1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 */ 24 25 #include <sys/dmu_objset.h> 26 #include <sys/dsl_dataset.h> 27 #include <sys/dsl_dir.h> 28 #include <sys/dsl_prop.h> 29 #include <sys/dsl_synctask.h> 30 #include <sys/dmu_traverse.h> 31 #include <sys/dmu_tx.h> 32 #include <sys/arc.h> 33 #include <sys/zio.h> 34 #include <sys/zap.h> 35 #include <sys/unique.h> 36 #include <sys/zfs_context.h> 37 #include <sys/zfs_ioctl.h> 38 #include <sys/spa.h> 39 #include <sys/zfs_znode.h> 40 #include <sys/zfs_onexit.h> 41 #include <sys/zvol.h> 42 #include <sys/dsl_scan.h> 43 #include <sys/dsl_deadlist.h> 44 45 static char *dsl_reaper = "the grim reaper"; 46 47 static dsl_checkfunc_t dsl_dataset_destroy_begin_check; 48 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync; 49 static dsl_syncfunc_t dsl_dataset_set_reservation_sync; 50 51 #define SWITCH64(x, y) \ 52 { \ 53 uint64_t __tmp = (x); \ 54 (x) = (y); \ 55 (y) = __tmp; \ 56 } 57 58 #define DS_REF_MAX (1ULL << 62) 59 60 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE 61 62 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper) 63 64 65 /* 66 * Figure out how much of this delta should be propogated to the dsl_dir 67 * layer. If there's a refreservation, that space has already been 68 * partially accounted for in our ancestors. 69 */ 70 static int64_t 71 parent_delta(dsl_dataset_t *ds, int64_t delta) 72 { 73 uint64_t old_bytes, new_bytes; 74 75 if (ds->ds_reserved == 0) 76 return (delta); 77 78 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 79 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved); 80 81 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta)); 82 return (new_bytes - old_bytes); 83 } 84 85 void 86 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx) 87 { 88 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 89 int compressed = BP_GET_PSIZE(bp); 90 int uncompressed = BP_GET_UCSIZE(bp); 91 int64_t delta; 92 93 dprintf_bp(bp, "ds=%p", ds); 94 95 ASSERT(dmu_tx_is_syncing(tx)); 96 /* It could have been compressed away to nothing */ 97 if (BP_IS_HOLE(bp)) 98 return; 99 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE); 100 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES); 101 if (ds == NULL) { 102 /* 103 * Account for the meta-objset space in its placeholder 104 * dsl_dir. 105 */ 106 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */ 107 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 108 used, compressed, uncompressed, tx); 109 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 110 return; 111 } 112 dmu_buf_will_dirty(ds->ds_dbuf, tx); 113 114 mutex_enter(&ds->ds_dir->dd_lock); 115 mutex_enter(&ds->ds_lock); 116 delta = parent_delta(ds, used); 117 ds->ds_phys->ds_used_bytes += used; 118 ds->ds_phys->ds_compressed_bytes += compressed; 119 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 120 ds->ds_phys->ds_unique_bytes += used; 121 mutex_exit(&ds->ds_lock); 122 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 123 compressed, uncompressed, tx); 124 dsl_dir_transfer_space(ds->ds_dir, used - delta, 125 DD_USED_REFRSRV, DD_USED_HEAD, tx); 126 mutex_exit(&ds->ds_dir->dd_lock); 127 } 128 129 int 130 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, 131 boolean_t async) 132 { 133 if (BP_IS_HOLE(bp)) 134 return (0); 135 136 ASSERT(dmu_tx_is_syncing(tx)); 137 ASSERT(bp->blk_birth <= tx->tx_txg); 138 139 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 140 int compressed = BP_GET_PSIZE(bp); 141 int uncompressed = BP_GET_UCSIZE(bp); 142 143 ASSERT(used > 0); 144 if (ds == NULL) { 145 /* 146 * Account for the meta-objset space in its placeholder 147 * dataset. 148 */ 149 dsl_free(tx->tx_pool, tx->tx_txg, bp); 150 151 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 152 -used, -compressed, -uncompressed, tx); 153 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 154 return (used); 155 } 156 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 157 158 ASSERT(!dsl_dataset_is_snapshot(ds)); 159 dmu_buf_will_dirty(ds->ds_dbuf, tx); 160 161 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 162 int64_t delta; 163 164 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object); 165 dsl_free(tx->tx_pool, tx->tx_txg, bp); 166 167 mutex_enter(&ds->ds_dir->dd_lock); 168 mutex_enter(&ds->ds_lock); 169 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 170 !DS_UNIQUE_IS_ACCURATE(ds)); 171 delta = parent_delta(ds, -used); 172 ds->ds_phys->ds_unique_bytes -= used; 173 mutex_exit(&ds->ds_lock); 174 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 175 delta, -compressed, -uncompressed, tx); 176 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 177 DD_USED_REFRSRV, DD_USED_HEAD, tx); 178 mutex_exit(&ds->ds_dir->dd_lock); 179 } else { 180 dprintf_bp(bp, "putting on dead list: %s", ""); 181 if (async) { 182 /* 183 * We are here as part of zio's write done callback, 184 * which means we're a zio interrupt thread. We can't 185 * call dsl_deadlist_insert() now because it may block 186 * waiting for I/O. Instead, put bp on the deferred 187 * queue and let dsl_pool_sync() finish the job. 188 */ 189 bplist_append(&ds->ds_pending_deadlist, bp); 190 } else { 191 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx); 192 } 193 ASSERT3U(ds->ds_prev->ds_object, ==, 194 ds->ds_phys->ds_prev_snap_obj); 195 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 196 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 197 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 198 ds->ds_object && bp->blk_birth > 199 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 200 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 201 mutex_enter(&ds->ds_prev->ds_lock); 202 ds->ds_prev->ds_phys->ds_unique_bytes += used; 203 mutex_exit(&ds->ds_prev->ds_lock); 204 } 205 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) { 206 dsl_dir_transfer_space(ds->ds_dir, used, 207 DD_USED_HEAD, DD_USED_SNAP, tx); 208 } 209 } 210 mutex_enter(&ds->ds_lock); 211 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used); 212 ds->ds_phys->ds_used_bytes -= used; 213 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 214 ds->ds_phys->ds_compressed_bytes -= compressed; 215 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 216 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 217 mutex_exit(&ds->ds_lock); 218 219 return (used); 220 } 221 222 uint64_t 223 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 224 { 225 uint64_t trysnap = 0; 226 227 if (ds == NULL) 228 return (0); 229 /* 230 * The snapshot creation could fail, but that would cause an 231 * incorrect FALSE return, which would only result in an 232 * overestimation of the amount of space that an operation would 233 * consume, which is OK. 234 * 235 * There's also a small window where we could miss a pending 236 * snapshot, because we could set the sync task in the quiescing 237 * phase. So this should only be used as a guess. 238 */ 239 if (ds->ds_trysnap_txg > 240 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 241 trysnap = ds->ds_trysnap_txg; 242 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 243 } 244 245 boolean_t 246 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp, 247 uint64_t blk_birth) 248 { 249 if (blk_birth <= dsl_dataset_prev_snap_txg(ds)) 250 return (B_FALSE); 251 252 ddt_prefetch(dsl_dataset_get_spa(ds), bp); 253 254 return (B_TRUE); 255 } 256 257 /* ARGSUSED */ 258 static void 259 dsl_dataset_evict(dmu_buf_t *db, void *dsv) 260 { 261 dsl_dataset_t *ds = dsv; 262 263 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 264 265 unique_remove(ds->ds_fsid_guid); 266 267 if (ds->ds_objset != NULL) 268 dmu_objset_evict(ds->ds_objset); 269 270 if (ds->ds_prev) { 271 dsl_dataset_drop_ref(ds->ds_prev, ds); 272 ds->ds_prev = NULL; 273 } 274 275 bplist_destroy(&ds->ds_pending_deadlist); 276 if (db != NULL) { 277 dsl_deadlist_close(&ds->ds_deadlist); 278 } else { 279 ASSERT(ds->ds_deadlist.dl_dbuf == NULL); 280 ASSERT(!ds->ds_deadlist.dl_oldfmt); 281 } 282 if (ds->ds_dir) 283 dsl_dir_close(ds->ds_dir, ds); 284 285 ASSERT(!list_link_active(&ds->ds_synced_link)); 286 287 mutex_destroy(&ds->ds_lock); 288 mutex_destroy(&ds->ds_recvlock); 289 mutex_destroy(&ds->ds_opening_lock); 290 rw_destroy(&ds->ds_rwlock); 291 cv_destroy(&ds->ds_exclusive_cv); 292 293 kmem_free(ds, sizeof (dsl_dataset_t)); 294 } 295 296 static int 297 dsl_dataset_get_snapname(dsl_dataset_t *ds) 298 { 299 dsl_dataset_phys_t *headphys; 300 int err; 301 dmu_buf_t *headdbuf; 302 dsl_pool_t *dp = ds->ds_dir->dd_pool; 303 objset_t *mos = dp->dp_meta_objset; 304 305 if (ds->ds_snapname[0]) 306 return (0); 307 if (ds->ds_phys->ds_next_snap_obj == 0) 308 return (0); 309 310 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 311 FTAG, &headdbuf); 312 if (err) 313 return (err); 314 headphys = headdbuf->db_data; 315 err = zap_value_search(dp->dp_meta_objset, 316 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 317 dmu_buf_rele(headdbuf, FTAG); 318 return (err); 319 } 320 321 static int 322 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 323 { 324 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 325 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 326 matchtype_t mt; 327 int err; 328 329 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 330 mt = MT_FIRST; 331 else 332 mt = MT_EXACT; 333 334 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 335 value, mt, NULL, 0, NULL); 336 if (err == ENOTSUP && mt == MT_FIRST) 337 err = zap_lookup(mos, snapobj, name, 8, 1, value); 338 return (err); 339 } 340 341 static int 342 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 343 { 344 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 345 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 346 matchtype_t mt; 347 int err; 348 349 dsl_dir_snap_cmtime_update(ds->ds_dir); 350 351 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 352 mt = MT_FIRST; 353 else 354 mt = MT_EXACT; 355 356 err = zap_remove_norm(mos, snapobj, name, mt, tx); 357 if (err == ENOTSUP && mt == MT_FIRST) 358 err = zap_remove(mos, snapobj, name, tx); 359 return (err); 360 } 361 362 static int 363 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 364 dsl_dataset_t **dsp) 365 { 366 objset_t *mos = dp->dp_meta_objset; 367 dmu_buf_t *dbuf; 368 dsl_dataset_t *ds; 369 int err; 370 371 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 372 dsl_pool_sync_context(dp)); 373 374 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 375 if (err) 376 return (err); 377 ds = dmu_buf_get_user(dbuf); 378 if (ds == NULL) { 379 dsl_dataset_t *winner; 380 381 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 382 ds->ds_dbuf = dbuf; 383 ds->ds_object = dsobj; 384 ds->ds_phys = dbuf->db_data; 385 386 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 387 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 388 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 389 rw_init(&ds->ds_rwlock, 0, 0, 0); 390 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 391 392 bplist_create(&ds->ds_pending_deadlist); 393 dsl_deadlist_open(&ds->ds_deadlist, 394 mos, ds->ds_phys->ds_deadlist_obj); 395 396 if (err == 0) { 397 err = dsl_dir_open_obj(dp, 398 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 399 } 400 if (err) { 401 mutex_destroy(&ds->ds_lock); 402 mutex_destroy(&ds->ds_recvlock); 403 mutex_destroy(&ds->ds_opening_lock); 404 rw_destroy(&ds->ds_rwlock); 405 cv_destroy(&ds->ds_exclusive_cv); 406 bplist_destroy(&ds->ds_pending_deadlist); 407 dsl_deadlist_close(&ds->ds_deadlist); 408 kmem_free(ds, sizeof (dsl_dataset_t)); 409 dmu_buf_rele(dbuf, tag); 410 return (err); 411 } 412 413 if (!dsl_dataset_is_snapshot(ds)) { 414 ds->ds_snapname[0] = '\0'; 415 if (ds->ds_phys->ds_prev_snap_obj) { 416 err = dsl_dataset_get_ref(dp, 417 ds->ds_phys->ds_prev_snap_obj, 418 ds, &ds->ds_prev); 419 } 420 } else { 421 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 422 err = dsl_dataset_get_snapname(ds); 423 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 424 err = zap_count( 425 ds->ds_dir->dd_pool->dp_meta_objset, 426 ds->ds_phys->ds_userrefs_obj, 427 &ds->ds_userrefs); 428 } 429 } 430 431 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 432 /* 433 * In sync context, we're called with either no lock 434 * or with the write lock. If we're not syncing, 435 * we're always called with the read lock held. 436 */ 437 boolean_t need_lock = 438 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 439 dsl_pool_sync_context(dp); 440 441 if (need_lock) 442 rw_enter(&dp->dp_config_rwlock, RW_READER); 443 444 err = dsl_prop_get_ds(ds, 445 "refreservation", sizeof (uint64_t), 1, 446 &ds->ds_reserved, NULL); 447 if (err == 0) { 448 err = dsl_prop_get_ds(ds, 449 "refquota", sizeof (uint64_t), 1, 450 &ds->ds_quota, NULL); 451 } 452 453 if (need_lock) 454 rw_exit(&dp->dp_config_rwlock); 455 } else { 456 ds->ds_reserved = ds->ds_quota = 0; 457 } 458 459 if (err == 0) { 460 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 461 dsl_dataset_evict); 462 } 463 if (err || winner) { 464 bplist_destroy(&ds->ds_pending_deadlist); 465 dsl_deadlist_close(&ds->ds_deadlist); 466 if (ds->ds_prev) 467 dsl_dataset_drop_ref(ds->ds_prev, ds); 468 dsl_dir_close(ds->ds_dir, ds); 469 mutex_destroy(&ds->ds_lock); 470 mutex_destroy(&ds->ds_recvlock); 471 mutex_destroy(&ds->ds_opening_lock); 472 rw_destroy(&ds->ds_rwlock); 473 cv_destroy(&ds->ds_exclusive_cv); 474 kmem_free(ds, sizeof (dsl_dataset_t)); 475 if (err) { 476 dmu_buf_rele(dbuf, tag); 477 return (err); 478 } 479 ds = winner; 480 } else { 481 ds->ds_fsid_guid = 482 unique_insert(ds->ds_phys->ds_fsid_guid); 483 } 484 } 485 ASSERT3P(ds->ds_dbuf, ==, dbuf); 486 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 487 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 488 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 489 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 490 mutex_enter(&ds->ds_lock); 491 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 492 mutex_exit(&ds->ds_lock); 493 dmu_buf_rele(ds->ds_dbuf, tag); 494 return (ENOENT); 495 } 496 mutex_exit(&ds->ds_lock); 497 *dsp = ds; 498 return (0); 499 } 500 501 static int 502 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 503 { 504 dsl_pool_t *dp = ds->ds_dir->dd_pool; 505 506 /* 507 * In syncing context we don't want the rwlock lock: there 508 * may be an existing writer waiting for sync phase to 509 * finish. We don't need to worry about such writers, since 510 * sync phase is single-threaded, so the writer can't be 511 * doing anything while we are active. 