dmu_traverse.c revision 288544
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2012, 2014 by Delphix. All rights reserved. 24 * Copyright (c) 2015 Chunwei Chen. All rights reserved. 25 */ 26 27#include <sys/zfs_context.h> 28#include <sys/dmu_objset.h> 29#include <sys/dmu_traverse.h> 30#include <sys/dsl_dataset.h> 31#include <sys/dsl_dir.h> 32#include <sys/dsl_pool.h> 33#include <sys/dnode.h> 34#include <sys/spa.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 42int32_t zfs_pd_bytes_max = 50 * 1024 * 1024; /* 50MB */ 43 44typedef struct prefetch_data { 45 kmutex_t pd_mtx; 46 kcondvar_t pd_cv; 47 int32_t pd_bytes_fetched; 48 int pd_flags; 49 boolean_t pd_cancel; 50 boolean_t pd_exited; 51} prefetch_data_t; 52 53typedef struct traverse_data { 54 spa_t *td_spa; 55 uint64_t td_objset; 56 blkptr_t *td_rootbp; 57 uint64_t td_min_txg; 58 zbookmark_phys_t *td_resume; 59 int td_flags; 60 prefetch_data_t *td_pfd; 61 boolean_t td_paused; 62 uint64_t td_hole_birth_enabled_txg; 63 blkptr_cb_t *td_func; 64 void *td_arg; 65} traverse_data_t; 66 67static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, 68 uint64_t objset, uint64_t object); 69static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *, 70 uint64_t objset, uint64_t object); 71 72static int 73traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 74{ 75 traverse_data_t *td = arg; 76 zbookmark_phys_t zb; 77 78 if (BP_IS_HOLE(bp)) 79 return (0); 80 81 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa)) 82 return (0); 83 84 SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 85 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 86 87 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, td->td_arg); 88 89 return (0); 90} 91 92static int 93traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) 94{ 95 traverse_data_t *td = arg; 96 97 if (lrc->lrc_txtype == TX_WRITE) { 98 lr_write_t *lr = (lr_write_t *)lrc; 99 blkptr_t *bp = &lr->lr_blkptr; 100 zbookmark_phys_t zb; 101 102 if (BP_IS_HOLE(bp)) 103 return (0); 104 105 if (claim_txg == 0 || bp->blk_birth < claim_txg) 106 return (0); 107 108 SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid, 109 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 110 111 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, 112 td->td_arg); 113 } 114 return (0); 115} 116 117static void 118traverse_zil(traverse_data_t *td, zil_header_t *zh) 119{ 120 uint64_t claim_txg = zh->zh_claim_txg; 121 zilog_t *zilog; 122 123 /* 124 * We only want to visit blocks that have been claimed but not yet 125 * replayed; plus, in read-only mode, blocks that are already stable. 126 */ 127 if (claim_txg == 0 && spa_writeable(td->td_spa)) 128 return; 129 130 zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh); 131 132 (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td, 133 claim_txg); 134 135 zil_free(zilog); 136} 137 138typedef enum resume_skip { 139 RESUME_SKIP_ALL, 140 RESUME_SKIP_NONE, 141 RESUME_SKIP_CHILDREN 142} resume_skip_t; 143 144/* 145 * Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and 146 * the block indicated by zb does not need to be visited at all. Returns 147 * RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the 148 * resume point. This indicates that this block should be visited but not its 149 * children (since they must have been visited in a previous traversal). 150 * Otherwise returns RESUME_SKIP_NONE. 151 */ 152static resume_skip_t 153resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp, 154 const zbookmark_phys_t *zb) 155{ 156 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) { 157 /* 158 * If we already visited this bp & everything below, 159 * don't bother doing it again. 