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 = NULL; 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 || (winner = dmu_buf_set_user_ie(dbuf, ds, 464 &ds->ds_phys, dsl_dataset_evict)) != NULL) { 465 bplist_destroy(&ds->ds_pending_deadlist); 466 dsl_deadlist_close(&ds->ds_deadlist); 467 if (ds->ds_prev) 468 dsl_dataset_drop_ref(ds->ds_prev, ds); 469 dsl_dir_close(ds->ds_dir, ds); 470 mutex_destroy(&ds->ds_lock); 471 mutex_destroy(&ds->ds_recvlock); 472 mutex_destroy(&ds->ds_opening_lock); 473 rw_destroy(&ds->ds_rwlock); 474 cv_destroy(&ds->ds_exclusive_cv); 475 kmem_free(ds, sizeof (dsl_dataset_t)); 476 if (err) { 477 dmu_buf_rele(dbuf, tag); 478 return (err); 479 } 480 ds = winner; 481 } else { 482 ds->ds_fsid_guid = 483 unique_insert(ds->ds_phys->ds_fsid_guid); 484 } 485 } 486 ASSERT3P(ds->ds_dbuf, ==, dbuf); 487 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 488 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 489 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 490 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 491 mutex_enter(&ds->ds_lock); 492 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 493 mutex_exit(&ds->ds_lock); 494 dmu_buf_rele(ds->ds_dbuf, tag); 495 return (ENOENT); 496 } 497 mutex_exit(&ds->ds_lock); 498 *dsp = ds; 499 return (0); 500 } 501 502 static int 503 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 504 { 505 dsl_pool_t *dp = ds->ds_dir->dd_pool; 506 507 /* 508 * In syncing context we don't want the rwlock lock: there 509 * may be an existing writer waiting for sync phase to 510 * finish. We don't need to worry about such writers, since 511 * sync phase is single-threaded, so the writer can't be 512 * doing anything while we are active. 513 */ 514 if (dsl_pool_sync_context(dp)) { 515 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 516 return (0); 517 } 518 519 /* 520 * Normal users will hold the ds_rwlock as a READER until they 521 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 522 * drop their READER lock after they set the ds_owner field. 523 * 524 * If the dataset is being destroyed, the destroy thread will 525 * obtain a WRITER lock for exclusive access after it's done its 526 * open-context work and then change the ds_owner to 527 * dsl_reaper once destruction is assured. So threads 528 * may block here temporarily, until the "destructability" of 529 * the dataset is determined. 530 */ 531 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 532 mutex_enter(&ds->ds_lock); 533 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 534 rw_exit(&dp->dp_config_rwlock); 535 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 536 if (DSL_DATASET_IS_DESTROYED(ds)) { 537 mutex_exit(&ds->ds_lock); 538 dsl_dataset_drop_ref(ds, tag); 539 rw_enter(&dp->dp_config_rwlock, RW_READER); 540 return (ENOENT); 541 } 542 /* 543 * The dp_config_rwlock lives above the ds_lock. And 544 * we need to check DSL_DATASET_IS_DESTROYED() while 545 * holding the ds_lock, so we have to drop and reacquire 546 * the ds_lock here. 547 */ 548 mutex_exit(&ds->ds_lock); 549 rw_enter(&dp->dp_config_rwlock, RW_READER); 550 mutex_enter(&ds->ds_lock); 551 } 552 mutex_exit(&ds->ds_lock); 553 return (0); 554 } 555 556 int 557 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 558 dsl_dataset_t **dsp) 559 { 560 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 561 562 if (err) 563 return (err); 564 return (dsl_dataset_hold_ref(*dsp, tag)); 565 } 566 567 int 568 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 569 void *tag, dsl_dataset_t **dsp) 570 { 571 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 572 if (err) 573 return (err); 574 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 575 dsl_dataset_rele(*dsp, tag); 576 *dsp = NULL; 577 return (EBUSY); 578 } 579 return (0); 580 } 581 582 int 583 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 584 { 585 dsl_dir_t *dd; 586 dsl_pool_t *dp; 587 const char *snapname; 588 uint64_t obj; 589 int err = 0; 590 591 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 592 if (err) 593 return (err); 594 595 dp = dd->dd_pool; 596 obj = dd->dd_phys->dd_head_dataset_obj; 597 rw_enter(&dp->dp_config_rwlock, RW_READER); 598 if (obj) 599 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 600 else 601 err = ENOENT; 602 if (err) 603 goto out; 604 605 err = dsl_dataset_hold_ref(*dsp, tag); 606 607 /* we may be looking for a snapshot */ 608 if (err == 0 && snapname != NULL) { 609 dsl_dataset_t *ds = NULL; 610 611 if (*snapname++ != '@') { 612 dsl_dataset_rele(*dsp, tag); 613 err = ENOENT; 614 goto out; 615 } 616 617 dprintf("looking for snapshot '%s'\n", snapname); 618 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 619 if (err == 0) 620 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 621 dsl_dataset_rele(*dsp, tag); 622 623 ASSERT3U((err == 0), ==, (ds != NULL)); 624 625 if (ds) { 626 mutex_enter(&ds->ds_lock); 627 if (ds->ds_snapname[0] == 0) 628 (void) strlcpy(ds->ds_snapname, snapname, 629 sizeof (ds->ds_snapname)); 630 mutex_exit(&ds->ds_lock); 631 err = dsl_dataset_hold_ref(ds, tag); 632 *dsp = err ? NULL : ds; 633 } 634 } 635 out: 636 rw_exit(&dp->dp_config_rwlock); 637 dsl_dir_close(dd, FTAG); 638 return (err); 639 } 640 641 int 642 dsl_dataset_own(const char *name, boolean_t inconsistentok, 643 void *tag, dsl_dataset_t **dsp) 644 { 645 int err = dsl_dataset_hold(name, tag, dsp); 646 if (err) 647 return (err); 648 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 649 dsl_dataset_rele(*dsp, tag); 650 return (EBUSY); 651 } 652 return (0); 653 } 654 655 void 656 dsl_dataset_name(dsl_dataset_t *ds, char *name) 657 { 658 if (ds == NULL) { 659 (void) strcpy(name, "mos"); 660 } else { 661 dsl_dir_name(ds->ds_dir, name); 662 VERIFY(0 == dsl_dataset_get_snapname(ds)); 663 if (ds->ds_snapname[0]) { 664 (void) strcat(name, "@"); 665 /* 666 * We use a "recursive" mutex so that we 667 * can call dprintf_ds() with ds_lock held. 668 */ 669 if (!MUTEX_HELD(&ds->ds_lock)) { 670 mutex_enter(&ds->ds_lock); 671 (void) strcat(name, ds->ds_snapname); 672 mutex_exit(&ds->ds_lock); 673 } else { 674 (void) strcat(name, ds->ds_snapname); 675 } 676 } 677 } 678 } 679 680 static int 681 dsl_dataset_namelen(dsl_dataset_t *ds) 682 { 683 int result; 684 685 if (ds == NULL) { 686 result = 3; /* "mos" */ 687 } else { 688 result = dsl_dir_namelen(ds->ds_dir); 689 VERIFY(0 == dsl_dataset_get_snapname(ds)); 690 if (ds->ds_snapname[0]) { 691 ++result; /* adding one for the @-sign */ 692 if (!MUTEX_HELD(&ds->ds_lock)) { 693 mutex_enter(&ds->ds_lock); 694 result += strlen(ds->ds_snapname); 695 mutex_exit(&ds->ds_lock); 696 } else { 697 result += strlen(ds->ds_snapname); 698 } 699 } 700 } 701 702 return (result); 703 } 704 705 void 706 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 707 { 708 dmu_buf_rele(ds->ds_dbuf, tag); 709 } 710 711 void 712 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 713 { 714 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 715 rw_exit(&ds->ds_rwlock); 716 } 717 dsl_dataset_drop_ref(ds, tag); 718 } 719 720 void 721 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 722 { 723 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 724 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 725 726 mutex_enter(&ds->ds_lock); 727 ds->ds_owner = NULL; 728 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 729 rw_exit(&ds->ds_rwlock); 730 cv_broadcast(&ds->ds_exclusive_cv); 731 } 732 mutex_exit(&ds->ds_lock); 733 if (ds->ds_dbuf) 734 dsl_dataset_drop_ref(ds, tag); 735 else 736 dsl_dataset_evict(NULL, ds); 737 } 738 739 boolean_t 740 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 741 { 742 boolean_t gotit = FALSE; 743 744 mutex_enter(&ds->ds_lock); 745 if (ds->ds_owner == NULL && 746 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 747 ds->ds_owner = tag; 748 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 749 rw_exit(&ds->ds_rwlock); 750 gotit = TRUE; 751 } 752 mutex_exit(&ds->ds_lock); 753 return (gotit); 754 } 755 756 void 757 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 758 { 759 ASSERT3P(owner, ==, ds->ds_owner); 760 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 761 rw_enter(&ds->ds_rwlock, RW_WRITER); 762 } 763 764 uint64_t 765 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 766 uint64_t flags, dmu_tx_t *tx) 767 { 768 dsl_pool_t *dp = dd->dd_pool; 769 dmu_buf_t *dbuf; 770 dsl_dataset_phys_t *dsphys; 771 uint64_t dsobj; 772 objset_t *mos = dp->dp_meta_objset; 773 774 if (origin == NULL) 775 origin = dp->dp_origin_snap; 776 777 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 778 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 779 ASSERT(dmu_tx_is_syncing(tx)); 780 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 781 782 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 783 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 784 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 785 dmu_buf_will_dirty(dbuf, tx); 786 dsphys = dbuf->db_data; 787 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 788 dsphys->ds_dir_obj = dd->dd_object; 789 dsphys->ds_flags = flags; 790 dsphys->ds_fsid_guid = unique_create(); 791 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 792 sizeof (dsphys->ds_guid)); 793 dsphys->ds_snapnames_zapobj = 794 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 795 DMU_OT_NONE, 0, tx); 796 dsphys->ds_creation_time = gethrestime_sec(); 797 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 798 799 if (origin == NULL) { 800 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx); 801 } else { 802 dsl_dataset_t *ohds; 803 804 dsphys->ds_prev_snap_obj = origin->ds_object; 805 dsphys->ds_prev_snap_txg = 806 origin->ds_phys->ds_creation_txg; 807 dsphys->ds_referenced_bytes = 808 origin->ds_phys->ds_referenced_bytes; 809 dsphys->ds_compressed_bytes = 810 origin->ds_phys->ds_compressed_bytes; 811 dsphys->ds_uncompressed_bytes = 812 origin->ds_phys->ds_uncompressed_bytes; 813 dsphys->ds_bp = origin->ds_phys->ds_bp; 814 dsphys->ds_flags |= origin->ds_phys->ds_flags; 815 816 dmu_buf_will_dirty(origin->ds_dbuf, tx); 817 origin->ds_phys->ds_num_children++; 818 819 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 820 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds)); 821 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist, 822 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx); 823 dsl_dataset_rele(ohds, FTAG); 824 825 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 826 if (origin->ds_phys->ds_next_clones_obj == 0) { 827 origin->ds_phys->ds_next_clones_obj = 828 zap_create(mos, 829 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 830 } 831 VERIFY(0 == zap_add_int(mos, 832 origin->ds_phys->ds_next_clones_obj, 833 dsobj, tx)); 834 } 835 836 dmu_buf_will_dirty(dd->dd_dbuf, tx); 837 dd->dd_phys->dd_origin_obj = origin->ds_object; 838 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 839 if (origin->ds_dir->dd_phys->dd_clones == 0) { 840 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); 841 origin->ds_dir->dd_phys->dd_clones = 842 zap_create(mos, 843 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 844 } 845 VERIFY3U(0, ==, zap_add_int(mos, 846 origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); 847 } 848 } 849 850 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 851 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 852 853 dmu_buf_rele(dbuf, FTAG); 854 855 dmu_buf_will_dirty(dd->dd_dbuf, tx); 856 dd->dd_phys->dd_head_dataset_obj = dsobj; 857 858 return (dsobj); 859 } 860 861 uint64_t 862 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 863 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 864 { 865 dsl_pool_t *dp = pdd->dd_pool; 866 uint64_t dsobj, ddobj; 867 dsl_dir_t *dd; 868 869 ASSERT(lastname[0] != '@'); 870 871 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 872 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 873 874 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 875 876 dsl_deleg_set_create_perms(dd, tx, cr); 877 878 dsl_dir_close(dd, FTAG); 879 880 /* 881 * If we are creating a clone, make sure we zero out any stale 882 * data from the origin snapshots zil header. 883 */ 884 if (origin != NULL) { 885 dsl_dataset_t *ds; 886 objset_t *os; 887 888 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 889 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); 890 bzero(&os->os_zil_header, sizeof (os->os_zil_header)); 891 dsl_dataset_dirty(ds, tx); 892 dsl_dataset_rele(ds, FTAG); 893 } 894 895 return (dsobj); 896 } 897 898 /* 899 * The snapshots must all be in the same pool. 900 */ 901 int 902 dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, 903 nvlist_t *errlist) 904 { 905 int err; 906 dsl_sync_task_t *dst; 907 spa_t *spa; 908 nvpair_t *pair; 909 dsl_sync_task_group_t *dstg; 910 911 pair = nvlist_next_nvpair(snaps, NULL); 912 if (pair == NULL) 913 return (0); 914 915 err = spa_open(nvpair_name(pair), &spa, FTAG); 916 if (err) 917 return (err); 918 dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 919 920 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL; 921 pair = nvlist_next_nvpair(snaps, pair)) { 922 dsl_dataset_t *ds; 923 924 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds); 925 if (err == 0) { 926 struct dsl_ds_destroyarg *dsda; 927 928 dsl_dataset_make_exclusive(ds, dstg); 929 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), 930 KM_SLEEP); 931 dsda->ds = ds; 932 dsda->defer = defer; 933 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 934 dsl_dataset_destroy_sync, dsda, dstg, 0); 935 } else if (err == ENOENT) { 936 err = 0; 937 } else { 938 fnvlist_add_int32(errlist, nvpair_name(pair), err); 939 break; 940 } 941 } 942 943 if (err == 0) 944 err = dsl_sync_task_group_wait(dstg); 945 946 for (dst = list_head(&dstg->dstg_tasks); dst; 947 dst = list_next(&dstg->dstg_tasks, dst)) { 948 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 949 dsl_dataset_t *ds = dsda->ds; 950 951 /* 952 * Return the snapshots that triggered the error. 