Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/contrib/openzfs/module/zfs/dmu_traverse.c
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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) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2012, 2018 by Delphix. All rights reserved. 24 */ 25 26 #include <sys/zfs_context.h> 27 #include <sys/dmu_objset.h> 28 #include <sys/dmu_traverse.h> 29 #include <sys/dsl_dataset.h> 30 #include <sys/dsl_dir.h> 31 #include <sys/dsl_pool.h> 32 #include <sys/dnode.h> 33 #include <sys/spa.h> 34 #include <sys/spa_impl.h> 35 #include <sys/zio.h> 36 #include <sys/dmu_impl.h> 37 #include <sys/sa.h> 38 #include <sys/sa_impl.h> 39 #include <sys/callb.h> 40 #include <sys/zfeature.h> 41 42 static int32_t zfs_pd_bytes_max = 50 * 1024 * 1024; /* 50MB */ 43 static int32_t send_holes_without_birth_time = 1; 44 static uint_t zfs_traverse_indirect_prefetch_limit = 32; 45 46 typedef struct prefetch_data { 47 kmutex_t pd_mtx; 48 kcondvar_t pd_cv; 49 int32_t pd_bytes_fetched; 50 int pd_flags; 51 boolean_t pd_cancel; 52 boolean_t pd_exited; 53 zbookmark_phys_t pd_resume; 54 } prefetch_data_t; 55 56 typedef struct traverse_data { 57 spa_t *td_spa; 58 uint64_t td_objset; 59 blkptr_t *td_rootbp; 60 uint64_t td_min_txg; 61 zbookmark_phys_t *td_resume; 62 int td_flags; 63 prefetch_data_t *td_pfd; 64 boolean_t td_paused; 65 uint64_t td_hole_birth_enabled_txg; 66 blkptr_cb_t *td_func; 67 void *td_arg; 68 boolean_t td_realloc_possible; 69 } traverse_data_t; 70 71 static int traverse_dnode(traverse_data_t *td, const blkptr_t *bp, 72 const dnode_phys_t *dnp, uint64_t objset, uint64_t object); 73 static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *, 74 uint64_t objset, uint64_t object); 75 76 static int 77 traverse_zil_block(zilog_t *zilog, const blkptr_t *bp, void *arg, 78 uint64_t claim_txg) 79 { 80 traverse_data_t *td = arg; 81 zbookmark_phys_t zb; 82 83 if (BP_IS_HOLE(bp)) 84 return (0); 85 86 if (claim_txg == 0 && bp->blk_birth >= spa_min_claim_txg(td->td_spa)) 87 return (-1); 88 89 SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 90 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 91 92 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, td->td_arg); 93 94 return (0); 95 } 96 97 static int 98 traverse_zil_record(zilog_t *zilog, const lr_t *lrc, void *arg, 99 uint64_t claim_txg) 100 { 101 traverse_data_t *td = arg; 102 103 if (lrc->lrc_txtype == TX_WRITE) { 104 lr_write_t *lr = (lr_write_t *)lrc; 105 blkptr_t *bp = &lr->lr_blkptr; 106 zbookmark_phys_t zb; 107 108 if (BP_IS_HOLE(bp)) 109 return (0); 110 111 if (claim_txg == 0 || bp->blk_birth < claim_txg) 112 return (0); 113 114 ASSERT3U(BP_GET_LSIZE(bp), !=, 0); 115 SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid, 116 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 117 118 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, 119 td->td_arg); 120 } 121 return (0); 122 } 123 124 static void 125 traverse_zil(traverse_data_t *td, zil_header_t *zh) 126 { 127 uint64_t claim_txg = zh->zh_claim_txg; 128 129 /* 130 * We only want to visit blocks that have been claimed but not yet 131 * replayed; plus blocks that are already stable in read-only mode. 132 */ 133 if (claim_txg == 0 && spa_writeable(td->td_spa)) 134 return; 135 136 zilog_t *zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh); 137 (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td, 138 claim_txg, !