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) 2013 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/zio.h> 35 #include <sys/dmu_impl.h> 36 #include <sys/sa.h> 37 #include <sys/sa_impl.h> 38 #include <sys/callb.h> 39 #include <sys/zfeature.h> 40 41 int zfs_pd_blks_max = 100; 42 43 typedef struct prefetch_data { 44 kmutex_t pd_mtx; 45 kcondvar_t pd_cv; 46 int pd_blks_max; 47 int pd_blks_fetched; 48 int pd_flags; 49 boolean_t pd_cancel; 50 boolean_t pd_exited; 51 } prefetch_data_t; 52 53 typedef 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_t *td_resume; 59 int td_flags; 60 prefetch_data_t *td_pfd; 61 blkptr_cb_t *td_func; 62 void *td_arg; 63 } traverse_data_t; 64 65 static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, 66 uint64_t objset, uint64_t object); 67 static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *, 68 uint64_t objset, uint64_t object); 69 70 static int 71 traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 72 { 73 traverse_data_t *td = arg; 74 zbookmark_t zb; 75 76 if (BP_IS_HOLE(bp)) 77 return (0); 78 79 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa)) 80 return (0); 81 82 SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 83 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 84 85 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, td->td_arg); 86 87 return (0); 88 } 89 90 static int 91 traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) 92 { 93 traverse_data_t *td = arg; 94 95 if (lrc->lrc_txtype == TX_WRITE) { 96 lr_write_t *lr = (lr_write_t *)lrc; 97 blkptr_t *bp = &lr->lr_blkptr; 98 zbookmark_t zb; 99 100 if (BP_IS_HOLE(bp)) 101 return (0); 102 103 if (claim_txg == 0 || bp->blk_birth < claim_txg) 104 return (0); 105 106 SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid, 107 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 108 109 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, 110 td->td_arg); 111 } 112 return (0); 113 } 114 115 static void 116 traverse_zil(traverse_data_t *td, zil_header_t *zh) 117 { 118 uint64_t claim_txg = zh->zh_claim_txg; 119 zilog_t *zilog; 120 121 /* 122 * We only want to visit blocks that have been claimed but not yet 123 * replayed; plus, in read-only mode, blocks that are already stable. 124 */ 125 if (claim_txg == 0 && spa_writeable(td->td_spa)) 126 return; 127 128 zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh); 129 130 (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td, 131 claim_txg); 132 133 zil_free(zilog); 134 } 135 136 typedef enum resume_skip { 137 RESUME_SKIP_ALL, 138 RESUME_SKIP_NONE, 139 RESUME_SKIP_CHILDREN 140 } resume_skip_t; 141 142 /* 143 * Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and 144 * the block indicated by zb does not need to be visited at all. Returns 145 * RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the 146 * resume point. This indicates that this block should be visited but not its 147 * children (since they must have been visited in a previous traversal). 148 * Otherwise returns RESUME_SKIP_NONE. 149 */ 150 static resume_skip_t 151 resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp, 152 const zbookmark_t *zb) 153 { 154 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) { 155 /* 156 * If we already visited this bp & everything below, 157 * don't bother doing it again. 158 */ 159 if (zbookmark_is_before(dnp, zb, td->td_resume)) 160 return (RESUME_SKIP_ALL); 161 162 /* 163 * If we found the block we're trying to resume from, zero 164 * the bookmark out to indicate that we have resumed. 