1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/dmu_objset.h> 27 #include <sys/dsl_dataset.h> 28 #include <sys/dsl_dir.h> 29 #include <sys/dsl_prop.h> 30 #include <sys/dsl_synctask.h> 31 #include <sys/dmu_traverse.h> 32 #include <sys/dmu_tx.h> 33 #include <sys/arc.h> 34 #include <sys/zio.h> 35 #include <sys/zap.h> 36 #include <sys/unique.h> 37 #include <sys/zfs_context.h> 38 #include <sys/zfs_ioctl.h> 39 #include <sys/spa.h> 40 #include <sys/zfs_znode.h> 41 #include <sys/zvol.h> 42 43 static char *dsl_reaper = "the grim reaper"; 44 45 static dsl_checkfunc_t dsl_dataset_destroy_begin_check; 46 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync; 47 static dsl_syncfunc_t dsl_dataset_set_reservation_sync; 48 49 #define DS_REF_MAX (1ULL << 62) 50 51 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE 52 53 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper) 54 55 56 /* 57 * Figure out how much of this delta should be propogated to the dsl_dir 58 * layer. If there's a refreservation, that space has already been 59 * partially accounted for in our ancestors. 60 */ 61 static int64_t 62 parent_delta(dsl_dataset_t *ds, int64_t delta) 63 { 64 uint64_t old_bytes, new_bytes; 65 66 if (ds->ds_reserved == 0) 67 return (delta); 68 69 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 70 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved); 71 72 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta)); 73 return (new_bytes - old_bytes); 74 } 75 76 void 77 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx) 78 { 79 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 80 int compressed = BP_GET_PSIZE(bp); 81 int uncompressed = BP_GET_UCSIZE(bp); 82 int64_t delta; 83 84 dprintf_bp(bp, "born, ds=%p\n", ds); 85 86 ASSERT(dmu_tx_is_syncing(tx)); 87 /* It could have been compressed away to nothing */ 88 if (BP_IS_HOLE(bp)) 89 return; 90 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE); 91 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES); 92 if (ds == NULL) { 93 /* 94 * Account for the meta-objset space in its placeholder 95 * dsl_dir. 96 */ 97 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */ 98 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 99 used, compressed, uncompressed, tx); 100 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 101 return; 102 } 103 dmu_buf_will_dirty(ds->ds_dbuf, tx); 104 mutex_enter(&ds->ds_dir->dd_lock); 105 mutex_enter(&ds->ds_lock); 106 delta = parent_delta(ds, used); 107 ds->ds_phys->ds_used_bytes += used; 108 ds->ds_phys->ds_compressed_bytes += compressed; 109 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 110 ds->ds_phys->ds_unique_bytes += used; 111 mutex_exit(&ds->ds_lock); 112 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 113 compressed, uncompressed, tx); 114 dsl_dir_transfer_space(ds->ds_dir, used - delta, 115 DD_USED_REFRSRV, DD_USED_HEAD, tx); 116 mutex_exit(&ds->ds_dir->dd_lock); 117 } 118 119 int 120 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, 121 boolean_t async) 122 { 123 if (BP_IS_HOLE(bp)) 124 return (0); 125 126 ASSERT(dmu_tx_is_syncing(tx)); 127 ASSERT(bp->blk_birth <= tx->tx_txg); 128 129 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 130 int compressed = BP_GET_PSIZE(bp); 131 int uncompressed = BP_GET_UCSIZE(bp); 132 133 ASSERT(used > 0); 134 if (ds == NULL) { 135 /* 136 * Account for the meta-objset space in its placeholder 137 * dataset. 138 */ 139 dsl_free(tx->tx_pool, tx->tx_txg, bp); 140 141 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 142 -used, -compressed, -uncompressed, tx); 143 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 144 return (used); 145 } 146 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 147 148 ASSERT(!dsl_dataset_is_snapshot(ds)); 149 dmu_buf_will_dirty(ds->ds_dbuf, tx); 150 151 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 152 int64_t delta; 153 154 dprintf_bp(bp, "freeing: %s", ""); 155 dsl_free(tx->tx_pool, tx->tx_txg, bp); 156 157 mutex_enter(&ds->ds_dir->dd_lock); 158 mutex_enter(&ds->ds_lock); 159 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 160 !DS_UNIQUE_IS_ACCURATE(ds)); 161 delta = parent_delta(ds, -used); 162 ds->ds_phys->ds_unique_bytes -= used; 163 mutex_exit(&ds->ds_lock); 164 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 165 delta, -compressed, -uncompressed, tx); 166 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 167 DD_USED_REFRSRV, DD_USED_HEAD, tx); 168 mutex_exit(&ds->ds_dir->dd_lock); 169 } else { 170 dprintf_bp(bp, "putting on dead list: %s", ""); 171 if (async) { 172 /* 173 * We are here as part of zio's write done callback, 174 * which means we're a zio interrupt thread. We can't 175 * call bplist_enqueue() now because it may block 176 * waiting for I/O. Instead, put bp on the deferred 177 * queue and let dsl_pool_sync() finish the job. 178 */ 179 bplist_enqueue_deferred(&ds->ds_deadlist, bp); 180 } else { 181 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, bp, tx)); 182 } 183 ASSERT3U(ds->ds_prev->ds_object, ==, 184 ds->ds_phys->ds_prev_snap_obj); 185 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 186 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 187 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 188 ds->ds_object && bp->blk_birth > 189 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 190 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 191 mutex_enter(&ds->ds_prev->ds_lock); 192 ds->ds_prev->ds_phys->ds_unique_bytes += used; 193 mutex_exit(&ds->ds_prev->ds_lock); 194 } 195 if (bp->blk_birth > ds->ds_origin_txg) { 196 dsl_dir_transfer_space(ds->ds_dir, used, 197 DD_USED_HEAD, DD_USED_SNAP, tx); 198 } 199 } 200 mutex_enter(&ds->ds_lock); 201 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used); 202 ds->ds_phys->ds_used_bytes -= used; 203 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 204 ds->ds_phys->ds_compressed_bytes -= compressed; 205 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 206 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 207 mutex_exit(&ds->ds_lock); 208 209 return (used); 210 } 211 212 uint64_t 213 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 214 { 215 uint64_t trysnap = 0; 216 217 if (ds == NULL) 218 return (0); 219 /* 220 * The snapshot creation could fail, but that would cause an 221 * incorrect FALSE return, which would only result in an 222 * overestimation of the amount of space that an operation would 223 * consume, which is OK. 224 * 225 * There's also a small window where we could miss a pending 226 * snapshot, because we could set the sync task in the quiescing 227 * phase. So this should only be used as a guess. 228 */ 229 if (ds->ds_trysnap_txg > 230 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 231 trysnap = ds->ds_trysnap_txg; 232 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 233 } 234 235 boolean_t 236 dsl_dataset_block_freeable(dsl_dataset_t *ds, uint64_t blk_birth) 237 { 238 return (blk_birth > dsl_dataset_prev_snap_txg(ds)); 239 } 240 241 /* ARGSUSED */ 242 static void 243 dsl_dataset_evict(dmu_buf_t *db, void *dsv) 244 { 245 dsl_dataset_t *ds = dsv; 246 247 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 248 249 unique_remove(ds->ds_fsid_guid); 250 251 if (ds->ds_objset != NULL) 252 dmu_objset_evict(ds->ds_objset); 253 254 if (ds->ds_prev) { 255 dsl_dataset_drop_ref(ds->ds_prev, ds); 256 ds->ds_prev = NULL; 257 } 258 259 bplist_close(&ds->ds_deadlist); 260 if (ds->ds_dir) 261 dsl_dir_close(ds->ds_dir, ds); 262 263 ASSERT(!list_link_active(&ds->ds_synced_link)); 264 265 mutex_destroy(&ds->ds_lock); 266 mutex_destroy(&ds->ds_recvlock); 267 mutex_destroy(&ds->ds_opening_lock); 268 rw_destroy(&ds->ds_rwlock); 269 cv_destroy(&ds->ds_exclusive_cv); 270 bplist_fini(&ds->ds_deadlist); 271 272 kmem_free(ds, sizeof (dsl_dataset_t)); 273 } 274 275 static int 276 dsl_dataset_get_snapname(dsl_dataset_t *ds) 277 { 278 dsl_dataset_phys_t *headphys; 279 int err; 280 dmu_buf_t *headdbuf; 281 dsl_pool_t *dp = ds->ds_dir->dd_pool; 282 objset_t *mos = dp->dp_meta_objset; 283 284 if (ds->ds_snapname[0]) 285 return (0); 286 if (ds->ds_phys->ds_next_snap_obj == 0) 287 return (0); 288 289 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 290 FTAG, &headdbuf); 291 if (err) 292 return (err); 293 headphys = headdbuf->db_data; 294 err = zap_value_search(dp->dp_meta_objset, 295 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 296 dmu_buf_rele(headdbuf, FTAG); 297 return (err); 298 } 299 300 static int 301 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 302 { 303 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 304 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 305 matchtype_t mt; 306 int err; 307 308 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 309 mt = MT_FIRST; 310 else 311 mt = MT_EXACT; 312 313 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 314 value, mt, NULL, 0, NULL); 315 if (err == ENOTSUP && mt == MT_FIRST) 316 err = zap_lookup(mos, snapobj, name, 8, 1, value); 317 return (err); 318 } 319 320 static int 321 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 322 { 323 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 324 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 325 matchtype_t mt; 326 int err; 327 328 dsl_dir_snap_cmtime_update(ds->ds_dir); 329 330 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 331 mt = MT_FIRST; 332 else 333 mt = MT_EXACT; 334 335 err = zap_remove_norm(mos, snapobj, name, mt, tx); 336 if (err == ENOTSUP && mt == MT_FIRST) 337 err = zap_remove(mos, snapobj, name, tx); 338 return (err); 339 } 340 341 static int 342 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 343 dsl_dataset_t **dsp) 344 { 345 objset_t *mos = dp->dp_meta_objset; 346 dmu_buf_t *dbuf; 347 dsl_dataset_t *ds; 348 int err; 349 350 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 351 dsl_pool_sync_context(dp)); 352 353 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 354 if (err) 355 return (err); 356 ds = dmu_buf_get_user(dbuf); 357 if (ds == NULL) { 358 dsl_dataset_t *winner; 359 360 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 361 ds->ds_dbuf = dbuf; 362 ds->ds_object = dsobj; 363 ds->ds_phys = dbuf->db_data; 364 365 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 366 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 367 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 368 rw_init(&ds->ds_rwlock, 0, 0, 0); 369 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 370 bplist_init(&ds->ds_deadlist); 371 372 err = bplist_open(&ds->ds_deadlist, 373 mos, ds->ds_phys->ds_deadlist_obj); 374 if (err == 0) { 375 err = dsl_dir_open_obj(dp, 376 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 377 } 378 if (err) { 379 /* 380 * we don't really need to close the blist if we 381 * just opened it. 382 */ 383 mutex_destroy(&ds->ds_lock); 384 mutex_destroy(&ds->ds_recvlock); 385 mutex_destroy(&ds->ds_opening_lock); 386 rw_destroy(&ds->ds_rwlock); 387 cv_destroy(&ds->ds_exclusive_cv); 388 bplist_fini(&ds->ds_deadlist); 389 kmem_free(ds, sizeof (dsl_dataset_t)); 390 dmu_buf_rele(dbuf, tag); 391 return (err); 392 } 393 394 if (!dsl_dataset_is_snapshot(ds)) { 395 ds->ds_snapname[0] = '\0'; 396 if (ds->ds_phys->ds_prev_snap_obj) { 397 err = dsl_dataset_get_ref(dp, 398 ds->ds_phys->ds_prev_snap_obj, 399 ds, &ds->ds_prev); 400 } 401 402 if (err == 0 && dsl_dir_is_clone(ds->ds_dir)) { 403 dsl_dataset_t *origin; 404 405 err = dsl_dataset_hold_obj(dp, 406 ds->ds_dir->dd_phys->dd_origin_obj, 407 FTAG, &origin); 408 if (err == 0) { 409 ds->ds_origin_txg = 410 origin->ds_phys->ds_creation_txg; 411 dsl_dataset_rele(origin, FTAG); 412 } 413 } 414 } else { 415 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 416 err = dsl_dataset_get_snapname(ds); 417 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 418 err = zap_count( 419 ds->ds_dir->dd_pool->dp_meta_objset, 420 ds->ds_phys->ds_userrefs_obj, 421 &ds->ds_userrefs); 422 } 423 } 424 425 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 426 /* 427 * In sync context, we're called with either no lock 428 * or with the write lock. If we're not syncing, 429 * we're always called with the read lock held. 430 */ 431 boolean_t need_lock = 432 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 433 dsl_pool_sync_context(dp); 434 435 if (need_lock) 436 rw_enter(&dp->dp_config_rwlock, RW_READER); 437 438 err = dsl_prop_get_ds(ds, 439 "refreservation", sizeof (uint64_t), 1, 440 &ds->ds_reserved, NULL); 441 if (err == 0) { 442 err = dsl_prop_get_ds(ds, 443 "refquota", sizeof (uint64_t), 1, 444 &ds->ds_quota, NULL); 445 } 446 447 if (need_lock) 448 rw_exit(&dp->dp_config_rwlock); 449 } else { 450 ds->ds_reserved = ds->ds_quota = 0; 451 } 452 453 if (err == 0) { 454 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 455 dsl_dataset_evict); 456 } 457 if (err || winner) { 458 bplist_close(&ds->ds_deadlist); 459 if (ds->ds_prev) 460 dsl_dataset_drop_ref(ds->ds_prev, ds); 461 dsl_dir_close(ds->ds_dir, ds); 462 mutex_destroy(&ds->ds_lock); 463 mutex_destroy(&ds->ds_recvlock); 464 mutex_destroy(&ds->ds_opening_lock); 465 rw_destroy(&ds->ds_rwlock); 466 cv_destroy(&ds->ds_exclusive_cv); 467 bplist_fini(&ds->ds_deadlist); 468 kmem_free(ds, sizeof (dsl_dataset_t)); 469 if (err) { 470 dmu_buf_rele(dbuf, tag); 471 return (err); 472 } 473 ds = winner; 474 } else { 475 ds->ds_fsid_guid = 476 unique_insert(ds->ds_phys->ds_fsid_guid); 477 } 478 } 479 ASSERT3P(ds->ds_dbuf, ==, dbuf); 480 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 481 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 482 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 483 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 484 mutex_enter(&ds->ds_lock); 485 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 486 mutex_exit(&ds->ds_lock); 487 dmu_buf_rele(ds->ds_dbuf, tag); 488 return (ENOENT); 489 } 490 mutex_exit(&ds->ds_lock); 491 *dsp = ds; 492 return (0); 493 } 494 495 static int 496 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 497 { 498 dsl_pool_t *dp = ds->ds_dir->dd_pool; 499 500 /* 501 * In syncing context we don't want the rwlock lock: there 502 * may be an existing writer waiting for sync phase to 503 * finish. We don't need to worry about such writers, since 504 * sync phase is single-threaded, so the writer can't be 505 * doing anything while we are active. 