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 https://opensource.org/licenses/CDDL-1.0. 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, 2021 by Delphix. All rights reserved. 24 * Copyright 2016 Gary Mills 25 * Copyright (c) 2017, 2019, Datto Inc. All rights reserved. 26 * Copyright (c) 2015, Nexenta Systems, Inc. All rights reserved. 27 * Copyright 2019 Joyent, Inc. 28 */ 29 30 #include <sys/dsl_scan.h> 31 #include <sys/dsl_pool.h> 32 #include <sys/dsl_dataset.h> 33 #include <sys/dsl_prop.h> 34 #include <sys/dsl_dir.h> 35 #include <sys/dsl_synctask.h> 36 #include <sys/dnode.h> 37 #include <sys/dmu_tx.h> 38 #include <sys/dmu_objset.h> 39 #include <sys/arc.h> 40 #include <sys/arc_impl.h> 41 #include <sys/zap.h> 42 #include <sys/zio.h> 43 #include <sys/zfs_context.h> 44 #include <sys/fs/zfs.h> 45 #include <sys/zfs_znode.h> 46 #include <sys/spa_impl.h> 47 #include <sys/vdev_impl.h> 48 #include <sys/zil_impl.h> 49 #include <sys/zio_checksum.h> 50 #include <sys/brt.h> 51 #include <sys/ddt.h> 52 #include <sys/sa.h> 53 #include <sys/sa_impl.h> 54 #include <sys/zfeature.h> 55 #include <sys/abd.h> 56 #include <sys/range_tree.h> 57 #include <sys/dbuf.h> 58 #ifdef _KERNEL 59 #include <sys/zfs_vfsops.h> 60 #endif 61 62 /* 63 * Grand theory statement on scan queue sorting 64 * 65 * Scanning is implemented by recursively traversing all indirection levels 66 * in an object and reading all blocks referenced from said objects. This 67 * results in us approximately traversing the object from lowest logical 68 * offset to the highest. For best performance, we would want the logical 69 * blocks to be physically contiguous. However, this is frequently not the 70 * case with pools given the allocation patterns of copy-on-write filesystems. 71 * So instead, we put the I/Os into a reordering queue and issue them in a 72 * way that will most benefit physical disks (LBA-order). 73 * 74 * Queue management: 75 * 76 * Ideally, we would want to scan all metadata and queue up all block I/O 77 * prior to starting to issue it, because that allows us to do an optimal 78 * sorting job. This can however consume large amounts of memory. Therefore 79 * we continuously monitor the size of the queues and constrain them to 5% 80 * (zfs_scan_mem_lim_fact) of physmem. If the queues grow larger than this 81 * limit, we clear out a few of the largest extents at the head of the queues 82 * to make room for more scanning. Hopefully, these extents will be fairly 83 * large and contiguous, allowing us to approach sequential I/O throughput 84 * even without a fully sorted tree. 85 * 86 * Metadata scanning takes place in dsl_scan_visit(), which is called from 87 * dsl_scan_sync() every spa_sync(). If we have either fully scanned all 88 * metadata on the pool, or we need to make room in memory because our 89 * queues are too large, dsl_scan_visit() is postponed and 90 * scan_io_queues_run() is called from dsl_scan_sync() instead. This implies 91 * that metadata scanning and queued I/O issuing are mutually exclusive. This 92 * allows us to provide maximum sequential I/O throughput for the majority of 93 * I/O's issued since sequential I/O performance is significantly negatively 94 * impacted if it is interleaved with random I/O. 95 * 96 * Implementation Notes 97 * 98 * One side effect of the queued scanning algorithm is that the scanning code 99 * needs to be notified whenever a block is freed. This is needed to allow 100 * the scanning code to remove these I/Os from the issuing queue. Additionally, 101 * we do not attempt to queue gang blocks to be issued sequentially since this 102 * is very hard to do and would have an extremely limited performance benefit. 103 * Instead, we simply issue gang I/Os as soon as we find them using the legacy 104 * algorithm. 105 * 106 * Backwards compatibility 107 * 108 * This new algorithm is backwards compatible with the legacy on-disk data 109 * structures (and therefore does not require a new feature flag). 110 * Periodically during scanning (see zfs_scan_checkpoint_intval), the scan 111 * will stop scanning metadata (in logical order) and wait for all outstanding 112 * sorted I/O to complete. Once this is done, we write out a checkpoint 113 * bookmark, indicating that we have scanned everything logically before it. 114 * If the pool is imported on a machine without the new sorting algorithm, 115 * the scan simply resumes from the last checkpoint using the legacy algorithm. 116 */ 117 118 typedef int (scan_cb_t)(dsl_pool_t *, const blkptr_t *, 119 const zbookmark_phys_t *); 120 121 static scan_cb_t dsl_scan_scrub_cb; 122 123 static int scan_ds_queue_compare(const void *a, const void *b); 124 static int scan_prefetch_queue_compare(const void *a, const void *b); 125 static void scan_ds_queue_clear(dsl_scan_t *scn); 126 static void scan_ds_prefetch_queue_clear(dsl_scan_t *scn); 127 static boolean_t scan_ds_queue_contains(dsl_scan_t *scn, uint64_t dsobj, 128 uint64_t *txg); 129 static void scan_ds_queue_insert(dsl_scan_t *scn, uint64_t dsobj, uint64_t txg); 130 static void scan_ds_queue_remove(dsl_scan_t *scn, uint64_t dsobj); 131 static void scan_ds_queue_sync(dsl_scan_t *scn, dmu_tx_t *tx); 132 static uint64_t dsl_scan_count_data_disks(spa_t *spa); 133 static void read_by_block_level(dsl_scan_t *scn, zbookmark_phys_t zb); 134 135 extern uint_t zfs_vdev_async_write_active_min_dirty_percent; 136 static int zfs_scan_blkstats = 0; 137 138 /* 139 * 'zpool status' uses bytes processed per pass to report throughput and 140 * estimate time remaining. We define a pass to start when the scanning 141 * phase completes for a sequential resilver. Optionally, this value 142 * may be used to reset the pass statistics every N txgs to provide an 143 * estimated completion time based on currently observed performance. 144 */ 145 static uint_t zfs_scan_report_txgs = 0; 146 147 /* 148 * By default zfs will check to ensure it is not over the hard memory 149 * limit before each txg. If finer-grained control of this is needed 150 * this value can be set to 1 to enable checking before scanning each 151 * block. 152 */ 153 static int zfs_scan_strict_mem_lim = B_FALSE; 154 155 /* 156 * Maximum number of parallelly executed bytes per leaf vdev. We attempt 157 * to strike a balance here between keeping the vdev queues full of I/Os 158 * at all times and not overflowing the queues to cause long latency, 159 * which would cause long txg sync times. No matter what, we will not 160 * overload the drives with I/O, since that is protected by 161 * zfs_vdev_scrub_max_active. 162 */ 163 static uint64_t zfs_scan_vdev_limit = 16 << 20; 164 165 static uint_t zfs_scan_issue_strategy = 0; 166 167 /* don't queue & sort zios, go direct */ 168 static int zfs_scan_legacy = B_FALSE; 169 static uint64_t zfs_scan_max_ext_gap = 2 << 20; /* in bytes */ 170 171 /* 172 * fill_weight is non-tunable at runtime, so we copy it at module init from 173 * zfs_scan_fill_weight. Runtime adjustments to zfs_scan_fill_weight would 174 * break queue sorting. 175 */ 176 static uint_t zfs_scan_fill_weight = 3; 177 static uint64_t fill_weight; 178 179 /* See dsl_scan_should_clear() for details on the memory limit tunables */ 180 static const uint64_t zfs_scan_mem_lim_min = 16 << 20; /* bytes */ 181 static const uint64_t zfs_scan_mem_lim_soft_max = 128 << 20; /* bytes */ 182 183 184 /* fraction of physmem */ 185 static uint_t zfs_scan_mem_lim_fact = 20; 186 187 /* fraction of mem lim above */ 188 static uint_t zfs_scan_mem_lim_soft_fact = 20; 189 190 /* minimum milliseconds to scrub per txg */ 191 static uint_t zfs_scrub_min_time_ms = 1000; 192 193 /* minimum milliseconds to obsolete per txg */ 194 static uint_t zfs_obsolete_min_time_ms = 500; 195 196 /* minimum milliseconds to free per txg */ 197 static uint_t zfs_free_min_time_ms = 1000; 198 199 /* minimum milliseconds to resilver per txg */ 200 static uint_t zfs_resilver_min_time_ms = 3000; 201 202 static uint_t zfs_scan_checkpoint_intval = 7200; /* in seconds */ 203 int zfs_scan_suspend_progress = 0; /* set to prevent scans from progressing */ 204 static int zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */ 205 static int zfs_no_scrub_prefetch = B_FALSE; /* set to disable scrub prefetch */ 206 static const enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE; 207 /* max number of blocks to free in a single TXG */ 208 static uint64_t zfs_async_block_max_blocks = UINT64_MAX; 209 /* max number of dedup blocks to free in a single TXG */ 210 static uint64_t zfs_max_async_dedup_frees = 100000; 211 212 /* set to disable resilver deferring */ 213 static int zfs_resilver_disable_defer = B_FALSE; 214 215 /* 216 * We wait a few txgs after importing a pool to begin scanning so that 217 * the import / mounting code isn't held up by scrub / resilver IO. 218 * Unfortunately, it is a bit difficult to determine exactly how long 219 * this will take since userspace will trigger fs mounts asynchronously 220 * and the kernel will create zvol minors asynchronously. As a result, 221 * the value provided here is a bit arbitrary, but represents a 222 * reasonable estimate of how many txgs it will take to finish fully 223 * importing a pool 224 */ 225 #define SCAN_IMPORT_WAIT_TXGS 5 226 227 #define DSL_SCAN_IS_SCRUB_RESILVER(scn) \ 228 ((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \ 229 (scn)->scn_phys.scn_func == POOL_SCAN_RESILVER) 230 231 /* 232 * Enable/disable the processing of the free_bpobj object. 233 */ 234 static int zfs_free_bpobj_enabled = 1; 235 236 /* Error blocks to be scrubbed in one txg. */ 237 static uint_t zfs_scrub_error_blocks_per_txg = 1 << 12; 238 239 /* the order has to match pool_scan_type */ 240 static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = { 241 NULL, 242 dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */ 243 dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */ 244 }; 245 246 /* In core node for the scn->scn_queue. Represents a dataset to be scanned */ 247 typedef struct { 248 uint64_t sds_dsobj; 249 uint64_t sds_txg; 250 avl_node_t sds_node; 251 } scan_ds_t; 252 253 /* 254 * This controls what conditions are placed on dsl_scan_sync_state(): 255 * SYNC_OPTIONAL) write out scn_phys iff scn_queues_pending == 0 256 * SYNC_MANDATORY) write out scn_phys always. scn_queues_pending must be 0. 257 * SYNC_CACHED) if scn_queues_pending == 0, write out scn_phys. Otherwise 258 * write out the scn_phys_cached version. 259 * See dsl_scan_sync_state for details. 260 */ 261 typedef enum { 262 SYNC_OPTIONAL, 263 SYNC_MANDATORY, 264 SYNC_CACHED 265 } state_sync_type_t; 266 267 /* 268 * This struct represents the minimum information needed to reconstruct a 269 * zio for sequential scanning. This is useful because many of these will 270 * accumulate in the sequential IO queues before being issued, so saving 271 * memory matters here. 272 */ 273 typedef struct scan_io { 274 /* fields from blkptr_t */ 275 uint64_t sio_blk_prop; 276 uint64_t sio_phys_birth; 277 uint64_t sio_birth; 278 zio_cksum_t sio_cksum; 279 uint32_t sio_nr_dvas; 280 281 /* fields from zio_t */ 282 uint32_t sio_flags; 283 zbookmark_phys_t sio_zb; 284 285 /* members for queue sorting */ 286 union { 287 avl_node_t sio_addr_node; /* link into issuing queue */ 288 list_node_t sio_list_node; /* link for issuing to disk */ 289 } sio_nodes; 290 291 /* 292 * There may be up to SPA_DVAS_PER_BP DVAs here from the bp, 293 * depending on how many were in the original bp. Only the 294 * first DVA is really used for sorting and issuing purposes. 295 * The other DVAs (if provided) simply exist so that the zio 296 * layer can find additional copies to repair from in the 297 * event of an error. This array must go at the end of the 298 * struct to allow this for the variable number of elements. 299 */ 300 dva_t sio_dva[]; 301 } scan_io_t; 302 303 #define SIO_SET_OFFSET(sio, x) DVA_SET_OFFSET(&(sio)->sio_dva[0], x) 304 #define SIO_SET_ASIZE(sio, x) DVA_SET_ASIZE(&(sio)->sio_dva[0], x) 305 #define SIO_GET_OFFSET(sio) DVA_GET_OFFSET(&(sio)->sio_dva[0]) 306 #define SIO_GET_ASIZE(sio) DVA_GET_ASIZE(&(sio)->sio_dva[0]) 307 #define SIO_GET_END_OFFSET(sio) \ 308 (SIO_GET_OFFSET(sio) + SIO_GET_ASIZE(sio)) 309 #define SIO_GET_MUSED(sio) \ 310 (sizeof (scan_io_t) + ((sio)->sio_nr_dvas * sizeof (dva_t))) 311 312 struct dsl_scan_io_queue { 313 dsl_scan_t *q_scn; /* associated dsl_scan_t */ 314 vdev_t *q_vd; /* top-level vdev that this queue represents */ 315 zio_t *q_zio; /* scn_zio_root child for waiting on IO */ 316 317 /* trees used for sorting I/Os and extents of I/Os */ 318 range_tree_t *q_exts_by_addr; 319 zfs_btree_t q_exts_by_size; 320 avl_tree_t q_sios_by_addr; 321 uint64_t q_sio_memused; 322 uint64_t q_last_ext_addr; 323 324 /* members for zio rate limiting */ 325 uint64_t q_maxinflight_bytes; 326 uint64_t q_inflight_bytes; 327 kcondvar_t q_zio_cv; /* used under vd->vdev_scan_io_queue_lock */ 328 329 /* per txg statistics */ 330 uint64_t q_total_seg_size_this_txg; 331 uint64_t q_segs_this_txg; 332 uint64_t q_total_zio_size_this_txg; 333 uint64_t q_zios_this_txg; 334 }; 335 336 /* private data for dsl_scan_prefetch_cb() */ 337 typedef struct scan_prefetch_ctx { 338 zfs_refcount_t spc_refcnt; /* refcount for memory management */ 339 dsl_scan_t *spc_scn; /* dsl_scan_t for the pool */ 340 boolean_t spc_root; /* is this prefetch for an objset? */ 341 uint8_t spc_indblkshift; /* dn_indblkshift of current dnode */ 342 uint16_t spc_datablkszsec; /* dn_idatablkszsec of current dnode */ 343 } scan_prefetch_ctx_t; 344 345 /* private data for dsl_scan_prefetch() */ 346 typedef struct scan_prefetch_issue_ctx { 347 avl_node_t spic_avl_node; /* link into scn->scn_prefetch_queue */ 348 scan_prefetch_ctx_t *spic_spc; /* spc for the callback */ 349 blkptr_t spic_bp; /* bp to prefetch */ 350 zbookmark_phys_t spic_zb; /* bookmark to prefetch */ 351 } scan_prefetch_issue_ctx_t; 352 353 static void scan_exec_io(dsl_pool_t *dp, const blkptr_t *bp, int zio_flags, 354 const zbookmark_phys_t *zb, dsl_scan_io_queue_t *queue); 355 static void scan_io_queue_insert_impl(dsl_scan_io_queue_t *queue, 356 scan_io_t *sio); 357 358 static dsl_scan_io_queue_t *scan_io_queue_create(vdev_t *vd); 359 static void scan_io_queues_destroy(dsl_scan_t *scn); 360 361 static kmem_cache_t *sio_cache[SPA_DVAS_PER_BP]; 362 363 /* sio->sio_nr_dvas must be set so we know which cache to free from */ 364 static void 365 sio_free(scan_io_t *sio) 366 { 367 ASSERT3U(sio->sio_nr_dvas, >, 0); 368 ASSERT3U(sio->sio_nr_dvas, <=, SPA_DVAS_PER_BP); 369 370 kmem_cache_free(sio_cache[sio->sio_nr_dvas - 1], sio); 371 } 372 373 /* It is up to the caller to set sio->sio_nr_dvas for freeing */ 374 static scan_io_t * 375 sio_alloc(unsigned short nr_dvas) 376 { 377 ASSERT3U(nr_dvas, >, 0); 378 ASSERT3U(nr_dvas, <=, SPA_DVAS_PER_BP); 379 380 return (kmem_cache_alloc(sio_cache[nr_dvas - 1], KM_SLEEP)); 381 } 382 383 void 384 scan_init(void) 385 { 386 /* 387 * This is used in ext_size_compare() to weight segments 388 * based on how sparse they are. This cannot be changed 389 * mid-scan and the tree comparison functions don't currently 390 * have a mechanism for passing additional context to the 391 * compare functions. Thus we store this value globally and 392 * we only allow it to be set at module initialization time 393 */ 394 fill_weight = zfs_scan_fill_weight; 395 396 for (int i = 0; i < SPA_DVAS_PER_BP; i++) { 397 char name[36]; 398 399 (void) snprintf(name, sizeof (name), "sio_cache_%d", i); 400 sio_cache[i] = kmem_cache_create(name, 401 (sizeof (scan_io_t) + ((i + 1) * sizeof (dva_t))), 402 0, NULL, NULL, NULL, NULL, NULL, 0); 403 } 404 } 405 406 void 407 scan_fini(void) 408 { 409 for (int i = 0; i < SPA_DVAS_PER_BP; i++) { 410 kmem_cache_destroy(sio_cache[i]); 411 } 412 } 413 414 static inline boolean_t 415 dsl_scan_is_running(const dsl_scan_t *scn) 416 { 417 return (scn->scn_phys.scn_state == DSS_SCANNING); 418 } 419 420 boolean_t 421 dsl_scan_resilvering(dsl_pool_t *dp) 422 { 423 return (dsl_scan_is_running(dp->dp_scan) && 424 dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER); 425 } 426 427 static inline void 428 sio2bp(const scan_io_t *sio, blkptr_t *bp) 429 { 430 memset(bp, 0, sizeof (*bp)); 431 bp->blk_prop = sio->sio_blk_prop; 432 bp->blk_phys_birth = sio->sio_phys_birth; 433 bp->blk_birth = sio->sio_birth; 434 bp->blk_fill = 1; /* we always only work with data pointers */ 435 bp->blk_cksum = sio->sio_cksum; 436 437 ASSERT3U(sio->sio_nr_dvas, >, 0); 438 ASSERT3U(sio->sio_nr_dvas, <=, SPA_DVAS_PER_BP); 439 440 memcpy(bp->blk_dva, sio->sio_dva, sio->sio_nr_dvas * sizeof (dva_t)); 441 } 442 443 static inline void 444 bp2sio(const blkptr_t *bp, scan_io_t *sio, int dva_i) 445 { 446 sio->sio_blk_prop = bp->blk_prop; 447 sio->sio_phys_birth = bp->blk_phys_birth; 448 sio->sio_birth = bp->blk_birth; 449 sio->sio_cksum = bp->blk_cksum; 450 sio->sio_nr_dvas = BP_GET_NDVAS(bp); 451 452 /* 453 * Copy the DVAs to the sio. We need all copies of the block so 454 * that the self healing code can use the alternate copies if the 455 * first is corrupted. We want the DVA at index dva_i to be first 456 * in the sio since this is the primary one that we want to issue. 457 */ 458 for (int i = 0, j = dva_i; i < sio->sio_nr_dvas; i++, j++) { 459 sio->sio_dva[i] = bp->blk_dva[j % sio->sio_nr_dvas]; 460 } 461 } 462 463 int 464 dsl_scan_init(dsl_pool_t *dp, uint64_t txg) 465 { 466 int err; 467 dsl_scan_t *scn; 468 spa_t *spa = dp->dp_spa; 469 uint64_t f; 470 471 scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP); 472 scn->scn_dp = dp; 473 474 /* 475 * It's possible that we're resuming a scan after a reboot so 476 * make sure that the scan_async_destroying flag is initialized 477 * appropriately. 478 */ 479 ASSERT(!scn->scn_async_destroying); 480 scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa, 481 SPA_FEATURE_ASYNC_DESTROY); 482 483 /* 484 * Calculate the max number of in-flight bytes for pool-wide 485 * scanning operations (minimum 1MB, maximum 1/4 of arc_c_max). 486 * Limits for the issuing phase are done per top-level vdev and 487 * are handled separately. 488 */ 489 scn->scn_maxinflight_bytes = MIN(arc_c_max / 4, MAX(1ULL << 20, 490 zfs_scan_vdev_limit * dsl_scan_count_data_disks(spa))); 491 492 avl_create(&scn->scn_queue, scan_ds_queue_compare, sizeof (scan_ds_t), 493 offsetof(scan_ds_t, sds_node)); 494 avl_create(&scn->scn_prefetch_queue, scan_prefetch_queue_compare, 495 sizeof (scan_prefetch_issue_ctx_t), 496 offsetof(scan_prefetch_issue_ctx_t, spic_avl_node)); 497 498 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 499 "scrub_func", sizeof (uint64_t), 1, &f); 500 if (err == 0) { 501 /* 502 * There was an old-style scrub in progress. Restart a 503 * new-style scrub from the beginning. 504 */ 505 scn->scn_restart_txg = txg; 506 zfs_dbgmsg("old-style scrub was in progress for %s; " 507 "restarting new-style scrub in txg %llu", 508 spa->spa_name, 509 (longlong_t)scn->scn_restart_txg); 510 511 /* 512 * Load the queue obj from the old location so that it 513 * can be freed by dsl_scan_done(). 514 */ 515 (void) zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 516 "scrub_queue", sizeof (uint64_t), 1, 517 &scn->scn_phys.scn_queue_obj); 518 } else { 519 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 520 DMU_POOL_ERRORSCRUB, sizeof (uint64_t), 521 ERRORSCRUB_PHYS_NUMINTS, &scn->errorscrub_phys); 522 523 if (err != 0 && err != ENOENT) 524 return (err); 525 526 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 527 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 528 &scn->scn_phys); 529 530 /* 531 * Detect if the pool contains the signature of #2094. If it 532 * does properly update the scn->scn_phys structure and notify 533 * the administrator by setting an errata for the pool. 534 */ 535 if (err == EOVERFLOW) { 536 uint64_t zaptmp[SCAN_PHYS_NUMINTS + 1]; 537 VERIFY3S(SCAN_PHYS_NUMINTS, ==, 24); 538 VERIFY3S(offsetof(dsl_scan_phys_t, scn_flags), ==, 539 (23 * sizeof (uint64_t))); 540 541 err = zap_lookup(dp->dp_meta_objset, 542 DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SCAN, 543 sizeof (uint64_t), SCAN_PHYS_NUMINTS + 1, &zaptmp); 544 if (err == 0) { 545 uint64_t overflow = zaptmp[SCAN_PHYS_NUMINTS]; 546 547 if (overflow & ~DSL_SCAN_FLAGS_MASK || 548 scn->scn_async_destroying) { 549 spa->spa_errata = 550 ZPOOL_ERRATA_ZOL_2094_ASYNC_DESTROY; 551 return (EOVERFLOW); 552 } 553 554 memcpy(&scn->scn_phys, zaptmp, 555 SCAN_PHYS_NUMINTS * sizeof (uint64_t)); 556 scn->scn_phys.scn_flags = overflow; 557 558 /* Required scrub already in progress. */ 559 if (scn->scn_phys.scn_state == DSS_FINISHED || 560 scn->scn_phys.scn_state == DSS_CANCELED) 561 spa->spa_errata = 562 ZPOOL_ERRATA_ZOL_2094_SCRUB; 563 } 564 } 565 566 if (err == ENOENT) 567 return (0); 568 else if (err) 569 return (err); 570 571 /* 572 * We might be restarting after a reboot, so jump the issued 573 * counter to how far we've scanned. We know we're consistent 574 * up to here. 575 */ 576 scn->scn_issued_before_pass = scn->scn_phys.scn_examined - 577 scn->scn_phys.scn_skipped; 578 579 if (dsl_scan_is_running(scn) && 580 spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) { 581 /* 582 * A new-type scrub was in progress on an old 583 * pool, and the pool was accessed by old 584 * software. Restart from the beginning, since 585 * the old software may have changed the pool in 586 * the meantime. 587 */ 588 scn->scn_restart_txg = txg; 589 zfs_dbgmsg("new-style scrub for %s was modified " 590 "by old software; restarting in txg %llu", 591 spa->spa_name, 592 (longlong_t)scn->scn_restart_txg); 593 } else if (dsl_scan_resilvering(dp)) { 594 /* 595 * If a resilver is in progress and there are already 596 * errors, restart it instead of finishing this scan and 597 * then restarting it. If there haven't been any errors 598 * then remember that the incore DTL is valid. 