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 (dsl_dataset_phys(ds)->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 <= dsl_dataset_phys(poa->ds)->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 dsl_dataset_phys(poa->ds_prev)->ds_prev_snap_txg) { 155 dsl_dataset_phys(poa->ds_prev)->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, ==, dsl_dataset_phys(ds)->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 = dsl_dataset_phys(ds)->ds_deadlist_obj; 196 dsl_dataset_phys(ds)->ds_deadlist_obj = 197 dsl_dataset_phys(ds_next)->ds_deadlist_obj; 198 dsl_dataset_phys(ds_next)->ds_deadlist_obj = deadlist_obj; 199 dsl_deadlist_open(&ds->ds_deadlist, mos, 200 dsl_dataset_phys(ds)->ds_deadlist_obj); 201 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 202 dsl_dataset_phys(ds_next)->ds_deadlist_obj); 203 } 204 205 static void 206 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 207 { 208 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 209 zap_cursor_t zc; 210 zap_attribute_t za; 211 212 /* 213 * If it is the old version, dd_clones doesn't exist so we can't 214 * find the clones, but dsl_deadlist_remove_key() is a no-op so it 215 * doesn't matter. 216 */ 217 if (dsl_dir_phys(ds->ds_dir)->dd_clones == 0) 218 return; 219 220 for (zap_cursor_init(&zc, mos, dsl_dir_phys(ds->ds_dir)->dd_clones); 221 zap_cursor_retrieve(&zc, &za) == 0; 222 zap_cursor_advance(&zc)) { 223 dsl_dataset_t *clone; 224 225 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 226 za.za_first_integer, FTAG, &clone)); 227 if (clone->ds_dir->dd_origin_txg > mintxg) { 228 dsl_deadlist_remove_key(&clone->ds_deadlist, 229 mintxg, tx); 230 dsl_dataset_remove_clones_key(clone, mintxg, tx); 231 } 232 dsl_dataset_rele(clone, FTAG); 233 } 234 zap_cursor_fini(&zc); 235 } 236 237 void 238 dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx) 239 { 240 int err; 241 int after_branch_point = FALSE; 242 dsl_pool_t *dp = ds->ds_dir->dd_pool; 243 objset_t *mos = dp->dp_meta_objset; 244 dsl_dataset_t *ds_prev = NULL; 245 uint64_t obj; 246 247 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock)); 248 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg); 249 ASSERT(refcount_is_zero(&ds->ds_longholds)); 250 251 if (defer && 252 (ds->ds_userrefs > 0 || 253 dsl_dataset_phys(ds)->ds_num_children > 1)) { 254 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 255 dmu_buf_will_dirty(ds->ds_dbuf, tx); 256 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_DEFER_DESTROY; 257 spa_history_log_internal_ds(ds, "defer_destroy", tx, ""); 258 return; 259 } 260 261 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1); 262 263 /* We need to log before removing it from the namespace. */ 264 spa_history_log_internal_ds(ds, "destroy", tx, ""); 265 266 dsl_scan_ds_destroyed(ds, tx); 267 268 obj = ds->ds_object; 269 270 if (ds->ds_large_blocks) { 271 ASSERT0(zap_contains(mos, obj, DS_FIELD_LARGE_BLOCKS)); 272 spa_feature_decr(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS, tx); 273 } 274 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 275 ASSERT3P(ds->ds_prev, ==, NULL); 276 VERIFY0(dsl_dataset_hold_obj(dp, 277 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &ds_prev)); 278 after_branch_point = 279 (dsl_dataset_phys(ds_prev)->ds_next_snap_obj != obj); 280 281 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 282 if (after_branch_point && 283 dsl_dataset_phys(ds_prev)->ds_next_clones_obj != 0) { 284 dsl_dataset_remove_from_next_clones(ds_prev, obj, tx); 285 