512 */ 513 if (dsl_pool_sync_context(dp)) { 514 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 515 return (0); 516 } 517 518 /* 519 * Normal users will hold the ds_rwlock as a READER until they 520 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 521 * drop their READER lock after they set the ds_owner field. 522 * 523 * If the dataset is being destroyed, the destroy thread will 524 * obtain a WRITER lock for exclusive access after it's done its 525 * open-context work and then change the ds_owner to 526 * dsl_reaper once destruction is assured. So threads 527 * may block here temporarily, until the "destructability" of 528 * the dataset is determined. 529 */ 530 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 531 mutex_enter(&ds->ds_lock); 532 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 533 rw_exit(&dp->dp_config_rwlock); 534 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 535 if (DSL_DATASET_IS_DESTROYED(ds)) { 536 mutex_exit(&ds->ds_lock); 537 dsl_dataset_drop_ref(ds, tag); 538 rw_enter(&dp->dp_config_rwlock, RW_READER); 539 return (ENOENT); 540 } 541 /* 542 * The dp_config_rwlock lives above the ds_lock. And 543 * we need to check DSL_DATASET_IS_DESTROYED() while 544 * holding the ds_lock, so we have to drop and reacquire 545 * the ds_lock here. 546 */ 547 mutex_exit(&ds->ds_lock); 548 rw_enter(&dp->dp_config_rwlock, RW_READER); 549 mutex_enter(&ds->ds_lock); 550 } 551 mutex_exit(&ds->ds_lock); 552 return (0); 553 } 554 555 int 556 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 557 dsl_dataset_t **dsp) 558 { 559 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 560 561 if (err) 562 return (err); 563 return (dsl_dataset_hold_ref(*dsp, tag)); 564 } 565 566 int 567 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 568 void *tag, dsl_dataset_t **dsp) 569 { 570 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 571 if (err) 572 return (err); 573 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 574 dsl_dataset_rele(*dsp, tag); 575 *dsp = NULL; 576 return (EBUSY); 577 } 578 return (0); 579 } 580 581 int 582 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 583 { 584 dsl_dir_t *dd; 585 dsl_pool_t *dp; 586 const char *snapname; 587 uint64_t obj; 588 int err = 0; 589 590 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 591 if (err) 592 return (err); 593 594 dp = dd->dd_pool; 595 obj = dd->dd_phys->dd_head_dataset_obj; 596 rw_enter(&dp->dp_config_rwlock, RW_READER); 597 if (obj) 598 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 599 else 600 err = ENOENT; 601 if (err) 602 goto out; 603 604 err = dsl_dataset_hold_ref(*dsp, tag); 605 606 /* we may be looking for a snapshot */ 607 if (err == 0 && snapname != NULL) { 608 dsl_dataset_t *ds = NULL; 609 610 if (*snapname++ != '@') { 611 dsl_dataset_rele(*dsp, tag); 612 err = ENOENT; 613 goto out; 614 } 615 616 dprintf("looking for snapshot '%s'\n", snapname); 617 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 618 if (err == 0) 619 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 620 dsl_dataset_rele(*dsp, tag); 621 622 ASSERT3U((err == 0), ==, (ds != NULL)); 623 624 if (ds) { 625 mutex_enter(&ds->ds_lock); 626 if (ds->ds_snapname[0] == 0) 627 (void) strlcpy(ds->ds_snapname, snapname, 628 sizeof (ds->ds_snapname)); 629 mutex_exit(&ds->ds_lock); 630 err = dsl_dataset_hold_ref(ds, tag); 631 *dsp = err ? NULL : ds; 632 } 633 } 634 out: 635 rw_exit(&dp->dp_config_rwlock); 636 dsl_dir_close(dd, FTAG); 637 return (err); 638 } 639 640 int 641 dsl_dataset_own(const char *name, boolean_t inconsistentok, 642 void *tag, dsl_dataset_t **dsp) 643 { 644 int err = dsl_dataset_hold(name, tag, dsp); 645 if (err) 646 return (err); 647 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 648 dsl_dataset_rele(*dsp, tag); 649 return (EBUSY); 650 } 651 return (0); 652 } 653 654 void 655 dsl_dataset_name(dsl_dataset_t *ds, char *name) 656 { 657 if (ds == NULL) { 658 (void) strcpy(name, "mos"); 659 } else { 660 dsl_dir_name(ds->ds_dir, name); 661 VERIFY(0 == dsl_dataset_get_snapname(ds)); 662 if (ds->ds_snapname[0]) { 663 (void) strcat(name, "@"); 664 /* 665 * We use a "recursive" mutex so that we 666 * can call dprintf_ds() with ds_lock held. 667 */ 668 if (!MUTEX_HELD(&ds->ds_lock)) { 669 mutex_enter(&ds->ds_lock); 670 (void) strcat(name, ds->ds_snapname); 671 mutex_exit(&ds->ds_lock); 672 } else { 673 (void) strcat(name, ds->ds_snapname); 674 } 675 } 676 } 677 } 678 679 static int 680 dsl_dataset_namelen(dsl_dataset_t *ds) 681 { 682 int result; 683 684 if (ds == NULL) { 685 result = 3; /* "mos" */ 686 } else { 687 result = dsl_dir_namelen(ds->ds_dir); 688 VERIFY(0 == dsl_dataset_get_snapname(ds)); 689 if (ds->ds_snapname[0]) { 690 ++result; /* adding one for the @-sign */ 691 if (!MUTEX_HELD(&ds->ds_lock)) { 692 mutex_enter(&ds->ds_lock); 693 result += strlen(ds->ds_snapname); 694 mutex_exit(&ds->ds_lock); 695 } else { 696 result += strlen(ds->ds_snapname); 697 } 698 } 699 } 700 701 return (result); 702 } 703 704 void 705 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 706 { 707 dmu_buf_rele(ds->ds_dbuf, tag); 708 } 709 710 void 711 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 712 { 713 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 714 rw_exit(&ds->ds_rwlock); 715 } 716 dsl_dataset_drop_ref(ds, tag); 717 } 718 719 void 720 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 721 { 722 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 723 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 724 725 mutex_enter(&ds->ds_lock); 726 ds->ds_owner = NULL; 727 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 728 rw_exit(&ds->ds_rwlock); 729 cv_broadcast(&ds->ds_exclusive_cv); 730 } 731 mutex_exit(&ds->ds_lock); 732 if (ds->ds_dbuf) 733 dsl_dataset_drop_ref(ds, tag); 734 else 735 dsl_dataset_evict(NULL, ds); 736 } 737 738 boolean_t 739 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 740 { 741 boolean_t gotit = FALSE; 742 743 mutex_enter(&ds->ds_lock); 744 if (ds->ds_owner == NULL && 745 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 746 ds->ds_owner = tag; 747 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 748 rw_exit(&ds->ds_rwlock); 749 gotit = TRUE; 750 } 751 mutex_exit(&ds->ds_lock); 752 return (gotit); 753 } 754 755 void 756 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 757 { 758 ASSERT3P(owner, ==, ds->ds_owner); 759 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 760 rw_enter(&ds->ds_rwlock, RW_WRITER); 761 } 762 763 uint64_t 764 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 765 uint64_t flags, dmu_tx_t *tx) 766 { 767 dsl_pool_t *dp = dd->dd_pool; 768 dmu_buf_t *dbuf; 769 dsl_dataset_phys_t *dsphys; 770 uint64_t dsobj; 771 objset_t *mos = dp->dp_meta_objset; 772 773 if (origin == NULL) 774 origin = dp->dp_origin_snap; 775 776 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 777 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 778 ASSERT(dmu_tx_is_syncing(tx)); 779 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 780 781 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 782 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 783 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 784 dmu_buf_will_dirty(dbuf, tx); 785 dsphys = dbuf->db_data; 786 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 787 dsphys->ds_dir_obj = dd->dd_object; 788 dsphys->ds_flags = flags; 789 dsphys->ds_fsid_guid = unique_create(); 790 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 791 sizeof (dsphys->ds_guid)); 792 dsphys->ds_snapnames_zapobj = 793 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 794 DMU_OT_NONE, 0, tx); 795 dsphys->ds_creation_time = gethrestime_sec(); 796 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 797 798 if (origin == NULL) { 799 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx); 800 } else { 801 dsl_dataset_t *ohds; 802 803 dsphys->ds_prev_snap_obj = origin->ds_object; 804 dsphys->ds_prev_snap_txg = 805 origin->ds_phys->ds_creation_txg; 806 dsphys->ds_used_bytes = 807 origin->ds_phys->ds_used_bytes; 808 dsphys->ds_compressed_bytes = 809 origin->ds_phys->ds_compressed_bytes; 810 dsphys->ds_uncompressed_bytes = 811 origin->ds_phys->ds_uncompressed_bytes; 812 dsphys->ds_bp = origin->ds_phys->ds_bp; 813 dsphys->ds_flags |= origin->ds_phys->ds_flags; 814 815 dmu_buf_will_dirty(origin->ds_dbuf, tx); 816 origin->ds_phys->ds_num_children++; 817 818 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 819 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds)); 820 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist, 821 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx); 822 dsl_dataset_rele(ohds, FTAG); 823 824 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 825 if (origin->ds_phys->ds_next_clones_obj == 0) { 826 origin->ds_phys->ds_next_clones_obj = 827 zap_create(mos, 828 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 829 } 830 VERIFY(0 == zap_add_int(mos, 831 origin->ds_phys->ds_next_clones_obj, 832 dsobj, tx)); 833 } 834 835 dmu_buf_will_dirty(dd->dd_dbuf, tx); 836 dd->dd_phys->dd_origin_obj = origin->ds_object; 837 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 838 if (origin->ds_dir->dd_phys->dd_clones == 0) { 839 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); 840 origin->ds_dir->dd_phys->dd_clones = 841 zap_create(mos, 842 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 843 } 844 VERIFY3U(0, ==, zap_add_int(mos, 845 origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); 846 } 847 } 848 849 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 850 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 851 852 dmu_buf_rele(dbuf, FTAG); 853 854 dmu_buf_will_dirty(dd->dd_dbuf, tx); 855 dd->dd_phys->dd_head_dataset_obj = dsobj; 856 857 return (dsobj); 858 } 859 860 uint64_t 861 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 862 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 863 { 864 dsl_pool_t *dp = pdd->dd_pool; 865 uint64_t dsobj, ddobj; 866 dsl_dir_t *dd; 867 868 ASSERT(lastname[0] != '@'); 869 870 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 871 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 872 873 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 874 875 dsl_deleg_set_create_perms(dd, tx, cr); 876 877 dsl_dir_close(dd, FTAG); 878 879 return (dsobj); 880 } 881 882 struct destroyarg { 883 dsl_sync_task_group_t *dstg; 884 char *snapname; 885 char *failed; 886 boolean_t defer; 887 }; 888 889 static int 890 dsl_snapshot_destroy_one(const char *name, void *arg) 891 { 892 struct destroyarg *da = arg; 893 dsl_dataset_t *ds; 894 int err; 895 char *dsname; 896 897 dsname = kmem_asprintf("%s@%s", name, da->snapname); 898 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds); 899 strfree(dsname); 900 if (err == 0) { 901 struct dsl_ds_destroyarg *dsda; 902 903 dsl_dataset_make_exclusive(ds, da->dstg); 904 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP); 905 dsda->ds = ds; 906 dsda->defer = da->defer; 907 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check, 908 dsl_dataset_destroy_sync, dsda, da->dstg, 0); 909 } else if (err == ENOENT) { 910 err = 0; 911 } else { 912 (void) strcpy(da->failed, name); 913 } 914 return (err); 915 } 916 917 /* 918 * Destroy 'snapname' in all descendants of 'fsname'. 919 */ 920 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy 921 int 922 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer) 923 { 924 int err; 925 struct destroyarg da; 926 dsl_sync_task_t *dst; 927 spa_t *spa; 928 929 err = spa_open(fsname, &spa, FTAG); 930 if (err) 931 return (err); 932 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 933 da.snapname = snapname; 934 da.failed = fsname; 935 da.defer = defer; 936 937 err = dmu_objset_find(fsname, 938 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN); 939 940 if (err == 0) 941 err = dsl_sync_task_group_wait(da.dstg); 942 943 for (dst = list_head(&da.dstg->dstg_tasks); dst; 944 dst = list_next(&da.dstg->dstg_tasks, dst)) { 945 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 946 dsl_dataset_t *ds = dsda->ds; 947 948 /* 949 * Return the file system name that triggered the error 950 */ 951 if (dst->dst_err) { 952 dsl_dataset_name(ds, fsname); 953 *strchr(fsname, '@') = '\0'; 954 } 955 ASSERT3P(dsda->rm_origin, ==, NULL); 956 dsl_dataset_disown(ds, da.dstg); 957 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 958 } 959 960 dsl_sync_task_group_destroy(da.dstg); 961 spa_close(spa, FTAG); 962 return (err); 963 } 964 965 static boolean_t 966 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 967 { 968 boolean_t might_destroy = B_FALSE; 969 970 mutex_enter(&ds->ds_lock); 971 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 972 DS_IS_DEFER_DESTROY(ds)) 973 might_destroy = B_TRUE; 974 mutex_exit(&ds->ds_lock); 975 976 return (might_destroy); 977 } 978 979 /* 980 * If we're removing a clone, and these three conditions are true: 981 * 1) the clone's origin has no other children 982 * 2) the clone's origin has no user references 983 * 3) the clone's origin has been marked for deferred destruction 984 * Then, prepare to remove the origin as part of this sync task group. 985 */ 986 static int 987 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 988 { 989 dsl_dataset_t *ds = dsda->ds; 990 dsl_dataset_t *origin = ds->ds_prev; 991 992 if (dsl_dataset_might_destroy_origin(origin)) { 993 char *name; 994 int namelen; 995 int error; 996 997 namelen = dsl_dataset_namelen(origin) + 1; 998 name = kmem_alloc(namelen, KM_SLEEP); 999 dsl_dataset_name(origin, name); 1000 #ifdef _KERNEL 1001 error = zfs_unmount_snap(name, NULL); 1002 if (error) { 1003 kmem_free(name, namelen); 1004 return (error); 1005 } 1006 #endif 1007 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 1008 kmem_free(name, namelen); 1009 if (error) 1010 return (error); 1011 dsda->rm_origin = origin; 1012 dsl_dataset_make_exclusive(origin, tag); 1013 } 1014 1015 return (0); 1016 } 1017 1018 /* 1019 * ds must be opened as OWNER. On return (whether successful or not), 1020 * ds will be closed and caller can no longer dereference it. 1021 */ 1022 int 1023 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1024 { 1025 int err; 1026 dsl_sync_task_group_t *dstg; 1027 objset_t *os; 1028 dsl_dir_t *dd; 1029 uint64_t obj; 1030 struct dsl_ds_destroyarg dsda = { 0 }; 1031 dsl_dataset_t dummy_ds = { 0 }; 1032 1033 dsda.ds = ds; 1034 1035 if (dsl_dataset_is_snapshot(ds)) { 1036 /* Destroying a snapshot is simpler */ 1037 dsl_dataset_make_exclusive(ds, tag); 1038 1039 dsda.defer = defer; 1040 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1041 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1042 &dsda, tag, 0); 1043 ASSERT3P(dsda.rm_origin, ==, NULL); 1044 goto out; 1045 } else if (defer) { 1046 err = EINVAL; 1047 goto out; 1048 } 1049 1050 dd = ds->ds_dir; 1051 dummy_ds.ds_dir = dd; 1052 dummy_ds.ds_object = ds->ds_object; 1053 1054 /* 1055 * Check for errors and mark this ds as inconsistent, in 1056 * case we crash while freeing the objects. 