953 */ 954 if (dst->dst_err != 0) { 955 char name[ZFS_MAXNAMELEN]; 956 dsl_dataset_name(ds, name); 957 fnvlist_add_int32(errlist, name, dst->dst_err); 958 } 959 ASSERT3P(dsda->rm_origin, ==, NULL); 960 dsl_dataset_disown(ds, dstg); 961 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 962 } 963 964 dsl_sync_task_group_destroy(dstg); 965 spa_close(spa, FTAG); 966 return (err); 967 968 } 969 970 static boolean_t 971 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 972 { 973 boolean_t might_destroy = B_FALSE; 974 975 mutex_enter(&ds->ds_lock); 976 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 977 DS_IS_DEFER_DESTROY(ds)) 978 might_destroy = B_TRUE; 979 mutex_exit(&ds->ds_lock); 980 981 return (might_destroy); 982 } 983 984 /* 985 * If we're removing a clone, and these three conditions are true: 986 * 1) the clone's origin has no other children 987 * 2) the clone's origin has no user references 988 * 3) the clone's origin has been marked for deferred destruction 989 * Then, prepare to remove the origin as part of this sync task group. 990 */ 991 static int 992 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 993 { 994 dsl_dataset_t *ds = dsda->ds; 995 dsl_dataset_t *origin = ds->ds_prev; 996 997 if (dsl_dataset_might_destroy_origin(origin)) { 998 char *name; 999 int namelen; 1000 int error; 1001 1002 namelen = dsl_dataset_namelen(origin) + 1; 1003 name = kmem_alloc(namelen, KM_SLEEP); 1004 dsl_dataset_name(origin, name); 1005 #ifdef _KERNEL 1006 error = zfs_unmount_snap(name, NULL); 1007 if (error) { 1008 kmem_free(name, namelen); 1009 return (error); 1010 } 1011 #endif 1012 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 1013 kmem_free(name, namelen); 1014 if (error) 1015 return (error); 1016 dsda->rm_origin = origin; 1017 dsl_dataset_make_exclusive(origin, tag); 1018 } 1019 1020 return (0); 1021 } 1022 1023 /* 1024 * ds must be opened as OWNER. On return (whether successful or not), 1025 * ds will be closed and caller can no longer dereference it. 1026 */ 1027 int 1028 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1029 { 1030 int err; 1031 dsl_sync_task_group_t *dstg; 1032 objset_t *os; 1033 dsl_dir_t *dd; 1034 uint64_t obj; 1035 struct dsl_ds_destroyarg dsda = { 0 }; 1036 1037 dsda.ds = ds; 1038 1039 if (dsl_dataset_is_snapshot(ds)) { 1040 /* Destroying a snapshot is simpler */ 1041 dsl_dataset_make_exclusive(ds, tag); 1042 1043 dsda.defer = defer; 1044 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1045 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1046 &dsda, tag, 0); 1047 ASSERT3P(dsda.rm_origin, ==, NULL); 1048 goto out; 1049 } else if (defer) { 1050 err = EINVAL; 1051 goto out; 1052 } 1053 1054 dd = ds->ds_dir; 1055 1056 if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds), 1057 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) { 1058 /* 1059 * Check for errors and mark this ds as inconsistent, in 1060 * case we crash while freeing the objects. 1061 */ 1062 err = dsl_sync_task_do(dd->dd_pool, 1063 dsl_dataset_destroy_begin_check, 1064 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1065 if (err) 1066 goto out; 1067 1068 err = dmu_objset_from_ds(ds, &os); 1069 if (err) 1070 goto out; 1071 1072 /* 1073 * Remove all objects while in the open context so that 1074 * there is less work to do in the syncing context. 1075 */ 1076 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1077 ds->ds_phys->ds_prev_snap_txg)) { 1078 /* 1079 * Ignore errors, if there is not enough disk space 1080 * we will deal with it in dsl_dataset_destroy_sync(). 1081 */ 1082 (void) dmu_free_object(os, obj); 1083 } 1084 if (err != ESRCH) 1085 goto out; 1086 1087 /* 1088 * Sync out all in-flight IO. 1089 */ 1090 txg_wait_synced(dd->dd_pool, 0); 1091 1092 /* 1093 * If we managed to free all the objects in open 1094 * context, the user space accounting should be zero. 1095 */ 1096 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1097 dmu_objset_userused_enabled(os)) { 1098 uint64_t count; 1099 1100 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, 1101 &count) != 0 || count == 0); 1102 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, 1103 &count) != 0 || count == 0); 1104 } 1105 } 1106 1107 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1108 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1109 rw_exit(&dd->dd_pool->dp_config_rwlock); 1110 1111 if (err) 1112 goto out; 1113 1114 /* 1115 * Blow away the dsl_dir + head dataset. 1116 */ 1117 dsl_dataset_make_exclusive(ds, tag); 1118 /* 1119 * If we're removing a clone, we might also need to remove its 1120 * origin. 1121 */ 1122 do { 1123 dsda.need_prep = B_FALSE; 1124 if (dsl_dir_is_clone(dd)) { 1125 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1126 if (err) { 1127 dsl_dir_close(dd, FTAG); 1128 goto out; 1129 } 1130 } 1131 1132 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1133 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1134 dsl_dataset_destroy_sync, &dsda, tag, 0); 1135 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1136 dsl_dir_destroy_sync, dd, FTAG, 0); 1137 err = dsl_sync_task_group_wait(dstg); 1138 dsl_sync_task_group_destroy(dstg); 1139 1140 /* 1141 * We could be racing against 'zfs release' or 'zfs destroy -d' 1142 * on the origin snap, in which case we can get EBUSY if we 1143 * needed to destroy the origin snap but were not ready to 1144 * do so. 1145 */ 1146 if (dsda.need_prep) { 1147 ASSERT(err == EBUSY); 1148 ASSERT(dsl_dir_is_clone(dd)); 1149 ASSERT(dsda.rm_origin == NULL); 1150 } 1151 } while (dsda.need_prep); 1152 1153 if (dsda.rm_origin != NULL) 1154 dsl_dataset_disown(dsda.rm_origin, tag); 1155 1156 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1157 if (err) 1158 dsl_dir_close(dd, FTAG); 1159 out: 1160 dsl_dataset_disown(ds, tag); 1161 return (err); 1162 } 1163 1164 blkptr_t * 1165 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1166 { 1167 return (&ds->ds_phys->ds_bp); 1168 } 1169 1170 void 1171 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1172 { 1173 ASSERT(dmu_tx_is_syncing(tx)); 1174 /* If it's the meta-objset, set dp_meta_rootbp */ 1175 if (ds == NULL) { 1176 tx->tx_pool->dp_meta_rootbp = *bp; 1177 } else { 1178 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1179 ds->ds_phys->ds_bp = *bp; 1180 } 1181 } 1182 1183 spa_t * 1184 dsl_dataset_get_spa(dsl_dataset_t *ds) 1185 { 1186 return (ds->ds_dir->dd_pool->dp_spa); 1187 } 1188 1189 void 1190 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1191 { 1192 dsl_pool_t *dp; 1193 1194 if (ds == NULL) /* this is the meta-objset */ 1195 return; 1196 1197 ASSERT(ds->ds_objset != NULL); 1198 1199 if (ds->ds_phys->ds_next_snap_obj != 0) 1200 panic("dirtying snapshot!"); 1201 1202 dp = ds->ds_dir->dd_pool; 1203 1204 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1205 /* up the hold count until we can be written out */ 1206 dmu_buf_add_ref(ds->ds_dbuf, ds); 1207 } 1208 } 1209 1210 boolean_t 1211 dsl_dataset_is_dirty(dsl_dataset_t *ds) 1212 { 1213 for (int t = 0; t < TXG_SIZE; t++) { 1214 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets, 1215 ds, t)) 1216 return (B_TRUE); 1217 } 1218 return (B_FALSE); 1219 } 1220 1221 /* 1222 * The unique space in the head dataset can be calculated by subtracting 1223 * the space used in the most recent snapshot, that is still being used 1224 * in this file system, from the space currently in use. To figure out 1225 * the space in the most recent snapshot still in use, we need to take 1226 * the total space used in the snapshot and subtract out the space that 1227 * has been freed up since the snapshot was taken. 1228 */ 1229 static void 1230 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1231 { 1232 uint64_t mrs_used; 1233 uint64_t dlused, dlcomp, dluncomp; 1234 1235 ASSERT(!dsl_dataset_is_snapshot(ds)); 1236 1237 if (ds->ds_phys->ds_prev_snap_obj != 0) 1238 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes; 1239 else 1240 mrs_used = 0; 1241 1242 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); 1243 1244 ASSERT3U(dlused, <=, mrs_used); 1245 ds->ds_phys->ds_unique_bytes = 1246 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused); 1247 1248 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1249 SPA_VERSION_UNIQUE_ACCURATE) 1250 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1251 } 1252 1253 struct killarg { 1254 dsl_dataset_t *ds; 1255 dmu_tx_t *tx; 1256 }; 1257 1258 /* ARGSUSED */ 1259 static int 1260 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 1261 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1262 { 1263 struct killarg *ka = arg; 1264 dmu_tx_t *tx = ka->tx; 1265 1266 if (bp == NULL) 1267 return (0); 1268 1269 if (zb->zb_level == ZB_ZIL_LEVEL) { 1270 ASSERT(zilog != NULL); 1271 /* 1272 * It's a block in the intent log. It has no 1273 * accounting, so just free it. 1274 */ 1275 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1276 } else { 1277 ASSERT(zilog == NULL); 1278 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1279 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1280 } 1281 1282 return (0); 1283 } 1284 1285 /* ARGSUSED */ 1286 static int 1287 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1288 { 1289 dsl_dataset_t *ds = arg1; 1290 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1291 uint64_t count; 1292 int err; 1293 1294 /* 1295 * Can't delete a head dataset if there are snapshots of it. 1296 * (Except if the only snapshots are from the branch we cloned 1297 * from.) 1298 */ 1299 if (ds->ds_prev != NULL && 1300 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1301 return (EBUSY); 1302 1303 /* 1304 * This is really a dsl_dir thing, but check it here so that 1305 * we'll be less likely to leave this dataset inconsistent & 1306 * nearly destroyed. 1307 */ 1308 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1309 if (err) 1310 return (err); 1311 if (count != 0) 1312 return (EEXIST); 1313 1314 return (0); 1315 } 1316 1317 /* ARGSUSED */ 1318 static void 1319 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1320 { 1321 dsl_dataset_t *ds = arg1; 1322 1323 /* Mark it as inconsistent on-disk, in case we crash */ 1324 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1325 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1326 1327 spa_history_log_internal_ds(ds, "destroy begin", tx, ""); 1328 } 1329 1330 static int 1331 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1332 dmu_tx_t *tx) 1333 { 1334 dsl_dataset_t *ds = dsda->ds; 1335 dsl_dataset_t *ds_prev = ds->ds_prev; 1336 1337 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1338 struct dsl_ds_destroyarg ndsda = {0}; 1339 1340 /* 1341 * If we're not prepared to remove the origin, don't remove 1342 * the clone either. 1343 */ 1344 if (dsda->rm_origin == NULL) { 1345 dsda->need_prep = B_TRUE; 1346 return (EBUSY); 1347 } 1348 1349 ndsda.ds = ds_prev; 1350 ndsda.is_origin_rm = B_TRUE; 1351 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1352 } 1353 1354 /* 1355 * If we're not going to remove the origin after all, 1356 * undo the open context setup. 1357 */ 1358 if (dsda->rm_origin != NULL) { 1359 dsl_dataset_disown(dsda->rm_origin, tag); 1360 dsda->rm_origin = NULL; 1361 } 1362 1363 return (0); 1364 } 1365 1366 /* 1367 * If you add new checks here, you may need to add 1368 * additional checks to the "temporary" case in 1369 * snapshot_check() in dmu_objset.c. 1370 */ 1371 /* ARGSUSED */ 1372 int 1373 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1374 { 1375 struct dsl_ds_destroyarg *dsda = arg1; 1376 dsl_dataset_t *ds = dsda->ds; 1377 1378 /* we have an owner hold, so noone else can destroy us */ 1379 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1380 1381 /* 1382 * Only allow deferred destroy on pools that support it. 1383 * NOTE: deferred destroy is only supported on snapshots. 1384 */ 1385 if (dsda->defer) { 1386 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1387 SPA_VERSION_USERREFS) 1388 return (ENOTSUP); 1389 ASSERT(dsl_dataset_is_snapshot(ds)); 1390 return (0); 1391 } 1392 1393 /* 1394 * Can't delete a head dataset if there are snapshots of it. 1395 * (Except if the only snapshots are from the branch we cloned 1396 * from.) 1397 */ 1398 if (ds->ds_prev != NULL && 1399 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1400 return (EBUSY); 1401 1402 /* 1403 * If we made changes this txg, traverse_dsl_dataset won't find 1404 * them. Try again. 1405 */ 1406 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1407 return (EAGAIN); 1408 1409 if (dsl_dataset_is_snapshot(ds)) { 1410 /* 1411 * If this snapshot has an elevated user reference count, 1412 * we can't destroy it yet. 1413 */ 1414 if (ds->ds_userrefs > 0 && !dsda->releasing) 1415 return (EBUSY); 1416 1417 mutex_enter(&ds->ds_lock); 1418 /* 1419 * Can't delete a branch point. However, if we're destroying 1420 * a clone and removing its origin due to it having a user 1421 * hold count of 0 and having been marked for deferred destroy, 1422 * it's OK for the origin to have a single clone. 1423 */ 1424 if (ds->ds_phys->ds_num_children > 1425 (dsda->is_origin_rm ? 2 : 1)) { 1426 mutex_exit(&ds->ds_lock); 1427 return (EEXIST); 1428 } 1429 mutex_exit(&ds->ds_lock); 1430 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1431 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1432 } 1433 1434 /* XXX we should do some i/o error checking... */ 1435 return (0); 1436 } 1437 1438 struct refsarg { 1439 kmutex_t lock; 1440 boolean_t gone; 1441 kcondvar_t cv; 1442 }; 1443 1444 /* ARGSUSED */ 1445 static void 1446 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1447 { 1448 struct refsarg *arg = argv; 1449 1450 mutex_enter(&arg->lock); 1451 arg->gone = TRUE; 1452 cv_signal(&arg->cv); 1453 mutex_exit(&arg->lock); 1454 } 1455 1456 static void 1457 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1458 { 1459 struct refsarg arg; 1460 1461 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1462 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1463 arg.gone = FALSE; 1464 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1465 dsl_dataset_refs_gone); 1466 dmu_buf_rele(ds->ds_dbuf, tag); 1467 mutex_enter(&arg.lock); 1468 while (!arg.gone) 1469 cv_wait(&arg.cv, &arg.lock); 1470 ASSERT(arg.gone); 1471 mutex_exit(&arg.lock); 1472 ds->ds_dbuf = NULL; 1473 ds->ds_phys = NULL; 1474 mutex_destroy(&arg.lock); 1475 cv_destroy(&arg.cv); 1476 } 1477 1478 static void 1479 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1480 { 1481 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1482 uint64_t count; 1483 int err; 1484 1485 ASSERT(ds->ds_phys->ds_num_children >= 2); 1486 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1487 /* 1488 * The err should not be ENOENT, but a bug in a previous version 1489 * of the code could cause upgrade_clones_cb() to not set 1490 * ds_next_snap_obj when it should, leading to a missing entry. 