165 */ 166 ASSERT3U(zb->zb_object, <=, td->td_resume->zb_object); 167 if (bcmp(zb, td->td_resume, sizeof (*zb)) == 0) { 168 bzero(td->td_resume, sizeof (*zb)); 169 if (td->td_flags & TRAVERSE_POST) 170 return (RESUME_SKIP_CHILDREN); 171 } 172 } 173 return (RESUME_SKIP_NONE); 174 } 175 176 static void 177 traverse_pause(traverse_data_t *td, const zbookmark_t *zb) 178 { 179 ASSERT(td->td_resume != NULL); 180 ASSERT0(zb->zb_level); 181 bcopy(zb, td->td_resume, sizeof (*td->td_resume)); 182 } 183 184 static void 185 traverse_prefetch_metadata(traverse_data_t *td, 186 const blkptr_t *bp, const zbookmark_t *zb) 187 { 188 uint32_t flags = ARC_NOWAIT | ARC_PREFETCH; 189 190 if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA)) 191 return; 192 /* 193 * If we are in the process of resuming, don't prefetch, because 194 * some children will not be needed (and in fact may have already 195 * been freed). 196 */ 197 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) 198 return; 199 if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg) 200 return; 201 if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE) 202 return; 203 204 (void) arc_read(NULL, td->td_spa, bp, NULL, NULL, 205 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 206 } 207 208 static int 209 traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, 210 const blkptr_t *bp, const zbookmark_t *zb) 211 { 212 zbookmark_t czb; 213 int err = 0, lasterr = 0; 214 arc_buf_t *buf = NULL; 215 prefetch_data_t *pd = td->td_pfd; 216 boolean_t hard = td->td_flags & TRAVERSE_HARD; 217 boolean_t pause = B_FALSE; 218 219 switch (resume_skip_check(td, dnp, zb)) { 220 case RESUME_SKIP_ALL: 221 return (0); 222 case RESUME_SKIP_CHILDREN: 223 goto post; 224 case RESUME_SKIP_NONE: 225 break; 226 default: 227 ASSERT(0); 228 } 229 230 if (bp->blk_birth == 0) { 231 if (spa_feature_is_active(td->td_spa, SPA_FEATURE_HOLE_BIRTH)) { 232 /* 233 * Since this block has a birth time of 0 it must be a 234 * hole created before the SPA_FEATURE_HOLE_BIRTH 235 * feature was enabled. If SPA_FEATURE_HOLE_BIRTH 236 * was enabled before the min_txg for this traveral we 237 * know the hole must have been created before the 238 * min_txg for this traveral, so we can skip it. If 239 * SPA_FEATURE_HOLE_BIRTH was enabled after the min_txg 240 * for this traveral we cannot tell if the hole was 241 * created before or after the min_txg for this 242 * traversal, so we cannot skip it. 243 */ 244 uint64_t hole_birth_enabled_txg; 245 VERIFY(spa_feature_enabled_txg(td->td_spa, 246 SPA_FEATURE_HOLE_BIRTH, &hole_birth_enabled_txg)); 247 if (hole_birth_enabled_txg < td->td_min_txg) 248 return (0); 249 } 250 } else if (bp->blk_birth <= td->td_min_txg) { 251 return (0); 252 } 253 254 if (BP_IS_HOLE(bp)) { 255 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); 256 return (err); 257 } 258 259 if (pd && !pd->pd_exited && 260 ((pd->pd_flags & TRAVERSE_PREFETCH_DATA) || 261 BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0)) { 262 mutex_enter(&pd->pd_mtx); 263 ASSERT(pd->pd_blks_fetched >= 0); 264 while (pd->pd_blks_fetched == 0 && !pd->pd_exited) 265 cv_wait(&pd->pd_cv, &pd->pd_mtx); 266 pd->pd_blks_fetched--; 267 cv_broadcast(&pd->pd_cv); 268 mutex_exit(&pd->pd_mtx); 269 } 270 271 if (td->td_flags & TRAVERSE_PRE) { 272 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, 273 td->td_arg); 274 if (err == TRAVERSE_VISIT_NO_CHILDREN) 275 return (0); 276 if (err == ERESTART) 277 pause = B_TRUE; /* handle pausing at a common