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 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/dmu_objset.h> 27 #include <sys/dsl_dataset.h> 28 #include <sys/dsl_dir.h> 29 #include <sys/dsl_prop.h> 30 #include <sys/dsl_synctask.h> 31 #include <sys/dmu_traverse.h> 32 #include <sys/dmu_tx.h> 33 #include <sys/arc.h> 34 #include <sys/zio.h> 35 #include <sys/zap.h> 36 #include <sys/unique.h> 37 #include <sys/zfs_context.h> 38 #include <sys/zfs_ioctl.h> 39 #include <sys/spa.h> 40 #include <sys/zfs_znode.h> 41 #include <sys/zvol.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, "born, ds=%p\n", 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 mutex_enter(&ds->ds_dir->dd_lock); 105 mutex_enter(&ds->ds_lock); 106 delta = parent_delta(ds, used); 107 ds->ds_phys->ds_used_bytes += used; 108 ds->ds_phys->ds_compressed_bytes += compressed; 109 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 110 ds->ds_phys->ds_unique_bytes += used; 111 mutex_exit(&ds->ds_lock); 112 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 113 compressed, uncompressed, tx); 114 dsl_dir_transfer_space(ds->ds_dir, used - delta, 115 DD_USED_REFRSRV, DD_USED_HEAD, tx); 116 mutex_exit(&ds->ds_dir->dd_lock); 117 } 118 119 int 120 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, 121 boolean_t async) 122 { 123 if (BP_IS_HOLE(bp)) 124 return (0); 125 126 ASSERT(dmu_tx_is_syncing(tx)); 127 ASSERT(bp->blk_birth <= tx->tx_txg); 128 129 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 130 int compressed = BP_GET_PSIZE(bp); 131 int uncompressed = BP_GET_UCSIZE(bp); 132 133 ASSERT(used > 0); 134 if (ds == NULL) { 135 /* 136 * Account for the meta-objset space in its placeholder 137 * dataset. 138 */ 139 dsl_free(tx->tx_pool, tx->tx_txg, bp); 140 141 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 142 -used, -compressed, -uncompressed, tx); 143 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 144 return (used); 145 } 146 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 147 148 ASSERT(!dsl_dataset_is_snapshot(ds)); 149 dmu_buf_will_dirty(ds->ds_dbuf, tx); 150 151 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 152 int64_t delta; 153 154 dprintf_bp(bp, "freeing: %s", ""); 155 dsl_free(tx->tx_pool, tx->tx_txg, bp); 156 157 mutex_enter(&ds->ds_dir->dd_lock); 158 mutex_enter(&ds->ds_lock); 159 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 160 !DS_UNIQUE_IS_ACCURATE(ds)); 161 delta = parent_delta(ds, -used); 162 ds->ds_phys->ds_unique_bytes -= used; 163 mutex_exit(&ds->ds_lock); 164 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 165 delta, -compressed, -uncompressed, tx); 166 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 167 DD_USED_REFRSRV, DD_USED_HEAD, tx); 168 mutex_exit(&ds->ds_dir->dd_lock); 169 } else { 170 dprintf_bp(bp, "putting on dead list: %s", ""); 171 if (async) { 172 /* 173 * We are here as part of zio's write done callback, 174 * which means we're a zio interrupt thread. We can't 175 * call bplist_enqueue() now because it may block 176 * waiting for I/O. Instead, put bp on the deferred 177 * queue and let dsl_pool_sync() finish the job. 178 */ 179 bplist_enqueue_deferred(&ds->ds_deadlist, bp); 180 } else { 181 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, bp, tx)); 182 } 183 ASSERT3U(ds->ds_prev->ds_object, ==, 184 ds->ds_phys->ds_prev_snap_obj); 185 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 186 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 187 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 188 ds->ds_object && bp->blk_birth > 189 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 190 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 191 mutex_enter(&ds->ds_prev->ds_lock); 192 ds->ds_prev->ds_phys->ds_unique_bytes += used; 193 mutex_exit(&ds->ds_prev->ds_lock); 194 } 195 if (bp->blk_birth > ds->ds_origin_txg) { 196 dsl_dir_transfer_space(ds->ds_dir, used, 197 DD_USED_HEAD, DD_USED_SNAP, tx); 198 } 199 } 200 mutex_enter(&ds->ds_lock); 201 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used); 202 ds->ds_phys->ds_used_bytes -= used; 203 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 204 ds->ds_phys->ds_compressed_bytes -= compressed; 205 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 206 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 207 mutex_exit(&ds->ds_lock); 208 209 return (used); 210 } 211 212 uint64_t 213 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 214 { 215 uint64_t trysnap = 0; 216 217 if (ds == NULL) 218 return (0); 219 /* 220 * The snapshot creation could fail, but that would cause an 221 * incorrect FALSE return, which would only result in an 222 * overestimation of the amount of space that an operation would 223 * consume, which is OK. 224 * 225 * There's also a small window where we could miss a pending 226 * snapshot, because we could set the sync task in the quiescing 227 * phase. So this should only be used as a guess. 228 */ 229 if (ds->ds_trysnap_txg > 230 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 231 trysnap = ds->ds_trysnap_txg; 232 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 233 } 234 235 boolean_t 236 dsl_dataset_block_freeable(dsl_dataset_t *ds, uint64_t blk_birth) 237 { 238 return (blk_birth > dsl_dataset_prev_snap_txg(ds)); 239 } 240 241 /* ARGSUSED */ 242 static void 243 dsl_dataset_evict(dmu_buf_t *db, void *dsv) 244 { 245 dsl_dataset_t *ds = dsv; 246 247 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 248 249 unique_remove(ds->ds_fsid_guid); 250 251 if (ds->ds_objset != NULL) 252 dmu_objset_evict(ds->ds_objset); 253 254 if (ds->ds_prev) { 255 dsl_dataset_drop_ref(ds->ds_prev, ds); 256 ds->ds_prev = NULL; 257 } 258 259 bplist_close(&ds->ds_deadlist); 260 if (ds->ds_dir) 261 dsl_dir_close(ds->ds_dir, ds); 262 263 ASSERT(!list_link_active(&ds->ds_synced_link)); 264 265 mutex_destroy(&ds->ds_lock); 266 mutex_destroy(&ds->ds_recvlock); 267 mutex_destroy(&ds->ds_opening_lock); 268 rw_destroy(&ds->ds_rwlock); 269 cv_destroy(&ds->ds_exclusive_cv); 270 bplist_fini(&ds->ds_deadlist); 271 272 kmem_free(ds, sizeof (dsl_dataset_t)); 273 } 274 275 static int 276 dsl_dataset_get_snapname(dsl_dataset_t *ds) 277 { 278 dsl_dataset_phys_t *headphys; 279 int err; 280 dmu_buf_t *headdbuf; 281 dsl_pool_t *dp = ds->ds_dir->dd_pool; 282 objset_t *mos = dp->dp_meta_objset; 283 284 if (ds->ds_snapname[0]) 285 return (0); 286 if (ds->ds_phys->ds_next_snap_obj == 0) 287 return (0); 288 289 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 290 FTAG, &headdbuf); 291 if (err) 292 return (err); 293 headphys = headdbuf->db_data; 294 err = zap_value_search(dp->dp_meta_objset, 295 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 296 dmu_buf_rele(headdbuf, FTAG); 297 return (err); 298 } 299 300 static int 301 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 302 { 303 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 304 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 305 matchtype_t mt; 306 int err; 307 308 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 309 mt = MT_FIRST; 310 else 311 mt = MT_EXACT; 312 313 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 314 value, mt, NULL, 0, NULL); 315 if (err == ENOTSUP && mt == MT_FIRST) 316 err = zap_lookup(mos, snapobj, name, 8, 1, value); 317 return (err); 318 } 319 320 static int 321 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 322 { 323 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 324 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 325 matchtype_t mt; 326 int err; 327 328 dsl_dir_snap_cmtime_update(ds->ds_dir); 329 330 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 331 mt = MT_FIRST; 332 else 333 mt = MT_EXACT; 334 335 err = zap_remove_norm(mos, snapobj, name, mt, tx); 336 if (err == ENOTSUP && mt == MT_FIRST) 337 err = zap_remove(mos, snapobj, name, tx); 338 return (err); 339 } 340 341 static int 342 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 343 dsl_dataset_t **dsp) 344 { 345 objset_t *mos = dp->dp_meta_objset; 346 dmu_buf_t *dbuf; 347 dsl_dataset_t *ds; 348 int err; 349 350 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 351 dsl_pool_sync_context(dp)); 352 353 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 354 if (err) 355 return (err); 356 ds = dmu_buf_get_user(dbuf); 357 if (ds == NULL) { 358 dsl_dataset_t *winner; 359 360 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 361 ds->ds_dbuf = dbuf; 362 ds->ds_object = dsobj; 363 ds->ds_phys = dbuf->db_data; 364 365 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 366 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 367 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 368 rw_init(&ds->ds_rwlock, 0, 0, 0); 369 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 370 bplist_init(&ds->ds_deadlist); 371 372 err = bplist_open(&ds->ds_deadlist, 373 mos, ds->ds_phys->ds_deadlist_obj); 374 if (err == 0) { 375 err = dsl_dir_open_obj(dp, 376 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 377 } 378 if (err) { 379 /* 380 * we don't really need to close the blist if we 381 * just opened it. 382 */ 383 mutex_destroy(&ds->ds_lock); 384 mutex_destroy(&ds->ds_recvlock); 385 mutex_destroy(&ds->ds_opening_lock); 386 rw_destroy(&ds->ds_rwlock); 387 cv_destroy(&ds->ds_exclusive_cv); 388 bplist_fini(&ds->ds_deadlist); 389 kmem_free(ds, sizeof (dsl_dataset_t)); 390 dmu_buf_rele(dbuf, tag); 391 return (err); 392 } 393 394 if (!dsl_dataset_is_snapshot(ds)) { 395 ds->ds_snapname[0] = '\0'; 396 if (ds->ds_phys->ds_prev_snap_obj) { 397 err = dsl_dataset_get_ref(dp, 398 ds->ds_phys->ds_prev_snap_obj, 399 ds, &ds->ds_prev); 400 } 401 402 if (err == 0 && dsl_dir_is_clone(ds->ds_dir)) { 403 dsl_dataset_t *origin; 404 405 err = dsl_dataset_hold_obj(dp, 406 ds->ds_dir->dd_phys->dd_origin_obj, 407 FTAG, &origin); 408 if (err == 0) { 409 ds->ds_origin_txg = 410 origin->ds_phys->ds_creation_txg; 411 dsl_dataset_rele(origin, FTAG); 412 } 413 } 414 } else { 415 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 416 err = dsl_dataset_get_snapname(ds); 417 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 418 err = zap_count( 419 ds->ds_dir->dd_pool->dp_meta_objset, 420 ds->ds_phys->ds_userrefs_obj, 421 &ds->ds_userrefs); 422 } 423 } 424 425 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 426 /* 427 * In sync context, we're called with either no lock 428 * or with the write lock. If we're not syncing, 429 * we're always called with the read lock held. 430 */ 431 boolean_t need_lock = 432 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 433 dsl_pool_sync_context(dp); 434 435 if (need_lock) 436 rw_enter(&dp->dp_config_rwlock, RW_READER); 437 438 err = dsl_prop_get_ds(ds, 439 "refreservation", sizeof (uint64_t), 1, 440 &ds->ds_reserved, NULL); 441 if (err == 0) { 442 err = dsl_prop_get_ds(ds, 443 "refquota", sizeof (uint64_t), 1, 444 &ds->ds_quota, NULL); 445 } 446 447 if (need_lock) 448 rw_exit(&dp->dp_config_rwlock); 449 } else { 450 ds->ds_reserved = ds->ds_quota = 0; 451 } 452 453 if (err == 0) { 454 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 455 dsl_dataset_evict); 456 } 457 if (err || winner) { 458 bplist_close(&ds->ds_deadlist); 459 if (ds->ds_prev) 460 dsl_dataset_drop_ref(ds->ds_prev, ds); 461 dsl_dir_close(ds->ds_dir, ds); 462 mutex_destroy(&ds->ds_lock); 463 mutex_destroy(&ds->ds_recvlock); 464 mutex_destroy(&ds->ds_opening_lock); 465 rw_destroy(&ds->ds_rwlock); 466 cv_destroy(&ds->ds_exclusive_cv); 467 bplist_fini(&ds->ds_deadlist); 468 kmem_free(ds, sizeof (dsl_dataset_t)); 469 if (err) { 470 dmu_buf_rele(dbuf, tag); 471 return (err); 472 } 473 ds = winner; 474 } else { 475 ds->ds_fsid_guid = 476 unique_insert(ds->ds_phys->ds_fsid_guid); 477 } 478 } 479 ASSERT3P(ds->ds_dbuf, ==, dbuf); 480 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 481 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 482 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 483 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 484 mutex_enter(&ds->ds_lock); 485 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 486 mutex_exit(&ds->ds_lock); 487 dmu_buf_rele(ds->ds_dbuf, tag); 488 return (ENOENT); 489 } 490 mutex_exit(&ds->ds_lock); 491 *dsp = ds; 492 return (0); 493 } 494 495 static int 496 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 497 { 498 dsl_pool_t *dp = ds->ds_dir->dd_pool; 499 500 /* 501 * In syncing context we don't want the rwlock lock: there 502 * may be an existing writer waiting for sync phase to 503 * finish. We don't need to worry about such writers, since 504 * sync phase is single-threaded, so the writer can't be 505 * doing anything while we are active. 506 */ 507 if (dsl_pool_sync_context(dp)) { 508 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 509 return (0); 510 } 511 512 /* 513 * Normal users will hold the ds_rwlock as a READER until they 514 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 515 * drop their READER lock after they set the ds_owner field. 516 * 517 * If the dataset is being destroyed, the destroy thread will 518 * obtain a WRITER lock for exclusive access after it's done its 519 * open-context work and then change the ds_owner to 520 * dsl_reaper once destruction is assured. So threads 521 * may block here temporarily, until the "destructability" of 522 * the dataset is determined. 