dsl_scan.c revision 297110
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 *tx); 60 61unsigned int zfs_top_maxinflight = 32; /* maximum I/Os per top-level */ 62unsigned int zfs_resilver_delay = 2; /* number of ticks to delay resilver */ 63unsigned int zfs_scrub_delay = 4; /* number of ticks to delay scrub */ 64unsigned int zfs_scan_idle = 50; /* idle window in clock ticks */ 65 66unsigned int zfs_scan_min_time_ms = 1000; /* min millisecs to scrub per txg */ 67unsigned int zfs_free_min_time_ms = 1000; /* min millisecs to free per txg */ 68unsigned int zfs_resilver_min_time_ms = 3000; /* min millisecs to resilver 69 per txg */ 70boolean_t zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */ 71boolean_t zfs_no_scrub_prefetch = B_FALSE; /* set to disable scrub prefetch */ 72 73SYSCTL_DECL(_vfs_zfs); 74TUNABLE_INT("vfs.zfs.top_maxinflight", &zfs_top_maxinflight); 75SYSCTL_UINT(_vfs_zfs, OID_AUTO, top_maxinflight, CTLFLAG_RW, 76 &zfs_top_maxinflight, 0, "Maximum I/Os per top-level vdev"); 77TUNABLE_INT("vfs.zfs.resilver_delay", &zfs_resilver_delay); 78SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_delay, CTLFLAG_RW, 79 &zfs_resilver_delay, 0, "Number of ticks to delay resilver"); 80TUNABLE_INT("vfs.zfs.scrub_delay", &zfs_scrub_delay); 81SYSCTL_UINT(_vfs_zfs, OID_AUTO, scrub_delay, CTLFLAG_RW, 82 &zfs_scrub_delay, 0, "Number of ticks to delay scrub"); 83TUNABLE_INT("vfs.zfs.scan_idle", &zfs_scan_idle); 84SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_idle, CTLFLAG_RW, 85 &zfs_scan_idle, 0, "Idle scan window in clock ticks"); 86TUNABLE_INT("vfs.zfs.scan_min_time_ms", &zfs_scan_min_time_ms); 87SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_min_time_ms, CTLFLAG_RW, 88 &zfs_scan_min_time_ms, 0, "Min millisecs to scrub per txg"); 89TUNABLE_INT("vfs.zfs.free_min_time_ms", &zfs_free_min_time_ms); 90SYSCTL_UINT(_vfs_zfs, OID_AUTO, free_min_time_ms, CTLFLAG_RW, 91 &zfs_free_min_time_ms, 0, "Min millisecs to free per txg"); 92TUNABLE_INT("vfs.zfs.resilver_min_time_ms", &zfs_resilver_min_time_ms); 93SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_min_time_ms, CTLFLAG_RW, 94 &zfs_resilver_min_time_ms, 0, "Min millisecs to resilver per txg"); 95TUNABLE_INT("vfs.zfs.no_scrub_io", &zfs_no_scrub_io); 96SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_io, CTLFLAG_RW, 97 &zfs_no_scrub_io, 0, "Disable scrub I/O"); 98TUNABLE_INT("vfs.zfs.no_scrub_prefetch", &zfs_no_scrub_prefetch); 99SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_prefetch, CTLFLAG_RW, 100 &zfs_no_scrub_prefetch, 0, "Disable scrub prefetching"); 101 102enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE; 103/* max number of blocks to free in a single TXG */ 104uint64_t zfs_free_max_blocks = UINT64_MAX; 105SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, free_max_blocks, CTLFLAG_RWTUN, 106 &zfs_free_max_blocks, 0, "Maximum number of blocks to free in one TXG"); 107 108 109#define DSL_SCAN_IS_SCRUB_RESILVER(scn) \ 110 ((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \ 111 (scn)->scn_phys.scn_func == POOL_SCAN_RESILVER) 112 113extern int zfs_txg_timeout; 114 115/* 116 * Enable/disable the processing of the free_bpobj object. 117 */ 118boolean_t zfs_free_bpobj_enabled = B_TRUE; 119 120SYSCTL_INT(_vfs_zfs, OID_AUTO, free_bpobj_enabled, CTLFLAG_RWTUN, 121 &zfs_free_bpobj_enabled, 0, "Enable free_bpobj processing"); 122 123/* the order has to match pool_scan_type */ 124static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = { 125 NULL, 126 dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */ 127 dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */ 128}; 129 130int 131dsl_scan_init(dsl_pool_t *dp, uint64_t txg) 132{ 133 int err; 134 dsl_scan_t *scn; 135 spa_t *spa = dp->dp_spa; 136 uint64_t f; 137 138 scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP); 139 scn->scn_dp = dp; 140 141 /* 142 * It's possible that we're resuming a scan after a reboot so 143 * make sure that the scan_async_destroying flag is initialized 144 * appropriately. 145 */ 146 ASSERT(!scn->scn_async_destroying); 147 scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa, 148 SPA_FEATURE_ASYNC_DESTROY); 149 150 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 151 "scrub_func", sizeof (uint64_t), 1, &f); 152 if (err == 0) { 153 /* 154 * There was an old-style scrub in progress. Restart a 155 * new-style scrub from the beginning. 156 */ 157 scn->scn_restart_txg = txg; 158 zfs_dbgmsg("old-style scrub was in progress; " 159 "restarting new-style scrub in txg %llu", 160 scn->scn_restart_txg); 161 162 /* 163 * Load the queue obj from the old location so that it 164 * can be freed by dsl_scan_done(). 165 */ 166 (void) zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 167 "scrub_queue", sizeof (uint64_t), 1, 168 &scn->scn_phys.scn_queue_obj); 169 } else { 170 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 171 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 172 &scn->scn_phys); 173 if (err == ENOENT) 174 return (0); 175 else if (err) 176 return (err); 177 178 if (scn->scn_phys.scn_state == DSS_SCANNING && 179 spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) { 180 /* 181 * A new-type scrub was in progress on an old 182 * pool, and the pool was accessed by old 183 * software. Restart from the beginning, since 184 * the old software may have changed the pool in 185 * the meantime. 186 */ 187 scn->scn_restart_txg = txg; 188 zfs_dbgmsg("new-style scrub was modified " 189 "by old software; restarting in txg %llu", 190 scn->scn_restart_txg); 191 } 192 } 193 194 spa_scan_stat_init(spa); 195 return (0); 196} 197 198void 199dsl_scan_fini(dsl_pool_t *dp) 200{ 201 if (dp->dp_scan) { 202 kmem_free(dp->dp_scan, sizeof (dsl_scan_t)); 203 dp->dp_scan = NULL; 204 } 205} 206 207/* ARGSUSED */ 208static int 209dsl_scan_setup_check(void *arg, dmu_tx_t *tx) 210{ 211 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 212 213 if (scn->scn_phys.scn_state == DSS_SCANNING) 214 return (SET_ERROR(EBUSY)); 215 216 return (0); 217} 218 219static void 220dsl_scan_setup_sync(void *arg, dmu_tx_t *tx) 221{ 222 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 223 pool_scan_func_t *funcp = arg; 224 dmu_object_type_t ot = 0; 225 dsl_pool_t *dp = scn->scn_dp; 226 spa_t *spa = dp->dp_spa; 227 228 ASSERT(scn->scn_phys.scn_state != DSS_SCANNING); 229 ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS); 230 bzero(&scn->scn_phys, sizeof (scn->scn_phys)); 231 scn->scn_phys.scn_func = *funcp; 232 scn->scn_phys.scn_state = DSS_SCANNING; 233 scn->scn_phys.scn_min_txg = 0; 234 scn->scn_phys.scn_max_txg = tx->tx_txg; 235 scn->scn_phys.scn_ddt_class_max = DDT_CLASSES - 1; /* the entire DDT */ 236 scn->scn_phys.scn_start_time = gethrestime_sec(); 237 scn->scn_phys.scn_errors = 0; 238 scn->scn_phys.scn_to_examine = spa->spa_root_vdev->vdev_stat.vs_alloc; 239 scn->scn_restart_txg = 0; 240 scn->scn_done_txg = 0; 241 spa_scan_stat_init(spa); 242 243 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 244 scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max; 245 246 /* rewrite all disk labels */ 247 vdev_config_dirty(spa->spa_root_vdev); 248 249 if (vdev_resilver_needed(spa->spa_root_vdev, 250 &scn->scn_phys.scn_min_txg, &scn->scn_phys.scn_max_txg)) { 251 spa_event_notify(spa, NULL, ESC_ZFS_RESILVER_START); 252 } else { 253 spa_event_notify(spa, NULL, ESC_ZFS_SCRUB_START); 254 } 255 256 spa->spa_scrub_started = B_TRUE; 257 /* 258 * If this is an incremental scrub, limit the DDT scrub phase 259 * to just the auto-ditto class (for correctness); the rest 260 * of the scrub should go faster using top-down pruning. 