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 /* 107 * Account for the meta-objset space in its placeholder 108 * dsl_dir. 109 */ 110 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */ 111 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 112 used, compressed, uncompressed, tx); 113 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 114 return; 115 } 116 dmu_buf_will_dirty(ds->ds_dbuf, tx); 117 118 mutex_enter(&ds->ds_dir->dd_lock); 119 mutex_enter(&ds->ds_lock); 120 delta = parent_delta(ds, used); 121 ds->ds_phys->ds_referenced_bytes += used; 122 ds->ds_phys->ds_compressed_bytes += compressed; 123 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 124 ds->ds_phys->ds_unique_bytes += used; 125 mutex_exit(&ds->ds_lock); 126 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 127 compressed, uncompressed, tx); 128 dsl_dir_transfer_space(ds->ds_dir, used - delta, 129 DD_USED_REFRSRV, DD_USED_HEAD, tx); 130 mutex_exit(&ds->ds_dir->dd_lock); 131 } 132 133 int 134 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, 135 boolean_t async) 136 { 137 if (BP_IS_HOLE(bp)) 138 return (0); 139 140 ASSERT(dmu_tx_is_syncing(tx)); 141 ASSERT(bp->blk_birth <= tx->tx_txg); 142 143 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 144 int compressed = BP_GET_PSIZE(bp); 145 int uncompressed = BP_GET_UCSIZE(bp); 146 147 ASSERT(used > 0); 148 if (ds == NULL) { 149 /* 150 * Account for the meta-objset space in its placeholder 151 * dataset. 152 */ 153 dsl_free(tx->tx_pool, tx->tx_txg, bp); 154 155 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 156 -used, -compressed, -uncompressed, tx); 157 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 158 return (used); 159 } 160 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 161 162 ASSERT(!dsl_dataset_is_snapshot(ds)); 163 dmu_buf_will_dirty(ds->ds_dbuf, tx); 164 165 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 166 int64_t delta; 167 168 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object); 169 dsl_free(tx->tx_pool, tx->tx_txg, bp); 170 171 mutex_enter(&ds->ds_dir->dd_lock); 172 mutex_enter(&ds->ds_lock); 173 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 174 !DS_UNIQUE_IS_ACCURATE(ds)); 175 delta = parent_delta(ds, -used); 176 ds->ds_phys->ds_unique_bytes -= used; 177 mutex_exit(&ds->ds_lock); 178 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 179 delta, -compressed, -uncompressed, tx); 180 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 181 DD_USED_REFRSRV, DD_USED_HEAD, tx); 182 mutex_exit(&ds->ds_dir->dd_lock); 183 } else { 184 dprintf_bp(bp, "putting on dead list: %s", ""); 185 if (async) { 186 /* 187 * We are here as part of zio's write done callback, 188 * which means we're a zio interrupt thread. We can't 189 * call dsl_deadlist_insert() now because it may block 190 * waiting for I/O. Instead, put bp on the deferred 191 * queue and let dsl_pool_sync() finish the job. 192 */ 193 bplist_append(&ds->ds_pending_deadlist, bp); 194 } else { 195 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx); 196 } 197 ASSERT3U(ds->ds_prev->ds_object, ==, 198 ds->ds_phys->ds_prev_snap_obj); 199 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 200 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 201 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 202 ds->ds_object && bp->blk_birth > 203 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 204 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 205 mutex_enter(&ds->ds_prev->ds_lock); 206 ds->ds_prev->ds_phys->ds_unique_bytes += used; 207 mutex_exit(&ds->ds_prev->ds_lock); 208 } 209 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) { 210 dsl_dir_transfer_space(ds->ds_dir, used, 211 DD_USED_HEAD, DD_USED_SNAP, tx); 212 } 213 } 214 mutex_enter(&ds->ds_lock); 215 ASSERT3U(ds->ds_phys->ds_referenced_bytes, >=, used); 216 ds->ds_phys->ds_referenced_bytes -= used; 217 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 218 ds->ds_phys->ds_compressed_bytes -= compressed; 219 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 220 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 221 mutex_exit(&ds->ds_lock); 222 223 return (used); 224 } 225 226 uint64_t 227 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 228 { 229 uint64_t trysnap = 0; 230 231 if (ds == NULL) 232 return (0); 233 /* 234 * The snapshot creation could fail, but that would cause an 235 * incorrect FALSE return, which would only result in an 236 * overestimation of the amount of space that an operation would 237 * consume, which is OK. 238 * 239 * There's also a small window where we could miss a pending 240 * snapshot, because we could set the sync task in the quiescing 241 * phase. So this should only be used as a guess. 242 */ 243 if (ds->ds_trysnap_txg > 244 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 245 trysnap = ds->ds_trysnap_txg; 246 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 247 } 248 249 boolean_t 250 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp, 251 uint64_t blk_birth) 252 { 253 if (blk_birth <= dsl_dataset_prev_snap_txg(ds)) 254 return (B_FALSE); 255 256 ddt_prefetch(dsl_dataset_get_spa(ds), bp); 257 258 return (B_TRUE); 259 } 260 261 /* ARGSUSED */ 262 static void 263 dsl_dataset_evict(dmu_buf_t *db, void *dsv) 264 { 265 dsl_dataset_t *ds = dsv; 266 267 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 268 269 unique_remove(ds->ds_fsid_guid); 270 271 if (ds->ds_objset != NULL) 272 dmu_objset_evict(ds->ds_objset); 273 274 if (ds->ds_prev) { 275 dsl_dataset_drop_ref(ds->ds_prev, ds); 276 ds->ds_prev = NULL; 277 } 278 279 bplist_destroy(&ds->ds_pending_deadlist); 280 if (db != NULL) { 281 dsl_deadlist_close(&ds->ds_deadlist); 282 } else { 283 ASSERT(ds->ds_deadlist.dl_dbuf == NULL); 284 ASSERT(!ds->ds_deadlist.dl_oldfmt); 285 } 286 if (ds->ds_dir) 287 dsl_dir_close(ds->ds_dir, ds); 288 289 ASSERT(!list_link_active(&ds->ds_synced_link)); 290 291 mutex_destroy(&ds->ds_lock); 292 mutex_destroy(&ds->ds_recvlock); 293 mutex_destroy(&ds->ds_opening_lock); 294 rw_destroy(&ds->ds_rwlock); 295 cv_destroy(&ds->ds_exclusive_cv); 296 297 kmem_free(ds, sizeof (dsl_dataset_t)); 298 } 299 300 static int 301 dsl_dataset_get_snapname(dsl_dataset_t *ds) 302 { 303 dsl_dataset_phys_t *headphys; 304 int err; 305 dmu_buf_t *headdbuf; 306 dsl_pool_t *dp = ds->ds_dir->dd_pool; 307 objset_t *mos = dp->dp_meta_objset; 308 309 if (ds->ds_snapname[0]) 310 return (0); 311 if (ds->ds_phys->ds_next_snap_obj == 0) 312 return (0); 313 314 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 315 FTAG, &headdbuf); 316 if (err) 317 return (err); 318 headphys = headdbuf->db_data; 319 err = zap_value_search(dp->dp_meta_objset, 320 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 321 dmu_buf_rele(headdbuf, FTAG); 322 return (err); 323 } 324 325 static int 326 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 327 { 328 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 329 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 330 matchtype_t mt; 331 int err; 332 333 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 334 mt = MT_FIRST; 335 else 336 mt = MT_EXACT; 337 338 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 339 value, mt, NULL, 0, NULL); 340 if (err == ENOTSUP && mt == MT_FIRST) 341 err = zap_lookup(mos, snapobj, name, 8, 1, value); 342 return (err); 343 } 344 345 static int 346 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 347 { 348 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 349 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 350 matchtype_t mt; 351 int err; 352 353 dsl_dir_snap_cmtime_update(ds->ds_dir); 354 355 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 356 mt = MT_FIRST; 357 else 358 mt = MT_EXACT; 359 360 err = zap_remove_norm(mos, snapobj, name, mt, tx); 361 if (err == ENOTSUP && mt == MT_FIRST) 362 err = zap_remove(mos, snapobj, name, tx); 363 return (err); 364 } 365 366 static int 367 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 368 dsl_dataset_t **dsp) 369 { 370 objset_t *mos = dp->dp_meta_objset; 371 dmu_buf_t *dbuf; 372 dsl_dataset_t *ds; 373 int err; 374 dmu_object_info_t doi; 375 376 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 377 dsl_pool_sync_context(dp)); 378 379 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 380 if (err) 381 return (err); 382 383 /* Make sure dsobj has the correct object type. */ 384 dmu_object_info_from_db(dbuf, &doi); 385 if (doi.doi_type != DMU_OT_DSL_DATASET) 386 return (EINVAL); 387 388 ds = dmu_buf_get_user(dbuf); 389 if (ds == NULL) { 390 dsl_dataset_t *winner; 391 392 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 393 ds->ds_dbuf = dbuf; 394 ds->ds_object = dsobj; 395 ds->ds_phys = dbuf->db_data; 396 397 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 398 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 399 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 400 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL); 401 402 rw_init(&ds->ds_rwlock, 0, 0, 0); 403 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 404 405 bplist_create(&ds->ds_pending_deadlist); 406 dsl_deadlist_open(&ds->ds_deadlist, 407 mos, ds->ds_phys->ds_deadlist_obj); 408 409 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t), 410 offsetof(dmu_sendarg_t, dsa_link)); 411 412 if (err == 0) { 413 err = dsl_dir_open_obj(dp, 414 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 415 } 416 if (err) { 417 mutex_destroy(&ds->ds_lock); 418 mutex_destroy(&ds->ds_recvlock); 419 mutex_destroy(&ds->ds_opening_lock); 420 rw_destroy(&ds->ds_rwlock); 421 cv_destroy(&ds->ds_exclusive_cv); 422 bplist_destroy(&ds->ds_pending_deadlist); 423 dsl_deadlist_close(&ds->ds_deadlist); 424 kmem_free(ds, sizeof (dsl_dataset_t)); 425 dmu_buf_rele(dbuf, tag); 426 return (err); 427 } 428 429 if (!dsl_dataset_is_snapshot(ds)) { 430 ds->ds_snapname[0] = '\0'; 431 if (ds->ds_phys->ds_prev_snap_obj) { 432 err = dsl_dataset_get_ref(dp, 433 ds->ds_phys->ds_prev_snap_obj, 434 ds, &ds->ds_prev); 435 } 436 } else { 437 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 438 err = dsl_dataset_get_snapname(ds); 439 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 440 err = zap_count( 441 ds->ds_dir->dd_pool->dp_meta_objset, 442 ds->ds_phys->ds_userrefs_obj, 443 &ds->ds_userrefs); 444 } 445 } 446 447 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 448 /* 449 * In sync context, we're called with either no lock 450 * or with the write lock. If we're not syncing, 451 * we're always called with the read lock held. 452 */ 453 boolean_t need_lock = 454 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 455 dsl_pool_sync_context(dp); 456 457 if (need_lock) 458 rw_enter(&dp->dp_config_rwlock, RW_READER); 459 460 err = dsl_prop_get_ds(ds, 461 "refreservation", sizeof (uint64_t), 1, 462 &ds->ds_reserved, NULL); 463 if (err == 0) { 464 err = dsl_prop_get_ds(ds, 465 "refquota", sizeof (uint64_t), 1, 466 &ds->ds_quota, NULL); 467 } 468 469 if (need_lock) 470 rw_exit(&dp->dp_config_rwlock); 471 } else { 472 ds->ds_reserved = ds->ds_quota = 0; 473 } 474 475 if (err == 0) { 476 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 477 dsl_dataset_evict); 478 } 479 if (err || winner) { 480 bplist_destroy(&ds->ds_pending_deadlist); 481 dsl_deadlist_close(&ds->ds_deadlist); 482 if (ds->ds_prev) 483 dsl_dataset_drop_ref(ds->ds_prev, ds); 484 dsl_dir_close(ds->ds_dir, ds); 485 mutex_destroy(&ds->ds_lock); 486 mutex_destroy(&ds->ds_recvlock); 487 mutex_destroy(&ds->ds_opening_lock); 488 rw_destroy(&ds->ds_rwlock); 489 cv_destroy(&ds->ds_exclusive_cv); 490 kmem_free(ds, sizeof (dsl_dataset_t)); 491 if (err) { 492 dmu_buf_rele(dbuf, tag); 493 return (err); 494 } 495 ds = winner; 496 } else { 497 ds->ds_fsid_guid = 498 unique_insert(ds->ds_phys->ds_fsid_guid); 499 } 500 } 501 ASSERT3P(ds->ds_dbuf, ==, dbuf); 502 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 503 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 504 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 505 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 506 mutex_enter(&ds->ds_lock); 507 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 508 mutex_exit(&ds->ds_lock); 509 dmu_buf_rele(ds->ds_dbuf, tag); 510 return (ENOENT); 511 } 512 mutex_exit(&ds->ds_lock); 513 *dsp = ds; 514 return (0); 515 } 516 517 static int 518 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 519 { 520 dsl_pool_t *dp = ds->ds_dir->dd_pool; 521 522 /* 523 * In syncing context we don't want the rwlock lock: there 524 * may be an existing writer waiting for sync phase to 525 * finish. We don't need to worry about such writers, since 526 * sync phase is single-threaded, so the writer can't be 527 * doing anything while we are active. 528 */ 529 if (dsl_pool_sync_context(dp)) { 530 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 531 return (0); 532 } 533 534 /* 535 * Normal users will hold the ds_rwlock as a READER until they 536 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 537 * drop their READER lock after they set the ds_owner field. 538 * 539 * If the dataset is being destroyed, the destroy thread will 540 * obtain a WRITER lock for exclusive access after it's done its 541 * open-context work and then change the ds_owner to 542 * dsl_reaper once destruction is assured. So threads 543 * may block here temporarily, until the "destructability" of 544 * the dataset is determined. 545 */ 546 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 547 mutex_enter(&ds->ds_lock); 548 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 549 rw_exit(&dp->dp_config_rwlock); 550 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 551 if (DSL_DATASET_IS_DESTROYED(ds)) { 552 mutex_exit(&ds->ds_lock); 553 dsl_dataset_drop_ref(ds, tag); 554 rw_enter(&dp->dp_config_rwlock, RW_READER); 555 return (ENOENT); 556 } 557 /* 558 * The dp_config_rwlock lives above the ds_lock. And 559 * we need to check DSL_DATASET_IS_DESTROYED() while 560 * holding the ds_lock, so we have to drop and reacquire 561 * the ds_lock here. 562 */ 563 mutex_exit(&ds->ds_lock); 564 rw_enter(&dp->dp_config_rwlock, RW_READER); 565 mutex_enter(&ds->ds_lock); 566 } 567 mutex_exit(&ds->ds_lock); 568 return (0); 569 } 570 571 int 572 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 573 dsl_dataset_t **dsp) 574 { 575 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 576 577 if (err) 578 return (err); 579 return (dsl_dataset_hold_ref(*dsp, tag)); 580 } 581 582 int 583 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 584 void *tag, dsl_dataset_t **dsp) 585 { 586 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 587 if (err) 588 return (err); 589 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 590 dsl_dataset_rele(*dsp, tag); 591 *dsp = NULL; 592 return (EBUSY); 593 } 594 return (0); 595 } 596 597 int 598 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 599 { 600 dsl_dir_t *dd; 601 dsl_pool_t *dp; 602 const char *snapname; 603 uint64_t obj; 604 int err = 0; 605 606 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 607 if (err) 608 return (err); 609 610 dp = dd->dd_pool; 611 obj = dd->dd_phys->dd_head_dataset_obj; 612 rw_enter(&dp->dp_config_rwlock, RW_READER); 613 if (obj) 614 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 615 else 616 err = ENOENT; 617 if (err) 618 goto out; 619 620 err = dsl_dataset_hold_ref(*dsp, tag); 621 622 /* we may be looking for a snapshot */ 623 if (err == 0 && snapname != NULL) { 624 dsl_dataset_t *ds = NULL; 625 626 if (*snapname++ != '@') { 627 dsl_dataset_rele(*dsp, tag); 628 err = ENOENT; 629 goto out; 630 } 631 632 dprintf("looking for snapshot '%s'\n", snapname); 633 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 634 if (err == 0) 635 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 636 dsl_dataset_rele(*dsp, tag); 637 638 ASSERT3U((err == 0), ==, (ds != NULL)); 639 640 if (ds) { 641 