dsl_scan.c revision 288571
1/* 2 * CDDL HEADER START 3 * 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. 7 * 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. 12 * 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] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved. 24 */ 25 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> 35#include <sys/arc.h> 36#include <sys/zap.h> 37#include <sys/zio.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> 45#include <sys/ddt.h> 46#include <sys/sa.h> 47#include <sys/sa_impl.h> 48#include <sys/zfeature.h> 49#ifdef _KERNEL 50#include <sys/zfs_vfsops.h> 51#endif 52 53typedef int (scan_cb_t)(dsl_pool_t *, const blkptr_t *, 54 const zbookmark_phys_t *); 55 56static scan_cb_t dsl_scan_scrub_cb; 57static void dsl_scan_cancel_sync(void *, dmu_tx_t *); 58static void dsl_scan_sync_state(dsl_scan_t *, dmu_tx_t *tx); 59 60unsigned int zfs_top_maxinflight = 32; /* maximum I/Os per top-level */ 61unsigned int zfs_resilver_delay = 2; /* number of ticks to delay resilver */ 62unsigned int zfs_scrub_delay = 4; /* number of ticks to delay scrub */ 63unsigned int zfs_scan_idle = 50; /* idle window in clock ticks */ 64 65unsigned int zfs_scan_min_time_ms = 1000; /* min millisecs to scrub per txg */ 66unsigned int zfs_free_min_time_ms = 1000; /* min millisecs to free per txg */ 67unsigned int zfs_resilver_min_time_ms = 3000; /* min millisecs to resilver 68 per txg */ 69boolean_t zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */ 70boolean_t zfs_no_scrub_prefetch = B_FALSE; /* set to disable scrub prefetch */ 71 72SYSCTL_DECL(_vfs_zfs); 73TUNABLE_INT("vfs.zfs.top_maxinflight", &zfs_top_maxinflight); 74SYSCTL_UINT(_vfs_zfs, OID_AUTO, top_maxinflight, CTLFLAG_RW, 75 &zfs_top_maxinflight, 0, "Maximum I/Os per top-level vdev"); 76TUNABLE_INT("vfs.zfs.resilver_delay", &zfs_resilver_delay); 77SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_delay, CTLFLAG_RW, 78 &zfs_resilver_delay, 0, "Number of ticks to delay resilver"); 79TUNABLE_INT("vfs.zfs.scrub_delay", &zfs_scrub_delay); 80SYSCTL_UINT(_vfs_zfs, OID_AUTO, scrub_delay, CTLFLAG_RW, 81 &zfs_scrub_delay, 0, "Number of ticks to delay scrub"); 82TUNABLE_INT("vfs.zfs.scan_idle", &zfs_scan_idle); 83SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_idle, CTLFLAG_RW, 84 &zfs_scan_idle, 0, "Idle scan window in clock ticks"); 85TUNABLE_INT("vfs.zfs.scan_min_time_ms", &zfs_scan_min_time_ms); 86SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_min_time_ms, CTLFLAG_RW, 87 &zfs_scan_min_time_ms, 0, "Min millisecs to scrub per txg"); 88TUNABLE_INT("vfs.zfs.free_min_time_ms", &zfs_free_min_time_ms); 89SYSCTL_UINT(_vfs_zfs, OID_AUTO, free_min_time_ms, CTLFLAG_RW, 90 &zfs_free_min_time_ms, 0, "Min millisecs to free per txg"); 91TUNABLE_INT("vfs.zfs.resilver_min_time_ms", &zfs_resilver_min_time_ms); 92SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_min_time_ms, CTLFLAG_RW, 93 &zfs_resilver_min_time_ms, 0, "Min millisecs to resilver per txg"); 94TUNABLE_INT("vfs.zfs.no_scrub_io", &zfs_no_scrub_io); 95SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_io, CTLFLAG_RW, 96 &zfs_no_scrub_io, 0, "Disable scrub I/O"); 97TUNABLE_INT("vfs.zfs.no_scrub_prefetch", &zfs_no_scrub_prefetch); 98SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_prefetch, CTLFLAG_RW, 99 &zfs_no_scrub_prefetch, 0, "Disable scrub prefetching"); 100 101enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE; 102/* max number of blocks to free in a single TXG */ 103uint64_t zfs_free_max_blocks = UINT64_MAX; 104SYSCTL_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"); 106 107 108#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) 111 112extern int zfs_txg_timeout; 113 114/* the order has to match pool_scan_type */ 115static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = { 116 NULL, 117 dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */ 118 dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */ 119}; 120 121int 122dsl_scan_init(dsl_pool_t *dp, uint64_t txg) 123{ 124 int err; 125 dsl_scan_t *scn; 126 spa_t *spa = dp->dp_spa; 127 uint64_t f; 128 129 scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP); 130 scn->scn_dp = dp; 131 132 /* 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 135 * appropriately. 136 */ 137 ASSERT(!scn->scn_async_destroying); 138 scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa, 139 SPA_FEATURE_ASYNC_DESTROY); 140 141 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 142 "scrub_func", sizeof (uint64_t), 1, &f); 143 if (err == 0) { 144 /* 145 * There was an old-style scrub in progress. Restart a 146 * new-style scrub from the beginning. 147 */ 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); 152 153 /* 154 * Load the queue obj from the old location so that it 155 * can be freed by dsl_scan_done(). 156 */ 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); 160 } else { 161 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 162 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 163 &scn->scn_phys); 164 if (err == ENOENT) 165 return (0); 166 else if (err) 167 return (err); 168 169 if (scn->scn_phys.scn_state == DSS_SCANNING && 170 spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) { 171 /* 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 176 * the meantime. 177 */ 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); 182 } 183 } 184 185 spa_scan_stat_init(spa); 186 return (0); 187} 188 189void 190dsl_scan_fini(dsl_pool_t *dp) 191{ 192 if (dp->dp_scan) { 193 kmem_free(dp->dp_scan, sizeof (dsl_scan_t)); 194 dp->dp_scan = NULL; 195 } 196} 197 198/* ARGSUSED */ 199static int 200dsl_scan_setup_check(void *arg, dmu_tx_t *tx) 201{ 202 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 203 204 if (scn->scn_phys.scn_state == DSS_SCANNING) 205 return (SET_ERROR(EBUSY)); 206 207 return (0); 208} 209 210static void 211dsl_scan_setup_sync(void *arg, dmu_tx_t *tx) 212{ 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; 218 219 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); 233 234 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 235 scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max; 236 237 /* rewrite all disk labels */ 238 vdev_config_dirty(spa->spa_root_vdev); 239 240 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); 243 } else { 244 spa_event_notify(spa, NULL, ESC_ZFS_SCRUB_START); 245 } 246 247 spa->spa_scrub_started = B_TRUE; 248 /* 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. 