dsl_scan.c revision 290747
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, 2015 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/* 115 * Enable/disable the processing of the free_bpobj object. 116 */ 117boolean_t zfs_free_bpobj_enabled = B_TRUE; 118 119SYSCTL_INT(_vfs_zfs, OID_AUTO, free_bpobj_enabled, CTLFLAG_RWTUN, 120 &zfs_free_bpobj_enabled, 0, "Enable free_bpobj processing"); 121 122/* the order has to match pool_scan_type */ 123static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = { 124 NULL, 125 dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */ 126 dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */ 127}; 128 129int 130dsl_scan_init(dsl_pool_t *dp, uint64_t txg) 131{ 132 int err; 133 dsl_scan_t *scn; 134 spa_t *spa = dp->dp_spa; 135 uint64_t f; 136 137 scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP); 138 scn->scn_dp = dp; 139 140 /* 141 * It's possible that we're resuming a scan after a reboot so 142 * make sure that the scan_async_destroying flag is initialized 143 * appropriately. 144 */ 145 ASSERT(!scn->scn_async_destroying); 146 scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa, 147 SPA_FEATURE_ASYNC_DESTROY); 148 149 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 150 "scrub_func", sizeof (uint64_t), 1, &f); 151 if (err == 0) { 152 /* 153 * There was an old-style scrub in progress. Restart a 154 * new-style scrub from the beginning. 155 */ 156 scn->scn_restart_txg = txg; 157 zfs_dbgmsg("old-style scrub was in progress; " 158 "restarting new-style scrub in txg %llu", 159 scn->scn_restart_txg); 160 161 /* 162 * Load the queue obj from the old location so that it 163 * can be freed by dsl_scan_done(). 164 */ 165 (void) zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 166 "scrub_queue", sizeof (uint64_t), 1, 167 &scn->scn_phys.scn_queue_obj); 168 } else { 169 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 170 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 171 &scn->scn_phys); 172 if (err == ENOENT) 173 return (0); 174 else if (err) 175 return (err); 176 177 if (scn->scn_phys.scn_state == DSS_SCANNING && 178 spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) { 179 /* 180 * A new-type scrub was in progress on an old 181 * pool, and the pool was accessed by old 182 * software. Restart from the beginning, since 183 * the old software may have changed the pool in 184 * the meantime. 185 */ 186 scn->scn_restart_txg = txg; 187 zfs_dbgmsg("new-style scrub was modified " 188 "by old software; restarting in txg %llu", 189 scn->scn_restart_txg); 190 } 191 } 192 193 spa_scan_stat_init(spa); 194 return (0); 195} 196 197void 198dsl_scan_fini(dsl_pool_t *dp) 199{ 200 if (dp->dp_scan) { 201 kmem_free(dp->dp_scan, sizeof (dsl_scan_t)); 202 dp->dp_scan = NULL; 203 } 204} 205 206/* ARGSUSED */ 207static int 208dsl_scan_setup_check(void *arg, dmu_tx_t *tx) 209{ 210 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 211 212 if (scn->scn_phys.scn_state == DSS_SCANNING) 213 return (SET_ERROR(EBUSY)); 214 215 return (0); 216} 217 218static void 219dsl_scan_setup_sync(void *arg, dmu_tx_t *tx) 220{ 221 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 222 pool_scan_func_t *funcp = arg; 223 dmu_object_type_t ot = 0; 224 dsl_pool_t *dp = scn->scn_dp; 225 spa_t *spa = dp->dp_spa; 226 227 ASSERT(scn->scn_phys.scn_state != DSS_SCANNING); 228 ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS); 229 bzero(&scn->scn_phys, sizeof (scn->scn_phys)); 230 scn->scn_phys.scn_func = *funcp; 231 scn->scn_phys.scn_state = DSS_SCANNING; 232 scn->scn_phys.scn_min_txg = 0; 233 scn->scn_phys.scn_max_txg = tx->tx_txg; 234 scn->scn_phys.scn_ddt_class_max = DDT_CLASSES - 1; /* the entire DDT */ 235 scn->scn_phys.scn_start_time = gethrestime_sec(); 236 scn->scn_phys.scn_errors = 0; 237 scn->scn_phys.scn_to_examine = spa->spa_root_vdev->vdev_stat.vs_alloc; 238 scn->scn_restart_txg = 0; 239 scn->scn_done_txg = 0; 240 spa_scan_stat_init(spa); 241 242 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 243 scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max; 244 245 /* rewrite all disk labels */ 246 vdev_config_dirty(spa->spa_root_vdev); 247 248 if (vdev_resilver_needed(spa->spa_root_vdev, 249 &scn->scn_phys.scn_min_txg, &scn->scn_phys.scn_max_txg)) { 250 spa_event_notify(spa, NULL, ESC_ZFS_RESILVER_START); 251 } else { 252 spa_event_notify(spa, NULL, ESC_ZFS_SCRUB_START); 253 } 254 255 spa->spa_scrub_started = B_TRUE; 256 /* 257 * If this is an incremental scrub, limit the DDT scrub phase 258 * to just the auto-ditto class (for correctness); the rest 259 * of the scrub should go faster using top-down pruning. 260 */ 261 if (scn->scn_phys.scn_min_txg > TXG_INITIAL) 262 scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO; 263 264 } 265 266 /* back to the generic stuff */ 267 268 if (dp->dp_blkstats == NULL) { 269 dp->dp_blkstats = 270 kmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP); 271 } 272 bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); 273 274 if (spa_version(spa) < SPA_VERSION_DSL_SCRUB) 275 ot = DMU_OT_ZAP_OTHER; 276 277 scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset, 278 ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx); 279 280 dsl_scan_sync_state(scn, tx); 281 282 spa_history_log_internal(spa, "scan setup", tx, 283 "func=%u mintxg=%llu maxtxg=%llu", 284 *funcp, scn->scn_phys.scn_min_txg, scn->scn_phys.scn_max_txg); 285} 286 287/* ARGSUSED */ 288static void 289dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx) 290{ 291 static const char *old_names[] = { 292 "scrub_bookmark", 293 "scrub_ddt_bookmark", 294 "scrub_ddt_class_max", 295 "scrub_queue", 296 "scrub_min_txg", 297 "scrub_max_txg", 298 "scrub_func", 299 "scrub_errors", 300 NULL 301 }; 302 303 dsl_pool_t *dp = scn->scn_dp; 304 spa_t *spa = dp->dp_spa; 305 int i; 306 307 /* Remove any remnants of an old-style scrub. */ 308 for (i = 0; old_names[i]; i++) { 309 (void) zap_remove(dp->dp_meta_objset, 310 DMU_POOL_DIRECTORY_OBJECT, old_names[i], tx); 311 } 312 313 if (scn->scn_phys.scn_queue_obj != 0) { 314 VERIFY(0 == dmu_object_free(dp->dp_meta_objset, 315 scn->scn_phys.scn_queue_obj, tx)); 316 scn->scn_phys.scn_queue_obj = 0; 317 } 318 319 /* 320 * If we were "restarted" from a stopped state, don't bother 321 * with anything else. 322 */ 323 if (scn->scn_phys.scn_state != DSS_SCANNING) 324 return; 325 326 if (complete) 327 scn->scn_phys.scn_state = DSS_FINISHED; 328 else 329 scn->scn_phys.scn_state = DSS_CANCELED; 330 331 spa_history_log_internal(spa, "scan done", tx, 332 "complete=%u", complete); 333 334 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 335 mutex_enter(&spa->spa_scrub_lock); 336 while (spa->spa_scrub_inflight > 0) { 337 cv_wait(&spa->spa_scrub_io_cv, 338 &spa->spa_scrub_lock); 339 } 340 mutex_exit(&spa->spa_scrub_lock); 341 spa->spa_scrub_started = B_FALSE; 342 spa->spa_scrub_active = B_FALSE; 343 344 /* 345 * If the scrub/resilver completed, update all DTLs to 346 * reflect this. Whether it succeeded or not, vacate 347 * all temporary scrub DTLs. 348 */ 349 vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg, 350 complete ? scn->scn_phys.scn_max_txg : 0, B_TRUE); 351 if (complete) { 352 spa_event_notify(spa, NULL, scn->scn_phys.scn_min_txg ? 