523 */ 524 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 525 mutex_enter(&ds->ds_lock); 526 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 527 rw_exit(&dp->dp_config_rwlock); 528 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 529 if (DSL_DATASET_IS_DESTROYED(ds)) { 530 mutex_exit(&ds->ds_lock); 531 dsl_dataset_drop_ref(ds, tag); 532 rw_enter(&dp->dp_config_rwlock, RW_READER); 533 return (ENOENT); 534 } 535 rw_enter(&dp->dp_config_rwlock, RW_READER); 536 } 537 mutex_exit(&ds->ds_lock); 538 return (0); 539 } 540 541 int 542 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 543 dsl_dataset_t **dsp) 544 { 545 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 546 547 if (err) 548 return (err); 549 return (dsl_dataset_hold_ref(*dsp, tag)); 550 } 551 552 int 553 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 554 void *tag, dsl_dataset_t **dsp) 555 { 556 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 557 if (err) 558 return (err); 559 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 560 dsl_dataset_rele(*dsp, tag); 561 *dsp = NULL; 562 return (EBUSY); 563 } 564 return (0); 565 } 566 567 int 568 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 569 { 570 dsl_dir_t *dd; 571 dsl_pool_t *dp; 572 const char *snapname; 573 uint64_t obj; 574 int err = 0; 575 576 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 577 if (err) 578 return (err); 579 580 dp = dd->dd_pool; 581 obj = dd->dd_phys->dd_head_dataset_obj; 582 rw_enter(&dp->dp_config_rwlock, RW_READER); 583 if (obj) 584 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 585 else 586 err = ENOENT; 587 if (err) 588 goto out; 589 590 err = dsl_dataset_hold_ref(*dsp, tag); 591 592 /* we may be looking for a snapshot */ 593 if (err == 0 && snapname != NULL) { 594 dsl_dataset_t *ds = NULL; 595 596 if (*snapname++ != '@') { 597 dsl_dataset_rele(*dsp, tag); 598 err = ENOENT; 599 goto out; 600 } 601 602 dprintf("looking for snapshot '%s'\n", snapname); 603 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 604 if (err == 0) 605 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 606 dsl_dataset_rele(*dsp, tag); 607 608 ASSERT3U((err == 0), ==, (ds != NULL)); 609 610 if (ds) { 611 mutex_enter(&ds->ds_lock); 612 if (ds->ds_snapname[0] == 0) 613 (void) strlcpy(ds->ds_snapname, snapname, 614 sizeof (ds->ds_snapname)); 615 mutex_exit(&ds->ds_lock); 616 err = dsl_dataset_hold_ref(ds, tag); 617 *dsp = err ? NULL : ds; 618 } 619 } 620 out: 621 rw_exit(&dp->dp_config_rwlock); 622 dsl_dir_close(dd, FTAG); 623 return (err); 624 } 625 626 int 627 dsl_dataset_own(const char *name, boolean_t inconsistentok, 628 void *tag, dsl_dataset_t **dsp) 629 { 630 int err = dsl_dataset_hold(name, tag, dsp); 631 if (err) 632 return (err); 633 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 634 dsl_dataset_rele(*dsp, tag); 635 return (EBUSY); 636 } 637 return (0); 638 } 639 640 void 641 dsl_dataset_name(dsl_dataset_t *ds, char *name) 642 { 643 if (ds == NULL) { 644 (void) strcpy(name, "mos"); 645 } else { 646 dsl_dir_name(ds->ds_dir, name); 647 VERIFY(0 == dsl_dataset_get_snapname(ds)); 648 if (ds->ds_snapname[0]) { 649 (void) strcat(name, "@"); 650 /* 651 * We use a "recursive" mutex so that we 652 * can call dprintf_ds() with ds_lock held. 653 */ 654 if (!MUTEX_HELD(&ds->ds_lock)) { 655 mutex_enter(&ds->ds_lock); 656 (void) strcat(name, ds->ds_snapname); 657 mutex_exit(&ds->ds_lock); 658 } else { 659 (void) strcat(name, ds->ds_snapname); 660 } 661 } 662 } 663 } 664 665 static int 666 dsl_dataset_namelen(dsl_dataset_t *ds) 667 { 668 int result; 669 670 if (ds == NULL) { 671 result = 3; /* "mos" */ 672 } else { 673 result = dsl_dir_namelen(ds->ds_dir); 674 VERIFY(0 == dsl_dataset_get_snapname(ds)); 675 if (ds->ds_snapname[0]) { 676 ++result; /* adding one for the @-sign */ 677 if (!MUTEX_HELD(&ds->ds_lock)) { 678 mutex_enter(&ds->ds_lock); 679 result += strlen(ds->ds_snapname); 680 mutex_exit(&ds->ds_lock); 681 } else { 682 result += strlen(ds->ds_snapname); 683 } 684 } 685 } 686 687 return (result); 688 } 689 690 void 691 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 692 { 693 dmu_buf_rele(ds->ds_dbuf, tag); 694 } 695 696 void 697 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 698 { 699 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 700 rw_exit(&ds->ds_rwlock); 701 } 702 dsl_dataset_drop_ref(ds, tag); 703 } 704 705 void 706 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 707 { 708 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 709 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 710 711 mutex_enter(&ds->ds_lock); 712 ds->ds_owner = NULL; 713 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 714 rw_exit(&ds->ds_rwlock); 715 cv_broadcast(&ds->ds_exclusive_cv); 716 } 717 mutex_exit(&ds->ds_lock); 718 if (ds->ds_dbuf) 719 dsl_dataset_drop_ref(ds, tag); 720 else 721 dsl_dataset_evict(ds->ds_dbuf, ds); 722 } 723 724 boolean_t 725 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 726 { 727 boolean_t gotit = FALSE; 728 729 mutex_enter(&ds->ds_lock); 730 if (ds->ds_owner == NULL && 731 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 732 ds->ds_owner = tag; 733 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 734 rw_exit(&ds->ds_rwlock); 735 gotit = TRUE; 736 } 737 mutex_exit(&ds->ds_lock); 738 return (gotit); 739 } 740 741 void 742 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 743 { 744 ASSERT3P(owner, ==, ds->ds_owner); 745 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 746 rw_enter(&ds->ds_rwlock, RW_WRITER); 747 } 748 749 uint64_t 750 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 751 uint64_t flags, dmu_tx_t *tx) 752 { 753 dsl_pool_t *dp = dd->dd_pool; 754 dmu_buf_t *dbuf; 755 dsl_dataset_phys_t *dsphys; 756 uint64_t dsobj; 757 objset_t *mos = dp->dp_meta_objset; 758 759 if (origin == NULL) 760 origin = dp->dp_origin_snap; 761 762 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 763 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 764 ASSERT(dmu_tx_is_syncing(tx)); 765 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 766 767 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 768 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 769 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 770 dmu_buf_will_dirty(dbuf, tx); 771 dsphys = dbuf->db_data; 772 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 773 dsphys->ds_dir_obj = dd->dd_object; 774 dsphys->ds_flags = flags; 775 dsphys->ds_fsid_guid = unique_create(); 776 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 777 sizeof (dsphys->ds_guid)); 778 dsphys->ds_snapnames_zapobj = 779 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 780 DMU_OT_NONE, 0, tx); 781 dsphys->ds_creation_time = gethrestime_sec(); 782 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 783 dsphys->ds_deadlist_obj = 784 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx); 785 786 if (origin) { 787 dsphys->ds_prev_snap_obj = origin->ds_object; 788 dsphys->ds_prev_snap_txg = 789 origin->ds_phys->ds_creation_txg; 790 dsphys->ds_used_bytes = 791 origin->ds_phys->ds_used_bytes; 792 dsphys->ds_compressed_bytes = 793 origin->ds_phys->ds_compressed_bytes; 794 dsphys->ds_uncompressed_bytes = 795 origin->ds_phys->ds_uncompressed_bytes; 796 dsphys->ds_bp = origin->ds_phys->ds_bp; 797 dsphys->ds_flags |= origin->ds_phys->ds_flags; 798 799 dmu_buf_will_dirty(origin->ds_dbuf, tx); 800 origin->ds_phys->ds_num_children++; 801 802 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 803 if (origin->ds_phys->ds_next_clones_obj == 0) { 804 origin->ds_phys->ds_next_clones_obj = 805 zap_create(mos, 806 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 807 } 808 VERIFY(0 == zap_add_int(mos, 809 origin->ds_phys->ds_next_clones_obj, 810 dsobj, tx)); 811 } 812 813 dmu_buf_will_dirty(dd->dd_dbuf, tx); 814 dd->dd_phys->dd_origin_obj = origin->ds_object; 815 } 816 817 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 818 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 819 820 dmu_buf_rele(dbuf, FTAG); 821 822 dmu_buf_will_dirty(dd->dd_dbuf, tx); 823 dd->dd_phys->dd_head_dataset_obj = dsobj; 824 825 return (dsobj); 826 } 827 828 uint64_t 829 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 830 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 831 { 832 dsl_pool_t *dp = pdd->dd_pool; 833 uint64_t dsobj, ddobj; 834 dsl_dir_t *dd; 835 836 ASSERT(lastname[0] != '@'); 837 838 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 839 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 840 841 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 842 843 dsl_deleg_set_create_perms(dd, tx, cr); 844 845 dsl_dir_close(dd, FTAG); 846 847 return (dsobj); 848 } 849 850 struct destroyarg { 851 dsl_sync_task_group_t *dstg; 852 char *snapname; 853 char *failed; 854 boolean_t defer; 855 }; 856 857 static int 858 dsl_snapshot_destroy_one(char *name, void *arg) 859 { 860 struct destroyarg *da = arg; 861 dsl_dataset_t *ds; 862 int err; 863 char *dsname; 864 865 dsname = kmem_asprintf("%s@%s", name, da->snapname); 866 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds); 867 strfree(dsname); 868 if (err == 0) { 869 struct dsl_ds_destroyarg *dsda; 870 871 dsl_dataset_make_exclusive(ds, da->dstg); 872 if (ds->ds_objset != NULL) { 873 dmu_objset_evict(ds->ds_objset); 874 ds->ds_objset = NULL; 875 } 876 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP); 877 dsda->ds = ds; 878 dsda->defer = da->defer; 879 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check, 880 dsl_dataset_destroy_sync, dsda, da->dstg, 0); 881 } else if (err == ENOENT) { 882 err = 0; 883 } else { 884 (void) strcpy(da->failed, name); 885 } 886 return (err); 887 } 888 889 /* 890 * Destroy 'snapname' in all descendants of 'fsname'. 891 */ 892 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy 893 int 894 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer) 895 { 896 int err; 897 struct destroyarg da; 898 dsl_sync_task_t *dst; 899 spa_t *spa; 900 901 err = spa_open(fsname, &spa, FTAG); 902 if (err) 903 return (err); 904 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 905 da.snapname = snapname; 906 da.failed = fsname; 907 da.defer = defer; 908 909 err = dmu_objset_find(fsname, 910 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN); 911 912 if (err == 0) 913 err = dsl_sync_task_group_wait(da.dstg); 914 915 for (dst = list_head(&da.dstg->dstg_tasks); dst; 916 dst = list_next(&da.dstg->dstg_tasks, dst)) { 917 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 918 dsl_dataset_t *ds = dsda->ds; 919 920 /* 921 * Return the file system name that triggered the error 922 */ 923 if (dst->dst_err) { 924 dsl_dataset_name(ds, fsname); 925 *strchr(fsname, '@') = '\0'; 926 } 927 ASSERT3P(dsda->rm_origin, ==, NULL); 928 dsl_dataset_disown(ds, da.dstg); 929 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 930 } 931 932 dsl_sync_task_group_destroy(da.dstg); 933 spa_close(spa, FTAG); 934 return (err); 935 } 936 937 static boolean_t 938 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 939 { 940 boolean_t might_destroy = B_FALSE; 941 942 mutex_enter(&ds->ds_lock); 943 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 944 DS_IS_DEFER_DESTROY(ds)) 945 might_destroy = B_TRUE; 946 mutex_exit(&ds->ds_lock); 947 948 return (might_destroy); 949 } 950 951 /* 952 * If we're removing a clone, and these three conditions are true: 953 * 1) the clone's origin has no other children 954 * 2) the clone's origin has no user references 955 * 3) the clone's origin has been marked for deferred destruction 956 * Then, prepare to remove the origin as part of this sync task group. 957 */ 958 static int 959 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 960 { 961 dsl_dataset_t *ds = dsda->ds; 962 dsl_dataset_t *origin = ds->ds_prev; 963 964 if (dsl_dataset_might_destroy_origin(origin)) { 965 char *name; 966 int namelen; 967 int error; 968 969 namelen = dsl_dataset_namelen(origin) + 1; 970 name = kmem_alloc(namelen, KM_SLEEP); 971 dsl_dataset_name(origin, name); 972 #ifdef _KERNEL 973 error = zfs_unmount_snap(name, NULL); 974 if (error) { 975 kmem_free(name, namelen); 976 return (error); 977 } 978 #endif 979 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 980 kmem_free(name, namelen); 981 if (error) 982 return (error); 983 dsda->rm_origin = origin; 984 dsl_dataset_make_exclusive(origin, tag); 985 986 if (origin->ds_objset != NULL) { 987 dmu_objset_evict(origin->ds_objset); 988 origin->ds_objset = NULL; 989 } 990 } 991 992 return (0); 993 } 994 995 /* 996 * ds must be opened as OWNER. On return (whether successful or not), 997 * ds will be closed and caller can no longer dereference it. 998 */ 999 int 1000 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1001 { 1002 int err; 1003 dsl_sync_task_group_t *dstg; 1004 objset_t *os; 1005 dsl_dir_t *dd; 1006 uint64_t obj; 1007 struct dsl_ds_destroyarg dsda = { 0 }; 1008 dsl_dataset_t dummy_ds = { 0 }; 1009 1010 dsda.ds = ds; 1011 1012 if (dsl_dataset_is_snapshot(ds)) { 1013 /* Destroying a snapshot is simpler */ 1014 dsl_dataset_make_exclusive(ds, tag); 1015 1016 if (ds->ds_objset != NULL) { 1017 dmu_objset_evict(ds->ds_objset); 1018 ds->ds_objset = NULL; 1019 } 1020 dsda.defer = defer; 1021 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1022 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1023 &dsda, tag, 0); 1024 ASSERT3P(dsda.rm_origin, ==, NULL); 1025 goto out; 1026 } else if (defer) { 1027 err = EINVAL; 1028 goto out; 1029 } 1030 1031 dd = ds->ds_dir; 1032 dummy_ds.ds_dir = dd; 1033 dummy_ds.ds_object = ds->ds_object; 1034 1035 /* 1036 * Check for errors and mark this ds as inconsistent, in 1037 * case we crash while freeing the objects. 