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) 2013 Steven Hartland. All rights reserved. 25 * Copyright (c) 2013 by Joyent, Inc. All rights reserved. 26 */ 27 28 #include <sys/zfs_context.h> 29 #include <sys/dsl_userhold.h> 30 #include <sys/dsl_dataset.h> 31 #include <sys/dsl_synctask.h> 32 #include <sys/dmu_tx.h> 33 #include <sys/dsl_pool.h> 34 #include <sys/dsl_dir.h> 35 #include <sys/dmu_traverse.h> 36 #include <sys/dsl_scan.h> 37 #include <sys/dmu_objset.h> 38 #include <sys/zap.h> 39 #include <sys/zfeature.h> 40 #include <sys/zfs_ioctl.h> 41 #include <sys/dsl_deleg.h> 42 #include <sys/dmu_impl.h> 43 44 typedef struct dmu_snapshots_destroy_arg { 45 nvlist_t *dsda_snaps; 46 nvlist_t *dsda_successful_snaps; 47 boolean_t dsda_defer; 48 nvlist_t *dsda_errlist; 49 } dmu_snapshots_destroy_arg_t; 50 51 int 52 dsl_destroy_snapshot_check_impl(dsl_dataset_t *ds, boolean_t defer) 53 { 54 if (!dsl_dataset_is_snapshot(ds)) 55 return (SET_ERROR(EINVAL)); 56 57 if (dsl_dataset_long_held(ds)) 58 return (SET_ERROR(EBUSY)); 59 60 /* 61 * Only allow deferred destroy on pools that support it. 62 * NOTE: deferred destroy is only supported on snapshots. 63 */ 64 if (defer) { 65 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 66 SPA_VERSION_USERREFS) 67 return (SET_ERROR(ENOTSUP)); 68 return (0); 69 } 70 71 /* 72 * If this snapshot has an elevated user reference count, 73 * we can't destroy it yet. 74 */ 75 if (ds->ds_userrefs > 0) 76 return (SET_ERROR(EBUSY)); 77 78 /* 79 * Can't delete a branch point. 80 */ 81 if (ds->ds_phys->ds_num_children > 1) 82 return (SET_ERROR(EEXIST)); 83 84 return (0); 85 } 86 87 static int 88 dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx) 89 { 90 dmu_snapshots_destroy_arg_t *dsda = arg; 91 dsl_pool_t *dp = dmu_tx_pool(tx); 92 nvpair_t *pair; 93 int error = 0; 94 95 if (!dmu_tx_is_syncing(tx)) 96 return (0); 97 98 for (pair = nvlist_next_nvpair(dsda->dsda_snaps, NULL); 99 pair != NULL; pair = nvlist_next_nvpair(dsda->dsda_snaps, pair)) { 100 dsl_dataset_t *ds; 101 102 error = dsl_dataset_hold(dp, nvpair_name(pair), 103 FTAG, &ds); 104 105 /* 106 * If the snapshot does not exist, silently ignore it 107 * (it's "already destroyed"). 108 */ 109 if (error == ENOENT) 110 continue; 111 112 if (error == 0) { 113 error = dsl_destroy_snapshot_check_impl(ds, 114 dsda->dsda_defer); 115 dsl_dataset_rele(ds, FTAG); 116 } 117 118 if (error == 0) { 119 fnvlist_add_boolean(dsda->dsda_successful_snaps, 120 nvpair_name(pair)); 121 } else { 122 fnvlist_add_int32(dsda->dsda_errlist, 123 nvpair_name(pair), error); 124 } 125 } 126 127 pair = nvlist_next_nvpair(dsda->dsda_errlist, NULL); 128 if (pair != NULL) 129 return (fnvpair_value_int32(pair)); 130 131 return (0); 132 } 133 134 struct process_old_arg { 135 dsl_dataset_t *ds; 136 dsl_dataset_t *ds_prev; 137 boolean_t after_branch_point; 138 zio_t *pio; 139 uint64_t used, comp, uncomp; 140 }; 141 142 static int 143 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 144 { 145 struct process_old_arg *poa = arg; 146 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; 147 148 ASSERT(!BP_IS_HOLE(bp)); 149 150 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { 151 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); 152 if (poa->ds_prev && !poa->after_branch_point && 153 bp->blk_birth > 154 poa->ds_prev->ds_phys->ds_prev_snap_txg) { 155 poa->ds_prev->ds_phys->ds_unique_bytes += 156 bp_get_dsize_sync(dp->dp_spa, bp); 157 } 158 } else { 159 poa->used += bp_get_dsize_sync(dp->dp_spa, bp); 160 poa->comp += BP_GET_PSIZE(bp); 161 poa->uncomp += BP_GET_UCSIZE(bp); 162 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); 163 } 164 return (0); 165 } 166 167 static void 168 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, 169 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) 170 { 171 struct process_old_arg poa = { 0 }; 172 dsl_pool_t *dp = ds->ds_dir->dd_pool; 173 objset_t *mos = dp->dp_meta_objset; 174 uint64_t deadlist_obj; 175 176 ASSERT(ds->ds_deadlist.dl_oldfmt); 177 ASSERT(ds_next->ds_deadlist.dl_oldfmt); 178 179 poa.ds = ds; 180 poa.ds_prev = ds_prev; 181 poa.after_branch_point = after_branch_point; 182 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 183 VERIFY0(bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, 184 process_old_cb, &poa, tx)); 185 VERIFY0(zio_wait(poa.pio)); 186 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); 187 188 /* change snapused */ 189 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 190 -poa.used, -poa.comp, -poa.uncomp, tx); 191 192 /* swap next's deadlist to our deadlist */ 193 dsl_deadlist_close(&ds->ds_deadlist); 194 dsl_deadlist_close(&ds_next->ds_deadlist); 195 deadlist_obj = ds->ds_phys->ds_deadlist_obj; 196 ds->ds_phys->ds_deadlist_obj = ds_next->ds_phys->ds_deadlist_obj; 197 ds_next->ds_phys->ds_deadlist_obj = deadlist_obj; 198 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 199 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 200 ds_next->ds_phys->ds_deadlist_obj); 201 } 202 203 static void 204 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 205 { 206 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 207 zap_cursor_t zc; 208 zap_attribute_t za; 209 210 /* 211 * If it is the old version, dd_clones doesn't exist so we can't 212 * find the clones, but dsl_deadlist_remove_key() is a no-op so it 213 * doesn't matter. 214 */ 215 if (ds->ds_dir->dd_phys->dd_clones == 0) 216 return; 217 218 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); 219 zap_cursor_retrieve(&zc, &za) == 0; 220 zap_cursor_advance(&zc)) { 221 dsl_dataset_t *clone; 222 223 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 224 za.za_first_integer, FTAG, &clone)); 225 if (clone->ds_dir->dd_origin_txg > mintxg) { 226 dsl_deadlist_remove_key(&clone->ds_deadlist, 227 mintxg, tx); 228 dsl_dataset_remove_clones_key(clone, mintxg, tx); 229 } 230 dsl_dataset_rele(clone, FTAG); 231 } 232 zap_cursor_fini(&zc); 233 } 234 235 void 236 dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx) 237 { 238 int err; 239 int after_branch_point = FALSE; 240 dsl_pool_t *dp = ds->ds_dir->dd_pool; 241 objset_t *mos = dp->dp_meta_objset; 242 dsl_dataset_t *ds_prev = NULL; 243 uint64_t obj; 244 245 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock)); 246 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 247 ASSERT(refcount_is_zero(&ds->ds_longholds)); 248 249 if (defer && 250 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)) { 251 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 252 dmu_buf_will_dirty(ds->ds_dbuf, tx); 253 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 254 spa_history_log_internal_ds(ds, "defer_destroy", tx, ""); 255 return; 256 } 257 258 ASSERT3U(ds->ds_phys->ds_num_children, <=, 1); 259 260 /* We need to log before removing it from the namespace. */ 261 spa_history_log_internal_ds(ds, "destroy", tx, ""); 262 263 dsl_scan_ds_destroyed(ds, tx); 264 265 obj = ds->ds_object; 266 267 if (ds->ds_large_blocks) { 268 