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 */ 24 25 #include <sys/dmu_objset.h> 26 #include <sys/dsl_dataset.h> 27 #include <sys/dsl_dir.h> 28 #include <sys/dsl_prop.h> 29 #include <sys/dsl_synctask.h> 30 #include <sys/dmu_traverse.h> 31 #include <sys/dmu_tx.h> 32 #include <sys/arc.h> 33 #include <sys/zio.h> 34 #include <sys/zap.h> 35 #include <sys/unique.h> 36 #include <sys/zfs_context.h> 37 #include <sys/zfs_ioctl.h> 38 #include <sys/spa.h> 39 #include <sys/zfs_znode.h> 40 #include <sys/zvol.h> 41 #include <sys/dsl_scan.h> 42 #include <sys/dsl_deadlist.h> 43 44 /* 45 * Enable/disable prefetching of dedup-ed blocks which are going to be freed. 46 */ 47 int zfs_dedup_prefetch = 1; 48 49 static char *dsl_reaper = "the grim reaper"; 50 51 static dsl_checkfunc_t dsl_dataset_destroy_begin_check; 52 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync; 53 static dsl_syncfunc_t dsl_dataset_set_reservation_sync; 54 55 #define SWITCH64(x, y) \ 56 { \ 57 uint64_t __tmp = (x); \ 58 (x) = (y); \ 59 (y) = __tmp; \ 60 } 61 62 #define DS_REF_MAX (1ULL << 62) 63 64 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE 65 66 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper) 67 68 69 /* 70 * Figure out how much of this delta should be propogated to the dsl_dir 71 * layer. If there's a refreservation, that space has already been 72 * partially accounted for in our ancestors. 73 */ 74 static int64_t 75 parent_delta(dsl_dataset_t *ds, int64_t delta) 76 { 77 uint64_t old_bytes, new_bytes; 78 79 if (ds->ds_reserved == 0) 80 return (delta); 81 82 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 83 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved); 84 85 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta)); 86 return (new_bytes - old_bytes); 87 } 88 89 void 90 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx) 91 { 92 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 93 int compressed = BP_GET_PSIZE(bp); 94 int uncompressed = BP_GET_UCSIZE(bp); 95 int64_t delta; 96 97 dprintf_bp(bp, "ds=%p", ds); 98 99 ASSERT(dmu_tx_is_syncing(tx)); 100 /* It could have been compressed away to nothing */ 101 if (BP_IS_HOLE(bp)) 102 return; 103 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE); 104 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES); 105 if (ds == NULL) { 106 /* 107 * Account for the meta-objset space in its placeholder 108 * dsl_dir. 109 */ 110 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */ 111 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 112 used, compressed, uncompressed, tx); 113 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 114 return; 115 } 116 dmu_buf_will_dirty(ds->ds_dbuf, tx); 117 118 mutex_enter(&ds->ds_dir->dd_lock); 119 mutex_enter(&ds->ds_lock); 120 delta = parent_delta(ds, used); 121 ds->ds_phys->ds_used_bytes += used; 122 ds->ds_phys->ds_compressed_bytes += compressed; 123 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 124 ds->ds_phys->ds_unique_bytes += used; 125 mutex_exit(&ds->ds_lock); 126 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 127 compressed, uncompressed, tx); 128 dsl_dir_transfer_space(ds->ds_dir, used - delta, 129 DD_USED_REFRSRV, DD_USED_HEAD, tx); 130 mutex_exit(&ds->ds_dir->dd_lock); 131 } 132 133 int 134 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, 135 boolean_t async) 136 { 137 if (BP_IS_HOLE(bp)) 138 return (0); 139 140 ASSERT(dmu_tx_is_syncing(tx)); 141 ASSERT(bp->blk_birth <= tx->tx_txg); 142 143 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 144 int compressed = BP_GET_PSIZE(bp); 145 int uncompressed = BP_GET_UCSIZE(bp); 146 147 ASSERT(used > 0); 148 if (ds == NULL) { 149 /* 150 * Account for the meta-objset space in its placeholder 151 * dataset. 152 */ 153 dsl_free(tx->tx_pool, tx->tx_txg, bp); 154 155 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 156 -used, -compressed, -uncompressed, tx); 157 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 158 return (used); 159 } 160 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 161 162 ASSERT(!dsl_dataset_is_snapshot(ds)); 163 dmu_buf_will_dirty(ds->ds_dbuf, tx); 164 165 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 166 int64_t delta; 167 168 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object); 169 dsl_free(tx->tx_pool, tx->tx_txg, bp); 170 171 mutex_enter(&ds->ds_dir->dd_lock); 172 mutex_enter(&ds->ds_lock); 173 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 174 !DS_UNIQUE_IS_ACCURATE(ds)); 175 delta = parent_delta(ds, -used); 176 ds->ds_phys->ds_unique_bytes -= used; 177 mutex_exit(&ds->ds_lock); 178 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 179 delta, -compressed, -uncompressed, tx); 180 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 181 DD_USED_REFRSRV, DD_USED_HEAD, tx); 182 mutex_exit(&ds->ds_dir->dd_lock); 183 } else { 184 dprintf_bp(bp, "putting on dead list: %s", ""); 185 if (async) { 186 /* 187 * We are here as part of zio's write done callback, 188 * which means we're a zio interrupt thread. We can't 189 * call dsl_deadlist_insert() now because it may block 190 * waiting for I/O. Instead, put bp on the deferred 191 * queue and let dsl_pool_sync() finish the job. 192 */ 193 bplist_append(&ds->ds_pending_deadlist, bp); 194 } else { 195 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx); 196 } 197 ASSERT3U(ds->ds_prev->ds_object, ==, 198 ds->ds_phys->ds_prev_snap_obj); 199 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 200 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 201 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 202 ds->ds_object && bp->blk_birth > 203 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 204 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 205 mutex_enter(&ds->ds_prev->ds_lock); 206 ds->ds_prev->ds_phys->ds_unique_bytes += used; 207 mutex_exit(&ds->ds_prev->ds_lock); 208 } 209 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) { 210 dsl_dir_transfer_space(ds->ds_dir, used, 211 DD_USED_HEAD, DD_USED_SNAP, tx); 212 } 213 } 214 mutex_enter(&ds->ds_lock); 215 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used); 216 ds->ds_phys->ds_used_bytes -= used; 217 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 218 ds->ds_phys->ds_compressed_bytes -= compressed; 219 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 220 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 221 mutex_exit(&ds->ds_lock); 222 223 return (used); 224 } 225 226 uint64_t 227 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 228 { 229 uint64_t trysnap = 0; 230 231 if (ds == NULL) 232 return (0); 233 /* 234 * The snapshot creation could fail, but that would cause an 235 * incorrect FALSE return, which would only result in an 236 * overestimation of the amount of space that an operation would 237 * consume, which is OK. 238 * 239 * There's also a small window where we could miss a pending 240 * snapshot, because we could set the sync task in the quiescing 241 * phase. So this should only be used as a guess. 242 */ 243 if (ds->ds_trysnap_txg > 244 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 245 trysnap = ds->ds_trysnap_txg; 246 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 247 } 248 249 boolean_t 250 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp, 251 uint64_t blk_birth) 252 { 253 if (blk_birth <= dsl_dataset_prev_snap_txg(ds)) 254 return (B_FALSE); 255 256 if (zfs_dedup_prefetch && bp && BP_GET_DEDUP(bp)) 257 ddt_prefetch(dsl_dataset_get_spa(ds), bp); 258 259 return (B_TRUE); 260 } 261 262 /* ARGSUSED */ 263 static void 264 dsl_dataset_evict(dmu_buf_t *db, void *dsv) 265 { 266 dsl_dataset_t *ds = dsv; 267 268 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 269 270 unique_remove(ds->ds_fsid_guid); 271 272 if (ds->ds_objset != NULL) 273 dmu_objset_evict(ds->ds_objset); 274 275 if (ds->ds_prev) { 276 dsl_dataset_drop_ref(ds->ds_prev, ds); 277 ds->ds_prev = NULL; 278 } 279 280 bplist_destroy(&ds->ds_pending_deadlist); 281 if (db != NULL) { 282 dsl_deadlist_close(&ds->ds_deadlist); 283 } else { 284 ASSERT(ds->ds_deadlist.dl_dbuf == NULL); 285 ASSERT(!ds->ds_deadlist.dl_oldfmt); 286 } 287 if (ds->ds_dir) 288 dsl_dir_close(ds->ds_dir, ds); 289 290 ASSERT(!list_link_active(&ds->ds_synced_link)); 291 292 mutex_destroy(&ds->ds_lock); 293 mutex_destroy(&ds->ds_recvlock); 294 mutex_destroy(&ds->ds_opening_lock); 295 rw_destroy(&ds->ds_rwlock); 296 cv_destroy(&ds->ds_exclusive_cv); 297 298 kmem_free(ds, sizeof (dsl_dataset_t)); 299 } 300 301 static int 302 dsl_dataset_get_snapname(dsl_dataset_t *ds) 303 { 304 dsl_dataset_phys_t *headphys; 305 int err; 306 dmu_buf_t *headdbuf; 307 dsl_pool_t *dp = ds->ds_dir->dd_pool; 308 objset_t *mos = dp->dp_meta_objset; 309 310 if (ds->ds_snapname[0]) 311 return (0); 312 if (ds->ds_phys->ds_next_snap_obj == 0) 313 return (0); 314 315 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 316 FTAG, &headdbuf); 317 if (err) 318 return (err); 319 headphys = headdbuf->db_data; 320 err = zap_value_search(dp->dp_meta_objset, 321 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 322 dmu_buf_rele(headdbuf, FTAG); 323 return (err); 324 } 325 326 static int 327 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 328 { 329 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 330 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 331 matchtype_t mt; 332 int err; 333 334 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 335 mt = MT_FIRST; 336 else 337 mt = MT_EXACT; 338 339 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 340 value, mt, NULL, 0, NULL); 341 if (err == ENOTSUP && mt == MT_FIRST) 342 err = zap_lookup(mos, snapobj, name, 8, 1, value); 343 return (err); 344 } 345 346 static int 347 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 348 { 349 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 350 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 351 matchtype_t mt; 352 int err; 353 354 dsl_dir_snap_cmtime_update(ds->ds_dir); 355 356 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 357 mt = MT_FIRST; 358 else 359 mt = MT_EXACT; 360 361 err = zap_remove_norm(mos, snapobj, name, mt, tx); 362 if (err == ENOTSUP && mt == MT_FIRST) 363 err = zap_remove(mos, snapobj, name, tx); 364 return (err); 365 } 366 367 static int 368 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 369 dsl_dataset_t **dsp) 370 { 371 objset_t *mos = dp->dp_meta_objset; 372 dmu_buf_t *dbuf; 373 dsl_dataset_t *ds; 374 int err; 375 376 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 377 dsl_pool_sync_context(dp)); 378 379 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 380 if (err) 381 return (err); 382 ds = dmu_buf_get_user(dbuf); 383 if (ds == NULL) { 384 dsl_dataset_t *winner; 385 386 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 387 ds->ds_dbuf = dbuf; 388 ds->ds_object = dsobj; 389 ds->ds_phys = dbuf->db_data; 390 391 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 392 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 393 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 394 rw_init(&ds->ds_rwlock, 0, 0, 0); 395 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 396 397 bplist_create(&ds->ds_pending_deadlist); 398 dsl_deadlist_open(&ds->ds_deadlist, 399 mos, ds->ds_phys->ds_deadlist_obj); 400 401 if (err == 0) { 402 err = dsl_dir_open_obj(dp, 403 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 404 } 405 if (err) { 406 mutex_destroy(&ds->ds_lock); 407 mutex_destroy(&ds->ds_recvlock); 408 mutex_destroy(&ds->ds_opening_lock); 409 rw_destroy(&ds->ds_rwlock); 410 cv_destroy(&ds->ds_exclusive_cv); 411 bplist_destroy(&ds->ds_pending_deadlist); 412 dsl_deadlist_close(&ds->ds_deadlist); 413 kmem_free(ds, sizeof (dsl_dataset_t)); 414 dmu_buf_rele(dbuf, tag); 415 return (err); 416 } 417 418 if (!dsl_dataset_is_snapshot(ds)) { 419 ds->ds_snapname[0] = '\0'; 420 if (ds->ds_phys->ds_prev_snap_obj) { 421 err = dsl_dataset_get_ref(dp, 422 ds->ds_phys->ds_prev_snap_obj, 423 ds, &ds->ds_prev); 424 } 425 } else { 426 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 427 err = dsl_dataset_get_snapname(ds); 428 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 429 err = zap_count( 430 ds->ds_dir->dd_pool->dp_meta_objset, 431 ds->ds_phys->ds_userrefs_obj, 432 &ds->ds_userrefs); 433 } 434 } 435 436 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 437 /* 438 * In sync context, we're called with either no lock 439 * or with the write lock. If we're not syncing, 440 * we're always called with the read lock held. 441 */ 442 boolean_t need_lock = 443 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 444 dsl_pool_sync_context(dp); 445 446 if (need_lock) 447 rw_enter(&dp->dp_config_rwlock, RW_READER); 448 449 err = dsl_prop_get_ds(ds, 450 "refreservation", sizeof (uint64_t), 1, 451 &ds->ds_reserved, NULL); 452 if (err == 0) { 453 err = dsl_prop_get_ds(ds, 454 "refquota", sizeof (uint64_t), 1, 455 &ds->ds_quota, NULL); 456 } 457 458 if (need_lock) 459 rw_exit(&dp->dp_config_rwlock); 460 } else { 461 ds->ds_reserved = ds->ds_quota = 0; 462 } 463 464 if (err == 0) { 465 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 466 dsl_dataset_evict); 467 } 468 if (err || winner) { 469 bplist_destroy(&ds->ds_pending_deadlist); 470 dsl_deadlist_close(&ds->ds_deadlist); 471 if (ds->ds_prev) 472 dsl_dataset_drop_ref(ds->ds_prev, ds); 473 dsl_dir_close(ds->ds_dir, ds); 474 mutex_destroy(&ds->ds_lock); 475 mutex_destroy(&ds->ds_recvlock); 476 mutex_destroy(&ds->ds_opening_lock); 477 rw_destroy(&ds->ds_rwlock); 478 cv_destroy(&ds->ds_exclusive_cv); 479 kmem_free(ds, sizeof (dsl_dataset_t)); 480 if (err) { 481 dmu_buf_rele(dbuf, tag); 482 return (err); 483 } 484 ds = winner; 485 } else { 486 ds->ds_fsid_guid = 487 unique_insert(ds->ds_phys->ds_fsid_guid); 488 } 489 } 490 ASSERT3P(ds->ds_dbuf, ==, dbuf); 491 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 492 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 493 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 494 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 495 mutex_enter(&ds->ds_lock); 496 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 497 mutex_exit(&ds->ds_lock); 498 dmu_buf_rele(ds->ds_dbuf, tag); 499 return (ENOENT); 500 } 501 mutex_exit(&ds->ds_lock); 502 *dsp = ds; 503 return (0); 504 } 505 506 static int 507 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 508 { 509 dsl_pool_t *dp = ds->ds_dir->dd_pool; 510 511 /* 512 * In syncing context we don't want the rwlock lock: there 513 * may be an existing writer waiting for sync phase to 514 * finish. We don't need to worry about such writers, since 515 * sync phase is single-threaded, so the writer can't be 516 * doing anything while we are active. 