160 */ 161 if (zbookmark_is_before(dnp, zb, td->td_resume)) 162 return (RESUME_SKIP_ALL); 163 164 /* 165 * If we found the block we're trying to resume from, zero 166 * the bookmark out to indicate that we have resumed. 167 */ 168 if (bcmp(zb, td->td_resume, sizeof (*zb)) == 0) { 169 bzero(td->td_resume, sizeof (*zb)); 170 if (td->td_flags & TRAVERSE_POST) 171 return (RESUME_SKIP_CHILDREN); 172 } 173 } 174 return (RESUME_SKIP_NONE); 175} 176 177static void 178traverse_prefetch_metadata(traverse_data_t *td, 179 const blkptr_t *bp, const zbookmark_phys_t *zb) 180{ 181 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH; 182 183 if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA)) 184 return; 185 /* 186 * If we are in the process of resuming, don't prefetch, because 187 * some children will not be needed (and in fact may have already 188 * been freed). 189 */ 190 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) 191 return; 192 if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg) 193 return; 194 if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE) 195 return; 196 197 (void) arc_read(NULL, td->td_spa, bp, NULL, NULL, 198 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 199} 200 201static boolean_t 202prefetch_needed(prefetch_data_t *pfd, const blkptr_t *bp) 203{ 204 ASSERT(pfd->pd_flags & TRAVERSE_PREFETCH_DATA); 205 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) || 206 BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG) 207 return (B_FALSE); 208 return (B_TRUE); 209} 210 211static int 212traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, 213 const blkptr_t *bp, const zbookmark_phys_t *zb) 214{ 215 zbookmark_phys_t czb; 216 int err = 0; 217 arc_buf_t *buf = NULL; 218 prefetch_data_t *pd = td->td_pfd; 219 boolean_t hard = td->td_flags & TRAVERSE_HARD; 220 221 switch (resume_skip_check(td, dnp, zb)) { 222 case RESUME_SKIP_ALL: 223 return (0); 224 case RESUME_SKIP_CHILDREN: 225 goto post; 226 case RESUME_SKIP_NONE: 227 break; 228 default: 229 ASSERT(0); 230 } 231 232 if (bp->blk_birth == 0) { 233 /* 234 * Since this block has a birth time of 0 it must be a 235 * hole created before the SPA_FEATURE_HOLE_BIRTH 236 * feature was enabled. If SPA_FEATURE_HOLE_BIRTH 237 * was enabled before the min_txg for this traveral we 238 * know the hole must have been created before the 239 * min_txg for this traveral, so we can skip it. If 240 * SPA_FEATURE_HOLE_BIRTH was enabled after the min_txg 241 * for this traveral we cannot tell if the hole was 242 * created before or after the min_txg for this 243 * traversal, so we cannot skip it. 244 */ 245 if (td->td_hole_birth_enabled_txg < td->td_min_txg) 246 return (0); 247 } else if (bp->blk_birth <= td->td_min_txg) { 248 return (0); 249 } 250 251 if (pd != NULL && !pd->pd_exited && prefetch_needed(pd, bp)) { 252 uint64_t size = BP_GET_LSIZE(bp); 253 mutex_enter(&pd->pd_mtx); 254 ASSERT(pd->pd_bytes_fetched >= 0); 255 while (pd->pd_bytes_fetched < size && !pd->pd_exited) 256 cv_wait(&pd->pd_cv, &pd->pd_mtx); 257 pd->pd_bytes_fetched -= size; 258 cv_broadcast(&pd->pd_cv); 259 mutex_exit(&pd->pd_mtx); 260 } 261 262 if (BP_IS_HOLE(bp)) { 263 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); 264 if (err != 0) 265 goto post; 266 return (0); 267 } 268 269 if (td->td_flags & TRAVERSE_PRE) { 270 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, 271 td->td_arg); 272 if (err == TRAVERSE_VISIT_NO_CHILDREN) 273 