ASSERT0(zap_contains(mos, obj, DS_FIELD_LARGE_BLOCKS)); 269 spa_feature_decr(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS, tx); 270 } 271 if (ds->ds_phys->ds_prev_snap_obj != 0) { 272 ASSERT3P(ds->ds_prev, ==, NULL); 273 VERIFY0(dsl_dataset_hold_obj(dp, 274 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 275 after_branch_point = 276 (ds_prev->ds_phys->ds_next_snap_obj != obj); 277 278 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 279 if (after_branch_point && 280 ds_prev->ds_phys->ds_next_clones_obj != 0) { 281 dsl_dataset_remove_from_next_clones(ds_prev, obj, tx); 282 if (ds->ds_phys->ds_next_snap_obj != 0) { 283 VERIFY0(zap_add_int(mos, 284 ds_prev->ds_phys->ds_next_clones_obj, 285 ds->ds_phys->ds_next_snap_obj, tx)); 286 } 287 } 288 if (!after_branch_point) { 289 ds_prev->ds_phys->ds_next_snap_obj = 290 ds->ds_phys->ds_next_snap_obj; 291 } 292 } 293 294 dsl_dataset_t *ds_next; 295 uint64_t old_unique; 296 uint64_t used = 0, comp = 0, uncomp = 0; 297 298 VERIFY0(dsl_dataset_hold_obj(dp, 299 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 300 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 301 302 old_unique = ds_next->ds_phys->ds_unique_bytes; 303 304 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 305 ds_next->ds_phys->ds_prev_snap_obj = 306 ds->ds_phys->ds_prev_snap_obj; 307 ds_next->ds_phys->ds_prev_snap_txg = 308 ds->ds_phys->ds_prev_snap_txg; 309 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 310 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 311 312 if (ds_next->ds_deadlist.dl_oldfmt) { 313 process_old_deadlist(ds, ds_prev, ds_next, 314 after_branch_point, tx); 315 } else { 316 /* Adjust prev's unique space. */ 317 if (ds_prev && !after_branch_point) { 318 dsl_deadlist_space_range(&ds_next->ds_deadlist, 319 ds_prev->ds_phys->ds_prev_snap_txg, 320 ds->ds_phys->ds_prev_snap_txg, 321 &used, &comp, &uncomp); 322 ds_prev->ds_phys->ds_unique_bytes += used; 323 } 324 325 /* Adjust snapused. */ 326 dsl_deadlist_space_range(&ds_next->ds_deadlist, 327 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 328 &used, &comp, &uncomp); 329 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 330 -used, -comp, -uncomp, tx); 331 332 /* Move blocks to be freed to pool's free list. */ 333 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 334 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, 335 tx); 336 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 337 DD_USED_HEAD, used, comp, uncomp, tx); 338 339 /* Merge our deadlist into next's and free it. */ 340 dsl_deadlist_merge(&ds_next->ds_deadlist, 341 ds->ds_phys->ds_deadlist_obj, tx); 342 } 343 dsl_deadlist_close(&ds->ds_deadlist); 344 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 345 dmu_buf_will_dirty(ds->ds_dbuf, tx); 346 ds->ds_phys->ds_deadlist_obj = 0; 347 348 /* Collapse range in clone heads */ 349 dsl_dataset_remove_clones_key(ds, 350 ds->ds_phys->ds_creation_txg, tx); 351 352 if (dsl_dataset_is_snapshot(ds_next)) { 353 dsl_dataset_t *ds_nextnext; 354 355 /* 356 * Update next's unique to include blocks which 357 * were previously shared by only this snapshot 358 * and it. Those blocks will be born after the 359 * prev snap and before this snap, and will have 360 * died after the next snap and before the one 361 * after that (ie. be on the snap after next's 362 * deadlist). 