dsl_scan.c revision 307122
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 * Copyright 2016 Gary Mills 25 */ 26 27#include <sys/dsl_scan.h> 28#include <sys/dsl_pool.h> 29#include <sys/dsl_dataset.h> 30#include <sys/dsl_prop.h> 31#include <sys/dsl_dir.h> 32#include <sys/dsl_synctask.h> 33#include <sys/dnode.h> 34#include <sys/dmu_tx.h> 35#include <sys/dmu_objset.h> 36#include <sys/arc.h> 37#include <sys/zap.h> 38#include <sys/zio.h> 39#include <sys/zfs_context.h> 40#include <sys/fs/zfs.h> 41#include <sys/zfs_znode.h> 42#include <sys/spa_impl.h> 43#include <sys/vdev_impl.h> 44#include <sys/zil_impl.h> 45#include <sys/zio_checksum.h> 46#include <sys/ddt.h> 47#include <sys/sa.h> 48#include <sys/sa_impl.h> 49#include <sys/zfeature.h> 50#ifdef _KERNEL 51#include <sys/zfs_vfsops.h> 52#endif 53 54typedef int (scan_cb_t)(dsl_pool_t *, const blkptr_t *, 55 const zbookmark_phys_t *); 56 57static scan_cb_t dsl_scan_scrub_cb; 58static void dsl_scan_cancel_sync(void *, dmu_tx_t *); 59static void dsl_scan_sync_state(dsl_scan_t *, dmu_tx_t *); 60static boolean_t dsl_scan_restarting(dsl_scan_t *, dmu_tx_t *); 61 62unsigned int zfs_top_maxinflight = 32; /* maximum I/Os per top-level */ 63unsigned int zfs_resilver_delay = 2; /* number of ticks to delay resilver */ 64unsigned int zfs_scrub_delay = 4; /* number of ticks to delay scrub */ 65unsigned int zfs_scan_idle = 50; /* idle window in clock ticks */ 66 67unsigned int zfs_scan_min_time_ms = 1000; /* min millisecs to scrub per txg */ 68unsigned int zfs_free_min_time_ms = 1000; /* min millisecs to free per txg */ 69unsigned int zfs_resilver_min_time_ms = 3000; /* min millisecs to resilver 70 per txg */ 71boolean_t zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */ 72boolean_t zfs_no_scrub_prefetch = B_FALSE; /* set to disable scrub prefetch */ 73 74SYSCTL_DECL(_vfs_zfs); 75TUNABLE_INT("vfs.zfs.top_maxinflight", &zfs_top_maxinflight); 76SYSCTL_UINT(_vfs_zfs, OID_AUTO, top_maxinflight, CTLFLAG_RW, 77 &zfs_top_maxinflight, 0, "Maximum I/Os per top-level vdev"); 78TUNABLE_INT("vfs.zfs.resilver_delay", &zfs_resilver_delay); 79SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_delay, CTLFLAG_RW, 80 &zfs_resilver_delay, 0, "Number of ticks to delay resilver"); 81TUNABLE_INT("vfs.zfs.scrub_delay", &zfs_scrub_delay); 82SYSCTL_UINT(_vfs_zfs, OID_AUTO, scrub_delay, CTLFLAG_RW, 83 &zfs_scrub_delay, 0, "Number of ticks to delay scrub"); 84TUNABLE_INT("vfs.zfs.scan_idle", &zfs_scan_idle); 85SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_idle, CTLFLAG_RW, 86 &zfs_scan_idle, 0, "Idle scan window in clock ticks"); 87TUNABLE_INT("vfs.zfs.scan_min_time_ms", &zfs_scan_min_time_ms); 88SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_min_time_ms, CTLFLAG_RW, 89 &zfs_scan_min_time_ms, 0, "Min millisecs to scrub per txg"); 90TUNABLE_INT("vfs.zfs.free_min_time_ms", &zfs_free_min_time_ms); 91SYSCTL_UINT(_vfs_zfs, OID_AUTO, free_min_time_ms, CTLFLAG_RW, 92 &zfs_free_min_time_ms, 0, "Min millisecs to free per txg"); 93TUNABLE_INT("vfs.zfs.resilver_min_time_ms", &zfs_resilver_min_time_ms); 94SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_min_time_ms, CTLFLAG_RW, 95 &zfs_resilver_min_time_ms, 0, "Min millisecs to resilver per txg"); 96TUNABLE_INT("vfs.zfs.no_scrub_io", &zfs_no_scrub_io); 97SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_io, CTLFLAG_RW, 98 &zfs_no_scrub_io, 0, "Disable scrub I/O"); 99TUNABLE_INT("vfs.zfs.no_scrub_prefetch", &zfs_no_scrub_prefetch); 100SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_prefetch, CTLFLAG_RW, 101 &zfs_no_scrub_prefetch, 0, "Disable scrub prefetching"); 102 103enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE; 104/* max number of blocks to free in a single TXG */ 105uint64_t zfs_free_max_blocks = UINT64_MAX; 106SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, free_max_blocks, CTLFLAG_RWTUN, 107 &zfs_free_max_blocks, 0, "Maximum number of blocks to free in one TXG"); 108 109 110#define DSL_SCAN_IS_SCRUB_RESILVER(scn) \ 111 ((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \ 112 (scn)->scn_phys.scn_func == POOL_SCAN_RESILVER) 113 114extern int zfs_txg_timeout; 115 116/* 117 * Enable/disable the processing of the free_bpobj object. 118 */ 119boolean_t zfs_free_bpobj_enabled = B_TRUE; 120 121SYSCTL_INT(_vfs_zfs, OID_AUTO, free_bpobj_enabled, CTLFLAG_RWTUN, 122 &zfs_free_bpobj_enabled, 0, "Enable free_bpobj processing"); 123 124/* the order has to match pool_scan_type */ 125static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = { 126 NULL, 127 dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */ 128 dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */ 129}; 130 131int 132dsl_scan_init(dsl_pool_t *dp, uint64_t txg) 133{ 134 int err; 135 dsl_scan_t *scn; 136 spa_t *spa = dp->dp_spa; 137 uint64_t f; 138 139 scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP); 140 scn->scn_dp = dp; 141 142 /* 143 * It's possible that we're resuming a scan after a reboot so 144 * make sure that the scan_async_destroying flag is initialized 145 * appropriately. 146 */ 147 ASSERT(!scn->scn_async_destroying); 148 scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa, 149 SPA_FEATURE_ASYNC_DESTROY); 150 151 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 152 "scrub_func", sizeof (uint64_t), 1, &f); 153 if (err == 0) { 154 /* 155 * There was an old-style scrub in progress. Restart a 156 * new-style scrub from the beginning. 157 */ 158 scn->scn_restart_txg = txg; 159 zfs_dbgmsg("old-style scrub was in progress; " 160 "restarting new-style scrub in txg %llu", 161 scn->scn_restart_txg); 162 163 /* 164 * Load the queue obj from the old location so that it 165 * can be freed by dsl_scan_done(). 166 */ 167 (void) zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 168 "scrub_queue", sizeof (uint64_t), 1, 169 &scn->scn_phys.scn_queue_obj); 170 } else { 171 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 172 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 173 &scn->scn_phys); 174 if (err == ENOENT) 175 return (0); 176 else if (err) 177 return (err); 178 179 if (scn->scn_phys.scn_state == DSS_SCANNING && 180 spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) { 181 /* 182 * A new-type scrub was in progress on an old 183 * pool, and the pool was accessed by old 184 * software. Restart from the beginning, since 185 * the old software may have changed the pool in 186 * the meantime. 187 */ 188 scn->scn_restart_txg = txg; 189 zfs_dbgmsg("new-style scrub was modified " 190 "by old software; restarting in txg %llu", 191 scn->scn_restart_txg); 192 } 193 } 194 195 spa_scan_stat_init(spa); 196 return (0); 197} 198 199void 200dsl_scan_fini(dsl_pool_t *dp) 201{ 202 if (dp->dp_scan) { 203 kmem_free(dp->dp_scan, sizeof (dsl_scan_t)); 204 dp->dp_scan = NULL; 205 } 206} 207 208/* ARGSUSED */ 209static int 210dsl_scan_setup_check(void *arg, dmu_tx_t *tx) 211{ 212 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 213 214 if (scn->scn_phys.scn_state == DSS_SCANNING) 215 return (SET_ERROR(EBUSY)); 216 217 return (0); 218} 219 220static void 221dsl_scan_setup_sync(void *arg, dmu_tx_t *tx) 222{ 223 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 224 pool_scan_func_t *funcp = arg; 225 dmu_object_type_t ot = 0; 226 dsl_pool_t *dp = scn->scn_dp; 227 spa_t *spa = dp->dp_spa; 228 229 ASSERT(scn->scn_phys.scn_state != DSS_SCANNING); 230 ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS); 231 bzero(&scn->scn_phys, sizeof (scn->scn_phys)); 232 scn->scn_phys.scn_func = *funcp; 233 scn->scn_phys.scn_state = DSS_SCANNING; 234 scn->scn_phys.scn_min_txg = 0; 235 scn->scn_phys.scn_max_txg = tx->tx_txg; 236 scn->scn_phys.scn_ddt_class_max = DDT_CLASSES - 1; /* the entire DDT */ 237 scn->scn_phys.scn_start_time = gethrestime_sec(); 238 scn->scn_phys.scn_errors = 0; 239 scn->scn_phys.scn_to_examine = spa->spa_root_vdev->vdev_stat.vs_alloc; 240 scn->scn_restart_txg = 0; 241 scn->scn_done_txg = 0; 242 spa_scan_stat_init(spa); 243 244 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 245 scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max; 246 247 /* rewrite all disk labels */ 248 vdev_config_dirty(spa->spa_root_vdev); 249 250 if (vdev_resilver_needed(spa->spa_root_vdev, 251 &scn->scn_phys.scn_min_txg, &scn->scn_phys.scn_max_txg)) { 252 spa_event_notify(spa, NULL, ESC_ZFS_RESILVER_START); 253 } else { 254 spa_event_notify(spa, NULL, ESC_ZFS_SCRUB_START); 255 } 256 257 spa->spa_scrub_started = B_TRUE; 258 /* 259 * If this is an incremental scrub, limit the DDT scrub phase 260 * to just the auto-ditto class (for correctness); the rest 261 * of the scrub should go faster using top-down pruning. 