353 ESC_ZFS_RESILVER_FINISH : ESC_ZFS_SCRUB_FINISH); 354 } 355 spa_errlog_rotate(spa); 356 357 /* 358 * We may have finished replacing a device. 359 * Let the async thread assess this and handle the detach. 360 */ 361 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE); 362 } 363 364 scn->scn_phys.scn_end_time = gethrestime_sec(); 365} 366 367/* ARGSUSED */ 368static int 369dsl_scan_cancel_check(void *arg, dmu_tx_t *tx) 370{ 371 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 372 373 if (scn->scn_phys.scn_state != DSS_SCANNING) 374 return (SET_ERROR(ENOENT)); 375 return (0); 376} 377 378/* ARGSUSED */ 379static void 380dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx) 381{ 382 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 383 384 dsl_scan_done(scn, B_FALSE, tx); 385 dsl_scan_sync_state(scn, tx); 386} 387 388int 389dsl_scan_cancel(dsl_pool_t *dp) 390{ 391 return (dsl_sync_task(spa_name(dp->dp_spa), dsl_scan_cancel_check, 392 dsl_scan_cancel_sync, NULL, 3, ZFS_SPACE_CHECK_RESERVED)); 393} 394 395static void dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 396 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 397 dmu_objset_type_t ostype, dmu_tx_t *tx); 398static void dsl_scan_visitdnode(dsl_scan_t *, dsl_dataset_t *ds, 399 dmu_objset_type_t ostype, 400 dnode_phys_t *dnp, uint64_t object, dmu_tx_t *tx); 401 402void 403dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp) 404{ 405 zio_free(dp->dp_spa, txg, bp); 406} 407 408void 409dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp) 410{ 411 ASSERT(dsl_pool_sync_context(dp)); 412 zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, BP_GET_PSIZE(bpp), 413 pio->io_flags)); 414} 415 416static uint64_t 417dsl_scan_ds_maxtxg(dsl_dataset_t *ds) 418{ 419 uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg; 420 if (ds->ds_is_snapshot) 421 return (MIN(smt, dsl_dataset_phys(ds)->ds_creation_txg)); 422 return (smt); 423} 424 425static void 426dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx) 427{ 428 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, 429 DMU_POOL_DIRECTORY_OBJECT, 430 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 431 &scn->scn_phys, tx)); 432} 433 434extern int zfs_vdev_async_write_active_min_dirty_percent; 435 436static boolean_t 437dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_phys_t *zb) 438{ 439 /* we never skip user/group accounting objects */ 440 if (zb && (int64_t)zb->zb_object < 0) 441 return (B_FALSE); 442 443 if (scn->scn_pausing) 444 return (B_TRUE); /* we're already pausing */ 445 446 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark)) 447 return (B_FALSE); /* we're resuming */ 448 449 /* We only know how to resume from level-0 blocks. */ 450 if (zb && zb->zb_level != 0) 451 return (B_FALSE); 452 453 /* 454 * We pause if: 455 * - we have scanned for the maximum time: an entire txg 456 * timeout (default 5 sec) 457 * or 458 * - we have scanned for at least the minimum time (default 1 sec 459 * for scrub, 3 sec for resilver), and either we have sufficient 460 * dirty data that we are starting to write more quickly 461 * (default 30%), or someone is explicitly waiting for this txg 462 * to complete. 463 * or 464 * - the spa is shutting down because this pool is being exported 465 * or the machine is rebooting. 466 */ 467 int mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ? 468 zfs_resilver_min_time_ms : zfs_scan_min_time_ms; 469 uint64_t elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 470 int dirty_pct = scn->scn_dp->dp_dirty_total * 100 / zfs_dirty_data_max; 471 if (elapsed_nanosecs / NANOSEC >= zfs_txg_timeout || 472 (NSEC2MSEC(elapsed_nanosecs) > mintime && 473 (txg_sync_waiting(scn->scn_dp) || 474 dirty_pct >= zfs_vdev_async_write_active_min_dirty_percent)) || 475 spa_shutting_down(scn->scn_dp->dp_spa)) { 476 if (zb) { 477 dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n", 478 (longlong_t)zb->zb_objset, 479 (longlong_t)zb->zb_object, 480 (longlong_t)zb->zb_level, 481 (longlong_t)zb->zb_blkid); 482 scn->scn_phys.scn_bookmark = *zb; 483 } 484 dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n", 485 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 486 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 487 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 488 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 489 scn->scn_pausing = B_TRUE; 490 return (B_TRUE); 491 } 492 return (B_FALSE); 493} 494 495typedef struct zil_scan_arg { 496 dsl_pool_t *zsa_dp; 497 zil_header_t *zsa_zh; 498} zil_scan_arg_t; 499 500/* ARGSUSED */ 501static int 502dsl_scan_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 503{ 504 zil_scan_arg_t *zsa = arg; 505 dsl_pool_t *dp = zsa->zsa_dp; 506 dsl_scan_t *scn = dp->dp_scan; 507 zil_header_t *zh = zsa->zsa_zh; 508 zbookmark_phys_t zb; 509 510 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 511 return (0); 512 513 /* 514 * One block ("stubby") can be allocated a long time ago; we 515 * want to visit that one because it has been allocated 516 * (on-disk) even if it hasn't been claimed (even though for 517 * scrub there's nothing to do to it). 518 */ 519 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa)) 520 return (0); 521 522 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 523 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 524 525 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 526 return (0); 527} 528 529/* ARGSUSED */ 530static int 531dsl_scan_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) 532{ 533 if (lrc->lrc_txtype == TX_WRITE) { 534 zil_scan_arg_t *zsa = arg; 535 dsl_pool_t *dp = zsa->zsa_dp; 536 dsl_scan_t *scn = dp->dp_scan; 537 zil_header_t *zh = zsa->zsa_zh; 538 lr_write_t *lr = (lr_write_t *)lrc; 539 blkptr_t *bp = &lr->lr_blkptr; 540 zbookmark_phys_t zb; 541 542 if (BP_IS_HOLE(bp) || 543 bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 544 return (0); 545 546 /* 547 * birth can be < claim_txg if this record's txg is 548 * already txg sync'ed (but this log block contains 549 * other records that are not synced) 550 */ 551 if (claim_txg == 0 || bp->blk_birth < claim_txg) 552 return (0); 553 554 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 555 lr->lr_foid, ZB_ZIL_LEVEL, 556 lr->lr_offset / BP_GET_LSIZE(bp)); 557 558 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 559 } 560 return (0); 561} 562 563static void 564dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh) 565{ 566 uint64_t claim_txg = zh->zh_claim_txg; 567 zil_scan_arg_t zsa = { dp, zh }; 568 zilog_t *zilog; 569 570 /* 571 * We only want to visit blocks that have been claimed but not yet 572 * replayed (or, in read-only mode, blocks that *would* be claimed). 