363 */ 364 VERIFY0(dsl_dataset_hold_obj(dp, 365 ds_next->ds_phys->ds_next_snap_obj, FTAG, &ds_nextnext)); 366 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 367 ds->ds_phys->ds_prev_snap_txg, 368 ds->ds_phys->ds_creation_txg, 369 &used, &comp, &uncomp); 370 ds_next->ds_phys->ds_unique_bytes += used; 371 dsl_dataset_rele(ds_nextnext, FTAG); 372 ASSERT3P(ds_next->ds_prev, ==, NULL); 373 374 /* Collapse range in this head. */ 375 dsl_dataset_t *hds; 376 VERIFY0(dsl_dataset_hold_obj(dp, 377 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 378 dsl_deadlist_remove_key(&hds->ds_deadlist, 379 ds->ds_phys->ds_creation_txg, tx); 380 dsl_dataset_rele(hds, FTAG); 381 382 } else { 383 ASSERT3P(ds_next->ds_prev, ==, ds); 384 dsl_dataset_rele(ds_next->ds_prev, ds_next); 385 ds_next->ds_prev = NULL; 386 if (ds_prev) { 387 VERIFY0(dsl_dataset_hold_obj(dp, 388 ds->ds_phys->ds_prev_snap_obj, 389 ds_next, &ds_next->ds_prev)); 390 } 391 392 dsl_dataset_recalc_head_uniq(ds_next); 393 394 /* 395 * Reduce the amount of our unconsumed refreservation 396 * being charged to our parent by the amount of 397 * new unique data we have gained. 398 */ 399 if (old_unique < ds_next->ds_reserved) { 400 int64_t mrsdelta; 401 uint64_t new_unique = 402 ds_next->ds_phys->ds_unique_bytes; 403 404 ASSERT(old_unique <= new_unique); 405 mrsdelta = MIN(new_unique - old_unique, 406 ds_next->ds_reserved - old_unique); 407 dsl_dir_diduse_space(ds->ds_dir, 408 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 409 } 410 } 411 dsl_dataset_rele(ds_next, FTAG); 412 413 /* 414 * This must be done after the dsl_traverse(), because it will 415 * re-open the objset. 416 */ 417 if (ds->ds_objset) { 418 dmu_objset_evict(ds->ds_objset); 419 ds->ds_objset = NULL; 420 } 421 422 /* remove from snapshot namespace */ 423 dsl_dataset_t *ds_head; 424 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 425 VERIFY0(dsl_dataset_hold_obj(dp, 426 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 427 VERIFY0(dsl_dataset_get_snapname(ds)); 428 #ifdef ZFS_DEBUG 429 { 430 uint64_t val; 431 432 err = dsl_dataset_snap_lookup(ds_head, 433 ds->ds_snapname, &val); 434 ASSERT0(err); 435 ASSERT3U(val, ==, obj); 436 } 437 #endif 438 VERIFY0(dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx, B_TRUE)); 439 dsl_dataset_rele(ds_head, FTAG); 440 441 if (ds_prev != NULL) 442 dsl_dataset_rele(ds_prev, FTAG); 443 444 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 445 446 if (ds->ds_phys->ds_next_clones_obj != 0) { 447 uint64_t count; 448 ASSERT0(zap_count(mos, 449 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 450 VERIFY0(dmu_object_free(mos, 451 ds->ds_phys->ds_next_clones_obj, tx)); 452 } 453 if (ds->ds_phys->ds_props_obj != 0) 454 VERIFY0(zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 455 if (ds->ds_phys->ds_userrefs_obj != 0) 456 VERIFY0(zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 457 dsl_dir_rele(ds->ds_dir, ds); 458 ds->ds_dir = NULL; 459 dmu_object_free_zapified(mos, obj, tx); 460 } 461 462 static void 463 dsl_destroy_snapshot_sync(void *arg, dmu_tx_t *tx) 464 { 465 dmu_snapshots_destroy_arg_t *dsda = arg; 466 dsl_pool_t *dp = dmu_tx_pool(tx); 467 nvpair_t *pair; 468 469 for (pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, NULL); 470 pair != NULL; 471 pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, pair)) { 472 dsl_dataset_t *ds; 473 474 VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds)); 475 476 dsl_destroy_snapshot_sync_impl(ds, dsda->dsda_defer, tx); 477 dsl_dataset_rele(ds, FTAG); 478 } 479 } 480 481 /* 482 * The semantics of this function are described in the comment above 483 * lzc_destroy_snaps(). To summarize: 484 * 485 * The snapshots must all be in the same pool. 486 * 487 * Snapshots that don't exist will be silently ignored (considered to be 488 * "already deleted"). 