506 */ 507 if (dsl_pool_sync_context(dp)) { 508 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 509 return (0); 510 } 511 512 /* 513 * Normal users will hold the ds_rwlock as a READER until they 514 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 515 * drop their READER lock after they set the ds_owner field. 516 * 517 * If the dataset is being destroyed, the destroy thread will 518 * obtain a WRITER lock for exclusive access after it's done its 519 * open-context work and then change the ds_owner to 520 * dsl_reaper once destruction is assured. So threads 521 * may block here temporarily, until the "destructability" of 522 * the dataset is determined. 523 */ 524 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 525 mutex_enter(&ds->ds_lock); 526 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 527 rw_exit(&dp->dp_config_rwlock); 528 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 529 if (DSL_DATASET_IS_DESTROYED(ds)) { 530 mutex_exit(&ds->ds_lock); 531 dsl_dataset_drop_ref(ds, tag); 532 rw_enter(&dp->dp_config_rwlock, RW_READER); 533 return (ENOENT); 534 } 535 rw_enter(&dp->dp_config_rwlock, RW_READER); 536 } 537 mutex_exit(&ds->ds_lock); 538 return (0); 539 } 540 541 int 542 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 543 dsl_dataset_t **dsp) 544 { 545 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 546 547 if (err) 548 return (err); 549 return (dsl_dataset_hold_ref(*dsp, tag)); 550 } 551 552 int 553 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 554 void *tag, dsl_dataset_t **dsp) 555 { 556 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 557 if (err) 558 return (err); 559 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 560 dsl_dataset_rele(*dsp, tag); 561 *dsp = NULL; 562 return (EBUSY); 563 } 564 return (0); 565 } 566 567 int 568 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 569 { 570 dsl_dir_t *dd; 571 dsl_pool_t *dp; 572 const char *snapname; 573 uint64_t obj; 574 int err = 0; 575 576 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 577 if (err) 578 return (err); 579 580 dp = dd->dd_pool; 581 obj = dd->dd_phys->dd_head_dataset_obj; 582 rw_enter(&dp->dp_config_rwlock, RW_READER); 583 if (obj) 584 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 585 else 586 err = ENOENT; 587 if (err) 588 goto out; 589 590 err = dsl_dataset_hold_ref(*dsp, tag); 591 592 /* we may be looking for a snapshot */ 593 if (err == 0 && snapname != NULL) { 594 dsl_dataset_t *ds = NULL; 595 596 if (*snapname++ != '@') { 597 dsl_dataset_rele(*dsp, tag); 598 err = ENOENT; 599 goto out; 600 } 601 602 dprintf("looking for snapshot '%s'\n", snapname); 603 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 604 if (err == 0) 605 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 606 dsl_dataset_rele(*dsp, tag); 607 608 ASSERT3U((err == 0), ==, (ds != NULL)); 609 610 if (ds) { 611 mutex_enter(&ds->ds_lock); 612 if (ds->ds_snapname[0] == 0) 613 (void) strlcpy(ds->ds_snapname, snapname, 614 sizeof (ds->ds_snapname)); 615 mutex_exit(&ds->ds_lock); 616 err = dsl_dataset_hold_ref(ds, tag); 617 *dsp = err ? NULL : ds; 618 } 619 } 620 out: 621 rw_exit(&dp->dp_config_rwlock); 622 dsl_dir_close(dd, FTAG); 623 return (err); 624 } 625 626 int 627 dsl_dataset_own(const char *name, boolean_t inconsistentok, 628 void *tag, dsl_dataset_t **dsp) 629 { 630 int err = dsl_dataset_hold(name, tag, dsp); 631 if (err) 632 return (err); 633 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 634 dsl_dataset_rele(*dsp, tag); 635 return (EBUSY); 636 } 637 return (0); 638 } 639 640 void 641 dsl_dataset_name(dsl_dataset_t *ds, char *name) 642 { 643 if (ds == NULL) { 644 (void) strcpy(name, "mos"); 645 } else { 646 dsl_dir_name(ds->ds_dir, name); 647 VERIFY(0 == dsl_dataset_get_snapname(ds)); 648 if (ds->ds_snapname[0]) { 649 (void) strcat(name, "@"); 650 /* 651 * We use a "recursive" mutex so that we 652 * can call dprintf_ds() with ds_lock held. 653 */ 654 if (!MUTEX_HELD(&ds->ds_lock)) { 655 mutex_enter(&ds->ds_lock); 656 (void) strcat(name, ds->ds_snapname); 657 mutex_exit(&ds->ds_lock); 658 } else { 659 (void) strcat(name, ds->ds_snapname); 660 } 661 } 662 } 663 } 664 665 static int 666 dsl_dataset_namelen(dsl_dataset_t *ds) 667 { 668 int result; 669 670 if (ds == NULL) { 671 result = 3; /* "mos" */ 672 } else { 673 result = dsl_dir_namelen(ds->ds_dir); 674 VERIFY(0 == dsl_dataset_get_snapname(ds)); 675 if (ds->ds_snapname[0]) { 676 ++result; /* adding one for the @-sign */ 677 if (!MUTEX_HELD(&ds->ds_lock)) { 678 mutex_enter(&ds->ds_lock); 679 result += strlen(ds->ds_snapname); 680 mutex_exit(&ds->ds_lock); 681 } else { 682 result += strlen(ds->ds_snapname); 683 } 684 } 685 } 686 687 return (result); 688 } 689 690 void 691 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 692 { 693 dmu_buf_rele(ds->ds_dbuf, tag); 694 } 695 696 void 697 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 698 { 699 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 700 rw_exit(&ds->ds_rwlock); 701 } 702 dsl_dataset_drop_ref(ds, tag); 703 } 704 705 void 706 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 707 { 708 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 709 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 710 711 mutex_enter(&ds->ds_lock); 712 ds->ds_owner = NULL; 713 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 714 rw_exit(&ds->ds_rwlock); 715 cv_broadcast(&ds->ds_exclusive_cv); 716 } 717 mutex_exit(&ds->ds_lock); 718 if (ds->ds_dbuf) 719 dsl_dataset_drop_ref(ds, tag); 720 else 721 dsl_dataset_evict(ds->ds_dbuf, ds); 722 } 723 724 boolean_t 725 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 726 { 727 boolean_t gotit = FALSE; 728 729 mutex_enter(&ds->ds_lock); 730 if (ds->ds_owner == NULL && 731 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 732 ds->ds_owner = tag; 733 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 734 rw_exit(&ds->ds_rwlock); 735 gotit = TRUE; 736 } 737 mutex_exit(&ds->ds_lock); 738 return (gotit); 739 } 740 741 void 742 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 743 { 744 ASSERT3P(owner, ==, ds->ds_owner); 745 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 746 rw_enter(&ds->ds_rwlock, RW_WRITER); 747 } 748 749 uint64_t 750 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 751 uint64_t flags, dmu_tx_t *tx) 752 { 753 dsl_pool_t *dp = dd->dd_pool; 754 dmu_buf_t *dbuf; 755 dsl_dataset_phys_t *dsphys; 756 uint64_t dsobj; 757 objset_t *mos = dp->dp_meta_objset; 758 759 if (origin == NULL) 760 origin = dp->dp_origin_snap; 761 762 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 763 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 764 ASSERT(dmu_tx_is_syncing(tx)); 765 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 766 767 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 768 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 769 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 770 dmu_buf_will_dirty(dbuf, tx); 771 dsphys = dbuf->db_data; 772 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 773 dsphys->ds_dir_obj = dd->dd_object; 774 dsphys->ds_flags = flags; 775 dsphys->ds_fsid_guid = unique_create(); 776 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 777 sizeof (dsphys->ds_guid)); 778 dsphys->ds_snapnames_zapobj = 779 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 780 DMU_OT_NONE, 0, tx); 781 dsphys->ds_creation_time = gethrestime_sec(); 782 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 783 dsphys->ds_deadlist_obj = 784 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx); 785 786 if (origin) { 787 dsphys->ds_prev_snap_obj = origin->ds_object; 788 dsphys->ds_prev_snap_txg = 789 origin->ds_phys->ds_creation_txg; 790 dsphys->ds_used_bytes = 791 origin->ds_phys->ds_used_bytes; 792 dsphys->ds_compressed_bytes = 793 origin->ds_phys->ds_compressed_bytes; 794 dsphys->ds_uncompressed_bytes = 795 origin->ds_phys->ds_uncompressed_bytes; 796 dsphys->ds_bp = origin->ds_phys->ds_bp; 797 dsphys->ds_flags |= origin->ds_phys->ds_flags; 798 799 dmu_buf_will_dirty(origin->ds_dbuf, tx); 800 origin->ds_phys->ds_num_children++; 801 802 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 803 if (origin->ds_phys->ds_next_clones_obj == 0) { 804 origin->ds_phys->ds_next_clones_obj = 805 zap_create(mos, 806 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 807 } 808 VERIFY(0 == zap_add_int(mos, 809 origin->ds_phys->ds_next_clones_obj, 810 dsobj, tx)); 811 } 812 813 dmu_buf_will_dirty(dd->dd_dbuf, tx); 814 dd->dd_phys->dd_origin_obj = origin->ds_object; 815 } 816 817 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 818 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 819 820 dmu_buf_rele(dbuf, FTAG); 821 822 dmu_buf_will_dirty(dd->dd_dbuf, tx); 823 dd->dd_phys->dd_head_dataset_obj = dsobj; 824 825 return (dsobj); 826 } 827 828 uint64_t 829 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 830 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 831 { 832 dsl_pool_t *dp = pdd->dd_pool; 833 uint64_t dsobj, ddobj; 834 dsl_dir_t *dd; 835 836 ASSERT(lastname[0] != '@'); 837 838 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 839 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 840 841 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 842 843 dsl_deleg_set_create_perms(dd, tx, cr); 844 845 dsl_dir_close(dd, FTAG); 846 847 return (dsobj); 848 } 849 850 struct destroyarg { 851 dsl_sync_task_group_t *dstg; 852 char *snapname; 853 char *failed; 854 boolean_t defer; 855 }; 856 857 static int 858 dsl_snapshot_destroy_one(const char *name, void *arg) 859 { 860 struct destroyarg *da = arg; 861 dsl_dataset_t *ds; 862 int err; 863 char *dsname; 864 865 dsname = kmem_asprintf("%s@%s", name, da->snapname); 866 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds); 867 strfree(dsname); 868 if (err == 0) { 869 struct dsl_ds_destroyarg *dsda; 870 871 dsl_dataset_make_exclusive(ds, da->dstg); 872 if (ds->ds_objset != NULL) { 873 dmu_objset_evict(ds->ds_objset); 874 ds->ds_objset = NULL; 875 } 876 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP); 877 dsda->ds = ds; 878 dsda->defer = da->defer; 879 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check, 880 dsl_dataset_destroy_sync, dsda, da->dstg, 0); 881 } else if (err == ENOENT) { 882 err = 0; 883 } else { 884 (void) strcpy(da->failed, name); 885 } 886 return (err); 887 } 888 889 /* 890 * Destroy 'snapname' in all descendants of 'fsname'. 891 */ 892 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy 893 int 894 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer) 895 { 896 int err; 897 struct destroyarg da; 898 dsl_sync_task_t *dst; 899 spa_t *spa; 900 901 err = spa_open(fsname, &spa, FTAG); 902 if (err) 903 return (err); 904 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 905 da.snapname = snapname; 906 da.failed = fsname; 907 da.defer = defer; 908 909 err = dmu_objset_find(fsname, 910 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN); 911 912 if (err == 0) 913 err = dsl_sync_task_group_wait(da.dstg); 914 915 for (dst = list_head(&da.dstg->dstg_tasks); dst; 916 dst = list_next(&da.dstg->dstg_tasks, dst)) { 917 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 918 dsl_dataset_t *ds = dsda->ds; 919 920 /* 921 * Return the file system name that triggered the error 922 */ 923 if (dst->dst_err) { 924 dsl_dataset_name(ds, fsname); 925 *strchr(fsname, '@') = '\0'; 926 } 927 ASSERT3P(dsda->rm_origin, ==, NULL); 928 dsl_dataset_disown(ds, da.dstg); 929 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 930 } 931 932 dsl_sync_task_group_destroy(da.dstg); 933 spa_close(spa, FTAG); 934 return (err); 935 } 936 937 static boolean_t 938 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 939 { 940 boolean_t might_destroy = B_FALSE; 941 942 mutex_enter(&ds->ds_lock); 943 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 944 DS_IS_DEFER_DESTROY(ds)) 945 might_destroy = B_TRUE; 946 mutex_exit(&ds->ds_lock); 947 948 return (might_destroy); 949 } 950 951 /* 952 * If we're removing a clone, and these three conditions are true: 953 * 1) the clone's origin has no other children 954 * 2) the clone's origin has no user references 955 * 3) the clone's origin has been marked for deferred destruction 956 * Then, prepare to remove the origin as part of this sync task group. 