1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/dmu_objset.h> 27 #include <sys/dsl_dataset.h> 28 #include <sys/dsl_dir.h> 29 #include <sys/dsl_prop.h> 30 #include <sys/dsl_synctask.h> 31 #include <sys/dmu_traverse.h> 32 #include <sys/dmu_tx.h> 33 #include <sys/arc.h> 34 #include <sys/zio.h> 35 #include <sys/zap.h> 36 #include <sys/unique.h> 37 #include <sys/zfs_context.h> 38 #include <sys/zfs_ioctl.h> 39 #include <sys/spa.h> 40 #include <sys/zfs_znode.h> 41 #include <sys/sunddi.h> 42 #include <sys/zvol.h> 43 44 static char *dsl_reaper = "the grim reaper"; 45 46 static dsl_checkfunc_t dsl_dataset_destroy_begin_check; 47 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync; 48 static dsl_syncfunc_t dsl_dataset_set_reservation_sync; 49 50 #define DS_REF_MAX (1ULL << 62) 51 52 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE 53 54 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper) 55 56 57 /* 58 * Figure out how much of this delta should be propogated to the dsl_dir 59 * layer. If there's a refreservation, that space has already been 60 * partially accounted for in our ancestors. 61 */ 62 static int64_t 63 parent_delta(dsl_dataset_t *ds, int64_t delta) 64 { 65 uint64_t old_bytes, new_bytes; 66 67 if (ds->ds_reserved == 0) 68 return (delta); 69 70 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 71 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved); 72 73 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta)); 74 return (new_bytes - old_bytes); 75 } 76 77 void 78 dsl_dataset_block_born(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 79 { 80 int used = bp_get_dasize(tx->tx_pool->dp_spa, bp); 81 int compressed = BP_GET_PSIZE(bp); 82 int uncompressed = BP_GET_UCSIZE(bp); 83 int64_t delta; 84 85 dprintf_bp(bp, "born, ds=%p\n", ds); 86 87 ASSERT(dmu_tx_is_syncing(tx)); 88 /* It could have been compressed away to nothing */ 89 if (BP_IS_HOLE(bp)) 90 return; 91 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE); 92 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES); 93 if (ds == NULL) { 94 /* 95 * Account for the meta-objset space in its placeholder 96 * dsl_dir. 97 */ 98 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */ 99 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 100 used, compressed, uncompressed, tx); 101 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 102 return; 103 } 104 dmu_buf_will_dirty(ds->ds_dbuf, tx); 105 mutex_enter(&ds->ds_dir->dd_lock); 106 mutex_enter(&ds->ds_lock); 107 delta = parent_delta(ds, used); 108 ds->ds_phys->ds_used_bytes += used; 109 ds->ds_phys->ds_compressed_bytes += compressed; 110 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 111 ds->ds_phys->ds_unique_bytes += used; 112 mutex_exit(&ds->ds_lock); 113 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 114 compressed, uncompressed, tx); 115 dsl_dir_transfer_space(ds->ds_dir, used - delta, 116 DD_USED_REFRSRV, DD_USED_HEAD, tx); 117 mutex_exit(&ds->ds_dir->dd_lock); 118 } 119 120 int 121 dsl_dataset_block_kill(dsl_dataset_t *ds, blkptr_t *bp, zio_t *pio, 122 dmu_tx_t *tx) 123 { 124 int used = bp_get_dasize(tx->tx_pool->dp_spa, bp); 125 int compressed = BP_GET_PSIZE(bp); 126 int uncompressed = BP_GET_UCSIZE(bp); 127 128 ASSERT(pio != NULL); 129 ASSERT(dmu_tx_is_syncing(tx)); 130 /* No block pointer => nothing to free */ 131 if (BP_IS_HOLE(bp)) 132 return (0); 133 134 ASSERT(used > 0); 135 if (ds == NULL) { 136 int err; 137 /* 138 * Account for the meta-objset space in its placeholder 139 * dataset. 