252 */ 253 if (scn->scn_phys.scn_min_txg > TXG_INITIAL) 254 scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO; 255 256 } 257 258 /* back to the generic stuff */ 259 260 if (dp->dp_blkstats == NULL) { 261 dp->dp_blkstats = 262 kmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP); 263 } 264 bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); 265 266 if (spa_version(spa) < SPA_VERSION_DSL_SCRUB) 267 ot = DMU_OT_ZAP_OTHER; 268 269 scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset, 270 ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx); 271 272 dsl_scan_sync_state(scn, tx); 273 274 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); 277} 278 279/* ARGSUSED */ 280static void 281dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx) 282{ 283 static const char *old_names[] = { 284 "scrub_bookmark", 285 "scrub_ddt_bookmark", 286 "scrub_ddt_class_max", 287 "scrub_queue", 288 "scrub_min_txg", 289 "scrub_max_txg", 290 "scrub_func", 291 "scrub_errors", 292 NULL 293 }; 294 295 dsl_pool_t *dp = scn->scn_dp; 296 spa_t *spa = dp->dp_spa; 297 int i; 298 299 /* 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); 303 } 304 305 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; 309 } 310 311 /* 312 * If we were "restarted" from a stopped state, don't bother 313 * with anything else. 314 */ 315 if (scn->scn_phys.scn_state != DSS_SCANNING) 316 return; 317 318 if (complete) 319 scn->scn_phys.scn_state = DSS_FINISHED; 320 else 321 scn->scn_phys.scn_state = DSS_CANCELED; 322 323 spa_history_log_internal(spa, "scan done", tx, 324 "complete=%u", complete); 325 326 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); 331 } 332 mutex_exit(&spa->spa_scrub_lock); 333 spa->spa_scrub_started = B_FALSE; 334 spa->spa_scrub_active = B_FALSE; 335 336 /* 337 * If the scrub/resilver completed, update all DTLs to 338 * reflect this. Whether it succeeded or not, vacate 339 * all temporary scrub DTLs. 340 */ 341 vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg, 342 complete ? scn->scn_phys.scn_max_txg : 0, B_TRUE); 343 if (complete) { 344 spa_event_notify(spa, NULL, scn->scn_phys.scn_min_txg ? 345 ESC_ZFS_RESILVER_FINISH : ESC_ZFS_SCRUB_FINISH); 346 } 347 spa_errlog_rotate(spa); 348 349 /* 350 * We may have finished replacing a device. 351 * Let the async thread assess this and handle the detach. 352 */ 353 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE); 354 } 355 356 scn->scn_phys.scn_end_time = gethrestime_sec(); 357} 358 359/* ARGSUSED */ 360static int 361dsl_scan_cancel_check(void *arg, dmu_tx_t *tx) 362{ 363 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 364 365 if (scn->scn_phys.scn_state != DSS_SCANNING) 366 return (SET_ERROR(ENOENT)); 367 return (0); 368} 369 370/* ARGSUSED */ 371static void 372dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx) 373{ 374 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 375 376 dsl_scan_done(scn, B_FALSE, tx); 377 dsl_scan_sync_state(scn, tx); 378} 379 380int 381dsl_scan_cancel(dsl_pool_t *dp) 382{ 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)); 385} 386 387static void dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 388 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 389 dmu_objset_type_t ostype, dmu_tx_t *tx); 390static void dsl_scan_visitdnode(dsl_scan_t *, dsl_dataset_t *ds, 391 dmu_objset_type_t ostype, 392 dnode_phys_t *dnp, uint64_t object, dmu_tx_t *tx); 393 394void 395dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp) 396{ 397 zio_free(dp->dp_spa, txg, bp); 398} 399 400void 401dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp) 402{ 403 ASSERT(dsl_pool_sync_context(dp)); 404 zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, BP_GET_PSIZE(bpp), 405 pio->io_flags)); 406} 407 408static uint64_t 409dsl_scan_ds_maxtxg(dsl_dataset_t *ds) 410{ 411 uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg; 412 if (ds->ds_is_snapshot) 413 return (MIN(smt, dsl_dataset_phys(ds)->ds_creation_txg)); 414 return (smt); 415} 416 417static void 418dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx) 419{ 420 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, 421 DMU_POOL_DIRECTORY_OBJECT, 422 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 423 &scn->scn_phys, tx)); 424} 425 426extern int zfs_vdev_async_write_active_min_dirty_percent; 427 428static boolean_t 429dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_phys_t *zb) 430{ 431 /* we never skip user/group accounting objects */ 432 if (zb && (int64_t)zb->zb_object < 0) 433 return (B_FALSE); 434 435 if (scn->scn_pausing) 436 return (B_TRUE); /* we're already pausing */ 437 438 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark)) 439 return (B_FALSE); /* we're resuming */ 440 441 /* We only know how to resume from level-0 blocks. */ 442 if (zb && zb->zb_level != 0) 443 return (B_FALSE); 444 445 /* 446 * We pause if: 447 * - we have scanned for the maximum time: an entire txg 448 * timeout (default 5 sec) 449 * or 450 * - we have scanned for at least the minimum time (default 1 sec 451 * for scrub, 3 sec for resilver), and either we have sufficient 452 * dirty data that we are starting to write more quickly 453 * (default 30%), or someone is explicitly waiting for this txg 454 * to complete. 455 * or 456 * - the spa is shutting down because this pool is being exported 457 * or the machine is rebooting. 458 */ 459 int mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ? 460 zfs_resilver_min_time_ms : zfs_scan_min_time_ms; 461 uint64_t elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 462 int dirty_pct = scn->scn_dp->dp_dirty_total * 100 / zfs_dirty_data_max; 463 if (elapsed_nanosecs / NANOSEC >= zfs_txg_timeout || 464 (NSEC2MSEC(elapsed_nanosecs) > mintime && 465 (txg_sync_waiting(scn->scn_dp) || 466 dirty_pct >= zfs_vdev_async_write_active_min_dirty_percent)) || 467 spa_shutting_down(scn->scn_dp->dp_spa)) { 468 if (zb) { 469 dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n", 470 (longlong_t)zb->zb_objset, 471 (longlong_t)zb->zb_object, 472 (longlong_t)zb->zb_level, 473 (longlong_t)zb->zb_blkid); 474 scn->scn_phys.scn_bookmark = *zb; 475 } 476 dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n", 477 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 478 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 479 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 480 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 481 scn->scn_pausing = B_TRUE; 482 return (B_TRUE); 483 } 484 return (B_FALSE); 485} 486 487typedef struct zil_scan_arg { 488 dsl_pool_t *zsa_dp; 489 zil_header_t *zsa_zh; 490} zil_scan_arg_t; 491 492/* ARGSUSED */ 493static int 494dsl_scan_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 495{ 496 zil_scan_arg_t *zsa = arg; 497 dsl_pool_t *dp = zsa->zsa_dp; 498 dsl_scan_t *scn = dp->dp_scan; 499 zil_header_t *zh = zsa->zsa_zh; 500 zbookmark_phys_t zb; 501 502 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 503 return (0); 504 505 /* 506 * One block ("stubby") can be allocated a long time ago; we 507 * want to visit that one because it has been allocated 508 * (on-disk) even if it hasn't been claimed (even though for 509 * scrub there's nothing to do to it). 