599 */ 600 if (scn->scn_phys.scn_errors > 0) { 601 scn->scn_restart_txg = txg; 602 zfs_dbgmsg("resilver can't excise DTL_MISSING " 603 "when finished; restarting on %s in txg " 604 "%llu", 605 spa->spa_name, 606 (u_longlong_t)scn->scn_restart_txg); 607 } else { 608 /* it's safe to excise DTL when finished */ 609 spa->spa_scrub_started = B_TRUE; 610 } 611 } 612 } 613 614 memcpy(&scn->scn_phys_cached, &scn->scn_phys, sizeof (scn->scn_phys)); 615 616 /* reload the queue into the in-core state */ 617 if (scn->scn_phys.scn_queue_obj != 0) { 618 zap_cursor_t zc; 619 zap_attribute_t za; 620 621 for (zap_cursor_init(&zc, dp->dp_meta_objset, 622 scn->scn_phys.scn_queue_obj); 623 zap_cursor_retrieve(&zc, &za) == 0; 624 (void) zap_cursor_advance(&zc)) { 625 scan_ds_queue_insert(scn, 626 zfs_strtonum(za.za_name, NULL), 627 za.za_first_integer); 628 } 629 zap_cursor_fini(&zc); 630 } 631 632 spa_scan_stat_init(spa); 633 vdev_scan_stat_init(spa->spa_root_vdev); 634 635 return (0); 636 } 637 638 void 639 dsl_scan_fini(dsl_pool_t *dp) 640 { 641 if (dp->dp_scan != NULL) { 642 dsl_scan_t *scn = dp->dp_scan; 643 644 if (scn->scn_taskq != NULL) 645 taskq_destroy(scn->scn_taskq); 646 647 scan_ds_queue_clear(scn); 648 avl_destroy(&scn->scn_queue); 649 scan_ds_prefetch_queue_clear(scn); 650 avl_destroy(&scn->scn_prefetch_queue); 651 652 kmem_free(dp->dp_scan, sizeof (dsl_scan_t)); 653 dp->dp_scan = NULL; 654 } 655 } 656 657 static boolean_t 658 dsl_scan_restarting(dsl_scan_t *scn, dmu_tx_t *tx) 659 { 660 return (scn->scn_restart_txg != 0 && 661 scn->scn_restart_txg <= tx->tx_txg); 662 } 663 664 boolean_t 665 dsl_scan_resilver_scheduled(dsl_pool_t *dp) 666 { 667 return ((dp->dp_scan && dp->dp_scan->scn_restart_txg != 0) || 668 (spa_async_tasks(dp->dp_spa) & SPA_ASYNC_RESILVER)); 669 } 670 671 boolean_t 672 dsl_scan_scrubbing(const dsl_pool_t *dp) 673 { 674 dsl_scan_phys_t *scn_phys = &dp->dp_scan->scn_phys; 675 676 return (scn_phys->scn_state == DSS_SCANNING && 677 scn_phys->scn_func == POOL_SCAN_SCRUB); 678 } 679 680 boolean_t 681 dsl_errorscrubbing(const dsl_pool_t *dp) 682 { 683 dsl_errorscrub_phys_t *errorscrub_phys = &dp->dp_scan->errorscrub_phys; 684 685 return (errorscrub_phys->dep_state == DSS_ERRORSCRUBBING && 686 errorscrub_phys->dep_func == POOL_SCAN_ERRORSCRUB); 687 } 688 689 boolean_t 690 dsl_errorscrub_is_paused(const dsl_scan_t *scn) 691 { 692 return (dsl_errorscrubbing(scn->scn_dp) && 693 scn->errorscrub_phys.dep_paused_flags); 694 } 695 696 boolean_t 697 dsl_scan_is_paused_scrub(const dsl_scan_t *scn) 698 { 699 return (dsl_scan_scrubbing(scn->scn_dp) && 700 scn->scn_phys.scn_flags & DSF_SCRUB_PAUSED); 701 } 702 703 static void 704 dsl_errorscrub_sync_state(dsl_scan_t *scn, dmu_tx_t *tx) 705 { 706 scn->errorscrub_phys.dep_cursor = 707 zap_cursor_serialize(&scn->errorscrub_cursor); 708 709 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, 710 DMU_POOL_DIRECTORY_OBJECT, 711 DMU_POOL_ERRORSCRUB, sizeof (uint64_t), ERRORSCRUB_PHYS_NUMINTS, 712 &scn->errorscrub_phys, tx)); 713 } 714 715 static void 716 dsl_errorscrub_setup_sync(void *arg, dmu_tx_t *tx) 717 { 718 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 719 pool_scan_func_t *funcp = arg; 720 dsl_pool_t *dp = scn->scn_dp; 721 spa_t *spa = dp->dp_spa; 722 723 ASSERT(!dsl_scan_is_running(scn)); 724 ASSERT(!dsl_errorscrubbing(scn->scn_dp)); 725 ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS); 726 727 memset(&scn->errorscrub_phys, 0, sizeof (scn->errorscrub_phys)); 728 scn->errorscrub_phys.dep_func = *funcp; 729 scn->errorscrub_phys.dep_state = DSS_ERRORSCRUBBING; 730 scn->errorscrub_phys.dep_start_time = gethrestime_sec(); 731 scn->errorscrub_phys.dep_to_examine = spa_get_last_errlog_size(spa); 732 scn->errorscrub_phys.dep_examined = 0; 733 scn->errorscrub_phys.dep_errors = 0; 734 scn->errorscrub_phys.dep_cursor = 0; 735 zap_cursor_init_serialized(&scn->errorscrub_cursor, 736 spa->spa_meta_objset, spa->spa_errlog_last, 737 scn->errorscrub_phys.dep_cursor); 738 739 vdev_config_dirty(spa->spa_root_vdev); 740 spa_event_notify(spa, NULL, NULL, ESC_ZFS_ERRORSCRUB_START); 741 742 dsl_errorscrub_sync_state(scn, tx); 743 744 spa_history_log_internal(spa, "error scrub setup", tx, 745 "func=%u mintxg=%u maxtxg=%llu", 746 *funcp, 0, (u_longlong_t)tx->tx_txg); 747 } 748 749 static int 750 dsl_errorscrub_setup_check(void *arg, dmu_tx_t *tx) 751 { 752 (void) arg; 753 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 754 755 if (dsl_scan_is_running(scn) || (dsl_errorscrubbing(scn->scn_dp))) { 756 return (SET_ERROR(EBUSY)); 757 } 758 759 if (spa_get_last_errlog_size(scn->scn_dp->dp_spa) == 0) { 760 return (ECANCELED); 761 } 762 return (0); 763 } 764 765 /* 766 * Writes out a persistent dsl_scan_phys_t record to the pool directory. 767 * Because we can be running in the block sorting algorithm, we do not always 768 * want to write out the record, only when it is "safe" to do so. This safety 769 * condition is achieved by making sure that the sorting queues are empty 770 * (scn_queues_pending == 0). When this condition is not true, the sync'd state 771 * is inconsistent with how much actual scanning progress has been made. The 772 * kind of sync to be performed is specified by the sync_type argument. If the 773 * sync is optional, we only sync if the queues are empty. If the sync is 774 * mandatory, we do a hard ASSERT to make sure that the queues are empty. The 775 * third possible state is a "cached" sync. This is done in response to: 776 * 1) The dataset that was in the last sync'd dsl_scan_phys_t having been 777 * destroyed, so we wouldn't be able to restart scanning from it. 778 * 2) The snapshot that was in the last sync'd dsl_scan_phys_t having been 779 * superseded by a newer snapshot. 780 * 3) The dataset that was in the last sync'd dsl_scan_phys_t having been 781 * swapped with its clone. 782 * In all cases, a cached sync simply rewrites the last record we've written, 783 * just slightly modified. For the modifications that are performed to the 784 * last written dsl_scan_phys_t, see dsl_scan_ds_destroyed, 785 * dsl_scan_ds_snapshotted and dsl_scan_ds_clone_swapped. 786 */ 787 static void 788 dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx, state_sync_type_t sync_type) 789 { 790 int i; 791 spa_t *spa = scn->scn_dp->dp_spa; 792 793 ASSERT(sync_type != SYNC_MANDATORY || scn->scn_queues_pending == 0); 794 if (scn->scn_queues_pending == 0) { 795 for (i = 0; i < spa->spa_root_vdev->vdev_children; i++) { 796 vdev_t *vd = spa->spa_root_vdev->vdev_child[i]; 797 dsl_scan_io_queue_t *q = vd->vdev_scan_io_queue; 798 799 if (q == NULL) 800 continue; 801 802 mutex_enter(&vd->vdev_scan_io_queue_lock); 803 ASSERT3P(avl_first(&q->q_sios_by_addr), ==, NULL); 804 ASSERT3P(zfs_btree_first(&q->q_exts_by_size, NULL), ==, 805 NULL); 806 ASSERT3P(range_tree_first(q->q_exts_by_addr), ==, NULL); 807 mutex_exit(&vd->vdev_scan_io_queue_lock); 808 } 809 810 if (scn->scn_phys.scn_queue_obj != 0) 811 scan_ds_queue_sync(scn, tx); 812 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, 813 DMU_POOL_DIRECTORY_OBJECT, 814 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 815 &scn->scn_phys, tx)); 816 memcpy(&scn->scn_phys_cached, &scn->scn_phys, 817 sizeof (scn->scn_phys)); 818 819 if (scn->scn_checkpointing) 820 zfs_dbgmsg("finish scan checkpoint for %s", 821 spa->spa_name); 822 823 scn->scn_checkpointing = B_FALSE; 824 scn->scn_last_checkpoint = ddi_get_lbolt(); 825 } else if (sync_type == SYNC_CACHED) { 826 VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, 827 DMU_POOL_DIRECTORY_OBJECT, 828 DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, 829 &scn->scn_phys_cached, tx)); 830 } 831 } 832 833 int 834 dsl_scan_setup_check(void *arg, dmu_tx_t *tx) 835 { 836 (void) arg; 837 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 838 vdev_t *rvd = scn->scn_dp->dp_spa->spa_root_vdev; 839 840 if (dsl_scan_is_running(scn) || vdev_rebuild_active(rvd) || 841 dsl_errorscrubbing(scn->scn_dp)) 842 return (SET_ERROR(EBUSY)); 843 844 return (0); 845 } 846 847 void 848 dsl_scan_setup_sync(void *arg, dmu_tx_t *tx) 849 { 850 (void) arg; 851 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 852 pool_scan_func_t *funcp = arg; 853 dmu_object_type_t ot = 0; 854 dsl_pool_t *dp = scn->scn_dp; 855 spa_t *spa = dp->dp_spa; 856 857 ASSERT(!dsl_scan_is_running(scn)); 858 ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS); 859 memset(&scn->scn_phys, 0, sizeof (scn->scn_phys)); 860 861 /* 862 * If we are starting a fresh scrub, we erase the error scrub 863 * information from disk. 864 */ 865 memset(&scn->errorscrub_phys, 0, sizeof (scn->errorscrub_phys)); 866 dsl_errorscrub_sync_state(scn, tx); 867 868 scn->scn_phys.scn_func = *funcp; 869 scn->scn_phys.scn_state = DSS_SCANNING; 870 scn->scn_phys.scn_min_txg = 0; 871 scn->scn_phys.scn_max_txg = tx->tx_txg; 872 scn->scn_phys.scn_ddt_class_max = DDT_CLASSES - 1; /* the entire DDT */ 873 scn->scn_phys.scn_start_time = gethrestime_sec(); 874 scn->scn_phys.scn_errors = 0; 875 scn->scn_phys.scn_to_examine = spa->spa_root_vdev->vdev_stat.vs_alloc; 876 scn->scn_issued_before_pass = 0; 877 scn->scn_restart_txg = 0; 878 scn->scn_done_txg = 0; 879 scn->scn_last_checkpoint = 0; 880 scn->scn_checkpointing = B_FALSE; 881 spa_scan_stat_init(spa); 882 vdev_scan_stat_init(spa->spa_root_vdev); 883 884 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 885 scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max; 886 887 /* rewrite all disk labels */ 888 vdev_config_dirty(spa->spa_root_vdev); 889 890 if (vdev_resilver_needed(spa->spa_root_vdev, 891 &scn->scn_phys.scn_min_txg, &scn->scn_phys.scn_max_txg)) { 892 nvlist_t *aux = fnvlist_alloc(); 893 fnvlist_add_string(aux, ZFS_EV_RESILVER_TYPE, 894 "healing"); 895 spa_event_notify(spa, NULL, aux, 896 ESC_ZFS_RESILVER_START); 897 nvlist_free(aux); 898 } else { 899 spa_event_notify(spa, NULL, NULL, ESC_ZFS_SCRUB_START); 900 } 901 902 spa->spa_scrub_started = B_TRUE; 903 /* 904 * If this is an incremental scrub, limit the DDT scrub phase 905 * to just the auto-ditto class (for correctness); the rest 906 * of the scrub should go faster using top-down pruning. 907 */ 908 if (scn->scn_phys.scn_min_txg > TXG_INITIAL) 909 scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO; 910 911 /* 912 * When starting a resilver clear any existing rebuild state. 913 * This is required to prevent stale rebuild status from 914 * being reported when a rebuild is run, then a resilver and 915 * finally a scrub. In which case only the scrub status 916 * should be reported by 'zpool status'. 917 */ 918 if (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) { 919 vdev_t *rvd = spa->spa_root_vdev; 920 for (uint64_t i = 0; i < rvd->vdev_children; i++) { 921 vdev_t *vd = rvd->vdev_child[i]; 922 vdev_rebuild_clear_sync( 923 (void *)(uintptr_t)vd->vdev_id, tx); 924 } 925 } 926 } 927 928 /* back to the generic stuff */ 929 930 if (zfs_scan_blkstats) { 931 if (dp->dp_blkstats == NULL) { 932 dp->dp_blkstats = 933 vmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP); 934 } 935 memset(&dp->dp_blkstats->zab_type, 0, 936 sizeof (dp->dp_blkstats->zab_type)); 937 } else { 938 if (dp->dp_blkstats) { 939 vmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); 940 dp->dp_blkstats = NULL; 941 } 942 } 943 944 if (spa_version(spa) < SPA_VERSION_DSL_SCRUB) 945 ot = DMU_OT_ZAP_OTHER; 946 947 scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset, 948 ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx); 949 950 memcpy(&scn->scn_phys_cached, &scn->scn_phys, sizeof (scn->scn_phys)); 951 952 dsl_scan_sync_state(scn, tx, SYNC_MANDATORY); 953 954 spa_history_log_internal(spa, "scan setup", tx, 955 "func=%u mintxg=%llu maxtxg=%llu", 956 *funcp, (u_longlong_t)scn->scn_phys.scn_min_txg, 957 (u_longlong_t)scn->scn_phys.scn_max_txg); 958 } 959 960 /* 961 * Called by ZFS_IOC_POOL_SCRUB and ZFS_IOC_POOL_SCAN ioctl to start a scrub, 962 * error scrub or resilver. Can also be called to resume a paused scrub or 963 * error scrub. 964 */ 965 int 966 dsl_scan(dsl_pool_t *dp, pool_scan_func_t func) 967 { 968 spa_t *spa = dp->dp_spa; 969 dsl_scan_t *scn = dp->dp_scan; 970 971 /* 972 * Purge all vdev caches and probe all devices. We do this here 973 * rather than in sync context because this requires a writer lock 974 * on the spa_config lock, which we can't do from sync context. The 975 * spa_scrub_reopen flag indicates that vdev_open() should not 976 * attempt to start another scrub. 977 */ 978 spa_vdev_state_enter(spa, SCL_NONE); 979 spa->spa_scrub_reopen = B_TRUE; 980 vdev_reopen(spa->spa_root_vdev); 981 spa->spa_scrub_reopen = B_FALSE; 982 (void) spa_vdev_state_exit(spa, NULL, 0); 983 984 if (func == POOL_SCAN_RESILVER) { 985 dsl_scan_restart_resilver(spa->spa_dsl_pool, 0); 986 return (0); 987 } 988 989 if (func == POOL_SCAN_ERRORSCRUB) { 990 if (dsl_errorscrub_is_paused(dp->dp_scan)) { 991 /* 992 * got error scrub start cmd, resume paused error scrub. 993 */ 994 int err = dsl_scrub_set_pause_resume(scn->scn_dp, 995 POOL_SCRUB_NORMAL); 996 if (err == 0) { 997 spa_event_notify(spa, NULL, NULL, 998 ESC_ZFS_ERRORSCRUB_RESUME); 999 return (ECANCELED); 1000 } 1001 return (SET_ERROR(err)); 1002 } 1003 1004 return (dsl_sync_task(spa_name(dp->dp_spa), 1005 dsl_errorscrub_setup_check, dsl_errorscrub_setup_sync, 1006 &func, 0, ZFS_SPACE_CHECK_RESERVED)); 1007 } 1008 1009 if (func == POOL_SCAN_SCRUB && dsl_scan_is_paused_scrub(scn)) { 1010 /* got scrub start cmd, resume paused scrub */ 1011 int err = dsl_scrub_set_pause_resume(scn->scn_dp, 1012 POOL_SCRUB_NORMAL); 1013 if (err == 0) { 1014 spa_event_notify(spa, NULL, NULL, ESC_ZFS_SCRUB_RESUME); 1015 return (SET_ERROR(ECANCELED)); 1016 } 1017 return (SET_ERROR(err)); 1018 } 1019 1020 return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check, 1021 dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_EXTRA_RESERVED)); 1022 } 1023 1024 static void 1025 dsl_errorscrub_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx) 1026 { 1027 dsl_pool_t *dp = scn->scn_dp; 1028 spa_t *spa = dp->dp_spa; 1029 1030 if (complete) { 1031 spa_event_notify(spa, NULL, NULL, ESC_ZFS_ERRORSCRUB_FINISH); 1032 spa_history_log_internal(spa, "error scrub done", tx, 1033 "errors=%llu", (u_longlong_t)spa_approx_errlog_size(spa)); 1034 } else { 1035 spa_history_log_internal(spa, "error scrub canceled", tx, 1036 "errors=%llu", (u_longlong_t)spa_approx_errlog_size(spa)); 1037 } 1038 1039 scn->errorscrub_phys.dep_state = complete ? DSS_FINISHED : DSS_CANCELED; 1040 spa->spa_scrub_active = B_FALSE; 1041 spa_errlog_rotate(spa); 1042 scn->errorscrub_phys.dep_end_time = gethrestime_sec(); 1043 zap_cursor_fini(&scn->errorscrub_cursor); 1044 1045 if (spa->spa_errata == ZPOOL_ERRATA_ZOL_2094_SCRUB) 1046 spa->spa_errata = 0; 1047 1048 ASSERT(!dsl_errorscrubbing(scn->scn_dp)); 1049 } 1050 1051 static void 1052 dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx) 1053 { 1054 static const char *old_names[] = { 1055 "scrub_bookmark", 1056 "scrub_ddt_bookmark", 1057 "scrub_ddt_class_max", 1058 "scrub_queue", 1059 "scrub_min_txg", 1060 "scrub_max_txg", 1061 "scrub_func", 1062 "scrub_errors", 1063 NULL 1064 }; 1065 1066 dsl_pool_t *dp = scn->scn_dp; 1067 spa_t *spa = dp->dp_spa; 1068 int i; 1069 1070 /* Remove any remnants of an old-style scrub. */ 1071 for (i = 0; old_names[i]; i++) { 1072 (void) zap_remove(dp->dp_meta_objset, 1073 DMU_POOL_DIRECTORY_OBJECT, old_names[i], tx); 1074 } 1075 1076 if (scn->scn_phys.scn_queue_obj != 0) { 1077 VERIFY0(dmu_object_free(dp->dp_meta_objset, 1078 scn->scn_phys.scn_queue_obj, tx)); 1079 scn->scn_phys.scn_queue_obj = 0; 1080 } 1081 scan_ds_queue_clear(scn); 1082 scan_ds_prefetch_queue_clear(scn); 1083 1084 scn->scn_phys.scn_flags &= ~DSF_SCRUB_PAUSED; 1085 1086 /* 1087 * If we were "restarted" from a stopped state, don't bother 1088 * with anything else. 1089 */ 1090 if (!dsl_scan_is_running(scn)) { 1091 ASSERT(!scn->scn_is_sorted); 1092 return; 1093 } 1094 1095 if (scn->scn_is_sorted) { 1096 scan_io_queues_destroy(scn); 1097 scn->scn_is_sorted = B_FALSE; 1098 1099 if (scn->scn_taskq != NULL) { 1100 taskq_destroy(scn->scn_taskq); 1101 scn->scn_taskq = NULL; 1102 } 1103 } 1104 1105 scn->scn_phys.scn_state = complete ? DSS_FINISHED : DSS_CANCELED; 1106 1107 spa_notify_waiters(spa); 1108 1109 if (dsl_scan_restarting(scn, tx)) 1110 spa_history_log_internal(spa, "scan aborted, restarting", tx, 1111 "errors=%llu", (u_longlong_t)spa_approx_errlog_size(spa)); 1112 else if (!complete) 1113 spa_history_log_internal(spa, "scan cancelled", tx, 1114 "errors=%llu", (u_longlong_t)spa_approx_errlog_size(spa)); 1115 else 1116 spa_history_log_internal(spa, "scan done", tx, 1117 "errors=%llu", (u_longlong_t)spa_approx_errlog_size(spa)); 1118 1119 if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { 1120 spa->spa_scrub_active = B_FALSE; 1121 1122 /* 1123 * If the scrub/resilver completed, update all DTLs to 1124 * reflect this. Whether it succeeded or not, vacate 1125 * all temporary scrub DTLs. 1126 * 1127 * As the scrub does not currently support traversing 1128 * data that have been freed but are part of a checkpoint, 1129 * we don't mark the scrub as done in the DTLs as faults 1130 * may still exist in those vdevs. 1131 */ 1132 if (complete && 1133 !spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) { 1134 vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg, 1135 scn->scn_phys.scn_max_txg, B_TRUE, B_FALSE); 1136 1137 if (scn->scn_phys.scn_min_txg) { 1138 nvlist_t *aux = fnvlist_alloc(); 1139 fnvlist_add_string(aux, ZFS_EV_RESILVER_TYPE, 1140 "healing"); 1141 spa_event_notify(spa, NULL, aux, 1142 ESC_ZFS_RESILVER_FINISH); 1143 nvlist_free(aux); 1144 } else { 1145 spa_event_notify(spa, NULL, NULL, 1146 ESC_ZFS_SCRUB_FINISH); 1147 } 1148 } else { 1149 vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg, 1150 0, B_TRUE, B_FALSE); 1151 } 1152 spa_errlog_rotate(spa); 1153 1154 /* 1155 * Don't clear flag until after vdev_dtl_reassess to ensure that 1156 * DTL_MISSING will get updated when possible. 1157 */ 1158 spa->spa_scrub_started = B_FALSE; 1159 1160 /* 1161 * We may have finished replacing a device. 1162 * Let the async thread assess this and handle the detach. 1163 */ 1164 spa_async_request(spa, SPA_ASYNC_RESILVER_DONE); 1165 1166 /* 1167 * Clear any resilver_deferred flags in the config. 1168 * If there are drives that need resilvering, kick 1169 * off an asynchronous request to start resilver. 1170 * vdev_clear_resilver_deferred() may update the config 1171 * before the resilver can restart. In the event of 1172 * a crash during this period, the spa loading code 1173 * will find the drives that need to be resilvered 1174 * and start the resilver then. 1175 */ 1176 if (spa_feature_is_enabled(spa, SPA_FEATURE_RESILVER_DEFER) && 1177 vdev_clear_resilver_deferred(spa->spa_root_vdev, tx)) { 1178 spa_history_log_internal(spa, 1179 "starting deferred resilver", tx, "errors=%llu", 1180 (u_longlong_t)spa_approx_errlog_size(spa)); 1181 spa_async_request(spa, SPA_ASYNC_RESILVER); 1182 } 1183 1184 /* Clear recent error events (i.e. duplicate events tracking) */ 1185 if (complete) 1186 zfs_ereport_clear(spa, NULL); 1187 } 1188 1189 scn->scn_phys.scn_end_time = gethrestime_sec(); 1190 1191 if (spa->spa_errata == ZPOOL_ERRATA_ZOL_2094_SCRUB) 1192 spa->spa_errata = 0; 1193 1194 ASSERT(!dsl_scan_is_running(scn)); 1195 } 1196 1197 static int 1198 dsl_errorscrub_pause_resume_check(void *arg, dmu_tx_t *tx) 1199 { 1200 pool_scrub_cmd_t *cmd = arg; 1201 dsl_pool_t *dp = dmu_tx_pool(tx); 1202 dsl_scan_t *scn = dp->dp_scan; 1203 1204 if (*cmd == POOL_SCRUB_PAUSE) { 1205 /* 1206 * can't pause a error scrub when there is no in-progress 1207 * error scrub. 1208 */ 1209 if (!dsl_errorscrubbing(dp)) 1210 return (SET_ERROR(ENOENT)); 1211 1212 /* can't pause a paused error scrub */ 1213 if (dsl_errorscrub_is_paused(scn)) 1214 return (SET_ERROR(EBUSY)); 1215 } else if (*cmd != POOL_SCRUB_NORMAL) { 1216 return (SET_ERROR(ENOTSUP)); 1217 } 1218 1219 return (0); 1220 } 1221 1222 static void 1223 dsl_errorscrub_pause_resume_sync(void *arg, dmu_tx_t *tx) 1224 { 1225 pool_scrub_cmd_t *cmd = arg; 1226 dsl_pool_t *dp = dmu_tx_pool(tx); 1227 spa_t *spa = dp->dp_spa; 1228 dsl_scan_t *scn = dp->dp_scan; 1229 1230 if (*cmd == POOL_SCRUB_PAUSE) { 1231 spa->spa_scan_pass_errorscrub_pause = gethrestime_sec(); 1232 scn->errorscrub_phys.dep_paused_flags = B_TRUE; 1233 dsl_errorscrub_sync_state(scn, tx); 1234 spa_event_notify(spa, NULL, NULL, ESC_ZFS_ERRORSCRUB_PAUSED); 1235 } else { 1236 ASSERT3U(*cmd, ==, POOL_SCRUB_NORMAL); 1237 if (dsl_errorscrub_is_paused(scn)) { 1238 /* 1239 * We need to keep track of how much time we spend 1240 * paused per pass so that we can adjust the error scrub 1241 * rate shown in the output of 'zpool status'. 