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 * Copyright (c) 2012 by Delphix. All rights reserved. 24 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 25 */ 26 27 #include <sys/dmu_objset.h> 28 #include <sys/dsl_dataset.h> 29 #include <sys/dsl_dir.h> 30 #include <sys/dsl_prop.h> 31 #include <sys/dsl_synctask.h> 32 #include <sys/dmu_traverse.h> 33 #include <sys/dmu_impl.h> 34 #include <sys/dmu_tx.h> 35 #include <sys/arc.h> 36 #include <sys/zio.h> 37 #include <sys/zap.h> 38 #include <sys/zfeature.h> 39 #include <sys/unique.h> 40 #include <sys/zfs_context.h> 41 #include <sys/zfs_ioctl.h> 42 #include <sys/spa.h> 43 #include <sys/zfs_znode.h> 44 #include <sys/zfs_onexit.h> 45 #include <sys/zvol.h> 46 #include <sys/dsl_scan.h> 47 #include <sys/dsl_deadlist.h> 48 49 static char *dsl_reaper = "the grim reaper"; 50 51 static dsl_checkfunc_t dsl_dataset_destroy_begin_check; 52 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync; 53 static dsl_syncfunc_t dsl_dataset_set_reservation_sync; 54 55 #define SWITCH64(x, y) \ 56 { \ 57 uint64_t __tmp = (x); \ 58 (x) = (y); \ 59 (y) = __tmp; \ 60 } 61 62 #define DS_REF_MAX (1ULL << 62) 63 64 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE 65 66 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper) 67 68 69 /* 70 * Figure out how much of this delta should be propogated to the dsl_dir 71 * layer. If there's a refreservation, that space has already been 72 * partially accounted for in our ancestors. 73 */ 74 static int64_t 75 parent_delta(dsl_dataset_t *ds, int64_t delta) 76 { 77 uint64_t old_bytes, new_bytes; 78 79 if (ds->ds_reserved == 0) 80 return (delta); 81 82 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 83 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved); 84 85 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta)); 86 return (new_bytes - old_bytes); 87 } 88 89 void 90 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx) 91 { 92 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 93 int compressed = BP_GET_PSIZE(bp); 94 int uncompressed = BP_GET_UCSIZE(bp); 95 int64_t delta; 96 97 dprintf_bp(bp, "ds=%p", ds); 98 99 ASSERT(dmu_tx_is_syncing(tx)); 100 /* It could have been compressed away to nothing */ 101 if (BP_IS_HOLE(bp)) 102 return; 103 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE); 104 ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp))); 105 if (ds == NULL) { 106 dsl_pool_mos_diduse_space(tx->tx_pool, 107 used, compressed, uncompressed); 108 return; 109 } 110 dmu_buf_will_dirty(ds->ds_dbuf, tx); 111 112 mutex_enter(&ds->ds_dir->dd_lock); 113 mutex_enter(&ds->ds_lock); 114 delta = parent_delta(ds, used); 115 ds->ds_phys->ds_referenced_bytes += used; 116 ds->ds_phys->ds_compressed_bytes += compressed; 117 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 118 ds->ds_phys->ds_unique_bytes += used; 119 mutex_exit(&ds->ds_lock); 120 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 121 compressed, uncompressed, tx); 122 dsl_dir_transfer_space(ds->ds_dir, used - delta, 123 DD_USED_REFRSRV, DD_USED_HEAD, tx); 124 mutex_exit(&ds->ds_dir->dd_lock); 125 } 126 127 int 128 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, 129 boolean_t async) 130 { 131 if (BP_IS_HOLE(bp)) 132 return (0); 133 134 ASSERT(dmu_tx_is_syncing(tx)); 135 ASSERT(bp->blk_birth <= tx->tx_txg); 136 137 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 138 int compressed = BP_GET_PSIZE(bp); 139 int uncompressed = BP_GET_UCSIZE(bp); 140 141 ASSERT(used > 0); 142 if (ds == NULL) { 143 dsl_free(tx->tx_pool, tx->tx_txg, bp); 144 dsl_pool_mos_diduse_space(tx->tx_pool, 145 -used, -compressed, -uncompressed); 146 return (used); 147 } 148 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 149 150 ASSERT(!dsl_dataset_is_snapshot(ds)); 151 dmu_buf_will_dirty(ds->ds_dbuf, tx); 152 153 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 154 int64_t delta; 155 156 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object); 157 dsl_free(tx->tx_pool, tx->tx_txg, bp); 158 159 mutex_enter(&ds->ds_dir->dd_lock); 160 mutex_enter(&ds->ds_lock); 161 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 162 !DS_UNIQUE_IS_ACCURATE(ds)); 163 delta = parent_delta(ds, -used); 164 ds->ds_phys->ds_unique_bytes -= used; 165 mutex_exit(&ds->ds_lock); 166 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 167 delta, -compressed, -uncompressed, tx); 168 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 169 DD_USED_REFRSRV, DD_USED_HEAD, tx); 170 mutex_exit(&ds->ds_dir->dd_lock); 171 } else { 172 dprintf_bp(bp, "putting on dead list: %s", ""); 173 if (async) { 174 /* 175 * We are here as part of zio's write done callback, 176 * which means we're a zio interrupt thread. We can't 177 * call dsl_deadlist_insert() now because it may block 178 * waiting for I/O. Instead, put bp on the deferred 179 * queue and let dsl_pool_sync() finish the job. 180 */ 181 bplist_append(&ds->ds_pending_deadlist, bp); 182 } else { 183 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx); 184 } 185 ASSERT3U(ds->ds_prev->ds_object, ==, 186 ds->ds_phys->ds_prev_snap_obj); 187 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 188 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 189 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 190 ds->ds_object && bp->blk_birth > 191 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 192 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 193 mutex_enter(&ds->ds_prev->ds_lock); 194 ds->ds_prev->ds_phys->ds_unique_bytes += used; 195 mutex_exit(&ds->ds_prev->ds_lock); 196 } 197 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) { 198 dsl_dir_transfer_space(ds->ds_dir, used, 199 DD_USED_HEAD, DD_USED_SNAP, tx); 200 } 201 } 202 mutex_enter(&ds->ds_lock); 203 ASSERT3U(ds->ds_phys->ds_referenced_bytes, >=, used); 204 ds->ds_phys->ds_referenced_bytes -= used; 205 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 206 ds->ds_phys->ds_compressed_bytes -= compressed; 207 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 208 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 209 mutex_exit(&ds->ds_lock); 210 211 return (used); 212 } 213 214 uint64_t 215 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 216 { 217 uint64_t trysnap = 0; 218 219 if (ds == NULL) 220 return (0); 221 /* 222 * The snapshot creation could fail, but that would cause an 223 * incorrect FALSE return, which would only result in an 224 * overestimation of the amount of space that an operation would 225 * consume, which is OK. 226 * 227 * There's also a small window where we could miss a pending 228 * snapshot, because we could set the sync task in the quiescing 229 * phase. So this should only be used as a guess. 230 */ 231 if (ds->ds_trysnap_txg > 232 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 233 trysnap = ds->ds_trysnap_txg; 234 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 235 } 236 237 boolean_t 238 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp, 239 uint64_t blk_birth) 240 { 241 if (blk_birth <= dsl_dataset_prev_snap_txg(ds)) 242 return (B_FALSE); 243 244 ddt_prefetch(dsl_dataset_get_spa(ds), bp); 245 246 return (B_TRUE); 247 } 248 249 /* ARGSUSED */ 250 static void 251 dsl_dataset_evict(dmu_buf_t *db, void *dsv) 252 { 253 dsl_dataset_t *ds = dsv; 254 255 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 256 257 unique_remove(ds->ds_fsid_guid); 258 259 if (ds->ds_objset != NULL) 260 dmu_objset_evict(ds->ds_objset); 261 262 if (ds->ds_prev) { 263 dsl_dataset_drop_ref(ds->ds_prev, ds); 264 ds->ds_prev = NULL; 265 } 266 267 bplist_destroy(&ds->ds_pending_deadlist); 268 if (db != NULL) { 269 dsl_deadlist_close(&ds->ds_deadlist); 270 } else { 271 ASSERT(ds->ds_deadlist.dl_dbuf == NULL); 272 ASSERT(!ds->ds_deadlist.dl_oldfmt); 273 } 274 if (ds->ds_dir) 275 dsl_dir_close(ds->ds_dir, ds); 276 277 ASSERT(!list_link_active(&ds->ds_synced_link)); 278 279 mutex_destroy(&ds->ds_lock); 280 mutex_destroy(&ds->ds_recvlock); 281 mutex_destroy(&ds->ds_opening_lock); 282 rw_destroy(&ds->ds_rwlock); 283 cv_destroy(&ds->ds_exclusive_cv); 284 285 kmem_free(ds, sizeof (dsl_dataset_t)); 286 } 287 288 static int 289 dsl_dataset_get_snapname(dsl_dataset_t *ds) 290 { 291 dsl_dataset_phys_t *headphys; 292 int err; 293 dmu_buf_t *headdbuf; 294 dsl_pool_t *dp = ds->ds_dir->dd_pool; 295 objset_t *mos = dp->dp_meta_objset; 296 297 if (ds->ds_snapname[0]) 298 return (0); 299 if (ds->ds_phys->ds_next_snap_obj == 0) 300 return (0); 301 302 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 303 FTAG, &headdbuf); 304 if (err) 305 return (err); 306 headphys = headdbuf->db_data; 307 err = zap_value_search(dp->dp_meta_objset, 308 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 309 dmu_buf_rele(headdbuf, FTAG); 310 return (err); 311 } 312 313 static int 314 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 315 { 316 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 317 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 318 matchtype_t mt; 319 int err; 320 321 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 322 mt = MT_FIRST; 323 else 324 mt = MT_EXACT; 325 326 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 327 value, mt, NULL, 0, NULL); 328 if (err == ENOTSUP && mt == MT_FIRST) 329 err = zap_lookup(mos, snapobj, name, 8, 1, value); 330 return (err); 331 } 332 333 static int 334 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 335 { 336 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 337 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 338 matchtype_t mt; 339 int err; 340 341 dsl_dir_snap_cmtime_update(ds->ds_dir); 342 343 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 344 mt = MT_FIRST; 345 else 346 mt = MT_EXACT; 347 348 err = zap_remove_norm(mos, snapobj, name, mt, tx); 349 if (err == ENOTSUP && mt == MT_FIRST) 350 err = zap_remove(mos, snapobj, name, tx); 351 return (err); 352 } 353 354 static int 355 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 356 dsl_dataset_t **dsp) 357 { 358 objset_t *mos = dp->dp_meta_objset; 359 dmu_buf_t *dbuf; 360 dsl_dataset_t *ds; 361 int err; 362 dmu_object_info_t doi; 363 364 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 365 dsl_pool_sync_context(dp)); 366 367 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 368 if (err) 369 return (err); 370 371 /* Make sure dsobj has the correct object type. */ 372 dmu_object_info_from_db(dbuf, &doi); 373 if (doi.doi_type != DMU_OT_DSL_DATASET) 374 return (EINVAL); 375 376 ds = dmu_buf_get_user(dbuf); 377 if (ds == NULL) { 378 dsl_dataset_t *winner; 379 380 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 381 ds->ds_dbuf = dbuf; 382 ds->ds_object = dsobj; 383 ds->ds_phys = dbuf->db_data; 384 385 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 386 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 387 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 388 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL); 389 390 rw_init(&ds->ds_rwlock, 0, 0, 0); 391 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 392 393 bplist_create(&ds->ds_pending_deadlist); 394 dsl_deadlist_open(&ds->ds_deadlist, 395 mos, ds->ds_phys->ds_deadlist_obj); 396 397 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t), 398 offsetof(dmu_sendarg_t, dsa_link)); 399 400 if (err == 0) { 401 err = dsl_dir_open_obj(dp, 402 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 403 } 404 if (err) { 405 mutex_destroy(&ds->ds_lock); 406 mutex_destroy(&ds->ds_recvlock); 407 mutex_destroy(&ds->ds_opening_lock); 408 rw_destroy(&ds->ds_rwlock); 409 cv_destroy(&ds->ds_exclusive_cv); 410 bplist_destroy(&ds->ds_pending_deadlist); 411 dsl_deadlist_close(&ds->ds_deadlist); 412 kmem_free(ds, sizeof (dsl_dataset_t)); 413 dmu_buf_rele(dbuf, tag); 414 return (err); 415 } 416 417 if (!dsl_dataset_is_snapshot(ds)) { 418 ds->ds_snapname[0] = '\0'; 419 if (ds->ds_phys->ds_prev_snap_obj) { 420 err = dsl_dataset_get_ref(dp, 421 ds->ds_phys->ds_prev_snap_obj, 422 ds, &ds->ds_prev); 423 } 424 } else { 425 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 426 err = dsl_dataset_get_snapname(ds); 427 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 428 err = zap_count( 429 ds->ds_dir->dd_pool->dp_meta_objset, 430 ds->ds_phys->ds_userrefs_obj, 431 &ds->ds_userrefs); 432 } 433 } 434 435 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 436 /* 437 * In sync context, we're called with either no lock 438 * or with the write lock. If we're not syncing, 439 * we're always called with the read lock held. 440 */ 441 boolean_t need_lock = 442 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 443 dsl_pool_sync_context(dp); 444 445 if (need_lock) 446 rw_enter(&dp->dp_config_rwlock, RW_READER); 447 448 err = dsl_prop_get_ds(ds, 449 "refreservation", sizeof (uint64_t), 1, 450 &ds->ds_reserved, NULL); 451 if (err == 0) { 452 err = dsl_prop_get_ds(ds, 453 "refquota", sizeof (uint64_t), 1, 454 &ds->ds_quota, NULL); 455 } 456 457 if (need_lock) 458 rw_exit(&dp->dp_config_rwlock); 459 } else { 460 ds->ds_reserved = ds->ds_quota = 0; 461 } 462 463 if (err == 0) { 464 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 465 dsl_dataset_evict); 466 } 467 if (err || winner) { 468 bplist_destroy(&ds->ds_pending_deadlist); 469 dsl_deadlist_close(&ds->ds_deadlist); 470 if (ds->ds_prev) 471 dsl_dataset_drop_ref(ds->ds_prev, ds); 472 dsl_dir_close(ds->ds_dir, ds); 473 mutex_destroy(&ds->ds_lock); 474 mutex_destroy(&ds->ds_recvlock); 475 mutex_destroy(&ds->ds_opening_lock); 476 rw_destroy(&ds->ds_rwlock); 477 cv_destroy(&ds->ds_exclusive_cv); 478 kmem_free(ds, sizeof (dsl_dataset_t)); 479 if (err) { 480 dmu_buf_rele(dbuf, tag); 481 return (err); 482 } 483 ds = winner; 484 } else { 485 ds->ds_fsid_guid = 486 unique_insert(ds->ds_phys->ds_fsid_guid); 487 } 488 } 489 ASSERT3P(ds->ds_dbuf, ==, dbuf); 490 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 491 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 492 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 493 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 494 mutex_enter(&ds->ds_lock); 495 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 496 mutex_exit(&ds->ds_lock); 497 dmu_buf_rele(ds->ds_dbuf, tag); 498 return (ENOENT); 499 } 500 mutex_exit(&ds->ds_lock); 501 *dsp = ds; 502 return (0); 503 } 504 505 static int 506 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 507 { 508 dsl_pool_t *dp = ds->ds_dir->dd_pool; 509 510 /* 511 * In syncing context we don't want the rwlock lock: there 512 * may be an existing writer waiting for sync phase to 513 * finish. We don't need to worry about such writers, since 514 * sync phase is single-threaded, so the writer can't be 515 * doing anything while we are active. 516 */ 517 if (dsl_pool_sync_context(dp)) { 518 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 519 return (0); 520 } 521 522 /* 523 * Normal users will hold the ds_rwlock as a READER until they 524 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 525 * drop their READER lock after they set the ds_owner field. 526 * 527 * If the dataset is being destroyed, the destroy thread will 528 * obtain a WRITER lock for exclusive access after it's done its 529 * open-context work and then change the ds_owner to 530 * dsl_reaper once destruction is assured. So threads 531 * may block here temporarily, until the "destructability" of 532 * the dataset is determined. 