510 */ 511 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa)) 512 return (0); 513 514 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 515 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 516 517 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 518 return (0); 519} 520 521/* ARGSUSED */ 522static int 523dsl_scan_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) 524{ 525 if (lrc->lrc_txtype == TX_WRITE) { 526 zil_scan_arg_t *zsa = arg; 527 dsl_pool_t *dp = zsa->zsa_dp; 528 dsl_scan_t *scn = dp->dp_scan; 529 zil_header_t *zh = zsa->zsa_zh; 530 lr_write_t *lr = (lr_write_t *)lrc; 531 blkptr_t *bp = &lr->lr_blkptr; 532 zbookmark_phys_t zb; 533 534 if (BP_IS_HOLE(bp) || 535 bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 536 return (0); 537 538 /* 539 * birth can be < claim_txg if this record's txg is 540 * already txg sync'ed (but this log block contains 541 * other records that are not synced) 542 */ 543 if (claim_txg == 0 || bp->blk_birth < claim_txg) 544 return (0); 545 546 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 547 lr->lr_foid, ZB_ZIL_LEVEL, 548 lr->lr_offset / BP_GET_LSIZE(bp)); 549 550 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 551 } 552 return (0); 553} 554 555static void 556dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh) 557{ 558 uint64_t claim_txg = zh->zh_claim_txg; 559 zil_scan_arg_t zsa = { dp, zh }; 560 zilog_t *zilog; 561 562 /* 563 * We only want to visit blocks that have been claimed but not yet 564 * replayed (or, in read-only mode, blocks that *would* be claimed). 565 */ 566 if (claim_txg == 0 && spa_writeable(dp->dp_spa)) 567 return; 568 569 zilog = zil_alloc(dp->dp_meta_objset, zh); 570 571 (void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa, 572 claim_txg); 573 574 zil_free(zilog); 575} 576 577/* ARGSUSED */ 578static void 579dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp, 580 uint64_t objset, uint64_t object, uint64_t blkid) 581{ 582 zbookmark_phys_t czb; 583 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH; 584 585 if (zfs_no_scrub_prefetch) 586 return; 587 588 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_min_txg || 589 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)) 590 return; 591 592 SET_BOOKMARK(&czb, objset, object, BP_GET_LEVEL(bp), blkid); 593 594 (void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp, 595 NULL, NULL, ZIO_PRIORITY_ASYNC_READ, 596 ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb); 597} 598 599static boolean_t 600dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp, 601 const zbookmark_phys_t *zb) 602{ 603 /* 604 * We never skip over user/group accounting objects (obj<0) 605 */ 606 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) && 607 (int64_t)zb->zb_object >= 0) { 608 /* 609 * If we already visited this bp & everything below (in 610 * a prior txg sync), don't bother doing it again. 611 */ 612 if (zbookmark_subtree_completed(dnp, zb, 613 &scn->scn_phys.scn_bookmark)) 614 return (B_TRUE); 615 616 /* 617 * If we found the block we're trying to resume from, or 618 * we went past it to a different object, zero it out to 619 * indicate that it's OK to start checking for pausing 620 * again. 621 */ 622 if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 || 623 zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) { 624 dprintf("resuming at %llx/%llx/%llx/%llx\n", 625 (longlong_t)zb->zb_objset, 626 (longlong_t)zb->zb_object, 627 (longlong_t)zb->zb_level, 628 (longlong_t)zb->zb_blkid); 629 bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb)); 630 } 631 } 632 return (B_FALSE); 633} 634 635/* 636 * Return nonzero on i/o error. 637 * Return new buf to write out in *bufp. 638 */ 639static int 640dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype, 641 dnode_phys_t *dnp, const blkptr_t *bp, 642 const zbookmark_phys_t *zb, dmu_tx_t *tx) 643{ 644 dsl_pool_t *dp = scn->scn_dp; 645 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD; 646 int err; 647 648 if (BP_GET_LEVEL(bp) > 0) { 649 arc_flags_t flags = ARC_FLAG_WAIT; 650 int i; 651 blkptr_t *cbp; 652 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 653 arc_buf_t *buf; 654 655 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 656 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 657 if (err) { 658 scn->scn_phys.scn_errors++; 659 return (err); 660 } 661 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 662 dsl_scan_prefetch(scn, buf, cbp, zb->zb_objset, 663 zb->zb_object, zb->zb_blkid * epb + i); 664 } 665 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 666 zbookmark_phys_t czb; 667 668 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 669 zb->zb_level - 1, 670 zb->zb_blkid * epb + i); 671 dsl_scan_visitbp(cbp, &czb, dnp, 672 ds, scn, ostype, tx); 673 } 674 (void) arc_buf_remove_ref(buf, &buf); 675 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 676 arc_flags_t flags = ARC_FLAG_WAIT; 677 dnode_phys_t *cdnp; 678 int i, j; 679 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 680 arc_buf_t *buf; 681 682 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 683 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 684 if (err) { 685 scn->scn_phys.scn_errors++; 686 return (err); 687 } 688 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 689 for (j = 0; j < cdnp->dn_nblkptr; j++) { 690 blkptr_t *cbp = &cdnp->dn_blkptr[j]; 691 dsl_scan_prefetch(scn, buf, cbp, 692 zb->zb_objset, zb->zb_blkid * epb + i, j); 693 } 694 } 695 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 696 dsl_scan_visitdnode(scn, ds, ostype, 697 cdnp, zb->zb_blkid * epb + i, tx); 698 } 699 700 (void) arc_buf_remove_ref(buf, &buf); 701 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 702 arc_flags_t flags = ARC_FLAG_WAIT; 703 objset_phys_t *osp; 704 arc_buf_t *buf; 705 706 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 707 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 708 if (err) { 709 scn->scn_phys.scn_errors++; 710 return (err); 711 } 712 713 osp = buf->b_data; 714 715 dsl_scan_visitdnode(scn, ds, osp->os_type, 716 &osp->os_meta_dnode, DMU_META_DNODE_OBJECT, tx); 717 718 if (OBJSET_BUF_HAS_USERUSED(buf)) { 719 /* 720 * We also always visit user/group accounting 721 * objects, and never skip them, even if we are 722 * pausing. This is necessary so that the space 723 * deltas from this txg get integrated. 724 */ 725 dsl_scan_visitdnode(scn, ds, osp->os_type, 726 &osp->os_groupused_dnode, 727 DMU_GROUPUSED_OBJECT, tx); 728 dsl_scan_visitdnode(scn, ds, osp->os_type, 729 &osp->os_userused_dnode, 730 DMU_USERUSED_OBJECT, tx); 731 } 732 (void) arc_buf_remove_ref(buf, &buf); 733 } 734 735 return (0); 736} 737 738static void 739dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds, 740 dmu_objset_type_t ostype, dnode_phys_t *dnp, 741 uint64_t object, dmu_tx_t *tx) 742{ 743 int j; 744 745 for (j = 0; j < dnp->dn_nblkptr; j++) { 746 zbookmark_phys_t czb; 747 748 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 749 dnp->dn_nlevels - 1, j); 750 dsl_scan_visitbp(&dnp->dn_blkptr[j], 751 &czb, dnp, ds, scn, ostype, tx); 752 } 753 754 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 755 zbookmark_phys_t czb; 756 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 757 0, DMU_SPILL_BLKID); 758 dsl_scan_visitbp(&dnp->dn_spill, 759 &czb, dnp, ds, scn, ostype, tx); 760 } 761} 762 763/* 764 * The arguments are in this order because mdb can only print the 765 * first 5; we want them to be useful. 