1242 */ 1243 spa->spa_scan_pass_errorscrub_spent_paused += 1244 gethrestime_sec() - 1245 spa->spa_scan_pass_errorscrub_pause; 1246 1247 spa->spa_scan_pass_errorscrub_pause = 0; 1248 scn->errorscrub_phys.dep_paused_flags = B_FALSE; 1249 1250 zap_cursor_init_serialized( 1251 &scn->errorscrub_cursor, 1252 spa->spa_meta_objset, spa->spa_errlog_last, 1253 scn->errorscrub_phys.dep_cursor); 1254 1255 dsl_errorscrub_sync_state(scn, tx); 1256 } 1257 } 1258 } 1259 1260 static int 1261 dsl_errorscrub_cancel_check(void *arg, dmu_tx_t *tx) 1262 { 1263 (void) arg; 1264 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 1265 /* can't cancel a error scrub when there is no one in-progress */ 1266 if (!dsl_errorscrubbing(scn->scn_dp)) 1267 return (SET_ERROR(ENOENT)); 1268 return (0); 1269 } 1270 1271 static void 1272 dsl_errorscrub_cancel_sync(void *arg, dmu_tx_t *tx) 1273 { 1274 (void) arg; 1275 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 1276 1277 dsl_errorscrub_done(scn, B_FALSE, tx); 1278 dsl_errorscrub_sync_state(scn, tx); 1279 spa_event_notify(scn->scn_dp->dp_spa, NULL, NULL, 1280 ESC_ZFS_ERRORSCRUB_ABORT); 1281 } 1282 1283 static int 1284 dsl_scan_cancel_check(void *arg, dmu_tx_t *tx) 1285 { 1286 (void) arg; 1287 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 1288 1289 if (!dsl_scan_is_running(scn)) 1290 return (SET_ERROR(ENOENT)); 1291 return (0); 1292 } 1293 1294 static void 1295 dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx) 1296 { 1297 (void) arg; 1298 dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; 1299 1300 dsl_scan_done(scn, B_FALSE, tx); 1301 dsl_scan_sync_state(scn, tx, SYNC_MANDATORY); 1302 spa_event_notify(scn->scn_dp->dp_spa, NULL, NULL, ESC_ZFS_SCRUB_ABORT); 1303 } 1304 1305 int 1306 dsl_scan_cancel(dsl_pool_t *dp) 1307 { 1308 if (dsl_errorscrubbing(dp)) { 1309 return (dsl_sync_task(spa_name(dp->dp_spa), 1310 dsl_errorscrub_cancel_check, dsl_errorscrub_cancel_sync, 1311 NULL, 3, ZFS_SPACE_CHECK_RESERVED)); 1312 } 1313 return (dsl_sync_task(spa_name(dp->dp_spa), dsl_scan_cancel_check, 1314 dsl_scan_cancel_sync, NULL, 3, ZFS_SPACE_CHECK_RESERVED)); 1315 } 1316 1317 static int 1318 dsl_scrub_pause_resume_check(void *arg, dmu_tx_t *tx) 1319 { 1320 pool_scrub_cmd_t *cmd = arg; 1321 dsl_pool_t *dp = dmu_tx_pool(tx); 1322 dsl_scan_t *scn = dp->dp_scan; 1323 1324 if (*cmd == POOL_SCRUB_PAUSE) { 1325 /* can't pause a scrub when there is no in-progress scrub */ 1326 if (!dsl_scan_scrubbing(dp)) 1327 return (SET_ERROR(ENOENT)); 1328 1329 /* can't pause a paused scrub */ 1330 if (dsl_scan_is_paused_scrub(scn)) 1331 return (SET_ERROR(EBUSY)); 1332 } else if (*cmd != POOL_SCRUB_NORMAL) { 1333 return (SET_ERROR(ENOTSUP)); 1334 } 1335 1336 return (0); 1337 } 1338 1339 static void 1340 dsl_scrub_pause_resume_sync(void *arg, dmu_tx_t *tx) 1341 { 1342 pool_scrub_cmd_t *cmd = arg; 1343 dsl_pool_t *dp = dmu_tx_pool(tx); 1344 spa_t *spa = dp->dp_spa; 1345 dsl_scan_t *scn = dp->dp_scan; 1346 1347 if (*cmd == POOL_SCRUB_PAUSE) { 1348 /* can't pause a scrub when there is no in-progress scrub */ 1349 spa->spa_scan_pass_scrub_pause = gethrestime_sec(); 1350 scn->scn_phys.scn_flags |= DSF_SCRUB_PAUSED; 1351 scn->scn_phys_cached.scn_flags |= DSF_SCRUB_PAUSED; 1352 dsl_scan_sync_state(scn, tx, SYNC_CACHED); 1353 spa_event_notify(spa, NULL, NULL, ESC_ZFS_SCRUB_PAUSED); 1354 spa_notify_waiters(spa); 1355 } else { 1356 ASSERT3U(*cmd, ==, POOL_SCRUB_NORMAL); 1357 if (dsl_scan_is_paused_scrub(scn)) { 1358 /* 1359 * We need to keep track of how much time we spend 1360 * paused per pass so that we can adjust the scrub rate 1361 * shown in the output of 'zpool status' 1362 */ 1363 spa->spa_scan_pass_scrub_spent_paused += 1364 gethrestime_sec() - spa->spa_scan_pass_scrub_pause; 1365 spa->spa_scan_pass_scrub_pause = 0; 1366 scn->scn_phys.scn_flags &= ~DSF_SCRUB_PAUSED; 1367 scn->scn_phys_cached.scn_flags &= ~DSF_SCRUB_PAUSED; 1368 dsl_scan_sync_state(scn, tx, SYNC_CACHED); 1369 } 1370 } 1371 } 1372 1373 /* 1374 * Set scrub pause/resume state if it makes sense to do so 1375 */ 1376 int 1377 dsl_scrub_set_pause_resume(const dsl_pool_t *dp, pool_scrub_cmd_t cmd) 1378 { 1379 if (dsl_errorscrubbing(dp)) { 1380 return (dsl_sync_task(spa_name(dp->dp_spa), 1381 dsl_errorscrub_pause_resume_check, 1382 dsl_errorscrub_pause_resume_sync, &cmd, 3, 1383 ZFS_SPACE_CHECK_RESERVED)); 1384 } 1385 return (dsl_sync_task(spa_name(dp->dp_spa), 1386 dsl_scrub_pause_resume_check, dsl_scrub_pause_resume_sync, &cmd, 3, 1387 ZFS_SPACE_CHECK_RESERVED)); 1388 } 1389 1390 1391 /* start a new scan, or restart an existing one. */ 1392 void 1393 dsl_scan_restart_resilver(dsl_pool_t *dp, uint64_t txg) 1394 { 1395 if (txg == 0) { 1396 dmu_tx_t *tx; 1397 tx = dmu_tx_create_dd(dp->dp_mos_dir); 1398 VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT)); 1399 1400 txg = dmu_tx_get_txg(tx); 1401 dp->dp_scan->scn_restart_txg = txg; 1402 dmu_tx_commit(tx); 1403 } else { 1404 dp->dp_scan->scn_restart_txg = txg; 1405 } 1406 zfs_dbgmsg("restarting resilver for %s at txg=%llu", 1407 dp->dp_spa->spa_name, (longlong_t)txg); 1408 } 1409 1410 void 1411 dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp) 1412 { 1413 zio_free(dp->dp_spa, txg, bp); 1414 } 1415 1416 void 1417 dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp) 1418 { 1419 ASSERT(dsl_pool_sync_context(dp)); 1420 zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, pio->io_flags)); 1421 } 1422 1423 static int 1424 scan_ds_queue_compare(const void *a, const void *b) 1425 { 1426 const scan_ds_t *sds_a = a, *sds_b = b; 1427 1428 if (sds_a->sds_dsobj < sds_b->sds_dsobj) 1429 return (-1); 1430 if (sds_a->sds_dsobj == sds_b->sds_dsobj) 1431 return (0); 1432 return (1); 1433 } 1434 1435 static void 1436 scan_ds_queue_clear(dsl_scan_t *scn) 1437 { 1438 void *cookie = NULL; 1439 scan_ds_t *sds; 1440 while ((sds = avl_destroy_nodes(&scn->scn_queue, &cookie)) != NULL) { 1441 kmem_free(sds, sizeof (*sds)); 1442 } 1443 } 1444 1445 static boolean_t 1446 scan_ds_queue_contains(dsl_scan_t *scn, uint64_t dsobj, uint64_t *txg) 1447 { 1448 scan_ds_t srch, *sds; 1449 1450 srch.sds_dsobj = dsobj; 1451 sds = avl_find(&scn->scn_queue, &srch, NULL); 1452 if (sds != NULL && txg != NULL) 1453 *txg = sds->sds_txg; 1454 return (sds != NULL); 1455 } 1456 1457 static void 1458 scan_ds_queue_insert(dsl_scan_t *scn, uint64_t dsobj, uint64_t txg) 1459 { 1460 scan_ds_t *sds; 1461 avl_index_t where; 1462 1463 sds = kmem_zalloc(sizeof (*sds), KM_SLEEP); 1464 sds->sds_dsobj = dsobj; 1465 sds->sds_txg = txg; 1466 1467 VERIFY3P(avl_find(&scn->scn_queue, sds, &where), ==, NULL); 1468 avl_insert(&scn->scn_queue, sds, where); 1469 } 1470 1471 static void 1472 scan_ds_queue_remove(dsl_scan_t *scn, uint64_t dsobj) 1473 { 1474 scan_ds_t srch, *sds; 1475 1476 srch.sds_dsobj = dsobj; 1477 1478 sds = avl_find(&scn->scn_queue, &srch, NULL); 1479 VERIFY(sds != NULL); 1480 avl_remove(&scn->scn_queue, sds); 1481 kmem_free(sds, sizeof (*sds)); 1482 } 1483 1484 static void 1485 scan_ds_queue_sync(dsl_scan_t *scn, dmu_tx_t *tx) 1486 { 1487 dsl_pool_t *dp = scn->scn_dp; 1488 spa_t *spa = dp->dp_spa; 1489 dmu_object_type_t ot = (spa_version(spa) >= SPA_VERSION_DSL_SCRUB) ? 1490 DMU_OT_SCAN_QUEUE : DMU_OT_ZAP_OTHER; 1491 1492 ASSERT0(scn->scn_queues_pending); 1493 ASSERT(scn->scn_phys.scn_queue_obj != 0); 1494 1495 VERIFY0(dmu_object_free(dp->dp_meta_objset, 1496 scn->scn_phys.scn_queue_obj, tx)); 1497 scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset, ot, 1498 DMU_OT_NONE, 0, tx); 1499 for (scan_ds_t *sds = avl_first(&scn->scn_queue); 1500 sds != NULL; sds = AVL_NEXT(&scn->scn_queue, sds)) { 1501 VERIFY0(zap_add_int_key(dp->dp_meta_objset, 1502 scn->scn_phys.scn_queue_obj, sds->sds_dsobj, 1503 sds->sds_txg, tx)); 1504 } 1505 } 1506 1507 /* 1508 * Computes the memory limit state that we're currently in. A sorted scan 1509 * needs quite a bit of memory to hold the sorting queue, so we need to 1510 * reasonably constrain the size so it doesn't impact overall system 1511 * performance. We compute two limits: 1512 * 1) Hard memory limit: if the amount of memory used by the sorting 1513 * queues on a pool gets above this value, we stop the metadata 1514 * scanning portion and start issuing the queued up and sorted 1515 * I/Os to reduce memory usage. 1516 * This limit is calculated as a fraction of physmem (by default 5%). 1517 * We constrain the lower bound of the hard limit to an absolute 1518 * minimum of zfs_scan_mem_lim_min (default: 16 MiB). We also constrain 1519 * the upper bound to 5% of the total pool size - no chance we'll 1520 * ever need that much memory, but just to keep the value in check. 1521 * 2) Soft memory limit: once we hit the hard memory limit, we start 1522 * issuing I/O to reduce queue memory usage, but we don't want to 1523 * completely empty out the queues, since we might be able to find I/Os 1524 * that will fill in the gaps of our non-sequential IOs at some point 1525 * in the future. So we stop the issuing of I/Os once the amount of 1526 * memory used drops below the soft limit (at which point we stop issuing 1527 * I/O and start scanning metadata again). 1528 * 1529 * This limit is calculated by subtracting a fraction of the hard 1530 * limit from the hard limit. By default this fraction is 5%, so 1531 * the soft limit is 95% of the hard limit. We cap the size of the 1532 * difference between the hard and soft limits at an absolute 1533 * maximum of zfs_scan_mem_lim_soft_max (default: 128 MiB) - this is 1534 * sufficient to not cause too frequent switching between the 1535 * metadata scan and I/O issue (even at 2k recordsize, 128 MiB's 1536 * worth of queues is about 1.2 GiB of on-pool data, so scanning 1537 * that should take at least a decent fraction of a second). 1538 */ 1539 static boolean_t 1540 dsl_scan_should_clear(dsl_scan_t *scn) 1541 { 1542 spa_t *spa = scn->scn_dp->dp_spa; 1543 vdev_t *rvd = scn->scn_dp->dp_spa->spa_root_vdev; 1544 uint64_t alloc, mlim_hard, mlim_soft, mused; 1545 1546 alloc = metaslab_class_get_alloc(spa_normal_class(spa)); 1547 alloc += metaslab_class_get_alloc(spa_special_class(spa)); 1548 alloc += metaslab_class_get_alloc(spa_dedup_class(spa)); 1549 1550 mlim_hard = MAX((physmem / zfs_scan_mem_lim_fact) * PAGESIZE, 1551 zfs_scan_mem_lim_min); 1552 mlim_hard = MIN(mlim_hard, alloc / 20); 1553 mlim_soft = mlim_hard - MIN(mlim_hard / zfs_scan_mem_lim_soft_fact, 1554 zfs_scan_mem_lim_soft_max); 1555 mused = 0; 1556 for (uint64_t i = 0; i < rvd->vdev_children; i++) { 1557 vdev_t *tvd = rvd->vdev_child[i]; 1558 dsl_scan_io_queue_t *queue; 1559 1560 mutex_enter(&tvd->vdev_scan_io_queue_lock); 1561 queue = tvd->vdev_scan_io_queue; 1562 if (queue != NULL) { 1563 /* 1564 * # of extents in exts_by_addr = # in exts_by_size. 1565 * B-tree efficiency is ~75%, but can be as low as 50%. 1566 */ 1567 mused += zfs_btree_numnodes(&queue->q_exts_by_size) * 1568 ((sizeof (range_seg_gap_t) + sizeof (uint64_t)) * 1569 3 / 2) + queue->q_sio_memused; 1570 } 1571 mutex_exit(&tvd->vdev_scan_io_queue_lock); 1572 } 1573 1574 dprintf("current scan memory usage: %llu bytes\n", (longlong_t)mused); 1575 1576 if (mused == 0) 1577 ASSERT0(scn->scn_queues_pending); 1578 1579 /* 1580 * If we are above our hard limit, we need to clear out memory. 1581 * If we are below our soft limit, we need to accumulate sequential IOs. 1582 * Otherwise, we should keep doing whatever we are currently doing. 1583 */ 1584 if (mused >= mlim_hard) 1585 return (B_TRUE); 1586 else if (mused < mlim_soft) 1587 return (B_FALSE); 1588 else 1589 return (scn->scn_clearing); 1590 } 1591 1592 static boolean_t 1593 dsl_scan_check_suspend(dsl_scan_t *scn, const zbookmark_phys_t *zb) 1594 { 1595 /* we never skip user/group accounting objects */ 1596 if (zb && (int64_t)zb->zb_object < 0) 1597 return (B_FALSE); 1598 1599 if (scn->scn_suspending) 1600 return (B_TRUE); /* we're already suspending */ 1601 1602 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark)) 1603 return (B_FALSE); /* we're resuming */ 1604 1605 /* We only know how to resume from level-0 and objset blocks. */ 1606 if (zb && (zb->zb_level != 0 && zb->zb_level != ZB_ROOT_LEVEL)) 1607 return (B_FALSE); 1608 1609 /* 1610 * We suspend if: 1611 * - we have scanned for at least the minimum time (default 1 sec 1612 * for scrub, 3 sec for resilver), and either we have sufficient 1613 * dirty data that we are starting to write more quickly 1614 * (default 30%), someone is explicitly waiting for this txg 1615 * to complete, or we have used up all of the time in the txg 1616 * timeout (default 5 sec). 1617 * or 1618 * - the spa is shutting down because this pool is being exported 1619 * or the machine is rebooting. 1620 * or 1621 * - the scan queue has reached its memory use limit 1622 */ 1623 uint64_t curr_time_ns = gethrtime(); 1624 uint64_t scan_time_ns = curr_time_ns - scn->scn_sync_start_time; 1625 uint64_t sync_time_ns = curr_time_ns - 1626 scn->scn_dp->dp_spa->spa_sync_starttime; 1627 uint64_t dirty_min_bytes = zfs_dirty_data_max * 1628 zfs_vdev_async_write_active_min_dirty_percent / 100; 1629 uint_t mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ? 1630 zfs_resilver_min_time_ms : zfs_scrub_min_time_ms; 1631 1632 if ((NSEC2MSEC(scan_time_ns) > mintime && 1633 (scn->scn_dp->dp_dirty_total >= dirty_min_bytes || 1634 txg_sync_waiting(scn->scn_dp) || 1635 NSEC2SEC(sync_time_ns) >= zfs_txg_timeout)) || 1636 spa_shutting_down(scn->scn_dp->dp_spa) || 1637 (zfs_scan_strict_mem_lim && dsl_scan_should_clear(scn))) { 1638 if (zb && zb->zb_level == ZB_ROOT_LEVEL) { 1639 dprintf("suspending at first available bookmark " 1640 "%llx/%llx/%llx/%llx\n", 1641 (longlong_t)zb->zb_objset, 1642 (longlong_t)zb->zb_object, 1643 (longlong_t)zb->zb_level, 1644 (longlong_t)zb->zb_blkid); 1645 SET_BOOKMARK(&scn->scn_phys.scn_bookmark, 1646 zb->zb_objset, 0, 0, 0); 1647 } else if (zb != NULL) { 1648 dprintf("suspending at bookmark %llx/%llx/%llx/%llx\n", 1649 (longlong_t)zb->zb_objset, 1650 (longlong_t)zb->zb_object, 1651 (longlong_t)zb->zb_level, 1652 (longlong_t)zb->zb_blkid); 1653 scn->scn_phys.scn_bookmark = *zb; 1654 } else { 1655 #ifdef ZFS_DEBUG 1656 dsl_scan_phys_t *scnp = &scn->scn_phys; 1657 dprintf("suspending at at DDT bookmark " 1658 "%llx/%llx/%llx/%llx\n", 1659 (longlong_t)scnp->scn_ddt_bookmark.ddb_class, 1660 (longlong_t)scnp->scn_ddt_bookmark.ddb_type, 1661 (longlong_t)scnp->scn_ddt_bookmark.ddb_checksum, 1662 (longlong_t)scnp->scn_ddt_bookmark.ddb_cursor); 1663 #endif 1664 } 1665 scn->scn_suspending = B_TRUE; 1666 return (B_TRUE); 1667 } 1668 return (B_FALSE); 1669 } 1670 1671 static boolean_t 1672 dsl_error_scrub_check_suspend(dsl_scan_t *scn, const zbookmark_phys_t *zb) 1673 { 1674 /* 1675 * We suspend if: 1676 * - we have scrubbed for at least the minimum time (default 1 sec 1677 * for error scrub), someone is explicitly waiting for this txg 1678 * to complete, or we have used up all of the time in the txg 1679 * timeout (default 5 sec). 1680 * or 1681 * - the spa is shutting down because this pool is being exported 1682 * or the machine is rebooting. 1683 */ 1684 uint64_t curr_time_ns = gethrtime(); 1685 uint64_t error_scrub_time_ns = curr_time_ns - scn->scn_sync_start_time; 1686 uint64_t sync_time_ns = curr_time_ns - 1687 scn->scn_dp->dp_spa->spa_sync_starttime; 1688 int mintime = zfs_scrub_min_time_ms; 1689 1690 if ((NSEC2MSEC(error_scrub_time_ns) > mintime && 1691 (txg_sync_waiting(scn->scn_dp) || 1692 NSEC2SEC(sync_time_ns) >= zfs_txg_timeout)) || 1693 spa_shutting_down(scn->scn_dp->dp_spa)) { 1694 if (zb) { 1695 dprintf("error scrub suspending at bookmark " 1696 "%llx/%llx/%llx/%llx\n", 1697 (longlong_t)zb->zb_objset, 1698 (longlong_t)zb->zb_object, 1699 (longlong_t)zb->zb_level, 1700 (longlong_t)zb->zb_blkid); 1701 } 1702 return (B_TRUE); 1703 } 1704 return (B_FALSE); 1705 } 1706 1707 typedef struct zil_scan_arg { 1708 dsl_pool_t *zsa_dp; 1709 zil_header_t *zsa_zh; 1710 } zil_scan_arg_t; 1711 1712 static int 1713 dsl_scan_zil_block(zilog_t *zilog, const blkptr_t *bp, void *arg, 1714 uint64_t claim_txg) 1715 { 1716 (void) zilog; 1717 zil_scan_arg_t *zsa = arg; 1718 dsl_pool_t *dp = zsa->zsa_dp; 1719 dsl_scan_t *scn = dp->dp_scan; 1720 zil_header_t *zh = zsa->zsa_zh; 1721 zbookmark_phys_t zb; 1722 1723 ASSERT(!BP_IS_REDACTED(bp)); 1724 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 1725 return (0); 1726 1727 /* 1728 * One block ("stubby") can be allocated a long time ago; we 1729 * want to visit that one because it has been allocated 1730 * (on-disk) even if it hasn't been claimed (even though for 1731 * scrub there's nothing to do to it). 1732 */ 1733 if (claim_txg == 0 && bp->blk_birth >= spa_min_claim_txg(dp->dp_spa)) 1734 return (0); 1735 1736 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 1737 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 1738 1739 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 1740 return (0); 1741 } 1742 1743 static int 1744 dsl_scan_zil_record(zilog_t *zilog, const lr_t *lrc, void *arg, 1745 uint64_t claim_txg) 1746 { 1747 (void) zilog; 1748 if (lrc->lrc_txtype == TX_WRITE) { 1749 zil_scan_arg_t *zsa = arg; 1750 dsl_pool_t *dp = zsa->zsa_dp; 1751 dsl_scan_t *scn = dp->dp_scan; 1752 zil_header_t *zh = zsa->zsa_zh; 1753 const lr_write_t *lr = (const lr_write_t *)lrc; 1754 const blkptr_t *bp = &lr->lr_blkptr; 1755 zbookmark_phys_t zb; 1756 1757 ASSERT(!BP_IS_REDACTED(bp)); 1758 if (BP_IS_HOLE(bp) || 1759 bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) 1760 return (0); 1761 1762 /* 1763 * birth can be < claim_txg if this record's txg is 1764 * already txg sync'ed (but this log block contains 1765 * other records that are not synced) 1766 */ 1767 if (claim_txg == 0 || bp->blk_birth < claim_txg) 1768 return (0); 1769 1770 ASSERT3U(BP_GET_LSIZE(bp), !=, 0); 1771 SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], 1772 lr->lr_foid, ZB_ZIL_LEVEL, 1773 lr->lr_offset / BP_GET_LSIZE(bp)); 1774 1775 VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); 1776 } 1777 return (0); 1778 } 1779 1780 static void 1781 dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh) 1782 { 1783 uint64_t claim_txg = zh->zh_claim_txg; 1784 zil_scan_arg_t zsa = { dp, zh }; 1785 zilog_t *zilog; 1786 1787 ASSERT(spa_writeable(dp->dp_spa)); 1788 1789 /* 1790 * We only want to visit blocks that have been claimed but not yet 1791 * replayed (or, in read-only mode, blocks that *would* be claimed). 1792 */ 1793 if (claim_txg == 0) 1794 return; 1795 1796 zilog = zil_alloc(dp->dp_meta_objset, zh); 1797 1798 (void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa, 1799 claim_txg, B_FALSE); 1800 1801 zil_free(zilog); 1802 } 1803 1804 /* 1805 * We compare scan_prefetch_issue_ctx_t's based on their bookmarks. The idea 1806 * here is to sort the AVL tree by the order each block will be needed. 1807 */ 1808 static int 1809 scan_prefetch_queue_compare(const void *a, const void *b) 1810 { 1811 const scan_prefetch_issue_ctx_t *spic_a = a, *spic_b = b; 1812 const scan_prefetch_ctx_t *spc_a = spic_a->spic_spc; 1813 const scan_prefetch_ctx_t *spc_b = spic_b->spic_spc; 1814 1815 return (zbookmark_compare(spc_a->spc_datablkszsec, 1816 spc_a->spc_indblkshift, spc_b->spc_datablkszsec, 1817 spc_b->spc_indblkshift, &spic_a->spic_zb, &spic_b->spic_zb)); 1818 } 1819 1820 static void 1821 scan_prefetch_ctx_rele(scan_prefetch_ctx_t *spc, const void *tag) 1822 { 1823 if (zfs_refcount_remove(&spc->spc_refcnt, tag) == 0) { 1824 zfs_refcount_destroy(&spc->spc_refcnt); 1825 kmem_free(spc, sizeof (scan_prefetch_ctx_t)); 1826 } 1827 } 1828 1829 static scan_prefetch_ctx_t * 1830 scan_prefetch_ctx_create(dsl_scan_t *scn, dnode_phys_t *dnp, const void *tag) 1831 { 1832 scan_prefetch_ctx_t *spc; 1833 1834 spc = kmem_alloc(sizeof (scan_prefetch_ctx_t), KM_SLEEP); 1835 zfs_refcount_create(&spc->spc_refcnt); 1836 zfs_refcount_add(&spc->spc_refcnt, tag); 1837 spc->spc_scn = scn; 1838 if (dnp != NULL) { 1839 spc->spc_datablkszsec = dnp->dn_datablkszsec; 1840 spc->spc_indblkshift = dnp->dn_indblkshift; 1841 spc->spc_root = B_FALSE; 1842 } else { 1843 spc->spc_datablkszsec = 0; 1844 spc->spc_indblkshift = 0; 1845 spc->spc_root = B_TRUE; 1846 } 1847 1848 return (spc); 1849 } 1850 1851 static void 1852 scan_prefetch_ctx_add_ref(scan_prefetch_ctx_t *spc, const void *tag) 1853 { 1854 zfs_refcount_add(&spc->spc_refcnt, tag); 1855 } 1856 1857 static void 1858 scan_ds_prefetch_queue_clear(dsl_scan_t *scn) 1859 { 1860 spa_t *spa = scn->scn_dp->dp_spa; 1861 void *cookie = NULL; 1862 scan_prefetch_issue_ctx_t *spic = NULL; 1863 1864 mutex_enter(&spa->spa_scrub_lock); 1865 while ((spic = avl_destroy_nodes(&scn->scn_prefetch_queue, 1866 &cookie)) != NULL) { 1867 scan_prefetch_ctx_rele(spic->spic_spc, scn); 1868 kmem_free(spic, sizeof (scan_prefetch_issue_ctx_t)); 1869 } 1870 mutex_exit(&spa->spa_scrub_lock); 1871 } 1872 1873 static boolean_t 1874 dsl_scan_check_prefetch_resume(scan_prefetch_ctx_t *spc, 1875 const zbookmark_phys_t *zb) 1876 { 1877 zbookmark_phys_t *last_zb = &spc->spc_scn->scn_prefetch_bookmark; 1878 dnode_phys_t tmp_dnp; 1879 dnode_phys_t *dnp = (spc->spc_root) ? NULL : &tmp_dnp; 1880 1881 if (zb->zb_objset != last_zb->zb_objset) 1882 return (B_TRUE); 1883 if ((int64_t)zb->zb_object < 0) 1884 return (B_FALSE); 1885 1886 tmp_dnp.dn_datablkszsec = spc->spc_datablkszsec; 1887 tmp_dnp.dn_indblkshift = spc->spc_indblkshift; 1888 1889 if (zbookmark_subtree_completed(dnp, zb, last_zb)) 1890 return (B_TRUE); 1891 1892 return (B_FALSE); 1893 } 1894 1895 static void 1896 dsl_scan_prefetch(scan_prefetch_ctx_t *spc, blkptr_t *bp, zbookmark_phys_t *zb) 1897 { 1898 avl_index_t idx; 1899 dsl_scan_t *scn = spc->spc_scn; 1900 spa_t *spa = scn->scn_dp->dp_spa; 1901 scan_prefetch_issue_ctx_t *spic; 1902 1903 if (zfs_no_scrub_prefetch || BP_IS_REDACTED(bp)) 1904 return; 1905 1906 if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg || 1907 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE && 1908 BP_GET_TYPE(bp) != DMU_OT_OBJSET)) 1909 return; 1910 1911 if (dsl_scan_check_prefetch_resume(spc, zb)) 1912 return; 1913 1914 scan_prefetch_ctx_add_ref(spc, scn); 1915 spic = kmem_alloc(sizeof (scan_prefetch_issue_ctx_t), KM_SLEEP); 1916 spic->spic_spc = spc; 1917 spic->spic_bp = *bp; 1918 spic->spic_zb = *zb; 1919 1920 /* 1921 * Add the IO to the queue of blocks to prefetch. This allows us to 1922 * prioritize blocks that we will need first for the main traversal 1923 * thread. 1924 */ 1925 mutex_enter(&spa->spa_scrub_lock); 1926 if (avl_find(&scn->scn_prefetch_queue, spic, &idx) != NULL) { 1927 /* this block is already queued for prefetch */ 1928 kmem_free(spic, sizeof (scan_prefetch_issue_ctx_t)); 1929 scan_prefetch_ctx_rele(spc, scn); 1930 mutex_exit(&spa->spa_scrub_lock); 1931 return; 1932 } 1933 1934 avl_insert(&scn->scn_prefetch_queue, spic, idx); 1935 cv_broadcast(&spa->spa_scrub_io_cv); 1936 mutex_exit(&spa->spa_scrub_lock); 1937 } 1938 1939 static void 1940 dsl_scan_prefetch_dnode(dsl_scan_t *scn, dnode_phys_t *dnp, 1941 uint64_t objset, uint64_t object) 1942 { 1943 int i; 1944 zbookmark_phys_t zb; 1945 scan_prefetch_ctx_t *spc; 1946 1947 if (dnp->dn_nblkptr == 0 && !(dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) 1948 return; 1949 1950 SET_BOOKMARK(&zb, objset, object, 0, 0); 1951 1952 spc = scan_prefetch_ctx_create(scn, dnp, FTAG); 1953 1954 for (i = 0; i < dnp->dn_nblkptr; i++) { 1955 zb.zb_level = BP_GET_LEVEL(&dnp->dn_blkptr[i]); 1956 zb.zb_blkid = i; 1957 dsl_scan_prefetch(spc, &dnp->dn_blkptr[i], &zb); 1958 } 1959 1960 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 1961 zb.zb_level = 0; 1962 zb.zb_blkid = DMU_SPILL_BLKID; 1963 dsl_scan_prefetch(spc, DN_SPILL_BLKPTR(dnp), &zb); 1964 } 1965 1966 scan_prefetch_ctx_rele(spc, FTAG); 1967 } 1968 1969 static void 1970 dsl_scan_prefetch_cb(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp, 1971 arc_buf_t *buf, void *private) 1972 { 1973 (void) zio; 1974 scan_prefetch_ctx_t *spc = private; 1975 dsl_scan_t *scn = spc->spc_scn; 1976 spa_t *spa = scn->scn_dp->dp_spa; 1977 1978 /* broadcast that the IO has completed for rate limiting purposes */ 1979 mutex_enter(&spa->spa_scrub_lock); 1980 ASSERT3U(spa->spa_scrub_inflight, >=, BP_GET_PSIZE(bp)); 1981 spa->spa_scrub_inflight -= BP_GET_PSIZE(bp); 1982 cv_broadcast(&spa->spa_scrub_io_cv); 1983 mutex_exit(&spa->spa_scrub_lock); 1984 1985 /* if there was an error or we are done prefetching, just cleanup */ 1986 if (buf == NULL || scn->scn_prefetch_stop) 1987 goto out; 1988 1989 if (BP_GET_LEVEL(bp) > 0) { 1990 int i; 1991 blkptr_t *cbp; 1992 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 1993 zbookmark_phys_t czb; 1994 1995 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 1996 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 1997 zb->zb_level - 1, zb->zb_blkid * epb + i); 1998 dsl_scan_prefetch(spc, cbp, &czb); 1999 } 2000 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 2001 dnode_phys_t *cdnp; 2002 int i; 2003 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 2004 2005 for (i = 0, cdnp = buf->b_data; i < epb; 2006 i += cdnp->dn_extra_slots + 1, 2007 cdnp += cdnp->dn_extra_slots + 1) { 2008 dsl_scan_prefetch_dnode(scn, cdnp, 2009 zb->zb_objset, zb->zb_blkid * epb + i); 2010 } 2011 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 2012 objset_phys_t *osp = buf->b_data; 2013 2014 dsl_scan_prefetch_dnode(scn, &osp->os_meta_dnode, 2015 zb->zb_objset, DMU_META_DNODE_OBJECT); 2016 2017 if (OBJSET_BUF_HAS_USERUSED(buf)) { 2018 dsl_scan_prefetch_dnode(scn, 2019 &osp->os_groupused_dnode, zb->zb_objset, 2020 DMU_GROUPUSED_OBJECT); 2021 dsl_scan_prefetch_dnode(scn, 2022 &osp->os_userused_dnode, zb->zb_objset, 2023 DMU_USERUSED_OBJECT); 2024 } 2025 } 2026 2027 out: 2028 if (buf != NULL) 2029 arc_buf_destroy(buf, private); 2030 scan_prefetch_ctx_rele(spc, scn); 2031 } 2032 2033 static void 2034 dsl_scan_prefetch_thread(void *arg) 2035 { 2036 dsl_scan_t *scn = arg; 2037 spa_t *spa = scn->scn_dp->dp_spa; 2038 scan_prefetch_issue_ctx_t *spic; 2039 2040 /* loop until we are told to stop */ 2041 while (!scn->scn_prefetch_stop) { 2042 arc_flags_t flags = ARC_FLAG_NOWAIT | 2043 ARC_FLAG_PRESCIENT_PREFETCH | ARC_FLAG_PREFETCH; 2044 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD; 2045 2046 mutex_enter(&spa->spa_scrub_lock); 2047 2048 /* 2049 * Wait until we have an IO to issue and are not above our 2050 * maximum in flight limit. 2051 */ 2052 while (!scn->scn_prefetch_stop && 2053 (avl_numnodes(&scn->scn_prefetch_queue) == 0 || 2054 spa->spa_scrub_inflight >= scn->scn_maxinflight_bytes)) { 2055 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock); 2056 } 2057 2058 /* recheck if we should stop since we waited for the cv */ 2059 if (scn->scn_prefetch_stop) { 2060 mutex_exit(&spa->spa_scrub_lock); 2061 break; 2062 } 2063 2064 /* remove the prefetch IO from the tree */ 2065 spic = avl_first(&scn->scn_prefetch_queue); 2066 spa->spa_scrub_inflight += BP_GET_PSIZE(&spic->spic_bp); 2067 avl_remove(&scn->scn_prefetch_queue, spic); 2068 2069 mutex_exit(&spa->spa_scrub_lock); 2070 2071 if (BP_IS_PROTECTED(&spic->spic_bp)) { 2072 ASSERT(BP_GET_TYPE(&spic->spic_bp) == DMU_OT_DNODE || 2073 BP_GET_TYPE(&spic->spic_bp) == DMU_OT_OBJSET); 2074 ASSERT3U(BP_GET_LEVEL(&spic->spic_bp), ==, 0); 2075 zio_flags |= ZIO_FLAG_RAW; 2076 } 2077 2078 /* issue the prefetch asynchronously */ 2079 (void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, 2080 &spic->spic_bp, dsl_scan_prefetch_cb, spic->spic_spc, 2081 ZIO_PRIORITY_SCRUB, zio_flags, &flags, &spic->spic_zb); 2082 2083 kmem_free(spic, sizeof (scan_prefetch_issue_ctx_t)); 2084 } 2085 2086 ASSERT(scn->scn_prefetch_stop); 2087 2088 /* free any prefetches we didn't get to complete */ 2089 mutex_enter(&spa->spa_scrub_lock); 2090 while ((spic = avl_first(&scn->scn_prefetch_queue)) != NULL) { 2091 avl_remove(&scn->scn_prefetch_queue, spic); 2092 scan_prefetch_ctx_rele(spic->spic_spc, scn); 2093 kmem_free(spic, sizeof (scan_prefetch_issue_ctx_t)); 2094 } 2095 ASSERT0(avl_numnodes(&scn->scn_prefetch_queue)); 2096 mutex_exit(&spa->spa_scrub_lock); 2097 } 2098 2099 static boolean_t 2100 dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp, 2101 const zbookmark_phys_t *zb) 2102 { 2103 /* 2104 * We never skip over user/group accounting objects (obj<0) 2105 */ 2106 if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) && 2107 (int64_t)zb->zb_object >= 0) { 2108 /* 2109 * If we already visited this bp & everything below (in 2110 * a prior txg sync), don't bother doing it again. 2111 */ 2112 if (zbookmark_subtree_completed(dnp, zb, 2113 &scn->scn_phys.scn_bookmark)) 2114 return (B_TRUE); 2115 2116 /* 2117 * If we found the block we're trying to resume from, or 2118 * we went past it, zero it out to indicate that it's OK 2119 * to start checking for suspending again. 2120 */ 2121 if (zbookmark_subtree_tbd(dnp, zb, 2122 &scn->scn_phys.scn_bookmark)) { 2123 dprintf("resuming at %llx/%llx/%llx/%llx\n", 2124 (longlong_t)zb->zb_objset, 2125 (longlong_t)zb->zb_object, 2126 (longlong_t)zb->zb_level, 2127 (longlong_t)zb->zb_blkid); 2128 memset(&scn->scn_phys.scn_bookmark, 0, sizeof (*zb)); 2129 } 2130 } 2131 return (B_FALSE); 2132 } 2133 2134 static void dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 2135 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 2136 dmu_objset_type_t ostype, dmu_tx_t *tx); 2137 inline __attribute__((always_inline)) static void dsl_scan_visitdnode( 2138 dsl_scan_t *, dsl_dataset_t *ds, dmu_objset_type_t ostype, 2139 dnode_phys_t *dnp, uint64_t object, dmu_tx_t *tx); 2140 2141 /* 2142 * Return nonzero on i/o error. 2143 * Return new buf to write out in *bufp. 2144 */ 2145 inline __attribute__((always_inline)) static int 2146 dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype, 2147 dnode_phys_t *dnp, const blkptr_t *bp, 2148 const zbookmark_phys_t *zb, dmu_tx_t *tx) 2149 { 2150 dsl_pool_t *dp = scn->scn_dp; 2151 spa_t *spa = dp->dp_spa; 2152 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD; 2153 int err; 2154 2155 ASSERT(!BP_IS_REDACTED(bp)); 2156 2157 /* 2158 * There is an unlikely case of encountering dnodes with contradicting 2159 * dn_bonuslen and DNODE_FLAG_SPILL_BLKPTR flag before in files created 2160 * or modified before commit 4254acb was merged. As it is not possible 2161 * to know which of the two is correct, report an error. 2162 */ 2163 if (dnp != NULL && 2164 dnp->dn_bonuslen > DN_MAX_BONUS_LEN(dnp)) { 2165 scn->scn_phys.scn_errors++; 2166 spa_log_error(spa, zb, &bp->blk_birth); 2167 return (SET_ERROR(EINVAL)); 2168 } 2169 2170 if (BP_GET_LEVEL(bp) > 0) { 2171 arc_flags_t flags = ARC_FLAG_WAIT; 2172 int i; 2173 blkptr_t *cbp; 2174 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 2175 arc_buf_t *buf; 2176 2177 err = arc_read(NULL, spa, bp, arc_getbuf_func, &buf, 2178 ZIO_PRIORITY_SCRUB, zio_flags, &flags, zb); 2179 if (err) { 2180 scn->scn_phys.scn_errors++; 2181 return (err); 2182 } 2183 for (i = 0, cbp = buf->b_data; i < epb; i++, cbp++) { 2184 zbookmark_phys_t czb; 2185 2186 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 2187 zb->zb_level - 1, 2188 zb->zb_blkid * epb + i); 2189 dsl_scan_visitbp(cbp, &czb, dnp, 2190 ds, scn, ostype, tx); 2191 } 2192 arc_buf_destroy(buf, &buf); 2193 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 2194 arc_flags_t flags = ARC_FLAG_WAIT; 2195 dnode_phys_t *cdnp; 2196 int i; 2197 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 2198 arc_buf_t *buf; 2199 2200 if (BP_IS_PROTECTED(bp)) { 2201 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF); 2202 zio_flags |= ZIO_FLAG_RAW; 2203 } 2204 2205 err = arc_read(NULL, spa, bp, arc_getbuf_func, &buf, 2206 ZIO_PRIORITY_SCRUB, zio_flags, &flags, zb); 2207 if (err) { 2208 scn->scn_phys.scn_errors++; 2209 return (err); 2210 } 2211 for (i = 0, cdnp = buf->b_data; i < epb; 2212 i += cdnp->dn_extra_slots + 1, 2213 cdnp += cdnp->dn_extra_slots + 1) { 2214 dsl_scan_visitdnode(scn, ds, ostype, 2215 cdnp, zb->zb_blkid * epb + i, tx); 2216 } 2217 2218 arc_buf_destroy(buf, &buf); 2219 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 2220 arc_flags_t flags = ARC_FLAG_WAIT; 2221 objset_phys_t *osp; 2222 arc_buf_t *buf; 2223 2224 err = arc_read(NULL, spa, bp, arc_getbuf_func, &buf, 2225 ZIO_PRIORITY_SCRUB, zio_flags, &flags, zb); 2226 if (err) { 2227 scn->scn_phys.scn_errors++; 2228 return (err); 2229 } 2230 2231 osp = buf->b_data; 2232 2233 dsl_scan_visitdnode(scn, ds, osp->os_type, 2234 &osp->os_meta_dnode, DMU_META_DNODE_OBJECT, tx); 2235 2236 if (OBJSET_BUF_HAS_USERUSED(buf)) { 2237 /* 2238 * We also always visit user/group/project accounting 2239 * objects, and never skip them, even if we are 2240 * suspending. This is necessary so that the 2241 * space deltas from this txg get integrated. 2242 */ 2243 if (OBJSET_BUF_HAS_PROJECTUSED(buf)) 2244 dsl_scan_visitdnode(scn, ds, osp->os_type, 2245 &osp->os_projectused_dnode, 2246 DMU_PROJECTUSED_OBJECT, tx); 2247 dsl_scan_visitdnode(scn, ds, osp->os_type, 2248 &osp->os_groupused_dnode, 2249 DMU_GROUPUSED_OBJECT, tx); 2250 dsl_scan_visitdnode(scn, ds, osp->os_type, 2251 &osp->os_userused_dnode, 2252 DMU_USERUSED_OBJECT, tx); 2253 } 2254 arc_buf_destroy(buf, &buf); 2255 } else if (!zfs_blkptr_verify(spa, bp, 2256 BLK_CONFIG_NEEDED, BLK_VERIFY_LOG)) { 2257 /* 2258 * Sanity check the block pointer contents, this is handled 2259 * by arc_read() for the cases above. 2260 */ 2261 scn->scn_phys.scn_errors++; 2262 spa_log_error(spa, zb, &bp->blk_birth); 2263 return (SET_ERROR(EINVAL)); 2264 } 2265 2266 return (0); 2267 } 2268 2269 inline __attribute__((always_inline)) static void 2270 dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds, 2271 dmu_objset_type_t ostype, dnode_phys_t *dnp, 2272 uint64_t object, dmu_tx_t *tx) 2273 { 2274 int j; 2275 2276 for (j = 0; j < dnp->dn_nblkptr; j++) { 2277 zbookmark_phys_t czb; 2278 2279 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 2280 dnp->dn_nlevels - 1, j); 2281 dsl_scan_visitbp(&dnp->dn_blkptr[j], 2282 &czb, dnp, ds, scn, ostype, tx); 2283 } 2284 2285 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 2286 zbookmark_phys_t czb; 2287 SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, 2288 0, DMU_SPILL_BLKID); 2289 dsl_scan_visitbp(DN_SPILL_BLKPTR(dnp), 2290 &czb, dnp, ds, scn, ostype, tx); 2291 } 2292 } 2293 2294 /* 2295 * The arguments are in this order because mdb can only print the 2296 * first 5; we want them to be useful. 2297 */ 2298 static void 2299 dsl_scan_visitbp(blkptr_t *bp, const zbookmark_phys_t *zb, 2300 dnode_phys_t *dnp, dsl_dataset_t *ds, dsl_scan_t *scn, 2301 dmu_objset_type_t ostype, dmu_tx_t *tx) 2302 { 2303 dsl_pool_t *dp = scn->scn_dp; 2304 blkptr_t *bp_toread = NULL; 2305 2306 if (dsl_scan_check_suspend(scn, zb)) 2307 return; 2308 2309 if (dsl_scan_check_resume(scn, dnp, zb)) 2310 return; 2311 2312 scn->scn_visited_this_txg++; 2313 2314 if (BP_IS_HOLE(bp)) { 2315 scn->scn_holes_this_txg++; 2316 return; 2317 } 2318 2319 if (BP_IS_REDACTED(bp)) { 2320 ASSERT(dsl_dataset_feature_is_active(ds, 2321 SPA_FEATURE_REDACTED_DATASETS)); 2322 return; 2323 } 2324 2325 /* 2326 * Check if this block contradicts any filesystem flags. 2327 */ 2328 spa_feature_t f = SPA_FEATURE_LARGE_BLOCKS; 2329 if (BP_GET_LSIZE(bp) > SPA_OLD_MAXBLOCKSIZE) 2330 ASSERT(dsl_dataset_feature_is_active(ds, f)); 2331 2332 f = zio_checksum_to_feature(BP_GET_CHECKSUM(bp)); 2333 if (f != SPA_FEATURE_NONE) 2334 ASSERT(dsl_dataset_feature_is_active(ds, f)); 2335 2336 f = zio_compress_to_feature(BP_GET_COMPRESS(bp)); 2337 if (f != SPA_FEATURE_NONE) 2338 ASSERT(dsl_dataset_feature_is_active(ds, f)); 2339 2340 if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) { 2341 scn->scn_lt_min_this_txg++; 2342 return; 2343 } 2344 2345 bp_toread = kmem_alloc(sizeof (blkptr_t), KM_SLEEP); 2346 *bp_toread = *bp; 2347 2348 if (dsl_scan_recurse(scn, ds, ostype, dnp, bp_toread, zb, tx) != 0) 2349 goto out; 2350 2351 /* 2352 * If dsl_scan_ddt() has already visited this block, it will have 2353 * already done any translations or scrubbing, so don't call the 2354 * callback again. 2355 */ 2356 if (ddt_class_contains(dp->dp_spa, 2357 scn->scn_phys.scn_ddt_class_max, bp)) { 2358 scn->scn_ddt_contained_this_txg++; 2359 goto out; 2360 } 2361 2362 /* 2363 * If this block is from the future (after cur_max_txg), then we 2364 * are doing this on behalf of a deleted snapshot, and we will 2365 * revisit the future block on the next pass of this dataset. 2366 * Don't scan it now unless we need to because something 2367 * under it was modified. 2368 */ 2369 if (BP_PHYSICAL_BIRTH(bp) > scn->scn_phys.scn_cur_max_txg) { 2370 scn->scn_gt_max_this_txg++; 2371 goto out; 2372 } 2373 2374 scan_funcs[scn->scn_phys.scn_func](dp, bp, zb); 2375 2376 out: 2377 kmem_free(bp_toread, sizeof (blkptr_t)); 2378 } 2379 2380 static void 2381 dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp, 2382 dmu_tx_t *tx) 2383 { 2384 zbookmark_phys_t zb; 2385 scan_prefetch_ctx_t *spc; 2386 2387 SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET, 2388 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 2389 2390 if (ZB_IS_ZERO(&scn->scn_phys.scn_bookmark)) { 2391 SET_BOOKMARK(&scn->scn_prefetch_bookmark, 2392 zb.zb_objset, 0, 0, 0); 2393 } else { 2394 scn->scn_prefetch_bookmark = scn->scn_phys.scn_bookmark; 2395 } 2396 2397 scn->scn_objsets_visited_this_txg++; 2398 2399 spc = scan_prefetch_ctx_create(scn, NULL, FTAG); 2400 dsl_scan_prefetch(spc, bp, &zb); 2401 scan_prefetch_ctx_rele(spc, FTAG); 2402 2403 dsl_scan_visitbp(bp, &zb, NULL, ds, scn, DMU_OST_NONE, tx); 2404 2405 dprintf_ds(ds, "finished scan%s", ""); 2406 } 2407 2408 static void 2409 ds_destroyed_scn_phys(dsl_dataset_t *ds, dsl_scan_phys_t *scn_phys) 2410 { 2411 if (scn_phys->scn_bookmark.zb_objset == ds->ds_object) { 2412 if (ds->ds_is_snapshot) { 2413 /* 2414 * Note: 2415 * - scn_cur_{min,max}_txg stays the same. 2416 * - Setting the flag is not really necessary if 2417 * scn_cur_max_txg == scn_max_txg, because there 2418 * is nothing after this snapshot that we care 2419 * about. However, we set it anyway and then 2420 * ignore it when we retraverse it in 2421 * dsl_scan_visitds(). 2422 */ 2423 scn_phys->scn_bookmark.zb_objset = 2424 dsl_dataset_phys(ds)->ds_next_snap_obj; 2425 zfs_dbgmsg("destroying ds %llu on %s; currently " 2426 "traversing; reset zb_objset to %llu", 2427 (u_longlong_t)ds->ds_object, 2428 ds->ds_dir->dd_pool->dp_spa->spa_name, 2429 (u_longlong_t)dsl_dataset_phys(ds)-> 2430 ds_next_snap_obj); 2431 scn_phys->scn_flags |= DSF_VISIT_DS_AGAIN; 2432 } else { 2433 SET_BOOKMARK(&scn_phys->scn_bookmark, 2434 ZB_DESTROYED_OBJSET, 0, 0, 0); 2435 zfs_dbgmsg("destroying ds %llu on %s; currently " 2436 "traversing; reset bookmark to -1,0,0,0", 2437 (u_longlong_t)ds->ds_object, 2438 ds->ds_dir->dd_pool->dp_spa->spa_name); 2439 } 2440 } 2441 } 2442 2443 /* 2444 * Invoked when a dataset is destroyed. We need to make sure that: 2445 * 2446 * 1) If it is the dataset that was currently being scanned, we write 2447 * a new dsl_scan_phys_t and marking the objset reference in it 2448 * as destroyed. 2449 * 2) Remove it from the work queue, if it was present. 2450 * 2451 * If the dataset was actually a snapshot, instead of marking the dataset 2452 * as destroyed, we instead substitute the next snapshot in line. 2453 */ 2454 void 2455 dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx) 2456 { 2457 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2458 dsl_scan_t *scn = dp->dp_scan; 2459 uint64_t mintxg; 2460 2461 if (!dsl_scan_is_running(scn)) 2462 return; 2463 2464 ds_destroyed_scn_phys(ds, &scn->scn_phys); 2465 ds_destroyed_scn_phys(ds, &scn->scn_phys_cached); 2466 2467 if (scan_ds_queue_contains(scn, ds->ds_object, &mintxg)) { 2468 scan_ds_queue_remove(scn, ds->ds_object); 2469 if (ds->ds_is_snapshot) 2470 scan_ds_queue_insert(scn, 2471 dsl_dataset_phys(ds)->ds_next_snap_obj, mintxg); 2472 } 2473 2474 if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 2475 ds->ds_object, &mintxg) == 0) { 2476 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1); 2477 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2478 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 2479 if (ds->ds_is_snapshot) { 2480 /* 2481 * We keep the same mintxg; it could be > 2482 * ds_creation_txg if the previous snapshot was 2483 * deleted too. 2484 */ 2485 VERIFY(zap_add_int_key(dp->dp_meta_objset, 2486 scn->scn_phys.scn_queue_obj, 2487 dsl_dataset_phys(ds)->ds_next_snap_obj, 2488 mintxg, tx) == 0); 2489 zfs_dbgmsg("destroying ds %llu on %s; in queue; " 2490 "replacing with %llu", 2491 (u_longlong_t)ds->ds_object, 2492 dp->dp_spa->spa_name, 2493 (u_longlong_t)dsl_dataset_phys(ds)-> 2494 ds_next_snap_obj); 2495 } else { 2496 zfs_dbgmsg("destroying ds %llu on %s; in queue; " 2497 "removing", 2498 (u_longlong_t)ds->ds_object, 2499 dp->dp_spa->spa_name); 2500 } 2501 } 2502 2503 /* 2504 * dsl_scan_sync() should be called after this, and should sync 2505 * out our changed state, but just to be safe, do it here. 2506 */ 2507 dsl_scan_sync_state(scn, tx, SYNC_CACHED); 2508 } 2509 2510 static void 2511 ds_snapshotted_bookmark(dsl_dataset_t *ds, zbookmark_phys_t *scn_bookmark) 2512 { 2513 if (scn_bookmark->zb_objset == ds->ds_object) { 2514 scn_bookmark->zb_objset = 2515 dsl_dataset_phys(ds)->ds_prev_snap_obj; 2516 zfs_dbgmsg("snapshotting ds %llu on %s; currently traversing; " 2517 "reset zb_objset to %llu", 2518 (u_longlong_t)ds->ds_object, 2519 ds->ds_dir->dd_pool->dp_spa->spa_name, 2520 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 2521 } 2522 } 2523 2524 /* 2525 * Called when a dataset is snapshotted. If we were currently traversing 2526 * this snapshot, we reset our bookmark to point at the newly created 2527 * snapshot. We also modify our work queue to remove the old snapshot and 2528 * replace with the new one. 2529 */ 2530 void 2531 dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx) 2532 { 2533 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2534 dsl_scan_t *scn = dp->dp_scan; 2535 uint64_t mintxg; 2536 2537 if (!dsl_scan_is_running(scn)) 2538 return; 2539 2540 ASSERT(dsl_dataset_phys(ds)->ds_prev_snap_obj != 0); 2541 2542 ds_snapshotted_bookmark(ds, &scn->scn_phys.scn_bookmark); 2543 ds_snapshotted_bookmark(ds, &scn->scn_phys_cached.scn_bookmark); 2544 2545 if (scan_ds_queue_contains(scn, ds->ds_object, &mintxg)) { 2546 scan_ds_queue_remove(scn, ds->ds_object); 2547 scan_ds_queue_insert(scn, 2548 dsl_dataset_phys(ds)->ds_prev_snap_obj, mintxg); 2549 } 2550 2551 if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, 2552 ds->ds_object, &mintxg) == 0) { 2553 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2554 scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); 2555 VERIFY(zap_add_int_key(dp->dp_meta_objset, 2556 scn->scn_phys.scn_queue_obj, 2557 dsl_dataset_phys(ds)->ds_prev_snap_obj, mintxg, tx) == 0); 2558 zfs_dbgmsg("snapshotting ds %llu on %s; in queue; " 2559 "replacing with %llu", 2560 (u_longlong_t)ds->ds_object, 2561 dp->dp_spa->spa_name, 2562 (u_longlong_t)dsl_dataset_phys(ds)->ds_prev_snap_obj); 2563 } 2564 2565 dsl_scan_sync_state(scn, tx, SYNC_CACHED); 2566 } 2567 2568 static void 2569 ds_clone_swapped_bookmark(dsl_dataset_t *ds1, dsl_dataset_t *ds2, 2570 zbookmark_phys_t *scn_bookmark) 2571 { 2572 if (scn_bookmark->zb_objset == ds1->ds_object) { 2573 scn_bookmark->zb_objset = ds2->ds_object; 2574 zfs_dbgmsg("clone_swap ds %llu on %s; currently traversing; " 2575 "reset zb_objset to %llu", 2576 (u_longlong_t)ds1->ds_object, 2577 ds1->ds_dir->dd_pool->dp_spa->spa_name, 2578 (u_longlong_t)ds2->ds_object); 2579 } else if (scn_bookmark->zb_objset == ds2->ds_object) { 2580 scn_bookmark->zb_objset = ds1->ds_object; 2581 zfs_dbgmsg("clone_swap ds %llu on %s; currently traversing; " 2582 "reset zb_objset to %llu", 2583 (u_longlong_t)ds2->ds_object, 2584 ds2->ds_dir->dd_pool->dp_spa->spa_name, 2585 (u_longlong_t)ds1->ds_object); 2586 } 2587 } 2588 2589 /* 2590 * Called when an origin dataset and its clone are swapped. If we were 2591 * currently traversing the dataset, we need to switch to traversing the 2592 * newly promoted clone. 2593 */ 2594 void 2595 dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx) 2596 { 2597 dsl_pool_t *dp = ds1->ds_dir->dd_pool; 2598 dsl_scan_t *scn = dp->dp_scan; 2599 uint64_t mintxg1, mintxg2; 2600 boolean_t ds1_queued, ds2_queued; 2601 2602 if (!dsl_scan_is_running(scn)) 2603 return; 2604 2605 ds_clone_swapped_bookmark(ds1, ds2, &scn->scn_phys.scn_bookmark); 2606 ds_clone_swapped_bookmark(ds1, ds2, &scn->scn_phys_cached.scn_bookmark); 2607 2608 /* 2609 * Handle the in-memory scan queue. 2610 */ 2611 ds1_queued = scan_ds_queue_contains(scn, ds1->ds_object, &mintxg1); 2612 ds2_queued = scan_ds_queue_contains(scn, ds2->ds_object, &mintxg2); 2613 2614 /* Sanity checking. */ 2615 if (ds1_queued) { 2616 ASSERT3U(mintxg1, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 2617 ASSERT3U(mintxg1, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 2618 } 2619 if (ds2_queued) { 2620 ASSERT3U(mintxg2, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 2621 ASSERT3U(mintxg2, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 2622 } 2623 2624 if (ds1_queued && ds2_queued) { 2625 /* 2626 * If both are queued, we don't need to do anything. 2627 * The swapping code below would not handle this case correctly, 2628 * since we can't insert ds2 if it is already there. That's 2629 * because scan_ds_queue_insert() prohibits a duplicate insert 2630 * and panics. 