1057 */ 1058 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, 1059 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1060 if (err) 1061 goto out; 1062 1063 err = dmu_objset_from_ds(ds, &os); 1064 if (err) 1065 goto out; 1066 1067 /* 1068 * remove the objects in open context, so that we won't 1069 * have too much to do in syncing context. 1070 */ 1071 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1072 ds->ds_phys->ds_prev_snap_txg)) { 1073 /* 1074 * Ignore errors, if there is not enough disk space 1075 * we will deal with it in dsl_dataset_destroy_sync(). 1076 */ 1077 (void) dmu_free_object(os, obj); 1078 } 1079 1080 /* 1081 * We need to sync out all in-flight IO before we try to evict 1082 * (the dataset evict func is trying to clear the cached entries 1083 * for this dataset in the ARC). 1084 */ 1085 txg_wait_synced(dd->dd_pool, 0); 1086 1087 /* 1088 * If we managed to free all the objects in open 1089 * context, the user space accounting should be zero. 1090 */ 1091 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1092 dmu_objset_userused_enabled(os)) { 1093 uint64_t count; 1094 1095 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || 1096 count == 0); 1097 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || 1098 count == 0); 1099 } 1100 1101 if (err != ESRCH) 1102 goto out; 1103 1104 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1105 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1106 rw_exit(&dd->dd_pool->dp_config_rwlock); 1107 1108 if (err) 1109 goto out; 1110 1111 /* 1112 * Blow away the dsl_dir + head dataset. 1113 */ 1114 dsl_dataset_make_exclusive(ds, tag); 1115 /* 1116 * If we're removing a clone, we might also need to remove its 1117 * origin. 1118 */ 1119 do { 1120 dsda.need_prep = B_FALSE; 1121 if (dsl_dir_is_clone(dd)) { 1122 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1123 if (err) { 1124 dsl_dir_close(dd, FTAG); 1125 goto out; 1126 } 1127 } 1128 1129 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1130 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1131 dsl_dataset_destroy_sync, &dsda, tag, 0); 1132 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1133 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0); 1134 err = dsl_sync_task_group_wait(dstg); 1135 dsl_sync_task_group_destroy(dstg); 1136 1137 /* 1138 * We could be racing against 'zfs release' or 'zfs destroy -d' 1139 * on the origin snap, in which case we can get EBUSY if we 1140 * needed to destroy the origin snap but were not ready to 1141 * do so. 1142 */ 1143 if (dsda.need_prep) { 1144 ASSERT(err == EBUSY); 1145 ASSERT(dsl_dir_is_clone(dd)); 1146 ASSERT(dsda.rm_origin == NULL); 1147 } 1148 } while (dsda.need_prep); 1149 1150 if (dsda.rm_origin != NULL) 1151 dsl_dataset_disown(dsda.rm_origin, tag); 1152 1153 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1154 if (err) 1155 dsl_dir_close(dd, FTAG); 1156 out: 1157 dsl_dataset_disown(ds, tag); 1158 return (err); 1159 } 1160 1161 blkptr_t * 1162 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1163 { 1164 return (&ds->ds_phys->ds_bp); 1165 } 1166 1167 void 1168 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1169 { 1170 ASSERT(dmu_tx_is_syncing(tx)); 1171 /* If it's the meta-objset, set dp_meta_rootbp */ 1172 if (ds == NULL) { 1173 tx->tx_pool->dp_meta_rootbp = *bp; 1174 } else { 1175 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1176 ds->ds_phys->ds_bp = *bp; 1177 } 1178 } 1179 1180 spa_t * 1181 dsl_dataset_get_spa(dsl_dataset_t *ds) 1182 { 1183 return (ds->ds_dir->dd_pool->dp_spa); 1184 } 1185 1186 void 1187 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1188 { 1189 dsl_pool_t *dp; 1190 1191 if (ds == NULL) /* this is the meta-objset */ 1192 return; 1193 1194 ASSERT(ds->ds_objset != NULL); 1195 1196 if (ds->ds_phys->ds_next_snap_obj != 0) 1197 panic("dirtying snapshot!"); 1198 1199 dp = ds->ds_dir->dd_pool; 1200 1201 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1202 /* up the hold count until we can be written out */ 1203 dmu_buf_add_ref(ds->ds_dbuf, ds); 1204 } 1205 } 1206 1207 /* 1208 * The unique space in the head dataset can be calculated by subtracting 1209 * the space used in the most recent snapshot, that is still being used 1210 * in this file system, from the space currently in use. To figure out 1211 * the space in the most recent snapshot still in use, we need to take 1212 * the total space used in the snapshot and subtract out the space that 1213 * has been freed up since the snapshot was taken. 1214 */ 1215 static void 1216 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1217 { 1218 uint64_t mrs_used; 1219 uint64_t dlused, dlcomp, dluncomp; 1220 1221 ASSERT(!dsl_dataset_is_snapshot(ds)); 1222 1223 if (ds->ds_phys->ds_prev_snap_obj != 0) 1224 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes; 1225 else 1226 mrs_used = 0; 1227 1228 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); 1229 1230 ASSERT3U(dlused, <=, mrs_used); 1231 ds->ds_phys->ds_unique_bytes = 1232 ds->ds_phys->ds_used_bytes - (mrs_used - dlused); 1233 1234 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1235 SPA_VERSION_UNIQUE_ACCURATE) 1236 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1237 } 1238 1239 struct killarg { 1240 dsl_dataset_t *ds; 1241 dmu_tx_t *tx; 1242 }; 1243 1244 /* ARGSUSED */ 1245 static int 1246 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf, 1247 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1248 { 1249 struct killarg *ka = arg; 1250 dmu_tx_t *tx = ka->tx; 1251 1252 if (bp == NULL) 1253 return (0); 1254 1255 if (zb->zb_level == ZB_ZIL_LEVEL) { 1256 ASSERT(zilog != NULL); 1257 /* 1258 * It's a block in the intent log. It has no 1259 * accounting, so just free it. 1260 */ 1261 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1262 } else { 1263 ASSERT(zilog == NULL); 1264 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1265 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1266 } 1267 1268 return (0); 1269 } 1270 1271 /* ARGSUSED */ 1272 static int 1273 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1274 { 1275 dsl_dataset_t *ds = arg1; 1276 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1277 uint64_t count; 1278 int err; 1279 1280 /* 1281 * Can't delete a head dataset if there are snapshots of it. 1282 * (Except if the only snapshots are from the branch we cloned 1283 * from.) 1284 */ 1285 if (ds->ds_prev != NULL && 1286 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1287 return (EBUSY); 1288 1289 /* 1290 * This is really a dsl_dir thing, but check it here so that 1291 * we'll be less likely to leave this dataset inconsistent & 1292 * nearly destroyed. 1293 */ 1294 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1295 if (err) 1296 return (err); 1297 if (count != 0) 1298 return (EEXIST); 1299 1300 return (0); 1301 } 1302 1303 /* ARGSUSED */ 1304 static void 1305 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1306 { 1307 dsl_dataset_t *ds = arg1; 1308 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1309 1310 /* Mark it as inconsistent on-disk, in case we crash */ 1311 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1312 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1313 1314 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx, 1315 "dataset = %llu", ds->ds_object); 1316 } 1317 1318 static int 1319 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1320 dmu_tx_t *tx) 1321 { 1322 dsl_dataset_t *ds = dsda->ds; 1323 dsl_dataset_t *ds_prev = ds->ds_prev; 1324 1325 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1326 struct dsl_ds_destroyarg ndsda = {0}; 1327 1328 /* 1329 * If we're not prepared to remove the origin, don't remove 1330 * the clone either. 1331 */ 1332 if (dsda->rm_origin == NULL) { 1333 dsda->need_prep = B_TRUE; 1334 return (EBUSY); 1335 } 1336 1337 ndsda.ds = ds_prev; 1338 ndsda.is_origin_rm = B_TRUE; 1339 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1340 } 1341 1342 /* 1343 * If we're not going to remove the origin after all, 1344 * undo the open context setup. 1345 */ 1346 if (dsda->rm_origin != NULL) { 1347 dsl_dataset_disown(dsda->rm_origin, tag); 1348 dsda->rm_origin = NULL; 1349 } 1350 1351 return (0); 1352 } 1353 1354 /* ARGSUSED */ 1355 int 1356 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1357 { 1358 struct dsl_ds_destroyarg *dsda = arg1; 1359 dsl_dataset_t *ds = dsda->ds; 1360 1361 /* we have an owner hold, so noone else can destroy us */ 1362 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1363 1364 /* 1365 * Only allow deferred destroy on pools that support it. 1366 * NOTE: deferred destroy is only supported on snapshots. 1367 */ 1368 if (dsda->defer) { 1369 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1370 SPA_VERSION_USERREFS) 1371 return (ENOTSUP); 1372 ASSERT(dsl_dataset_is_snapshot(ds)); 1373 return (0); 1374 } 1375 1376 /* 1377 * Can't delete a head dataset if there are snapshots of it. 1378 * (Except if the only snapshots are from the branch we cloned 1379 * from.) 1380 */ 1381 if (ds->ds_prev != NULL && 1382 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1383 return (EBUSY); 1384 1385 /* 1386 * If we made changes this txg, traverse_dsl_dataset won't find 1387 * them. Try again. 1388 */ 1389 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1390 return (EAGAIN); 1391 1392 if (dsl_dataset_is_snapshot(ds)) { 1393 /* 1394 * If this snapshot has an elevated user reference count, 1395 * we can't destroy it yet. 1396 */ 1397 if (ds->ds_userrefs > 0 && !dsda->releasing) 1398 return (EBUSY); 1399 1400 mutex_enter(&ds->ds_lock); 1401 /* 1402 * Can't delete a branch point. However, if we're destroying 1403 * a clone and removing its origin due to it having a user 1404 * hold count of 0 and having been marked for deferred destroy, 1405 * it's OK for the origin to have a single clone. 1406 */ 1407 if (ds->ds_phys->ds_num_children > 1408 (dsda->is_origin_rm ? 2 : 1)) { 1409 mutex_exit(&ds->ds_lock); 1410 return (EEXIST); 1411 } 1412 mutex_exit(&ds->ds_lock); 1413 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1414 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1415 } 1416 1417 /* XXX we should do some i/o error checking... */ 1418 return (0); 1419 } 1420 1421 struct refsarg { 1422 kmutex_t lock; 1423 boolean_t gone; 1424 kcondvar_t cv; 1425 }; 1426 1427 /* ARGSUSED */ 1428 static void 1429 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1430 { 1431 struct refsarg *arg = argv; 1432 1433 mutex_enter(&arg->lock); 1434 arg->gone = TRUE; 1435 cv_signal(&arg->cv); 1436 mutex_exit(&arg->lock); 1437 } 1438 1439 static void 1440 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1441 { 1442 struct refsarg arg; 1443 1444 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1445 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1446 arg.gone = FALSE; 1447 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1448 dsl_dataset_refs_gone); 1449 dmu_buf_rele(ds->ds_dbuf, tag); 1450 mutex_enter(&arg.lock); 1451 while (!arg.gone) 1452 cv_wait(&arg.cv, &arg.lock); 1453 ASSERT(arg.gone); 1454 mutex_exit(&arg.lock); 1455 ds->ds_dbuf = NULL; 1456 ds->ds_phys = NULL; 1457 mutex_destroy(&arg.lock); 1458 cv_destroy(&arg.cv); 1459 } 1460 1461 static void 1462 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1463 { 1464 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1465 uint64_t count; 1466 int err; 1467 1468 ASSERT(ds->ds_phys->ds_num_children >= 2); 1469 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1470 /* 1471 * The err should not be ENOENT, but a bug in a previous version 1472 * of the code could cause upgrade_clones_cb() to not set 1473 * ds_next_snap_obj when it should, leading to a missing entry. 1474 * If we knew that the pool was created after 1475 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1476 * ENOENT. However, at least we can check that we don't have 1477 * too many entries in the next_clones_obj even after failing to 1478 * remove this one. 1479 */ 1480 if (err != ENOENT) { 1481 VERIFY3U(err, ==, 0); 1482 } 1483 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1484 &count)); 1485 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1486 } 1487 1488 static void 1489 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 1490 { 1491 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1492 zap_cursor_t zc; 1493 zap_attribute_t za; 1494 1495 /* 1496 * If it is the old version, dd_clones doesn't exist so we can't 1497 * find the clones, but deadlist_remove_key() is a no-op so it 1498 * doesn't matter. 