517 */ 518 if (dsl_pool_sync_context(dp)) { 519 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 520 return (0); 521 } 522 523 /* 524 * Normal users will hold the ds_rwlock as a READER until they 525 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 526 * drop their READER lock after they set the ds_owner field. 527 * 528 * If the dataset is being destroyed, the destroy thread will 529 * obtain a WRITER lock for exclusive access after it's done its 530 * open-context work and then change the ds_owner to 531 * dsl_reaper once destruction is assured. So threads 532 * may block here temporarily, until the "destructability" of 533 * the dataset is determined. 534 */ 535 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 536 mutex_enter(&ds->ds_lock); 537 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 538 rw_exit(&dp->dp_config_rwlock); 539 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 540 if (DSL_DATASET_IS_DESTROYED(ds)) { 541 mutex_exit(&ds->ds_lock); 542 dsl_dataset_drop_ref(ds, tag); 543 rw_enter(&dp->dp_config_rwlock, RW_READER); 544 return (ENOENT); 545 } 546 /* 547 * The dp_config_rwlock lives above the ds_lock. And 548 * we need to check DSL_DATASET_IS_DESTROYED() while 549 * holding the ds_lock, so we have to drop and reacquire 550 * the ds_lock here. 551 */ 552 mutex_exit(&ds->ds_lock); 553 rw_enter(&dp->dp_config_rwlock, RW_READER); 554 mutex_enter(&ds->ds_lock); 555 } 556 mutex_exit(&ds->ds_lock); 557 return (0); 558 } 559 560 int 561 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 562 dsl_dataset_t **dsp) 563 { 564 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 565 566 if (err) 567 return (err); 568 return (dsl_dataset_hold_ref(*dsp, tag)); 569 } 570 571 int 572 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 573 void *tag, dsl_dataset_t **dsp) 574 { 575 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 576 if (err) 577 return (err); 578 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 579 dsl_dataset_rele(*dsp, tag); 580 *dsp = NULL; 581 return (EBUSY); 582 } 583 return (0); 584 } 585 586 int 587 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 588 { 589 dsl_dir_t *dd; 590 dsl_pool_t *dp; 591 const char *snapname; 592 uint64_t obj; 593 int err = 0; 594 595 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 596 if (err) 597 return (err); 598 599 dp = dd->dd_pool; 600 obj = dd->dd_phys->dd_head_dataset_obj; 601 rw_enter(&dp->dp_config_rwlock, RW_READER); 602 if (obj) 603 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 604 else 605 err = ENOENT; 606 if (err) 607 goto out; 608 609 err = dsl_dataset_hold_ref(*dsp, tag); 610 611 /* we may be looking for a snapshot */ 612 if (err == 0 && snapname != NULL) { 613 dsl_dataset_t *ds = NULL; 614 615 if (*snapname++ != '@') { 616 dsl_dataset_rele(*dsp, tag); 617 err = ENOENT; 618 goto out; 619 } 620 621 dprintf("looking for snapshot '%s'\n", snapname); 622 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 623 if (err == 0) 624 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 625 dsl_dataset_rele(*dsp, tag); 626 627 ASSERT3U((err == 0), ==, (ds != NULL)); 628 629 if (ds) { 630 mutex_enter(&ds->ds_lock); 631 if (ds->ds_snapname[0] == 0) 632 (void) strlcpy(ds->ds_snapname, snapname, 633 sizeof (ds->ds_snapname)); 634 mutex_exit(&ds->ds_lock); 635 err = dsl_dataset_hold_ref(ds, tag); 636 *dsp = err ? NULL : ds; 637 } 638 } 639 out: 640 rw_exit(&dp->dp_config_rwlock); 641 dsl_dir_close(dd, FTAG); 642 return (err); 643 } 644 645 int 646 dsl_dataset_own(const char *name, boolean_t inconsistentok, 647 void *tag, dsl_dataset_t **dsp) 648 { 649 int err = dsl_dataset_hold(name, tag, dsp); 650 if (err) 651 return (err); 652 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 653 dsl_dataset_rele(*dsp, tag); 654 return (EBUSY); 655 } 656 return (0); 657 } 658 659 void 660 dsl_dataset_name(dsl_dataset_t *ds, char *name) 661 { 662 if (ds == NULL) { 663 (void) strcpy(name, "mos"); 664 } else { 665 dsl_dir_name(ds->ds_dir, name); 666 VERIFY(0 == dsl_dataset_get_snapname(ds)); 667 if (ds->ds_snapname[0]) { 668 (void) strcat(name, "@"); 669 /* 670 * We use a "recursive" mutex so that we 671 * can call dprintf_ds() with ds_lock held. 672 */ 673 if (!MUTEX_HELD(&ds->ds_lock)) { 674 mutex_enter(&ds->ds_lock); 675 (void) strcat(name, ds->ds_snapname); 676 mutex_exit(&ds->ds_lock); 677 } else { 678 (void) strcat(name, ds->ds_snapname); 679 } 680 } 681 } 682 } 683 684 static int 685 dsl_dataset_namelen(dsl_dataset_t *ds) 686 { 687 int result; 688 689 if (ds == NULL) { 690 result = 3; /* "mos" */ 691 } else { 692 result = dsl_dir_namelen(ds->ds_dir); 693 VERIFY(0 == dsl_dataset_get_snapname(ds)); 694 if (ds->ds_snapname[0]) { 695 ++result; /* adding one for the @-sign */ 696 if (!MUTEX_HELD(&ds->ds_lock)) { 697 mutex_enter(&ds->ds_lock); 698 result += strlen(ds->ds_snapname); 699 mutex_exit(&ds->ds_lock); 700 } else { 701 result += strlen(ds->ds_snapname); 702 } 703 } 704 } 705 706 return (result); 707 } 708 709 void 710 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 711 { 712 dmu_buf_rele(ds->ds_dbuf, tag); 713 } 714 715 void 716 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 717 { 718 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 719 rw_exit(&ds->ds_rwlock); 720 } 721 dsl_dataset_drop_ref(ds, tag); 722 } 723 724 void 725 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 726 { 727 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 728 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 729 730 mutex_enter(&ds->ds_lock); 731 ds->ds_owner = NULL; 732 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 733 rw_exit(&ds->ds_rwlock); 734 cv_broadcast(&ds->ds_exclusive_cv); 735 } 736 mutex_exit(&ds->ds_lock); 737 if (ds->ds_dbuf) 738 dsl_dataset_drop_ref(ds, tag); 739 else 740 dsl_dataset_evict(NULL, ds); 741 } 742 743 boolean_t 744 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 745 { 746 boolean_t gotit = FALSE; 747 748 mutex_enter(&ds->ds_lock); 749 if (ds->ds_owner == NULL && 750 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 751 ds->ds_owner = tag; 752 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 753 rw_exit(&ds->ds_rwlock); 754 gotit = TRUE; 755 } 756 mutex_exit(&ds->ds_lock); 757 return (gotit); 758 } 759 760 void 761 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 762 { 763 ASSERT3P(owner, ==, ds->ds_owner); 764 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 765 rw_enter(&ds->ds_rwlock, RW_WRITER); 766 } 767 768 uint64_t 769 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 770 uint64_t flags, dmu_tx_t *tx) 771 { 772 dsl_pool_t *dp = dd->dd_pool; 773 dmu_buf_t *dbuf; 774 dsl_dataset_phys_t *dsphys; 775 uint64_t dsobj; 776 objset_t *mos = dp->dp_meta_objset; 777 778 if (origin == NULL) 779 origin = dp->dp_origin_snap; 780 781 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 782 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 783 ASSERT(dmu_tx_is_syncing(tx)); 784 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 785 786 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 787 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 788 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 789 dmu_buf_will_dirty(dbuf, tx); 790 dsphys = dbuf->db_data; 791 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 792 dsphys->ds_dir_obj = dd->dd_object; 793 dsphys->ds_flags = flags; 794 dsphys->ds_fsid_guid = unique_create(); 795 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 796 sizeof (dsphys->ds_guid)); 797 dsphys->ds_snapnames_zapobj = 798 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 799 DMU_OT_NONE, 0, tx); 800 dsphys->ds_creation_time = gethrestime_sec(); 801 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 802 803 if (origin == NULL) { 804 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx); 805 } else { 806 dsl_dataset_t *ohds; 807 808 dsphys->ds_prev_snap_obj = origin->ds_object; 809 dsphys->ds_prev_snap_txg = 810 origin->ds_phys->ds_creation_txg; 811 dsphys->ds_used_bytes = 812 origin->ds_phys->ds_used_bytes; 813 dsphys->ds_compressed_bytes = 814 origin->ds_phys->ds_compressed_bytes; 815 dsphys->ds_uncompressed_bytes = 816 origin->ds_phys->ds_uncompressed_bytes; 817 dsphys->ds_bp = origin->ds_phys->ds_bp; 818 dsphys->ds_flags |= origin->ds_phys->ds_flags; 819 820 dmu_buf_will_dirty(origin->ds_dbuf, tx); 821 origin->ds_phys->ds_num_children++; 822 823 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 824 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds)); 825 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist, 826 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx); 827 dsl_dataset_rele(ohds, FTAG); 828 829 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 830 if (origin->ds_phys->ds_next_clones_obj == 0) { 831 origin->ds_phys->ds_next_clones_obj = 832 zap_create(mos, 833 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 834 } 835 VERIFY(0 == zap_add_int(mos, 836 origin->ds_phys->ds_next_clones_obj, 837 dsobj, tx)); 838 } 839 840 dmu_buf_will_dirty(dd->dd_dbuf, tx); 841 dd->dd_phys->dd_origin_obj = origin->ds_object; 842 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 843 if (origin->ds_dir->dd_phys->dd_clones == 0) { 844 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); 845 origin->ds_dir->dd_phys->dd_clones = 846 zap_create(mos, 847 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 848 } 849 VERIFY3U(0, ==, zap_add_int(mos, 850 origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); 851 } 852 } 853 854 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 855 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 856 857 dmu_buf_rele(dbuf, FTAG); 858 859 dmu_buf_will_dirty(dd->dd_dbuf, tx); 860 dd->dd_phys->dd_head_dataset_obj = dsobj; 861 862 return (dsobj); 863 } 864 865 uint64_t 866 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 867 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 868 { 869 dsl_pool_t *dp = pdd->dd_pool; 870 uint64_t dsobj, ddobj; 871 dsl_dir_t *dd; 872 873 ASSERT(lastname[0] != '@'); 874 875 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 876 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 877 878 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 879 880 dsl_deleg_set_create_perms(dd, tx, cr); 881 882 dsl_dir_close(dd, FTAG); 883 884 return (dsobj); 885 } 886 887 struct destroyarg { 888 dsl_sync_task_group_t *dstg; 889 char *snapname; 890 char *failed; 891 boolean_t defer; 892 }; 893 894 static int 895 dsl_snapshot_destroy_one(const char *name, void *arg) 896 { 897 struct destroyarg *da = arg; 898 dsl_dataset_t *ds; 899 int err; 900 char *dsname; 901 902 dsname = kmem_asprintf("%s@%s", name, da->snapname); 903 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds); 904 strfree(dsname); 905 if (err == 0) { 906 struct dsl_ds_destroyarg *dsda; 907 908 dsl_dataset_make_exclusive(ds, da->dstg); 909 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP); 910 dsda->ds = ds; 911 dsda->defer = da->defer; 912 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check, 913 dsl_dataset_destroy_sync, dsda, da->dstg, 0); 914 } else if (err == ENOENT) { 915 err = 0; 916 } else { 917 (void) strcpy(da->failed, name); 918 } 919 return (err); 920 } 921 922 /* 923 * Destroy 'snapname' in all descendants of 'fsname'. 924 */ 925 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy 926 int 927 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer) 928 { 929 int err; 930 struct destroyarg da; 931 dsl_sync_task_t *dst; 932 spa_t *spa; 933 934 err = spa_open(fsname, &spa, FTAG); 935 if (err) 936 return (err); 937 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 938 da.snapname = snapname; 939 da.failed = fsname; 940 da.defer = defer; 941 942 err = dmu_objset_find(fsname, 943 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN); 944 945 if (err == 0) 946 err = dsl_sync_task_group_wait(da.dstg); 947 948 for (dst = list_head(&da.dstg->dstg_tasks); dst; 949 dst = list_next(&da.dstg->dstg_tasks, dst)) { 950 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 951 dsl_dataset_t *ds = dsda->ds; 952 953 /* 954 * Return the file system name that triggered the error 955 */ 956 if (dst->dst_err) { 957 dsl_dataset_name(ds, fsname); 958 *strchr(fsname, '@') = '\0'; 959 } 960 ASSERT3P(dsda->rm_origin, ==, NULL); 961 dsl_dataset_disown(ds, da.dstg); 962 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 963 } 964 965 dsl_sync_task_group_destroy(da.dstg); 966 spa_close(spa, FTAG); 967 return (err); 968 } 969 970 static boolean_t 971 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 972 { 973 boolean_t might_destroy = B_FALSE; 974 975 mutex_enter(&ds->ds_lock); 976 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 977 DS_IS_DEFER_DESTROY(ds)) 978 might_destroy = B_TRUE; 979 mutex_exit(&ds->ds_lock); 980 981 return (might_destroy); 982 } 983 984 /* 985 * If we're removing a clone, and these three conditions are true: 986 * 1) the clone's origin has no other children 987 * 2) the clone's origin has no user references 988 * 3) the clone's origin has been marked for deferred destruction 989 * Then, prepare to remove the origin as part of this sync task group. 990 */ 991 static int 992 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 993 { 994 dsl_dataset_t *ds = dsda->ds; 995 dsl_dataset_t *origin = ds->ds_prev; 996 997 if (dsl_dataset_might_destroy_origin(origin)) { 998 char *name; 999 int namelen; 1000 int error; 1001 1002 namelen = dsl_dataset_namelen(origin) + 1; 1003 name = kmem_alloc(namelen, KM_SLEEP); 1004 dsl_dataset_name(origin, name); 1005 #ifdef _KERNEL 1006 error = zfs_unmount_snap(name, NULL); 1007 if (error) { 1008 kmem_free(name, namelen); 1009 return (error); 1010 } 1011 #endif 1012 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 1013 kmem_free(name, namelen); 1014 if (error) 1015 return (error); 1016 dsda->rm_origin = origin; 1017 dsl_dataset_make_exclusive(origin, tag); 1018 } 1019 1020 return (0); 1021 } 1022 1023 /* 1024 * ds must be opened as OWNER. On return (whether successful or not), 1025 * ds will be closed and caller can no longer dereference it. 1026 */ 1027 int 1028 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1029 { 1030 int err; 1031 dsl_sync_task_group_t *dstg; 1032 objset_t *os; 1033 dsl_dir_t *dd; 1034 uint64_t obj; 1035 struct dsl_ds_destroyarg dsda = { 0 }; 1036 dsl_dataset_t dummy_ds = { 0 }; 1037 1038 dsda.ds = ds; 1039 1040 if (dsl_dataset_is_snapshot(ds)) { 1041 /* Destroying a snapshot is simpler */ 1042 dsl_dataset_make_exclusive(ds, tag); 1043 1044 dsda.defer = defer; 1045 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1046 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1047 &dsda, tag, 0); 1048 ASSERT3P(dsda.rm_origin, ==, NULL); 1049 goto out; 1050 } else if (defer) { 1051 err = EINVAL; 1052 goto out; 1053 } 1054 1055 dd = ds->ds_dir; 1056 dummy_ds.ds_dir = dd; 1057 dummy_ds.ds_object = ds->ds_object; 1058 1059 /* 1060 * Check for errors and mark this ds as inconsistent, in 1061 * case we crash while freeing the objects. 