mutex_enter(&ds->ds_lock); 642 if (ds->ds_snapname[0] == 0) 643 (void) strlcpy(ds->ds_snapname, snapname, 644 sizeof (ds->ds_snapname)); 645 mutex_exit(&ds->ds_lock); 646 err = dsl_dataset_hold_ref(ds, tag); 647 *dsp = err ? NULL : ds; 648 } 649 } 650 out: 651 rw_exit(&dp->dp_config_rwlock); 652 dsl_dir_close(dd, FTAG); 653 return (err); 654 } 655 656 int 657 dsl_dataset_own(const char *name, boolean_t inconsistentok, 658 void *tag, dsl_dataset_t **dsp) 659 { 660 int err = dsl_dataset_hold(name, tag, dsp); 661 if (err) 662 return (err); 663 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 664 dsl_dataset_rele(*dsp, tag); 665 return (EBUSY); 666 } 667 return (0); 668 } 669 670 void 671 dsl_dataset_name(dsl_dataset_t *ds, char *name) 672 { 673 if (ds == NULL) { 674 (void) strcpy(name, "mos"); 675 } else { 676 dsl_dir_name(ds->ds_dir, name); 677 VERIFY(0 == dsl_dataset_get_snapname(ds)); 678 if (ds->ds_snapname[0]) { 679 (void) strcat(name, "@"); 680 /* 681 * We use a "recursive" mutex so that we 682 * can call dprintf_ds() with ds_lock held. 683 */ 684 if (!MUTEX_HELD(&ds->ds_lock)) { 685 mutex_enter(&ds->ds_lock); 686 (void) strcat(name, ds->ds_snapname); 687 mutex_exit(&ds->ds_lock); 688 } else { 689 (void) strcat(name, ds->ds_snapname); 690 } 691 } 692 } 693 } 694 695 static int 696 dsl_dataset_namelen(dsl_dataset_t *ds) 697 { 698 int result; 699 700 if (ds == NULL) { 701 result = 3; /* "mos" */ 702 } else { 703 result = dsl_dir_namelen(ds->ds_dir); 704 VERIFY(0 == dsl_dataset_get_snapname(ds)); 705 if (ds->ds_snapname[0]) { 706 ++result; /* adding one for the @-sign */ 707 if (!MUTEX_HELD(&ds->ds_lock)) { 708 mutex_enter(&ds->ds_lock); 709 result += strlen(ds->ds_snapname); 710 mutex_exit(&ds->ds_lock); 711 } else { 712 result += strlen(ds->ds_snapname); 713 } 714 } 715 } 716 717 return (result); 718 } 719 720 void 721 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 722 { 723 dmu_buf_rele(ds->ds_dbuf, tag); 724 } 725 726 void 727 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 728 { 729 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 730 rw_exit(&ds->ds_rwlock); 731 } 732 dsl_dataset_drop_ref(ds, tag); 733 } 734 735 void 736 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 737 { 738 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 739 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 740 741 mutex_enter(&ds->ds_lock); 742 ds->ds_owner = NULL; 743 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 744 rw_exit(&ds->ds_rwlock); 745 cv_broadcast(&ds->ds_exclusive_cv); 746 } 747 mutex_exit(&ds->ds_lock); 748 if (ds->ds_dbuf) 749 dsl_dataset_drop_ref(ds, tag); 750 else 751 dsl_dataset_evict(NULL, ds); 752 } 753 754 boolean_t 755 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 756 { 757 boolean_t gotit = FALSE; 758 759 mutex_enter(&ds->ds_lock); 760 if (ds->ds_owner == NULL && 761 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 762 ds->ds_owner = tag; 763 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 764 rw_exit(&ds->ds_rwlock); 765 gotit = TRUE; 766 } 767 mutex_exit(&ds->ds_lock); 768 return (gotit); 769 } 770 771 void 772 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 773 { 774 ASSERT3P(owner, ==, ds->ds_owner); 775 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 776 rw_enter(&ds->ds_rwlock, RW_WRITER); 777 } 778 779 uint64_t 780 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 781 uint64_t flags, dmu_tx_t *tx) 782 { 783 dsl_pool_t *dp = dd->dd_pool; 784 dmu_buf_t *dbuf; 785 dsl_dataset_phys_t *dsphys; 786 uint64_t dsobj; 787 objset_t *mos = dp->dp_meta_objset; 788 789 if (origin == NULL) 790 origin = dp->dp_origin_snap; 791 792 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 793 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 794 ASSERT(dmu_tx_is_syncing(tx)); 795 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 796 797 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 798 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 799 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 800 dmu_buf_will_dirty(dbuf, tx); 801 dsphys = dbuf->db_data; 802 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 803 dsphys->ds_dir_obj = dd->dd_object; 804 dsphys->ds_flags = flags; 805 dsphys->ds_fsid_guid = unique_create(); 806 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 807 sizeof (dsphys->ds_guid)); 808 dsphys->ds_snapnames_zapobj = 809 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 810 DMU_OT_NONE, 0, tx); 811 dsphys->ds_creation_time = gethrestime_sec(); 812 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 813 814 if (origin == NULL) { 815 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx); 816 } else { 817 dsl_dataset_t *ohds; 818 819 dsphys->ds_prev_snap_obj = origin->ds_object; 820 dsphys->ds_prev_snap_txg = 821 origin->ds_phys->ds_creation_txg; 822 dsphys->ds_referenced_bytes = 823 origin->ds_phys->ds_referenced_bytes; 824 dsphys->ds_compressed_bytes = 825 origin->ds_phys->ds_compressed_bytes; 826 dsphys->ds_uncompressed_bytes = 827 origin->ds_phys->ds_uncompressed_bytes; 828 dsphys->ds_bp = origin->ds_phys->ds_bp; 829 dsphys->ds_flags |= origin->ds_phys->ds_flags; 830 831 dmu_buf_will_dirty(origin->ds_dbuf, tx); 832 origin->ds_phys->ds_num_children++; 833 834 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 835 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds)); 836 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist, 837 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx); 838 dsl_dataset_rele(ohds, FTAG); 839 840 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 841 if (origin->ds_phys->ds_next_clones_obj == 0) { 842 origin->ds_phys->ds_next_clones_obj = 843 zap_create(mos, 844 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 845 } 846 VERIFY(0 == zap_add_int(mos, 847 origin->ds_phys->ds_next_clones_obj, 848 dsobj, tx)); 849 } 850 851 dmu_buf_will_dirty(dd->dd_dbuf, tx); 852 dd->dd_phys->dd_origin_obj = origin->ds_object; 853 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 854 if (origin->ds_dir->dd_phys->dd_clones == 0) { 855 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); 856 origin->ds_dir->dd_phys->dd_clones = 857 zap_create(mos, 858 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 859 } 860 VERIFY3U(0, ==, zap_add_int(mos, 861 origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); 862 } 863 } 864 865 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 866 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 867 868 dmu_buf_rele(dbuf, FTAG); 869 870 dmu_buf_will_dirty(dd->dd_dbuf, tx); 871 dd->dd_phys->dd_head_dataset_obj = dsobj; 872 873 return (dsobj); 874 } 875 876 uint64_t 877 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 878 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 879 { 880 dsl_pool_t *dp = pdd->dd_pool; 881 uint64_t dsobj, ddobj; 882 dsl_dir_t *dd; 883 884 ASSERT(lastname[0] != '@'); 885 886 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 887 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 888 889 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 890 891 dsl_deleg_set_create_perms(dd, tx, cr); 892 893 dsl_dir_close(dd, FTAG); 894 895 /* 896 * If we are creating a clone, make sure we zero out any stale 897 * data from the origin snapshots zil header. 898 */ 899 if (origin != NULL) { 900 dsl_dataset_t *ds; 901 objset_t *os; 902 903 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 904 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); 905 bzero(&os->os_zil_header, sizeof (os->os_zil_header)); 906 dsl_dataset_dirty(ds, tx); 907 dsl_dataset_rele(ds, FTAG); 908 } 909 910 return (dsobj); 911 } 912 913 /* 914 * The snapshots must all be in the same pool. 915 */ 916 int 917 dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, char *failed) 918 { 919 int err; 920 dsl_sync_task_t *dst; 921 spa_t *spa; 922 nvpair_t *pair; 923 dsl_sync_task_group_t *dstg; 924 925 pair = nvlist_next_nvpair(snaps, NULL); 926 if (pair == NULL) 927 return (0); 928 929 err = spa_open(nvpair_name(pair), &spa, FTAG); 930 if (err) 931 return (err); 932 dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 933 934 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL; 935 pair = nvlist_next_nvpair(snaps, pair)) { 936 dsl_dataset_t *ds; 937 938 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds); 939 if (err == 0) { 940 struct dsl_ds_destroyarg *dsda; 941 942 dsl_dataset_make_exclusive(ds, dstg); 943 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), 944 KM_SLEEP); 945 dsda->ds = ds; 946 dsda->defer = defer; 947 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 948 dsl_dataset_destroy_sync, dsda, dstg, 0); 949 } else if (err == ENOENT) { 950 err = 0; 951 } else { 952 (void) strcpy(failed, nvpair_name(pair)); 953 break; 954 } 955 } 956 957 if (err == 0) 958 err = dsl_sync_task_group_wait(dstg); 959 960 for (dst = list_head(&dstg->dstg_tasks); dst; 961 dst = list_next(&dstg->dstg_tasks, dst)) { 962 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 963 dsl_dataset_t *ds = dsda->ds; 964 965 /* 966 * Return the file system name that triggered the error 967 */ 968 if (dst->dst_err) { 969 dsl_dataset_name(ds, failed); 970 } 971 ASSERT3P(dsda->rm_origin, ==, NULL); 972 dsl_dataset_disown(ds, dstg); 973 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 974 } 975 976 dsl_sync_task_group_destroy(dstg); 977 spa_close(spa, FTAG); 978 return (err); 979 980 } 981 982 static boolean_t 983 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 984 { 985 boolean_t might_destroy = B_FALSE; 986 987 mutex_enter(&ds->ds_lock); 988 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 989 DS_IS_DEFER_DESTROY(ds)) 990 might_destroy = B_TRUE; 991 mutex_exit(&ds->ds_lock); 992 993 return (might_destroy); 994 } 995 996 /* 997 * If we're removing a clone, and these three conditions are true: 998 * 1) the clone's origin has no other children 999 * 2) the clone's origin has no user references 1000 * 3) the clone's origin has been marked for deferred destruction 1001 * Then, prepare to remove the origin as part of this sync task group. 1002 */ 1003 static int 1004 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 1005 { 1006 dsl_dataset_t *ds = dsda->ds; 1007 dsl_dataset_t *origin = ds->ds_prev; 1008 1009 if (dsl_dataset_might_destroy_origin(origin)) { 1010 char *name; 1011 int namelen; 1012 int error; 1013 1014 namelen = dsl_dataset_namelen(origin) + 1; 1015 name = kmem_alloc(namelen, KM_SLEEP); 1016 dsl_dataset_name(origin, name); 1017 #ifdef _KERNEL 1018 error = zfs_unmount_snap(name, NULL); 1019 if (error) { 1020 kmem_free(name, namelen); 1021 return (error); 1022 } 1023 #endif 1024 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 1025 kmem_free(name, namelen); 1026 if (error) 1027 return (error); 1028 dsda->rm_origin = origin; 1029 dsl_dataset_make_exclusive(origin, tag); 1030 } 1031 1032 return (0); 1033 } 1034 1035 /* 1036 * ds must be opened as OWNER. On return (whether successful or not), 1037 * ds will be closed and caller can no longer dereference it. 1038 */ 1039 int 1040 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1041 { 1042 int err; 1043 dsl_sync_task_group_t *dstg; 1044 objset_t *os; 1045 dsl_dir_t *dd; 1046 uint64_t obj; 1047 struct dsl_ds_destroyarg dsda = { 0 }; 1048 dsl_dataset_t dummy_ds = { 0 }; 1049 1050 dsda.ds = ds; 1051 1052 if (dsl_dataset_is_snapshot(ds)) { 1053 /* Destroying a snapshot is simpler */ 1054 dsl_dataset_make_exclusive(ds, tag); 1055 1056 dsda.defer = defer; 1057 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1058 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1059 &dsda, tag, 0); 1060 ASSERT3P(dsda.rm_origin, ==, NULL); 1061 goto out; 1062 } else if (defer) { 1063 err = EINVAL; 1064 goto out; 1065 } 1066 1067 dd = ds->ds_dir; 1068 dummy_ds.ds_dir = dd; 1069 dummy_ds.ds_object = ds->ds_object; 1070 1071 /* 1072 * Check for errors and mark this ds as inconsistent, in 1073 * case we crash while freeing the objects. 1074 */ 1075 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, 1076 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1077 if (err) 1078 goto out; 1079 1080 err = dmu_objset_from_ds(ds, &os); 1081 if (err) 1082 goto out; 1083 1084 /* 1085 * If async destruction is not enabled try to remove all objects 1086 * while in the open context so that there is less work to do in 1087 * the syncing context. 1088 */ 1089 if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds), 1090 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) { 1091 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1092 ds->ds_phys->ds_prev_snap_txg)) { 1093 /* 1094 * Ignore errors, if there is not enough disk space 1095 * we will deal with it in dsl_dataset_destroy_sync(). 1096 */ 1097 (void) dmu_free_object(os, obj); 1098 } 1099 if (err != ESRCH) 1100 goto out; 1101 } 1102 1103 /* 1104 * Only the ZIL knows how to free log blocks. 1105 */ 1106 zil_destroy(dmu_objset_zil(os), B_FALSE); 1107 1108 /* 1109 * Sync out all in-flight IO. 1110 */ 1111 txg_wait_synced(dd->dd_pool, 0); 1112 1113 /* 1114 * If we managed to free all the objects in open 1115 * context, the user space accounting should be zero. 1116 */ 1117 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1118 dmu_objset_userused_enabled(os)) { 1119 uint64_t count; 1120 1121 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || 1122 count == 0); 1123 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || 1124 count == 0); 1125 } 1126 1127 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1128 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1129 rw_exit(&dd->dd_pool->dp_config_rwlock); 1130 1131 if (err) 1132 goto out; 1133 1134 /* 1135 * Blow away the dsl_dir + head dataset. 1136 */ 1137 dsl_dataset_make_exclusive(ds, tag); 1138 /* 1139 * If we're removing a clone, we might also need to remove its 1140 * origin. 1141 */ 1142 do { 1143 dsda.need_prep = B_FALSE; 1144 if (dsl_dir_is_clone(dd)) { 1145 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1146 if (err) { 1147 dsl_dir_close(dd, FTAG); 1148 goto out; 1149 } 1150 } 1151 1152 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1153 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1154 dsl_dataset_destroy_sync, &dsda, tag, 0); 1155 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1156 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0); 1157 err = dsl_sync_task_group_wait(dstg); 1158 dsl_sync_task_group_destroy(dstg); 1159 1160 /* 1161 * We could be racing against 'zfs release' or 'zfs destroy -d' 1162 * on the origin snap, in which case we can get EBUSY if we 1163 * needed to destroy the origin snap but were not ready to 1164 * do so. 1165 */ 1166 if (dsda.need_prep) { 1167 ASSERT(err == EBUSY); 1168 ASSERT(dsl_dir_is_clone(dd)); 1169 ASSERT(dsda.rm_origin == NULL); 1170 } 1171 } while (dsda.need_prep); 1172 1173 if (dsda.rm_origin != NULL) 1174 dsl_dataset_disown(dsda.rm_origin, tag); 1175 1176 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1177 if (err) 1178 dsl_dir_close(dd, FTAG); 1179 out: 1180 dsl_dataset_disown(ds, tag); 1181 return (err); 1182 } 1183 1184 blkptr_t * 1185 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1186 { 1187 return (&ds->ds_phys->ds_bp); 1188 } 1189 1190 void 1191 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1192 { 1193 ASSERT(dmu_tx_is_syncing(tx)); 1194 /* If it's the meta-objset, set dp_meta_rootbp */ 1195 if (ds == NULL) { 1196 tx->tx_pool->dp_meta_rootbp = *bp; 1197 } else { 1198 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1199 ds->ds_phys->ds_bp = *bp; 1200 } 1201 } 1202 1203 spa_t * 1204 dsl_dataset_get_spa(dsl_dataset_t *ds) 1205 { 1206 return (ds->ds_dir->dd_pool->dp_spa); 1207 } 1208 1209 void 1210 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1211 { 1212 dsl_pool_t *dp; 1213 1214 if (ds == NULL) /* this is the meta-objset */ 1215 return; 1216 1217 ASSERT(ds->ds_objset != NULL); 1218 1219 if (ds->ds_phys->ds_next_snap_obj != 0) 1220 panic("dirtying snapshot!"); 1221 1222 dp = ds->ds_dir->dd_pool; 1223 1224 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1225 /* up the hold count until we can be written out */ 1226 dmu_buf_add_ref(ds->ds_dbuf, ds); 1227 } 1228 } 1229 1230 /* 1231 * The unique space in the head dataset can be calculated by subtracting 1232 * the space used in the most recent snapshot, that is still being used 1233 * in this file system, from the space currently in use. To figure out 1234 * the space in the most recent snapshot still in use, we need to take 1235 * the total space used in the snapshot and subtract out the space that 1236 * has been freed up since the snapshot was taken. 