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) { 286 VERIFY0(zap_add_int(mos, 287 dsl_dataset_phys(ds_prev)-> 288 ds_next_clones_obj, 289 dsl_dataset_phys(ds)->ds_next_snap_obj, 290 tx)); 291 } 292 } 293 if (!after_branch_point) { 294 dsl_dataset_phys(ds_prev)->ds_next_snap_obj = 295 dsl_dataset_phys(ds)->ds_next_snap_obj; 296 } 297 } 298 299 dsl_dataset_t *ds_next; 300 uint64_t old_unique; 301 uint64_t used = 0, comp = 0, uncomp = 0; 302 303 VERIFY0(dsl_dataset_hold_obj(dp, 304 dsl_dataset_phys(ds)->ds_next_snap_obj, FTAG, &ds_next)); 305 ASSERT3U(dsl_dataset_phys(ds_next)->ds_prev_snap_obj, ==, obj); 306 307 old_unique = dsl_dataset_phys(ds_next)->ds_unique_bytes; 308 309 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 310 dsl_dataset_phys(ds_next)->ds_prev_snap_obj = 311 dsl_dataset_phys(ds)->ds_prev_snap_obj; 312 dsl_dataset_phys(ds_next)->ds_prev_snap_txg = 313 dsl_dataset_phys(ds)->ds_prev_snap_txg; 314 ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_txg, ==, 315 ds_prev ? dsl_dataset_phys(ds_prev)->ds_creation_txg : 0); 316 317 if (ds_next->ds_deadlist.dl_oldfmt) { 318 process_old_deadlist(ds, ds_prev, ds_next, 319 after_branch_point, tx); 320 } else { 321 /* Adjust prev's unique space. */ 322 if (ds_prev && !after_branch_point) { 323 dsl_deadlist_space_range(&ds_next->ds_deadlist, 324 dsl_dataset_phys(ds_prev)->ds_prev_snap_txg, 325 dsl_dataset_phys(ds)->ds_prev_snap_txg, 326 &used, &comp, &uncomp); 327 dsl_dataset_phys(ds_prev)->ds_unique_bytes += used; 328 } 329 330 /* Adjust snapused. */ 331 dsl_deadlist_space_range(&ds_next->ds_deadlist, 332 dsl_dataset_phys(ds)->ds_prev_snap_txg, UINT64_MAX, 333 &used, &comp, &uncomp); 334 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 335 -used, -comp, -uncomp, tx); 336 337 /* Move blocks to be freed to pool's free list. */ 338 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 339 &dp->dp_free_bpobj, dsl_dataset_phys(ds)->ds_prev_snap_txg, 340 tx); 341 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 342 DD_USED_HEAD, used, comp, uncomp, tx); 343 344 /* Merge our deadlist into next's and free it. */ 345 dsl_deadlist_merge(&ds_next->ds_deadlist, 346 dsl_dataset_phys(ds)->ds_deadlist_obj, tx); 347 } 348 dsl_deadlist_close(&ds->ds_deadlist); 349 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx); 350 dmu_buf_will_dirty(ds->ds_dbuf, tx); 351 dsl_dataset_phys(ds)->ds_deadlist_obj = 0; 352 353 /* Collapse range in clone heads */ 354 dsl_dataset_remove_clones_key(ds, 355 dsl_dataset_phys(ds)->ds_creation_txg, tx); 356 357 if (dsl_dataset_is_snapshot(ds_next)) { 358 dsl_dataset_t *ds_nextnext; 359 360 /* 361 * Update next's unique to include blocks which 362 * were previously shared by only this snapshot 363 * and it. Those blocks will be born after the 364 * prev snap and before this snap, and will have 365 * died after the next snap and before the one 366 * after that (ie. be on the snap after next's 367 * deadlist). 368 */ 369 VERIFY0(dsl_dataset_hold_obj(dp, 370 dsl_dataset_phys(ds_next)->ds_next_snap_obj, 371 FTAG, &ds_nextnext)); 372 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 373 dsl_dataset_phys(ds)->ds_prev_snap_txg, 374 dsl_dataset_phys(ds)->ds_creation_txg, 375 &used, &comp, &uncomp); 376 dsl_dataset_phys(ds_next)->ds_unique_bytes += used; 377 dsl_dataset_rele(ds_nextnext, FTAG); 378 ASSERT3P(ds_next->ds_prev, ==, NULL); 379 380 /* Collapse range in this head. */ 381 dsl_dataset_t *hds; 382 VERIFY0(dsl_dataset_hold_obj(dp, 383 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &hds)); 