1062 */ 1063 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, 1064 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1065 if (err) 1066 goto out; 1067 1068 err = dmu_objset_from_ds(ds, &os); 1069 if (err) 1070 goto out; 1071 1072 /* 1073 * remove the objects in open context, so that we won't 1074 * have too much to do in syncing context. 1075 */ 1076 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1077 ds->ds_phys->ds_prev_snap_txg)) { 1078 /* 1079 * Ignore errors, if there is not enough disk space 1080 * we will deal with it in dsl_dataset_destroy_sync(). 1081 */ 1082 (void) dmu_free_object(os, obj); 1083 } 1084 1085 /* 1086 * We need to sync out all in-flight IO before we try to evict 1087 * (the dataset evict func is trying to clear the cached entries 1088 * for this dataset in the ARC). 1089 */ 1090 txg_wait_synced(dd->dd_pool, 0); 1091 1092 /* 1093 * If we managed to free all the objects in open 1094 * context, the user space accounting should be zero. 1095 */ 1096 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1097 dmu_objset_userused_enabled(os)) { 1098 uint64_t count; 1099 1100 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || 1101 count == 0); 1102 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || 1103 count == 0); 1104 } 1105 1106 if (err != ESRCH) 1107 goto out; 1108 1109 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1110 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1111 rw_exit(&dd->dd_pool->dp_config_rwlock); 1112 1113 if (err) 1114 goto out; 1115 1116 /* 1117 * Blow away the dsl_dir + head dataset. 1118 */ 1119 dsl_dataset_make_exclusive(ds, tag); 1120 /* 1121 * If we're removing a clone, we might also need to remove its 1122 * origin. 1123 */ 1124 do { 1125 dsda.need_prep = B_FALSE; 1126 if (dsl_dir_is_clone(dd)) { 1127 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1128 if (err) { 1129 dsl_dir_close(dd, FTAG); 1130 goto out; 1131 } 1132 } 1133 1134 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1135 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1136 dsl_dataset_destroy_sync, &dsda, tag, 0); 1137 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1138 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0); 1139 err = dsl_sync_task_group_wait(dstg); 1140 dsl_sync_task_group_destroy(dstg); 1141 1142 /* 1143 * We could be racing against 'zfs release' or 'zfs destroy -d' 1144 * on the origin snap, in which case we can get EBUSY if we 1145 * needed to destroy the origin snap but were not ready to 1146 * do so. 1147 */ 1148 if (dsda.need_prep) { 1149 ASSERT(err == EBUSY); 1150 ASSERT(dsl_dir_is_clone(dd)); 1151 ASSERT(dsda.rm_origin == NULL); 1152 } 1153 } while (dsda.need_prep); 1154 1155 if (dsda.rm_origin != NULL) 1156 dsl_dataset_disown(dsda.rm_origin, tag); 1157 1158 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1159 if (err) 1160 dsl_dir_close(dd, FTAG); 1161 out: 1162 dsl_dataset_disown(ds, tag); 1163 return (err); 1164 } 1165 1166 blkptr_t * 1167 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1168 { 1169 return (&ds->ds_phys->ds_bp); 1170 } 1171 1172 void 1173 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1174 { 1175 ASSERT(dmu_tx_is_syncing(tx)); 1176 /* If it's the meta-objset, set dp_meta_rootbp */ 1177 if (ds == NULL) { 1178 tx->tx_pool->dp_meta_rootbp = *bp; 1179 } else { 1180 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1181 ds->ds_phys->ds_bp = *bp; 1182 } 1183 } 1184 1185 spa_t * 1186 dsl_dataset_get_spa(dsl_dataset_t *ds) 1187 { 1188 return (ds->ds_dir->dd_pool->dp_spa); 1189 } 1190 1191 void 1192 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1193 { 1194 dsl_pool_t *dp; 1195 1196 if (ds == NULL) /* this is the meta-objset */ 1197 return; 1198 1199 ASSERT(ds->ds_objset != NULL); 1200 1201 if (ds->ds_phys->ds_next_snap_obj != 0) 1202 panic("dirtying snapshot!"); 1203 1204 dp = ds->ds_dir->dd_pool; 1205 1206 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1207 /* up the hold count until we can be written out */ 1208 dmu_buf_add_ref(ds->ds_dbuf, ds); 1209 } 1210 } 1211 1212 /* 1213 * The unique space in the head dataset can be calculated by subtracting 1214 * the space used in the most recent snapshot, that is still being used 1215 * in this file system, from the space currently in use. To figure out 1216 * the space in the most recent snapshot still in use, we need to take 1217 * the total space used in the snapshot and subtract out the space that 1218 * has been freed up since the snapshot was taken. 1219 */ 1220 static void 1221 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1222 { 1223 uint64_t mrs_used; 1224 uint64_t dlused, dlcomp, dluncomp; 1225 1226 ASSERT(!dsl_dataset_is_snapshot(ds)); 1227 1228 if (ds->ds_phys->ds_prev_snap_obj != 0) 1229 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes; 1230 else 1231 mrs_used = 0; 1232 1233 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); 1234 1235 ASSERT3U(dlused, <=, mrs_used); 1236 ds->ds_phys->ds_unique_bytes = 1237 ds->ds_phys->ds_used_bytes - (mrs_used - dlused); 1238 1239 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1240 SPA_VERSION_UNIQUE_ACCURATE) 1241 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1242 } 1243 1244 struct killarg { 1245 dsl_dataset_t *ds; 1246 dmu_tx_t *tx; 1247 }; 1248 1249 /* ARGSUSED */ 1250 static int 1251 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf, 1252 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1253 { 1254 struct killarg *ka = arg; 1255 dmu_tx_t *tx = ka->tx; 1256 1257 if (bp == NULL) 1258 return (0); 1259 1260 if (zb->zb_level == ZB_ZIL_LEVEL) { 1261 ASSERT(zilog != NULL); 1262 /* 1263 * It's a block in the intent log. It has no 1264 * accounting, so just free it. 1265 */ 1266 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1267 } else { 1268 ASSERT(zilog == NULL); 1269 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1270 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1271 } 1272 1273 return (0); 1274 } 1275 1276 /* ARGSUSED */ 1277 static int 1278 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1279 { 1280 dsl_dataset_t *ds = arg1; 1281 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1282 uint64_t count; 1283 int err; 1284 1285 /* 1286 * Can't delete a head dataset if there are snapshots of it. 1287 * (Except if the only snapshots are from the branch we cloned 1288 * from.) 1289 */ 1290 if (ds->ds_prev != NULL && 1291 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1292 return (EBUSY); 1293 1294 /* 1295 * This is really a dsl_dir thing, but check it here so that 1296 * we'll be less likely to leave this dataset inconsistent & 1297 * nearly destroyed. 1298 */ 1299 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1300 if (err) 1301 return (err); 1302 if (count != 0) 1303 return (EEXIST); 1304 1305 return (0); 1306 } 1307 1308 /* ARGSUSED */ 1309 static void 1310 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1311 { 1312 dsl_dataset_t *ds = arg1; 1313 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1314 1315 /* Mark it as inconsistent on-disk, in case we crash */ 1316 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1317 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1318 1319 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx, 1320 "dataset = %llu", ds->ds_object); 1321 } 1322 1323 static int 1324 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1325 dmu_tx_t *tx) 1326 { 1327 dsl_dataset_t *ds = dsda->ds; 1328 dsl_dataset_t *ds_prev = ds->ds_prev; 1329 1330 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1331 struct dsl_ds_destroyarg ndsda = {0}; 1332 1333 /* 1334 * If we're not prepared to remove the origin, don't remove 1335 * the clone either. 1336 */ 1337 if (dsda->rm_origin == NULL) { 1338 dsda->need_prep = B_TRUE; 1339 return (EBUSY); 1340 } 1341 1342 ndsda.ds = ds_prev; 1343 ndsda.is_origin_rm = B_TRUE; 1344 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1345 } 1346 1347 /* 1348 * If we're not going to remove the origin after all, 1349 * undo the open context setup. 1350 */ 1351 if (dsda->rm_origin != NULL) { 1352 dsl_dataset_disown(dsda->rm_origin, tag); 1353 dsda->rm_origin = NULL; 1354 } 1355 1356 return (0); 1357 } 1358 1359 /* ARGSUSED */ 1360 int 1361 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1362 { 1363 struct dsl_ds_destroyarg *dsda = arg1; 1364 dsl_dataset_t *ds = dsda->ds; 1365 1366 /* we have an owner hold, so noone else can destroy us */ 1367 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1368 1369 /* 1370 * Only allow deferred destroy on pools that support it. 1371 * NOTE: deferred destroy is only supported on snapshots. 1372 */ 1373 if (dsda->defer) { 1374 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1375 SPA_VERSION_USERREFS) 1376 return (ENOTSUP); 1377 ASSERT(dsl_dataset_is_snapshot(ds)); 1378 return (0); 1379 } 1380 1381 /* 1382 * Can't delete a head dataset if there are snapshots of it. 1383 * (Except if the only snapshots are from the branch we cloned 1384 * from.) 1385 */ 1386 if (ds->ds_prev != NULL && 1387 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1388 return (EBUSY); 1389 1390 /* 1391 * If we made changes this txg, traverse_dsl_dataset won't find 1392 * them. Try again. 1393 */ 1394 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1395 return (EAGAIN); 1396 1397 if (dsl_dataset_is_snapshot(ds)) { 1398 /* 1399 * If this snapshot has an elevated user reference count, 1400 * we can't destroy it yet. 1401 */ 1402 if (ds->ds_userrefs > 0 && !dsda->releasing) 1403 return (EBUSY); 1404 1405 mutex_enter(&ds->ds_lock); 1406 /* 1407 * Can't delete a branch point. However, if we're destroying 1408 * a clone and removing its origin due to it having a user 1409 * hold count of 0 and having been marked for deferred destroy, 1410 * it's OK for the origin to have a single clone. 1411 */ 1412 if (ds->ds_phys->ds_num_children > 1413 (dsda->is_origin_rm ? 2 : 1)) { 1414 mutex_exit(&ds->ds_lock); 1415 return (EEXIST); 1416 } 1417 mutex_exit(&ds->ds_lock); 1418 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1419 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1420 } 1421 1422 /* XXX we should do some i/o error checking... */ 1423 return (0); 1424 } 1425 1426 struct refsarg { 1427 kmutex_t lock; 1428 boolean_t gone; 1429 kcondvar_t cv; 1430 }; 1431 1432 /* ARGSUSED */ 1433 static void 1434 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1435 { 1436 struct refsarg *arg = argv; 1437 1438 mutex_enter(&arg->lock); 1439 arg->gone = TRUE; 1440 cv_signal(&arg->cv); 1441 mutex_exit(&arg->lock); 1442 } 1443 1444 static void 1445 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1446 { 1447 struct refsarg arg; 1448 1449 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1450 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1451 arg.gone = FALSE; 1452 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1453 dsl_dataset_refs_gone); 1454 dmu_buf_rele(ds->ds_dbuf, tag); 1455 mutex_enter(&arg.lock); 1456 while (!arg.gone) 1457 cv_wait(&arg.cv, &arg.lock); 1458 ASSERT(arg.gone); 1459 mutex_exit(&arg.lock); 1460 ds->ds_dbuf = NULL; 1461 ds->ds_phys = NULL; 1462 mutex_destroy(&arg.lock); 1463 cv_destroy(&arg.cv); 1464 } 1465 1466 static void 1467 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1468 { 1469 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1470 uint64_t count; 1471 int err; 1472 1473 ASSERT(ds->ds_phys->ds_num_children >= 2); 1474 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1475 /* 1476 * The err should not be ENOENT, but a bug in a previous version 1477 * of the code could cause upgrade_clones_cb() to not set 1478 * ds_next_snap_obj when it should, leading to a missing entry. 1479 * If we knew that the pool was created after 1480 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1481 * ENOENT. However, at least we can check that we don't have 1482 * too many entries in the next_clones_obj even after failing to 1483 * remove this one. 1484 */ 1485 if (err != ENOENT) { 1486 VERIFY3U(err, ==, 0); 1487 } 1488 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1489 &count)); 1490 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1491 } 1492 1493 static void 1494 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 1495 { 1496 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1497 zap_cursor_t zc; 1498 zap_attribute_t za; 1499 1500 /* 1501 * If it is the old version, dd_clones doesn't exist so we can't 1502 * find the clones, but deadlist_remove_key() is a no-op so it 1503 * doesn't matter. 