2631 */ 2632 } else if (ds1_queued) { 2633 scan_ds_queue_remove(scn, ds1->ds_object); 2634 scan_ds_queue_insert(scn, ds2->ds_object, mintxg1); 2635 } else if (ds2_queued) { 2636 scan_ds_queue_remove(scn, ds2->ds_object); 2637 scan_ds_queue_insert(scn, ds1->ds_object, mintxg2); 2638 } 2639 2640 /* 2641 * Handle the on-disk scan queue. 2642 * The on-disk state is an out-of-date version of the in-memory state, 2643 * so the in-memory and on-disk values for ds1_queued and ds2_queued may 2644 * be different. Therefore we need to apply the swap logic to the 2645 * on-disk state independently of the in-memory state. 2646 */ 2647 ds1_queued = zap_lookup_int_key(dp->dp_meta_objset, 2648 scn->scn_phys.scn_queue_obj, ds1->ds_object, &mintxg1) == 0; 2649 ds2_queued = zap_lookup_int_key(dp->dp_meta_objset, 2650 scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg2) == 0; 2651 2652 /* Sanity checking. */ 2653 if (ds1_queued) { 2654 ASSERT3U(mintxg1, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 2655 ASSERT3U(mintxg1, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 2656 } 2657 if (ds2_queued) { 2658 ASSERT3U(mintxg2, ==, dsl_dataset_phys(ds1)->ds_prev_snap_txg); 2659 ASSERT3U(mintxg2, ==, dsl_dataset_phys(ds2)->ds_prev_snap_txg); 2660 } 2661 2662 if (ds1_queued && ds2_queued) { 2663 /* 2664 * If both are queued, we don't need to do anything. 2665 * Alternatively, we could check for EEXIST from 2666 * zap_add_int_key() and back out to the original state, but 2667 * that would be more work than checking for this case upfront. 2668 */ 2669 } else if (ds1_queued) { 2670 VERIFY3S(0, ==, zap_remove_int(dp->dp_meta_objset, 2671 scn->scn_phys.scn_queue_obj, ds1->ds_object, tx)); 2672 VERIFY3S(0, ==, zap_add_int_key(dp->dp_meta_objset, 2673 scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg1, tx)); 2674 zfs_dbgmsg("clone_swap ds %llu on %s; in queue; " 2675 "replacing with %llu", 2676 (u_longlong_t)ds1->ds_object, 2677 dp->dp_spa->spa_name, 2678 (u_longlong_t)ds2->ds_object); 2679 } else if (ds2_queued) { 2680 VERIFY3S(0, ==, zap_remove_int(dp->dp_meta_objset, 2681 scn->scn_phys.scn_queue_obj, ds2->ds_object, tx)); 2682 VERIFY3S(0, ==, zap_add_int_key(dp->dp_meta_objset, 2683 scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg2, tx)); 2684 zfs_dbgmsg("clone_swap ds %llu on %s; in queue; " 2685 "replacing with %llu", 2686 (u_longlong_t)ds2->ds_object, 2687 dp->dp_spa->spa_name, 2688 (u_longlong_t)ds1->ds_object); 2689 } 2690 2691 dsl_scan_sync_state(scn, tx, SYNC_CACHED); 2692 } 2693 2694 static int 2695 enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 2696 { 2697 uint64_t originobj = *(uint64_t *)arg; 2698 dsl_dataset_t *ds; 2699 int err; 2700 dsl_scan_t *scn = dp->dp_scan; 2701 2702 if (dsl_dir_phys(hds->ds_dir)->dd_origin_obj != originobj) 2703 return (0); 2704 2705 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 2706 if (err) 2707 return (err); 2708 2709 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != originobj) { 2710 dsl_dataset_t *prev; 2711 err = dsl_dataset_hold_obj(dp, 2712 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 2713 2714 dsl_dataset_rele(ds, FTAG); 2715 if (err) 2716 return (err); 2717 ds = prev; 2718 } 2719 scan_ds_queue_insert(scn, ds->ds_object, 2720 dsl_dataset_phys(ds)->ds_prev_snap_txg); 2721 dsl_dataset_rele(ds, FTAG); 2722 return (0); 2723 } 2724 2725 static void 2726 dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx) 2727 { 2728 dsl_pool_t *dp = scn->scn_dp; 2729 dsl_dataset_t *ds; 2730 2731 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 2732 2733 if (scn->scn_phys.scn_cur_min_txg >= 2734 scn->scn_phys.scn_max_txg) { 2735 /* 2736 * This can happen if this snapshot was created after the 2737 * scan started, and we already completed a previous snapshot 2738 * that was created after the scan started. This snapshot 2739 * only references blocks with: 2740 * 2741 * birth < our ds_creation_txg 2742 * cur_min_txg is no less than ds_creation_txg. 2743 * We have already visited these blocks. 2744 * or 2745 * birth > scn_max_txg 2746 * The scan requested not to visit these blocks. 2747 * 2748 * Subsequent snapshots (and clones) can reference our 2749 * blocks, or blocks with even higher birth times. 2750 * Therefore we do not need to visit them either, 2751 * so we do not add them to the work queue. 2752 * 2753 * Note that checking for cur_min_txg >= cur_max_txg 2754 * is not sufficient, because in that case we may need to 2755 * visit subsequent snapshots. This happens when min_txg > 0, 2756 * which raises cur_min_txg. In this case we will visit 2757 * this dataset but skip all of its blocks, because the 2758 * rootbp's birth time is < cur_min_txg. Then we will 2759 * add the next snapshots/clones to the work queue. 2760 */ 2761 char *dsname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP); 2762 dsl_dataset_name(ds, dsname); 2763 zfs_dbgmsg("scanning dataset %llu (%s) is unnecessary because " 2764 "cur_min_txg (%llu) >= max_txg (%llu)", 2765 (longlong_t)dsobj, dsname, 2766 (longlong_t)scn->scn_phys.scn_cur_min_txg, 2767 (longlong_t)scn->scn_phys.scn_max_txg); 2768 kmem_free(dsname, MAXNAMELEN); 2769 2770 goto out; 2771 } 2772 2773 /* 2774 * Only the ZIL in the head (non-snapshot) is valid. Even though 2775 * snapshots can have ZIL block pointers (which may be the same 2776 * BP as in the head), they must be ignored. In addition, $ORIGIN 2777 * doesn't have a objset (i.e. its ds_bp is a hole) so we don't 2778 * need to look for a ZIL in it either. So we traverse the ZIL here, 2779 * rather than in scan_recurse(), because the regular snapshot 2780 * block-sharing rules don't apply to it. 2781 */ 2782 if (!dsl_dataset_is_snapshot(ds) && 2783 (dp->dp_origin_snap == NULL || 2784 ds->ds_dir != dp->dp_origin_snap->ds_dir)) { 2785 objset_t *os; 2786 if (dmu_objset_from_ds(ds, &os) != 0) { 2787 goto out; 2788 } 2789 dsl_scan_zil(dp, &os->os_zil_header); 2790 } 2791 2792 /* 2793 * Iterate over the bps in this ds. 2794 */ 2795 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2796 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG); 2797 dsl_scan_visit_rootbp(scn, ds, &dsl_dataset_phys(ds)->ds_bp, tx); 2798 rrw_exit(&ds->ds_bp_rwlock, FTAG); 2799 2800 char *dsname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP); 2801 dsl_dataset_name(ds, dsname); 2802 zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; " 2803 "suspending=%u", 2804 (longlong_t)dsobj, dsname, 2805 (longlong_t)scn->scn_phys.scn_cur_min_txg, 2806 (longlong_t)scn->scn_phys.scn_cur_max_txg, 2807 (int)scn->scn_suspending); 2808 kmem_free(dsname, ZFS_MAX_DATASET_NAME_LEN); 2809 2810 if (scn->scn_suspending) 2811 goto out; 2812 2813 /* 2814 * We've finished this pass over this dataset. 2815 */ 2816 2817 /* 2818 * If we did not completely visit this dataset, do another pass. 2819 */ 2820 if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) { 2821 zfs_dbgmsg("incomplete pass on %s; visiting again", 2822 dp->dp_spa->spa_name); 2823 scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN; 2824 scan_ds_queue_insert(scn, ds->ds_object, 2825 scn->scn_phys.scn_cur_max_txg); 2826 goto out; 2827 } 2828 2829 /* 2830 * Add descendant datasets to work queue. 2831 */ 2832 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) { 2833 scan_ds_queue_insert(scn, 2834 dsl_dataset_phys(ds)->ds_next_snap_obj, 2835 dsl_dataset_phys(ds)->ds_creation_txg); 2836 } 2837 if (dsl_dataset_phys(ds)->ds_num_children > 1) { 2838 boolean_t usenext = B_FALSE; 2839 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) { 2840 uint64_t count; 2841 /* 2842 * A bug in a previous version of the code could 2843 * cause upgrade_clones_cb() to not set 2844 * ds_next_snap_obj when it should, leading to a 2845 * missing entry. Therefore we can only use the 2846 * next_clones_obj when its count is correct. 2847 */ 2848 int err = zap_count(dp->dp_meta_objset, 2849 dsl_dataset_phys(ds)->ds_next_clones_obj, &count); 2850 if (err == 0 && 2851 count == dsl_dataset_phys(ds)->ds_num_children - 1) 2852 usenext = B_TRUE; 2853 } 2854 2855 if (usenext) { 2856 zap_cursor_t zc; 2857 zap_attribute_t za; 2858 for (zap_cursor_init(&zc, dp->dp_meta_objset, 2859 dsl_dataset_phys(ds)->ds_next_clones_obj); 2860 zap_cursor_retrieve(&zc, &za) == 0; 2861 (void) zap_cursor_advance(&zc)) { 2862 scan_ds_queue_insert(scn, 2863 zfs_strtonum(za.za_name, NULL), 2864 dsl_dataset_phys(ds)->ds_creation_txg); 2865 } 2866 zap_cursor_fini(&zc); 2867 } else { 2868 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 2869 enqueue_clones_cb, &ds->ds_object, 2870 DS_FIND_CHILDREN)); 2871 } 2872 } 2873 2874 out: 2875 dsl_dataset_rele(ds, FTAG); 2876 } 2877 2878 static int 2879 enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 2880 { 2881 (void) arg; 2882 dsl_dataset_t *ds; 2883 int err; 2884 dsl_scan_t *scn = dp->dp_scan; 2885 2886 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 2887 if (err) 2888 return (err); 2889 2890 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 2891 dsl_dataset_t *prev; 2892 err = dsl_dataset_hold_obj(dp, 2893 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 2894 if (err) { 2895 dsl_dataset_rele(ds, FTAG); 2896 return (err); 2897 } 2898 2899 /* 2900 * If this is a clone, we don't need to worry about it for now. 2901 */ 2902 if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object) { 2903 dsl_dataset_rele(ds, FTAG); 2904 dsl_dataset_rele(prev, FTAG); 2905 return (0); 2906 } 2907 dsl_dataset_rele(ds, FTAG); 2908 ds = prev; 2909 } 2910 2911 scan_ds_queue_insert(scn, ds->ds_object, 2912 dsl_dataset_phys(ds)->ds_prev_snap_txg); 2913 dsl_dataset_rele(ds, FTAG); 2914 return (0); 2915 } 2916 2917 void 2918 dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum, 2919 ddt_entry_t *dde, dmu_tx_t *tx) 2920 { 2921 (void) tx; 2922 const ddt_key_t *ddk = &dde->dde_key; 2923 ddt_phys_t *ddp = dde->dde_phys; 2924 blkptr_t bp; 2925 zbookmark_phys_t zb = { 0 }; 2926 2927 if (!dsl_scan_is_running(scn)) 2928 return; 2929 2930 /* 2931 * This function is special because it is the only thing 2932 * that can add scan_io_t's to the vdev scan queues from 2933 * outside dsl_scan_sync(). For the most part this is ok 2934 * as long as it is called from within syncing context. 2935 * However, dsl_scan_sync() expects that no new sio's will 2936 * be added between when all the work for a scan is done 2937 * and the next txg when the scan is actually marked as 2938 * completed. This check ensures we do not issue new sio's 2939 * during this period. 2940 */ 2941 if (scn->scn_done_txg != 0) 2942 return; 2943 2944 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2945 if (ddp->ddp_phys_birth == 0 || 2946 ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg) 2947 continue; 2948 ddt_bp_create(checksum, ddk, ddp, &bp); 2949 2950 scn->scn_visited_this_txg++; 2951 scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb); 2952 } 2953 } 2954 2955 /* 2956 * Scrub/dedup interaction. 2957 * 2958 * If there are N references to a deduped block, we don't want to scrub it 2959 * N times -- ideally, we should scrub it exactly once. 2960 * 2961 * We leverage the fact that the dde's replication class (enum ddt_class) 2962 * is ordered from highest replication class (DDT_CLASS_DITTO) to lowest 2963 * (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order. 2964 * 2965 * To prevent excess scrubbing, the scrub begins by walking the DDT 2966 * to find all blocks with refcnt > 1, and scrubs each of these once. 2967 * Since there are two replication classes which contain blocks with 2968 * refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first. 2969 * Finally the top-down scrub begins, only visiting blocks with refcnt == 1. 2970 * 2971 * There would be nothing more to say if a block's refcnt couldn't change 2972 * during a scrub, but of course it can so we must account for changes 2973 * in a block's replication class. 2974 * 2975 * Here's an example of what can occur: 2976 * 2977 * If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1 2978 * when visited during the top-down scrub phase, it will be scrubbed twice. 2979 * This negates our scrub optimization, but is otherwise harmless. 2980 * 2981 * If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1 2982 * on each visit during the top-down scrub phase, it will never be scrubbed. 2983 * To catch this, ddt_sync_entry() notifies the scrub code whenever a block's 2984 * reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to 2985 * DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1 2986 * while a scrub is in progress, it scrubs the block right then. 2987 */ 2988 static void 2989 dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx) 2990 { 2991 ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark; 2992 ddt_entry_t dde = {{{{0}}}}; 2993 int error; 2994 uint64_t n = 0; 2995 2996 while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) { 2997 ddt_t *ddt; 2998 2999 if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max) 3000 break; 3001 dprintf("visiting ddb=%llu/%llu/%llu/%llx\n", 3002 (longlong_t)ddb->ddb_class, 3003 (longlong_t)ddb->ddb_type, 3004 (longlong_t)ddb->ddb_checksum, 3005 (longlong_t)ddb->ddb_cursor); 3006 3007 /* There should be no pending changes to the dedup table */ 3008 ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum]; 3009 ASSERT(avl_first(&ddt->ddt_tree) == NULL); 3010 3011 dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx); 3012 n++; 3013 3014 if (dsl_scan_check_suspend(scn, NULL)) 3015 break; 3016 } 3017 3018 zfs_dbgmsg("scanned %llu ddt entries on %s with class_max = %u; " 3019 "suspending=%u", (longlong_t)n, scn->scn_dp->dp_spa->spa_name, 3020 (int)scn->scn_phys.scn_ddt_class_max, (int)scn->scn_suspending); 3021 3022 ASSERT(error == 0 || error == ENOENT); 3023 ASSERT(error != ENOENT || 3024 ddb->ddb_class > scn->scn_phys.scn_ddt_class_max); 3025 } 3026 3027 static uint64_t 3028 dsl_scan_ds_maxtxg(dsl_dataset_t *ds) 3029 { 3030 uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg; 3031 if (ds->ds_is_snapshot) 3032 return (MIN(smt, dsl_dataset_phys(ds)->ds_creation_txg)); 3033 return (smt); 3034 } 3035 3036 static void 3037 dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx) 3038 { 3039 scan_ds_t *sds; 3040 dsl_pool_t *dp = scn->scn_dp; 3041 3042 if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= 3043 scn->scn_phys.scn_ddt_class_max) { 3044 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 3045 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 3046 dsl_scan_ddt(scn, tx); 3047 if (scn->scn_suspending) 3048 return; 3049 } 3050 3051 if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) { 3052 /* First do the MOS & ORIGIN */ 3053 3054 scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; 3055 scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; 3056 dsl_scan_visit_rootbp(scn, NULL, 3057 &dp->dp_meta_rootbp, tx); 3058 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); 3059 if (scn->scn_suspending) 3060 return; 3061 3062 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) { 3063 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 3064 enqueue_cb, NULL, DS_FIND_CHILDREN)); 3065 } else { 3066 dsl_scan_visitds(scn, 3067 dp->dp_origin_snap->ds_object, tx); 3068 } 3069 ASSERT(!scn->scn_suspending); 3070 } else if (scn->scn_phys.scn_bookmark.zb_objset != 3071 ZB_DESTROYED_OBJSET) { 3072 uint64_t dsobj = scn->scn_phys.scn_bookmark.zb_objset; 3073 /* 3074 * If we were suspended, continue from here. Note if the 3075 * ds we were suspended on was deleted, the zb_objset may 3076 * be -1, so we will skip this and find a new objset 3077 * below. 3078 */ 3079 dsl_scan_visitds(scn, dsobj, tx); 3080 if (scn->scn_suspending) 3081 return; 3082 } 3083 3084 /* 3085 * In case we suspended right at the end of the ds, zero the 3086 * bookmark so we don't think that we're still trying to resume. 3087 */ 3088 memset(&scn->scn_phys.scn_bookmark, 0, sizeof (zbookmark_phys_t)); 3089 3090 /* 3091 * Keep pulling things out of the dataset avl queue. Updates to the 3092 * persistent zap-object-as-queue happen only at checkpoints. 3093 */ 3094 while ((sds = avl_first(&scn->scn_queue)) != NULL) { 3095 dsl_dataset_t *ds; 3096 uint64_t dsobj = sds->sds_dsobj; 3097 uint64_t txg = sds->sds_txg; 3098 3099 /* dequeue and free the ds from the queue */ 3100 scan_ds_queue_remove(scn, dsobj); 3101 sds = NULL; 3102 3103 /* set up min / max txg */ 3104 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 3105 if (txg != 0) { 3106 scn->scn_phys.scn_cur_min_txg = 3107 MAX(scn->scn_phys.scn_min_txg, txg); 3108 } else { 3109 scn->scn_phys.scn_cur_min_txg = 3110 MAX(scn->scn_phys.scn_min_txg, 3111 dsl_dataset_phys(ds)->ds_prev_snap_txg); 3112 } 3113 scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds); 3114 dsl_dataset_rele(ds, FTAG); 3115 3116 dsl_scan_visitds(scn, dsobj, tx); 3117 if (scn->scn_suspending) 3118 return; 3119 } 3120 3121 /* No more objsets to fetch, we're done */ 3122 scn->scn_phys.scn_bookmark.zb_objset = ZB_DESTROYED_OBJSET; 3123 ASSERT0(scn->scn_suspending); 3124 } 3125 3126 static uint64_t 3127 dsl_scan_count_data_disks(spa_t *spa) 3128 { 3129 vdev_t *rvd = spa->spa_root_vdev; 3130 uint64_t i, leaves = 0; 3131 3132 for (i = 0; i < rvd->vdev_children; i++) { 3133 vdev_t *vd = rvd->vdev_child[i]; 3134 if (vd->vdev_islog || vd->vdev_isspare || vd->vdev_isl2cache) 3135 continue; 3136 leaves += vdev_get_ndisks(vd) - vdev_get_nparity(vd); 3137 } 3138 return (leaves); 3139 } 3140 3141 static void 3142 scan_io_queues_update_zio_stats(dsl_scan_io_queue_t *q, const blkptr_t *bp) 3143 { 3144 int i; 3145 uint64_t cur_size = 0; 3146 3147 for (i = 0; i < BP_GET_NDVAS(bp); i++) { 3148 cur_size += DVA_GET_ASIZE(&bp->blk_dva[i]); 3149 } 3150 3151 q->q_total_zio_size_this_txg += cur_size; 3152 q->q_zios_this_txg++; 3153 } 3154 3155 static void 3156 scan_io_queues_update_seg_stats(dsl_scan_io_queue_t *q, uint64_t start, 3157 uint64_t end) 3158 { 3159 q->q_total_seg_size_this_txg += end - start; 3160 q->q_segs_this_txg++; 3161 } 3162 3163 static boolean_t 3164 scan_io_queue_check_suspend(dsl_scan_t *scn) 3165 { 3166 /* See comment in dsl_scan_check_suspend() */ 3167 uint64_t curr_time_ns = gethrtime(); 3168 uint64_t scan_time_ns = curr_time_ns - scn->scn_sync_start_time; 3169 uint64_t sync_time_ns = curr_time_ns - 3170 scn->scn_dp->dp_spa->spa_sync_starttime; 3171 uint64_t dirty_min_bytes = zfs_dirty_data_max * 3172 zfs_vdev_async_write_active_min_dirty_percent / 100; 3173 uint_t mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ? 3174 zfs_resilver_min_time_ms : zfs_scrub_min_time_ms; 3175 3176 return ((NSEC2MSEC(scan_time_ns) > mintime && 3177 (scn->scn_dp->dp_dirty_total >= dirty_min_bytes || 3178 txg_sync_waiting(scn->scn_dp) || 3179 NSEC2SEC(sync_time_ns) >= zfs_txg_timeout)) || 3180 spa_shutting_down(scn->scn_dp->dp_spa)); 3181 } 3182 3183 /* 3184 * Given a list of scan_io_t's in io_list, this issues the I/Os out to 3185 * disk. This consumes the io_list and frees the scan_io_t's. This is 3186 * called when emptying queues, either when we're up against the memory 3187 * limit or when we have finished scanning. Returns B_TRUE if we stopped 3188 * processing the list before we finished. Any sios that were not issued 3189 * will remain in the io_list. 3190 */ 3191 static boolean_t 3192 scan_io_queue_issue(dsl_scan_io_queue_t *queue, list_t *io_list) 3193 { 3194 dsl_scan_t *scn = queue->q_scn; 3195 scan_io_t *sio; 3196 boolean_t suspended = B_FALSE; 3197 3198 while ((sio = list_head(io_list)) != NULL) { 3199 blkptr_t bp; 3200 3201 if (scan_io_queue_check_suspend(scn)) { 3202 suspended = B_TRUE; 3203 break; 3204 } 3205 3206 sio2bp(sio, &bp); 3207 scan_exec_io(scn->scn_dp, &bp, sio->sio_flags, 3208 &sio->sio_zb, queue); 3209 (void) list_remove_head(io_list); 3210 scan_io_queues_update_zio_stats(queue, &bp); 3211 sio_free(sio); 3212 } 3213 return (suspended); 3214 } 3215 3216 /* 3217 * This function removes sios from an IO queue which reside within a given 3218 * range_seg_t and inserts them (in offset order) into a list. Note that 3219 * we only ever return a maximum of 32 sios at once. If there are more sios 3220 * to process within this segment that did not make it onto the list we 3221 * return B_TRUE and otherwise B_FALSE. 3222 */ 3223 static boolean_t 3224 scan_io_queue_gather(dsl_scan_io_queue_t *queue, range_seg_t *rs, list_t *list) 3225 { 3226 scan_io_t *srch_sio, *sio, *next_sio; 3227 avl_index_t idx; 3228 uint_t num_sios = 0; 3229 int64_t bytes_issued = 0; 3230 3231 ASSERT(rs != NULL); 3232 ASSERT(MUTEX_HELD(&queue->q_vd->vdev_scan_io_queue_lock)); 3233 3234 srch_sio = sio_alloc(1); 3235 srch_sio->sio_nr_dvas = 1; 3236 SIO_SET_OFFSET(srch_sio, rs_get_start(rs, queue->q_exts_by_addr)); 3237 3238 /* 3239 * The exact start of the extent might not contain any matching zios, 3240 * so if that's the case, examine the next one in the tree. 3241 */ 3242 sio = avl_find(&queue->q_sios_by_addr, srch_sio, &idx); 3243 sio_free(srch_sio); 3244 3245 if (sio == NULL) 3246 sio = avl_nearest(&queue->q_sios_by_addr, idx, AVL_AFTER); 3247 3248 while (sio != NULL && SIO_GET_OFFSET(sio) < rs_get_end(rs, 3249 queue->q_exts_by_addr) && num_sios <= 32) { 3250 ASSERT3U(SIO_GET_OFFSET(sio), >=, rs_get_start(rs, 3251 queue->q_exts_by_addr)); 3252 ASSERT3U(SIO_GET_END_OFFSET(sio), <=, rs_get_end(rs, 3253 queue->q_exts_by_addr)); 3254 3255 next_sio = AVL_NEXT(&queue->q_sios_by_addr, sio); 3256 avl_remove(&queue->q_sios_by_addr, sio); 3257 if (avl_is_empty(&queue->q_sios_by_addr)) 3258 atomic_add_64(&queue->q_scn->scn_queues_pending, -1); 3259 queue->q_sio_memused -= SIO_GET_MUSED(sio); 3260 3261 bytes_issued += SIO_GET_ASIZE(sio); 3262 num_sios++; 3263 list_insert_tail(list, sio); 3264 sio = next_sio; 3265 } 3266 3267 /* 3268 * We limit the number of sios we process at once to 32 to avoid 3269 * biting off more than we can chew. If we didn't take everything 3270 * in the segment we update it to reflect the work we were able to 3271 * complete. Otherwise, we remove it from the range tree entirely. 