261 */ 262 if (scn->scn_phys.scn_min_txg > TXG_INITIAL) 263 scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO; 264 265 } 266 267 /* back to the generic stuff */ 268 269 if (dp->dp_blkstats == NULL) { 270 dp->dp_blkstats = 271 kmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP); 272 } 273 bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); 274 275 if (spa_version(spa) < SPA_VERSION_DSL_SCRUB) 276 ot = DMU_OT_ZAP_OTHER; 277 278 scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset, 279 ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx); 280 281 dsl_scan_sync_state(scn, tx); 282 283 spa_history_log_internal(spa, "scan setup", tx, 284 "func=%u mintxg=%llu maxtxg=%llu", 285 *funcp, scn->scn_phys.scn_min_txg, scn->scn_phys.scn_max_txg); 286} 287 288/* ARGSUSED */ 289static void 290dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx) 291{ 292 static const char *old_names[] = { 293 "scrub_bookmark", 294 "scrub_ddt_bookmark", 295 "scrub_ddt_class_max", 296 "scrub_queue", 297 "scrub_min_txg", 298 "scrub_max_txg", 299 "scrub_func", 300 "scrub_errors", 301 NULL 302 }; 303 304 dsl_pool_t *dp = scn->scn_dp; 305 spa_t *spa = dp->dp_spa; 306 int i; 307 308 /* Remove any remnants of an old-style scrub. */ 309 for (i = 0; old_names[i]; i++) { 310 (void) zap_remove(dp->dp_meta_objset, 311 DMU_POOL_DIRECTORY_OBJECT, old_names[i], tx); 312 } 313 314 if (scn->scn_phys.scn_queue_obj != 0) { 315 VERIFY(0 == dmu_object_free(dp->dp_meta_objset, 316 scn->scn_phys.scn_queue_obj, tx)); 317 scn->scn_phys.scn_queue_obj = 0; 318 } 319 320 /* 321 * If we were "restarted" from a stopped state, don't bother 322 * with anything else. 323 */ 324 if (scn->scn_phys.scn_state != DSS_SCANNING) 325 return; 326 327 if (complete) 328 scn->scn_phys.scn_state = DSS_FINISHED; 329 else 330 scn->scn_phys.scn_state = DSS_CANCELED; 331 332 spa_history_log_internal(spa, "scan done", tx, 333 "complete=%u", complete); 334 335 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 336 mutex_enter(&spa->spa_scrub_lock); 337 while (spa->spa_scrub_inflight > 0) { 338 cv_wait(&spa->spa_scrub_io_cv, 339 &spa->spa_scrub_lock); 340 } 341 mutex_exit(&spa->spa_scrub_lock); 342 spa->spa_scrub_started = B_FALSE; 343 spa->spa_scrub_active = B_FALSE; 344 345 /* 346 * If the scrub/resilver completed, update all DTLs to 347 * reflect this. Whether it succeeded or not, vacate 348 * all temporary scrub DTLs. 349 */ 350 vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg, 351 complete ? scn->scn_phys.scn_max_txg : 0, B_TRUE); 352 if (complete) { 353 spa_event_notify(spa, NULL, scn->scn_phys.scn_min_txg ? 354 ESC_ZFS_RESILVER_FINISH : ESC_ZFS_SCRUB_FINISH); 355 } 356 spa_errlog_rotate(spa); 357 358 /* 359 * We may have finished replacing a device. 360 * Let the async thread assess this and handle the detach. 361 */ 362 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE); 363 } 364 365 scn->scn_phys.scn_end_time = gethrestime_sec(); 366} 367 368/* ARGSUSED */ 369static int 370dsl_scan_cancel_check(void *arg, dmu_tx_t *tx) 371{ 372 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 373 374 if (scn->scn_phys.scn_state != DSS_SCANNING) 375 return (SET_ERROR(ENOENT)); 376 return (0); 377} 378 379/* ARGSUSED */ 380static void 381dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx) 382{ 383 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 384 385 dsl_scan_done(scn, B_FALSE, tx); 386 dsl_scan_sync_state(scn, tx); 387} 388 389int 390dsl_scan_cancel(dsl_pool_t *dp) 391{ 392 return (dsl_sync_task(spa_name(dp->dp_spa), dsl_scan_cancel_check, 393 dsl_scan_cancel_sync, NULL, 3, ZFS_SPACE_CHECK_RESERVED)); 394} 395 396static void dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 397 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 398 dmu_objset_type_t ostype, dmu_tx_t *tx); 399static void dsl_scan_visitdnode(dsl_scan_t *, dsl_dataset_t *ds, 400 dmu_objset_type_t ostype, 401 dnode_phys_t *dnp, uint64_t object, dmu_tx_t *tx); 402 403void 404dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp) 405{ 406 zio_free(dp->dp_spa, txg, bp); 407} 408 409void 410dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp) 411{ 412 ASSERT(dsl_pool_sync_context(dp)); 413 zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, BP_GET_PSIZE(bpp), 414 pio->io_flags)); 415} 416 417static uint64_t 418dsl_scan_ds_maxtxg(dsl_dataset_t *ds) 419{ 420 uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg; 421 if (ds->ds_is_snapshot) 422 return (MIN(smt, dsl_dataset_phys(ds)->ds_creation_txg)); 423 return (smt); 424} 425 426static void 427dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx) 428{ 429 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, 430 DMU_POOL_DIRECTORY_OBJECT, 431 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 432 &scn->scn_phys, tx)); 433} 434 435extern int zfs_vdev_async_write_active_min_dirty_percent; 436 437static boolean_t 438dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_phys_t *zb) 439{ 440 /* we never skip user/group accounting objects */ 441 if (zb && (int64_t)zb->zb_object < 0) 442 return (B_FALSE); 443 444 if (scn->scn_pausing) 445 return (B_TRUE); /* we're already pausing */ 446 447 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark)) 448 return (B_FALSE); /* we're resuming */ 449 450 /* We only know how to resume from level-0 blocks. */ 451 if (zb && zb->zb_level != 0) 452 return (B_FALSE); 453 454 /* 455 * We pause if: 456 * - we have scanned for the maximum time: an entire txg 457 * timeout (default 5 sec) 458 * or 459 * - we have scanned for at least the minimum time (default 1 sec 460 * for scrub, 3 sec for resilver), and either we have sufficient 461 * dirty data that we are starting to write more quickly 462 * (default 30%), or someone is explicitly waiting for this txg 463 * to complete. 464 * or 465 * - the spa is shutting down because this pool is being exported 466 * or the machine is rebooting. 467 */ 468 int mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ? 469 zfs_resilver_min_time_ms : zfs_scan_min_time_ms; 470 uint64_t elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 471 int dirty_pct = scn->scn_dp->dp_dirty_total * 100 / zfs_dirty_data_max; 472 if (elapsed_nanosecs / NANOSEC >= zfs_txg_timeout || 473 (NSEC2MSEC(elapsed_nanosecs) > mintime && 474 (txg_sync_waiting(scn->scn_dp) || 475 dirty_pct >= zfs_vdev_async_write_active_min_dirty_percent)) || 476 spa_shutting_down(scn->scn_dp->dp_spa)) { 477 if (zb) { 478 dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n", 479 (longlong_t)zb->zb_objset, 480 (longlong_t)zb->zb_object, 481 (longlong_t)zb->zb_level, 482 (longlong_t)zb->zb_blkid); 483 scn->scn_phys.scn_bookmark = *zb; 484 } 485 dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n", 486 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 487 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 488 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 489 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 490 scn->scn_pausing = B_TRUE; 491 return (B_TRUE); 492 } 493 return (B_FALSE); 494} 495 496typedef struct zil_scan_arg { 497 dsl_pool_t *zsa_dp; 498 zil_header_t *zsa_zh; 499} zil_scan_arg_t; 500 501/* ARGSUSED */ 502static int 503dsl_scan_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 504{ 505 zil_scan_arg_t *zsa = arg; 506 dsl_pool_t *dp = zsa->zsa_dp; 507 dsl_scan_t *scn = dp->dp_scan; 508 zil_header_t *zh = zsa->zsa_zh; 509 zbookmark_phys_t zb; 510 511 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 512 return (0); 513 514 /* 515 * One block ("stubby") can be allocated a long time ago; we 516 * want to visit that one because it has been allocated 517 * (on-disk) even if it hasn't been claimed (even though for 518 * scrub there's nothing to do to it). 