1038 */ 1039 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, 1040 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1041 if (err) 1042 goto out; 1043 1044 err = dmu_objset_from_ds(ds, &os); 1045 if (err) 1046 goto out; 1047 1048 /* 1049 * remove the objects in open context, so that we won't 1050 * have too much to do in syncing context. 1051 */ 1052 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1053 ds->ds_phys->ds_prev_snap_txg)) { 1054 /* 1055 * Ignore errors, if there is not enough disk space 1056 * we will deal with it in dsl_dataset_destroy_sync(). 1057 */ 1058 (void) dmu_free_object(os, obj); 1059 } 1060 1061 /* 1062 * We need to sync out all in-flight IO before we try to evict 1063 * (the dataset evict func is trying to clear the cached entries 1064 * for this dataset in the ARC). 1065 */ 1066 txg_wait_synced(dd->dd_pool, 0); 1067 1068 /* 1069 * If we managed to free all the objects in open 1070 * context, the user space accounting should be zero. 1071 */ 1072 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1073 dmu_objset_userused_enabled(os)) { 1074 uint64_t count; 1075 1076 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || 1077 count == 0); 1078 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || 1079 count == 0); 1080 } 1081 1082 if (err != ESRCH) 1083 goto out; 1084 1085 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1086 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1087 rw_exit(&dd->dd_pool->dp_config_rwlock); 1088 1089 if (err) 1090 goto out; 1091 1092 if (ds->ds_objset) { 1093 /* 1094 * We need to sync out all in-flight IO before we try 1095 * to evict (the dataset evict func is trying to clear 1096 * the cached entries for this dataset in the ARC). 1097 */ 1098 txg_wait_synced(dd->dd_pool, 0); 1099 } 1100 1101 /* 1102 * Blow away the dsl_dir + head dataset. 1103 */ 1104 dsl_dataset_make_exclusive(ds, tag); 1105 if (ds->ds_objset) { 1106 dmu_objset_evict(ds->ds_objset); 1107 ds->ds_objset = NULL; 1108 } 1109 1110 /* 1111 * If we're removing a clone, we might also need to remove its 1112 * origin. 1113 */ 1114 do { 1115 dsda.need_prep = B_FALSE; 1116 if (dsl_dir_is_clone(dd)) { 1117 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1118 if (err) { 1119 dsl_dir_close(dd, FTAG); 1120 goto out; 1121 } 1122 } 1123 1124 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1125 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1126 dsl_dataset_destroy_sync, &dsda, tag, 0); 1127 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1128 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0); 1129 err = dsl_sync_task_group_wait(dstg); 1130 dsl_sync_task_group_destroy(dstg); 1131 1132 /* 1133 * We could be racing against 'zfs release' or 'zfs destroy -d' 1134 * on the origin snap, in which case we can get EBUSY if we 1135 * needed to destroy the origin snap but were not ready to 1136 * do so. 1137 */ 1138 if (dsda.need_prep) { 1139 ASSERT(err == EBUSY); 1140 ASSERT(dsl_dir_is_clone(dd)); 1141 ASSERT(dsda.rm_origin == NULL); 1142 } 1143 } while (dsda.need_prep); 1144 1145 if (dsda.rm_origin != NULL) 1146 dsl_dataset_disown(dsda.rm_origin, tag); 1147 1148 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1149 if (err) 1150 dsl_dir_close(dd, FTAG); 1151 out: 1152 dsl_dataset_disown(ds, tag); 1153 return (err); 1154 } 1155 1156 blkptr_t * 1157 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1158 { 1159 return (&ds->ds_phys->ds_bp); 1160 } 1161 1162 void 1163 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1164 { 1165 ASSERT(dmu_tx_is_syncing(tx)); 1166 /* If it's the meta-objset, set dp_meta_rootbp */ 1167 if (ds == NULL) { 1168 tx->tx_pool->dp_meta_rootbp = *bp; 1169 } else { 1170 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1171 ds->ds_phys->ds_bp = *bp; 1172 } 1173 } 1174 1175 spa_t * 1176 dsl_dataset_get_spa(dsl_dataset_t *ds) 1177 { 1178 return (ds->ds_dir->dd_pool->dp_spa); 1179 } 1180 1181 void 1182 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1183 { 1184 dsl_pool_t *dp; 1185 1186 if (ds == NULL) /* this is the meta-objset */ 1187 return; 1188 1189 ASSERT(ds->ds_objset != NULL); 1190 1191 if (ds->ds_phys->ds_next_snap_obj != 0) 1192 panic("dirtying snapshot!"); 1193 1194 dp = ds->ds_dir->dd_pool; 1195 1196 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1197 /* up the hold count until we can be written out */ 1198 dmu_buf_add_ref(ds->ds_dbuf, ds); 1199 } 1200 } 1201 1202 /* 1203 * The unique space in the head dataset can be calculated by subtracting 1204 * the space used in the most recent snapshot, that is still being used 1205 * in this file system, from the space currently in use. To figure out 1206 * the space in the most recent snapshot still in use, we need to take 1207 * the total space used in the snapshot and subtract out the space that 1208 * has been freed up since the snapshot was taken. 1209 */ 1210 static void 1211 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1212 { 1213 uint64_t mrs_used; 1214 uint64_t dlused, dlcomp, dluncomp; 1215 1216 ASSERT(ds->ds_object == ds->ds_dir->dd_phys->dd_head_dataset_obj); 1217 1218 if (ds->ds_phys->ds_prev_snap_obj != 0) 1219 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes; 1220 else 1221 mrs_used = 0; 1222 1223 VERIFY(0 == bplist_space(&ds->ds_deadlist, &dlused, &dlcomp, 1224 &dluncomp)); 1225 1226 ASSERT3U(dlused, <=, mrs_used); 1227 ds->ds_phys->ds_unique_bytes = 1228 ds->ds_phys->ds_used_bytes - (mrs_used - dlused); 1229 1230 if (!DS_UNIQUE_IS_ACCURATE(ds) && 1231 spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1232 SPA_VERSION_UNIQUE_ACCURATE) 1233 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1234 } 1235 1236 static uint64_t 1237 dsl_dataset_unique(dsl_dataset_t *ds) 1238 { 1239 if (!DS_UNIQUE_IS_ACCURATE(ds) && !dsl_dataset_is_snapshot(ds)) 1240 dsl_dataset_recalc_head_uniq(ds); 1241 1242 return (ds->ds_phys->ds_unique_bytes); 1243 } 1244 1245 struct killarg { 1246 dsl_dataset_t *ds; 1247 dmu_tx_t *tx; 1248 }; 1249 1250 /* ARGSUSED */ 1251 static int 1252 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 1253 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1254 { 1255 struct killarg *ka = arg; 1256 dmu_tx_t *tx = ka->tx; 1257 1258 if (bp == NULL) 1259 return (0); 1260 1261 if (zb->zb_level == ZB_ZIL_LEVEL) { 1262 ASSERT(zilog != NULL); 1263 /* 1264 * It's a block in the intent log. It has no 1265 * accounting, so just free it. 1266 */ 1267 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1268 } else { 1269 ASSERT(zilog == NULL); 1270 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1271 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1272 } 1273 1274 return (0); 1275 } 1276 1277 /* ARGSUSED */ 1278 static int 1279 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1280 { 1281 dsl_dataset_t *ds = arg1; 1282 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1283 uint64_t count; 1284 int err; 1285 1286 /* 1287 * Can't delete a head dataset if there are snapshots of it. 1288 * (Except if the only snapshots are from the branch we cloned 1289 * from.) 1290 */ 1291 if (ds->ds_prev != NULL && 1292 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1293 return (EBUSY); 1294 1295 /* 1296 * This is really a dsl_dir thing, but check it here so that 1297 * we'll be less likely to leave this dataset inconsistent & 1298 * nearly destroyed. 1299 */ 1300 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1301 if (err) 1302 return (err); 1303 if (count != 0) 1304 return (EEXIST); 1305 1306 return (0); 1307 } 1308 1309 /* ARGSUSED */ 1310 static void 1311 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 1312 { 1313 dsl_dataset_t *ds = arg1; 1314 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1315 1316 /* Mark it as inconsistent on-disk, in case we crash */ 1317 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1318 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1319 1320 spa_history_internal_log(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx, 1321 cr, "dataset = %llu", ds->ds_object); 1322 } 1323 1324 static int 1325 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1326 dmu_tx_t *tx) 1327 { 1328 dsl_dataset_t *ds = dsda->ds; 1329 dsl_dataset_t *ds_prev = ds->ds_prev; 1330 1331 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1332 struct dsl_ds_destroyarg ndsda = {0}; 1333 1334 /* 1335 * If we're not prepared to remove the origin, don't remove 1336 * the clone either. 1337 */ 1338 if (dsda->rm_origin == NULL) { 1339 dsda->need_prep = B_TRUE; 1340 return (EBUSY); 1341 } 1342 1343 ndsda.ds = ds_prev; 1344 ndsda.is_origin_rm = B_TRUE; 1345 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1346 } 1347 1348 /* 1349 * If we're not going to remove the origin after all, 1350 * undo the open context setup. 1351 */ 1352 if (dsda->rm_origin != NULL) { 1353 dsl_dataset_disown(dsda->rm_origin, tag); 1354 dsda->rm_origin = NULL; 1355 } 1356 1357 return (0); 1358 } 1359 1360 /* ARGSUSED */ 1361 int 1362 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1363 { 1364 struct dsl_ds_destroyarg *dsda = arg1; 1365 dsl_dataset_t *ds = dsda->ds; 1366 1367 /* we have an owner hold, so noone else can destroy us */ 1368 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1369 1370 /* 1371 * Only allow deferred destroy on pools that support it. 1372 * NOTE: deferred destroy is only supported on snapshots. 1373 */ 1374 if (dsda->defer) { 1375 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1376 SPA_VERSION_USERREFS) 1377 return (ENOTSUP); 1378 ASSERT(dsl_dataset_is_snapshot(ds)); 1379 return (0); 1380 } 1381 1382 /* 1383 * Can't delete a head dataset if there are snapshots of it. 1384 * (Except if the only snapshots are from the branch we cloned 1385 * from.) 1386 */ 1387 if (ds->ds_prev != NULL && 1388 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1389 return (EBUSY); 1390 1391 /* 1392 * If we made changes this txg, traverse_dsl_dataset won't find 1393 * them. Try again. 1394 */ 1395 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1396 return (EAGAIN); 1397 1398 if (dsl_dataset_is_snapshot(ds)) { 1399 /* 1400 * If this snapshot has an elevated user reference count, 1401 * we can't destroy it yet. 1402 */ 1403 if (ds->ds_userrefs > 0 && !dsda->releasing) 1404 return (EBUSY); 1405 1406 mutex_enter(&ds->ds_lock); 1407 /* 1408 * Can't delete a branch point. However, if we're destroying 1409 * a clone and removing its origin due to it having a user 1410 * hold count of 0 and having been marked for deferred destroy, 1411 * it's OK for the origin to have a single clone. 1412 */ 1413 if (ds->ds_phys->ds_num_children > 1414 (dsda->is_origin_rm ? 2 : 1)) { 1415 mutex_exit(&ds->ds_lock); 1416 return (EEXIST); 1417 } 1418 mutex_exit(&ds->ds_lock); 1419 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1420 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1421 } 1422 1423 /* XXX we should do some i/o error checking... */ 1424 return (0); 1425 } 1426 1427 struct refsarg { 1428 kmutex_t lock; 1429 boolean_t gone; 1430 kcondvar_t cv; 1431 }; 1432 1433 /* ARGSUSED */ 1434 static void 1435 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1436 { 1437 struct refsarg *arg = argv; 1438 1439 mutex_enter(&arg->lock); 1440 arg->gone = TRUE; 1441 cv_signal(&arg->cv); 1442 mutex_exit(&arg->lock); 1443 } 1444 1445 static void 1446 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1447 { 1448 struct refsarg arg; 1449 1450 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1451 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1452 arg.gone = FALSE; 1453 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1454 dsl_dataset_refs_gone); 1455 dmu_buf_rele(ds->ds_dbuf, tag); 1456 mutex_enter(&arg.lock); 1457 while (!arg.gone) 1458 cv_wait(&arg.cv, &arg.lock); 1459 ASSERT(arg.gone); 1460 mutex_exit(&arg.lock); 1461 ds->ds_dbuf = NULL; 1462 ds->ds_phys = NULL; 1463 mutex_destroy(&arg.lock); 1464 cv_destroy(&arg.cv); 1465 } 1466 1467 static void 1468 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1469 { 1470 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1471 uint64_t count; 1472 int err; 1473 1474 ASSERT(ds->ds_phys->ds_num_children >= 2); 1475 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1476 /* 1477 * The err should not be ENOENT, but a bug in a previous version 1478 * of the code could cause upgrade_clones_cb() to not set 1479 * ds_next_snap_obj when it should, leading to a missing entry. 