(td->td_flags & TRAVERSE_NO_DECRYPT)); 139 zil_free(zilog); 140 } 141 142 typedef enum resume_skip { 143 RESUME_SKIP_ALL, 144 RESUME_SKIP_NONE, 145 RESUME_SKIP_CHILDREN 146 } resume_skip_t; 147 148 /* 149 * Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and 150 * the block indicated by zb does not need to be visited at all. Returns 151 * RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the 152 * resume point. This indicates that this block should be visited but not its 153 * children (since they must have been visited in a previous traversal). 154 * Otherwise returns RESUME_SKIP_NONE. 155 */ 156 static resume_skip_t 157 resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp, 158 const zbookmark_phys_t *zb) 159 { 160 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) { 161 /* 162 * If we already visited this bp & everything below, 163 * don't bother doing it again. 164 */ 165 if (zbookmark_subtree_completed(dnp, zb, td->td_resume)) 166 return (RESUME_SKIP_ALL); 167 168 /* 169 * If we found the block we're trying to resume from, zero 170 * the bookmark out to indicate that we have resumed. 171 */ 172 if (memcmp(zb, td->td_resume, sizeof (*zb)) == 0) { 173 memset(td->td_resume, 0, sizeof (*zb)); 174 if (td->td_flags & TRAVERSE_POST) 175 return (RESUME_SKIP_CHILDREN); 176 } 177 } 178 return (RESUME_SKIP_NONE); 179 } 180 181 /* 182 * Returns B_TRUE, if prefetch read is issued, otherwise B_FALSE. 183 */ 184 static boolean_t 185 traverse_prefetch_metadata(traverse_data_t *td, 186 const blkptr_t *bp, const zbookmark_phys_t *zb) 187 { 188 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH | 189 ARC_FLAG_PRESCIENT_PREFETCH; 190 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE; 191 192 if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA)) 193 return (B_FALSE); 194 /* 195 * If we are in the process of resuming, don't prefetch, because 196 * some children will not be needed (and in fact may have already 197 * been freed). 198 */ 199 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) 200 return (B_FALSE); 201 if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg) 202 return (B_FALSE); 203 if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE) 204 return (B_FALSE); 205 ASSERT(!BP_IS_REDACTED(bp)); 206 207 if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp)) 208 zio_flags |= ZIO_FLAG_RAW; 209 210 (void) arc_read(NULL, td->td_spa, bp, NULL, NULL, 211 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 212 return (B_TRUE); 213 } 214 215 static boolean_t 216 prefetch_needed(prefetch_data_t *pfd, const blkptr_t *bp) 217 { 218 ASSERT(pfd->pd_flags & TRAVERSE_PREFETCH_DATA); 219 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) || 220 BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG || BP_IS_REDACTED(bp)) 221 return (B_FALSE); 222 return (B_TRUE); 223 } 224 225 static int 226 traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, 227 const blkptr_t *bp, const zbookmark_phys_t *zb) 228 { 229 int err = 0; 230 arc_buf_t *buf = NULL; 231 prefetch_data_t *pd = td->td_pfd; 232 233 switch (resume_skip_check(td, dnp, zb)) { 234 case RESUME_SKIP_ALL: 235 return (0); 236 case RESUME_SKIP_CHILDREN: 237 goto post; 238 case RESUME_SKIP_NONE: 239 break; 240 default: 241 ASSERT(0); 242 } 243 244 if (bp->blk_birth == 0) { 245 /* 246 * Since this block has a birth time of 0 it must be one of 247 * two things: a hole created before the 248 * SPA_FEATURE_HOLE_BIRTH feature was enabled, or a hole 249 * which has always been a hole in an object. 250 * 251 * If a file is written sparsely, then the unwritten parts of 252 * the file were "always holes" -- that is, they have been 253 * holes since this object was allocated. However, we (and 254 * our callers) can not necessarily tell when an object was 255 * allocated. Therefore, if it's possible that this object 256 * was freed and then its object number reused, we need to 257 * visit all the holes with birth==0. 