1499 */ 1500 if (ds->ds_dir->dd_phys->dd_clones == 0) 1501 return; 1502 1503 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); 1504 zap_cursor_retrieve(&zc, &za) == 0; 1505 zap_cursor_advance(&zc)) { 1506 dsl_dataset_t *clone; 1507 1508 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 1509 za.za_first_integer, FTAG, &clone)); 1510 if (clone->ds_dir->dd_origin_txg > mintxg) { 1511 dsl_deadlist_remove_key(&clone->ds_deadlist, 1512 mintxg, tx); 1513 dsl_dataset_remove_clones_key(clone, mintxg, tx); 1514 } 1515 dsl_dataset_rele(clone, FTAG); 1516 } 1517 zap_cursor_fini(&zc); 1518 } 1519 1520 struct process_old_arg { 1521 dsl_dataset_t *ds; 1522 dsl_dataset_t *ds_prev; 1523 boolean_t after_branch_point; 1524 zio_t *pio; 1525 uint64_t used, comp, uncomp; 1526 }; 1527 1528 static int 1529 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1530 { 1531 struct process_old_arg *poa = arg; 1532 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; 1533 1534 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { 1535 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); 1536 if (poa->ds_prev && !poa->after_branch_point && 1537 bp->blk_birth > 1538 poa->ds_prev->ds_phys->ds_prev_snap_txg) { 1539 poa->ds_prev->ds_phys->ds_unique_bytes += 1540 bp_get_dsize_sync(dp->dp_spa, bp); 1541 } 1542 } else { 1543 poa->used += bp_get_dsize_sync(dp->dp_spa, bp); 1544 poa->comp += BP_GET_PSIZE(bp); 1545 poa->uncomp += BP_GET_UCSIZE(bp); 1546 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); 1547 } 1548 return (0); 1549 } 1550 1551 static void 1552 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, 1553 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) 1554 { 1555 struct process_old_arg poa = { 0 }; 1556 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1557 objset_t *mos = dp->dp_meta_objset; 1558 1559 ASSERT(ds->ds_deadlist.dl_oldfmt); 1560 ASSERT(ds_next->ds_deadlist.dl_oldfmt); 1561 1562 poa.ds = ds; 1563 poa.ds_prev = ds_prev; 1564 poa.after_branch_point = after_branch_point; 1565 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1566 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, 1567 process_old_cb, &poa, tx)); 1568 VERIFY3U(zio_wait(poa.pio), ==, 0); 1569 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); 1570 1571 /* change snapused */ 1572 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1573 -poa.used, -poa.comp, -poa.uncomp, tx); 1574 1575 /* swap next's deadlist to our deadlist */ 1576 dsl_deadlist_close(&ds->ds_deadlist); 1577 dsl_deadlist_close(&ds_next->ds_deadlist); 1578 SWITCH64(ds_next->ds_phys->ds_deadlist_obj, 1579 ds->ds_phys->ds_deadlist_obj); 1580 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 1581 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 1582 ds_next->ds_phys->ds_deadlist_obj); 1583 } 1584 1585 void 1586 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx) 1587 { 1588 struct dsl_ds_destroyarg *dsda = arg1; 1589 dsl_dataset_t *ds = dsda->ds; 1590 int err; 1591 int after_branch_point = FALSE; 1592 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1593 objset_t *mos = dp->dp_meta_objset; 1594 dsl_dataset_t *ds_prev = NULL; 1595 uint64_t obj; 1596 1597 ASSERT(ds->ds_owner); 1598 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1599 ASSERT(ds->ds_prev == NULL || 1600 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1601 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1602 1603 if (dsda->defer) { 1604 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1605 if (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1) { 1606 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1607 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1608 return; 1609 } 1610 } 1611 1612 /* signal any waiters that this dataset is going away */ 1613 mutex_enter(&ds->ds_lock); 1614 ds->ds_owner = dsl_reaper; 1615 cv_broadcast(&ds->ds_exclusive_cv); 1616 mutex_exit(&ds->ds_lock); 1617 1618 if (ds->ds_objset) { 1619 dmu_objset_evict(ds->ds_objset); 1620 ds->ds_objset = NULL; 1621 } 1622 1623 /* Remove our reservation */ 1624 if (ds->ds_reserved != 0) { 1625 dsl_prop_setarg_t psa; 1626 uint64_t value = 0; 1627 1628 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1629 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1630 &value); 1631 psa.psa_effective_value = 0; /* predict default value */ 1632 1633 dsl_dataset_set_reservation_sync(ds, &psa, tx); 1634 ASSERT3U(ds->ds_reserved, ==, 0); 1635 } 1636 1637 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1638 1639 dsl_scan_ds_destroyed(ds, tx); 1640 1641 obj = ds->ds_object; 1642 1643 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1644 if (ds->ds_prev) { 1645 ds_prev = ds->ds_prev; 1646 } else { 1647 VERIFY(0 == dsl_dataset_hold_obj(dp, 1648 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1649 } 1650 after_branch_point = 1651 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1652 1653 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1654 if (after_branch_point && 1655 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1656 remove_from_next_clones(ds_prev, obj, tx); 1657 if (ds->ds_phys->ds_next_snap_obj != 0) { 1658 VERIFY(0 == zap_add_int(mos, 1659 ds_prev->ds_phys->ds_next_clones_obj, 1660 ds->ds_phys->ds_next_snap_obj, tx)); 1661 } 1662 } 1663 if (after_branch_point && 1664 ds->ds_phys->ds_next_snap_obj == 0) { 1665 /* This clone is toast. */ 1666 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1667 ds_prev->ds_phys->ds_num_children--; 1668 1669 /* 1670 * If the clone's origin has no other clones, no 1671 * user holds, and has been marked for deferred 1672 * deletion, then we should have done the necessary 1673 * destroy setup for it. 1674 */ 1675 if (ds_prev->ds_phys->ds_num_children == 1 && 1676 ds_prev->ds_userrefs == 0 && 1677 DS_IS_DEFER_DESTROY(ds_prev)) { 1678 ASSERT3P(dsda->rm_origin, !=, NULL); 1679 } else { 1680 ASSERT3P(dsda->rm_origin, ==, NULL); 1681 } 1682 } else if (!after_branch_point) { 1683 ds_prev->ds_phys->ds_next_snap_obj = 1684 ds->ds_phys->ds_next_snap_obj; 1685 } 1686 } 1687 1688 if (dsl_dataset_is_snapshot(ds)) { 1689 dsl_dataset_t *ds_next; 1690 uint64_t old_unique; 1691 uint64_t used = 0, comp = 0, uncomp = 0; 1692 1693 VERIFY(0 == dsl_dataset_hold_obj(dp, 1694 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1695 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1696 1697 old_unique = ds_next->ds_phys->ds_unique_bytes; 1698 1699 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1700 ds_next->ds_phys->ds_prev_snap_obj = 1701 ds->ds_phys->ds_prev_snap_obj; 1702 ds_next->ds_phys->ds_prev_snap_txg = 1703 ds->ds_phys->ds_prev_snap_txg; 1704 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1705 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1706 1707 1708 if (ds_next->ds_deadlist.dl_oldfmt) { 1709 process_old_deadlist(ds, ds_prev, ds_next, 1710 after_branch_point, tx); 1711 } else { 1712 /* Adjust prev's unique space. */ 1713 if (ds_prev && !after_branch_point) { 1714 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1715 ds_prev->ds_phys->ds_prev_snap_txg, 1716 ds->ds_phys->ds_prev_snap_txg, 1717 &used, &comp, &uncomp); 1718 ds_prev->ds_phys->ds_unique_bytes += used; 1719 } 1720 1721 /* Adjust snapused. */ 1722 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1723 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 1724 &used, &comp, &uncomp); 1725 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1726 -used, -comp, -uncomp, tx); 1727 1728 /* Move blocks to be freed to pool's free list. */ 1729 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 1730 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, 1731 tx); 1732 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 1733 DD_USED_HEAD, used, comp, uncomp, tx); 1734 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx); 1735 1736 /* Merge our deadlist into next's and free it. */ 1737 dsl_deadlist_merge(&ds_next->ds_deadlist, 1738 ds->ds_phys->ds_deadlist_obj, tx); 1739 } 1740 dsl_deadlist_close(&ds->ds_deadlist); 1741 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1742 1743 /* Collapse range in clone heads */ 1744 dsl_dataset_remove_clones_key(ds, 1745 ds->ds_phys->ds_creation_txg, tx); 1746 1747 if (dsl_dataset_is_snapshot(ds_next)) { 1748 dsl_dataset_t *ds_nextnext; 1749 1750 /* 1751 * Update next's unique to include blocks which 1752 * were previously shared by only this snapshot 1753 * and it. Those blocks will be born after the 1754 * prev snap and before this snap, and will have 1755 * died after the next snap and before the one 1756 * after that (ie. be on the snap after next's 1757 * deadlist). 1758 */ 1759 VERIFY(0 == dsl_dataset_hold_obj(dp, 1760 ds_next->ds_phys->ds_next_snap_obj, 1761 FTAG, &ds_nextnext)); 1762 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 1763 ds->ds_phys->ds_prev_snap_txg, 1764 ds->ds_phys->ds_creation_txg, 1765 &used, &comp, &uncomp); 1766 ds_next->ds_phys->ds_unique_bytes += used; 1767 dsl_dataset_rele(ds_nextnext, FTAG); 1768 ASSERT3P(ds_next->ds_prev, ==, NULL); 1769 1770 /* Collapse range in this head. */ 1771 dsl_dataset_t *hds; 1772 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 1773 ds->ds_dir->dd_phys->dd_head_dataset_obj, 1774 FTAG, &hds)); 1775 dsl_deadlist_remove_key(&hds->ds_deadlist, 1776 ds->ds_phys->ds_creation_txg, tx); 1777 dsl_dataset_rele(hds, FTAG); 1778 1779 } else { 1780 ASSERT3P(ds_next->ds_prev, ==, ds); 1781 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1782 ds_next->ds_prev = NULL; 1783 if (ds_prev) { 1784 VERIFY(0 == dsl_dataset_get_ref(dp, 1785 ds->ds_phys->ds_prev_snap_obj, 1786 ds_next, &ds_next->ds_prev)); 1787 } 1788 1789 dsl_dataset_recalc_head_uniq(ds_next); 1790 1791 /* 1792 * Reduce the amount of our unconsmed refreservation 1793 * being charged to our parent by the amount of 1794 * new unique data we have gained. 1795 */ 1796 if (old_unique < ds_next->ds_reserved) { 1797 int64_t mrsdelta; 1798 uint64_t new_unique = 1799 ds_next->ds_phys->ds_unique_bytes; 1800 1801 ASSERT(old_unique <= new_unique); 1802 mrsdelta = MIN(new_unique - old_unique, 1803 ds_next->ds_reserved - old_unique); 1804 dsl_dir_diduse_space(ds->ds_dir, 1805 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1806 } 1807 } 1808 dsl_dataset_rele(ds_next, FTAG); 1809 } else { 1810 /* 1811 * There's no next snapshot, so this is a head dataset. 1812 * Destroy the deadlist. Unless it's a clone, the 1813 * deadlist should be empty. (If it's a clone, it's 1814 * safe to ignore the deadlist contents.) 1815 */ 1816 struct killarg ka; 1817 1818 dsl_deadlist_close(&ds->ds_deadlist); 1819 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1820 ds->ds_phys->ds_deadlist_obj = 0; 1821 1822 /* 1823 * Free everything that we point to (that's born after 1824 * the previous snapshot, if we are a clone) 1825 * 1826 * NB: this should be very quick, because we already 1827 * freed all the objects in open context. 1828 */ 1829 ka.ds = ds; 1830 ka.tx = tx; 1831 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, 1832 TRAVERSE_POST, kill_blkptr, &ka); 1833 ASSERT3U(err, ==, 0); 1834 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1835 ds->ds_phys->ds_unique_bytes == 0); 1836 1837 if (ds->ds_prev != NULL) { 1838 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 1839 VERIFY3U(0, ==, zap_remove_int(mos, 1840 ds->ds_prev->ds_dir->dd_phys->dd_clones, 1841 ds->ds_object, tx)); 1842 } 1843 dsl_dataset_rele(ds->ds_prev, ds); 1844 ds->ds_prev = ds_prev = NULL; 1845 } 1846 } 1847 1848 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1849 /* Erase the link in the dir */ 1850 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1851 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1852 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1853 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1854 ASSERT(err == 0); 1855 } else { 1856 /* remove from snapshot namespace */ 1857 dsl_dataset_t *ds_head; 1858 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1859 VERIFY(0 == dsl_dataset_hold_obj(dp, 1860 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1861 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1862 #ifdef ZFS_DEBUG 1863 { 1864 uint64_t val; 1865 1866 err = dsl_dataset_snap_lookup(ds_head, 1867 ds->ds_snapname, &val); 1868 ASSERT3U(err, ==, 0); 1869 ASSERT3U(val, ==, obj); 1870 } 1871 #endif 1872 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1873 ASSERT(err == 0); 1874 dsl_dataset_rele(ds_head, FTAG); 1875 } 1876 1877 if (ds_prev && ds->ds_prev != ds_prev) 1878 dsl_dataset_rele(ds_prev, FTAG); 1879 1880 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1881 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx, 1882 "dataset = %llu", ds->ds_object); 1883 1884 if (ds->ds_phys->ds_next_clones_obj != 0) { 1885 uint64_t count; 1886 ASSERT(0 == zap_count(mos, 1887 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1888 VERIFY(0 == dmu_object_free(mos, 1889 ds->ds_phys->ds_next_clones_obj, tx)); 1890 } 1891 if (ds->ds_phys->ds_props_obj != 0) 1892 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1893 if (ds->ds_phys->ds_userrefs_obj != 0) 1894 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1895 dsl_dir_close(ds->ds_dir, ds); 1896 ds->ds_dir = NULL; 1897 dsl_dataset_drain_refs(ds, tag); 1898 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1899 1900 if (dsda->rm_origin) { 1901 /* 1902 * Remove the origin of the clone we just destroyed. 1903 */ 1904 struct dsl_ds_destroyarg ndsda = {0}; 1905 1906 ndsda.ds = dsda->rm_origin; 1907 dsl_dataset_destroy_sync(&ndsda, tag, tx); 1908 } 1909 } 1910 1911 static int 1912 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1913 { 1914 uint64_t asize; 1915 1916 if (!dmu_tx_is_syncing(tx)) 1917 return (0); 1918 1919 /* 1920 * If there's an fs-only reservation, any blocks that might become 1921 * owned by the snapshot dataset must be accommodated by space 1922 * outside of the reservation. 1923 */ 1924 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds)); 1925 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 1926 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE)) 1927 return (ENOSPC); 1928 1929 /* 1930 * Propogate any reserved space for this snapshot to other 1931 * snapshot checks in this sync group. 1932 */ 1933 if (asize > 0) 1934 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 1935 1936 return (0); 1937 } 1938 1939 int 1940 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 1941 { 1942 dsl_dataset_t *ds = arg1; 1943 const char *snapname = arg2; 1944 int err; 1945 uint64_t value; 1946 1947 /* 1948 * We don't allow multiple snapshots of the same txg. If there 1949 * is already one, try again. 