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