return (0); 274 if (err != 0) 275 goto post; 276 } 277 278 if (BP_GET_LEVEL(bp) > 0) { 279 arc_flags_t flags = ARC_FLAG_WAIT; 280 int i; 281 blkptr_t *cbp; 282 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 283 284 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 285 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 286 if (err != 0) 287 goto post; 288 cbp = buf->b_data; 289 290 for (i = 0; i < epb; i++) { 291 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 292 zb->zb_level - 1, 293 zb->zb_blkid * epb + i); 294 traverse_prefetch_metadata(td, &cbp[i], &czb); 295 } 296 297 /* recursively visitbp() blocks below this */ 298 for (i = 0; i < epb; i++) { 299 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 300 zb->zb_level - 1, 301 zb->zb_blkid * epb + i); 302 err = traverse_visitbp(td, dnp, &cbp[i], &czb); 303 if (err != 0) 304 break; 305 } 306 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 307 arc_flags_t flags = ARC_FLAG_WAIT; 308 int i; 309 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 310 dnode_phys_t *cdnp; 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 cdnp = buf->b_data; 317 318 for (i = 0; i < epb; i++) { 319 prefetch_dnode_metadata(td, &cdnp[i], zb->zb_objset, 320 zb->zb_blkid * epb + i); 321 } 322 323 /* recursively visitbp() blocks below this */ 324 for (i = 0; i < epb; i++) { 325 err = traverse_dnode(td, &cdnp[i], zb->zb_objset, 326 zb->zb_blkid * epb + i); 327 if (err != 0) 328 break; 329 } 330 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 331 arc_flags_t flags = ARC_FLAG_WAIT; 332 objset_phys_t *osp; 333 dnode_phys_t *mdnp, *gdnp, *udnp; 334 335 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 336 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 337 if (err != 0) 338 goto post; 339 340 osp = buf->b_data; 341 mdnp = &osp->os_meta_dnode; 342 gdnp = &osp->os_groupused_dnode; 343 udnp = &osp->os_userused_dnode; 344 345 prefetch_dnode_metadata(td, mdnp, zb->zb_objset, 346 DMU_META_DNODE_OBJECT); 347 if (arc_buf_size(buf) >= sizeof (objset_phys_t)) { 348 prefetch_dnode_metadata(td, gdnp, zb->zb_objset, 349 DMU_GROUPUSED_OBJECT); 350 prefetch_dnode_metadata(td, udnp, zb->zb_objset, 351 DMU_USERUSED_OBJECT); 352 } 353 354 err = traverse_dnode(td, mdnp, zb->zb_objset, 355 DMU_META_DNODE_OBJECT); 356 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { 357 err = traverse_dnode(td, gdnp, zb->zb_objset, 358 DMU_GROUPUSED_OBJECT); 359 } 360 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { 361 err = traverse_dnode(td, udnp, zb->zb_objset, 362 DMU_USERUSED_OBJECT); 363 } 364 } 365 366 if (buf) 367 (void) arc_buf_remove_ref(buf, &buf); 368 369post: 370 if (err == 0 && (td->td_flags & TRAVERSE_POST)) 371 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); 372 373 if (hard && (err == EIO || err == ECKSUM)) { 374 /* 375 * Ignore this disk error as requested by the HARD flag, 376 * and continue traversal. 377 */ 378 err = 0; 379 } 380 381 /* 382 * If we are stopping here, set td_resume. 383 */ 384 if (td->td_resume != NULL && err != 0 && !td->td_paused) { 385 td->td_resume->zb_objset = zb->zb_objset; 386 td->td_resume->zb_object = zb->zb_object; 387 td->td_resume->zb_level = 0; 388 /* 389 * If we have stopped on an indirect block (e.g. due to 390 * i/o error), we have not visited anything below it. 391 * Set the bookmark to the first level-0 block that we need 392 * to visit. This way, the resuming code does not need to 393 * deal with resuming from indirect blocks. 