1950 */ 1951 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 1952 return (EAGAIN); 1953 1954 /* 1955 * Check for conflicting name snapshot name. 1956 */ 1957 err = dsl_dataset_snap_lookup(ds, snapname, &value); 1958 if (err == 0) 1959 return (EEXIST); 1960 if (err != ENOENT) 1961 return (err); 1962 1963 /* 1964 * Check that the dataset's name is not too long. Name consists 1965 * of the dataset's length + 1 for the @-sign + snapshot name's length 1966 */ 1967 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 1968 return (ENAMETOOLONG); 1969 1970 err = dsl_dataset_snapshot_reserve_space(ds, tx); 1971 if (err) 1972 return (err); 1973 1974 ds->ds_trysnap_txg = tx->tx_txg; 1975 return (0); 1976 } 1977 1978 void 1979 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1980 { 1981 dsl_dataset_t *ds = arg1; 1982 const char *snapname = arg2; 1983 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1984 dmu_buf_t *dbuf; 1985 dsl_dataset_phys_t *dsphys; 1986 uint64_t dsobj, crtxg; 1987 objset_t *mos = dp->dp_meta_objset; 1988 int err; 1989 1990 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1991 1992 /* 1993 * The origin's ds_creation_txg has to be < TXG_INITIAL 1994 */ 1995 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 1996 crtxg = 1; 1997 else 1998 crtxg = tx->tx_txg; 1999 2000 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 2001 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 2002 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 2003 dmu_buf_will_dirty(dbuf, tx); 2004 dsphys = dbuf->db_data; 2005 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 2006 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 2007 dsphys->ds_fsid_guid = unique_create(); 2008 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 2009 sizeof (dsphys->ds_guid)); 2010 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 2011 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 2012 dsphys->ds_next_snap_obj = ds->ds_object; 2013 dsphys->ds_num_children = 1; 2014 dsphys->ds_creation_time = gethrestime_sec(); 2015 dsphys->ds_creation_txg = crtxg; 2016 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 2017 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes; 2018 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 2019 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 2020 dsphys->ds_flags = ds->ds_phys->ds_flags; 2021 dsphys->ds_bp = ds->ds_phys->ds_bp; 2022 dmu_buf_rele(dbuf, FTAG); 2023 2024 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 2025 if (ds->ds_prev) { 2026 uint64_t next_clones_obj = 2027 ds->ds_prev->ds_phys->ds_next_clones_obj; 2028 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 2029 ds->ds_object || 2030 ds->ds_prev->ds_phys->ds_num_children > 1); 2031 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 2032 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 2033 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 2034 ds->ds_prev->ds_phys->ds_creation_txg); 2035 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 2036 } else if (next_clones_obj != 0) { 2037 remove_from_next_clones(ds->ds_prev, 2038 dsphys->ds_next_snap_obj, tx); 2039 VERIFY3U(0, ==, zap_add_int(mos, 2040 next_clones_obj, dsobj, tx)); 2041 } 2042 } 2043 2044 /* 2045 * If we have a reference-reservation on this dataset, we will 2046 * need to increase the amount of refreservation being charged 2047 * since our unique space is going to zero. 2048 */ 2049 if (ds->ds_reserved) { 2050 int64_t delta; 2051 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 2052 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2053 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 2054 delta, 0, 0, tx); 2055 } 2056 2057 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2058 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu", 2059 ds->ds_dir->dd_myname, snapname, dsobj, 2060 ds->ds_phys->ds_prev_snap_txg); 2061 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist, 2062 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx); 2063 dsl_deadlist_close(&ds->ds_deadlist); 2064 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 2065 dsl_deadlist_add_key(&ds->ds_deadlist, 2066 ds->ds_phys->ds_prev_snap_txg, tx); 2067 2068 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 2069 ds->ds_phys->ds_prev_snap_obj = dsobj; 2070 ds->ds_phys->ds_prev_snap_txg = crtxg; 2071 ds->ds_phys->ds_unique_bytes = 0; 2072 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 2073 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 2074 2075 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 2076 snapname, 8, 1, &dsobj, tx); 2077 ASSERT(err == 0); 2078 2079 if (ds->ds_prev) 2080 dsl_dataset_drop_ref(ds->ds_prev, ds); 2081 VERIFY(0 == dsl_dataset_get_ref(dp, 2082 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 2083 2084 dsl_scan_ds_snapshotted(ds, tx); 2085 2086 dsl_dir_snap_cmtime_update(ds->ds_dir); 2087 2088 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx, 2089 "dataset = %llu", dsobj); 2090 } 2091 2092 void 2093 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 2094 { 2095 ASSERT(dmu_tx_is_syncing(tx)); 2096 ASSERT(ds->ds_objset != NULL); 2097 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 2098 2099 /* 2100 * in case we had to change ds_fsid_guid when we opened it, 2101 * sync it out now. 2102 */ 2103 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2104 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2105 2106 dsl_dir_dirty(ds->ds_dir, tx); 2107 dmu_objset_sync(ds->ds_objset, zio, tx); 2108 } 2109 2110 void 2111 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2112 { 2113 uint64_t refd, avail, uobjs, aobjs; 2114 2115 dsl_dir_stats(ds->ds_dir, nv); 2116 2117 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2118 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2119 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2120 2121 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2122 ds->ds_phys->ds_creation_time); 2123 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2124 ds->ds_phys->ds_creation_txg); 2125 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2126 ds->ds_quota); 2127 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2128 ds->ds_reserved); 2129 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2130 ds->ds_phys->ds_guid); 2131 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2132 ds->ds_phys->ds_unique_bytes); 2133 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2134 ds->ds_object); 2135 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2136 ds->ds_userrefs); 2137 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2138 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2139 2140 if (ds->ds_phys->ds_next_snap_obj) { 2141 /* 2142 * This is a snapshot; override the dd's space used with 2143 * our unique space and compression ratio. 2144 */ 2145 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2146 ds->ds_phys->ds_unique_bytes); 2147 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, 2148 ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2149 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2150 ds->ds_phys->ds_compressed_bytes)); 2151 } 2152 } 2153 2154 void 2155 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2156 { 2157 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2158 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2159 stat->dds_guid = ds->ds_phys->ds_guid; 2160 if (ds->ds_phys->ds_next_snap_obj) { 2161 stat->dds_is_snapshot = B_TRUE; 2162 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2163 } else { 2164 stat->dds_is_snapshot = B_FALSE; 2165 stat->dds_num_clones = 0; 2166 } 2167 2168 /* clone origin is really a dsl_dir thing... */ 2169 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2170 if (dsl_dir_is_clone(ds->ds_dir)) { 2171 dsl_dataset_t *ods; 2172 2173 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2174 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2175 dsl_dataset_name(ods, stat->dds_origin); 2176 dsl_dataset_drop_ref(ods, FTAG); 2177 } else { 2178 stat->dds_origin[0] = '\0'; 2179 } 2180 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2181 } 2182 2183 uint64_t 2184 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2185 { 2186 return (ds->ds_fsid_guid); 2187 } 2188 2189 void 2190 dsl_dataset_space(dsl_dataset_t *ds, 2191 uint64_t *refdbytesp, uint64_t *availbytesp, 2192 uint64_t *usedobjsp, uint64_t *availobjsp) 2193 { 2194 *refdbytesp = ds->ds_phys->ds_used_bytes; 2195 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2196 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2197 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2198 if (ds->ds_quota != 0) { 2199 /* 2200 * Adjust available bytes according to refquota 2201 */ 2202 if (*refdbytesp < ds->ds_quota) 2203 *availbytesp = MIN(*availbytesp, 2204 ds->ds_quota - *refdbytesp); 2205 else 2206 *availbytesp = 0; 2207 } 2208 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2209 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2210 } 2211 2212 boolean_t 2213 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2214 { 2215 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2216 2217 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2218 dsl_pool_sync_context(dp)); 2219 if (ds->ds_prev == NULL) 2220 return (B_FALSE); 2221 if (ds->ds_phys->ds_bp.blk_birth > 2222 ds->ds_prev->ds_phys->ds_creation_txg) 2223 return (B_TRUE); 2224 return (B_FALSE); 2225 } 2226 2227 /* ARGSUSED */ 2228 static int 2229 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2230 { 2231 dsl_dataset_t *ds = arg1; 2232 char *newsnapname = arg2; 2233 dsl_dir_t *dd = ds->ds_dir; 2234 dsl_dataset_t *hds; 2235 uint64_t val; 2236 int err; 2237 2238 err = dsl_dataset_hold_obj(dd->dd_pool, 2239 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2240 if (err) 2241 return (err); 2242 2243 /* new name better not be in use */ 2244 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2245 dsl_dataset_rele(hds, FTAG); 2246 2247 if (err == 0) 2248 err = EEXIST; 2249 else if (err == ENOENT) 2250 err = 0; 2251 2252 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2253 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2254 err = ENAMETOOLONG; 2255 2256 return (err); 2257 } 2258 2259 static void 2260 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2261 { 2262 dsl_dataset_t *ds = arg1; 2263 const char *newsnapname = arg2; 2264 dsl_dir_t *dd = ds->ds_dir; 2265 objset_t *mos = dd->dd_pool->dp_meta_objset; 2266 dsl_dataset_t *hds; 2267 int err; 2268 2269 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2270 2271 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2272 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2273 2274 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2275 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2276 ASSERT3U(err, ==, 0); 2277 mutex_enter(&ds->ds_lock); 2278 (void) strcpy(ds->ds_snapname, newsnapname); 2279 mutex_exit(&ds->ds_lock); 2280 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2281 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2282 ASSERT3U(err, ==, 0); 2283 2284 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2285 "dataset = %llu", ds->ds_object); 2286 dsl_dataset_rele(hds, FTAG); 2287 } 2288 2289 struct renamesnaparg { 2290 dsl_sync_task_group_t *dstg; 2291 char failed[MAXPATHLEN]; 2292 char *oldsnap; 2293 char *newsnap; 2294 }; 2295 2296 static int 2297 dsl_snapshot_rename_one(const char *name, void *arg) 2298 { 2299 struct renamesnaparg *ra = arg; 2300 dsl_dataset_t *ds = NULL; 2301 char *snapname; 2302 int err; 2303 2304 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); 2305 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); 2306 2307 /* 2308 * For recursive snapshot renames the parent won't be changing 2309 * so we just pass name for both the to/from argument. 2310 */ 2311 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); 2312 if (err != 0) { 2313 strfree(snapname); 2314 return (err == ENOENT ? 0 : err); 2315 } 2316 2317 #ifdef _KERNEL 2318 /* 2319 * For all filesystems undergoing rename, we'll need to unmount it. 2320 */ 2321 (void) zfs_unmount_snap(snapname, NULL); 2322 #endif 2323 err = dsl_dataset_hold(snapname, ra->dstg, &ds); 2324 strfree(snapname); 2325 if (err != 0) 2326 return (err == ENOENT ? 0 : err); 2327 2328 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2329 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2330 2331 return (0); 2332 } 2333 2334 static int 2335 dsl_recursive_rename(char *oldname, const char *newname) 2336 { 2337 int err; 2338 struct renamesnaparg *ra; 2339 dsl_sync_task_t *dst; 2340 spa_t *spa; 2341 char *cp, *fsname = spa_strdup(oldname); 2342 int len = strlen(oldname) + 1; 2343 2344 /* truncate the snapshot name to get the fsname */ 2345 cp = strchr(fsname, '@'); 2346 *cp = '\0'; 2347 2348 err = spa_open(fsname, &spa, FTAG); 2349 if (err) { 2350 kmem_free(fsname, len); 2351 return (err); 2352 } 2353 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2354 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2355 2356 ra->oldsnap = strchr(oldname, '@') + 1; 2357 ra->newsnap = strchr(newname, '@') + 1; 2358 *ra->failed = '\0'; 2359 2360 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2361 DS_FIND_CHILDREN); 2362 kmem_free(fsname, len); 2363 2364 if (err == 0) { 2365 err = dsl_sync_task_group_wait(ra->dstg); 2366 } 2367 2368 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2369 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2370 dsl_dataset_t *ds = dst->dst_arg1; 2371 if (dst->dst_err) { 2372 dsl_dir_name(ds->ds_dir, ra->failed); 2373 (void) strlcat(ra->failed, "@", sizeof (ra->failed)); 2374 (void) strlcat(ra->failed, ra->newsnap, 2375 sizeof (ra->failed)); 2376 } 2377 dsl_dataset_rele(ds, ra->dstg); 2378 } 2379 2380 if (err) 2381 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); 2382 2383 dsl_sync_task_group_destroy(ra->dstg); 2384 kmem_free(ra, sizeof (struct renamesnaparg)); 2385 spa_close(spa, FTAG); 2386 return (err); 2387 } 2388 2389 static int 2390 dsl_valid_rename(const char *oldname, void *arg) 2391 { 2392 int delta = *(int *)arg; 2393 2394 if (strlen(oldname) + delta >= MAXNAMELEN) 2395 return (ENAMETOOLONG); 2396 2397 return (0); 2398 } 2399 2400 #pragma weak dmu_objset_rename = dsl_dataset_rename 2401 int 2402 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2403 { 2404 dsl_dir_t *dd; 2405 dsl_dataset_t *ds; 2406 const char *tail; 2407 int err; 2408 2409 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2410 if (err) 2411 return (err); 2412 2413 if (tail == NULL) { 2414 int delta = strlen(newname) - strlen(oldname); 2415 2416 /* if we're growing, validate child name lengths */ 2417 if (delta > 0) 2418 err = dmu_objset_find(oldname, dsl_valid_rename, 2419 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2420 2421 if (err == 0) 2422 err = dsl_dir_rename(dd, newname); 2423 dsl_dir_close(dd, FTAG); 2424 return (err); 2425 } 2426 2427 if (tail[0] != '@') { 2428 /* the name ended in a nonexistent component */ 2429 dsl_dir_close(dd, FTAG); 2430 return (ENOENT); 2431 } 2432 2433 dsl_dir_close(dd, FTAG); 2434 2435 /* new name must be snapshot in same filesystem */ 2436 tail = strchr(newname, '@'); 2437 if (tail == NULL) 2438 return (EINVAL); 2439 tail++; 2440 if (strncmp(oldname, newname, tail - newname) != 0) 2441 return (EXDEV); 2442 2443 if (recursive) { 2444 err = dsl_recursive_rename(oldname, newname); 2445 } else { 2446 err = dsl_dataset_hold(oldname, FTAG, &ds); 2447 if (err) 2448 return (err); 2449 2450 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2451 dsl_dataset_snapshot_rename_check, 2452 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2453 2454 dsl_dataset_rele(ds, FTAG); 2455 } 2456 2457 return (err); 2458 } 2459 2460 struct promotenode { 2461 list_node_t link; 2462 dsl_dataset_t *ds; 2463 }; 2464 2465 struct promotearg { 2466 list_t shared_snaps, origin_snaps, clone_snaps; 2467 dsl_dataset_t *origin_origin; 2468 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2469 char *err_ds; 2470 }; 2471 2472 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2473 static boolean_t snaplist_unstable(list_t *l); 2474 2475 static int 2476 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2477 { 2478 dsl_dataset_t *hds = arg1; 2479 struct promotearg *pa = arg2; 2480 struct promotenode *snap = list_head(&pa->shared_snaps); 2481 dsl_dataset_t *origin_ds = snap->ds; 2482 int err; 2483 uint64_t unused; 2484 2485 /* Check that it is a real clone */ 2486 if (!dsl_dir_is_clone(hds->ds_dir)) 2487 return (EINVAL); 2488 2489 /* Since this is so expensive, don't do the preliminary check */ 2490 if (!dmu_tx_is_syncing(tx)) 2491 return (0); 2492 2493 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2494 return (EXDEV); 2495 2496 /* compute origin's new unique space */ 2497 snap = list_tail(&pa->clone_snaps); 2498 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2499 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2500 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2501 &pa->unique, &unused, &unused); 2502 2503 /* 2504 * Walk the snapshots that we are moving 2505 * 2506 * Compute space to transfer. Consider the incremental changes 2507 * to used for each snapshot: 2508 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2509 * So each snapshot gave birth to: 2510 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2511 * So a sequence would look like: 2512 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2513 * Which simplifies to: 2514 * uN + kN + kN-1 + ... + k1 + k0 2515 * Note however, if we stop before we reach the ORIGIN we get: 2516 * uN + kN + kN-1 + ... + kM - uM-1 2517 */ 2518 pa->used = origin_ds->ds_phys->ds_used_bytes; 2519 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2520 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2521 for (snap = list_head(&pa->shared_snaps); snap; 2522 snap = list_next(&pa->shared_snaps, snap)) { 2523 uint64_t val, dlused, dlcomp, dluncomp; 2524 dsl_dataset_t *ds = snap->ds; 2525 2526 /* Check that the snapshot name does not conflict */ 2527 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2528 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2529 if (err == 0) { 2530 err = EEXIST; 2531 goto out; 2532 } 2533 if (err != ENOENT) 2534 goto out; 2535 2536 /* The very first snapshot does not have a deadlist */ 2537 if (ds->ds_phys->ds_prev_snap_obj == 0) 2538 continue; 2539 2540 dsl_deadlist_space(&ds->ds_deadlist, 2541 &dlused, &dlcomp, &dluncomp); 2542 pa->used += dlused; 2543 pa->comp += dlcomp; 2544 pa->uncomp += dluncomp; 2545 } 2546 2547 /* 2548 * If we are a clone of a clone then we never reached ORIGIN, 2549 * so we need to subtract out the clone origin's used space. 2550 */ 2551 if (pa->origin_origin) { 2552 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes; 2553 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2554 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2555 } 2556 2557 /* Check that there is enough space here */ 2558 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2559 pa->used); 2560 if (err) 2561 return (err); 2562 2563 /* 2564 * Compute the amounts of space that will be used by snapshots 2565 * after the promotion (for both origin and clone). For each, 2566 * it is the amount of space that will be on all of their 2567 * deadlists (that was not born before their new origin). 2568 */ 2569 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2570 uint64_t space; 2571 2572 /* 2573 * Note, typically this will not be a clone of a clone, 2574 * so dd_origin_txg will be < TXG_INITIAL, so 2575 * these snaplist_space() -> dsl_deadlist_space_range() 2576 * calls will be fast because they do not have to 2577 * iterate over all bps. 2578 */ 2579 snap = list_head(&pa->origin_snaps); 2580 err = snaplist_space(&pa->shared_snaps, 2581 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap); 2582 if (err) 2583 return (err); 2584 2585 err = snaplist_space(&pa->clone_snaps, 2586 snap->ds->ds_dir->dd_origin_txg, &space); 2587 if (err) 2588 return (err); 2589 pa->cloneusedsnap += space; 2590 } 2591 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2592 err = snaplist_space(&pa->origin_snaps, 2593 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2594 if (err) 2595 return (err); 2596 } 2597 2598 return (0); 2599 out: 2600 pa->err_ds = snap->ds->ds_snapname; 2601 return (err); 2602 } 2603 2604 static void 2605 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2606 { 2607 dsl_dataset_t *hds = arg1; 2608 struct promotearg *pa = arg2; 2609 struct promotenode *snap = list_head(&pa->shared_snaps); 2610 dsl_dataset_t *origin_ds = snap->ds; 2611 dsl_dataset_t *origin_head; 2612 dsl_dir_t *dd = hds->ds_dir; 2613 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2614 dsl_dir_t *odd = NULL; 2615 uint64_t oldnext_obj; 2616 int64_t delta; 2617 2618 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2619 2620 snap = list_head(&pa->origin_snaps); 2621 origin_head = snap->ds; 2622 2623 /* 2624 * We need to explicitly open odd, since origin_ds's dd will be 2625 * changing. 2626 */ 2627 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2628 NULL, FTAG, &odd)); 2629 2630 /* change origin's next snap */ 2631 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2632 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2633 snap = list_tail(&pa->clone_snaps); 2634 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2635 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2636 2637 /* change the origin's next clone */ 2638 if (origin_ds->ds_phys->ds_next_clones_obj) { 2639 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2640 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2641 origin_ds->ds_phys->ds_next_clones_obj, 2642 oldnext_obj, tx)); 2643 } 2644 2645 /* change origin */ 2646 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2647 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2648 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2649 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg; 2650 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2651 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2652 origin_head->ds_dir->dd_origin_txg = 2653 origin_ds->ds_phys->ds_creation_txg; 2654 2655 /* change dd_clone entries */ 2656 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2657 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2658 odd->dd_phys->dd_clones, hds->ds_object, tx)); 2659 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2660 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2661 hds->ds_object, tx)); 2662 2663 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2664 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2665 origin_head->ds_object, tx)); 2666 if (dd->dd_phys->dd_clones == 0) { 2667 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset, 2668 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 2669 } 2670 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2671 dd->dd_phys->dd_clones, origin_head->ds_object, tx)); 2672 2673 } 2674 2675 /* move snapshots to this dir */ 2676 for (snap = list_head(&pa->shared_snaps); snap; 2677 snap = list_next(&pa->shared_snaps, snap)) { 2678 dsl_dataset_t *ds = snap->ds; 2679 2680 /* unregister props as dsl_dir is changing */ 2681 if (ds->ds_objset) { 2682 dmu_objset_evict(ds->ds_objset); 2683 ds->ds_objset = NULL; 2684 } 2685 /* move snap name entry */ 2686 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2687 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2688 ds->ds_snapname, tx)); 2689 VERIFY(0 == zap_add(dp->dp_meta_objset, 2690 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2691 8, 1, &ds->ds_object, tx)); 2692 2693 /* change containing dsl_dir */ 2694 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2695 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2696 ds->ds_phys->ds_dir_obj = dd->dd_object; 2697 ASSERT3P(ds->ds_dir, ==, odd); 2698 dsl_dir_close(ds->ds_dir, ds); 2699 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2700 NULL, ds, &ds->ds_dir)); 2701 2702 /* move any clone references */ 2703 if (ds->ds_phys->ds_next_clones_obj && 2704 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2705 zap_cursor_t zc; 2706 zap_attribute_t za; 2707 2708 for (zap_cursor_init(&zc, dp->dp_meta_objset, 2709 ds->ds_phys->ds_next_clones_obj); 2710 zap_cursor_retrieve(&zc, &za) == 0; 2711 zap_cursor_advance(&zc)) { 2712 dsl_dataset_t *cnds; 2713 uint64_t o; 2714 2715 if (za.za_first_integer == oldnext_obj) { 2716 /* 2717 * We've already moved the 2718 * origin's reference. 2719 */ 2720 continue; 2721 } 2722 2723 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 2724 za.za_first_integer, FTAG, &cnds)); 2725 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj; 2726 2727 VERIFY3U(zap_remove_int(dp->dp_meta_objset, 2728 odd->dd_phys->dd_clones, o, tx), ==, 0); 2729 VERIFY3U(zap_add_int(dp->dp_meta_objset, 2730 dd->dd_phys->dd_clones, o, tx), ==, 0); 2731 dsl_dataset_rele(cnds, FTAG); 2732 } 2733 zap_cursor_fini(&zc); 2734 } 2735 2736 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2737 } 2738 2739 /* 2740 * Change space accounting. 2741 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2742 * both be valid, or both be 0 (resulting in delta == 0). This 2743 * is true for each of {clone,origin} independently. 2744 */ 2745 2746 delta = pa->cloneusedsnap - 2747 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2748 ASSERT3S(delta, >=, 0); 2749 ASSERT3U(pa->used, >=, delta); 2750 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2751 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2752 pa->used - delta, pa->comp, pa->uncomp, tx); 2753 2754 delta = pa->originusedsnap - 2755 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2756 ASSERT3S(delta, <=, 0); 2757 ASSERT3U(pa->used, >=, -delta); 2758 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2759 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2760 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2761 2762 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2763 2764 /* log history record */ 2765 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2766 "dataset = %llu", hds->ds_object); 2767 2768 dsl_dir_close(odd, FTAG); 2769 } 2770 2771 static char *snaplist_tag = "snaplist"; 2772 /* 2773 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2774 * (exclusive) and last_obj (inclusive). The list will be in reverse 2775 * order (last_obj will be the list_head()). If first_obj == 0, do all 2776 * snapshots back to this dataset's origin. 2777 */ 2778 static int 2779 snaplist_make(dsl_pool_t *dp, boolean_t own, 2780 uint64_t first_obj, uint64_t last_obj, list_t *l) 2781 { 2782 uint64_t obj = last_obj; 2783 2784 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2785 2786 list_create(l, sizeof (struct promotenode), 2787 offsetof(struct promotenode, link)); 2788 2789 while (obj != first_obj) { 2790 dsl_dataset_t *ds; 2791 struct promotenode *snap; 2792 int err; 2793 2794 if (own) { 2795 err = dsl_dataset_own_obj(dp, obj, 2796 0, snaplist_tag, &ds); 2797 if (err == 0) 2798 dsl_dataset_make_exclusive(ds, snaplist_tag); 2799 } else { 2800 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2801 } 2802 if (err == ENOENT) { 2803 /* lost race with snapshot destroy */ 2804 struct promotenode *last = list_tail(l); 2805 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2806 obj = last->ds->ds_phys->ds_prev_snap_obj; 2807 continue; 2808 } else if (err) { 2809 return (err); 2810 } 2811 2812 if (first_obj == 0) 2813 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2814 2815 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2816 snap->ds = ds; 2817 list_insert_tail(l, snap); 2818 obj = ds->ds_phys->ds_prev_snap_obj; 2819 } 2820 2821 return (0); 2822 } 2823 2824 static int 2825 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2826 { 2827 struct promotenode *snap; 2828 2829 *spacep = 0; 2830 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2831 uint64_t used, comp, uncomp; 2832 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2833 mintxg, UINT64_MAX, &used, &comp, &uncomp); 2834 *spacep += used; 2835 } 2836 return (0); 2837 } 2838 2839 static void 2840 snaplist_destroy(list_t *l, boolean_t own) 2841 { 2842 struct promotenode *snap; 2843 2844 if (!l || !list_link_active(&l->list_head)) 2845 return; 2846 2847 while ((snap = list_tail(l)) != NULL) { 2848 list_remove(l, snap); 2849 if (own) 2850 dsl_dataset_disown(snap->ds, snaplist_tag); 2851 else 2852 dsl_dataset_rele(snap->ds, snaplist_tag); 2853 kmem_free(snap, sizeof (struct promotenode)); 2854 } 2855 list_destroy(l); 2856 } 2857 2858 /* 2859 * Promote a clone. Nomenclature note: 2860 * "clone" or "cds": the original clone which is being promoted 2861 * "origin" or "ods": the snapshot which is originally clone's origin 2862 * "origin head" or "ohds": the dataset which is the head 2863 * (filesystem/volume) for the origin 2864 * "origin origin": the origin of the origin's filesystem (typically 2865 * NULL, indicating that the clone is not a clone of a clone). 2866 */ 2867 int 2868 dsl_dataset_promote(const char *name, char *conflsnap) 2869 { 2870 dsl_dataset_t *ds; 2871 dsl_dir_t *dd; 2872 dsl_pool_t *dp; 2873 dmu_object_info_t doi; 2874 struct promotearg pa = { 0 }; 2875 struct promotenode *snap; 2876 int err; 2877 2878 err = dsl_dataset_hold(name, FTAG, &ds); 2879 if (err) 2880 return (err); 2881 dd = ds->ds_dir; 2882 dp = dd->dd_pool; 2883 2884 err = dmu_object_info(dp->dp_meta_objset, 2885 ds->ds_phys->ds_snapnames_zapobj, &doi); 2886 if (err) { 2887 dsl_dataset_rele(ds, FTAG); 2888 return (err); 2889 } 2890 2891 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 2892 dsl_dataset_rele(ds, FTAG); 2893 return (EINVAL); 2894 } 2895 2896 /* 2897 * We are going to inherit all the snapshots taken before our 2898 * origin (i.e., our new origin will be our parent's origin). 2899 * Take ownership of them so that we can rename them into our 2900 * namespace. 2901 */ 2902 rw_enter(&dp->dp_config_rwlock, RW_READER); 2903 2904 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 2905 &pa.shared_snaps); 2906 if (err != 0) 2907 goto out; 2908 2909 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 2910 if (err != 0) 2911 goto out; 2912 2913 snap = list_head(&pa.shared_snaps); 2914 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 2915 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 2916 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 2917 if (err != 0) 2918 goto out; 2919 2920 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) { 2921 err = dsl_dataset_hold_obj(dp, 2922 snap->ds->ds_dir->dd_phys->dd_origin_obj, 2923 FTAG, &pa.origin_origin); 2924 if (err != 0) 2925 goto out; 2926 } 2927 2928 out: 2929 rw_exit(&dp->dp_config_rwlock); 2930 2931 /* 2932 * Add in 128x the snapnames zapobj size, since we will be moving 2933 * a bunch of snapnames to the promoted ds, and dirtying their 2934 * bonus buffers. 