1504 */ 1505 if (ds->ds_dir->dd_phys->dd_clones == 0) 1506 return; 1507 1508 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); 1509 zap_cursor_retrieve(&zc, &za) == 0; 1510 zap_cursor_advance(&zc)) { 1511 dsl_dataset_t *clone; 1512 1513 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 1514 za.za_first_integer, FTAG, &clone)); 1515 if (clone->ds_dir->dd_origin_txg > mintxg) { 1516 dsl_deadlist_remove_key(&clone->ds_deadlist, 1517 mintxg, tx); 1518 dsl_dataset_remove_clones_key(clone, mintxg, tx); 1519 } 1520 dsl_dataset_rele(clone, FTAG); 1521 } 1522 zap_cursor_fini(&zc); 1523 } 1524 1525 struct process_old_arg { 1526 dsl_dataset_t *ds; 1527 dsl_dataset_t *ds_prev; 1528 boolean_t after_branch_point; 1529 zio_t *pio; 1530 uint64_t used, comp, uncomp; 1531 }; 1532 1533 static int 1534 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1535 { 1536 struct process_old_arg *poa = arg; 1537 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; 1538 1539 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { 1540 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); 1541 if (poa->ds_prev && !poa->after_branch_point && 1542 bp->blk_birth > 1543 poa->ds_prev->ds_phys->ds_prev_snap_txg) { 1544 poa->ds_prev->ds_phys->ds_unique_bytes += 1545 bp_get_dsize_sync(dp->dp_spa, bp); 1546 } 1547 } else { 1548 poa->used += bp_get_dsize_sync(dp->dp_spa, bp); 1549 poa->comp += BP_GET_PSIZE(bp); 1550 poa->uncomp += BP_GET_UCSIZE(bp); 1551 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); 1552 } 1553 return (0); 1554 } 1555 1556 static void 1557 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, 1558 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) 1559 { 1560 struct process_old_arg poa = { 0 }; 1561 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1562 objset_t *mos = dp->dp_meta_objset; 1563 1564 ASSERT(ds->ds_deadlist.dl_oldfmt); 1565 ASSERT(ds_next->ds_deadlist.dl_oldfmt); 1566 1567 poa.ds = ds; 1568 poa.ds_prev = ds_prev; 1569 poa.after_branch_point = after_branch_point; 1570 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1571 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, 1572 process_old_cb, &poa, tx)); 1573 VERIFY3U(zio_wait(poa.pio), ==, 0); 1574 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); 1575 1576 /* change snapused */ 1577 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1578 -poa.used, -poa.comp, -poa.uncomp, tx); 1579 1580 /* swap next's deadlist to our deadlist */ 1581 dsl_deadlist_close(&ds->ds_deadlist); 1582 dsl_deadlist_close(&ds_next->ds_deadlist); 1583 SWITCH64(ds_next->ds_phys->ds_deadlist_obj, 1584 ds->ds_phys->ds_deadlist_obj); 1585 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 1586 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 1587 ds_next->ds_phys->ds_deadlist_obj); 1588 } 1589 1590 void 1591 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx) 1592 { 1593 struct dsl_ds_destroyarg *dsda = arg1; 1594 dsl_dataset_t *ds = dsda->ds; 1595 int err; 1596 int after_branch_point = FALSE; 1597 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1598 objset_t *mos = dp->dp_meta_objset; 1599 dsl_dataset_t *ds_prev = NULL; 1600 uint64_t obj; 1601 1602 ASSERT(ds->ds_owner); 1603 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1604 ASSERT(ds->ds_prev == NULL || 1605 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1606 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1607 1608 if (dsda->defer) { 1609 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1610 if (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1) { 1611 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1612 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1613 return; 1614 } 1615 } 1616 1617 /* signal any waiters that this dataset is going away */ 1618 mutex_enter(&ds->ds_lock); 1619 ds->ds_owner = dsl_reaper; 1620 cv_broadcast(&ds->ds_exclusive_cv); 1621 mutex_exit(&ds->ds_lock); 1622 1623 if (ds->ds_objset) { 1624 dmu_objset_evict(ds->ds_objset); 1625 ds->ds_objset = NULL; 1626 } 1627 1628 /* Remove our reservation */ 1629 if (ds->ds_reserved != 0) { 1630 dsl_prop_setarg_t psa; 1631 uint64_t value = 0; 1632 1633 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1634 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1635 &value); 1636 psa.psa_effective_value = 0; /* predict default value */ 1637 1638 dsl_dataset_set_reservation_sync(ds, &psa, tx); 1639 ASSERT3U(ds->ds_reserved, ==, 0); 1640 } 1641 1642 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1643 1644 dsl_scan_ds_destroyed(ds, tx); 1645 1646 obj = ds->ds_object; 1647 1648 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1649 if (ds->ds_prev) { 1650 ds_prev = ds->ds_prev; 1651 } else { 1652 VERIFY(0 == dsl_dataset_hold_obj(dp, 1653 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1654 } 1655 after_branch_point = 1656 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1657 1658 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1659 if (after_branch_point && 1660 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1661 remove_from_next_clones(ds_prev, obj, tx); 1662 if (ds->ds_phys->ds_next_snap_obj != 0) { 1663 VERIFY(0 == zap_add_int(mos, 1664 ds_prev->ds_phys->ds_next_clones_obj, 1665 ds->ds_phys->ds_next_snap_obj, tx)); 1666 } 1667 } 1668 if (after_branch_point && 1669 ds->ds_phys->ds_next_snap_obj == 0) { 1670 /* This clone is toast. */ 1671 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1672 ds_prev->ds_phys->ds_num_children--; 1673 1674 /* 1675 * If the clone's origin has no other clones, no 1676 * user holds, and has been marked for deferred 1677 * deletion, then we should have done the necessary 1678 * destroy setup for it. 1679 */ 1680 if (ds_prev->ds_phys->ds_num_children == 1 && 1681 ds_prev->ds_userrefs == 0 && 1682 DS_IS_DEFER_DESTROY(ds_prev)) { 1683 ASSERT3P(dsda->rm_origin, !=, NULL); 1684 } else { 1685 ASSERT3P(dsda->rm_origin, ==, NULL); 1686 } 1687 } else if (!after_branch_point) { 1688 ds_prev->ds_phys->ds_next_snap_obj = 1689 ds->ds_phys->ds_next_snap_obj; 1690 } 1691 } 1692 1693 if (dsl_dataset_is_snapshot(ds)) { 1694 dsl_dataset_t *ds_next; 1695 uint64_t old_unique; 1696 uint64_t used = 0, comp = 0, uncomp = 0; 1697 1698 VERIFY(0 == dsl_dataset_hold_obj(dp, 1699 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1700 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1701 1702 old_unique = ds_next->ds_phys->ds_unique_bytes; 1703 1704 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1705 ds_next->ds_phys->ds_prev_snap_obj = 1706 ds->ds_phys->ds_prev_snap_obj; 1707 ds_next->ds_phys->ds_prev_snap_txg = 1708 ds->ds_phys->ds_prev_snap_txg; 1709 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1710 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1711 1712 1713 if (ds_next->ds_deadlist.dl_oldfmt) { 1714 process_old_deadlist(ds, ds_prev, ds_next, 1715 after_branch_point, tx); 1716 } else { 1717 /* Adjust prev's unique space. */ 1718 if (ds_prev && !after_branch_point) { 1719 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1720 ds_prev->ds_phys->ds_prev_snap_txg, 1721 ds->ds_phys->ds_prev_snap_txg, 1722 &used, &comp, &uncomp); 1723 ds_prev->ds_phys->ds_unique_bytes += used; 1724 } 1725 1726 /* Adjust snapused. */ 1727 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1728 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 1729 &used, &comp, &uncomp); 1730 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1731 -used, -comp, -uncomp, tx); 1732 1733 /* Move blocks to be freed to pool's free list. */ 1734 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 1735 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, 1736 tx); 1737 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 1738 DD_USED_HEAD, used, comp, uncomp, tx); 1739 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx); 1740 1741 /* Merge our deadlist into next's and free it. */ 1742 dsl_deadlist_merge(&ds_next->ds_deadlist, 1743 ds->ds_phys->ds_deadlist_obj, tx); 1744 } 1745 dsl_deadlist_close(&ds->ds_deadlist); 1746 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1747 1748 /* Collapse range in clone heads */ 1749 dsl_dataset_remove_clones_key(ds, 1750 ds->ds_phys->ds_creation_txg, tx); 1751 1752 if (dsl_dataset_is_snapshot(ds_next)) { 1753 dsl_dataset_t *ds_nextnext; 1754 1755 /* 1756 * Update next's unique to include blocks which 1757 * were previously shared by only this snapshot 1758 * and it. Those blocks will be born after the 1759 * prev snap and before this snap, and will have 1760 * died after the next snap and before the one 1761 * after that (ie. be on the snap after next's 1762 * deadlist). 1763 */ 1764 VERIFY(0 == dsl_dataset_hold_obj(dp, 1765 ds_next->ds_phys->ds_next_snap_obj, 1766 FTAG, &ds_nextnext)); 1767 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 1768 ds->ds_phys->ds_prev_snap_txg, 1769 ds->ds_phys->ds_creation_txg, 1770 &used, &comp, &uncomp); 1771 ds_next->ds_phys->ds_unique_bytes += used; 1772 dsl_dataset_rele(ds_nextnext, FTAG); 1773 ASSERT3P(ds_next->ds_prev, ==, NULL); 1774 1775 /* Collapse range in this head. */ 1776 dsl_dataset_t *hds; 1777 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 1778 ds->ds_dir->dd_phys->dd_head_dataset_obj, 1779 FTAG, &hds)); 1780 dsl_deadlist_remove_key(&hds->ds_deadlist, 1781 ds->ds_phys->ds_creation_txg, tx); 1782 dsl_dataset_rele(hds, FTAG); 1783 1784 } else { 1785 ASSERT3P(ds_next->ds_prev, ==, ds); 1786 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1787 ds_next->ds_prev = NULL; 1788 if (ds_prev) { 1789 VERIFY(0 == dsl_dataset_get_ref(dp, 1790 ds->ds_phys->ds_prev_snap_obj, 1791 ds_next, &ds_next->ds_prev)); 1792 } 1793 1794 dsl_dataset_recalc_head_uniq(ds_next); 1795 1796 /* 1797 * Reduce the amount of our unconsmed refreservation 1798 * being charged to our parent by the amount of 1799 * new unique data we have gained. 1800 */ 1801 if (old_unique < ds_next->ds_reserved) { 1802 int64_t mrsdelta; 1803 uint64_t new_unique = 1804 ds_next->ds_phys->ds_unique_bytes; 1805 1806 ASSERT(old_unique <= new_unique); 1807 mrsdelta = MIN(new_unique - old_unique, 1808 ds_next->ds_reserved - old_unique); 1809 dsl_dir_diduse_space(ds->ds_dir, 1810 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1811 } 1812 } 1813 dsl_dataset_rele(ds_next, FTAG); 1814 } else { 1815 /* 1816 * There's no next snapshot, so this is a head dataset. 1817 * Destroy the deadlist. Unless it's a clone, the 1818 * deadlist should be empty. (If it's a clone, it's 1819 * safe to ignore the deadlist contents.) 1820 */ 1821 struct killarg ka; 1822 1823 dsl_deadlist_close(&ds->ds_deadlist); 1824 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1825 ds->ds_phys->ds_deadlist_obj = 0; 1826 1827 /* 1828 * Free everything that we point to (that's born after 1829 * the previous snapshot, if we are a clone) 1830 * 1831 * NB: this should be very quick, because we already 1832 * freed all the objects in open context. 1833 */ 1834 ka.ds = ds; 1835 ka.tx = tx; 1836 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, 1837 TRAVERSE_POST, kill_blkptr, &ka); 1838 ASSERT3U(err, ==, 0); 1839 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1840 ds->ds_phys->ds_unique_bytes == 0); 1841 1842 if (ds->ds_prev != NULL) { 1843 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 1844 VERIFY3U(0, ==, zap_remove_int(mos, 1845 ds->ds_prev->ds_dir->dd_phys->dd_clones, 1846 ds->ds_object, tx)); 1847 } 1848 dsl_dataset_rele(ds->ds_prev, ds); 1849 ds->ds_prev = ds_prev = NULL; 1850 } 1851 } 1852 1853 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1854 /* Erase the link in the dir */ 1855 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1856 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1857 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1858 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1859 ASSERT(err == 0); 1860 } else { 1861 /* remove from snapshot namespace */ 1862 dsl_dataset_t *ds_head; 1863 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1864 VERIFY(0 == dsl_dataset_hold_obj(dp, 1865 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1866 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1867 #ifdef ZFS_DEBUG 1868 { 1869 uint64_t val; 1870 1871 err = dsl_dataset_snap_lookup(ds_head, 1872 ds->ds_snapname, &val); 1873 ASSERT3U(err, ==, 0); 1874 ASSERT3U(val, ==, obj); 1875 } 1876 #endif 1877 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1878 ASSERT(err == 0); 1879 dsl_dataset_rele(ds_head, FTAG); 1880 } 1881 1882 if (ds_prev && ds->ds_prev != ds_prev) 1883 dsl_dataset_rele(ds_prev, FTAG); 1884 1885 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1886 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx, 1887 "dataset = %llu", ds->ds_object); 1888 1889 if (ds->ds_phys->ds_next_clones_obj != 0) { 1890 uint64_t count; 1891 ASSERT(0 == zap_count(mos, 1892 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1893 VERIFY(0 == dmu_object_free(mos, 1894 ds->ds_phys->ds_next_clones_obj, tx)); 1895 } 1896 if (ds->ds_phys->ds_props_obj != 0) 1897 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1898 if (ds->ds_phys->ds_userrefs_obj != 0) 1899 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1900 dsl_dir_close(ds->ds_dir, ds); 1901 ds->ds_dir = NULL; 1902 dsl_dataset_drain_refs(ds, tag); 1903 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1904 1905 if (dsda->rm_origin) { 1906 /* 1907 * Remove the origin of the clone we just destroyed. 1908 */ 1909 struct dsl_ds_destroyarg ndsda = {0}; 1910 1911 ndsda.ds = dsda->rm_origin; 1912 dsl_dataset_destroy_sync(&ndsda, tag, tx); 1913 } 1914 } 1915 1916 static int 1917 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1918 { 1919 uint64_t asize; 1920 1921 if (!dmu_tx_is_syncing(tx)) 1922 return (0); 1923 1924 /* 1925 * If there's an fs-only reservation, any blocks that might become 1926 * owned by the snapshot dataset must be accommodated by space 1927 * outside of the reservation. 1928 */ 1929 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds)); 1930 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 1931 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE)) 1932 return (ENOSPC); 1933 1934 /* 1935 * Propogate any reserved space for this snapshot to other 1936 * snapshot checks in this sync group. 1937 */ 1938 if (asize > 0) 1939 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 1940 1941 return (0); 1942 } 1943 1944 int 1945 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 1946 { 1947 dsl_dataset_t *ds = arg1; 1948 const char *snapname = arg2; 1949 int err; 1950 uint64_t value; 1951 1952 /* 1953 * We don't allow multiple snapshots of the same txg. If there 1954 * is already one, try again. 