1237 */ 1238 static void 1239 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1240 { 1241 uint64_t mrs_used; 1242 uint64_t dlused, dlcomp, dluncomp; 1243 1244 ASSERT(!dsl_dataset_is_snapshot(ds)); 1245 1246 if (ds->ds_phys->ds_prev_snap_obj != 0) 1247 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes; 1248 else 1249 mrs_used = 0; 1250 1251 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); 1252 1253 ASSERT3U(dlused, <=, mrs_used); 1254 ds->ds_phys->ds_unique_bytes = 1255 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused); 1256 1257 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1258 SPA_VERSION_UNIQUE_ACCURATE) 1259 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1260 } 1261 1262 struct killarg { 1263 dsl_dataset_t *ds; 1264 dmu_tx_t *tx; 1265 }; 1266 1267 /* ARGSUSED */ 1268 static int 1269 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf, 1270 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1271 { 1272 struct killarg *ka = arg; 1273 dmu_tx_t *tx = ka->tx; 1274 1275 if (bp == NULL) 1276 return (0); 1277 1278 if (zb->zb_level == ZB_ZIL_LEVEL) { 1279 ASSERT(zilog != NULL); 1280 /* 1281 * It's a block in the intent log. It has no 1282 * accounting, so just free it. 1283 */ 1284 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1285 } else { 1286 ASSERT(zilog == NULL); 1287 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1288 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1289 } 1290 1291 return (0); 1292 } 1293 1294 /* ARGSUSED */ 1295 static int 1296 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1297 { 1298 dsl_dataset_t *ds = arg1; 1299 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1300 uint64_t count; 1301 int err; 1302 1303 /* 1304 * Can't delete a head dataset if there are snapshots of it. 1305 * (Except if the only snapshots are from the branch we cloned 1306 * from.) 1307 */ 1308 if (ds->ds_prev != NULL && 1309 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1310 return (EBUSY); 1311 1312 /* 1313 * This is really a dsl_dir thing, but check it here so that 1314 * we'll be less likely to leave this dataset inconsistent & 1315 * nearly destroyed. 1316 */ 1317 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1318 if (err) 1319 return (err); 1320 if (count != 0) 1321 return (EEXIST); 1322 1323 return (0); 1324 } 1325 1326 /* ARGSUSED */ 1327 static void 1328 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1329 { 1330 dsl_dataset_t *ds = arg1; 1331 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1332 1333 /* Mark it as inconsistent on-disk, in case we crash */ 1334 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1335 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1336 1337 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx, 1338 "dataset = %llu", ds->ds_object); 1339 } 1340 1341 static int 1342 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1343 dmu_tx_t *tx) 1344 { 1345 dsl_dataset_t *ds = dsda->ds; 1346 dsl_dataset_t *ds_prev = ds->ds_prev; 1347 1348 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1349 struct dsl_ds_destroyarg ndsda = {0}; 1350 1351 /* 1352 * If we're not prepared to remove the origin, don't remove 1353 * the clone either. 1354 */ 1355 if (dsda->rm_origin == NULL) { 1356 dsda->need_prep = B_TRUE; 1357 return (EBUSY); 1358 } 1359 1360 ndsda.ds = ds_prev; 1361 ndsda.is_origin_rm = B_TRUE; 1362 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1363 } 1364 1365 /* 1366 * If we're not going to remove the origin after all, 1367 * undo the open context setup. 1368 */ 1369 if (dsda->rm_origin != NULL) { 1370 dsl_dataset_disown(dsda->rm_origin, tag); 1371 dsda->rm_origin = NULL; 1372 } 1373 1374 return (0); 1375 } 1376 1377 /* 1378 * If you add new checks here, you may need to add 1379 * additional checks to the "temporary" case in 1380 * snapshot_check() in dmu_objset.c. 1381 */ 1382 /* ARGSUSED */ 1383 int 1384 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1385 { 1386 struct dsl_ds_destroyarg *dsda = arg1; 1387 dsl_dataset_t *ds = dsda->ds; 1388 1389 /* we have an owner hold, so noone else can destroy us */ 1390 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1391 1392 /* 1393 * Only allow deferred destroy on pools that support it. 1394 * NOTE: deferred destroy is only supported on snapshots. 1395 */ 1396 if (dsda->defer) { 1397 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1398 SPA_VERSION_USERREFS) 1399 return (ENOTSUP); 1400 ASSERT(dsl_dataset_is_snapshot(ds)); 1401 return (0); 1402 } 1403 1404 /* 1405 * Can't delete a head dataset if there are snapshots of it. 1406 * (Except if the only snapshots are from the branch we cloned 1407 * from.) 1408 */ 1409 if (ds->ds_prev != NULL && 1410 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1411 return (EBUSY); 1412 1413 /* 1414 * If we made changes this txg, traverse_dsl_dataset won't find 1415 * them. Try again. 1416 */ 1417 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1418 return (EAGAIN); 1419 1420 if (dsl_dataset_is_snapshot(ds)) { 1421 /* 1422 * If this snapshot has an elevated user reference count, 1423 * we can't destroy it yet. 1424 */ 1425 if (ds->ds_userrefs > 0 && !dsda->releasing) 1426 return (EBUSY); 1427 1428 mutex_enter(&ds->ds_lock); 1429 /* 1430 * Can't delete a branch point. However, if we're destroying 1431 * a clone and removing its origin due to it having a user 1432 * hold count of 0 and having been marked for deferred destroy, 1433 * it's OK for the origin to have a single clone. 1434 */ 1435 if (ds->ds_phys->ds_num_children > 1436 (dsda->is_origin_rm ? 2 : 1)) { 1437 mutex_exit(&ds->ds_lock); 1438 return (EEXIST); 1439 } 1440 mutex_exit(&ds->ds_lock); 1441 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1442 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1443 } 1444 1445 /* XXX we should do some i/o error checking... */ 1446 return (0); 1447 } 1448 1449 struct refsarg { 1450 kmutex_t lock; 1451 boolean_t gone; 1452 kcondvar_t cv; 1453 }; 1454 1455 /* ARGSUSED */ 1456 static void 1457 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1458 { 1459 struct refsarg *arg = argv; 1460 1461 mutex_enter(&arg->lock); 1462 arg->gone = TRUE; 1463 cv_signal(&arg->cv); 1464 mutex_exit(&arg->lock); 1465 } 1466 1467 static void 1468 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1469 { 1470 struct refsarg arg; 1471 1472 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1473 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1474 arg.gone = FALSE; 1475 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1476 dsl_dataset_refs_gone); 1477 dmu_buf_rele(ds->ds_dbuf, tag); 1478 mutex_enter(&arg.lock); 1479 while (!arg.gone) 1480 cv_wait(&arg.cv, &arg.lock); 1481 ASSERT(arg.gone); 1482 mutex_exit(&arg.lock); 1483 ds->ds_dbuf = NULL; 1484 ds->ds_phys = NULL; 1485 mutex_destroy(&arg.lock); 1486 cv_destroy(&arg.cv); 1487 } 1488 1489 static void 1490 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1491 { 1492 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1493 uint64_t count; 1494 int err; 1495 1496 ASSERT(ds->ds_phys->ds_num_children >= 2); 1497 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1498 /* 1499 * The err should not be ENOENT, but a bug in a previous version 1500 * of the code could cause upgrade_clones_cb() to not set 1501 * ds_next_snap_obj when it should, leading to a missing entry. 1502 * If we knew that the pool was created after 1503 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1504 * ENOENT. However, at least we can check that we don't have 1505 * too many entries in the next_clones_obj even after failing to 1506 * remove this one. 1507 */ 1508 if (err != ENOENT) { 1509 VERIFY3U(err, ==, 0); 1510 } 1511 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1512 &count)); 1513 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1514 } 1515 1516 static void 1517 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 1518 { 1519 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1520 zap_cursor_t zc; 1521 zap_attribute_t za; 1522 1523 /* 1524 * If it is the old version, dd_clones doesn't exist so we can't 1525 * find the clones, but deadlist_remove_key() is a no-op so it 1526 * doesn't matter. 1527 */ 1528 if (ds->ds_dir->dd_phys->dd_clones == 0) 1529 return; 1530 1531 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); 1532 zap_cursor_retrieve(&zc, &za) == 0; 1533 zap_cursor_advance(&zc)) { 1534 dsl_dataset_t *clone; 1535 1536 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 1537 za.za_first_integer, FTAG, &clone)); 1538 if (clone->ds_dir->dd_origin_txg > mintxg) { 1539 dsl_deadlist_remove_key(&clone->ds_deadlist, 1540 mintxg, tx); 1541 dsl_dataset_remove_clones_key(clone, mintxg, tx); 1542 } 1543 dsl_dataset_rele(clone, FTAG); 1544 } 1545 zap_cursor_fini(&zc); 1546 } 1547 1548 struct process_old_arg { 1549 dsl_dataset_t *ds; 1550 dsl_dataset_t *ds_prev; 1551 boolean_t after_branch_point; 1552 zio_t *pio; 1553 uint64_t used, comp, uncomp; 1554 }; 1555 1556 static int 1557 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1558 { 1559 struct process_old_arg *poa = arg; 1560 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; 1561 1562 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { 1563 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); 1564 if (poa->ds_prev && !poa->after_branch_point && 1565 bp->blk_birth > 1566 poa->ds_prev->ds_phys->ds_prev_snap_txg) { 1567 poa->ds_prev->ds_phys->ds_unique_bytes += 1568 bp_get_dsize_sync(dp->dp_spa, bp); 1569 } 1570 } else { 1571 poa->used += bp_get_dsize_sync(dp->dp_spa, bp); 1572 poa->comp += BP_GET_PSIZE(bp); 1573 poa->uncomp += BP_GET_UCSIZE(bp); 1574 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); 1575 } 1576 return (0); 1577 } 1578 1579 static void 1580 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, 1581 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) 1582 { 1583 struct process_old_arg poa = { 0 }; 1584 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1585 objset_t *mos = dp->dp_meta_objset; 1586 1587 ASSERT(ds->ds_deadlist.dl_oldfmt); 1588 ASSERT(ds_next->ds_deadlist.dl_oldfmt); 1589 1590 poa.ds = ds; 1591 poa.ds_prev = ds_prev; 1592 poa.after_branch_point = after_branch_point; 1593 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1594 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, 1595 process_old_cb, &poa, tx)); 1596 VERIFY3U(zio_wait(poa.pio), ==, 0); 1597 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); 1598 1599 /* change snapused */ 1600 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1601 -poa.used, -poa.comp, -poa.uncomp, tx); 1602 1603 /* swap next's deadlist to our deadlist */ 1604 dsl_deadlist_close(&ds->ds_deadlist); 1605 dsl_deadlist_close(&ds_next->ds_deadlist); 1606 SWITCH64(ds_next->ds_phys->ds_deadlist_obj, 1607 ds->ds_phys->ds_deadlist_obj); 1608 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 1609 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 1610 ds_next->ds_phys->ds_deadlist_obj); 1611 } 1612 1613 static int 1614 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx) 1615 { 1616 int err; 1617 struct killarg ka; 1618 1619 /* 1620 * Free everything that we point to (that's born after 1621 * the previous snapshot, if we are a clone) 1622 * 1623 * NB: this should be very quick, because we already 1624 * freed all the objects in open context. 1625 */ 1626 ka.ds = ds; 1627 ka.tx = tx; 1628 err = traverse_dataset(ds, 1629 ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST, 1630 kill_blkptr, &ka); 1631 ASSERT3U(err, ==, 0); 1632 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0); 1633 1634 return (err); 1635 } 1636 1637 void 1638 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx) 1639 { 1640 struct dsl_ds_destroyarg *dsda = arg1; 1641 dsl_dataset_t *ds = dsda->ds; 1642 int err; 1643 int after_branch_point = FALSE; 1644 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1645 objset_t *mos = dp->dp_meta_objset; 1646 dsl_dataset_t *ds_prev = NULL; 1647 boolean_t wont_destroy; 1648 uint64_t obj; 1649 1650 wont_destroy = (dsda->defer && 1651 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)); 1652 1653 ASSERT(ds->ds_owner || wont_destroy); 1654 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1655 ASSERT(ds->ds_prev == NULL || 1656 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1657 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1658 1659 if (wont_destroy) { 1660 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1661 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1662 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1663 return; 1664 } 1665 1666 /* signal any waiters that this dataset is going away */ 1667 mutex_enter(&ds->ds_lock); 1668 ds->ds_owner = dsl_reaper; 1669 cv_broadcast(&ds->ds_exclusive_cv); 1670 mutex_exit(&ds->ds_lock); 1671 1672 /* Remove our reservation */ 1673 if (ds->ds_reserved != 0) { 1674 dsl_prop_setarg_t psa; 1675 uint64_t value = 0; 1676 1677 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1678 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1679 &value); 1680 psa.psa_effective_value = 0; /* predict default value */ 1681 1682 dsl_dataset_set_reservation_sync(ds, &psa, tx); 1683 ASSERT3U(ds->ds_reserved, ==, 0); 1684 } 1685 1686 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1687 1688 dsl_scan_ds_destroyed(ds, tx); 1689 1690 obj = ds->ds_object; 1691 1692 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1693 if (ds->ds_prev) { 1694 ds_prev = ds->ds_prev; 1695 } else { 1696 VERIFY(0 == dsl_dataset_hold_obj(dp, 1697 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1698 } 1699 after_branch_point = 1700 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1701 1702 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1703 if (after_branch_point && 1704 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1705 remove_from_next_clones(ds_prev, obj, tx); 1706 if (ds->ds_phys->ds_next_snap_obj != 0) { 1707 VERIFY(0 == zap_add_int(mos, 1708 ds_prev->ds_phys->ds_next_clones_obj, 1709 ds->ds_phys->ds_next_snap_obj, tx)); 1710 } 1711 } 1712 if (after_branch_point && 1713 ds->ds_phys->ds_next_snap_obj == 0) { 1714 /* This clone is toast. */ 1715 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1716 ds_prev->ds_phys->ds_num_children--; 1717 1718 /* 1719 * If the clone's origin has no other clones, no 1720 * user holds, and has been marked for deferred 1721 * deletion, then we should have done the necessary 1722 * destroy setup for it. 1723 */ 1724 if (ds_prev->ds_phys->ds_num_children == 1 && 1725 ds_prev->ds_userrefs == 0 && 1726 DS_IS_DEFER_DESTROY(ds_prev)) { 1727 ASSERT3P(dsda->rm_origin, !