519 */ 520 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa)) 521 return (0); 522 523 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 524 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 525 526 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 527 return (0); 528} 529 530/* ARGSUSED */ 531static int 532dsl_scan_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) 533{ 534 if (lrc->lrc_txtype == TX_WRITE) { 535 zil_scan_arg_t *zsa = arg; 536 dsl_pool_t *dp = zsa->zsa_dp; 537 dsl_scan_t *scn = dp->dp_scan; 538 zil_header_t *zh = zsa->zsa_zh; 539 lr_write_t *lr = (lr_write_t *)lrc; 540 blkptr_t *bp = &lr->lr_blkptr; 541 zbookmark_phys_t zb; 542 543 if (BP_IS_HOLE(bp) || 544 bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 545 return (0); 546 547 /* 548 * birth can be < claim_txg if this record's txg is 549 * already txg sync'ed (but this log block contains 550 * other records that are not synced) 551 */ 552 if (claim_txg == 0 || bp->blk_birth < claim_txg) 553 return (0); 554 555 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 556 lr->lr_foid, ZB_ZIL_LEVEL, 557 lr->lr_offset / BP_GET_LSIZE(bp)); 558 559 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 560 } 561 return (0); 562} 563 564static void 565dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh) 566{ 567 uint64_t claim_txg = zh->zh_claim_txg; 568 zil_scan_arg_t zsa = { dp, zh }; 569 zilog_t *zilog; 570 571 /* 572 * We only want to visit blocks that have been claimed but not yet 573 * replayed (or, in read-only mode, blocks that *would* be claimed). 574 */ 575 if (claim_txg == 0 && spa_writeable(dp->dp_spa)) 576 return; 577 578 zilog = zil_alloc(dp->dp_meta_objset, zh); 579 580 (void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa, 581 claim_txg); 582 583 zil_free(zilog); 584} 585 586/* ARGSUSED */ 587static void 588dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp, 589 uint64_t objset, uint64_t object, uint64_t blkid) 590{ 591 zbookmark_phys_t czb; 592 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH; 593 594 if (zfs_no_scrub_prefetch) 595 return; 596 597 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_min_txg || 598 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)) 599 return; 600 601 SET_BOOKMARK(&czb, objset, object, BP_GET_LEVEL(bp), blkid); 602 603 (void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp, 604 NULL, NULL, ZIO_PRIORITY_ASYNC_READ, 605 ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb); 606} 607 608static boolean_t 609dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp, 610 const zbookmark_phys_t *zb) 611{ 612 /* 613 * We never skip over user/group accounting objects (obj<0) 614 */ 615 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) && 616 (int64_t)zb->zb_object >= 0) { 617 /* 618 * If we already visited this bp & everything below (in 619 * a prior txg sync), don't bother doing it again. 620 */ 621 if (zbookmark_subtree_completed(dnp, zb, 622 &scn->scn_phys.scn_bookmark)) 623 return (B_TRUE); 624 625 /* 626 * If we found the block we're trying to resume from, or 627 * we went past it to a different object, zero it out to 628 * indicate that it's OK to start checking for pausing 629 * again. 630 */ 631 if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 || 632 zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) { 633 dprintf("resuming at %llx/%llx/%llx/%llx\n", 634 (longlong_t)zb->zb_objset, 635 (longlong_t)zb->zb_object, 636 (longlong_t)zb->zb_level, 637 (longlong_t)zb->zb_blkid); 638 bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb)); 639 } 640 } 641 return (B_FALSE); 642} 643 644/* 645 * Return nonzero on i/o error. 646 * Return new buf to write out in *bufp. 647 */ 648static int 649dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype, 650 dnode_phys_t *dnp, const blkptr_t *bp, 651 const zbookmark_phys_t *zb, dmu_tx_t *tx) 652{ 653 dsl_pool_t *dp = scn->scn_dp; 654 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD; 655 int err; 656 657 if (BP_GET_LEVEL(bp) > 0) { 658 arc_flags_t flags = ARC_FLAG_WAIT; 659 int i; 660 blkptr_t *cbp; 661 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 662 arc_buf_t *buf; 663 664 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 665 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 666 if (err) { 667 scn->scn_phys.scn_errors++; 668 return (err); 669 } 670 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 671 dsl_scan_prefetch(scn, buf, cbp, zb->zb_objset, 672 zb->zb_object, zb->zb_blkid * epb + i); 673 } 674 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 675 zbookmark_phys_t czb; 676 677 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 678 zb->zb_level - 1, 679 zb->zb_blkid * epb + i); 680 dsl_scan_visitbp(cbp, &czb, dnp, 681 ds, scn, ostype, tx); 682 } 683 (void) arc_buf_remove_ref(buf, &buf); 684 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 685 arc_flags_t flags = ARC_FLAG_WAIT; 686 dnode_phys_t *cdnp; 687 int i, j; 688 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 689 arc_buf_t *buf; 690 691 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 692 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 693 if (err) { 694 scn->scn_phys.scn_errors++; 695 return (err); 696 } 697 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 698 for (j = 0; j < cdnp->dn_nblkptr; j++) { 699 blkptr_t *cbp = &cdnp->dn_blkptr[j]; 700 dsl_scan_prefetch(scn, buf, cbp, 701 zb->zb_objset, zb->zb_blkid * epb + i, j); 702 } 703 } 704 for (i = 0, cdnp = buf->b_data; i < epb; i++, cdnp++) { 705 dsl_scan_visitdnode(scn, ds, ostype, 706 cdnp, zb->zb_blkid * epb + i, tx); 707 } 708 709 (void) arc_buf_remove_ref(buf, &buf); 710 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 711 arc_flags_t flags = ARC_FLAG_WAIT; 712 objset_phys_t *osp; 713 arc_buf_t *buf; 714 715 err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, &buf, 716 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 717 if (err) { 718 scn->scn_phys.scn_errors++; 719 return (err); 720 } 721 722 osp = buf->b_data; 723 724 dsl_scan_visitdnode(scn, ds, osp->os_type, 725 &osp->os_meta_dnode, DMU_META_DNODE_OBJECT, tx); 726 727 if (OBJSET_BUF_HAS_USERUSED(buf)) { 728 /* 729 * We also always visit user/group accounting 730 * objects, and never skip them, even if we are 731 * pausing. This is necessary so that the space 732 * deltas from this txg get integrated. 733 */ 734 dsl_scan_visitdnode(scn, ds, osp->os_type, 735 &osp->os_groupused_dnode, 736 DMU_GROUPUSED_OBJECT, tx); 737 dsl_scan_visitdnode(scn, ds, osp->os_type, 738 &osp->os_userused_dnode, 739 DMU_USERUSED_OBJECT, tx); 740 } 741 (void) arc_buf_remove_ref(buf, &buf); 742 } 743 744 return (0); 745} 746 747static void 748dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds, 749 dmu_objset_type_t ostype, dnode_phys_t *dnp, 750 uint64_t object, dmu_tx_t *tx) 751{ 752 int j; 753 754 for (j = 0; j < dnp->dn_nblkptr; j++) { 755 zbookmark_phys_t czb; 756 757 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 758 dnp->dn_nlevels - 1, j); 759 dsl_scan_visitbp(&dnp->dn_blkptr[j], 760 &czb, dnp, ds, scn, ostype, tx); 761 } 762 763 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 764 zbookmark_phys_t czb; 765 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 766 0, DMU_SPILL_BLKID); 767 dsl_scan_visitbp(&dnp->dn_spill, 768 &czb, dnp, ds, scn, ostype, tx); 769 } 770} 771 772/* 773 * The arguments are in this order because mdb can only print the 774 * first 5; we want them to be useful. 