957 */ 958 static int 959 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 960 { 961 dsl_dataset_t *ds = dsda->ds; 962 dsl_dataset_t *origin = ds->ds_prev; 963 964 if (dsl_dataset_might_destroy_origin(origin)) { 965 char *name; 966 int namelen; 967 int error; 968 969 namelen = dsl_dataset_namelen(origin) + 1; 970 name = kmem_alloc(namelen, KM_SLEEP); 971 dsl_dataset_name(origin, name); 972 #ifdef _KERNEL 973 error = zfs_unmount_snap(name, NULL); 974 if (error) { 975 kmem_free(name, namelen); 976 return (error); 977 } 978 #endif 979 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 980 kmem_free(name, namelen); 981 if (error) 982 return (error); 983 dsda->rm_origin = origin; 984 dsl_dataset_make_exclusive(origin, tag); 985 986 if (origin->ds_objset != NULL) { 987 dmu_objset_evict(origin->ds_objset); 988 origin->ds_objset = NULL; 989 } 990 } 991 992 return (0); 993 } 994 995 /* 996 * ds must be opened as OWNER. On return (whether successful or not), 997 * ds will be closed and caller can no longer dereference it. 998 */ 999 int 1000 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1001 { 1002 int err; 1003 dsl_sync_task_group_t *dstg; 1004 objset_t *os; 1005 dsl_dir_t *dd; 1006 uint64_t obj; 1007 struct dsl_ds_destroyarg dsda = { 0 }; 1008 dsl_dataset_t dummy_ds = { 0 }; 1009 1010 dsda.ds = ds; 1011 1012 if (dsl_dataset_is_snapshot(ds)) { 1013 /* Destroying a snapshot is simpler */ 1014 dsl_dataset_make_exclusive(ds, tag); 1015 1016 if (ds->ds_objset != NULL) { 1017 dmu_objset_evict(ds->ds_objset); 1018 ds->ds_objset = NULL; 1019 } 1020 dsda.defer = defer; 1021 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1022 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1023 &dsda, tag, 0); 1024 ASSERT3P(dsda.rm_origin, ==, NULL); 1025 goto out; 1026 } else if (defer) { 1027 err = EINVAL; 1028 goto out; 1029 } 1030 1031 dd = ds->ds_dir; 1032 dummy_ds.ds_dir = dd; 1033 dummy_ds.ds_object = ds->ds_object; 1034 1035 /* 1036 * Check for errors and mark this ds as inconsistent, in 1037 * case we crash while freeing the objects. 1038 */ 1039 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, 1040 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1041 if (err) 1042 goto out; 1043 1044 err = dmu_objset_from_ds(ds, &os); 1045 if (err) 1046 goto out; 1047 1048 /* 1049 * remove the objects in open context, so that we won't 1050 * have too much to do in syncing context. 1051 */ 1052 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1053 ds->ds_phys->ds_prev_snap_txg)) { 1054 /* 1055 * Ignore errors, if there is not enough disk space 1056 * we will deal with it in dsl_dataset_destroy_sync(). 1057 */ 1058 (void) dmu_free_object(os, obj); 1059 } 1060 1061 /* 1062 * We need to sync out all in-flight IO before we try to evict 1063 * (the dataset evict func is trying to clear the cached entries 1064 * for this dataset in the ARC). 1065 */ 1066 txg_wait_synced(dd->dd_pool, 0); 1067 1068 /* 1069 * If we managed to free all the objects in open 1070 * context, the user space accounting should be zero. 1071 */ 1072 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1073 dmu_objset_userused_enabled(os)) { 1074 uint64_t count; 1075 1076 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || 1077 count == 0); 1078 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || 1079 count == 0); 1080 } 1081 1082 if (err != ESRCH) 1083 goto out; 1084 1085 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1086 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1087 rw_exit(&dd->dd_pool->dp_config_rwlock); 1088 1089 if (err) 1090 goto out; 1091 1092 if (ds->ds_objset) { 1093 /* 1094 * We need to sync out all in-flight IO before we try 1095 * to evict (the dataset evict func is trying to clear 1096 * the cached entries for this dataset in the ARC). 1097 */ 1098 txg_wait_synced(dd->dd_pool, 0); 1099 } 1100 1101 /* 1102 * Blow away the dsl_dir + head dataset. 1103 */ 1104 dsl_dataset_make_exclusive(ds, tag); 1105 if (ds->ds_objset) { 1106 dmu_objset_evict(ds->ds_objset); 1107 ds->ds_objset = NULL; 1108 } 1109 1110 /* 1111 * If we're removing a clone, we might also need to remove its 1112 * origin. 1113 */ 1114 do { 1115 dsda.need_prep = B_FALSE; 1116 if (dsl_dir_is_clone(dd)) { 1117 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1118 if (err) { 1119 dsl_dir_close(dd, FTAG); 1120 goto out; 1121 } 1122 } 1123 1124 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1125 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1126 dsl_dataset_destroy_sync, &dsda, tag, 0); 1127 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1128 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0); 1129 err = dsl_sync_task_group_wait(dstg); 1130 dsl_sync_task_group_destroy(dstg); 1131 1132 /* 1133 * We could be racing against 'zfs release' or 'zfs destroy -d' 1134 * on the origin snap, in which case we can get EBUSY if we 1135 * needed to destroy the origin snap but were not ready to 1136 * do so. 1137 */ 1138 if (dsda.need_prep) { 1139 ASSERT(err == EBUSY); 1140 ASSERT(dsl_dir_is_clone(dd)); 1141 ASSERT(dsda.rm_origin == NULL); 1142 } 1143 } while (dsda.need_prep); 1144 1145 if (dsda.rm_origin != NULL) 1146 dsl_dataset_disown(dsda.rm_origin, tag); 1147 1148 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1149 if (err) 1150 dsl_dir_close(dd, FTAG); 1151 out: 1152 dsl_dataset_disown(ds, tag); 1153 return (err); 1154 } 1155 1156 blkptr_t * 1157 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1158 { 1159 return (&ds->ds_phys->ds_bp); 1160 } 1161 1162 void 1163 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1164 { 1165 ASSERT(dmu_tx_is_syncing(tx)); 1166 /* If it's the meta-objset, set dp_meta_rootbp */ 1167 if (ds == NULL) { 1168 tx->tx_pool->dp_meta_rootbp = *bp; 1169 } else { 1170 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1171 ds->ds_phys->ds_bp = *bp; 1172 } 1173 } 1174 1175 spa_t * 1176 dsl_dataset_get_spa(dsl_dataset_t *ds) 1177 { 1178 return (ds->ds_dir->dd_pool->dp_spa); 1179 } 1180 1181 void 1182 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1183 { 1184 dsl_pool_t *dp; 1185 1186 if (ds == NULL) /* this is the meta-objset */ 1187 return; 1188 1189 ASSERT(ds->ds_objset != NULL); 1190 1191 if (ds->ds_phys->ds_next_snap_obj != 0) 1192 panic("dirtying snapshot!"); 1193 1194 dp = ds->ds_dir->dd_pool; 1195 1196 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1197 /* up the hold count until we can be written out */ 1198 dmu_buf_add_ref(ds->ds_dbuf, ds); 1199 } 1200 } 1201 1202 /* 1203 * The unique space in the head dataset can be calculated by subtracting 1204 * the space used in the most recent snapshot, that is still being used 1205 * in this file system, from the space currently in use. To figure out 1206 * the space in the most recent snapshot still in use, we need to take 1207 * the total space used in the snapshot and subtract out the space that 1208 * has been freed up since the snapshot was taken. 1209 */ 1210 static void 1211 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1212 { 1213 uint64_t mrs_used; 1214 uint64_t dlused, dlcomp, dluncomp; 1215 1216 ASSERT(ds->ds_object == ds->ds_dir->dd_phys->dd_head_dataset_obj); 1217 1218 if (ds->ds_phys->ds_prev_snap_obj != 0) 1219 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes; 1220 else 1221 mrs_used = 0; 1222 1223 VERIFY(0 == bplist_space(&ds->ds_deadlist, &dlused, &dlcomp, 1224 &dluncomp)); 1225 1226 ASSERT3U(dlused, <=, mrs_used); 1227 ds->ds_phys->ds_unique_bytes = 1228 ds->ds_phys->ds_used_bytes - (mrs_used - dlused); 1229 1230 if (!DS_UNIQUE_IS_ACCURATE(ds) && 1231 spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1232 SPA_VERSION_UNIQUE_ACCURATE) 1233 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1234 } 1235 1236 static uint64_t 1237 dsl_dataset_unique(dsl_dataset_t *ds) 1238 { 1239 if (!DS_UNIQUE_IS_ACCURATE(ds) && !dsl_dataset_is_snapshot(ds)) 1240 dsl_dataset_recalc_head_uniq(ds); 1241 1242 return (ds->ds_phys->ds_unique_bytes); 1243 } 1244 1245 struct killarg { 1246 dsl_dataset_t *ds; 1247 dmu_tx_t *tx; 1248 }; 1249 1250 /* ARGSUSED */ 1251 static int 1252 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 1253 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1254 { 1255 struct killarg *ka = arg; 1256 dmu_tx_t *tx = ka->tx; 1257 1258 if (bp == NULL) 1259 return (0); 1260 1261 if (zb->zb_level == ZB_ZIL_LEVEL) { 1262 ASSERT(zilog != NULL); 1263 /* 1264 * It's a block in the intent log. It has no 1265 * accounting, so just free it. 1266 */ 1267 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1268 } else { 1269 ASSERT(zilog == NULL); 1270 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1271 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1272 } 1273 1274 return (0); 1275 } 1276 1277 /* ARGSUSED */ 1278 static int 1279 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1280 { 1281 dsl_dataset_t *ds = arg1; 1282 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1283 uint64_t count; 1284 int err; 1285 1286 /* 1287 * Can't delete a head dataset if there are snapshots of it. 1288 * (Except if the only snapshots are from the branch we cloned 1289 * from.) 1290 */ 1291 if (ds->ds_prev != NULL && 1292 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1293 return (EBUSY); 1294 1295 /* 1296 * This is really a dsl_dir thing, but check it here so that 1297 * we'll be less likely to leave this dataset inconsistent & 1298 * nearly destroyed. 1299 */ 1300 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1301 if (err) 1302 return (err); 1303 if (count != 0) 1304 return (EEXIST); 1305 1306 return (0); 1307 } 1308 1309 /* ARGSUSED */ 1310 static void 1311 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 1312 { 1313 dsl_dataset_t *ds = arg1; 1314 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1315 1316 /* Mark it as inconsistent on-disk, in case we crash */ 1317 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1318 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1319 1320 spa_history_internal_log(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx, 1321 cr, "dataset = %llu", ds->ds_object); 1322 } 1323 1324 static int 1325 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1326 dmu_tx_t *tx) 1327 { 1328 dsl_dataset_t *ds = dsda->ds; 1329 dsl_dataset_t *ds_prev = ds->ds_prev; 1330 1331 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1332 struct dsl_ds_destroyarg ndsda = {0}; 1333 1334 /* 1335 * If we're not prepared to remove the origin, don't remove 1336 * the clone either. 1337 */ 1338 if (dsda->rm_origin == NULL) { 1339 dsda->need_prep = B_TRUE; 1340 return (EBUSY); 1341 } 1342 1343 ndsda.ds = ds_prev; 1344 ndsda.is_origin_rm = B_TRUE; 1345 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1346 } 1347 1348 /* 1349 * If we're not going to remove the origin after all, 1350 * undo the open context setup. 1351 */ 1352 if (dsda->rm_origin != NULL) { 1353 dsl_dataset_disown(dsda->rm_origin, tag); 1354 dsda->rm_origin = NULL; 1355 } 1356 1357 return (0); 1358 } 1359 1360 /* ARGSUSED */ 1361 int 1362 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1363 { 1364 struct dsl_ds_destroyarg *dsda = arg1; 1365 dsl_dataset_t *ds = dsda->ds; 1366 1367 /* we have an owner hold, so noone else can destroy us */ 1368 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1369 1370 /* 1371 * Only allow deferred destroy on pools that support it. 1372 * NOTE: deferred destroy is only supported on snapshots. 1373 */ 1374 if (dsda->defer) { 1375 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1376 SPA_VERSION_USERREFS) 1377 return (ENOTSUP); 1378 ASSERT(dsl_dataset_is_snapshot(ds)); 1379 return (0); 1380 } 1381 1382 /* 1383 * Can't delete a head dataset if there are snapshots of it. 1384 * (Except if the only snapshots are from the branch we cloned 1385 * from.) 1386 */ 1387 if (ds->ds_prev != NULL && 1388 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1389 return (EBUSY); 1390 1391 /* 1392 * If we made changes this txg, traverse_dsl_dataset won't find 1393 * them. Try again. 1394 */ 1395 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1396 return (EAGAIN); 1397 1398 if (dsl_dataset_is_snapshot(ds)) { 1399 /* 1400 * If this snapshot has an elevated user reference count, 1401 * we can't destroy it yet. 1402 */ 1403 if (ds->ds_userrefs > 0 && !dsda->releasing) 1404 return (EBUSY); 1405 1406 mutex_enter(&ds->ds_lock); 1407 /* 1408 * Can't delete a branch point. However, if we're destroying 1409 * a clone and removing its origin due to it having a user 1410 * hold count of 0 and having been marked for deferred destroy, 1411 * it's OK for the origin to have a single clone. 1412 */ 1413 if (ds->ds_phys->ds_num_children > 1414 (dsda->is_origin_rm ? 2 : 1)) { 1415 mutex_exit(&ds->ds_lock); 1416 return (EEXIST); 1417 } 1418 mutex_exit(&ds->ds_lock); 1419 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1420 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1421 } 1422 1423 /* XXX we should do some i/o error checking... */ 1424 return (0); 1425 } 1426 1427 struct refsarg { 1428 kmutex_t lock; 1429 boolean_t gone; 1430 kcondvar_t cv; 1431 }; 1432 1433 /* ARGSUSED */ 1434 static void 1435 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1436 { 1437 struct refsarg *arg = argv; 1438 1439 mutex_enter(&arg->lock); 1440 arg->gone = TRUE; 1441 cv_signal(&arg->cv); 1442 mutex_exit(&arg->lock); 1443 } 1444 1445 static void 1446 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1447 { 1448 struct refsarg arg; 1449 1450 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1451 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1452 arg.gone = FALSE; 1453 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1454 dsl_dataset_refs_gone); 1455 dmu_buf_rele(ds->ds_dbuf, tag); 1456 mutex_enter(&arg.lock); 1457 while (!arg.gone) 1458 cv_wait(&arg.cv, &arg.lock); 1459 ASSERT(arg.gone); 1460 mutex_exit(&arg.lock); 1461 ds->ds_dbuf = NULL; 1462 ds->ds_phys = NULL; 1463 mutex_destroy(&arg.lock); 1464 cv_destroy(&arg.cv); 1465 } 1466 1467 static void 1468 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1469 { 1470 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1471 uint64_t count; 1472 int err; 1473 1474 ASSERT(ds->ds_phys->ds_num_children >= 2); 1475 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1476 /* 1477 * The err should not be ENOENT, but a bug in a previous version 1478 * of the code could cause upgrade_clones_cb() to not set 1479 * ds_next_snap_obj when it should, leading to a missing entry. 