point */ 278 if (err != 0) 279 goto post; 280 } 281 282 if (BP_GET_LEVEL(bp) > 0) { 283 uint32_t flags = ARC_WAIT; 284 int i; 285 blkptr_t *cbp; 286 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; 287 288 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 289 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 290 if (err != 0) 291 return (err); 292 cbp = buf->b_data; 293 294 for (i = 0; i < epb; i++) { 295 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 296 zb->zb_level - 1, 297 zb->zb_blkid * epb + i); 298 traverse_prefetch_metadata(td, &cbp[i], &czb); 299 } 300 301 /* recursively visitbp() blocks below this */ 302 for (i = 0; i < epb; i++) { 303 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, 304 zb->zb_level - 1, 305 zb->zb_blkid * epb + i); 306 err = traverse_visitbp(td, dnp, &cbp[i], &czb); 307 if (err != 0) { 308 if (!hard) 309 break; 310 lasterr = err; 311 } 312 } 313 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { 314 uint32_t flags = ARC_WAIT; 315 int i; 316 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; 317 318 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 319 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 320 if (err != 0) 321 return (err); 322 dnp = buf->b_data; 323 324 for (i = 0; i < epb; i++) { 325 prefetch_dnode_metadata(td, &dnp[i], zb->zb_objset, 326 zb->zb_blkid * epb + i); 327 } 328 329 /* recursively visitbp() blocks below this */ 330 for (i = 0; i < epb; i++) { 331 err = traverse_dnode(td, &dnp[i], zb->zb_objset, 332 zb->zb_blkid * epb + i); 333 if (err != 0) { 334 if (!hard) 335 break; 336 lasterr = err; 337 } 338 } 339 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { 340 uint32_t flags = ARC_WAIT; 341 objset_phys_t *osp; 342 dnode_phys_t *dnp; 343 344 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, 345 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); 346 if (err != 0) 347 return (err); 348 349 osp = buf->b_data; 350 dnp = &osp->os_meta_dnode; 351 prefetch_dnode_metadata(td, dnp, zb->zb_objset, 352 DMU_META_DNODE_OBJECT); 353 if (arc_buf_size(buf) >= sizeof (objset_phys_t)) { 354 prefetch_dnode_metadata(td, &osp->os_userused_dnode, 355 zb->zb_objset, DMU_USERUSED_OBJECT); 356 prefetch_dnode_metadata(td, &osp->os_groupused_dnode, 357 zb->zb_objset, DMU_USERUSED_OBJECT); 358 } 359 360 err = traverse_dnode(td, dnp, zb->zb_objset, 361 DMU_META_DNODE_OBJECT); 362 if (err && hard) { 363 lasterr = err; 364 err = 0; 365 } 366 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { 367 dnp = &osp->os_userused_dnode; 368 err = traverse_dnode(td, dnp, zb->zb_objset, 369 DMU_USERUSED_OBJECT); 370 } 371 if (err && hard) { 372 lasterr = err; 373 err = 0; 374 } 375 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { 376 dnp = &osp->os_groupused_dnode; 377 err = traverse_dnode(td, dnp, zb->zb_objset, 378 DMU_GROUPUSED_OBJECT); 379 } 380 } 381 382 if (buf) 383 (void) arc_buf_remove_ref(buf, &buf); 384 385 post: 386 if (err == 0 && lasterr == 0 && (td->td_flags & TRAVERSE_POST)) { 387 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); 388 if (err == ERESTART) 389 pause = B_TRUE; 390 } 391 392 if (pause && td->td_resume != NULL) { 393 ASSERT3U(err, ==, ERESTART); 394 ASSERT(!hard); 395 traverse_pause(td, zb); 396 } 397 398 return (err != 0 ? err : lasterr); 399 } 400 401 static void 402 prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp, 403 uint64_t objset, uint64_t object) 404 { 405 int j; 406 zbookmark_t czb; 407 408 for (j = 0; j < dnp->dn_nblkptr; j++) { 409 