384 dsl_deadlist_remove_key(&hds->ds_deadlist, 385 dsl_dataset_phys(ds)->ds_creation_txg, tx); 386 dsl_dataset_rele(hds, FTAG); 387 388 } else { 389 ASSERT3P(ds_next->ds_prev, ==, ds); 390 dsl_dataset_rele(ds_next->ds_prev, ds_next); 391 ds_next->ds_prev = NULL; 392 if (ds_prev) { 393 VERIFY0(dsl_dataset_hold_obj(dp, 394 dsl_dataset_phys(ds)->ds_prev_snap_obj, 395 ds_next, &ds_next->ds_prev)); 396 } 397 398 dsl_dataset_recalc_head_uniq(ds_next); 399 400 /* 401 * Reduce the amount of our unconsumed refreservation 402 * being charged to our parent by the amount of 403 * new unique data we have gained. 404 */ 405 if (old_unique < ds_next->ds_reserved) { 406 int64_t mrsdelta; 407 uint64_t new_unique = 408 dsl_dataset_phys(ds_next)->ds_unique_bytes; 409 410 ASSERT(old_unique <= new_unique); 411 mrsdelta = MIN(new_unique - old_unique, 412 ds_next->ds_reserved - old_unique); 413 dsl_dir_diduse_space(ds->ds_dir, 414 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 415 } 416 } 417 dsl_dataset_rele(ds_next, FTAG); 418 419 /* 420 * This must be done after the dsl_traverse(), because it will 421 * re-open the objset. 422 */ 423 if (ds->ds_objset) { 424 dmu_objset_evict(ds->ds_objset); 425 ds->ds_objset = NULL; 426 } 427 428 /* remove from snapshot namespace */ 429 dsl_dataset_t *ds_head; 430 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj == 0); 431 VERIFY0(dsl_dataset_hold_obj(dp, 432 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &ds_head)); 433 VERIFY0(dsl_dataset_get_snapname(ds)); 434 #ifdef ZFS_DEBUG 435 { 436 uint64_t val; 437 438 err = dsl_dataset_snap_lookup(ds_head, 439 ds->ds_snapname, &val); 440 ASSERT0(err); 441 ASSERT3U(val, ==, obj); 442 } 443 #endif 444 VERIFY0(dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx, B_TRUE)); 445 dsl_dataset_rele(ds_head, FTAG); 446 447 if (ds_prev != NULL) 448 dsl_dataset_rele(ds_prev, FTAG); 449 450 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 451 452 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) { 453 uint64_t count; 454 ASSERT0(zap_count(mos, 455 dsl_dataset_phys(ds)->ds_next_clones_obj, &count) && 456 count == 0); 457 VERIFY0(dmu_object_free(mos, 458 dsl_dataset_phys(ds)->ds_next_clones_obj, tx)); 459 } 460 if (dsl_dataset_phys(ds)->ds_props_obj != 0) 461 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_props_obj, 462 tx)); 463 if (dsl_dataset_phys(ds)->ds_userrefs_obj != 0) 464 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_userrefs_obj, 465 tx)); 466 dsl_dir_rele(ds->ds_dir, ds); 467 ds->ds_dir = NULL; 468 dmu_object_free_zapified(mos, obj, tx); 469 } 470 471 static void 472 dsl_destroy_snapshot_sync(void *arg, dmu_tx_t *tx) 473 { 474 dmu_snapshots_destroy_arg_t *dsda = arg; 475 dsl_pool_t *dp = dmu_tx_pool(tx); 476 nvpair_t *pair; 477 478 for (pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, NULL); 479 pair != NULL; 480 pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, pair)) { 481 dsl_dataset_t *ds; 482 483 VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds)); 484 485 dsl_destroy_snapshot_sync_impl(ds, dsda->dsda_defer, tx); 486 dsl_dataset_rele(ds, FTAG); 487 } 488 } 489 490 /* 491 * The semantics of this function are described in the comment above 492 * lzc_destroy_snaps(). To summarize: 493 * 494 * The snapshots must all be in the same pool. 495 * 496 * Snapshots that don't exist will be silently ignored (considered to be 497 * "already deleted"). 498 * 499 * On success, all snaps will be destroyed and this will return 0. 