766 */ 767static void 768dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 769 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 770 dmu_objset_type_t ostype, dmu_tx_t *tx) 771{ 772 dsl_pool_t *dp = scn->scn_dp; 773 arc_buf_t *buf = NULL; 774 blkptr_t bp_toread = *bp; 775 776 /* ASSERT(pbuf == NULL || arc_released(pbuf)); */ 777 778 if (dsl_scan_check_pause(scn, zb)) 779 return; 780 781 if (dsl_scan_check_resume(scn, dnp, zb)) 782 return; 783 784 if (BP_IS_HOLE(bp)) 785 return; 786 787 scn->scn_visited_this_txg++; 788 789 dprintf_bp(bp, 790 "visiting ds=%p/%llu zb=%llx/%llx/%llx/%llx bp=%p", 791 ds, ds ? ds->ds_object : 0, 792 zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid, 793 bp); 794 795 if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 796 return; 797 798 if (dsl_scan_recurse(scn, ds, ostype, dnp, &bp_toread, zb, tx) != 0) 799 return; 800 801 /* 802 * If dsl_scan_ddt() has aready visited this block, it will have 803 * already done any translations or scrubbing, so don't call the 804 * callback again. 805 */ 806 if (ddt_class_contains(dp->dp_spa, 807 scn->scn_phys.scn_ddt_class_max, bp)) { 808 ASSERT(buf == NULL); 809 return; 810 } 811 812 /* 813 * If this block is from the future (after cur_max_txg), then we 814 * are doing this on behalf of a deleted snapshot, and we will 815 * revisit the future block on the next pass of this dataset. 816 * Don't scan it now unless we need to because something 817 * under it was modified. 818 */ 819 if (BP_PHYSICAL_BIRTH(bp) <= scn->scn_phys.scn_cur_max_txg) { 820 scan_funcs[scn->scn_phys.scn_func](dp, bp, zb); 821 } 822} 823 824static void 825dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp, 826 dmu_tx_t *tx) 827{ 828 zbookmark_phys_t zb; 829 830 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET, 831 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 832 dsl_scan_visitbp(bp, &zb, NULL, 833 ds, scn, DMU_OST_NONE, tx); 834 835 dprintf_ds(ds, "finished scan%s", ""); 836} 837 838void 839dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx) 840{ 841 dsl_pool_t *dp = ds->ds_dir->dd_pool; 842 dsl_scan_t *scn = dp->dp_scan; 843 uint64_t mintxg; 844 845 if (scn->scn_phys.scn_state != DSS_SCANNING) 846 return; 847 848 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 849 if (ds->ds_is_snapshot) { 850 /* Note, scn_cur_{min,max}_txg stays the same. */ 851 scn->scn_phys.scn_bookmark.zb_objset = 852 dsl_dataset_phys(ds)->ds_next_snap_obj; 853 zfs_dbgmsg("destroying ds %llu; currently traversing; " 854 "reset zb_objset to %llu", 855 (u_longlong_t)ds->ds_object, 856 (u_longlong_t)dsl_dataset_phys(ds)-> 857 ds_next_snap_obj); 858 scn->scn_phys.scn_flags |= DSF_VISIT_DS_AGAIN; 859 } else { 860 SET_BOOKMARK(&scn->scn_phys.scn_bookmark, 861 ZB_DESTROYED_OBJSET, 0, 0, 0); 862 zfs_dbgmsg("destroying ds %llu; currently traversing; " 863 "reset bookmark to -1,0,0,0", 864 (u_longlong_t)ds->ds_object); 865 } 866 } else if (zap_lookup_int_key(dp->dp_meta_objset, 867 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 868 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1); 869 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 870 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 871 if (ds->ds_is_snapshot) { 872 /* 873 * We keep the same mintxg; it could be > 874 * ds_creation_txg if the previous snapshot was 875 * deleted too. 876 */ 877 VERIFY(zap_add_int_key(dp->dp_meta_objset, 878 scn->scn_phys.scn_queue_obj, 879 dsl_dataset_phys(ds)->ds_next_snap_obj, 880 mintxg, tx) == 0); 881 zfs_dbgmsg("destroying ds %llu; in queue; " 882 "replacing with %llu", 883 (u_longlong_t)ds->ds_object, 884 (u_longlong_t)dsl_dataset_phys(ds)-> 885 ds_next_snap_obj); 886 } else { 887 zfs_dbgmsg("destroying ds %llu; in queue; removing", 888 (u_longlong_t)ds->ds_object); 889 } 890 } else { 891 zfs_dbgmsg("destroying ds %llu; ignoring", 892 (u_longlong_t)ds->ds_object); 893 } 894 895 /* 896 * dsl_scan_sync() should be called after this, and should sync 897 * out our changed state, but just to be safe, do it here. 898 */ 899 dsl_scan_sync_state(scn, tx); 900} 901 902void 903dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx) 904{ 905 dsl_pool_t *dp = ds->ds_dir->dd_pool; 906 dsl_scan_t *scn = dp->dp_scan; 907 uint64_t mintxg; 908 909 if (scn->scn_phys.scn_state != DSS_SCANNING) 910 return; 911 912 ASSERT(dsl_dataset_phys(ds)->ds_prev_snap_obj != 0); 913 914 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 915 scn->scn_phys.scn_bookmark.zb_objset = 916 dsl_dataset_phys(ds)->ds_prev_snap_obj; 917 zfs_dbgmsg("snapshotting ds %llu; currently traversing; " 918 "reset zb_objset to %llu", 919 (u_longlong_t)ds->ds_object, 920 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 921 } else if (zap_lookup_int_key(dp->dp_meta_objset, 922 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 923 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 924 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 925 VERIFY(zap_add_int_key(dp->dp_meta_objset, 926 scn->scn_phys.scn_queue_obj, 927 dsl_dataset_phys(ds)->ds_prev_snap_obj, mintxg, tx) == 0); 928 zfs_dbgmsg("snapshotting ds %llu; in queue; " 929 "replacing with %llu", 930 (u_longlong_t)ds->ds_object, 931 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 932 } 933 dsl_scan_sync_state(scn, tx); 934} 935 936void 937dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx) 938{ 939 dsl_pool_t *dp = ds1->ds_dir->dd_pool; 940 dsl_scan_t *scn = dp->dp_scan; 941 uint64_t mintxg; 942 943 if (scn->scn_phys.scn_state != DSS_SCANNING) 944 return; 945 946 if (scn->scn_phys.scn_bookmark.zb_objset == ds1->ds_object) { 947 scn->scn_phys.scn_bookmark.zb_objset = ds2->ds_object; 948 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 949 "reset zb_objset to %llu", 950 (u_longlong_t)ds1->ds_object, 951 (u_longlong_t)ds2->ds_object); 952 } else if (scn->scn_phys.scn_bookmark.zb_objset == ds2->ds_object) { 953 scn->scn_phys.scn_bookmark.zb_objset = ds1->ds_object; 954 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 955 "reset zb_objset to %llu", 956 (u_longlong_t)ds2->ds_object, 957 (u_longlong_t)ds1->ds_object); 958 } 959 960 if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 961 ds1->ds_object, &mintxg) == 0) { 962 int err; 963 964 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 965 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 966 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 967 scn->scn_phys.scn_queue_obj, ds1->ds_object, tx)); 968 err = zap_add_int_key(dp->dp_meta_objset, 969 scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg, tx); 970 VERIFY(err == 0 || err == EEXIST); 971 if (err == EEXIST) { 972 /* Both were there to begin with */ 973 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 974 scn->scn_phys.scn_queue_obj, 975 ds1->ds_object, mintxg, tx)); 976 } 977 zfs_dbgmsg("clone_swap ds %llu; in queue; " 978 "replacing with %llu", 979 (u_longlong_t)ds1->ds_object, 980 (u_longlong_t)ds2->ds_object); 981 } else if (zap_lookup_int_key(dp->dp_meta_objset, 982 scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg) == 0) { 983 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 984 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 985 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 986 scn->scn_phys.scn_queue_obj, ds2->ds_object, tx)); 987 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 988 scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg, tx)); 989 zfs_dbgmsg("clone_swap ds %llu; in queue; " 990 "replacing with %llu", 991 (u_longlong_t)ds2->ds_object, 992 (u_longlong_t)ds1->ds_object); 993 } 994 995 dsl_scan_sync_state(scn, tx); 996} 997 998struct enqueue_clones_arg { 999 dmu_tx_t *tx; 1000 uint64_t originobj; 1001}; 1002 1003/* ARGSUSED */ 1004static int 1005enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1006{ 1007 struct enqueue_clones_arg *eca = arg; 1008 dsl_dataset_t *ds; 1009 int err; 1010 dsl_scan_t *scn = dp->dp_scan; 1011 1012 if (dsl_dir_phys(hds->ds_dir)->dd_origin_obj != eca->originobj) 1013 return (0); 1014 1015 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1016 if (err) 1017 return (err); 1018 1019 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != eca->originobj) { 1020 dsl_dataset_t *prev; 1021 err = dsl_dataset_hold_obj(dp, 1022 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1023 1024 dsl_dataset_rele(ds, FTAG); 1025 if (err) 1026 return (err); 1027 ds = prev; 1028 } 1029 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1030 scn->scn_phys.scn_queue_obj, ds->ds_object, 1031 dsl_dataset_phys(ds)->ds_prev_snap_txg, eca->tx) == 0); 1032 dsl_dataset_rele(ds, FTAG); 1033 return (0); 1034} 1035 1036static void 1037dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx) 1038{ 1039 dsl_pool_t *dp = scn->scn_dp; 1040 dsl_dataset_t *ds; 1041 objset_t *os; 1042 1043 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1044 1045 if (dmu_objset_from_ds(ds, &os)) 1046 goto out; 1047 1048 /* 1049 * Only the ZIL in the head (non-snapshot) is valid. Even though 1050 * snapshots can have ZIL block pointers (which may be the same 1051 * BP as in the head), they must be ignored. So we traverse the 1052 * ZIL here, rather than in scan_recurse(), because the regular 1053 * snapshot block-sharing rules don't apply to it. 1054 */ 1055 if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !ds->ds_is_snapshot) 1056 dsl_scan_zil(dp, &os->os_zil_header); 1057 1058 /* 1059 * Iterate over the bps in this ds. 1060 */ 1061 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1062 dsl_scan_visit_rootbp(scn, ds, &dsl_dataset_phys(ds)->ds_bp, tx); 1063 1064 char *dsname = kmem_alloc(ZFS_MAXNAMELEN, KM_SLEEP); 1065 dsl_dataset_name(ds, dsname); 1066 zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; " 1067 "pausing=%u", 1068 (longlong_t)dsobj, dsname, 1069 (longlong_t)scn->scn_phys.scn_cur_min_txg, 1070 (longlong_t)scn->scn_phys.scn_cur_max_txg, 1071 (int)scn->scn_pausing); 1072 kmem_free(dsname, ZFS_MAXNAMELEN); 1073 1074 if (scn->scn_pausing) 1075 goto out; 1076 1077 /* 1078 * We've finished this pass over this dataset. 1079 */ 1080 1081 /* 1082 * If we did not completely visit this dataset, do another pass. 1083 */ 1084 if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) { 1085 zfs_dbgmsg("incomplete pass; visiting again"); 1086 scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN; 1087 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1088 scn->scn_phys.scn_queue_obj, ds->ds_object, 1089 scn->scn_phys.scn_cur_max_txg, tx) == 0); 1090 goto out; 1091 } 1092 1093 /* 1094 * Add descendent datasets to work queue. 1095 */ 1096 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) { 1097 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1098 scn->scn_phys.scn_queue_obj, 1099 dsl_dataset_phys(ds)->ds_next_snap_obj, 1100 dsl_dataset_phys(ds)->ds_creation_txg, tx) == 0); 1101 } 1102 if (dsl_dataset_phys(ds)->ds_num_children > 1) { 1103 boolean_t usenext = B_FALSE; 1104 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) { 1105 uint64_t count; 1106 /* 1107 * A bug in a previous version of the code could 1108 * cause upgrade_clones_cb() to not set 1109 * ds_next_snap_obj when it should, leading to a 1110 * missing entry. Therefore we can only use the 1111 * next_clones_obj when its count is correct. 1112 */ 1113 int err = zap_count(dp->dp_meta_objset, 1114 dsl_dataset_phys(ds)->ds_next_clones_obj, &count); 1115 if (err == 0 && 1116 count == dsl_dataset_phys(ds)->ds_num_children - 1) 1117 usenext = B_TRUE; 1118 } 1119 1120 if (usenext) { 1121 VERIFY0(zap_join_key(dp->dp_meta_objset, 1122 dsl_dataset_phys(ds)->ds_next_clones_obj, 1123 scn->scn_phys.scn_queue_obj, 1124 dsl_dataset_phys(ds)->ds_creation_txg, tx)); 1125 } else { 1126 struct enqueue_clones_arg eca; 1127 eca.tx = tx; 1128 eca.originobj = ds->ds_object; 1129 1130 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1131 enqueue_clones_cb, &eca, DS_FIND_CHILDREN)); 1132 } 1133 } 1134 1135out: 1136 dsl_dataset_rele(ds, FTAG); 1137} 1138 1139/* ARGSUSED */ 1140static int 1141enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1142{ 1143 dmu_tx_t *tx = arg; 1144 dsl_dataset_t *ds; 1145 int err; 1146 dsl_scan_t *scn = dp->dp_scan; 1147 1148 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1149 if (err) 1150 return (err); 1151 1152 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 1153 dsl_dataset_t *prev; 1154 err = dsl_dataset_hold_obj(dp, 1155 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1156 if (err) { 1157 dsl_dataset_rele(ds, FTAG); 1158 return (err); 1159 } 1160 1161 /* 1162 * If this is a clone, we don't need to worry about it for now. 1163 */ 1164 if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object) { 1165 dsl_dataset_rele(ds, FTAG); 1166 dsl_dataset_rele(prev, FTAG); 1167 return (0); 1168 } 1169 dsl_dataset_rele(ds, FTAG); 1170 ds = prev; 1171 } 1172 1173 VERIFY(zap_add_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 1174 ds->ds_object, dsl_dataset_phys(ds)->ds_prev_snap_txg, tx) == 0); 1175 dsl_dataset_rele(ds, FTAG); 1176 return (0); 1177} 1178 1179/* 1180 * Scrub/dedup interaction. 1181 * 1182 * If there are N references to a deduped block, we don't want to scrub it 1183 * N times -- ideally, we should scrub it exactly once. 1184 * 1185 * We leverage the fact that the dde's replication class (enum ddt_class) 1186 * is ordered from highest replication class (DDT_CLASS_DITTO) to lowest 1187 * (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order. 1188 * 1189 * To prevent excess scrubbing, the scrub begins by walking the DDT 1190 * to find all blocks with refcnt > 1, and scrubs each of these once. 1191 * Since there are two replication classes which contain blocks with 1192 * refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first. 1193 * Finally the top-down scrub begins, only visiting blocks with refcnt == 1. 1194 * 1195 * There would be nothing more to say if a block's refcnt couldn't change 1196 * during a scrub, but of course it can so we must account for changes 1197 * in a block's replication class. 1198 * 1199 * Here's an example of what can occur: 1200 * 1201 * If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1 1202 * when visited during the top-down scrub phase, it will be scrubbed twice. 