262 */ 263 if (scn->scn_phys.scn_min_txg > TXG_INITIAL) 264 scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO; 265 266 } 267 268 /* back to the generic stuff */ 269 270 if (dp->dp_blkstats == NULL) { 271 dp->dp_blkstats = 272 kmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP); 273 } 274 bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); 275 276 if (spa_version(spa) < SPA_VERSION_DSL_SCRUB) 277 ot = DMU_OT_ZAP_OTHER; 278 279 scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset, 280 ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx); 281 282 dsl_scan_sync_state(scn, tx); 283 284 spa_history_log_internal(spa, "scan setup", tx, 285 "func=%u mintxg=%llu maxtxg=%llu", 286 *funcp, scn->scn_phys.scn_min_txg, scn->scn_phys.scn_max_txg); 287} 288 289/* ARGSUSED */ 290static void 291dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx) 292{ 293 static const char *old_names[] = { 294 "scrub_bookmark", 295 "scrub_ddt_bookmark", 296 "scrub_ddt_class_max", 297 "scrub_queue", 298 "scrub_min_txg", 299 "scrub_max_txg", 300 "scrub_func", 301 "scrub_errors", 302 NULL 303 }; 304 305 dsl_pool_t *dp = scn->scn_dp; 306 spa_t *spa = dp->dp_spa; 307 int i; 308 309 /* Remove any remnants of an old-style scrub. */ 310 for (i = 0; old_names[i]; i++) { 311 (void) zap_remove(dp->dp_meta_objset, 312 DMU_POOL_DIRECTORY_OBJECT, old_names[i], tx); 313 } 314 315 if (scn->scn_phys.scn_queue_obj != 0) { 316 VERIFY(0 == dmu_object_free(dp->dp_meta_objset, 317 scn->scn_phys.scn_queue_obj, tx)); 318 scn->scn_phys.scn_queue_obj = 0; 319 } 320 321 /* 322 * If we were "restarted" from a stopped state, don't bother 323 * with anything else. 324 */ 325 if (scn->scn_phys.scn_state != DSS_SCANNING) 326 return; 327 328 if (complete) 329 scn->scn_phys.scn_state = DSS_FINISHED; 330 else 331 scn->scn_phys.scn_state = DSS_CANCELED; 332 333 if (dsl_scan_restarting(scn, tx)) 334 spa_history_log_internal(spa, "scan aborted, restarting", tx, 335 "errors=%llu", spa_get_errlog_size(spa)); 336 else if (!complete) 337 spa_history_log_internal(spa, "scan cancelled", tx, 338 "errors=%llu", spa_get_errlog_size(spa)); 339 else 340 spa_history_log_internal(spa, "scan done", tx, 341 "errors=%llu", spa_get_errlog_size(spa)); 342 343 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 344 mutex_enter(&spa->spa_scrub_lock); 345 while (spa->spa_scrub_inflight > 0) { 346 cv_wait(&spa->spa_scrub_io_cv, 347 &spa->spa_scrub_lock); 348 } 349 mutex_exit(&spa->spa_scrub_lock); 350 spa->spa_scrub_started = B_FALSE; 351 spa->spa_scrub_active = B_FALSE; 352 353 /* 354 * If the scrub/resilver completed, update all DTLs to 355 * reflect this. Whether it succeeded or not, vacate 356 * all temporary scrub DTLs. 357 */ 358 vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg, 359 complete ? scn->scn_phys.scn_max_txg : 0, B_TRUE); 360 if (complete) { 361 spa_event_notify(spa, NULL, scn->scn_phys.scn_min_txg ? 362 ESC_ZFS_RESILVER_FINISH : ESC_ZFS_SCRUB_FINISH); 363 } 364 spa_errlog_rotate(spa); 365 366 /* 367 * We may have finished replacing a device. 368 * Let the async thread assess this and handle the detach. 369 */ 370 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE); 371 } 372 373 scn->scn_phys.scn_end_time = gethrestime_sec(); 374} 375 376/* ARGSUSED */ 377static int 378dsl_scan_cancel_check(void *arg, dmu_tx_t *tx) 379{ 380 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 381 382 if (scn->scn_phys.scn_state != DSS_SCANNING) 383 return (SET_ERROR(ENOENT)); 384 return (0); 385} 386 387/* ARGSUSED */ 388static void 389dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx) 390{ 391 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 392 393 dsl_scan_done(scn, B_FALSE, tx); 394 dsl_scan_sync_state(scn, tx); 395} 396 397int 398dsl_scan_cancel(dsl_pool_t *dp) 399{ 400 return (dsl_sync_task(spa_name(dp->dp_spa), dsl_scan_cancel_check, 401 dsl_scan_cancel_sync, NULL, 3, ZFS_SPACE_CHECK_RESERVED)); 402} 403 404static void dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 405 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 406 dmu_objset_type_t ostype, dmu_tx_t *tx); 407static void dsl_scan_visitdnode(dsl_scan_t *, dsl_dataset_t *ds, 408 dmu_objset_type_t ostype, 409 dnode_phys_t *dnp, uint64_t object, dmu_tx_t *tx); 410 411void 412dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp) 413{ 414 zio_free(dp->dp_spa, txg, bp); 415} 416 417void 418dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp) 419{ 420 ASSERT(dsl_pool_sync_context(dp)); 421 zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, BP_GET_PSIZE(bpp), 422 pio->io_flags)); 423} 424 425static uint64_t 426dsl_scan_ds_maxtxg(dsl_dataset_t *ds) 427{ 428 uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg; 429 if (ds->ds_is_snapshot) 430 return (MIN(smt, dsl_dataset_phys(ds)->ds_creation_txg)); 431 return (smt); 432} 433 434static void 435dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx) 436{ 437 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, 438 DMU_POOL_DIRECTORY_OBJECT, 439 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 440 &scn->scn_phys, tx)); 441} 442 443extern int zfs_vdev_async_write_active_min_dirty_percent; 444 445static boolean_t 446dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_phys_t *zb) 447{ 448 /* we never skip user/group accounting objects */ 449 if (zb && (int64_t)zb->zb_object < 0) 450 return (B_FALSE); 451 452 if (scn->scn_pausing) 453 return (B_TRUE); /* we're already pausing */ 454 455 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark)) 456 return (B_FALSE); /* we're resuming */ 457 458 /* We only know how to resume from level-0 blocks. */ 459 if (zb && zb->zb_level != 0) 460 return (B_FALSE); 461 462 /* 463 * We pause if: 464 * - we have scanned for the maximum time: an entire txg 465 * timeout (default 5 sec) 466 * or 467 * - we have scanned for at least the minimum time (default 1 sec 468 * for scrub, 3 sec for resilver), and either we have sufficient 469 * dirty data that we are starting to write more quickly 470 * (default 30%), or someone is explicitly waiting for this txg 471 * to complete. 472 * or 473 * - the spa is shutting down because this pool is being exported 474 * or the machine is rebooting. 475 */ 476 int mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ? 