573 */ 574 if (claim_txg == 0 && spa_writeable(dp->dp_spa)) 575 return; 576 577 zilog = zil_alloc(dp->dp_meta_objset, zh); 578 579 (void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa, 580 claim_txg); 581 582 zil_free(zilog); 583} 584 585/* ARGSUSED */ 586static void 587dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp, 588 uint64_t objset, uint64_t object, uint64_t blkid) 589{ 590 zbookmark_phys_t czb; 591 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH; 592 593 if (zfs_no_scrub_prefetch) 594 return; 595 596 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_min_txg || 597 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)) 598 return; 599 600 SET_BOOKMARK(&czb, objset, object, BP_GET_LEVEL(bp), blkid); 601 602 (void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp, 603 NULL, NULL, ZIO_PRIORITY_ASYNC_READ, 604 ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb); 605} 606 607static boolean_t 608dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp, 609 const zbookmark_phys_t *zb) 610{ 611 /* 612 * We never skip over user/group accounting objects (obj<0) 613 */ 614 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) && 615 (int64_t)zb->zb_object >= 0) { 616 /* 617 * If we already visited this bp & everything below (in 618 * a prior txg sync), don't bother doing it again. 619 */ 620 if (zbookmark_subtree_completed(dnp, zb, 621 &scn->scn_phys.scn_bookmark)) 622 return (B_TRUE); 623 624 /* 625 * If we found the block we're trying to resume from, or 626 * we went past it to a different object, zero it out to 627 * indicate that it's OK to start checking for pausing 628 * again. 629 */ 630 if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 || 631 zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) { 632 dprintf("resuming at %llx/%llx/%llx/%llx\n", 633 (longlong_t)zb->zb_objset, 634 (longlong_t)zb->zb_object, 635 (longlong_t)zb->zb_level, 636 (longlong_t)zb->zb_blkid); 637 bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb)); 638 } 639 } 640 return (B_FALSE); 641} 642 643/* 644 * Return nonzero on i/o error. 645 * Return new buf to write out in *bufp. 646 */ 647static int 648dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype, 649 dnode_phys_t *dnp, const blkptr_t *bp, 650 const zbookmark_phys_t *zb, dmu_tx_t *tx) 651{ 652 dsl_pool_t *dp = scn->scn_dp; 653 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD; 654 int err; 655 656 if (BP_GET_LEVEL(bp) > 0) { 657 arc_flags_t flags = ARC_FLAG_WAIT; 658 int i; 659 blkptr_t *cbp; 660 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 661 arc_buf_t *buf; 662 663 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 664 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 665 if (err) { 666 scn->scn_phys.scn_errors++; 667 return (err); 668 } 669 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 670 dsl_scan_prefetch(scn, buf, cbp, zb->zb_objset, 671 zb->zb_object, zb->zb_blkid * epb + i); 672 } 673 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 674 zbookmark_phys_t czb; 675 676 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 677 zb->zb_level - 1, 678 zb->zb_blkid * epb + i); 679 dsl_scan_visitbp(cbp, &czb, dnp, 680 ds, scn, ostype, tx); 681 } 682 (void) arc_buf_remove_ref(buf, &buf); 683 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 684 arc_flags_t flags = ARC_FLAG_WAIT; 685 dnode_phys_t *cdnp; 686 int i, j; 687 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 688 arc_buf_t *buf; 689 690 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 691 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 692 if (err) { 693 scn->scn_phys.scn_errors++; 694 return (err); 695 } 696 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 697 for (j = 0; j < cdnp->dn_nblkptr; j++) { 698 blkptr_t *cbp = &cdnp->dn_blkptr[j]; 699 dsl_scan_prefetch(scn, buf, cbp, 700 zb->zb_objset, zb->zb_blkid * epb + i, j); 701 } 702 } 703 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 704 dsl_scan_visitdnode(scn, ds, ostype, 705 cdnp, zb->zb_blkid * epb + i, tx); 706 } 707 708 (void) arc_buf_remove_ref(buf, &buf); 709 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 710 arc_flags_t flags = ARC_FLAG_WAIT; 711 objset_phys_t *osp; 712 arc_buf_t *buf; 713 714 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 715 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 716 if (err) { 717 scn->scn_phys.scn_errors++; 718 return (err); 719 } 720 721 osp = buf->b_data; 722 723 dsl_scan_visitdnode(scn, ds, osp->os_type, 724 &osp->os_meta_dnode, DMU_META_DNODE_OBJECT, tx); 725 726 if (OBJSET_BUF_HAS_USERUSED(buf)) { 727 /* 728 * We also always visit user/group accounting 729 * objects, and never skip them, even if we are 730 * pausing. This is necessary so that the space 731 * deltas from this txg get integrated. 732 */ 733 dsl_scan_visitdnode(scn, ds, osp->os_type, 734 &osp->os_groupused_dnode, 735 DMU_GROUPUSED_OBJECT, tx); 736 dsl_scan_visitdnode(scn, ds, osp->os_type, 737 &osp->os_userused_dnode, 738 DMU_USERUSED_OBJECT, tx); 739 } 740 (void) arc_buf_remove_ref(buf, &buf); 741 } 742 743 return (0); 744} 745 746static void 747dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds, 748 dmu_objset_type_t ostype, dnode_phys_t *dnp, 749 uint64_t object, dmu_tx_t *tx) 750{ 751 int j; 752 753 for (j = 0; j < dnp->dn_nblkptr; j++) { 754 zbookmark_phys_t czb; 755 756 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 757 dnp->dn_nlevels - 1, j); 758 dsl_scan_visitbp(&dnp->dn_blkptr[j], 759 &czb, dnp, ds, scn, ostype, tx); 760 } 761 762 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 763 zbookmark_phys_t czb; 764 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 765 0, DMU_SPILL_BLKID); 766 dsl_scan_visitbp(&dnp->dn_spill, 767 &czb, dnp, ds, scn, ostype, tx); 768 } 769} 770 771/* 772 * The arguments are in this order because mdb can only print the 773 * first 5; we want them to be useful. 774 */ 775static void 776dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 777 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 778 dmu_objset_type_t ostype, dmu_tx_t *tx) 779{ 780 dsl_pool_t *dp = scn->scn_dp; 781 arc_buf_t *buf = NULL; 782 blkptr_t bp_toread = *bp; 783 784 /* ASSERT(pbuf == NULL || arc_released(pbuf)); */ 785 786 if (dsl_scan_check_pause(scn, zb)) 787 return; 788 789 if (dsl_scan_check_resume(scn, dnp, zb)) 790 return; 791 792 if (BP_IS_HOLE(bp)) 793 return; 794 795 scn->scn_visited_this_txg++; 796 797 dprintf_bp(bp, 798 "visiting ds=%p/%llu zb=%llx/%llx/%llx/%llx bp=%p", 799 ds, ds ? ds->ds_object : 0, 800 zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid, 801 bp); 802 803 if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 804 return; 805 806 if (dsl_scan_recurse(scn, ds, ostype, dnp, &bp_toread, zb, tx) != 0) 807 return; 808 809 /* 810 * If dsl_scan_ddt() has aready visited this block, it will have 811 * already done any translations or scrubbing, so don't call the 812 * callback again. 