533 */ 534 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 535 mutex_enter(&ds->ds_lock); 536 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 537 rw_exit(&dp->dp_config_rwlock); 538 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 539 if (DSL_DATASET_IS_DESTROYED(ds)) { 540 mutex_exit(&ds->ds_lock); 541 dsl_dataset_drop_ref(ds, tag); 542 rw_enter(&dp->dp_config_rwlock, RW_READER); 543 return (ENOENT); 544 } 545 /* 546 * The dp_config_rwlock lives above the ds_lock. And 547 * we need to check DSL_DATASET_IS_DESTROYED() while 548 * holding the ds_lock, so we have to drop and reacquire 549 * the ds_lock here. 550 */ 551 mutex_exit(&ds->ds_lock); 552 rw_enter(&dp->dp_config_rwlock, RW_READER); 553 mutex_enter(&ds->ds_lock); 554 } 555 mutex_exit(&ds->ds_lock); 556 return (0); 557 } 558 559 int 560 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 561 dsl_dataset_t **dsp) 562 { 563 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 564 565 if (err) 566 return (err); 567 return (dsl_dataset_hold_ref(*dsp, tag)); 568 } 569 570 int 571 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 572 void *tag, dsl_dataset_t **dsp) 573 { 574 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 575 if (err) 576 return (err); 577 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 578 dsl_dataset_rele(*dsp, tag); 579 *dsp = NULL; 580 return (EBUSY); 581 } 582 return (0); 583 } 584 585 int 586 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 587 { 588 dsl_dir_t *dd; 589 dsl_pool_t *dp; 590 const char *snapname; 591 uint64_t obj; 592 int err = 0; 593 594 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 595 if (err) 596 return (err); 597 598 dp = dd->dd_pool; 599 obj = dd->dd_phys->dd_head_dataset_obj; 600 rw_enter(&dp->dp_config_rwlock, RW_READER); 601 if (obj) 602 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 603 else 604 err = ENOENT; 605 if (err) 606 goto out; 607 608 err = dsl_dataset_hold_ref(*dsp, tag); 609 610 /* we may be looking for a snapshot */ 611 if (err == 0 && snapname != NULL) { 612 dsl_dataset_t *ds = NULL; 613 614 if (*snapname++ != '@') { 615 dsl_dataset_rele(*dsp, tag); 616 err = ENOENT; 617 goto out; 618 } 619 620 dprintf("looking for snapshot '%s'\n", snapname); 621 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 622 if (err == 0) 623 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 624 dsl_dataset_rele(*dsp, tag); 625 626 ASSERT3U((err == 0), ==, (ds != NULL)); 627 628 if (ds) { 629 mutex_enter(&ds->ds_lock); 630 if (ds->ds_snapname[0] == 0) 631 (void) strlcpy(ds->ds_snapname, snapname, 632 sizeof (ds->ds_snapname)); 633 mutex_exit(&ds->ds_lock); 634 err = dsl_dataset_hold_ref(ds, tag); 635 *dsp = err ? NULL : ds; 636 } 637 } 638 out: 639 rw_exit(&dp->dp_config_rwlock); 640 dsl_dir_close(dd, FTAG); 641 return (err); 642 } 643 644 int 645 dsl_dataset_own(const char *name, boolean_t inconsistentok, 646 void *tag, dsl_dataset_t **dsp) 647 { 648 int err = dsl_dataset_hold(name, tag, dsp); 649 if (err) 650 return (err); 651 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 652 dsl_dataset_rele(*dsp, tag); 653 return (EBUSY); 654 } 655 return (0); 656 } 657 658 void 659 dsl_dataset_name(dsl_dataset_t *ds, char *name) 660 { 661 if (ds == NULL) { 662 (void) strcpy(name, "mos"); 663 } else { 664 dsl_dir_name(ds->ds_dir, name); 665 VERIFY(0 == dsl_dataset_get_snapname(ds)); 666 if (ds->ds_snapname[0]) { 667 (void) strcat(name, "@"); 668 /* 669 * We use a "recursive" mutex so that we 670 * can call dprintf_ds() with ds_lock held. 671 */ 672 if (!MUTEX_HELD(&ds->ds_lock)) { 673 mutex_enter(&ds->ds_lock); 674 (void) strcat(name, ds->ds_snapname); 675 mutex_exit(&ds->ds_lock); 676 } else { 677 (void) strcat(name, ds->ds_snapname); 678 } 679 } 680 } 681 } 682 683 static int 684 dsl_dataset_namelen(dsl_dataset_t *ds) 685 { 686 int result; 687 688 if (ds == NULL) { 689 result = 3; /* "mos" */ 690 } else { 691 result = dsl_dir_namelen(ds->ds_dir); 692 VERIFY(0 == dsl_dataset_get_snapname(ds)); 693 if (ds->ds_snapname[0]) { 694 ++result; /* adding one for the @-sign */ 695 if (!MUTEX_HELD(&ds->ds_lock)) { 696 mutex_enter(&ds->ds_lock); 697 result += strlen(ds->ds_snapname); 698 mutex_exit(&ds->ds_lock); 699 } else { 700 result += strlen(ds->ds_snapname); 701 } 702 } 703 } 704 705 return (result); 706 } 707 708 void 709 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 710 { 711 dmu_buf_rele(ds->ds_dbuf, tag); 712 } 713 714 void 715 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 716 { 717 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 718 rw_exit(&ds->ds_rwlock); 719 } 720 dsl_dataset_drop_ref(ds, tag); 721 } 722 723 void 724 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 725 { 726 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 727 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 728 729 mutex_enter(&ds->ds_lock); 730 ds->ds_owner = NULL; 731 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 732 rw_exit(&ds->ds_rwlock); 733 cv_broadcast(&ds->ds_exclusive_cv); 734 } 735 mutex_exit(&ds->ds_lock); 736 if (ds->ds_dbuf) 737 dsl_dataset_drop_ref(ds, tag); 738 else 739 dsl_dataset_evict(NULL, ds); 740 } 741 742 boolean_t 743 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 744 { 745 boolean_t gotit = FALSE; 746 747 mutex_enter(&ds->ds_lock); 748 if (ds->ds_owner == NULL && 749 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 750 ds->ds_owner = tag; 751 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 752 rw_exit(&ds->ds_rwlock); 753 gotit = TRUE; 754 } 755 mutex_exit(&ds->ds_lock); 756 return (gotit); 757 } 758 759 void 760 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 761 { 762 ASSERT3P(owner, ==, ds->ds_owner); 763 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 764 rw_enter(&ds->ds_rwlock, RW_WRITER); 765 } 766 767 uint64_t 768 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 769 uint64_t flags, dmu_tx_t *tx) 770 { 771 dsl_pool_t *dp = dd->dd_pool; 772 dmu_buf_t *dbuf; 773 dsl_dataset_phys_t *dsphys; 774 uint64_t dsobj; 775 objset_t *mos = dp->dp_meta_objset; 776 777 if (origin == NULL) 778 origin = dp->dp_origin_snap; 779 780 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 781 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 782 ASSERT(dmu_tx_is_syncing(tx)); 783 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 784 785 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 786 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 787 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 788 dmu_buf_will_dirty(dbuf, tx); 789 dsphys = dbuf->db_data; 790 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 791 dsphys->ds_dir_obj = dd->dd_object; 792 dsphys->ds_flags = flags; 793 dsphys->ds_fsid_guid = unique_create(); 794 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 795 sizeof (dsphys->ds_guid)); 796 dsphys->ds_snapnames_zapobj = 797 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 798 DMU_OT_NONE, 0, tx); 799 dsphys->ds_creation_time = gethrestime_sec(); 800 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 801 802 if (origin == NULL) { 803 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx); 804 } else { 805 dsl_dataset_t *ohds; 806 807 dsphys->ds_prev_snap_obj = origin->ds_object; 808 dsphys->ds_prev_snap_txg = 809 origin->ds_phys->ds_creation_txg; 810 dsphys->ds_referenced_bytes = 811 origin->ds_phys->ds_referenced_bytes; 812 dsphys->ds_compressed_bytes = 813 origin->ds_phys->ds_compressed_bytes; 814 dsphys->ds_uncompressed_bytes = 815 origin->ds_phys->ds_uncompressed_bytes; 816 dsphys->ds_bp = origin->ds_phys->ds_bp; 817 dsphys->ds_flags |= origin->ds_phys->ds_flags; 818 819 dmu_buf_will_dirty(origin->ds_dbuf, tx); 820 origin->ds_phys->ds_num_children++; 821 822 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 823 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds)); 824 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist, 825 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx); 826 dsl_dataset_rele(ohds, FTAG); 827 828 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 829 if (origin->ds_phys->ds_next_clones_obj == 0) { 830 origin->ds_phys->ds_next_clones_obj = 831 zap_create(mos, 832 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 833 } 834 VERIFY(0 == zap_add_int(mos, 835 origin->ds_phys->ds_next_clones_obj, 836 dsobj, tx)); 837 } 838 839 dmu_buf_will_dirty(dd->dd_dbuf, tx); 840 dd->dd_phys->dd_origin_obj = origin->ds_object; 841 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 842 if (origin->ds_dir->dd_phys->dd_clones == 0) { 843 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); 844 origin->ds_dir->dd_phys->dd_clones = 845 zap_create(mos, 846 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 847 } 848 VERIFY3U(0, ==, zap_add_int(mos, 849 origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); 850 } 851 } 852 853 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 854 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 855 856 dmu_buf_rele(dbuf, FTAG); 857 858 dmu_buf_will_dirty(dd->dd_dbuf, tx); 859 dd->dd_phys->dd_head_dataset_obj = dsobj; 860 861 return (dsobj); 862 } 863 864 uint64_t 865 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 866 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 867 { 868 dsl_pool_t *dp = pdd->dd_pool; 869 uint64_t dsobj, ddobj; 870 dsl_dir_t *dd; 871 872 ASSERT(lastname[0] != '@'); 873 874 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 875 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 876 877 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 878 879 dsl_deleg_set_create_perms(dd, tx, cr); 880 881 dsl_dir_close(dd, FTAG); 882 883 /* 884 * If we are creating a clone, make sure we zero out any stale 885 * data from the origin snapshots zil header. 886 */ 887 if (origin != NULL) { 888 dsl_dataset_t *ds; 889 objset_t *os; 890 891 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 892 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); 893 bzero(&os->os_zil_header, sizeof (os->os_zil_header)); 894 dsl_dataset_dirty(ds, tx); 895 dsl_dataset_rele(ds, FTAG); 896 } 897 898 return (dsobj); 899 } 900 901 /* 902 * The snapshots must all be in the same pool. 903 */ 904 int 905 dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, 906 nvlist_t *errlist) 907 { 908 int err; 909 dsl_sync_task_t *dst; 910 spa_t *spa; 911 nvpair_t *pair; 912 dsl_sync_task_group_t *dstg; 913 914 pair = nvlist_next_nvpair(snaps, NULL); 915 if (pair == NULL) 916 return (0); 917 918 err = spa_open(nvpair_name(pair), &spa, FTAG); 919 if (err) 920 return (err); 921 dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 922 923 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL; 924 pair = nvlist_next_nvpair(snaps, pair)) { 925 dsl_dataset_t *ds; 926 927 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds); 928 if (err == 0) { 929 struct dsl_ds_destroyarg *dsda; 930 931 dsl_dataset_make_exclusive(ds, dstg); 932 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), 933 KM_SLEEP); 934 dsda->ds = ds; 935 dsda->defer = defer; 936 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 937 dsl_dataset_destroy_sync, dsda, dstg, 0); 938 } else if (err == ENOENT) { 939 err = 0; 940 } else { 941 fnvlist_add_int32(errlist, nvpair_name(pair), err); 942 break; 943 } 944 } 945 946 if (err == 0) 947 err = dsl_sync_task_group_wait(dstg); 948 949 for (dst = list_head(&dstg->dstg_tasks); dst; 950 dst = list_next(&dstg->dstg_tasks, dst)) { 951 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 952 dsl_dataset_t *ds = dsda->ds; 953 954 /* 955 * Return the snapshots that triggered the error. 956 */ 957 if (dst->dst_err != 0) { 958 char name[ZFS_MAXNAMELEN]; 959 dsl_dataset_name(ds, name); 960 fnvlist_add_int32(errlist, name, dst->dst_err); 961 } 962 ASSERT3P(dsda->rm_origin, ==, NULL); 963 dsl_dataset_disown(ds, dstg); 964 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 965 } 966 967 dsl_sync_task_group_destroy(dstg); 968 spa_close(spa, FTAG); 969 return (err); 970 971 } 972 973 static boolean_t 974 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 975 { 976 boolean_t might_destroy = B_FALSE; 977 978 mutex_enter(&ds->ds_lock); 979 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 980 DS_IS_DEFER_DESTROY(ds)) 981 might_destroy = B_TRUE; 982 mutex_exit(&ds->ds_lock); 983 984 return (might_destroy); 985 } 986 987 /* 988 * If we're removing a clone, and these three conditions are true: 989 * 1) the clone's origin has no other children 990 * 2) the clone's origin has no user references 991 * 3) the clone's origin has been marked for deferred destruction 992 * Then, prepare to remove the origin as part of this sync task group. 993 */ 994 static int 995 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 996 { 997 dsl_dataset_t *ds = dsda->ds; 998 dsl_dataset_t *origin = ds->ds_prev; 999 1000 if (dsl_dataset_might_destroy_origin(origin)) { 1001 char *name; 1002 int namelen; 1003 int error; 1004 1005 namelen = dsl_dataset_namelen(origin) + 1; 1006 name = kmem_alloc(namelen, KM_SLEEP); 1007 dsl_dataset_name(origin, name); 1008 #ifdef _KERNEL 1009 error = zfs_unmount_snap(name, NULL); 1010 if (error) { 1011 kmem_free(name, namelen); 1012 return (error); 1013 } 1014 #endif 1015 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 1016 kmem_free(name, namelen); 1017 if (error) 1018 return (error); 1019 dsda->rm_origin = origin; 1020 dsl_dataset_make_exclusive(origin, tag); 1021 } 1022 1023 return (0); 1024 } 1025 1026 /* 1027 * ds must be opened as OWNER. On return (whether successful or not), 1028 * ds will be closed and caller can no longer dereference it. 1029 */ 1030 int 1031 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1032 { 1033 int err; 1034 dsl_sync_task_group_t *dstg; 1035 objset_t *os; 1036 dsl_dir_t *dd; 1037 uint64_t obj; 1038 struct dsl_ds_destroyarg dsda = { 0 }; 1039 1040 dsda.ds = ds; 1041 1042 if (dsl_dataset_is_snapshot(ds)) { 1043 /* Destroying a snapshot is simpler */ 1044 dsl_dataset_make_exclusive(ds, tag); 1045 1046 dsda.defer = defer; 1047 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1048 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1049 &dsda, tag, 0); 1050 ASSERT3P(dsda.rm_origin, ==, NULL); 1051 goto out; 1052 } else if (defer) { 1053 err = EINVAL; 1054 goto out; 1055 } 1056 1057 dd = ds->ds_dir; 1058 1059 if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds), 1060 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) { 1061 /* 1062 * Check for errors and mark this ds as inconsistent, in 1063 * case we crash while freeing the objects. 1064 */ 1065 err = dsl_sync_task_do(dd->dd_pool, 1066 dsl_dataset_destroy_begin_check, 1067 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1068 if (err) 1069 goto out; 1070 1071 err = dmu_objset_from_ds(ds, &os); 1072 if (err) 1073 goto out; 1074 1075 /* 1076 * Remove all objects while in the open context so that 1077 * there is less work to do in the syncing context. 1078 */ 1079 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1080 ds->ds_phys->ds_prev_snap_txg)) { 1081 /* 1082 * Ignore errors, if there is not enough disk space 1083 * we will deal with it in dsl_dataset_destroy_sync(). 1084 */ 1085 (void) dmu_free_object(os, obj); 1086 } 1087 if (err != ESRCH) 1088 goto out; 1089 1090 /* 1091 * Sync out all in-flight IO. 1092 */ 1093 txg_wait_synced(dd->dd_pool, 0); 1094 1095 /* 1096 * If we managed to free all the objects in open 1097 * context, the user space accounting should be zero. 1098 */ 1099 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1100 dmu_objset_userused_enabled(os)) { 1101 uint64_t count; 1102 1103 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, 1104 &count) != 0 || count == 0); 1105 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, 1106 &count) != 0 || count == 0); 1107 } 1108 } 1109 1110 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1111 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1112 rw_exit(&dd->dd_pool->dp_config_rwlock); 1113 1114 if (err) 1115 goto out; 1116 1117 /* 1118 * Blow away the dsl_dir + head dataset. 1119 */ 1120 dsl_dataset_make_exclusive(ds, tag); 1121 /* 1122 * If we're removing a clone, we might also need to remove its 1123 * origin. 