dp_free_dir->dd_phys->dd_compressed_bytes);
1548 ASSERT0(dp->dp_free_dir->dd_phys->dd_uncompressed_bytes);
1551 if (scn->scn_phys.scn_state != DSS_SCANNING)
1554 if (scn->scn_done_txg == tx->tx_txg) {
1555 ASSERT(!scn->scn_pausing);
1556 /* finished with scan. */
1557 zfs_dbgmsg("txg %llu scan complete", tx->tx_txg);
1558 dsl_scan_done(scn, B_TRUE, tx);
1559 ASSERT3U(spa->spa_scrub_inflight, ==, 0);
1560 dsl_scan_sync_state(scn, tx);
1564 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <=
1565 scn->scn_phys.scn_ddt_class_max) {
1566 zfs_dbgmsg("doing scan sync txg %llu; "
1567 "ddt bm=%llu/%llu/%llu/%llx",
1568 (longlong_t)tx->tx_txg,
1569 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class,
1570 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type,
1571 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum,
1572 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor);
1573 ASSERT(scn->scn_phys.scn_bookmark.zb_objset == 0);
1574 ASSERT(scn->scn_phys.scn_bookmark.zb_object == 0);
1575 ASSERT(scn->scn_phys.scn_bookmark.zb_level == 0);
1576 ASSERT(scn->scn_phys.scn_bookmark.zb_blkid == 0);
1578 zfs_dbgmsg("doing scan sync txg %llu; bm=%llu/%llu/%llu/%llu",
1579 (longlong_t)tx->tx_txg,
1580 (longlong_t)scn->scn_phys.scn_bookmark.zb_objset,
1581 (longlong_t)scn->scn_phys.scn_bookmark.zb_object,
1582 (longlong_t)scn->scn_phys.scn_bookmark.zb_level,
1583 (longlong_t)scn->scn_phys.scn_bookmark.zb_blkid);
1586 scn->scn_zio_root = zio_root(dp->dp_spa, NULL,
1587 NULL, ZIO_FLAG_CANFAIL);
1588 dsl_pool_config_enter(dp, FTAG);
1589 dsl_scan_visit(scn, tx);
1590 dsl_pool_config_exit(dp, FTAG);
1591 (void) zio_wait(scn->scn_zio_root);
1592 scn->scn_zio_root = NULL;
1594 zfs_dbgmsg("visited %llu blocks in %llums",
1595 (longlong_t)scn->scn_visited_this_txg,
1596 (longlong_t)NSEC2MSEC(gethrtime() - scn->scn_sync_start_time));
1598 if (!scn->scn_pausing) {
1599 scn->scn_done_txg = tx->tx_txg + 1;
1600 zfs_dbgmsg("txg %llu traversal complete, waiting till txg %llu",
1601 tx->tx_txg, scn->scn_done_txg);
1604 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) {
1605 mutex_enter(&spa->spa_scrub_lock);
1606 while (spa->spa_scrub_inflight > 0) {
1607 cv_wait(&spa->spa_scrub_io_cv,
1608 &spa->spa_scrub_lock);
1610 mutex_exit(&spa->spa_scrub_lock);
1613 dsl_scan_sync_state(scn, tx);
1617 * This will start a new scan, or restart an existing one.
1620 dsl_resilver_restart(dsl_pool_t *dp, uint64_t txg)
1624 tx = dmu_tx_create_dd(dp->dp_mos_dir);
1625 VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT));
1627 txg = dmu_tx_get_txg(tx);
1628 dp->dp_scan->scn_restart_txg = txg;
1631 dp->dp_scan->scn_restart_txg = txg;
1633 zfs_dbgmsg("restarting resilver txg=%llu", txg);
1637 dsl_scan_resilvering(dsl_pool_t *dp)
1639 return (dp->dp_scan->scn_phys.scn_state == DSS_SCANNING &&
1640 dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER);
1648 count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp)
1653 * If we resume after a reboot, zab will be NULL; don't record
1654 * incomplete stats in that case.