1491 * If we knew that the pool was created after 1492 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1493 * ENOENT. However, at least we can check that we don't have 1494 * too many entries in the next_clones_obj even after failing to 1495 * remove this one. 1496 */ 1497 if (err != ENOENT) { 1498 VERIFY0(err); 1499 } 1500 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1501 &count)); 1502 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1503 } 1504 1505 static void 1506 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 1507 { 1508 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1509 zap_cursor_t zc; 1510 zap_attribute_t za; 1511 1512 /* 1513 * If it is the old version, dd_clones doesn't exist so we can't 1514 * find the clones, but deadlist_remove_key() is a no-op so it 1515 * doesn't matter. 1516 */ 1517 if (ds->ds_dir->dd_phys->dd_clones == 0) 1518 return; 1519 1520 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); 1521 zap_cursor_retrieve(&zc, &za) == 0; 1522 zap_cursor_advance(&zc)) { 1523 dsl_dataset_t *clone; 1524 1525 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 1526 za.za_first_integer, FTAG, &clone)); 1527 if (clone->ds_dir->dd_origin_txg > mintxg) { 1528 dsl_deadlist_remove_key(&clone->ds_deadlist, 1529 mintxg, tx); 1530 dsl_dataset_remove_clones_key(clone, mintxg, tx); 1531 } 1532 dsl_dataset_rele(clone, FTAG); 1533 } 1534 zap_cursor_fini(&zc); 1535 } 1536 1537 struct process_old_arg { 1538 dsl_dataset_t *ds; 1539 dsl_dataset_t *ds_prev; 1540 boolean_t after_branch_point; 1541 zio_t *pio; 1542 uint64_t used, comp, uncomp; 1543 }; 1544 1545 static int 1546 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1547 { 1548 struct process_old_arg *poa = arg; 1549 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; 1550 1551 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { 1552 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); 1553 if (poa->ds_prev && !poa->after_branch_point && 1554 bp->blk_birth > 1555 poa->ds_prev->ds_phys->ds_prev_snap_txg) { 1556 poa->ds_prev->ds_phys->ds_unique_bytes += 1557 bp_get_dsize_sync(dp->dp_spa, bp); 1558 } 1559 } else { 1560 poa->used += bp_get_dsize_sync(dp->dp_spa, bp); 1561 poa->comp += BP_GET_PSIZE(bp); 1562 poa->uncomp += BP_GET_UCSIZE(bp); 1563 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); 1564 } 1565 return (0); 1566 } 1567 1568 static void 1569 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, 1570 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) 1571 { 1572 struct process_old_arg poa = { 0 }; 1573 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1574 objset_t *mos = dp->dp_meta_objset; 1575 1576 ASSERT(ds->ds_deadlist.dl_oldfmt); 1577 ASSERT(ds_next->ds_deadlist.dl_oldfmt); 1578 1579 poa.ds = ds; 1580 poa.ds_prev = ds_prev; 1581 poa.after_branch_point = after_branch_point; 1582 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1583 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, 1584 process_old_cb, &poa, tx)); 1585 VERIFY0(zio_wait(poa.pio)); 1586 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); 1587 1588 /* change snapused */ 1589 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1590 -poa.used, -poa.comp, -poa.uncomp, tx); 1591 1592 /* swap next's deadlist to our deadlist */ 1593 dsl_deadlist_close(&ds->ds_deadlist); 1594 dsl_deadlist_close(&ds_next->ds_deadlist); 1595 SWITCH64(ds_next->ds_phys->ds_deadlist_obj, 1596 ds->ds_phys->ds_deadlist_obj); 1597 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 1598 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 1599 ds_next->ds_phys->ds_deadlist_obj); 1600 } 1601 1602 static int 1603 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx) 1604 { 1605 int err; 1606 struct killarg ka; 1607 1608 /* 1609 * Free everything that we point to (that's born after 1610 * the previous snapshot, if we are a clone) 1611 * 1612 * NB: this should be very quick, because we already 1613 * freed all the objects in open context. 1614 */ 1615 ka.ds = ds; 1616 ka.tx = tx; 1617 err = traverse_dataset(ds, 1618 ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST, 1619 kill_blkptr, &ka); 1620 ASSERT0(err); 1621 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0); 1622 1623 return (err); 1624 } 1625 1626 void 1627 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx) 1628 { 1629 struct dsl_ds_destroyarg *dsda = arg1; 1630 dsl_dataset_t *ds = dsda->ds; 1631 int err; 1632 int after_branch_point = FALSE; 1633 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1634 objset_t *mos = dp->dp_meta_objset; 1635 dsl_dataset_t *ds_prev = NULL; 1636 boolean_t wont_destroy; 1637 uint64_t obj; 1638 1639 wont_destroy = (dsda->defer && 1640 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)); 1641 1642 ASSERT(ds->ds_owner || wont_destroy); 1643 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1644 ASSERT(ds->ds_prev == NULL || 1645 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1646 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1647 1648 if (wont_destroy) { 1649 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1650 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1651 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1652 spa_history_log_internal_ds(ds, "defer_destroy", tx, ""); 1653 return; 1654 } 1655 1656 /* We need to log before removing it from the namespace. */ 1657 spa_history_log_internal_ds(ds, "destroy", tx, ""); 1658 1659 /* signal any waiters that this dataset is going away */ 1660 mutex_enter(&ds->ds_lock); 1661 ds->ds_owner = dsl_reaper; 1662 cv_broadcast(&ds->ds_exclusive_cv); 1663 mutex_exit(&ds->ds_lock); 1664 1665 /* Remove our reservation */ 1666 if (ds->ds_reserved != 0) { 1667 dsl_prop_setarg_t psa; 1668 uint64_t value = 0; 1669 1670 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1671 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1672 &value); 1673 psa.psa_effective_value = 0; /* predict default value */ 1674 1675 dsl_dataset_set_reservation_sync(ds, &psa, tx); 1676 ASSERT0(ds->ds_reserved); 1677 } 1678 1679 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1680 1681 dsl_scan_ds_destroyed(ds, tx); 1682 1683 obj = ds->ds_object; 1684 1685 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1686 if (ds->ds_prev) { 1687 ds_prev = ds->ds_prev; 1688 } else { 1689 VERIFY(0 == dsl_dataset_hold_obj(dp, 1690 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1691 } 1692 after_branch_point = 1693 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1694 1695 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1696 if (after_branch_point && 1697 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1698 remove_from_next_clones(ds_prev, obj, tx); 1699 if (ds->ds_phys->ds_next_snap_obj != 0) { 1700 VERIFY(0 == zap_add_int(mos, 1701 ds_prev->ds_phys->ds_next_clones_obj, 1702 ds->ds_phys->ds_next_snap_obj, tx)); 1703 } 1704 } 1705 if (after_branch_point && 1706 ds->ds_phys->ds_next_snap_obj == 0) { 1707 /* This clone is toast. */ 1708 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1709 ds_prev->ds_phys->ds_num_children--; 1710 1711 /* 1712 * If the clone's origin has no other clones, no 1713 * user holds, and has been marked for deferred 1714 * deletion, then we should have done the necessary 1715 * destroy setup for it. 1716 */ 1717 if (ds_prev->ds_phys->ds_num_children == 1 && 1718 ds_prev->ds_userrefs == 0 && 1719 DS_IS_DEFER_DESTROY(ds_prev)) { 1720 ASSERT3P(dsda->rm_origin, !=, NULL); 1721 } else { 1722 ASSERT3P(dsda->rm_origin, ==, NULL); 1723 } 1724 } else if (!after_branch_point) { 1725 ds_prev->ds_phys->ds_next_snap_obj = 1726 ds->ds_phys->ds_next_snap_obj; 1727 } 1728 } 1729 1730 if (dsl_dataset_is_snapshot(ds)) { 1731 dsl_dataset_t *ds_next; 1732 uint64_t old_unique; 1733 uint64_t used = 0, comp = 0, uncomp = 0; 1734 1735 VERIFY(0 == dsl_dataset_hold_obj(dp, 1736 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1737 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1738 1739 old_unique = ds_next->ds_phys->ds_unique_bytes; 1740 1741 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1742 ds_next->ds_phys->ds_prev_snap_obj = 1743 ds->ds_phys->ds_prev_snap_obj; 1744 ds_next->ds_phys->ds_prev_snap_txg = 1745 ds->ds_phys->ds_prev_snap_txg; 1746 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1747 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1748 1749 1750 if (ds_next->ds_deadlist.dl_oldfmt) { 1751 process_old_deadlist(ds, ds_prev, ds_next, 1752 after_branch_point, tx); 1753 } else { 1754 /* Adjust prev's unique space. */ 1755 if (ds_prev && !after_branch_point) { 1756 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1757 ds_prev->ds_phys->ds_prev_snap_txg, 1758 ds->ds_phys->ds_prev_snap_txg, 1759 &used, &comp, &uncomp); 1760 ds_prev->ds_phys->ds_unique_bytes += used; 1761 } 1762 1763 /* Adjust snapused. */ 1764 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1765 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 1766 &used, &comp, &uncomp); 1767 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1768 -used, -comp, -uncomp, tx); 1769 1770 /* Move blocks to be freed to pool's free list. */ 1771 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 1772 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, 1773 tx); 1774 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 1775 DD_USED_HEAD, used, comp, uncomp, tx); 1776 1777 /* Merge our deadlist into next's and free it. */ 1778 dsl_deadlist_merge(&ds_next->ds_deadlist, 1779 ds->ds_phys->ds_deadlist_obj, tx); 1780 } 1781 dsl_deadlist_close(&ds->ds_deadlist); 1782 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1783 1784 /* Collapse range in clone heads */ 1785 dsl_dataset_remove_clones_key(ds, 1786 ds->ds_phys->ds_creation_txg, tx); 1787 1788 if (dsl_dataset_is_snapshot(ds_next)) { 1789 dsl_dataset_t *ds_nextnext; 1790 1791 /* 1792 * Update next's unique to include blocks which 1793 * were previously shared by only this snapshot 1794 * and it. Those blocks will be born after the 1795 * prev snap and before this snap, and will have 1796 * died after the next snap and before the one 1797 * after that (ie. be on the snap after next's 1798 * deadlist). 1799 */ 1800 VERIFY(0 == dsl_dataset_hold_obj(dp, 1801 ds_next->ds_phys->ds_next_snap_obj, 1802 FTAG, &ds_nextnext)); 1803 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 1804 ds->ds_phys->ds_prev_snap_txg, 1805 ds->ds_phys->ds_creation_txg, 1806 &used, &comp, &uncomp); 1807 ds_next->ds_phys->ds_unique_bytes += used; 1808 dsl_dataset_rele(ds_nextnext, FTAG); 1809 ASSERT3P(ds_next->ds_prev, ==, NULL); 1810 1811 /* Collapse range in this head. */ 1812 dsl_dataset_t *hds; 1813 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 1814 ds->ds_dir->dd_phys->dd_head_dataset_obj, 1815 FTAG, &hds)); 1816 dsl_deadlist_remove_key(&hds->ds_deadlist, 1817 ds->ds_phys->ds_creation_txg, tx); 1818 dsl_dataset_rele(hds, FTAG); 1819 1820 } else { 1821 ASSERT3P(ds_next->ds_prev, ==, ds); 1822 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1823 ds_next->ds_prev = NULL; 1824 if (ds_prev) { 1825 VERIFY(0 == dsl_dataset_get_ref(dp, 1826 ds->ds_phys->ds_prev_snap_obj, 1827 ds_next, &ds_next->ds_prev)); 1828 } 1829 1830 dsl_dataset_recalc_head_uniq(ds_next); 1831 1832 /* 1833 * Reduce the amount of our unconsmed refreservation 1834 * being charged to our parent by the amount of 1835 * new unique data we have gained. 1836 */ 1837 if (old_unique < ds_next->ds_reserved) { 1838 int64_t mrsdelta; 1839 uint64_t new_unique = 1840 ds_next->ds_phys->ds_unique_bytes; 1841 1842 ASSERT(old_unique <= new_unique); 1843 mrsdelta = MIN(new_unique - old_unique, 1844 ds_next->ds_reserved - old_unique); 1845 dsl_dir_diduse_space(ds->ds_dir, 1846 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1847 } 1848 } 1849 dsl_dataset_rele(ds_next, FTAG); 1850 } else { 1851 zfeature_info_t *async_destroy = 1852 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY]; 1853 objset_t *os; 1854 1855 /* 1856 * There's no next snapshot, so this is a head dataset. 1857 * Destroy the deadlist. Unless it's a clone, the 1858 * deadlist should be empty. (If it's a clone, it's 1859 * safe to ignore the deadlist contents.) 1860 */ 1861 dsl_deadlist_close(&ds->ds_deadlist); 1862 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1863 ds->ds_phys->ds_deadlist_obj = 0; 1864 1865 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); 1866 1867 if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) { 1868 err = old_synchronous_dataset_destroy(ds, tx); 1869 } else { 1870 /* 1871 * Move the bptree into the pool's list of trees to 1872 * clean up and update space accounting information. 1873 */ 1874 uint64_t used, comp, uncomp; 1875 1876 zil_destroy_sync(dmu_objset_zil(os), tx); 1877 1878 if (!spa_feature_is_active(dp->dp_spa, async_destroy)) { 1879 spa_feature_incr(dp->dp_spa, async_destroy, tx); 1880 dp->dp_bptree_obj = bptree_alloc(mos, tx); 1881 VERIFY(zap_add(mos, 1882 DMU_POOL_DIRECTORY_OBJECT, 1883 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1, 1884 &dp->dp_bptree_obj, tx) == 0); 1885 } 1886 1887 used = ds->ds_dir->dd_phys->dd_used_bytes; 1888 comp = ds->ds_dir->dd_phys->dd_compressed_bytes; 1889 uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes; 1890 1891 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1892 ds->ds_phys->ds_unique_bytes == used); 1893 1894 bptree_add(mos, dp->dp_bptree_obj, 1895 &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg, 1896 used, comp, uncomp, tx); 1897 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 1898 -used, -comp, -uncomp, tx); 1899 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 1900 used, comp, uncomp, tx); 1901 } 1902 1903 if (ds->ds_prev != NULL) { 1904 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 1905 VERIFY3U(0, ==, zap_remove_int(mos, 1906 ds->ds_prev->ds_dir->dd_phys->dd_clones, 1907 ds->ds_object, tx)); 1908 } 1909 dsl_dataset_rele(ds->ds_prev, ds); 1910 ds->ds_prev = ds_prev = NULL; 1911 } 1912 } 1913 1914 /* 1915 * This must be done after the dsl_traverse(), because it will 1916 * re-open the objset. 