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