1124 */ 1125 do { 1126 dsda.need_prep = B_FALSE; 1127 if (dsl_dir_is_clone(dd)) { 1128 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1129 if (err) { 1130 dsl_dir_close(dd, FTAG); 1131 goto out; 1132 } 1133 } 1134 1135 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1136 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1137 dsl_dataset_destroy_sync, &dsda, tag, 0); 1138 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1139 dsl_dir_destroy_sync, dd, FTAG, 0); 1140 err = dsl_sync_task_group_wait(dstg); 1141 dsl_sync_task_group_destroy(dstg); 1142 1143 /* 1144 * We could be racing against 'zfs release' or 'zfs destroy -d' 1145 * on the origin snap, in which case we can get EBUSY if we 1146 * needed to destroy the origin snap but were not ready to 1147 * do so. 1148 */ 1149 if (dsda.need_prep) { 1150 ASSERT(err == EBUSY); 1151 ASSERT(dsl_dir_is_clone(dd)); 1152 ASSERT(dsda.rm_origin == NULL); 1153 } 1154 } while (dsda.need_prep); 1155 1156 if (dsda.rm_origin != NULL) 1157 dsl_dataset_disown(dsda.rm_origin, tag); 1158 1159 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1160 if (err) 1161 dsl_dir_close(dd, FTAG); 1162 out: 1163 dsl_dataset_disown(ds, tag); 1164 return (err); 1165 } 1166 1167 blkptr_t * 1168 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1169 { 1170 return (&ds->ds_phys->ds_bp); 1171 } 1172 1173 void 1174 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1175 { 1176 ASSERT(dmu_tx_is_syncing(tx)); 1177 /* If it's the meta-objset, set dp_meta_rootbp */ 1178 if (ds == NULL) { 1179 tx->tx_pool->dp_meta_rootbp = *bp; 1180 } else { 1181 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1182 ds->ds_phys->ds_bp = *bp; 1183 } 1184 } 1185 1186 spa_t * 1187 dsl_dataset_get_spa(dsl_dataset_t *ds) 1188 { 1189 return (ds->ds_dir->dd_pool->dp_spa); 1190 } 1191 1192 void 1193 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1194 { 1195 dsl_pool_t *dp; 1196 1197 if (ds == NULL) /* this is the meta-objset */ 1198 return; 1199 1200 ASSERT(ds->ds_objset != NULL); 1201 1202 if (ds->ds_phys->ds_next_snap_obj != 0) 1203 panic("dirtying snapshot!"); 1204 1205 dp = ds->ds_dir->dd_pool; 1206 1207 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1208 /* up the hold count until we can be written out */ 1209 dmu_buf_add_ref(ds->ds_dbuf, ds); 1210 } 1211 } 1212 1213 boolean_t 1214 dsl_dataset_is_dirty(dsl_dataset_t *ds) 1215 { 1216 for (int t = 0; t < TXG_SIZE; t++) { 1217 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets, 1218 ds, t)) 1219 return (B_TRUE); 1220 } 1221 return (B_FALSE); 1222 } 1223 1224 /* 1225 * The unique space in the head dataset can be calculated by subtracting 1226 * the space used in the most recent snapshot, that is still being used 1227 * in this file system, from the space currently in use. To figure out 1228 * the space in the most recent snapshot still in use, we need to take 1229 * the total space used in the snapshot and subtract out the space that 1230 * has been freed up since the snapshot was taken. 1231 */ 1232 static void 1233 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1234 { 1235 uint64_t mrs_used; 1236 uint64_t dlused, dlcomp, dluncomp; 1237 1238 ASSERT(!dsl_dataset_is_snapshot(ds)); 1239 1240 if (ds->ds_phys->ds_prev_snap_obj != 0) 1241 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes; 1242 else 1243 mrs_used = 0; 1244 1245 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); 1246 1247 ASSERT3U(dlused, <=, mrs_used); 1248 ds->ds_phys->ds_unique_bytes = 1249 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused); 1250 1251 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1252 SPA_VERSION_UNIQUE_ACCURATE) 1253 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1254 } 1255 1256 struct killarg { 1257 dsl_dataset_t *ds; 1258 dmu_tx_t *tx; 1259 }; 1260 1261 /* ARGSUSED */ 1262 static int 1263 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf, 1264 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1265 { 1266 struct killarg *ka = arg; 1267 dmu_tx_t *tx = ka->tx; 1268 1269 if (bp == NULL) 1270 return (0); 1271 1272 if (zb->zb_level == ZB_ZIL_LEVEL) { 1273 ASSERT(zilog != NULL); 1274 /* 1275 * It's a block in the intent log. It has no 1276 * accounting, so just free it. 1277 */ 1278 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1279 } else { 1280 ASSERT(zilog == NULL); 1281 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1282 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1283 } 1284 1285 return (0); 1286 } 1287 1288 /* ARGSUSED */ 1289 static int 1290 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1291 { 1292 dsl_dataset_t *ds = arg1; 1293 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1294 uint64_t count; 1295 int err; 1296 1297 /* 1298 * Can't delete a head dataset if there are snapshots of it. 1299 * (Except if the only snapshots are from the branch we cloned 1300 * from.) 1301 */ 1302 if (ds->ds_prev != NULL && 1303 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1304 return (EBUSY); 1305 1306 /* 1307 * This is really a dsl_dir thing, but check it here so that 1308 * we'll be less likely to leave this dataset inconsistent & 1309 * nearly destroyed. 1310 */ 1311 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1312 if (err) 1313 return (err); 1314 if (count != 0) 1315 return (EEXIST); 1316 1317 return (0); 1318 } 1319 1320 /* ARGSUSED */ 1321 static void 1322 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1323 { 1324 dsl_dataset_t *ds = arg1; 1325 1326 /* Mark it as inconsistent on-disk, in case we crash */ 1327 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1328 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1329 1330 spa_history_log_internal_ds(ds, "destroy begin", tx, ""); 1331 } 1332 1333 static int 1334 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1335 dmu_tx_t *tx) 1336 { 1337 dsl_dataset_t *ds = dsda->ds; 1338 dsl_dataset_t *ds_prev = ds->ds_prev; 1339 1340 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1341 struct dsl_ds_destroyarg ndsda = {0}; 1342 1343 /* 1344 * If we're not prepared to remove the origin, don't remove 1345 * the clone either. 1346 */ 1347 if (dsda->rm_origin == NULL) { 1348 dsda->need_prep = B_TRUE; 1349 return (EBUSY); 1350 } 1351 1352 ndsda.ds = ds_prev; 1353 ndsda.is_origin_rm = B_TRUE; 1354 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1355 } 1356 1357 /* 1358 * If we're not going to remove the origin after all, 1359 * undo the open context setup. 1360 */ 1361 if (dsda->rm_origin != NULL) { 1362 dsl_dataset_disown(dsda->rm_origin, tag); 1363 dsda->rm_origin = NULL; 1364 } 1365 1366 return (0); 1367 } 1368 1369 /* 1370 * If you add new checks here, you may need to add 1371 * additional checks to the "temporary" case in 1372 * snapshot_check() in dmu_objset.c. 1373 */ 1374 /* ARGSUSED */ 1375 int 1376 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1377 { 1378 struct dsl_ds_destroyarg *dsda = arg1; 1379 dsl_dataset_t *ds = dsda->ds; 1380 1381 /* we have an owner hold, so noone else can destroy us */ 1382 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1383 1384 /* 1385 * Only allow deferred destroy on pools that support it. 1386 * NOTE: deferred destroy is only supported on snapshots. 1387 */ 1388 if (dsda->defer) { 1389 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1390 SPA_VERSION_USERREFS) 1391 return (ENOTSUP); 1392 ASSERT(dsl_dataset_is_snapshot(ds)); 1393 return (0); 1394 } 1395 1396 /* 1397 * Can't delete a head dataset if there are snapshots of it. 1398 * (Except if the only snapshots are from the branch we cloned 1399 * from.) 1400 */ 1401 if (ds->ds_prev != NULL && 1402 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1403 return (EBUSY); 1404 1405 /* 1406 * If we made changes this txg, traverse_dsl_dataset won't find 1407 * them. Try again. 1408 */ 1409 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1410 return (EAGAIN); 1411 1412 if (dsl_dataset_is_snapshot(ds)) { 1413 /* 1414 * If this snapshot has an elevated user reference count, 1415 * we can't destroy it yet. 1416 */ 1417 if (ds->ds_userrefs > 0 && !dsda->releasing) 1418 return (EBUSY); 1419 1420 mutex_enter(&ds->ds_lock); 1421 /* 1422 * Can't delete a branch point. However, if we're destroying 1423 * a clone and removing its origin due to it having a user 1424 * hold count of 0 and having been marked for deferred destroy, 1425 * it's OK for the origin to have a single clone. 1426 */ 1427 if (ds->ds_phys->ds_num_children > 1428 (dsda->is_origin_rm ? 2 : 1)) { 1429 mutex_exit(&ds->ds_lock); 1430 return (EEXIST); 1431 } 1432 mutex_exit(&ds->ds_lock); 1433 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1434 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1435 } 1436 1437 /* XXX we should do some i/o error checking... */ 1438 return (0); 1439 } 1440 1441 struct refsarg { 1442 kmutex_t lock; 1443 boolean_t gone; 1444 kcondvar_t cv; 1445 }; 1446 1447 /* ARGSUSED */ 1448 static void 1449 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1450 { 1451 struct refsarg *arg = argv; 1452 1453 mutex_enter(&arg->lock); 1454 arg->gone = TRUE; 1455 cv_signal(&arg->cv); 1456 mutex_exit(&arg->lock); 1457 } 1458 1459 static void 1460 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1461 { 1462 struct refsarg arg; 1463 1464 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1465 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1466 arg.gone = FALSE; 1467 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1468 dsl_dataset_refs_gone); 1469 dmu_buf_rele(ds->ds_dbuf, tag); 1470 mutex_enter(&arg.lock); 1471 while (!arg.gone) 1472 cv_wait(&arg.cv, &arg.lock); 1473 ASSERT(arg.gone); 1474 mutex_exit(&arg.lock); 1475 ds->ds_dbuf = NULL; 1476 ds->ds_phys = NULL; 1477 mutex_destroy(&arg.lock); 1478 cv_destroy(&arg.cv); 1479 } 1480 1481 static void 1482 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1483 { 1484 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1485 uint64_t count; 1486 int err; 1487 1488 ASSERT(ds->ds_phys->ds_num_children >= 2); 1489 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1490 /* 1491 * The err should not be ENOENT, but a bug in a previous version 1492 * of the code could cause upgrade_clones_cb() to not set 1493 * ds_next_snap_obj when it should, leading to a missing entry. 1494 * If we knew that the pool was created after 1495 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1496 * ENOENT. However, at least we can check that we don't have 1497 * too many entries in the next_clones_obj even after failing to 1498 * remove this one. 1499 */ 1500 if (err != ENOENT) { 1501 VERIFY3U(err, ==, 0); 1502 } 1503 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1504 &count)); 1505 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1506 } 1507 1508 static void 1509 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 1510 { 1511 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1512 zap_cursor_t zc; 1513 zap_attribute_t za; 1514 1515 /* 1516 * If it is the old version, dd_clones doesn't exist so we can't 1517 * find the clones, but deadlist_remove_key() is a no-op so it 1518 * doesn't matter. 1519 */ 1520 if (ds->ds_dir->dd_phys->dd_clones == 0) 1521 return; 1522 1523 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); 1524 zap_cursor_retrieve(&zc, &za) == 0; 1525 zap_cursor_advance(&zc)) { 1526 dsl_dataset_t *clone; 1527 1528 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 1529 za.za_first_integer, FTAG, &clone)); 1530 if (clone->ds_dir->dd_origin_txg > mintxg) { 1531 dsl_deadlist_remove_key(&clone->ds_deadlist, 1532 mintxg, tx); 1533 dsl_dataset_remove_clones_key(clone, mintxg, tx); 1534 } 1535 dsl_dataset_rele(clone, FTAG); 1536 } 1537 zap_cursor_fini(&zc); 1538 } 1539 1540 struct process_old_arg { 1541 dsl_dataset_t *ds; 1542 dsl_dataset_t *ds_prev; 1543 boolean_t after_branch_point; 1544 zio_t *pio; 1545 uint64_t used, comp, uncomp; 1546 }; 1547 1548 static int 1549 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1550 { 1551 struct process_old_arg *poa = arg; 1552 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; 1553 1554 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { 1555 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); 1556 if (poa->ds_prev && !poa->after_branch_point && 1557 bp->blk_birth > 1558 poa->ds_prev->ds_phys->ds_prev_snap_txg) { 1559 poa->ds_prev->ds_phys->ds_unique_bytes += 1560 bp_get_dsize_sync(dp->dp_spa, bp); 1561 } 1562 } else { 1563 poa->used += bp_get_dsize_sync(dp->dp_spa, bp); 1564 poa->comp += BP_GET_PSIZE(bp); 1565 poa->uncomp += BP_GET_UCSIZE(bp); 1566 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); 1567 } 1568 return (0); 1569 } 1570 1571 static void 1572 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, 1573 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) 1574 { 1575 struct process_old_arg poa = { 0 }; 1576 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1577 objset_t *mos = dp->dp_meta_objset; 1578 1579 ASSERT(ds->ds_deadlist.dl_oldfmt); 1580 ASSERT(ds_next->ds_deadlist.dl_oldfmt); 1581 1582 poa.ds = ds; 1583 poa.ds_prev = ds_prev; 1584 poa.after_branch_point = after_branch_point; 1585 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1586 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, 1587 process_old_cb, &poa, tx)); 1588 VERIFY3U(zio_wait(poa.pio), ==, 0); 1589 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); 1590 1591 /* change snapused */ 1592 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1593 -poa.used, -poa.comp, -poa.uncomp, tx); 1594 1595 /* swap next's deadlist to our deadlist */ 1596 dsl_deadlist_close(&ds->ds_deadlist); 1597 dsl_deadlist_close(&ds_next->ds_deadlist); 1598 SWITCH64(ds_next->ds_phys->ds_deadlist_obj, 1599 ds->ds_phys->ds_deadlist_obj); 1600 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 1601 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 1602 ds_next->ds_phys->ds_deadlist_obj); 1603 } 1604 1605 static int 1606 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx) 1607 { 1608 int err; 1609 struct killarg ka; 1610 1611 /* 1612 * Free everything that we point to (that's born after 1613 * the previous snapshot, if we are a clone) 1614 * 1615 * NB: this should be very quick, because we already 1616 * freed all the objects in open context. 1617 */ 1618 ka.ds = ds; 1619 ka.tx = tx; 1620 err = traverse_dataset(ds, 1621 ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST, 1622 kill_blkptr, &ka); 1623 ASSERT3U(err, ==, 0); 1624 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0); 1625 1626 return (err); 1627 } 1628 1629 void 1630 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx) 1631 { 1632 struct dsl_ds_destroyarg *dsda = arg1; 1633 dsl_dataset_t *ds = dsda->ds; 1634 int err; 1635 int after_branch_point = FALSE; 1636 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1637 objset_t *mos = dp->dp_meta_objset; 1638 dsl_dataset_t *ds_prev = NULL; 1639 boolean_t wont_destroy; 1640 uint64_t obj; 1641 1642 wont_destroy = (dsda->defer && 1643 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)); 1644 1645 ASSERT(ds->ds_owner || wont_destroy); 1646 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1647 ASSERT(ds->ds_prev == NULL || 1648 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1649 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1650 1651 if (wont_destroy) { 1652 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1653 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1654 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1655 spa_history_log_internal_ds(ds, "defer_destroy", tx, ""); 1656 return; 1657 } 1658 1659 /* We need to log before removing it from the namespace. */ 1660 spa_history_log_internal_ds(ds, "destroy", tx, ""); 1661 1662 /* signal any waiters that this dataset is going away */ 1663 mutex_enter(&ds->ds_lock); 1664 ds->ds_owner = dsl_reaper; 1665 cv_broadcast(&ds->ds_exclusive_cv); 1666 mutex_exit(&ds->ds_lock); 1667 1668 /* Remove our reservation */ 1669 if (ds->ds_reserved != 0) { 1670 dsl_prop_setarg_t psa; 1671 uint64_t value = 0; 1672 1673 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1674 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1675 &value); 1676 psa.psa_effective_value = 0; /* predict default value */ 1677 1678 dsl_dataset_set_reservation_sync(ds, &psa, tx); 1679 ASSERT3U(ds->ds_reserved, ==, 0); 1680 } 1681 1682 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1683 1684 dsl_scan_ds_destroyed(ds, tx); 1685 1686 obj = ds->ds_object; 1687 1688 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1689 if (ds->ds_prev) { 1690 ds_prev = ds->ds_prev; 1691 } else { 1692 VERIFY(0 == dsl_dataset_hold_obj(dp, 1693 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1694 } 1695 after_branch_point = 1696 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1697 1698 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1699 if (after_branch_point && 1700 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1701 remove_from_next_clones(ds_prev, obj, tx); 1702 if (ds->ds_phys->ds_next_snap_obj != 0) { 1703 VERIFY(0 == zap_add_int(mos, 1704 ds_prev->ds_phys->ds_next_clones_obj, 1705 ds->ds_phys->ds_next_snap_obj, tx)); 1706 } 1707 } 1708 if (after_branch_point && 1709 ds->ds_phys->ds_next_snap_obj == 0) { 1710 /* This clone is toast. */ 1711 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1712 ds_prev->ds_phys->ds_num_children--; 1713 1714 /* 1715 * If the clone's origin has no other clones, no 1716 * user holds, and has been marked for deferred 1717 * deletion, then we should have done the necessary 1718 * destroy setup for it. 1719 */ 1720 if (ds_prev->ds_phys->ds_num_children == 1 && 1721 ds_prev->ds_userrefs == 0 && 1722 DS_IS_DEFER_DESTROY(ds_prev)) { 1723 ASSERT3P(dsda->rm_origin, !