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); 410 traverse_prefetch_metadata(td, &dnp->dn_blkptr[j], &czb); 411 } 412 413 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 414 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); 415 traverse_prefetch_metadata(td, &dnp->dn_spill, &czb); 416 } 417 } 418 419 static int 420 traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, 421 uint64_t objset, uint64_t object) 422 { 423 int j, err = 0, lasterr = 0; 424 zbookmark_t czb; 425 boolean_t hard = (td->td_flags & TRAVERSE_HARD); 426 427 for (j = 0; j < dnp->dn_nblkptr; j++) { 428 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); 429 err = traverse_visitbp(td, dnp, &dnp->dn_blkptr[j], &czb); 430 if (err != 0) { 431 if (!hard) 432 break; 433 lasterr = err; 434 } 435 } 436 437 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 438 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); 439 err = traverse_visitbp(td, dnp, &dnp->dn_spill, &czb); 440 if (err != 0) { 441 if (!hard) 442 return (err); 443 lasterr = err; 444 } 445 } 446 return (err != 0 ? err : lasterr); 447 } 448 449 /* ARGSUSED */ 450 static int 451 traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 452 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 453 { 454 prefetch_data_t *pfd = arg; 455 uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH; 456 457 ASSERT(pfd->pd_blks_fetched >= 0); 458 if (pfd->pd_cancel) 459 return (SET_ERROR(EINTR)); 460 461 if (BP_IS_HOLE(bp) || 462 !((pfd->pd_flags & TRAVERSE_PREFETCH_DATA) || 463 BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0) || 464 BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG) 465 return (0); 466 467 mutex_enter(&pfd->pd_mtx); 468 while (!pfd->pd_cancel && pfd->pd_blks_fetched >= pfd->pd_blks_max) 469 cv_wait(&pfd->pd_cv, &pfd->pd_mtx); 470 pfd->pd_blks_fetched++; 471 cv_broadcast(&pfd->pd_cv); 472 mutex_exit(&pfd->pd_mtx); 473 474 (void) arc_read(NULL, spa, bp, NULL, NULL, ZIO_PRIORITY_ASYNC_READ, 475 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &aflags, zb); 476 477 return (0); 478 } 479 480 static void 481 traverse_prefetch_thread(void *arg) 482 { 483 traverse_data_t *td_main = arg; 484 traverse_data_t td = *td_main; 485 zbookmark_t czb; 486 487 td.td_func = traverse_prefetcher; 488 td.td_arg = td_main->td_pfd; 489 td.td_pfd = NULL; 490 491 SET_BOOKMARK(&czb, td.td_objset, 492 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 493 (void) traverse_visitbp(&td, NULL, td.td_rootbp, &czb); 494 495 mutex_enter(&td_main->td_pfd->pd_mtx); 496 td_main->td_pfd->pd_exited = B_TRUE; 497 cv_broadcast(&td_main->td_pfd->pd_cv); 498 mutex_exit(&td_main->td_pfd->pd_mtx); 499 } 500 501 /* 502 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are 503 * in syncing context). 504 */ 505 static int 506 traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp, 507 uint64_t txg_start, zbookmark_t *resume, int flags, 508 blkptr_cb_t func, void *arg) 509 { 510 traverse_data_t td; 511 prefetch_data_t pd = { 0 }; 512 zbookmark_t czb; 513 int err; 514 515 ASSERT(ds == NULL || objset == ds->ds_object); 516 ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST)); 517 518 /* 519 * The data prefetching mechanism (the prefetch thread) is incompatible 520 * with resuming from a bookmark. 521 */ 522 ASSERT(resume == NULL || !