489 * 490 * On success, all snaps will be destroyed and this will return 0. 491 * On failure, no snaps will be destroyed, the errlist will be filled in, 492 * and this will return an errno. 493 */ 494 int 495 dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t defer, 496 nvlist_t *errlist) 497 { 498 dmu_snapshots_destroy_arg_t dsda; 499 int error; 500 nvpair_t *pair; 501 502 pair = nvlist_next_nvpair(snaps, NULL); 503 if (pair == NULL) 504 return (0); 505 506 dsda.dsda_snaps = snaps; 507 dsda.dsda_successful_snaps = fnvlist_alloc(); 508 dsda.dsda_defer = defer; 509 dsda.dsda_errlist = errlist; 510 511 error = dsl_sync_task(nvpair_name(pair), 512 dsl_destroy_snapshot_check, dsl_destroy_snapshot_sync, 513 &dsda, 0, ZFS_SPACE_CHECK_NONE); 514 fnvlist_free(dsda.dsda_successful_snaps); 515 516 return (error); 517 } 518 519 int 520 dsl_destroy_snapshot(const char *name, boolean_t defer) 521 { 522 int error; 523 nvlist_t *nvl = fnvlist_alloc(); 524 nvlist_t *errlist = fnvlist_alloc(); 525 526 fnvlist_add_boolean(nvl, name); 527 error = dsl_destroy_snapshots_nvl(nvl, defer, errlist); 528 fnvlist_free(errlist); 529 fnvlist_free(nvl); 530 return (error); 531 } 532 533 struct killarg { 534 dsl_dataset_t *ds; 535 dmu_tx_t *tx; 536 }; 537 538 /* ARGSUSED */ 539 static int 540 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 541 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg) 542 { 543 struct killarg *ka = arg; 544 dmu_tx_t *tx = ka->tx; 545 546 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp)) 547 return (0); 548 549 if (zb->zb_level == ZB_ZIL_LEVEL) { 550 ASSERT(zilog != NULL); 551 /* 552 * It's a block in the intent log. It has no 553 * accounting, so just free it. 554 */ 555 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 556 } else { 557 ASSERT(zilog == NULL); 558 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 559 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 560 } 561 562 return (0); 563 } 564 565 static void 566 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx) 567 { 568 struct killarg ka; 569 570 /* 571 * Free everything that we point to (that's born after 572 * the previous snapshot, if we are a clone) 573 * 574 * NB: this should be very quick, because we already 575 * freed all the objects in open context. 576 */ 577 ka.ds = ds; 578 ka.tx = tx; 579 VERIFY0(traverse_dataset(ds, 580 ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST, 581 kill_blkptr, &ka)); 582 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0); 583 } 584 585 typedef struct dsl_destroy_head_arg { 586 const char *ddha_name; 587 } dsl_destroy_head_arg_t; 588 589 int 590 dsl_destroy_head_check_impl(dsl_dataset_t *ds, int expected_holds) 591 { 592 int error; 593 uint64_t count; 594 objset_t *mos; 595 596 ASSERT(!dsl_dataset_is_snapshot(ds)); 597 if (dsl_dataset_is_snapshot(ds)) 598 return (SET_ERROR(EINVAL)); 599 600 if (refcount_count(&ds->ds_longholds) != expected_holds) 601 return (SET_ERROR(EBUSY)); 602 603 mos = ds->ds_dir->dd_pool->dp_meta_objset; 604 605 /* 606 * Can't delete a head dataset if there are snapshots of it. 607 * (Except if the only snapshots are from the branch we cloned 608 * from.) 609 */ 610 if (ds->ds_prev != NULL && 611 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 612 return (SET_ERROR(EBUSY)); 