1480 * If we knew that the pool was created after 1481 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1482 * ENOENT. However, at least we can check that we don't have 1483 * too many entries in the next_clones_obj even after failing to 1484 * remove this one. 1485 */ 1486 if (err != ENOENT) { 1487 VERIFY3U(err, ==, 0); 1488 } 1489 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1490 &count)); 1491 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1492 } 1493 1494 void 1495 dsl_dataset_destroy_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 1496 { 1497 struct dsl_ds_destroyarg *dsda = arg1; 1498 dsl_dataset_t *ds = dsda->ds; 1499 int err; 1500 int after_branch_point = FALSE; 1501 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1502 objset_t *mos = dp->dp_meta_objset; 1503 dsl_dataset_t *ds_prev = NULL; 1504 uint64_t obj; 1505 1506 ASSERT(ds->ds_owner); 1507 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1508 ASSERT(ds->ds_prev == NULL || 1509 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1510 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1511 1512 if (dsda->defer) { 1513 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1514 if (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1) { 1515 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1516 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1517 return; 1518 } 1519 } 1520 1521 /* signal any waiters that this dataset is going away */ 1522 mutex_enter(&ds->ds_lock); 1523 ds->ds_owner = dsl_reaper; 1524 cv_broadcast(&ds->ds_exclusive_cv); 1525 mutex_exit(&ds->ds_lock); 1526 1527 /* Remove our reservation */ 1528 if (ds->ds_reserved != 0) { 1529 dsl_prop_setarg_t psa; 1530 uint64_t value = 0; 1531 1532 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1533 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1534 &value); 1535 psa.psa_effective_value = 0; /* predict default value */ 1536 1537 dsl_dataset_set_reservation_sync(ds, &psa, cr, tx); 1538 ASSERT3U(ds->ds_reserved, ==, 0); 1539 } 1540 1541 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1542 1543 dsl_pool_ds_destroyed(ds, tx); 1544 1545 obj = ds->ds_object; 1546 1547 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1548 if (ds->ds_prev) { 1549 ds_prev = ds->ds_prev; 1550 } else { 1551 VERIFY(0 == dsl_dataset_hold_obj(dp, 1552 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1553 } 1554 after_branch_point = 1555 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1556 1557 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1558 if (after_branch_point && 1559 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1560 remove_from_next_clones(ds_prev, obj, tx); 1561 if (ds->ds_phys->ds_next_snap_obj != 0) { 1562 VERIFY(0 == zap_add_int(mos, 1563 ds_prev->ds_phys->ds_next_clones_obj, 1564 ds->ds_phys->ds_next_snap_obj, tx)); 1565 } 1566 } 1567 if (after_branch_point && 1568 ds->ds_phys->ds_next_snap_obj == 0) { 1569 /* This clone is toast. */ 1570 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1571 ds_prev->ds_phys->ds_num_children--; 1572 1573 /* 1574 * If the clone's origin has no other clones, no 1575 * user holds, and has been marked for deferred 1576 * deletion, then we should have done the necessary 1577 * destroy setup for it. 1578 */ 1579 if (ds_prev->ds_phys->ds_num_children == 1 && 1580 ds_prev->ds_userrefs == 0 && 1581 DS_IS_DEFER_DESTROY(ds_prev)) { 1582 ASSERT3P(dsda->rm_origin, !=, NULL); 1583 } else { 1584 ASSERT3P(dsda->rm_origin, ==, NULL); 1585 } 1586 } else if (!after_branch_point) { 1587 ds_prev->ds_phys->ds_next_snap_obj = 1588 ds->ds_phys->ds_next_snap_obj; 1589 } 1590 } 1591 1592 if (ds->ds_phys->ds_next_snap_obj != 0) { 1593 blkptr_t bp; 1594 dsl_dataset_t *ds_next; 1595 uint64_t itor = 0; 1596 uint64_t old_unique; 1597 int64_t used = 0, compressed = 0, uncompressed = 0; 1598 1599 VERIFY(0 == dsl_dataset_hold_obj(dp, 1600 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1601 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1602 1603 old_unique = dsl_dataset_unique(ds_next); 1604 1605 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1606 ds_next->ds_phys->ds_prev_snap_obj = 1607 ds->ds_phys->ds_prev_snap_obj; 1608 ds_next->ds_phys->ds_prev_snap_txg = 1609 ds->ds_phys->ds_prev_snap_txg; 1610 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1611 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1612 1613 /* 1614 * Transfer to our deadlist (which will become next's 1615 * new deadlist) any entries from next's current 1616 * deadlist which were born before prev, and free the 1617 * other entries. 1618 * 1619 * XXX we're doing this long task with the config lock held 1620 */ 1621 while (bplist_iterate(&ds_next->ds_deadlist, &itor, &bp) == 0) { 1622 if (bp.blk_birth <= ds->ds_phys->ds_prev_snap_txg) { 1623 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, 1624 &bp, tx)); 1625 if (ds_prev && !after_branch_point && 1626 bp.blk_birth > 1627 ds_prev->ds_phys->ds_prev_snap_txg) { 1628 ds_prev->ds_phys->ds_unique_bytes += 1629 bp_get_dsize_sync(dp->dp_spa, &bp); 1630 } 1631 } else { 1632 used += bp_get_dsize_sync(dp->dp_spa, &bp); 1633 compressed += BP_GET_PSIZE(&bp); 1634 uncompressed += BP_GET_UCSIZE(&bp); 1635 dsl_free(dp, tx->tx_txg, &bp); 1636 } 1637 } 1638 1639 ASSERT3U(used, ==, ds->ds_phys->ds_unique_bytes); 1640 1641 /* change snapused */ 1642 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1643 -used, -compressed, -uncompressed, tx); 1644 1645 /* free next's deadlist */ 1646 bplist_close(&ds_next->ds_deadlist); 1647 bplist_destroy(mos, ds_next->ds_phys->ds_deadlist_obj, tx); 1648 1649 /* set next's deadlist to our deadlist */ 1650 bplist_close(&ds->ds_deadlist); 1651 ds_next->ds_phys->ds_deadlist_obj = 1652 ds->ds_phys->ds_deadlist_obj; 1653 VERIFY(0 == bplist_open(&ds_next->ds_deadlist, mos, 1654 ds_next->ds_phys->ds_deadlist_obj)); 1655 ds->ds_phys->ds_deadlist_obj = 0; 1656 1657 if (ds_next->ds_phys->ds_next_snap_obj != 0) { 1658 /* 1659 * Update next's unique to include blocks which 1660 * were previously shared by only this snapshot 1661 * and it. Those blocks will be born after the 1662 * prev snap and before this snap, and will have 1663 * died after the next snap and before the one 1664 * after that (ie. be on the snap after next's 1665 * deadlist). 1666 * 1667 * XXX we're doing this long task with the 1668 * config lock held 1669 */ 1670 dsl_dataset_t *ds_after_next; 1671 uint64_t space; 1672 1673 VERIFY(0 == dsl_dataset_hold_obj(dp, 1674 ds_next->ds_phys->ds_next_snap_obj, 1675 FTAG, &ds_after_next)); 1676 1677 VERIFY(0 == 1678 bplist_space_birthrange(&ds_after_next->ds_deadlist, 1679 ds->ds_phys->ds_prev_snap_txg, 1680 ds->ds_phys->ds_creation_txg, &space)); 1681 ds_next->ds_phys->ds_unique_bytes += space; 1682 1683 dsl_dataset_rele(ds_after_next, FTAG); 1684 ASSERT3P(ds_next->ds_prev, ==, NULL); 1685 } else { 1686 ASSERT3P(ds_next->ds_prev, ==, ds); 1687 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1688 ds_next->ds_prev = NULL; 1689 if (ds_prev) { 1690 VERIFY(0 == dsl_dataset_get_ref(dp, 1691 ds->ds_phys->ds_prev_snap_obj, 1692 ds_next, &ds_next->ds_prev)); 1693 } 1694 1695 dsl_dataset_recalc_head_uniq(ds_next); 1696 1697 /* 1698 * Reduce the amount of our unconsmed refreservation 1699 * being charged to our parent by the amount of 1700 * new unique data we have gained. 1701 */ 1702 if (old_unique < ds_next->ds_reserved) { 1703 int64_t mrsdelta; 1704 uint64_t new_unique = 1705 ds_next->ds_phys->ds_unique_bytes; 1706 1707 ASSERT(old_unique <= new_unique); 1708 mrsdelta = MIN(new_unique - old_unique, 1709 ds_next->ds_reserved - old_unique); 1710 dsl_dir_diduse_space(ds->ds_dir, 1711 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1712 } 1713 } 1714 dsl_dataset_rele(ds_next, FTAG); 1715 } else { 1716 /* 1717 * There's no next snapshot, so this is a head dataset. 1718 * Destroy the deadlist. Unless it's a clone, the 1719 * deadlist should be empty. (If it's a clone, it's 1720 * safe to ignore the deadlist contents.) 1721 */ 1722 struct killarg ka; 1723 1724 ASSERT(after_branch_point || bplist_empty(&ds->ds_deadlist)); 1725 bplist_close(&ds->ds_deadlist); 1726 bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx); 1727 ds->ds_phys->ds_deadlist_obj = 0; 1728 1729 /* 1730 * Free everything that we point to (that's born after 1731 * the previous snapshot, if we are a clone) 1732 * 1733 * NB: this should be very quick, because we already 1734 * freed all the objects in open context. 1735 */ 1736 ka.ds = ds; 1737 ka.tx = tx; 1738 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, 1739 TRAVERSE_POST, kill_blkptr, &ka); 1740 ASSERT3U(err, ==, 0); 1741 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1742 ds->ds_phys->ds_unique_bytes == 0); 1743 1744 if (ds->ds_prev != NULL) { 1745 dsl_dataset_rele(ds->ds_prev, ds); 1746 ds->ds_prev = ds_prev = NULL; 1747 } 1748 } 1749 1750 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1751 /* Erase the link in the dir */ 1752 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1753 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1754 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1755 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1756 ASSERT(err == 0); 1757 } else { 1758 /* remove from snapshot namespace */ 1759 dsl_dataset_t *ds_head; 1760 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1761 VERIFY(0 == dsl_dataset_hold_obj(dp, 1762 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1763 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1764 #ifdef ZFS_DEBUG 1765 { 1766 uint64_t val; 1767 1768 err = dsl_dataset_snap_lookup(ds_head, 1769 ds->ds_snapname, &val); 1770 ASSERT3U(err, ==, 0); 1771 ASSERT3U(val, ==, obj); 1772 } 1773 #endif 1774 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1775 ASSERT(err == 0); 1776 dsl_dataset_rele(ds_head, FTAG); 1777 } 1778 1779 if (ds_prev && ds->ds_prev != ds_prev) 1780 dsl_dataset_rele(ds_prev, FTAG); 1781 1782 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1783 spa_history_internal_log(LOG_DS_DESTROY, dp->dp_spa, tx, 1784 cr, "dataset = %llu", ds->ds_object); 1785 1786 if (ds->ds_phys->ds_next_clones_obj != 0) { 1787 uint64_t count; 1788 ASSERT(0 == zap_count(mos, 1789 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1790 VERIFY(0 == dmu_object_free(mos, 1791 ds->ds_phys->ds_next_clones_obj, tx)); 1792 } 1793 if (ds->ds_phys->ds_props_obj != 0) 1794 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1795 if (ds->ds_phys->ds_userrefs_obj != 0) 1796 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1797 dsl_dir_close(ds->ds_dir, ds); 1798 ds->ds_dir = NULL; 1799 dsl_dataset_drain_refs(ds, tag); 1800 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1801 1802 if (dsda->rm_origin) { 1803 /* 1804 * Remove the origin of the clone we just destroyed. 1805 */ 1806 struct dsl_ds_destroyarg ndsda = {0}; 1807 1808 ndsda.ds = dsda->rm_origin; 1809 dsl_dataset_destroy_sync(&ndsda, tag, cr, tx); 1810 } 1811 } 1812 1813 static int 1814 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1815 { 1816 uint64_t asize; 1817 1818 if (!dmu_tx_is_syncing(tx)) 1819 return (0); 1820 1821 /* 1822 * If there's an fs-only reservation, any blocks that might become 1823 * owned by the snapshot dataset must be accommodated by space 1824 * outside of the reservation. 1825 */ 1826 asize = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1827 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE)) 1828 return (ENOSPC); 1829 1830 /* 1831 * Propogate any reserved space for this snapshot to other 1832 * snapshot checks in this sync group. 1833 */ 1834 if (asize > 0) 1835 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 1836 1837 return (0); 1838 } 1839 1840 /* ARGSUSED */ 1841 int 1842 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 1843 { 1844 dsl_dataset_t *ds = arg1; 1845 const char *snapname = arg2; 1846 int err; 1847 uint64_t value; 1848 1849 /* 1850 * We don't allow multiple snapshots of the same txg. If there 1851 * is already one, try again. 