1659 for (i = 0; i < 4; i++) {
1660 int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS;
1661 int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL;
1662 if (t & DMU_OT_NEWTYPE)
1664 zfs_blkstat_t *zb = &zab->zab_type[l][t];
1668 zb->zb_asize += BP_GET_ASIZE(bp);
1669 zb->zb_lsize += BP_GET_LSIZE(bp);
1670 zb->zb_psize += BP_GET_PSIZE(bp);
1671 zb->zb_gangs += BP_COUNT_GANG(bp);
1673 switch (BP_GET_NDVAS(bp)) {
1675 if (DVA_GET_VDEV(&bp->blk_dva[0]) ==
1676 DVA_GET_VDEV(&bp->blk_dva[1]))
1677 zb->zb_ditto_2_of_2_samevdev++;
1680 equal = (DVA_GET_VDEV(&bp->blk_dva[0]) ==
1681 DVA_GET_VDEV(&bp->blk_dva[1])) +
1682 (DVA_GET_VDEV(&bp->blk_dva[0]) ==
1683 DVA_GET_VDEV(&bp->blk_dva[2])) +
1684 (DVA_GET_VDEV(&bp->blk_dva[1]) ==
1685 DVA_GET_VDEV(&bp->blk_dva[2]));
1687 zb->zb_ditto_2_of_3_samevdev++;
1688 else if (equal == 3)
1689 zb->zb_ditto_3_of_3_samevdev++;
1696 dsl_scan_scrub_done(zio_t *zio)
1698 spa_t *spa = zio->io_spa;
1700 zio_data_buf_free(zio->io_data, zio->io_size);
1702 mutex_enter(&spa->spa_scrub_lock);
1703 spa->spa_scrub_inflight--;
1704 cv_broadcast(&spa->spa_scrub_io_cv);
1706 if (zio->io_error && (zio->io_error != ECKSUM ||
1707 !(zio->io_flags & ZIO_FLAG_SPECULATIVE))) {
1708 spa->spa_dsl_pool->dp_scan->scn_phys.scn_errors++;
1710 mutex_exit(&spa->spa_scrub_lock);
1714 dsl_scan_scrub_cb(dsl_pool_t *dp,
1715 const blkptr_t *bp, const zbookmark_phys_t *zb)
1717 dsl_scan_t *scn = dp->dp_scan;
1718 size_t size = BP_GET_PSIZE(bp);
1719 spa_t *spa = dp->dp_spa;
1720 uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp);
1722 int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL;
1723 unsigned int scan_delay = 0;
1725 if (phys_birth <= scn->scn_phys.scn_min_txg ||
1726 phys_birth >= scn->scn_phys.scn_max_txg)
1729 count_block(dp->dp_blkstats, bp);
1731 if (BP_IS_EMBEDDED(bp))
1734 ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn));
1735 if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) {
1736 zio_flags |= ZIO_FLAG_SCRUB;
1738 scan_delay = zfs_scrub_delay;
1740 ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER);
1741 zio_flags |= ZIO_FLAG_RESILVER;
1743 scan_delay = zfs_resilver_delay;
1746 /* If it's an intent log block, failure is expected. */
1747 if (zb->zb_level == ZB_ZIL_LEVEL)
1748 zio_flags |= ZIO_FLAG_SPECULATIVE;
1750 for (int d = 0; d < BP_GET_NDVAS(bp); d++) {
1751 vdev_t *vd = vdev_lookup_top(spa,
1752 DVA_GET_VDEV(&bp->blk_dva[d]));
1755 * Keep track of how much data we've examined so that
1756 * zpool(1M) status can make useful progress reports.
1758 scn->scn_phys.scn_examined += DVA_GET_ASIZE(&bp->blk_dva[d]);
1759 spa->spa_scan_pass_exam += DVA_GET_ASIZE(&bp->blk_dva[d]);
1761 /* if it's a resilver, this may not be in the target range */
1763 if (DVA_GET_GANG(&bp->blk_dva[d])) {
1765 * Gang members may be spread across multiple
1766 * vdevs, so the best estimate we have is the
1767 * scrub range, which has already been checked.
1768 * XXX -- it would be better to change our
1769 * allocation policy to ensure that all
1770 * gang members reside on the same vdev.
1774 needs_io = vdev_dtl_contains(vd, DTL_PARTIAL,
1780 if (needs_io && !zfs_no_scrub_io) {
1781 vdev_t *rvd = spa->spa_root_vdev;
1782 uint64_t maxinflight = rvd->vdev_children *
1783 MAX(zfs_top_maxinflight, 1);
1784 void *data = zio_data_buf_alloc(size);
1786 mutex_enter(&spa->spa_scrub_lock);
1787 while (spa->spa_scrub_inflight >= maxinflight)
1788 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
1789 spa->spa_scrub_inflight++;
1790 mutex_exit(&spa->spa_scrub_lock);
1793 * If we're seeing recent (zfs_scan_idle) "important" I/Os
1794 * then throttle our workload to limit the impact of a scan.
1796 if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle)
1797 delay(MAX((int)scan_delay, 0));
1799 zio_nowait(zio_read(NULL, spa, bp, data, size,
1800 dsl_scan_scrub_done, NULL, ZIO_PRIORITY_SCRUB,
1804 /* do not relocate this block */
1809 dsl_scan(dsl_pool_t *dp, pool_scan_func_t func)
1811 spa_t *spa = dp->dp_spa;
1814 * Purge all vdev caches and probe all devices. We do this here
1815 * rather than in sync context because this requires a writer lock
1816 * on the spa_config lock, which we can't do from sync context. The
1817 * spa_scrub_reopen flag indicates that vdev_open() should not
1818 * attempt to start another scrub.
1820 spa_vdev_state_enter(spa, SCL_NONE);
1821 spa->spa_scrub_reopen = B_TRUE;
1822 vdev_reopen(spa->spa_root_vdev);
1823 spa->spa_scrub_reopen = B_FALSE;
1824 (void) spa_vdev_state_exit(spa, NULL, 0);
1826 return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check,
1827 dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_NONE));