1480 * If we knew that the pool was created after 1481 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1482 * ENOENT. However, at least we can check that we don't have 1483 * too many entries in the next_clones_obj even after failing to 1484 * remove this one. 1485 */ 1486 if (err != ENOENT) { 1487 VERIFY3U(err, ==, 0); 1488 } 1489 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1490 &count)); 1491 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1492 } 1493 1494 void 1495 dsl_dataset_destroy_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 1496 { 1497 struct dsl_ds_destroyarg *dsda = arg1; 1498 dsl_dataset_t *ds = dsda->ds; 1499 int err; 1500 int after_branch_point = FALSE; 1501 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1502 objset_t *mos = dp->dp_meta_objset; 1503 dsl_dataset_t *ds_prev = NULL; 1504 uint64_t obj; 1505 1506 ASSERT(ds->ds_owner); 1507 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1508 ASSERT(ds->ds_prev == NULL || 1509 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1510 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1511 1512 if (dsda->defer) { 1513 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1514 if (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1) { 1515 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1516 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1517 return; 1518 } 1519 } 1520 1521 /* signal any waiters that this dataset is going away */ 1522 mutex_enter(&ds->ds_lock); 1523 ds->ds_owner = dsl_reaper; 1524 cv_broadcast(&ds->ds_exclusive_cv); 1525 mutex_exit(&ds->ds_lock); 1526 1527 /* Remove our reservation */ 1528 if (ds->ds_reserved != 0) { 1529 dsl_prop_setarg_t psa; 1530 uint64_t value = 0; 1531 1532 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1533 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1534 &value); 1535 psa.psa_effective_value = 0; /* predict default value */ 1536 1537 dsl_dataset_set_reservation_sync(ds, &psa, cr, tx); 1538 ASSERT3U(ds->ds_reserved, ==, 0); 1539 } 1540 1541 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1542 1543 dsl_pool_ds_destroyed(ds, tx); 1544 1545 obj = ds->ds_object; 1546 1547 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1548 if (ds->ds_prev) { 1549 ds_prev = ds->ds_prev; 1550 } else { 1551 VERIFY(0 == dsl_dataset_hold_obj(dp, 1552 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1553 } 1554 after_branch_point = 1555 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1556 1557 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1558 if (after_branch_point && 1559 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1560 remove_from_next_clones(ds_prev, obj, tx); 1561 if (ds->ds_phys->ds_next_snap_obj != 0) { 1562 VERIFY(0 == zap_add_int(mos, 1563 ds_prev->ds_phys->ds_next_clones_obj, 1564 ds->ds_phys->ds_next_snap_obj, tx)); 1565 } 1566 } 1567 if (after_branch_point && 1568 ds->ds_phys->ds_next_snap_obj == 0) { 1569 /* This clone is toast. */ 1570 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1571 ds_prev->ds_phys->ds_num_children--; 1572 1573 /* 1574 * If the clone's origin has no other clones, no 1575 * user holds, and has been marked for deferred 1576 * deletion, then we should have done the necessary 1577 * destroy setup for it. 1578 */ 1579 if (ds_prev->ds_phys->ds_num_children == 1 && 1580 ds_prev->ds_userrefs == 0 && 1581 DS_IS_DEFER_DESTROY(ds_prev)) { 1582 ASSERT3P(dsda->rm_origin, !=, NULL); 1583 } else { 1584 ASSERT3P(dsda->rm_origin, ==, NULL); 1585 } 1586 } else if (!after_branch_point) { 1587 ds_prev->ds_phys->ds_next_snap_obj = 1588 ds->ds_phys->ds_next_snap_obj; 1589 } 1590 } 1591 1592 if (ds->ds_phys->ds_next_snap_obj != 0) { 1593 blkptr_t bp; 1594 dsl_dataset_t *ds_next; 1595 uint64_t itor = 0; 1596 uint64_t old_unique; 1597 int64_t used = 0, compressed = 0, uncompressed = 0; 1598 1599 VERIFY(0 == dsl_dataset_hold_obj(dp, 1600 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1601 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1602 1603 old_unique = dsl_dataset_unique(ds_next); 1604 1605 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1606 ds_next->ds_phys->ds_prev_snap_obj = 1607 ds->ds_phys->ds_prev_snap_obj; 1608 ds_next->ds_phys->ds_prev_snap_txg = 1609 ds->ds_phys->ds_prev_snap_txg; 1610 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1611 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1612 1613 /* 1614 * Transfer to our deadlist (which will become next's 1615 * new deadlist) any entries from next's current 1616 * deadlist which were born before prev, and free the 1617 * other entries. 1618 * 1619 * XXX we're doing this long task with the config lock held 1620 */ 1621 while (bplist_iterate(&ds_next->ds_deadlist, &itor, &bp) == 0) { 1622 if (bp.blk_birth <= ds->ds_phys->ds_prev_snap_txg) { 1623 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, 1624 &bp, tx)); 1625 if (ds_prev && !after_branch_point && 1626 bp.blk_birth > 1627 ds_prev->ds_phys->ds_prev_snap_txg) { 1628 ds_prev->ds_phys->ds_unique_bytes += 1629 bp_get_dsize_sync(dp->dp_spa, &bp); 1630 } 1631 } else { 1632 used += bp_get_dsize_sync(dp->dp_spa, &bp); 1633 compressed += BP_GET_PSIZE(&bp); 1634 uncompressed += BP_GET_UCSIZE(&bp); 1635 dsl_free(dp, tx->tx_txg, &bp); 1636 } 1637 } 1638 1639 ASSERT3U(used, ==, ds->ds_phys->ds_unique_bytes); 1640 1641 /* change snapused */ 1642 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1643 -used, -compressed, -uncompressed, tx); 1644 1645 /* free next's deadlist */ 1646 bplist_close(&ds_next->ds_deadlist); 1647 bplist_destroy(mos, ds_next->ds_phys->ds_deadlist_obj, tx); 1648 1649 /* set next's deadlist to our deadlist */ 1650 bplist_close(&ds->ds_deadlist); 1651 ds_next->ds_phys->ds_deadlist_obj = 1652 ds->ds_phys->ds_deadlist_obj; 1653 VERIFY(0 == bplist_open(&ds_next->ds_deadlist, mos, 1654 ds_next->ds_phys->ds_deadlist_obj)); 1655 ds->ds_phys->ds_deadlist_obj = 0; 1656 1657 if (ds_next->ds_phys->ds_next_snap_obj != 0) { 1658 /* 1659 * Update next's unique to include blocks which 1660 * were previously shared by only this snapshot 1661 * and it. Those blocks will be born after the 1662 * prev snap and before this snap, and will have 1663 * died after the next snap and before the one 1664 * after that (ie. be on the snap after next's 1665 * deadlist). 1666 * 1667 * XXX we're doing this long task with the 1668 * config lock held 1669 */ 1670 dsl_dataset_t *ds_after_next; 1671 uint64_t space; 1672 1673 VERIFY(0 == dsl_dataset_hold_obj(dp, 1674 ds_next->ds_phys->ds_next_snap_obj, 1675 FTAG, &ds_after_next)); 1676 1677 VERIFY(0 == 1678 bplist_space_birthrange(&ds_after_next->ds_deadlist, 1679 ds->ds_phys->ds_prev_snap_txg, 1680 ds->ds_phys->ds_creation_txg, &space)); 1681 ds_next->ds_phys->ds_unique_bytes += space; 1682 1683 dsl_dataset_rele(ds_after_next, FTAG); 1684 ASSERT3P(ds_next->ds_prev, ==, NULL); 1685 } else { 1686 ASSERT3P(ds_next->ds_prev, ==, ds); 1687 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1688 ds_next->ds_prev = NULL; 1689 if (ds_prev) { 1690 VERIFY(0 == dsl_dataset_get_ref(dp, 1691 ds->ds_phys->ds_prev_snap_obj, 1692 ds_next, &ds_next->ds_prev)); 1693 } 1694 1695 dsl_dataset_recalc_head_uniq(ds_next); 1696 1697 /* 1698 * Reduce the amount of our unconsmed refreservation 1699 * being charged to our parent by the amount of 1700 * new unique data we have gained. 1701 */ 1702 if (old_unique < ds_next->ds_reserved) { 1703 int64_t mrsdelta; 1704 uint64_t new_unique = 1705 ds_next->ds_phys->ds_unique_bytes; 1706 1707 ASSERT(old_unique <= new_unique); 1708 mrsdelta = MIN(new_unique - old_unique, 1709 ds_next->ds_reserved - old_unique); 1710 dsl_dir_diduse_space(ds->ds_dir, 1711 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1712 } 1713 } 1714 dsl_dataset_rele(ds_next, FTAG); 1715 } else { 1716 /* 1717 * There's no next snapshot, so this is a head dataset. 1718 * Destroy the deadlist. Unless it's a clone, the 1719 * deadlist should be empty. (If it's a clone, it's 1720 * safe to ignore the deadlist contents.) 1721 */ 1722 struct killarg ka; 1723 1724 ASSERT(after_branch_point || bplist_empty(&ds->ds_deadlist)); 1725 bplist_close(&ds->ds_deadlist); 1726 bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx); 1727 ds->ds_phys->ds_deadlist_obj = 0; 1728 1729 /* 1730 * Free everything that we point to (that's born after 1731 * the previous snapshot, if we are a clone) 1732 * 1733 * NB: this should be very quick, because we already 1734 * freed all the objects in open context. 1735 */ 1736 ka.ds = ds; 1737 ka.tx = tx; 1738 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, 1739 TRAVERSE_POST, kill_blkptr, &ka); 1740 ASSERT3U(err, ==, 0); 1741 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1742 ds->ds_phys->ds_unique_bytes == 0); 1743 1744 if (ds->ds_prev != NULL) { 1745 dsl_dataset_rele(ds->ds_prev, ds); 1746 ds->ds_prev = ds_prev = NULL; 1747 } 1748 } 1749 1750 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1751 /* Erase the link in the dir */ 1752 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1753 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1754 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1755 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1756 ASSERT(err == 0); 1757 } else { 1758 /* remove from snapshot namespace */ 1759 dsl_dataset_t *ds_head; 1760 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1761 VERIFY(0 == dsl_dataset_hold_obj(dp, 1762 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1763 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1764 #ifdef ZFS_DEBUG 1765 { 1766 uint64_t val; 1767 1768 err = dsl_dataset_snap_lookup(ds_head, 1769 ds->ds_snapname, &val); 1770 ASSERT3U(err, ==, 0); 1771 ASSERT3U(val, ==, obj); 1772 } 1773 #endif 1774 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1775 ASSERT(err == 0); 1776 dsl_dataset_rele(ds_head, FTAG); 1777 } 1778 1779 if (ds_prev && ds->ds_prev != ds_prev) 1780 dsl_dataset_rele(ds_prev, FTAG); 1781 1782 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1783 spa_history_internal_log(LOG_DS_DESTROY, dp->dp_spa, tx, 1784 cr, "dataset = %llu", ds->ds_object); 1785 1786 if (ds->ds_phys->ds_next_clones_obj != 0) { 1787 uint64_t count; 1788 ASSERT(0 == zap_count(mos, 1789 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1790 VERIFY(0 == dmu_object_free(mos, 1791 ds->ds_phys->ds_next_clones_obj, tx)); 1792 } 1793 if (ds->ds_phys->ds_props_obj != 0) 1794 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1795 if (ds->ds_phys->ds_userrefs_obj != 0) 1796 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1797 dsl_dir_close(ds->ds_dir, ds); 1798 ds->ds_dir = NULL; 1799 dsl_dataset_drain_refs(ds, tag); 1800 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1801 1802 if (dsda->rm_origin) { 1803 /* 1804 * Remove the origin of the clone we just destroyed. 1805 */ 1806 struct dsl_ds_destroyarg ndsda = {0}; 1807 1808 ndsda.ds = dsda->rm_origin; 1809 dsl_dataset_destroy_sync(&ndsda, tag, cr, tx); 1810 } 1811 } 1812 1813 static int 1814 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1815 { 1816 uint64_t asize; 1817 1818 if (!dmu_tx_is_syncing(tx)) 1819 return (0); 1820 1821 /* 1822 * If there's an fs-only reservation, any blocks that might become 1823 * owned by the snapshot dataset must be accommodated by space 1824 * outside of the reservation. 1825 */ 1826 asize = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1827 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE)) 1828 return (ENOSPC); 1829 1830 /* 1831 * Propogate any reserved space for this snapshot to other 1832 * snapshot checks in this sync group. 1833 */ 1834 if (asize > 0) 1835 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 1836 1837 return (0); 1838 } 1839 1840 /* ARGSUSED */ 1841 int 1842 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 1843 { 1844 dsl_dataset_t *ds = arg1; 1845 const char *snapname = arg2; 1846 int err; 1847 uint64_t value; 1848 1849 /* 1850 * We don't allow multiple snapshots of the same txg. If there 1851 * is already one, try again. 1852 */ 1853 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 1854 return (EAGAIN); 1855 1856 /* 1857 * Check for conflicting name snapshot name. 1858 */ 1859 err = dsl_dataset_snap_lookup(ds, snapname, &value); 1860 if (err == 0) 1861 return (EEXIST); 1862 if (err != ENOENT) 1863 return (err); 1864 1865 /* 1866 * Check that the dataset's name is not too long. Name consists 1867 * of the dataset's length + 1 for the @-sign + snapshot name's length 1868 */ 1869 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 1870 return (ENAMETOOLONG); 1871 1872 err = dsl_dataset_snapshot_reserve_space(ds, tx); 1873 if (err) 1874 return (err); 1875 1876 ds->ds_trysnap_txg = tx->tx_txg; 1877 return (0); 1878 } 1879 1880 void 1881 dsl_dataset_snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 1882 { 1883 dsl_dataset_t *ds = arg1; 1884 const char *snapname = arg2; 1885 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1886 dmu_buf_t *dbuf; 1887 dsl_dataset_phys_t *dsphys; 1888 uint64_t dsobj, crtxg; 1889 objset_t *mos = dp->dp_meta_objset; 1890 int err; 1891 1892 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1893 1894 /* 1895 * The origin's ds_creation_txg has to be < TXG_INITIAL 1896 */ 1897 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 1898 crtxg = 1; 1899 else 1900 crtxg = tx->tx_txg; 1901 1902 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 1903 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 1904 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 1905 dmu_buf_will_dirty(dbuf, tx); 1906 dsphys = dbuf->db_data; 1907 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 1908 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 1909 dsphys->ds_fsid_guid = unique_create(); 1910 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 1911 sizeof (dsphys->ds_guid)); 1912 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 1913 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 1914 dsphys->ds_next_snap_obj = ds->ds_object; 1915 dsphys->ds_num_children = 1; 1916 dsphys->ds_creation_time = gethrestime_sec(); 1917 dsphys->ds_creation_txg = crtxg; 1918 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 1919 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes; 1920 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 1921 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 1922 dsphys->ds_flags = ds->ds_phys->ds_flags; 1923 dsphys->ds_bp = ds->ds_phys->ds_bp; 1924 dmu_buf_rele(dbuf, FTAG); 1925 1926 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 1927 if (ds->ds_prev) { 1928 uint64_t next_clones_obj = 1929 ds->ds_prev->ds_phys->ds_next_clones_obj; 