613 614 /* 615 * Can't delete if there are children of this fs. 616 */ 617 error = zap_count(mos, 618 ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 619 if (error != 0) 620 return (error); 621 if (count != 0) 622 return (SET_ERROR(EEXIST)); 623 624 if (dsl_dir_is_clone(ds->ds_dir) && DS_IS_DEFER_DESTROY(ds->ds_prev) && 625 ds->ds_prev->ds_phys->ds_num_children == 2 && 626 ds->ds_prev->ds_userrefs == 0) { 627 /* We need to remove the origin snapshot as well. */ 628 if (!refcount_is_zero(&ds->ds_prev->ds_longholds)) 629 return (SET_ERROR(EBUSY)); 630 } 631 return (0); 632 } 633 634 static int 635 dsl_destroy_head_check(void *arg, dmu_tx_t *tx) 636 { 637 dsl_destroy_head_arg_t *ddha = arg; 638 dsl_pool_t *dp = dmu_tx_pool(tx); 639 dsl_dataset_t *ds; 640 int error; 641 642 error = dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds); 643 if (error != 0) 644 return (error); 645 646 error = dsl_destroy_head_check_impl(ds, 0); 647 dsl_dataset_rele(ds, FTAG); 648 return (error); 649 } 650 651 static void 652 dsl_dir_destroy_sync(uint64_t ddobj, dmu_tx_t *tx) 653 { 654 dsl_dir_t *dd; 655 dsl_pool_t *dp = dmu_tx_pool(tx); 656 objset_t *mos = dp->dp_meta_objset; 657 dd_used_t t; 658 659 ASSERT(RRW_WRITE_HELD(&dmu_tx_pool(tx)->dp_config_rwlock)); 660 661 VERIFY0(dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd)); 662 663 ASSERT0(dd->dd_phys->dd_head_dataset_obj); 664 665 /* 666 * Decrement the filesystem count for all parent filesystems. 667 * 668 * When we receive an incremental stream into a filesystem that already 669 * exists, a temporary clone is created. We never count this temporary 670 * clone, whose name begins with a '%'. 671 */ 672 if (dd->dd_myname[0] != '%' && dd->dd_parent != NULL) 673 dsl_fs_ss_count_adjust(dd->dd_parent, -1, 674 DD_FIELD_FILESYSTEM_COUNT, tx); 675 676 /* 677 * Remove our reservation. The impl() routine avoids setting the 678 * actual property, which would require the (already destroyed) ds. 679 */ 680 dsl_dir_set_reservation_sync_impl(dd, 0, tx); 681 682 ASSERT0(dd->dd_phys->dd_used_bytes); 683 ASSERT0(dd->dd_phys->dd_reserved); 684 for (t = 0; t < DD_USED_NUM; t++) 685 ASSERT0(dd->dd_phys->dd_used_breakdown[t]); 686 687 VERIFY0(zap_destroy(mos, dd->dd_phys->dd_child_dir_zapobj, tx)); 688 VERIFY0(zap_destroy(mos, dd->dd_phys->dd_props_zapobj, tx)); 689 VERIFY0(dsl_deleg_destroy(mos, dd->dd_phys->dd_deleg_zapobj, tx)); 690 VERIFY0(zap_remove(mos, 691 dd->dd_parent->dd_phys->dd_child_dir_zapobj, dd->dd_myname, tx)); 692 693 dsl_dir_rele(dd, FTAG); 694 dmu_object_free_zapified(mos, ddobj, tx); 695 } 696 697 void 698 dsl_destroy_head_sync_impl(dsl_dataset_t *ds, dmu_tx_t *tx) 699 { 700 dsl_pool_t *dp = dmu_tx_pool(tx); 701 objset_t *mos = dp->dp_meta_objset; 702 uint64_t obj, ddobj, prevobj = 0; 703 boolean_t rmorigin; 704 705 ASSERT3U(ds->ds_phys->ds_num_children, <=, 1); 706 ASSERT(ds->ds_prev == NULL || 707 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 708 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 709 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock)); 710 711 /* We need to log before removing it from the namespace. */ 712 spa_history_log_internal_ds(ds, "destroy", tx, ""); 713 714 rmorigin = (dsl_dir_is_clone(ds->ds_dir) && 715 DS_IS_DEFER_DESTROY(ds->ds_prev) && 716 ds->ds_prev->ds_phys->ds_num_children == 2 && 717 ds->ds_prev->ds_userrefs == 0); 718 719 /* Remove our reservation. */ 720 if (ds->ds_reserved != 0) { 721 dsl_dataset_set_refreservation_sync_impl(ds, 722 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 723 0, tx); 724 ASSERT0(ds->ds_reserved); 725 } 726 727 if (ds->ds_large_blocks) 728 spa_feature_decr(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS, tx); 729 730 dsl_scan_ds_destroyed(ds, tx); 731 732 obj = ds->ds_object; 733 734 if (ds->ds_phys->ds_prev_snap_obj != 0) { 735 /* This is a clone */ 736 ASSERT(ds->ds_prev != NULL); 737 ASSERT3U(ds->ds_prev->ds_phys->ds_next_snap_obj, !