500 * On failure, no snaps will be destroyed, the errlist will be filled in, 501 * and this will return an errno. 502 */ 503 int 504 dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t defer, 505 nvlist_t *errlist) 506 { 507 dmu_snapshots_destroy_arg_t dsda; 508 int error; 509 nvpair_t *pair; 510 511 pair = nvlist_next_nvpair(snaps, NULL); 512 if (pair == NULL) 513 return (0); 514 515 dsda.dsda_snaps = snaps; 516 dsda.dsda_successful_snaps = fnvlist_alloc(); 517 dsda.dsda_defer = defer; 518 dsda.dsda_errlist = errlist; 519 520 error = dsl_sync_task(nvpair_name(pair), 521 dsl_destroy_snapshot_check, dsl_destroy_snapshot_sync, 522 &dsda, 0, ZFS_SPACE_CHECK_NONE); 523 fnvlist_free(dsda.dsda_successful_snaps); 524 525 return (error); 526 } 527 528 int 529 dsl_destroy_snapshot(const char *name, boolean_t defer) 530 { 531 int error; 532 nvlist_t *nvl = fnvlist_alloc(); 533 nvlist_t *errlist = fnvlist_alloc(); 534 535 fnvlist_add_boolean(nvl, name); 536 error = dsl_destroy_snapshots_nvl(nvl, defer, errlist); 537 fnvlist_free(errlist); 538 fnvlist_free(nvl); 539 return (error); 540 } 541 542 struct killarg { 543 dsl_dataset_t *ds; 544 dmu_tx_t *tx; 545 }; 546 547 /* ARGSUSED */ 548 static int 549 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 550 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg) 551 { 552 struct killarg *ka = arg; 553 dmu_tx_t *tx = ka->tx; 554 555 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp)) 556 return (0); 557 558 if (zb->zb_level == ZB_ZIL_LEVEL) { 559 ASSERT(zilog != NULL); 560 /* 561 * It's a block in the intent log. It has no 562 * accounting, so just free it. 563 */ 564 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 565 } else { 566 ASSERT(zilog == NULL); 567 ASSERT3U(bp->blk_birth, >, 568 dsl_dataset_phys(ka->ds)->ds_prev_snap_txg); 569 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 570 } 571 572 return (0); 573 } 574 575 static void 576 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx) 577 { 578 struct killarg ka; 579 580 /* 581 * Free everything that we point to (that's born after 582 * the previous snapshot, if we are a clone) 583 * 584 * NB: this should be very quick, because we already 585 * freed all the objects in open context. 586 */ 587 ka.ds = ds; 588 ka.tx = tx; 589 VERIFY0(traverse_dataset(ds, 590 dsl_dataset_phys(ds)->ds_prev_snap_txg, TRAVERSE_POST, 591 kill_blkptr, &ka)); 592 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 593 dsl_dataset_phys(ds)->ds_unique_bytes == 0); 594 } 595 596 typedef struct dsl_destroy_head_arg { 597 const char *ddha_name; 598 } dsl_destroy_head_arg_t; 599 600 int 601 dsl_destroy_head_check_impl(dsl_dataset_t *ds, int expected_holds) 602 { 603 int error; 604 uint64_t count; 605 objset_t *mos; 606 607 ASSERT(!dsl_dataset_is_snapshot(ds)); 608 if (dsl_dataset_is_snapshot(ds)) 609 return (SET_ERROR(EINVAL)); 610 611 if (refcount_count(&ds->ds_longholds) != expected_holds) 612 return (SET_ERROR(EBUSY)); 613 614 mos = ds->ds_dir->dd_pool->dp_meta_objset; 615 616 /* 617 * Can't delete a head dataset if there are snapshots of it. 618 * (Except if the only snapshots are from the branch we cloned 619 * from.) 620 */ 621 if (ds->ds_prev != NULL && 622 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj == ds->ds_object) 623 return (SET_ERROR(EBUSY)); 624 625 /* 626 * Can't delete if there are children of this fs. 627 */ 628 error = zap_count(mos, 629 dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, &count); 630 if (error != 0) 631 return (error); 632 if (count != 0) 633 