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