394 */ 395 td->td_resume->zb_blkid = zb->zb_blkid << 396 (zb->zb_level * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)); 397 td->td_paused = B_TRUE; 398 } 399 400 return (err); 401} 402 403static void 404prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp, 405 uint64_t objset, uint64_t object) 406{ 407 int j; 408 zbookmark_phys_t czb; 409 410 for (j = 0; j < dnp->dn_nblkptr; j++) { 411 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); 412 traverse_prefetch_metadata(td, &dnp->dn_blkptr[j], &czb); 413 } 414 415 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 416 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); 417 traverse_prefetch_metadata(td, &dnp->dn_spill, &czb); 418 } 419} 420 421static int 422traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, 423 uint64_t objset, uint64_t object) 424{ 425 int j, err = 0; 426 zbookmark_phys_t czb; 427 428 for (j = 0; j < dnp->dn_nblkptr; j++) { 429 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); 430 err = traverse_visitbp(td, dnp, &dnp->dn_blkptr[j], &czb); 431 if (err != 0) 432 break; 433 } 434 435 if (err == 0 && dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 436 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); 437 err = traverse_visitbp(td, dnp, &dnp->dn_spill, &czb); 438 } 439 return (err); 440} 441 442/* ARGSUSED */ 443static int 444traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 445 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg) 446{ 447 prefetch_data_t *pfd = arg; 448 arc_flags_t aflags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH; 449 450 ASSERT(pfd->pd_bytes_fetched >= 0); 451 if (pfd->pd_cancel) 452 return (SET_ERROR(EINTR)); 453 454 if (!prefetch_needed(pfd, bp)) 455 return (0); 456 457 mutex_enter(&pfd->pd_mtx); 458 while (!pfd->pd_cancel && pfd->pd_bytes_fetched >= zfs_pd_bytes_max) 459 cv_wait(&pfd->pd_cv, &pfd->pd_mtx); 460 pfd->pd_bytes_fetched += BP_GET_LSIZE(bp); 461 cv_broadcast(&pfd->pd_cv); 462 mutex_exit(&pfd->pd_mtx); 463 464 (void) arc_read(NULL, spa, bp, NULL, NULL, ZIO_PRIORITY_ASYNC_READ, 465 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &aflags, zb); 466 467 return (0); 468} 469 470static void 471traverse_prefetch_thread(void *arg) 472{ 473 traverse_data_t *td_main = arg; 474 traverse_data_t td = *td_main; 475 zbookmark_phys_t czb; 476 477 td.td_func = traverse_prefetcher; 478 td.td_arg = td_main->td_pfd; 479 td.td_pfd = NULL; 480 481 SET_BOOKMARK(&czb, td.td_objset, 482 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 483 (void) traverse_visitbp(&td, NULL, td.td_rootbp, &czb); 484 485 mutex_enter(&td_main->td_pfd->pd_mtx); 486 td_main->td_pfd->pd_exited = B_TRUE; 487 cv_broadcast(&td_main->td_pfd->pd_cv); 488 mutex_exit(&td_main->td_pfd->pd_mtx); 489} 490 491/* 492 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are 493 * in syncing context). 494 */ 495static int 496traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp, 497 uint64_t txg_start, zbookmark_phys_t *resume, int flags, 498 blkptr_cb_t func, void *arg) 499{ 500 traverse_data_t td; 501 prefetch_data_t pd = { 0 }; 502 zbookmark_phys_t czb; 503 int err; 504 505 ASSERT(ds == NULL || objset == ds->ds_object); 506 ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST)); 507 508 /* 509 * The data prefetching mechanism (the prefetch thread) is incompatible 510 * with resuming from a bookmark. 511 */ 512 ASSERT(resume == NULL || !