258 * 259 * If it isn't possible that the object number was reused, 260 * then if SPA_FEATURE_HOLE_BIRTH was enabled before we wrote 261 * all the blocks we will visit as part of this traversal, 262 * then this hole must have always existed, so we can skip 263 * it. We visit blocks born after (exclusive) td_min_txg. 264 * 265 * Note that the meta-dnode cannot be reallocated. 266 */ 267 if (!send_holes_without_birth_time && 268 (!td->td_realloc_possible || 269 zb->zb_object == DMU_META_DNODE_OBJECT) && 270 td->td_hole_birth_enabled_txg <= td->td_min_txg) 271 return (0); 272 } else if (bp->blk_birth <= td->td_min_txg) { 273 return (0); 274 } 275 276 if (pd != NULL && !pd->pd_exited && prefetch_needed(pd, bp)) { 277 uint64_t size = BP_GET_LSIZE(bp); 278 mutex_enter(&pd->pd_mtx); 279 ASSERT(pd->pd_bytes_fetched >= 0); 280 while (pd->pd_bytes_fetched < size && !pd->pd_exited) 281 cv_wait_sig(&pd->pd_cv, &pd->pd_mtx); 282 pd->pd_bytes_fetched -= size; 283 cv_broadcast(&pd->pd_cv); 284 mutex_exit(&pd->pd_mtx); 285 } 286 287 if (BP_IS_HOLE(bp) || BP_IS_REDACTED(bp)) { 288 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); 289 if (err != 0) 290 goto post; 291 return (0); 292 } 293 294 if (td->td_flags & TRAVERSE_PRE) { 295 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, 296 td->td_arg); 297 if (err == TRAVERSE_VISIT_NO_CHILDREN) 298 return (0); 299 if (err != 0) 300 goto post; 301 } 302 303 if (BP_GET_LEVEL(bp) > 0) { 304 uint32_t flags = ARC_FLAG_WAIT; 305 int32_t i, ptidx, pidx; 306 uint32_t prefetchlimit; 307 int32_t epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 308 zbookmark_phys_t *czb; 309 310 ASSERT(!BP_IS_PROTECTED(bp)); 311 312 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 313 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 314 if (err != 0) 315 goto post; 316 317 czb = kmem_alloc(sizeof (zbookmark_phys_t), KM_SLEEP); 318 319 /* 320 * When performing a traversal it is beneficial to 321 * asynchronously read-ahead the upcoming indirect 322 * blocks since they will be needed shortly. However, 323 * since a 128k indirect (non-L0) block may contain up 324 * to 1024 128-byte block pointers, its preferable to not 325 * prefetch them all at once. Issuing a large number of 326 * async reads may effect performance, and the earlier 327 * the indirect blocks are prefetched the less likely 328 * they are to still be resident in the ARC when needed. 329 * Therefore, prefetching indirect blocks is limited to 330 * zfs_traverse_indirect_prefetch_limit=32 blocks by 331 * default. 332 * 333 * pidx: Index for which next prefetch to be issued. 334 * ptidx: Index at which next prefetch to be triggered. 335 */ 336 ptidx = 0; 337 pidx = 1; 338 prefetchlimit = zfs_traverse_indirect_prefetch_limit; 339 for (i = 0; i < epb; i++) { 340 if (prefetchlimit && i == ptidx) { 341 ASSERT3S(ptidx, <=, pidx); 342 for (uint32_t prefetched = 0; pidx < epb && 343 prefetched < prefetchlimit; pidx++) { 344 SET_BOOKMARK(czb, zb->zb_objset, 345 zb->zb_object, zb->zb_level - 1, 346 zb->zb_blkid * epb + pidx); 347 if (traverse_prefetch_metadata(td, 348 &((blkptr_t *)buf->b_data)[pidx], 349 czb) == B_TRUE) { 350 prefetched++; 351 if (prefetched == 352 MAX(prefetchlimit / 2, 1)) 353 ptidx = pidx; 354 } 355 } 356 } 357 358 /* recursively visitbp() blocks below this */ 359 SET_BOOKMARK(czb, zb->zb_objset, zb->zb_object, 360 