1852 */ 1853 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 1854 return (EAGAIN); 1855 1856 /* 1857 * Check for conflicting name snapshot name. 1858 */ 1859 err = dsl_dataset_snap_lookup(ds, snapname, &value); 1860 if (err == 0) 1861 return (EEXIST); 1862 if (err != ENOENT) 1863 return (err); 1864 1865 /* 1866 * Check that the dataset's name is not too long. Name consists 1867 * of the dataset's length + 1 for the @-sign + snapshot name's length 1868 */ 1869 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 1870 return (ENAMETOOLONG); 1871 1872 err = dsl_dataset_snapshot_reserve_space(ds, tx); 1873 if (err) 1874 return (err); 1875 1876 ds->ds_trysnap_txg = tx->tx_txg; 1877 return (0); 1878 } 1879 1880 void 1881 dsl_dataset_snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 1882 { 1883 dsl_dataset_t *ds = arg1; 1884 const char *snapname = arg2; 1885 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1886 dmu_buf_t *dbuf; 1887 dsl_dataset_phys_t *dsphys; 1888 uint64_t dsobj, crtxg; 1889 objset_t *mos = dp->dp_meta_objset; 1890 int err; 1891 1892 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1893 1894 /* 1895 * The origin's ds_creation_txg has to be < TXG_INITIAL 1896 */ 1897 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 1898 crtxg = 1; 1899 else 1900 crtxg = tx->tx_txg; 1901 1902 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 1903 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 1904 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 1905 dmu_buf_will_dirty(dbuf, tx); 1906 dsphys = dbuf->db_data; 1907 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 1908 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 1909 dsphys->ds_fsid_guid = unique_create(); 1910 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 1911 sizeof (dsphys->ds_guid)); 1912 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 1913 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 1914 dsphys->ds_next_snap_obj = ds->ds_object; 1915 dsphys->ds_num_children = 1; 1916 dsphys->ds_creation_time = gethrestime_sec(); 1917 dsphys->ds_creation_txg = crtxg; 1918 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 1919 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes; 1920 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 1921 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 1922 dsphys->ds_flags = ds->ds_phys->ds_flags; 1923 dsphys->ds_bp = ds->ds_phys->ds_bp; 1924 dmu_buf_rele(dbuf, FTAG); 1925 1926 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 1927 if (ds->ds_prev) { 1928 uint64_t next_clones_obj = 1929 ds->ds_prev->ds_phys->ds_next_clones_obj; 1930 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 1931 ds->ds_object || 1932 ds->ds_prev->ds_phys->ds_num_children > 1); 1933 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 1934 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 1935 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1936 ds->ds_prev->ds_phys->ds_creation_txg); 1937 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 1938 } else if (next_clones_obj != 0) { 1939 remove_from_next_clones(ds->ds_prev, 1940 dsphys->ds_next_snap_obj, tx); 1941 VERIFY3U(0, ==, zap_add_int(mos, 1942 next_clones_obj, dsobj, tx)); 1943 } 1944 } 1945 1946 /* 1947 * If we have a reference-reservation on this dataset, we will 1948 * need to increase the amount of refreservation being charged 1949 * since our unique space is going to zero. 1950 */ 1951 if (ds->ds_reserved) { 1952 int64_t add = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1953 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 1954 add, 0, 0, tx); 1955 } 1956 1957 bplist_close(&ds->ds_deadlist); 1958 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1959 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 1960 ds->ds_phys->ds_prev_snap_obj = dsobj; 1961 ds->ds_phys->ds_prev_snap_txg = crtxg; 1962 ds->ds_phys->ds_unique_bytes = 0; 1963 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 1964 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1965 ds->ds_phys->ds_deadlist_obj = 1966 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx); 1967 VERIFY(0 == bplist_open(&ds->ds_deadlist, mos, 1968 ds->ds_phys->ds_deadlist_obj)); 1969 1970 dprintf("snap '%s' -> obj %llu\n", snapname, dsobj); 1971 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 1972 snapname, 8, 1, &dsobj, tx); 1973 ASSERT(err == 0); 1974 1975 if (ds->ds_prev) 1976 dsl_dataset_drop_ref(ds->ds_prev, ds); 1977 VERIFY(0 == dsl_dataset_get_ref(dp, 1978 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 1979 1980 dsl_pool_ds_snapshotted(ds, tx); 1981 1982 dsl_dir_snap_cmtime_update(ds->ds_dir); 1983 1984 spa_history_internal_log(LOG_DS_SNAPSHOT, dp->dp_spa, tx, cr, 1985 "dataset = %llu", dsobj); 1986 } 1987 1988 void 1989 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 1990 { 1991 ASSERT(dmu_tx_is_syncing(tx)); 1992 ASSERT(ds->ds_objset != NULL); 1993 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 1994 1995 /* 1996 * in case we had to change ds_fsid_guid when we opened it, 1997 * sync it out now. 1998 */ 1999 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2000 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2001 2002 dsl_dir_dirty(ds->ds_dir, tx); 2003 dmu_objset_sync(ds->ds_objset, zio, tx); 2004 } 2005 2006 void 2007 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2008 { 2009 uint64_t refd, avail, uobjs, aobjs; 2010 2011 dsl_dir_stats(ds->ds_dir, nv); 2012 2013 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2014 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2015 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2016 2017 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2018 ds->ds_phys->ds_creation_time); 2019 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2020 ds->ds_phys->ds_creation_txg); 2021 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2022 ds->ds_quota); 2023 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2024 ds->ds_reserved); 2025 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2026 ds->ds_phys->ds_guid); 2027 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2028 dsl_dataset_unique(ds)); 2029 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2030 ds->ds_object); 2031 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2032 ds->ds_userrefs); 2033 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2034 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2035 2036 if (ds->ds_phys->ds_next_snap_obj) { 2037 /* 2038 * This is a snapshot; override the dd's space used with 2039 * our unique space and compression ratio. 2040 */ 2041 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2042 ds->ds_phys->ds_unique_bytes); 2043 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, 2044 ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2045 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2046 ds->ds_phys->ds_compressed_bytes)); 2047 } 2048 } 2049 2050 void 2051 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2052 { 2053 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2054 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2055 stat->dds_guid = ds->ds_phys->ds_guid; 2056 if (ds->ds_phys->ds_next_snap_obj) { 2057 stat->dds_is_snapshot = B_TRUE; 2058 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2059 } else { 2060 stat->dds_is_snapshot = B_FALSE; 2061 stat->dds_num_clones = 0; 2062 } 2063 2064 /* clone origin is really a dsl_dir thing... */ 2065 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2066 if (dsl_dir_is_clone(ds->ds_dir)) { 2067 dsl_dataset_t *ods; 2068 2069 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2070 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2071 dsl_dataset_name(ods, stat->dds_origin); 2072 dsl_dataset_drop_ref(ods, FTAG); 2073 } else { 2074 stat->dds_origin[0] = '\0'; 2075 } 2076 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2077 } 2078 2079 uint64_t 2080 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2081 { 2082 return (ds->ds_fsid_guid); 2083 } 2084 2085 void 2086 dsl_dataset_space(dsl_dataset_t *ds, 2087 uint64_t *refdbytesp, uint64_t *availbytesp, 2088 uint64_t *usedobjsp, uint64_t *availobjsp) 2089 { 2090 *refdbytesp = ds->ds_phys->ds_used_bytes; 2091 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2092 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2093 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2094 if (ds->ds_quota != 0) { 2095 /* 2096 * Adjust available bytes according to refquota 2097 */ 2098 if (*refdbytesp < ds->ds_quota) 2099 *availbytesp = MIN(*availbytesp, 2100 ds->ds_quota - *refdbytesp); 2101 else 2102 *availbytesp = 0; 2103 } 2104 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2105 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2106 } 2107 2108 boolean_t 2109 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2110 { 2111 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2112 2113 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2114 dsl_pool_sync_context(dp)); 2115 if (ds->ds_prev == NULL) 2116 return (B_FALSE); 2117 if (ds->ds_phys->ds_bp.blk_birth > 2118 ds->ds_prev->ds_phys->ds_creation_txg) 2119 return (B_TRUE); 2120 return (B_FALSE); 2121 } 2122 2123 /* ARGSUSED */ 2124 static int 2125 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2126 { 2127 dsl_dataset_t *ds = arg1; 2128 char *newsnapname = arg2; 2129 dsl_dir_t *dd = ds->ds_dir; 2130 dsl_dataset_t *hds; 2131 uint64_t val; 2132 int err; 2133 2134 err = dsl_dataset_hold_obj(dd->dd_pool, 2135 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2136 if (err) 2137 return (err); 2138 2139 /* new name better not be in use */ 2140 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2141 dsl_dataset_rele(hds, FTAG); 2142 2143 if (err == 0) 2144 err = EEXIST; 2145 else if (err == ENOENT) 2146 err = 0; 2147 2148 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2149 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2150 err = ENAMETOOLONG; 2151 2152 return (err); 2153 } 2154 2155 static void 2156 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, 2157 cred_t *cr, dmu_tx_t *tx) 2158 { 2159 dsl_dataset_t *ds = arg1; 2160 const char *newsnapname = arg2; 2161 dsl_dir_t *dd = ds->ds_dir; 2162 objset_t *mos = dd->dd_pool->dp_meta_objset; 2163 dsl_dataset_t *hds; 2164 int err; 2165 2166 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2167 2168 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2169 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2170 2171 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2172 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2173 ASSERT3U(err, ==, 0); 2174 mutex_enter(&ds->ds_lock); 2175 (void) strcpy(ds->ds_snapname, newsnapname); 2176 mutex_exit(&ds->ds_lock); 2177 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2178 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2179 ASSERT3U(err, ==, 0); 2180 2181 spa_history_internal_log(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2182 cr, "dataset = %llu", ds->ds_object); 2183 dsl_dataset_rele(hds, FTAG); 2184 } 2185 2186 struct renamesnaparg { 2187 dsl_sync_task_group_t *dstg; 2188 char failed[MAXPATHLEN]; 2189 char *oldsnap; 2190 char *newsnap; 2191 }; 2192 2193 static int 2194 dsl_snapshot_rename_one(const char *name, void *arg) 2195 { 2196 struct renamesnaparg *ra = arg; 2197 dsl_dataset_t *ds = NULL; 2198 char *snapname; 2199 int err; 2200 2201 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); 2202 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); 2203 2204 /* 2205 * For recursive snapshot renames the parent won't be changing 2206 * so we just pass name for both the to/from argument. 2207 */ 2208 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); 2209 if (err != 0) { 2210 strfree(snapname); 2211 return (err == ENOENT ? 0 : err); 2212 } 2213 2214 #ifdef _KERNEL 2215 /* 2216 * For all filesystems undergoing rename, we'll need to unmount it. 2217 */ 2218 (void) zfs_unmount_snap(snapname, NULL); 2219 #endif 2220 err = dsl_dataset_hold(snapname, ra->dstg, &ds); 2221 if (err != 0) { 2222 strfree(snapname); 2223 return (err == ENOENT ? 0 : err); 2224 } 2225 2226 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2227 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2228 2229 strfree(snapname); 2230 return (0); 2231 } 2232 2233 static int 2234 dsl_recursive_rename(char *oldname, const char *newname) 2235 { 2236 int err; 2237 struct renamesnaparg *ra; 2238 dsl_sync_task_t *dst; 2239 spa_t *spa; 2240 char *cp, *fsname = spa_strdup(oldname); 2241 int len = strlen(oldname) + 1; 2242 2243 /* truncate the snapshot name to get the fsname */ 2244 cp = strchr(fsname, '@'); 2245 *cp = '\0'; 2246 2247 err = spa_open(fsname, &spa, FTAG); 2248 if (err) { 2249 kmem_free(fsname, len); 2250 return (err); 2251 } 2252 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2253 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2254 2255 ra->oldsnap = strchr(oldname, '@') + 1; 2256 ra->newsnap = strchr(newname, '@') + 1; 2257 *ra->failed = '\0'; 2258 2259 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2260 DS_FIND_CHILDREN); 2261 kmem_free(fsname, len); 2262 2263 if (err == 0) { 2264 err = dsl_sync_task_group_wait(ra->dstg); 2265 } 2266 2267 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2268 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2269 dsl_dataset_t *ds = dst->dst_arg1; 2270 if (dst->dst_err) { 2271 dsl_dir_name(ds->ds_dir, ra->failed); 2272 (void) strlcat(ra->failed, "@", sizeof (ra->failed)); 2273 (void) strlcat(ra->failed, ra->newsnap, 2274 sizeof (ra->failed)); 2275 } 2276 dsl_dataset_rele(ds, ra->dstg); 2277 } 2278 2279 if (err) 2280 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); 2281 2282 dsl_sync_task_group_destroy(ra->dstg); 2283 kmem_free(ra, sizeof (struct renamesnaparg)); 2284 spa_close(spa, FTAG); 2285 return (err); 2286 } 2287 2288 static int 2289 dsl_valid_rename(const char *oldname, void *arg) 2290 { 2291 int delta = *(int *)arg; 2292 2293 if (strlen(oldname) + delta >= MAXNAMELEN) 2294 return (ENAMETOOLONG); 2295 2296 return (0); 2297 } 2298 2299 #pragma weak dmu_objset_rename = dsl_dataset_rename 2300 int 2301 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2302 { 2303 dsl_dir_t *dd; 2304 dsl_dataset_t *ds; 2305 const char *tail; 2306 int err; 2307 2308 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2309 if (err) 2310 return (err); 2311 /* 2312 * If there are more than 2 references there may be holds 2313 * hanging around that haven't been cleared out yet. 2314 */ 2315 if (dmu_buf_refcount(dd->dd_dbuf) > 2) 2316 txg_wait_synced(dd->dd_pool, 0); 2317 if (tail == NULL) { 2318 int delta = strlen(newname) - strlen(oldname); 2319 2320 /* if we're growing, validate child name lengths */ 2321 if (delta > 0) 2322 err = dmu_objset_find(oldname, dsl_valid_rename, 2323 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2324 2325 if (!err) 2326 err = dsl_dir_rename(dd, newname); 2327 dsl_dir_close(dd, FTAG); 2328 return (err); 2329 } 2330 if (tail[0] != '@') { 2331 /* the name ended in a nonexistent component */ 2332 dsl_dir_close(dd, FTAG); 2333 return (ENOENT); 2334 } 2335 2336 dsl_dir_close(dd, FTAG); 2337 2338 /* new name must be snapshot in same filesystem */ 2339 tail = strchr(newname, '@'); 2340 if (tail == NULL) 2341 return (EINVAL); 2342 tail++; 2343 if (strncmp(oldname, newname, tail - newname) != 0) 2344 return (EXDEV); 2345 2346 if (recursive) { 2347 err = dsl_recursive_rename(oldname, newname); 2348 } else { 2349 err = dsl_dataset_hold(oldname, FTAG, &ds); 2350 if (err) 2351 return (err); 2352 2353 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2354 dsl_dataset_snapshot_rename_check, 2355 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2356 2357 dsl_dataset_rele(ds, FTAG); 2358 } 2359 2360 return (err); 2361 } 2362 2363 struct promotenode { 2364 list_node_t link; 2365 dsl_dataset_t *ds; 2366 }; 2367 2368 struct promotearg { 2369 list_t shared_snaps, origin_snaps, clone_snaps; 2370 dsl_dataset_t *origin_origin, *origin_head; 2371 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2372 char *err_ds; 2373 }; 2374 2375 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2376 2377 /* ARGSUSED */ 2378 static int 2379 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2380 { 2381 dsl_dataset_t *hds = arg1; 2382 struct promotearg *pa = arg2; 2383 struct promotenode *snap = list_head(&pa->shared_snaps); 2384 dsl_dataset_t *origin_ds = snap->ds; 2385 int err; 2386 2387 /* Check that it is a real clone */ 2388 if (!dsl_dir_is_clone(hds->ds_dir)) 2389 return (EINVAL); 2390 2391 /* Since this is so expensive, don't do the preliminary check */ 2392 if (!dmu_tx_is_syncing(tx)) 2393 return (0); 2394 2395 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2396 return (EXDEV); 2397 2398 /* compute origin's new unique space */ 2399 snap = list_tail(&pa->clone_snaps); 2400 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2401 err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2402 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &pa->unique); 2403 if (err) 2404 return (err); 2405 2406 /* 2407 * Walk the snapshots that we are moving 2408 * 2409 * Compute space to transfer. Consider the incremental changes 2410 * to used for each snapshot: 2411 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2412 * So each snapshot gave birth to: 2413 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2414 * So a sequence would look like: 2415 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2416 * Which simplifies to: 2417 * uN + kN + kN-1 + ... + k1 + k0 2418 * Note however, if we stop before we reach the ORIGIN we get: 2419 * uN + kN + kN-1 + ... + kM - uM-1 2420 */ 2421 pa->used = origin_ds->ds_phys->ds_used_bytes; 2422 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2423 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2424 for (snap = list_head(&pa->shared_snaps); snap; 2425 snap = list_next(&pa->shared_snaps, snap)) { 2426 uint64_t val, dlused, dlcomp, dluncomp; 2427 dsl_dataset_t *ds = snap->ds; 2428 2429 /* Check that the snapshot name does not conflict */ 2430 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2431 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2432 if (err == 0) { 2433 err = EEXIST; 2434 goto out; 2435 } 2436 if (err != ENOENT) 2437 goto out; 2438 2439 /* The very first snapshot does not have a deadlist */ 2440 if (ds->ds_phys->ds_prev_snap_obj == 0) 2441 continue; 2442 2443 if (err = bplist_space(&ds->ds_deadlist, 2444 &dlused, &dlcomp, &dluncomp)) 2445 goto out; 2446 pa->used += dlused; 2447 pa->comp += dlcomp; 2448 pa->uncomp += dluncomp; 2449 } 2450 2451 /* 2452 * If we are a clone of a clone then we never reached ORIGIN, 2453 * so we need to subtract out the clone origin's used space. 2454 */ 2455 if (pa->origin_origin) { 2456 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes; 2457 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2458 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2459 } 2460 2461 /* Check that there is enough space here */ 2462 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2463 pa->used); 2464 if (err) 2465 return (err); 2466 2467 /* 2468 * Compute the amounts of space that will be used by snapshots 2469 * after the promotion (for both origin and clone). For each, 2470 * it is the amount of space that will be on all of their 2471 * deadlists (that was not born before their new origin). 2472 */ 2473 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2474 uint64_t space; 2475 2476 /* 2477 * Note, typically this will not be a clone of a clone, 2478 * so snap->ds->ds_origin_txg will be < TXG_INITIAL, so 2479 * these snaplist_space() -> bplist_space_birthrange() 2480 * calls will be fast because they do not have to 2481 * iterate over all bps. 2482 */ 2483 snap = list_head(&pa->origin_snaps); 2484 err = snaplist_space(&pa->shared_snaps, 2485 snap->ds->ds_origin_txg, &pa->cloneusedsnap); 2486 if (err) 2487 return (err); 2488 2489 err = snaplist_space(&pa->clone_snaps, 2490 snap->ds->ds_origin_txg, &space); 2491 if (err) 2492 return (err); 2493 pa->cloneusedsnap += space; 2494 } 2495 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2496 err = snaplist_space(&pa->origin_snaps, 2497 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2498 if (err) 2499 return (err); 2500 } 2501 2502 return (0); 2503 out: 2504 pa->err_ds = snap->ds->ds_snapname; 2505 return (err); 2506 } 2507 2508 static void 2509 dsl_dataset_promote_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2510 { 2511 dsl_dataset_t *hds = arg1; 2512 struct promotearg *pa = arg2; 2513 struct promotenode *snap = list_head(&pa->shared_snaps); 2514 dsl_dataset_t *origin_ds = snap->ds; 2515 dsl_dataset_t *origin_head; 2516 dsl_dir_t *dd = hds->ds_dir; 2517 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2518 dsl_dir_t *odd = NULL; 2519 uint64_t oldnext_obj; 2520 int64_t delta; 2521 2522 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2523 2524 snap = list_head(&pa->origin_snaps); 2525 origin_head = snap->ds; 2526 2527 /* 2528 * We need to explicitly open odd, since origin_ds's dd will be 2529 * changing. 2530 */ 2531 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2532 NULL, FTAG, &odd)); 2533 2534 /* change origin's next snap */ 2535 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2536 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2537 snap = list_tail(&pa->clone_snaps); 2538 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2539 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2540 2541 /* change the origin's next clone */ 2542 if (origin_ds->ds_phys->ds_next_clones_obj) { 2543 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2544 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2545 origin_ds->ds_phys->ds_next_clones_obj, 2546 oldnext_obj, tx)); 2547 } 2548 2549 /* change origin */ 2550 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2551 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2552 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2553 hds->ds_origin_txg = origin_head->ds_origin_txg; 2554 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2555 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2556 origin_head->ds_origin_txg = origin_ds->ds_phys->ds_creation_txg; 2557 2558 /* move snapshots to this dir */ 2559 for (snap = list_head(&pa->shared_snaps); snap; 2560 snap = list_next(&pa->shared_snaps, snap)) { 2561 dsl_dataset_t *ds = snap->ds; 2562 2563 /* unregister props as dsl_dir is changing */ 2564 if (ds->ds_objset) { 2565 dmu_objset_evict(ds->ds_objset); 2566 ds->ds_objset = NULL; 2567 } 2568 /* move snap name entry */ 2569 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2570 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2571 ds->ds_snapname, tx)); 2572 VERIFY(0 == zap_add(dp->dp_meta_objset, 2573 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2574 8, 1, &ds->ds_object, tx)); 2575 /* change containing dsl_dir */ 2576 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2577 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2578 ds->ds_phys->ds_dir_obj = dd->dd_object; 2579 ASSERT3P(ds->ds_dir, ==, odd); 2580 dsl_dir_close(ds->ds_dir, ds); 2581 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2582 NULL, ds, &ds->ds_dir)); 2583 2584 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2585 } 2586 2587 /* 2588 * Change space accounting. 2589 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2590 * both be valid, or both be 0 (resulting in delta == 0). This 2591 * is true for each of {clone,origin} independently. 2592 */ 2593 2594 delta = pa->cloneusedsnap - 2595 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2596 ASSERT3S(delta, >=, 0); 2597 ASSERT3U(pa->used, >=, delta); 2598 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2599 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2600 pa->used - delta, pa->comp, pa->uncomp, tx); 2601 2602 delta = pa->originusedsnap - 2603 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2604 ASSERT3S(delta, <=, 0); 2605 ASSERT3U(pa->used, >=, -delta); 2606 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2607 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2608 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2609 2610 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2611 2612 /* log history record */ 2613 spa_history_internal_log(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2614 cr, "dataset = %llu", hds->ds_object); 2615 2616 dsl_dir_close(odd, FTAG); 2617 } 2618 2619 static char *snaplist_tag = "snaplist"; 2620 /* 2621 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2622 * (exclusive) and last_obj (inclusive). The list will be in reverse 2623 * order (last_obj will be the list_head()). If first_obj == 0, do all 2624 * snapshots back to this dataset's origin. 2625 */ 2626 static int 2627 snaplist_make(dsl_pool_t *dp, boolean_t own, 2628 uint64_t first_obj, uint64_t last_obj, list_t *l) 2629 { 2630 uint64_t obj = last_obj; 2631 2632 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2633 2634 list_create(l, sizeof (struct promotenode), 2635 offsetof(struct promotenode, link)); 2636 2637 while (obj != first_obj) { 2638 dsl_dataset_t *ds; 2639 struct promotenode *snap; 2640 int err; 2641 2642 if (own) { 2643 err = dsl_dataset_own_obj(dp, obj, 2644 0, snaplist_tag, &ds); 2645 if (err == 0) 2646 dsl_dataset_make_exclusive(ds, snaplist_tag); 2647 } else { 2648 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2649 } 2650 if (err == ENOENT) { 2651 /* lost race with snapshot destroy */ 2652 struct promotenode *last = list_tail(l); 2653 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2654 obj = last->ds->ds_phys->ds_prev_snap_obj; 2655 continue; 2656 } else if (err) { 2657 return (err); 2658 } 2659 2660 if (first_obj == 0) 2661 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2662 2663 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2664 snap->ds = ds; 2665 list_insert_tail(l, snap); 2666 obj = ds->ds_phys->ds_prev_snap_obj; 2667 } 2668 2669 return (0); 2670 } 2671 2672 static int 2673 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2674 { 2675 struct promotenode *snap; 2676 2677 *spacep = 0; 2678 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2679 uint64_t used; 2680 int err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2681 mintxg, UINT64_MAX, &used); 2682 if (err) 2683 return (err); 2684 *spacep += used; 2685 } 2686 return (0); 2687 } 2688 2689 static void 2690 snaplist_destroy(list_t *l, boolean_t own) 2691 { 2692 struct promotenode *snap; 2693 2694 if (!l || !list_link_active(&l->list_head)) 2695 return; 2696 2697 while ((snap = list_tail(l)) != NULL) { 2698 list_remove(l, snap); 2699 if (own) 2700 dsl_dataset_disown(snap->ds, snaplist_tag); 2701 else 2702 dsl_dataset_rele(snap->ds, snaplist_tag); 2703 kmem_free(snap, sizeof (struct promotenode)); 2704 } 2705 list_destroy(l); 2706 } 2707 2708 /* 2709 * Promote a clone. Nomenclature note: 2710 * "clone" or "cds": the original clone which is being promoted 2711 * "origin" or "ods": the snapshot which is originally clone's origin 2712 * "origin head" or "ohds": the dataset which is the head 2713 * (filesystem/volume) for the origin 2714 * "origin origin": the origin of the origin's filesystem (typically 2715 * NULL, indicating that the clone is not a clone of a clone). 2716 */ 2717 int 2718 dsl_dataset_promote(const char *name, char *conflsnap) 2719 { 2720 dsl_dataset_t *ds; 2721 dsl_dir_t *dd; 2722 dsl_pool_t *dp; 2723 dmu_object_info_t doi; 2724 struct promotearg pa = { 0 }; 2725 struct promotenode *snap; 2726 int err; 2727 2728 err = dsl_dataset_hold(name, FTAG, &ds); 2729 if (err) 2730 return (err); 2731 dd = ds->ds_dir; 2732 dp = dd->dd_pool; 2733 2734 err = dmu_object_info(dp->dp_meta_objset, 2735 ds->ds_phys->ds_snapnames_zapobj, &doi); 2736 if (err) { 2737 dsl_dataset_rele(ds, FTAG); 2738 return (err); 2739 } 2740 2741 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 2742 dsl_dataset_rele(ds, FTAG); 2743 return (EINVAL); 2744 } 2745 2746 /* 2747 * We are going to inherit all the snapshots taken before our 2748 * origin (i.e., our new origin will be our parent's origin). 2749 * Take ownership of them so that we can rename them into our 2750 * namespace. 2751 */ 2752 rw_enter(&dp->dp_config_rwlock, RW_READER); 2753 2754 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 2755 &pa.shared_snaps); 2756 if (err != 0) 2757 goto out; 2758 2759 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 2760 if (err != 0) 2761 goto out; 2762 2763 snap = list_head(&pa.shared_snaps); 2764 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 2765 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 2766 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 2767 if (err != 0) 2768 goto out; 2769 2770 if (dsl_dir_is_clone(snap->ds->ds_dir)) { 2771 err = dsl_dataset_own_obj(dp, 2772 snap->ds->ds_dir->dd_phys->dd_origin_obj, 2773 0, FTAG, &pa.origin_origin); 2774 if (err != 0) 2775 goto out; 2776 } 2777 2778 out: 2779 rw_exit(&dp->dp_config_rwlock); 2780 2781 /* 2782 * Add in 128x the snapnames zapobj size, since we will be moving 2783 * a bunch of snapnames to the promoted ds, and dirtying their 2784 * bonus buffers. 