=, NULL); 1724 } else { 1725 ASSERT3P(dsda->rm_origin, ==, NULL); 1726 } 1727 } else if (!after_branch_point) { 1728 ds_prev->ds_phys->ds_next_snap_obj = 1729 ds->ds_phys->ds_next_snap_obj; 1730 } 1731 } 1732 1733 if (dsl_dataset_is_snapshot(ds)) { 1734 dsl_dataset_t *ds_next; 1735 uint64_t old_unique; 1736 uint64_t used = 0, comp = 0, uncomp = 0; 1737 1738 VERIFY(0 == dsl_dataset_hold_obj(dp, 1739 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1740 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1741 1742 old_unique = ds_next->ds_phys->ds_unique_bytes; 1743 1744 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1745 ds_next->ds_phys->ds_prev_snap_obj = 1746 ds->ds_phys->ds_prev_snap_obj; 1747 ds_next->ds_phys->ds_prev_snap_txg = 1748 ds->ds_phys->ds_prev_snap_txg; 1749 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1750 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1751 1752 1753 if (ds_next->ds_deadlist.dl_oldfmt) { 1754 process_old_deadlist(ds, ds_prev, ds_next, 1755 after_branch_point, tx); 1756 } else { 1757 /* Adjust prev's unique space. */ 1758 if (ds_prev && !after_branch_point) { 1759 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1760 ds_prev->ds_phys->ds_prev_snap_txg, 1761 ds->ds_phys->ds_prev_snap_txg, 1762 &used, &comp, &uncomp); 1763 ds_prev->ds_phys->ds_unique_bytes += used; 1764 } 1765 1766 /* Adjust snapused. */ 1767 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1768 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 1769 &used, &comp, &uncomp); 1770 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1771 -used, -comp, -uncomp, tx); 1772 1773 /* Move blocks to be freed to pool's free list. */ 1774 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 1775 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, 1776 tx); 1777 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 1778 DD_USED_HEAD, used, comp, uncomp, tx); 1779 1780 /* Merge our deadlist into next's and free it. */ 1781 dsl_deadlist_merge(&ds_next->ds_deadlist, 1782 ds->ds_phys->ds_deadlist_obj, tx); 1783 } 1784 dsl_deadlist_close(&ds->ds_deadlist); 1785 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1786 1787 /* Collapse range in clone heads */ 1788 dsl_dataset_remove_clones_key(ds, 1789 ds->ds_phys->ds_creation_txg, tx); 1790 1791 if (dsl_dataset_is_snapshot(ds_next)) { 1792 dsl_dataset_t *ds_nextnext; 1793 1794 /* 1795 * Update next's unique to include blocks which 1796 * were previously shared by only this snapshot 1797 * and it. Those blocks will be born after the 1798 * prev snap and before this snap, and will have 1799 * died after the next snap and before the one 1800 * after that (ie. be on the snap after next's 1801 * deadlist). 1802 */ 1803 VERIFY(0 == dsl_dataset_hold_obj(dp, 1804 ds_next->ds_phys->ds_next_snap_obj, 1805 FTAG, &ds_nextnext)); 1806 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 1807 ds->ds_phys->ds_prev_snap_txg, 1808 ds->ds_phys->ds_creation_txg, 1809 &used, &comp, &uncomp); 1810 ds_next->ds_phys->ds_unique_bytes += used; 1811 dsl_dataset_rele(ds_nextnext, FTAG); 1812 ASSERT3P(ds_next->ds_prev, ==, NULL); 1813 1814 /* Collapse range in this head. */ 1815 dsl_dataset_t *hds; 1816 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 1817 ds->ds_dir->dd_phys->dd_head_dataset_obj, 1818 FTAG, &hds)); 1819 dsl_deadlist_remove_key(&hds->ds_deadlist, 1820 ds->ds_phys->ds_creation_txg, tx); 1821 dsl_dataset_rele(hds, FTAG); 1822 1823 } else { 1824 ASSERT3P(ds_next->ds_prev, ==, ds); 1825 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1826 ds_next->ds_prev = NULL; 1827 if (ds_prev) { 1828 VERIFY(0 == dsl_dataset_get_ref(dp, 1829 ds->ds_phys->ds_prev_snap_obj, 1830 ds_next, &ds_next->ds_prev)); 1831 } 1832 1833 dsl_dataset_recalc_head_uniq(ds_next); 1834 1835 /* 1836 * Reduce the amount of our unconsmed refreservation 1837 * being charged to our parent by the amount of 1838 * new unique data we have gained. 1839 */ 1840 if (old_unique < ds_next->ds_reserved) { 1841 int64_t mrsdelta; 1842 uint64_t new_unique = 1843 ds_next->ds_phys->ds_unique_bytes; 1844 1845 ASSERT(old_unique <= new_unique); 1846 mrsdelta = MIN(new_unique - old_unique, 1847 ds_next->ds_reserved - old_unique); 1848 dsl_dir_diduse_space(ds->ds_dir, 1849 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1850 } 1851 } 1852 dsl_dataset_rele(ds_next, FTAG); 1853 } else { 1854 zfeature_info_t *async_destroy = 1855 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY]; 1856 objset_t *os; 1857 1858 /* 1859 * There's no next snapshot, so this is a head dataset. 1860 * Destroy the deadlist. Unless it's a clone, the 1861 * deadlist should be empty. (If it's a clone, it's 1862 * safe to ignore the deadlist contents.) 1863 */ 1864 dsl_deadlist_close(&ds->ds_deadlist); 1865 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1866 ds->ds_phys->ds_deadlist_obj = 0; 1867 1868 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); 1869 1870 if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) { 1871 err = old_synchronous_dataset_destroy(ds, tx); 1872 } else { 1873 /* 1874 * Move the bptree into the pool's list of trees to 1875 * clean up and update space accounting information. 1876 */ 1877 uint64_t used, comp, uncomp; 1878 1879 zil_destroy_sync(dmu_objset_zil(os), tx); 1880 1881 if (!spa_feature_is_active(dp->dp_spa, async_destroy)) { 1882 spa_feature_incr(dp->dp_spa, async_destroy, tx); 1883 dp->dp_bptree_obj = bptree_alloc(mos, tx); 1884 VERIFY(zap_add(mos, 1885 DMU_POOL_DIRECTORY_OBJECT, 1886 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1, 1887 &dp->dp_bptree_obj, tx) == 0); 1888 } 1889 1890 used = ds->ds_dir->dd_phys->dd_used_bytes; 1891 comp = ds->ds_dir->dd_phys->dd_compressed_bytes; 1892 uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes; 1893 1894 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1895 ds->ds_phys->ds_unique_bytes == used); 1896 1897 bptree_add(mos, dp->dp_bptree_obj, 1898 &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg, 1899 used, comp, uncomp, tx); 1900 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 1901 -used, -comp, -uncomp, tx); 1902 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 1903 used, comp, uncomp, tx); 1904 } 1905 1906 if (ds->ds_prev != NULL) { 1907 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 1908 VERIFY3U(0, ==, zap_remove_int(mos, 1909 ds->ds_prev->ds_dir->dd_phys->dd_clones, 1910 ds->ds_object, tx)); 1911 } 1912 dsl_dataset_rele(ds->ds_prev, ds); 1913 ds->ds_prev = ds_prev = NULL; 1914 } 1915 } 1916 1917 /* 1918 * This must be done after the dsl_traverse(), because it will 1919 * re-open the objset. 1920 */ 1921 if (ds->ds_objset) { 1922 dmu_objset_evict(ds->ds_objset); 1923 ds->ds_objset = NULL; 1924 } 1925 1926 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1927 /* Erase the link in the dir */ 1928 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1929 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1930 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1931 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1932 ASSERT(err == 0); 1933 } else { 1934 /* remove from snapshot namespace */ 1935 dsl_dataset_t *ds_head; 1936 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1937 VERIFY(0 == dsl_dataset_hold_obj(dp, 1938 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1939 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1940 #ifdef ZFS_DEBUG 1941 { 1942 uint64_t val; 1943 1944 err = dsl_dataset_snap_lookup(ds_head, 1945 ds->ds_snapname, &val); 1946 ASSERT3U(err, ==, 0); 1947 ASSERT3U(val, ==, obj); 1948 } 1949 #endif 1950 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1951 ASSERT(err == 0); 1952 dsl_dataset_rele(ds_head, FTAG); 1953 } 1954 1955 if (ds_prev && ds->ds_prev != ds_prev) 1956 dsl_dataset_rele(ds_prev, FTAG); 1957 1958 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1959 1960 if (ds->ds_phys->ds_next_clones_obj != 0) { 1961 uint64_t count; 1962 ASSERT(0 == zap_count(mos, 1963 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1964 VERIFY(0 == dmu_object_free(mos, 1965 ds->ds_phys->ds_next_clones_obj, tx)); 1966 } 1967 if (ds->ds_phys->ds_props_obj != 0) 1968 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1969 if (ds->ds_phys->ds_userrefs_obj != 0) 1970 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1971 dsl_dir_close(ds->ds_dir, ds); 1972 ds->ds_dir = NULL; 1973 dsl_dataset_drain_refs(ds, tag); 1974 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1975 1976 if (dsda->rm_origin) { 1977 /* 1978 * Remove the origin of the clone we just destroyed. 1979 */ 1980 struct dsl_ds_destroyarg ndsda = {0}; 1981 1982 ndsda.ds = dsda->rm_origin; 1983 dsl_dataset_destroy_sync(&ndsda, tag, tx); 1984 } 1985 } 1986 1987 static int 1988 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1989 { 1990 uint64_t asize; 1991 1992 if (!dmu_tx_is_syncing(tx)) 1993 return (0); 1994 1995 /* 1996 * If there's an fs-only reservation, any blocks that might become 1997 * owned by the snapshot dataset must be accommodated by space 1998 * outside of the reservation. 1999 */ 2000 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds)); 2001 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2002 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 2003 return (ENOSPC); 2004 2005 /* 2006 * Propagate any reserved space for this snapshot to other 2007 * snapshot checks in this sync group. 2008 */ 2009 if (asize > 0) 2010 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 2011 2012 return (0); 2013 } 2014 2015 int 2016 dsl_dataset_snapshot_check(dsl_dataset_t *ds, const char *snapname, 2017 dmu_tx_t *tx) 2018 { 2019 int err; 2020 uint64_t value; 2021 2022 /* 2023 * We don't allow multiple snapshots of the same txg. If there 2024 * is already one, try again. 2025 */ 2026 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 2027 return (EAGAIN); 2028 2029 /* 2030 * Check for conflicting snapshot name. 2031 */ 2032 err = dsl_dataset_snap_lookup(ds, snapname, &value); 2033 if (err == 0) 2034 return (EEXIST); 2035 if (err != ENOENT) 2036 return (err); 2037 2038 /* 2039 * Check that the dataset's name is not too long. Name consists 2040 * of the dataset's length + 1 for the @-sign + snapshot name's length 2041 */ 2042 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 2043 return (ENAMETOOLONG); 2044 2045 err = dsl_dataset_snapshot_reserve_space(ds, tx); 2046 if (err) 2047 return (err); 2048 2049 ds->ds_trysnap_txg = tx->tx_txg; 2050 return (0); 2051 } 2052 2053 void 2054 dsl_dataset_snapshot_sync(dsl_dataset_t *ds, const char *snapname, 2055 dmu_tx_t *tx) 2056 { 2057 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2058 dmu_buf_t *dbuf; 2059 dsl_dataset_phys_t *dsphys; 2060 uint64_t dsobj, crtxg; 2061 objset_t *mos = dp->dp_meta_objset; 2062 int err; 2063 2064 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 2065 2066 /* 2067 * The origin's ds_creation_txg has to be < TXG_INITIAL 2068 */ 2069 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 2070 crtxg = 1; 2071 else 2072 crtxg = tx->tx_txg; 2073 2074 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 2075 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 2076 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 2077 dmu_buf_will_dirty(dbuf, tx); 2078 dsphys = dbuf->db_data; 2079 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 2080 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 2081 dsphys->ds_fsid_guid = unique_create(); 2082 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 2083 sizeof (dsphys->ds_guid)); 2084 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 2085 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 2086 dsphys->ds_next_snap_obj = ds->ds_object; 2087 dsphys->ds_num_children = 1; 2088 dsphys->ds_creation_time = gethrestime_sec(); 2089 dsphys->ds_creation_txg = crtxg; 2090 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 2091 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes; 2092 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 2093 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 2094 dsphys->ds_flags = ds->ds_phys->ds_flags; 2095 dsphys->ds_bp = ds->ds_phys->ds_bp; 2096 dmu_buf_rele(dbuf, FTAG); 2097 2098 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 2099 if (ds->ds_prev) { 2100 uint64_t next_clones_obj = 2101 ds->ds_prev->ds_phys->ds_next_clones_obj; 2102 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 2103 ds->ds_object || 2104 ds->ds_prev->ds_phys->ds_num_children > 1); 2105 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 2106 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 2107 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 2108 ds->ds_prev->ds_phys->ds_creation_txg); 2109 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 2110 } else if (next_clones_obj != 0) { 2111 remove_from_next_clones(ds->ds_prev, 2112 dsphys->ds_next_snap_obj, tx); 2113 VERIFY3U(0, ==, zap_add_int(mos, 2114 next_clones_obj, dsobj, tx)); 2115 } 2116 } 2117 2118 /* 2119 * If we have a reference-reservation on this dataset, we will 2120 * need to increase the amount of refreservation being charged 2121 * since our unique space is going to zero. 2122 */ 2123 if (ds->ds_reserved) { 2124 int64_t delta; 2125 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 2126 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2127 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 2128 delta, 0, 0, tx); 2129 } 2130 2131 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2132 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu", 2133 ds->ds_dir->dd_myname, snapname, dsobj, 2134 ds->ds_phys->ds_prev_snap_txg); 2135 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist, 2136 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx); 2137 dsl_deadlist_close(&ds->ds_deadlist); 2138 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 2139 dsl_deadlist_add_key(&ds->ds_deadlist, 2140 ds->ds_phys->ds_prev_snap_txg, tx); 2141 2142 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 2143 ds->ds_phys->ds_prev_snap_obj = dsobj; 2144 ds->ds_phys->ds_prev_snap_txg = crtxg; 2145 ds->ds_phys->ds_unique_bytes = 0; 2146 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 2147 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 2148 2149 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 2150 snapname, 8, 1, &dsobj, tx); 2151 ASSERT(err == 0); 2152 2153 if (ds->ds_prev) 2154 dsl_dataset_drop_ref(ds->ds_prev, ds); 2155 VERIFY(0 == dsl_dataset_get_ref(dp, 2156 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 2157 2158 dsl_scan_ds_snapshotted(ds, tx); 2159 2160 dsl_dir_snap_cmtime_update(ds->ds_dir); 2161 2162 spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, ""); 2163 } 2164 2165 void 2166 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 2167 { 2168 ASSERT(dmu_tx_is_syncing(tx)); 2169 ASSERT(ds->ds_objset != NULL); 2170 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 2171 2172 /* 2173 * in case we had to change ds_fsid_guid when we opened it, 2174 * sync it out now. 2175 */ 2176 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2177 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2178 2179 dmu_objset_sync(ds->ds_objset, zio, tx); 2180 } 2181 2182 static void 2183 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv) 2184 { 2185 uint64_t count = 0; 2186 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 2187 zap_cursor_t zc; 2188 zap_attribute_t za; 2189 nvlist_t *propval; 2190 nvlist_t *val; 2191 2192 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2193 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0); 2194 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0); 2195 2196 /* 2197 * There may me missing entries in ds_next_clones_obj 2198 * due to a bug in a previous version of the code. 2199 * Only trust it if it has the right number of entries. 