1203 * This negates our scrub optimization, but is otherwise harmless. 1204 * 1205 * If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1 1206 * on each visit during the top-down scrub phase, it will never be scrubbed. 1207 * To catch this, ddt_sync_entry() notifies the scrub code whenever a block's 1208 * reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to 1209 * DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1 1210 * while a scrub is in progress, it scrubs the block right then. 1211 */ 1212static void 1213dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx) 1214{ 1215 ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark; 1216 ddt_entry_t dde = { 0 }; 1217 int error; 1218 uint64_t n = 0; 1219 1220 while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) { 1221 ddt_t *ddt; 1222 1223 if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max) 1224 break; 1225 dprintf("visiting ddb=%llu/%llu/%llu/%llx\n", 1226 (longlong_t)ddb->ddb_class, 1227 (longlong_t)ddb->ddb_type, 1228 (longlong_t)ddb->ddb_checksum, 1229 (longlong_t)ddb->ddb_cursor); 1230 1231 /* There should be no pending changes to the dedup table */ 1232 ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum]; 1233 ASSERT(avl_first(&ddt->ddt_tree) == NULL); 1234 1235 dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx); 1236 n++; 1237 1238 if (dsl_scan_check_pause(scn, NULL)) 1239 break; 1240 } 1241 1242 zfs_dbgmsg("scanned %llu ddt entries with class_max = %u; pausing=%u", 1243 (longlong_t)n, (int)scn->scn_phys.scn_ddt_class_max, 1244 (int)scn->scn_pausing); 1245 1246 ASSERT(error == 0 || error == ENOENT); 1247 ASSERT(error != ENOENT || 1248 ddb->ddb_class > scn->scn_phys.scn_ddt_class_max); 1249} 1250 1251/* ARGSUSED */ 1252void 1253dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum, 1254 ddt_entry_t *dde, dmu_tx_t *tx) 1255{ 1256 const ddt_key_t *ddk = &dde->dde_key; 1257 ddt_phys_t *ddp = dde->dde_phys; 1258 blkptr_t bp; 1259 zbookmark_phys_t zb = { 0 }; 1260 1261 if (scn->scn_phys.scn_state != DSS_SCANNING) 1262 return; 1263 1264 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1265 if (ddp->ddp_phys_birth == 0 || 1266 ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg) 1267 continue; 1268 ddt_bp_create(checksum, ddk, ddp, &bp); 1269 1270 scn->scn_visited_this_txg++; 1271 scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb); 1272 } 1273} 1274 1275static void 1276dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx) 1277{ 1278 dsl_pool_t *dp = scn->scn_dp; 1279 zap_cursor_t zc; 1280 zap_attribute_t za; 1281 1282 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1283 scn->scn_phys.scn_ddt_class_max) { 1284 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1285 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1286 dsl_scan_ddt(scn, tx); 1287 if (scn->scn_pausing) 1288 return; 1289 } 1290 1291 if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) { 1292 /* First do the MOS & ORIGIN */ 1293 1294 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1295 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1296 dsl_scan_visit_rootbp(scn, NULL, 1297 &dp->dp_meta_rootbp, tx); 1298 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); 1299 if (scn->scn_pausing) 1300 return; 1301 1302 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) { 1303 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1304 enqueue_cb, tx, DS_FIND_CHILDREN)); 1305 } else { 1306 dsl_scan_visitds(scn, 1307 dp->dp_origin_snap->ds_object, tx); 1308 } 1309 ASSERT(!scn->scn_pausing); 1310 } else if (scn->scn_phys.scn_bookmark.zb_objset != 1311 ZB_DESTROYED_OBJSET) { 1312 /* 1313 * If we were paused, continue from here. Note if the 1314 * ds we were paused on was deleted, the zb_objset may 1315 * be -1, so we will skip this and find a new objset 1316 * below. 1317 */ 1318 dsl_scan_visitds(scn, scn->scn_phys.scn_bookmark.zb_objset, tx); 1319 if (scn->scn_pausing) 1320 return; 1321 } 1322 1323 /* 1324 * In case we were paused right at the end of the ds, zero the 1325 * bookmark so we don't think that we're still trying to resume. 1326 */ 1327 bzero(&scn->scn_phys.scn_bookmark, sizeof (zbookmark_phys_t)); 1328 1329 /* keep pulling things out of the zap-object-as-queue */ 1330 while (zap_cursor_init(&zc, dp->dp_meta_objset, 1331 scn->scn_phys.scn_queue_obj), 1332 zap_cursor_retrieve(&zc, &za) == 0) { 1333 dsl_dataset_t *ds; 1334 uint64_t dsobj; 1335 1336 dsobj = strtonum(za.za_name, NULL); 1337 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 1338 scn->scn_phys.scn_queue_obj, dsobj, tx)); 1339 1340 /* Set up min/max txg */ 1341 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1342 if (za.za_first_integer != 0) { 1343 scn->scn_phys.scn_cur_min_txg = 1344 MAX(scn->scn_phys.scn_min_txg, 1345 za.za_first_integer); 1346 } else { 1347 scn->scn_phys.scn_cur_min_txg = 1348 MAX(scn->scn_phys.scn_min_txg, 1349 dsl_dataset_phys(ds)->ds_prev_snap_txg); 1350 } 1351 scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds); 1352 dsl_dataset_rele(ds, FTAG); 1353 1354 dsl_scan_visitds(scn, dsobj, tx); 1355 zap_cursor_fini(&zc); 1356 if (scn->scn_pausing) 1357 return; 1358 } 1359 zap_cursor_fini(&zc); 1360} 1361 1362static boolean_t 1363dsl_scan_free_should_pause(dsl_scan_t *scn) 1364{ 1365 uint64_t elapsed_nanosecs; 1366 1367 if (zfs_recover) 1368 return (B_FALSE); 1369 1370 if (scn->scn_visited_this_txg >= zfs_free_max_blocks) 1371 return (B_TRUE); 1372 1373 elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 1374 return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || 1375 (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms && 1376 txg_sync_waiting(scn->scn_dp)) || 1377 spa_shutting_down(scn->scn_dp->dp_spa)); 1378} 1379 1380static int 1381dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1382{ 1383 dsl_scan_t *scn = arg; 1384 1385 if (!scn->scn_is_bptree || 1386 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) { 1387 if (dsl_scan_free_should_pause(scn)) 1388 return (SET_ERROR(ERESTART)); 1389 } 1390 1391 zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa, 1392 dmu_tx_get_txg(tx), bp, BP_GET_PSIZE(bp), 0)); 1393 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD, 1394 -bp_get_dsize_sync(scn->scn_dp->dp_spa, bp), 1395 -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx); 1396 scn->scn_visited_this_txg++; 1397 return (0); 1398} 1399 1400boolean_t 1401dsl_scan_active(dsl_scan_t *scn) 1402{ 1403 spa_t *spa = scn->scn_dp->dp_spa; 1404 uint64_t used = 0, comp, uncomp; 1405 1406 if (spa->spa_load_state != SPA_LOAD_NONE) 1407 return (B_FALSE); 1408 if (spa_shutting_down(spa)) 1409 return (B_FALSE); 1410 if (scn->scn_phys.scn_state == DSS_SCANNING || 1411 (scn->scn_async_destroying && !scn->scn_async_stalled)) 1412 return (B_TRUE); 1413 1414 if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1415 (void) bpobj_space(&scn->scn_dp->dp_free_bpobj, 1416 &used, &comp, &uncomp); 1417 } 1418 return (used != 0); 1419} 1420 1421void 1422dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) 1423{ 1424 dsl_scan_t *scn = dp->dp_scan; 1425 spa_t *spa = dp->dp_spa; 1426 int err = 0; 1427 1428 /* 1429 * Check for scn_restart_txg before checking spa_load_state, so 1430 * that we can restart an old-style scan while the pool is being 1431 * imported (see dsl_scan_init). 