1917 */ 1918 if (ds->ds_objset) { 1919 dmu_objset_evict(ds->ds_objset); 1920 ds->ds_objset = NULL; 1921 } 1922 1923 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1924 /* Erase the link in the dir */ 1925 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1926 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1927 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1928 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1929 ASSERT(err == 0); 1930 } else { 1931 /* remove from snapshot namespace */ 1932 dsl_dataset_t *ds_head; 1933 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1934 VERIFY(0 == dsl_dataset_hold_obj(dp, 1935 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1936 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1937 #ifdef ZFS_DEBUG 1938 { 1939 uint64_t val; 1940 1941 err = dsl_dataset_snap_lookup(ds_head, 1942 ds->ds_snapname, &val); 1943 ASSERT0(err); 1944 ASSERT3U(val, ==, obj); 1945 } 1946 #endif 1947 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1948 ASSERT(err == 0); 1949 dsl_dataset_rele(ds_head, FTAG); 1950 } 1951 1952 if (ds_prev && ds->ds_prev != ds_prev) 1953 dsl_dataset_rele(ds_prev, FTAG); 1954 1955 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1956 1957 if (ds->ds_phys->ds_next_clones_obj != 0) { 1958 uint64_t count; 1959 ASSERT(0 == zap_count(mos, 1960 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1961 VERIFY(0 == dmu_object_free(mos, 1962 ds->ds_phys->ds_next_clones_obj, tx)); 1963 } 1964 if (ds->ds_phys->ds_props_obj != 0) 1965 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1966 if (ds->ds_phys->ds_userrefs_obj != 0) 1967 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1968 dsl_dir_close(ds->ds_dir, ds); 1969 ds->ds_dir = NULL; 1970 dsl_dataset_drain_refs(ds, tag); 1971 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1972 1973 if (dsda->rm_origin) { 1974 /* 1975 * Remove the origin of the clone we just destroyed. 1976 */ 1977 struct dsl_ds_destroyarg ndsda = {0}; 1978 1979 ndsda.ds = dsda->rm_origin; 1980 dsl_dataset_destroy_sync(&ndsda, tag, tx); 1981 } 1982 } 1983 1984 static int 1985 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1986 { 1987 uint64_t asize; 1988 1989 if (!dmu_tx_is_syncing(tx)) 1990 return (0); 1991 1992 /* 1993 * If there's an fs-only reservation, any blocks that might become 1994 * owned by the snapshot dataset must be accommodated by space 1995 * outside of the reservation. 1996 */ 1997 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds)); 1998 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 1999 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 2000 return (ENOSPC); 2001 2002 /* 2003 * Propagate any reserved space for this snapshot to other 2004 * snapshot checks in this sync group. 2005 */ 2006 if (asize > 0) 2007 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 2008 2009 return (0); 2010 } 2011 2012 int 2013 dsl_dataset_snapshot_check(dsl_dataset_t *ds, const char *snapname, 2014 dmu_tx_t *tx) 2015 { 2016 int err; 2017 uint64_t value; 2018 2019 /* 2020 * We don't allow multiple snapshots of the same txg. If there 2021 * is already one, try again. 2022 */ 2023 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 2024 return (EAGAIN); 2025 2026 /* 2027 * Check for conflicting snapshot name. 2028 */ 2029 err = dsl_dataset_snap_lookup(ds, snapname, &value); 2030 if (err == 0) 2031 return (EEXIST); 2032 if (err != ENOENT) 2033 return (err); 2034 2035 /* 2036 * Check that the dataset's name is not too long. Name consists 2037 * of the dataset's length + 1 for the @-sign + snapshot name's length 2038 */ 2039 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 2040 return (ENAMETOOLONG); 2041 2042 err = dsl_dataset_snapshot_reserve_space(ds, tx); 2043 if (err) 2044 return (err); 2045 2046 ds->ds_trysnap_txg = tx->tx_txg; 2047 return (0); 2048 } 2049 2050 void 2051 dsl_dataset_snapshot_sync(dsl_dataset_t *ds, const char *snapname, 2052 dmu_tx_t *tx) 2053 { 2054 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2055 dmu_buf_t *dbuf; 2056 dsl_dataset_phys_t *dsphys; 2057 uint64_t dsobj, crtxg; 2058 objset_t *mos = dp->dp_meta_objset; 2059 int err; 2060 2061 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 2062 2063 /* 2064 * The origin's ds_creation_txg has to be < TXG_INITIAL 2065 */ 2066 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 2067 crtxg = 1; 2068 else 2069 crtxg = tx->tx_txg; 2070 2071 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 2072 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 2073 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 2074 dmu_buf_will_dirty(dbuf, tx); 2075 dsphys = dbuf->db_data; 2076 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 2077 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 2078 dsphys->ds_fsid_guid = unique_create(); 2079 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 2080 sizeof (dsphys->ds_guid)); 2081 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 2082 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 2083 dsphys->ds_next_snap_obj = ds->ds_object; 2084 dsphys->ds_num_children = 1; 2085 dsphys->ds_creation_time = gethrestime_sec(); 2086 dsphys->ds_creation_txg = crtxg; 2087 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 2088 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes; 2089 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 2090 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 2091 dsphys->ds_flags = ds->ds_phys->ds_flags; 2092 dsphys->ds_bp = ds->ds_phys->ds_bp; 2093 dmu_buf_rele(dbuf, FTAG); 2094 2095 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 2096 if (ds->ds_prev) { 2097 uint64_t next_clones_obj = 2098 ds->ds_prev->ds_phys->ds_next_clones_obj; 2099 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 2100 ds->ds_object || 2101 ds->ds_prev->ds_phys->ds_num_children > 1); 2102 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 2103 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 2104 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 2105 ds->ds_prev->ds_phys->ds_creation_txg); 2106 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 2107 } else if (next_clones_obj != 0) { 2108 remove_from_next_clones(ds->ds_prev, 2109 dsphys->ds_next_snap_obj, tx); 2110 VERIFY3U(0, ==, zap_add_int(mos, 2111 next_clones_obj, dsobj, tx)); 2112 } 2113 } 2114 2115 /* 2116 * If we have a reference-reservation on this dataset, we will 2117 * need to increase the amount of refreservation being charged 2118 * since our unique space is going to zero. 2119 */ 2120 if (ds->ds_reserved) { 2121 int64_t delta; 2122 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 2123 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2124 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 2125 delta, 0, 0, tx); 2126 } 2127 2128 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2129 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu", 2130 ds->ds_dir->dd_myname, snapname, dsobj, 2131 ds->ds_phys->ds_prev_snap_txg); 2132 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist, 2133 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx); 2134 dsl_deadlist_close(&ds->ds_deadlist); 2135 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 2136 dsl_deadlist_add_key(&ds->ds_deadlist, 2137 ds->ds_phys->ds_prev_snap_txg, tx); 2138 2139 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 2140 ds->ds_phys->ds_prev_snap_obj = dsobj; 2141 ds->ds_phys->ds_prev_snap_txg = crtxg; 2142 ds->ds_phys->ds_unique_bytes = 0; 2143 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 2144 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 2145 2146 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 2147 snapname, 8, 1, &dsobj, tx); 2148 ASSERT(err == 0); 2149 2150 if (ds->ds_prev) 2151 dsl_dataset_drop_ref(ds->ds_prev, ds); 2152 VERIFY(0 == dsl_dataset_get_ref(dp, 2153 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 2154 2155 dsl_scan_ds_snapshotted(ds, tx); 2156 2157 dsl_dir_snap_cmtime_update(ds->ds_dir); 2158 2159 spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, ""); 2160 } 2161 2162 void 2163 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 2164 { 2165 ASSERT(dmu_tx_is_syncing(tx)); 2166 ASSERT(ds->ds_objset != NULL); 2167 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 2168 2169 /* 2170 * in case we had to change ds_fsid_guid when we opened it, 2171 * sync it out now. 2172 */ 2173 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2174 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2175 2176 dmu_objset_sync(ds->ds_objset, zio, tx); 2177 } 2178 2179 static void 2180 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv) 2181 { 2182 uint64_t count = 0; 2183 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 2184 zap_cursor_t zc; 2185 zap_attribute_t za; 2186 nvlist_t *propval; 2187 nvlist_t *val; 2188 2189 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2190 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0); 2191 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0); 2192 2193 /* 2194 * There may me missing entries in ds_next_clones_obj 2195 * due to a bug in a previous version of the code. 2196 * Only trust it if it has the right number of entries. 2197 */ 2198 if (ds->ds_phys->ds_next_clones_obj != 0) { 2199 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 2200 &count)); 2201 } 2202 if (count != ds->ds_phys->ds_num_children - 1) { 2203 goto fail; 2204 } 2205 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj); 2206 zap_cursor_retrieve(&zc, &za) == 0; 2207 zap_cursor_advance(&zc)) { 2208 dsl_dataset_t *clone; 2209 char buf[ZFS_MAXNAMELEN]; 2210 /* 2211 * Even though we hold the dp_config_rwlock, the dataset 2212 * may fail to open, returning ENOENT. If there is a 2213 * thread concurrently attempting to destroy this 2214 * dataset, it will have the ds_rwlock held for 2215 * RW_WRITER. Our call to dsl_dataset_hold_obj() -> 2216 * dsl_dataset_hold_ref() will fail its 2217 * rw_tryenter(&ds->ds_rwlock, RW_READER), drop the 2218 * dp_config_rwlock, and wait for the destroy progress 2219 * and signal ds_exclusive_cv. If the destroy was 2220 * successful, we will see that 2221 * DSL_DATASET_IS_DESTROYED(), and return ENOENT. 2222 */ 2223 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 2224 za.za_first_integer, FTAG, &clone) != 0) 2225 continue; 2226 dsl_dir_name(clone->ds_dir, buf); 2227 VERIFY(nvlist_add_boolean(val, buf) == 0); 2228 dsl_dataset_rele(clone, FTAG); 2229 } 2230 zap_cursor_fini(&zc); 2231 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0); 2232 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), 2233 propval) == 0); 2234 fail: 2235 nvlist_free(val); 2236 nvlist_free(propval); 2237 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2238 } 2239 2240 void 2241 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2242 { 2243 uint64_t refd, avail, uobjs, aobjs, ratio; 2244 2245 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2246 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2247 ds->ds_phys->ds_compressed_bytes); 2248 2249 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio); 2250 2251 if (dsl_dataset_is_snapshot(ds)) { 2252 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio); 2253 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2254 ds->ds_phys->ds_unique_bytes); 2255 get_clones_stat(ds, nv); 2256 } else { 2257 dsl_dir_stats(ds->ds_dir, nv); 2258 } 2259 2260 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2261 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2262 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2263 2264 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2265 ds->ds_phys->ds_creation_time); 2266 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2267 ds->ds_phys->ds_creation_txg); 2268 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2269 ds->ds_quota); 2270 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2271 ds->ds_reserved); 2272 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2273 ds->ds_phys->ds_guid); 2274 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2275 ds->ds_phys->ds_unique_bytes); 2276 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2277 ds->ds_object); 2278 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2279 ds->ds_userrefs); 2280 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2281 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2282 2283 if (ds->ds_phys->ds_prev_snap_obj != 0) { 2284 uint64_t written, comp, uncomp; 2285 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2286 dsl_dataset_t *prev; 2287 2288 rw_enter(&dp->dp_config_rwlock, RW_READER); 2289 int err = dsl_dataset_hold_obj(dp, 2290 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev); 2291 rw_exit(&dp->dp_config_rwlock); 2292 if (err == 0) { 2293 err = dsl_dataset_space_written(prev, ds, &written, 2294 &comp, &uncomp); 2295 dsl_dataset_rele(prev, FTAG); 2296 if (err == 0) { 2297 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN, 2298 written); 2299 } 2300 } 2301 } 2302 } 2303 2304 void 2305 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2306 { 2307 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2308 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2309 stat->dds_guid = ds->ds_phys->ds_guid; 2310 stat->dds_origin[0] = '\0'; 2311 if (dsl_dataset_is_snapshot(ds)) { 2312 stat->dds_is_snapshot = B_TRUE; 2313 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2314 } else { 2315 stat->dds_is_snapshot = B_FALSE; 2316 stat->dds_num_clones = 0; 2317 2318 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2319 if (dsl_dir_is_clone(ds->ds_dir)) { 2320 dsl_dataset_t *ods; 2321 2322 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2323 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2324 dsl_dataset_name(ods, stat->dds_origin); 2325 dsl_dataset_drop_ref(ods, FTAG); 2326 } 2327 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2328 } 2329 } 2330 2331 uint64_t 2332 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2333 { 2334 return (ds->ds_fsid_guid); 2335 } 2336 2337 void 2338 dsl_dataset_space(dsl_dataset_t *ds, 2339 uint64_t *refdbytesp, uint64_t *availbytesp, 2340 uint64_t *usedobjsp, uint64_t *availobjsp) 2341 { 2342 *refdbytesp = ds->ds_phys->ds_referenced_bytes; 2343 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2344 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2345 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2346 if (ds->ds_quota != 0) { 2347 /* 2348 * Adjust available bytes according to refquota 2349 */ 2350 if (*refdbytesp < ds->ds_quota) 2351 *availbytesp = MIN(*availbytesp, 2352 ds->ds_quota - *refdbytesp); 2353 else 2354 *availbytesp = 0; 2355 } 2356 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2357 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2358 } 2359 2360 boolean_t 2361 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2362 { 2363 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2364 2365 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2366 dsl_pool_sync_context(dp)); 2367 if (ds->ds_prev == NULL) 2368 return (B_FALSE); 2369 if (ds->ds_phys->ds_bp.blk_birth > 2370 ds->ds_prev->ds_phys->ds_creation_txg) { 2371 objset_t *os, *os_prev; 2372 /* 2373 * It may be that only the ZIL differs, because it was 2374 * reset in the head. Don't count that as being 2375 * modified. 