813 */ 814 if (ddt_class_contains(dp->dp_spa, 815 scn->scn_phys.scn_ddt_class_max, bp)) { 816 ASSERT(buf == NULL); 817 return; 818 } 819 820 /* 821 * If this block is from the future (after cur_max_txg), then we 822 * are doing this on behalf of a deleted snapshot, and we will 823 * revisit the future block on the next pass of this dataset. 824 * Don't scan it now unless we need to because something 825 * under it was modified. 826 */ 827 if (BP_PHYSICAL_BIRTH(bp) <= scn->scn_phys.scn_cur_max_txg) { 828 scan_funcs[scn->scn_phys.scn_func](dp, bp, zb); 829 } 830} 831 832static void 833dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp, 834 dmu_tx_t *tx) 835{ 836 zbookmark_phys_t zb; 837 838 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET, 839 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 840 dsl_scan_visitbp(bp, &zb, NULL, 841 ds, scn, DMU_OST_NONE, tx); 842 843 dprintf_ds(ds, "finished scan%s", ""); 844} 845 846void 847dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx) 848{ 849 dsl_pool_t *dp = ds->ds_dir->dd_pool; 850 dsl_scan_t *scn = dp->dp_scan; 851 uint64_t mintxg; 852 853 if (scn->scn_phys.scn_state != DSS_SCANNING) 854 return; 855 856 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 857 if (ds->ds_is_snapshot) { 858 /* Note, scn_cur_{min,max}_txg stays the same. */ 859 scn->scn_phys.scn_bookmark.zb_objset = 860 dsl_dataset_phys(ds)->ds_next_snap_obj; 861 zfs_dbgmsg("destroying ds %llu; currently traversing; " 862 "reset zb_objset to %llu", 863 (u_longlong_t)ds->ds_object, 864 (u_longlong_t)dsl_dataset_phys(ds)-> 865 ds_next_snap_obj); 866 scn->scn_phys.scn_flags |= DSF_VISIT_DS_AGAIN; 867 } else { 868 SET_BOOKMARK(&scn->scn_phys.scn_bookmark, 869 ZB_DESTROYED_OBJSET, 0, 0, 0); 870 zfs_dbgmsg("destroying ds %llu; currently traversing; " 871 "reset bookmark to -1,0,0,0", 872 (u_longlong_t)ds->ds_object); 873 } 874 } else if (zap_lookup_int_key(dp->dp_meta_objset, 875 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 876 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1); 877 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 878 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 879 if (ds->ds_is_snapshot) { 880 /* 881 * We keep the same mintxg; it could be > 882 * ds_creation_txg if the previous snapshot was 883 * deleted too. 884 */ 885 VERIFY(zap_add_int_key(dp->dp_meta_objset, 886 scn->scn_phys.scn_queue_obj, 887 dsl_dataset_phys(ds)->ds_next_snap_obj, 888 mintxg, tx) == 0); 889 zfs_dbgmsg("destroying ds %llu; in queue; " 890 "replacing with %llu", 891 (u_longlong_t)ds->ds_object, 892 (u_longlong_t)dsl_dataset_phys(ds)-> 893 ds_next_snap_obj); 894 } else { 895 zfs_dbgmsg("destroying ds %llu; in queue; removing", 896 (u_longlong_t)ds->ds_object); 897 } 898 } else { 899 zfs_dbgmsg("destroying ds %llu; ignoring", 900 (u_longlong_t)ds->ds_object); 901 } 902 903 /* 904 * dsl_scan_sync() should be called after this, and should sync 905 * out our changed state, but just to be safe, do it here. 906 */ 907 dsl_scan_sync_state(scn, tx); 908} 909 910void 911dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx) 912{ 913 dsl_pool_t *dp = ds->ds_dir->dd_pool; 914 dsl_scan_t *scn = dp->dp_scan; 915 uint64_t mintxg; 916 917 if (scn->scn_phys.scn_state != DSS_SCANNING) 918 return; 919 920 ASSERT(dsl_dataset_phys(ds)->ds_prev_snap_obj != 0); 921 922 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 923 scn->scn_phys.scn_bookmark.zb_objset = 924 dsl_dataset_phys(ds)->ds_prev_snap_obj; 925 zfs_dbgmsg("snapshotting ds %llu; currently traversing; " 926 "reset zb_objset to %llu", 927 (u_longlong_t)ds->ds_object, 928 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 929 } else if (zap_lookup_int_key(dp->dp_meta_objset, 930 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 931 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 932 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 933 VERIFY(zap_add_int_key(dp->dp_meta_objset, 934 scn->scn_phys.scn_queue_obj, 935 dsl_dataset_phys(ds)->ds_prev_snap_obj, mintxg, tx) == 0); 936 zfs_dbgmsg("snapshotting ds %llu; in queue; " 937 "replacing with %llu", 938 (u_longlong_t)ds->ds_object, 939 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 940 } 941 dsl_scan_sync_state(scn, tx); 942} 943 944void 945dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx) 946{ 947 dsl_pool_t *dp = ds1->ds_dir->dd_pool; 948 dsl_scan_t *scn = dp->dp_scan; 949 uint64_t mintxg; 950 951 if (scn->scn_phys.scn_state != DSS_SCANNING) 952 return; 953 954 if (scn->scn_phys.scn_bookmark.zb_objset == ds1->ds_object) { 955 scn->scn_phys.scn_bookmark.zb_objset = ds2->ds_object; 956 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 957 "reset zb_objset to %llu", 958 (u_longlong_t)ds1->ds_object, 959 (u_longlong_t)ds2->ds_object); 960 } else if (scn->scn_phys.scn_bookmark.zb_objset == ds2->ds_object) { 961 scn->scn_phys.scn_bookmark.zb_objset = ds1->ds_object; 962 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 963 "reset zb_objset to %llu", 964 (u_longlong_t)ds2->ds_object, 965 (u_longlong_t)ds1->ds_object); 966 } 967 968 if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 969 ds1->ds_object, &mintxg) == 0) { 970 int err; 971 972 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 973 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 974 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 975 scn->scn_phys.scn_queue_obj, ds1->ds_object, tx)); 976 err = zap_add_int_key(dp->dp_meta_objset, 977 scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg, tx); 978 VERIFY(err == 0 || err == EEXIST); 979 if (err == EEXIST) { 980 /* Both were there to begin with */ 981 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 982 scn->scn_phys.scn_queue_obj, 983 ds1->ds_object, mintxg, tx)); 984 } 985 zfs_dbgmsg("clone_swap ds %llu; in queue; " 986 "replacing with %llu", 987 (u_longlong_t)ds1->ds_object, 988 (u_longlong_t)ds2->ds_object); 989 } else if (zap_lookup_int_key(dp->dp_meta_objset, 990 scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg) == 0) { 991 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 992 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 993 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 994 scn->scn_phys.scn_queue_obj, ds2->ds_object, tx)); 995 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 996 scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg, tx)); 997 zfs_dbgmsg("clone_swap ds %llu; in queue; " 998 "replacing with %llu", 999 (u_longlong_t)ds2->ds_object, 1000 (u_longlong_t)ds1->ds_object); 1001 } 1002 1003 dsl_scan_sync_state(scn, tx); 1004} 1005 1006struct enqueue_clones_arg { 1007 dmu_tx_t *tx; 1008 uint64_t originobj; 1009}; 1010 1011/* ARGSUSED */ 1012static int 1013enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1014{ 1015 struct enqueue_clones_arg *eca = arg; 1016 dsl_dataset_t *ds; 1017 int err; 1018 dsl_scan_t *scn = dp->dp_scan; 1019 1020 if (dsl_dir_phys(hds->ds_dir)->dd_origin_obj != eca->originobj) 1021 return (0); 1022 1023 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1024 if (err) 1025 return (err); 1026 1027 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != eca->originobj) { 1028 dsl_dataset_t *prev; 1029 err = dsl_dataset_hold_obj(dp, 1030 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1031 1032 dsl_dataset_rele(ds, FTAG); 1033 if (err) 1034 return (err); 1035 ds = prev; 1036 } 1037 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1038 scn->scn_phys.scn_queue_obj, ds->ds_object, 1039 dsl_dataset_phys(ds)->ds_prev_snap_txg, eca->tx) == 0); 1040 dsl_dataset_rele(ds, FTAG); 1041 return (0); 1042} 1043 1044static void 1045dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx) 1046{ 1047 dsl_pool_t *dp = scn->scn_dp; 1048 dsl_dataset_t *ds; 1049 objset_t *os; 1050 1051 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1052 1053 if (dmu_objset_from_ds(ds, &os)) 1054 goto out; 1055 1056 /* 1057 * Only the ZIL in the head (non-snapshot) is valid. Even though 1058 * snapshots can have ZIL block pointers (which may be the same 1059 * BP as in the head), they must be ignored. So we traverse the 1060 * ZIL here, rather than in scan_recurse(), because the regular 1061 * snapshot block-sharing rules don't apply to it. 1062 */ 1063 if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !ds->ds_is_snapshot) 1064 dsl_scan_zil(dp, &os->os_zil_header); 1065 1066 /* 1067 * Iterate over the bps in this ds. 1068 */ 1069 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1070 dsl_scan_visit_rootbp(scn, ds, &dsl_dataset_phys(ds)->ds_bp, tx); 1071 1072 char *dsname = kmem_alloc(ZFS_MAXNAMELEN, KM_SLEEP); 1073 dsl_dataset_name(ds, dsname); 1074 zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; " 1075 "pausing=%u", 1076 (longlong_t)dsobj, dsname, 1077 (longlong_t)scn->scn_phys.scn_cur_min_txg, 1078 (longlong_t)scn->scn_phys.scn_cur_max_txg, 1079 (int)scn->scn_pausing); 1080 kmem_free(dsname, ZFS_MAXNAMELEN); 1081 1082 if (scn->scn_pausing) 1083 goto out; 1084 1085 /* 1086 * We've finished this pass over this dataset. 1087 */ 1088 1089 /* 1090 * If we did not completely visit this dataset, do another pass. 1091 */ 1092 if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) { 1093 zfs_dbgmsg("incomplete pass; visiting again"); 1094 scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN; 1095 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1096 scn->scn_phys.scn_queue_obj, ds->ds_object, 1097 scn->scn_phys.scn_cur_max_txg, tx) == 0); 1098 goto out; 1099 } 1100 1101 /* 1102 * Add descendent datasets to work queue. 1103 */ 1104 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) { 1105 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1106 scn->scn_phys.scn_queue_obj, 1107 dsl_dataset_phys(ds)->ds_next_snap_obj, 1108 dsl_dataset_phys(ds)->ds_creation_txg, tx) == 0); 1109 } 1110 if (dsl_dataset_phys(ds)->ds_num_children > 1) { 1111 boolean_t usenext = B_FALSE; 1112 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) { 1113 uint64_t count; 1114 /* 1115 * A bug in a previous version of the code could 1116 * cause upgrade_clones_cb() to not set 1117 * ds_next_snap_obj when it should, leading to a 1118 * missing entry. Therefore we can only use the 1119 * next_clones_obj when its count is correct. 1120 */ 1121 int err = zap_count(dp->dp_meta_objset, 1122 dsl_dataset_phys(ds)->ds_next_clones_obj, &count); 1123 if (err == 0 && 1124 count == dsl_dataset_phys(ds)->ds_num_children - 1) 1125 usenext = B_TRUE; 1126 } 1127 1128 if (usenext) { 1129 VERIFY0(zap_join_key(dp->dp_meta_objset, 1130 dsl_dataset_phys(ds)->ds_next_clones_obj, 1131 scn->scn_phys.scn_queue_obj, 1132 dsl_dataset_phys(ds)->ds_creation_txg, tx)); 1133 } else { 1134 struct enqueue_clones_arg eca; 1135 eca.tx = tx; 1136 eca.originobj = ds->ds_object; 1137 1138 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1139 enqueue_clones_cb, &eca, DS_FIND_CHILDREN)); 1140 } 1141 } 1142 1143out: 1144 dsl_dataset_rele(ds, FTAG); 1145} 1146 1147/* ARGSUSED */ 1148static int 1149enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1150{ 1151 dmu_tx_t *tx = arg; 1152 dsl_dataset_t *ds; 1153 int err; 1154 dsl_scan_t *scn = dp->dp_scan; 1155 1156 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1157 if (err) 1158 return (err); 1159 1160 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 1161 dsl_dataset_t *prev; 1162 err = dsl_dataset_hold_obj(dp, 1163 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1164 if (err) { 1165 dsl_dataset_rele(ds, FTAG); 1166 return (err); 1167 } 1168 1169 /* 1170 * If this is a clone, we don't need to worry about it for now. 1171 */ 1172 if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object) { 1173 dsl_dataset_rele(ds, FTAG); 1174 dsl_dataset_rele(prev, FTAG); 1175 return (0); 1176 } 1177 dsl_dataset_rele(ds, FTAG); 1178 ds = prev; 1179 } 1180 1181 VERIFY(zap_add_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 1182 ds->ds_object, dsl_dataset_phys(ds)->ds_prev_snap_txg, tx) == 0); 1183 dsl_dataset_rele(ds, FTAG); 1184 return (0); 1185} 1186 1187/* 1188 * Scrub/dedup interaction. 1189 * 1190 * If there are N references to a deduped block, we don't want to scrub it 1191 * N times -- ideally, we should scrub it exactly once. 1192 * 1193 * We leverage the fact that the dde's replication class (enum ddt_class) 1194 * is ordered from highest replication class (DDT_CLASS_DITTO) to lowest 1195 * (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order. 1196 * 1197 * To prevent excess scrubbing, the scrub begins by walking the DDT 1198 * to find all blocks with refcnt > 1, and scrubs each of these once. 1199 * Since there are two replication classes which contain blocks with 1200 * refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first. 1201 * Finally the top-down scrub begins, only visiting blocks with refcnt == 1. 1202 * 1203 * There would be nothing more to say if a block's refcnt couldn't change 1204 * during a scrub, but of course it can so we must account for changes 1205 * in a block's replication class. 1206 * 1207 * Here's an example of what can occur: 1208 * 1209 * If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1 1210 * when visited during the top-down scrub phase, it will be scrubbed twice. 1211 * This negates our scrub optimization, but is otherwise harmless. 1212 * 1213 * If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1 1214 * on each visit during the top-down scrub phase, it will never be scrubbed. 