1930 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 1931 ds->ds_object || 1932 ds->ds_prev->ds_phys->ds_num_children > 1); 1933 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 1934 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 1935 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1936 ds->ds_prev->ds_phys->ds_creation_txg); 1937 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 1938 } else if (next_clones_obj != 0) { 1939 remove_from_next_clones(ds->ds_prev, 1940 dsphys->ds_next_snap_obj, tx); 1941 VERIFY3U(0, ==, zap_add_int(mos, 1942 next_clones_obj, dsobj, tx)); 1943 } 1944 } 1945 1946 /* 1947 * If we have a reference-reservation on this dataset, we will 1948 * need to increase the amount of refreservation being charged 1949 * since our unique space is going to zero. 1950 */ 1951 if (ds->ds_reserved) { 1952 int64_t add = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1953 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 1954 add, 0, 0, tx); 1955 } 1956 1957 bplist_close(&ds->ds_deadlist); 1958 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1959 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 1960 ds->ds_phys->ds_prev_snap_obj = dsobj; 1961 ds->ds_phys->ds_prev_snap_txg = crtxg; 1962 ds->ds_phys->ds_unique_bytes = 0; 1963 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 1964 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1965 ds->ds_phys->ds_deadlist_obj = 1966 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx); 1967 VERIFY(0 == bplist_open(&ds->ds_deadlist, mos, 1968 ds->ds_phys->ds_deadlist_obj)); 1969 1970 dprintf("snap '%s' -> obj %llu\n", snapname, dsobj); 1971 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 1972 snapname, 8, 1, &dsobj, tx); 1973 ASSERT(err == 0); 1974 1975 if (ds->ds_prev) 1976 dsl_dataset_drop_ref(ds->ds_prev, ds); 1977 VERIFY(0 == dsl_dataset_get_ref(dp, 1978 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 1979 1980 dsl_pool_ds_snapshotted(ds, tx); 1981 1982 dsl_dir_snap_cmtime_update(ds->ds_dir); 1983 1984 spa_history_internal_log(LOG_DS_SNAPSHOT, dp->dp_spa, tx, cr, 1985 "dataset = %llu", dsobj); 1986 } 1987 1988 void 1989 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 1990 { 1991 ASSERT(dmu_tx_is_syncing(tx)); 1992 ASSERT(ds->ds_objset != NULL); 1993 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 1994 1995 /* 1996 * in case we had to change ds_fsid_guid when we opened it, 1997 * sync it out now. 1998 */ 1999 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2000 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2001 2002 dsl_dir_dirty(ds->ds_dir, tx); 2003 dmu_objset_sync(ds->ds_objset, zio, tx); 2004 } 2005 2006 void 2007 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2008 { 2009 uint64_t refd, avail, uobjs, aobjs; 2010 2011 dsl_dir_stats(ds->ds_dir, nv); 2012 2013 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2014 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2015 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2016 2017 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2018 ds->ds_phys->ds_creation_time); 2019 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2020 ds->ds_phys->ds_creation_txg); 2021 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2022 ds->ds_quota); 2023 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2024 ds->ds_reserved); 2025 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2026 ds->ds_phys->ds_guid); 2027 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2028 dsl_dataset_unique(ds)); 2029 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2030 ds->ds_object); 2031 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2032 ds->ds_userrefs); 2033 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2034 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2035 2036 if (ds->ds_phys->ds_next_snap_obj) { 2037 /* 2038 * This is a snapshot; override the dd's space used with 2039 * our unique space and compression ratio. 2040 */ 2041 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2042 ds->ds_phys->ds_unique_bytes); 2043 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, 2044 ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2045 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2046 ds->ds_phys->ds_compressed_bytes)); 2047 } 2048 } 2049 2050 void 2051 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2052 { 2053 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2054 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2055 stat->dds_guid = ds->ds_phys->ds_guid; 2056 if (ds->ds_phys->ds_next_snap_obj) { 2057 stat->dds_is_snapshot = B_TRUE; 2058 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2059 } else { 2060 stat->dds_is_snapshot = B_FALSE; 2061 stat->dds_num_clones = 0; 2062 } 2063 2064 /* clone origin is really a dsl_dir thing... */ 2065 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2066 if (dsl_dir_is_clone(ds->ds_dir)) { 2067 dsl_dataset_t *ods; 2068 2069 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2070 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2071 dsl_dataset_name(ods, stat->dds_origin); 2072 dsl_dataset_drop_ref(ods, FTAG); 2073 } else { 2074 stat->dds_origin[0] = '\0'; 2075 } 2076 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2077 } 2078 2079 uint64_t 2080 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2081 { 2082 return (ds->ds_fsid_guid); 2083 } 2084 2085 void 2086 dsl_dataset_space(dsl_dataset_t *ds, 2087 uint64_t *refdbytesp, uint64_t *availbytesp, 2088 uint64_t *usedobjsp, uint64_t *availobjsp) 2089 { 2090 *refdbytesp = ds->ds_phys->ds_used_bytes; 2091 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2092 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2093 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2094 if (ds->ds_quota != 0) { 2095 /* 2096 * Adjust available bytes according to refquota 2097 */ 2098 if (*refdbytesp < ds->ds_quota) 2099 *availbytesp = MIN(*availbytesp, 2100 ds->ds_quota - *refdbytesp); 2101 else 2102 *availbytesp = 0; 2103 } 2104 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2105 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2106 } 2107 2108 boolean_t 2109 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2110 { 2111 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2112 2113 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2114 dsl_pool_sync_context(dp)); 2115 if (ds->ds_prev == NULL) 2116 return (B_FALSE); 2117 if (ds->ds_phys->ds_bp.blk_birth > 2118 ds->ds_prev->ds_phys->ds_creation_txg) 2119 return (B_TRUE); 2120 return (B_FALSE); 2121 } 2122 2123 /* ARGSUSED */ 2124 static int 2125 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2126 { 2127 dsl_dataset_t *ds = arg1; 2128 char *newsnapname = arg2; 2129 dsl_dir_t *dd = ds->ds_dir; 2130 dsl_dataset_t *hds; 2131 uint64_t val; 2132 int err; 2133 2134 err = dsl_dataset_hold_obj(dd->dd_pool, 2135 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2136 if (err) 2137 return (err); 2138 2139 /* new name better not be in use */ 2140 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2141 dsl_dataset_rele(hds, FTAG); 2142 2143 if (err == 0) 2144 err = EEXIST; 2145 else if (err == ENOENT) 2146 err = 0; 2147 2148 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2149 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2150 err = ENAMETOOLONG; 2151 2152 return (err); 2153 } 2154 2155 static void 2156 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, 2157 cred_t *cr, dmu_tx_t *tx) 2158 { 2159 dsl_dataset_t *ds = arg1; 2160 const char *newsnapname = arg2; 2161 dsl_dir_t *dd = ds->ds_dir; 2162 objset_t *mos = dd->dd_pool->dp_meta_objset; 2163 dsl_dataset_t *hds; 2164 int err; 2165 2166 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2167 2168 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2169 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2170 2171 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2172 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2173 ASSERT3U(err, ==, 0); 2174 mutex_enter(&ds->ds_lock); 2175 (void) strcpy(ds->ds_snapname, newsnapname); 2176 mutex_exit(&ds->ds_lock); 2177 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2178 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2179 ASSERT3U(err, ==, 0); 2180 2181 spa_history_internal_log(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2182 cr, "dataset = %llu", ds->ds_object); 2183 dsl_dataset_rele(hds, FTAG); 2184 } 2185 2186 struct renamesnaparg { 2187 dsl_sync_task_group_t *dstg; 2188 char failed[MAXPATHLEN]; 2189 char *oldsnap; 2190 char *newsnap; 2191 }; 2192 2193 static int 2194 dsl_snapshot_rename_one(char *name, void *arg) 2195 { 2196 struct renamesnaparg *ra = arg; 2197 dsl_dataset_t *ds = NULL; 2198 char *cp; 2199 int err; 2200 2201 cp = name + strlen(name); 2202 *cp = '@'; 2203 (void) strcpy(cp + 1, ra->oldsnap); 2204 2205 /* 2206 * For recursive snapshot renames the parent won't be changing 2207 * so we just pass name for both the to/from argument. 2208 */ 2209 err = zfs_secpolicy_rename_perms(name, name, CRED()); 2210 if (err == ENOENT) { 2211 return (0); 2212 } else if (err) { 2213 (void) strcpy(ra->failed, name); 2214 return (err); 2215 } 2216 2217 #ifdef _KERNEL 2218 /* 2219 * For all filesystems undergoing rename, we'll need to unmount it. 2220 */ 2221 (void) zfs_unmount_snap(name, NULL); 2222 #endif 2223 err = dsl_dataset_hold(name, ra->dstg, &ds); 2224 *cp = '\0'; 2225 if (err == ENOENT) { 2226 return (0); 2227 } else if (err) { 2228 (void) strcpy(ra->failed, name); 2229 return (err); 2230 } 2231 2232 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2233 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2234 2235 return (0); 2236 } 2237 2238 static int 2239 dsl_recursive_rename(char *oldname, const char *newname) 2240 { 2241 int err; 2242 struct renamesnaparg *ra; 2243 dsl_sync_task_t *dst; 2244 spa_t *spa; 2245 char *cp, *fsname = spa_strdup(oldname); 2246 int len = strlen(oldname); 2247 2248 /* truncate the snapshot name to get the fsname */ 2249 cp = strchr(fsname, '@'); 2250 *cp = '\0'; 2251 2252 err = spa_open(fsname, &spa, FTAG); 2253 if (err) { 2254 kmem_free(fsname, len + 1); 2255 return (err); 2256 } 2257 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2258 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2259 2260 ra->oldsnap = strchr(oldname, '@') + 1; 2261 ra->newsnap = strchr(newname, '@') + 1; 2262 *ra->failed = '\0'; 2263 2264 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2265 DS_FIND_CHILDREN); 2266 kmem_free(fsname, len + 1); 2267 2268 if (err == 0) { 2269 err = dsl_sync_task_group_wait(ra->dstg); 2270 } 2271 2272 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2273 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2274 dsl_dataset_t *ds = dst->dst_arg1; 2275 if (dst->dst_err) { 2276 dsl_dir_name(ds->ds_dir, ra->failed); 2277 (void) strcat(ra->failed, "@"); 2278 (void) strcat(ra->failed, ra->newsnap); 2279 } 2280 dsl_dataset_rele(ds, ra->dstg); 2281 } 2282 2283 if (err) 2284 (void) strcpy(oldname, ra->failed); 2285 2286 dsl_sync_task_group_destroy(ra->dstg); 2287 kmem_free(ra, sizeof (struct renamesnaparg)); 2288 spa_close(spa, FTAG); 2289 return (err); 2290 } 2291 2292 static int 2293 dsl_valid_rename(char *oldname, void *arg) 2294 { 2295 int delta = *(int *)arg; 2296 2297 if (strlen(oldname) + delta >= MAXNAMELEN) 2298 return (ENAMETOOLONG); 2299 2300 return (0); 2301 } 2302 2303 #pragma weak dmu_objset_rename = dsl_dataset_rename 2304 int 2305 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2306 { 2307 dsl_dir_t *dd; 2308 dsl_dataset_t *ds; 2309 const char *tail; 2310 int err; 2311 2312 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2313 if (err) 2314 return (err); 2315 /* 2316 * If there are more than 2 references there may be holds 2317 * hanging around that haven't been cleared out yet. 2318 */ 2319 if (dmu_buf_refcount(dd->dd_dbuf) > 2) 2320 txg_wait_synced(dd->dd_pool, 0); 2321 if (tail == NULL) { 2322 int delta = strlen(newname) - strlen(oldname); 2323 2324 /* if we're growing, validate child name lengths */ 2325 if (delta > 0) 2326 err = dmu_objset_find(oldname, dsl_valid_rename, 2327 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2328 2329 if (!err) 2330 err = dsl_dir_rename(dd, newname); 2331 dsl_dir_close(dd, FTAG); 2332 return (err); 2333 } 2334 if (tail[0] != '@') { 2335 /* the name ended in a nonexistent component */ 2336 dsl_dir_close(dd, FTAG); 2337 return (ENOENT); 2338 } 2339 2340 dsl_dir_close(dd, FTAG); 2341 2342 /* new name must be snapshot in same filesystem */ 2343 tail = strchr(newname, '@'); 2344 if (tail == NULL) 2345 return (EINVAL); 2346 tail++; 2347 if (strncmp(oldname, newname, tail - newname) != 0) 2348 return (EXDEV); 2349 2350 if (recursive) { 2351 err = dsl_recursive_rename(oldname, newname); 2352 } else { 2353 err = dsl_dataset_hold(oldname, FTAG, &ds); 2354 if (err) 2355 return (err); 2356 2357 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2358 dsl_dataset_snapshot_rename_check, 2359 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2360 2361 dsl_dataset_rele(ds, FTAG); 2362 } 2363 2364 return (err); 2365 } 2366 2367 struct promotenode { 2368 list_node_t link; 2369 dsl_dataset_t *ds; 2370 }; 2371 2372 struct promotearg { 2373 list_t shared_snaps, origin_snaps, clone_snaps; 2374 dsl_dataset_t *origin_origin, *origin_head; 2375 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2376 char *err_ds; 2377 }; 2378 2379 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2380 