2200 */ 2201 if (ds->ds_phys->ds_next_clones_obj != 0) { 2202 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 2203 &count)); 2204 } 2205 if (count != ds->ds_phys->ds_num_children - 1) { 2206 goto fail; 2207 } 2208 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj); 2209 zap_cursor_retrieve(&zc, &za) == 0; 2210 zap_cursor_advance(&zc)) { 2211 dsl_dataset_t *clone; 2212 char buf[ZFS_MAXNAMELEN]; 2213 /* 2214 * Even though we hold the dp_config_rwlock, the dataset 2215 * may fail to open, returning ENOENT. If there is a 2216 * thread concurrently attempting to destroy this 2217 * dataset, it will have the ds_rwlock held for 2218 * RW_WRITER. Our call to dsl_dataset_hold_obj() -> 2219 * dsl_dataset_hold_ref() will fail its 2220 * rw_tryenter(&ds->ds_rwlock, RW_READER), drop the 2221 * dp_config_rwlock, and wait for the destroy progress 2222 * and signal ds_exclusive_cv. If the destroy was 2223 * successful, we will see that 2224 * DSL_DATASET_IS_DESTROYED(), and return ENOENT. 2225 */ 2226 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 2227 za.za_first_integer, FTAG, &clone) != 0) 2228 continue; 2229 dsl_dir_name(clone->ds_dir, buf); 2230 VERIFY(nvlist_add_boolean(val, buf) == 0); 2231 dsl_dataset_rele(clone, FTAG); 2232 } 2233 zap_cursor_fini(&zc); 2234 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0); 2235 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), 2236 propval) == 0); 2237 fail: 2238 nvlist_free(val); 2239 nvlist_free(propval); 2240 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2241 } 2242 2243 void 2244 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2245 { 2246 uint64_t refd, avail, uobjs, aobjs, ratio; 2247 2248 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2249 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2250 ds->ds_phys->ds_compressed_bytes); 2251 2252 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio); 2253 2254 if (dsl_dataset_is_snapshot(ds)) { 2255 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio); 2256 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2257 ds->ds_phys->ds_unique_bytes); 2258 get_clones_stat(ds, nv); 2259 } else { 2260 dsl_dir_stats(ds->ds_dir, nv); 2261 } 2262 2263 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2264 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2265 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2266 2267 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2268 ds->ds_phys->ds_creation_time); 2269 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2270 ds->ds_phys->ds_creation_txg); 2271 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2272 ds->ds_quota); 2273 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2274 ds->ds_reserved); 2275 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2276 ds->ds_phys->ds_guid); 2277 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2278 ds->ds_phys->ds_unique_bytes); 2279 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2280 ds->ds_object); 2281 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2282 ds->ds_userrefs); 2283 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2284 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2285 2286 if (ds->ds_phys->ds_prev_snap_obj != 0) { 2287 uint64_t written, comp, uncomp; 2288 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2289 dsl_dataset_t *prev; 2290 2291 rw_enter(&dp->dp_config_rwlock, RW_READER); 2292 int err = dsl_dataset_hold_obj(dp, 2293 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev); 2294 rw_exit(&dp->dp_config_rwlock); 2295 if (err == 0) { 2296 err = dsl_dataset_space_written(prev, ds, &written, 2297 &comp, &uncomp); 2298 dsl_dataset_rele(prev, FTAG); 2299 if (err == 0) { 2300 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN, 2301 written); 2302 } 2303 } 2304 } 2305 } 2306 2307 void 2308 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2309 { 2310 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2311 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2312 stat->dds_guid = ds->ds_phys->ds_guid; 2313 stat->dds_origin[0] = '\0'; 2314 if (dsl_dataset_is_snapshot(ds)) { 2315 stat->dds_is_snapshot = B_TRUE; 2316 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2317 } else { 2318 stat->dds_is_snapshot = B_FALSE; 2319 stat->dds_num_clones = 0; 2320 2321 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2322 if (dsl_dir_is_clone(ds->ds_dir)) { 2323 dsl_dataset_t *ods; 2324 2325 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2326 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2327 dsl_dataset_name(ods, stat->dds_origin); 2328 dsl_dataset_drop_ref(ods, FTAG); 2329 } 2330 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2331 } 2332 } 2333 2334 uint64_t 2335 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2336 { 2337 return (ds->ds_fsid_guid); 2338 } 2339 2340 void 2341 dsl_dataset_space(dsl_dataset_t *ds, 2342 uint64_t *refdbytesp, uint64_t *availbytesp, 2343 uint64_t *usedobjsp, uint64_t *availobjsp) 2344 { 2345 *refdbytesp = ds->ds_phys->ds_referenced_bytes; 2346 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2347 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2348 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2349 if (ds->ds_quota != 0) { 2350 /* 2351 * Adjust available bytes according to refquota 2352 */ 2353 if (*refdbytesp < ds->ds_quota) 2354 *availbytesp = MIN(*availbytesp, 2355 ds->ds_quota - *refdbytesp); 2356 else 2357 *availbytesp = 0; 2358 } 2359 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2360 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2361 } 2362 2363 boolean_t 2364 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2365 { 2366 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2367 2368 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2369 dsl_pool_sync_context(dp)); 2370 if (ds->ds_prev == NULL) 2371 return (B_FALSE); 2372 if (ds->ds_phys->ds_bp.blk_birth > 2373 ds->ds_prev->ds_phys->ds_creation_txg) { 2374 objset_t *os, *os_prev; 2375 /* 2376 * It may be that only the ZIL differs, because it was 2377 * reset in the head. Don't count that as being 2378 * modified. 2379 */ 2380 if (dmu_objset_from_ds(ds, &os) != 0) 2381 return (B_TRUE); 2382 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0) 2383 return (B_TRUE); 2384 return (bcmp(&os->os_phys->os_meta_dnode, 2385 &os_prev->os_phys->os_meta_dnode, 2386 sizeof (os->os_phys->os_meta_dnode)) != 0); 2387 } 2388 return (B_FALSE); 2389 } 2390 2391 /* ARGSUSED */ 2392 static int 2393 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2394 { 2395 dsl_dataset_t *ds = arg1; 2396 char *newsnapname = arg2; 2397 dsl_dir_t *dd = ds->ds_dir; 2398 dsl_dataset_t *hds; 2399 uint64_t val; 2400 int err; 2401 2402 err = dsl_dataset_hold_obj(dd->dd_pool, 2403 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2404 if (err) 2405 return (err); 2406 2407 /* new name better not be in use */ 2408 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2409 dsl_dataset_rele(hds, FTAG); 2410 2411 if (err == 0) 2412 err = EEXIST; 2413 else if (err == ENOENT) 2414 err = 0; 2415 2416 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2417 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2418 err = ENAMETOOLONG; 2419 2420 return (err); 2421 } 2422 2423 static void 2424 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2425 { 2426 dsl_dataset_t *ds = arg1; 2427 const char *newsnapname = arg2; 2428 dsl_dir_t *dd = ds->ds_dir; 2429 objset_t *mos = dd->dd_pool->dp_meta_objset; 2430 dsl_dataset_t *hds; 2431 int err; 2432 2433 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2434 2435 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2436 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2437 2438 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2439 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2440 ASSERT3U(err, ==, 0); 2441 mutex_enter(&ds->ds_lock); 2442 (void) strcpy(ds->ds_snapname, newsnapname); 2443 mutex_exit(&ds->ds_lock); 2444 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2445 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2446 ASSERT3U(err, ==, 0); 2447 2448 spa_history_log_internal_ds(ds, "rename", tx, 2449 "-> @%s", newsnapname); 2450 dsl_dataset_rele(hds, FTAG); 2451 } 2452 2453 struct renamesnaparg { 2454 dsl_sync_task_group_t *dstg; 2455 char failed[MAXPATHLEN]; 2456 char *oldsnap; 2457 char *newsnap; 2458 }; 2459 2460 static int 2461 dsl_snapshot_rename_one(const char *name, void *arg) 2462 { 2463 struct renamesnaparg *ra = arg; 2464 dsl_dataset_t *ds = NULL; 2465 char *snapname; 2466 int err; 2467 2468 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); 2469 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); 2470 2471 /* 2472 * For recursive snapshot renames the parent won't be changing 2473 * so we just pass name for both the to/from argument. 2474 */ 2475 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); 2476 if (err != 0) { 2477 strfree(snapname); 2478 return (err == ENOENT ? 0 : err); 2479 } 2480 2481 #ifdef _KERNEL 2482 /* 2483 * For all filesystems undergoing rename, we'll need to unmount it. 2484 */ 2485 (void) zfs_unmount_snap(snapname, NULL); 2486 #endif 2487 err = dsl_dataset_hold(snapname, ra->dstg, &ds); 2488 strfree(snapname); 2489 if (err != 0) 2490 return (err == ENOENT ? 0 : err); 2491 2492 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2493 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2494 2495 return (0); 2496 } 2497 2498 static int 2499 dsl_recursive_rename(char *oldname, const char *newname) 2500 { 2501 int err; 2502 struct renamesnaparg *ra; 2503 dsl_sync_task_t *dst; 2504 spa_t *spa; 2505 char *cp, *fsname = spa_strdup(oldname); 2506 int len = strlen(oldname) + 1; 2507 2508 /* truncate the snapshot name to get the fsname */ 2509 cp = strchr(fsname, '@'); 2510 *cp = '\0'; 2511 2512 err = spa_open(fsname, &spa, FTAG); 2513 if (err) { 2514 kmem_free(fsname, len); 2515 return (err); 2516 } 2517 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2518 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2519 2520 ra->oldsnap = strchr(oldname, '@') + 1; 2521 ra->newsnap = strchr(newname, '@') + 1; 2522 *ra->failed = '\0'; 2523 2524 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2525 DS_FIND_CHILDREN); 2526 kmem_free(fsname, len); 2527 2528 if (err == 0) { 2529 err = dsl_sync_task_group_wait(ra->dstg); 2530 } 2531 2532 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2533 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2534 dsl_dataset_t *ds = dst->dst_arg1; 2535 if (dst->dst_err) { 2536 dsl_dir_name(ds->ds_dir, ra->failed); 2537 (void) strlcat(ra->failed, "@", sizeof (ra->failed)); 2538 (void) strlcat(ra->failed, ra->newsnap, 2539 sizeof (ra->failed)); 2540 } 2541 dsl_dataset_rele(ds, ra->dstg); 2542 } 2543 2544 if (err) 2545 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); 2546 2547 dsl_sync_task_group_destroy(ra->dstg); 2548 kmem_free(ra, sizeof (struct renamesnaparg)); 2549 spa_close(spa, FTAG); 2550 return (err); 2551 } 2552 2553 static int 2554 dsl_valid_rename(const char *oldname, void *arg) 2555 { 2556 int delta = *(int *)arg; 2557 2558 if (strlen(oldname) + delta >= MAXNAMELEN) 2559 return (ENAMETOOLONG); 2560 2561 return (0); 2562 } 2563 2564 #pragma weak dmu_objset_rename = dsl_dataset_rename 2565 int 2566 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2567 { 2568 dsl_dir_t *dd; 2569 dsl_dataset_t *ds; 2570 const char *tail; 2571 int err; 2572 2573 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2574 if (err) 2575 return (err); 2576 2577 if (tail == NULL) { 2578 int delta = strlen(newname) - strlen(oldname); 2579 2580 /* if we're growing, validate child name lengths */ 2581 if (delta > 0) 2582 err = dmu_objset_find(oldname, dsl_valid_rename, 2583 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2584 2585 if (err == 0) 2586 err = dsl_dir_rename(dd, newname); 2587 dsl_dir_close(dd, FTAG); 2588 return (err); 2589 } 2590 2591 if (tail[0] != '@') { 2592 /* the name ended in a nonexistent component */ 2593 dsl_dir_close(dd, FTAG); 2594 return (ENOENT); 2595 } 2596 2597 dsl_dir_close(dd, FTAG); 2598 2599 /* new name must be snapshot in same filesystem */ 2600 tail = strchr(newname, '@'); 2601 if (tail == NULL) 2602 return (EINVAL); 2603 tail++; 2604 if (strncmp(oldname, newname, tail - newname) != 0) 2605 return (EXDEV); 2606 2607 if (recursive) { 2608 err = dsl_recursive_rename(oldname, newname); 2609 } else { 2610 err = dsl_dataset_hold(oldname, FTAG, &ds); 2611 if (err) 2612 return (err); 2613 2614 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2615 dsl_dataset_snapshot_rename_check, 2616 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2617 2618 dsl_dataset_rele(ds, FTAG); 2619 } 2620 2621 return (err); 2622 } 2623 2624 struct promotenode { 2625 list_node_t link; 2626 dsl_dataset_t *ds; 2627 }; 2628 2629 struct promotearg { 2630 list_t shared_snaps, origin_snaps, clone_snaps; 2631 dsl_dataset_t *origin_origin; 2632 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2633 char *err_ds; 2634 }; 2635 2636 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2637 static boolean_t snaplist_unstable(list_t *l); 2638 2639 static int 2640 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2641 { 2642 dsl_dataset_t *hds = arg1; 2643 struct promotearg *pa = arg2; 2644 struct promotenode *snap = list_head(&pa->shared_snaps); 2645 dsl_dataset_t *origin_ds = snap->ds; 2646 int err; 2647 uint64_t unused; 2648 2649 /* Check that it is a real clone */ 2650 if (!dsl_dir_is_clone(hds->ds_dir)) 2651 return (EINVAL); 2652 2653 /* Since this is so expensive, don't do the preliminary check */ 2654 if (!dmu_tx_is_syncing(tx)) 2655 return (0); 2656 2657 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2658 return (EXDEV); 2659 2660 /* compute origin's new unique space */ 2661 snap = list_tail(&pa->clone_snaps); 2662 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2663 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2664 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2665 &pa->unique, &unused, &unused); 2666 2667 /* 2668 * Walk the snapshots that we are moving 2669 * 2670 * Compute space to transfer. Consider the incremental changes 2671 * to used for each snapshot: 2672 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2673 * So each snapshot gave birth to: 2674 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2675 * So a sequence would look like: 2676 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2677 * Which simplifies to: 2678 * uN + kN + kN-1 + ... + k1 + k0 2679 * Note however, if we stop before we reach the ORIGIN we get: 2680 * uN + kN + kN-1 + ... + kM - uM-1 2681 */ 2682 pa->used = origin_ds->ds_phys->ds_referenced_bytes; 2683 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2684 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2685 for (snap = list_head(&pa->shared_snaps); snap; 2686 snap = list_next(&pa->shared_snaps, snap)) { 2687 uint64_t val, dlused, dlcomp, dluncomp; 2688 dsl_dataset_t *ds = snap->ds; 2689 2690 /* Check that the snapshot name does not conflict */ 2691 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2692 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2693 if (err == 0) { 2694 err = EEXIST; 2695 goto out; 2696 } 2697 if (err != ENOENT) 2698 goto out; 2699 2700 /* The very first snapshot does not have a deadlist */ 2701 if (ds->ds_phys->ds_prev_snap_obj == 0) 2702 continue; 2703 2704 dsl_deadlist_space(&ds->ds_deadlist, 2705 &dlused, &dlcomp, &dluncomp); 2706 pa->used += dlused; 2707 pa->comp += dlcomp; 2708 pa->uncomp += dluncomp; 2709 } 2710 2711 /* 2712 * If we are a clone of a clone then we never reached ORIGIN, 2713 * so we need to subtract out the clone origin's used space. 