477 zfs_resilver_min_time_ms : zfs_scan_min_time_ms; 478 uint64_t elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 479 int dirty_pct = scn->scn_dp->dp_dirty_total * 100 / zfs_dirty_data_max; 480 if (elapsed_nanosecs / NANOSEC >= zfs_txg_timeout || 481 (NSEC2MSEC(elapsed_nanosecs) > mintime && 482 (txg_sync_waiting(scn->scn_dp) || 483 dirty_pct >= zfs_vdev_async_write_active_min_dirty_percent)) || 484 spa_shutting_down(scn->scn_dp->dp_spa)) { 485 if (zb) { 486 dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n", 487 (longlong_t)zb->zb_objset, 488 (longlong_t)zb->zb_object, 489 (longlong_t)zb->zb_level, 490 (longlong_t)zb->zb_blkid); 491 scn->scn_phys.scn_bookmark = *zb; 492 } 493 dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n", 494 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 495 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 496 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 497 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 498 scn->scn_pausing = B_TRUE; 499 return (B_TRUE); 500 } 501 return (B_FALSE); 502} 503 504typedef struct zil_scan_arg { 505 dsl_pool_t *zsa_dp; 506 zil_header_t *zsa_zh; 507} zil_scan_arg_t; 508 509/* ARGSUSED */ 510static int 511dsl_scan_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 512{ 513 zil_scan_arg_t *zsa = arg; 514 dsl_pool_t *dp = zsa->zsa_dp; 515 dsl_scan_t *scn = dp->dp_scan; 516 zil_header_t *zh = zsa->zsa_zh; 517 zbookmark_phys_t zb; 518 519 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 520 return (0); 521 522 /* 523 * One block ("stubby") can be allocated a long time ago; we 524 * want to visit that one because it has been allocated 525 * (on-disk) even if it hasn't been claimed (even though for 526 * scrub there's nothing to do to it). 527 */ 528 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa)) 529 return (0); 530 531 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 532 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 533 534 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 535 return (0); 536} 537 538/* ARGSUSED */ 539static int 540dsl_scan_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) 541{ 542 if (lrc->lrc_txtype == TX_WRITE) { 543 zil_scan_arg_t *zsa = arg; 544 dsl_pool_t *dp = zsa->zsa_dp; 545 dsl_scan_t *scn = dp->dp_scan; 546 zil_header_t *zh = zsa->zsa_zh; 547 lr_write_t *lr = (lr_write_t *)lrc; 548 blkptr_t *bp = &lr->lr_blkptr; 549 zbookmark_phys_t zb; 550 551 if (BP_IS_HOLE(bp) || 552 bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 553 return (0); 554 555 /* 556 * birth can be < claim_txg if this record's txg is 557 * already txg sync'ed (but this log block contains 558 * other records that are not synced) 559 */ 560 if (claim_txg == 0 || bp->blk_birth < claim_txg) 561 return (0); 562 563 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 564 lr->lr_foid, ZB_ZIL_LEVEL, 565 lr->lr_offset / BP_GET_LSIZE(bp)); 566 567 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 568 } 569 return (0); 570} 571 572static void 573dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh) 574{ 575 uint64_t claim_txg = zh->zh_claim_txg; 576 zil_scan_arg_t zsa = { dp, zh }; 577 zilog_t *zilog; 578 579 /* 580 * We only want to visit blocks that have been claimed but not yet 581 * replayed (or, in read-only mode, blocks that *would* be claimed). 582 */ 583 if (claim_txg == 0 && spa_writeable(dp->dp_spa)) 584 return; 585 586 zilog = zil_alloc(dp->dp_meta_objset, zh); 587 588 (void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa, 589 claim_txg); 590 591 zil_free(zilog); 592} 593 594/* ARGSUSED */ 595static void 596dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp, 597 uint64_t objset, uint64_t object, uint64_t blkid) 598{ 599 zbookmark_phys_t czb; 600 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH; 601 602 if (zfs_no_scrub_prefetch) 603 return; 604 605 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_min_txg || 606 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)) 607 return; 608 609 SET_BOOKMARK(&czb, objset, object, BP_GET_LEVEL(bp), blkid); 610 611 (void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp, 612 NULL, NULL, ZIO_PRIORITY_ASYNC_READ, 613 ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb); 614} 615 616static boolean_t 617dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp, 618 const zbookmark_phys_t *zb) 619{ 620 /* 621 * We never skip over user/group accounting objects (obj<0) 622 */ 623 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) && 624 (int64_t)zb->zb_object >= 0) { 625 /* 626 * If we already visited this bp & everything below (in 627 * a prior txg sync), don't bother doing it again. 628 */ 629 if (zbookmark_subtree_completed(dnp, zb, 630 &scn->scn_phys.scn_bookmark)) 631 return (B_TRUE); 632 633 /* 634 * If we found the block we're trying to resume from, or 635 * we went past it to a different object, zero it out to 636 * indicate that it's OK to start checking for pausing 637 * again. 638 */ 639 if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 || 640 zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) { 641 dprintf("resuming at %llx/%llx/%llx/%llx\n", 642 (longlong_t)zb->zb_objset, 643 (longlong_t)zb->zb_object, 644 (longlong_t)zb->zb_level, 645 (longlong_t)zb->zb_blkid); 646 bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb)); 647 } 648 } 649 return (B_FALSE); 650} 651 652/* 653 * Return nonzero on i/o error. 654 * Return new buf to write out in *bufp. 655 */ 656static int 657dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype, 658 dnode_phys_t *dnp, const blkptr_t *bp, 659 const zbookmark_phys_t *zb, dmu_tx_t *tx) 660{ 661 dsl_pool_t *dp = scn->scn_dp; 662 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD; 663 int err; 664 665 if (BP_GET_LEVEL(bp) > 0) { 666 arc_flags_t flags = ARC_FLAG_WAIT; 667 int i; 668 blkptr_t *cbp; 669 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 670 arc_buf_t *buf; 671 672 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 673 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 674 if (err) { 675 scn->scn_phys.scn_errors++; 676 return (err); 677 } 678 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 679 dsl_scan_prefetch(scn, buf, cbp, zb->zb_objset, 680 zb->zb_object, zb->zb_blkid * epb + i); 681 } 682 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 683 zbookmark_phys_t czb; 684 685 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 686 zb->zb_level - 1, 687 zb->zb_blkid * epb + i); 688 dsl_scan_visitbp(cbp, &czb, dnp, 689 ds, scn, ostype, tx); 690 } 691 (void) arc_buf_remove_ref(buf, &buf); 692 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 693 arc_flags_t flags = ARC_FLAG_WAIT; 694 dnode_phys_t *cdnp; 695 int i, j; 696 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 697 arc_buf_t *buf; 698 699 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 700 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 701 if (err) { 702 scn->scn_phys.scn_errors++; 703 return (err); 704 } 705 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 706 for (j = 0; j < cdnp->dn_nblkptr; j++) { 707 blkptr_t *cbp = &cdnp->dn_blkptr[j]; 708 dsl_scan_prefetch(scn, buf, cbp, 709 zb->zb_objset, zb->zb_blkid * epb + i, j); 710 } 711 } 712 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 713 dsl_scan_visitdnode(scn, ds, ostype, 714 cdnp, zb->zb_blkid * epb + i, tx); 715 } 716 717 (void) arc_buf_remove_ref(buf, &buf); 718 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 719 arc_flags_t flags = ARC_FLAG_WAIT; 720 objset_phys_t *osp; 721 arc_buf_t *buf; 722 723 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 724 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 725 if (err) { 726 scn->scn_phys.scn_errors++; 727 return (err); 728 } 729 730 osp = buf->b_data; 731 732 dsl_scan_visitdnode(scn, ds, osp->os_type, 733 &osp->os_meta_dnode, DMU_META_DNODE_OBJECT, tx); 734 735 if (OBJSET_BUF_HAS_USERUSED(buf)) { 736 /* 737 * We also always visit user/group accounting 738 * objects, and never skip them, even if we are 739 * pausing. This is necessary so that the space 740 * deltas from this txg get integrated. 