=, obj); 738 ASSERT0(ds->ds_phys->ds_next_snap_obj); 739 740 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 741 if (ds->ds_prev->ds_phys->ds_next_clones_obj != 0) { 742 dsl_dataset_remove_from_next_clones(ds->ds_prev, 743 obj, tx); 744 } 745 746 ASSERT3U(ds->ds_prev->ds_phys->ds_num_children, >, 1); 747 ds->ds_prev->ds_phys->ds_num_children--; 748 } 749 750 /* 751 * Destroy the deadlist. Unless it's a clone, the 752 * deadlist should be empty. (If it's a clone, it's 753 * safe to ignore the deadlist contents.) 754 */ 755 dsl_deadlist_close(&ds->ds_deadlist); 756 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 757 dmu_buf_will_dirty(ds->ds_dbuf, tx); 758 ds->ds_phys->ds_deadlist_obj = 0; 759 760 objset_t *os; 761 VERIFY0(dmu_objset_from_ds(ds, &os)); 762 763 if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) { 764 old_synchronous_dataset_destroy(ds, tx); 765 } else { 766 /* 767 * Move the bptree into the pool's list of trees to 768 * clean up and update space accounting information. 769 */ 770 uint64_t used, comp, uncomp; 771 772 zil_destroy_sync(dmu_objset_zil(os), tx); 773 774 if (!spa_feature_is_active(dp->dp_spa, 775 SPA_FEATURE_ASYNC_DESTROY)) { 776 dsl_scan_t *scn = dp->dp_scan; 777 spa_feature_incr(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY, 778 tx); 779 dp->dp_bptree_obj = bptree_alloc(mos, tx); 780 VERIFY0(zap_add(mos, 781 DMU_POOL_DIRECTORY_OBJECT, 782 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1, 783 &dp->dp_bptree_obj, tx)); 784 ASSERT(!scn->scn_async_destroying); 785 scn->scn_async_destroying = B_TRUE; 786 } 787 788 used = ds->ds_dir->dd_phys->dd_used_bytes; 789 comp = ds->ds_dir->dd_phys->dd_compressed_bytes; 790 uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes; 791 792 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 793 ds->ds_phys->ds_unique_bytes == used); 794 795 bptree_add(mos, dp->dp_bptree_obj, 796 &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg, 797 used, comp, uncomp, tx); 798 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 799 -used, -comp, -uncomp, tx); 800 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 801 used, comp, uncomp, tx); 802 } 803 804 if (ds->ds_prev != NULL) { 805 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 806 VERIFY0(zap_remove_int(mos, 807 ds->ds_prev->ds_dir->dd_phys->dd_clones, 808 ds->ds_object, tx)); 809 } 810 prevobj = ds->ds_prev->ds_object; 811 dsl_dataset_rele(ds->ds_prev, ds); 812 ds->ds_prev = NULL; 813 } 814 815 /* 816 * This must be done after the dsl_traverse(), because it will 817 * re-open the objset. 