2714 */ 2715 if (pa->origin_origin) { 2716 pa->used -= pa->origin_origin->ds_phys->ds_referenced_bytes; 2717 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2718 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2719 } 2720 2721 /* Check that there is enough space here */ 2722 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2723 pa->used); 2724 if (err) 2725 return (err); 2726 2727 /* 2728 * Compute the amounts of space that will be used by snapshots 2729 * after the promotion (for both origin and clone). For each, 2730 * it is the amount of space that will be on all of their 2731 * deadlists (that was not born before their new origin). 2732 */ 2733 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2734 uint64_t space; 2735 2736 /* 2737 * Note, typically this will not be a clone of a clone, 2738 * so dd_origin_txg will be < TXG_INITIAL, so 2739 * these snaplist_space() -> dsl_deadlist_space_range() 2740 * calls will be fast because they do not have to 2741 * iterate over all bps. 2742 */ 2743 snap = list_head(&pa->origin_snaps); 2744 err = snaplist_space(&pa->shared_snaps, 2745 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap); 2746 if (err) 2747 return (err); 2748 2749 err = snaplist_space(&pa->clone_snaps, 2750 snap->ds->ds_dir->dd_origin_txg, &space); 2751 if (err) 2752 return (err); 2753 pa->cloneusedsnap += space; 2754 } 2755 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2756 err = snaplist_space(&pa->origin_snaps, 2757 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2758 if (err) 2759 return (err); 2760 } 2761 2762 return (0); 2763 out: 2764 pa->err_ds = snap->ds->ds_snapname; 2765 return (err); 2766 } 2767 2768 static void 2769 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2770 { 2771 dsl_dataset_t *hds = arg1; 2772 struct promotearg *pa = arg2; 2773 struct promotenode *snap = list_head(&pa->shared_snaps); 2774 dsl_dataset_t *origin_ds = snap->ds; 2775 dsl_dataset_t *origin_head; 2776 dsl_dir_t *dd = hds->ds_dir; 2777 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2778 dsl_dir_t *odd = NULL; 2779 uint64_t oldnext_obj; 2780 int64_t delta; 2781 2782 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2783 2784 snap = list_head(&pa->origin_snaps); 2785 origin_head = snap->ds; 2786 2787 /* 2788 * We need to explicitly open odd, since origin_ds's dd will be 2789 * changing. 2790 */ 2791 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2792 NULL, FTAG, &odd)); 2793 2794 /* change origin's next snap */ 2795 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2796 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2797 snap = list_tail(&pa->clone_snaps); 2798 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2799 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2800 2801 /* change the origin's next clone */ 2802 if (origin_ds->ds_phys->ds_next_clones_obj) { 2803 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2804 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2805 origin_ds->ds_phys->ds_next_clones_obj, 2806 oldnext_obj, tx)); 2807 } 2808 2809 /* change origin */ 2810 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2811 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2812 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2813 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg; 2814 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2815 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2816 origin_head->ds_dir->dd_origin_txg = 2817 origin_ds->ds_phys->ds_creation_txg; 2818 2819 /* change dd_clone entries */ 2820 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2821 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2822 odd->dd_phys->dd_clones, hds->ds_object, tx)); 2823 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2824 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2825 hds->ds_object, tx)); 2826 2827 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2828 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2829 origin_head->ds_object, tx)); 2830 if (dd->dd_phys->dd_clones == 0) { 2831 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset, 2832 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 2833 } 2834 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2835 dd->dd_phys->dd_clones, origin_head->ds_object, tx)); 2836 2837 } 2838 2839 /* move snapshots to this dir */ 2840 for (snap = list_head(&pa->shared_snaps); snap; 2841 snap = list_next(&pa->shared_snaps, snap)) { 2842 dsl_dataset_t *ds = snap->ds; 2843 2844 /* unregister props as dsl_dir is changing */ 2845 if (ds->ds_objset) { 2846 dmu_objset_evict(ds->ds_objset); 2847 ds->ds_objset = NULL; 2848 } 2849 /* move snap name entry */ 2850 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2851 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2852 ds->ds_snapname, tx)); 2853 VERIFY(0 == zap_add(dp->dp_meta_objset, 2854 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2855 8, 1, &ds->ds_object, tx)); 2856 2857 /* change containing dsl_dir */ 2858 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2859 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2860 ds->ds_phys->ds_dir_obj = dd->dd_object; 2861 ASSERT3P(ds->ds_dir, ==, odd); 2862 dsl_dir_close(ds->ds_dir, ds); 2863 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2864 NULL, ds, &ds->ds_dir)); 2865 2866 /* move any clone references */ 2867 if (ds->ds_phys->ds_next_clones_obj && 2868 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2869 zap_cursor_t zc; 2870 zap_attribute_t za; 2871 2872 for (zap_cursor_init(&zc, dp->dp_meta_objset, 2873 ds->ds_phys->ds_next_clones_obj); 2874 zap_cursor_retrieve(&zc, &za) == 0; 2875 zap_cursor_advance(&zc)) { 2876 dsl_dataset_t *cnds; 2877 uint64_t o; 2878 2879 if (za.za_first_integer == oldnext_obj) { 2880 /* 2881 * We've already moved the 2882 * origin's reference. 2883 */ 2884 continue; 2885 } 2886 2887 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 2888 za.za_first_integer, FTAG, &cnds)); 2889 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj; 2890 2891 VERIFY3U(zap_remove_int(dp->dp_meta_objset, 2892 odd->dd_phys->dd_clones, o, tx), ==, 0); 2893 VERIFY3U(zap_add_int(dp->dp_meta_objset, 2894 dd->dd_phys->dd_clones, o, tx), ==, 0); 2895 dsl_dataset_rele(cnds, FTAG); 2896 } 2897 zap_cursor_fini(&zc); 2898 } 2899 2900 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2901 } 2902 2903 /* 2904 * Change space accounting. 2905 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2906 * both be valid, or both be 0 (resulting in delta == 0). This 2907 * is true for each of {clone,origin} independently. 2908 */ 2909 2910 delta = pa->cloneusedsnap - 2911 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2912 ASSERT3S(delta, >=, 0); 2913 ASSERT3U(pa->used, >=, delta); 2914 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2915 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2916 pa->used - delta, pa->comp, pa->uncomp, tx); 2917 2918 delta = pa->originusedsnap - 2919 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2920 ASSERT3S(delta, <=, 0); 2921 ASSERT3U(pa->used, >=, -delta); 2922 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2923 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2924 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2925 2926 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2927 2928 /* log history record */ 2929 spa_history_log_internal_ds(hds, "promote", tx, ""); 2930 2931 dsl_dir_close(odd, FTAG); 2932 } 2933 2934 static char *snaplist_tag = "snaplist"; 2935 /* 2936 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2937 * (exclusive) and last_obj (inclusive). The list will be in reverse 2938 * order (last_obj will be the list_head()). If first_obj == 0, do all 2939 * snapshots back to this dataset's origin. 2940 */ 2941 static int 2942 snaplist_make(dsl_pool_t *dp, boolean_t own, 2943 uint64_t first_obj, uint64_t last_obj, list_t *l) 2944 { 2945 uint64_t obj = last_obj; 2946 2947 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2948 2949 list_create(l, sizeof (struct promotenode), 2950 offsetof(struct promotenode, link)); 2951 2952 while (obj != first_obj) { 2953 dsl_dataset_t *ds; 2954 struct promotenode *snap; 2955 int err; 2956 2957 if (own) { 2958 err = dsl_dataset_own_obj(dp, obj, 2959 0, snaplist_tag, &ds); 2960 if (err == 0) 2961 dsl_dataset_make_exclusive(ds, snaplist_tag); 2962 } else { 2963 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2964 } 2965 if (err == ENOENT) { 2966 /* lost race with snapshot destroy */ 2967 struct promotenode *last = list_tail(l); 2968 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2969 obj = last->ds->ds_phys->ds_prev_snap_obj; 2970 continue; 2971 } else if (err) { 2972 return (err); 2973 } 2974 2975 if (first_obj == 0) 2976 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2977 2978 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2979 snap->ds = ds; 2980 list_insert_tail(l, snap); 2981 obj = ds->ds_phys->ds_prev_snap_obj; 2982 } 2983 2984 return (0); 2985 } 2986 2987 static int 2988 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2989 { 2990 struct promotenode *snap; 2991 2992 *spacep = 0; 2993 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2994 uint64_t used, comp, uncomp; 2995 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2996 mintxg, UINT64_MAX, &used, &comp, &uncomp); 2997 *spacep += used; 2998 } 2999 return (0); 3000 } 3001 3002 static void 3003 snaplist_destroy(list_t *l, boolean_t own) 3004 { 3005 struct promotenode *snap; 3006 3007 if (!l || !list_link_active(&l->list_head)) 3008 return; 3009 3010 while ((snap = list_tail(l)) != NULL) { 3011 list_remove(l, snap); 3012 if (own) 3013 dsl_dataset_disown(snap->ds, snaplist_tag); 3014 else 3015 dsl_dataset_rele(snap->ds, snaplist_tag); 3016 kmem_free(snap, sizeof (struct promotenode)); 3017 } 3018 list_destroy(l); 3019 } 3020 3021 /* 3022 * Promote a clone. Nomenclature note: 3023 * "clone" or "cds": the original clone which is being promoted 3024 * "origin" or "ods": the snapshot which is originally clone's origin 3025 * "origin head" or "ohds": the dataset which is the head 3026 * (filesystem/volume) for the origin 3027 * "origin origin": the origin of the origin's filesystem (typically 3028 * NULL, indicating that the clone is not a clone of a clone). 3029 */ 3030 int 3031 dsl_dataset_promote(const char *name, char *conflsnap) 3032 { 3033 dsl_dataset_t *ds; 3034 dsl_dir_t *dd; 3035 dsl_pool_t *dp; 3036 dmu_object_info_t doi; 3037 struct promotearg pa = { 0 }; 3038 struct promotenode *snap; 3039 int err; 3040 3041 err = dsl_dataset_hold(name, FTAG, &ds); 3042 if (err) 3043 return (err); 3044 dd = ds->ds_dir; 3045 dp = dd->dd_pool; 3046 3047 err = dmu_object_info(dp->dp_meta_objset, 3048 ds->ds_phys->ds_snapnames_zapobj, &doi); 3049 if (err) { 3050 dsl_dataset_rele(ds, FTAG); 3051 return (err); 3052 } 3053 3054 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 3055 dsl_dataset_rele(ds, FTAG); 3056 return (EINVAL); 3057 } 3058 3059 /* 3060 * We are going to inherit all the snapshots taken before our 3061 * origin (i.e., our new origin will be our parent's origin). 3062 * Take ownership of them so that we can rename them into our 3063 * namespace. 3064 */ 3065 rw_enter(&dp->dp_config_rwlock, RW_READER); 3066 3067 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 3068 &pa.shared_snaps); 3069 if (err != 0) 3070 goto out; 3071 3072 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 3073 if (err != 0) 3074 goto out; 3075 3076 snap = list_head(&pa.shared_snaps); 3077 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 3078 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 3079 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 3080 if (err != 0) 3081 goto out; 3082 3083 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) { 3084 err = dsl_dataset_hold_obj(dp, 3085 snap->ds->ds_dir->dd_phys->dd_origin_obj, 3086 FTAG, &pa.origin_origin); 3087 if (err != 0) 3088 goto out; 3089 } 3090 3091 out: 3092 rw_exit(&dp->dp_config_rwlock); 3093 3094 /* 3095 * Add in 128x the snapnames zapobj size, since we will be moving 3096 * a bunch of snapnames to the promoted ds, and dirtying their 3097 * bonus buffers. 3098 */ 3099 if (err == 0) { 3100 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 3101 dsl_dataset_promote_sync, ds, &pa, 3102 2 + 2 * doi.doi_physical_blocks_512); 3103 if (err && pa.err_ds && conflsnap) 3104 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 3105 } 3106 3107 snaplist_destroy(&pa.shared_snaps, B_TRUE); 3108 snaplist_destroy(&pa.clone_snaps, B_FALSE); 3109 snaplist_destroy(&pa.origin_snaps, B_FALSE); 3110 if (pa.origin_origin) 3111 dsl_dataset_rele(pa.origin_origin, FTAG); 3112 dsl_dataset_rele(ds, FTAG); 3113 return (err); 3114 } 3115 3116 struct cloneswaparg { 3117 dsl_dataset_t *cds; /* clone dataset */ 3118 dsl_dataset_t *ohds; /* origin's head dataset */ 3119 boolean_t force; 3120 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 3121 }; 3122 3123 /* ARGSUSED */ 3124 static int 3125 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 3126 { 3127 struct cloneswaparg *csa = arg1; 3128 3129 /* they should both be heads */ 3130 if (dsl_dataset_is_snapshot(csa->cds) || 3131 dsl_dataset_is_snapshot(csa->ohds)) 3132 return (EINVAL); 3133 3134 /* the branch point should be just before them */ 3135 if (csa->cds->ds_prev != csa->ohds->ds_prev) 3136 return (EINVAL); 3137 3138 /* cds should be the clone (unless they are unrelated) */ 3139 if (csa->cds->ds_prev != NULL && 3140 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 3141 csa->ohds->ds_object != 3142 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 3143 return (EINVAL); 3144 3145 /* the clone should be a child of the origin */ 3146 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 3147 return (EINVAL); 3148 3149 /* ohds shouldn't be modified unless 'force' */ 3150 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 3151 return (ETXTBSY); 3152 3153 /* adjust amount of any unconsumed refreservation */ 3154 csa->unused_refres_delta = 3155 (int64_t)MIN(csa->ohds->ds_reserved, 3156 csa->ohds->ds_phys->ds_unique_bytes) - 3157 (int64_t)MIN(csa->ohds->ds_reserved, 3158 csa->cds->ds_phys->ds_unique_bytes); 3159 3160 if (csa->unused_refres_delta > 0 && 3161 csa->unused_refres_delta > 3162 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 3163 return (ENOSPC); 3164 3165 if (csa->ohds->ds_quota != 0 && 3166 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 3167 return (EDQUOT); 3168 3169 return (0); 3170 } 3171 3172 /* ARGSUSED */ 3173 static void 3174 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3175 { 3176 struct cloneswaparg *csa = arg1; 3177 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 3178 3179 ASSERT(csa->cds->ds_reserved == 0); 3180 ASSERT(csa->ohds->ds_quota == 0 || 3181 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 3182 3183 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 3184 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 3185 3186 if (csa->cds->ds_objset != NULL) { 3187 dmu_objset_evict(csa->cds->ds_objset); 3188 csa->cds->ds_objset = NULL; 3189 } 3190 3191 if (csa->ohds->ds_objset != NULL) { 3192 dmu_objset_evict(csa->ohds->ds_objset); 3193 csa->ohds->ds_objset = NULL; 3194 } 3195 3196 /* 3197 * Reset origin's unique bytes, if it exists. 