(flags & TRAVERSE_PREFETCH_DATA)); 523 524 td.td_spa = spa; 525 td.td_objset = objset; 526 td.td_rootbp = rootbp; 527 td.td_min_txg = txg_start; 528 td.td_resume = resume; 529 td.td_func = func; 530 td.td_arg = arg; 531 td.td_pfd = &pd; 532 td.td_flags = flags; 533 534 pd.pd_blks_max = zfs_pd_blks_max; 535 pd.pd_flags = flags; 536 mutex_init(&pd.pd_mtx, NULL, MUTEX_DEFAULT, NULL); 537 cv_init(&pd.pd_cv, NULL, CV_DEFAULT, NULL); 538 539 /* See comment on ZIL traversal in dsl_scan_visitds. */ 540 if (ds != NULL && !dsl_dataset_is_snapshot(ds) && !BP_IS_HOLE(rootbp)) { 541 uint32_t flags = ARC_WAIT; 542 objset_phys_t *osp; 543 arc_buf_t *buf; 544 545 err = arc_read(NULL, td.td_spa, rootbp, 546 arc_getbuf_func, &buf, 547 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, NULL); 548 if (err != 0) 549 return (err); 550 551 osp = buf->b_data; 552 traverse_zil(&td, &osp->os_zil_header); 553 (void) arc_buf_remove_ref(buf, &buf); 554 } 555 556 if (!(flags & TRAVERSE_PREFETCH_DATA) || 557 0 == taskq_dispatch(system_taskq, traverse_prefetch_thread, 558 &td, TQ_NOQUEUE)) 559 pd.pd_exited = B_TRUE; 560 561 SET_BOOKMARK(&czb, td.td_objset, 562 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); 563 err = traverse_visitbp(&td, NULL, rootbp, &czb); 564 565 mutex_enter(&pd.pd_mtx); 566 pd.pd_cancel = B_TRUE; 567 cv_broadcast(&pd.pd_cv); 568 while (!pd.pd_exited) 569 cv_wait(&pd.pd_cv, &pd.pd_mtx); 570 mutex_exit(&pd.pd_mtx); 571 572 mutex_destroy(&pd.pd_mtx); 573 cv_destroy(&pd.pd_cv); 574 575 return (err); 576 } 577 578 /* 579 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are 580 * in syncing context). 581 */ 582 int 583 traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, int flags, 584 blkptr_cb_t func, void *arg) 585 { 586 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object, 587 &ds->ds_phys->ds_bp, txg_start, NULL, flags, func, arg)); 588 } 589 590 int 591 traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr, 592 uint64_t txg_start, zbookmark_t *resume, int flags, 593 blkptr_cb_t func, void *arg) 594 { 595 return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET, 596 blkptr, txg_start, resume, flags, func, arg)); 597 } 598 599 /* 600 * NB: pool must not be changing on-disk (eg, from zdb or sync context). 601 */ 602 int 603 traverse_pool(spa_t *spa, uint64_t txg_start, int flags, 604 blkptr_cb_t func, void *arg) 605 { 606 int err, lasterr = 0; 607 uint64_t obj; 608 dsl_pool_t *dp = spa_get_dsl(spa); 609 objset_t *mos = dp->dp_meta_objset; 610 boolean_t hard = (flags & TRAVERSE_HARD); 611 612 /* visit the MOS */ 613 err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa), 614 txg_start, NULL, flags, func, arg); 615 if (err != 0) 616 return (err); 617 618 /* visit each dataset */ 619 for (obj = 1; err == 0 || (err != ESRCH && hard); 620 err = dmu_object_next(mos, &obj, FALSE, txg_start)) { 621 dmu_object_info_t doi; 622 623 err = dmu_object_info(mos, obj, &doi); 624 if (err != 0) { 625 if (!hard) 626 return (err); 627 lasterr = err; 628 continue; 629 } 630 631 if (doi.doi_bonus_type == DMU_OT_DSL_DATASET) { 632 dsl_dataset_t *ds; 633 uint64_t txg = txg_start; 634 635 dsl_pool_config_enter(dp, FTAG); 636 err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds); 637 dsl_pool_config_exit(dp, FTAG); 638 if (err != 0) { 639 if (!hard) 640 return (err); 641 lasterr = err; 642 continue; 643 } 644 if (ds->ds_phys->ds_prev_snap_txg > txg) 645 txg = ds->ds_phys->ds_prev_snap_txg; 646 err = traverse_dataset(ds, txg, flags, func, arg); 647 dsl_dataset_rele(ds, FTAG); 648 if (err != 0) { 649 if (!hard) 650 return (err); 651 lasterr = err; 652 } 653 } 654 } 655 if (err == ESRCH) 656 err = 0; 657 return (err != 0 ? err : lasterr); 658 } 659