return (SET_ERROR(EEXIST)); 634 635 if (dsl_dir_is_clone(ds->ds_dir) && DS_IS_DEFER_DESTROY(ds->ds_prev) && 636 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 && 637 ds->ds_prev->ds_userrefs == 0) { 638 /* We need to remove the origin snapshot as well. */ 639 if (!refcount_is_zero(&ds->ds_prev->ds_longholds)) 640 return (SET_ERROR(EBUSY)); 641 } 642 return (0); 643 } 644 645 static int 646 dsl_destroy_head_check(void *arg, dmu_tx_t *tx) 647 { 648 dsl_destroy_head_arg_t *ddha = arg; 649 dsl_pool_t *dp = dmu_tx_pool(tx); 650 dsl_dataset_t *ds; 651 int error; 652 653 error = dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds); 654 if (error != 0) 655 return (error); 656 657 error = dsl_destroy_head_check_impl(ds, 0); 658 dsl_dataset_rele(ds, FTAG); 659 return (error); 660 } 661 662 static void 663 dsl_dir_destroy_sync(uint64_t ddobj, dmu_tx_t *tx) 664 { 665 dsl_dir_t *dd; 666 dsl_pool_t *dp = dmu_tx_pool(tx); 667 objset_t *mos = dp->dp_meta_objset; 668 dd_used_t t; 669 670 ASSERT(RRW_WRITE_HELD(&dmu_tx_pool(tx)->dp_config_rwlock)); 671 672 VERIFY0(dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd)); 673 674 ASSERT0(dsl_dir_phys(dd)->dd_head_dataset_obj); 675 676 /* 677 * Decrement the filesystem count for all parent filesystems. 678 * 679 * When we receive an incremental stream into a filesystem that already 680 * exists, a temporary clone is created. We never count this temporary 681 * clone, whose name begins with a '%'. 682 */ 683 if (dd->dd_myname[0] != '%' && dd->dd_parent != NULL) 684 dsl_fs_ss_count_adjust(dd->dd_parent, -1, 685 DD_FIELD_FILESYSTEM_COUNT, tx); 686 687 /* 688 * Remove our reservation. The impl() routine avoids setting the 689 * actual property, which would require the (already destroyed) ds. 690 */ 691 dsl_dir_set_reservation_sync_impl(dd, 0, tx); 692 693 ASSERT0(dsl_dir_phys(dd)->dd_used_bytes); 694 ASSERT0(dsl_dir_phys(dd)->dd_reserved); 695 for (t = 0; t < DD_USED_NUM; t++) 696 ASSERT0(dsl_dir_phys(dd)->dd_used_breakdown[t]); 697 698 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_child_dir_zapobj, tx)); 699 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_props_zapobj, tx)); 700 VERIFY0(dsl_deleg_destroy(mos, dsl_dir_phys(dd)->dd_deleg_zapobj, tx)); 701 VERIFY0(zap_remove(mos, 702 dsl_dir_phys(dd->dd_parent)->dd_child_dir_zapobj, 703 dd->dd_myname, tx)); 704 705 dsl_dir_rele(dd, FTAG); 706 dmu_object_free_zapified(mos, ddobj, tx); 707 } 708 709 void 710 dsl_destroy_head_sync_impl(dsl_dataset_t *ds, dmu_tx_t *tx) 711 { 712 dsl_pool_t *dp = dmu_tx_pool(tx); 713 objset_t *mos = dp->dp_meta_objset; 714 uint64_t obj, ddobj, prevobj = 0; 715 boolean_t rmorigin; 716 717 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1); 718 ASSERT(ds->ds_prev == NULL || 719 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj != ds->ds_object); 720 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg); 721 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock)); 722 723 /* We need to log before removing it from the namespace. */ 724 spa_history_log_internal_ds(ds, "destroy", tx, ""); 725 726 rmorigin = (dsl_dir_is_clone(ds->ds_dir) && 727 DS_IS_DEFER_DESTROY(ds->ds_prev) && 728 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 && 729 ds->ds_prev->ds_userrefs == 0); 730 731 /* Remove our reservation. */ 732 if (ds->ds_reserved != 0) { 733 dsl_dataset_set_refreservation_sync_impl(ds, 734 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 735 0, tx); 736 ASSERT0(ds->ds_reserved); 737 } 738 739 if (ds->ds_large_blocks) 740 spa_feature_decr(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS, tx); 741 742 dsl_scan_ds_destroyed(ds, tx); 743 744 obj = ds->ds_object; 745 746 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 747 /* This is a clone */ 748 ASSERT(ds->ds_prev != NULL); 749 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj, !