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