2785 */ 2786 if (err == 0) { 2787 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 2788 dsl_dataset_promote_sync, ds, &pa, 2789 2 + 2 * doi.doi_physical_blocks_512); 2790 if (err && pa.err_ds && conflsnap) 2791 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 2792 } 2793 2794 snaplist_destroy(&pa.shared_snaps, B_TRUE); 2795 snaplist_destroy(&pa.clone_snaps, B_FALSE); 2796 snaplist_destroy(&pa.origin_snaps, B_FALSE); 2797 if (pa.origin_origin) 2798 dsl_dataset_disown(pa.origin_origin, FTAG); 2799 dsl_dataset_rele(ds, FTAG); 2800 return (err); 2801 } 2802 2803 struct cloneswaparg { 2804 dsl_dataset_t *cds; /* clone dataset */ 2805 dsl_dataset_t *ohds; /* origin's head dataset */ 2806 boolean_t force; 2807 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 2808 }; 2809 2810 /* ARGSUSED */ 2811 static int 2812 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 2813 { 2814 struct cloneswaparg *csa = arg1; 2815 2816 /* they should both be heads */ 2817 if (dsl_dataset_is_snapshot(csa->cds) || 2818 dsl_dataset_is_snapshot(csa->ohds)) 2819 return (EINVAL); 2820 2821 /* the branch point should be just before them */ 2822 if (csa->cds->ds_prev != csa->ohds->ds_prev) 2823 return (EINVAL); 2824 2825 /* cds should be the clone (unless they are unrelated) */ 2826 if (csa->cds->ds_prev != NULL && 2827 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 2828 csa->ohds->ds_object != 2829 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 2830 return (EINVAL); 2831 2832 /* the clone should be a child of the origin */ 2833 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 2834 return (EINVAL); 2835 2836 /* ohds shouldn't be modified unless 'force' */ 2837 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 2838 return (ETXTBSY); 2839 2840 /* adjust amount of any unconsumed refreservation */ 2841 csa->unused_refres_delta = 2842 (int64_t)MIN(csa->ohds->ds_reserved, 2843 csa->ohds->ds_phys->ds_unique_bytes) - 2844 (int64_t)MIN(csa->ohds->ds_reserved, 2845 csa->cds->ds_phys->ds_unique_bytes); 2846 2847 if (csa->unused_refres_delta > 0 && 2848 csa->unused_refres_delta > 2849 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 2850 return (ENOSPC); 2851 2852 if (csa->ohds->ds_quota != 0 && 2853 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 2854 return (EDQUOT); 2855 2856 return (0); 2857 } 2858 2859 /* ARGSUSED */ 2860 static void 2861 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2862 { 2863 struct cloneswaparg *csa = arg1; 2864 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 2865 2866 ASSERT(csa->cds->ds_reserved == 0); 2867 ASSERT(csa->ohds->ds_quota == 0 || 2868 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 2869 2870 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 2871 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 2872 2873 if (csa->cds->ds_objset != NULL) { 2874 dmu_objset_evict(csa->cds->ds_objset); 2875 csa->cds->ds_objset = NULL; 2876 } 2877 2878 if (csa->ohds->ds_objset != NULL) { 2879 dmu_objset_evict(csa->ohds->ds_objset); 2880 csa->ohds->ds_objset = NULL; 2881 } 2882 2883 /* 2884 * Reset origin's unique bytes, if it exists. 2885 */ 2886 if (csa->cds->ds_prev) { 2887 dsl_dataset_t *origin = csa->cds->ds_prev; 2888 dmu_buf_will_dirty(origin->ds_dbuf, tx); 2889 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2890 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2891 &origin->ds_phys->ds_unique_bytes)); 2892 } 2893 2894 /* swap blkptrs */ 2895 { 2896 blkptr_t tmp; 2897 tmp = csa->ohds->ds_phys->ds_bp; 2898 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 2899 csa->cds->ds_phys->ds_bp = tmp; 2900 } 2901 2902 /* set dd_*_bytes */ 2903 { 2904 int64_t dused, dcomp, duncomp; 2905 uint64_t cdl_used, cdl_comp, cdl_uncomp; 2906 uint64_t odl_used, odl_comp, odl_uncomp; 2907 2908 ASSERT3U(csa->cds->ds_dir->dd_phys-> 2909 dd_used_breakdown[DD_USED_SNAP], ==, 0); 2910 2911 VERIFY(0 == bplist_space(&csa->cds->ds_deadlist, &cdl_used, 2912 &cdl_comp, &cdl_uncomp)); 2913 VERIFY(0 == bplist_space(&csa->ohds->ds_deadlist, &odl_used, 2914 &odl_comp, &odl_uncomp)); 2915 2916 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used - 2917 (csa->ohds->ds_phys->ds_used_bytes + odl_used); 2918 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 2919 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 2920 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 2921 cdl_uncomp - 2922 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 2923 2924 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 2925 dused, dcomp, duncomp, tx); 2926 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 2927 -dused, -dcomp, -duncomp, tx); 2928 2929 /* 2930 * The difference in the space used by snapshots is the 2931 * difference in snapshot space due to the head's 2932 * deadlist (since that's the only thing that's 2933 * changing that affects the snapused). 2934 */ 2935 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2936 csa->ohds->ds_origin_txg, UINT64_MAX, &cdl_used)); 2937 VERIFY(0 == bplist_space_birthrange(&csa->ohds->ds_deadlist, 2938 csa->ohds->ds_origin_txg, UINT64_MAX, &odl_used)); 2939 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 2940 DD_USED_HEAD, DD_USED_SNAP, tx); 2941 } 2942 2943 #define SWITCH64(x, y) \ 2944 { \ 2945 uint64_t __tmp = (x); \ 2946 (x) = (y); \ 2947 (y) = __tmp; \ 2948 } 2949 2950 /* swap ds_*_bytes */ 2951 SWITCH64(csa->ohds->ds_phys->ds_used_bytes, 2952 csa->cds->ds_phys->ds_used_bytes); 2953 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 2954 csa->cds->ds_phys->ds_compressed_bytes); 2955 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 2956 csa->cds->ds_phys->ds_uncompressed_bytes); 2957 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 2958 csa->cds->ds_phys->ds_unique_bytes); 2959 2960 /* apply any parent delta for change in unconsumed refreservation */ 2961 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 2962 csa->unused_refres_delta, 0, 0, tx); 2963 2964 /* swap deadlists */ 2965 bplist_close(&csa->cds->ds_deadlist); 2966 bplist_close(&csa->ohds->ds_deadlist); 2967 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 2968 csa->cds->ds_phys->ds_deadlist_obj); 2969 VERIFY(0 == bplist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 2970 csa->cds->ds_phys->ds_deadlist_obj)); 2971 VERIFY(0 == bplist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 2972 csa->ohds->ds_phys->ds_deadlist_obj)); 2973 2974 dsl_pool_ds_clone_swapped(csa->ohds, csa->cds, tx); 2975 } 2976 2977 /* 2978 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 2979 * recv" into an existing fs to swizzle the file system to the new 2980 * version, and by "zfs rollback". Can also be used to swap two 2981 * independent head datasets if neither has any snapshots. 2982 */ 2983 int 2984 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 2985 boolean_t force) 2986 { 2987 struct cloneswaparg csa; 2988 int error; 2989 2990 ASSERT(clone->ds_owner); 2991 ASSERT(origin_head->ds_owner); 2992 retry: 2993 /* Need exclusive access for the swap */ 2994 rw_enter(&clone->ds_rwlock, RW_WRITER); 2995 if (!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 2996 rw_exit(&clone->ds_rwlock); 2997 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 2998 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 2999 rw_exit(&origin_head->ds_rwlock); 3000 goto retry; 3001 } 3002 } 3003 csa.cds = clone; 3004 csa.ohds = origin_head; 3005 csa.force = force; 3006 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3007 dsl_dataset_clone_swap_check, 3008 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3009 return (error); 3010 } 3011 3012 /* 3013 * Given a pool name and a dataset object number in that pool, 3014 * return the name of that dataset. 3015 */ 3016 int 3017 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3018 { 3019 spa_t *spa; 3020 dsl_pool_t *dp; 3021 dsl_dataset_t *ds; 3022 int error; 3023 3024 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3025 return (error); 3026 dp = spa_get_dsl(spa); 3027 rw_enter(&dp->dp_config_rwlock, RW_READER); 3028 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3029 dsl_dataset_name(ds, buf); 3030 dsl_dataset_rele(ds, FTAG); 3031 } 3032 rw_exit(&dp->dp_config_rwlock); 3033 spa_close(spa, FTAG); 3034 3035 return (error); 3036 } 3037 3038 int 3039 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3040 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3041 { 3042 int error = 0; 3043 3044 ASSERT3S(asize, >, 0); 3045 3046 /* 3047 * *ref_rsrv is the portion of asize that will come from any 3048 * unconsumed refreservation space. 3049 */ 3050 *ref_rsrv = 0; 3051 3052 mutex_enter(&ds->ds_lock); 3053 /* 3054 * Make a space adjustment for reserved bytes. 3055 */ 3056 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3057 ASSERT3U(*used, >=, 3058 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3059 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3060 *ref_rsrv = 3061 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3062 } 3063 3064 if (!check_quota || ds->ds_quota == 0) { 3065 mutex_exit(&ds->ds_lock); 3066 return (0); 3067 } 3068 /* 3069 * If they are requesting more space, and our current estimate 3070 * is over quota, they get to try again unless the actual 3071 * on-disk is over quota and there are no pending changes (which 3072 * may free up space for us). 3073 */ 3074 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) { 3075 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota) 3076 error = ERESTART; 3077 else 3078 error = EDQUOT; 3079 } 3080 mutex_exit(&ds->ds_lock); 3081 3082 return (error); 3083 } 3084 3085 /* ARGSUSED */ 3086 static int 3087 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3088 { 3089 dsl_dataset_t *ds = arg1; 3090 dsl_prop_setarg_t *psa = arg2; 3091 int err; 3092 3093 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3094 return (ENOTSUP); 3095 3096 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3097 return (err); 3098 3099 if (psa->psa_effective_value == 0) 3100 return (0); 3101 3102 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes || 3103 psa->psa_effective_value < ds->ds_reserved) 3104 return (ENOSPC); 3105 3106 return (0); 3107 } 3108 3109 extern void dsl_prop_set_sync(void *, void *, cred_t *, dmu_tx_t *); 3110 3111 void 3112 dsl_dataset_set_quota_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3113 { 3114 dsl_dataset_t *ds = arg1; 3115 dsl_prop_setarg_t *psa = arg2; 3116 uint64_t effective_value = psa->psa_effective_value; 3117 3118 dsl_prop_set_sync(ds, psa, cr, tx); 3119 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3120 3121 if (ds->ds_quota != effective_value) { 3122 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3123 ds->ds_quota = effective_value; 3124 3125 spa_history_internal_log(LOG_DS_REFQUOTA, 3126 ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu ", 3127 (longlong_t)ds->ds_quota, ds->ds_object); 3128 } 3129 } 3130 3131 int 3132 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3133 { 3134 dsl_dataset_t *ds; 3135 dsl_prop_setarg_t psa; 3136 int err; 3137 3138 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3139 3140 err = dsl_dataset_hold(dsname, FTAG, &ds); 3141 if (err) 3142 return (err); 3143 3144 /* 3145 * If someone removes a file, then tries to set the quota, we 3146 * want to make sure the file freeing takes effect. 3147 */ 3148 txg_wait_open(ds->ds_dir->dd_pool, 0); 3149 3150 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3151 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3152 ds, &psa, 0); 3153 3154 dsl_dataset_rele(ds, FTAG); 3155 return (err); 3156 } 3157 3158 static int 3159 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3160 { 3161 dsl_dataset_t *ds = arg1; 3162 dsl_prop_setarg_t *psa = arg2; 3163 uint64_t effective_value; 3164 uint64_t unique; 3165 int err; 3166 3167 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3168 SPA_VERSION_REFRESERVATION) 3169 return (ENOTSUP); 3170 3171 if (dsl_dataset_is_snapshot(ds)) 3172 return (EINVAL); 3173 3174 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3175 return (err); 3176 3177 effective_value = psa->psa_effective_value; 3178 3179 /* 3180 * If we are doing the preliminary check in open context, the 3181 * space estimates may be inaccurate. 3182 */ 3183 if (!dmu_tx_is_syncing(tx)) 3184 return (0); 3185 3186 mutex_enter(&ds->ds_lock); 3187 unique = dsl_dataset_unique(ds); 3188 mutex_exit(&ds->ds_lock); 3189 3190 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3191 uint64_t delta = MAX(unique, effective_value) - 3192 MAX(unique, ds->ds_reserved); 3193 3194 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3195 return (ENOSPC); 3196 if (ds->ds_quota > 0 && 3197 effective_value > ds->ds_quota) 3198 return (ENOSPC); 3199 } 3200 3201 return (0); 3202 } 3203 3204 /* ARGSUSED */ 3205 static void 3206 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, cred_t *cr, 3207 dmu_tx_t *tx) 3208 { 3209 dsl_dataset_t *ds = arg1; 3210 dsl_prop_setarg_t *psa = arg2; 3211 uint64_t effective_value = psa->psa_effective_value; 3212 uint64_t unique; 3213 int64_t delta; 3214 3215 dsl_prop_set_sync(ds, psa, cr, tx); 3216 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3217 3218 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3219 3220 mutex_enter(&ds->ds_dir->dd_lock); 3221 mutex_enter(&ds->ds_lock); 3222 unique = dsl_dataset_unique(ds); 3223 delta = MAX(0, (int64_t)(effective_value - unique)) - 3224 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3225 ds->ds_reserved = effective_value; 3226 mutex_exit(&ds->ds_lock); 3227 3228 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3229 mutex_exit(&ds->ds_dir->dd_lock); 3230 3231 spa_history_internal_log(LOG_DS_REFRESERV, 3232 ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu", 3233 (longlong_t)effective_value, ds->ds_object); 3234 } 3235 3236 int 3237 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3238 uint64_t reservation) 3239 { 3240 dsl_dataset_t *ds; 3241 dsl_prop_setarg_t psa; 3242 int err; 3243 3244 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3245 &reservation); 3246 3247 err = dsl_dataset_hold(dsname, FTAG, &ds); 3248 if (err) 3249 return (err); 3250 3251 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3252 dsl_dataset_set_reservation_check, 3253 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3254 3255 dsl_dataset_rele(ds, FTAG); 3256 return (err); 3257 } 3258 3259 struct dsl_ds_holdarg { 3260 dsl_sync_task_group_t *dstg; 3261 char *htag; 3262 char *snapname; 3263 boolean_t recursive; 3264 boolean_t gotone; 3265 boolean_t temphold; 3266 char failed[MAXPATHLEN]; 3267 }; 3268 3269 /* 3270 * The max length of a temporary tag prefix is the number of hex digits 3271 * required to express UINT64_MAX plus one for the hyphen. 