3272 */ 3273 if (sio != NULL && SIO_GET_OFFSET(sio) < rs_get_end(rs, 3274 queue->q_exts_by_addr)) { 3275 range_tree_adjust_fill(queue->q_exts_by_addr, rs, 3276 -bytes_issued); 3277 range_tree_resize_segment(queue->q_exts_by_addr, rs, 3278 SIO_GET_OFFSET(sio), rs_get_end(rs, 3279 queue->q_exts_by_addr) - SIO_GET_OFFSET(sio)); 3280 queue->q_last_ext_addr = SIO_GET_OFFSET(sio); 3281 return (B_TRUE); 3282 } else { 3283 uint64_t rstart = rs_get_start(rs, queue->q_exts_by_addr); 3284 uint64_t rend = rs_get_end(rs, queue->q_exts_by_addr); 3285 range_tree_remove(queue->q_exts_by_addr, rstart, rend - rstart); 3286 queue->q_last_ext_addr = -1; 3287 return (B_FALSE); 3288 } 3289 } 3290 3291 /* 3292 * This is called from the queue emptying thread and selects the next 3293 * extent from which we are to issue I/Os. The behavior of this function 3294 * depends on the state of the scan, the current memory consumption and 3295 * whether or not we are performing a scan shutdown. 3296 * 1) We select extents in an elevator algorithm (LBA-order) if the scan 3297 * needs to perform a checkpoint 3298 * 2) We select the largest available extent if we are up against the 3299 * memory limit. 3300 * 3) Otherwise we don't select any extents. 3301 */ 3302 static range_seg_t * 3303 scan_io_queue_fetch_ext(dsl_scan_io_queue_t *queue) 3304 { 3305 dsl_scan_t *scn = queue->q_scn; 3306 range_tree_t *rt = queue->q_exts_by_addr; 3307 3308 ASSERT(MUTEX_HELD(&queue->q_vd->vdev_scan_io_queue_lock)); 3309 ASSERT(scn->scn_is_sorted); 3310 3311 if (!scn->scn_checkpointing && !scn->scn_clearing) 3312 return (NULL); 3313 3314 /* 3315 * During normal clearing, we want to issue our largest segments 3316 * first, keeping IO as sequential as possible, and leaving the 3317 * smaller extents for later with the hope that they might eventually 3318 * grow to larger sequential segments. However, when the scan is 3319 * checkpointing, no new extents will be added to the sorting queue, 3320 * so the way we are sorted now is as good as it will ever get. 3321 * In this case, we instead switch to issuing extents in LBA order. 3322 */ 3323 if ((zfs_scan_issue_strategy < 1 && scn->scn_checkpointing) || 3324 zfs_scan_issue_strategy == 1) 3325 return (range_tree_first(rt)); 3326 3327 /* 3328 * Try to continue previous extent if it is not completed yet. After 3329 * shrink in scan_io_queue_gather() it may no longer be the best, but 3330 * otherwise we leave shorter remnant every txg. 3331 */ 3332 uint64_t start; 3333 uint64_t size = 1ULL << rt->rt_shift; 3334 range_seg_t *addr_rs; 3335 if (queue->q_last_ext_addr != -1) { 3336 start = queue->q_last_ext_addr; 3337 addr_rs = range_tree_find(rt, start, size); 3338 if (addr_rs != NULL) 3339 return (addr_rs); 3340 } 3341 3342 /* 3343 * Nothing to continue, so find new best extent. 3344 */ 3345 uint64_t *v = zfs_btree_first(&queue->q_exts_by_size, NULL); 3346 if (v == NULL) 3347 return (NULL); 3348 queue->q_last_ext_addr = start = *v << rt->rt_shift; 3349 3350 /* 3351 * We need to get the original entry in the by_addr tree so we can 3352 * modify it. 3353 */ 3354 addr_rs = range_tree_find(rt, start, size); 3355 ASSERT3P(addr_rs, !=, NULL); 3356 ASSERT3U(rs_get_start(addr_rs, rt), ==, start); 3357 ASSERT3U(rs_get_end(addr_rs, rt), >, start); 3358 return (addr_rs); 3359 } 3360 3361 static void 3362 scan_io_queues_run_one(void *arg) 3363 { 3364 dsl_scan_io_queue_t *queue = arg; 3365 kmutex_t *q_lock = &queue->q_vd->vdev_scan_io_queue_lock; 3366 boolean_t suspended = B_FALSE; 3367 range_seg_t *rs; 3368 scan_io_t *sio; 3369 zio_t *zio; 3370 list_t sio_list; 3371 3372 ASSERT(queue->q_scn->scn_is_sorted); 3373 3374 list_create(&sio_list, sizeof (scan_io_t), 3375 offsetof(scan_io_t, sio_nodes.sio_list_node)); 3376 zio = zio_null(queue->q_scn->scn_zio_root, queue->q_scn->scn_dp->dp_spa, 3377 NULL, NULL, NULL, ZIO_FLAG_CANFAIL); 3378 mutex_enter(q_lock); 3379 queue->q_zio = zio; 3380 3381 /* Calculate maximum in-flight bytes for this vdev. */ 3382 queue->q_maxinflight_bytes = MAX(1, zfs_scan_vdev_limit * 3383 (vdev_get_ndisks(queue->q_vd) - vdev_get_nparity(queue->q_vd))); 3384 3385 /* reset per-queue scan statistics for this txg */ 3386 queue->q_total_seg_size_this_txg = 0; 3387 queue->q_segs_this_txg = 0; 3388 queue->q_total_zio_size_this_txg = 0; 3389 queue->q_zios_this_txg = 0; 3390 3391 /* loop until we run out of time or sios */ 3392 while ((rs = scan_io_queue_fetch_ext(queue)) != NULL) { 3393 uint64_t seg_start = 0, seg_end = 0; 3394 boolean_t more_left; 3395 3396 ASSERT(list_is_empty(&sio_list)); 3397 3398 /* loop while we still have sios left to process in this rs */ 3399 do { 3400 scan_io_t *first_sio, *last_sio; 3401 3402 /* 3403 * We have selected which extent needs to be 3404 * processed next. Gather up the corresponding sios. 3405 */ 3406 more_left = scan_io_queue_gather(queue, rs, &sio_list); 3407 ASSERT(!list_is_empty(&sio_list)); 3408 first_sio = list_head(&sio_list); 3409 last_sio = list_tail(&sio_list); 3410 3411 seg_end = SIO_GET_END_OFFSET(last_sio); 3412 if (seg_start == 0) 3413 seg_start = SIO_GET_OFFSET(first_sio); 3414 3415 /* 3416 * Issuing sios can take a long time so drop the 3417 * queue lock. The sio queue won't be updated by 3418 * other threads since we're in syncing context so 3419 * we can be sure that our trees will remain exactly 3420 * as we left them. 3421 */ 3422 mutex_exit(q_lock); 3423 suspended = scan_io_queue_issue(queue, &sio_list); 3424 mutex_enter(q_lock); 3425 3426 if (suspended) 3427 break; 3428 } while (more_left); 3429 3430 /* update statistics for debugging purposes */ 3431 scan_io_queues_update_seg_stats(queue, seg_start, seg_end); 3432 3433 if (suspended) 3434 break; 3435 } 3436 3437 /* 3438 * If we were suspended in the middle of processing, 3439 * requeue any unfinished sios and exit. 3440 */ 3441 while ((sio = list_remove_head(&sio_list)) != NULL) 3442 scan_io_queue_insert_impl(queue, sio); 3443 3444 queue->q_zio = NULL; 3445 mutex_exit(q_lock); 3446 zio_nowait(zio); 3447 list_destroy(&sio_list); 3448 } 3449 3450 /* 3451 * Performs an emptying run on all scan queues in the pool. This just 3452 * punches out one thread per top-level vdev, each of which processes 3453 * only that vdev's scan queue. We can parallelize the I/O here because 3454 * we know that each queue's I/Os only affect its own top-level vdev. 3455 * 3456 * This function waits for the queue runs to complete, and must be 3457 * called from dsl_scan_sync (or in general, syncing context). 3458 */ 3459 static void 3460 scan_io_queues_run(dsl_scan_t *scn) 3461 { 3462 spa_t *spa = scn->scn_dp->dp_spa; 3463 3464 ASSERT(scn->scn_is_sorted); 3465 ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER)); 3466 3467 if (scn->scn_queues_pending == 0) 3468 return; 3469 3470 if (scn->scn_taskq == NULL) { 3471 int nthreads = spa->spa_root_vdev->vdev_children; 3472 3473 /* 3474 * We need to make this taskq *always* execute as many 3475 * threads in parallel as we have top-level vdevs and no 3476 * less, otherwise strange serialization of the calls to 3477 * scan_io_queues_run_one can occur during spa_sync runs 3478 * and that significantly impacts performance. 3479 */ 3480 scn->scn_taskq = taskq_create("dsl_scan_iss", nthreads, 3481 minclsyspri, nthreads, nthreads, TASKQ_PREPOPULATE); 3482 } 3483 3484 for (uint64_t i = 0; i < spa->spa_root_vdev->vdev_children; i++) { 3485 vdev_t *vd = spa->spa_root_vdev->vdev_child[i]; 3486 3487 mutex_enter(&vd->vdev_scan_io_queue_lock); 3488 if (vd->vdev_scan_io_queue != NULL) { 3489 VERIFY(taskq_dispatch(scn->scn_taskq, 3490 scan_io_queues_run_one, vd->vdev_scan_io_queue, 3491 TQ_SLEEP) != TASKQID_INVALID); 3492 } 3493 mutex_exit(&vd->vdev_scan_io_queue_lock); 3494 } 3495 3496 /* 3497 * Wait for the queues to finish issuing their IOs for this run 3498 * before we return. There may still be IOs in flight at this 3499 * point. 3500 */ 3501 taskq_wait(scn->scn_taskq); 3502 } 3503 3504 static boolean_t 3505 dsl_scan_async_block_should_pause(dsl_scan_t *scn) 3506 { 3507 uint64_t elapsed_nanosecs; 3508 3509 if (zfs_recover) 3510 return (B_FALSE); 3511 3512 if (zfs_async_block_max_blocks != 0 && 3513 scn->scn_visited_this_txg >= zfs_async_block_max_blocks) { 3514 return (B_TRUE); 3515 } 3516 3517 if (zfs_max_async_dedup_frees != 0 && 3518 scn->scn_dedup_frees_this_txg >= zfs_max_async_dedup_frees) { 3519 return (B_TRUE); 3520 } 3521 3522 elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; 3523 return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || 3524 (NSEC2MSEC(elapsed_nanosecs) > scn->scn_async_block_min_time_ms && 3525 txg_sync_waiting(scn->scn_dp)) || 3526 spa_shutting_down(scn->scn_dp->dp_spa)); 3527 } 3528 3529 static int 3530 dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 3531 { 3532 dsl_scan_t *scn = arg; 3533 3534 if (!scn->scn_is_bptree || 3535 (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) { 3536 if (dsl_scan_async_block_should_pause(scn)) 3537 return (SET_ERROR(ERESTART)); 3538 } 3539 3540 zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa, 3541 dmu_tx_get_txg(tx), bp, 0)); 3542 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD, 3543 -bp_get_dsize_sync(scn->scn_dp->dp_spa, bp), 3544 -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx); 3545 scn->scn_visited_this_txg++; 3546 if (BP_GET_DEDUP(bp)) 3547 scn->scn_dedup_frees_this_txg++; 3548 return (0); 3549 } 3550 3551 static void 3552 dsl_scan_update_stats(dsl_scan_t *scn) 3553 { 3554 spa_t *spa = scn->scn_dp->dp_spa; 3555 uint64_t i; 3556 uint64_t seg_size_total = 0, zio_size_total = 0; 3557 uint64_t seg_count_total = 0, zio_count_total = 0; 3558 3559 for (i = 0; i < spa->spa_root_vdev->vdev_children; i++) { 3560 vdev_t *vd = spa->spa_root_vdev->vdev_child[i]; 3561 dsl_scan_io_queue_t *queue = vd->vdev_scan_io_queue; 3562 3563 if (queue == NULL) 3564 continue; 3565 3566 seg_size_total += queue->q_total_seg_size_this_txg; 3567 zio_size_total += queue->q_total_zio_size_this_txg; 3568 seg_count_total += queue->q_segs_this_txg; 3569 zio_count_total += queue->q_zios_this_txg; 3570 } 3571 3572 if (seg_count_total == 0 || zio_count_total == 0) { 3573 scn->scn_avg_seg_size_this_txg = 0; 3574 scn->scn_avg_zio_size_this_txg = 0; 3575 scn->scn_segs_this_txg = 0; 3576 scn->scn_zios_this_txg = 0; 3577 return; 3578 } 3579 3580 scn->scn_avg_seg_size_this_txg = seg_size_total / seg_count_total; 3581 scn->scn_avg_zio_size_this_txg = zio_size_total / zio_count_total; 3582 scn->scn_segs_this_txg = seg_count_total; 3583 scn->scn_zios_this_txg = zio_count_total; 3584 } 3585 3586 static int 3587 bpobj_dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed, 3588 dmu_tx_t *tx) 3589 { 3590 ASSERT(!bp_freed); 3591 return (dsl_scan_free_block_cb(arg, bp, tx)); 3592 } 3593 3594 static int 3595 dsl_scan_obsolete_block_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed, 3596 dmu_tx_t *tx) 3597 { 3598 ASSERT(!bp_freed); 3599 dsl_scan_t *scn = arg; 3600 const dva_t *dva = &bp->blk_dva[0]; 3601 3602 if (dsl_scan_async_block_should_pause(scn)) 3603 return (SET_ERROR(ERESTART)); 3604 3605 spa_vdev_indirect_mark_obsolete(scn->scn_dp->dp_spa, 3606 DVA_GET_VDEV(dva), DVA_GET_OFFSET(dva), 3607 DVA_GET_ASIZE(dva), tx); 3608 scn->scn_visited_this_txg++; 3609 return (0); 3610 } 3611 3612 boolean_t 3613 dsl_scan_active(dsl_scan_t *scn) 3614 { 3615 spa_t *spa = scn->scn_dp->dp_spa; 3616 uint64_t used = 0, comp, uncomp; 3617 boolean_t clones_left; 3618 3619 if (spa->spa_load_state != SPA_LOAD_NONE) 3620 return (B_FALSE); 3621 if (spa_shutting_down(spa)) 3622 return (B_FALSE); 3623 if ((dsl_scan_is_running(scn) && !dsl_scan_is_paused_scrub(scn)) || 3624 (scn->scn_async_destroying && !scn->scn_async_stalled)) 3625 return (B_TRUE); 3626 3627 if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 3628 (void) bpobj_space(&scn->scn_dp->dp_free_bpobj, 3629 &used, &comp, &uncomp); 3630 } 3631 clones_left = spa_livelist_delete_check(spa); 3632 return ((used != 0) || (clones_left)); 3633 } 3634 3635 boolean_t 3636 dsl_errorscrub_active(dsl_scan_t *scn) 3637 { 3638 spa_t *spa = scn->scn_dp->dp_spa; 3639 if (spa->spa_load_state != SPA_LOAD_NONE) 3640 return (B_FALSE); 3641 if (spa_shutting_down(spa)) 3642 return (B_FALSE); 3643 if (dsl_errorscrubbing(scn->scn_dp)) 3644 return (B_TRUE); 3645 return (B_FALSE); 3646 } 3647 3648 static boolean_t 3649 dsl_scan_check_deferred(vdev_t *vd) 3650 { 3651 boolean_t need_resilver = B_FALSE; 3652 3653 for (int c = 0; c < vd->vdev_children; c++) { 3654 need_resilver |= 3655 dsl_scan_check_deferred(vd->vdev_child[c]); 3656 } 3657 3658 if (!vdev_is_concrete(vd) || vd->vdev_aux || 3659 !vd->vdev_ops->vdev_op_leaf) 3660 return (need_resilver); 3661 3662 if (!vd->vdev_resilver_deferred) 3663 need_resilver = B_TRUE; 3664 3665 return (need_resilver); 3666 } 3667 3668 static boolean_t 3669 dsl_scan_need_resilver(spa_t *spa, const dva_t *dva, size_t psize, 3670 uint64_t phys_birth) 3671 { 3672 vdev_t *vd; 3673 3674 vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); 3675 3676 if (vd->vdev_ops == &vdev_indirect_ops) { 3677 /* 3678 * The indirect vdev can point to multiple 3679 * vdevs. For simplicity, always create 3680 * the resilver zio_t. zio_vdev_io_start() 3681 * will bypass the child resilver i/o's if 3682 * they are on vdevs that don't have DTL's. 3683 */ 3684 return (B_TRUE); 3685 } 3686 3687 if (DVA_GET_GANG(dva)) { 3688 /* 3689 * Gang members may be spread across multiple 3690 * vdevs, so the best estimate we have is the 3691 * scrub range, which has already been checked. 3692 * XXX -- it would be better to change our 3693 * allocation policy to ensure that all 3694 * gang members reside on the same vdev. 3695 */ 3696 return (B_TRUE); 3697 } 3698 3699 /* 3700 * Check if the top-level vdev must resilver this offset. 3701 * When the offset does not intersect with a dirty leaf DTL 3702 * then it may be possible to skip the resilver IO. The psize 3703 * is provided instead of asize to simplify the check for RAIDZ. 3704 */ 3705 if (!vdev_dtl_need_resilver(vd, dva, psize, phys_birth)) 3706 return (B_FALSE); 3707 3708 /* 3709 * Check that this top-level vdev has a device under it which 3710 * is resilvering and is not deferred. 3711 */ 3712 if (!dsl_scan_check_deferred(vd)) 3713 return (B_FALSE); 3714 3715 return (B_TRUE); 3716 } 3717 3718 static int 3719 dsl_process_async_destroys(dsl_pool_t *dp, dmu_tx_t *tx) 3720 { 3721 dsl_scan_t *scn = dp->dp_scan; 3722 spa_t *spa = dp->dp_spa; 3723 int err = 0; 3724 3725 if (spa_suspend_async_destroy(spa)) 3726 return (0); 3727 3728 if (zfs_free_bpobj_enabled && 3729 spa_version(spa) >= SPA_VERSION_DEADLISTS) { 3730 scn->scn_is_bptree = B_FALSE; 3731 scn->scn_async_block_min_time_ms = zfs_free_min_time_ms; 3732 scn->scn_zio_root = zio_root(spa, NULL, 3733 NULL, ZIO_FLAG_MUSTSUCCEED); 3734 err = bpobj_iterate(&dp->dp_free_bpobj, 3735 bpobj_dsl_scan_free_block_cb, scn, tx); 3736 VERIFY0(zio_wait(scn->scn_zio_root)); 3737 scn->scn_zio_root = NULL; 3738 3739 if (err != 0 && err != ERESTART) 3740 zfs_panic_recover("error %u from bpobj_iterate()", err); 3741 } 3742 3743 if (err == 0 && spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY)) { 3744 ASSERT(scn->scn_async_destroying); 3745 scn->scn_is_bptree = B_TRUE; 3746 scn->scn_zio_root = zio_root(spa, NULL, 3747 NULL, ZIO_FLAG_MUSTSUCCEED); 3748 err = bptree_iterate(dp->dp_meta_objset, 3749 dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, scn, tx); 3750 VERIFY0(zio_wait(scn->scn_zio_root)); 3751 scn->scn_zio_root = NULL; 3752 3753 if (err == EIO || err == ECKSUM) { 3754 err = 0; 3755 } else if (err != 0 && err != ERESTART) { 3756 zfs_panic_recover("error %u from " 3757 "traverse_dataset_destroyed()", err); 3758 } 3759 3760 if (bptree_is_empty(dp->dp_meta_objset, dp->dp_bptree_obj)) { 3761 /* finished; deactivate async destroy feature */ 3762 spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, tx); 3763 ASSERT(!spa_feature_is_active(spa, 3764 SPA_FEATURE_ASYNC_DESTROY)); 3765 VERIFY0(zap_remove(dp->dp_meta_objset, 3766 DMU_POOL_DIRECTORY_OBJECT, 3767 DMU_POOL_BPTREE_OBJ, tx)); 3768 VERIFY0(bptree_free(dp->dp_meta_objset, 3769 dp->dp_bptree_obj, tx)); 3770 dp->dp_bptree_obj = 0; 3771 scn->scn_async_destroying = B_FALSE; 3772 scn->scn_async_stalled = B_FALSE; 3773 } else { 3774 /* 3775 * If we didn't make progress, mark the async 3776 * destroy as stalled, so that we will not initiate 3777 * a spa_sync() on its behalf. Note that we only 3778 * check this if we are not finished, because if the 3779 * bptree had no blocks for us to visit, we can 3780 * finish without "making progress". 3781 */ 3782 scn->scn_async_stalled = 3783 (scn->scn_visited_this_txg == 0); 3784 } 3785 } 3786 if (scn->scn_visited_this_txg) { 3787 zfs_dbgmsg("freed %llu blocks in %llums from " 3788 "free_bpobj/bptree on %s in txg %llu; err=%u", 3789 (longlong_t)scn->scn_visited_this_txg, 3790 (longlong_t) 3791 NSEC2MSEC(gethrtime() - scn->scn_sync_start_time), 3792 spa->spa_name, (longlong_t)tx->tx_txg, err); 3793 scn->scn_visited_this_txg = 0; 3794 scn->scn_dedup_frees_this_txg = 0; 3795 3796 /* 3797 * Write out changes to the DDT and the BRT that may be required 3798 * as a result of the blocks freed. This ensures that the DDT 3799 * and the BRT are clean when a scrub/resilver runs. 3800 */ 3801 ddt_sync(spa, tx->tx_txg); 3802 brt_sync(spa, tx->tx_txg); 3803 } 3804 if (err != 0) 3805 return (err); 3806 if (dp->dp_free_dir != NULL && !scn->scn_async_destroying && 3807 zfs_free_leak_on_eio && 3808 (dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes != 0 || 3809 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes != 0 || 3810 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes != 0)) { 3811 /* 3812 * We have finished background destroying, but there is still 3813 * some space left in the dp_free_dir. Transfer this leaked 3814 * space to the dp_leak_dir. 3815 */ 3816 if (dp->dp_leak_dir == NULL) { 3817 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); 3818 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, 3819 LEAK_DIR_NAME, tx); 3820 VERIFY0(dsl_pool_open_special_dir(dp, 3821 LEAK_DIR_NAME, &dp->dp_leak_dir)); 3822 rrw_exit(&dp->dp_config_rwlock, FTAG); 3823 } 3824 dsl_dir_diduse_space(dp->dp_leak_dir, DD_USED_HEAD, 3825 dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 3826 dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 3827 dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 3828 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 3829 -dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes, 3830 -dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes, 3831 -dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes, tx); 3832 } 3833 3834 if (dp->dp_free_dir != NULL && !scn->scn_async_destroying && 3835 !spa_livelist_delete_check(spa)) { 3836 /* finished; verify that space accounting went to zero */ 3837 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_used_bytes); 3838 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_compressed_bytes); 3839 ASSERT0(dsl_dir_phys(dp->dp_free_dir)->dd_uncompressed_bytes); 3840 } 3841 3842 spa_notify_waiters(spa); 3843 3844 EQUIV(bpobj_is_open(&dp->dp_obsolete_bpobj), 3845 0 == zap_contains(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 3846 DMU_POOL_OBSOLETE_BPOBJ)); 3847 if (err == 0 && bpobj_is_open(&dp->dp_obsolete_bpobj)) { 3848 ASSERT(spa_feature_is_active(dp->dp_spa, 3849 SPA_FEATURE_OBSOLETE_COUNTS)); 3850 3851 scn->scn_is_bptree = B_FALSE; 3852 scn->scn_async_block_min_time_ms = zfs_obsolete_min_time_ms; 3853 err = bpobj_iterate(&dp->dp_obsolete_bpobj, 3854 dsl_scan_obsolete_block_cb, scn, tx); 3855 if (err != 0 && err != ERESTART) 3856 zfs_panic_recover("error %u from bpobj_iterate()", err); 3857 3858 if (bpobj_is_empty(&dp->dp_obsolete_bpobj)) 3859 dsl_pool_destroy_obsolete_bpobj(dp, tx); 3860 } 3861 return (0); 3862 } 3863 3864 static void 3865 name_to_bookmark(char *buf, zbookmark_phys_t *zb) 3866 { 3867 zb->zb_objset = zfs_strtonum(buf, &buf); 3868 ASSERT(*buf == ':'); 3869 zb->zb_object = zfs_strtonum(buf + 1, &buf); 3870 ASSERT(*buf == ':'); 3871 zb->zb_level = (int)zfs_strtonum(buf + 1, &buf); 3872 ASSERT(*buf == ':'); 3873 zb->zb_blkid = zfs_strtonum(buf + 1, &buf); 3874 ASSERT(*buf == '\0'); 3875 } 3876 3877 static void 3878 name_to_object(char *buf, uint64_t *obj) 3879 { 3880 *obj = zfs_strtonum(buf, &buf); 3881 ASSERT(*buf == '\0'); 3882 } 3883 3884 static void 3885 read_by_block_level(dsl_scan_t *scn, zbookmark_phys_t zb) 3886 { 3887 dsl_pool_t *dp = scn->scn_dp; 3888 dsl_dataset_t *ds; 3889 objset_t *os; 3890 if (dsl_dataset_hold_obj(dp, zb.zb_objset, FTAG, &ds) != 0) 3891 return; 3892 3893 if (dmu_objset_from_ds(ds, &os) != 0) { 3894 dsl_dataset_rele(ds, FTAG); 3895 return; 3896 } 3897 3898 /* 3899 * If the key is not loaded dbuf_dnode_findbp() will error out with 3900 * EACCES. However in that case dnode_hold() will eventually call 3901 * dbuf_read()->zio_wait() which may call spa_log_error(). This will 3902 * lead to a deadlock due to us holding the mutex spa_errlist_lock. 3903 * Avoid this by checking here if the keys are loaded, if not return. 3904 * If the keys are not loaded the head_errlog feature is meaningless 3905 * as we cannot figure out the birth txg of the block pointer. 3906 */ 3907 if (dsl_dataset_get_keystatus(ds->ds_dir) == 3908 ZFS_KEYSTATUS_UNAVAILABLE) { 3909 dsl_dataset_rele(ds, FTAG); 3910 return; 3911 } 3912 3913 dnode_t *dn; 3914 blkptr_t bp; 3915 3916 if (dnode_hold(os, zb.zb_object, FTAG, &dn) != 0) { 3917 dsl_dataset_rele(ds, FTAG); 3918 return; 3919 } 3920 3921 rw_enter(&dn->dn_struct_rwlock, RW_READER); 3922 int error = dbuf_dnode_findbp(dn, zb.zb_level, zb.zb_blkid, &bp, NULL, 3923 NULL); 3924 3925 if (error) { 3926 rw_exit(&dn->dn_struct_rwlock); 3927 dnode_rele(dn, FTAG); 3928 dsl_dataset_rele(ds, FTAG); 3929 return; 3930 } 3931 3932 if (!error && BP_IS_HOLE(&bp)) { 3933 rw_exit(&dn->dn_struct_rwlock); 3934 dnode_rele(dn, FTAG); 3935 dsl_dataset_rele(ds, FTAG); 3936 return; 3937 } 3938 3939 int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | 3940 ZIO_FLAG_CANFAIL | ZIO_FLAG_SCRUB; 3941 3942 /* If it's an intent log block, failure is expected. */ 3943 if (zb.zb_level == ZB_ZIL_LEVEL) 3944 zio_flags |= ZIO_FLAG_SPECULATIVE; 3945 3946 ASSERT(!BP_IS_EMBEDDED(&bp)); 3947 scan_exec_io(dp, &bp, zio_flags, &zb, NULL); 3948 rw_exit(&dn->dn_struct_rwlock); 3949 dnode_rele(dn, FTAG); 3950 dsl_dataset_rele(ds, FTAG); 3951 } 3952 3953 /* 3954 * We keep track of the scrubbed error blocks in "count". This will be used 3955 * when deciding whether we exceeded zfs_scrub_error_blocks_per_txg. This 3956 * function is modelled after check_filesystem(). 