140 */ 141 err = dsl_free(pio, tx->tx_pool, 142 tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT); 143 ASSERT(err == 0); 144 145 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 146 -used, -compressed, -uncompressed, tx); 147 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 148 return (used); 149 } 150 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 151 152 ASSERT(!dsl_dataset_is_snapshot(ds)); 153 dmu_buf_will_dirty(ds->ds_dbuf, tx); 154 155 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 156 int err; 157 int64_t delta; 158 159 dprintf_bp(bp, "freeing: %s", ""); 160 err = dsl_free(pio, tx->tx_pool, 161 tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT); 162 ASSERT(err == 0); 163 164 mutex_enter(&ds->ds_dir->dd_lock); 165 mutex_enter(&ds->ds_lock); 166 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 167 !DS_UNIQUE_IS_ACCURATE(ds)); 168 delta = parent_delta(ds, -used); 169 ds->ds_phys->ds_unique_bytes -= used; 170 mutex_exit(&ds->ds_lock); 171 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 172 delta, -compressed, -uncompressed, tx); 173 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 174 DD_USED_REFRSRV, DD_USED_HEAD, tx); 175 mutex_exit(&ds->ds_dir->dd_lock); 176 } else { 177 dprintf_bp(bp, "putting on dead list: %s", ""); 178 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, bp, tx)); 179 ASSERT3U(ds->ds_prev->ds_object, ==, 180 ds->ds_phys->ds_prev_snap_obj); 181 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 182 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 183 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 184 ds->ds_object && bp->blk_birth > 185 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 186 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 187 mutex_enter(&ds->ds_prev->ds_lock); 188 ds->ds_prev->ds_phys->ds_unique_bytes += used; 189 mutex_exit(&ds->ds_prev->ds_lock); 190 } 191 if (bp->blk_birth > ds->ds_origin_txg) { 192 dsl_dir_transfer_space(ds->ds_dir, used, 193 DD_USED_HEAD, DD_USED_SNAP, tx); 194 } 195 } 196 mutex_enter(&ds->ds_lock); 197 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used); 198 ds->ds_phys->ds_used_bytes -= used; 199 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 200 ds->ds_phys->ds_compressed_bytes -= compressed; 201 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 202 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 203 mutex_exit(&ds->ds_lock); 204 205 return (used); 206 } 207 208 uint64_t 209 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 210 { 211 uint64_t trysnap = 0; 212 213 if (ds == NULL) 214 return (0); 215 /* 216 * The snapshot creation could fail, but that would cause an 217 * incorrect FALSE return, which would only result in an 218 * overestimation of the amount of space that an operation would 219 * consume, which is OK. 220 * 221 * There's also a small window where we could miss a pending 222 * snapshot, because we could set the sync task in the quiescing 223 * phase. So this should only be used as a guess. 224 */ 225 if (ds->ds_trysnap_txg > 226 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 227 trysnap = ds->ds_trysnap_txg; 228 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 229 } 230 231 boolean_t 232 dsl_dataset_block_freeable(dsl_dataset_t *ds, uint64_t blk_birth) 233 { 234 return (blk_birth > dsl_dataset_prev_snap_txg(ds)); 235 } 236 237 /* ARGSUSED */ 238 static void 239 dsl_dataset_evict(dmu_buf_t *db, void *dsv) 240 { 241 dsl_dataset_t *ds = dsv; 242 243 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 244 245 unique_remove(ds->ds_fsid_guid); 246 247 if (ds->ds_objset != NULL) 248 dmu_objset_evict(ds->ds_objset); 249 250 if (ds->ds_prev) { 251 dsl_dataset_drop_ref(ds->ds_prev, ds); 252 ds->ds_prev = NULL; 253 } 254 255 bplist_close(&ds->ds_deadlist); 256 if (ds->ds_dir) 257 dsl_dir_close(ds->ds_dir, ds); 258 259 ASSERT(!list_link_active(&ds->ds_synced_link)); 260 261 mutex_destroy(&ds->ds_lock); 262 mutex_destroy(&ds->ds_recvlock); 263 