1215 * To catch this, ddt_sync_entry() notifies the scrub code whenever a block's 1216 * reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to 1217 * DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1 1218 * while a scrub is in progress, it scrubs the block right then. 1219 */ 1220static void 1221dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx) 1222{ 1223 ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark; 1224 ddt_entry_t dde = { 0 }; 1225 int error; 1226 uint64_t n = 0; 1227 1228 while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) { 1229 ddt_t *ddt; 1230 1231 if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max) 1232 break; 1233 dprintf("visiting ddb=%llu/%llu/%llu/%llx\n", 1234 (longlong_t)ddb->ddb_class, 1235 (longlong_t)ddb->ddb_type, 1236 (longlong_t)ddb->ddb_checksum, 1237 (longlong_t)ddb->ddb_cursor); 1238 1239 /* There should be no pending changes to the dedup table */ 1240 ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum]; 1241 ASSERT(avl_first(&ddt->ddt_tree) == NULL); 1242 1243 dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx); 1244 n++; 1245 1246 if (dsl_scan_check_pause(scn, NULL)) 1247 break; 1248 } 1249 1250 zfs_dbgmsg("scanned %llu ddt entries with class_max = %u; pausing=%u", 1251 (longlong_t)n, (int)scn->scn_phys.scn_ddt_class_max, 1252 (int)scn->scn_pausing); 1253 1254 ASSERT(error == 0 || error == ENOENT); 1255 ASSERT(error != ENOENT || 1256 ddb->ddb_class > scn->scn_phys.scn_ddt_class_max); 1257} 1258 1259/* ARGSUSED */ 1260void 1261dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum, 1262 ddt_entry_t *dde, dmu_tx_t *tx) 1263{ 1264 const ddt_key_t *ddk = &dde->dde_key; 1265 ddt_phys_t *ddp = dde->dde_phys; 1266 blkptr_t bp; 1267 zbookmark_phys_t zb = { 0 }; 1268 1269 if (scn->scn_phys.scn_state != DSS_SCANNING) 1270 return; 1271 1272 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1273 if (ddp->ddp_phys_birth == 0 || 1274 ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg) 1275 continue; 1276 ddt_bp_create(checksum, ddk, ddp, &bp); 1277 1278 scn->scn_visited_this_txg++; 1279 scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb); 1280 } 1281} 1282 1283static void 1284dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx) 1285{ 1286 dsl_pool_t *dp = scn->scn_dp; 1287 zap_cursor_t zc; 1288 zap_attribute_t za; 1289 1290 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1291 scn->scn_phys.scn_ddt_class_max) { 1292 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1293 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1294 dsl_scan_ddt(scn, tx); 1295 if (scn->scn_pausing) 1296 return; 1297 } 1298 1299 if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) { 1300 /* First do the MOS & ORIGIN */ 1301 1302 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1303 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1304 dsl_scan_visit_rootbp(scn, NULL, 1305 &dp->dp_meta_rootbp, tx); 1306 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); 1307 if (scn->scn_pausing) 1308 return; 1309 1310 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) { 1311 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1312 enqueue_cb, tx, DS_FIND_CHILDREN)); 1313 } else { 1314 dsl_scan_visitds(scn, 1315 dp->dp_origin_snap->ds_object, tx); 1316 } 1317 ASSERT(!scn->scn_pausing); 1318 } else if (scn->scn_phys.scn_bookmark.zb_objset != 1319 ZB_DESTROYED_OBJSET) { 1320 /* 1321 * If we were paused, continue from here. Note if the 1322 * ds we were paused on was deleted, the zb_objset may 1323 * be -1, so we will skip this and find a new objset 1324 * below. 1325 */ 1326 dsl_scan_visitds(scn, scn->scn_phys.scn_bookmark.zb_objset, tx); 1327 if (scn->scn_pausing) 1328 return; 1329 } 1330 1331 /* 1332 * In case we were paused right at the end of the ds, zero the 1333 * bookmark so we don't think that we're still trying to resume. 1334 */ 1335 bzero(&scn->scn_phys.scn_bookmark, sizeof (zbookmark_phys_t)); 1336 1337 /* keep pulling things out of the zap-object-as-queue */ 1338 while (zap_cursor_init(&zc, dp->dp_meta_objset, 1339 scn->scn_phys.scn_queue_obj), 1340 zap_cursor_retrieve(&zc, &za) == 0) { 1341 dsl_dataset_t *ds; 1342 uint64_t dsobj; 1343 1344 dsobj = strtonum(za.za_name, NULL); 1345 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 1346 scn->scn_phys.scn_queue_obj, dsobj, tx)); 1347 1348 /* Set up min/max txg */ 1349 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1350 if (za.za_first_integer != 0) { 1351 scn->scn_phys.scn_cur_min_txg = 1352 MAX(scn->scn_phys.scn_min_txg, 1353 za.za_first_integer); 1354 } else { 1355 scn->scn_phys.scn_cur_min_txg = 1356 MAX(scn->scn_phys.scn_min_txg, 1357 dsl_dataset_phys(ds)->ds_prev_snap_txg); 1358 } 1359 scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds); 1360 dsl_dataset_rele(ds, FTAG); 1361 1362 dsl_scan_visitds(scn, dsobj, tx); 1363 zap_cursor_fini(&zc); 1364 if (scn->scn_pausing) 1365 return; 1366 } 1367 zap_cursor_fini(&zc); 1368} 1369 1370static boolean_t 1371dsl_scan_free_should_pause(dsl_scan_t *scn) 1372{ 1373 uint64_t elapsed_nanosecs; 1374 1375 if (zfs_recover) 1376 return (B_FALSE); 1377 1378 if (scn->scn_visited_this_txg >= zfs_free_max_blocks) 1379 return (B_TRUE); 1380 1381 elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 1382 return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || 1383 (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms && 1384 txg_sync_waiting(scn->scn_dp)) || 1385 spa_shutting_down(scn->scn_dp->dp_spa)); 1386} 1387 1388static int 1389dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1390{ 1391 dsl_scan_t *scn = arg; 1392 1393 if (!scn->scn_is_bptree || 1394 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) { 1395 if (dsl_scan_free_should_pause(scn)) 1396 return (SET_ERROR(ERESTART)); 1397 } 1398 1399 zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa, 1400 dmu_tx_get_txg(tx), bp, BP_GET_PSIZE(bp), 0)); 1401 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD, 1402 -bp_get_dsize_sync(scn->scn_dp->dp_spa, bp), 1403 -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx); 1404 scn->scn_visited_this_txg++; 1405 return (0); 1406} 1407 1408boolean_t 1409dsl_scan_active(dsl_scan_t *scn) 1410{ 1411 spa_t *spa = scn->scn_dp->dp_spa; 1412 uint64_t used = 0, comp, uncomp; 1413 1414 if (spa->spa_load_state != SPA_LOAD_NONE) 1415 return (B_FALSE); 1416 if (spa_shutting_down(spa)) 1417 return (B_FALSE); 1418 if (scn->scn_phys.scn_state == DSS_SCANNING || 1419 (scn->scn_async_destroying && !scn->scn_async_stalled)) 1420 return (B_TRUE); 1421 1422 if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1423 (void) bpobj_space(&scn->scn_dp->dp_free_bpobj, 1424 &used, &comp, &uncomp); 1425 } 1426 return (used != 0); 1427} 1428 1429void 1430dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) 1431{ 1432 dsl_scan_t *scn = dp->dp_scan; 1433 spa_t *spa = dp->dp_spa; 1434 int err = 0; 1435 1436 /* 1437 * Check for scn_restart_txg before checking spa_load_state, so 1438 * that we can restart an old-style scan while the pool is being 1439 * imported (see dsl_scan_init). 