=, 750 obj); 751 ASSERT0(dsl_dataset_phys(ds)->ds_next_snap_obj); 752 753 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 754 if (dsl_dataset_phys(ds->ds_prev)->ds_next_clones_obj != 0) { 755 dsl_dataset_remove_from_next_clones(ds->ds_prev, 756 obj, tx); 757 } 758 759 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_num_children, >, 1); 760 dsl_dataset_phys(ds->ds_prev)->ds_num_children--; 761 } 762 763 /* 764 * Destroy the deadlist. Unless it's a clone, the 765 * deadlist should be empty. (If it's a clone, it's 766 * safe to ignore the deadlist contents.) 767 */ 768 dsl_deadlist_close(&ds->ds_deadlist); 769 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx); 770 dmu_buf_will_dirty(ds->ds_dbuf, tx); 771 dsl_dataset_phys(ds)->ds_deadlist_obj = 0; 772 773 objset_t *os; 774 VERIFY0(dmu_objset_from_ds(ds, &os)); 775 776 if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) { 777 old_synchronous_dataset_destroy(ds, tx); 778 } else { 779 /* 780 * Move the bptree into the pool's list of trees to 781 * clean up and update space accounting information. 782 */ 783 uint64_t used, comp, uncomp; 784 785 zil_destroy_sync(dmu_objset_zil(os), tx); 786 787 if (!spa_feature_is_active(dp->dp_spa, 788 SPA_FEATURE_ASYNC_DESTROY)) { 789 dsl_scan_t *scn = dp->dp_scan; 790 spa_feature_incr(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY, 791 tx); 792 dp->dp_bptree_obj = bptree_alloc(mos, tx); 793 VERIFY0(zap_add(mos, 794 DMU_POOL_DIRECTORY_OBJECT, 795 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1, 796 &dp->dp_bptree_obj, tx)); 797 ASSERT(!scn->scn_async_destroying); 798 scn->scn_async_destroying = B_TRUE; 799 } 800 801 used = dsl_dir_phys(ds->ds_dir)->dd_used_bytes; 802 comp = dsl_dir_phys(ds->ds_dir)->dd_compressed_bytes; 803 uncomp = dsl_dir_phys(ds->ds_dir)->dd_uncompressed_bytes; 804 805 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 806 dsl_dataset_phys(ds)->ds_unique_bytes == used); 807 808 bptree_add(mos, dp->dp_bptree_obj, 809 &dsl_dataset_phys(ds)->ds_bp, 810 dsl_dataset_phys(ds)->ds_prev_snap_txg, 811 used, comp, uncomp, tx); 812 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 813 -used, -comp, -uncomp, tx); 814 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 815 used, comp, uncomp, tx); 816 } 817 818 if (ds->ds_prev != NULL) { 819 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 820 VERIFY0(zap_remove_int(mos, 821 dsl_dir_phys(ds->ds_prev->ds_dir)->dd_clones, 822 ds->ds_object, tx)); 823 } 824 prevobj = ds->ds_prev->ds_object; 825 dsl_dataset_rele(ds->ds_prev, ds); 826 ds->ds_prev = NULL; 827 } 828 829 /* 830 * This must be done after the dsl_traverse(), because it will 831 * re-open the objset. 