1955 */ 1956 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 1957 return (EAGAIN); 1958 1959 /* 1960 * Check for conflicting name snapshot name. 1961 */ 1962 err = dsl_dataset_snap_lookup(ds, snapname, &value); 1963 if (err == 0) 1964 return (EEXIST); 1965 if (err != ENOENT) 1966 return (err); 1967 1968 /* 1969 * Check that the dataset's name is not too long. Name consists 1970 * of the dataset's length + 1 for the @-sign + snapshot name's length 1971 */ 1972 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 1973 return (ENAMETOOLONG); 1974 1975 err = dsl_dataset_snapshot_reserve_space(ds, tx); 1976 if (err) 1977 return (err); 1978 1979 ds->ds_trysnap_txg = tx->tx_txg; 1980 return (0); 1981 } 1982 1983 void 1984 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1985 { 1986 dsl_dataset_t *ds = arg1; 1987 const char *snapname = arg2; 1988 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1989 dmu_buf_t *dbuf; 1990 dsl_dataset_phys_t *dsphys; 1991 uint64_t dsobj, crtxg; 1992 objset_t *mos = dp->dp_meta_objset; 1993 int err; 1994 1995 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1996 1997 /* 1998 * The origin's ds_creation_txg has to be < TXG_INITIAL 1999 */ 2000 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 2001 crtxg = 1; 2002 else 2003 crtxg = tx->tx_txg; 2004 2005 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 2006 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 2007 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 2008 dmu_buf_will_dirty(dbuf, tx); 2009 dsphys = dbuf->db_data; 2010 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 2011 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 2012 dsphys->ds_fsid_guid = unique_create(); 2013 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 2014 sizeof (dsphys->ds_guid)); 2015 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 2016 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 2017 dsphys->ds_next_snap_obj = ds->ds_object; 2018 dsphys->ds_num_children = 1; 2019 dsphys->ds_creation_time = gethrestime_sec(); 2020 dsphys->ds_creation_txg = crtxg; 2021 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 2022 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes; 2023 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 2024 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 2025 dsphys->ds_flags = ds->ds_phys->ds_flags; 2026 dsphys->ds_bp = ds->ds_phys->ds_bp; 2027 dmu_buf_rele(dbuf, FTAG); 2028 2029 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 2030 if (ds->ds_prev) { 2031 uint64_t next_clones_obj = 2032 ds->ds_prev->ds_phys->ds_next_clones_obj; 2033 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 2034 ds->ds_object || 2035 ds->ds_prev->ds_phys->ds_num_children > 1); 2036 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 2037 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 2038 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 2039 ds->ds_prev->ds_phys->ds_creation_txg); 2040 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 2041 } else if (next_clones_obj != 0) { 2042 remove_from_next_clones(ds->ds_prev, 2043 dsphys->ds_next_snap_obj, tx); 2044 VERIFY3U(0, ==, zap_add_int(mos, 2045 next_clones_obj, dsobj, tx)); 2046 } 2047 } 2048 2049 /* 2050 * If we have a reference-reservation on this dataset, we will 2051 * need to increase the amount of refreservation being charged 2052 * since our unique space is going to zero. 2053 */ 2054 if (ds->ds_reserved) { 2055 int64_t delta; 2056 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 2057 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2058 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 2059 delta, 0, 0, tx); 2060 } 2061 2062 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2063 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu", 2064 ds->ds_dir->dd_myname, snapname, dsobj, 2065 ds->ds_phys->ds_prev_snap_txg); 2066 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist, 2067 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx); 2068 dsl_deadlist_close(&ds->ds_deadlist); 2069 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 2070 dsl_deadlist_add_key(&ds->ds_deadlist, 2071 ds->ds_phys->ds_prev_snap_txg, tx); 2072 2073 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 2074 ds->ds_phys->ds_prev_snap_obj = dsobj; 2075 ds->ds_phys->ds_prev_snap_txg = crtxg; 2076 ds->ds_phys->ds_unique_bytes = 0; 2077 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 2078 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 2079 2080 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 2081 snapname, 8, 1, &dsobj, tx); 2082 ASSERT(err == 0); 2083 2084 if (ds->ds_prev) 2085 dsl_dataset_drop_ref(ds->ds_prev, ds); 2086 VERIFY(0 == dsl_dataset_get_ref(dp, 2087 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 2088 2089 dsl_scan_ds_snapshotted(ds, tx); 2090 2091 dsl_dir_snap_cmtime_update(ds->ds_dir); 2092 2093 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx, 2094 "dataset = %llu", dsobj); 2095 } 2096 2097 void 2098 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 2099 { 2100 ASSERT(dmu_tx_is_syncing(tx)); 2101 ASSERT(ds->ds_objset != NULL); 2102 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 2103 2104 /* 2105 * in case we had to change ds_fsid_guid when we opened it, 2106 * sync it out now. 2107 */ 2108 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2109 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2110 2111 dsl_dir_dirty(ds->ds_dir, tx); 2112 dmu_objset_sync(ds->ds_objset, zio, tx); 2113 } 2114 2115 void 2116 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2117 { 2118 uint64_t refd, avail, uobjs, aobjs; 2119 2120 dsl_dir_stats(ds->ds_dir, nv); 2121 2122 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2123 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2124 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2125 2126 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2127 ds->ds_phys->ds_creation_time); 2128 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2129 ds->ds_phys->ds_creation_txg); 2130 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2131 ds->ds_quota); 2132 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2133 ds->ds_reserved); 2134 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2135 ds->ds_phys->ds_guid); 2136 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2137 ds->ds_phys->ds_unique_bytes); 2138 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2139 ds->ds_object); 2140 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2141 ds->ds_userrefs); 2142 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2143 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2144 2145 if (ds->ds_phys->ds_next_snap_obj) { 2146 /* 2147 * This is a snapshot; override the dd's space used with 2148 * our unique space and compression ratio. 2149 */ 2150 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2151 ds->ds_phys->ds_unique_bytes); 2152 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, 2153 ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2154 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2155 ds->ds_phys->ds_compressed_bytes)); 2156 } 2157 } 2158 2159 void 2160 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2161 { 2162 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2163 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2164 stat->dds_guid = ds->ds_phys->ds_guid; 2165 if (ds->ds_phys->ds_next_snap_obj) { 2166 stat->dds_is_snapshot = B_TRUE; 2167 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2168 } else { 2169 stat->dds_is_snapshot = B_FALSE; 2170 stat->dds_num_clones = 0; 2171 } 2172 2173 /* clone origin is really a dsl_dir thing... */ 2174 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2175 if (dsl_dir_is_clone(ds->ds_dir)) { 2176 dsl_dataset_t *ods; 2177 2178 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2179 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2180 dsl_dataset_name(ods, stat->dds_origin); 2181 dsl_dataset_drop_ref(ods, FTAG); 2182 } else { 2183 stat->dds_origin[0] = '\0'; 2184 } 2185 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2186 } 2187 2188 uint64_t 2189 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2190 { 2191 return (ds->ds_fsid_guid); 2192 } 2193 2194 void 2195 dsl_dataset_space(dsl_dataset_t *ds, 2196 uint64_t *refdbytesp, uint64_t *availbytesp, 2197 uint64_t *usedobjsp, uint64_t *availobjsp) 2198 { 2199 *refdbytesp = ds->ds_phys->ds_used_bytes; 2200 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2201 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2202 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2203 if (ds->ds_quota != 0) { 2204 /* 2205 * Adjust available bytes according to refquota 2206 */ 2207 if (*refdbytesp < ds->ds_quota) 2208 *availbytesp = MIN(*availbytesp, 2209 ds->ds_quota - *refdbytesp); 2210 else 2211 *availbytesp = 0; 2212 } 2213 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2214 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2215 } 2216 2217 boolean_t 2218 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2219 { 2220 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2221 2222 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2223 dsl_pool_sync_context(dp)); 2224 if (ds->ds_prev == NULL) 2225 return (B_FALSE); 2226 if (ds->ds_phys->ds_bp.blk_birth > 2227 ds->ds_prev->ds_phys->ds_creation_txg) 2228 return (B_TRUE); 2229 return (B_FALSE); 2230 } 2231 2232 /* ARGSUSED */ 2233 static int 2234 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2235 { 2236 dsl_dataset_t *ds = arg1; 2237 char *newsnapname = arg2; 2238 dsl_dir_t *dd = ds->ds_dir; 2239 dsl_dataset_t *hds; 2240 uint64_t val; 2241 int err; 2242 2243 err = dsl_dataset_hold_obj(dd->dd_pool, 2244 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2245 if (err) 2246 return (err); 2247 2248 /* new name better not be in use */ 2249 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2250 dsl_dataset_rele(hds, FTAG); 2251 2252 if (err == 0) 2253 err = EEXIST; 2254 else if (err == ENOENT) 2255 err = 0; 2256 2257 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2258 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2259 err = ENAMETOOLONG; 2260 2261 return (err); 2262 } 2263 2264 static void 2265 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2266 { 2267 dsl_dataset_t *ds = arg1; 2268 const char *newsnapname = arg2; 2269 dsl_dir_t *dd = ds->ds_dir; 2270 objset_t *mos = dd->dd_pool->dp_meta_objset; 2271 dsl_dataset_t *hds; 2272 int err; 2273 2274 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2275 2276 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2277 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2278 2279 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2280 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2281 ASSERT3U(err, ==, 0); 2282 mutex_enter(&ds->ds_lock); 2283 (void) strcpy(ds->ds_snapname, newsnapname); 2284 mutex_exit(&ds->ds_lock); 2285 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2286 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2287 ASSERT3U(err, ==, 0); 2288 2289 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2290 "dataset = %llu", ds->ds_object); 2291 dsl_dataset_rele(hds, FTAG); 2292 } 2293 2294 struct renamesnaparg { 2295 dsl_sync_task_group_t *dstg; 2296 char failed[MAXPATHLEN]; 2297 char *oldsnap; 2298 char *newsnap; 2299 }; 2300 2301 static int 2302 dsl_snapshot_rename_one(const char *name, void *arg) 2303 { 2304 struct renamesnaparg *ra = arg; 2305 dsl_dataset_t *ds = NULL; 2306 char *snapname; 2307 int err; 2308 2309 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); 2310 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); 2311 2312 /* 2313 * For recursive snapshot renames the parent won't be changing 2314 * so we just pass name for both the to/from argument. 2315 */ 2316 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); 2317 if (err != 0) { 2318 strfree(snapname); 2319 return (err == ENOENT ? 0 : err); 2320 } 2321 2322 #ifdef _KERNEL 2323 /* 2324 * For all filesystems undergoing rename, we'll need to unmount it. 2325 */ 2326 (void) zfs_unmount_snap(snapname, NULL); 2327 #endif 2328 err = dsl_dataset_hold(snapname, ra->dstg, &ds); 2329 strfree(snapname); 2330 if (err != 0) 2331 return (err == ENOENT ? 0 : err); 2332 2333 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2334 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2335 2336 return (0); 2337 } 2338 2339 static int 2340 dsl_recursive_rename(char *oldname, const char *newname) 2341 { 2342 int err; 2343 struct renamesnaparg *ra; 2344 dsl_sync_task_t *dst; 2345 spa_t *spa; 2346 char *cp, *fsname = spa_strdup(oldname); 2347 int len = strlen(oldname) + 1; 2348 2349 /* truncate the snapshot name to get the fsname */ 2350 cp = strchr(fsname, '@'); 2351 *cp = '\0'; 2352 2353 err = spa_open(fsname, &spa, FTAG); 2354 if (err) { 2355 kmem_free(fsname, len); 2356 return (err); 2357 } 2358 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2359 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2360 2361 ra->oldsnap = strchr(oldname, '@') + 1; 2362 ra->newsnap = strchr(newname, '@') + 1; 2363 *ra->failed = '\0'; 2364 2365 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2366 DS_FIND_CHILDREN); 2367 kmem_free(fsname, len); 2368 2369 if (err == 0) { 2370 err = dsl_sync_task_group_wait(ra->dstg); 2371 } 2372 2373 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2374 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2375 dsl_dataset_t *ds = dst->dst_arg1; 2376 if (dst->dst_err) { 2377 dsl_dir_name(ds->ds_dir, ra->failed); 2378 (void) strlcat(ra->failed, "@", sizeof (ra->failed)); 2379 (void) strlcat(ra->failed, ra->newsnap, 2380 sizeof (ra->failed)); 2381 } 2382 dsl_dataset_rele(ds, ra->dstg); 2383 } 2384 2385 if (err) 2386 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); 2387 2388 dsl_sync_task_group_destroy(ra->dstg); 2389 kmem_free(ra, sizeof (struct renamesnaparg)); 2390 spa_close(spa, FTAG); 2391 return (err); 2392 } 2393 2394 static int 2395 dsl_valid_rename(const char *oldname, void *arg) 2396 { 2397 int delta = *(int *)arg; 2398 2399 if (strlen(oldname) + delta >= MAXNAMELEN) 2400 return (ENAMETOOLONG); 2401 2402 return (0); 2403 } 2404 2405 #pragma weak dmu_objset_rename = dsl_dataset_rename 2406 int 2407 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2408 { 2409 dsl_dir_t *dd; 2410 dsl_dataset_t *ds; 2411 const char *tail; 2412 int err; 2413 2414 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2415 if (err) 2416 return (err); 2417 2418 if (tail == NULL) { 2419 int delta = strlen(newname) - strlen(oldname); 2420 2421 /* if we're growing, validate child name lengths */ 2422 if (delta > 0) 2423 err = dmu_objset_find(oldname, dsl_valid_rename, 2424 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2425 2426 if (err == 0) 2427 err = dsl_dir_rename(dd, newname); 2428 dsl_dir_close(dd, FTAG); 2429 return (err); 2430 } 2431 2432 if (tail[0] != '@') { 2433 /* the name ended in a nonexistent component */ 2434 dsl_dir_close(dd, FTAG); 2435 return (ENOENT); 2436 } 2437 2438 dsl_dir_close(dd, FTAG); 2439 2440 /* new name must be snapshot in same filesystem */ 2441 tail = strchr(newname, '@'); 2442 if (tail == NULL) 2443 return (EINVAL); 2444 tail++; 2445 if (strncmp(oldname, newname, tail - newname) != 0) 2446 return (EXDEV); 2447 2448 if (recursive) { 2449 err = dsl_recursive_rename(oldname, newname); 2450 } else { 2451 err = dsl_dataset_hold(oldname, FTAG, &ds); 2452 if (err) 2453 return (err); 2454 2455 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2456 