1440 */ 1441 if (scn->scn_restart_txg != 0 && 1442 scn->scn_restart_txg <= tx->tx_txg) { 1443 pool_scan_func_t func = POOL_SCAN_SCRUB; 1444 dsl_scan_done(scn, B_FALSE, tx); 1445 if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) 1446 func = POOL_SCAN_RESILVER; 1447 zfs_dbgmsg("restarting scan func=%u txg=%llu", 1448 func, tx->tx_txg); 1449 dsl_scan_setup_sync(&func, tx); 1450 } 1451 1452 /* 1453 * If the scan is inactive due to a stalled async destroy, try again. 1454 */ 1455 if ((!scn->scn_async_stalled && !dsl_scan_active(scn)) || 1456 spa_sync_pass(dp->dp_spa) > 1) 1457 return; 1458 1459 scn->scn_visited_this_txg = 0; 1460 scn->scn_pausing = B_FALSE; 1461 scn->scn_sync_start_time = gethrtime(); 1462 spa->spa_scrub_active = B_TRUE; 1463 1464 /* 1465 * First process the async destroys. If we pause, don't do 1466 * any scrubbing or resilvering. This ensures that there are no 1467 * async destroys while we are scanning, so the scan code doesn't 1468 * have to worry about traversing it. It is also faster to free the 1469 * blocks than to scrub them. 1470 */ 1471 if (zfs_free_bpobj_enabled && 1472 spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1473 scn->scn_is_bptree = B_FALSE; 1474 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1475 NULL, ZIO_FLAG_MUSTSUCCEED); 1476 err = bpobj_iterate(&dp->dp_free_bpobj, 1477 dsl_scan_free_block_cb, scn, tx); 1478 VERIFY3U(0, ==, zio_wait(scn->scn_zio_root)); 1479 1480 if (err != 0 && err != ERESTART) 1481 zfs_panic_recover("error %u from bpobj_iterate()", err); 1482 } 1483 1484 if (err == 0 && spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) { 1485 ASSERT(scn->scn_async_destroying); 1486 scn->scn_is_bptree = B_TRUE; 1487 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1488 NULL, ZIO_FLAG_MUSTSUCCEED); 1489 err = bptree_iterate(dp->dp_meta_objset, 1490 dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, scn, tx); 1491 VERIFY0(zio_wait(scn->scn_zio_root)); 1492 1493 if (err == EIO || err == ECKSUM) { 1494 err = 0; 1495 } else if (err != 0 && err != ERESTART) { 1496 zfs_panic_recover("error %u from " 1497 "traverse_dataset_destroyed()", err); 1498 } 1499 1500 if (bptree_is_empty(dp->dp_meta_objset, dp->dp_bptree_obj)) { 1501 /* finished; deactivate async destroy feature */ 1502 spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, tx); 1503 ASSERT(!spa_feature_is_active(spa, 1504 SPA_FEATURE_ASYNC_DESTROY)); 1505 VERIFY0(zap_remove(dp->dp_meta_objset, 1506 DMU_POOL_DIRECTORY_OBJECT, 1507 DMU_POOL_BPTREE_OBJ, tx)); 1508 VERIFY0(bptree_free(dp->dp_meta_objset, 1509 dp->dp_bptree_obj, tx)); 1510 dp->dp_bptree_obj = 0; 1511 scn->scn_async_destroying = B_FALSE; 1512 scn->scn_async_stalled = B_FALSE; 1513 } else { 1514 /* 1515 * If we didn't make progress, mark the async 1516 * destroy as stalled, so that we will not initiate 1517 * a spa_sync() on its behalf. Note that we only 1518 * check this if we are not finished, because if the 1519 * bptree had no blocks for us to visit, we can 1520 * finish without "making progress". 1521 */ 1522 scn->scn_async_stalled = 1523 (scn->scn_visited_this_txg == 0); 1524 } 1525 } 1526 if (scn->scn_visited_this_txg) { 1527 zfs_dbgmsg("freed %llu blocks in %llums from " 1528 "free_bpobj/bptree txg %llu; err=%d", 1529 (longlong_t)scn->scn_visited_this_txg, 1530 (longlong_t) 1531 NSEC2MSEC(gethrtime() - scn->scn_sync_start_time), 1532 (longlong_t)tx->tx_txg, err); 1533 scn->scn_visited_this_txg = 0; 1534 1535 /* 1536 * Write out changes to the DDT that may be required as a 1537 * result of the blocks freed. This ensures that the DDT 1538 * is clean when a scrub/resilver runs. 1539 */ 1540 ddt_sync(spa, tx->tx_txg); 1541 } 1542 if (err != 0) 1543 return; 1544 if (!scn->scn_async_destroying && zfs_free_leak_on_eio && 1545 (dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes != 0 || 1546 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes != 0 || 1547 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes != 0)) { 1548 /* 1549 * We have finished background destroying, but there is still 1550 * some space left in the dp_free_dir. Transfer this leaked 1551 * space to the dp_leak_dir. 1552 */ 1553 if (dp->dp_leak_dir == NULL) { 1554 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); 1555 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, 1556 LEAK_DIR_NAME, tx); 1557 VERIFY0(dsl_pool_open_special_dir(dp, 1558 LEAK_DIR_NAME, &dp->dp_leak_dir)); 1559 rrw_exit(&dp->dp_config_rwlock, FTAG); 1560 } 1561 dsl_dir_diduse_space(dp->dp_leak_dir, DD_USED_HEAD, 1562 dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1563 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1564 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1565 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 1566 -dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1567 -dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1568 -dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1569 } 1570 if (!scn->scn_async_destroying) { 1571 /* finished; verify that space accounting went to zero */ 1572 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes); 1573 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes); 1574 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes); 1575 } 1576 1577 if (scn->scn_phys.scn_state != DSS_SCANNING) 1578 return; 1579 1580 if (scn->scn_done_txg == tx->tx_txg) { 1581 ASSERT(!scn->scn_pausing); 1582 /* finished with scan. */ 1583 zfs_dbgmsg("txg %llu scan complete", tx->tx_txg); 1584 dsl_scan_done(scn, B_TRUE, tx); 1585 ASSERT3U(spa->spa_scrub_inflight, ==, 0); 1586 dsl_scan_sync_state(scn, tx); 1587 return; 1588 } 1589 1590 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1591 scn->scn_phys.scn_ddt_class_max) { 1592 zfs_dbgmsg("doing scan sync txg %llu; " 1593 "ddt bm=%llu/%llu/%llu/%llx", 1594 (longlong_t)tx->tx_txg, 1595 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 1596 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 1597 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 1598 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 1599 ASSERT(scn->scn_phys.scn_bookmark.zb_objset == 0); 1600 ASSERT(scn->scn_phys.scn_bookmark.zb_object == 0); 1601 ASSERT(scn->scn_phys.scn_bookmark.zb_level == 0); 1602 ASSERT(scn->scn_phys.scn_bookmark.zb_blkid == 0); 1603 } else { 1604 zfs_dbgmsg("doing scan sync txg %llu; bm=%llu/%llu/%llu/%llu", 1605 (longlong_t)tx->tx_txg, 1606 (longlong_t)scn->scn_phys.scn_bookmark.zb_objset, 1607 (longlong_t)scn->scn_phys.scn_bookmark.zb_object, 1608 (longlong_t)scn->scn_phys.scn_bookmark.zb_level, 1609 (longlong_t)scn->scn_phys.scn_bookmark.zb_blkid); 1610 } 1611 1612 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1613 NULL, ZIO_FLAG_CANFAIL); 1614 dsl_pool_config_enter(dp, FTAG); 1615 dsl_scan_visit(scn, tx); 1616 dsl_pool_config_exit(dp, FTAG); 1617 (void) zio_wait(scn->scn_zio_root); 1618 scn->scn_zio_root = NULL; 1619 1620 zfs_dbgmsg("visited %llu blocks in %llums", 1621 (longlong_t)scn->scn_visited_this_txg, 1622 (longlong_t)NSEC2MSEC(gethrtime() - scn->scn_sync_start_time)); 1623 1624 if (!scn->scn_pausing) { 1625 scn->scn_done_txg = tx->tx_txg + 1; 1626 zfs_dbgmsg("txg %llu traversal complete, waiting till txg %llu", 1627 tx->tx_txg, scn->scn_done_txg); 1628 } 1629 1630 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 1631 mutex_enter(&spa->spa_scrub_lock); 1632 while (spa->spa_scrub_inflight > 0) { 1633 cv_wait(&spa->spa_scrub_io_cv, 1634 &spa->spa_scrub_lock); 1635 } 1636 mutex_exit(&spa->spa_scrub_lock); 1637 } 1638 1639 dsl_scan_sync_state(scn, tx); 1640} 1641 1642/* 1643 * This will start a new scan, or restart an existing one. 1644 */ 1645void 1646dsl_resilver_restart(dsl_pool_t *dp, uint64_t txg) 1647{ 1648 if (txg == 0) { 1649 dmu_tx_t *tx; 1650 tx = dmu_tx_create_dd(dp->dp_mos_dir); 1651 VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT)); 1652 1653 txg = dmu_tx_get_txg(tx); 1654 dp->dp_scan->scn_restart_txg = txg; 1655 dmu_tx_commit(tx); 1656 } else { 1657 dp->dp_scan->scn_restart_txg = txg; 1658 } 1659 zfs_dbgmsg("restarting resilver txg=%llu", txg); 1660} 1661 1662boolean_t 1663dsl_scan_resilvering(dsl_pool_t *dp) 1664{ 1665 return (dp->dp_scan->scn_phys.scn_state == DSS_SCANNING && 1666 dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER); 1667} 1668 1669/* 1670 * scrub consumers 1671 */ 1672 1673static void 1674count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp) 1675{ 1676 int i; 1677 1678 /* 1679 * If we resume after a reboot, zab will be NULL; don't record 1680 * incomplete stats in that case. 1681 */ 1682 if (zab == NULL) 1683 return; 1684 1685 for (i = 0; i < 4; i++) { 1686 int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS; 1687 int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL; 1688 if (t & DMU_OT_NEWTYPE) 1689 t = DMU_OT_OTHER; 1690 zfs_blkstat_t *zb = &zab->zab_type[l][t]; 1691 int equal; 1692 1693 zb->zb_count++; 1694 zb->zb_asize += BP_GET_ASIZE(bp); 1695 zb->zb_lsize += BP_GET_LSIZE(bp); 1696 zb->zb_psize += BP_GET_PSIZE(bp); 1697 zb->zb_gangs += BP_COUNT_GANG(bp); 1698 1699 switch (BP_GET_NDVAS(bp)) { 1700 case 2: 1701 if (DVA_GET_VDEV(&bp->blk_dva[0]) == 1702 DVA_GET_VDEV(&bp->blk_dva[1])) 1703 zb->zb_ditto_2_of_2_samevdev++; 1704 break; 1705 case 3: 1706 equal = (DVA_GET_VDEV(&bp->blk_dva[0]) == 1707 DVA_GET_VDEV(&bp->blk_dva[1])) + 1708 (DVA_GET_VDEV(&bp->blk_dva[0]) == 1709 DVA_GET_VDEV(&bp->blk_dva[2])) + 1710 (DVA_GET_VDEV(&bp->blk_dva[1]) == 1711 DVA_GET_VDEV(&bp->blk_dva[2])); 1712 if (equal == 1) 1713 zb->zb_ditto_2_of_3_samevdev++; 1714 else if (equal == 3) 1715 zb->zb_ditto_3_of_3_samevdev++; 1716 break; 1717 } 1718 } 1719} 1720 1721static void 1722dsl_scan_scrub_done(zio_t *zio) 1723{ 1724 spa_t *spa = zio->io_spa; 1725 1726 zio_data_buf_free(zio->io_data, zio->io_size); 1727 1728 mutex_enter(&spa->spa_scrub_lock); 1729 spa->spa_scrub_inflight--; 1730 cv_broadcast(&spa->spa_scrub_io_cv); 1731 1732 if (zio->io_error && (zio->io_error != ECKSUM || 1733 !(zio->io_flags & ZIO_FLAG_SPECULATIVE))) { 1734 spa->spa_dsl_pool->dp_scan->scn_phys.scn_errors++; 1735 } 1736 mutex_exit(&spa->spa_scrub_lock); 1737} 1738 1739static int 1740dsl_scan_scrub_cb(dsl_pool_t *dp, 1741 const blkptr_t *bp, const zbookmark_phys_t *zb) 1742{ 1743 dsl_scan_t *scn = dp->dp_scan; 1744 size_t size = BP_GET_PSIZE(bp); 1745 spa_t *spa = dp->dp_spa; 1746 uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp); 1747 boolean_t needs_io; 1748 int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL; 1749 unsigned int scan_delay = 0; 1750 1751 if (phys_birth <= scn->scn_phys.scn_min_txg || 1752 phys_birth >= scn->scn_phys.scn_max_txg) 1753 return (0); 1754 1755 count_block(dp->dp_blkstats, bp); 1756 1757 if (BP_IS_EMBEDDED(bp)) 1758 return (0); 1759 1760 ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn)); 1761 if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) { 1762 zio_flags |= ZIO_FLAG_SCRUB; 1763 needs_io = B_TRUE; 1764 scan_delay = zfs_scrub_delay; 1765 } else { 1766 ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER); 1767 zio_flags |= ZIO_FLAG_RESILVER; 1768 needs_io = B_FALSE; 1769 scan_delay = zfs_resilver_delay; 1770 } 1771 1772 /* If it's an intent log block, failure is expected. */ 1773 if (zb->zb_level == ZB_ZIL_LEVEL) 1774 zio_flags |= ZIO_FLAG_SPECULATIVE; 1775 1776 for (int d = 0; d < BP_GET_NDVAS(bp); d++) { 1777 vdev_t *vd = vdev_lookup_top(spa, 1778 DVA_GET_VDEV(&bp->blk_dva[d])); 1779 1780 /* 1781 * Keep track of how much data we've examined so that 1782 * zpool(1M) status can make useful progress reports. 1783 */ 1784 scn->scn_phys.scn_examined += DVA_GET_ASIZE(&bp->blk_dva[d]); 1785 spa->spa_scan_pass_exam += DVA_GET_ASIZE(&bp->blk_dva[d]); 1786 1787 /* if it's a resilver, this may not be in the target range */ 1788 if (!needs_io) { 1789 if (DVA_GET_GANG(&bp->blk_dva[d])) { 1790 /* 1791 * Gang members may be spread across multiple 1792 * vdevs, so the best estimate we have is the 1793 * scrub range, which has already been checked. 1794 * XXX -- it would be better to change our 1795 * allocation policy to ensure that all 1796 * gang members reside on the same vdev. 1797 */ 1798 needs_io = B_TRUE; 1799 } else { 1800 needs_io = vdev_dtl_contains(vd, DTL_PARTIAL, 1801 phys_birth, 1); 1802 } 1803 } 1804 } 1805 1806 if (needs_io && !zfs_no_scrub_io) { 1807 vdev_t *rvd = spa->spa_root_vdev; 1808 uint64_t maxinflight = rvd->vdev_children * 1809 MAX(zfs_top_maxinflight, 1); 1810 void *data = zio_data_buf_alloc(size); 1811 1812 mutex_enter(&spa->spa_scrub_lock); 1813 while (spa->spa_scrub_inflight >= maxinflight) 1814 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock); 1815 spa->spa_scrub_inflight++; 1816 mutex_exit(&spa->spa_scrub_lock); 1817 1818 /* 1819 * If we're seeing recent (zfs_scan_idle) "important" I/Os 1820 * then throttle our workload to limit the impact of a scan. 1821 */ 1822 if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle) 1823 delay(MAX((int)scan_delay, 0)); 1824 1825 zio_nowait(zio_read(NULL, spa, bp, data, size, 1826 dsl_scan_scrub_done, NULL, ZIO_PRIORITY_SCRUB, 1827 zio_flags, zb)); 1828 } 1829 1830 /* do not relocate this block */ 1831 return (0); 1832} 1833 1834int 1835dsl_scan(dsl_pool_t *dp, pool_scan_func_t func) 1836{ 1837 spa_t *spa = dp->dp_spa; 1838 1839 /* 1840 * Purge all vdev caches and probe all devices. We do this here 1841 * rather than in sync context because this requires a writer lock 1842 * on the spa_config lock, which we can't do from sync context. The 1843 * spa_scrub_reopen flag indicates that vdev_open() should not 1844 * attempt to start another scrub. 1845 */ 1846 spa_vdev_state_enter(spa, SCL_NONE); 1847 spa->spa_scrub_reopen = B_TRUE; 1848 vdev_reopen(spa->spa_root_vdev); 1849 spa->spa_scrub_reopen = B_FALSE; 1850 (void) spa_vdev_state_exit(spa, NULL, 0); 1851 1852 return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check, 1853 dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_NONE)); 1854} 1855