zb->zb_level - 1, 361 zb->zb_blkid * epb + i); 362 err = traverse_visitbp(td, dnp, 363 &((blkptr_t *)buf->b_data)[i], czb); 364 if (err != 0) 365 break; 366 } 367 368 kmem_free(czb, sizeof (zbookmark_phys_t)); 369 370 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 371 uint32_t flags = ARC_FLAG_WAIT; 372 uint32_t zio_flags = ZIO_FLAG_CANFAIL; 373 int32_t i; 374 int32_t epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 375 dnode_phys_t *child_dnp; 376 377 /* 378 * dnode blocks might have their bonus buffers encrypted, so 379 * we must be careful to honor TRAVERSE_NO_DECRYPT 380 */ 381 if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp)) 382 zio_flags |= ZIO_FLAG_RAW; 383 384 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 385 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 386 if (err != 0) 387 goto post; 388 389 child_dnp = buf->b_data; 390 391 for (i = 0; i < epb; i += child_dnp[i].dn_extra_slots + 1) { 392 prefetch_dnode_metadata(td, &child_dnp[i], 393 zb->zb_objset, zb->zb_blkid * epb + i); 394 } 395 396 /* recursively visitbp() blocks below this */ 397 for (i = 0; i < epb; i += child_dnp[i].dn_extra_slots + 1) { 398 err = traverse_dnode(td, bp, &child_dnp[i], 399 zb->zb_objset, zb->zb_blkid * epb + i); 400 if (err != 0) 401 break; 402 } 403 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 404 uint32_t zio_flags = ZIO_FLAG_CANFAIL; 405 arc_flags_t flags = ARC_FLAG_WAIT; 406 objset_phys_t *osp; 407 408 if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp)) 409 zio_flags |= ZIO_FLAG_RAW; 410 411 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 412 ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); 413 if (err != 0) 414 goto post; 415 416 osp = buf->b_data; 417 prefetch_dnode_metadata(td, &osp->os_meta_dnode, zb->zb_objset, 418 DMU_META_DNODE_OBJECT); 419 /* 420 * See the block comment above for the goal of this variable. 421 * If the maxblkid of the meta-dnode is 0, then we know that 422 * we've never had more than DNODES_PER_BLOCK objects in the 423 * dataset, which means we can't have reused any object ids. 424 */ 425 if (osp->os_meta_dnode.dn_maxblkid == 0) 426 td->td_realloc_possible = B_FALSE; 427 428 if (OBJSET_BUF_HAS_USERUSED(buf)) { 429 if (OBJSET_BUF_HAS_PROJECTUSED(buf)) 430 prefetch_dnode_metadata(td, 431 &osp->os_projectused_dnode, 432 zb->zb_objset, DMU_PROJECTUSED_OBJECT); 433 prefetch_dnode_metadata(td, &osp->os_groupused_dnode, 434 zb->zb_objset, DMU_GROUPUSED_OBJECT); 435 prefetch_dnode_metadata(td, &osp->os_userused_dnode, 436 zb->zb_objset, DMU_USERUSED_OBJECT); 437 } 438 439 err = traverse_dnode(td, bp, &osp->os_meta_dnode, zb->zb_objset, 440 DMU_META_DNODE_OBJECT); 441 if (err == 0 && OBJSET_BUF_HAS_USERUSED(buf)) { 442 if (OBJSET_BUF_HAS_PROJECTUSED(buf)) 443 err = traverse_dnode(td, bp, 444 &osp->os_projectused_dnode, zb->zb_objset, 445 DMU_PROJECTUSED_OBJECT); 446 if (err == 0) 447 err = traverse_dnode(td, bp, 448 &osp->os_groupused_dnode, zb->zb_objset, 449 DMU_GROUPUSED_OBJECT); 450 if (err == 0) 451 err = traverse_dnode(td, bp, 452 &osp->os_userused_dnode, zb->zb_objset, 453 DMU_USERUSED_OBJECT); 454 } 455 } 456 457 if (buf) 458 arc_buf_destroy(buf, &buf); 459 460 post: 461 if (err == 0 && (td->td_flags & TRAVERSE_POST)) 462 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); 463 464 if ((td->td_flags & TRAVERSE_HARD) && (err == EIO || err == ECKSUM)) { 465 /* 466 * Ignore this disk error as requested by the HARD flag, 467 * and continue traversal. 468 */ 469 err = 0; 470 } 471 472 /* 473 * If we are stopping here, set td_resume. 