2381 /* ARGSUSED */ 2382 static int 2383 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2384 { 2385 dsl_dataset_t *hds = arg1; 2386 struct promotearg *pa = arg2; 2387 struct promotenode *snap = list_head(&pa->shared_snaps); 2388 dsl_dataset_t *origin_ds = snap->ds; 2389 int err; 2390 2391 /* Check that it is a real clone */ 2392 if (!dsl_dir_is_clone(hds->ds_dir)) 2393 return (EINVAL); 2394 2395 /* Since this is so expensive, don't do the preliminary check */ 2396 if (!dmu_tx_is_syncing(tx)) 2397 return (0); 2398 2399 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2400 return (EXDEV); 2401 2402 /* compute origin's new unique space */ 2403 snap = list_tail(&pa->clone_snaps); 2404 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2405 err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2406 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &pa->unique); 2407 if (err) 2408 return (err); 2409 2410 /* 2411 * Walk the snapshots that we are moving 2412 * 2413 * Compute space to transfer. Consider the incremental changes 2414 * to used for each snapshot: 2415 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2416 * So each snapshot gave birth to: 2417 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2418 * So a sequence would look like: 2419 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2420 * Which simplifies to: 2421 * uN + kN + kN-1 + ... + k1 + k0 2422 * Note however, if we stop before we reach the ORIGIN we get: 2423 * uN + kN + kN-1 + ... + kM - uM-1 2424 */ 2425 pa->used = origin_ds->ds_phys->ds_used_bytes; 2426 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2427 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2428 for (snap = list_head(&pa->shared_snaps); snap; 2429 snap = list_next(&pa->shared_snaps, snap)) { 2430 uint64_t val, dlused, dlcomp, dluncomp; 2431 dsl_dataset_t *ds = snap->ds; 2432 2433 /* Check that the snapshot name does not conflict */ 2434 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2435 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2436 if (err == 0) { 2437 err = EEXIST; 2438 goto out; 2439 } 2440 if (err != ENOENT) 2441 goto out; 2442 2443 /* The very first snapshot does not have a deadlist */ 2444 if (ds->ds_phys->ds_prev_snap_obj == 0) 2445 continue; 2446 2447 if (err = bplist_space(&ds->ds_deadlist, 2448 &dlused, &dlcomp, &dluncomp)) 2449 goto out; 2450 pa->used += dlused; 2451 pa->comp += dlcomp; 2452 pa->uncomp += dluncomp; 2453 } 2454 2455 /* 2456 * If we are a clone of a clone then we never reached ORIGIN, 2457 * so we need to subtract out the clone origin's used space. 2458 */ 2459 if (pa->origin_origin) { 2460 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes; 2461 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2462 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2463 } 2464 2465 /* Check that there is enough space here */ 2466 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2467 pa->used); 2468 if (err) 2469 return (err); 2470 2471 /* 2472 * Compute the amounts of space that will be used by snapshots 2473 * after the promotion (for both origin and clone). For each, 2474 * it is the amount of space that will be on all of their 2475 * deadlists (that was not born before their new origin). 2476 */ 2477 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2478 uint64_t space; 2479 2480 /* 2481 * Note, typically this will not be a clone of a clone, 2482 * so snap->ds->ds_origin_txg will be < TXG_INITIAL, so 2483 * these snaplist_space() -> bplist_space_birthrange() 2484 * calls will be fast because they do not have to 2485 * iterate over all bps. 2486 */ 2487 snap = list_head(&pa->origin_snaps); 2488 err = snaplist_space(&pa->shared_snaps, 2489 snap->ds->ds_origin_txg, &pa->cloneusedsnap); 2490 if (err) 2491 return (err); 2492 2493 err = snaplist_space(&pa->clone_snaps, 2494 snap->ds->ds_origin_txg, &space); 2495 if (err) 2496 return (err); 2497 pa->cloneusedsnap += space; 2498 } 2499 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2500 err = snaplist_space(&pa->origin_snaps, 2501 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2502 if (err) 2503 return (err); 2504 } 2505 2506 return (0); 2507 out: 2508 pa->err_ds = snap->ds->ds_snapname; 2509 return (err); 2510 } 2511 2512 static void 2513 dsl_dataset_promote_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2514 { 2515 dsl_dataset_t *hds = arg1; 2516 struct promotearg *pa = arg2; 2517 struct promotenode *snap = list_head(&pa->shared_snaps); 2518 dsl_dataset_t *origin_ds = snap->ds; 2519 dsl_dataset_t *origin_head; 2520 dsl_dir_t *dd = hds->ds_dir; 2521 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2522 dsl_dir_t *odd = NULL; 2523 uint64_t oldnext_obj; 2524 int64_t delta; 2525 2526 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2527 2528 snap = list_head(&pa->origin_snaps); 2529 origin_head = snap->ds; 2530 2531 /* 2532 * We need to explicitly open odd, since origin_ds's dd will be 2533 * changing. 2534 */ 2535 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2536 NULL, FTAG, &odd)); 2537 2538 /* change origin's next snap */ 2539 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2540 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2541 snap = list_tail(&pa->clone_snaps); 2542 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2543 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2544 2545 /* change the origin's next clone */ 2546 if (origin_ds->ds_phys->ds_next_clones_obj) { 2547 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2548 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2549 origin_ds->ds_phys->ds_next_clones_obj, 2550 oldnext_obj, tx)); 2551 } 2552 2553 /* change origin */ 2554 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2555 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2556 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2557 hds->ds_origin_txg = origin_head->ds_origin_txg; 2558 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2559 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2560 origin_head->ds_origin_txg = origin_ds->ds_phys->ds_creation_txg; 2561 2562 /* move snapshots to this dir */ 2563 for (snap = list_head(&pa->shared_snaps); snap; 2564 snap = list_next(&pa->shared_snaps, snap)) { 2565 dsl_dataset_t *ds = snap->ds; 2566 2567 /* unregister props as dsl_dir is changing */ 2568 if (ds->ds_objset) { 2569 dmu_objset_evict(ds->ds_objset); 2570 ds->ds_objset = NULL; 2571 } 2572 /* move snap name entry */ 2573 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2574 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2575 ds->ds_snapname, tx)); 2576 VERIFY(0 == zap_add(dp->dp_meta_objset, 2577 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2578 8, 1, &ds->ds_object, tx)); 2579 /* change containing dsl_dir */ 2580 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2581 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2582 ds->ds_phys->ds_dir_obj = dd->dd_object; 2583 ASSERT3P(ds->ds_dir, ==, odd); 2584 dsl_dir_close(ds->ds_dir, ds); 2585 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2586 NULL, ds, &ds->ds_dir)); 2587 2588 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2589 } 2590 2591 /* 2592 * Change space accounting. 2593 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2594 * both be valid, or both be 0 (resulting in delta == 0). This 2595 * is true for each of {clone,origin} independently. 2596 */ 2597 2598 delta = pa->cloneusedsnap - 2599 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2600 ASSERT3S(delta, >=, 0); 2601 ASSERT3U(pa->used, >=, delta); 2602 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2603 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2604 pa->used - delta, pa->comp, pa->uncomp, tx); 2605 2606 delta = pa->originusedsnap - 2607 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2608 ASSERT3S(delta, <=, 0); 2609 ASSERT3U(pa->used, >=, -delta); 2610 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2611 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2612 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2613 2614 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2615 2616 /* log history record */ 2617 spa_history_internal_log(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2618 cr, "dataset = %llu", hds->ds_object); 2619 2620 dsl_dir_close(odd, FTAG); 2621 } 2622 2623 static char *snaplist_tag = "snaplist"; 2624 /* 2625 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2626 * (exclusive) and last_obj (inclusive). The list will be in reverse 2627 * order (last_obj will be the list_head()). If first_obj == 0, do all 2628 * snapshots back to this dataset's origin. 2629 */ 2630 static int 2631 snaplist_make(dsl_pool_t *dp, boolean_t own, 2632 uint64_t first_obj, uint64_t last_obj, list_t *l) 2633 { 2634 uint64_t obj = last_obj; 2635 2636 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2637 2638 list_create(l, sizeof (struct promotenode), 2639 offsetof(struct promotenode, link)); 2640 2641 while (obj != first_obj) { 2642 dsl_dataset_t *ds; 2643 struct promotenode *snap; 2644 int err; 2645 2646 if (own) { 2647 err = dsl_dataset_own_obj(dp, obj, 2648 0, snaplist_tag, &ds); 2649 if (err == 0) 2650 dsl_dataset_make_exclusive(ds, snaplist_tag); 2651 } else { 2652 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2653 } 2654 if (err == ENOENT) { 2655 /* lost race with snapshot destroy */ 2656 struct promotenode *last = list_tail(l); 2657 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2658 obj = last->ds->ds_phys->ds_prev_snap_obj; 2659 continue; 2660 } else if (err) { 2661 return (err); 2662 } 2663 2664 if (first_obj == 0) 2665 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2666 2667 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2668 snap->ds = ds; 2669 list_insert_tail(l, snap); 2670 obj = ds->ds_phys->ds_prev_snap_obj; 2671 } 2672 2673 return (0); 2674 } 2675 2676 static int 2677 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2678 { 2679 struct promotenode *snap; 2680 2681 *spacep = 0; 2682 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2683 uint64_t used; 2684 int err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2685 mintxg, UINT64_MAX, &used); 2686 if (err) 2687 return (err); 2688 *spacep += used; 2689 } 2690 return (0); 2691 } 2692 2693 static void 2694 snaplist_destroy(list_t *l, boolean_t own) 2695 { 2696 struct promotenode *snap; 2697 2698 if (!l || !list_link_active(&l->list_head)) 2699 return; 2700 2701 while ((snap = list_tail(l)) != NULL) { 2702 list_remove(l, snap); 2703 if (own) 2704 dsl_dataset_disown(snap->ds, snaplist_tag); 2705 else 2706 dsl_dataset_rele(snap->ds, snaplist_tag); 2707 kmem_free(snap, sizeof (struct promotenode)); 2708 } 2709 list_destroy(l); 2710 } 2711 2712 /* 2713 * Promote a clone. Nomenclature note: 2714 * "clone" or "cds": the original clone which is being promoted 2715 * "origin" or "ods": the snapshot which is originally clone's origin 2716 * "origin head" or "ohds": the dataset which is the head 2717 * (filesystem/volume) for the origin 2718 * "origin origin": the origin of the origin's filesystem (typically 2719 * NULL, indicating that the clone is not a clone of a clone). 2720 */ 2721 int 2722 dsl_dataset_promote(const char *name, char *conflsnap) 2723 { 2724 dsl_dataset_t *ds; 2725 dsl_dir_t *dd; 2726 dsl_pool_t *dp; 2727 dmu_object_info_t doi; 2728 struct promotearg pa = { 0 }; 2729 struct promotenode *snap; 2730 int err; 2731 2732 err = dsl_dataset_hold(name, FTAG, &ds); 2733 if (err) 2734 return (err); 2735 dd = ds->ds_dir; 2736 dp = dd->dd_pool; 2737 2738 err = dmu_object_info(dp->dp_meta_objset, 2739 ds->ds_phys->ds_snapnames_zapobj, &doi); 2740 if (err) { 2741 dsl_dataset_rele(ds, FTAG); 2742 return (err); 2743 } 2744 2745 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 2746 dsl_dataset_rele(ds, FTAG); 2747 return (EINVAL); 2748 } 2749 2750 /* 2751 * We are going to inherit all the snapshots taken before our 2752 * origin (i.e., our new origin will be our parent's origin). 2753 * Take ownership of them so that we can rename them into our 2754 * namespace. 2755 */ 2756 rw_enter(&dp->dp_config_rwlock, RW_READER); 2757 2758 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 2759 &pa.shared_snaps); 2760 if (err != 0) 2761 goto out; 2762 2763 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 2764 if (err != 0) 2765 goto out; 2766 2767 snap = list_head(&pa.shared_snaps); 2768 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 2769 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 2770 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 2771 if (err != 0) 2772 goto out; 2773 2774 if (dsl_dir_is_clone(snap->ds->ds_dir)) { 2775 err = dsl_dataset_own_obj(dp, 2776 snap->ds->ds_dir->dd_phys->dd_origin_obj, 2777 0, FTAG, &pa.origin_origin); 2778 if (err != 0) 2779 goto out; 2780 } 2781 2782 out: 2783 rw_exit(&dp->dp_config_rwlock); 2784 2785 /* 2786 * Add in 128x the snapnames zapobj size, since we will be moving 2787 * a bunch of snapnames to the promoted ds, and dirtying their 2788 * bonus buffers. 