2376 */ 2377 if (dmu_objset_from_ds(ds, &os) != 0) 2378 return (B_TRUE); 2379 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0) 2380 return (B_TRUE); 2381 return (bcmp(&os->os_phys->os_meta_dnode, 2382 &os_prev->os_phys->os_meta_dnode, 2383 sizeof (os->os_phys->os_meta_dnode)) != 0); 2384 } 2385 return (B_FALSE); 2386 } 2387 2388 /* ARGSUSED */ 2389 static int 2390 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2391 { 2392 dsl_dataset_t *ds = arg1; 2393 char *newsnapname = arg2; 2394 dsl_dir_t *dd = ds->ds_dir; 2395 dsl_dataset_t *hds; 2396 uint64_t val; 2397 int err; 2398 2399 err = dsl_dataset_hold_obj(dd->dd_pool, 2400 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2401 if (err) 2402 return (err); 2403 2404 /* new name better not be in use */ 2405 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2406 dsl_dataset_rele(hds, FTAG); 2407 2408 if (err == 0) 2409 err = EEXIST; 2410 else if (err == ENOENT) 2411 err = 0; 2412 2413 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2414 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2415 err = ENAMETOOLONG; 2416 2417 return (err); 2418 } 2419 2420 static void 2421 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2422 { 2423 dsl_dataset_t *ds = arg1; 2424 const char *newsnapname = arg2; 2425 dsl_dir_t *dd = ds->ds_dir; 2426 objset_t *mos = dd->dd_pool->dp_meta_objset; 2427 dsl_dataset_t *hds; 2428 int err; 2429 2430 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2431 2432 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2433 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2434 2435 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2436 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2437 ASSERT0(err); 2438 mutex_enter(&ds->ds_lock); 2439 (void) strcpy(ds->ds_snapname, newsnapname); 2440 mutex_exit(&ds->ds_lock); 2441 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2442 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2443 ASSERT0(err); 2444 2445 spa_history_log_internal_ds(ds, "rename", tx, 2446 "-> @%s", newsnapname); 2447 dsl_dataset_rele(hds, FTAG); 2448 } 2449 2450 struct renamesnaparg { 2451 dsl_sync_task_group_t *dstg; 2452 char failed[MAXPATHLEN]; 2453 char *oldsnap; 2454 char *newsnap; 2455 }; 2456 2457 static int 2458 dsl_snapshot_rename_one(const char *name, void *arg) 2459 { 2460 struct renamesnaparg *ra = arg; 2461 dsl_dataset_t *ds = NULL; 2462 char *snapname; 2463 int err; 2464 2465 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); 2466 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); 2467 2468 /* 2469 * For recursive snapshot renames the parent won't be changing 2470 * so we just pass name for both the to/from argument. 2471 */ 2472 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); 2473 if (err != 0) { 2474 strfree(snapname); 2475 return (err == ENOENT ? 0 : err); 2476 } 2477 2478 #ifdef _KERNEL 2479 /* 2480 * For all filesystems undergoing rename, we'll need to unmount it. 2481 */ 2482 (void) zfs_unmount_snap(snapname, NULL); 2483 #endif 2484 err = dsl_dataset_hold(snapname, ra->dstg, &ds); 2485 strfree(snapname); 2486 if (err != 0) 2487 return (err == ENOENT ? 0 : err); 2488 2489 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2490 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2491 2492 return (0); 2493 } 2494 2495 static int 2496 dsl_recursive_rename(char *oldname, const char *newname) 2497 { 2498 int err; 2499 struct renamesnaparg *ra; 2500 dsl_sync_task_t *dst; 2501 spa_t *spa; 2502 char *cp, *fsname = spa_strdup(oldname); 2503 int len = strlen(oldname) + 1; 2504 2505 /* truncate the snapshot name to get the fsname */ 2506 cp = strchr(fsname, '@'); 2507 *cp = '\0'; 2508 2509 err = spa_open(fsname, &spa, FTAG); 2510 if (err) { 2511 kmem_free(fsname, len); 2512 return (err); 2513 } 2514 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2515 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2516 2517 ra->oldsnap = strchr(oldname, '@') + 1; 2518 ra->newsnap = strchr(newname, '@') + 1; 2519 *ra->failed = '\0'; 2520 2521 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2522 DS_FIND_CHILDREN); 2523 kmem_free(fsname, len); 2524 2525 if (err == 0) { 2526 err = dsl_sync_task_group_wait(ra->dstg); 2527 } 2528 2529 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2530 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2531 dsl_dataset_t *ds = dst->dst_arg1; 2532 if (dst->dst_err) { 2533 dsl_dir_name(ds->ds_dir, ra->failed); 2534 (void) strlcat(ra->failed, "@", sizeof (ra->failed)); 2535 (void) strlcat(ra->failed, ra->newsnap, 2536 sizeof (ra->failed)); 2537 } 2538 dsl_dataset_rele(ds, ra->dstg); 2539 } 2540 2541 if (err) 2542 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); 2543 2544 dsl_sync_task_group_destroy(ra->dstg); 2545 kmem_free(ra, sizeof (struct renamesnaparg)); 2546 spa_close(spa, FTAG); 2547 return (err); 2548 } 2549 2550 static int 2551 dsl_valid_rename(const char *oldname, void *arg) 2552 { 2553 int delta = *(int *)arg; 2554 2555 if (strlen(oldname) + delta >= MAXNAMELEN) 2556 return (ENAMETOOLONG); 2557 2558 return (0); 2559 } 2560 2561 #pragma weak dmu_objset_rename = dsl_dataset_rename 2562 int 2563 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2564 { 2565 dsl_dir_t *dd; 2566 dsl_dataset_t *ds; 2567 const char *tail; 2568 int err; 2569 2570 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2571 if (err) 2572 return (err); 2573 2574 if (tail == NULL) { 2575 int delta = strlen(newname) - strlen(oldname); 2576 2577 /* if we're growing, validate child name lengths */ 2578 if (delta > 0) 2579 err = dmu_objset_find(oldname, dsl_valid_rename, 2580 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2581 2582 if (err == 0) 2583 err = dsl_dir_rename(dd, newname); 2584 dsl_dir_close(dd, FTAG); 2585 return (err); 2586 } 2587 2588 if (tail[0] != '@') { 2589 /* the name ended in a nonexistent component */ 2590 dsl_dir_close(dd, FTAG); 2591 return (ENOENT); 2592 } 2593 2594 dsl_dir_close(dd, FTAG); 2595 2596 /* new name must be snapshot in same filesystem */ 2597 tail = strchr(newname, '@'); 2598 if (tail == NULL) 2599 return (EINVAL); 2600 tail++; 2601 if (strncmp(oldname, newname, tail - newname) != 0) 2602 return (EXDEV); 2603 2604 if (recursive) { 2605 err = dsl_recursive_rename(oldname, newname); 2606 } else { 2607 err = dsl_dataset_hold(oldname, FTAG, &ds); 2608 if (err) 2609 return (err); 2610 2611 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2612 dsl_dataset_snapshot_rename_check, 2613 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2614 2615 dsl_dataset_rele(ds, FTAG); 2616 } 2617 2618 return (err); 2619 } 2620 2621 struct promotenode { 2622 list_node_t link; 2623 dsl_dataset_t *ds; 2624 }; 2625 2626 struct promotearg { 2627 list_t shared_snaps, origin_snaps, clone_snaps; 2628 dsl_dataset_t *origin_origin; 2629 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2630 char *err_ds; 2631 }; 2632 2633 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2634 static boolean_t snaplist_unstable(list_t *l); 2635 2636 static int 2637 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2638 { 2639 dsl_dataset_t *hds = arg1; 2640 struct promotearg *pa = arg2; 2641 struct promotenode *snap = list_head(&pa->shared_snaps); 2642 dsl_dataset_t *origin_ds = snap->ds; 2643 int err; 2644 uint64_t unused; 2645 2646 /* Check that it is a real clone */ 2647 if (!dsl_dir_is_clone(hds->ds_dir)) 2648 return (EINVAL); 2649 2650 /* Since this is so expensive, don't do the preliminary check */ 2651 if (!dmu_tx_is_syncing(tx)) 2652 return (0); 2653 2654 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2655 return (EXDEV); 2656 2657 /* compute origin's new unique space */ 2658 snap = list_tail(&pa->clone_snaps); 2659 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2660 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2661 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2662 &pa->unique, &unused, &unused); 2663 2664 /* 2665 * Walk the snapshots that we are moving 2666 * 2667 * Compute space to transfer. Consider the incremental changes 2668 * to used for each snapshot: 2669 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2670 * So each snapshot gave birth to: 2671 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2672 * So a sequence would look like: 2673 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2674 * Which simplifies to: 2675 * uN + kN + kN-1 + ... + k1 + k0 2676 * Note however, if we stop before we reach the ORIGIN we get: 2677 * uN + kN + kN-1 + ... + kM - uM-1 2678 */ 2679 pa->used = origin_ds->ds_phys->ds_referenced_bytes; 2680 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2681 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2682 for (snap = list_head(&pa->shared_snaps); snap; 2683 snap = list_next(&pa->shared_snaps, snap)) { 2684 uint64_t val, dlused, dlcomp, dluncomp; 2685 dsl_dataset_t *ds = snap->ds; 2686 2687 /* Check that the snapshot name does not conflict */ 2688 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2689 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2690 if (err == 0) { 2691 err = EEXIST; 2692 goto out; 2693 } 2694 if (err != ENOENT) 2695 goto out; 2696 2697 /* The very first snapshot does not have a deadlist */ 2698 if (ds->ds_phys->ds_prev_snap_obj == 0) 2699 continue; 2700 2701 dsl_deadlist_space(&ds->ds_deadlist, 2702 &dlused, &dlcomp, &dluncomp); 2703 pa->used += dlused; 2704 pa->comp += dlcomp; 2705 pa->uncomp += dluncomp; 2706 } 2707 2708 /* 2709 * If we are a clone of a clone then we never reached ORIGIN, 2710 * so we need to subtract out the clone origin's used space. 2711 */ 2712 if (pa->origin_origin) { 2713 pa->used -= pa->origin_origin->ds_phys->ds_referenced_bytes; 2714 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2715 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2716 } 2717 2718 /* Check that there is enough space here */ 2719 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2720 pa->used); 2721 if (err) 2722 return (err); 2723 2724 /* 2725 * Compute the amounts of space that will be used by snapshots 2726 * after the promotion (for both origin and clone). For each, 2727 * it is the amount of space that will be on all of their 2728 * deadlists (that was not born before their new origin). 2729 */ 2730 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2731 uint64_t space; 2732 2733 /* 2734 * Note, typically this will not be a clone of a clone, 2735 * so dd_origin_txg will be < TXG_INITIAL, so 2736 * these snaplist_space() -> dsl_deadlist_space_range() 2737 * calls will be fast because they do not have to 2738 * iterate over all bps. 2739 */ 2740 snap = list_head(&pa->origin_snaps); 2741 err = snaplist_space(&pa->shared_snaps, 2742 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap); 2743 if (err) 2744 return (err); 2745 2746 err = snaplist_space(&pa->clone_snaps, 2747 snap->ds->ds_dir->dd_origin_txg, &space); 2748 if (err) 2749 return (err); 2750 pa->cloneusedsnap += space; 2751 } 2752 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2753 err = snaplist_space(&pa->origin_snaps, 2754 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2755 if (err) 2756 return (err); 2757 } 2758 2759 return (0); 2760 out: 2761 pa->err_ds = snap->ds->ds_snapname; 2762 return (err); 2763 } 2764 2765 static void 2766 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2767 { 2768 dsl_dataset_t *hds = arg1; 2769 struct promotearg *pa = arg2; 2770 struct promotenode *snap = list_head(&pa->shared_snaps); 2771 dsl_dataset_t *origin_ds = snap->ds; 2772 dsl_dataset_t *origin_head; 2773 dsl_dir_t *dd = hds->ds_dir; 2774 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2775 dsl_dir_t *odd = NULL; 2776 uint64_t oldnext_obj; 2777 int64_t delta; 2778 2779 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2780 2781 snap = list_head(&pa->origin_snaps); 2782 origin_head = snap->ds; 2783 2784 /* 2785 * We need to explicitly open odd, since origin_ds's dd will be 2786 * changing. 2787 */ 2788 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2789 NULL, FTAG, &odd)); 2790 2791 /* change origin's next snap */ 2792 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2793 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2794 snap = list_tail(&pa->clone_snaps); 2795 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2796 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2797 2798 /* change the origin's next clone */ 2799 if (origin_ds->ds_phys->ds_next_clones_obj) { 2800 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2801 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2802 origin_ds->ds_phys->ds_next_clones_obj, 2803 oldnext_obj, tx)); 2804 } 2805 2806 /* change origin */ 2807 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2808 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2809 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2810 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg; 2811 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2812 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2813 origin_head->ds_dir->dd_origin_txg = 2814 origin_ds->ds_phys->ds_creation_txg; 2815 2816 /* change dd_clone entries */ 2817 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2818 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2819 odd->dd_phys->dd_clones, hds->ds_object, tx)); 2820 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2821 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2822 hds->ds_object, tx)); 2823 2824 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2825 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2826 origin_head->ds_object, tx)); 2827 if (dd->dd_phys->dd_clones == 0) { 2828 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset, 2829 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 2830 } 2831 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2832 dd->dd_phys->dd_clones, origin_head->ds_object, tx)); 2833 2834 } 2835 2836 /* move snapshots to this dir */ 2837 for (snap = list_head(&pa->shared_snaps); snap; 2838 snap = list_next(&pa->shared_snaps, snap)) { 2839 dsl_dataset_t *ds = snap->ds; 2840 2841 /* unregister props as dsl_dir is changing */ 2842 if (ds->ds_objset) { 2843 dmu_objset_evict(ds->ds_objset); 2844 ds->ds_objset = NULL; 2845 } 2846 /* move snap name entry */ 2847 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2848 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2849 ds->ds_snapname, tx)); 2850 VERIFY(0 == zap_add(dp->dp_meta_objset, 2851 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2852 8, 1, &ds->ds_object, tx)); 2853 2854 /* change containing dsl_dir */ 2855 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2856 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2857 ds->ds_phys->ds_dir_obj = dd->dd_object; 2858 ASSERT3P(ds->ds_dir, ==, odd); 2859 dsl_dir_close(ds->ds_dir, ds); 2860 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2861 NULL, ds, &ds->ds_dir)); 2862 2863 /* move any clone references */ 2864 if (ds->ds_phys->ds_next_clones_obj && 2865 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2866 zap_cursor_t zc; 2867 zap_attribute_t za; 2868 2869 for (zap_cursor_init(&zc, dp->dp_meta_objset, 2870 ds->ds_phys->ds_next_clones_obj); 2871 zap_cursor_retrieve(&zc, &za) == 0; 2872 zap_cursor_advance(&zc)) { 2873 dsl_dataset_t *cnds; 2874 uint64_t o; 2875 2876 if (za.za_first_integer == oldnext_obj) { 2877 /* 2878 * We've already moved the 2879 * origin's reference. 