3198 */ 3199 if (csa->cds->ds_prev) { 3200 dsl_dataset_t *origin = csa->cds->ds_prev; 3201 uint64_t comp, uncomp; 3202 3203 dmu_buf_will_dirty(origin->ds_dbuf, tx); 3204 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3205 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 3206 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp); 3207 } 3208 3209 /* swap blkptrs */ 3210 { 3211 blkptr_t tmp; 3212 tmp = csa->ohds->ds_phys->ds_bp; 3213 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 3214 csa->cds->ds_phys->ds_bp = tmp; 3215 } 3216 3217 /* set dd_*_bytes */ 3218 { 3219 int64_t dused, dcomp, duncomp; 3220 uint64_t cdl_used, cdl_comp, cdl_uncomp; 3221 uint64_t odl_used, odl_comp, odl_uncomp; 3222 3223 ASSERT3U(csa->cds->ds_dir->dd_phys-> 3224 dd_used_breakdown[DD_USED_SNAP], ==, 0); 3225 3226 dsl_deadlist_space(&csa->cds->ds_deadlist, 3227 &cdl_used, &cdl_comp, &cdl_uncomp); 3228 dsl_deadlist_space(&csa->ohds->ds_deadlist, 3229 &odl_used, &odl_comp, &odl_uncomp); 3230 3231 dused = csa->cds->ds_phys->ds_referenced_bytes + cdl_used - 3232 (csa->ohds->ds_phys->ds_referenced_bytes + odl_used); 3233 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 3234 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 3235 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 3236 cdl_uncomp - 3237 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 3238 3239 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 3240 dused, dcomp, duncomp, tx); 3241 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 3242 -dused, -dcomp, -duncomp, tx); 3243 3244 /* 3245 * The difference in the space used by snapshots is the 3246 * difference in snapshot space due to the head's 3247 * deadlist (since that's the only thing that's 3248 * changing that affects the snapused). 3249 */ 3250 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3251 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3252 &cdl_used, &cdl_comp, &cdl_uncomp); 3253 dsl_deadlist_space_range(&csa->ohds->ds_deadlist, 3254 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3255 &odl_used, &odl_comp, &odl_uncomp); 3256 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 3257 DD_USED_HEAD, DD_USED_SNAP, tx); 3258 } 3259 3260 /* swap ds_*_bytes */ 3261 SWITCH64(csa->ohds->ds_phys->ds_referenced_bytes, 3262 csa->cds->ds_phys->ds_referenced_bytes); 3263 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 3264 csa->cds->ds_phys->ds_compressed_bytes); 3265 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 3266 csa->cds->ds_phys->ds_uncompressed_bytes); 3267 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 3268 csa->cds->ds_phys->ds_unique_bytes); 3269 3270 /* apply any parent delta for change in unconsumed refreservation */ 3271 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 3272 csa->unused_refres_delta, 0, 0, tx); 3273 3274 /* 3275 * Swap deadlists. 3276 */ 3277 dsl_deadlist_close(&csa->cds->ds_deadlist); 3278 dsl_deadlist_close(&csa->ohds->ds_deadlist); 3279 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 3280 csa->cds->ds_phys->ds_deadlist_obj); 3281 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 3282 csa->cds->ds_phys->ds_deadlist_obj); 3283 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 3284 csa->ohds->ds_phys->ds_deadlist_obj); 3285 3286 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx); 3287 3288 spa_history_log_internal_ds(csa->cds, "clone swap", tx, 3289 "parent=%s", csa->ohds->ds_dir->dd_myname); 3290 } 3291 3292 /* 3293 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 3294 * recv" into an existing fs to swizzle the file system to the new 3295 * version, and by "zfs rollback". Can also be used to swap two 3296 * independent head datasets if neither has any snapshots. 3297 */ 3298 int 3299 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 3300 boolean_t force) 3301 { 3302 struct cloneswaparg csa; 3303 int error; 3304 3305 ASSERT(clone->ds_owner); 3306 ASSERT(origin_head->ds_owner); 3307 retry: 3308 /* 3309 * Need exclusive access for the swap. If we're swapping these 3310 * datasets back after an error, we already hold the locks. 3311 */ 3312 if (!RW_WRITE_HELD(&clone->ds_rwlock)) 3313 rw_enter(&clone->ds_rwlock, RW_WRITER); 3314 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) && 3315 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 3316 rw_exit(&clone->ds_rwlock); 3317 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 3318 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 3319 rw_exit(&origin_head->ds_rwlock); 3320 goto retry; 3321 } 3322 } 3323 csa.cds = clone; 3324 csa.ohds = origin_head; 3325 csa.force = force; 3326 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3327 dsl_dataset_clone_swap_check, 3328 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3329 return (error); 3330 } 3331 3332 /* 3333 * Given a pool name and a dataset object number in that pool, 3334 * return the name of that dataset. 3335 */ 3336 int 3337 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3338 { 3339 spa_t *spa; 3340 dsl_pool_t *dp; 3341 dsl_dataset_t *ds; 3342 int error; 3343 3344 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3345 return (error); 3346 dp = spa_get_dsl(spa); 3347 rw_enter(&dp->dp_config_rwlock, RW_READER); 3348 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3349 dsl_dataset_name(ds, buf); 3350 dsl_dataset_rele(ds, FTAG); 3351 } 3352 rw_exit(&dp->dp_config_rwlock); 3353 spa_close(spa, FTAG); 3354 3355 return (error); 3356 } 3357 3358 int 3359 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3360 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3361 { 3362 int error = 0; 3363 3364 ASSERT3S(asize, >, 0); 3365 3366 /* 3367 * *ref_rsrv is the portion of asize that will come from any 3368 * unconsumed refreservation space. 3369 */ 3370 *ref_rsrv = 0; 3371 3372 mutex_enter(&ds->ds_lock); 3373 /* 3374 * Make a space adjustment for reserved bytes. 3375 */ 3376 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3377 ASSERT3U(*used, >=, 3378 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3379 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3380 *ref_rsrv = 3381 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3382 } 3383 3384 if (!check_quota || ds->ds_quota == 0) { 3385 mutex_exit(&ds->ds_lock); 3386 return (0); 3387 } 3388 /* 3389 * If they are requesting more space, and our current estimate 3390 * is over quota, they get to try again unless the actual 3391 * on-disk is over quota and there are no pending changes (which 3392 * may free up space for us). 3393 */ 3394 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) { 3395 if (inflight > 0 || 3396 ds->ds_phys->ds_referenced_bytes < ds->ds_quota) 3397 error = ERESTART; 3398 else 3399 error = EDQUOT; 3400 } 3401 mutex_exit(&ds->ds_lock); 3402 3403 return (error); 3404 } 3405 3406 /* ARGSUSED */ 3407 static int 3408 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3409 { 3410 dsl_dataset_t *ds = arg1; 3411 dsl_prop_setarg_t *psa = arg2; 3412 int err; 3413 3414 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3415 return (ENOTSUP); 3416 3417 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3418 return (err); 3419 3420 if (psa->psa_effective_value == 0) 3421 return (0); 3422 3423 if (psa->psa_effective_value < ds->ds_phys->ds_referenced_bytes || 3424 psa->psa_effective_value < ds->ds_reserved) 3425 return (ENOSPC); 3426 3427 return (0); 3428 } 3429 3430 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *); 3431 3432 void 3433 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3434 { 3435 dsl_dataset_t *ds = arg1; 3436 dsl_prop_setarg_t *psa = arg2; 3437 uint64_t effective_value = psa->psa_effective_value; 3438 3439 dsl_prop_set_sync(ds, psa, tx); 3440 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3441 3442 if (ds->ds_quota != effective_value) { 3443 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3444 ds->ds_quota = effective_value; 3445 } 3446 } 3447 3448 int 3449 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3450 { 3451 dsl_dataset_t *ds; 3452 dsl_prop_setarg_t psa; 3453 int err; 3454 3455 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3456 3457 err = dsl_dataset_hold(dsname, FTAG, &ds); 3458 if (err) 3459 return (err); 3460 3461 /* 3462 * If someone removes a file, then tries to set the quota, we 3463 * want to make sure the file freeing takes effect. 3464 */ 3465 txg_wait_open(ds->ds_dir->dd_pool, 0); 3466 3467 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3468 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3469 ds, &psa, 0); 3470 3471 dsl_dataset_rele(ds, FTAG); 3472 return (err); 3473 } 3474 3475 static int 3476 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3477 { 3478 dsl_dataset_t *ds = arg1; 3479 dsl_prop_setarg_t *psa = arg2; 3480 uint64_t effective_value; 3481 uint64_t unique; 3482 int err; 3483 3484 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3485 SPA_VERSION_REFRESERVATION) 3486 return (ENOTSUP); 3487 3488 if (dsl_dataset_is_snapshot(ds)) 3489 return (EINVAL); 3490 3491 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3492 return (err); 3493 3494 effective_value = psa->psa_effective_value; 3495 3496 /* 3497 * If we are doing the preliminary check in open context, the 3498 * space estimates may be inaccurate. 3499 */ 3500 if (!dmu_tx_is_syncing(tx)) 3501 return (0); 3502 3503 mutex_enter(&ds->ds_lock); 3504 if (!DS_UNIQUE_IS_ACCURATE(ds)) 3505 dsl_dataset_recalc_head_uniq(ds); 3506 unique = ds->ds_phys->ds_unique_bytes; 3507 mutex_exit(&ds->ds_lock); 3508 3509 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3510 uint64_t delta = MAX(unique, effective_value) - 3511 MAX(unique, ds->ds_reserved); 3512 3513 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3514 return (ENOSPC); 3515 if (ds->ds_quota > 0 && 3516 effective_value > ds->ds_quota) 3517 return (ENOSPC); 3518 } 3519 3520 return (0); 3521 } 3522 3523 static void 3524 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3525 { 3526 dsl_dataset_t *ds = arg1; 3527 dsl_prop_setarg_t *psa = arg2; 3528 uint64_t effective_value = psa->psa_effective_value; 3529 uint64_t unique; 3530 int64_t delta; 3531 3532 dsl_prop_set_sync(ds, psa, tx); 3533 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3534 3535 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3536 3537 mutex_enter(&ds->ds_dir->dd_lock); 3538 mutex_enter(&ds->ds_lock); 3539 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 3540 unique = ds->ds_phys->ds_unique_bytes; 3541 delta = MAX(0, (int64_t)(effective_value - unique)) - 3542 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3543 ds->ds_reserved = effective_value; 3544 mutex_exit(&ds->ds_lock); 3545 3546 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3547 mutex_exit(&ds->ds_dir->dd_lock); 3548 } 3549 3550 int 3551 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3552 uint64_t reservation) 3553 { 3554 dsl_dataset_t *ds; 3555 dsl_prop_setarg_t psa; 3556 int err; 3557 3558 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3559 &reservation); 3560 3561 err = dsl_dataset_hold(dsname, FTAG, &ds); 3562 if (err) 3563 return (err); 3564 3565 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3566 dsl_dataset_set_reservation_check, 3567 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3568 3569 dsl_dataset_rele(ds, FTAG); 3570 return (err); 3571 } 3572 3573 typedef struct zfs_hold_cleanup_arg { 3574 dsl_pool_t *dp; 3575 uint64_t dsobj; 3576 char htag[MAXNAMELEN]; 3577 } zfs_hold_cleanup_arg_t; 3578 3579 static void 3580 dsl_dataset_user_release_onexit(void *arg) 3581 { 3582 zfs_hold_cleanup_arg_t *ca = arg; 3583 3584 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag, 3585 B_TRUE); 3586 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t)); 3587 } 3588 3589 void 3590 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag, 3591 minor_t minor) 3592 { 3593 zfs_hold_cleanup_arg_t *ca; 3594 3595 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP); 3596 ca->dp = ds->ds_dir->dd_pool; 3597 ca->dsobj = ds->ds_object; 3598 (void) strlcpy(ca->htag, htag, sizeof (ca->htag)); 3599 VERIFY3U(0, ==, zfs_onexit_add_cb(minor, 3600 dsl_dataset_user_release_onexit, ca, NULL)); 3601 } 3602 3603 /* 3604 * If you add new checks here, you may need to add 3605 * additional checks to the "temporary" case in 3606 * snapshot_check() in dmu_objset.c. 3607 */ 3608 static int 3609 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3610 { 3611 dsl_dataset_t *ds = arg1; 3612 struct dsl_ds_holdarg *ha = arg2; 3613 const char *htag = ha->htag; 3614 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3615 int error = 0; 3616 3617 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3618 return (ENOTSUP); 3619 3620 if (!dsl_dataset_is_snapshot(ds)) 3621 return (EINVAL); 3622 3623 /* tags must be unique */ 3624 mutex_enter(&ds->ds_lock); 3625 if (ds->ds_phys->ds_userrefs_obj) { 3626 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3627 8, 1, tx); 3628 if (error == 0) 3629 error = EEXIST; 3630 else if (error == ENOENT) 3631 error = 0; 3632 } 3633 mutex_exit(&ds->ds_lock); 3634 3635 if (error == 0 && ha->temphold && 3636 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3637 error = E2BIG; 3638 3639 return (error); 3640 } 3641 3642 void 3643 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3644 { 3645 dsl_dataset_t *ds = arg1; 3646 struct dsl_ds_holdarg *ha = arg2; 3647 const char *htag = ha->htag; 3648 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3649 objset_t *mos = dp->dp_meta_objset; 3650 uint64_t now = gethrestime_sec(); 3651 uint64_t zapobj; 3652 3653 mutex_enter(&ds->ds_lock); 3654 if (ds->ds_phys->ds_userrefs_obj == 0) { 3655 /* 3656 * This is the first user hold for this dataset. Create 3657 * the userrefs zap object. 3658 */ 3659 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3660 zapobj = ds->ds_phys->ds_userrefs_obj = 3661 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3662 } else { 3663 zapobj = ds->ds_phys->ds_userrefs_obj; 3664 } 3665 ds->ds_userrefs++; 3666 mutex_exit(&ds->ds_lock); 3667 3668 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3669 3670 if (ha->temphold) { 3671 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3672 htag, &now, tx)); 3673 } 3674 3675 spa_history_log_internal_ds(ds, "hold", tx, 3676 "tag = %s temp = %d holds now = %llu", 3677 htag, (int)ha->temphold, ds->ds_userrefs); 3678 } 3679 3680 static int 3681 dsl_dataset_user_hold_one(const char *dsname, void *arg) 3682 { 3683 struct dsl_ds_holdarg *ha = arg; 3684 dsl_dataset_t *ds; 3685 int error; 3686 char *name; 3687 3688 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3689 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3690 error = dsl_dataset_hold(name, ha->dstg, &ds); 3691 strfree(name); 3692 if (error == 0) { 3693 ha->gotone = B_TRUE; 3694 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3695 dsl_dataset_user_hold_sync, ds, ha, 0); 3696 } else if (error == ENOENT && ha->recursive) { 3697 error = 0; 3698 } else { 3699 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3700 } 3701 return (error); 3702 } 3703 3704 int 3705 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag, 3706 boolean_t temphold) 3707 { 3708 struct dsl_ds_holdarg *ha; 3709 int error; 3710 3711 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3712 ha->htag = htag; 3713 ha->temphold = temphold; 3714 error = dsl_sync_task_do(ds->ds_dir->dd_pool, 3715 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync, 3716 ds, ha, 0); 3717 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3718 3719 return (error); 3720 } 3721 3722 int 3723 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3724 boolean_t recursive, boolean_t temphold, int cleanup_fd) 3725 { 3726 struct dsl_ds_holdarg *ha; 3727 dsl_sync_task_t *dst; 3728 spa_t *spa; 3729 int error; 3730 minor_t minor = 0; 3731 3732 if (cleanup_fd != -1) { 3733 /* Currently we only support cleanup-on-exit of tempholds. */ 3734 if (!temphold) 3735 return (EINVAL); 3736 error = zfs_onexit_fd_hold(cleanup_fd, &minor); 3737 if (error) 3738 return (error); 3739 } 3740 3741 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3742 3743 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3744 3745 error = spa_open(dsname, &spa, FTAG); 3746 if (error) { 3747 