741 */ 742 dsl_scan_visitdnode(scn, ds, osp->os_type, 743 &osp->os_groupused_dnode, 744 DMU_GROUPUSED_OBJECT, tx); 745 dsl_scan_visitdnode(scn, ds, osp->os_type, 746 &osp->os_userused_dnode, 747 DMU_USERUSED_OBJECT, tx); 748 } 749 (void) arc_buf_remove_ref(buf, &buf); 750 } 751 752 return (0); 753} 754 755static void 756dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds, 757 dmu_objset_type_t ostype, dnode_phys_t *dnp, 758 uint64_t object, dmu_tx_t *tx) 759{ 760 int j; 761 762 for (j = 0; j < dnp->dn_nblkptr; j++) { 763 zbookmark_phys_t czb; 764 765 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 766 dnp->dn_nlevels - 1, j); 767 dsl_scan_visitbp(&dnp->dn_blkptr[j], 768 &czb, dnp, ds, scn, ostype, tx); 769 } 770 771 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 772 zbookmark_phys_t czb; 773 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 774 0, DMU_SPILL_BLKID); 775 dsl_scan_visitbp(&dnp->dn_spill, 776 &czb, dnp, ds, scn, ostype, tx); 777 } 778} 779 780/* 781 * The arguments are in this order because mdb can only print the 782 * first 5; we want them to be useful. 783 */ 784static void 785dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 786 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 787 dmu_objset_type_t ostype, dmu_tx_t *tx) 788{ 789 dsl_pool_t *dp = scn->scn_dp; 790 arc_buf_t *buf = NULL; 791 blkptr_t bp_toread = *bp; 792 793 /* ASSERT(pbuf == NULL || arc_released(pbuf)); */ 794 795 if (dsl_scan_check_pause(scn, zb)) 796 return; 797 798 if (dsl_scan_check_resume(scn, dnp, zb)) 799 return; 800 801 if (BP_IS_HOLE(bp)) 802 return; 803 804 scn->scn_visited_this_txg++; 805 806 dprintf_bp(bp, 807 "visiting ds=%p/%llu zb=%llx/%llx/%llx/%llx bp=%p", 808 ds, ds ? ds->ds_object : 0, 809 zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid, 810 bp); 811 812 if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 813 return; 814 815 if (dsl_scan_recurse(scn, ds, ostype, dnp, &bp_toread, zb, tx) != 0) 816 return; 817 818 /* 819 * If dsl_scan_ddt() has aready visited this block, it will have 820 * already done any translations or scrubbing, so don't call the 821 * callback again. 822 */ 823 if (ddt_class_contains(dp->dp_spa, 824 scn->scn_phys.scn_ddt_class_max, bp)) { 825 ASSERT(buf == NULL); 826 return; 827 } 828 829 /* 830 * If this block is from the future (after cur_max_txg), then we 831 * are doing this on behalf of a deleted snapshot, and we will 832 * revisit the future block on the next pass of this dataset. 833 * Don't scan it now unless we need to because something 834 * under it was modified. 835 */ 836 if (BP_PHYSICAL_BIRTH(bp) <= scn->scn_phys.scn_cur_max_txg) { 837 scan_funcs[scn->scn_phys.scn_func](dp, bp, zb); 838 } 839} 840 841static void 842dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp, 843 dmu_tx_t *tx) 844{ 845 zbookmark_phys_t zb; 846 847 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET, 848 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 849 dsl_scan_visitbp(bp, &zb, NULL, 850 ds, scn, DMU_OST_NONE, tx); 851 852 dprintf_ds(ds, "finished scan%s", ""); 853} 854 855void 856dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx) 857{ 858 dsl_pool_t *dp = ds->ds_dir->dd_pool; 859 dsl_scan_t *scn = dp->dp_scan; 860 uint64_t mintxg; 861 862 if (scn->scn_phys.scn_state != DSS_SCANNING) 863 return; 864 865 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 866 if (ds->ds_is_snapshot) { 867 /* 868 * Note: 869 * - scn_cur_{min,max}_txg stays the same. 870 * - Setting the flag is not really necessary if 871 * scn_cur_max_txg == scn_max_txg, because there 872 * is nothing after this snapshot that we care 873 * about. However, we set it anyway and then 874 * ignore it when we retraverse it in 875 * dsl_scan_visitds(). 876 */ 877 scn->scn_phys.scn_bookmark.zb_objset = 878 dsl_dataset_phys(ds)->ds_next_snap_obj; 879 zfs_dbgmsg("destroying ds %llu; currently traversing; " 880 "reset zb_objset to %llu", 881 (u_longlong_t)ds->ds_object, 882 (u_longlong_t)dsl_dataset_phys(ds)-> 883 ds_next_snap_obj); 884 scn->scn_phys.scn_flags |= DSF_VISIT_DS_AGAIN; 885 } else { 886 SET_BOOKMARK(&scn->scn_phys.scn_bookmark, 887 ZB_DESTROYED_OBJSET, 0, 0, 0); 888 zfs_dbgmsg("destroying ds %llu; currently traversing; " 889 "reset bookmark to -1,0,0,0", 890 (u_longlong_t)ds->ds_object); 891 } 892 } else if (zap_lookup_int_key(dp->dp_meta_objset, 893 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 894 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1); 895 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 896 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 897 if (ds->ds_is_snapshot) { 898 /* 899 * We keep the same mintxg; it could be > 900 * ds_creation_txg if the previous snapshot was 901 * deleted too. 902 */ 903 VERIFY(zap_add_int_key(dp->dp_meta_objset, 904 scn->scn_phys.scn_queue_obj, 905 dsl_dataset_phys(ds)->ds_next_snap_obj, 906 mintxg, tx) == 0); 907 zfs_dbgmsg("destroying ds %llu; in queue; " 908 "replacing with %llu", 909 (u_longlong_t)ds->ds_object, 910 (u_longlong_t)dsl_dataset_phys(ds)-> 911 ds_next_snap_obj); 912 } else { 913 zfs_dbgmsg("destroying ds %llu; in queue; removing", 914 (u_longlong_t)ds->ds_object); 915 } 916 } 917 918 /* 919 * dsl_scan_sync() should be called after this, and should sync 920 * out our changed state, but just to be safe, do it here. 921 */ 922 dsl_scan_sync_state(scn, tx); 923} 924 925void 926dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx) 927{ 928 dsl_pool_t *dp = ds->ds_dir->dd_pool; 929 dsl_scan_t *scn = dp->dp_scan; 930 uint64_t mintxg; 931 932 if (scn->scn_phys.scn_state != DSS_SCANNING) 933 return; 934 935 ASSERT(dsl_dataset_phys(ds)->ds_prev_snap_obj != 0); 936 937 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 938 scn->scn_phys.scn_bookmark.zb_objset = 939 dsl_dataset_phys(ds)->ds_prev_snap_obj; 940 zfs_dbgmsg("snapshotting ds %llu; currently traversing; " 941 "reset zb_objset to %llu", 942 (u_longlong_t)ds->ds_object, 943 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 944 } else if (zap_lookup_int_key(dp->dp_meta_objset, 945 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 946 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 947 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 948 VERIFY(zap_add_int_key(dp->dp_meta_objset, 949 scn->scn_phys.scn_queue_obj, 950 dsl_dataset_phys(ds)->ds_prev_snap_obj, mintxg, tx) == 0); 951 zfs_dbgmsg("snapshotting ds %llu; in queue; " 952 "replacing with %llu", 953 (u_longlong_t)ds->ds_object, 954 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 955 } 956 dsl_scan_sync_state(scn, tx); 957} 958 959void 960dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx) 961{ 962 dsl_pool_t *dp = ds1->ds_dir->dd_pool; 963 dsl_scan_t *scn = dp->dp_scan; 964 uint64_t mintxg; 965 966 if (scn->scn_phys.scn_state != DSS_SCANNING) 967 return; 968 969 if (scn->scn_phys.scn_bookmark.zb_objset == ds1->ds_object) { 970 scn->scn_phys.scn_bookmark.zb_objset = ds2->ds_object; 971 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 972 "reset zb_objset to %llu", 973 (u_longlong_t)ds1->ds_object, 974 (u_longlong_t)ds2->ds_object); 975 } else if (scn->scn_phys.scn_bookmark.zb_objset == ds2->ds_object) { 976 scn->scn_phys.scn_bookmark.zb_objset = ds1->ds_object; 977 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 978 "reset zb_objset to %llu", 979 (u_longlong_t)ds2->ds_object, 980 (u_longlong_t)ds1->ds_object); 981 } 982 983 if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 984 ds1->ds_object, &mintxg) == 0) { 985 int err; 986 987 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 988 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 989 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 990 scn->scn_phys.scn_queue_obj, ds1->ds_object, tx)); 991 err = zap_add_int_key(dp->dp_meta_objset, 992 scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg, tx); 993 VERIFY(err == 0 || err == EEXIST); 