474 */ 475 if (td->td_resume != NULL && err != 0 && !td->td_paused) { 476 td->td_resume->zb_objset = zb->zb_objset; 477 td->td_resume->zb_object = zb->zb_object; 478 td->td_resume->zb_level = 0; 479 /* 480 * If we have stopped on an indirect block (e.g. due to 481 * i/o error), we have not visited anything below it. 482 * Set the bookmark to the first level-0 block that we need 483 * to visit. This way, the resuming code does not need to 484 * deal with resuming from indirect blocks. 485 * 486 * Note, if zb_level <= 0, dnp may be NULL, so we don't want 487 * to dereference it. 488 */ 489 td->td_resume->zb_blkid = zb->zb_blkid; 490 if (zb->zb_level > 0) { 491 td->td_resume->zb_blkid <<= zb->zb_level * 492 (dnp->dn_indblkshift - SPA_BLKPTRSHIFT); 493 } 494 td->td_paused = B_TRUE; 495 } 496 497 return (err); 498 } 499 500 static void 501 prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp, 502 uint64_t objset, uint64_t object) 503 { 504 int j; 505 zbookmark_phys_t czb; 506 507 for (j = 0; j < dnp->dn_nblkptr; j++) { 508 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); 509 traverse_prefetch_metadata(td, &dnp->dn_blkptr[j], &czb); 510 } 511 512 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 513 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); 514 traverse_prefetch_metadata(td, DN_SPILL_BLKPTR(dnp), &czb); 515 } 516 } 517 518 static int 519 traverse_dnode(traverse_data_t *td, const blkptr_t *bp, const dnode_phys_t *dnp, 520 uint64_t objset, uint64_t object) 521 { 522 int j, err = 0; 523 zbookmark_phys_t czb; 524 525 if (object != DMU_META_DNODE_OBJECT && td->td_resume != NULL && 526 object < td->td_resume->zb_object) 527 return (0); 528 529 if (td->td_flags & TRAVERSE_PRE) { 530 SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL, 531 ZB_DNODE_BLKID); 532 err = td->td_func(td->td_spa, NULL, bp, &czb, dnp, 533 td->td_arg); 534 if (err == TRAVERSE_VISIT_NO_CHILDREN) 535 return (0); 536 if (err != 0) 537 return (err); 538 } 539 540 for (j = 0; j < dnp->dn_nblkptr; j++) { 541 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); 542 err = traverse_visitbp(td, dnp, &dnp->dn_blkptr[j], &czb); 543 if (err != 0) 544 break; 545 } 546 547 if (err == 0 && (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { 548 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); 549 err = traverse_visitbp(td, dnp, DN_SPILL_BLKPTR(dnp), &czb); 550 } 551 552 if (err == 0 && (td->td_flags & TRAVERSE_POST)) { 553 SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL, 554 ZB_DNODE_BLKID); 555 err = td->td_func(td->td_spa, NULL, bp, &czb, dnp, 556 td->td_arg); 557 if (err == TRAVERSE_VISIT_NO_CHILDREN) 558 return (0); 559 if (err != 0) 560 return (err); 561 } 562 return (err); 563 } 564 565 static int 566 traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 567 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg) 568 { 569 (void) zilog, (void) dnp; 570 prefetch_data_t *pfd = arg; 571 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE; 572 arc_flags_t aflags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH | 573 ARC_FLAG_PRESCIENT_PREFETCH; 574 575 ASSERT(pfd->pd_bytes_fetched >= 0); 576 if (zb->zb_level == ZB_DNODE_LEVEL) 577 return (0); 578 if (pfd->pd_cancel) 579 return (SET_ERROR(EINTR)); 580 581 if (!prefetch_needed(pfd, bp)) 582 return (0); 583 584 mutex_enter(&pfd->pd_mtx); 585 while (!pfd->pd_cancel && pfd->pd_bytes_fetched >= zfs_pd_bytes_max) 586 cv_wait_sig(&pfd->pd_cv, &pfd->pd_mtx); 587 pfd->pd_bytes_fetched += BP_GET_LSIZE(bp); 588 cv_broadcast(&pfd->pd_cv); 589 mutex_exit(&pfd->pd_mtx); 590 591 if ((pfd->pd_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp)) 592 zio_flags |= ZIO_FLAG_RAW; 593 594 (void) arc_read(NULL, spa, bp, NULL, NULL, ZIO_PRIORITY_ASYNC_READ, 595 zio_flags, &aflags, zb); 596 597 return (0); 598 } 599 600 static void 601 traverse_prefetch_thread(void *arg) 602 { 603 traverse_data_t *td_main = arg; 604 traverse_data_t td = *td_main; 605 zbookmark_phys_t czb; 606 fstrans_cookie_t cookie = spl_fstrans_mark(); 607 608 td.td_func = traverse_prefetcher; 609 td.td_arg = td_main->td_pfd; 610 td.td_pfd = NULL; 611 td.td_resume = &td_main->td_pfd->pd_resume; 612 613 SET_BOOKMARK(&czb, td.td_objset, 614 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 615 (void) traverse_visitbp(&td, NULL, td.td_rootbp, &czb); 616 617 mutex_enter(&td_main->td_pfd->pd_mtx); 618 td_main->td_pfd->pd_exited = B_TRUE; 619 cv_broadcast(&td_main->td_pfd->pd_cv); 620 mutex_exit(&td_main->td_pfd->pd_mtx); 621 spl_fstrans_unmark(cookie); 622 } 623 624 /* 625 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are 626 * in syncing context). 627 */ 628 static int 629 traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp, 630 uint64_t txg_start, zbookmark_phys_t *resume, int flags, 631 blkptr_cb_t func, void *arg) 632 { 633 traverse_data_t *td; 634 prefetch_data_t *pd; 635 zbookmark_phys_t *czb; 636 int err; 637 638 ASSERT(ds == NULL || objset == ds->ds_object); 639 ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST)); 640 641 td = kmem_alloc(sizeof (traverse_data_t), KM_SLEEP); 642 pd = kmem_zalloc(sizeof (prefetch_data_t), KM_SLEEP); 643 czb = kmem_alloc(sizeof (zbookmark_phys_t), KM_SLEEP); 644 645 td->td_spa = spa; 646 td->td_objset = objset; 647 td->td_rootbp = rootbp; 648 td->td_min_txg = txg_start; 649 td->td_resume = resume; 650 td->td_func = func; 651 td->td_arg = arg; 652 td->td_pfd = pd; 653 td->td_flags = flags; 654 td->td_paused = B_FALSE; 655 td->td_realloc_possible = (txg_start == 0 ? B_FALSE : B_TRUE); 656 657 if (spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 658 VERIFY(spa_feature_enabled_txg(spa, 659 SPA_FEATURE_HOLE_BIRTH, &td->td_hole_birth_enabled_txg)); 660 } else { 661 td->td_hole_birth_enabled_txg = UINT64_MAX; 662 } 663 664 pd->pd_flags = flags; 665 if (resume != NULL) 666 pd->pd_resume = *resume; 667 mutex_init(&pd->pd_mtx, NULL, MUTEX_DEFAULT, NULL); 668 cv_init(&pd->pd_cv, NULL, CV_DEFAULT, NULL); 669 670 SET_BOOKMARK(czb, td->td_objset, 671 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 672 673 /* See comment on ZIL traversal in dsl_scan_visitds. */ 674 if (ds != NULL && !ds->ds_is_snapshot && !BP_IS_HOLE(rootbp)) { 675 zio_flag_t zio_flags = ZIO_FLAG_CANFAIL; 676 uint32_t flags = ARC_FLAG_WAIT; 677 objset_phys_t *osp; 678 arc_buf_t *buf; 679 ASSERT(!BP_IS_REDACTED(rootbp)); 680 681 if ((td->td_flags & TRAVERSE_NO_DECRYPT) && 682 BP_IS_PROTECTED(rootbp)) 683 zio_flags |= ZIO_FLAG_RAW; 684 685 err = arc_read(NULL, td->td_spa, rootbp, arc_getbuf_func, 686 &buf, ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, czb); 687 if (err != 0) { 688 /* 689 * If both TRAVERSE_HARD and TRAVERSE_PRE are set, 690 * continue to visitbp so that td_func can be called 691 * in pre stage, and err will reset to zero. 692 */ 693 if (!(td->td_flags & TRAVERSE_HARD) || 694 !(td->td_flags & TRAVERSE_PRE)) 695 goto out; 696 } else { 697 osp = buf->b_data; 698 traverse_zil(td, &osp->os_zil_header); 699 arc_buf_destroy(buf, &buf); 700 } 701 } 702 703 if (!