=, NULL); 1728 } else { 1729 ASSERT3P(dsda->rm_origin, ==, NULL); 1730 } 1731 } else if (!after_branch_point) { 1732 ds_prev->ds_phys->ds_next_snap_obj = 1733 ds->ds_phys->ds_next_snap_obj; 1734 } 1735 } 1736 1737 if (dsl_dataset_is_snapshot(ds)) { 1738 dsl_dataset_t *ds_next; 1739 uint64_t old_unique; 1740 uint64_t used = 0, comp = 0, uncomp = 0; 1741 1742 VERIFY(0 == dsl_dataset_hold_obj(dp, 1743 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1744 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1745 1746 old_unique = ds_next->ds_phys->ds_unique_bytes; 1747 1748 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1749 ds_next->ds_phys->ds_prev_snap_obj = 1750 ds->ds_phys->ds_prev_snap_obj; 1751 ds_next->ds_phys->ds_prev_snap_txg = 1752 ds->ds_phys->ds_prev_snap_txg; 1753 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1754 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1755 1756 1757 if (ds_next->ds_deadlist.dl_oldfmt) { 1758 process_old_deadlist(ds, ds_prev, ds_next, 1759 after_branch_point, tx); 1760 } else { 1761 /* Adjust prev's unique space. */ 1762 if (ds_prev && !after_branch_point) { 1763 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1764 ds_prev->ds_phys->ds_prev_snap_txg, 1765 ds->ds_phys->ds_prev_snap_txg, 1766 &used, &comp, &uncomp); 1767 ds_prev->ds_phys->ds_unique_bytes += used; 1768 } 1769 1770 /* Adjust snapused. */ 1771 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1772 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 1773 &used, &comp, &uncomp); 1774 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1775 -used, -comp, -uncomp, tx); 1776 1777 /* Move blocks to be freed to pool's free list. */ 1778 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 1779 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, 1780 tx); 1781 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 1782 DD_USED_HEAD, used, comp, uncomp, tx); 1783 1784 /* Merge our deadlist into next's and free it. */ 1785 dsl_deadlist_merge(&ds_next->ds_deadlist, 1786 ds->ds_phys->ds_deadlist_obj, tx); 1787 } 1788 dsl_deadlist_close(&ds->ds_deadlist); 1789 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1790 1791 /* Collapse range in clone heads */ 1792 dsl_dataset_remove_clones_key(ds, 1793 ds->ds_phys->ds_creation_txg, tx); 1794 1795 if (dsl_dataset_is_snapshot(ds_next)) { 1796 dsl_dataset_t *ds_nextnext; 1797 1798 /* 1799 * Update next's unique to include blocks which 1800 * were previously shared by only this snapshot 1801 * and it. Those blocks will be born after the 1802 * prev snap and before this snap, and will have 1803 * died after the next snap and before the one 1804 * after that (ie. be on the snap after next's 1805 * deadlist). 1806 */ 1807 VERIFY(0 == dsl_dataset_hold_obj(dp, 1808 ds_next->ds_phys->ds_next_snap_obj, 1809 FTAG, &ds_nextnext)); 1810 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 1811 ds->ds_phys->ds_prev_snap_txg, 1812 ds->ds_phys->ds_creation_txg, 1813 &used, &comp, &uncomp); 1814 ds_next->ds_phys->ds_unique_bytes += used; 1815 dsl_dataset_rele(ds_nextnext, FTAG); 1816 ASSERT3P(ds_next->ds_prev, ==, NULL); 1817 1818 /* Collapse range in this head. */ 1819 dsl_dataset_t *hds; 1820 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 1821 ds->ds_dir->dd_phys->dd_head_dataset_obj, 1822 FTAG, &hds)); 1823 dsl_deadlist_remove_key(&hds->ds_deadlist, 1824 ds->ds_phys->ds_creation_txg, tx); 1825 dsl_dataset_rele(hds, FTAG); 1826 1827 } else { 1828 ASSERT3P(ds_next->ds_prev, ==, ds); 1829 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1830 ds_next->ds_prev = NULL; 1831 if (ds_prev) { 1832 VERIFY(0 == dsl_dataset_get_ref(dp, 1833 ds->ds_phys->ds_prev_snap_obj, 1834 ds_next, &ds_next->ds_prev)); 1835 } 1836 1837 dsl_dataset_recalc_head_uniq(ds_next); 1838 1839 /* 1840 * Reduce the amount of our unconsmed refreservation 1841 * being charged to our parent by the amount of 1842 * new unique data we have gained. 1843 */ 1844 if (old_unique < ds_next->ds_reserved) { 1845 int64_t mrsdelta; 1846 uint64_t new_unique = 1847 ds_next->ds_phys->ds_unique_bytes; 1848 1849 ASSERT(old_unique <= new_unique); 1850 mrsdelta = MIN(new_unique - old_unique, 1851 ds_next->ds_reserved - old_unique); 1852 dsl_dir_diduse_space(ds->ds_dir, 1853 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1854 } 1855 } 1856 dsl_dataset_rele(ds_next, FTAG); 1857 } else { 1858 zfeature_info_t *async_destroy = 1859 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY]; 1860 1861 /* 1862 * There's no next snapshot, so this is a head dataset. 1863 * Destroy the deadlist. Unless it's a clone, the 1864 * deadlist should be empty. (If it's a clone, it's 1865 * safe to ignore the deadlist contents.) 1866 */ 1867 dsl_deadlist_close(&ds->ds_deadlist); 1868 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1869 ds->ds_phys->ds_deadlist_obj = 0; 1870 1871 if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) { 1872 err = old_synchronous_dataset_destroy(ds, tx); 1873 } else { 1874 /* 1875 * Move the bptree into the pool's list of trees to 1876 * clean up and update space accounting information. 1877 */ 1878 uint64_t used, comp, uncomp; 1879 1880 ASSERT(err == 0 || err == EBUSY); 1881 if (!spa_feature_is_active(dp->dp_spa, async_destroy)) { 1882 spa_feature_incr(dp->dp_spa, async_destroy, tx); 1883 dp->dp_bptree_obj = bptree_alloc( 1884 dp->dp_meta_objset, tx); 1885 VERIFY(zap_add(dp->dp_meta_objset, 1886 DMU_POOL_DIRECTORY_OBJECT, 1887 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1, 1888 &dp->dp_bptree_obj, tx) == 0); 1889 } 1890 1891 used = ds->ds_dir->dd_phys->dd_used_bytes; 1892 comp = ds->ds_dir->dd_phys->dd_compressed_bytes; 1893 uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes; 1894 1895 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1896 ds->ds_phys->ds_unique_bytes == used); 1897 1898 bptree_add(dp->dp_meta_objset, dp->dp_bptree_obj, 1899 &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg, 1900 used, comp, uncomp, tx); 1901 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 1902 -used, -comp, -uncomp, tx); 1903 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD, 1904 used, comp, uncomp, tx); 1905 } 1906 1907 if (ds->ds_prev != NULL) { 1908 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 1909 VERIFY3U(0, ==, zap_remove_int(mos, 1910 ds->ds_prev->ds_dir->dd_phys->dd_clones, 1911 ds->ds_object, tx)); 1912 } 1913 dsl_dataset_rele(ds->ds_prev, ds); 1914 ds->ds_prev = ds_prev = NULL; 1915 } 1916 } 1917 1918 /* 1919 * This must be done after the dsl_traverse(), because it will 1920 * re-open the objset. 1921 */ 1922 if (ds->ds_objset) { 1923 dmu_objset_evict(ds->ds_objset); 1924 ds->ds_objset = NULL; 1925 } 1926 1927 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1928 /* Erase the link in the dir */ 1929 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1930 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1931 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1932 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1933 ASSERT(err == 0); 1934 } else { 1935 /* remove from snapshot namespace */ 1936 dsl_dataset_t *ds_head; 1937 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1938 VERIFY(0 == dsl_dataset_hold_obj(dp, 1939 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1940 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1941 #ifdef ZFS_DEBUG 1942 { 1943 uint64_t val; 1944 1945 err = dsl_dataset_snap_lookup(ds_head, 1946 ds->ds_snapname, &val); 1947 ASSERT3U(err, ==, 0); 1948 ASSERT3U(val, ==, obj); 1949 } 1950 #endif 1951 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1952 ASSERT(err == 0); 1953 dsl_dataset_rele(ds_head, FTAG); 1954 } 1955 1956 if (ds_prev && ds->ds_prev != ds_prev) 1957 dsl_dataset_rele(ds_prev, FTAG); 1958 1959 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1960 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx, 1961 "dataset = %llu", ds->ds_object); 1962 1963 if (ds->ds_phys->ds_next_clones_obj != 0) { 1964 uint64_t count; 1965 ASSERT(0 == zap_count(mos, 1966 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1967 VERIFY(0 == dmu_object_free(mos, 1968 ds->ds_phys->ds_next_clones_obj, tx)); 1969 } 1970 if (ds->ds_phys->ds_props_obj != 0) 1971 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1972 if (ds->ds_phys->ds_userrefs_obj != 0) 1973 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1974 dsl_dir_close(ds->ds_dir, ds); 1975 ds->ds_dir = NULL; 1976 dsl_dataset_drain_refs(ds, tag); 1977 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1978 1979 if (dsda->rm_origin) { 1980 /* 1981 * Remove the origin of the clone we just destroyed. 1982 */ 1983 struct dsl_ds_destroyarg ndsda = {0}; 1984 1985 ndsda.ds = dsda->rm_origin; 1986 dsl_dataset_destroy_sync(&ndsda, tag, tx); 1987 } 1988 } 1989 1990 static int 1991 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1992 { 1993 uint64_t asize; 1994 1995 if (!dmu_tx_is_syncing(tx)) 1996 return (0); 1997 1998 /* 1999 * If there's an fs-only reservation, any blocks that might become 2000 * owned by the snapshot dataset must be accommodated by space 2001 * outside of the reservation. 2002 */ 2003 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds)); 2004 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2005 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 2006 return (ENOSPC); 2007 2008 /* 2009 * Propogate any reserved space for this snapshot to other 2010 * snapshot checks in this sync group. 2011 */ 2012 if (asize > 0) 2013 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 2014 2015 return (0); 2016 } 2017 2018 int 2019 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 2020 { 2021 dsl_dataset_t *ds = arg1; 2022 const char *snapname = arg2; 2023 int err; 2024 uint64_t value; 2025 2026 /* 2027 * We don't allow multiple snapshots of the same txg. If there 2028 * is already one, try again. 2029 */ 2030 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 2031 return (EAGAIN); 2032 2033 /* 2034 * Check for conflicting name snapshot name. 2035 */ 2036 err = dsl_dataset_snap_lookup(ds, snapname, &value); 2037 if (err == 0) 2038 return (EEXIST); 2039 if (err != ENOENT) 2040 return (err); 2041 2042 /* 2043 * Check that the dataset's name is not too long. Name consists 2044 * of the dataset's length + 1 for the @-sign + snapshot name's length 2045 */ 2046 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 2047 return (ENAMETOOLONG); 2048 2049 err = dsl_dataset_snapshot_reserve_space(ds, tx); 2050 if (err) 2051 return (err); 2052 2053 ds->ds_trysnap_txg = tx->tx_txg; 2054 return (0); 2055 } 2056 2057 void 2058 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2059 { 2060 dsl_dataset_t *ds = arg1; 2061 const char *snapname = arg2; 2062 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2063 dmu_buf_t *dbuf; 2064 dsl_dataset_phys_t *dsphys; 2065 uint64_t dsobj, crtxg; 2066 objset_t *mos = dp->dp_meta_objset; 2067 int err; 2068 2069 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 2070 2071 /* 2072 * The origin's ds_creation_txg has to be < TXG_INITIAL 2073 */ 2074 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 2075 crtxg = 1; 2076 else 2077 crtxg = tx->tx_txg; 2078 2079 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 2080 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 2081 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 2082 dmu_buf_will_dirty(dbuf, tx); 2083 dsphys = dbuf->db_data; 2084 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 2085 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 2086 dsphys->ds_fsid_guid = unique_create(); 2087 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 2088 sizeof (dsphys->ds_guid)); 2089 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 2090 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 2091 dsphys->ds_next_snap_obj = ds->ds_object; 2092 dsphys->ds_num_children = 1; 2093 dsphys->ds_creation_time = gethrestime_sec(); 2094 dsphys->ds_creation_txg = crtxg; 2095 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 2096 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes; 2097 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 2098 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 2099 dsphys->ds_flags = ds->ds_phys->ds_flags; 2100 dsphys->ds_bp = ds->ds_phys->ds_bp; 2101 dmu_buf_rele(dbuf, FTAG); 2102 2103 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 2104 if (ds->ds_prev) { 2105 uint64_t next_clones_obj = 2106 ds->ds_prev->ds_phys->ds_next_clones_obj; 2107 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 2108 ds->ds_object || 2109 ds->ds_prev->ds_phys->ds_num_children > 1); 2110 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 2111 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 2112 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 2113 ds->ds_prev->ds_phys->ds_creation_txg); 2114 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 2115 } else if (next_clones_obj != 0) { 2116 remove_from_next_clones(ds->ds_prev, 2117 dsphys->ds_next_snap_obj, tx); 2118 VERIFY3U(0, ==, zap_add_int(mos, 2119 next_clones_obj, dsobj, tx)); 2120 } 2121 } 2122 2123 /* 2124 * If we have a reference-reservation on this dataset, we will 2125 * need to increase the amount of refreservation being charged 2126 * since our unique space is going to zero. 2127 */ 2128 if (ds->ds_reserved) { 2129 int64_t delta; 2130 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 2131 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2132 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 2133 delta, 0, 0, tx); 2134 } 2135 2136 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2137 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu", 2138 ds->ds_dir->dd_myname, snapname, dsobj, 2139 ds->ds_phys->ds_prev_snap_txg); 2140 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist, 2141 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx); 2142 dsl_deadlist_close(&ds->ds_deadlist); 2143 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 2144 dsl_deadlist_add_key(&ds->ds_deadlist, 2145 ds->ds_phys->ds_prev_snap_txg, tx); 2146 2147 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 2148 ds->ds_phys->ds_prev_snap_obj = dsobj; 2149 ds->ds_phys->ds_prev_snap_txg = crtxg; 2150 ds->ds_phys->ds_unique_bytes = 0; 2151 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 2152 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 2153 2154 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 2155 snapname, 8, 1, &dsobj, tx); 2156 ASSERT(err == 0); 2157 2158 if (ds->ds_prev) 2159 dsl_dataset_drop_ref(ds->ds_prev, ds); 2160 VERIFY(0 == dsl_dataset_get_ref(dp, 2161 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 2162 2163 dsl_scan_ds_snapshotted(ds, tx); 2164 2165 dsl_dir_snap_cmtime_update(ds->ds_dir); 2166 2167 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx, 2168 "dataset = %llu", dsobj); 2169 } 2170 2171 void 2172 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 2173 { 2174 ASSERT(dmu_tx_is_syncing(tx)); 2175 ASSERT(ds->ds_objset != NULL); 2176 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 2177 2178 /* 2179 * in case we had to change ds_fsid_guid when we opened it, 2180 * sync it out now. 2181 */ 2182 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2183 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2184 2185 dsl_dir_dirty(ds->ds_dir, tx); 2186 dmu_objset_sync(ds->ds_objset, zio, tx); 2187 } 2188 2189 static void 2190 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv) 2191 { 2192 uint64_t count = 0; 2193 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 2194 zap_cursor_t zc; 2195 zap_attribute_t za; 2196 nvlist_t *propval; 2197 nvlist_t *val; 2198 2199 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2200 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0); 2201 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0); 2202 2203 /* 2204 * There may me missing entries in ds_next_clones_obj 2205 * due to a bug in a previous version of the code. 2206 * Only trust it if it has the right number of entries. 