994 if (err == EEXIST) { 995 /* Both were there to begin with */ 996 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 997 scn->scn_phys.scn_queue_obj, 998 ds1->ds_object, mintxg, tx)); 999 } 1000 zfs_dbgmsg("clone_swap ds %llu; in queue; " 1001 "replacing with %llu", 1002 (u_longlong_t)ds1->ds_object, 1003 (u_longlong_t)ds2->ds_object); 1004 } else if (zap_lookup_int_key(dp->dp_meta_objset, 1005 scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg) == 0) { 1006 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 1007 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 1008 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 1009 scn->scn_phys.scn_queue_obj, ds2->ds_object, tx)); 1010 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 1011 scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg, tx)); 1012 zfs_dbgmsg("clone_swap ds %llu; in queue; " 1013 "replacing with %llu", 1014 (u_longlong_t)ds2->ds_object, 1015 (u_longlong_t)ds1->ds_object); 1016 } 1017 1018 dsl_scan_sync_state(scn, tx); 1019} 1020 1021struct enqueue_clones_arg { 1022 dmu_tx_t *tx; 1023 uint64_t originobj; 1024}; 1025 1026/* ARGSUSED */ 1027static int 1028enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1029{ 1030 struct enqueue_clones_arg *eca = arg; 1031 dsl_dataset_t *ds; 1032 int err; 1033 dsl_scan_t *scn = dp->dp_scan; 1034 1035 if (dsl_dir_phys(hds->ds_dir)->dd_origin_obj != eca->originobj) 1036 return (0); 1037 1038 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1039 if (err) 1040 return (err); 1041 1042 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != eca->originobj) { 1043 dsl_dataset_t *prev; 1044 err = dsl_dataset_hold_obj(dp, 1045 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1046 1047 dsl_dataset_rele(ds, FTAG); 1048 if (err) 1049 return (err); 1050 ds = prev; 1051 } 1052 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1053 scn->scn_phys.scn_queue_obj, ds->ds_object, 1054 dsl_dataset_phys(ds)->ds_prev_snap_txg, eca->tx) == 0); 1055 dsl_dataset_rele(ds, FTAG); 1056 return (0); 1057} 1058 1059static void 1060dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx) 1061{ 1062 dsl_pool_t *dp = scn->scn_dp; 1063 dsl_dataset_t *ds; 1064 objset_t *os; 1065 1066 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1067 1068 if (scn->scn_phys.scn_cur_min_txg >= 1069 scn->scn_phys.scn_max_txg) { 1070 /* 1071 * This can happen if this snapshot was created after the 1072 * scan started, and we already completed a previous snapshot 1073 * that was created after the scan started. This snapshot 1074 * only references blocks with: 1075 * 1076 * birth < our ds_creation_txg 1077 * cur_min_txg is no less than ds_creation_txg. 1078 * We have already visited these blocks. 1079 * or 1080 * birth > scn_max_txg 1081 * The scan requested not to visit these blocks. 1082 * 1083 * Subsequent snapshots (and clones) can reference our 1084 * blocks, or blocks with even higher birth times. 1085 * Therefore we do not need to visit them either, 1086 * so we do not add them to the work queue. 1087 * 1088 * Note that checking for cur_min_txg >= cur_max_txg 1089 * is not sufficient, because in that case we may need to 1090 * visit subsequent snapshots. This happens when min_txg > 0, 1091 * which raises cur_min_txg. In this case we will visit 1092 * this dataset but skip all of its blocks, because the 1093 * rootbp's birth time is < cur_min_txg. Then we will 1094 * add the next snapshots/clones to the work queue. 1095 */ 1096 char *dsname = kmem_alloc(MAXNAMELEN, KM_SLEEP); 1097 dsl_dataset_name(ds, dsname); 1098 zfs_dbgmsg("scanning dataset %llu (%s) is unnecessary because " 1099 "cur_min_txg (%llu) >= max_txg (%llu)", 1100 dsobj, dsname, 1101 scn->scn_phys.scn_cur_min_txg, 1102 scn->scn_phys.scn_max_txg); 1103 kmem_free(dsname, MAXNAMELEN); 1104 1105 goto out; 1106 } 1107 1108 if (dmu_objset_from_ds(ds, &os)) 1109 goto out; 1110 1111 /* 1112 * Only the ZIL in the head (non-snapshot) is valid. Even though 1113 * snapshots can have ZIL block pointers (which may be the same 1114 * BP as in the head), they must be ignored. So we traverse the 1115 * ZIL here, rather than in scan_recurse(), because the regular 1116 * snapshot block-sharing rules don't apply to it. 1117 */ 1118 if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !ds->ds_is_snapshot) 1119 dsl_scan_zil(dp, &os->os_zil_header); 1120 1121 /* 1122 * Iterate over the bps in this ds. 1123 */ 1124 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1125 dsl_scan_visit_rootbp(scn, ds, &dsl_dataset_phys(ds)->ds_bp, tx); 1126 1127 char *dsname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP); 1128 dsl_dataset_name(ds, dsname); 1129 zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; " 1130 "pausing=%u", 1131 (longlong_t)dsobj, dsname, 1132 (longlong_t)scn->scn_phys.scn_cur_min_txg, 1133 (longlong_t)scn->scn_phys.scn_cur_max_txg, 1134 (int)scn->scn_pausing); 1135 kmem_free(dsname, ZFS_MAX_DATASET_NAME_LEN); 1136 1137 if (scn->scn_pausing) 1138 goto out; 1139 1140 /* 1141 * We've finished this pass over this dataset. 1142 */ 1143 1144 /* 1145 * If we did not completely visit this dataset, do another pass. 1146 */ 1147 if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) { 1148 zfs_dbgmsg("incomplete pass; visiting again"); 1149 scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN; 1150 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1151 scn->scn_phys.scn_queue_obj, ds->ds_object, 1152 scn->scn_phys.scn_cur_max_txg, tx) == 0); 1153 goto out; 1154 } 1155 1156 /* 1157 * Add descendent datasets to work queue. 1158 */ 1159 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) { 1160 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1161 scn->scn_phys.scn_queue_obj, 1162 dsl_dataset_phys(ds)->ds_next_snap_obj, 1163 dsl_dataset_phys(ds)->ds_creation_txg, tx) == 0); 1164 } 1165 if (dsl_dataset_phys(ds)->ds_num_children > 1) { 1166 boolean_t usenext = B_FALSE; 1167 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) { 1168 uint64_t count; 1169 /* 1170 * A bug in a previous version of the code could 1171 * cause upgrade_clones_cb() to not set 1172 * ds_next_snap_obj when it should, leading to a 1173 * missing entry. Therefore we can only use the 1174 * next_clones_obj when its count is correct. 1175 */ 1176 int err = zap_count(dp->dp_meta_objset, 1177 dsl_dataset_phys(ds)->ds_next_clones_obj, &count); 1178 if (err == 0 && 1179 count == dsl_dataset_phys(ds)->ds_num_children - 1) 1180 usenext = B_TRUE; 1181 } 1182 1183 if (usenext) { 1184 VERIFY0(zap_join_key(dp->dp_meta_objset, 1185 dsl_dataset_phys(ds)->ds_next_clones_obj, 1186 scn->scn_phys.scn_queue_obj, 1187 dsl_dataset_phys(ds)->ds_creation_txg, tx)); 1188 } else { 1189 struct enqueue_clones_arg eca; 1190 eca.tx = tx; 1191 eca.originobj = ds->ds_object; 1192 1193 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1194 enqueue_clones_cb, &eca, DS_FIND_CHILDREN)); 1195 } 1196 } 1197 1198out: 1199 dsl_dataset_rele(ds, FTAG); 1200} 1201 1202/* ARGSUSED */ 1203static int 1204enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1205{ 1206 dmu_tx_t *tx = arg; 1207 dsl_dataset_t *ds; 1208 int err; 1209 dsl_scan_t *scn = dp->dp_scan; 1210 1211 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1212 if (err) 1213 return (err); 1214 1215 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 1216 dsl_dataset_t *prev; 1217 err = dsl_dataset_hold_obj(dp, 1218 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1219 if (err) { 1220 dsl_dataset_rele(ds, FTAG); 1221 return (err); 1222 } 1223 1224 /* 1225 * If this is a clone, we don't need to worry about it for now. 1226 */ 1227 if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object) { 1228 dsl_dataset_rele(ds, FTAG); 1229 dsl_dataset_rele(prev, FTAG); 1230 return (0); 1231 } 1232 dsl_dataset_rele(ds, FTAG); 1233 ds = prev; 1234 } 1235 1236 VERIFY(zap_add_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 1237 ds->ds_object, dsl_dataset_phys(ds)->ds_prev_snap_txg, tx) == 0); 1238 dsl_dataset_rele(ds, FTAG); 1239 return (0); 1240} 1241 1242/* 1243 * Scrub/dedup interaction. 