2789 */ 2790 if (err == 0) { 2791 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 2792 dsl_dataset_promote_sync, ds, &pa, 2793 2 + 2 * doi.doi_physical_blocks_512); 2794 if (err && pa.err_ds && conflsnap) 2795 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 2796 } 2797 2798 snaplist_destroy(&pa.shared_snaps, B_TRUE); 2799 snaplist_destroy(&pa.clone_snaps, B_FALSE); 2800 snaplist_destroy(&pa.origin_snaps, B_FALSE); 2801 if (pa.origin_origin) 2802 dsl_dataset_disown(pa.origin_origin, FTAG); 2803 dsl_dataset_rele(ds, FTAG); 2804 return (err); 2805 } 2806 2807 struct cloneswaparg { 2808 dsl_dataset_t *cds; /* clone dataset */ 2809 dsl_dataset_t *ohds; /* origin's head dataset */ 2810 boolean_t force; 2811 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 2812 }; 2813 2814 /* ARGSUSED */ 2815 static int 2816 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 2817 { 2818 struct cloneswaparg *csa = arg1; 2819 2820 /* they should both be heads */ 2821 if (dsl_dataset_is_snapshot(csa->cds) || 2822 dsl_dataset_is_snapshot(csa->ohds)) 2823 return (EINVAL); 2824 2825 /* the branch point should be just before them */ 2826 if (csa->cds->ds_prev != csa->ohds->ds_prev) 2827 return (EINVAL); 2828 2829 /* cds should be the clone (unless they are unrelated) */ 2830 if (csa->cds->ds_prev != NULL && 2831 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 2832 csa->ohds->ds_object != 2833 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 2834 return (EINVAL); 2835 2836 /* the clone should be a child of the origin */ 2837 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 2838 return (EINVAL); 2839 2840 /* ohds shouldn't be modified unless 'force' */ 2841 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 2842 return (ETXTBSY); 2843 2844 /* adjust amount of any unconsumed refreservation */ 2845 csa->unused_refres_delta = 2846 (int64_t)MIN(csa->ohds->ds_reserved, 2847 csa->ohds->ds_phys->ds_unique_bytes) - 2848 (int64_t)MIN(csa->ohds->ds_reserved, 2849 csa->cds->ds_phys->ds_unique_bytes); 2850 2851 if (csa->unused_refres_delta > 0 && 2852 csa->unused_refres_delta > 2853 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 2854 return (ENOSPC); 2855 2856 if (csa->ohds->ds_quota != 0 && 2857 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 2858 return (EDQUOT); 2859 2860 return (0); 2861 } 2862 2863 /* ARGSUSED */ 2864 static void 2865 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2866 { 2867 struct cloneswaparg *csa = arg1; 2868 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 2869 2870 ASSERT(csa->cds->ds_reserved == 0); 2871 ASSERT(csa->ohds->ds_quota == 0 || 2872 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 2873 2874 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 2875 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 2876 2877 if (csa->cds->ds_objset != NULL) { 2878 dmu_objset_evict(csa->cds->ds_objset); 2879 csa->cds->ds_objset = NULL; 2880 } 2881 2882 if (csa->ohds->ds_objset != NULL) { 2883 dmu_objset_evict(csa->ohds->ds_objset); 2884 csa->ohds->ds_objset = NULL; 2885 } 2886 2887 /* 2888 * Reset origin's unique bytes, if it exists. 2889 */ 2890 if (csa->cds->ds_prev) { 2891 dsl_dataset_t *origin = csa->cds->ds_prev; 2892 dmu_buf_will_dirty(origin->ds_dbuf, tx); 2893 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2894 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2895 &origin->ds_phys->ds_unique_bytes)); 2896 } 2897 2898 /* swap blkptrs */ 2899 { 2900 blkptr_t tmp; 2901 tmp = csa->ohds->ds_phys->ds_bp; 2902 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 2903 csa->cds->ds_phys->ds_bp = tmp; 2904 } 2905 2906 /* set dd_*_bytes */ 2907 { 2908 int64_t dused, dcomp, duncomp; 2909 uint64_t cdl_used, cdl_comp, cdl_uncomp; 2910 uint64_t odl_used, odl_comp, odl_uncomp; 2911 2912 ASSERT3U(csa->cds->ds_dir->dd_phys-> 2913 dd_used_breakdown[DD_USED_SNAP], ==, 0); 2914 2915 VERIFY(0 == bplist_space(&csa->cds->ds_deadlist, &cdl_used, 2916 &cdl_comp, &cdl_uncomp)); 2917 VERIFY(0 == bplist_space(&csa->ohds->ds_deadlist, &odl_used, 2918 &odl_comp, &odl_uncomp)); 2919 2920 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used - 2921 (csa->ohds->ds_phys->ds_used_bytes + odl_used); 2922 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 2923 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 2924 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 2925 cdl_uncomp - 2926 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 2927 2928 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 2929 dused, dcomp, duncomp, tx); 2930 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 2931 -dused, -dcomp, -duncomp, tx); 2932 2933 /* 2934 * The difference in the space used by snapshots is the 2935 * difference in snapshot space due to the head's 2936 * deadlist (since that's the only thing that's 2937 * changing that affects the snapused). 2938 */ 2939 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2940 csa->ohds->ds_origin_txg, UINT64_MAX, &cdl_used)); 2941 VERIFY(0 == bplist_space_birthrange(&csa->ohds->ds_deadlist, 2942 csa->ohds->ds_origin_txg, UINT64_MAX, &odl_used)); 2943 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 2944 DD_USED_HEAD, DD_USED_SNAP, tx); 2945 } 2946 2947 #define SWITCH64(x, y) \ 2948 { \ 2949 uint64_t __tmp = (x); \ 2950 (x) = (y); \ 2951 (y) = __tmp; \ 2952 } 2953 2954 /* swap ds_*_bytes */ 2955 SWITCH64(csa->ohds->ds_phys->ds_used_bytes, 2956 csa->cds->ds_phys->ds_used_bytes); 2957 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 2958 csa->cds->ds_phys->ds_compressed_bytes); 2959 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 2960 csa->cds->ds_phys->ds_uncompressed_bytes); 2961 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 2962 csa->cds->ds_phys->ds_unique_bytes); 2963 2964 /* apply any parent delta for change in unconsumed refreservation */ 2965 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 2966 csa->unused_refres_delta, 0, 0, tx); 2967 2968 /* swap deadlists */ 2969 bplist_close(&csa->cds->ds_deadlist); 2970 bplist_close(&csa->ohds->ds_deadlist); 2971 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 2972 csa->cds->ds_phys->ds_deadlist_obj); 2973 VERIFY(0 == bplist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 2974 csa->cds->ds_phys->ds_deadlist_obj)); 2975 VERIFY(0 == bplist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 2976 csa->ohds->ds_phys->ds_deadlist_obj)); 2977 2978 dsl_pool_ds_clone_swapped(csa->ohds, csa->cds, tx); 2979 } 2980 2981 /* 2982 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 2983 * recv" into an existing fs to swizzle the file system to the new 2984 * version, and by "zfs rollback". Can also be used to swap two 2985 * independent head datasets if neither has any snapshots. 2986 */ 2987 int 2988 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 2989 boolean_t force) 2990 { 2991 struct cloneswaparg csa; 2992 int error; 2993 2994 ASSERT(clone->ds_owner); 2995 ASSERT(origin_head->ds_owner); 2996 retry: 2997 /* Need exclusive access for the swap */ 2998 rw_enter(&clone->ds_rwlock, RW_WRITER); 2999 if (!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 3000 rw_exit(&clone->ds_rwlock); 3001 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 3002 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 3003 rw_exit(&origin_head->ds_rwlock); 3004 goto retry; 3005 } 3006 } 3007 csa.cds = clone; 3008 csa.ohds = origin_head; 3009 csa.force = force; 3010 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3011 dsl_dataset_clone_swap_check, 3012 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3013 return (error); 3014 } 3015 3016 /* 3017 * Given a pool name and a dataset object number in that pool, 3018 * return the name of that dataset. 3019 */ 3020 int 3021 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3022 { 3023 spa_t *spa; 3024 dsl_pool_t *dp; 3025 dsl_dataset_t *ds; 3026 int error; 3027 3028 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3029 return (error); 3030 dp = spa_get_dsl(spa); 3031 rw_enter(&dp->dp_config_rwlock, RW_READER); 3032 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3033 dsl_dataset_name(ds, buf); 3034 dsl_dataset_rele(ds, FTAG); 3035 } 3036 rw_exit(&dp->dp_config_rwlock); 3037 spa_close(spa, FTAG); 3038 3039 return (error); 3040 } 3041 3042 int 3043 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3044 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3045 { 3046 int error = 0; 3047 3048 ASSERT3S(asize, >, 0); 3049 3050 /* 3051 * *ref_rsrv is the portion of asize that will come from any 3052 * unconsumed refreservation space. 3053 */ 3054 *ref_rsrv = 0; 3055 3056 mutex_enter(&ds->ds_lock); 3057 /* 3058 * Make a space adjustment for reserved bytes. 3059 */ 3060 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3061 ASSERT3U(*used, >=, 3062 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3063 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3064 *ref_rsrv = 3065 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3066 } 3067 3068 if (!check_quota || ds->ds_quota == 0) { 3069 mutex_exit(&ds->ds_lock); 3070 return (0); 3071 } 3072 /* 3073 * If they are requesting more space, and our current estimate 3074 * is over quota, they get to try again unless the actual 3075 * on-disk is over quota and there are no pending changes (which 3076 * may free up space for us). 3077 */ 3078 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) { 3079 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota) 3080 error = ERESTART; 3081 else 3082 error = EDQUOT; 3083 } 3084 mutex_exit(&ds->ds_lock); 3085 3086 return (error); 3087 } 3088 3089 /* ARGSUSED */ 3090 static int 3091 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3092 { 3093 dsl_dataset_t *ds = arg1; 3094 dsl_prop_setarg_t *psa = arg2; 3095 int err; 3096 3097 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3098 return (ENOTSUP); 3099 3100 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3101 return (err); 3102 3103 if (psa->psa_effective_value == 0) 3104 return (0); 3105 3106 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes || 3107 psa->psa_effective_value < ds->ds_reserved) 3108 return (ENOSPC); 3109 3110 return (0); 3111 } 3112 3113 extern void dsl_prop_set_sync(void *, void *, cred_t *, dmu_tx_t *); 3114 3115 void 3116 dsl_dataset_set_quota_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3117 { 3118 dsl_dataset_t *ds = arg1; 3119 dsl_prop_setarg_t *psa = arg2; 3120 uint64_t effective_value = psa->psa_effective_value; 3121 3122 dsl_prop_set_sync(ds, psa, cr, tx); 3123 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3124 3125 if (ds->ds_quota != effective_value) { 3126 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3127 ds->ds_quota = effective_value; 3128 3129 spa_history_internal_log(LOG_DS_REFQUOTA, 3130 ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu ", 3131 (longlong_t)ds->ds_quota, ds->ds_object); 3132 } 3133 } 3134 3135 int 3136 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3137 { 3138 dsl_dataset_t *ds; 3139 dsl_prop_setarg_t psa; 3140 int err; 3141 3142 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3143 3144 err = dsl_dataset_hold(dsname, FTAG, &ds); 3145 if (err) 3146 return (err); 3147 3148 /* 3149 * If someone removes a file, then tries to set the quota, we 3150 * want to make sure the file freeing takes effect. 3151 */ 3152 txg_wait_open(ds->ds_dir->dd_pool, 0); 3153 3154 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3155 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3156 ds, &psa, 0); 3157 3158 dsl_dataset_rele(ds, FTAG); 3159 return (err); 3160 } 3161 3162 static int 3163 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3164 { 3165 dsl_dataset_t *ds = arg1; 3166 dsl_prop_setarg_t *psa = arg2; 3167 uint64_t effective_value; 3168 uint64_t unique; 3169 int err; 3170 3171 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3172 SPA_VERSION_REFRESERVATION) 3173 return (ENOTSUP); 3174 3175 if (dsl_dataset_is_snapshot(ds)) 3176 return (EINVAL); 3177 3178 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3179 return (err); 3180 3181 effective_value = psa->psa_effective_value; 3182 3183 /* 3184 * If we are doing the preliminary check in open context, the 3185 * space estimates may be inaccurate. 3186 */ 3187 if (!dmu_tx_is_syncing(tx)) 3188 return (0); 3189 3190 mutex_enter(&ds->ds_lock); 3191 unique = dsl_dataset_unique(ds); 3192 mutex_exit(&ds->ds_lock); 3193 3194 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3195 uint64_t delta = MAX(unique, effective_value) - 3196 MAX(unique, ds->ds_reserved); 3197 3198 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3199 return (ENOSPC); 3200 if (ds->ds_quota > 0 && 3201 effective_value > ds->ds_quota) 3202 return (ENOSPC); 3203 } 3204 3205 return (0); 3206 } 3207 3208 /* ARGSUSED */ 3209 static void 3210 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, cred_t *cr, 3211 dmu_tx_t *tx) 3212 { 3213 dsl_dataset_t *ds = arg1; 3214 dsl_prop_setarg_t *psa = arg2; 3215 uint64_t effective_value = psa->psa_effective_value; 3216 uint64_t unique; 3217 int64_t delta; 3218 3219 dsl_prop_set_sync(ds, psa, cr, tx); 3220 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3221 3222 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3223 3224 mutex_enter(&ds->ds_dir->dd_lock); 3225 mutex_enter(&ds->ds_lock); 3226 unique = dsl_dataset_unique(ds); 3227 delta = MAX(0, (int64_t)(effective_value - unique)) - 3228 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3229 ds->ds_reserved = effective_value; 3230 mutex_exit(&ds->ds_lock); 3231 3232 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3233 mutex_exit(&ds->ds_dir->dd_lock); 3234 3235 spa_history_internal_log(LOG_DS_REFRESERV, 3236 ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu", 3237 (longlong_t)effective_value, ds->ds_object); 3238 } 3239 3240 int 3241 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3242 uint64_t reservation) 3243 { 3244 dsl_dataset_t *ds; 3245 dsl_prop_setarg_t psa; 3246 int err; 3247 3248 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3249 &reservation); 3250 3251 err = dsl_dataset_hold(dsname, FTAG, &ds); 3252 if (err) 3253 return (err); 3254 3255 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3256 dsl_dataset_set_reservation_check, 3257 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3258 3259 dsl_dataset_rele(ds, FTAG); 3260 return (err); 3261 } 3262 3263 struct dsl_ds_holdarg { 3264 dsl_sync_task_group_t *dstg; 3265 char *htag; 3266 char *snapname; 3267 boolean_t recursive; 3268 boolean_t gotone; 3269 boolean_t temphold; 3270 char failed[MAXPATHLEN]; 3271 }; 3272 3273 /* 3274 * The max length of a temporary tag prefix is the number of hex digits 3275 * required to express UINT64_MAX plus one for the hyphen. 