dsl_destroy.c revision 263390
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#include <sys/dmu_impl.h> 42 43typedef struct dmu_snapshots_destroy_arg { 44 nvlist_t *dsda_snaps; 45 nvlist_t *dsda_successful_snaps; 46 boolean_t dsda_defer; 47 nvlist_t *dsda_errlist; 48} dmu_snapshots_destroy_arg_t; 49 50int 51dsl_destroy_snapshot_check_impl(dsl_dataset_t *ds, boolean_t defer) 52{ 53 if (!dsl_dataset_is_snapshot(ds)) 54 return (SET_ERROR(EINVAL)); 55 56 if (dsl_dataset_long_held(ds)) 57 return (SET_ERROR(EBUSY)); 58 59 /* 60 * Only allow deferred destroy on pools that support it. 61 * NOTE: deferred destroy is only supported on snapshots. 62 */ 63 if (defer) { 64 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 65 SPA_VERSION_USERREFS) 66 return (SET_ERROR(ENOTSUP)); 67 return (0); 68 } 69 70 /* 71 * If this snapshot has an elevated user reference count, 72 * we can't destroy it yet. 73 */ 74 if (ds->ds_userrefs > 0) 75 return (SET_ERROR(EBUSY)); 76 77 /* 78 * Can't delete a branch point. 79 */ 80 if (ds->ds_phys->ds_num_children > 1) 81 return (SET_ERROR(EEXIST)); 82 83 return (0); 84} 85 86static int 87dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx) 88{ 89 dmu_snapshots_destroy_arg_t *dsda = arg; 90 dsl_pool_t *dp = dmu_tx_pool(tx); 91 nvpair_t *pair; 92 int error = 0; 93 94 if (!dmu_tx_is_syncing(tx)) 95 return (0); 96 97 for (pair = nvlist_next_nvpair(dsda->dsda_snaps, NULL); 98 pair != NULL; pair = nvlist_next_nvpair(dsda->dsda_snaps, pair)) { 99 dsl_dataset_t *ds; 100 101 error = dsl_dataset_hold(dp, nvpair_name(pair), 102 FTAG, &ds); 103 104 /* 105 * If the snapshot does not exist, silently ignore it 106 * (it's "already destroyed"). 107 */ 108 if (error == ENOENT) 109 continue; 110 111 if (error == 0) { 112 error = dsl_destroy_snapshot_check_impl(ds, 113 dsda->dsda_defer); 114 dsl_dataset_rele(ds, FTAG); 115 } 116 117 if (error == 0) { 118 fnvlist_add_boolean(dsda->dsda_successful_snaps, 119 nvpair_name(pair)); 120 } else { 121 fnvlist_add_int32(dsda->dsda_errlist, 122 nvpair_name(pair), error); 123 } 124 } 125 126 pair = nvlist_next_nvpair(dsda->dsda_errlist, NULL); 127 if (pair != NULL) 128 return (fnvpair_value_int32(pair)); 129 130 return (0); 131} 132 133struct 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 141static int 142process_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 164static void 165process_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 200static void 201dsl_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 232void 233dsl_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 dmu_object_free_zapified(mos, obj, tx); 453} 454 455static void 456dsl_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 */ 487int 488dsl_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 512int 513dsl_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 526struct killarg { 527 dsl_dataset_t *ds; 528 dmu_tx_t *tx; 529}; 530 531/* ARGSUSED */ 532static int 533kill_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 558static void 559old_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 578typedef struct dsl_destroy_head_arg { 579 const char *ddha_name; 580} dsl_destroy_head_arg_t; 581 582int 583dsl_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 626static int 627dsl_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 643static void 644dsl_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 dmu_object_free_zapified(mos, ddobj, tx); 676} 677 678void 679dsl_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 /* 729 * Destroy the deadlist. Unless it's a clone, the 730 * deadlist should be empty. (If it's a clone, it's 731 * safe to ignore the deadlist contents.) 732 */ 733 dsl_deadlist_close(&ds->ds_deadlist); 734 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 735 dmu_buf_will_dirty(ds->ds_dbuf, tx); 736 ds->ds_phys->ds_deadlist_obj = 0; 737 738 objset_t *os; 739 VERIFY0(dmu_objset_from_ds(ds, &os)); 740 741 if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) { 742 old_synchronous_dataset_destroy(ds, tx); 743 } else { 744 /* 745 * Move the bptree into the pool's list of trees to 746 * clean up and update space accounting information. 