2207 */ 2208 if (ds->ds_phys->ds_next_clones_obj != 0) { 2209 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 2210 &count)); 2211 } 2212 if (count != ds->ds_phys->ds_num_children - 1) { 2213 goto fail; 2214 } 2215 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj); 2216 zap_cursor_retrieve(&zc, &za) == 0; 2217 zap_cursor_advance(&zc)) { 2218 dsl_dataset_t *clone; 2219 char buf[ZFS_MAXNAMELEN]; 2220 /* 2221 * Even though we hold the dp_config_rwlock, the dataset 2222 * may fail to open, returning ENOENT. If there is a 2223 * thread concurrently attempting to destroy this 2224 * dataset, it will have the ds_rwlock held for 2225 * RW_WRITER. Our call to dsl_dataset_hold_obj() -> 2226 * dsl_dataset_hold_ref() will fail its 2227 * rw_tryenter(&ds->ds_rwlock, RW_READER), drop the 2228 * dp_config_rwlock, and wait for the destroy progress 2229 * and signal ds_exclusive_cv. If the destroy was 2230 * successful, we will see that 2231 * DSL_DATASET_IS_DESTROYED(), and return ENOENT. 2232 */ 2233 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 2234 za.za_first_integer, FTAG, &clone) != 0) 2235 continue; 2236 dsl_dir_name(clone->ds_dir, buf); 2237 VERIFY(nvlist_add_boolean(val, buf) == 0); 2238 dsl_dataset_rele(clone, FTAG); 2239 } 2240 zap_cursor_fini(&zc); 2241 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0); 2242 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), 2243 propval) == 0); 2244 fail: 2245 nvlist_free(val); 2246 nvlist_free(propval); 2247 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2248 } 2249 2250 void 2251 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2252 { 2253 uint64_t refd, avail, uobjs, aobjs, ratio; 2254 2255 dsl_dir_stats(ds->ds_dir, nv); 2256 2257 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2258 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2259 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2260 2261 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2262 ds->ds_phys->ds_creation_time); 2263 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2264 ds->ds_phys->ds_creation_txg); 2265 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2266 ds->ds_quota); 2267 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2268 ds->ds_reserved); 2269 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2270 ds->ds_phys->ds_guid); 2271 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2272 ds->ds_phys->ds_unique_bytes); 2273 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2274 ds->ds_object); 2275 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2276 ds->ds_userrefs); 2277 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2278 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2279 2280 if (ds->ds_phys->ds_prev_snap_obj != 0) { 2281 uint64_t written, comp, uncomp; 2282 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2283 dsl_dataset_t *prev; 2284 2285 rw_enter(&dp->dp_config_rwlock, RW_READER); 2286 int err = dsl_dataset_hold_obj(dp, 2287 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev); 2288 rw_exit(&dp->dp_config_rwlock); 2289 if (err == 0) { 2290 err = dsl_dataset_space_written(prev, ds, &written, 2291 &comp, &uncomp); 2292 dsl_dataset_rele(prev, FTAG); 2293 if (err == 0) { 2294 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN, 2295 written); 2296 } 2297 } 2298 } 2299 2300 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2301 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2302 ds->ds_phys->ds_compressed_bytes); 2303 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio); 2304 2305 if (ds->ds_phys->ds_next_snap_obj) { 2306 /* 2307 * This is a snapshot; override the dd's space used with 2308 * our unique space and compression ratio. 2309 */ 2310 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2311 ds->ds_phys->ds_unique_bytes); 2312 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio); 2313 2314 get_clones_stat(ds, nv); 2315 } 2316 } 2317 2318 void 2319 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2320 { 2321 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2322 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2323 stat->dds_guid = ds->ds_phys->ds_guid; 2324 if (ds->ds_phys->ds_next_snap_obj) { 2325 stat->dds_is_snapshot = B_TRUE; 2326 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2327 } else { 2328 stat->dds_is_snapshot = B_FALSE; 2329 stat->dds_num_clones = 0; 2330 } 2331 2332 /* clone origin is really a dsl_dir thing... */ 2333 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2334 if (dsl_dir_is_clone(ds->ds_dir)) { 2335 dsl_dataset_t *ods; 2336 2337 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2338 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2339 dsl_dataset_name(ods, stat->dds_origin); 2340 dsl_dataset_drop_ref(ods, FTAG); 2341 } else { 2342 stat->dds_origin[0] = '\0'; 2343 } 2344 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2345 } 2346 2347 uint64_t 2348 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2349 { 2350 return (ds->ds_fsid_guid); 2351 } 2352 2353 void 2354 dsl_dataset_space(dsl_dataset_t *ds, 2355 uint64_t *refdbytesp, uint64_t *availbytesp, 2356 uint64_t *usedobjsp, uint64_t *availobjsp) 2357 { 2358 *refdbytesp = ds->ds_phys->ds_referenced_bytes; 2359 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2360 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2361 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2362 if (ds->ds_quota != 0) { 2363 /* 2364 * Adjust available bytes according to refquota 2365 */ 2366 if (*refdbytesp < ds->ds_quota) 2367 *availbytesp = MIN(*availbytesp, 2368 ds->ds_quota - *refdbytesp); 2369 else 2370 *availbytesp = 0; 2371 } 2372 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2373 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2374 } 2375 2376 boolean_t 2377 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2378 { 2379 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2380 2381 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2382 dsl_pool_sync_context(dp)); 2383 if (ds->ds_prev == NULL) 2384 return (B_FALSE); 2385 if (ds->ds_phys->ds_bp.blk_birth > 2386 ds->ds_prev->ds_phys->ds_creation_txg) { 2387 objset_t *os, *os_prev; 2388 /* 2389 * It may be that only the ZIL differs, because it was 2390 * reset in the head. Don't count that as being 2391 * modified. 2392 */ 2393 if (dmu_objset_from_ds(ds, &os) != 0) 2394 return (B_TRUE); 2395 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0) 2396 return (B_TRUE); 2397 return (bcmp(&os->os_phys->os_meta_dnode, 2398 &os_prev->os_phys->os_meta_dnode, 2399 sizeof (os->os_phys->os_meta_dnode)) != 0); 2400 } 2401 return (B_FALSE); 2402 } 2403 2404 /* ARGSUSED */ 2405 static int 2406 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2407 { 2408 dsl_dataset_t *ds = arg1; 2409 char *newsnapname = arg2; 2410 dsl_dir_t *dd = ds->ds_dir; 2411 dsl_dataset_t *hds; 2412 uint64_t val; 2413 int err; 2414 2415 err = dsl_dataset_hold_obj(dd->dd_pool, 2416 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2417 if (err) 2418 return (err); 2419 2420 /* new name better not be in use */ 2421 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2422 dsl_dataset_rele(hds, FTAG); 2423 2424 if (err == 0) 2425 err = EEXIST; 2426 else if (err == ENOENT) 2427 err = 0; 2428 2429 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2430 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2431 err = ENAMETOOLONG; 2432 2433 return (err); 2434 } 2435 2436 static void 2437 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2438 { 2439 dsl_dataset_t *ds = arg1; 2440 const char *newsnapname = arg2; 2441 dsl_dir_t *dd = ds->ds_dir; 2442 objset_t *mos = dd->dd_pool->dp_meta_objset; 2443 dsl_dataset_t *hds; 2444 int err; 2445 2446 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2447 2448 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2449 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2450 2451 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2452 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2453 ASSERT3U(err, ==, 0); 2454 mutex_enter(&ds->ds_lock); 2455 (void) strcpy(ds->ds_snapname, newsnapname); 2456 mutex_exit(&ds->ds_lock); 2457 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2458 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2459 ASSERT3U(err, ==, 0); 2460 2461 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2462 "dataset = %llu", ds->ds_object); 2463 dsl_dataset_rele(hds, FTAG); 2464 } 2465 2466 struct renamesnaparg { 2467 dsl_sync_task_group_t *dstg; 2468 char failed[MAXPATHLEN]; 2469 char *oldsnap; 2470 char *newsnap; 2471 }; 2472 2473 static int 2474 dsl_snapshot_rename_one(const char *name, void *arg) 2475 { 2476 struct renamesnaparg *ra = arg; 2477 dsl_dataset_t *ds = NULL; 2478 char *snapname; 2479 int err; 2480 2481 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); 2482 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); 2483 2484 /* 2485 * For recursive snapshot renames the parent won't be changing 2486 * so we just pass name for both the to/from argument. 2487 */ 2488 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); 2489 if (err != 0) { 2490 strfree(snapname); 2491 return (err == ENOENT ? 0 : err); 2492 } 2493 2494 #ifdef _KERNEL 2495 /* 2496 * For all filesystems undergoing rename, we'll need to unmount it. 2497 */ 2498 (void) zfs_unmount_snap(snapname, NULL); 2499 #endif 2500 err = dsl_dataset_hold(snapname, ra->dstg, &ds); 2501 strfree(snapname); 2502 if (err != 0) 2503 return (err == ENOENT ? 0 : err); 2504 2505 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2506 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2507 2508 return (0); 2509 } 2510 2511 static int 2512 dsl_recursive_rename(char *oldname, const char *newname) 2513 { 2514 int err; 2515 struct renamesnaparg *ra; 2516 dsl_sync_task_t *dst; 2517 spa_t *spa; 2518 char *cp, *fsname = spa_strdup(oldname); 2519 int len = strlen(oldname) + 1; 2520 2521 /* truncate the snapshot name to get the fsname */ 2522 cp = strchr(fsname, '@'); 2523 *cp = '\0'; 2524 2525 err = spa_open(fsname, &spa, FTAG); 2526 if (err) { 2527 kmem_free(fsname, len); 2528 return (err); 2529 } 2530 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2531 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2532 2533 ra->oldsnap = strchr(oldname, '@') + 1; 2534 ra->newsnap = strchr(newname, '@') + 1; 2535 *ra->failed = '\0'; 2536 2537 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2538 DS_FIND_CHILDREN); 2539 kmem_free(fsname, len); 2540 2541 if (err == 0) { 2542 err = dsl_sync_task_group_wait(ra->dstg); 2543 } 2544 2545 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2546 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2547 dsl_dataset_t *ds = dst->dst_arg1; 2548 if (dst->dst_err) { 2549 dsl_dir_name(ds->ds_dir, ra->failed); 2550 (void) strlcat(ra->failed, "@", sizeof (ra->failed)); 2551 (void) strlcat(ra->failed, ra->newsnap, 2552 sizeof (ra->failed)); 2553 } 2554 dsl_dataset_rele(ds, ra->dstg); 2555 } 2556 2557 if (err) 2558 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); 2559 2560 dsl_sync_task_group_destroy(ra->dstg); 2561 kmem_free(ra, sizeof (struct renamesnaparg)); 2562 spa_close(spa, FTAG); 2563 return (err); 2564 } 2565 2566 static int 2567 dsl_valid_rename(const char *oldname, void *arg) 2568 { 2569 int delta = *(int *)arg; 2570 2571 if (strlen(oldname) + delta >= MAXNAMELEN) 2572 return (ENAMETOOLONG); 2573 2574 return (0); 2575 } 2576 2577 #pragma weak dmu_objset_rename = dsl_dataset_rename 2578 int 2579 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2580 { 2581 dsl_dir_t *dd; 2582 dsl_dataset_t *ds; 2583 const char *tail; 2584 int err; 2585 2586 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2587 if (err) 2588 return (err); 2589 2590 if (tail == NULL) { 2591 int delta = strlen(newname) - strlen(oldname); 2592 2593 /* if we're growing, validate child name lengths */ 2594 if (delta > 0) 2595 err = dmu_objset_find(oldname, dsl_valid_rename, 2596 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2597 2598 if (err == 0) 2599 err = dsl_dir_rename(dd, newname); 2600 dsl_dir_close(dd, FTAG); 2601 return (err); 2602 } 2603 2604 if (tail[0] != '@') { 2605 /* the name ended in a nonexistent component */ 2606 dsl_dir_close(dd, FTAG); 2607 return (ENOENT); 2608 } 2609 2610 dsl_dir_close(dd, FTAG); 2611 2612 /* new name must be snapshot in same filesystem */ 2613 tail = strchr(newname, '@'); 2614 if (tail == NULL) 2615 return (EINVAL); 2616 tail++; 2617 if (strncmp(oldname, newname, tail - newname) != 0) 2618 return (EXDEV); 2619 2620 if (recursive) { 2621 err = dsl_recursive_rename(oldname, newname); 2622 } else { 2623 err = dsl_dataset_hold(oldname, FTAG, &ds); 2624 if (err) 2625 return (err); 2626 2627 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2628 dsl_dataset_snapshot_rename_check, 2629 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2630 2631 dsl_dataset_rele(ds, FTAG); 2632 } 2633 2634 return (err); 2635 } 2636 2637 struct promotenode { 2638 list_node_t link; 2639 dsl_dataset_t *ds; 2640 }; 2641 2642 struct promotearg { 2643 list_t shared_snaps, origin_snaps, clone_snaps; 2644 dsl_dataset_t *origin_origin; 2645 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2646 char *err_ds; 2647 }; 2648 2649 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2650 static boolean_t snaplist_unstable(list_t *l); 2651 2652 static int 2653 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2654 { 2655 dsl_dataset_t *hds = arg1; 2656 struct promotearg *pa = arg2; 2657 struct promotenode *snap = list_head(&pa->shared_snaps); 2658 dsl_dataset_t *origin_ds = snap->ds; 2659 int err; 2660 uint64_t unused; 2661 2662 /* Check that it is a real clone */ 2663 if (!dsl_dir_is_clone(hds->ds_dir)) 2664 return (EINVAL); 2665 2666 /* Since this is so expensive, don't do the preliminary check */ 2667 if (!dmu_tx_is_syncing(tx)) 2668 return (0); 2669 2670 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2671 return (EXDEV); 2672 2673 /* compute origin's new unique space */ 2674 snap = list_tail(&pa->clone_snaps); 2675 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2676 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2677 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2678 &pa->unique, &unused, &unused); 2679 2680 /* 2681 * Walk the snapshots that we are moving 2682 * 2683 * Compute space to transfer. Consider the incremental changes 2684 * to used for each snapshot: 2685 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2686 * So each snapshot gave birth to: 2687 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2688 * So a sequence would look like: 2689 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2690 * Which simplifies to: 2691 * uN + kN + kN-1 + ... + k1 + k0 2692 * Note however, if we stop before we reach the ORIGIN we get: 2693 * uN + kN + kN-1 + ... + kM - uM-1 2694 */ 2695 pa->used = origin_ds->ds_phys->ds_referenced_bytes; 2696 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2697 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2698 for (snap = list_head(&pa->shared_snaps); snap; 2699 snap = list_next(&pa->shared_snaps, snap)) { 2700 uint64_t val, dlused, dlcomp, dluncomp; 2701 dsl_dataset_t *ds = snap->ds; 2702 2703 /* Check that the snapshot name does not conflict */ 2704 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2705 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2706 if (err == 0) { 2707 err = EEXIST; 2708 goto out; 2709 } 2710 if (err != ENOENT) 2711 goto out; 2712 2713 /* The very first snapshot does not have a deadlist */ 2714 if (ds->ds_phys->ds_prev_snap_obj == 0) 2715 continue; 2716 2717 dsl_deadlist_space(&ds->ds_deadlist, 2718 &dlused, &dlcomp, &dluncomp); 2719 pa->used += dlused; 2720 pa->comp += dlcomp; 2721 pa->uncomp += dluncomp; 2722 } 2723 2724 /* 2725 * If we are a clone of a clone then we never reached ORIGIN, 2726 * so we need to subtract out the clone origin's used space. 