1244 * 1245 * If there are N references to a deduped block, we don't want to scrub it 1246 * N times -- ideally, we should scrub it exactly once. 1247 * 1248 * We leverage the fact that the dde's replication class (enum ddt_class) 1249 * is ordered from highest replication class (DDT_CLASS_DITTO) to lowest 1250 * (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order. 1251 * 1252 * To prevent excess scrubbing, the scrub begins by walking the DDT 1253 * to find all blocks with refcnt > 1, and scrubs each of these once. 1254 * Since there are two replication classes which contain blocks with 1255 * refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first. 1256 * Finally the top-down scrub begins, only visiting blocks with refcnt == 1. 1257 * 1258 * There would be nothing more to say if a block's refcnt couldn't change 1259 * during a scrub, but of course it can so we must account for changes 1260 * in a block's replication class. 1261 * 1262 * Here's an example of what can occur: 1263 * 1264 * If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1 1265 * when visited during the top-down scrub phase, it will be scrubbed twice. 1266 * This negates our scrub optimization, but is otherwise harmless. 1267 * 1268 * If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1 1269 * on each visit during the top-down scrub phase, it will never be scrubbed. 1270 * To catch this, ddt_sync_entry() notifies the scrub code whenever a block's 1271 * reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to 1272 * DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1 1273 * while a scrub is in progress, it scrubs the block right then. 1274 */ 1275static void 1276dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx) 1277{ 1278 ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark; 1279 ddt_entry_t dde = { 0 }; 1280 int error; 1281 uint64_t n = 0; 1282 1283 while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) { 1284 ddt_t *ddt; 1285 1286 if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max) 1287 break; 1288 dprintf("visiting ddb=%llu/%llu/%llu/%llx\n", 1289 (longlong_t)ddb->ddb_class, 1290 (longlong_t)ddb->ddb_type, 1291 (longlong_t)ddb->ddb_checksum, 1292 (longlong_t)ddb->ddb_cursor); 1293 1294 /* There should be no pending changes to the dedup table */ 1295 ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum]; 1296 ASSERT(avl_first(&ddt->ddt_tree) == NULL); 1297 1298 dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx); 1299 n++; 1300 1301 if (dsl_scan_check_pause(scn, NULL)) 1302 break; 1303 } 1304 1305 zfs_dbgmsg("scanned %llu ddt entries with class_max = %u; pausing=%u", 1306 (longlong_t)n, (int)scn->scn_phys.scn_ddt_class_max, 1307 (int)scn->scn_pausing); 1308 1309 ASSERT(error == 0 || error == ENOENT); 1310 ASSERT(error != ENOENT || 1311 ddb->ddb_class > scn->scn_phys.scn_ddt_class_max); 1312} 1313 1314/* ARGSUSED */ 1315void 1316dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum, 1317 ddt_entry_t *dde, dmu_tx_t *tx) 1318{ 1319 const ddt_key_t *ddk = &dde->dde_key; 1320 ddt_phys_t *ddp = dde->dde_phys; 1321 blkptr_t bp; 1322 zbookmark_phys_t zb = { 0 }; 1323 1324 if (scn->scn_phys.scn_state != DSS_SCANNING) 1325 return; 1326 1327 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1328 if (ddp->ddp_phys_birth == 0 || 1329 ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg) 1330 continue; 1331 ddt_bp_create(checksum, ddk, ddp, &bp); 1332 1333 scn->scn_visited_this_txg++; 1334 scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb); 1335 } 1336} 1337 1338static void 1339dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx) 1340{ 1341 dsl_pool_t *dp = scn->scn_dp; 1342 zap_cursor_t zc; 1343 zap_attribute_t za; 1344 1345 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1346 scn->scn_phys.scn_ddt_class_max) { 1347 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1348 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1349 dsl_scan_ddt(scn, tx); 1350 if (scn->scn_pausing) 1351 return; 1352 } 1353 1354 if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) { 1355 /* First do the MOS & ORIGIN */ 1356 1357 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1358 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1359 dsl_scan_visit_rootbp(scn, NULL, 1360 &dp->dp_meta_rootbp, tx); 1361 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); 1362 if (scn->scn_pausing) 1363 return; 1364 1365 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) { 1366 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1367 enqueue_cb, tx, DS_FIND_CHILDREN)); 1368 } else { 1369 dsl_scan_visitds(scn, 1370 dp->dp_origin_snap->ds_object, tx); 1371 } 1372 ASSERT(!scn->scn_pausing); 1373 } else if (scn->scn_phys.scn_bookmark.zb_objset != 1374 ZB_DESTROYED_OBJSET) { 1375 /* 1376 * If we were paused, continue from here. Note if the 1377 * ds we were paused on was deleted, the zb_objset may 1378 * be -1, so we will skip this and find a new objset 1379 * below. 1380 */ 1381 dsl_scan_visitds(scn, scn->scn_phys.scn_bookmark.zb_objset, tx); 1382 if (scn->scn_pausing) 1383 return; 1384 } 1385 1386 /* 1387 * In case we were paused right at the end of the ds, zero the 1388 * bookmark so we don't think that we're still trying to resume. 1389 */ 1390 bzero(&scn->scn_phys.scn_bookmark, sizeof (zbookmark_phys_t)); 1391 1392 /* keep pulling things out of the zap-object-as-queue */ 1393 while (zap_cursor_init(&zc, dp->dp_meta_objset, 1394 scn->scn_phys.scn_queue_obj), 1395 zap_cursor_retrieve(&zc, &za) == 0) { 1396 dsl_dataset_t *ds; 1397 uint64_t dsobj; 1398 1399 dsobj = strtonum(za.za_name, NULL); 1400 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 1401 scn->scn_phys.scn_queue_obj, dsobj, tx)); 1402 1403 /* Set up min/max txg */ 1404 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1405 if (za.za_first_integer != 0) { 1406 scn->scn_phys.scn_cur_min_txg = 1407 MAX(scn->scn_phys.scn_min_txg, 1408 za.za_first_integer); 1409 } else { 1410 scn->scn_phys.scn_cur_min_txg = 1411 MAX(scn->scn_phys.scn_min_txg, 1412 dsl_dataset_phys(ds)->ds_prev_snap_txg); 1413 } 1414 scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds); 1415 dsl_dataset_rele(ds, FTAG); 1416 1417 dsl_scan_visitds(scn, dsobj, tx); 1418 zap_cursor_fini(&zc); 1419 if (scn->scn_pausing) 1420 return; 1421 } 1422 zap_cursor_fini(&zc); 1423} 1424 1425static boolean_t 1426dsl_scan_free_should_pause(dsl_scan_t *scn) 1427{ 1428 uint64_t elapsed_nanosecs; 1429 1430 if (zfs_recover) 1431 return (B_FALSE); 1432 1433 if (scn->scn_visited_this_txg >= zfs_free_max_blocks) 1434 return (B_TRUE); 1435 1436 elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 1437 return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || 1438 (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms && 1439 txg_sync_waiting(scn->scn_dp)) || 1440 spa_shutting_down(scn->scn_dp->dp_spa)); 1441} 1442 1443static int 1444dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1445{ 1446 dsl_scan_t *scn = arg; 1447 1448 if (!scn->scn_is_bptree || 1449 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) { 1450 if (dsl_scan_free_should_pause(scn)) 1451 return (SET_ERROR(ERESTART)); 1452 } 1453 1454 zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa, 1455 dmu_tx_get_txg(tx), bp, BP_GET_PSIZE(bp), 0)); 1456 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD, 1457 -bp_get_dsize_sync(scn->scn_dp->dp_spa, bp), 1458 -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx); 1459 scn->scn_visited_this_txg++; 1460 return (0); 1461} 1462 1463boolean_t 1464dsl_scan_active(dsl_scan_t *scn) 1465{ 1466 spa_t *spa = scn->scn_dp->dp_spa; 1467 uint64_t used = 0, comp, uncomp; 1468 1469 if (spa->spa_load_state != SPA_LOAD_NONE) 1470 return (B_FALSE); 1471 if (spa_shutting_down(spa)) 1472 return (B_FALSE); 1473 if (scn->scn_phys.scn_state == DSS_SCANNING || 1474 (scn->scn_async_destroying && !scn->scn_async_stalled)) 1475 return (B_TRUE); 1476 1477 if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1478 (void) bpobj_space(&scn->scn_dp->dp_free_bpobj, 1479 &used, &comp, &uncomp); 1480 } 1481 return (used != 0); 1482} 1483 1484void 1485dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) 1486{ 1487 dsl_scan_t *scn = dp->dp_scan; 1488 spa_t *spa = dp->dp_spa; 1489 int err = 0; 1490 1491 /* 1492 * Check for scn_restart_txg before checking spa_load_state, so 1493 * that we can restart an old-style scan while the pool is being 1494 * imported (see dsl_scan_init). 