775 */ 776static void 777dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 778 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 779 dmu_objset_type_t ostype, dmu_tx_t *tx) 780{ 781 dsl_pool_t *dp = scn->scn_dp; 782 arc_buf_t *buf = NULL; 783 blkptr_t bp_toread = *bp; 784 785 /* ASSERT(pbuf == NULL || arc_released(pbuf)); */ 786 787 if (dsl_scan_check_pause(scn, zb)) 788 return; 789 790 if (dsl_scan_check_resume(scn, dnp, zb)) 791 return; 792 793 if (BP_IS_HOLE(bp)) 794 return; 795 796 scn->scn_visited_this_txg++; 797 798 dprintf_bp(bp, 799 "visiting ds=%p/%llu zb=%llx/%llx/%llx/%llx bp=%p", 800 ds, ds ? ds->ds_object : 0, 801 zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid, 802 bp); 803 804 if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 805 return; 806 807 if (dsl_scan_recurse(scn, ds, ostype, dnp, &bp_toread, zb, tx) != 0) 808 return; 809 810 /* 811 * If dsl_scan_ddt() has aready visited this block, it will have 812 * already done any translations or scrubbing, so don't call the 813 * callback again. 814 */ 815 if (ddt_class_contains(dp->dp_spa, 816 scn->scn_phys.scn_ddt_class_max, bp)) { 817 ASSERT(buf == NULL); 818 return; 819 } 820 821 /* 822 * If this block is from the future (after cur_max_txg), then we 823 * are doing this on behalf of a deleted snapshot, and we will 824 * revisit the future block on the next pass of this dataset. 825 * Don't scan it now unless we need to because something 826 * under it was modified. 827 */ 828 if (BP_PHYSICAL_BIRTH(bp) <= scn->scn_phys.scn_cur_max_txg) { 829 scan_funcs[scn->scn_phys.scn_func](dp, bp, zb); 830 } 831} 832 833static void 834dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp, 835 dmu_tx_t *tx) 836{ 837 zbookmark_phys_t zb; 838 839 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET, 840 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 841 dsl_scan_visitbp(bp, &zb, NULL, 842 ds, scn, DMU_OST_NONE, tx); 843 844 dprintf_ds(ds, "finished scan%s", ""); 845} 846 847void 848dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx) 849{ 850 dsl_pool_t *dp = ds->ds_dir->dd_pool; 851 dsl_scan_t *scn = dp->dp_scan; 852 uint64_t mintxg; 853 854 if (scn->scn_phys.scn_state != DSS_SCANNING) 855 return; 856 857 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 858 if (ds->ds_is_snapshot) { 859 /* 860 * Note: 861 * - scn_cur_{min,max}_txg stays the same. 862 * - Setting the flag is not really necessary if 863 * scn_cur_max_txg == scn_max_txg, because there 864 * is nothing after this snapshot that we care 865 * about. However, we set it anyway and then 866 * ignore it when we retraverse it in 867 * dsl_scan_visitds(). 868 */ 869 scn->scn_phys.scn_bookmark.zb_objset = 870 dsl_dataset_phys(ds)->ds_next_snap_obj; 871 zfs_dbgmsg("destroying ds %llu; currently traversing; " 872 "reset zb_objset to %llu", 873 (u_longlong_t)ds->ds_object, 874 (u_longlong_t)dsl_dataset_phys(ds)-> 875 ds_next_snap_obj); 876 scn->scn_phys.scn_flags |= DSF_VISIT_DS_AGAIN; 877 } else { 878 SET_BOOKMARK(&scn->scn_phys.scn_bookmark, 879 ZB_DESTROYED_OBJSET, 0, 0, 0); 880 zfs_dbgmsg("destroying ds %llu; currently traversing; " 881 "reset bookmark to -1,0,0,0", 882 (u_longlong_t)ds->ds_object); 883 } 884 } else if (zap_lookup_int_key(dp->dp_meta_objset, 885 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 886 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1); 887 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 888 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 889 if (ds->ds_is_snapshot) { 890 /* 891 * We keep the same mintxg; it could be > 892 * ds_creation_txg if the previous snapshot was 893 * deleted too. 894 */ 895 VERIFY(zap_add_int_key(dp->dp_meta_objset, 896 scn->scn_phys.scn_queue_obj, 897 dsl_dataset_phys(ds)->ds_next_snap_obj, 898 mintxg, tx) == 0); 899 zfs_dbgmsg("destroying ds %llu; in queue; " 900 "replacing with %llu", 901 (u_longlong_t)ds->ds_object, 902 (u_longlong_t)dsl_dataset_phys(ds)-> 903 ds_next_snap_obj); 904 } else { 905 zfs_dbgmsg("destroying ds %llu; in queue; removing", 906 (u_longlong_t)ds->ds_object); 907 } 908 } 909 910 /* 911 * dsl_scan_sync() should be called after this, and should sync 912 * out our changed state, but just to be safe, do it here. 913 */ 914 dsl_scan_sync_state(scn, tx); 915} 916 917void 918dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx) 919{ 920 dsl_pool_t *dp = ds->ds_dir->dd_pool; 921 dsl_scan_t *scn = dp->dp_scan; 922 uint64_t mintxg; 923 924 if (scn->scn_phys.scn_state != DSS_SCANNING) 925 return; 926 927 ASSERT(dsl_dataset_phys(ds)->ds_prev_snap_obj != 0); 928 929 if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { 930 scn->scn_phys.scn_bookmark.zb_objset = 931 dsl_dataset_phys(ds)->ds_prev_snap_obj; 932 zfs_dbgmsg("snapshotting ds %llu; currently traversing; " 933 "reset zb_objset to %llu", 934 (u_longlong_t)ds->ds_object, 935 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 936 } else if (zap_lookup_int_key(dp->dp_meta_objset, 937 scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { 938 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 939 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 940 VERIFY(zap_add_int_key(dp->dp_meta_objset, 941 scn->scn_phys.scn_queue_obj, 942 dsl_dataset_phys(ds)->ds_prev_snap_obj, mintxg, tx) == 0); 943 zfs_dbgmsg("snapshotting ds %llu; in queue; " 944 "replacing with %llu", 945 (u_longlong_t)ds->ds_object, 946 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 947 } 948 dsl_scan_sync_state(scn, tx); 949} 950 951void 952dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx) 953{ 954 dsl_pool_t *dp = ds1->ds_dir->dd_pool; 955 dsl_scan_t *scn = dp->dp_scan; 956 uint64_t mintxg; 957 958 if (scn->scn_phys.scn_state != DSS_SCANNING) 959 return; 960 961 if (scn->scn_phys.scn_bookmark.zb_objset == ds1->ds_object) { 962 scn->scn_phys.scn_bookmark.zb_objset = ds2->ds_object; 963 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 964 "reset zb_objset to %llu", 965 (u_longlong_t)ds1->ds_object, 966 (u_longlong_t)ds2->ds_object); 967 } else if (scn->scn_phys.scn_bookmark.zb_objset == ds2->ds_object) { 968 scn->scn_phys.scn_bookmark.zb_objset = ds1->ds_object; 969 zfs_dbgmsg("clone_swap ds %llu; currently traversing; " 970 "reset zb_objset to %llu", 971 (u_longlong_t)ds2->ds_object, 972 (u_longlong_t)ds1->ds_object); 973 } 974 975 if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 976 ds1->ds_object, &mintxg) == 0) { 977 int err; 978 979 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 980 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 981 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 982 scn->scn_phys.scn_queue_obj, ds1->ds_object, tx)); 983 err = zap_add_int_key(dp->dp_meta_objset, 984 scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg, tx); 985 VERIFY(err == 0 || err == EEXIST); 986 if (err == EEXIST) { 987 /* Both were there to begin with */ 988 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 989 scn->scn_phys.scn_queue_obj, 990 ds1->ds_object, mintxg, tx)); 991 } 992 zfs_dbgmsg("clone_swap ds %llu; in queue; " 993 "replacing with %llu", 994 (u_longlong_t)ds1->ds_object, 995 (u_longlong_t)ds2->ds_object); 996 } else if (zap_lookup_int_key(dp->dp_meta_objset, 997 scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg) == 0) { 998 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 999 ASSERT3U(mintxg, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 1000 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 1001 scn->scn_phys.scn_queue_obj, ds2->ds_object, tx)); 1002 VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, 1003 scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg, tx)); 1004 zfs_dbgmsg("clone_swap ds %llu; in queue; " 1005 "replacing with %llu", 1006 (u_longlong_t)ds2->ds_object, 1007 (u_longlong_t)ds1->ds_object); 1008 } 1009 1010 dsl_scan_sync_state(scn, tx); 1011} 1012 1013struct enqueue_clones_arg { 1014 dmu_tx_t *tx; 1015 uint64_t originobj; 1016}; 1017 1018/* ARGSUSED */ 1019static int 1020enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1021{ 1022 struct enqueue_clones_arg *eca = arg; 1023 dsl_dataset_t *ds; 1024 int err; 1025 dsl_scan_t *scn = dp->dp_scan; 1026 1027 if (dsl_dir_phys(hds->ds_dir)->dd_origin_obj != eca->originobj) 1028 return (0); 1029 1030 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1031 if (err) 1032 return (err); 1033 1034 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != eca->originobj) { 1035 dsl_dataset_t *prev; 1036 err = dsl_dataset_hold_obj(dp, 1037 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1038 1039 dsl_dataset_rele(ds, FTAG); 1040 if (err) 1041 return (err); 1042 ds = prev; 1043 } 1044 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1045 scn->scn_phys.scn_queue_obj, ds->ds_object, 1046 dsl_dataset_phys(ds)->ds_prev_snap_txg, eca->tx) == 0); 1047 dsl_dataset_rele(ds, FTAG); 1048 return (0); 1049} 1050 1051static void 1052dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx) 1053{ 1054 dsl_pool_t *dp = scn->scn_dp; 1055 dsl_dataset_t *ds; 1056 objset_t *os; 1057 1058 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1059 1060 if (scn->scn_phys.scn_cur_min_txg >= 1061 scn->scn_phys.scn_max_txg) { 1062 /* 1063 * This can happen if this snapshot was created after the 1064 * scan started, and we already completed a previous snapshot 1065 * that was created after the scan started. This snapshot 1066 * only references blocks with: 1067 * 1068 * birth < our ds_creation_txg 1069 * cur_min_txg is no less than ds_creation_txg. 1070 * We have already visited these blocks. 1071 * or 1072 * birth > scn_max_txg 1073 * The scan requested not to visit these blocks. 1074 * 1075 * Subsequent snapshots (and clones) can reference our 1076 * blocks, or blocks with even higher birth times. 1077 * Therefore we do not need to visit them either, 1078 * so we do not add them to the work queue. 1079 * 1080 * Note that checking for cur_min_txg >= cur_max_txg 1081 * is not sufficient, because in that case we may need to 1082 * visit subsequent snapshots. This happens when min_txg > 0, 1083 * which raises cur_min_txg. In this case we will visit 1084 * this dataset but skip all of its blocks, because the 1085 * rootbp's birth time is < cur_min_txg. Then we will 1086 * add the next snapshots/clones to the work queue. 1087 */ 1088 char *dsname = kmem_alloc(MAXNAMELEN, KM_SLEEP); 1089 dsl_dataset_name(ds, dsname); 1090 zfs_dbgmsg("scanning dataset %llu (%s) is unnecessary because " 1091 "cur_min_txg (%llu) >= max_txg (%llu)", 1092 dsobj, dsname, 1093 scn->scn_phys.scn_cur_min_txg, 1094 scn->scn_phys.scn_max_txg); 1095 kmem_free(dsname, MAXNAMELEN); 1096 1097 goto out; 1098 } 1099 1100 if (dmu_objset_from_ds(ds, &os)) 1101 goto out; 1102 1103 /* 1104 * Only the ZIL in the head (non-snapshot) is valid. Even though 1105 * snapshots can have ZIL block pointers (which may be the same 1106 * BP as in the head), they must be ignored. So we traverse the 1107 * ZIL here, rather than in scan_recurse(), because the regular 1108 * snapshot block-sharing rules don't apply to it. 1109 */ 1110 if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !ds->ds_is_snapshot) 1111 dsl_scan_zil(dp, &os->os_zil_header); 1112 1113 /* 1114 * Iterate over the bps in this ds. 1115 */ 1116 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1117 dsl_scan_visit_rootbp(scn, ds, &dsl_dataset_phys(ds)->ds_bp, tx); 1118 1119 char *dsname = kmem_alloc(ZFS_MAXNAMELEN, KM_SLEEP); 1120 dsl_dataset_name(ds, dsname); 1121 zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; " 1122 "pausing=%u", 1123 (longlong_t)dsobj, dsname, 1124 (longlong_t)scn->scn_phys.scn_cur_min_txg, 1125 (longlong_t)scn->scn_phys.scn_cur_max_txg, 1126 (int)scn->scn_pausing); 1127 kmem_free(dsname, ZFS_MAXNAMELEN); 1128 1129 if (scn->scn_pausing) 1130 goto out; 1131 1132 /* 1133 * We've finished this pass over this dataset. 1134 */ 1135 1136 /* 1137 * If we did not completely visit this dataset, do another pass. 1138 */ 1139 if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) { 1140 zfs_dbgmsg("incomplete pass; visiting again"); 1141 scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN; 1142 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1143 scn->scn_phys.scn_queue_obj, ds->ds_object, 1144 scn->scn_phys.scn_cur_max_txg, tx) == 0); 1145 goto out; 1146 } 1147 1148 /* 1149 * Add descendent datasets to work queue. 1150 */ 1151 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) { 1152 VERIFY(zap_add_int_key(dp->dp_meta_objset, 1153 scn->scn_phys.scn_queue_obj, 1154 dsl_dataset_phys(ds)->ds_next_snap_obj, 1155 dsl_dataset_phys(ds)->ds_creation_txg, tx) == 0); 1156 } 1157 if (dsl_dataset_phys(ds)->ds_num_children > 1) { 1158 boolean_t usenext = B_FALSE; 1159 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) { 1160 uint64_t count; 1161 /* 1162 * A bug in a previous version of the code could 1163 * cause upgrade_clones_cb() to not set 1164 * ds_next_snap_obj when it should, leading to a 1165 * missing entry. Therefore we can only use the 1166 * next_clones_obj when its count is correct. 1167 */ 1168 int err = zap_count(dp->dp_meta_objset, 1169 dsl_dataset_phys(ds)->ds_next_clones_obj, &count); 1170 if (err == 0 && 1171 count == dsl_dataset_phys(ds)->ds_num_children - 1) 1172 usenext = B_TRUE; 1173 } 1174 1175 if (usenext) { 1176 VERIFY0(zap_join_key(dp->dp_meta_objset, 1177 dsl_dataset_phys(ds)->ds_next_clones_obj, 1178 scn->scn_phys.scn_queue_obj, 1179 dsl_dataset_phys(ds)->ds_creation_txg, tx)); 1180 } else { 1181 struct enqueue_clones_arg eca; 1182 eca.tx = tx; 1183 eca.originobj = ds->ds_object; 1184 1185 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1186 enqueue_clones_cb, &eca, DS_FIND_CHILDREN)); 1187 } 1188 } 1189 1190out: 1191 dsl_dataset_rele(ds, FTAG); 1192} 1193 1194/* ARGSUSED */ 1195static int 1196enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 1197{ 1198 dmu_tx_t *tx = arg; 1199 dsl_dataset_t *ds; 1200 int err; 1201 dsl_scan_t *scn = dp->dp_scan; 1202 1203 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 1204 if (err) 1205 return (err); 1206 1207 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 1208 dsl_dataset_t *prev; 1209 err = dsl_dataset_hold_obj(dp, 1210 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 1211 if (err) { 1212 dsl_dataset_rele(ds, FTAG); 1213 return (err); 1214 } 1215 1216 /* 1217 * If this is a clone, we don't need to worry about it for now. 1218 */ 1219 if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object) { 1220 dsl_dataset_rele(ds, FTAG); 1221 dsl_dataset_rele(prev, FTAG); 1222 return (0); 1223 } 1224 dsl_dataset_rele(ds, FTAG); 1225 ds = prev; 1226 } 1227 1228 VERIFY(zap_add_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 1229 ds->ds_object, dsl_dataset_phys(ds)->ds_prev_snap_txg, tx) == 0); 1230 dsl_dataset_rele(ds, FTAG); 1231 return (0); 1232} 1233 1234/* 1235 * Scrub/dedup interaction. 