dsl_dataset_snapshot_rename_check, 2457 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2458 2459 dsl_dataset_rele(ds, FTAG); 2460 } 2461 2462 return (err); 2463 } 2464 2465 struct promotenode { 2466 list_node_t link; 2467 dsl_dataset_t *ds; 2468 }; 2469 2470 struct promotearg { 2471 list_t shared_snaps, origin_snaps, clone_snaps; 2472 dsl_dataset_t *origin_origin; 2473 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2474 char *err_ds; 2475 }; 2476 2477 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2478 static boolean_t snaplist_unstable(list_t *l); 2479 2480 static int 2481 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2482 { 2483 dsl_dataset_t *hds = arg1; 2484 struct promotearg *pa = arg2; 2485 struct promotenode *snap = list_head(&pa->shared_snaps); 2486 dsl_dataset_t *origin_ds = snap->ds; 2487 int err; 2488 uint64_t unused; 2489 2490 /* Check that it is a real clone */ 2491 if (!dsl_dir_is_clone(hds->ds_dir)) 2492 return (EINVAL); 2493 2494 /* Since this is so expensive, don't do the preliminary check */ 2495 if (!dmu_tx_is_syncing(tx)) 2496 return (0); 2497 2498 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2499 return (EXDEV); 2500 2501 /* compute origin's new unique space */ 2502 snap = list_tail(&pa->clone_snaps); 2503 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2504 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2505 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2506 &pa->unique, &unused, &unused); 2507 2508 /* 2509 * Walk the snapshots that we are moving 2510 * 2511 * Compute space to transfer. Consider the incremental changes 2512 * to used for each snapshot: 2513 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2514 * So each snapshot gave birth to: 2515 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2516 * So a sequence would look like: 2517 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2518 * Which simplifies to: 2519 * uN + kN + kN-1 + ... + k1 + k0 2520 * Note however, if we stop before we reach the ORIGIN we get: 2521 * uN + kN + kN-1 + ... + kM - uM-1 2522 */ 2523 pa->used = origin_ds->ds_phys->ds_used_bytes; 2524 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2525 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2526 for (snap = list_head(&pa->shared_snaps); snap; 2527 snap = list_next(&pa->shared_snaps, snap)) { 2528 uint64_t val, dlused, dlcomp, dluncomp; 2529 dsl_dataset_t *ds = snap->ds; 2530 2531 /* Check that the snapshot name does not conflict */ 2532 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2533 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2534 if (err == 0) { 2535 err = EEXIST; 2536 goto out; 2537 } 2538 if (err != ENOENT) 2539 goto out; 2540 2541 /* The very first snapshot does not have a deadlist */ 2542 if (ds->ds_phys->ds_prev_snap_obj == 0) 2543 continue; 2544 2545 dsl_deadlist_space(&ds->ds_deadlist, 2546 &dlused, &dlcomp, &dluncomp); 2547 pa->used += dlused; 2548 pa->comp += dlcomp; 2549 pa->uncomp += dluncomp; 2550 } 2551 2552 /* 2553 * If we are a clone of a clone then we never reached ORIGIN, 2554 * so we need to subtract out the clone origin's used space. 2555 */ 2556 if (pa->origin_origin) { 2557 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes; 2558 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2559 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2560 } 2561 2562 /* Check that there is enough space here */ 2563 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2564 pa->used); 2565 if (err) 2566 return (err); 2567 2568 /* 2569 * Compute the amounts of space that will be used by snapshots 2570 * after the promotion (for both origin and clone). For each, 2571 * it is the amount of space that will be on all of their 2572 * deadlists (that was not born before their new origin). 2573 */ 2574 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2575 uint64_t space; 2576 2577 /* 2578 * Note, typically this will not be a clone of a clone, 2579 * so dd_origin_txg will be < TXG_INITIAL, so 2580 * these snaplist_space() -> dsl_deadlist_space_range() 2581 * calls will be fast because they do not have to 2582 * iterate over all bps. 2583 */ 2584 snap = list_head(&pa->origin_snaps); 2585 err = snaplist_space(&pa->shared_snaps, 2586 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap); 2587 if (err) 2588 return (err); 2589 2590 err = snaplist_space(&pa->clone_snaps, 2591 snap->ds->ds_dir->dd_origin_txg, &space); 2592 if (err) 2593 return (err); 2594 pa->cloneusedsnap += space; 2595 } 2596 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2597 err = snaplist_space(&pa->origin_snaps, 2598 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2599 if (err) 2600 return (err); 2601 } 2602 2603 return (0); 2604 out: 2605 pa->err_ds = snap->ds->ds_snapname; 2606 return (err); 2607 } 2608 2609 static void 2610 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2611 { 2612 dsl_dataset_t *hds = arg1; 2613 struct promotearg *pa = arg2; 2614 struct promotenode *snap = list_head(&pa->shared_snaps); 2615 dsl_dataset_t *origin_ds = snap->ds; 2616 dsl_dataset_t *origin_head; 2617 dsl_dir_t *dd = hds->ds_dir; 2618 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2619 dsl_dir_t *odd = NULL; 2620 uint64_t oldnext_obj; 2621 int64_t delta; 2622 2623 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2624 2625 snap = list_head(&pa->origin_snaps); 2626 origin_head = snap->ds; 2627 2628 /* 2629 * We need to explicitly open odd, since origin_ds's dd will be 2630 * changing. 2631 */ 2632 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2633 NULL, FTAG, &odd)); 2634 2635 /* change origin's next snap */ 2636 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2637 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2638 snap = list_tail(&pa->clone_snaps); 2639 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2640 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2641 2642 /* change the origin's next clone */ 2643 if (origin_ds->ds_phys->ds_next_clones_obj) { 2644 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2645 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2646 origin_ds->ds_phys->ds_next_clones_obj, 2647 oldnext_obj, tx)); 2648 } 2649 2650 /* change origin */ 2651 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2652 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2653 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2654 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg; 2655 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2656 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2657 origin_head->ds_dir->dd_origin_txg = 2658 origin_ds->ds_phys->ds_creation_txg; 2659 2660 /* change dd_clone entries */ 2661 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2662 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2663 odd->dd_phys->dd_clones, hds->ds_object, tx)); 2664 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2665 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2666 hds->ds_object, tx)); 2667 2668 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2669 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2670 origin_head->ds_object, tx)); 2671 if (dd->dd_phys->dd_clones == 0) { 2672 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset, 2673 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 2674 } 2675 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2676 dd->dd_phys->dd_clones, origin_head->ds_object, tx)); 2677 2678 } 2679 2680 /* move snapshots to this dir */ 2681 for (snap = list_head(&pa->shared_snaps); snap; 2682 snap = list_next(&pa->shared_snaps, snap)) { 2683 dsl_dataset_t *ds = snap->ds; 2684 2685 /* unregister props as dsl_dir is changing */ 2686 if (ds->ds_objset) { 2687 dmu_objset_evict(ds->ds_objset); 2688 ds->ds_objset = NULL; 2689 } 2690 /* move snap name entry */ 2691 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2692 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2693 ds->ds_snapname, tx)); 2694 VERIFY(0 == zap_add(dp->dp_meta_objset, 2695 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2696 8, 1, &ds->ds_object, tx)); 2697 2698 /* change containing dsl_dir */ 2699 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2700 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2701 ds->ds_phys->ds_dir_obj = dd->dd_object; 2702 ASSERT3P(ds->ds_dir, ==, odd); 2703 dsl_dir_close(ds->ds_dir, ds); 2704 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2705 NULL, ds, &ds->ds_dir)); 2706 2707 /* move any clone references */ 2708 if (ds->ds_phys->ds_next_clones_obj && 2709 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2710 zap_cursor_t zc; 2711 zap_attribute_t za; 2712 2713 for (zap_cursor_init(&zc, dp->dp_meta_objset, 2714 ds->ds_phys->ds_next_clones_obj); 2715 zap_cursor_retrieve(&zc, &za) == 0; 2716 zap_cursor_advance(&zc)) { 2717 dsl_dataset_t *cnds; 2718 uint64_t o; 2719 2720 if (za.za_first_integer == oldnext_obj) { 2721 /* 2722 * We've already moved the 2723 * origin's reference. 2724 */ 2725 continue; 2726 } 2727 2728 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 2729 za.za_first_integer, FTAG, &cnds)); 2730 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj; 2731 2732 VERIFY3U(zap_remove_int(dp->dp_meta_objset, 2733 odd->dd_phys->dd_clones, o, tx), ==, 0); 2734 VERIFY3U(zap_add_int(dp->dp_meta_objset, 2735 dd->dd_phys->dd_clones, o, tx), ==, 0); 2736 dsl_dataset_rele(cnds, FTAG); 2737 } 2738 zap_cursor_fini(&zc); 2739 } 2740 2741 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2742 } 2743 2744 /* 2745 * Change space accounting. 2746 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2747 * both be valid, or both be 0 (resulting in delta == 0). This 2748 * is true for each of {clone,origin} independently. 2749 */ 2750 2751 delta = pa->cloneusedsnap - 2752 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2753 ASSERT3S(delta, >=, 0); 2754 ASSERT3U(pa->used, >=, delta); 2755 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2756 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2757 pa->used - delta, pa->comp, pa->uncomp, tx); 2758 2759 delta = pa->originusedsnap - 2760 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2761 ASSERT3S(delta, <=, 0); 2762 ASSERT3U(pa->used, >=, -delta); 2763 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2764 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2765 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2766 2767 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2768 2769 /* log history record */ 2770 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2771 "dataset = %llu", hds->ds_object); 2772 2773 dsl_dir_close(odd, FTAG); 2774 } 2775 2776 static char *snaplist_tag = "snaplist"; 2777 /* 2778 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2779 * (exclusive) and last_obj (inclusive). The list will be in reverse 2780 * order (last_obj will be the list_head()). If first_obj == 0, do all 2781 * snapshots back to this dataset's origin. 2782 */ 2783 static int 2784 snaplist_make(dsl_pool_t *dp, boolean_t own, 2785 uint64_t first_obj, uint64_t last_obj, list_t *l) 2786 { 2787 uint64_t obj = last_obj; 2788 2789 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2790 2791 list_create(l, sizeof (struct promotenode), 2792 offsetof(struct promotenode, link)); 2793 2794 while (obj != first_obj) { 2795 dsl_dataset_t *ds; 2796 struct promotenode *snap; 2797 int err; 2798 2799 if (own) { 2800 err = dsl_dataset_own_obj(dp, obj, 2801 0, snaplist_tag, &ds); 2802 if (err == 0) 2803 dsl_dataset_make_exclusive(ds, snaplist_tag); 2804 } else { 2805 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2806 } 2807 if (err == ENOENT) { 2808 /* lost race with snapshot destroy */ 2809 struct promotenode *last = list_tail(l); 2810 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2811 obj = last->ds->ds_phys->ds_prev_snap_obj; 2812 continue; 2813 } else if (err) { 2814 return (err); 2815 } 2816 2817 if (first_obj == 0) 2818 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2819 2820 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2821 snap->ds = ds; 2822 list_insert_tail(l, snap); 2823 obj = ds->ds_phys->ds_prev_snap_obj; 2824 } 2825 2826 return (0); 2827 } 2828 2829 static int 2830 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2831 { 2832 struct promotenode *snap; 2833 2834 *spacep = 0; 2835 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2836 uint64_t used, comp, uncomp; 2837 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2838 mintxg, UINT64_MAX, &used, &comp, &uncomp); 2839 *spacep += used; 2840 } 2841 return (0); 2842 } 2843 2844 static void 2845 snaplist_destroy(list_t *l, boolean_t own) 2846 { 2847 struct promotenode *snap; 2848 2849 if (!l || !list_link_active(&l->list_head)) 2850 return; 2851 2852 while ((snap = list_tail(l)) != NULL) { 2853 list_remove(l, snap); 2854 if (own) 2855 dsl_dataset_disown(snap->ds, snaplist_tag); 2856 else 2857 dsl_dataset_rele(snap->ds, snaplist_tag); 2858 kmem_free(snap, sizeof (struct promotenode)); 2859 } 2860 list_destroy(l); 2861 } 2862 2863 /* 2864 * Promote a clone. Nomenclature note: 2865 * "clone" or "cds": the original clone which is being promoted 2866 * "origin" or "ods": the snapshot which is originally clone's origin 2867 * "origin head" or "ohds": the dataset which is the head 2868 * (filesystem/volume) for the origin 2869 * "origin origin": the origin of the origin's filesystem (typically 2870 * NULL, indicating that the clone is not a clone of a clone). 2871 */ 2872 int 2873 dsl_dataset_promote(const char *name, char *conflsnap) 2874 { 2875 dsl_dataset_t *ds; 2876 dsl_dir_t *dd; 2877 dsl_pool_t *dp; 2878 dmu_object_info_t doi; 2879 struct promotearg pa = { 0 }; 2880 struct promotenode *snap; 2881 int err; 2882 2883 err = dsl_dataset_hold(name, FTAG, &ds); 2884 if (err) 2885 return (err); 2886 dd = ds->ds_dir; 2887 dp = dd->dd_pool; 2888 2889 err = dmu_object_info(dp->dp_meta_objset, 2890 ds->ds_phys->ds_snapnames_zapobj, &doi); 2891 if (err) { 2892 dsl_dataset_rele(ds, FTAG); 2893 return (err); 2894 } 2895 2896 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 2897 dsl_dataset_rele(ds, FTAG); 2898 return (EINVAL); 2899 } 2900 2901 /* 2902 * We are going to inherit all the snapshots taken before our 2903 * origin (i.e., our new origin will be our parent's origin). 2904 * Take ownership of them so that we can rename them into our 2905 * namespace. 