747 */ 748 uint64_t used, comp, uncomp; 749 750 zil_destroy_sync(dmu_objset_zil(os), tx); 751 752 if (!spa_feature_is_active(dp->dp_spa, 753 SPA_FEATURE_ASYNC_DESTROY)) { 754 dsl_scan_t *scn = dp->dp_scan; 755 spa_feature_incr(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY, 756 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 ASSERT(!scn->scn_async_destroying); 763 scn->scn_async_destroying = B_TRUE; 764 } 765 766 used = ds->ds_dir->dd_phys->dd_used_bytes; 767 comp = ds->ds_dir->dd_phys->dd_compressed_bytes; 768 uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes; 769 770 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 771 ds->ds_phys->ds_unique_bytes == used); 772 773 bptree_add(mos, dp->dp_bptree_obj, 774 &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg, 775 used, comp, uncomp, tx); 776 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 777 -used, -comp, -uncomp, tx); 778 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 779 used, comp, uncomp, tx); 780 } 781 782 if (ds->ds_prev != NULL) { 783 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 784 VERIFY0(zap_remove_int(mos, 785 ds->ds_prev->ds_dir->dd_phys->dd_clones, 786 ds->ds_object, tx)); 787 } 788 prevobj = ds->ds_prev->ds_object; 789 dsl_dataset_rele(ds->ds_prev, ds); 790 ds->ds_prev = NULL; 791 } 792 793 /* 794 * This must be done after the dsl_traverse(), because it will 795 * re-open the objset. 796 */ 797 if (ds->ds_objset) { 798 dmu_objset_evict(ds->ds_objset); 799 ds->ds_objset = NULL; 800 } 801 802 /* Erase the link in the dir */ 803 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 804 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 805 ddobj = ds->ds_dir->dd_object; 806 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 807 VERIFY0(zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx)); 808 809 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 810 811 ASSERT0(ds->ds_phys->ds_next_clones_obj); 812 ASSERT0(ds->ds_phys->ds_props_obj); 813 ASSERT0(ds->ds_phys->ds_userrefs_obj); 814 dsl_dir_rele(ds->ds_dir, ds); 815 ds->ds_dir = NULL; 816 dmu_object_free_zapified(mos, obj, tx); 817 818 dsl_dir_destroy_sync(ddobj, tx); 819 820 if (rmorigin) { 821 dsl_dataset_t *prev; 822 VERIFY0(dsl_dataset_hold_obj(dp, prevobj, FTAG, &prev)); 823 dsl_destroy_snapshot_sync_impl(prev, B_FALSE, tx); 824 dsl_dataset_rele(prev, FTAG); 825 } 826} 827 828static void 829dsl_destroy_head_sync(void *arg, dmu_tx_t *tx) 830{ 831 dsl_destroy_head_arg_t *ddha = arg; 832 dsl_pool_t *dp = dmu_tx_pool(tx); 833 dsl_dataset_t *ds; 834 835 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds)); 836 dsl_destroy_head_sync_impl(ds, tx); 837 dsl_dataset_rele(ds, FTAG); 838} 839 840static void 841dsl_destroy_head_begin_sync(void *arg, dmu_tx_t *tx) 842{ 843 dsl_destroy_head_arg_t *ddha = arg; 844 dsl_pool_t *dp = dmu_tx_pool(tx); 845 dsl_dataset_t *ds; 846 847 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds)); 848 849 /* Mark it as inconsistent on-disk, in case we crash */ 850 dmu_buf_will_dirty(ds->ds_dbuf, tx); 851 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 852 853 spa_history_log_internal_ds(ds, "destroy begin", tx, ""); 854 dsl_dataset_rele(ds, FTAG); 855} 856 857int 858dsl_destroy_head(const char *name) 859{ 860 dsl_destroy_head_arg_t ddha; 861 int error; 862 spa_t *spa; 863 boolean_t isenabled; 864 865#ifdef _KERNEL 866 zfs_destroy_unmount_origin(name); 867#endif 868 869 error = spa_open(name, &spa, FTAG); 870 if (error != 0) 871 return (error); 872 isenabled = spa_feature_is_enabled(spa, SPA_FEATURE_ASYNC_DESTROY); 873 spa_close(spa, FTAG); 874 875 ddha.ddha_name = name; 876 877 if (!isenabled) { 878 objset_t *os; 879 880 error = dsl_sync_task(name, dsl_destroy_head_check, 881 dsl_destroy_head_begin_sync, &ddha, 0); 882 if (error != 0) 883 return (error); 884 885 /* 886 * Head deletion is processed in one txg on old pools; 887 * remove the objects from open context so that the txg sync 888 * is not too long. 889 */ 890 error = dmu_objset_own(name, DMU_OST_ANY, B_FALSE, FTAG, &os); 891 if (error == 0) { 892 uint64_t prev_snap_txg = 893 dmu_objset_ds(os)->ds_phys->ds_prev_snap_txg; 894 for (uint64_t obj = 0; error == 0; 895 error = dmu_object_next(os, &obj, FALSE, 896 prev_snap_txg)) 897 (void) dmu_free_long_object(os, obj); 898 /* sync out all frees */ 899 txg_wait_synced(dmu_objset_pool(os), 0); 900 dmu_objset_disown(os, FTAG); 901 } 902 } 903 904 return (dsl_sync_task(name, dsl_destroy_head_check, 905 dsl_destroy_head_sync, &ddha, 0)); 906} 907 908/* 909 * Note, this function is used as the callback for dmu_objset_find(). We 910 * always return 0 so that we will continue to find and process 911 * inconsistent datasets, even if we encounter an error trying to 912 * process one of them. 913 */ 914/* ARGSUSED */ 915int 916dsl_destroy_inconsistent(const char *dsname, void *arg) 917{ 918 objset_t *os; 919 920 if (dmu_objset_hold(dsname, FTAG, &os) == 0) { 921 boolean_t inconsistent = DS_IS_INCONSISTENT(dmu_objset_ds(os)); 922 dmu_objset_rele(os, FTAG); 923 if (inconsistent) 924 (void) dsl_destroy_head(dsname); 925 } 926 return (0); 927} 928