1236 * 1237 * If there are N references to a deduped block, we don't want to scrub it 1238 * N times -- ideally, we should scrub it exactly once. 1239 * 1240 * We leverage the fact that the dde's replication class (enum ddt_class) 1241 * is ordered from highest replication class (DDT_CLASS_DITTO) to lowest 1242 * (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order. 1243 * 1244 * To prevent excess scrubbing, the scrub begins by walking the DDT 1245 * to find all blocks with refcnt > 1, and scrubs each of these once. 1246 * Since there are two replication classes which contain blocks with 1247 * refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first. 1248 * Finally the top-down scrub begins, only visiting blocks with refcnt == 1. 1249 * 1250 * There would be nothing more to say if a block's refcnt couldn't change 1251 * during a scrub, but of course it can so we must account for changes 1252 * in a block's replication class. 1253 * 1254 * Here's an example of what can occur: 1255 * 1256 * If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1 1257 * when visited during the top-down scrub phase, it will be scrubbed twice. 1258 * This negates our scrub optimization, but is otherwise harmless. 1259 * 1260 * If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1 1261 * on each visit during the top-down scrub phase, it will never be scrubbed. 1262 * To catch this, ddt_sync_entry() notifies the scrub code whenever a block's 1263 * reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to 1264 * DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1 1265 * while a scrub is in progress, it scrubs the block right then. 1266 */ 1267static void 1268dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx) 1269{ 1270 ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark; 1271 ddt_entry_t dde = { 0 }; 1272 int error; 1273 uint64_t n = 0; 1274 1275 while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) { 1276 ddt_t *ddt; 1277 1278 if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max) 1279 break; 1280 dprintf("visiting ddb=%llu/%llu/%llu/%llx\n", 1281 (longlong_t)ddb->ddb_class, 1282 (longlong_t)ddb->ddb_type, 1283 (longlong_t)ddb->ddb_checksum, 1284 (longlong_t)ddb->ddb_cursor); 1285 1286 /* There should be no pending changes to the dedup table */ 1287 ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum]; 1288 ASSERT(avl_first(&ddt->ddt_tree) == NULL); 1289 1290 dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx); 1291 n++; 1292 1293 if (dsl_scan_check_pause(scn, NULL)) 1294 break; 1295 } 1296 1297 zfs_dbgmsg("scanned %llu ddt entries with class_max = %u; pausing=%u", 1298 (longlong_t)n, (int)scn->scn_phys.scn_ddt_class_max, 1299 (int)scn->scn_pausing); 1300 1301 ASSERT(error == 0 || error == ENOENT); 1302 ASSERT(error != ENOENT || 1303 ddb->ddb_class > scn->scn_phys.scn_ddt_class_max); 1304} 1305 1306/* ARGSUSED */ 1307void 1308dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum, 1309 ddt_entry_t *dde, dmu_tx_t *tx) 1310{ 1311 const ddt_key_t *ddk = &dde->dde_key; 1312 ddt_phys_t *ddp = dde->dde_phys; 1313 blkptr_t bp; 1314 zbookmark_phys_t zb = { 0 }; 1315 1316 if (scn->scn_phys.scn_state != DSS_SCANNING) 1317 return; 1318 1319 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1320 if (ddp->ddp_phys_birth == 0 || 1321 ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg) 1322 continue; 1323 ddt_bp_create(checksum, ddk, ddp, &bp); 1324 1325 scn->scn_visited_this_txg++; 1326 scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb); 1327 } 1328} 1329 1330static void 1331dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx) 1332{ 1333 dsl_pool_t *dp = scn->scn_dp; 1334 zap_cursor_t zc; 1335 zap_attribute_t za; 1336 1337 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1338 scn->scn_phys.scn_ddt_class_max) { 1339 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1340 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1341 dsl_scan_ddt(scn, tx); 1342 if (scn->scn_pausing) 1343 return; 1344 } 1345 1346 if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) { 1347 /* First do the MOS & ORIGIN */ 1348 1349 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 1350 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 1351 dsl_scan_visit_rootbp(scn, NULL, 1352 &dp->dp_meta_rootbp, tx); 1353 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); 1354 if (scn->scn_pausing) 1355 return; 1356 1357 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) { 1358 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 1359 enqueue_cb, tx, DS_FIND_CHILDREN)); 1360 } else { 1361 dsl_scan_visitds(scn, 1362 dp->dp_origin_snap->ds_object, tx); 1363 } 1364 ASSERT(!scn->scn_pausing); 1365 } else if (scn->scn_phys.scn_bookmark.zb_objset != 1366 ZB_DESTROYED_OBJSET) { 1367 /* 1368 * If we were paused, continue from here. Note if the 1369 * ds we were paused on was deleted, the zb_objset may 1370 * be -1, so we will skip this and find a new objset 1371 * below. 1372 */ 1373 dsl_scan_visitds(scn, scn->scn_phys.scn_bookmark.zb_objset, tx); 1374 if (scn->scn_pausing) 1375 return; 1376 } 1377 1378 /* 1379 * In case we were paused right at the end of the ds, zero the 1380 * bookmark so we don't think that we're still trying to resume. 1381 */ 1382 bzero(&scn->scn_phys.scn_bookmark, sizeof (zbookmark_phys_t)); 1383 1384 /* keep pulling things out of the zap-object-as-queue */ 1385 while (zap_cursor_init(&zc, dp->dp_meta_objset, 1386 scn->scn_phys.scn_queue_obj), 1387 zap_cursor_retrieve(&zc, &za) == 0) { 1388 dsl_dataset_t *ds; 1389 uint64_t dsobj; 1390 1391 dsobj = strtonum(za.za_name, NULL); 1392 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 1393 scn->scn_phys.scn_queue_obj, dsobj, tx)); 1394 1395 /* Set up min/max txg */ 1396 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 1397 if (za.za_first_integer != 0) { 1398 scn->scn_phys.scn_cur_min_txg = 1399 MAX(scn->scn_phys.scn_min_txg, 1400 za.za_first_integer); 1401 } else { 1402 scn->scn_phys.scn_cur_min_txg = 1403 MAX(scn->scn_phys.scn_min_txg, 1404 dsl_dataset_phys(ds)->ds_prev_snap_txg); 1405 } 1406 scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds); 1407 dsl_dataset_rele(ds, FTAG); 1408 1409 dsl_scan_visitds(scn, dsobj, tx); 1410 zap_cursor_fini(&zc); 1411 if (scn->scn_pausing) 1412 return; 1413 } 1414 zap_cursor_fini(&zc); 1415} 1416 1417static boolean_t 1418dsl_scan_free_should_pause(dsl_scan_t *scn) 1419{ 1420 uint64_t elapsed_nanosecs; 1421 1422 if (zfs_recover) 1423 return (B_FALSE); 1424 1425 if (scn->scn_visited_this_txg >= zfs_free_max_blocks) 1426 return (B_TRUE); 1427 1428 elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 1429 return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || 1430 (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms && 1431 txg_sync_waiting(scn->scn_dp)) || 1432 spa_shutting_down(scn->scn_dp->dp_spa)); 1433} 1434 1435static int 1436dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1437{ 1438 dsl_scan_t *scn = arg; 1439 1440 if (!scn->scn_is_bptree || 1441 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) { 1442 if (dsl_scan_free_should_pause(scn)) 1443 return (SET_ERROR(ERESTART)); 1444 } 1445 1446 zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa, 1447 dmu_tx_get_txg(tx), bp, BP_GET_PSIZE(bp), 0)); 1448 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD, 1449 -bp_get_dsize_sync(scn->scn_dp->dp_spa, bp), 1450 -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx); 1451 scn->scn_visited_this_txg++; 1452 return (0); 1453} 1454 1455boolean_t 1456dsl_scan_active(dsl_scan_t *scn) 1457{ 1458 spa_t *spa = scn->scn_dp->dp_spa; 1459 uint64_t used = 0, comp, uncomp; 1460 1461 if (spa->spa_load_state != SPA_LOAD_NONE) 1462 return (B_FALSE); 1463 if (spa_shutting_down(spa)) 1464 return (B_FALSE); 1465 if (scn->scn_phys.scn_state == DSS_SCANNING || 1466 (scn->scn_async_destroying && !scn->scn_async_stalled)) 1467 return (B_TRUE); 1468 1469 if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1470 (void) bpobj_space(&scn->scn_dp->dp_free_bpobj, 1471 &used, &comp, &uncomp); 1472 } 1473 return (used != 0); 1474} 1475 1476void 1477dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) 1478{ 1479 dsl_scan_t *scn = dp->dp_scan; 1480 spa_t *spa = dp->dp_spa; 1481 int err = 0; 1482 1483 /* 1484 * Check for scn_restart_txg before checking spa_load_state, so 1485 * that we can restart an old-style scan while the pool is being 1486 * imported (see dsl_scan_init). 