1495 */ 1496 if (dsl_scan_restarting(scn, tx)) { 1497 pool_scan_func_t func = POOL_SCAN_SCRUB; 1498 dsl_scan_done(scn, B_FALSE, tx); 1499 if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) 1500 func = POOL_SCAN_RESILVER; 1501 zfs_dbgmsg("restarting scan func=%u txg=%llu", 1502 func, tx->tx_txg); 1503 dsl_scan_setup_sync(&func, tx); 1504 } 1505 1506 /* 1507 * Only process scans in sync pass 1. 1508 */ 1509 if (spa_sync_pass(dp->dp_spa) > 1) 1510 return; 1511 1512 /* 1513 * If the spa is shutting down, then stop scanning. This will 1514 * ensure that the scan does not dirty any new data during the 1515 * shutdown phase. 1516 */ 1517 if (spa_shutting_down(spa)) 1518 return; 1519 1520 /* 1521 * If the scan is inactive due to a stalled async destroy, try again. 1522 */ 1523 if (!scn->scn_async_stalled && !dsl_scan_active(scn)) 1524 return; 1525 1526 scn->scn_visited_this_txg = 0; 1527 scn->scn_pausing = B_FALSE; 1528 scn->scn_sync_start_time = gethrtime(); 1529 spa->spa_scrub_active = B_TRUE; 1530 1531 /* 1532 * First process the async destroys. If we pause, don't do 1533 * any scrubbing or resilvering. This ensures that there are no 1534 * async destroys while we are scanning, so the scan code doesn't 1535 * have to worry about traversing it. It is also faster to free the 1536 * blocks than to scrub them. 1537 */ 1538 if (zfs_free_bpobj_enabled && 1539 spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1540 scn->scn_is_bptree = B_FALSE; 1541 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1542 NULL, ZIO_FLAG_MUSTSUCCEED); 1543 err = bpobj_iterate(&dp->dp_free_bpobj, 1544 dsl_scan_free_block_cb, scn, tx); 1545 VERIFY3U(0, ==, zio_wait(scn->scn_zio_root)); 1546 1547 if (err != 0 && err != ERESTART) 1548 zfs_panic_recover("error %u from bpobj_iterate()", err); 1549 } 1550 1551 if (err == 0 && spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) { 1552 ASSERT(scn->scn_async_destroying); 1553 scn->scn_is_bptree = B_TRUE; 1554 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1555 NULL, ZIO_FLAG_MUSTSUCCEED); 1556 err = bptree_iterate(dp->dp_meta_objset, 1557 dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, scn, tx); 1558 VERIFY0(zio_wait(scn->scn_zio_root)); 1559 1560 if (err == EIO || err == ECKSUM) { 1561 err = 0; 1562 } else if (err != 0 && err != ERESTART) { 1563 zfs_panic_recover("error %u from " 1564 "traverse_dataset_destroyed()", err); 1565 } 1566 1567 if (bptree_is_empty(dp->dp_meta_objset, dp->dp_bptree_obj)) { 1568 /* finished; deactivate async destroy feature */ 1569 spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, tx); 1570 ASSERT(!spa_feature_is_active(spa, 1571 SPA_FEATURE_ASYNC_DESTROY)); 1572 VERIFY0(zap_remove(dp->dp_meta_objset, 1573 DMU_POOL_DIRECTORY_OBJECT, 1574 DMU_POOL_BPTREE_OBJ, tx)); 1575 VERIFY0(bptree_free(dp->dp_meta_objset, 1576 dp->dp_bptree_obj, tx)); 1577 dp->dp_bptree_obj = 0; 1578 scn->scn_async_destroying = B_FALSE; 1579 scn->scn_async_stalled = B_FALSE; 1580 } else { 1581 /* 1582 * If we didn't make progress, mark the async 1583 * destroy as stalled, so that we will not initiate 1584 * a spa_sync() on its behalf. Note that we only 1585 * check this if we are not finished, because if the 1586 * bptree had no blocks for us to visit, we can 1587 * finish without "making progress". 1588 */ 1589 scn->scn_async_stalled = 1590 (scn->scn_visited_this_txg == 0); 1591 } 1592 } 1593 if (scn->scn_visited_this_txg) { 1594 zfs_dbgmsg("freed %llu blocks in %llums from " 1595 "free_bpobj/bptree txg %llu; err=%d", 1596 (longlong_t)scn->scn_visited_this_txg, 1597 (longlong_t) 1598 NSEC2MSEC(gethrtime() - scn->scn_sync_start_time), 1599 (longlong_t)tx->tx_txg, err); 1600 scn->scn_visited_this_txg = 0; 1601 1602 /* 1603 * Write out changes to the DDT that may be required as a 1604 * result of the blocks freed. This ensures that the DDT 1605 * is clean when a scrub/resilver runs. 1606 */ 1607 ddt_sync(spa, tx->tx_txg); 1608 } 1609 if (err != 0) 1610 return; 1611 if (dp->dp_free_dir != NULL && !scn->scn_async_destroying && 1612 zfs_free_leak_on_eio && 1613 (dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes != 0 || 1614 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes != 0 || 1615 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes != 0)) { 1616 /* 1617 * We have finished background destroying, but there is still 1618 * some space left in the dp_free_dir. Transfer this leaked 1619 * space to the dp_leak_dir. 1620 */ 1621 if (dp->dp_leak_dir == NULL) { 1622 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); 1623 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, 1624 LEAK_DIR_NAME, tx); 1625 VERIFY0(dsl_pool_open_special_dir(dp, 1626 LEAK_DIR_NAME, &dp->dp_leak_dir)); 1627 rrw_exit(&dp->dp_config_rwlock, FTAG); 1628 } 1629 dsl_dir_diduse_space(dp->dp_leak_dir, DD_USED_HEAD, 1630 dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1631 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1632 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1633 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 1634 -dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1635 -dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1636 -dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1637 } 1638 if (dp->dp_free_dir != NULL && !scn->scn_async_destroying) { 1639 /* finished; verify that space accounting went to zero */ 1640 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes); 1641 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes); 1642 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes); 1643 } 1644 1645 if (scn->scn_phys.scn_state != DSS_SCANNING) 1646 return; 1647 1648 if (scn->scn_done_txg == tx->tx_txg) { 1649 ASSERT(!scn->scn_pausing); 1650 /* finished with scan. */ 1651 zfs_dbgmsg("txg %llu scan complete", tx->tx_txg); 1652 dsl_scan_done(scn, B_TRUE, tx); 1653 ASSERT3U(spa->spa_scrub_inflight, ==, 0); 1654 dsl_scan_sync_state(scn, tx); 1655 return; 1656 } 1657 1658 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1659 scn->scn_phys.scn_ddt_class_max) { 1660 zfs_dbgmsg("doing scan sync txg %llu; " 1661 "ddt bm=%llu/%llu/%llu/%llx", 1662 (longlong_t)tx->tx_txg, 1663 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 1664 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 1665 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 1666 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 1667 ASSERT(scn->scn_phys.scn_bookmark.zb_objset == 0); 1668 ASSERT(scn->scn_phys.scn_bookmark.zb_object == 0); 1669 ASSERT(scn->scn_phys.scn_bookmark.zb_level == 0); 1670 ASSERT(scn->scn_phys.scn_bookmark.zb_blkid == 0); 1671 } else { 1672 zfs_dbgmsg("doing scan sync txg %llu; bm=%llu/%llu/%llu/%llu", 1673 (longlong_t)tx->tx_txg, 1674 (longlong_t)scn->scn_phys.scn_bookmark.zb_objset, 1675 (longlong_t)scn->scn_phys.scn_bookmark.zb_object, 1676 (longlong_t)scn->scn_phys.scn_bookmark.zb_level, 1677 (longlong_t)scn->scn_phys.scn_bookmark.zb_blkid); 1678 } 1679 1680 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1681 NULL, ZIO_FLAG_CANFAIL); 1682 dsl_pool_config_enter(dp, FTAG); 1683 dsl_scan_visit(scn, tx); 1684 dsl_pool_config_exit(dp, FTAG); 1685 (void) zio_wait(scn->scn_zio_root); 1686 scn->scn_zio_root = NULL; 1687 1688 zfs_dbgmsg("visited %llu blocks in %llums", 1689 (longlong_t)scn->scn_visited_this_txg, 1690 (longlong_t)NSEC2MSEC(gethrtime() - scn->scn_sync_start_time)); 1691 1692 if (!scn->scn_pausing) { 1693 scn->scn_done_txg = tx->tx_txg + 1; 1694 zfs_dbgmsg("txg %llu traversal complete, waiting till txg %llu", 1695 tx->tx_txg, scn->scn_done_txg); 1696 } 1697 1698 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 1699 mutex_enter(&spa->spa_scrub_lock); 1700 while (spa->spa_scrub_inflight > 0) { 1701 cv_wait(&spa->spa_scrub_io_cv, 1702 &spa->spa_scrub_lock); 1703 } 1704 mutex_exit(&spa->spa_scrub_lock); 1705 } 1706 1707 dsl_scan_sync_state(scn, tx); 1708} 1709 1710/* 1711 * This will start a new scan, or restart an existing one. 1712 */ 1713void 1714dsl_resilver_restart(dsl_pool_t *dp, uint64_t txg) 1715{ 1716 if (txg == 0) { 1717 dmu_tx_t *tx; 1718 tx = dmu_tx_create_dd(dp->dp_mos_dir); 1719 VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT)); 1720 1721 txg = dmu_tx_get_txg(tx); 1722 dp->dp_scan->scn_restart_txg = txg; 1723 dmu_tx_commit(tx); 1724 } else { 1725 dp->dp_scan->scn_restart_txg = txg; 1726 } 1727 zfs_dbgmsg("restarting resilver txg=%llu", txg); 1728} 1729 1730boolean_t 1731dsl_scan_resilvering(dsl_pool_t *dp) 1732{ 1733 return (dp->dp_scan->scn_phys.scn_state == DSS_SCANNING && 1734 dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER); 1735} 1736 1737/* 1738 * scrub consumers 1739 */ 1740 1741static void 1742count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp) 1743{ 1744 int i; 1745 1746 /* 1747 * If we resume after a reboot, zab will be NULL; don't record 1748 * incomplete stats in that case. 1749 */ 1750 if (zab == NULL) 1751 return; 1752 1753 for (i = 0; i < 4; i++) { 1754 int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS; 1755 int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL; 1756 if (t & DMU_OT_NEWTYPE) 1757 t = DMU_OT_OTHER; 1758 zfs_blkstat_t *zb = &zab->zab_type[l][t]; 1759 int equal; 1760 1761 zb->zb_count++; 1762 zb->zb_asize += BP_GET_ASIZE(bp); 1763 zb->zb_lsize += BP_GET_LSIZE(bp); 1764 zb->zb_psize += BP_GET_PSIZE(bp); 1765 zb->zb_gangs += BP_COUNT_GANG(bp); 1766 1767 switch (BP_GET_NDVAS(bp)) { 1768 case 2: 1769 if (DVA_GET_VDEV(&bp->blk_dva[0]) == 1770 DVA_GET_VDEV(&bp->blk_dva[1])) 1771 zb->zb_ditto_2_of_2_samevdev++; 1772 break; 1773 case 3: 1774 equal = (DVA_GET_VDEV(&bp->blk_dva[0]) == 1775 DVA_GET_VDEV(&bp->blk_dva[1])) + 1776 (DVA_GET_VDEV(&bp->blk_dva[0]) == 1777 DVA_GET_VDEV(&bp->blk_dva[2])) + 1778 (DVA_GET_VDEV(&bp->blk_dva[1]) == 1779 DVA_GET_VDEV(&bp->blk_dva[2])); 1780 if (equal == 1) 1781 zb->zb_ditto_2_of_3_samevdev++; 1782 else if (equal == 3) 1783 zb->zb_ditto_3_of_3_samevdev++; 1784 break; 1785 } 1786 } 1787} 1788 1789static void 1790dsl_scan_scrub_done(zio_t *zio) 1791{ 1792 spa_t *spa = zio->io_spa; 1793 1794 zio_data_buf_free(zio->io_data, zio->io_size); 1795 1796 mutex_enter(&spa->spa_scrub_lock); 1797 spa->spa_scrub_inflight--; 1798 cv_broadcast(&spa->spa_scrub_io_cv); 1799 1800 if (zio->io_error && (zio->io_error != ECKSUM || 1801 !(zio->io_flags & ZIO_FLAG_SPECULATIVE))) { 1802 spa->spa_dsl_pool->dp_scan->scn_phys.scn_errors++; 1803 } 1804 mutex_exit(&spa->spa_scrub_lock); 1805} 1806 1807static int 1808dsl_scan_scrub_cb(dsl_pool_t *dp, 1809 const blkptr_t *bp, const zbookmark_phys_t *zb) 1810{ 1811 dsl_scan_t *scn = dp->dp_scan; 1812 size_t size = BP_GET_PSIZE(bp); 1813 spa_t *spa = dp->dp_spa; 1814 uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp); 1815 boolean_t needs_io; 1816 int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL; 1817 unsigned int scan_delay = 0; 1818 1819 if (phys_birth <= scn->scn_phys.scn_min_txg || 1820 phys_birth >= scn->scn_phys.scn_max_txg) 1821 return (0); 1822 1823 count_block(dp->dp_blkstats, bp); 1824 1825 if (BP_IS_EMBEDDED(bp)) 1826 return (0); 1827 1828 ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn)); 1829 if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) { 1830 zio_flags |= ZIO_FLAG_SCRUB; 1831 needs_io = B_TRUE; 1832 scan_delay = zfs_scrub_delay; 1833 } else { 1834 ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER); 1835 zio_flags |= ZIO_FLAG_RESILVER; 1836 needs_io = B_FALSE; 1837 scan_delay = zfs_resilver_delay; 1838 } 1839 1840 /* If it's an intent log block, failure is expected. */ 1841 if (zb->zb_level == ZB_ZIL_LEVEL) 1842 zio_flags |= ZIO_FLAG_SPECULATIVE; 1843 1844 for (int d = 0; d < BP_GET_NDVAS(bp); d++) { 1845 vdev_t *vd = vdev_lookup_top(spa, 1846 DVA_GET_VDEV(&bp->blk_dva[d])); 1847 1848 /* 1849 * Keep track of how much data we've examined so that 1850 * zpool(1M) status can make useful progress reports. 1851 */ 1852 scn->scn_phys.scn_examined += DVA_GET_ASIZE(&bp->blk_dva[d]); 1853 spa->spa_scan_pass_exam += DVA_GET_ASIZE(&bp->blk_dva[d]); 1854 1855 /* if it's a resilver, this may not be in the target range */ 1856 if (!needs_io) { 1857 if (DVA_GET_GANG(&bp->blk_dva[d])) { 1858 /* 1859 * Gang members may be spread across multiple 1860 * vdevs, so the best estimate we have is the 1861 * scrub range, which has already been checked. 1862 * XXX -- it would be better to change our 1863 * allocation policy to ensure that all 1864 * gang members reside on the same vdev. 1865 */ 1866 needs_io = B_TRUE; 1867 } else { 1868 needs_io = vdev_dtl_contains(vd, DTL_PARTIAL, 1869 phys_birth, 1); 1870 } 1871 } 1872 } 1873 1874 if (needs_io && !zfs_no_scrub_io) { 1875 vdev_t *rvd = spa->spa_root_vdev; 1876 uint64_t maxinflight = rvd->vdev_children * 1877 MAX(zfs_top_maxinflight, 1); 1878 void *data = zio_data_buf_alloc(size); 1879 1880 mutex_enter(&spa->spa_scrub_lock); 1881 while (spa->spa_scrub_inflight >= maxinflight) 1882 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock); 1883 spa->spa_scrub_inflight++; 1884 mutex_exit(&spa->spa_scrub_lock); 1885 1886 /* 1887 * If we're seeing recent (zfs_scan_idle) "important" I/Os 1888 * then throttle our workload to limit the impact of a scan. 1889 */ 1890 if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle) 1891 delay(MAX((int)scan_delay, 0)); 1892 1893 zio_nowait(zio_read(NULL, spa, bp, data, size, 1894 dsl_scan_scrub_done, NULL, ZIO_PRIORITY_SCRUB, 1895 zio_flags, zb)); 1896 } 1897 1898 /* do not relocate this block */ 1899 return (0); 1900} 1901 1902int 1903dsl_scan(dsl_pool_t *dp, pool_scan_func_t func) 1904{ 1905 spa_t *spa = dp->dp_spa; 1906 1907 /* 1908 * Purge all vdev caches and probe all devices. We do this here 1909 * rather than in sync context because this requires a writer lock 1910 * on the spa_config lock, which we can't do from sync context. The 1911 * spa_scrub_reopen flag indicates that vdev_open() should not 1912 * attempt to start another scrub. 1913 */ 1914 spa_vdev_state_enter(spa, SCL_NONE); 1915 spa->spa_scrub_reopen = B_TRUE; 1916 vdev_reopen(spa->spa_root_vdev); 1917 spa->spa_scrub_reopen = B_FALSE; 1918 (void) spa_vdev_state_exit(spa, NULL, 0); 1919 1920 return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check, 1921 dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_NONE)); 1922} 1923 1924static boolean_t 1925dsl_scan_restarting(dsl_scan_t *scn, dmu_tx_t *tx) 1926{ 1927 return (scn->scn_restart_txg != 0 && 1928 scn->scn_restart_txg <= tx->tx_txg); 1929} 1930