(flags & TRAVERSE_PREFETCH_DATA) || 704 taskq_dispatch(spa->spa_prefetch_taskq, traverse_prefetch_thread, 705 td, TQ_NOQUEUE) == TASKQID_INVALID) 706 pd->pd_exited = B_TRUE; 707 708 err = traverse_visitbp(td, NULL, rootbp, czb); 709 710 mutex_enter(&pd->pd_mtx); 711 pd->pd_cancel = B_TRUE; 712 cv_broadcast(&pd->pd_cv); 713 while (!pd->pd_exited) 714 cv_wait_sig(&pd->pd_cv, &pd->pd_mtx); 715 mutex_exit(&pd->pd_mtx); 716 out: 717 mutex_destroy(&pd->pd_mtx); 718 cv_destroy(&pd->pd_cv); 719 720 kmem_free(czb, sizeof (zbookmark_phys_t)); 721 kmem_free(pd, sizeof (struct prefetch_data)); 722 kmem_free(td, sizeof (struct traverse_data)); 723 724 return (err); 725 } 726 727 /* 728 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are 729 * in syncing context). 730 */ 731 int 732 traverse_dataset_resume(dsl_dataset_t *ds, uint64_t txg_start, 733 zbookmark_phys_t *resume, 734 int flags, blkptr_cb_t func, void *arg) 735 { 736 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object, 737 &dsl_dataset_phys(ds)->ds_bp, txg_start, resume, flags, func, arg)); 738 } 739 740 int 741 traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, 742 int flags, blkptr_cb_t func, void *arg) 743 { 744 return (traverse_dataset_resume(ds, txg_start, NULL, flags, func, arg)); 745 } 746 747 int 748 traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr, 749 uint64_t txg_start, zbookmark_phys_t *resume, int flags, 750 blkptr_cb_t func, void *arg) 751 { 752 return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET, 753 blkptr, txg_start, resume, flags, func, arg)); 754 } 755 756 /* 757 * NB: pool must not be changing on-disk (eg, from zdb or sync context). 758 */ 759 int 760 traverse_pool(spa_t *spa, uint64_t txg_start, int flags, 761 blkptr_cb_t func, void *arg) 762 { 763 int err; 764 dsl_pool_t *dp = spa_get_dsl(spa); 765 objset_t *mos = dp->dp_meta_objset; 766 boolean_t hard = (flags & TRAVERSE_HARD); 767 768 /* visit the MOS */ 769 err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa), 770 txg_start, NULL, flags, func, arg); 771 if (err != 0) 772 return (err); 773 774 /* visit each dataset */ 775 for (uint64_t obj = 1; err == 0; 776 err = dmu_object_next(mos, &obj, B_FALSE, txg_start)) { 777 dmu_object_info_t doi; 778 779 err = dmu_object_info(mos, obj, &doi); 780 if (err != 0) { 781 if (hard) 782 continue; 783 break; 784 } 785 786 if (doi.doi_bonus_type == DMU_OT_DSL_DATASET) { 787 dsl_dataset_t *ds; 788 uint64_t txg = txg_start; 789 790 dsl_pool_config_enter(dp, FTAG); 791 err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds); 792 dsl_pool_config_exit(dp, FTAG); 793 if (err != 0) { 794 if (hard) 795 continue; 796 break; 797 } 798 if (dsl_dataset_phys(ds)->ds_prev_snap_txg > txg) 799 txg = dsl_dataset_phys(ds)->ds_prev_snap_txg; 800 err = traverse_dataset(ds, txg, flags, func, arg); 801 dsl_dataset_rele(ds, FTAG); 802 if (err != 0) 803 break; 804 } 805 } 806 if (err == ESRCH) 807 err = 0; 808 return (err); 809 } 810 811 EXPORT_SYMBOL(traverse_dataset); 812 EXPORT_SYMBOL(traverse_pool); 813 814 ZFS_MODULE_PARAM(zfs, zfs_, pd_bytes_max, INT, ZMOD_RW, 815 "Max number of bytes to prefetch"); 816 817 ZFS_MODULE_PARAM(zfs, zfs_, traverse_indirect_prefetch_limit, UINT, ZMOD_RW, 818 "Traverse prefetch number of blocks pointed by indirect block"); 819 820 #if defined(_KERNEL) 821 module_param_named(ignore_hole_birth, send_holes_without_birth_time, int, 0644); 822 MODULE_PARM_DESC(ignore_hole_birth, 823 "Alias for send_holes_without_birth_time"); 824 #endif 825 826 /* CSTYLED */ 827 ZFS_MODULE_PARAM(zfs, , send_holes_without_birth_time, INT, ZMOD_RW, 828 "Ignore hole_birth txg for zfs send");
Cache object: ade8a77ef3644534e7311a404d1e3eb7
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