1487 */ 1488 if (scn->scn_restart_txg != 0 && 1489 scn->scn_restart_txg <= tx->tx_txg) { 1490 pool_scan_func_t func = POOL_SCAN_SCRUB; 1491 dsl_scan_done(scn, B_FALSE, tx); 1492 if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) 1493 func = POOL_SCAN_RESILVER; 1494 zfs_dbgmsg("restarting scan func=%u txg=%llu", 1495 func, tx->tx_txg); 1496 dsl_scan_setup_sync(&func, tx); 1497 } 1498 1499 /* 1500 * Only process scans in sync pass 1. 1501 */ 1502 if (spa_sync_pass(dp->dp_spa) > 1) 1503 return; 1504 1505 /* 1506 * If the spa is shutting down, then stop scanning. This will 1507 * ensure that the scan does not dirty any new data during the 1508 * shutdown phase. 1509 */ 1510 if (spa_shutting_down(spa)) 1511 return; 1512 1513 /* 1514 * If the scan is inactive due to a stalled async destroy, try again. 1515 */ 1516 if (!scn->scn_async_stalled && !dsl_scan_active(scn)) 1517 return; 1518 1519 scn->scn_visited_this_txg = 0; 1520 scn->scn_pausing = B_FALSE; 1521 scn->scn_sync_start_time = gethrtime(); 1522 spa->spa_scrub_active = B_TRUE; 1523 1524 /* 1525 * First process the async destroys. If we pause, don't do 1526 * any scrubbing or resilvering. This ensures that there are no 1527 * async destroys while we are scanning, so the scan code doesn't 1528 * have to worry about traversing it. It is also faster to free the 1529 * blocks than to scrub them. 1530 */ 1531 if (zfs_free_bpobj_enabled && 1532 spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 1533 scn->scn_is_bptree = B_FALSE; 1534 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1535 NULL, ZIO_FLAG_MUSTSUCCEED); 1536 err = bpobj_iterate(&dp->dp_free_bpobj, 1537 dsl_scan_free_block_cb, scn, tx); 1538 VERIFY3U(0, ==, zio_wait(scn->scn_zio_root)); 1539 1540 if (err != 0 && err != ERESTART) 1541 zfs_panic_recover("error %u from bpobj_iterate()", err); 1542 } 1543 1544 if (err == 0 && spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) { 1545 ASSERT(scn->scn_async_destroying); 1546 scn->scn_is_bptree = B_TRUE; 1547 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1548 NULL, ZIO_FLAG_MUSTSUCCEED); 1549 err = bptree_iterate(dp->dp_meta_objset, 1550 dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, scn, tx); 1551 VERIFY0(zio_wait(scn->scn_zio_root)); 1552 1553 if (err == EIO || err == ECKSUM) { 1554 err = 0; 1555 } else if (err != 0 && err != ERESTART) { 1556 zfs_panic_recover("error %u from " 1557 "traverse_dataset_destroyed()", err); 1558 } 1559 1560 if (bptree_is_empty(dp->dp_meta_objset, dp->dp_bptree_obj)) { 1561 /* finished; deactivate async destroy feature */ 1562 spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, tx); 1563 ASSERT(!spa_feature_is_active(spa, 1564 SPA_FEATURE_ASYNC_DESTROY)); 1565 VERIFY0(zap_remove(dp->dp_meta_objset, 1566 DMU_POOL_DIRECTORY_OBJECT, 1567 DMU_POOL_BPTREE_OBJ, tx)); 1568 VERIFY0(bptree_free(dp->dp_meta_objset, 1569 dp->dp_bptree_obj, tx)); 1570 dp->dp_bptree_obj = 0; 1571 scn->scn_async_destroying = B_FALSE; 1572 scn->scn_async_stalled = B_FALSE; 1573 } else { 1574 /* 1575 * If we didn't make progress, mark the async 1576 * destroy as stalled, so that we will not initiate 1577 * a spa_sync() on its behalf. Note that we only 1578 * check this if we are not finished, because if the 1579 * bptree had no blocks for us to visit, we can 1580 * finish without "making progress". 1581 */ 1582 scn->scn_async_stalled = 1583 (scn->scn_visited_this_txg == 0); 1584 } 1585 } 1586 if (scn->scn_visited_this_txg) { 1587 zfs_dbgmsg("freed %llu blocks in %llums from " 1588 "free_bpobj/bptree txg %llu; err=%d", 1589 (longlong_t)scn->scn_visited_this_txg, 1590 (longlong_t) 1591 NSEC2MSEC(gethrtime() - scn->scn_sync_start_time), 1592 (longlong_t)tx->tx_txg, err); 1593 scn->scn_visited_this_txg = 0; 1594 1595 /* 1596 * Write out changes to the DDT that may be required as a 1597 * result of the blocks freed. This ensures that the DDT 1598 * is clean when a scrub/resilver runs. 1599 */ 1600 ddt_sync(spa, tx->tx_txg); 1601 } 1602 if (err != 0) 1603 return; 1604 if (dp->dp_free_dir != NULL && !scn->scn_async_destroying && 1605 zfs_free_leak_on_eio && 1606 (dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes != 0 || 1607 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes != 0 || 1608 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes != 0)) { 1609 /* 1610 * We have finished background destroying, but there is still 1611 * some space left in the dp_free_dir. Transfer this leaked 1612 * space to the dp_leak_dir. 1613 */ 1614 if (dp->dp_leak_dir == NULL) { 1615 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); 1616 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, 1617 LEAK_DIR_NAME, tx); 1618 VERIFY0(dsl_pool_open_special_dir(dp, 1619 LEAK_DIR_NAME, &dp->dp_leak_dir)); 1620 rrw_exit(&dp->dp_config_rwlock, FTAG); 1621 } 1622 dsl_dir_diduse_space(dp->dp_leak_dir, DD_USED_HEAD, 1623 dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1624 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1625 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1626 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 1627 -dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 1628 -dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 1629 -dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 1630 } 1631 if (dp->dp_free_dir != NULL && !scn->scn_async_destroying) { 1632 /* finished; verify that space accounting went to zero */ 1633 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes); 1634 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes); 1635 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes); 1636 } 1637 1638 if (scn->scn_phys.scn_state != DSS_SCANNING) 1639 return; 1640 1641 if (scn->scn_done_txg == tx->tx_txg) { 1642 ASSERT(!scn->scn_pausing); 1643 /* finished with scan. */ 1644 zfs_dbgmsg("txg %llu scan complete", tx->tx_txg); 1645 dsl_scan_done(scn, B_TRUE, tx); 1646 ASSERT3U(spa->spa_scrub_inflight, ==, 0); 1647 dsl_scan_sync_state(scn, tx); 1648 return; 1649 } 1650 1651 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 1652 scn->scn_phys.scn_ddt_class_max) { 1653 zfs_dbgmsg("doing scan sync txg %llu; " 1654 "ddt bm=%llu/%llu/%llu/%llx", 1655 (longlong_t)tx->tx_txg, 1656 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, 1657 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, 1658 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, 1659 (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); 1660 ASSERT(scn->scn_phys.scn_bookmark.zb_objset == 0); 1661 ASSERT(scn->scn_phys.scn_bookmark.zb_object == 0); 1662 ASSERT(scn->scn_phys.scn_bookmark.zb_level == 0); 1663 ASSERT(scn->scn_phys.scn_bookmark.zb_blkid == 0); 1664 } else { 1665 zfs_dbgmsg("doing scan sync txg %llu; bm=%llu/%llu/%llu/%llu", 1666 (longlong_t)tx->tx_txg, 1667 (longlong_t)scn->scn_phys.scn_bookmark.zb_objset, 1668 (longlong_t)scn->scn_phys.scn_bookmark.zb_object, 1669 (longlong_t)scn->scn_phys.scn_bookmark.zb_level, 1670 (longlong_t)scn->scn_phys.scn_bookmark.zb_blkid); 1671 } 1672 1673 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 1674 NULL, ZIO_FLAG_CANFAIL); 1675 dsl_pool_config_enter(dp, FTAG); 1676 dsl_scan_visit(scn, tx); 1677 dsl_pool_config_exit(dp, FTAG); 1678 (void) zio_wait(scn->scn_zio_root); 1679 scn->scn_zio_root = NULL; 1680 1681 zfs_dbgmsg("visited %llu blocks in %llums", 1682 (longlong_t)scn->scn_visited_this_txg, 1683 (longlong_t)NSEC2MSEC(gethrtime() - scn->scn_sync_start_time)); 1684 1685 if (!scn->scn_pausing) { 1686 scn->scn_done_txg = tx->tx_txg + 1; 1687 zfs_dbgmsg("txg %llu traversal complete, waiting till txg %llu", 1688 tx->tx_txg, scn->scn_done_txg); 1689 } 1690 1691 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 1692 mutex_enter(&spa->spa_scrub_lock); 1693 while (spa->spa_scrub_inflight > 0) { 1694 cv_wait(&spa->spa_scrub_io_cv, 1695 &spa->spa_scrub_lock); 1696 } 1697 mutex_exit(&spa->spa_scrub_lock); 1698 } 1699 1700 dsl_scan_sync_state(scn, tx); 1701} 1702 1703/* 1704 * This will start a new scan, or restart an existing one. 1705 */ 1706void 1707dsl_resilver_restart(dsl_pool_t *dp, uint64_t txg) 1708{ 1709 if (txg == 0) { 1710 dmu_tx_t *tx; 1711 tx = dmu_tx_create_dd(dp->dp_mos_dir); 1712 VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT)); 1713 1714 txg = dmu_tx_get_txg(tx); 1715 dp->dp_scan->scn_restart_txg = txg; 1716 dmu_tx_commit(tx); 1717 } else { 1718 dp->dp_scan->scn_restart_txg = txg; 1719 } 1720 zfs_dbgmsg("restarting resilver txg=%llu", txg); 1721} 1722 1723boolean_t 1724dsl_scan_resilvering(dsl_pool_t *dp) 1725{ 1726 return (dp->dp_scan->scn_phys.scn_state == DSS_SCANNING && 1727 dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER); 1728} 1729 1730/* 1731 * scrub consumers 1732 */ 1733 1734static void 1735count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp) 1736{ 1737 int i; 1738 1739 /* 1740 * If we resume after a reboot, zab will be NULL; don't record 1741 * incomplete stats in that case. 1742 */ 1743 if (zab == NULL) 1744 return; 1745 1746 for (i = 0; i < 4; i++) { 1747 int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS; 1748 int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL; 1749 if (t & DMU_OT_NEWTYPE) 1750 t = DMU_OT_OTHER; 1751 zfs_blkstat_t *zb = &zab->zab_type[l][t]; 1752 int equal; 1753 1754 zb->zb_count++; 1755 zb->zb_asize += BP_GET_ASIZE(bp); 1756 zb->zb_lsize += BP_GET_LSIZE(bp); 1757 zb->zb_psize += BP_GET_PSIZE(bp); 1758 zb->zb_gangs += BP_COUNT_GANG(bp); 1759 1760 switch (BP_GET_NDVAS(bp)) { 1761 case 2: 1762 if (DVA_GET_VDEV(&bp->blk_dva[0]) == 1763 DVA_GET_VDEV(&bp->blk_dva[1])) 1764 zb->zb_ditto_2_of_2_samevdev++; 1765 break; 1766 case 3: 1767 equal = (DVA_GET_VDEV(&bp->blk_dva[0]) == 1768 DVA_GET_VDEV(&bp->blk_dva[1])) + 1769 (DVA_GET_VDEV(&bp->blk_dva[0]) == 1770 DVA_GET_VDEV(&bp->blk_dva[2])) + 1771 (DVA_GET_VDEV(&bp->blk_dva[1]) == 1772 DVA_GET_VDEV(&bp->blk_dva[2])); 1773 if (equal == 1) 1774 zb->zb_ditto_2_of_3_samevdev++; 1775 else if (equal == 3) 1776 zb->zb_ditto_3_of_3_samevdev++; 1777 break; 1778 } 1779 } 1780} 1781 1782static void 1783dsl_scan_scrub_done(zio_t *zio) 1784{ 1785 spa_t *spa = zio->io_spa; 1786 1787 zio_data_buf_free(zio->io_data, zio->io_size); 1788 1789 mutex_enter(&spa->spa_scrub_lock); 1790 spa->spa_scrub_inflight--; 1791 cv_broadcast(&spa->spa_scrub_io_cv); 1792 1793 if (zio->io_error && (zio->io_error != ECKSUM || 1794 !(zio->io_flags & ZIO_FLAG_SPECULATIVE))) { 1795 spa->spa_dsl_pool->dp_scan->scn_phys.scn_errors++; 1796 } 1797 mutex_exit(&spa->spa_scrub_lock); 1798} 1799 1800static int 1801dsl_scan_scrub_cb(dsl_pool_t *dp, 1802 const blkptr_t *bp, const zbookmark_phys_t *zb) 1803{ 1804 dsl_scan_t *scn = dp->dp_scan; 1805 size_t size = BP_GET_PSIZE(bp); 1806 spa_t *spa = dp->dp_spa; 1807 uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp); 1808 boolean_t needs_io; 1809 int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL; 1810 unsigned int scan_delay = 0; 1811 1812 if (phys_birth <= scn->scn_phys.scn_min_txg || 1813 phys_birth >= scn->scn_phys.scn_max_txg) 1814 return (0); 1815 1816 count_block(dp->dp_blkstats, bp); 1817 1818 if (BP_IS_EMBEDDED(bp)) 1819 return (0); 1820 1821 ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn)); 1822 if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) { 1823 zio_flags |= ZIO_FLAG_SCRUB; 1824 needs_io = B_TRUE; 1825 scan_delay = zfs_scrub_delay; 1826 } else { 1827 ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER); 1828 zio_flags |= ZIO_FLAG_RESILVER; 1829 needs_io = B_FALSE; 1830 scan_delay = zfs_resilver_delay; 1831 } 1832 1833 /* If it's an intent log block, failure is expected. */ 1834 if (zb->zb_level == ZB_ZIL_LEVEL) 1835 zio_flags |= ZIO_FLAG_SPECULATIVE; 1836 1837 for (int d = 0; d < BP_GET_NDVAS(bp); d++) { 1838 vdev_t *vd = vdev_lookup_top(spa, 1839 DVA_GET_VDEV(&bp->blk_dva[d])); 1840 1841 /* 1842 * Keep track of how much data we've examined so that 1843 * zpool(1M) status can make useful progress reports. 1844 */ 1845 scn->scn_phys.scn_examined += DVA_GET_ASIZE(&bp->blk_dva[d]); 1846 spa->spa_scan_pass_exam += DVA_GET_ASIZE(&bp->blk_dva[d]); 1847 1848 /* if it's a resilver, this may not be in the target range */ 1849 if (!needs_io) { 1850 if (DVA_GET_GANG(&bp->blk_dva[d])) { 1851 /* 1852 * Gang members may be spread across multiple 1853 * vdevs, so the best estimate we have is the 1854 * scrub range, which has already been checked. 1855 * XXX -- it would be better to change our 1856 * allocation policy to ensure that all 1857 * gang members reside on the same vdev. 1858 */ 1859 needs_io = B_TRUE; 1860 } else { 1861 needs_io = vdev_dtl_contains(vd, DTL_PARTIAL, 1862 phys_birth, 1); 1863 } 1864 } 1865 } 1866 1867 if (needs_io && !zfs_no_scrub_io) { 1868 vdev_t *rvd = spa->spa_root_vdev; 1869 uint64_t maxinflight = rvd->vdev_children * 1870 MAX(zfs_top_maxinflight, 1); 1871 void *data = zio_data_buf_alloc(size); 1872 1873 mutex_enter(&spa->spa_scrub_lock); 1874 while (spa->spa_scrub_inflight >= maxinflight) 1875 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock); 1876 spa->spa_scrub_inflight++; 1877 mutex_exit(&spa->spa_scrub_lock); 1878 1879 /* 1880 * If we're seeing recent (zfs_scan_idle) "important" I/Os 1881 * then throttle our workload to limit the impact of a scan. 1882 */ 1883 if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle) 1884 delay(MAX((int)scan_delay, 0)); 1885 1886 zio_nowait(zio_read(NULL, spa, bp, data, size, 1887 dsl_scan_scrub_done, NULL, ZIO_PRIORITY_SCRUB, 1888 zio_flags, zb)); 1889 } 1890 1891 /* do not relocate this block */ 1892 return (0); 1893} 1894 1895int 1896dsl_scan(dsl_pool_t *dp, pool_scan_func_t func) 1897{ 1898 spa_t *spa = dp->dp_spa; 1899 1900 /* 1901 * Purge all vdev caches and probe all devices. We do this here 1902 * rather than in sync context because this requires a writer lock 1903 * on the spa_config lock, which we can't do from sync context. The 1904 * spa_scrub_reopen flag indicates that vdev_open() should not 1905 * attempt to start another scrub. 1906 */ 1907 spa_vdev_state_enter(spa, SCL_NONE); 1908 spa->spa_scrub_reopen = B_TRUE; 1909 vdev_reopen(spa->spa_root_vdev); 1910 spa->spa_scrub_reopen = B_FALSE; 1911 (void) spa_vdev_state_exit(spa, NULL, 0); 1912 1913 return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check, 1914 dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_NONE)); 1915} 1916