3957 */ 3958 static int 3959 scrub_filesystem(spa_t *spa, uint64_t fs, zbookmark_err_phys_t *zep, 3960 int *count) 3961 { 3962 dsl_dataset_t *ds; 3963 dsl_pool_t *dp = spa->spa_dsl_pool; 3964 dsl_scan_t *scn = dp->dp_scan; 3965 3966 int error = dsl_dataset_hold_obj(dp, fs, FTAG, &ds); 3967 if (error != 0) 3968 return (error); 3969 3970 uint64_t latest_txg; 3971 uint64_t txg_to_consider = spa->spa_syncing_txg; 3972 boolean_t check_snapshot = B_TRUE; 3973 3974 error = find_birth_txg(ds, zep, &latest_txg); 3975 3976 /* 3977 * If find_birth_txg() errors out, then err on the side of caution and 3978 * proceed. In worst case scenario scrub all objects. If zep->zb_birth 3979 * is 0 (e.g. in case of encryption with unloaded keys) also proceed to 3980 * scrub all objects. 3981 */ 3982 if (error == 0 && zep->zb_birth == latest_txg) { 3983 /* Block neither free nor re written. */ 3984 zbookmark_phys_t zb; 3985 zep_to_zb(fs, zep, &zb); 3986 scn->scn_zio_root = zio_root(spa, NULL, NULL, 3987 ZIO_FLAG_CANFAIL); 3988 /* We have already acquired the config lock for spa */ 3989 read_by_block_level(scn, zb); 3990 3991 (void) zio_wait(scn->scn_zio_root); 3992 scn->scn_zio_root = NULL; 3993 3994 scn->errorscrub_phys.dep_examined++; 3995 scn->errorscrub_phys.dep_to_examine--; 3996 (*count)++; 3997 if ((*count) == zfs_scrub_error_blocks_per_txg || 3998 dsl_error_scrub_check_suspend(scn, &zb)) { 3999 dsl_dataset_rele(ds, FTAG); 4000 return (SET_ERROR(EFAULT)); 4001 } 4002 4003 check_snapshot = B_FALSE; 4004 } else if (error == 0) { 4005 txg_to_consider = latest_txg; 4006 } 4007 4008 /* 4009 * Retrieve the number of snapshots if the dataset is not a snapshot. 4010 */ 4011 uint64_t snap_count = 0; 4012 if (dsl_dataset_phys(ds)->ds_snapnames_zapobj != 0) { 4013 4014 error = zap_count(spa->spa_meta_objset, 4015 dsl_dataset_phys(ds)->ds_snapnames_zapobj, &snap_count); 4016 4017 if (error != 0) { 4018 dsl_dataset_rele(ds, FTAG); 4019 return (error); 4020 } 4021 } 4022 4023 if (snap_count == 0) { 4024 /* Filesystem without snapshots. */ 4025 dsl_dataset_rele(ds, FTAG); 4026 return (0); 4027 } 4028 4029 uint64_t snap_obj = dsl_dataset_phys(ds)->ds_prev_snap_obj; 4030 uint64_t snap_obj_txg = dsl_dataset_phys(ds)->ds_prev_snap_txg; 4031 4032 dsl_dataset_rele(ds, FTAG); 4033 4034 /* Check only snapshots created from this file system. */ 4035 while (snap_obj != 0 && zep->zb_birth < snap_obj_txg && 4036 snap_obj_txg <= txg_to_consider) { 4037 4038 error = dsl_dataset_hold_obj(dp, snap_obj, FTAG, &ds); 4039 if (error != 0) 4040 return (error); 4041 4042 if (dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj != fs) { 4043 snap_obj = dsl_dataset_phys(ds)->ds_prev_snap_obj; 4044 snap_obj_txg = dsl_dataset_phys(ds)->ds_prev_snap_txg; 4045 dsl_dataset_rele(ds, FTAG); 4046 continue; 4047 } 4048 4049 boolean_t affected = B_TRUE; 4050 if (check_snapshot) { 4051 uint64_t blk_txg; 4052 error = find_birth_txg(ds, zep, &blk_txg); 4053 4054 /* 4055 * Scrub the snapshot also when zb_birth == 0 or when 4056 * find_birth_txg() returns an error. 4057 */ 4058 affected = (error == 0 && zep->zb_birth == blk_txg) || 4059 (error != 0) || (zep->zb_birth == 0); 4060 } 4061 4062 /* Scrub snapshots. */ 4063 if (affected) { 4064 zbookmark_phys_t zb; 4065 zep_to_zb(snap_obj, zep, &zb); 4066 scn->scn_zio_root = zio_root(spa, NULL, NULL, 4067 ZIO_FLAG_CANFAIL); 4068 /* We have already acquired the config lock for spa */ 4069 read_by_block_level(scn, zb); 4070 4071 (void) zio_wait(scn->scn_zio_root); 4072 scn->scn_zio_root = NULL; 4073 4074 scn->errorscrub_phys.dep_examined++; 4075 scn->errorscrub_phys.dep_to_examine--; 4076 (*count)++; 4077 if ((*count) == zfs_scrub_error_blocks_per_txg || 4078 dsl_error_scrub_check_suspend(scn, &zb)) { 4079 dsl_dataset_rele(ds, FTAG); 4080 return (EFAULT); 4081 } 4082 } 4083 snap_obj_txg = dsl_dataset_phys(ds)->ds_prev_snap_txg; 4084 snap_obj = dsl_dataset_phys(ds)->ds_prev_snap_obj; 4085 dsl_dataset_rele(ds, FTAG); 4086 } 4087 return (0); 4088 } 4089 4090 void 4091 dsl_errorscrub_sync(dsl_pool_t *dp, dmu_tx_t *tx) 4092 { 4093 spa_t *spa = dp->dp_spa; 4094 dsl_scan_t *scn = dp->dp_scan; 4095 4096 /* 4097 * Only process scans in sync pass 1. 4098 */ 4099 4100 if (spa_sync_pass(spa) > 1) 4101 return; 4102 4103 /* 4104 * If the spa is shutting down, then stop scanning. This will 4105 * ensure that the scan does not dirty any new data during the 4106 * shutdown phase. 4107 */ 4108 if (spa_shutting_down(spa)) 4109 return; 4110 4111 if (!dsl_errorscrub_active(scn) || dsl_errorscrub_is_paused(scn)) { 4112 return; 4113 } 4114 4115 if (dsl_scan_resilvering(scn->scn_dp)) { 4116 /* cancel the error scrub if resilver started */ 4117 dsl_scan_cancel(scn->scn_dp); 4118 return; 4119 } 4120 4121 spa->spa_scrub_active = B_TRUE; 4122 scn->scn_sync_start_time = gethrtime(); 4123 4124 /* 4125 * zfs_scan_suspend_progress can be set to disable scrub progress. 4126 * See more detailed comment in dsl_scan_sync(). 4127 */ 4128 if (zfs_scan_suspend_progress) { 4129 uint64_t scan_time_ns = gethrtime() - scn->scn_sync_start_time; 4130 int mintime = zfs_scrub_min_time_ms; 4131 4132 while (zfs_scan_suspend_progress && 4133 !txg_sync_waiting(scn->scn_dp) && 4134 !spa_shutting_down(scn->scn_dp->dp_spa) && 4135 NSEC2MSEC(scan_time_ns) < mintime) { 4136 delay(hz); 4137 scan_time_ns = gethrtime() - scn->scn_sync_start_time; 4138 } 4139 return; 4140 } 4141 4142 int i = 0; 4143 zap_attribute_t *za; 4144 zbookmark_phys_t *zb; 4145 boolean_t limit_exceeded = B_FALSE; 4146 4147 za = kmem_zalloc(sizeof (zap_attribute_t), KM_SLEEP); 4148 zb = kmem_zalloc(sizeof (zbookmark_phys_t), KM_SLEEP); 4149 4150 if (!spa_feature_is_enabled(spa, SPA_FEATURE_HEAD_ERRLOG)) { 4151 for (; zap_cursor_retrieve(&scn->errorscrub_cursor, za) == 0; 4152 zap_cursor_advance(&scn->errorscrub_cursor)) { 4153 name_to_bookmark(za->za_name, zb); 4154 4155 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 4156 NULL, ZIO_FLAG_CANFAIL); 4157 dsl_pool_config_enter(dp, FTAG); 4158 read_by_block_level(scn, *zb); 4159 dsl_pool_config_exit(dp, FTAG); 4160 4161 (void) zio_wait(scn->scn_zio_root); 4162 scn->scn_zio_root = NULL; 4163 4164 scn->errorscrub_phys.dep_examined += 1; 4165 scn->errorscrub_phys.dep_to_examine -= 1; 4166 i++; 4167 if (i == zfs_scrub_error_blocks_per_txg || 4168 dsl_error_scrub_check_suspend(scn, zb)) { 4169 limit_exceeded = B_TRUE; 4170 break; 4171 } 4172 } 4173 4174 if (!limit_exceeded) 4175 dsl_errorscrub_done(scn, B_TRUE, tx); 4176 4177 dsl_errorscrub_sync_state(scn, tx); 4178 kmem_free(za, sizeof (*za)); 4179 kmem_free(zb, sizeof (*zb)); 4180 return; 4181 } 4182 4183 int error = 0; 4184 for (; zap_cursor_retrieve(&scn->errorscrub_cursor, za) == 0; 4185 zap_cursor_advance(&scn->errorscrub_cursor)) { 4186 4187 zap_cursor_t *head_ds_cursor; 4188 zap_attribute_t *head_ds_attr; 4189 zbookmark_err_phys_t head_ds_block; 4190 4191 head_ds_cursor = kmem_zalloc(sizeof (zap_cursor_t), KM_SLEEP); 4192 head_ds_attr = kmem_zalloc(sizeof (zap_attribute_t), KM_SLEEP); 4193 4194 uint64_t head_ds_err_obj = za->za_first_integer; 4195 uint64_t head_ds; 4196 name_to_object(za->za_name, &head_ds); 4197 boolean_t config_held = B_FALSE; 4198 uint64_t top_affected_fs; 4199 4200 for (zap_cursor_init(head_ds_cursor, spa->spa_meta_objset, 4201 head_ds_err_obj); zap_cursor_retrieve(head_ds_cursor, 4202 head_ds_attr) == 0; zap_cursor_advance(head_ds_cursor)) { 4203 4204 name_to_errphys(head_ds_attr->za_name, &head_ds_block); 4205 4206 /* 4207 * In case we are called from spa_sync the pool 4208 * config is already held. 4209 */ 4210 if (!dsl_pool_config_held(dp)) { 4211 dsl_pool_config_enter(dp, FTAG); 4212 config_held = B_TRUE; 4213 } 4214 4215 error = find_top_affected_fs(spa, 4216 head_ds, &head_ds_block, &top_affected_fs); 4217 if (error) 4218 break; 4219 4220 error = scrub_filesystem(spa, top_affected_fs, 4221 &head_ds_block, &i); 4222 4223 if (error == SET_ERROR(EFAULT)) { 4224 limit_exceeded = B_TRUE; 4225 break; 4226 } 4227 } 4228 4229 zap_cursor_fini(head_ds_cursor); 4230 kmem_free(head_ds_cursor, sizeof (*head_ds_cursor)); 4231 kmem_free(head_ds_attr, sizeof (*head_ds_attr)); 4232 4233 if (config_held) 4234 dsl_pool_config_exit(dp, FTAG); 4235 } 4236 4237 kmem_free(za, sizeof (*za)); 4238 kmem_free(zb, sizeof (*zb)); 4239 if (!limit_exceeded) 4240 dsl_errorscrub_done(scn, B_TRUE, tx); 4241 4242 dsl_errorscrub_sync_state(scn, tx); 4243 } 4244 4245 /* 4246 * This is the primary entry point for scans that is called from syncing 4247 * context. Scans must happen entirely during syncing context so that we 4248 * can guarantee that blocks we are currently scanning will not change out 4249 * from under us. While a scan is active, this function controls how quickly 4250 * transaction groups proceed, instead of the normal handling provided by 4251 * txg_sync_thread(). 4252 */ 4253 void 4254 dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) 4255 { 4256 int err = 0; 4257 dsl_scan_t *scn = dp->dp_scan; 4258 spa_t *spa = dp->dp_spa; 4259 state_sync_type_t sync_type = SYNC_OPTIONAL; 4260 4261 if (spa->spa_resilver_deferred && 4262 !spa_feature_is_active(dp->dp_spa, SPA_FEATURE_RESILVER_DEFER)) 4263 spa_feature_incr(spa, SPA_FEATURE_RESILVER_DEFER, tx); 4264 4265 /* 4266 * Check for scn_restart_txg before checking spa_load_state, so 4267 * that we can restart an old-style scan while the pool is being 4268 * imported (see dsl_scan_init). We also restart scans if there 4269 * is a deferred resilver and the user has manually disabled 4270 * deferred resilvers via the tunable. 4271 */ 4272 if (dsl_scan_restarting(scn, tx) || 4273 (spa->spa_resilver_deferred && zfs_resilver_disable_defer)) { 4274 pool_scan_func_t func = POOL_SCAN_SCRUB; 4275 dsl_scan_done(scn, B_FALSE, tx); 4276 if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) 4277 func = POOL_SCAN_RESILVER; 4278 zfs_dbgmsg("restarting scan func=%u on %s txg=%llu", 4279 func, dp->dp_spa->spa_name, (longlong_t)tx->tx_txg); 4280 dsl_scan_setup_sync(&func, tx); 4281 } 4282 4283 /* 4284 * Only process scans in sync pass 1. 4285 */ 4286 if (spa_sync_pass(spa) > 1) 4287 return; 4288 4289 /* 4290 * If the spa is shutting down, then stop scanning. This will 4291 * ensure that the scan does not dirty any new data during the 4292 * shutdown phase. 4293 */ 4294 if (spa_shutting_down(spa)) 4295 return; 4296 4297 /* 4298 * If the scan is inactive due to a stalled async destroy, try again. 4299 */ 4300 if (!scn->scn_async_stalled && !dsl_scan_active(scn)) 4301 return; 4302 4303 /* reset scan statistics */ 4304 scn->scn_visited_this_txg = 0; 4305 scn->scn_dedup_frees_this_txg = 0; 4306 scn->scn_holes_this_txg = 0; 4307 scn->scn_lt_min_this_txg = 0; 4308 scn->scn_gt_max_this_txg = 0; 4309 scn->scn_ddt_contained_this_txg = 0; 4310 scn->scn_objsets_visited_this_txg = 0; 4311 scn->scn_avg_seg_size_this_txg = 0; 4312 scn->scn_segs_this_txg = 0; 4313 scn->scn_avg_zio_size_this_txg = 0; 4314 scn->scn_zios_this_txg = 0; 4315 scn->scn_suspending = B_FALSE; 4316 scn->scn_sync_start_time = gethrtime(); 4317 spa->spa_scrub_active = B_TRUE; 4318 4319 /* 4320 * First process the async destroys. If we suspend, don't do 4321 * any scrubbing or resilvering. This ensures that there are no 4322 * async destroys while we are scanning, so the scan code doesn't 4323 * have to worry about traversing it. It is also faster to free the 4324 * blocks than to scrub them. 4325 */ 4326 err = dsl_process_async_destroys(dp, tx); 4327 if (err != 0) 4328 return; 4329 4330 if (!dsl_scan_is_running(scn) || dsl_scan_is_paused_scrub(scn)) 4331 return; 4332 4333 /* 4334 * Wait a few txgs after importing to begin scanning so that 4335 * we can get the pool imported quickly. 4336 */ 4337 if (spa->spa_syncing_txg < spa->spa_first_txg + SCAN_IMPORT_WAIT_TXGS) 4338 return; 4339 4340 /* 4341 * zfs_scan_suspend_progress can be set to disable scan progress. 4342 * We don't want to spin the txg_sync thread, so we add a delay 4343 * here to simulate the time spent doing a scan. This is mostly 4344 * useful for testing and debugging. 4345 */ 4346 if (zfs_scan_suspend_progress) { 4347 uint64_t scan_time_ns = gethrtime() - scn->scn_sync_start_time; 4348 uint_t mintime = (scn->scn_phys.scn_func == 4349 POOL_SCAN_RESILVER) ? zfs_resilver_min_time_ms : 4350 zfs_scrub_min_time_ms; 4351 4352 while (zfs_scan_suspend_progress && 4353 !txg_sync_waiting(scn->scn_dp) && 4354 !spa_shutting_down(scn->scn_dp->dp_spa) && 4355 NSEC2MSEC(scan_time_ns) < mintime) { 4356 delay(hz); 4357 scan_time_ns = gethrtime() - scn->scn_sync_start_time; 4358 } 4359 return; 4360 } 4361 4362 /* 4363 * Disabled by default, set zfs_scan_report_txgs to report 4364 * average performance over the last zfs_scan_report_txgs TXGs. 4365 */ 4366 if (zfs_scan_report_txgs != 0 && 4367 tx->tx_txg % zfs_scan_report_txgs == 0) { 4368 scn->scn_issued_before_pass += spa->spa_scan_pass_issued; 4369 spa_scan_stat_init(spa); 4370 } 4371 4372 /* 4373 * It is possible to switch from unsorted to sorted at any time, 4374 * but afterwards the scan will remain sorted unless reloaded from 4375 * a checkpoint after a reboot. 4376 */ 4377 if (!zfs_scan_legacy) { 4378 scn->scn_is_sorted = B_TRUE; 4379 if (scn->scn_last_checkpoint == 0) 4380 scn->scn_last_checkpoint = ddi_get_lbolt(); 4381 } 4382 4383 /* 4384 * For sorted scans, determine what kind of work we will be doing 4385 * this txg based on our memory limitations and whether or not we 4386 * need to perform a checkpoint. 4387 */ 4388 if (scn->scn_is_sorted) { 4389 /* 4390 * If we are over our checkpoint interval, set scn_clearing 4391 * so that we can begin checkpointing immediately. The 4392 * checkpoint allows us to save a consistent bookmark 4393 * representing how much data we have scrubbed so far. 4394 * Otherwise, use the memory limit to determine if we should 4395 * scan for metadata or start issue scrub IOs. We accumulate 4396 * metadata until we hit our hard memory limit at which point 4397 * we issue scrub IOs until we are at our soft memory limit. 4398 */ 4399 if (scn->scn_checkpointing || 4400 ddi_get_lbolt() - scn->scn_last_checkpoint > 4401 SEC_TO_TICK(zfs_scan_checkpoint_intval)) { 4402 if (!scn->scn_checkpointing) 4403 zfs_dbgmsg("begin scan checkpoint for %s", 4404 spa->spa_name); 4405 4406 scn->scn_checkpointing = B_TRUE; 4407 scn->scn_clearing = B_TRUE; 4408 } else { 4409 boolean_t should_clear = dsl_scan_should_clear(scn); 4410 if (should_clear && !scn->scn_clearing) { 4411 zfs_dbgmsg("begin scan clearing for %s", 4412 spa->spa_name); 4413 scn->scn_clearing = B_TRUE; 4414 } else if (!should_clear && scn->scn_clearing) { 4415 zfs_dbgmsg("finish scan clearing for %s", 4416 spa->spa_name); 4417 scn->scn_clearing = B_FALSE; 4418 } 4419 } 4420 } else { 4421 ASSERT0(scn->scn_checkpointing); 4422 ASSERT0(scn->scn_clearing); 4423 } 4424 4425 if (!scn->scn_clearing && scn->scn_done_txg == 0) { 4426 /* Need to scan metadata for more blocks to scrub */ 4427 dsl_scan_phys_t *scnp = &scn->scn_phys; 4428 taskqid_t prefetch_tqid; 4429 4430 /* 4431 * Calculate the max number of in-flight bytes for pool-wide 4432 * scanning operations (minimum 1MB, maximum 1/4 of arc_c_max). 4433 * Limits for the issuing phase are done per top-level vdev and 4434 * are handled separately. 4435 */ 4436 scn->scn_maxinflight_bytes = MIN(arc_c_max / 4, MAX(1ULL << 20, 4437 zfs_scan_vdev_limit * dsl_scan_count_data_disks(spa))); 4438 4439 if (scnp->scn_ddt_bookmark.ddb_class <= 4440 scnp->scn_ddt_class_max) { 4441 ASSERT(ZB_IS_ZERO(&scnp->scn_bookmark)); 4442 zfs_dbgmsg("doing scan sync for %s txg %llu; " 4443 "ddt bm=%llu/%llu/%llu/%llx", 4444 spa->spa_name, 4445 (longlong_t)tx->tx_txg, 4446 (longlong_t)scnp->scn_ddt_bookmark.ddb_class, 4447 (longlong_t)scnp->scn_ddt_bookmark.ddb_type, 4448 (longlong_t)scnp->scn_ddt_bookmark.ddb_checksum, 4449 (longlong_t)scnp->scn_ddt_bookmark.ddb_cursor); 4450 } else { 4451 zfs_dbgmsg("doing scan sync for %s txg %llu; " 4452 "bm=%llu/%llu/%llu/%llu", 4453 spa->spa_name, 4454 (longlong_t)tx->tx_txg, 4455 (longlong_t)scnp->scn_bookmark.zb_objset, 4456 (longlong_t)scnp->scn_bookmark.zb_object, 4457 (longlong_t)scnp->scn_bookmark.zb_level, 4458 (longlong_t)scnp->scn_bookmark.zb_blkid); 4459 } 4460 4461 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 4462 NULL, ZIO_FLAG_CANFAIL); 4463 4464 scn->scn_prefetch_stop = B_FALSE; 4465 prefetch_tqid = taskq_dispatch(dp->dp_sync_taskq, 4466 dsl_scan_prefetch_thread, scn, TQ_SLEEP); 4467 ASSERT(prefetch_tqid != TASKQID_INVALID); 4468 4469 dsl_pool_config_enter(dp, FTAG); 4470 dsl_scan_visit(scn, tx); 4471 dsl_pool_config_exit(dp, FTAG); 4472 4473 mutex_enter(&dp->dp_spa->spa_scrub_lock); 4474 scn->scn_prefetch_stop = B_TRUE; 4475 cv_broadcast(&spa->spa_scrub_io_cv); 4476 mutex_exit(&dp->dp_spa->spa_scrub_lock); 4477 4478 taskq_wait_id(dp->dp_sync_taskq, prefetch_tqid); 4479 (void) zio_wait(scn->scn_zio_root); 4480 scn->scn_zio_root = NULL; 4481 4482 zfs_dbgmsg("scan visited %llu blocks of %s in %llums " 4483 "(%llu os's, %llu holes, %llu < mintxg, " 4484 "%llu in ddt, %llu > maxtxg)", 4485 (longlong_t)scn->scn_visited_this_txg, 4486 spa->spa_name, 4487 (longlong_t)NSEC2MSEC(gethrtime() - 4488 scn->scn_sync_start_time), 4489 (longlong_t)scn->scn_objsets_visited_this_txg, 4490 (longlong_t)scn->scn_holes_this_txg, 4491 (longlong_t)scn->scn_lt_min_this_txg, 4492 (longlong_t)scn->scn_ddt_contained_this_txg, 4493 (longlong_t)scn->scn_gt_max_this_txg); 4494 4495 if (!scn->scn_suspending) { 4496 ASSERT0(avl_numnodes(&scn->scn_queue)); 4497 scn->scn_done_txg = tx->tx_txg + 1; 4498 if (scn->scn_is_sorted) { 4499 scn->scn_checkpointing = B_TRUE; 4500 scn->scn_clearing = B_TRUE; 4501 scn->scn_issued_before_pass += 4502 spa->spa_scan_pass_issued; 4503 spa_scan_stat_init(spa); 4504 } 4505 zfs_dbgmsg("scan complete for %s txg %llu", 4506 spa->spa_name, 4507 (longlong_t)tx->tx_txg); 4508 } 4509 } else if (scn->scn_is_sorted && scn->scn_queues_pending != 0) { 4510 ASSERT(scn->scn_clearing); 4511 4512 /* need to issue scrubbing IOs from per-vdev queues */ 4513 scn->scn_zio_root = zio_root(dp->dp_spa, NULL, 4514 NULL, ZIO_FLAG_CANFAIL); 4515 scan_io_queues_run(scn); 4516 (void) zio_wait(scn->scn_zio_root); 4517 scn->scn_zio_root = NULL; 4518 4519 /* calculate and dprintf the current memory usage */ 4520 (void) dsl_scan_should_clear(scn); 4521 dsl_scan_update_stats(scn); 4522 4523 zfs_dbgmsg("scan issued %llu blocks for %s (%llu segs) " 4524 "in %llums (avg_block_size = %llu, avg_seg_size = %llu)", 4525 (longlong_t)scn->scn_zios_this_txg, 4526 spa->spa_name, 4527 (longlong_t)scn->scn_segs_this_txg, 4528 (longlong_t)NSEC2MSEC(gethrtime() - 4529 scn->scn_sync_start_time), 4530 (longlong_t)scn->scn_avg_zio_size_this_txg, 4531 (longlong_t)scn->scn_avg_seg_size_this_txg); 4532 } else if (scn->scn_done_txg != 0 && scn->scn_done_txg <= tx->tx_txg) { 4533 /* Finished with everything. Mark the scrub as complete */ 4534 zfs_dbgmsg("scan issuing complete txg %llu for %s", 4535 (longlong_t)tx->tx_txg, 4536 spa->spa_name); 4537 ASSERT3U(scn->scn_done_txg, !=, 0); 4538 ASSERT0(spa->spa_scrub_inflight); 4539 ASSERT0(scn->scn_queues_pending); 4540 dsl_scan_done(scn, B_TRUE, tx); 4541 sync_type = SYNC_MANDATORY; 4542 } 4543 4544 dsl_scan_sync_state(scn, tx, sync_type); 4545 } 4546 4547 static void 4548 count_block_issued(spa_t *spa, const blkptr_t *bp, boolean_t all) 4549 { 4550 /* 4551 * Don't count embedded bp's, since we already did the work of 4552 * scanning these when we scanned the containing block. 4553 */ 4554 if (BP_IS_EMBEDDED(bp)) 4555 return; 4556 4557 /* 4558 * Update the spa's stats on how many bytes we have issued. 4559 * Sequential scrubs create a zio for each DVA of the bp. Each 4560 * of these will include all DVAs for repair purposes, but the 4561 * zio code will only try the first one unless there is an issue. 4562 * Therefore, we should only count the first DVA for these IOs. 4563 */ 4564 atomic_add_64(&spa->spa_scan_pass_issued, 4565 all ? BP_GET_ASIZE(bp) : DVA_GET_ASIZE(&bp->blk_dva[0])); 4566 } 4567 4568 static void 4569 count_block_skipped(dsl_scan_t *scn, const blkptr_t *bp, boolean_t all) 4570 { 4571 if (BP_IS_EMBEDDED(bp)) 4572 return; 4573 atomic_add_64(&scn->scn_phys.scn_skipped, 4574 all ? BP_GET_ASIZE(bp) : DVA_GET_ASIZE(&bp->blk_dva[0])); 4575 } 4576 4577 static void 4578 count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp) 4579 { 4580 /* 4581 * If we resume after a reboot, zab will be NULL; don't record 4582 * incomplete stats in that case. 4583 */ 4584 if (zab == NULL) 4585 return; 4586 4587 for (int i = 0; i < 4; i++) { 4588 int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS; 4589 int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL; 4590 4591 if (t & DMU_OT_NEWTYPE) 4592 t = DMU_OT_OTHER; 4593 zfs_blkstat_t *zb = &zab->zab_type[l][t]; 4594 int equal; 4595 4596 zb->zb_count++; 4597 zb->zb_asize += BP_GET_ASIZE(bp); 4598 zb->zb_lsize += BP_GET_LSIZE(bp); 4599 zb->zb_psize += BP_GET_PSIZE(bp); 4600 zb->zb_gangs += BP_COUNT_GANG(bp); 4601 4602 switch (BP_GET_NDVAS(bp)) { 4603 case 2: 4604 if (DVA_GET_VDEV(&bp->blk_dva[0]) == 4605 DVA_GET_VDEV(&bp->blk_dva[1])) 4606 zb->zb_ditto_2_of_2_samevdev++; 4607 break; 4608 case 3: 4609 equal = (DVA_GET_VDEV(&bp->blk_dva[0]) == 4610 DVA_GET_VDEV(&bp->blk_dva[1])) + 4611 (DVA_GET_VDEV(&bp->blk_dva[0]) == 4612 DVA_GET_VDEV(&bp->blk_dva[2])) + 4613 (DVA_GET_VDEV(&bp->blk_dva[1]) == 4614 DVA_GET_VDEV(&bp->blk_dva[2])); 4615 if (equal == 1) 4616 zb->zb_ditto_2_of_3_samevdev++; 4617 else if (equal == 3) 4618 zb->zb_ditto_3_of_3_samevdev++; 4619 break; 4620 } 4621 } 4622 } 4623 4624 static void 4625 scan_io_queue_insert_impl(dsl_scan_io_queue_t *queue, scan_io_t *sio) 4626 { 4627 avl_index_t idx; 4628 dsl_scan_t *scn = queue->q_scn; 4629 4630 ASSERT(MUTEX_HELD(&queue->q_vd->vdev_scan_io_queue_lock)); 4631 4632 if (unlikely(avl_is_empty(&queue->q_sios_by_addr))) 4633 atomic_add_64(&scn->scn_queues_pending, 1); 4634 if (avl_find(&queue->q_sios_by_addr, sio, &idx) != NULL) { 4635 /* block is already scheduled for reading */ 4636 sio_free(sio); 4637 return; 4638 } 4639 avl_insert(&queue->q_sios_by_addr, sio, idx); 4640 queue->q_sio_memused += SIO_GET_MUSED(sio); 4641 range_tree_add(queue->q_exts_by_addr, SIO_GET_OFFSET(sio), 4642 SIO_GET_ASIZE(sio)); 4643 } 4644 4645 /* 4646 * Given all the info we got from our metadata scanning process, we 4647 * construct a scan_io_t and insert it into the scan sorting queue. The 4648 * I/O must already be suitable for us to process. This is controlled 4649 * by dsl_scan_enqueue(). 