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3748 if (cleanup_fd != -1) 3749 zfs_onexit_fd_rele(cleanup_fd); 3750 return (error); 3751 } 3752 3753 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3754 ha->htag = htag; 3755 ha->snapname = snapname; 3756 ha->recursive = recursive; 3757 ha->temphold = temphold; 3758 3759 if (recursive) { 3760 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3761 ha, DS_FIND_CHILDREN); 3762 } else { 3763 error = dsl_dataset_user_hold_one(dsname, ha); 3764 } 3765 if (error == 0) 3766 error = dsl_sync_task_group_wait(ha->dstg); 3767 3768 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3769 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3770 dsl_dataset_t *ds = dst->dst_arg1; 3771 3772 if (dst->dst_err) { 3773 dsl_dataset_name(ds, ha->failed); 3774 *strchr(ha->failed, '@') = '\0'; 3775 } else if (error == 0 && minor != 0 && temphold) { 3776 /* 3777 * If this hold is to be released upon process exit, 3778 * register that action now. 3779 */ 3780 dsl_register_onexit_hold_cleanup(ds, htag, minor); 3781 } 3782 dsl_dataset_rele(ds, ha->dstg); 3783 } 3784 3785 if (error == 0 && recursive && !ha->gotone) 3786 error = ENOENT; 3787 3788 if (error) 3789 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3790 3791 dsl_sync_task_group_destroy(ha->dstg); 3792 3793 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3794 spa_close(spa, FTAG); 3795 if (cleanup_fd != -1) 3796 zfs_onexit_fd_rele(cleanup_fd); 3797 return (error); 3798 } 3799 3800 struct dsl_ds_releasearg { 3801 dsl_dataset_t *ds; 3802 const char *htag; 3803 boolean_t own; /* do we own or just hold ds? */ 3804 }; 3805 3806 static int 3807 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3808 boolean_t *might_destroy) 3809 { 3810 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3811 uint64_t zapobj; 3812 uint64_t tmp; 3813 int error; 3814 3815 *might_destroy = B_FALSE; 3816 3817 mutex_enter(&ds->ds_lock); 3818 zapobj = ds->ds_phys->ds_userrefs_obj; 3819 if (zapobj == 0) { 3820 /* The tag can't possibly exist */ 3821 mutex_exit(&ds->ds_lock); 3822 return (ESRCH); 3823 } 3824 3825 /* Make sure the tag exists */ 3826 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3827 if (error) { 3828 mutex_exit(&ds->ds_lock); 3829 if (error == ENOENT) 3830 error = ESRCH; 3831 return (error); 3832 } 3833 3834 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3835 DS_IS_DEFER_DESTROY(ds)) 3836 *might_destroy = B_TRUE; 3837 3838 mutex_exit(&ds->ds_lock); 3839 return (0); 3840 } 3841 3842 static int 3843 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3844 { 3845 struct dsl_ds_releasearg *ra = arg1; 3846 dsl_dataset_t *ds = ra->ds; 3847 boolean_t might_destroy; 3848 int error; 3849 3850 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3851 return (ENOTSUP); 3852 3853 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3854 if (error) 3855 return (error); 3856 3857 if (might_destroy) { 3858 struct dsl_ds_destroyarg dsda = {0}; 3859 3860 if (dmu_tx_is_syncing(tx)) { 3861 /* 3862 * If we're not prepared to remove the snapshot, 3863 * we can't allow the release to happen right now. 3864 */ 3865 if (!ra->own) 3866 return (EBUSY); 3867 } 3868 dsda.ds = ds; 3869 dsda.releasing = B_TRUE; 3870 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3871 } 3872 3873 return (0); 3874 } 3875 3876 static void 3877 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx) 3878 { 3879 struct dsl_ds_releasearg *ra = arg1; 3880 dsl_dataset_t *ds = ra->ds; 3881 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3882 objset_t *mos = dp->dp_meta_objset; 3883 uint64_t zapobj; 3884 uint64_t refs; 3885 int error; 3886 3887 mutex_enter(&ds->ds_lock); 3888 ds->ds_userrefs--; 3889 refs = ds->ds_userrefs; 3890 mutex_exit(&ds->ds_lock); 3891 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3892 VERIFY(error == 0 || error == ENOENT); 3893 zapobj = ds->ds_phys->ds_userrefs_obj; 3894 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3895 3896 spa_history_log_internal_ds(ds, "release", tx, 3897 "tag = %s refs now = %lld", ra->htag, (longlong_t)refs); 3898 3899 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3900 DS_IS_DEFER_DESTROY(ds)) { 3901 struct dsl_ds_destroyarg dsda = {0}; 3902 3903 ASSERT(ra->own); 3904 dsda.ds = ds; 3905 dsda.releasing = B_TRUE; 3906 /* We already did the destroy_check */ 3907 dsl_dataset_destroy_sync(&dsda, tag, tx); 3908 } 3909 } 3910 3911 static int 3912 dsl_dataset_user_release_one(const char *dsname, void *arg) 3913 { 3914 struct dsl_ds_holdarg *ha = arg; 3915 struct dsl_ds_releasearg *ra; 3916 dsl_dataset_t *ds; 3917 int error; 3918 void *dtag = ha->dstg; 3919 char *name; 3920 boolean_t own = B_FALSE; 3921 boolean_t might_destroy; 3922 3923 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3924 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3925 error = dsl_dataset_hold(name, dtag, &ds); 3926 strfree(name); 3927 if (error == ENOENT && ha->recursive) 3928 return (0); 3929 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3930 if (error) 3931 return (error); 3932 3933 ha->gotone = B_TRUE; 3934 3935 ASSERT(dsl_dataset_is_snapshot(ds)); 3936 3937 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3938 if (error) { 3939 dsl_dataset_rele(ds, dtag); 3940 return (error); 3941 } 3942 3943 if (might_destroy) { 3944 #ifdef _KERNEL 3945 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3946 error = zfs_unmount_snap(name, NULL); 3947 strfree(name); 3948 if (error) { 3949 dsl_dataset_rele(ds, dtag); 3950 return (error); 3951 } 3952 #endif 3953 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3954 dsl_dataset_rele(ds, dtag); 3955 return (EBUSY); 3956 } else { 3957 own = B_TRUE; 3958 dsl_dataset_make_exclusive(ds, dtag); 3959 } 3960 } 3961 3962 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3963 ra->ds = ds; 3964 ra->htag = ha->htag; 3965 ra->own = own; 3966 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3967 dsl_dataset_user_release_sync, ra, dtag, 0); 3968 3969 return (0); 3970 } 3971 3972 int 3973 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3974 boolean_t recursive) 3975 { 3976 struct dsl_ds_holdarg *ha; 3977 dsl_sync_task_t *dst; 3978 spa_t *spa; 3979 int error; 3980 3981 top: 3982 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3983 3984 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3985 3986 error = spa_open(dsname, &spa, FTAG); 3987 if (error) { 3988 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3989 return (error); 3990 } 3991 3992 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3993 ha->htag = htag; 3994 ha->snapname = snapname; 3995 ha->recursive = recursive; 3996 if (recursive) { 3997 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3998 ha, DS_FIND_CHILDREN); 3999 } else { 4000 error = dsl_dataset_user_release_one(dsname, ha); 4001 } 4002 if (error == 0) 4003 error = dsl_sync_task_group_wait(ha->dstg); 4004 4005 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 4006 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 4007 struct dsl_ds_releasearg *ra = dst->dst_arg1; 4008 dsl_dataset_t *ds = ra->ds; 4009 4010 if (dst->dst_err) 4011 dsl_dataset_name(ds, ha->failed); 4012 4013 if (ra->own) 4014 dsl_dataset_disown(ds, ha->dstg); 4015 else 4016 dsl_dataset_rele(ds, ha->dstg); 4017 4018 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 4019 } 4020 4021 if (error == 0 && recursive && !ha->gotone) 4022 error = ENOENT; 4023 4024 if (error && error != EBUSY) 4025 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 4026 4027 dsl_sync_task_group_destroy(ha->dstg); 4028 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 4029 spa_close(spa, FTAG); 4030 4031 /* 4032 * We can get EBUSY if we were racing with deferred destroy and 4033 * dsl_dataset_user_release_check() hadn't done the necessary 4034 * open context setup. We can also get EBUSY if we're racing 4035 * with destroy and that thread is the ds_owner. Either way 4036 * the busy condition should be transient, and we should retry 4037 * the release operation. 4038 */ 4039 if (error == EBUSY) 4040 goto top; 4041 4042 return (error); 4043 } 4044 4045 /* 4046 * Called at spa_load time (with retry == B_FALSE) to release a stale 4047 * temporary user hold. Also called by the onexit code (with retry == B_TRUE). 4048 */ 4049 int 4050 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag, 4051 boolean_t retry) 4052 { 4053 dsl_dataset_t *ds; 4054 char *snap; 4055 char *name; 4056 int namelen; 4057 int error; 4058 4059 do { 4060 rw_enter(&dp->dp_config_rwlock, RW_READER); 4061 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 4062 rw_exit(&dp->dp_config_rwlock); 4063 if (error) 4064 return (error); 4065 namelen = dsl_dataset_namelen(ds)+1; 4066 name = kmem_alloc(namelen, KM_SLEEP); 4067 dsl_dataset_name(ds, name); 4068 dsl_dataset_rele(ds, FTAG); 4069 4070 snap = strchr(name, '@'); 4071 *snap = '\0'; 4072 ++snap; 4073 error = dsl_dataset_user_release(name, snap, htag, B_FALSE); 4074 kmem_free(name, namelen); 4075 4076 /* 4077 * The object can't have been destroyed because we have a hold, 4078 * but it might have been renamed, resulting in ENOENT. Retry 4079 * if we've been requested to do so. 4080 * 4081 * It would be nice if we could use the dsobj all the way 4082 * through and avoid ENOENT entirely. But we might need to 4083 * unmount the snapshot, and there's currently no way to lookup 4084 * a vfsp using a ZFS object id. 4085 */ 4086 } while ((error == ENOENT) && retry); 4087 4088 return (error); 4089 } 4090 4091 int 4092 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 4093 { 4094 dsl_dataset_t *ds; 4095 int err; 4096 4097 err = dsl_dataset_hold(dsname, FTAG, &ds); 4098 if (err) 4099 return (err); 4100 4101 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 4102 if (ds->ds_phys->ds_userrefs_obj != 0) { 4103 zap_attribute_t *za; 4104 zap_cursor_t zc; 4105 4106 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 4107 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 4108 ds->ds_phys->ds_userrefs_obj); 4109 zap_cursor_retrieve(&zc, za) == 0; 4110 zap_cursor_advance(&zc)) { 4111 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 4112 za->za_first_integer)); 4113 } 4114 zap_cursor_fini(&zc); 4115 kmem_free(za, sizeof (zap_attribute_t)); 4116 } 4117 dsl_dataset_rele(ds, FTAG); 4118 return (0); 4119 } 4120 4121 /* 4122 * Note, this function is used as the callback for dmu_objset_find(). We 4123 * always return 0 so that we will continue to find and process 4124 * inconsistent datasets, even if we encounter an error trying to 4125 * process one of them. 4126 */ 4127 /* ARGSUSED */ 4128 int 4129 dsl_destroy_inconsistent(const char *dsname, void *arg) 4130 { 4131 dsl_dataset_t *ds; 4132 4133 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 4134 if (DS_IS_INCONSISTENT(ds)) 4135 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 4136 else 4137 dsl_dataset_disown(ds, FTAG); 4138 } 4139 return (0); 4140 } 4141 4142 /* 4143 * Return (in *usedp) the amount of space written in new that is not 4144 * present in oldsnap. New may be a snapshot or the head. Old must be 4145 * a snapshot before new, in new's filesystem (or its origin). If not then 4146 * fail and return EINVAL. 4147 * 4148 * The written space is calculated by considering two components: First, we 4149 * ignore any freed space, and calculate the written as new's used space 4150 * minus old's used space. Next, we add in the amount of space that was freed 4151 * between the two snapshots, thus reducing new's used space relative to old's. 4152 * Specifically, this is the space that was born before old->ds_creation_txg, 4153 * and freed before new (ie. on new's deadlist or a previous deadlist). 4154 * 4155 * space freed [---------------------] 4156 * snapshots ---O-------O--------O-------O------ 4157 * oldsnap new 4158 */ 4159 int 4160 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new, 4161 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) 4162 { 4163 int err = 0; 4164 uint64_t snapobj; 4165 dsl_pool_t *dp = new->ds_dir->dd_pool; 4166 4167 *usedp = 0; 4168 *usedp += new->ds_phys->ds_referenced_bytes; 4169 *usedp -= oldsnap->ds_phys->ds_referenced_bytes; 4170 4171 *compp = 0; 4172 *compp += new->ds_phys->ds_compressed_bytes; 4173 *compp -= oldsnap->ds_phys->ds_compressed_bytes; 4174 4175 *uncompp = 0; 4176 *uncompp += new->ds_phys->ds_uncompressed_bytes; 4177 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes; 4178 4179 rw_enter(&dp->dp_config_rwlock, RW_READER); 4180 snapobj = new->ds_object; 4181 while (snapobj != oldsnap->ds_object) { 4182 dsl_dataset_t *snap; 4183 uint64_t used, comp, uncomp; 4184 4185 if (snapobj == new->ds_object) { 4186 snap = new; 4187 } else { 4188 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap); 4189 if (err != 0) 4190 break; 4191 } 4192 4193 if (snap->ds_phys->ds_prev_snap_txg == 4194 oldsnap->ds_phys->ds_creation_txg) { 4195 /* 4196 * The blocks in the deadlist can not be born after 4197 * ds_prev_snap_txg, so get the whole deadlist space, 4198 * which is more efficient (especially for old-format 4199 * deadlists). Unfortunately the deadlist code 4200 * doesn't have enough information to make this 4201 * optimization itself. 4202 */ 4203 dsl_deadlist_space(&snap->ds_deadlist, 4204 &used, &comp, &uncomp); 4205 } else { 4206 dsl_deadlist_space_range(&snap->ds_deadlist, 4207 0, oldsnap->ds_phys->ds_creation_txg, 4208 &used, &comp, &uncomp); 4209 } 4210 *usedp += used; 4211 *compp += comp; 4212 *uncompp += uncomp; 4213 4214 /* 4215 * If we get to the beginning of the chain of snapshots 4216 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap 4217 * was not a snapshot of/before new. 4218 */ 4219 snapobj = snap->ds_phys->ds_prev_snap_obj; 4220 if (snap != new) 4221 dsl_dataset_rele(snap, FTAG); 4222 if (snapobj == 0) { 4223 err = EINVAL; 4224 break; 4225 } 4226 4227 } 4228 rw_exit(&dp->dp_config_rwlock); 4229 return (err); 4230 } 4231 4232 /* 4233 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap, 4234 * lastsnap, and all snapshots in between are deleted. 4235 * 4236 * blocks that would be freed [---------------------------] 4237 * snapshots ---O-------O--------O-------O--------O 4238 * firstsnap lastsnap 4239 * 4240 * This is the set of blocks that were born after the snap before firstsnap, 4241 * (birth > firstsnap->prev_snap_txg) and died before the snap after the 4242 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist). 4243 * We calculate this by iterating over the relevant deadlists (from the snap 4244 * after lastsnap, backward to the snap after firstsnap), summing up the 4245 * space on the deadlist that was born after the snap before firstsnap. 4246 */ 4247 int 4248 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap, 4249 dsl_dataset_t *lastsnap, 4250 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) 4251 { 4252 int err = 0; 4253 uint64_t snapobj; 4254 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool; 4255 4256 ASSERT(dsl_dataset_is_snapshot(firstsnap)); 4257 ASSERT(dsl_dataset_is_snapshot(lastsnap)); 4258 4259 /* 4260 * Check that the snapshots are in the same dsl_dir, and firstsnap 4261 * is before lastsnap. 4262 */ 4263 if (firstsnap->ds_dir != lastsnap->ds_dir || 4264 firstsnap->ds_phys->ds_creation_txg > 4265 lastsnap->ds_phys->ds_creation_txg) 4266 return (EINVAL); 4267 4268 *usedp = *compp = *uncompp = 0; 4269 4270 rw_enter(&dp->dp_config_rwlock, RW_READER); 4271 snapobj = lastsnap->ds_phys->ds_next_snap_obj; 4272 while (snapobj != firstsnap->ds_object) { 4273 dsl_dataset_t *ds; 4274 uint64_t used, comp, uncomp; 4275 4276 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds); 4277 if (err != 0) 4278 break; 4279 4280 dsl_deadlist_space_range(&ds->ds_deadlist, 4281 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX, 4282 &used, &comp, &uncomp); 4283 *usedp += used; 4284 *compp += comp; 4285 *uncompp += uncomp; 4286 4287 snapobj = ds->ds_phys->ds_prev_snap_obj; 4288 ASSERT3U(snapobj, !=, 0); 4289 dsl_dataset_rele(ds, FTAG); 4290 } 4291 rw_exit(&dp->dp_config_rwlock); 4292 return (err); 4293 } 4294