1432 */ 1433 if (scn->scn_restart_txg != 0 && 1434 scn->scn_restart_txg <= tx->tx_txg) { 1435 pool_scan_func_t func = POOL_SCAN_SCRUB; 1436 dsl_scan_done(scn, B_FALSE, tx); 1437 if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) 1438 func = POOL_SCAN_RESILVER; 1439 zfs_dbgmsg("restarting scan func=%u txg=%llu", 1440 func, tx->tx_txg); 1441 dsl_scan_setup_sync(&func, tx); 1442 } 1443 1444 /* 1445 * If the scan is inactive due to a stalled async destroy, try again. 1446 */ 1447 if ((!scn->scn_async_stalled && !dsl_scan_active(scn)) || 1448 spa_sync_pass(dp->dp_spa) > 1) 1449 return; 1450 1451 scn->scn_visited_this_txg = 0; 1452 scn->scn_pausing = B_FALSE; 1453 scn->scn_sync_start_time = gethrtime(); 1454 spa->spa_scrub_active = B_TRUE; 1455 1456 /* 1457 * First process the async destroys. If we pause, don't do 1458 * any scrubbing or resilvering. This ensures that there are no 1459 * async destroys while we are scanning, so the scan code doesn't 1460 * have to worry about traversing it. It is also faster to free the 1461 * blocks than to scrub them. 1462 */ 1463 if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1464 scn->scn_is_bptree = B_FALSE; 1465 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1466 NULL, ZIO_FLAG_MUSTSUCCEED); 1467 err = bpobj_iterate(&dp->dp_free_bpobj, 1468 dsl_scan_free_block_cb, scn, tx); 1469 VERIFY3U(0, ==, zio_wait(scn->scn_zio_root)); 1470 1471 if (err != 0 && err != ERESTART) 1472 zfs_panic_recover("error %u from bpobj_iterate()", err); 1473 } 1474 1475 if (err == 0 && spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) { 1476 ASSERT(scn->scn_async_destroying); 1477 scn->scn_is_bptree = B_TRUE; 1478 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1479 NULL, ZIO_FLAG_MUSTSUCCEED); 1480 err = bptree_iterate(dp->dp_meta_objset, 1481 dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, scn, tx); 1482 VERIFY0(zio_wait(scn->scn_zio_root)); 1483 1484 if (err == EIO || err == ECKSUM) { 1485 err = 0; 1486 } else if (err != 0 && err != ERESTART) { 1487 zfs_panic_recover("error %u from " 1488 "traverse_dataset_destroyed()", err); 1489 } 1490 1491 if (bptree_is_empty(dp->dp_meta_objset, dp->dp_bptree_obj)) { 1492 /* finished; deactivate async destroy feature */ 1493 spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, tx); 1494 ASSERT(!spa_feature_is_active(spa, 1495 SPA_FEATURE_ASYNC_DESTROY)); 1496 VERIFY0(zap_remove(dp->dp_meta_objset, 1497 DMU_POOL_DIRECTORY_OBJECT, 1498 DMU_POOL_BPTREE_OBJ, tx)); 1499 VERIFY0(bptree_free(dp->dp_meta_objset, 1500 dp->dp_bptree_obj, tx)); 1501 dp->dp_bptree_obj = 0; 1502 scn->scn_async_destroying = B_FALSE; 1503 scn->scn_async_stalled = B_FALSE; 1504 } else { 1505 /* 1506 * If we didn't make progress, mark the async 1507 * destroy as stalled, so that we will not initiate 1508 * a spa_sync() on its behalf. Note that we only 1509 * check this if we are not finished, because if the 1510 * bptree had no blocks for us to visit, we can 1511 * finish without "making progress". 1512 */ 1513 scn->scn_async_stalled = 1514 (scn->scn_visited_this_txg == 0); 1515 } 1516 } 1517 if (scn->scn_visited_this_txg) { 1518 zfs_dbgmsg("freed %llu blocks in %llums from " 1519 "free_bpobj/bptree txg %llu; err=%d", 1520 (longlong_t)scn->scn_visited_this_txg, 1521 (longlong_t) 1522 NSEC2MSEC(gethrtime() - scn->scn_sync_start_time), 1523 (longlong_t)tx->tx_txg, err); 1524 scn->scn_visited_this_txg = 0; 1525 1526 /* 1527 * Write out changes to the DDT that may be required as a 1528 * result of the blocks freed. This ensures that the DDT 1529 * is clean when a scrub/resilver runs. 1530 */ 1531 ddt_sync(spa, tx->tx_txg); 1532 } 1533 if (err != 0) 1534 return; 1535 if (!scn->scn_async_destroying && zfs_free_leak_on_eio && 1536 (dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes != 0 || 1537 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes != 0 || 1538 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes != 0)) { 1539 /* 1540 * We have finished background destroying, but there is still 1541 * some space left in the dp_free_dir. Transfer this leaked 1542 * space to the dp_leak_dir. 1543 */ 1544 if (dp->dp_leak_dir == NULL) { 1545 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); 1546 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, 1547 LEAK_DIR_NAME, tx); 1548 VERIFY0(dsl_pool_open_special_dir(dp, 1549 LEAK_DIR_NAME, &dp->dp_leak_dir)); 1550 rrw_exit(&dp->dp_config_rwlock, FTAG); 1551 } 1552 dsl_dir_diduse_space(dp->dp_leak_dir, DD_USED_HEAD, 1553 dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1554 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1555 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1556 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 1557 -dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1558 -dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1559 -dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1560 } 1561 if (!scn->scn_async_destroying) { 1562 /* finished; verify that space accounting went to zero */ 1563 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes); 1564 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes); 1565 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes); 1566 } 1567 1568 if (scn->scn_phys.scn_state != DSS_SCANNING) 1569 return; 1570 1571 if (scn->scn_done_txg == tx->tx_txg) { 1572 ASSERT(!scn->scn_pausing); 1573 /* finished with scan. */ 1574 zfs_dbgmsg("txg %llu scan complete", tx->tx_txg); 1575 dsl_scan_done(scn, B_TRUE, tx); 1576 ASSERT3U(spa->spa_scrub_inflight, ==, 0); 1577 dsl_scan_sync_state(scn, tx); 1578 return; 1579 } 1580 1581 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1582 scn->scn_phys.scn_ddt_class_max) { 1583 zfs_dbgmsg("doing scan sync txg %llu; " 1584 "ddt bm=%llu/%llu/%llu/%llx", 1585 (longlong_t)tx->tx_txg, 1586 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 1587 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 1588 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 1589 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 1590 ASSERT(scn->scn_phys.scn_bookmark.zb_objset == 0); 1591 ASSERT(scn->scn_phys.scn_bookmark.zb_object == 0); 1592 ASSERT(scn->scn_phys.scn_bookmark.zb_level == 0); 1593 ASSERT(scn->scn_phys.scn_bookmark.zb_blkid == 0); 1594 } else { 1595 zfs_dbgmsg("doing scan sync txg %llu; bm=%llu/%llu/%llu/%llu", 1596 (longlong_t)tx->tx_txg, 1597 (longlong_t)scn->scn_phys.scn_bookmark.zb_objset, 1598 (longlong_t)scn->scn_phys.scn_bookmark.zb_object, 1599 (longlong_t)scn->scn_phys.scn_bookmark.zb_level, 1600 (longlong_t)scn->scn_phys.scn_bookmark.zb_blkid); 1601 } 1602 1603 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1604 NULL, ZIO_FLAG_CANFAIL); 1605 dsl_pool_config_enter(dp, FTAG); 1606 dsl_scan_visit(scn, tx); 1607 dsl_pool_config_exit(dp, FTAG); 1608 (void) zio_wait(scn->scn_zio_root); 1609 