3272 */ 3273 #define MAX_TAG_PREFIX_LEN 17 3274 3275 static int 3276 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3277 { 3278 dsl_dataset_t *ds = arg1; 3279 struct dsl_ds_holdarg *ha = arg2; 3280 char *htag = ha->htag; 3281 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3282 int error = 0; 3283 3284 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3285 return (ENOTSUP); 3286 3287 if (!dsl_dataset_is_snapshot(ds)) 3288 return (EINVAL); 3289 3290 /* tags must be unique */ 3291 mutex_enter(&ds->ds_lock); 3292 if (ds->ds_phys->ds_userrefs_obj) { 3293 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3294 8, 1, tx); 3295 if (error == 0) 3296 error = EEXIST; 3297 else if (error == ENOENT) 3298 error = 0; 3299 } 3300 mutex_exit(&ds->ds_lock); 3301 3302 if (error == 0 && ha->temphold && 3303 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3304 error = E2BIG; 3305 3306 return (error); 3307 } 3308 3309 static void 3310 dsl_dataset_user_hold_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3311 { 3312 dsl_dataset_t *ds = arg1; 3313 struct dsl_ds_holdarg *ha = arg2; 3314 char *htag = ha->htag; 3315 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3316 objset_t *mos = dp->dp_meta_objset; 3317 uint64_t now = gethrestime_sec(); 3318 uint64_t zapobj; 3319 3320 mutex_enter(&ds->ds_lock); 3321 if (ds->ds_phys->ds_userrefs_obj == 0) { 3322 /* 3323 * This is the first user hold for this dataset. Create 3324 * the userrefs zap object. 3325 */ 3326 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3327 zapobj = ds->ds_phys->ds_userrefs_obj = 3328 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3329 } else { 3330 zapobj = ds->ds_phys->ds_userrefs_obj; 3331 } 3332 ds->ds_userrefs++; 3333 mutex_exit(&ds->ds_lock); 3334 3335 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3336 3337 if (ha->temphold) { 3338 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3339 htag, &now, tx)); 3340 } 3341 3342 spa_history_internal_log(LOG_DS_USER_HOLD, 3343 dp->dp_spa, tx, cr, "<%s> temp = %d dataset = %llu", htag, 3344 (int)ha->temphold, ds->ds_object); 3345 } 3346 3347 static int 3348 dsl_dataset_user_hold_one(const char *dsname, void *arg) 3349 { 3350 struct dsl_ds_holdarg *ha = arg; 3351 dsl_dataset_t *ds; 3352 int error; 3353 char *name; 3354 3355 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3356 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3357 error = dsl_dataset_hold(name, ha->dstg, &ds); 3358 strfree(name); 3359 if (error == 0) { 3360 ha->gotone = B_TRUE; 3361 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3362 dsl_dataset_user_hold_sync, ds, ha, 0); 3363 } else if (error == ENOENT && ha->recursive) { 3364 error = 0; 3365 } else { 3366 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3367 } 3368 return (error); 3369 } 3370 3371 int 3372 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3373 boolean_t recursive, boolean_t temphold) 3374 { 3375 struct dsl_ds_holdarg *ha; 3376 dsl_sync_task_t *dst; 3377 spa_t *spa; 3378 int error; 3379 3380 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3381 3382 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3383 3384 error = spa_open(dsname, &spa, FTAG); 3385 if (error) { 3386 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3387 return (error); 3388 } 3389 3390 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3391 ha->htag = htag; 3392 ha->snapname = snapname; 3393 ha->recursive = recursive; 3394 ha->temphold = temphold; 3395 if (recursive) { 3396 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3397 ha, DS_FIND_CHILDREN); 3398 } else { 3399 error = dsl_dataset_user_hold_one(dsname, ha); 3400 } 3401 if (error == 0) 3402 error = dsl_sync_task_group_wait(ha->dstg); 3403 3404 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3405 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3406 dsl_dataset_t *ds = dst->dst_arg1; 3407 3408 if (dst->dst_err) { 3409 dsl_dataset_name(ds, ha->failed); 3410 *strchr(ha->failed, '@') = '\0'; 3411 } 3412 dsl_dataset_rele(ds, ha->dstg); 3413 } 3414 3415 if (error == 0 && recursive && !ha->gotone) 3416 error = ENOENT; 3417 3418 if (error) 3419 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3420 3421 dsl_sync_task_group_destroy(ha->dstg); 3422 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3423 spa_close(spa, FTAG); 3424 return (error); 3425 } 3426 3427 struct dsl_ds_releasearg { 3428 dsl_dataset_t *ds; 3429 const char *htag; 3430 boolean_t own; /* do we own or just hold ds? */ 3431 }; 3432 3433 static int 3434 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3435 boolean_t *might_destroy) 3436 { 3437 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3438 uint64_t zapobj; 3439 uint64_t tmp; 3440 int error; 3441 3442 *might_destroy = B_FALSE; 3443 3444 mutex_enter(&ds->ds_lock); 3445 zapobj = ds->ds_phys->ds_userrefs_obj; 3446 if (zapobj == 0) { 3447 /* The tag can't possibly exist */ 3448 mutex_exit(&ds->ds_lock); 3449 return (ESRCH); 3450 } 3451 3452 /* Make sure the tag exists */ 3453 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3454 if (error) { 3455 mutex_exit(&ds->ds_lock); 3456 if (error == ENOENT) 3457 error = ESRCH; 3458 return (error); 3459 } 3460 3461 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3462 DS_IS_DEFER_DESTROY(ds)) 3463 *might_destroy = B_TRUE; 3464 3465 mutex_exit(&ds->ds_lock); 3466 return (0); 3467 } 3468 3469 static int 3470 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3471 { 3472 struct dsl_ds_releasearg *ra = arg1; 3473 dsl_dataset_t *ds = ra->ds; 3474 boolean_t might_destroy; 3475 int error; 3476 3477 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3478 return (ENOTSUP); 3479 3480 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3481 if (error) 3482 return (error); 3483 3484 if (might_destroy) { 3485 struct dsl_ds_destroyarg dsda = {0}; 3486 3487 if (dmu_tx_is_syncing(tx)) { 3488 /* 3489 * If we're not prepared to remove the snapshot, 3490 * we can't allow the release to happen right now. 3491 */ 3492 if (!ra->own) 3493 return (EBUSY); 3494 if (ds->ds_objset) { 3495 dmu_objset_evict(ds->ds_objset); 3496 ds->ds_objset = NULL; 3497 } 3498 } 3499 dsda.ds = ds; 3500 dsda.releasing = B_TRUE; 3501 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3502 } 3503 3504 return (0); 3505 } 3506 3507 static void 3508 dsl_dataset_user_release_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 3509 { 3510 struct dsl_ds_releasearg *ra = arg1; 3511 dsl_dataset_t *ds = ra->ds; 3512 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3513 objset_t *mos = dp->dp_meta_objset; 3514 uint64_t zapobj; 3515 uint64_t dsobj = ds->ds_object; 3516 uint64_t refs; 3517 int error; 3518 3519 mutex_enter(&ds->ds_lock); 3520 ds->ds_userrefs--; 3521 refs = ds->ds_userrefs; 3522 mutex_exit(&ds->ds_lock); 3523 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3524 VERIFY(error == 0 || error == ENOENT); 3525 zapobj = ds->ds_phys->ds_userrefs_obj; 3526 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3527 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3528 DS_IS_DEFER_DESTROY(ds)) { 3529 struct dsl_ds_destroyarg dsda = {0}; 3530 3531 ASSERT(ra->own); 3532 dsda.ds = ds; 3533 dsda.releasing = B_TRUE; 3534 /* We already did the destroy_check */ 3535 dsl_dataset_destroy_sync(&dsda, tag, cr, tx); 3536 } 3537 3538 spa_history_internal_log(LOG_DS_USER_RELEASE, 3539 dp->dp_spa, tx, cr, "<%s> %lld dataset = %llu", 3540 ra->htag, (longlong_t)refs, dsobj); 3541 } 3542 3543 static int 3544 dsl_dataset_user_release_one(const char *dsname, void *arg) 3545 { 3546 struct dsl_ds_holdarg *ha = arg; 3547 struct dsl_ds_releasearg *ra; 3548 dsl_dataset_t *ds; 3549 int error; 3550 void *dtag = ha->dstg; 3551 char *name; 3552 boolean_t own = B_FALSE; 3553 boolean_t might_destroy; 3554 3555 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3556 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3557 error = dsl_dataset_hold(name, dtag, &ds); 3558 strfree(name); 3559 if (error == ENOENT && ha->recursive) 3560 return (0); 3561 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3562 if (error) 3563 return (error); 3564 3565 ha->gotone = B_TRUE; 3566 3567 ASSERT(dsl_dataset_is_snapshot(ds)); 3568 3569 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3570 if (error) { 3571 dsl_dataset_rele(ds, dtag); 3572 return (error); 3573 } 3574 3575 if (might_destroy) { 3576 #ifdef _KERNEL 3577 error = zfs_unmount_snap(name, NULL); 3578 if (error) { 3579 dsl_dataset_rele(ds, dtag); 3580 return (error); 3581 } 3582 #endif 3583 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3584 dsl_dataset_rele(ds, dtag); 3585 return (EBUSY); 3586 } else { 3587 own = B_TRUE; 3588 dsl_dataset_make_exclusive(ds, dtag); 3589 } 3590 } 3591 3592 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3593 ra->ds = ds; 3594 ra->htag = ha->htag; 3595 ra->own = own; 3596 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3597 dsl_dataset_user_release_sync, ra, dtag, 0); 3598 3599 return (0); 3600 } 3601 3602 int 3603 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3604 boolean_t recursive) 3605 { 3606 struct dsl_ds_holdarg *ha; 3607 dsl_sync_task_t *dst; 3608 spa_t *spa; 3609 int error; 3610 3611 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3612 3613 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3614 3615 error = spa_open(dsname, &spa, FTAG); 3616 if (error) { 3617 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3618 return (error); 3619 } 3620 3621 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3622 ha->htag = htag; 3623 ha->snapname = snapname; 3624 ha->recursive = recursive; 3625 if (recursive) { 3626 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3627 ha, DS_FIND_CHILDREN); 3628 } else { 3629 error = dsl_dataset_user_release_one(dsname, ha); 3630 } 3631 if (error == 0) 3632 error = dsl_sync_task_group_wait(ha->dstg); 3633 3634 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3635 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3636 struct dsl_ds_releasearg *ra = dst->dst_arg1; 3637 dsl_dataset_t *ds = ra->ds; 3638 3639 if (dst->dst_err) 3640 dsl_dataset_name(ds, ha->failed); 3641 3642 if (ra->own) 3643 dsl_dataset_disown(ds, ha->dstg); 3644 else 3645 dsl_dataset_rele(ds, ha->dstg); 3646 3647 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 3648 } 3649 3650 if (error == 0 && recursive && !ha->gotone) 3651 error = ENOENT; 3652 3653 if (error) 3654 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3655 3656 dsl_sync_task_group_destroy(ha->dstg); 3657 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3658 spa_close(spa, FTAG); 3659 return (error); 3660 } 3661 3662 /* 3663 * Called at spa_load time to release a stale temporary user hold. 3664 */ 3665 int 3666 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag) 3667 { 3668 dsl_dataset_t *ds; 3669 char *snap; 3670 char *name; 3671 int namelen; 3672 int error; 3673 3674 rw_enter(&dp->dp_config_rwlock, RW_READER); 3675 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 3676 rw_exit(&dp->dp_config_rwlock); 3677 if (error) 3678 return (error); 3679 namelen = dsl_dataset_namelen(ds)+1; 3680 name = kmem_alloc(namelen, KM_SLEEP); 3681 dsl_dataset_name(ds, name); 3682 dsl_dataset_rele(ds, FTAG); 3683 3684 snap = strchr(name, '@'); 3685 *snap = '\0'; 3686 ++snap; 3687 return (dsl_dataset_user_release(name, snap, htag, B_FALSE)); 3688 } 3689 3690 int 3691 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 3692 { 3693 dsl_dataset_t *ds; 3694 int err; 3695 3696 err = dsl_dataset_hold(dsname, FTAG, &ds); 3697 if (err) 3698 return (err); 3699 3700 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 3701 if (ds->ds_phys->ds_userrefs_obj != 0) { 3702 zap_attribute_t *za; 3703 zap_cursor_t zc; 3704 3705 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 3706 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 3707 ds->ds_phys->ds_userrefs_obj); 3708 zap_cursor_retrieve(&zc, za) == 0; 3709 zap_cursor_advance(&zc)) { 3710 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 3711 za->za_first_integer)); 3712 } 3713 zap_cursor_fini(&zc); 3714 kmem_free(za, sizeof (zap_attribute_t)); 3715 } 3716 dsl_dataset_rele(ds, FTAG); 3717 return (0); 3718 } 3719 3720 /* 3721 * Note, this fuction is used as the callback for dmu_objset_find(). We 3722 * always return 0 so that we will continue to find and process 3723 * inconsistent datasets, even if we encounter an error trying to 3724 * process one of them. 3725 */ 3726 /* ARGSUSED */ 3727 int 3728 dsl_destroy_inconsistent(const char *dsname, void *arg) 3729 { 3730 dsl_dataset_t *ds; 3731 3732 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 3733 if (DS_IS_INCONSISTENT(ds)) 3734 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 3735 else 3736 dsl_dataset_disown(ds, FTAG); 3737 } 3738 return (0); 3739 } 3740