2906 */ 2907 rw_enter(&dp->dp_config_rwlock, RW_READER); 2908 2909 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 2910 &pa.shared_snaps); 2911 if (err != 0) 2912 goto out; 2913 2914 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 2915 if (err != 0) 2916 goto out; 2917 2918 snap = list_head(&pa.shared_snaps); 2919 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 2920 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 2921 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 2922 if (err != 0) 2923 goto out; 2924 2925 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) { 2926 err = dsl_dataset_hold_obj(dp, 2927 snap->ds->ds_dir->dd_phys->dd_origin_obj, 2928 FTAG, &pa.origin_origin); 2929 if (err != 0) 2930 goto out; 2931 } 2932 2933 out: 2934 rw_exit(&dp->dp_config_rwlock); 2935 2936 /* 2937 * Add in 128x the snapnames zapobj size, since we will be moving 2938 * a bunch of snapnames to the promoted ds, and dirtying their 2939 * bonus buffers. 2940 */ 2941 if (err == 0) { 2942 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 2943 dsl_dataset_promote_sync, ds, &pa, 2944 2 + 2 * doi.doi_physical_blocks_512); 2945 if (err && pa.err_ds && conflsnap) 2946 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 2947 } 2948 2949 snaplist_destroy(&pa.shared_snaps, B_TRUE); 2950 snaplist_destroy(&pa.clone_snaps, B_FALSE); 2951 snaplist_destroy(&pa.origin_snaps, B_FALSE); 2952 if (pa.origin_origin) 2953 dsl_dataset_rele(pa.origin_origin, FTAG); 2954 dsl_dataset_rele(ds, FTAG); 2955 return (err); 2956 } 2957 2958 struct cloneswaparg { 2959 dsl_dataset_t *cds; /* clone dataset */ 2960 dsl_dataset_t *ohds; /* origin's head dataset */ 2961 boolean_t force; 2962 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 2963 }; 2964 2965 /* ARGSUSED */ 2966 static int 2967 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 2968 { 2969 struct cloneswaparg *csa = arg1; 2970 2971 /* they should both be heads */ 2972 if (dsl_dataset_is_snapshot(csa->cds) || 2973 dsl_dataset_is_snapshot(csa->ohds)) 2974 return (EINVAL); 2975 2976 /* the branch point should be just before them */ 2977 if (csa->cds->ds_prev != csa->ohds->ds_prev) 2978 return (EINVAL); 2979 2980 /* cds should be the clone (unless they are unrelated) */ 2981 if (csa->cds->ds_prev != NULL && 2982 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 2983 csa->ohds->ds_object != 2984 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 2985 return (EINVAL); 2986 2987 /* the clone should be a child of the origin */ 2988 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 2989 return (EINVAL); 2990 2991 /* ohds shouldn't be modified unless 'force' */ 2992 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 2993 return (ETXTBSY); 2994 2995 /* adjust amount of any unconsumed refreservation */ 2996 csa->unused_refres_delta = 2997 (int64_t)MIN(csa->ohds->ds_reserved, 2998 csa->ohds->ds_phys->ds_unique_bytes) - 2999 (int64_t)MIN(csa->ohds->ds_reserved, 3000 csa->cds->ds_phys->ds_unique_bytes); 3001 3002 if (csa->unused_refres_delta > 0 && 3003 csa->unused_refres_delta > 3004 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 3005 return (ENOSPC); 3006 3007 if (csa->ohds->ds_quota != 0 && 3008 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 3009 return (EDQUOT); 3010 3011 return (0); 3012 } 3013 3014 /* ARGSUSED */ 3015 static void 3016 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3017 { 3018 struct cloneswaparg *csa = arg1; 3019 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 3020 3021 ASSERT(csa->cds->ds_reserved == 0); 3022 ASSERT(csa->ohds->ds_quota == 0 || 3023 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 3024 3025 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 3026 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 3027 3028 if (csa->cds->ds_objset != NULL) { 3029 dmu_objset_evict(csa->cds->ds_objset); 3030 csa->cds->ds_objset = NULL; 3031 } 3032 3033 if (csa->ohds->ds_objset != NULL) { 3034 dmu_objset_evict(csa->ohds->ds_objset); 3035 csa->ohds->ds_objset = NULL; 3036 } 3037 3038 /* 3039 * Reset origin's unique bytes, if it exists. 3040 */ 3041 if (csa->cds->ds_prev) { 3042 dsl_dataset_t *origin = csa->cds->ds_prev; 3043 uint64_t comp, uncomp; 3044 3045 dmu_buf_will_dirty(origin->ds_dbuf, tx); 3046 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3047 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 3048 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp); 3049 } 3050 3051 /* swap blkptrs */ 3052 { 3053 blkptr_t tmp; 3054 tmp = csa->ohds->ds_phys->ds_bp; 3055 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 3056 csa->cds->ds_phys->ds_bp = tmp; 3057 } 3058 3059 /* set dd_*_bytes */ 3060 { 3061 int64_t dused, dcomp, duncomp; 3062 uint64_t cdl_used, cdl_comp, cdl_uncomp; 3063 uint64_t odl_used, odl_comp, odl_uncomp; 3064 3065 ASSERT3U(csa->cds->ds_dir->dd_phys-> 3066 dd_used_breakdown[DD_USED_SNAP], ==, 0); 3067 3068 dsl_deadlist_space(&csa->cds->ds_deadlist, 3069 &cdl_used, &cdl_comp, &cdl_uncomp); 3070 dsl_deadlist_space(&csa->ohds->ds_deadlist, 3071 &odl_used, &odl_comp, &odl_uncomp); 3072 3073 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used - 3074 (csa->ohds->ds_phys->ds_used_bytes + odl_used); 3075 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 3076 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 3077 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 3078 cdl_uncomp - 3079 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 3080 3081 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 3082 dused, dcomp, duncomp, tx); 3083 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 3084 -dused, -dcomp, -duncomp, tx); 3085 3086 /* 3087 * The difference in the space used by snapshots is the 3088 * difference in snapshot space due to the head's 3089 * deadlist (since that's the only thing that's 3090 * changing that affects the snapused). 3091 */ 3092 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3093 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3094 &cdl_used, &cdl_comp, &cdl_uncomp); 3095 dsl_deadlist_space_range(&csa->ohds->ds_deadlist, 3096 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3097 &odl_used, &odl_comp, &odl_uncomp); 3098 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 3099 DD_USED_HEAD, DD_USED_SNAP, tx); 3100 } 3101 3102 /* swap ds_*_bytes */ 3103 SWITCH64(csa->ohds->ds_phys->ds_used_bytes, 3104 csa->cds->ds_phys->ds_used_bytes); 3105 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 3106 csa->cds->ds_phys->ds_compressed_bytes); 3107 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 3108 csa->cds->ds_phys->ds_uncompressed_bytes); 3109 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 3110 csa->cds->ds_phys->ds_unique_bytes); 3111 3112 /* apply any parent delta for change in unconsumed refreservation */ 3113 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 3114 csa->unused_refres_delta, 0, 0, tx); 3115 3116 /* 3117 * Swap deadlists. 3118 */ 3119 dsl_deadlist_close(&csa->cds->ds_deadlist); 3120 dsl_deadlist_close(&csa->ohds->ds_deadlist); 3121 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 3122 csa->cds->ds_phys->ds_deadlist_obj); 3123 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 3124 csa->cds->ds_phys->ds_deadlist_obj); 3125 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 3126 csa->ohds->ds_phys->ds_deadlist_obj); 3127 3128 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx); 3129 } 3130 3131 /* 3132 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 3133 * recv" into an existing fs to swizzle the file system to the new 3134 * version, and by "zfs rollback". Can also be used to swap two 3135 * independent head datasets if neither has any snapshots. 3136 */ 3137 int 3138 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 3139 boolean_t force) 3140 { 3141 struct cloneswaparg csa; 3142 int error; 3143 3144 ASSERT(clone->ds_owner); 3145 ASSERT(origin_head->ds_owner); 3146 retry: 3147 /* Need exclusive access for the swap */ 3148 rw_enter(&clone->ds_rwlock, RW_WRITER); 3149 if (!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 3150 rw_exit(&clone->ds_rwlock); 3151 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 3152 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 3153 rw_exit(&origin_head->ds_rwlock); 3154 goto retry; 3155 } 3156 } 3157 csa.cds = clone; 3158 csa.ohds = origin_head; 3159 csa.force = force; 3160 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3161 dsl_dataset_clone_swap_check, 3162 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3163 return (error); 3164 } 3165 3166 /* 3167 * Given a pool name and a dataset object number in that pool, 3168 * return the name of that dataset. 3169 */ 3170 int 3171 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3172 { 3173 spa_t *spa; 3174 dsl_pool_t *dp; 3175 dsl_dataset_t *ds; 3176 int error; 3177 3178 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3179 return (error); 3180 dp = spa_get_dsl(spa); 3181 rw_enter(&dp->dp_config_rwlock, RW_READER); 3182 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3183 dsl_dataset_name(ds, buf); 3184 dsl_dataset_rele(ds, FTAG); 3185 } 3186 rw_exit(&dp->dp_config_rwlock); 3187 spa_close(spa, FTAG); 3188 3189 return (error); 3190 } 3191 3192 int 3193 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3194 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3195 { 3196 int error = 0; 3197 3198 ASSERT3S(asize, >, 0); 3199 3200 /* 3201 * *ref_rsrv is the portion of asize that will come from any 3202 * unconsumed refreservation space. 3203 */ 3204 *ref_rsrv = 0; 3205 3206 mutex_enter(&ds->ds_lock); 3207 /* 3208 * Make a space adjustment for reserved bytes. 3209 */ 3210 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3211 ASSERT3U(*used, >=, 3212 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3213 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3214 *ref_rsrv = 3215 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3216 } 3217 3218 if (!check_quota || ds->ds_quota == 0) { 3219 mutex_exit(&ds->ds_lock); 3220 return (0); 3221 } 3222 /* 3223 * If they are requesting more space, and our current estimate 3224 * is over quota, they get to try again unless the actual 3225 * on-disk is over quota and there are no pending changes (which 3226 * may free up space for us). 3227 */ 3228 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) { 3229 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota) 3230 error = ERESTART; 3231 else 3232 error = EDQUOT; 3233 } 3234 mutex_exit(&ds->ds_lock); 3235 3236 return (error); 3237 } 3238 3239 /* ARGSUSED */ 3240 static int 3241 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3242 { 3243 dsl_dataset_t *ds = arg1; 3244 dsl_prop_setarg_t *psa = arg2; 3245 int err; 3246 3247 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3248 return (ENOTSUP); 3249 3250 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3251 return (err); 3252 3253 if (psa->psa_effective_value == 0) 3254 return (0); 3255 3256 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes || 3257 psa->psa_effective_value < ds->ds_reserved) 3258 return (ENOSPC); 3259 3260 return (0); 3261 } 3262 3263 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *); 3264 3265 void 3266 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3267 { 3268 dsl_dataset_t *ds = arg1; 3269 dsl_prop_setarg_t *psa = arg2; 3270 uint64_t effective_value = psa->psa_effective_value; 3271 3272 dsl_prop_set_sync(ds, psa, tx); 3273 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3274 3275 if (ds->ds_quota != effective_value) { 3276 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3277 ds->ds_quota = effective_value; 3278 3279 spa_history_log_internal(LOG_DS_REFQUOTA, 3280 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ", 3281 (longlong_t)ds->ds_quota, ds->ds_object); 3282 } 3283 } 3284 3285 int 3286 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3287 { 3288 dsl_dataset_t *ds; 3289 dsl_prop_setarg_t psa; 3290 int err; 3291 3292 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3293 3294 err = dsl_dataset_hold(dsname, FTAG, &ds); 3295 if (err) 3296 return (err); 3297 3298 /* 3299 * If someone removes a file, then tries to set the quota, we 3300 * want to make sure the file freeing takes effect. 3301 */ 3302 txg_wait_open(ds->ds_dir->dd_pool, 0); 3303 3304 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3305 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3306 ds, &psa, 0); 3307 3308 dsl_dataset_rele(ds, FTAG); 3309 return (err); 3310 } 3311 3312 static int 3313 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3314 { 3315 dsl_dataset_t *ds = arg1; 3316 dsl_prop_setarg_t *psa = arg2; 3317 uint64_t effective_value; 3318 uint64_t unique; 3319 int err; 3320 3321 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3322 SPA_VERSION_REFRESERVATION) 3323 return (ENOTSUP); 3324 3325 if (dsl_dataset_is_snapshot(ds)) 3326 return (EINVAL); 3327 3328 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3329 return (err); 3330 3331 effective_value = psa->psa_effective_value; 3332 3333 /* 3334 * If we are doing the preliminary check in open context, the 3335 * space estimates may be inaccurate. 3336 */ 3337 if (!dmu_tx_is_syncing(tx)) 3338 return (0); 3339 3340 mutex_enter(&ds->ds_lock); 3341 if (!DS_UNIQUE_IS_ACCURATE(ds)) 3342 dsl_dataset_recalc_head_uniq(ds); 3343 unique = ds->ds_phys->ds_unique_bytes; 3344 mutex_exit(&ds->ds_lock); 3345 3346 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3347 uint64_t delta = MAX(unique, effective_value) - 3348 MAX(unique, ds->ds_reserved); 3349 3350 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3351 return (ENOSPC); 3352 if (ds->ds_quota > 0 && 3353 effective_value > ds->ds_quota) 3354 return (ENOSPC); 3355 } 3356 3357 return (0); 3358 } 3359 3360 static void 3361 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3362 { 3363 dsl_dataset_t *ds = arg1; 3364 dsl_prop_setarg_t *psa = arg2; 3365 uint64_t effective_value = psa->psa_effective_value; 3366 uint64_t unique; 3367 int64_t delta; 3368 3369 dsl_prop_set_sync(ds, psa, tx); 3370 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3371 3372 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3373 3374 mutex_enter(&ds->ds_dir->dd_lock); 3375 mutex_enter(&ds->ds_lock); 3376 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 3377 unique = ds->ds_phys->ds_unique_bytes; 3378 delta = MAX(0, (int64_t)(effective_value - unique)) - 3379 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3380 ds->ds_reserved = effective_value; 3381 mutex_exit(&ds->ds_lock); 3382 3383 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3384 mutex_exit(&ds->ds_dir->dd_lock); 3385 3386 spa_history_log_internal(LOG_DS_REFRESERV, 3387 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu", 3388 (longlong_t)effective_value, ds->ds_object); 3389 } 3390 3391 int 3392 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3393 uint64_t reservation) 3394 { 3395 dsl_dataset_t *ds; 3396 dsl_prop_setarg_t psa; 3397 int err; 3398 3399 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3400 &reservation); 3401 3402 err = dsl_dataset_hold(dsname, FTAG, &ds); 3403 if (err) 3404 return (err); 3405 3406 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3407 dsl_dataset_set_reservation_check, 3408 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3409 3410 dsl_dataset_rele(ds, FTAG); 3411 return (err); 3412 } 3413 3414 struct dsl_ds_holdarg { 3415 dsl_sync_task_group_t *dstg; 3416 char *htag; 3417 char *snapname; 3418 boolean_t recursive; 3419 boolean_t gotone; 3420 boolean_t temphold; 3421 char failed[MAXPATHLEN]; 3422 }; 3423 3424 /* 3425 * The max length of a temporary tag prefix is the number of hex digits 3426 * required to express UINT64_MAX plus one for the hyphen. 