scn->scn_zio_root = NULL; 1610 1611 zfs_dbgmsg("visited %llu blocks in %llums", 1612 (longlong_t)scn->scn_visited_this_txg, 1613 (longlong_t)NSEC2MSEC(gethrtime() - scn->scn_sync_start_time)); 1614 1615 if (!scn->scn_pausing) { 1616 scn->scn_done_txg = tx->tx_txg + 1; 1617 zfs_dbgmsg("txg %llu traversal complete, waiting till txg %llu", 1618 tx->tx_txg, scn->scn_done_txg); 1619 } 1620 1621 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 1622 mutex_enter(&spa->spa_scrub_lock); 1623 while (spa->spa_scrub_inflight > 0) { 1624 cv_wait(&spa->spa_scrub_io_cv, 1625 &spa->spa_scrub_lock); 1626 } 1627 mutex_exit(&spa->spa_scrub_lock); 1628 } 1629 1630 dsl_scan_sync_state(scn, tx); 1631} 1632 1633/* 1634 * This will start a new scan, or restart an existing one. 1635 */ 1636void 1637dsl_resilver_restart(dsl_pool_t *dp, uint64_t txg) 1638{ 1639 if (txg == 0) { 1640 dmu_tx_t *tx; 1641 tx = dmu_tx_create_dd(dp->dp_mos_dir); 1642 VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT)); 1643 1644 txg = dmu_tx_get_txg(tx); 1645 dp->dp_scan->scn_restart_txg = txg; 1646 dmu_tx_commit(tx); 1647 } else { 1648 dp->dp_scan->scn_restart_txg = txg; 1649 } 1650 zfs_dbgmsg("restarting resilver txg=%llu", txg); 1651} 1652 1653boolean_t 1654dsl_scan_resilvering(dsl_pool_t *dp) 1655{ 1656 return (dp->dp_scan->scn_phys.scn_state == DSS_SCANNING && 1657 dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER); 1658} 1659 1660/* 1661 * scrub consumers 1662 */ 1663 1664static void 1665count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp) 1666{ 1667 int i; 1668 1669 /* 1670 * If we resume after a reboot, zab will be NULL; don't record 1671 * incomplete stats in that case. 1672 */ 1673 if (zab == NULL) 1674 return; 1675 1676 for (i = 0; i < 4; i++) { 1677 int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS; 1678 int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL; 1679 if (t & DMU_OT_NEWTYPE) 1680 t = DMU_OT_OTHER; 1681 zfs_blkstat_t *zb = &zab->zab_type[l][t]; 1682 int equal; 1683 1684 zb->zb_count++; 1685 zb->zb_asize += BP_GET_ASIZE(bp); 1686 zb->zb_lsize += BP_GET_LSIZE(bp); 1687 zb->zb_psize += BP_GET_PSIZE(bp); 1688 zb->zb_gangs += BP_COUNT_GANG(bp); 1689 1690 switch (BP_GET_NDVAS(bp)) { 1691 case 2: 1692 if (DVA_GET_VDEV(&bp->blk_dva[0]) == 1693 DVA_GET_VDEV(&bp->blk_dva[1])) 1694 zb->zb_ditto_2_of_2_samevdev++; 1695 break; 1696 case 3: 1697 equal = (DVA_GET_VDEV(&bp->blk_dva[0]) == 1698 DVA_GET_VDEV(&bp->blk_dva[1])) + 1699 (DVA_GET_VDEV(&bp->blk_dva[0]) == 1700 DVA_GET_VDEV(&bp->blk_dva[2])) + 1701 (DVA_GET_VDEV(&bp->blk_dva[1]) == 1702 DVA_GET_VDEV(&bp->blk_dva[2])); 1703 if (equal == 1) 1704 zb->zb_ditto_2_of_3_samevdev++; 1705 else if (equal == 3) 1706 zb->zb_ditto_3_of_3_samevdev++; 1707 break; 1708 } 1709 } 1710} 1711 1712static void 1713dsl_scan_scrub_done(zio_t *zio) 1714{ 1715 spa_t *spa = zio->io_spa; 1716 1717 zio_data_buf_free(zio->io_data, zio->io_size); 1718 1719 mutex_enter(&spa->spa_scrub_lock); 1720 spa->spa_scrub_inflight--; 1721 cv_broadcast(&spa->spa_scrub_io_cv); 1722 1723 if (zio->io_error && (zio->io_error != ECKSUM || 1724 !(zio->io_flags & ZIO_FLAG_SPECULATIVE))) { 1725 spa->spa_dsl_pool->dp_scan->scn_phys.scn_errors++; 1726 } 1727 mutex_exit(&spa->spa_scrub_lock); 1728} 1729 1730static int 1731dsl_scan_scrub_cb(dsl_pool_t *dp, 1732 const blkptr_t *bp, const zbookmark_phys_t *zb) 1733{ 1734 dsl_scan_t *scn = dp->dp_scan; 1735 size_t size = BP_GET_PSIZE(bp); 1736 spa_t *spa = dp->dp_spa; 1737 uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp); 1738 boolean_t needs_io; 1739 int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL; 1740 unsigned int scan_delay = 0; 1741 1742 if (phys_birth <= scn->scn_phys.scn_min_txg || 1743 phys_birth >= scn->scn_phys.scn_max_txg) 1744 return (0); 1745 1746 count_block(dp->dp_blkstats, bp); 1747 1748 if (BP_IS_EMBEDDED(bp)) 1749 return (0); 1750 1751 ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn)); 1752 if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) { 1753 zio_flags |= ZIO_FLAG_SCRUB; 1754 needs_io = B_TRUE; 1755 scan_delay = zfs_scrub_delay; 1756 } else { 1757 ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER); 1758 zio_flags |= ZIO_FLAG_RESILVER; 1759 needs_io = B_FALSE; 1760 scan_delay = zfs_resilver_delay; 1761 } 1762 1763 /* If it's an intent log block, failure is expected. */ 1764 if (zb->zb_level == ZB_ZIL_LEVEL) 1765 zio_flags |= ZIO_FLAG_SPECULATIVE; 1766 1767 for (int d = 0; d < BP_GET_NDVAS(bp); d++) { 1768 vdev_t *vd = vdev_lookup_top(spa, 1769 DVA_GET_VDEV(&bp->blk_dva[d])); 1770 1771 /* 1772 * Keep track of how much data we've examined so that 1773 * zpool(1M) status can make useful progress reports. 1774 */ 1775 scn->scn_phys.scn_examined += DVA_GET_ASIZE(&bp->blk_dva[d]); 1776 spa->spa_scan_pass_exam += DVA_GET_ASIZE(&bp->blk_dva[d]); 1777 1778 /* if it's a resilver, this may not be in the target range */ 1779 if (!needs_io) { 1780 if (DVA_GET_GANG(&bp->blk_dva[d])) { 1781 /* 1782 * Gang members may be spread across multiple 1783 * vdevs, so the best estimate we have is the 1784 * scrub range, which has already been checked. 1785 * XXX -- it would be better to change our 1786 * allocation policy to ensure that all 1787 * gang members reside on the same vdev. 1788 */ 1789 needs_io = B_TRUE; 1790 } else { 1791 needs_io = vdev_dtl_contains(vd, DTL_PARTIAL, 1792 phys_birth, 1); 1793 } 1794 } 1795 } 1796 1797 if (needs_io && !zfs_no_scrub_io) { 1798 vdev_t *rvd = spa->spa_root_vdev; 1799 uint64_t maxinflight = rvd->vdev_children * 1800 MAX(zfs_top_maxinflight, 1); 1801 void *data = zio_data_buf_alloc(size); 1802 1803 mutex_enter(&spa->spa_scrub_lock); 1804 while (spa->spa_scrub_inflight >= maxinflight) 1805 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock); 1806 spa->spa_scrub_inflight++; 1807 mutex_exit(&spa->spa_scrub_lock); 1808 1809 /* 1810 * If we're seeing recent (zfs_scan_idle) "important" I/Os 1811 * then throttle our workload to limit the impact of a scan. 1812 */ 1813 if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle) 1814 delay(MAX((int)scan_delay, 0)); 1815 1816 zio_nowait(zio_read(NULL, spa, bp, data, size, 1817 dsl_scan_scrub_done, NULL, ZIO_PRIORITY_SCRUB, 1818 zio_flags, zb)); 1819 } 1820 1821 /* do not relocate this block */ 1822 return (0); 1823} 1824 1825int 1826dsl_scan(dsl_pool_t *dp, pool_scan_func_t func) 1827{ 1828 spa_t *spa = dp->dp_spa; 1829 1830 /* 1831 * Purge all vdev caches and probe all devices. We do this here 1832 * rather than in sync context because this requires a writer lock 1833 * on the spa_config lock, which we can't do from sync context. The 1834 * spa_scrub_reopen flag indicates that vdev_open() should not 1835 * attempt to start another scrub. 1836 */ 1837 spa_vdev_state_enter(spa, SCL_NONE); 1838 spa->spa_scrub_reopen = B_TRUE; 1839 vdev_reopen(spa->spa_root_vdev); 1840 spa->spa_scrub_reopen = B_FALSE; 1841 (void) spa_vdev_state_exit(spa, NULL, 0); 1842 1843 return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check, 1844 dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_NONE)); 1845} 1846