2727 */ 2728 if (pa->origin_origin) { 2729 pa->used -= pa->origin_origin->ds_phys->ds_referenced_bytes; 2730 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2731 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2732 } 2733 2734 /* Check that there is enough space here */ 2735 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2736 pa->used); 2737 if (err) 2738 return (err); 2739 2740 /* 2741 * Compute the amounts of space that will be used by snapshots 2742 * after the promotion (for both origin and clone). For each, 2743 * it is the amount of space that will be on all of their 2744 * deadlists (that was not born before their new origin). 2745 */ 2746 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2747 uint64_t space; 2748 2749 /* 2750 * Note, typically this will not be a clone of a clone, 2751 * so dd_origin_txg will be < TXG_INITIAL, so 2752 * these snaplist_space() -> dsl_deadlist_space_range() 2753 * calls will be fast because they do not have to 2754 * iterate over all bps. 2755 */ 2756 snap = list_head(&pa->origin_snaps); 2757 err = snaplist_space(&pa->shared_snaps, 2758 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap); 2759 if (err) 2760 return (err); 2761 2762 err = snaplist_space(&pa->clone_snaps, 2763 snap->ds->ds_dir->dd_origin_txg, &space); 2764 if (err) 2765 return (err); 2766 pa->cloneusedsnap += space; 2767 } 2768 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2769 err = snaplist_space(&pa->origin_snaps, 2770 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2771 if (err) 2772 return (err); 2773 } 2774 2775 return (0); 2776 out: 2777 pa->err_ds = snap->ds->ds_snapname; 2778 return (err); 2779 } 2780 2781 static void 2782 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2783 { 2784 dsl_dataset_t *hds = arg1; 2785 struct promotearg *pa = arg2; 2786 struct promotenode *snap = list_head(&pa->shared_snaps); 2787 dsl_dataset_t *origin_ds = snap->ds; 2788 dsl_dataset_t *origin_head; 2789 dsl_dir_t *dd = hds->ds_dir; 2790 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2791 dsl_dir_t *odd = NULL; 2792 uint64_t oldnext_obj; 2793 int64_t delta; 2794 2795 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2796 2797 snap = list_head(&pa->origin_snaps); 2798 origin_head = snap->ds; 2799 2800 /* 2801 * We need to explicitly open odd, since origin_ds's dd will be 2802 * changing. 2803 */ 2804 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2805 NULL, FTAG, &odd)); 2806 2807 /* change origin's next snap */ 2808 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2809 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2810 snap = list_tail(&pa->clone_snaps); 2811 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2812 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2813 2814 /* change the origin's next clone */ 2815 if (origin_ds->ds_phys->ds_next_clones_obj) { 2816 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2817 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2818 origin_ds->ds_phys->ds_next_clones_obj, 2819 oldnext_obj, tx)); 2820 } 2821 2822 /* change origin */ 2823 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2824 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2825 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2826 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg; 2827 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2828 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2829 origin_head->ds_dir->dd_origin_txg = 2830 origin_ds->ds_phys->ds_creation_txg; 2831 2832 /* change dd_clone entries */ 2833 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2834 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2835 odd->dd_phys->dd_clones, hds->ds_object, tx)); 2836 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2837 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2838 hds->ds_object, tx)); 2839 2840 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2841 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2842 origin_head->ds_object, tx)); 2843 if (dd->dd_phys->dd_clones == 0) { 2844 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset, 2845 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 2846 } 2847 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2848 dd->dd_phys->dd_clones, origin_head->ds_object, tx)); 2849 2850 } 2851 2852 /* move snapshots to this dir */ 2853 for (snap = list_head(&pa->shared_snaps); snap; 2854 snap = list_next(&pa->shared_snaps, snap)) { 2855 dsl_dataset_t *ds = snap->ds; 2856 2857 /* unregister props as dsl_dir is changing */ 2858 if (ds->ds_objset) { 2859 dmu_objset_evict(ds->ds_objset); 2860 ds->ds_objset = NULL; 2861 } 2862 /* move snap name entry */ 2863 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2864 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2865 ds->ds_snapname, tx)); 2866 VERIFY(0 == zap_add(dp->dp_meta_objset, 2867 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2868 8, 1, &ds->ds_object, tx)); 2869 2870 /* change containing dsl_dir */ 2871 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2872 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2873 ds->ds_phys->ds_dir_obj = dd->dd_object; 2874 ASSERT3P(ds->ds_dir, ==, odd); 2875 dsl_dir_close(ds->ds_dir, ds); 2876 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2877 NULL, ds, &ds->ds_dir)); 2878 2879 /* move any clone references */ 2880 if (ds->ds_phys->ds_next_clones_obj && 2881 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2882 zap_cursor_t zc; 2883 zap_attribute_t za; 2884 2885 for (zap_cursor_init(&zc, dp->dp_meta_objset, 2886 ds->ds_phys->ds_next_clones_obj); 2887 zap_cursor_retrieve(&zc, &za) == 0; 2888 zap_cursor_advance(&zc)) { 2889 dsl_dataset_t *cnds; 2890 uint64_t o; 2891 2892 if (za.za_first_integer == oldnext_obj) { 2893 /* 2894 * We've already moved the 2895 * origin's reference. 2896 */ 2897 continue; 2898 } 2899 2900 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 2901 za.za_first_integer, FTAG, &cnds)); 2902 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj; 2903 2904 VERIFY3U(zap_remove_int(dp->dp_meta_objset, 2905 odd->dd_phys->dd_clones, o, tx), ==, 0); 2906 VERIFY3U(zap_add_int(dp->dp_meta_objset, 2907 dd->dd_phys->dd_clones, o, tx), ==, 0); 2908 dsl_dataset_rele(cnds, FTAG); 2909 } 2910 zap_cursor_fini(&zc); 2911 } 2912 2913 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2914 } 2915 2916 /* 2917 * Change space accounting. 2918 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2919 * both be valid, or both be 0 (resulting in delta == 0). This 2920 * is true for each of {clone,origin} independently. 2921 */ 2922 2923 delta = pa->cloneusedsnap - 2924 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2925 ASSERT3S(delta, >=, 0); 2926 ASSERT3U(pa->used, >=, delta); 2927 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2928 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2929 pa->used - delta, pa->comp, pa->uncomp, tx); 2930 2931 delta = pa->originusedsnap - 2932 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2933 ASSERT3S(delta, <=, 0); 2934 ASSERT3U(pa->used, >=, -delta); 2935 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2936 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2937 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2938 2939 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2940 2941 /* log history record */ 2942 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2943 "dataset = %llu", hds->ds_object); 2944 2945 dsl_dir_close(odd, FTAG); 2946 } 2947 2948 static char *snaplist_tag = "snaplist"; 2949 /* 2950 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2951 * (exclusive) and last_obj (inclusive). The list will be in reverse 2952 * order (last_obj will be the list_head()). If first_obj == 0, do all 2953 * snapshots back to this dataset's origin. 2954 */ 2955 static int 2956 snaplist_make(dsl_pool_t *dp, boolean_t own, 2957 uint64_t first_obj, uint64_t last_obj, list_t *l) 2958 { 2959 uint64_t obj = last_obj; 2960 2961 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2962 2963 list_create(l, sizeof (struct promotenode), 2964 offsetof(struct promotenode, link)); 2965 2966 while (obj != first_obj) { 2967 dsl_dataset_t *ds; 2968 struct promotenode *snap; 2969 int err; 2970 2971 if (own) { 2972 err = dsl_dataset_own_obj(dp, obj, 2973 0, snaplist_tag, &ds); 2974 if (err == 0) 2975 dsl_dataset_make_exclusive(ds, snaplist_tag); 2976 } else { 2977 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2978 } 2979 if (err == ENOENT) { 2980 /* lost race with snapshot destroy */ 2981 struct promotenode *last = list_tail(l); 2982 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2983 obj = last->ds->ds_phys->ds_prev_snap_obj; 2984 continue; 2985 } else if (err) { 2986 return (err); 2987 } 2988 2989 if (first_obj == 0) 2990 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2991 2992 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2993 snap->ds = ds; 2994 list_insert_tail(l, snap); 2995 obj = ds->ds_phys->ds_prev_snap_obj; 2996 } 2997 2998 return (0); 2999 } 3000 3001 static int 3002 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 3003 { 3004 struct promotenode *snap; 3005 3006 *spacep = 0; 3007 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 3008 uint64_t used, comp, uncomp; 3009 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 3010 mintxg, UINT64_MAX, &used, &comp, &uncomp); 3011 *spacep += used; 3012 } 3013 return (0); 3014 } 3015 3016 static void 3017 snaplist_destroy(list_t *l, boolean_t own) 3018 { 3019 struct promotenode *snap; 3020 3021 if (!l || !list_link_active(&l->list_head)) 3022 return; 3023 3024 while ((snap = list_tail(l)) != NULL) { 3025 list_remove(l, snap); 3026 if (own) 3027 dsl_dataset_disown(snap->ds, snaplist_tag); 3028 else 3029 dsl_dataset_rele(snap->ds, snaplist_tag); 3030 kmem_free(snap, sizeof (struct promotenode)); 3031 } 3032 list_destroy(l); 3033 } 3034 3035 /* 3036 * Promote a clone. Nomenclature note: 3037 * "clone" or "cds": the original clone which is being promoted 3038 * "origin" or "ods": the snapshot which is originally clone's origin 3039 * "origin head" or "ohds": the dataset which is the head 3040 * (filesystem/volume) for the origin 3041 * "origin origin": the origin of the origin's filesystem (typically 3042 * NULL, indicating that the clone is not a clone of a clone). 3043 */ 3044 int 3045 dsl_dataset_promote(const char *name, char *conflsnap) 3046 { 3047 dsl_dataset_t *ds; 3048 dsl_dir_t *dd; 3049 dsl_pool_t *dp; 3050 dmu_object_info_t doi; 3051 struct promotearg pa = { 0 }; 3052 struct promotenode *snap; 3053 int err; 3054 3055 err = dsl_dataset_hold(name, FTAG, &ds); 3056 if (err) 3057 return (err); 3058 dd = ds->ds_dir; 3059 dp = dd->dd_pool; 3060 3061 err = dmu_object_info(dp->dp_meta_objset, 3062 ds->ds_phys->ds_snapnames_zapobj, &doi); 3063 if (err) { 3064 dsl_dataset_rele(ds, FTAG); 3065 return (err); 3066 } 3067 3068 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 3069 dsl_dataset_rele(ds, FTAG); 3070 return (EINVAL); 3071 } 3072 3073 /* 3074 * We are going to inherit all the snapshots taken before our 3075 * origin (i.e., our new origin will be our parent's origin). 3076 * Take ownership of them so that we can rename them into our 3077 * namespace. 3078 */ 3079 rw_enter(&dp->dp_config_rwlock, RW_READER); 3080 3081 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 3082 &pa.shared_snaps); 3083 if (err != 0) 3084 goto out; 3085 3086 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 3087 if (err != 0) 3088 goto out; 3089 3090 snap = list_head(&pa.shared_snaps); 3091 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 3092 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 3093 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 3094 if (err != 0) 3095 goto out; 3096 3097 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) { 3098 err = dsl_dataset_hold_obj(dp, 3099 snap->ds->ds_dir->dd_phys->dd_origin_obj, 3100 FTAG, &pa.origin_origin); 3101 if (err != 0) 3102 goto out; 3103 } 3104 3105 out: 3106 rw_exit(&dp->dp_config_rwlock); 3107 3108 /* 3109 * Add in 128x the snapnames zapobj size, since we will be moving 3110 * a bunch of snapnames to the promoted ds, and dirtying their 3111 * bonus buffers. 3112 */ 3113 if (err == 0) { 3114 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 3115 dsl_dataset_promote_sync, ds, &pa, 3116 2 + 2 * doi.doi_physical_blocks_512); 3117 if (err && pa.err_ds && conflsnap) 3118 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 3119 } 3120 3121 snaplist_destroy(&pa.shared_snaps, B_TRUE); 3122 snaplist_destroy(&pa.clone_snaps, B_FALSE); 3123 snaplist_destroy(&pa.origin_snaps, B_FALSE); 3124 if (pa.origin_origin) 3125 dsl_dataset_rele(pa.origin_origin, FTAG); 3126 dsl_dataset_rele(ds, FTAG); 3127 return (err); 3128 } 3129 3130 struct cloneswaparg { 3131 dsl_dataset_t *cds; /* clone dataset */ 3132 dsl_dataset_t *ohds; /* origin's head dataset */ 3133 boolean_t force; 3134 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 3135 }; 3136 3137 /* ARGSUSED */ 3138 static int 3139 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 3140 { 3141 struct cloneswaparg *csa = arg1; 3142 3143 /* they should both be heads */ 3144 if (dsl_dataset_is_snapshot(csa->cds) || 3145 dsl_dataset_is_snapshot(csa->ohds)) 3146 return (EINVAL); 3147 3148 /* the branch point should be just before them */ 3149 if (csa->cds->ds_prev != csa->ohds->ds_prev) 3150 return (EINVAL); 3151 3152 /* cds should be the clone (unless they are unrelated) */ 3153 if (csa->cds->ds_prev != NULL && 3154 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 3155 csa->ohds->ds_object != 3156 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 3157 return (EINVAL); 3158 3159 /* the clone should be a child of the origin */ 3160 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 3161 return (EINVAL); 3162 3163 /* ohds shouldn't be modified unless 'force' */ 3164 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 3165 return (ETXTBSY); 3166 3167 /* adjust amount of any unconsumed refreservation */ 3168 csa->unused_refres_delta = 3169 (int64_t)MIN(csa->ohds->ds_reserved, 3170 csa->ohds->ds_phys->ds_unique_bytes) - 3171 (int64_t)MIN(csa->ohds->ds_reserved, 3172 csa->cds->ds_phys->ds_unique_bytes); 3173 3174 if (csa->unused_refres_delta > 0 && 3175 csa->unused_refres_delta > 3176 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 3177 return (ENOSPC); 3178 3179 if (csa->ohds->ds_quota != 0 && 3180 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 3181 return (EDQUOT); 3182 3183 return (0); 3184 } 3185 3186 /* ARGSUSED */ 3187 static void 3188 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3189 { 3190 struct cloneswaparg *csa = arg1; 3191 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 3192 3193 ASSERT(csa->cds->ds_reserved == 0); 3194 ASSERT(csa->ohds->ds_quota == 0 || 3195 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 3196 3197 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 3198 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 3199 3200 if (csa->cds->ds_objset != NULL) { 3201 dmu_objset_evict(csa->cds->ds_objset); 3202 csa->cds->ds_objset = NULL; 3203 } 3204 3205 if (csa->ohds->ds_objset != NULL) { 3206 dmu_objset_evict(csa->ohds->ds_objset); 3207 csa->ohds->ds_objset = NULL; 3208 } 3209 3210 /* 3211 * Reset origin's unique bytes, if it exists. 