818 */ 819 if (ds->ds_objset) { 820 dmu_objset_evict(ds->ds_objset); 821 ds->ds_objset = NULL; 822 } 823 824 /* Erase the link in the dir */ 825 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 826 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 827 ddobj = ds->ds_dir->dd_object; 828 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 829 VERIFY0(zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx)); 830 831 if (ds->ds_bookmarks != 0) { 832 VERIFY0(zap_destroy(mos, 833 ds->ds_bookmarks, tx)); 834 spa_feature_decr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx); 835 } 836 837 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 838 839 ASSERT0(ds->ds_phys->ds_next_clones_obj); 840 ASSERT0(ds->ds_phys->ds_props_obj); 841 ASSERT0(ds->ds_phys->ds_userrefs_obj); 842 dsl_dir_rele(ds->ds_dir, ds); 843 ds->ds_dir = NULL; 844 dmu_object_free_zapified(mos, obj, tx); 845 846 dsl_dir_destroy_sync(ddobj, tx); 847 848 if (rmorigin) { 849 dsl_dataset_t *prev; 850 VERIFY0(dsl_dataset_hold_obj(dp, prevobj, FTAG, &prev)); 851 dsl_destroy_snapshot_sync_impl(prev, B_FALSE, tx); 852 dsl_dataset_rele(prev, FTAG); 853 } 854 } 855 856 static void 857 dsl_destroy_head_sync(void *arg, dmu_tx_t *tx) 858 { 859 dsl_destroy_head_arg_t *ddha = arg; 860 dsl_pool_t *dp = dmu_tx_pool(tx); 861 dsl_dataset_t *ds; 862 863 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds)); 864 dsl_destroy_head_sync_impl(ds, tx); 865 dsl_dataset_rele(ds, FTAG); 866 } 867 868 static void 869 dsl_destroy_head_begin_sync(void *arg, dmu_tx_t *tx) 870 { 871 dsl_destroy_head_arg_t *ddha = arg; 872 dsl_pool_t *dp = dmu_tx_pool(tx); 873 dsl_dataset_t *ds; 874 875 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds)); 876 877 /* Mark it as inconsistent on-disk, in case we crash */ 878 dmu_buf_will_dirty(ds->ds_dbuf, tx); 879 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 880 881 spa_history_log_internal_ds(ds, "destroy begin", tx, ""); 882 dsl_dataset_rele(ds, FTAG); 883 } 884 885 int 886 dsl_destroy_head(const char *name) 887 { 888 dsl_destroy_head_arg_t ddha; 889 int error; 890 spa_t *spa; 891 boolean_t isenabled; 892 893 #ifdef _KERNEL 894 zfs_destroy_unmount_origin(name); 895 #endif 896 897 error = spa_open(name, &spa, FTAG); 898 if (error != 0) 899 return (error); 900 isenabled = spa_feature_is_enabled(spa, SPA_FEATURE_ASYNC_DESTROY); 901 spa_close(spa, FTAG); 902 903 ddha.ddha_name = name; 904 905 if (!isenabled) { 906 objset_t *os; 907 908 error = dsl_sync_task(name, dsl_destroy_head_check, 909 dsl_destroy_head_begin_sync, &ddha, 910 0, ZFS_SPACE_CHECK_NONE); 911 if (error != 0) 912 return (error); 913 914 /* 915 * Head deletion is processed in one txg on old pools; 916 * remove the objects from open context so that the txg sync 917 * is not too long. 918 */ 919 error = dmu_objset_own(name, DMU_OST_ANY, B_FALSE, FTAG, &os); 920 if (error == 0) { 921 uint64_t prev_snap_txg = 922 dmu_objset_ds(os)->ds_phys->ds_prev_snap_txg; 923 for (uint64_t obj = 0; error == 0; 924 error = dmu_object_next(os, &obj, FALSE, 925 prev_snap_txg)) 926 (void) dmu_free_long_object(os, obj); 927 /* sync out all frees */ 928 txg_wait_synced(dmu_objset_pool(os), 0); 929 dmu_objset_disown(os, FTAG); 930 } 931 } 932 933 return (dsl_sync_task(name, dsl_destroy_head_check, 934 dsl_destroy_head_sync, &ddha, 0, ZFS_SPACE_CHECK_NONE)); 935 } 936 937 /* 938 * Note, this function is used as the callback for dmu_objset_find(). We 939 * always return 0 so that we will continue to find and process 940 * inconsistent datasets, even if we encounter an error trying to 941 * process one of them. 942 */ 943 /* ARGSUSED */ 944 int 945 dsl_destroy_inconsistent(const char *dsname, void *arg) 946 { 947 objset_t *os; 948 949 if (dmu_objset_hold(dsname, FTAG, &os) == 0) { 950 boolean_t inconsistent = DS_IS_INCONSISTENT(dmu_objset_ds(os)); 951 dmu_objset_rele(os, FTAG); 952 if (inconsistent) 953 (void) dsl_destroy_head(dsname); 954 } 955 return (0); 956 } 957