2935 */ 2936 if (err == 0) { 2937 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 2938 dsl_dataset_promote_sync, ds, &pa, 2939 2 + 2 * doi.doi_physical_blocks_512); 2940 if (err && pa.err_ds && conflsnap) 2941 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 2942 } 2943 2944 snaplist_destroy(&pa.shared_snaps, B_TRUE); 2945 snaplist_destroy(&pa.clone_snaps, B_FALSE); 2946 snaplist_destroy(&pa.origin_snaps, B_FALSE); 2947 if (pa.origin_origin) 2948 dsl_dataset_rele(pa.origin_origin, FTAG); 2949 dsl_dataset_rele(ds, FTAG); 2950 return (err); 2951 } 2952 2953 struct cloneswaparg { 2954 dsl_dataset_t *cds; /* clone dataset */ 2955 dsl_dataset_t *ohds; /* origin's head dataset */ 2956 boolean_t force; 2957 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 2958 }; 2959 2960 /* ARGSUSED */ 2961 static int 2962 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 2963 { 2964 struct cloneswaparg *csa = arg1; 2965 2966 /* they should both be heads */ 2967 if (dsl_dataset_is_snapshot(csa->cds) || 2968 dsl_dataset_is_snapshot(csa->ohds)) 2969 return (EINVAL); 2970 2971 /* the branch point should be just before them */ 2972 if (csa->cds->ds_prev != csa->ohds->ds_prev) 2973 return (EINVAL); 2974 2975 /* cds should be the clone (unless they are unrelated) */ 2976 if (csa->cds->ds_prev != NULL && 2977 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 2978 csa->ohds->ds_object != 2979 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 2980 return (EINVAL); 2981 2982 /* the clone should be a child of the origin */ 2983 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 2984 return (EINVAL); 2985 2986 /* ohds shouldn't be modified unless 'force' */ 2987 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 2988 return (ETXTBSY); 2989 2990 /* adjust amount of any unconsumed refreservation */ 2991 csa->unused_refres_delta = 2992 (int64_t)MIN(csa->ohds->ds_reserved, 2993 csa->ohds->ds_phys->ds_unique_bytes) - 2994 (int64_t)MIN(csa->ohds->ds_reserved, 2995 csa->cds->ds_phys->ds_unique_bytes); 2996 2997 if (csa->unused_refres_delta > 0 && 2998 csa->unused_refres_delta > 2999 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 3000 return (ENOSPC); 3001 3002 if (csa->ohds->ds_quota != 0 && 3003 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 3004 return (EDQUOT); 3005 3006 return (0); 3007 } 3008 3009 /* ARGSUSED */ 3010 static void 3011 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3012 { 3013 struct cloneswaparg *csa = arg1; 3014 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 3015 3016 ASSERT(csa->cds->ds_reserved == 0); 3017 ASSERT(csa->ohds->ds_quota == 0 || 3018 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 3019 3020 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 3021 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 3022 3023 if (csa->cds->ds_objset != NULL) { 3024 dmu_objset_evict(csa->cds->ds_objset); 3025 csa->cds->ds_objset = NULL; 3026 } 3027 3028 if (csa->ohds->ds_objset != NULL) { 3029 dmu_objset_evict(csa->ohds->ds_objset); 3030 csa->ohds->ds_objset = NULL; 3031 } 3032 3033 /* 3034 * Reset origin's unique bytes, if it exists. 3035 */ 3036 if (csa->cds->ds_prev) { 3037 dsl_dataset_t *origin = csa->cds->ds_prev; 3038 uint64_t comp, uncomp; 3039 3040 dmu_buf_will_dirty(origin->ds_dbuf, tx); 3041 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3042 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 3043 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp); 3044 } 3045 3046 /* swap blkptrs */ 3047 { 3048 blkptr_t tmp; 3049 tmp = csa->ohds->ds_phys->ds_bp; 3050 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 3051 csa->cds->ds_phys->ds_bp = tmp; 3052 } 3053 3054 /* set dd_*_bytes */ 3055 { 3056 int64_t dused, dcomp, duncomp; 3057 uint64_t cdl_used, cdl_comp, cdl_uncomp; 3058 uint64_t odl_used, odl_comp, odl_uncomp; 3059 3060 ASSERT3U(csa->cds->ds_dir->dd_phys-> 3061 dd_used_breakdown[DD_USED_SNAP], ==, 0); 3062 3063 dsl_deadlist_space(&csa->cds->ds_deadlist, 3064 &cdl_used, &cdl_comp, &cdl_uncomp); 3065 dsl_deadlist_space(&csa->ohds->ds_deadlist, 3066 &odl_used, &odl_comp, &odl_uncomp); 3067 3068 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used - 3069 (csa->ohds->ds_phys->ds_used_bytes + odl_used); 3070 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 3071 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 3072 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 3073 cdl_uncomp - 3074 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 3075 3076 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 3077 dused, dcomp, duncomp, tx); 3078 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 3079 -dused, -dcomp, -duncomp, tx); 3080 3081 /* 3082 * The difference in the space used by snapshots is the 3083 * difference in snapshot space due to the head's 3084 * deadlist (since that's the only thing that's 3085 * changing that affects the snapused). 3086 */ 3087 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3088 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3089 &cdl_used, &cdl_comp, &cdl_uncomp); 3090 dsl_deadlist_space_range(&csa->ohds->ds_deadlist, 3091 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3092 &odl_used, &odl_comp, &odl_uncomp); 3093 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 3094 DD_USED_HEAD, DD_USED_SNAP, tx); 3095 } 3096 3097 /* swap ds_*_bytes */ 3098 SWITCH64(csa->ohds->ds_phys->ds_used_bytes, 3099 csa->cds->ds_phys->ds_used_bytes); 3100 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 3101 csa->cds->ds_phys->ds_compressed_bytes); 3102 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 3103 csa->cds->ds_phys->ds_uncompressed_bytes); 3104 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 3105 csa->cds->ds_phys->ds_unique_bytes); 3106 3107 /* apply any parent delta for change in unconsumed refreservation */ 3108 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 3109 csa->unused_refres_delta, 0, 0, tx); 3110 3111 /* 3112 * Swap deadlists. 3113 */ 3114 dsl_deadlist_close(&csa->cds->ds_deadlist); 3115 dsl_deadlist_close(&csa->ohds->ds_deadlist); 3116 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 3117 csa->cds->ds_phys->ds_deadlist_obj); 3118 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 3119 csa->cds->ds_phys->ds_deadlist_obj); 3120 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 3121 csa->ohds->ds_phys->ds_deadlist_obj); 3122 3123 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx); 3124 } 3125 3126 /* 3127 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 3128 * recv" into an existing fs to swizzle the file system to the new 3129 * version, and by "zfs rollback". Can also be used to swap two 3130 * independent head datasets if neither has any snapshots. 3131 */ 3132 int 3133 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 3134 boolean_t force) 3135 { 3136 struct cloneswaparg csa; 3137 int error; 3138 3139 ASSERT(clone->ds_owner); 3140 ASSERT(origin_head->ds_owner); 3141 retry: 3142 /* 3143 * Need exclusive access for the swap. If we're swapping these 3144 * datasets back after an error, we already hold the locks. 3145 */ 3146 if (!RW_WRITE_HELD(&clone->ds_rwlock)) 3147 rw_enter(&clone->ds_rwlock, RW_WRITER); 3148 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) && 3149 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 3150 rw_exit(&clone->ds_rwlock); 3151 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 3152 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 3153 rw_exit(&origin_head->ds_rwlock); 3154 goto retry; 3155 } 3156 } 3157 csa.cds = clone; 3158 csa.ohds = origin_head; 3159 csa.force = force; 3160 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3161 dsl_dataset_clone_swap_check, 3162 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3163 return (error); 3164 } 3165 3166 /* 3167 * Given a pool name and a dataset object number in that pool, 3168 * return the name of that dataset. 3169 */ 3170 int 3171 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3172 { 3173 spa_t *spa; 3174 dsl_pool_t *dp; 3175 dsl_dataset_t *ds; 3176 int error; 3177 3178 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3179 return (error); 3180 dp = spa_get_dsl(spa); 3181 rw_enter(&dp->dp_config_rwlock, RW_READER); 3182 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3183 dsl_dataset_name(ds, buf); 3184 dsl_dataset_rele(ds, FTAG); 3185 } 3186 rw_exit(&dp->dp_config_rwlock); 3187 spa_close(spa, FTAG); 3188 3189 return (error); 3190 } 3191 3192 int 3193 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3194 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3195 { 3196 int error = 0; 3197 3198 ASSERT3S(asize, >, 0); 3199 3200 /* 3201 * *ref_rsrv is the portion of asize that will come from any 3202 * unconsumed refreservation space. 3203 */ 3204 *ref_rsrv = 0; 3205 3206 mutex_enter(&ds->ds_lock); 3207 /* 3208 * Make a space adjustment for reserved bytes. 3209 */ 3210 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3211 ASSERT3U(*used, >=, 3212 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3213 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3214 *ref_rsrv = 3215 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3216 } 3217 3218 if (!check_quota || ds->ds_quota == 0) { 3219 mutex_exit(&ds->ds_lock); 3220 return (0); 3221 } 3222 /* 3223 * If they are requesting more space, and our current estimate 3224 * is over quota, they get to try again unless the actual 3225 * on-disk is over quota and there are no pending changes (which 3226 * may free up space for us). 3227 */ 3228 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) { 3229 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota) 3230 error = ERESTART; 3231 else 3232 error = EDQUOT; 3233 } 3234 mutex_exit(&ds->ds_lock); 3235 3236 return (error); 3237 } 3238 3239 /* ARGSUSED */ 3240 static int 3241 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3242 { 3243 dsl_dataset_t *ds = arg1; 3244 dsl_prop_setarg_t *psa = arg2; 3245 int err; 3246 3247 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3248 return (ENOTSUP); 3249 3250 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3251 return (err); 3252 3253 if (psa->psa_effective_value == 0) 3254 return (0); 3255 3256 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes || 3257 psa->psa_effective_value < ds->ds_reserved) 3258 return (ENOSPC); 3259 3260 return (0); 3261 } 3262 3263 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *); 3264 3265 void 3266 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3267 { 3268 dsl_dataset_t *ds = arg1; 3269 dsl_prop_setarg_t *psa = arg2; 3270 uint64_t effective_value = psa->psa_effective_value; 3271 3272 dsl_prop_set_sync(ds, psa, tx); 3273 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3274 3275 if (ds->ds_quota != effective_value) { 3276 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3277 ds->ds_quota = effective_value; 3278 3279 spa_history_log_internal(LOG_DS_REFQUOTA, 3280 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ", 3281 (longlong_t)ds->ds_quota, ds->ds_object); 3282 } 3283 } 3284 3285 int 3286 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3287 { 3288 dsl_dataset_t *ds; 3289 dsl_prop_setarg_t psa; 3290 int err; 3291 3292 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3293 3294 err = dsl_dataset_hold(dsname, FTAG, &ds); 3295 if (err) 3296 return (err); 3297 3298 /* 3299 * If someone removes a file, then tries to set the quota, we 3300 * want to make sure the file freeing takes effect. 3301 */ 3302 txg_wait_open(ds->ds_dir->dd_pool, 0); 3303 3304 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3305 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3306 ds, &psa, 0); 3307 3308 dsl_dataset_rele(ds, FTAG); 3309 return (err); 3310 } 3311 3312 static int 3313 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3314 { 3315 dsl_dataset_t *ds = arg1; 3316 dsl_prop_setarg_t *psa = arg2; 3317 uint64_t effective_value; 3318 uint64_t unique; 3319 int err; 3320 3321 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3322 SPA_VERSION_REFRESERVATION) 3323 return (ENOTSUP); 3324 3325 if (dsl_dataset_is_snapshot(ds)) 3326 return (EINVAL); 3327 3328 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3329 return (err); 3330 3331 effective_value = psa->psa_effective_value; 3332 3333 /* 3334 * If we are doing the preliminary check in open context, the 3335 * space estimates may be inaccurate. 3336 */ 3337 if (!dmu_tx_is_syncing(tx)) 3338 return (0); 3339 3340 mutex_enter(&ds->ds_lock); 3341 if (!DS_UNIQUE_IS_ACCURATE(ds)) 3342 dsl_dataset_recalc_head_uniq(ds); 3343 unique = ds->ds_phys->ds_unique_bytes; 3344 mutex_exit(&ds->ds_lock); 3345 3346 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3347 uint64_t delta = MAX(unique, effective_value) - 3348 MAX(unique, ds->ds_reserved); 3349 3350 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3351 return (ENOSPC); 3352 if (ds->ds_quota > 0 && 3353 effective_value > ds->ds_quota) 3354 return (ENOSPC); 3355 } 3356 3357 return (0); 3358 } 3359 3360 static void 3361 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3362 { 3363 dsl_dataset_t *ds = arg1; 3364 dsl_prop_setarg_t *psa = arg2; 3365 uint64_t effective_value = psa->psa_effective_value; 3366 uint64_t unique; 3367 int64_t delta; 3368 3369 dsl_prop_set_sync(ds, psa, tx); 3370 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3371 3372 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3373 3374 mutex_enter(&ds->ds_dir->dd_lock); 3375 mutex_enter(&ds->ds_lock); 3376 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 3377 unique = ds->ds_phys->ds_unique_bytes; 3378 delta = MAX(0, (int64_t)(effective_value - unique)) - 3379 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3380 ds->ds_reserved = effective_value; 3381 mutex_exit(&ds->ds_lock); 3382 3383 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3384 mutex_exit(&ds->ds_dir->dd_lock); 3385 3386 spa_history_log_internal(LOG_DS_REFRESERV, 3387 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu", 3388 (longlong_t)effective_value, ds->ds_object); 3389 } 3390 3391 int 3392 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3393 uint64_t reservation) 3394 { 3395 dsl_dataset_t *ds; 3396 dsl_prop_setarg_t psa; 3397 int err; 3398 3399 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3400 &reservation); 3401 3402 err = dsl_dataset_hold(dsname, FTAG, &ds); 3403 if (err) 3404 return (err); 3405 3406 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3407 dsl_dataset_set_reservation_check, 3408 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3409 3410 dsl_dataset_rele(ds, FTAG); 3411 return (err); 3412 } 3413 3414 struct dsl_ds_holdarg { 3415 dsl_sync_task_group_t *dstg; 3416 char *htag; 3417 char *snapname; 3418 boolean_t recursive; 3419 boolean_t gotone; 3420 boolean_t temphold; 3421 char failed[MAXPATHLEN]; 3422 }; 3423 3424 typedef struct zfs_hold_cleanup_arg { 3425 char dsname[MAXNAMELEN]; 3426 char snapname[MAXNAMELEN]; 3427 char htag[MAXNAMELEN]; 3428 boolean_t recursive; 3429 } zfs_hold_cleanup_arg_t; 3430 3431 static void 3432 dsl_dataset_user_release_onexit(void *arg) 3433 { 3434 zfs_hold_cleanup_arg_t *ca = arg; 3435 3436 (void) dsl_dataset_user_release(ca->dsname, ca->snapname, 3437 ca->htag, ca->recursive); 3438 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t)); 3439 } 3440 3441 /* 3442 * The max length of a temporary tag prefix is the number of hex digits 3443 * required to express UINT64_MAX plus one for the hyphen. 