3427 */ 3428 #define MAX_TAG_PREFIX_LEN 17 3429 3430 static int 3431 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3432 { 3433 dsl_dataset_t *ds = arg1; 3434 struct dsl_ds_holdarg *ha = arg2; 3435 char *htag = ha->htag; 3436 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3437 int error = 0; 3438 3439 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3440 return (ENOTSUP); 3441 3442 if (!dsl_dataset_is_snapshot(ds)) 3443 return (EINVAL); 3444 3445 /* tags must be unique */ 3446 mutex_enter(&ds->ds_lock); 3447 if (ds->ds_phys->ds_userrefs_obj) { 3448 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3449 8, 1, tx); 3450 if (error == 0) 3451 error = EEXIST; 3452 else if (error == ENOENT) 3453 error = 0; 3454 } 3455 mutex_exit(&ds->ds_lock); 3456 3457 if (error == 0 && ha->temphold && 3458 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3459 error = E2BIG; 3460 3461 return (error); 3462 } 3463 3464 static void 3465 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3466 { 3467 dsl_dataset_t *ds = arg1; 3468 struct dsl_ds_holdarg *ha = arg2; 3469 char *htag = ha->htag; 3470 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3471 objset_t *mos = dp->dp_meta_objset; 3472 uint64_t now = gethrestime_sec(); 3473 uint64_t zapobj; 3474 3475 mutex_enter(&ds->ds_lock); 3476 if (ds->ds_phys->ds_userrefs_obj == 0) { 3477 /* 3478 * This is the first user hold for this dataset. Create 3479 * the userrefs zap object. 3480 */ 3481 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3482 zapobj = ds->ds_phys->ds_userrefs_obj = 3483 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3484 } else { 3485 zapobj = ds->ds_phys->ds_userrefs_obj; 3486 } 3487 ds->ds_userrefs++; 3488 mutex_exit(&ds->ds_lock); 3489 3490 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3491 3492 if (ha->temphold) { 3493 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3494 htag, &now, tx)); 3495 } 3496 3497 spa_history_log_internal(LOG_DS_USER_HOLD, 3498 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag, 3499 (int)ha->temphold, ds->ds_object); 3500 } 3501 3502 static int 3503 dsl_dataset_user_hold_one(const char *dsname, void *arg) 3504 { 3505 struct dsl_ds_holdarg *ha = arg; 3506 dsl_dataset_t *ds; 3507 int error; 3508 char *name; 3509 3510 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3511 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3512 error = dsl_dataset_hold(name, ha->dstg, &ds); 3513 strfree(name); 3514 if (error == 0) { 3515 ha->gotone = B_TRUE; 3516 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3517 dsl_dataset_user_hold_sync, ds, ha, 0); 3518 } else if (error == ENOENT && ha->recursive) { 3519 error = 0; 3520 } else { 3521 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3522 } 3523 return (error); 3524 } 3525 3526 int 3527 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3528 boolean_t recursive, boolean_t temphold) 3529 { 3530 struct dsl_ds_holdarg *ha; 3531 dsl_sync_task_t *dst; 3532 spa_t *spa; 3533 int error; 3534 3535 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3536 3537 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3538 3539 error = spa_open(dsname, &spa, FTAG); 3540 if (error) { 3541 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3542 return (error); 3543 } 3544 3545 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3546 ha->htag = htag; 3547 ha->snapname = snapname; 3548 ha->recursive = recursive; 3549 ha->temphold = temphold; 3550 if (recursive) { 3551 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3552 ha, DS_FIND_CHILDREN); 3553 } else { 3554 error = dsl_dataset_user_hold_one(dsname, ha); 3555 } 3556 if (error == 0) 3557 error = dsl_sync_task_group_wait(ha->dstg); 3558 3559 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3560 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3561 dsl_dataset_t *ds = dst->dst_arg1; 3562 3563 if (dst->dst_err) { 3564 dsl_dataset_name(ds, ha->failed); 3565 *strchr(ha->failed, '@') = '\0'; 3566 } 3567 dsl_dataset_rele(ds, ha->dstg); 3568 } 3569 3570 if (error == 0 && recursive && !ha->gotone) 3571 error = ENOENT; 3572 3573 if (error) 3574 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3575 3576 dsl_sync_task_group_destroy(ha->dstg); 3577 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3578 spa_close(spa, FTAG); 3579 return (error); 3580 } 3581 3582 struct dsl_ds_releasearg { 3583 dsl_dataset_t *ds; 3584 const char *htag; 3585 boolean_t own; /* do we own or just hold ds? */ 3586 }; 3587 3588 static int 3589 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3590 boolean_t *might_destroy) 3591 { 3592 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3593 uint64_t zapobj; 3594 uint64_t tmp; 3595 int error; 3596 3597 *might_destroy = B_FALSE; 3598 3599 mutex_enter(&ds->ds_lock); 3600 zapobj = ds->ds_phys->ds_userrefs_obj; 3601 if (zapobj == 0) { 3602 /* The tag can't possibly exist */ 3603 mutex_exit(&ds->ds_lock); 3604 return (ESRCH); 3605 } 3606 3607 /* Make sure the tag exists */ 3608 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3609 if (error) { 3610 mutex_exit(&ds->ds_lock); 3611 if (error == ENOENT) 3612 error = ESRCH; 3613 return (error); 3614 } 3615 3616 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3617 DS_IS_DEFER_DESTROY(ds)) 3618 *might_destroy = B_TRUE; 3619 3620 mutex_exit(&ds->ds_lock); 3621 return (0); 3622 } 3623 3624 static int 3625 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3626 { 3627 struct dsl_ds_releasearg *ra = arg1; 3628 dsl_dataset_t *ds = ra->ds; 3629 boolean_t might_destroy; 3630 int error; 3631 3632 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3633 return (ENOTSUP); 3634 3635 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3636 if (error) 3637 return (error); 3638 3639 if (might_destroy) { 3640 struct dsl_ds_destroyarg dsda = {0}; 3641 3642 if (dmu_tx_is_syncing(tx)) { 3643 /* 3644 * If we're not prepared to remove the snapshot, 3645 * we can't allow the release to happen right now. 3646 */ 3647 if (!ra->own) 3648 return (EBUSY); 3649 } 3650 dsda.ds = ds; 3651 dsda.releasing = B_TRUE; 3652 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3653 } 3654 3655 return (0); 3656 } 3657 3658 static void 3659 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx) 3660 { 3661 struct dsl_ds_releasearg *ra = arg1; 3662 dsl_dataset_t *ds = ra->ds; 3663 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3664 objset_t *mos = dp->dp_meta_objset; 3665 uint64_t zapobj; 3666 uint64_t dsobj = ds->ds_object; 3667 uint64_t refs; 3668 int error; 3669 3670 if (ds->ds_objset) { 3671 dmu_objset_evict(ds->ds_objset); 3672 ds->ds_objset = NULL; 3673 } 3674 3675 mutex_enter(&ds->ds_lock); 3676 ds->ds_userrefs--; 3677 refs = ds->ds_userrefs; 3678 mutex_exit(&ds->ds_lock); 3679 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3680 VERIFY(error == 0 || error == ENOENT); 3681 zapobj = ds->ds_phys->ds_userrefs_obj; 3682 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3683 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3684 DS_IS_DEFER_DESTROY(ds)) { 3685 struct dsl_ds_destroyarg dsda = {0}; 3686 3687 ASSERT(ra->own); 3688 dsda.ds = ds; 3689 dsda.releasing = B_TRUE; 3690 /* We already did the destroy_check */ 3691 dsl_dataset_destroy_sync(&dsda, tag, tx); 3692 } 3693 3694 spa_history_log_internal(LOG_DS_USER_RELEASE, 3695 dp->dp_spa, tx, "<%s> %lld dataset = %llu", 3696 ra->htag, (longlong_t)refs, dsobj); 3697 } 3698 3699 static int 3700 dsl_dataset_user_release_one(const char *dsname, void *arg) 3701 { 3702 struct dsl_ds_holdarg *ha = arg; 3703 struct dsl_ds_releasearg *ra; 3704 dsl_dataset_t *ds; 3705 int error; 3706 void *dtag = ha->dstg; 3707 char *name; 3708 boolean_t own = B_FALSE; 3709 boolean_t might_destroy; 3710 3711 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3712 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3713 error = dsl_dataset_hold(name, dtag, &ds); 3714 strfree(name); 3715 if (error == ENOENT && ha->recursive) 3716 return (0); 3717 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3718 if (error) 3719 return (error); 3720 3721 ha->gotone = B_TRUE; 3722 3723 ASSERT(dsl_dataset_is_snapshot(ds)); 3724 3725 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3726 if (error) { 3727 dsl_dataset_rele(ds, dtag); 3728 return (error); 3729 } 3730 3731 if (might_destroy) { 3732 #ifdef _KERNEL 3733 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3734 error = zfs_unmount_snap(name, NULL); 3735 strfree(name); 3736 if (error) { 3737 dsl_dataset_rele(ds, dtag); 3738 return (error); 3739 } 3740 #endif 3741 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3742 dsl_dataset_rele(ds, dtag); 3743 return (EBUSY); 3744 } else { 3745 own = B_TRUE; 3746 dsl_dataset_make_exclusive(ds, dtag); 3747 } 3748 } 3749 3750 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3751 ra->ds = ds; 3752 ra->htag = ha->htag; 3753 ra->own = own; 3754 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3755 dsl_dataset_user_release_sync, ra, dtag, 0); 3756 3757 return (0); 3758 } 3759 3760 int 3761 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3762 boolean_t recursive) 3763 { 3764 struct dsl_ds_holdarg *ha; 3765 dsl_sync_task_t *dst; 3766 spa_t *spa; 3767 int error; 3768 3769 top: 3770 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3771 3772 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3773 3774 error = spa_open(dsname, &spa, FTAG); 3775 if (error) { 3776 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3777 return (error); 3778 } 3779 3780 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3781 ha->htag = htag; 3782 ha->snapname = snapname; 3783 ha->recursive = recursive; 3784 if (recursive) { 3785 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3786 ha, DS_FIND_CHILDREN); 3787 } else { 3788 error = dsl_dataset_user_release_one(dsname, ha); 3789 } 3790 if (error == 0) 3791 error = dsl_sync_task_group_wait(ha->dstg); 3792 3793 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3794 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3795 struct dsl_ds_releasearg *ra = dst->dst_arg1; 3796 dsl_dataset_t *ds = ra->ds; 3797 3798 if (dst->dst_err) 3799 dsl_dataset_name(ds, ha->failed); 3800 3801 if (ra->own) 3802 dsl_dataset_disown(ds, ha->dstg); 3803 else 3804 dsl_dataset_rele(ds, ha->dstg); 3805 3806 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 3807 } 3808 3809 if (error == 0 && recursive && !ha->gotone) 3810 error = ENOENT; 3811 3812 if (error && error != EBUSY) 3813 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3814 3815 dsl_sync_task_group_destroy(ha->dstg); 3816 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3817 spa_close(spa, FTAG); 3818 3819 /* 3820 * We can get EBUSY if we were racing with deferred destroy and 3821 * dsl_dataset_user_release_check() hadn't done the necessary 3822 * open context setup. We can also get EBUSY if we're racing 3823 * with destroy and that thread is the ds_owner. Either way 3824 * the busy condition should be transient, and we should retry 3825 * the release operation. 3826 */ 3827 if (error == EBUSY) 3828 goto top; 3829 3830 return (error); 3831 } 3832 3833 /* 3834 * Called at spa_load time to release a stale temporary user hold. 3835 */ 3836 int 3837 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag) 3838 { 3839 dsl_dataset_t *ds; 3840 char *snap; 3841 char *name; 3842 int namelen; 3843 int error; 3844 3845 rw_enter(&dp->dp_config_rwlock, RW_READER); 3846 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 3847 rw_exit(&dp->dp_config_rwlock); 3848 if (error) 3849 return (error); 3850 namelen = dsl_dataset_namelen(ds)+1; 3851 name = kmem_alloc(namelen, KM_SLEEP); 3852 dsl_dataset_name(ds, name); 3853 dsl_dataset_rele(ds, FTAG); 3854 3855 snap = strchr(name, '@'); 3856 *snap = '\0'; 3857 ++snap; 3858 return (dsl_dataset_user_release(name, snap, htag, B_FALSE)); 3859 } 3860 3861 int 3862 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 3863 { 3864 dsl_dataset_t *ds; 3865 int err; 3866 3867 err = dsl_dataset_hold(dsname, FTAG, &ds); 3868 if (err) 3869 return (err); 3870 3871 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 3872 if (ds->ds_phys->ds_userrefs_obj != 0) { 3873 zap_attribute_t *za; 3874 zap_cursor_t zc; 3875 3876 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 3877 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 3878 ds->ds_phys->ds_userrefs_obj); 3879 zap_cursor_retrieve(&zc, za) == 0; 3880 zap_cursor_advance(&zc)) { 3881 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 3882 za->za_first_integer)); 3883 } 3884 zap_cursor_fini(&zc); 3885 kmem_free(za, sizeof (zap_attribute_t)); 3886 } 3887 dsl_dataset_rele(ds, FTAG); 3888 return (0); 3889 } 3890 3891 /* 3892 * Note, this fuction is used as the callback for dmu_objset_find(). We 3893 * always return 0 so that we will continue to find and process 3894 * inconsistent datasets, even if we encounter an error trying to 3895 * process one of them. 3896 */ 3897 /* ARGSUSED */ 3898 int 3899 dsl_destroy_inconsistent(const char *dsname, void *arg) 3900 { 3901 dsl_dataset_t *ds; 3902 3903 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 3904 if (DS_IS_INCONSISTENT(ds)) 3905 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 3906 else 3907 dsl_dataset_disown(ds, FTAG); 3908 } 3909 return (0); 3910 } 3911