3276 */ 3277 #define MAX_TAG_PREFIX_LEN 17 3278 3279 static int 3280 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3281 { 3282 dsl_dataset_t *ds = arg1; 3283 struct dsl_ds_holdarg *ha = arg2; 3284 char *htag = ha->htag; 3285 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3286 int error = 0; 3287 3288 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3289 return (ENOTSUP); 3290 3291 if (!dsl_dataset_is_snapshot(ds)) 3292 return (EINVAL); 3293 3294 /* tags must be unique */ 3295 mutex_enter(&ds->ds_lock); 3296 if (ds->ds_phys->ds_userrefs_obj) { 3297 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3298 8, 1, tx); 3299 if (error == 0) 3300 error = EEXIST; 3301 else if (error == ENOENT) 3302 error = 0; 3303 } 3304 mutex_exit(&ds->ds_lock); 3305 3306 if (error == 0 && ha->temphold && 3307 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3308 error = E2BIG; 3309 3310 return (error); 3311 } 3312 3313 static void 3314 dsl_dataset_user_hold_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3315 { 3316 dsl_dataset_t *ds = arg1; 3317 struct dsl_ds_holdarg *ha = arg2; 3318 char *htag = ha->htag; 3319 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3320 objset_t *mos = dp->dp_meta_objset; 3321 uint64_t now = gethrestime_sec(); 3322 uint64_t zapobj; 3323 3324 mutex_enter(&ds->ds_lock); 3325 if (ds->ds_phys->ds_userrefs_obj == 0) { 3326 /* 3327 * This is the first user hold for this dataset. Create 3328 * the userrefs zap object. 3329 */ 3330 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3331 zapobj = ds->ds_phys->ds_userrefs_obj = 3332 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3333 } else { 3334 zapobj = ds->ds_phys->ds_userrefs_obj; 3335 } 3336 ds->ds_userrefs++; 3337 mutex_exit(&ds->ds_lock); 3338 3339 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3340 3341 if (ha->temphold) { 3342 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3343 htag, &now, tx)); 3344 } 3345 3346 spa_history_internal_log(LOG_DS_USER_HOLD, 3347 dp->dp_spa, tx, cr, "<%s> temp = %d dataset = %llu", htag, 3348 (int)ha->temphold, ds->ds_object); 3349 } 3350 3351 static int 3352 dsl_dataset_user_hold_one(char *dsname, void *arg) 3353 { 3354 struct dsl_ds_holdarg *ha = arg; 3355 dsl_dataset_t *ds; 3356 int error; 3357 char *name; 3358 3359 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3360 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3361 error = dsl_dataset_hold(name, ha->dstg, &ds); 3362 strfree(name); 3363 if (error == 0) { 3364 ha->gotone = B_TRUE; 3365 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3366 dsl_dataset_user_hold_sync, ds, ha, 0); 3367 } else if (error == ENOENT && ha->recursive) { 3368 error = 0; 3369 } else { 3370 (void) strcpy(ha->failed, dsname); 3371 } 3372 return (error); 3373 } 3374 3375 int 3376 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3377 boolean_t recursive, boolean_t temphold) 3378 { 3379 struct dsl_ds_holdarg *ha; 3380 dsl_sync_task_t *dst; 3381 spa_t *spa; 3382 int error; 3383 3384 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3385 3386 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3387 3388 error = spa_open(dsname, &spa, FTAG); 3389 if (error) { 3390 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3391 return (error); 3392 } 3393 3394 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3395 ha->htag = htag; 3396 ha->snapname = snapname; 3397 ha->recursive = recursive; 3398 ha->temphold = temphold; 3399 if (recursive) { 3400 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3401 ha, DS_FIND_CHILDREN); 3402 } else { 3403 error = dsl_dataset_user_hold_one(dsname, ha); 3404 } 3405 if (error == 0) 3406 error = dsl_sync_task_group_wait(ha->dstg); 3407 3408 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3409 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3410 dsl_dataset_t *ds = dst->dst_arg1; 3411 3412 if (dst->dst_err) { 3413 dsl_dataset_name(ds, ha->failed); 3414 *strchr(ha->failed, '@') = '\0'; 3415 } 3416 dsl_dataset_rele(ds, ha->dstg); 3417 } 3418 3419 if (error == 0 && recursive && !ha->gotone) 3420 error = ENOENT; 3421 3422 if (error) 3423 (void) strcpy(dsname, ha->failed); 3424 3425 dsl_sync_task_group_destroy(ha->dstg); 3426 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3427 spa_close(spa, FTAG); 3428 return (error); 3429 } 3430 3431 struct dsl_ds_releasearg { 3432 dsl_dataset_t *ds; 3433 const char *htag; 3434 boolean_t own; /* do we own or just hold ds? */ 3435 }; 3436 3437 static int 3438 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3439 boolean_t *might_destroy) 3440 { 3441 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3442 uint64_t zapobj; 3443 uint64_t tmp; 3444 int error; 3445 3446 *might_destroy = B_FALSE; 3447 3448 mutex_enter(&ds->ds_lock); 3449 zapobj = ds->ds_phys->ds_userrefs_obj; 3450 if (zapobj == 0) { 3451 /* The tag can't possibly exist */ 3452 mutex_exit(&ds->ds_lock); 3453 return (ESRCH); 3454 } 3455 3456 /* Make sure the tag exists */ 3457 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3458 if (error) { 3459 mutex_exit(&ds->ds_lock); 3460 if (error == ENOENT) 3461 error = ESRCH; 3462 return (error); 3463 } 3464 3465 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3466 DS_IS_DEFER_DESTROY(ds)) 3467 *might_destroy = B_TRUE; 3468 3469 mutex_exit(&ds->ds_lock); 3470 return (0); 3471 } 3472 3473 static int 3474 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3475 { 3476 struct dsl_ds_releasearg *ra = arg1; 3477 dsl_dataset_t *ds = ra->ds; 3478 boolean_t might_destroy; 3479 int error; 3480 3481 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3482 return (ENOTSUP); 3483 3484 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3485 if (error) 3486 return (error); 3487 3488 if (might_destroy) { 3489 struct dsl_ds_destroyarg dsda = {0}; 3490 3491 if (dmu_tx_is_syncing(tx)) { 3492 /* 3493 * If we're not prepared to remove the snapshot, 3494 * we can't allow the release to happen right now. 3495 */ 3496 if (!ra->own) 3497 return (EBUSY); 3498 if (ds->ds_objset) { 3499 dmu_objset_evict(ds->ds_objset); 3500 ds->ds_objset = NULL; 3501 } 3502 } 3503 dsda.ds = ds; 3504 dsda.releasing = B_TRUE; 3505 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3506 } 3507 3508 return (0); 3509 } 3510 3511 static void 3512 dsl_dataset_user_release_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 3513 { 3514 struct dsl_ds_releasearg *ra = arg1; 3515 dsl_dataset_t *ds = ra->ds; 3516 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3517 objset_t *mos = dp->dp_meta_objset; 3518 uint64_t zapobj; 3519 uint64_t dsobj = ds->ds_object; 3520 uint64_t refs; 3521 int error; 3522 3523 mutex_enter(&ds->ds_lock); 3524 ds->ds_userrefs--; 3525 refs = ds->ds_userrefs; 3526 mutex_exit(&ds->ds_lock); 3527 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3528 VERIFY(error == 0 || error == ENOENT); 3529 zapobj = ds->ds_phys->ds_userrefs_obj; 3530 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3531 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3532 DS_IS_DEFER_DESTROY(ds)) { 3533 struct dsl_ds_destroyarg dsda = {0}; 3534 3535 ASSERT(ra->own); 3536 dsda.ds = ds; 3537 dsda.releasing = B_TRUE; 3538 /* We already did the destroy_check */ 3539 dsl_dataset_destroy_sync(&dsda, tag, cr, tx); 3540 } 3541 3542 spa_history_internal_log(LOG_DS_USER_RELEASE, 3543 dp->dp_spa, tx, cr, "<%s> %lld dataset = %llu", 3544 ra->htag, (longlong_t)refs, dsobj); 3545 } 3546 3547 static int 3548 dsl_dataset_user_release_one(char *dsname, void *arg) 3549 { 3550 struct dsl_ds_holdarg *ha = arg; 3551 struct dsl_ds_releasearg *ra; 3552 dsl_dataset_t *ds; 3553 int error; 3554 void *dtag = ha->dstg; 3555 char *name; 3556 boolean_t own = B_FALSE; 3557 boolean_t might_destroy; 3558 3559 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3560 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3561 error = dsl_dataset_hold(name, dtag, &ds); 3562 strfree(name); 3563 if (error == ENOENT && ha->recursive) 3564 return (0); 3565 (void) strcpy(ha->failed, dsname); 3566 if (error) 3567 return (error); 3568 3569 ha->gotone = B_TRUE; 3570 3571 ASSERT(dsl_dataset_is_snapshot(ds)); 3572 3573 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3574 if (error) { 3575 dsl_dataset_rele(ds, dtag); 3576 return (error); 3577 } 3578 3579 if (might_destroy) { 3580 #ifdef _KERNEL 3581 error = zfs_unmount_snap(name, NULL); 3582 if (error) { 3583 dsl_dataset_rele(ds, dtag); 3584 return (error); 3585 } 3586 #endif 3587 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3588 dsl_dataset_rele(ds, dtag); 3589 return (EBUSY); 3590 } else { 3591 own = B_TRUE; 3592 dsl_dataset_make_exclusive(ds, dtag); 3593 } 3594 } 3595 3596 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3597 ra->ds = ds; 3598 ra->htag = ha->htag; 3599 ra->own = own; 3600 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3601 dsl_dataset_user_release_sync, ra, dtag, 0); 3602 3603 return (0); 3604 } 3605 3606 int 3607 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3608 boolean_t recursive) 3609 { 3610 struct dsl_ds_holdarg *ha; 3611 dsl_sync_task_t *dst; 3612 spa_t *spa; 3613 int error; 3614 3615 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3616 3617 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3618 3619 error = spa_open(dsname, &spa, FTAG); 3620 if (error) { 3621 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3622 return (error); 3623 } 3624 3625 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3626 ha->htag = htag; 3627 ha->snapname = snapname; 3628 ha->recursive = recursive; 3629 if (recursive) { 3630 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3631 ha, DS_FIND_CHILDREN); 3632 } else { 3633 error = dsl_dataset_user_release_one(dsname, ha); 3634 } 3635 if (error == 0) 3636 error = dsl_sync_task_group_wait(ha->dstg); 3637 3638 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3639 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3640 struct dsl_ds_releasearg *ra = dst->dst_arg1; 3641 dsl_dataset_t *ds = ra->ds; 3642 3643 if (dst->dst_err) 3644 dsl_dataset_name(ds, ha->failed); 3645 3646 if (ra->own) 3647 dsl_dataset_disown(ds, ha->dstg); 3648 else 3649 dsl_dataset_rele(ds, ha->dstg); 3650 3651 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 3652 } 3653 3654 if (error == 0 && recursive && !ha->gotone) 3655 error = ENOENT; 3656 3657 if (error) 3658 (void) strcpy(dsname, ha->failed); 3659 3660 dsl_sync_task_group_destroy(ha->dstg); 3661 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3662 spa_close(spa, FTAG); 3663 return (error); 3664 } 3665 3666 /* 3667 * Called at spa_load time to release a stale temporary user hold. 3668 */ 3669 int 3670 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag) 3671 { 3672 dsl_dataset_t *ds; 3673 char *snap; 3674 char *name; 3675 int namelen; 3676 int error; 3677 3678 rw_enter(&dp->dp_config_rwlock, RW_READER); 3679 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 3680 rw_exit(&dp->dp_config_rwlock); 3681 if (error) 3682 return (error); 3683 namelen = dsl_dataset_namelen(ds)+1; 3684 name = kmem_alloc(namelen, KM_SLEEP); 3685 dsl_dataset_name(ds, name); 3686 dsl_dataset_rele(ds, FTAG); 3687 3688 snap = strchr(name, '@'); 3689 *snap = '\0'; 3690 ++snap; 3691 return (dsl_dataset_user_release(name, snap, htag, B_FALSE)); 3692 } 3693 3694 int 3695 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 3696 { 3697 dsl_dataset_t *ds; 3698 int err; 3699 3700 err = dsl_dataset_hold(dsname, FTAG, &ds); 3701 if (err) 3702 return (err); 3703 3704 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 3705 if (ds->ds_phys->ds_userrefs_obj != 0) { 3706 zap_attribute_t *za; 3707 zap_cursor_t zc; 3708 3709 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 3710 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 3711 ds->ds_phys->ds_userrefs_obj); 3712 zap_cursor_retrieve(&zc, za) == 0; 3713 zap_cursor_advance(&zc)) { 3714 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 3715 za->za_first_integer)); 3716 } 3717 zap_cursor_fini(&zc); 3718 kmem_free(za, sizeof (zap_attribute_t)); 3719 } 3720 dsl_dataset_rele(ds, FTAG); 3721 return (0); 3722 } 3723 3724 /* 3725 * Note, this fuction is used as the callback for dmu_objset_find(). We 3726 * always return 0 so that we will continue to find and process 3727 * inconsistent datasets, even if we encounter an error trying to 3728 * process one of them. 3729 */ 3730 /* ARGSUSED */ 3731 int 3732 dsl_destroy_inconsistent(char *dsname, void *arg) 3733 { 3734 dsl_dataset_t *ds; 3735 3736 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 3737 if (DS_IS_INCONSISTENT(ds)) 3738 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 3739 else 3740 dsl_dataset_disown(ds, FTAG); 3741 } 3742 return (0); 3743 } 3744