2880 */ 2881 continue; 2882 } 2883 2884 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 2885 za.za_first_integer, FTAG, &cnds)); 2886 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj; 2887 2888 VERIFY3U(zap_remove_int(dp->dp_meta_objset, 2889 odd->dd_phys->dd_clones, o, tx), ==, 0); 2890 VERIFY3U(zap_add_int(dp->dp_meta_objset, 2891 dd->dd_phys->dd_clones, o, tx), ==, 0); 2892 dsl_dataset_rele(cnds, FTAG); 2893 } 2894 zap_cursor_fini(&zc); 2895 } 2896 2897 ASSERT0(dsl_prop_numcb(ds)); 2898 } 2899 2900 /* 2901 * Change space accounting. 2902 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2903 * both be valid, or both be 0 (resulting in delta == 0). This 2904 * is true for each of {clone,origin} independently. 2905 */ 2906 2907 delta = pa->cloneusedsnap - 2908 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2909 ASSERT3S(delta, >=, 0); 2910 ASSERT3U(pa->used, >=, delta); 2911 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2912 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2913 pa->used - delta, pa->comp, pa->uncomp, tx); 2914 2915 delta = pa->originusedsnap - 2916 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2917 ASSERT3S(delta, <=, 0); 2918 ASSERT3U(pa->used, >=, -delta); 2919 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2920 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2921 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2922 2923 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2924 2925 /* log history record */ 2926 spa_history_log_internal_ds(hds, "promote", tx, ""); 2927 2928 dsl_dir_close(odd, FTAG); 2929 } 2930 2931 static char *snaplist_tag = "snaplist"; 2932 /* 2933 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2934 * (exclusive) and last_obj (inclusive). The list will be in reverse 2935 * order (last_obj will be the list_head()). If first_obj == 0, do all 2936 * snapshots back to this dataset's origin. 2937 */ 2938 static int 2939 snaplist_make(dsl_pool_t *dp, boolean_t own, 2940 uint64_t first_obj, uint64_t last_obj, list_t *l) 2941 { 2942 uint64_t obj = last_obj; 2943 2944 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2945 2946 list_create(l, sizeof (struct promotenode), 2947 offsetof(struct promotenode, link)); 2948 2949 while (obj != first_obj) { 2950 dsl_dataset_t *ds; 2951 struct promotenode *snap; 2952 int err; 2953 2954 if (own) { 2955 err = dsl_dataset_own_obj(dp, obj, 2956 0, snaplist_tag, &ds); 2957 if (err == 0) 2958 dsl_dataset_make_exclusive(ds, snaplist_tag); 2959 } else { 2960 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2961 } 2962 if (err == ENOENT) { 2963 /* lost race with snapshot destroy */ 2964 struct promotenode *last = list_tail(l); 2965 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2966 obj = last->ds->ds_phys->ds_prev_snap_obj; 2967 continue; 2968 } else if (err) { 2969 return (err); 2970 } 2971 2972 if (first_obj == 0) 2973 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2974 2975 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2976 snap->ds = ds; 2977 list_insert_tail(l, snap); 2978 obj = ds->ds_phys->ds_prev_snap_obj; 2979 } 2980 2981 return (0); 2982 } 2983 2984 static int 2985 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2986 { 2987 struct promotenode *snap; 2988 2989 *spacep = 0; 2990 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2991 uint64_t used, comp, uncomp; 2992 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2993 mintxg, UINT64_MAX, &used, &comp, &uncomp); 2994 *spacep += used; 2995 } 2996 return (0); 2997 } 2998 2999 static void 3000 snaplist_destroy(list_t *l, boolean_t own) 3001 { 3002 struct promotenode *snap; 3003 3004 if (!l || !list_link_active(&l->list_head)) 3005 return; 3006 3007 while ((snap = list_tail(l)) != NULL) { 3008 list_remove(l, snap); 3009 if (own) 3010 dsl_dataset_disown(snap->ds, snaplist_tag); 3011 else 3012 dsl_dataset_rele(snap->ds, snaplist_tag); 3013 kmem_free(snap, sizeof (struct promotenode)); 3014 } 3015 list_destroy(l); 3016 } 3017 3018 /* 3019 * Promote a clone. Nomenclature note: 3020 * "clone" or "cds": the original clone which is being promoted 3021 * "origin" or "ods": the snapshot which is originally clone's origin 3022 * "origin head" or "ohds": the dataset which is the head 3023 * (filesystem/volume) for the origin 3024 * "origin origin": the origin of the origin's filesystem (typically 3025 * NULL, indicating that the clone is not a clone of a clone). 3026 */ 3027 int 3028 dsl_dataset_promote(const char *name, char *conflsnap) 3029 { 3030 dsl_dataset_t *ds; 3031 dsl_dir_t *dd; 3032 dsl_pool_t *dp; 3033 dmu_object_info_t doi; 3034 struct promotearg pa = { 0 }; 3035 struct promotenode *snap; 3036 int err; 3037 3038 err = dsl_dataset_hold(name, FTAG, &ds); 3039 if (err) 3040 return (err); 3041 dd = ds->ds_dir; 3042 dp = dd->dd_pool; 3043 3044 err = dmu_object_info(dp->dp_meta_objset, 3045 ds->ds_phys->ds_snapnames_zapobj, &doi); 3046 if (err) { 3047 dsl_dataset_rele(ds, FTAG); 3048 return (err); 3049 } 3050 3051 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 3052 dsl_dataset_rele(ds, FTAG); 3053 return (EINVAL); 3054 } 3055 3056 /* 3057 * We are going to inherit all the snapshots taken before our 3058 * origin (i.e., our new origin will be our parent's origin). 3059 * Take ownership of them so that we can rename them into our 3060 * namespace. 3061 */ 3062 rw_enter(&dp->dp_config_rwlock, RW_READER); 3063 3064 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 3065 &pa.shared_snaps); 3066 if (err != 0) 3067 goto out; 3068 3069 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 3070 if (err != 0) 3071 goto out; 3072 3073 snap = list_head(&pa.shared_snaps); 3074 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 3075 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 3076 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 3077 if (err != 0) 3078 goto out; 3079 3080 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) { 3081 err = dsl_dataset_hold_obj(dp, 3082 snap->ds->ds_dir->dd_phys->dd_origin_obj, 3083 FTAG, &pa.origin_origin); 3084 if (err != 0) 3085 goto out; 3086 } 3087 3088 out: 3089 rw_exit(&dp->dp_config_rwlock); 3090 3091 /* 3092 * Add in 128x the snapnames zapobj size, since we will be moving 3093 * a bunch of snapnames to the promoted ds, and dirtying their 3094 * bonus buffers. 3095 */ 3096 if (err == 0) { 3097 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 3098 dsl_dataset_promote_sync, ds, &pa, 3099 2 + 2 * doi.doi_physical_blocks_512); 3100 if (err && pa.err_ds && conflsnap) 3101 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 3102 } 3103 3104 snaplist_destroy(&pa.shared_snaps, B_TRUE); 3105 snaplist_destroy(&pa.clone_snaps, B_FALSE); 3106 snaplist_destroy(&pa.origin_snaps, B_FALSE); 3107 if (pa.origin_origin) 3108 dsl_dataset_rele(pa.origin_origin, FTAG); 3109 dsl_dataset_rele(ds, FTAG); 3110 return (err); 3111 } 3112 3113 struct cloneswaparg { 3114 dsl_dataset_t *cds; /* clone dataset */ 3115 dsl_dataset_t *ohds; /* origin's head dataset */ 3116 boolean_t force; 3117 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 3118 }; 3119 3120 /* ARGSUSED */ 3121 static int 3122 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 3123 { 3124 struct cloneswaparg *csa = arg1; 3125 3126 /* they should both be heads */ 3127 if (dsl_dataset_is_snapshot(csa->cds) || 3128 dsl_dataset_is_snapshot(csa->ohds)) 3129 return (EINVAL); 3130 3131 /* the branch point should be just before them */ 3132 if (csa->cds->ds_prev != csa->ohds->ds_prev) 3133 return (EINVAL); 3134 3135 /* cds should be the clone (unless they are unrelated) */ 3136 if (csa->cds->ds_prev != NULL && 3137 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 3138 csa->ohds->ds_object != 3139 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 3140 return (EINVAL); 3141 3142 /* the clone should be a child of the origin */ 3143 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 3144 return (EINVAL); 3145 3146 /* ohds shouldn't be modified unless 'force' */ 3147 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 3148 return (ETXTBSY); 3149 3150 /* adjust amount of any unconsumed refreservation */ 3151 csa->unused_refres_delta = 3152 (int64_t)MIN(csa->ohds->ds_reserved, 3153 csa->ohds->ds_phys->ds_unique_bytes) - 3154 (int64_t)MIN(csa->ohds->ds_reserved, 3155 csa->cds->ds_phys->ds_unique_bytes); 3156 3157 if (csa->unused_refres_delta > 0 && 3158 csa->unused_refres_delta > 3159 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 3160 return (ENOSPC); 3161 3162 if (csa->ohds->ds_quota != 0 && 3163 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 3164 return (EDQUOT); 3165 3166 return (0); 3167 } 3168 3169 /* ARGSUSED */ 3170 static void 3171 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3172 { 3173 struct cloneswaparg *csa = arg1; 3174 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 3175 3176 ASSERT(csa->cds->ds_reserved == 0); 3177 ASSERT(csa->ohds->ds_quota == 0 || 3178 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 3179 3180 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 3181 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 3182 3183 if (csa->cds->ds_objset != NULL) { 3184 dmu_objset_evict(csa->cds->ds_objset); 3185 csa->cds->ds_objset = NULL; 3186 } 3187 3188 if (csa->ohds->ds_objset != NULL) { 3189 dmu_objset_evict(csa->ohds->ds_objset); 3190 csa->ohds->ds_objset = NULL; 3191 } 3192 3193 /* 3194 * Reset origin's unique bytes, if it exists. 3195 */ 3196 if (csa->cds->ds_prev) { 3197 dsl_dataset_t *origin = csa->cds->ds_prev; 3198 uint64_t comp, uncomp; 3199 3200 dmu_buf_will_dirty(origin->ds_dbuf, tx); 3201 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3202 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 3203 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp); 3204 } 3205 3206 /* swap blkptrs */ 3207 { 3208 blkptr_t tmp; 3209 tmp = csa->ohds->ds_phys->ds_bp; 3210 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 3211 csa->cds->ds_phys->ds_bp = tmp; 3212 } 3213 3214 /* set dd_*_bytes */ 3215 { 3216 int64_t dused, dcomp, duncomp; 3217 uint64_t cdl_used, cdl_comp, cdl_uncomp; 3218 uint64_t odl_used, odl_comp, odl_uncomp; 3219 3220 ASSERT3U(csa->cds->ds_dir->dd_phys-> 3221 dd_used_breakdown[DD_USED_SNAP], ==, 0); 3222 3223 dsl_deadlist_space(&csa->cds->ds_deadlist, 3224 &cdl_used, &cdl_comp, &cdl_uncomp); 3225 dsl_deadlist_space(&csa->ohds->ds_deadlist, 3226 &odl_used, &odl_comp, &odl_uncomp); 3227 3228 dused = csa->cds->ds_phys->ds_referenced_bytes + cdl_used - 3229 (csa->ohds->ds_phys->ds_referenced_bytes + odl_used); 3230 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 3231 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 3232 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 3233 cdl_uncomp - 3234 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 3235 3236 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 3237 dused, dcomp, duncomp, tx); 3238 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 3239 -dused, -dcomp, -duncomp, tx); 3240 3241 /* 3242 * The difference in the space used by snapshots is the 3243 * difference in snapshot space due to the head's 3244 * deadlist (since that's the only thing that's 3245 * changing that affects the snapused). 3246 */ 3247 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3248 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3249 &cdl_used, &cdl_comp, &cdl_uncomp); 3250 dsl_deadlist_space_range(&csa->ohds->ds_deadlist, 3251 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3252 &odl_used, &odl_comp, &odl_uncomp); 3253 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 3254 DD_USED_HEAD, DD_USED_SNAP, tx); 3255 } 3256 3257 /* swap ds_*_bytes */ 3258 SWITCH64(csa->ohds->ds_phys->ds_referenced_bytes, 3259 csa->cds->ds_phys->ds_referenced_bytes); 3260 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 3261 csa->cds->ds_phys->ds_compressed_bytes); 3262 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 3263 csa->cds->ds_phys->ds_uncompressed_bytes); 3264 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 3265 csa->cds->ds_phys->ds_unique_bytes); 3266 3267 /* apply any parent delta for change in unconsumed refreservation */ 3268 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 3269 csa->unused_refres_delta, 0, 0, tx); 3270 3271 /* 3272 * Swap deadlists. 3273 */ 3274 dsl_deadlist_close(&csa->cds->ds_deadlist); 3275 dsl_deadlist_close(&csa->ohds->ds_deadlist); 3276 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 3277 csa->cds->ds_phys->ds_deadlist_obj); 3278 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 3279 csa->cds->ds_phys->ds_deadlist_obj); 3280 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 3281 csa->ohds->ds_phys->ds_deadlist_obj); 3282 3283 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx); 3284 3285 spa_history_log_internal_ds(csa->cds, "clone swap", tx, 3286 "parent=%s", csa->ohds->ds_dir->dd_myname); 3287 } 3288 3289 /* 3290 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 3291 * recv" into an existing fs to swizzle the file system to the new 3292 * version, and by "zfs rollback". Can also be used to swap two 3293 * independent head datasets if neither has any snapshots. 