3444 */ 3445 #define MAX_TAG_PREFIX_LEN 17 3446 3447 static int 3448 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3449 { 3450 dsl_dataset_t *ds = arg1; 3451 struct dsl_ds_holdarg *ha = arg2; 3452 char *htag = ha->htag; 3453 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3454 int error = 0; 3455 3456 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3457 return (ENOTSUP); 3458 3459 if (!dsl_dataset_is_snapshot(ds)) 3460 return (EINVAL); 3461 3462 /* tags must be unique */ 3463 mutex_enter(&ds->ds_lock); 3464 if (ds->ds_phys->ds_userrefs_obj) { 3465 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3466 8, 1, tx); 3467 if (error == 0) 3468 error = EEXIST; 3469 else if (error == ENOENT) 3470 error = 0; 3471 } 3472 mutex_exit(&ds->ds_lock); 3473 3474 if (error == 0 && ha->temphold && 3475 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3476 error = E2BIG; 3477 3478 return (error); 3479 } 3480 3481 static void 3482 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3483 { 3484 dsl_dataset_t *ds = arg1; 3485 struct dsl_ds_holdarg *ha = arg2; 3486 char *htag = ha->htag; 3487 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3488 objset_t *mos = dp->dp_meta_objset; 3489 uint64_t now = gethrestime_sec(); 3490 uint64_t zapobj; 3491 3492 mutex_enter(&ds->ds_lock); 3493 if (ds->ds_phys->ds_userrefs_obj == 0) { 3494 /* 3495 * This is the first user hold for this dataset. Create 3496 * the userrefs zap object. 3497 */ 3498 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3499 zapobj = ds->ds_phys->ds_userrefs_obj = 3500 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3501 } else { 3502 zapobj = ds->ds_phys->ds_userrefs_obj; 3503 } 3504 ds->ds_userrefs++; 3505 mutex_exit(&ds->ds_lock); 3506 3507 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3508 3509 if (ha->temphold) { 3510 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3511 htag, &now, tx)); 3512 } 3513 3514 spa_history_log_internal(LOG_DS_USER_HOLD, 3515 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag, 3516 (int)ha->temphold, ds->ds_object); 3517 } 3518 3519 static int 3520 dsl_dataset_user_hold_one(const char *dsname, void *arg) 3521 { 3522 struct dsl_ds_holdarg *ha = arg; 3523 dsl_dataset_t *ds; 3524 int error; 3525 char *name; 3526 3527 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3528 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3529 error = dsl_dataset_hold(name, ha->dstg, &ds); 3530 strfree(name); 3531 if (error == 0) { 3532 ha->gotone = B_TRUE; 3533 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3534 dsl_dataset_user_hold_sync, ds, ha, 0); 3535 } else if (error == ENOENT && ha->recursive) { 3536 error = 0; 3537 } else { 3538 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3539 } 3540 return (error); 3541 } 3542 3543 int 3544 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3545 boolean_t recursive, boolean_t temphold, int cleanup_fd) 3546 { 3547 struct dsl_ds_holdarg *ha; 3548 dsl_sync_task_t *dst; 3549 spa_t *spa; 3550 int error; 3551 3552 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3553 3554 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3555 3556 error = spa_open(dsname, &spa, FTAG); 3557 if (error) { 3558 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3559 return (error); 3560 } 3561 3562 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3563 ha->htag = htag; 3564 ha->snapname = snapname; 3565 ha->recursive = recursive; 3566 ha->temphold = temphold; 3567 3568 if (recursive) { 3569 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3570 ha, DS_FIND_CHILDREN); 3571 } else { 3572 error = dsl_dataset_user_hold_one(dsname, ha); 3573 } 3574 if (error == 0) 3575 error = dsl_sync_task_group_wait(ha->dstg); 3576 3577 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3578 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3579 dsl_dataset_t *ds = dst->dst_arg1; 3580 3581 if (dst->dst_err) { 3582 dsl_dataset_name(ds, ha->failed); 3583 *strchr(ha->failed, '@') = '\0'; 3584 } 3585 dsl_dataset_rele(ds, ha->dstg); 3586 } 3587 3588 if (error == 0 && recursive && !ha->gotone) 3589 error = ENOENT; 3590 3591 if (error) 3592 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3593 3594 dsl_sync_task_group_destroy(ha->dstg); 3595 3596 /* 3597 * If this set of temporary holds is to be removed upon process exit, 3598 * register that action now. 3599 */ 3600 if (error == 0 && cleanup_fd != -1 && temphold) { 3601 zfs_hold_cleanup_arg_t *ca; 3602 uint64_t action_handle; 3603 3604 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP); 3605 (void) strlcpy(ca->dsname, dsname, sizeof (ca->dsname)); 3606 (void) strlcpy(ca->snapname, snapname, sizeof (ca->snapname)); 3607 (void) strlcpy(ca->htag, htag, sizeof (ca->htag)); 3608 ca->recursive = recursive; 3609 (void) zfs_onexit_add_cb(cleanup_fd, 3610 dsl_dataset_user_release_onexit, ca, &action_handle); 3611 } 3612 3613 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3614 spa_close(spa, FTAG); 3615 return (error); 3616 } 3617 3618 struct dsl_ds_releasearg { 3619 dsl_dataset_t *ds; 3620 const char *htag; 3621 boolean_t own; /* do we own or just hold ds? */ 3622 }; 3623 3624 static int 3625 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3626 boolean_t *might_destroy) 3627 { 3628 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3629 uint64_t zapobj; 3630 uint64_t tmp; 3631 int error; 3632 3633 *might_destroy = B_FALSE; 3634 3635 mutex_enter(&ds->ds_lock); 3636 zapobj = ds->ds_phys->ds_userrefs_obj; 3637 if (zapobj == 0) { 3638 /* The tag can't possibly exist */ 3639 mutex_exit(&ds->ds_lock); 3640 return (ESRCH); 3641 } 3642 3643 /* Make sure the tag exists */ 3644 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3645 if (error) { 3646 mutex_exit(&ds->ds_lock); 3647 if (error == ENOENT) 3648 error = ESRCH; 3649 return (error); 3650 } 3651 3652 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3653 DS_IS_DEFER_DESTROY(ds)) 3654 *might_destroy = B_TRUE; 3655 3656 mutex_exit(&ds->ds_lock); 3657 return (0); 3658 } 3659 3660 static int 3661 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3662 { 3663 struct dsl_ds_releasearg *ra = arg1; 3664 dsl_dataset_t *ds = ra->ds; 3665 boolean_t might_destroy; 3666 int error; 3667 3668 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3669 return (ENOTSUP); 3670 3671 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3672 if (error) 3673 return (error); 3674 3675 if (might_destroy) { 3676 struct dsl_ds_destroyarg dsda = {0}; 3677 3678 if (dmu_tx_is_syncing(tx)) { 3679 /* 3680 * If we're not prepared to remove the snapshot, 3681 * we can't allow the release to happen right now. 3682 */ 3683 if (!ra->own) 3684 return (EBUSY); 3685 } 3686 dsda.ds = ds; 3687 dsda.releasing = B_TRUE; 3688 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3689 } 3690 3691 return (0); 3692 } 3693 3694 static void 3695 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx) 3696 { 3697 struct dsl_ds_releasearg *ra = arg1; 3698 dsl_dataset_t *ds = ra->ds; 3699 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3700 objset_t *mos = dp->dp_meta_objset; 3701 uint64_t zapobj; 3702 uint64_t dsobj = ds->ds_object; 3703 uint64_t refs; 3704 int error; 3705 3706 if (ds->ds_objset) { 3707 dmu_objset_evict(ds->ds_objset); 3708 ds->ds_objset = NULL; 3709 } 3710 3711 mutex_enter(&ds->ds_lock); 3712 ds->ds_userrefs--; 3713 refs = ds->ds_userrefs; 3714 mutex_exit(&ds->ds_lock); 3715 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3716 VERIFY(error == 0 || error == ENOENT); 3717 zapobj = ds->ds_phys->ds_userrefs_obj; 3718 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3719 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3720 DS_IS_DEFER_DESTROY(ds)) { 3721 struct dsl_ds_destroyarg dsda = {0}; 3722 3723 ASSERT(ra->own); 3724 dsda.ds = ds; 3725 dsda.releasing = B_TRUE; 3726 /* We already did the destroy_check */ 3727 dsl_dataset_destroy_sync(&dsda, tag, tx); 3728 } 3729 3730 spa_history_log_internal(LOG_DS_USER_RELEASE, 3731 dp->dp_spa, tx, "<%s> %lld dataset = %llu", 3732 ra->htag, (longlong_t)refs, dsobj); 3733 } 3734 3735 static int 3736 dsl_dataset_user_release_one(const char *dsname, void *arg) 3737 { 3738 struct dsl_ds_holdarg *ha = arg; 3739 struct dsl_ds_releasearg *ra; 3740 dsl_dataset_t *ds; 3741 int error; 3742 void *dtag = ha->dstg; 3743 char *name; 3744 boolean_t own = B_FALSE; 3745 boolean_t might_destroy; 3746 3747 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3748 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3749 error = dsl_dataset_hold(name, dtag, &ds); 3750 strfree(name); 3751 if (error == ENOENT && ha->recursive) 3752 return (0); 3753 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3754 if (error) 3755 return (error); 3756 3757 ha->gotone = B_TRUE; 3758 3759 ASSERT(dsl_dataset_is_snapshot(ds)); 3760 3761 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3762 if (error) { 3763 dsl_dataset_rele(ds, dtag); 3764 return (error); 3765 } 3766 3767 if (might_destroy) { 3768 #ifdef _KERNEL 3769 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3770 error = zfs_unmount_snap(name, NULL); 3771 strfree(name); 3772 if (error) { 3773 dsl_dataset_rele(ds, dtag); 3774 return (error); 3775 } 3776 #endif 3777 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3778 dsl_dataset_rele(ds, dtag); 3779 return (EBUSY); 3780 } else { 3781 own = B_TRUE; 3782 dsl_dataset_make_exclusive(ds, dtag); 3783 } 3784 } 3785 3786 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3787 ra->ds = ds; 3788 ra->htag = ha->htag; 3789 ra->own = own; 3790 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3791 dsl_dataset_user_release_sync, ra, dtag, 0); 3792 3793 return (0); 3794 } 3795 3796 int 3797 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3798 boolean_t recursive) 3799 { 3800 struct dsl_ds_holdarg *ha; 3801 dsl_sync_task_t *dst; 3802 spa_t *spa; 3803 int error; 3804 3805 top: 3806 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3807 3808 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3809 3810 error = spa_open(dsname, &spa, FTAG); 3811 if (error) { 3812 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3813 return (error); 3814 } 3815 3816 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3817 ha->htag = htag; 3818 ha->snapname = snapname; 3819 ha->recursive = recursive; 3820 if (recursive) { 3821 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3822 ha, DS_FIND_CHILDREN); 3823 } else { 3824 error = dsl_dataset_user_release_one(dsname, ha); 3825 } 3826 if (error == 0) 3827 error = dsl_sync_task_group_wait(ha->dstg); 3828 3829 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3830 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3831 struct dsl_ds_releasearg *ra = dst->dst_arg1; 3832 dsl_dataset_t *ds = ra->ds; 3833 3834 if (dst->dst_err) 3835 dsl_dataset_name(ds, ha->failed); 3836 3837 if (ra->own) 3838 dsl_dataset_disown(ds, ha->dstg); 3839 else 3840 dsl_dataset_rele(ds, ha->dstg); 3841 3842 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 3843 } 3844 3845 if (error == 0 && recursive && !ha->gotone) 3846 error = ENOENT; 3847 3848 if (error && error != EBUSY) 3849 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3850 3851 dsl_sync_task_group_destroy(ha->dstg); 3852 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3853 spa_close(spa, FTAG); 3854 3855 /* 3856 * We can get EBUSY if we were racing with deferred destroy and 3857 * dsl_dataset_user_release_check() hadn't done the necessary 3858 * open context setup. We can also get EBUSY if we're racing 3859 * with destroy and that thread is the ds_owner. Either way 3860 * the busy condition should be transient, and we should retry 3861 * the release operation. 3862 */ 3863 if (error == EBUSY) 3864 goto top; 3865 3866 return (error); 3867 } 3868 3869 /* 3870 * Called at spa_load time to release a stale temporary user hold. 3871 */ 3872 int 3873 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag) 3874 { 3875 dsl_dataset_t *ds; 3876 char *snap; 3877 char *name; 3878 int namelen; 3879 int error; 3880 3881 rw_enter(&dp->dp_config_rwlock, RW_READER); 3882 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 3883 rw_exit(&dp->dp_config_rwlock); 3884 if (error) 3885 return (error); 3886 namelen = dsl_dataset_namelen(ds)+1; 3887 name = kmem_alloc(namelen, KM_SLEEP); 3888 dsl_dataset_name(ds, name); 3889 dsl_dataset_rele(ds, FTAG); 3890 3891 snap = strchr(name, '@'); 3892 *snap = '\0'; 3893 ++snap; 3894 return (dsl_dataset_user_release(name, snap, htag, B_FALSE)); 3895 } 3896 3897 int 3898 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 3899 { 3900 dsl_dataset_t *ds; 3901 int err; 3902 3903 err = dsl_dataset_hold(dsname, FTAG, &ds); 3904 if (err) 3905 return (err); 3906 3907 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 3908 if (ds->ds_phys->ds_userrefs_obj != 0) { 3909 zap_attribute_t *za; 3910 zap_cursor_t zc; 3911 3912 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 3913 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 3914 ds->ds_phys->ds_userrefs_obj); 3915 zap_cursor_retrieve(&zc, za) == 0; 3916 zap_cursor_advance(&zc)) { 3917 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 3918 za->za_first_integer)); 3919 } 3920 zap_cursor_fini(&zc); 3921 kmem_free(za, sizeof (zap_attribute_t)); 3922 } 3923 dsl_dataset_rele(ds, FTAG); 3924 return (0); 3925 } 3926 3927 /* 3928 * Note, this fuction is used as the callback for dmu_objset_find(). We 3929 * always return 0 so that we will continue to find and process 3930 * inconsistent datasets, even if we encounter an error trying to 3931 * process one of them. 3932 */ 3933 /* ARGSUSED */ 3934 int 3935 dsl_destroy_inconsistent(const char *dsname, void *arg) 3936 { 3937 dsl_dataset_t *ds; 3938 3939 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 3940 if (DS_IS_INCONSISTENT(ds)) 3941 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 3942 else 3943 dsl_dataset_disown(ds, FTAG); 3944 } 3945 return (0); 3946 } 3947