(flags & TRAVERSE_PREFETCH_DATA)); 513 514 td.td_spa = spa; 515 td.td_objset = objset; 516 td.td_rootbp = rootbp; 517 td.td_min_txg = txg_start; 518 td.td_resume = resume; 519 td.td_func = func; 520 td.td_arg = arg; 521 td.td_pfd = &pd; 522 td.td_flags = flags; 523 td.td_paused = B_FALSE; 524 525 if (spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 526 VERIFY(spa_feature_enabled_txg(spa, 527 SPA_FEATURE_HOLE_BIRTH, &td.td_hole_birth_enabled_txg)); 528 } else { 529 td.td_hole_birth_enabled_txg = 0; 530 } 531 532 pd.pd_flags = flags; 533 mutex_init(&pd.pd_mtx, NULL, MUTEX_DEFAULT, NULL); 534 cv_init(&pd.pd_cv, NULL, CV_DEFAULT, NULL); 535 536 /* See comment on ZIL traversal in dsl_scan_visitds. */ 537 if (ds != NULL && !dsl_dataset_is_snapshot(ds) && !BP_IS_HOLE(rootbp)) { 538 arc_flags_t flags = ARC_FLAG_WAIT; 539 objset_phys_t *osp; 540 arc_buf_t *buf; 541 542 err = arc_read(NULL, td.td_spa, rootbp, 543 arc_getbuf_func, &buf, 544 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, NULL); 545 if (err != 0) 546 return (err); 547 548 osp = buf->b_data; 549 traverse_zil(&td, &osp->os_zil_header); 550 (void) arc_buf_remove_ref(buf, &buf); 551 } 552 553 if (!(flags & TRAVERSE_PREFETCH_DATA) || 554 0 == taskq_dispatch(system_taskq, traverse_prefetch_thread, 555 &td, TQ_NOQUEUE)) 556 pd.pd_exited = B_TRUE; 557 558 SET_BOOKMARK(&czb, td.td_objset, 559 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 560 err = traverse_visitbp(&td, NULL, rootbp, &czb); 561 562 mutex_enter(&pd.pd_mtx); 563 pd.pd_cancel = B_TRUE; 564 cv_broadcast(&pd.pd_cv); 565 while (!pd.pd_exited) 566 cv_wait(&pd.pd_cv, &pd.pd_mtx); 567 mutex_exit(&pd.pd_mtx); 568 569 mutex_destroy(&pd.pd_mtx); 570 cv_destroy(&pd.pd_cv); 571 572 return (err); 573} 574 575/* 576 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are 577 * in syncing context). 578 */ 579int 580traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, int flags, 581 blkptr_cb_t func, void *arg) 582{ 583 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object, 584 &dsl_dataset_phys(ds)->ds_bp, txg_start, NULL, flags, func, arg)); 585} 586 587int 588traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr, 589 uint64_t txg_start, zbookmark_phys_t *resume, int flags, 590 blkptr_cb_t func, void *arg) 591{ 592 return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET, 593 blkptr, txg_start, resume, flags, func, arg)); 594} 595 596/* 597 * NB: pool must not be changing on-disk (eg, from zdb or sync context). 598 */ 599int 600traverse_pool(spa_t *spa, uint64_t txg_start, int flags, 601 blkptr_cb_t func, void *arg) 602{ 603 int err; 604 uint64_t obj; 605 dsl_pool_t *dp = spa_get_dsl(spa); 606 objset_t *mos = dp->dp_meta_objset; 607 boolean_t hard = (flags & TRAVERSE_HARD); 608 609 /* visit the MOS */ 610 err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa), 611 txg_start, NULL, flags, func, arg); 612 if (err != 0) 613 return (err); 614 615 /* visit each dataset */ 616 for (obj = 1; err == 0; 617 err = dmu_object_next(mos, &obj, FALSE, txg_start)) { 618 dmu_object_info_t doi; 619 620 err = dmu_object_info(mos, obj, &doi); 621 if (err != 0) { 622 if (hard) 623 continue; 624 break; 625 } 626 627 if (doi.doi_bonus_type == DMU_OT_DSL_DATASET) { 628 dsl_dataset_t *ds; 629 uint64_t txg = txg_start; 630 631 dsl_pool_config_enter(dp, FTAG); 632 err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds); 633 dsl_pool_config_exit(dp, FTAG); 634 if (err != 0) { 635 if (hard) 636 continue; 637 break; 638 } 639 if (dsl_dataset_phys(ds)->ds_prev_snap_txg > txg) 640 txg = dsl_dataset_phys(ds)->ds_prev_snap_txg; 641 err = traverse_dataset(ds, txg, flags, func, arg); 642 dsl_dataset_rele(ds, FTAG); 643 if (err != 0) 644 break; 645 } 646 } 647 if (err == ESRCH) 648 err = 0; 649 return (err); 650} 651