3294 */ 3295 int 3296 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 3297 boolean_t force) 3298 { 3299 struct cloneswaparg csa; 3300 int error; 3301 3302 ASSERT(clone->ds_owner); 3303 ASSERT(origin_head->ds_owner); 3304 retry: 3305 /* 3306 * Need exclusive access for the swap. If we're swapping these 3307 * datasets back after an error, we already hold the locks. 3308 */ 3309 if (!RW_WRITE_HELD(&clone->ds_rwlock)) 3310 rw_enter(&clone->ds_rwlock, RW_WRITER); 3311 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) && 3312 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 3313 rw_exit(&clone->ds_rwlock); 3314 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 3315 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 3316 rw_exit(&origin_head->ds_rwlock); 3317 goto retry; 3318 } 3319 } 3320 csa.cds = clone; 3321 csa.ohds = origin_head; 3322 csa.force = force; 3323 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3324 dsl_dataset_clone_swap_check, 3325 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3326 return (error); 3327 } 3328 3329 /* 3330 * Given a pool name and a dataset object number in that pool, 3331 * return the name of that dataset. 3332 */ 3333 int 3334 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3335 { 3336 spa_t *spa; 3337 dsl_pool_t *dp; 3338 dsl_dataset_t *ds; 3339 int error; 3340 3341 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3342 return (error); 3343 dp = spa_get_dsl(spa); 3344 rw_enter(&dp->dp_config_rwlock, RW_READER); 3345 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3346 dsl_dataset_name(ds, buf); 3347 dsl_dataset_rele(ds, FTAG); 3348 } 3349 rw_exit(&dp->dp_config_rwlock); 3350 spa_close(spa, FTAG); 3351 3352 return (error); 3353 } 3354 3355 int 3356 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3357 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3358 { 3359 int error = 0; 3360 3361 ASSERT3S(asize, >, 0); 3362 3363 /* 3364 * *ref_rsrv is the portion of asize that will come from any 3365 * unconsumed refreservation space. 3366 */ 3367 *ref_rsrv = 0; 3368 3369 mutex_enter(&ds->ds_lock); 3370 /* 3371 * Make a space adjustment for reserved bytes. 3372 */ 3373 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3374 ASSERT3U(*used, >=, 3375 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3376 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3377 *ref_rsrv = 3378 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3379 } 3380 3381 if (!check_quota || ds->ds_quota == 0) { 3382 mutex_exit(&ds->ds_lock); 3383 return (0); 3384 } 3385 /* 3386 * If they are requesting more space, and our current estimate 3387 * is over quota, they get to try again unless the actual 3388 * on-disk is over quota and there are no pending changes (which 3389 * may free up space for us). 3390 */ 3391 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) { 3392 if (inflight > 0 || 3393 ds->ds_phys->ds_referenced_bytes < ds->ds_quota) 3394 error = ERESTART; 3395 else 3396 error = EDQUOT; 3397 } 3398 mutex_exit(&ds->ds_lock); 3399 3400 return (error); 3401 } 3402 3403 /* ARGSUSED */ 3404 static int 3405 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3406 { 3407 dsl_dataset_t *ds = arg1; 3408 dsl_prop_setarg_t *psa = arg2; 3409 int err; 3410 3411 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3412 return (ENOTSUP); 3413 3414 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3415 return (err); 3416 3417 if (psa->psa_effective_value == 0) 3418 return (0); 3419 3420 if (psa->psa_effective_value < ds->ds_phys->ds_referenced_bytes || 3421 psa->psa_effective_value < ds->ds_reserved) 3422 return (ENOSPC); 3423 3424 return (0); 3425 } 3426 3427 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *); 3428 3429 void 3430 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3431 { 3432 dsl_dataset_t *ds = arg1; 3433 dsl_prop_setarg_t *psa = arg2; 3434 uint64_t effective_value = psa->psa_effective_value; 3435 3436 dsl_prop_set_sync(ds, psa, tx); 3437 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3438 3439 if (ds->ds_quota != effective_value) { 3440 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3441 ds->ds_quota = effective_value; 3442 } 3443 } 3444 3445 int 3446 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3447 { 3448 dsl_dataset_t *ds; 3449 dsl_prop_setarg_t psa; 3450 int err; 3451 3452 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3453 3454 err = dsl_dataset_hold(dsname, FTAG, &ds); 3455 if (err) 3456 return (err); 3457 3458 /* 3459 * If someone removes a file, then tries to set the quota, we 3460 * want to make sure the file freeing takes effect. 3461 */ 3462 txg_wait_open(ds->ds_dir->dd_pool, 0); 3463 3464 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3465 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3466 ds, &psa, 0); 3467 3468 dsl_dataset_rele(ds, FTAG); 3469 return (err); 3470 } 3471 3472 static int 3473 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3474 { 3475 dsl_dataset_t *ds = arg1; 3476 dsl_prop_setarg_t *psa = arg2; 3477 uint64_t effective_value; 3478 uint64_t unique; 3479 int err; 3480 3481 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3482 SPA_VERSION_REFRESERVATION) 3483 return (ENOTSUP); 3484 3485 if (dsl_dataset_is_snapshot(ds)) 3486 return (EINVAL); 3487 3488 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3489 return (err); 3490 3491 effective_value = psa->psa_effective_value; 3492 3493 /* 3494 * If we are doing the preliminary check in open context, the 3495 * space estimates may be inaccurate. 3496 */ 3497 if (!dmu_tx_is_syncing(tx)) 3498 return (0); 3499 3500 mutex_enter(&ds->ds_lock); 3501 if (!DS_UNIQUE_IS_ACCURATE(ds)) 3502 dsl_dataset_recalc_head_uniq(ds); 3503 unique = ds->ds_phys->ds_unique_bytes; 3504 mutex_exit(&ds->ds_lock); 3505 3506 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3507 uint64_t delta = MAX(unique, effective_value) - 3508 MAX(unique, ds->ds_reserved); 3509 3510 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3511 return (ENOSPC); 3512 if (ds->ds_quota > 0 && 3513 effective_value > ds->ds_quota) 3514 return (ENOSPC); 3515 } 3516 3517 return (0); 3518 } 3519 3520 static void 3521 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3522 { 3523 dsl_dataset_t *ds = arg1; 3524 dsl_prop_setarg_t *psa = arg2; 3525 uint64_t effective_value = psa->psa_effective_value; 3526 uint64_t unique; 3527 int64_t delta; 3528 3529 dsl_prop_set_sync(ds, psa, tx); 3530 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3531 3532 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3533 3534 mutex_enter(&ds->ds_dir->dd_lock); 3535 mutex_enter(&ds->ds_lock); 3536 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 3537 unique = ds->ds_phys->ds_unique_bytes; 3538 delta = MAX(0, (int64_t)(effective_value - unique)) - 3539 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3540 ds->ds_reserved = effective_value; 3541 mutex_exit(&ds->ds_lock); 3542 3543 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3544 mutex_exit(&ds->ds_dir->dd_lock); 3545 } 3546 3547 int 3548 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3549 uint64_t reservation) 3550 { 3551 dsl_dataset_t *ds; 3552 dsl_prop_setarg_t psa; 3553 int err; 3554 3555 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3556 &reservation); 3557 3558 err = dsl_dataset_hold(dsname, FTAG, &ds); 3559 if (err) 3560 return (err); 3561 3562 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3563 dsl_dataset_set_reservation_check, 3564 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3565 3566 dsl_dataset_rele(ds, FTAG); 3567 return (err); 3568 } 3569 3570 typedef struct zfs_hold_cleanup_arg { 3571 dsl_pool_t *dp; 3572 uint64_t dsobj; 3573 char htag[MAXNAMELEN]; 3574 } zfs_hold_cleanup_arg_t; 3575 3576 static void 3577 dsl_dataset_user_release_onexit(void *arg) 3578 { 3579 zfs_hold_cleanup_arg_t *ca = arg; 3580 3581 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag, 3582 B_TRUE); 3583 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t)); 3584 } 3585 3586 void 3587 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag, 3588 minor_t minor) 3589 { 3590 zfs_hold_cleanup_arg_t *ca; 3591 3592 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP); 3593 ca->dp = ds->ds_dir->dd_pool; 3594 ca->dsobj = ds->ds_object; 3595 (void) strlcpy(ca->htag, htag, sizeof (ca->htag)); 3596 VERIFY3U(0, ==, zfs_onexit_add_cb(minor, 3597 dsl_dataset_user_release_onexit, ca, NULL)); 3598 } 3599 3600 /* 3601 * If you add new checks here, you may need to add 3602 * additional checks to the "temporary" case in 3603 * snapshot_check() in dmu_objset.c. 3604 */ 3605 static int 3606 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3607 { 3608 dsl_dataset_t *ds = arg1; 3609 struct dsl_ds_holdarg *ha = arg2; 3610 const char *htag = ha->htag; 3611 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3612 int error = 0; 3613 3614 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3615 return (ENOTSUP); 3616 3617 if (!dsl_dataset_is_snapshot(ds)) 3618 return (EINVAL); 3619 3620 /* tags must be unique */ 3621 mutex_enter(&ds->ds_lock); 3622 if (ds->ds_phys->ds_userrefs_obj) { 3623 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3624 8, 1, tx); 3625 if (error == 0) 3626 error = EEXIST; 3627 else if (error == ENOENT) 3628 error = 0; 3629 } 3630 mutex_exit(&ds->ds_lock); 3631 3632 if (error == 0 && ha->temphold && 3633 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3634 error = E2BIG; 3635 3636 return (error); 3637 } 3638 3639 void 3640 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3641 { 3642 dsl_dataset_t *ds = arg1; 3643 struct dsl_ds_holdarg *ha = arg2; 3644 const char *htag = ha->htag; 3645 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3646 objset_t *mos = dp->dp_meta_objset; 3647 uint64_t now = gethrestime_sec(); 3648 uint64_t zapobj; 3649 3650 mutex_enter(&ds->ds_lock); 3651 if (ds->ds_phys->ds_userrefs_obj == 0) { 3652 /* 3653 * This is the first user hold for this dataset. Create 3654 * the userrefs zap object. 3655 */ 3656 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3657 zapobj = ds->ds_phys->ds_userrefs_obj = 3658 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3659 } else { 3660 zapobj = ds->ds_phys->ds_userrefs_obj; 3661 } 3662 ds->ds_userrefs++; 3663 mutex_exit(&ds->ds_lock); 3664 3665 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3666 3667 if (ha->temphold) { 3668 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3669 htag, &now, tx)); 3670 } 3671 3672 spa_history_log_internal_ds(ds, "hold", tx, 3673 "tag = %s temp = %d holds now = %llu", 3674 htag, (int)ha->temphold, ds->ds_userrefs); 3675 } 3676 3677 static int 3678 dsl_dataset_user_hold_one(const char *dsname, void *arg) 3679 { 3680 struct dsl_ds_holdarg *ha = arg; 3681 dsl_dataset_t *ds; 3682 int error; 3683 char *name; 3684 3685 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3686 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3687 error = dsl_dataset_hold(name, ha->dstg, &ds); 3688 strfree(name); 3689 if (error == 0) { 3690 ha->gotone = B_TRUE; 3691 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3692 dsl_dataset_user_hold_sync, ds, ha, 0); 3693 } else if (error == ENOENT && ha->recursive) { 3694 error = 0; 3695 } else { 3696 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3697 } 3698 return (error); 3699 } 3700 3701 int 3702 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag, 3703 boolean_t temphold) 3704 { 3705 struct dsl_ds_holdarg *ha; 3706 int error; 3707 3708 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3709 ha->htag = htag; 3710 ha->temphold = temphold; 3711 error = dsl_sync_task_do(ds->ds_dir->dd_pool, 3712 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync, 3713 ds, ha, 0); 3714 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3715 3716 return (error); 3717 } 3718 3719 int 3720 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3721 boolean_t recursive, boolean_t temphold, int cleanup_fd) 3722 { 3723 struct dsl_ds_holdarg *ha; 3724 dsl_sync_task_t *dst; 3725 spa_t *spa; 3726 int error; 3727 minor_t minor = 0; 3728 3729 if (cleanup_fd != -1) { 3730 /* Currently we only support cleanup-on-exit of tempholds. */ 3731 if (!temphold) 3732 return (EINVAL); 3733 error = zfs_onexit_fd_hold(cleanup_fd, &minor); 3734 if (error) 3735 return (error); 3736 } 3737 3738 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3739 3740 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3741 3742 error = spa_open(dsname, &spa, FTAG); 3743 if (error) { 3744 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3745 if (cleanup_fd != -1) 3746 zfs_onexit_fd_rele(cleanup_fd); 3747 return (error); 3748 } 3749 3750 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3751 ha->htag = htag; 3752 ha->snapname = snapname; 3753 ha->recursive = recursive; 3754 ha->temphold = temphold; 3755 3756 if (recursive) { 3757 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3758 ha, DS_FIND_CHILDREN); 3759 } else { 3760 error = dsl_dataset_user_hold_one(dsname, ha); 3761 } 3762 if (error == 0) 3763 error = dsl_sync_task_group_wait(ha->dstg); 3764 3765 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3766 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3767 dsl_dataset_t *ds = dst->dst_arg1; 3768 3769 if (dst->dst_err) { 3770 dsl_dataset_name(ds, ha->failed); 3771 *strchr(ha->failed, '@') = '\0'; 3772 } else if (error == 0 && minor != 0 && temphold) { 3773 /* 3774 * If this hold is to be released upon process exit, 3775 * register that action now. 3776 */ 3777 dsl_register_onexit_hold_cleanup(ds, htag, minor); 3778 } 3779 dsl_dataset_rele(ds, ha->dstg); 3780 } 3781 3782 if (error == 0 && recursive && !ha->gotone) 3783 error = ENOENT; 3784 3785 if (error) 3786 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3787 3788 dsl_sync_task_group_destroy(ha->dstg); 3789 3790 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3791 spa_close(spa, FTAG); 3792 if (cleanup_fd != -1) 3793 zfs_onexit_fd_rele(cleanup_fd); 3794 return (error); 3795 } 3796 3797 struct dsl_ds_releasearg { 3798 dsl_dataset_t *ds; 3799 const char *htag; 3800 boolean_t own; /* do we own or just hold ds? */ 