4650 */ 4651 static void 4652 scan_io_queue_insert(dsl_scan_io_queue_t *queue, const blkptr_t *bp, int dva_i, 4653 int zio_flags, const zbookmark_phys_t *zb) 4654 { 4655 scan_io_t *sio = sio_alloc(BP_GET_NDVAS(bp)); 4656 4657 ASSERT0(BP_IS_GANG(bp)); 4658 ASSERT(MUTEX_HELD(&queue->q_vd->vdev_scan_io_queue_lock)); 4659 4660 bp2sio(bp, sio, dva_i); 4661 sio->sio_flags = zio_flags; 4662 sio->sio_zb = *zb; 4663 4664 queue->q_last_ext_addr = -1; 4665 scan_io_queue_insert_impl(queue, sio); 4666 } 4667 4668 /* 4669 * Given a set of I/O parameters as discovered by the metadata traversal 4670 * process, attempts to place the I/O into the sorted queues (if allowed), 4671 * or immediately executes the I/O. 4672 */ 4673 static void 4674 dsl_scan_enqueue(dsl_pool_t *dp, const blkptr_t *bp, int zio_flags, 4675 const zbookmark_phys_t *zb) 4676 { 4677 spa_t *spa = dp->dp_spa; 4678 4679 ASSERT(!BP_IS_EMBEDDED(bp)); 4680 4681 /* 4682 * Gang blocks are hard to issue sequentially, so we just issue them 4683 * here immediately instead of queuing them. 4684 */ 4685 if (!dp->dp_scan->scn_is_sorted || BP_IS_GANG(bp)) { 4686 scan_exec_io(dp, bp, zio_flags, zb, NULL); 4687 return; 4688 } 4689 4690 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 4691 dva_t dva; 4692 vdev_t *vdev; 4693 4694 dva = bp->blk_dva[i]; 4695 vdev = vdev_lookup_top(spa, DVA_GET_VDEV(&dva)); 4696 ASSERT(vdev != NULL); 4697 4698 mutex_enter(&vdev->vdev_scan_io_queue_lock); 4699 if (vdev->vdev_scan_io_queue == NULL) 4700 vdev->vdev_scan_io_queue = scan_io_queue_create(vdev); 4701 ASSERT(dp->dp_scan != NULL); 4702 scan_io_queue_insert(vdev->vdev_scan_io_queue, bp, 4703 i, zio_flags, zb); 4704 mutex_exit(&vdev->vdev_scan_io_queue_lock); 4705 } 4706 } 4707 4708 static int 4709 dsl_scan_scrub_cb(dsl_pool_t *dp, 4710 const blkptr_t *bp, const zbookmark_phys_t *zb) 4711 { 4712 dsl_scan_t *scn = dp->dp_scan; 4713 spa_t *spa = dp->dp_spa; 4714 uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp); 4715 size_t psize = BP_GET_PSIZE(bp); 4716 boolean_t needs_io = B_FALSE; 4717 int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL; 4718 4719 count_block(dp->dp_blkstats, bp); 4720 if (phys_birth <= scn->scn_phys.scn_min_txg || 4721 phys_birth >= scn->scn_phys.scn_max_txg) { 4722 count_block_skipped(scn, bp, B_TRUE); 4723 return (0); 4724 } 4725 4726 /* Embedded BP's have phys_birth==0, so we reject them above. */ 4727 ASSERT(!BP_IS_EMBEDDED(bp)); 4728 4729 ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn)); 4730 if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) { 4731 zio_flags |= ZIO_FLAG_SCRUB; 4732 needs_io = B_TRUE; 4733 } else { 4734 ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER); 4735 zio_flags |= ZIO_FLAG_RESILVER; 4736 needs_io = B_FALSE; 4737 } 4738 4739 /* If it's an intent log block, failure is expected. */ 4740 if (zb->zb_level == ZB_ZIL_LEVEL) 4741 zio_flags |= ZIO_FLAG_SPECULATIVE; 4742 4743 for (int d = 0; d < BP_GET_NDVAS(bp); d++) { 4744 const dva_t *dva = &bp->blk_dva[d]; 4745 4746 /* 4747 * Keep track of how much data we've examined so that 4748 * zpool(8) status can make useful progress reports. 4749 */ 4750 uint64_t asize = DVA_GET_ASIZE(dva); 4751 scn->scn_phys.scn_examined += asize; 4752 spa->spa_scan_pass_exam += asize; 4753 4754 /* if it's a resilver, this may not be in the target range */ 4755 if (!needs_io) 4756 needs_io = dsl_scan_need_resilver(spa, dva, psize, 4757 phys_birth); 4758 } 4759 4760 if (needs_io && !zfs_no_scrub_io) { 4761 dsl_scan_enqueue(dp, bp, zio_flags, zb); 4762 } else { 4763 count_block_skipped(scn, bp, B_TRUE); 4764 } 4765 4766 /* do not relocate this block */ 4767 return (0); 4768 } 4769 4770 static void 4771 dsl_scan_scrub_done(zio_t *zio) 4772 { 4773 spa_t *spa = zio->io_spa; 4774 blkptr_t *bp = zio->io_bp; 4775 dsl_scan_io_queue_t *queue = zio->io_private; 4776 4777 abd_free(zio->io_abd); 4778 4779 if (queue == NULL) { 4780 mutex_enter(&spa->spa_scrub_lock); 4781 ASSERT3U(spa->spa_scrub_inflight, >=, BP_GET_PSIZE(bp)); 4782 spa->spa_scrub_inflight -= BP_GET_PSIZE(bp); 4783 cv_broadcast(&spa->spa_scrub_io_cv); 4784 mutex_exit(&spa->spa_scrub_lock); 4785 } else { 4786 mutex_enter(&queue->q_vd->vdev_scan_io_queue_lock); 4787 ASSERT3U(queue->q_inflight_bytes, >=, BP_GET_PSIZE(bp)); 4788 queue->q_inflight_bytes -= BP_GET_PSIZE(bp); 4789 cv_broadcast(&queue->q_zio_cv); 4790 mutex_exit(&queue->q_vd->vdev_scan_io_queue_lock); 4791 } 4792 4793 if (zio->io_error && (zio->io_error != ECKSUM || 4794 !(zio->io_flags & ZIO_FLAG_SPECULATIVE))) { 4795 if (dsl_errorscrubbing(spa->spa_dsl_pool) && 4796 !dsl_errorscrub_is_paused(spa->spa_dsl_pool->dp_scan)) { 4797 atomic_inc_64(&spa->spa_dsl_pool->dp_scan 4798 ->errorscrub_phys.dep_errors); 4799 } else { 4800 atomic_inc_64(&spa->spa_dsl_pool->dp_scan->scn_phys 4801 .scn_errors); 4802 } 4803 } 4804 } 4805 4806 /* 4807 * Given a scanning zio's information, executes the zio. The zio need 4808 * not necessarily be only sortable, this function simply executes the 4809 * zio, no matter what it is. The optional queue argument allows the 4810 * caller to specify that they want per top level vdev IO rate limiting 4811 * instead of the legacy global limiting. 4812 */ 4813 static void 4814 scan_exec_io(dsl_pool_t *dp, const blkptr_t *bp, int zio_flags, 4815 const zbookmark_phys_t *zb, dsl_scan_io_queue_t *queue) 4816 { 4817 spa_t *spa = dp->dp_spa; 4818 dsl_scan_t *scn = dp->dp_scan; 4819 size_t size = BP_GET_PSIZE(bp); 4820 abd_t *data = abd_alloc_for_io(size, B_FALSE); 4821 zio_t *pio; 4822 4823 if (queue == NULL) { 4824 ASSERT3U(scn->scn_maxinflight_bytes, >, 0); 4825 mutex_enter(&spa->spa_scrub_lock); 4826 while (spa->spa_scrub_inflight >= scn->scn_maxinflight_bytes) 4827 cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock); 4828 spa->spa_scrub_inflight += BP_GET_PSIZE(bp); 4829 mutex_exit(&spa->spa_scrub_lock); 4830 pio = scn->scn_zio_root; 4831 } else { 4832 kmutex_t *q_lock = &queue->q_vd->vdev_scan_io_queue_lock; 4833 4834 ASSERT3U(queue->q_maxinflight_bytes, >, 0); 4835 mutex_enter(q_lock); 4836 while (queue->q_inflight_bytes >= queue->q_maxinflight_bytes) 4837 cv_wait(&queue->q_zio_cv, q_lock); 4838 queue->q_inflight_bytes += BP_GET_PSIZE(bp); 4839 pio = queue->q_zio; 4840 mutex_exit(q_lock); 4841 } 4842 4843 ASSERT(pio != NULL); 4844 count_block_issued(spa, bp, queue == NULL); 4845 zio_nowait(zio_read(pio, spa, bp, data, size, dsl_scan_scrub_done, 4846 queue, ZIO_PRIORITY_SCRUB, zio_flags, zb)); 4847 } 4848 4849 /* 4850 * This is the primary extent sorting algorithm. We balance two parameters: 4851 * 1) how many bytes of I/O are in an extent 4852 * 2) how well the extent is filled with I/O (as a fraction of its total size) 4853 * Since we allow extents to have gaps between their constituent I/Os, it's 4854 * possible to have a fairly large extent that contains the same amount of 4855 * I/O bytes than a much smaller extent, which just packs the I/O more tightly. 4856 * The algorithm sorts based on a score calculated from the extent's size, 4857 * the relative fill volume (in %) and a "fill weight" parameter that controls 4858 * the split between whether we prefer larger extents or more well populated 4859 * extents: 4860 * 4861 * SCORE = FILL_IN_BYTES + (FILL_IN_PERCENT * FILL_IN_BYTES * FILL_WEIGHT) 4862 * 4863 * Example: 4864 * 1) assume extsz = 64 MiB 4865 * 2) assume fill = 32 MiB (extent is half full) 4866 * 3) assume fill_weight = 3 4867 * 4) SCORE = 32M + (((32M * 100) / 64M) * 3 * 32M) / 100 4868 * SCORE = 32M + (50 * 3 * 32M) / 100 4869 * SCORE = 32M + (4800M / 100) 4870 * SCORE = 32M + 48M 4871 * ^ ^ 4872 * | +--- final total relative fill-based score 4873 * +--------- final total fill-based score 4874 * SCORE = 80M 4875 * 4876 * As can be seen, at fill_ratio=3, the algorithm is slightly biased towards 4877 * extents that are more completely filled (in a 3:2 ratio) vs just larger. 4878 * Note that as an optimization, we replace multiplication and division by 4879 * 100 with bitshifting by 7 (which effectively multiplies and divides by 128). 4880 * 4881 * Since we do not care if one extent is only few percent better than another, 4882 * compress the score into 6 bits via binary logarithm AKA highbit64() and 4883 * put into otherwise unused due to ashift high bits of offset. This allows 4884 * to reduce q_exts_by_size B-tree elements to only 64 bits and compare them 4885 * with single operation. Plus it makes scrubs more sequential and reduces 4886 * chances that minor extent change move it within the B-tree. 4887 */ 4888 __attribute__((always_inline)) inline 4889 static int 4890 ext_size_compare(const void *x, const void *y) 4891 { 4892 const uint64_t *a = x, *b = y; 4893 4894 return (TREE_CMP(*a, *b)); 4895 } 4896 4897 ZFS_BTREE_FIND_IN_BUF_FUNC(ext_size_find_in_buf, uint64_t, 4898 ext_size_compare) 4899 4900 static void 4901 ext_size_create(range_tree_t *rt, void *arg) 4902 { 4903 (void) rt; 4904 zfs_btree_t *size_tree = arg; 4905 4906 zfs_btree_create(size_tree, ext_size_compare, ext_size_find_in_buf, 4907 sizeof (uint64_t)); 4908 } 4909 4910 static void 4911 ext_size_destroy(range_tree_t *rt, void *arg) 4912 { 4913 (void) rt; 4914 zfs_btree_t *size_tree = arg; 4915 ASSERT0(zfs_btree_numnodes(size_tree)); 4916 4917 zfs_btree_destroy(size_tree); 4918 } 4919 4920 static uint64_t 4921 ext_size_value(range_tree_t *rt, range_seg_gap_t *rsg) 4922 { 4923 (void) rt; 4924 uint64_t size = rsg->rs_end - rsg->rs_start; 4925 uint64_t score = rsg->rs_fill + ((((rsg->rs_fill << 7) / size) * 4926 fill_weight * rsg->rs_fill) >> 7); 4927 ASSERT3U(rt->rt_shift, >=, 8); 4928 return (((uint64_t)(64 - highbit64(score)) << 56) | rsg->rs_start); 4929 } 4930 4931 static void 4932 ext_size_add(range_tree_t *rt, range_seg_t *rs, void *arg) 4933 { 4934 zfs_btree_t *size_tree = arg; 4935 ASSERT3U(rt->rt_type, ==, RANGE_SEG_GAP); 4936 uint64_t v = ext_size_value(rt, (range_seg_gap_t *)rs); 4937 zfs_btree_add(size_tree, &v); 4938 } 4939 4940 static void 4941 ext_size_remove(range_tree_t *rt, range_seg_t *rs, void *arg) 4942 { 4943 zfs_btree_t *size_tree = arg; 4944 ASSERT3U(rt->rt_type, ==, RANGE_SEG_GAP); 4945 uint64_t v = ext_size_value(rt, (range_seg_gap_t *)rs); 4946 zfs_btree_remove(size_tree, &v); 4947 } 4948 4949 static void 4950 ext_size_vacate(range_tree_t *rt, void *arg) 4951 { 4952 zfs_btree_t *size_tree = arg; 4953 zfs_btree_clear(size_tree); 4954 zfs_btree_destroy(size_tree); 4955 4956 ext_size_create(rt, arg); 4957 } 4958 4959 static const range_tree_ops_t ext_size_ops = { 4960 .rtop_create = ext_size_create, 4961 .rtop_destroy = ext_size_destroy, 4962 .rtop_add = ext_size_add, 4963 .rtop_remove = ext_size_remove, 4964 .rtop_vacate = ext_size_vacate 4965 }; 4966 4967 /* 4968 * Comparator for the q_sios_by_addr tree. Sorting is simply performed 4969 * based on LBA-order (from lowest to highest). 4970 */ 4971 static int 4972 sio_addr_compare(const void *x, const void *y) 4973 { 4974 const scan_io_t *a = x, *b = y; 4975 4976 return (TREE_CMP(SIO_GET_OFFSET(a), SIO_GET_OFFSET(b))); 4977 } 4978 4979 /* IO queues are created on demand when they are needed. */ 4980 static dsl_scan_io_queue_t * 4981 scan_io_queue_create(vdev_t *vd) 4982 { 4983 dsl_scan_t *scn = vd->vdev_spa->spa_dsl_pool->dp_scan; 4984 dsl_scan_io_queue_t *q = kmem_zalloc(sizeof (*q), KM_SLEEP); 4985 4986 q->q_scn = scn; 4987 q->q_vd = vd; 4988 q->q_sio_memused = 0; 4989 q->q_last_ext_addr = -1; 4990 cv_init(&q->q_zio_cv, NULL, CV_DEFAULT, NULL); 4991 q->q_exts_by_addr = range_tree_create_gap(&ext_size_ops, RANGE_SEG_GAP, 4992 &q->q_exts_by_size, 0, vd->vdev_ashift, zfs_scan_max_ext_gap); 4993 avl_create(&q->q_sios_by_addr, sio_addr_compare, 4994 sizeof (scan_io_t), offsetof(scan_io_t, sio_nodes.sio_addr_node)); 4995 4996 return (q); 4997 } 4998 4999 /* 5000 * Destroys a scan queue and all segments and scan_io_t's contained in it. 5001 * No further execution of I/O occurs, anything pending in the queue is 5002 * simply freed without being executed. 5003 */ 5004 void 5005 dsl_scan_io_queue_destroy(dsl_scan_io_queue_t *queue) 5006 { 5007 dsl_scan_t *scn = queue->q_scn; 5008 scan_io_t *sio; 5009 void *cookie = NULL; 5010 5011 ASSERT(MUTEX_HELD(&queue->q_vd->vdev_scan_io_queue_lock)); 5012 5013 if (!avl_is_empty(&queue->q_sios_by_addr)) 5014 atomic_add_64(&scn->scn_queues_pending, -1); 5015 while ((sio = avl_destroy_nodes(&queue->q_sios_by_addr, &cookie)) != 5016 NULL) { 5017 ASSERT(range_tree_contains(queue->q_exts_by_addr, 5018 SIO_GET_OFFSET(sio), SIO_GET_ASIZE(sio))); 5019 queue->q_sio_memused -= SIO_GET_MUSED(sio); 5020 sio_free(sio); 5021 } 5022 5023 ASSERT0(queue->q_sio_memused); 5024 range_tree_vacate(queue->q_exts_by_addr, NULL, queue); 5025 range_tree_destroy(queue->q_exts_by_addr); 5026 avl_destroy(&queue->q_sios_by_addr); 5027 cv_destroy(&queue->q_zio_cv); 5028 5029 kmem_free(queue, sizeof (*queue)); 5030 } 5031 5032 /* 5033 * Properly transfers a dsl_scan_queue_t from `svd' to `tvd'. This is 5034 * called on behalf of vdev_top_transfer when creating or destroying 5035 * a mirror vdev due to zpool attach/detach. 5036 */ 5037 void 5038 dsl_scan_io_queue_vdev_xfer(vdev_t *svd, vdev_t *tvd) 5039 { 5040 mutex_enter(&svd->vdev_scan_io_queue_lock); 5041 mutex_enter(&tvd->vdev_scan_io_queue_lock); 5042 5043 VERIFY3P(tvd->vdev_scan_io_queue, ==, NULL); 5044 tvd->vdev_scan_io_queue = svd->vdev_scan_io_queue; 5045 svd->vdev_scan_io_queue = NULL; 5046 if (tvd->vdev_scan_io_queue != NULL) 5047 tvd->vdev_scan_io_queue->q_vd = tvd; 5048 5049 mutex_exit(&tvd->vdev_scan_io_queue_lock); 5050 mutex_exit(&svd->vdev_scan_io_queue_lock); 5051 } 5052 5053 static void 5054 scan_io_queues_destroy(dsl_scan_t *scn) 5055 { 5056 vdev_t *rvd = scn->scn_dp->dp_spa->spa_root_vdev; 5057 5058 for (uint64_t i = 0; i < rvd->vdev_children; i++) { 5059 vdev_t *tvd = rvd->vdev_child[i]; 5060 5061 mutex_enter(&tvd->vdev_scan_io_queue_lock); 5062 if (tvd->vdev_scan_io_queue != NULL) 5063 dsl_scan_io_queue_destroy(tvd->vdev_scan_io_queue); 5064 tvd->vdev_scan_io_queue = NULL; 5065 mutex_exit(&tvd->vdev_scan_io_queue_lock); 5066 } 5067 } 5068 5069 static void 5070 dsl_scan_freed_dva(spa_t *spa, const blkptr_t *bp, int dva_i) 5071 { 5072 dsl_pool_t *dp = spa->spa_dsl_pool; 5073 dsl_scan_t *scn = dp->dp_scan; 5074 vdev_t *vdev; 5075 kmutex_t *q_lock; 5076 dsl_scan_io_queue_t *queue; 5077 scan_io_t *srch_sio, *sio; 5078 avl_index_t idx; 5079 uint64_t start, size; 5080 5081 vdev = vdev_lookup_top(spa, DVA_GET_VDEV(&bp->blk_dva[dva_i])); 5082 ASSERT(vdev != NULL); 5083 q_lock = &vdev->vdev_scan_io_queue_lock; 5084 queue = vdev->vdev_scan_io_queue; 5085 5086 mutex_enter(q_lock); 5087 if (queue == NULL) { 5088 mutex_exit(q_lock); 5089 return; 5090 } 5091 5092 srch_sio = sio_alloc(BP_GET_NDVAS(bp)); 5093 bp2sio(bp, srch_sio, dva_i); 5094 start = SIO_GET_OFFSET(srch_sio); 5095 size = SIO_GET_ASIZE(srch_sio); 5096 5097 /* 5098 * We can find the zio in two states: 5099 * 1) Cold, just sitting in the queue of zio's to be issued at 5100 * some point in the future. In this case, all we do is 5101 * remove the zio from the q_sios_by_addr tree, decrement 5102 * its data volume from the containing range_seg_t and 5103 * resort the q_exts_by_size tree to reflect that the 5104 * range_seg_t has lost some of its 'fill'. We don't shorten 5105 * the range_seg_t - this is usually rare enough not to be 5106 * worth the extra hassle of trying keep track of precise 5107 * extent boundaries. 5108 * 2) Hot, where the zio is currently in-flight in 5109 * dsl_scan_issue_ios. In this case, we can't simply 5110 * reach in and stop the in-flight zio's, so we instead 5111 * block the caller. Eventually, dsl_scan_issue_ios will 5112 * be done with issuing the zio's it gathered and will 5113 * signal us. 5114 */ 5115 sio = avl_find(&queue->q_sios_by_addr, srch_sio, &idx); 5116 sio_free(srch_sio); 5117 5118 if (sio != NULL) { 5119 blkptr_t tmpbp; 5120 5121 /* Got it while it was cold in the queue */ 5122 ASSERT3U(start, ==, SIO_GET_OFFSET(sio)); 5123 ASSERT3U(size, ==, SIO_GET_ASIZE(sio)); 5124 avl_remove(&queue->q_sios_by_addr, sio); 5125 if (avl_is_empty(&queue->q_sios_by_addr)) 5126 atomic_add_64(&scn->scn_queues_pending, -1); 5127 queue->q_sio_memused -= SIO_GET_MUSED(sio); 5128 5129 ASSERT(range_tree_contains(queue->q_exts_by_addr, start, size)); 5130 range_tree_remove_fill(queue->q_exts_by_addr, start, size); 5131 5132 /* count the block as though we skipped it */ 5133 sio2bp(sio, &tmpbp); 5134 count_block_skipped(scn, &tmpbp, B_FALSE); 5135 5136 sio_free(sio); 5137 } 5138 mutex_exit(q_lock); 5139 } 5140 5141 /* 5142 * Callback invoked when a zio_free() zio is executing. This needs to be 5143 * intercepted to prevent the zio from deallocating a particular portion 5144 * of disk space and it then getting reallocated and written to, while we 5145 * still have it queued up for processing. 5146 */ 5147 void 5148 dsl_scan_freed(spa_t *spa, const blkptr_t *bp) 5149 { 5150 dsl_pool_t *dp = spa->spa_dsl_pool; 5151 dsl_scan_t *scn = dp->dp_scan; 5152 5153 ASSERT(!BP_IS_EMBEDDED(bp)); 5154 ASSERT(scn != NULL); 5155 if (!dsl_scan_is_running(scn)) 5156 return; 5157 5158 for (int i = 0; i < BP_GET_NDVAS(bp); i++) 5159 dsl_scan_freed_dva(spa, bp, i); 5160 } 5161 5162 /* 5163 * Check if a vdev needs resilvering (non-empty DTL), if so, and resilver has 5164 * not started, start it. Otherwise, only restart if max txg in DTL range is 5165 * greater than the max txg in the current scan. If the DTL max is less than 5166 * the scan max, then the vdev has not missed any new data since the resilver 5167 * started, so a restart is not needed. 5168 */ 5169 void 5170 dsl_scan_assess_vdev(dsl_pool_t *dp, vdev_t *vd) 5171 { 5172 uint64_t min, max; 5173 5174 if (!vdev_resilver_needed(vd, &min, &max)) 5175 return; 5176 5177 if (!dsl_scan_resilvering(dp)) { 5178 spa_async_request(dp->dp_spa, SPA_ASYNC_RESILVER); 5179 return; 5180 } 5181 5182 if (max <= dp->dp_scan->scn_phys.scn_max_txg) 5183 return; 5184 5185 /* restart is needed, check if it can be deferred */ 5186 if (spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_RESILVER_DEFER)) 5187 vdev_defer_resilver(vd); 5188 else 5189 spa_async_request(dp->dp_spa, SPA_ASYNC_RESILVER); 5190 } 5191 5192 ZFS_MODULE_PARAM(zfs, zfs_, scan_vdev_limit, U64, ZMOD_RW, 5193 "Max bytes in flight per leaf vdev for scrubs and resilvers"); 5194 5195 ZFS_MODULE_PARAM(zfs, zfs_, scrub_min_time_ms, UINT, ZMOD_RW, 5196 "Min millisecs to scrub per txg"); 5197 5198 ZFS_MODULE_PARAM(zfs, zfs_, obsolete_min_time_ms, UINT, ZMOD_RW, 5199 "Min millisecs to obsolete per txg"); 5200 5201 ZFS_MODULE_PARAM(zfs, zfs_, free_min_time_ms, UINT, ZMOD_RW, 5202 "Min millisecs to free per txg"); 5203 5204 ZFS_MODULE_PARAM(zfs, zfs_, resilver_min_time_ms, UINT, ZMOD_RW, 5205 "Min millisecs to resilver per txg"); 5206 5207 ZFS_MODULE_PARAM(zfs, zfs_, scan_suspend_progress, INT, ZMOD_RW, 5208 "Set to prevent scans from progressing"); 5209 5210 ZFS_MODULE_PARAM(zfs, zfs_, no_scrub_io, INT, ZMOD_RW, 5211 "Set to disable scrub I/O"); 5212 5213 ZFS_MODULE_PARAM(zfs, zfs_, no_scrub_prefetch, INT, ZMOD_RW, 5214 "Set to disable scrub prefetching"); 5215 5216 ZFS_MODULE_PARAM(zfs, zfs_, async_block_max_blocks, U64, ZMOD_RW, 5217 "Max number of blocks freed in one txg"); 5218 5219 ZFS_MODULE_PARAM(zfs, zfs_, max_async_dedup_frees, U64, ZMOD_RW, 5220 "Max number of dedup blocks freed in one txg"); 5221 5222 ZFS_MODULE_PARAM(zfs, zfs_, free_bpobj_enabled, INT, ZMOD_RW, 5223 "Enable processing of the free_bpobj"); 5224 5225 ZFS_MODULE_PARAM(zfs, zfs_, scan_blkstats, INT, ZMOD_RW, 5226 "Enable block statistics calculation during scrub"); 5227 5228 ZFS_MODULE_PARAM(zfs, zfs_, scan_mem_lim_fact, UINT, ZMOD_RW, 5229 "Fraction of RAM for scan hard limit"); 5230 5231 ZFS_MODULE_PARAM(zfs, zfs_, scan_issue_strategy, UINT, ZMOD_RW, 5232 "IO issuing strategy during scrubbing. 0 = default, 1 = LBA, 2 = size"); 5233 5234 ZFS_MODULE_PARAM(zfs, zfs_, scan_legacy, INT, ZMOD_RW, 5235 "Scrub using legacy non-sequential method"); 5236 5237 ZFS_MODULE_PARAM(zfs, zfs_, scan_checkpoint_intval, UINT, ZMOD_RW, 5238 "Scan progress on-disk checkpointing interval"); 5239 5240 ZFS_MODULE_PARAM(zfs, zfs_, scan_max_ext_gap, U64, ZMOD_RW, 5241 "Max gap in bytes between sequential scrub / resilver I/Os"); 5242 5243 ZFS_MODULE_PARAM(zfs, zfs_, scan_mem_lim_soft_fact, UINT, ZMOD_RW, 5244 "Fraction of hard limit used as soft limit"); 5245 5246 ZFS_MODULE_PARAM(zfs, zfs_, scan_strict_mem_lim, INT, ZMOD_RW, 5247 "Tunable to attempt to reduce lock contention"); 5248 5249 ZFS_MODULE_PARAM(zfs, zfs_, scan_fill_weight, UINT, ZMOD_RW, 5250 "Tunable to adjust bias towards more filled segments during scans"); 5251 5252 ZFS_MODULE_PARAM(zfs, zfs_, scan_report_txgs, UINT, ZMOD_RW, 5253 "Tunable to report resilver performance over the last N txgs"); 5254 5255 ZFS_MODULE_PARAM(zfs, zfs_, resilver_disable_defer, INT, ZMOD_RW, 5256 "Process all resilvers immediately"); 5257 5258 ZFS_MODULE_PARAM(zfs, zfs_, scrub_error_blocks_per_txg, UINT, ZMOD_RW, 5259 "Error blocks to be scrubbed in one txg"); 5260 /* END CSTYLED */ 5261