3212 */ 3213 if (csa->cds->ds_prev) { 3214 dsl_dataset_t *origin = csa->cds->ds_prev; 3215 uint64_t comp, uncomp; 3216 3217 dmu_buf_will_dirty(origin->ds_dbuf, tx); 3218 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3219 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 3220 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp); 3221 } 3222 3223 /* swap blkptrs */ 3224 { 3225 blkptr_t tmp; 3226 tmp = csa->ohds->ds_phys->ds_bp; 3227 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 3228 csa->cds->ds_phys->ds_bp = tmp; 3229 } 3230 3231 /* set dd_*_bytes */ 3232 { 3233 int64_t dused, dcomp, duncomp; 3234 uint64_t cdl_used, cdl_comp, cdl_uncomp; 3235 uint64_t odl_used, odl_comp, odl_uncomp; 3236 3237 ASSERT3U(csa->cds->ds_dir->dd_phys-> 3238 dd_used_breakdown[DD_USED_SNAP], ==, 0); 3239 3240 dsl_deadlist_space(&csa->cds->ds_deadlist, 3241 &cdl_used, &cdl_comp, &cdl_uncomp); 3242 dsl_deadlist_space(&csa->ohds->ds_deadlist, 3243 &odl_used, &odl_comp, &odl_uncomp); 3244 3245 dused = csa->cds->ds_phys->ds_referenced_bytes + cdl_used - 3246 (csa->ohds->ds_phys->ds_referenced_bytes + odl_used); 3247 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 3248 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 3249 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 3250 cdl_uncomp - 3251 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 3252 3253 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 3254 dused, dcomp, duncomp, tx); 3255 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 3256 -dused, -dcomp, -duncomp, tx); 3257 3258 /* 3259 * The difference in the space used by snapshots is the 3260 * difference in snapshot space due to the head's 3261 * deadlist (since that's the only thing that's 3262 * changing that affects the snapused). 3263 */ 3264 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3265 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3266 &cdl_used, &cdl_comp, &cdl_uncomp); 3267 dsl_deadlist_space_range(&csa->ohds->ds_deadlist, 3268 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3269 &odl_used, &odl_comp, &odl_uncomp); 3270 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 3271 DD_USED_HEAD, DD_USED_SNAP, tx); 3272 } 3273 3274 /* swap ds_*_bytes */ 3275 SWITCH64(csa->ohds->ds_phys->ds_referenced_bytes, 3276 csa->cds->ds_phys->ds_referenced_bytes); 3277 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 3278 csa->cds->ds_phys->ds_compressed_bytes); 3279 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 3280 csa->cds->ds_phys->ds_uncompressed_bytes); 3281 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 3282 csa->cds->ds_phys->ds_unique_bytes); 3283 3284 /* apply any parent delta for change in unconsumed refreservation */ 3285 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 3286 csa->unused_refres_delta, 0, 0, tx); 3287 3288 /* 3289 * Swap deadlists. 3290 */ 3291 dsl_deadlist_close(&csa->cds->ds_deadlist); 3292 dsl_deadlist_close(&csa->ohds->ds_deadlist); 3293 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 3294 csa->cds->ds_phys->ds_deadlist_obj); 3295 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 3296 csa->cds->ds_phys->ds_deadlist_obj); 3297 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 3298 csa->ohds->ds_phys->ds_deadlist_obj); 3299 3300 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx); 3301 } 3302 3303 /* 3304 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 3305 * recv" into an existing fs to swizzle the file system to the new 3306 * version, and by "zfs rollback". Can also be used to swap two 3307 * independent head datasets if neither has any snapshots. 3308 */ 3309 int 3310 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 3311 boolean_t force) 3312 { 3313 struct cloneswaparg csa; 3314 int error; 3315 3316 ASSERT(clone->ds_owner); 3317 ASSERT(origin_head->ds_owner); 3318 retry: 3319 /* 3320 * Need exclusive access for the swap. If we're swapping these 3321 * datasets back after an error, we already hold the locks. 3322 */ 3323 if (!RW_WRITE_HELD(&clone->ds_rwlock)) 3324 rw_enter(&clone->ds_rwlock, RW_WRITER); 3325 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) && 3326 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 3327 rw_exit(&clone->ds_rwlock); 3328 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 3329 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 3330 rw_exit(&origin_head->ds_rwlock); 3331 goto retry; 3332 } 3333 } 3334 csa.cds = clone; 3335 csa.ohds = origin_head; 3336 csa.force = force; 3337 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3338 dsl_dataset_clone_swap_check, 3339 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3340 return (error); 3341 } 3342 3343 /* 3344 * Given a pool name and a dataset object number in that pool, 3345 * return the name of that dataset. 3346 */ 3347 int 3348 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3349 { 3350 spa_t *spa; 3351 dsl_pool_t *dp; 3352 dsl_dataset_t *ds; 3353 int error; 3354 3355 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3356 return (error); 3357 dp = spa_get_dsl(spa); 3358 rw_enter(&dp->dp_config_rwlock, RW_READER); 3359 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3360 dsl_dataset_name(ds, buf); 3361 dsl_dataset_rele(ds, FTAG); 3362 } 3363 rw_exit(&dp->dp_config_rwlock); 3364 spa_close(spa, FTAG); 3365 3366 return (error); 3367 } 3368 3369 int 3370 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3371 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3372 { 3373 int error = 0; 3374 3375 ASSERT3S(asize, >, 0); 3376 3377 /* 3378 * *ref_rsrv is the portion of asize that will come from any 3379 * unconsumed refreservation space. 3380 */ 3381 *ref_rsrv = 0; 3382 3383 mutex_enter(&ds->ds_lock); 3384 /* 3385 * Make a space adjustment for reserved bytes. 3386 */ 3387 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3388 ASSERT3U(*used, >=, 3389 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3390 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3391 *ref_rsrv = 3392 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3393 } 3394 3395 if (!check_quota || ds->ds_quota == 0) { 3396 mutex_exit(&ds->ds_lock); 3397 return (0); 3398 } 3399 /* 3400 * If they are requesting more space, and our current estimate 3401 * is over quota, they get to try again unless the actual 3402 * on-disk is over quota and there are no pending changes (which 3403 * may free up space for us). 3404 */ 3405 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) { 3406 if (inflight > 0 || 3407 ds->ds_phys->ds_referenced_bytes < ds->ds_quota) 3408 error = ERESTART; 3409 else 3410 error = EDQUOT; 3411 } 3412 mutex_exit(&ds->ds_lock); 3413 3414 return (error); 3415 } 3416 3417 /* ARGSUSED */ 3418 static int 3419 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3420 { 3421 dsl_dataset_t *ds = arg1; 3422 dsl_prop_setarg_t *psa = arg2; 3423 int err; 3424 3425 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3426 return (ENOTSUP); 3427 3428 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3429 return (err); 3430 3431 if (psa->psa_effective_value == 0) 3432 return (0); 3433 3434 if (psa->psa_effective_value < ds->ds_phys->ds_referenced_bytes || 3435 psa->psa_effective_value < ds->ds_reserved) 3436 return (ENOSPC); 3437 3438 return (0); 3439 } 3440 3441 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *); 3442 3443 void 3444 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3445 { 3446 dsl_dataset_t *ds = arg1; 3447 dsl_prop_setarg_t *psa = arg2; 3448 uint64_t effective_value = psa->psa_effective_value; 3449 3450 dsl_prop_set_sync(ds, psa, tx); 3451 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3452 3453 if (ds->ds_quota != effective_value) { 3454 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3455 ds->ds_quota = effective_value; 3456 3457 spa_history_log_internal(LOG_DS_REFQUOTA, 3458 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ", 3459 (longlong_t)ds->ds_quota, ds->ds_object); 3460 } 3461 } 3462 3463 int 3464 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3465 { 3466 dsl_dataset_t *ds; 3467 dsl_prop_setarg_t psa; 3468 int err; 3469 3470 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3471 3472 err = dsl_dataset_hold(dsname, FTAG, &ds); 3473 if (err) 3474 return (err); 3475 3476 /* 3477 * If someone removes a file, then tries to set the quota, we 3478 * want to make sure the file freeing takes effect. 3479 */ 3480 txg_wait_open(ds->ds_dir->dd_pool, 0); 3481 3482 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3483 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3484 ds, &psa, 0); 3485 3486 dsl_dataset_rele(ds, FTAG); 3487 return (err); 3488 } 3489 3490 static int 3491 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3492 { 3493 dsl_dataset_t *ds = arg1; 3494 dsl_prop_setarg_t *psa = arg2; 3495 uint64_t effective_value; 3496 uint64_t unique; 3497 int err; 3498 3499 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3500 SPA_VERSION_REFRESERVATION) 3501 return (ENOTSUP); 3502 3503 if (dsl_dataset_is_snapshot(ds)) 3504 return (EINVAL); 3505 3506 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3507 return (err); 3508 3509 effective_value = psa->psa_effective_value; 3510 3511 /* 3512 * If we are doing the preliminary check in open context, the 3513 * space estimates may be inaccurate. 3514 */ 3515 if (!dmu_tx_is_syncing(tx)) 3516 return (0); 3517 3518 mutex_enter(&ds->ds_lock); 3519 if (!DS_UNIQUE_IS_ACCURATE(ds)) 3520 dsl_dataset_recalc_head_uniq(ds); 3521 unique = ds->ds_phys->ds_unique_bytes; 3522 mutex_exit(&ds->ds_lock); 3523 3524 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3525 uint64_t delta = MAX(unique, effective_value) - 3526 MAX(unique, ds->ds_reserved); 3527 3528 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3529 return (ENOSPC); 3530 if (ds->ds_quota > 0 && 3531 effective_value > ds->ds_quota) 3532 return (ENOSPC); 3533 } 3534 3535 return (0); 3536 } 3537 3538 static void 3539 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3540 { 3541 dsl_dataset_t *ds = arg1; 3542 dsl_prop_setarg_t *psa = arg2; 3543 uint64_t effective_value = psa->psa_effective_value; 3544 uint64_t unique; 3545 int64_t delta; 3546 3547 dsl_prop_set_sync(ds, psa, tx); 3548 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3549 3550 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3551 3552 mutex_enter(&ds->ds_dir->dd_lock); 3553 mutex_enter(&ds->ds_lock); 3554 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 3555 unique = ds->ds_phys->ds_unique_bytes; 3556 delta = MAX(0, (int64_t)(effective_value - unique)) - 3557 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3558 ds->ds_reserved = effective_value; 3559 mutex_exit(&ds->ds_lock); 3560 3561 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3562 mutex_exit(&ds->ds_dir->dd_lock); 3563 3564 spa_history_log_internal(LOG_DS_REFRESERV, 3565 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu", 3566 (longlong_t)effective_value, ds->ds_object); 3567 } 3568 3569 int 3570 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3571 uint64_t reservation) 3572 { 3573 dsl_dataset_t *ds; 3574 dsl_prop_setarg_t psa; 3575 int err; 3576 3577 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3578 &reservation); 3579 3580 err = dsl_dataset_hold(dsname, FTAG, &ds); 3581 if (err) 3582 return (err); 3583 3584 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3585 dsl_dataset_set_reservation_check, 3586 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3587 3588 dsl_dataset_rele(ds, FTAG); 3589 return (err); 3590 } 3591 3592 typedef struct zfs_hold_cleanup_arg { 3593 dsl_pool_t *dp; 3594 uint64_t dsobj; 3595 char htag[MAXNAMELEN]; 3596 } zfs_hold_cleanup_arg_t; 3597 3598 static void 3599 dsl_dataset_user_release_onexit(void *arg) 3600 { 3601 zfs_hold_cleanup_arg_t *ca = arg; 3602 3603 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag, 3604 B_TRUE); 3605 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t)); 3606 } 3607 3608 void 3609 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag, 3610 minor_t minor) 3611 { 3612 zfs_hold_cleanup_arg_t *ca; 3613 3614 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP); 3615 ca->dp = ds->ds_dir->dd_pool; 3616 ca->dsobj = ds->ds_object; 3617 (void) strlcpy(ca->htag, htag, sizeof (ca->htag)); 3618 VERIFY3U(0, ==, zfs_onexit_add_cb(minor, 3619 dsl_dataset_user_release_onexit, ca, NULL)); 3620 } 3621 3622 /* 3623 * If you add new checks here, you may need to add 3624 * additional checks to the "temporary" case in 3625 * snapshot_check() in dmu_objset.c. 3626 */ 3627 static int 3628 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3629 { 3630 dsl_dataset_t *ds = arg1; 3631 struct dsl_ds_holdarg *ha = arg2; 3632 char *htag = ha->htag; 3633 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3634 int error = 0; 3635 3636 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3637 return (ENOTSUP); 3638 3639 if (!dsl_dataset_is_snapshot(ds)) 3640 return (EINVAL); 3641 3642 /* tags must be unique */ 3643 mutex_enter(&ds->ds_lock); 3644 if (ds->ds_phys->ds_userrefs_obj) { 3645 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3646 8, 1, tx); 3647 if (error == 0) 3648 error = EEXIST; 3649 else if (error == ENOENT) 3650 error = 0; 3651 } 3652 mutex_exit(&ds->ds_lock); 3653 3654 if (error == 0 && ha->temphold && 3655 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3656 error = E2BIG; 3657 3658 return (error); 3659 } 3660 3661 void 3662 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3663 { 3664 dsl_dataset_t *ds = arg1; 3665 struct dsl_ds_holdarg *ha = arg2; 3666 char *htag = ha->htag; 3667 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3668 objset_t *mos = dp->dp_meta_objset; 3669 uint64_t now = gethrestime_sec(); 3670 uint64_t zapobj; 3671 3672 mutex_enter(&ds->ds_lock); 3673 if (ds->ds_phys->ds_userrefs_obj == 0) { 3674 /* 3675 * This is the first user hold for this dataset. Create 3676 * the userrefs zap object. 3677 */ 3678 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3679 zapobj = ds->ds_phys->ds_userrefs_obj = 3680 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3681 } else { 3682 zapobj = ds->ds_phys->ds_userrefs_obj; 3683 } 3684 ds->ds_userrefs++; 3685 mutex_exit(&ds->ds_lock); 3686 3687 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3688 3689 if (ha->temphold) { 3690 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3691 htag, &now, tx)); 3692 } 3693 3694 spa_history_log_internal(LOG_DS_USER_HOLD, 3695 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag, 3696 (int)ha->temphold, ds->ds_object); 3697 } 3698 3699 static int 3700 dsl_dataset_user_hold_one(const char *dsname, void *arg) 3701 { 3702 struct dsl_ds_holdarg *ha = arg; 3703 dsl_dataset_t *ds; 3704 int error; 3705 char *name; 3706 3707 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3708 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3709 error = dsl_dataset_hold(name, ha->dstg, &ds); 3710 strfree(name); 3711 if (error == 0) { 3712 ha->gotone = B_TRUE; 3713 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3714 dsl_dataset_user_hold_sync, ds, ha, 0); 3715 } else if (error == ENOENT && ha->recursive) { 3716 error = 0; 3717 } else { 3718 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3719 } 3720 return (error); 3721 } 3722 3723 int 3724 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag, 3725 boolean_t temphold) 3726 { 3727 struct dsl_ds_holdarg *ha; 3728 int error; 3729 3730 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3731 ha->htag = htag; 3732 ha->temphold = temphold; 3733 error = dsl_sync_task_do(ds->ds_dir->dd_pool, 3734 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync, 3735 ds, ha, 0); 3736 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3737 3738 return (error); 3739 } 3740 3741 int 3742 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3743 boolean_t recursive, boolean_t temphold, int cleanup_fd) 3744 { 3745 struct dsl_ds_holdarg *ha; 3746 dsl_sync_task_t *dst; 3747 spa_t *spa; 3748 int error; 3749 minor_t minor = 0; 3750 3751 if (cleanup_fd != -1) { 3752 /* Currently we only support cleanup-on-exit of tempholds. */ 3753 if (!temphold) 3754 return (EINVAL); 3755 error = zfs_onexit_fd_hold(cleanup_fd, &minor); 3756 if (error) 3757 return (error); 3758 } 3759 3760 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3761 3762 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3763 3764 error = spa_open(dsname, &spa, FTAG); 3765 if (error) { 3766 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3767 if (cleanup_fd != -1) 3768 zfs_onexit_fd_rele(cleanup_fd); 3769 return (error); 3770 } 3771 3772 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3773 ha->htag = htag; 3774 ha->snapname = snapname; 3775 ha->recursive = recursive; 3776 ha->temphold = temphold; 3777 3778 if (recursive) { 3779 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3780 ha, DS_FIND_CHILDREN); 3781 } else { 3782 error = dsl_dataset_user_hold_one(dsname, ha); 3783 } 3784 if (error == 0) 3785 error = dsl_sync_task_group_wait(ha->dstg); 3786 3787 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3788 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3789 dsl_dataset_t *ds = dst->dst_arg1; 3790 3791 if (dst->dst_err) { 3792 dsl_dataset_name(ds, ha->failed); 3793 *strchr(ha->failed, '@') = '\0'; 3794 } else if (error == 0 && minor != 0 && temphold) { 3795 /* 3796 * If this hold is to be released upon process exit, 3797 * register that action now. 3798 */ 3799 dsl_register_onexit_hold_cleanup(ds, htag, minor); 3800 } 3801 dsl_dataset_rele(ds, ha->dstg); 3802 } 3803 3804 if (error == 0 && recursive && !ha->gotone) 3805 error = ENOENT; 3806 3807 if (error) 3808 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3809 3810 dsl_sync_task_group_destroy(ha->dstg); 3811 3812 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3813 spa_close(spa, FTAG); 3814 if (cleanup_fd != -1) 3815 zfs_onexit_fd_rele(cleanup_fd); 3816 return (error); 3817 } 3818 3819 struct dsl_ds_releasearg { 3820 dsl_dataset_t *ds; 3821 const char *htag; 3822 boolean_t own; /* do we own or just hold ds? */ 3823 }; 3824 3825 static int 3826 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3827 boolean_t *might_destroy) 3828 { 3829 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3830 uint64_t zapobj; 3831 uint64_t tmp; 3832 int error; 3833 3834 *might_destroy = B_FALSE; 3835 3836 mutex_enter(&ds->ds_lock); 3837 zapobj = ds->ds_phys->ds_userrefs_obj; 3838 if (zapobj == 0) { 3839 /* The tag can't possibly exist */ 3840 mutex_exit(&ds->ds_lock); 3841 return (ESRCH); 3842 } 3843 3844 /* Make sure the tag exists */ 3845 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3846 if (error) { 3847 mutex_exit(&ds->ds_lock); 3848 if (error == ENOENT) 3849 error = ESRCH; 3850 return (error); 3851 } 3852 3853 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3854 DS_IS_DEFER_DESTROY(ds)) 3855 *might_destroy = B_TRUE; 3856 3857 mutex_exit(&ds->ds_lock); 3858 return (0); 3859 } 3860 3861 static int 3862 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3863 { 3864 struct dsl_ds_releasearg *ra = arg1; 3865 dsl_dataset_t *ds = ra->ds; 3866 boolean_t might_destroy; 3867 int error; 3868 3869 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3870 return (ENOTSUP); 3871 3872 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3873 if (error) 3874 return (error); 3875 3876 if (might_destroy) { 3877 struct dsl_ds_destroyarg dsda = {0}; 3878 3879 if (dmu_tx_is_syncing(tx)) { 3880 /* 3881 * If we're not prepared to remove the snapshot, 3882 * we can't allow the release to happen right now. 3883 */ 3884 if (!ra->own) 3885 return (EBUSY); 3886 } 3887 dsda.ds = ds; 3888 dsda.releasing = B_TRUE; 3889 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3890 } 3891 3892 return (0); 3893 } 3894 3895 static void 3896 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx) 3897 { 3898 struct dsl_ds_releasearg *ra = arg1; 3899 dsl_dataset_t *ds = ra->ds; 3900 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3901 objset_t *mos = dp->dp_meta_objset; 3902 uint64_t zapobj; 3903 uint64_t dsobj = ds->ds_object; 3904 uint64_t refs; 3905 int error; 3906 3907 mutex_enter(&ds->ds_lock); 3908 ds->ds_userrefs--; 3909 refs = ds->ds_userrefs; 3910 mutex_exit(&ds->ds_lock); 3911 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3912 VERIFY(error == 0 || error == ENOENT); 3913 zapobj = ds->ds_phys->ds_userrefs_obj; 3914 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3915 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3916 DS_IS_DEFER_DESTROY(ds)) { 3917 struct dsl_ds_destroyarg dsda = {0}; 3918 3919 ASSERT(ra->own); 3920 dsda.ds = ds; 3921 dsda.releasing = B_TRUE; 3922 /* We already did the destroy_check */ 3923 dsl_dataset_destroy_sync(&dsda, tag, tx); 3924 } 3925 3926 spa_history_log_internal(LOG_DS_USER_RELEASE, 3927 dp->dp_spa, tx, "<%s> %lld dataset = %llu", 3928 ra->htag, (longlong_t)refs, dsobj); 3929 } 3930 3931 static int 3932 dsl_dataset_user_release_one(const char *dsname, void *arg) 3933 { 3934 struct dsl_ds_holdarg *ha = arg; 3935 struct dsl_ds_releasearg *ra; 3936 dsl_dataset_t *ds; 3937 int error; 3938 void *dtag = ha->dstg; 3939 char *name; 3940 boolean_t own = B_FALSE; 3941 boolean_t might_destroy; 3942 3943 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3944 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3945 error = dsl_dataset_hold(name, dtag, &ds); 3946 strfree(name); 3947 if (error == ENOENT && ha->recursive) 3948 return (0); 3949 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3950 if (error) 3951 return (error); 3952 3953 ha->gotone = B_TRUE; 3954 3955 ASSERT(dsl_dataset_is_snapshot(ds)); 3956 3957 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3958 if (error) { 3959 dsl_dataset_rele(ds, dtag); 3960 return (error); 3961 } 3962 3963 if (might_destroy) { 3964 #ifdef _KERNEL 3965 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3966 error = zfs_unmount_snap(name, NULL); 3967 strfree(name); 3968 if (error) { 3969 dsl_dataset_rele(ds, dtag); 3970 return (error); 3971 } 3972 #endif 3973 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3974 dsl_dataset_rele(ds, dtag); 3975 return (EBUSY); 3976 } else { 3977 own = B_TRUE; 3978 dsl_dataset_make_exclusive(ds, dtag); 3979 } 3980 } 3981 3982 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3983 ra->ds = ds; 3984 ra->htag = ha->htag; 3985 ra->own = own; 3986 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3987 dsl_dataset_user_release_sync, ra, dtag, 0); 3988 3989 return (0); 3990 } 3991 3992 int 3993 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3994 boolean_t recursive) 3995 { 3996 struct dsl_ds_holdarg *ha; 3997 dsl_sync_task_t *dst; 3998 spa_t *spa; 3999 int error; 4000 4001 top: 4002 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 4003 4004 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 4005 4006 error = spa_open(dsname, &spa, FTAG); 4007 if (error) { 4008 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 4009 return (error); 4010 } 4011 4012 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 4013 ha->htag = htag; 4014 ha->snapname = snapname; 4015 ha->recursive = recursive; 4016 if (recursive) { 4017 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 4018 ha, DS_FIND_CHILDREN); 4019 } else { 4020 error = dsl_dataset_user_release_one(dsname, ha); 4021 } 4022 if (error == 0) 4023 error = dsl_sync_task_group_wait(ha->dstg); 4024 4025 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 4026 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 4027 struct dsl_ds_releasearg *ra = dst->dst_arg1; 4028 dsl_dataset_t *ds = ra->ds; 4029 4030 if (dst->dst_err) 4031 dsl_dataset_name(ds, ha->failed); 4032 4033 if (ra->own) 4034 dsl_dataset_disown(ds, ha->dstg); 4035 else 4036 dsl_dataset_rele(ds, ha->dstg); 4037 4038 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 4039 } 4040 4041 if (error == 0 && recursive && !ha->gotone) 4042 error = ENOENT; 4043 4044 if (error && error != EBUSY) 4045 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 4046 4047 dsl_sync_task_group_destroy(ha->dstg); 4048 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 4049 spa_close(spa, FTAG); 4050 4051 /* 4052 * We can get EBUSY if we were racing with deferred destroy and 4053 * dsl_dataset_user_release_check() hadn't done the necessary 4054 * open context setup. We can also get EBUSY if we're racing 4055 * with destroy and that thread is the ds_owner. Either way 4056 * the busy condition should be transient, and we should retry 4057 * the release operation. 4058 */ 4059 if (error == EBUSY) 4060 goto top; 4061 4062 return (error); 4063 } 4064 4065 /* 4066 * Called at spa_load time (with retry == B_FALSE) to release a stale 4067 * temporary user hold. Also called by the onexit code (with retry == B_TRUE). 4068 */ 4069 int 4070 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag, 4071 boolean_t retry) 4072 { 4073 dsl_dataset_t *ds; 4074 char *snap; 4075 char *name; 4076 int namelen; 4077 int error; 4078 4079 do { 4080 rw_enter(&dp->dp_config_rwlock, RW_READER); 4081 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 4082 rw_exit(&dp->dp_config_rwlock); 4083 if (error) 4084 return (error); 4085 namelen = dsl_dataset_namelen(ds)+1; 4086 name = kmem_alloc(namelen, KM_SLEEP); 4087 dsl_dataset_name(ds, name); 4088 dsl_dataset_rele(ds, FTAG); 4089 4090 snap = strchr(name, '@'); 4091 *snap = '\0'; 4092 ++snap; 4093 error = dsl_dataset_user_release(name, snap, htag, B_FALSE); 4094 kmem_free(name, namelen); 4095 4096 /* 4097 * The object can't have been destroyed because we have a hold, 4098 * but it might have been renamed, resulting in ENOENT. Retry 4099 * if we've been requested to do so. 4100 * 4101 * It would be nice if we could use the dsobj all the way 4102 * through and avoid ENOENT entirely. But we might need to 4103 * unmount the snapshot, and there's currently no way to lookup 4104 * a vfsp using a ZFS object id. 4105 */ 4106 } while ((error == ENOENT) && retry); 4107 4108 return (error); 4109 } 4110 4111 int 4112 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 4113 { 4114 dsl_dataset_t *ds; 4115 int err; 4116 4117 err = dsl_dataset_hold(dsname, FTAG, &ds); 4118 if (err) 4119 return (err); 4120 4121 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 4122 if (ds->ds_phys->ds_userrefs_obj != 0) { 4123 zap_attribute_t *za; 4124 zap_cursor_t zc; 4125 4126 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 4127 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 4128 ds->ds_phys->ds_userrefs_obj); 4129 zap_cursor_retrieve(&zc, za) == 0; 4130 zap_cursor_advance(&zc)) { 4131 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 4132 za->za_first_integer)); 4133 } 4134 zap_cursor_fini(&zc); 4135 kmem_free(za, sizeof (zap_attribute_t)); 4136 } 4137 dsl_dataset_rele(ds, FTAG); 4138 return (0); 4139 } 4140 4141 /* 4142 * Note, this function is used as the callback for dmu_objset_find(). We 4143 * always return 0 so that we will continue to find and process 4144 * inconsistent datasets, even if we encounter an error trying to 4145 * process one of them. 4146 */ 4147 /* ARGSUSED */ 4148 int 4149 dsl_destroy_inconsistent(const char *dsname, void *arg) 4150 { 4151 dsl_dataset_t *ds; 4152 4153 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 4154 if (DS_IS_INCONSISTENT(ds)) 4155 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 4156 else 4157 dsl_dataset_disown(ds, FTAG); 4158 } 4159 return (0); 4160 } 4161 4162 /* 4163 * Return (in *usedp) the amount of space written in new that is not 4164 * present in oldsnap. New may be a snapshot or the head. Old must be 4165 * a snapshot before new, in new's filesystem (or its origin). If not then 4166 * fail and return EINVAL. 4167 * 4168 * The written space is calculated by considering two components: First, we 4169 * ignore any freed space, and calculate the written as new's used space 4170 * minus old's used space. Next, we add in the amount of space that was freed 4171 * between the two snapshots, thus reducing new's used space relative to old's. 4172 * Specifically, this is the space that was born before old->ds_creation_txg, 4173 * and freed before new (ie. on new's deadlist or a previous deadlist). 4174 * 4175 * space freed [---------------------] 4176 * snapshots ---O-------O--------O-------O------ 4177 * oldsnap new 4178 */ 4179 int 4180 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new, 4181 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) 4182 { 4183 int err = 0; 4184 uint64_t snapobj; 4185 dsl_pool_t *dp = new->ds_dir->dd_pool; 4186 4187 *usedp = 0; 4188 *usedp += new->ds_phys->ds_referenced_bytes; 4189 *usedp -= oldsnap->ds_phys->ds_referenced_bytes; 4190 4191 *compp = 0; 4192 *compp += new->ds_phys->ds_compressed_bytes; 4193 *compp -= oldsnap->ds_phys->ds_compressed_bytes; 4194 4195 *uncompp = 0; 4196 *uncompp += new->ds_phys->ds_uncompressed_bytes; 4197 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes; 4198 4199 rw_enter(&dp->dp_config_rwlock, RW_READER); 4200 snapobj = new->ds_object; 4201 while (snapobj != oldsnap->ds_object) { 4202 dsl_dataset_t *snap; 4203 uint64_t used, comp, uncomp; 4204 4205 if (snapobj == new->ds_object) { 4206 snap = new; 4207 } else { 4208 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap); 4209 if (err != 0) 4210 break; 4211 } 4212 4213 if (snap->ds_phys->ds_prev_snap_txg == 4214 oldsnap->ds_phys->ds_creation_txg) { 4215 /* 4216 * The blocks in the deadlist can not be born after 4217 * ds_prev_snap_txg, so get the whole deadlist space, 4218 * which is more efficient (especially for old-format 4219 * deadlists). Unfortunately the deadlist code 4220 * doesn't have enough information to make this 4221 * optimization itself. 4222 */ 4223 dsl_deadlist_space(&snap->ds_deadlist, 4224 &used, &comp, &uncomp); 4225 } else { 4226 dsl_deadlist_space_range(&snap->ds_deadlist, 4227 0, oldsnap->ds_phys->ds_creation_txg, 4228 &used, &comp, &uncomp); 4229 } 4230 *usedp += used; 4231 *compp += comp; 4232 *uncompp += uncomp; 4233 4234 /* 4235 * If we get to the beginning of the chain of snapshots 4236 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap 4237 * was not a snapshot of/before new. 4238 */ 4239 snapobj = snap->ds_phys->ds_prev_snap_obj; 4240 if (snap != new) 4241 dsl_dataset_rele(snap, FTAG); 4242 if (snapobj == 0) { 4243 err = EINVAL; 4244 break; 4245 } 4246 4247 } 4248 rw_exit(&dp->dp_config_rwlock); 4249 return (err); 4250 } 4251 4252 /* 4253 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap, 4254 * lastsnap, and all snapshots in between are deleted. 4255 * 4256 * blocks that would be freed [---------------------------] 4257 * snapshots ---O-------O--------O-------O--------O 4258 * firstsnap lastsnap 4259 * 4260 * This is the set of blocks that were born after the snap before firstsnap, 4261 * (birth > firstsnap->prev_snap_txg) and died before the snap after the 4262 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist). 4263 * We calculate this by iterating over the relevant deadlists (from the snap 4264 * after lastsnap, backward to the snap after firstsnap), summing up the 4265 * space on the deadlist that was born after the snap before firstsnap. 4266 */ 4267 int 4268 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap, 4269 dsl_dataset_t *lastsnap, 4270 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp) 4271 { 4272 int err = 0; 4273 uint64_t snapobj; 4274 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool; 4275 4276 ASSERT(dsl_dataset_is_snapshot(firstsnap)); 4277 ASSERT(dsl_dataset_is_snapshot(lastsnap)); 4278 4279 /* 4280 * Check that the snapshots are in the same dsl_dir, and firstsnap 4281 * is before lastsnap. 4282 */ 4283 if (firstsnap->ds_dir != lastsnap->ds_dir || 4284 firstsnap->ds_phys->ds_creation_txg > 4285 lastsnap->ds_phys->ds_creation_txg) 4286 return (EINVAL); 4287 4288 *usedp = *compp = *uncompp = 0; 4289 4290 rw_enter(&dp->dp_config_rwlock, RW_READER); 4291 snapobj = lastsnap->ds_phys->ds_next_snap_obj; 4292 while (snapobj != firstsnap->ds_object) { 4293 dsl_dataset_t *ds; 4294 uint64_t used, comp, uncomp; 4295 4296 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds); 4297 if (err != 0) 4298 break; 4299 4300 dsl_deadlist_space_range(&ds->ds_deadlist, 4301 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX, 4302 &used, &comp, &uncomp); 4303 *usedp += used; 4304 *compp += comp; 4305 *uncompp += uncomp; 4306 4307 snapobj = ds->ds_phys->ds_prev_snap_obj; 4308 ASSERT3U(snapobj, !=, 0); 4309 dsl_dataset_rele(ds, FTAG); 4310 } 4311 rw_exit(&dp->dp_config_rwlock); 4312 return (err); 4313 } 4314