3801 }; 3802 3803 static int 3804 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3805 boolean_t *might_destroy) 3806 { 3807 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3808 uint64_t zapobj; 3809 uint64_t tmp; 3810 int error; 3811 3812 *might_destroy = B_FALSE; 3813 3814 mutex_enter(&ds->ds_lock); 3815 zapobj = ds->ds_phys->ds_userrefs_obj; 3816 if (zapobj == 0) { 3817 /* The tag can't possibly exist */ 3818 mutex_exit(&ds->ds_lock); 3819 return (ESRCH); 3820 } 3821 3822 /* Make sure the tag exists */ 3823 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3824 if (error) { 3825 mutex_exit(&ds->ds_lock); 3826 if (error == ENOENT) 3827 error = ESRCH; 3828 return (error); 3829 } 3830 3831 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3832 DS_IS_DEFER_DESTROY(ds)) 3833 *might_destroy = B_TRUE; 3834 3835 mutex_exit(&ds->ds_lock); 3836 return (0); 3837 } 3838 3839 static int 3840 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3841 { 3842 struct dsl_ds_releasearg *ra = arg1; 3843 dsl_dataset_t *ds = ra->ds; 3844 boolean_t might_destroy; 3845 int error; 3846 3847 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3848 return (ENOTSUP); 3849 3850 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3851 if (error) 3852 return (error); 3853 3854 if (might_destroy) { 3855 struct dsl_ds_destroyarg dsda = {0}; 3856 3857 if (dmu_tx_is_syncing(tx)) { 3858 /* 3859 * If we're not prepared to remove the snapshot, 3860 * we can't allow the release to happen right now. 3861 */ 3862 if (!ra->own) 3863 return (EBUSY); 3864 } 3865 dsda.ds = ds; 3866 dsda.releasing = B_TRUE; 3867 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3868 } 3869 3870 return (0); 3871 } 3872 3873 static void 3874 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx) 3875 { 3876 struct dsl_ds_releasearg *ra = arg1; 3877 dsl_dataset_t *ds = ra->ds; 3878 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3879 objset_t *mos = dp->dp_meta_objset; 3880 uint64_t zapobj; 3881 uint64_t refs; 3882 int error; 3883 3884 mutex_enter(&ds->ds_lock); 3885 ds->ds_userrefs--; 3886 refs = ds->ds_userrefs; 3887 mutex_exit(&ds->ds_lock); 3888 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3889 VERIFY(error == 0 || error == ENOENT); 3890 zapobj = ds->ds_phys->ds_userrefs_obj; 3891 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3892 3893 spa_history_log_internal_ds(ds, "release", tx, 3894 "tag = %s refs now = %lld", ra->htag, (longlong_t)refs); 3895 3896 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3897 DS_IS_DEFER_DESTROY(ds)) { 3898 struct dsl_ds_destroyarg dsda = {0}; 3899 3900 ASSERT(ra->own); 3901 dsda.ds = ds; 3902 dsda.releasing = B_TRUE; 3903 /* We already did the destroy_check */ 3904 dsl_dataset_destroy_sync(&dsda, tag, tx); 3905 } 3906 } 3907 3908 static int 3909 dsl_dataset_user_release_one(const char *dsname, void *arg) 3910 { 3911 struct dsl_ds_holdarg *ha = arg; 3912 struct dsl_ds_releasearg *ra; 3913 dsl_dataset_t *ds; 3914 int error; 3915 void *dtag = ha->dstg; 3916 char *name; 3917 boolean_t own = B_FALSE; 3918 boolean_t might_destroy; 3919 3920 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3921 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3922 error = dsl_dataset_hold(name, dtag, &ds); 3923 strfree(name); 3924 if (error == ENOENT && ha->recursive) 3925 return (0); 3926 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3927 if (error) 3928 return (error); 3929 3930 ha->gotone = B_TRUE; 3931 3932 ASSERT(dsl_dataset_is_snapshot(ds)); 3933 3934 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3935 if (error) { 3936 dsl_dataset_rele(ds, dtag); 3937 return (error); 3938 } 3939 3940 if (might_destroy) { 3941 #ifdef _KERNEL 3942 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3943 error = zfs_unmount_snap(name, NULL); 3944 strfree(name); 3945 if (error) { 3946 dsl_dataset_rele(ds, dtag); 3947 return (error); 3948 } 3949 #endif 3950 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3951 dsl_dataset_rele(ds, dtag); 3952 return (EBUSY); 3953 } else { 3954 own = B_TRUE; 3955 dsl_dataset_make_exclusive(ds, dtag); 3956 } 3957 } 3958 3959 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3960 ra->ds = ds; 3961 ra->htag = ha->htag; 3962 ra->own = own; 3963 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3964 dsl_dataset_user_release_sync, ra, dtag, 0); 3965 3966 return (0); 3967 } 3968 3969 int 3970 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3971 boolean_t recursive) 3972 { 3973 struct dsl_ds_holdarg *ha; 3974 dsl_sync_task_t *dst; 3975 spa_t *spa; 3976 int error; 3977 3978 top: 3979 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3980 3981 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3982 3983 error = spa_open(dsname, &spa, FTAG); 3984 if (error) { 3985 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3986 return (error); 3987 } 3988 3989 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3990 ha->htag = htag; 3991 ha->snapname = snapname; 3992 ha->recursive = recursive; 3993 if (recursive) { 3994 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3995 ha, DS_FIND_CHILDREN); 3996 } else { 3997 error = dsl_dataset_user_release_one(dsname, ha); 3998 } 3999 if (error == 0) 4000 error = dsl_sync_task_group_wait(ha->dstg); 4001 4002 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 4003 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 4004 struct dsl_ds_releasearg *ra = dst->dst_arg1; 4005 dsl_dataset_t *ds = ra->ds; 4006 4007 if (dst->dst_err) 4008 dsl_dataset_name(ds, ha->failed); 4009 4010 if (ra->own) 4011 dsl_dataset_disown(ds, ha->dstg); 4012 else 4013 dsl_dataset_rele(ds, ha->dstg); 4014 4015 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 4016 } 4017 4018 if (error == 0 && recursive && !ha->gotone) 4019 error = ENOENT; 4020 4021 if (error && error != EBUSY) 4022 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 4023 4024 dsl_sync_task_group_destroy(ha->dstg); 4025 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 4026 spa_close(spa, FTAG); 4027 4028 /* 4029 * We can get EBUSY if we were racing with deferred destroy and 4030 * dsl_dataset_user_release_check() hadn't done the necessary 4031 * open context setup. We can also get EBUSY if we're racing 4032 * with destroy and that thread is the ds_owner. Either way 4033 * the busy condition should be transient, and we should retry 4034 * the release operation. 4035 */ 4036 if (error == EBUSY) 4037 goto top; 4038 4039 return (error); 4040 } 4041 4042 /* 4043 * Called at spa_load time (with retry == B_FALSE) to release a stale 4044 * temporary user hold. Also called by the onexit code (with retry == B_TRUE). 4045 */ 4046 int 4047 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag, 4048 boolean_t retry) 4049 { 4050 dsl_dataset_t *ds; 4051 char *snap; 4052 char *name; 4053 int namelen; 4054 int error; 4055 4056 do { 4057 rw_enter(&dp->dp_config_rwlock, RW_READER); 4058 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 4059 rw_exit(&dp->dp_config_rwlock); 4060 if (error) 4061 return (error); 4062 namelen = dsl_dataset_namelen(ds)+1; 4063 name = kmem_alloc(namelen, KM_SLEEP); 4064 dsl_dataset_name(ds, name); 4065 dsl_dataset_rele(ds, FTAG); 4066 4067 snap = strchr(name, '@'); 4068 *snap = '\0'; 4069 ++snap; 4070 error = dsl_dataset_user_release(name, snap, htag, B_FALSE); 4071 kmem_free(name, namelen); 4072 4073 /* 4074 * The object can't have been destroyed because we have a hold, 4075 * but it might have been renamed, resulting in ENOENT. Retry 4076 * if we've been requested to do so. 4077 * 4078 * It would be nice if we could use the dsobj all the way 4079 * through and avoid ENOENT entirely. But we might need to 4080 * unmount the snapshot, and there's currently no way to lookup 4081 * a vfsp using a ZFS object id. 4082 */ 4083 } while ((error == ENOENT) && retry); 4084 4085 return (error); 4086 } 4087 4088 int 4089 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 4090 { 4091 dsl_dataset_t *ds; 4092 int err; 4093 4094 err = dsl_dataset_hold(dsname, FTAG, &ds); 4095 if (err) 4096 return (err); 4097 4098 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 4099 if (ds->ds_phys->ds_userrefs_obj != 0) { 4100 zap_attribute_t *za; 4101 zap_cursor_t zc; 4102 4103 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 4104 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 4105 ds->ds_phys->ds_userrefs_obj); 4106 zap_cursor_retrieve(&zc, za) == 0; 4107 zap_cursor_advance(&zc)) { 4108 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 4109 za->za_first_integer)); 4110 } 4111 zap_cursor_fini(&zc); 4112 kmem_free(za, sizeof (zap_attribute_t)); 4113 } 4114 dsl_dataset_rele(ds, FTAG); 4115 return (0); 4116 } 4117 4118 /* 4119 * Note, this function is used as the callback for dmu_objset_find(). We 4120 * always return 0 so that we will continue to find and process 4121 * inconsistent datasets, even if we encounter an error trying to 4122 * process one of them. 4123 */ 4124 /* ARGSUSED */ 4125 int 4126 dsl_destroy_inconsistent(const char *dsname, void *arg) 4127 { 4128 dsl_dataset_t *ds; 4129 4130 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 4131 if (DS_IS_INCONSISTENT(ds)) 4132 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 4133 else 4134 dsl_dataset_disown(ds, FTAG); 4135 } 4136 return (0); 4137 } 4138 4139 /* 4140 * Return (in *usedp) the amount of space written in new that is not 4141 * present in oldsnap. New may be a snapshot or the head. Old must be 4142 * a snapshot before new, in new's filesystem (or its origin). If not then 4143 * fail and return EINVAL. 4144 * 4145 * The written space is calculated by considering two components: First, we 4146 * ignore any freed space, and calculate the written as new's used space 4147 * minus old's used space. Next, we add in the amount of space that was freed 4148 * between the two snapshots, thus reducing new's used space relative to old's. 4149 * Specifically, this is the space that was born before old->ds_creation_txg, 4150 * and freed before new (ie. on new's deadlist or a previous deadlist). 4151 * 4152 * space freed [---------------------] 4153 * snapshots ---O-------O--------O-------O------ 4154 * oldsnap new 4155 */ 4156 int 4157 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new, 4158 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) 4159 { 4160 int err = 0; 4161 uint64_t snapobj; 4162 dsl_pool_t *dp = new->ds_dir->dd_pool; 4163 4164 *usedp = 0; 4165 *usedp += new->ds_phys->ds_referenced_bytes; 4166 *usedp -= oldsnap->ds_phys->ds_referenced_bytes; 4167 4168 *compp = 0; 4169 *compp += new->ds_phys->ds_compressed_bytes; 4170 *compp -= oldsnap->ds_phys->ds_compressed_bytes; 4171 4172 *uncompp = 0; 4173 *uncompp += new->ds_phys->ds_uncompressed_bytes; 4174 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes; 4175 4176 rw_enter(&dp->dp_config_rwlock, RW_READER); 4177 snapobj = new->ds_object; 4178 while (snapobj != oldsnap->ds_object) { 4179 dsl_dataset_t *snap; 4180 uint64_t used, comp, uncomp; 4181 4182 if (snapobj == new->ds_object) { 4183 snap = new; 4184 } else { 4185 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap); 4186 if (err != 0) 4187 break; 4188 } 4189 4190 if (snap->ds_phys->ds_prev_snap_txg == 4191 oldsnap->ds_phys->ds_creation_txg) { 4192 /* 4193 * The blocks in the deadlist can not be born after 4194 * ds_prev_snap_txg, so get the whole deadlist space, 4195 * which is more efficient (especially for old-format 4196 * deadlists). Unfortunately the deadlist code 4197 * doesn't have enough information to make this 4198 * optimization itself. 4199 */ 4200 dsl_deadlist_space(&snap->ds_deadlist, 4201 &used, &comp, &uncomp); 4202 } else { 4203 dsl_deadlist_space_range(&snap->ds_deadlist, 4204 0, oldsnap->ds_phys->ds_creation_txg, 4205 &used, &comp, &uncomp); 4206 } 4207 *usedp += used; 4208 *compp += comp; 4209 *uncompp += uncomp; 4210 4211 /* 4212 * If we get to the beginning of the chain of snapshots 4213 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap 4214 * was not a snapshot of/before new. 4215 */ 4216 snapobj = snap->ds_phys->ds_prev_snap_obj; 4217 if (snap != new) 4218 dsl_dataset_rele(snap, FTAG); 4219 if (snapobj == 0) { 4220 err = EINVAL; 4221 break; 4222 } 4223 4224 } 4225 rw_exit(&dp->dp_config_rwlock); 4226 return (err); 4227 } 4228 4229 /* 4230 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap, 4231 * lastsnap, and all snapshots in between are deleted. 4232 * 4233 * blocks that would be freed [---------------------------] 4234 * snapshots ---O-------O--------O-------O--------O 4235 * firstsnap lastsnap 4236 * 4237 * This is the set of blocks that were born after the snap before firstsnap, 4238 * (birth > firstsnap->prev_snap_txg) and died before the snap after the 4239 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist). 4240 * We calculate this by iterating over the relevant deadlists (from the snap 4241 * after lastsnap, backward to the snap after firstsnap), summing up the 4242 * space on the deadlist that was born after the snap before firstsnap. 4243 */ 4244 int 4245 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap, 4246 dsl_dataset_t *lastsnap, 4247 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) 4248 { 4249 int err = 0; 4250 uint64_t snapobj; 4251 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool; 4252 4253 ASSERT(dsl_dataset_is_snapshot(firstsnap)); 4254 ASSERT(dsl_dataset_is_snapshot(lastsnap)); 4255 4256 /* 4257 * Check that the snapshots are in the same dsl_dir, and firstsnap 4258 * is before lastsnap. 4259 */ 4260 if (firstsnap->ds_dir != lastsnap->ds_dir || 4261 firstsnap->ds_phys->ds_creation_txg > 4262 lastsnap->ds_phys->ds_creation_txg) 4263 return (EINVAL); 4264 4265 *usedp = *compp = *uncompp = 0; 4266 4267 rw_enter(&dp->dp_config_rwlock, RW_READER); 4268 snapobj = lastsnap->ds_phys->ds_next_snap_obj; 4269 while (snapobj != firstsnap->ds_object) { 4270 dsl_dataset_t *ds; 4271 uint64_t used, comp, uncomp; 4272 4273 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds); 4274 if (err != 0) 4275 break; 4276 4277 dsl_deadlist_space_range(&ds->ds_deadlist, 4278 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX, 4279 &used, &comp, &uncomp); 4280 *usedp += used; 4281 *compp += comp; 4282 *uncompp += uncomp; 4283 4284 snapobj = ds->ds_phys->ds_prev_snap_obj; 4285 ASSERT3U(snapobj, !=, 0); 4286 dsl_dataset_rele(ds, FTAG); 4287 } 4288 rw_exit(&dp->dp_config_rwlock); 4289 return (err); 4290 } 4291