832 */ 833 if (ds->ds_objset) { 834 dmu_objset_evict(ds->ds_objset); 835 ds->ds_objset = NULL; 836 } 837 838 /* Erase the link in the dir */ 839 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 840 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj = 0; 841 ddobj = ds->ds_dir->dd_object; 842 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj != 0); 843 VERIFY0(zap_destroy(mos, 844 dsl_dataset_phys(ds)->ds_snapnames_zapobj, tx)); 845 846 if (ds->ds_bookmarks != 0) { 847 VERIFY0(zap_destroy(mos, ds->ds_bookmarks, tx)); 848 spa_feature_decr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx); 849 } 850 851 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 852 853 ASSERT0(dsl_dataset_phys(ds)->ds_next_clones_obj); 854 ASSERT0(dsl_dataset_phys(ds)->ds_props_obj); 855 ASSERT0(dsl_dataset_phys(ds)->ds_userrefs_obj); 856 dsl_dir_rele(ds->ds_dir, ds); 857 ds->ds_dir = NULL; 858 dmu_object_free_zapified(mos, obj, tx); 859 860 dsl_dir_destroy_sync(ddobj, tx); 861 862 if (rmorigin) { 863 dsl_dataset_t *prev; 864 VERIFY0(dsl_dataset_hold_obj(dp, prevobj, FTAG, &prev)); 865 dsl_destroy_snapshot_sync_impl(prev, B_FALSE, tx); 866 dsl_dataset_rele(prev, FTAG); 867 } 868 } 869 870 static void 871 dsl_destroy_head_sync(void *arg, dmu_tx_t *tx) 872 { 873 dsl_destroy_head_arg_t *ddha = arg; 874 dsl_pool_t *dp = dmu_tx_pool(tx); 875 dsl_dataset_t *ds; 876 877 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds)); 878 dsl_destroy_head_sync_impl(ds, tx); 879 dsl_dataset_rele(ds, FTAG); 880 } 881 882 static void 883 dsl_destroy_head_begin_sync(void *arg, dmu_tx_t *tx) 884 { 885 dsl_destroy_head_arg_t *ddha = arg; 886 dsl_pool_t *dp = dmu_tx_pool(tx); 887 dsl_dataset_t *ds; 888 889 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds)); 890 891 /* Mark it as inconsistent on-disk, in case we crash */ 892 dmu_buf_will_dirty(ds->ds_dbuf, tx); 893 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_INCONSISTENT; 894 895 spa_history_log_internal_ds(ds, "destroy begin", tx, ""); 896 dsl_dataset_rele(ds, FTAG); 897 } 898 899 int 900 dsl_destroy_head(const char *name) 901 { 902 dsl_destroy_head_arg_t ddha; 903 int error; 904 spa_t *spa; 905 boolean_t isenabled; 906 907 #ifdef _KERNEL 908 zfs_destroy_unmount_origin(name); 909 #endif 910 911 error = spa_open(name, &spa, FTAG); 912 if (error != 0) 913 return (error); 914 isenabled = spa_feature_is_enabled(spa, SPA_FEATURE_ASYNC_DESTROY); 915 spa_close(spa, FTAG); 916 917 ddha.ddha_name = name; 918 919 if (!isenabled) { 920 objset_t *os; 921 922 error = dsl_sync_task(name, dsl_destroy_head_check, 923 dsl_destroy_head_begin_sync, &ddha, 924 0, ZFS_SPACE_CHECK_NONE); 925 if (error != 0) 926 return (error); 927 928 /* 929 * Head deletion is processed in one txg on old pools; 930 * remove the objects from open context so that the txg sync 931 * is not too long. 932 */ 933 error = dmu_objset_own(name, DMU_OST_ANY, B_FALSE, FTAG, &os); 934 if (error == 0) { 935 uint64_t prev_snap_txg = 936 dsl_dataset_phys(dmu_objset_ds(os))-> 937 ds_prev_snap_txg; 938 for (uint64_t obj = 0; error == 0; 939 error = dmu_object_next(os, &obj, FALSE, 940 prev_snap_txg)) 941 (void) dmu_free_long_object(os, obj); 942 /* sync out all frees */ 943 txg_wait_synced(dmu_objset_pool(os), 0); 944 dmu_objset_disown(os, FTAG); 945 } 946 } 947 948 return (dsl_sync_task(name, dsl_destroy_head_check, 949 dsl_destroy_head_sync, &ddha, 0, ZFS_SPACE_CHECK_NONE)); 950 } 951 952 /* 953 * Note, this function is used as the callback for dmu_objset_find(). We 954 * always return 0 so that we will continue to find and process 955 * inconsistent datasets, even if we encounter an error trying to 956 * process one of them. 957 */ 958 /* ARGSUSED */ 959 int 960 dsl_destroy_inconsistent(const char *dsname, void *arg) 961 { 962 objset_t *os; 963 964 if (dmu_objset_hold(dsname, FTAG, &os) == 0) { 965 boolean_t inconsistent = DS_IS_INCONSISTENT(dmu_objset_ds(os)); 966 dmu_objset_rele(os, FTAG); 967 if (inconsistent) 968 (void) dsl_destroy_head(dsname); 969 } 970 return (0); 971 } 972