mutex_destroy(&ds->ds_opening_lock); 264 mutex_destroy(&ds->ds_deadlist.bpl_lock); 265 rw_destroy(&ds->ds_rwlock); 266 cv_destroy(&ds->ds_exclusive_cv); 267 268 kmem_free(ds, sizeof (dsl_dataset_t)); 269 } 270 271 static int 272 dsl_dataset_get_snapname(dsl_dataset_t *ds) 273 { 274 dsl_dataset_phys_t *headphys; 275 int err; 276 dmu_buf_t *headdbuf; 277 dsl_pool_t *dp = ds->ds_dir->dd_pool; 278 objset_t *mos = dp->dp_meta_objset; 279 280 if (ds->ds_snapname[0]) 281 return (0); 282 if (ds->ds_phys->ds_next_snap_obj == 0) 283 return (0); 284 285 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 286 FTAG, &headdbuf); 287 if (err) 288 return (err); 289 headphys = headdbuf->db_data; 290 err = zap_value_search(dp->dp_meta_objset, 291 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 292 dmu_buf_rele(headdbuf, FTAG); 293 return (err); 294 } 295 296 static int 297 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 298 { 299 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 300 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 301 matchtype_t mt; 302 int err; 303 304 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 305 mt = MT_FIRST; 306 else 307 mt = MT_EXACT; 308 309 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 310 value, mt, NULL, 0, NULL); 311 if (err == ENOTSUP && mt == MT_FIRST) 312 err = zap_lookup(mos, snapobj, name, 8, 1, value); 313 return (err); 314 } 315 316 static int 317 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 318 { 319 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 320 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 321 matchtype_t mt; 322 int err; 323 324 dsl_dir_snap_cmtime_update(ds->ds_dir); 325 326 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 327 mt = MT_FIRST; 328 else 329 mt = MT_EXACT; 330 331 err = zap_remove_norm(mos, snapobj, name, mt, tx); 332 if (err == ENOTSUP && mt == MT_FIRST) 333 err = zap_remove(mos, snapobj, name, tx); 334 return (err); 335 } 336 337 static int 338 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 339 dsl_dataset_t **dsp) 340 { 341 objset_t *mos = dp->dp_meta_objset; 342 dmu_buf_t *dbuf; 343 dsl_dataset_t *ds; 344 int err; 345 346 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 347 dsl_pool_sync_context(dp)); 348 349 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 350 if (err) 351 return (err); 352 ds = dmu_buf_get_user(dbuf); 353 if (ds == NULL) { 354 dsl_dataset_t *winner; 355 356 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 357 ds->ds_dbuf = dbuf; 358 ds->ds_object = dsobj; 359 ds->ds_phys = dbuf->db_data; 360 361 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 362 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 363 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 364 mutex_init(&ds->ds_deadlist.bpl_lock, NULL, MUTEX_DEFAULT, 365 NULL); 366 rw_init(&ds->ds_rwlock, 0, 0, 0); 367 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 368 369 err = bplist_open(&ds->ds_deadlist, 370 mos, ds->ds_phys->ds_deadlist_obj); 371 if (err == 0) { 372 err = dsl_dir_open_obj(dp, 373 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 374 } 375 if (err) { 376 /* 377 * we don't really need to close the blist if we 378 * just opened it. 379 */ 380 mutex_destroy(&ds->ds_lock); 381 mutex_destroy(&ds->ds_recvlock); 382 mutex_destroy(&ds->ds_opening_lock); 383 mutex_destroy(&ds->ds_deadlist.bpl_lock); 384 rw_destroy(&ds->ds_rwlock); 385 cv_destroy(&ds->ds_exclusive_cv); 386 kmem_free(ds, sizeof (dsl_dataset_t)); 387 dmu_buf_rele(dbuf, tag); 388 return (err); 389 } 390 391 if (!dsl_dataset_is_snapshot(ds)) { 392 ds->ds_snapname[0] = '\0'; 393 if (ds->ds_phys->ds_prev_snap_obj) { 394 err = dsl_dataset_get_ref(dp, 395 ds->ds_phys->ds_prev_snap_obj, 396 ds, &ds->ds_prev); 397 } 398 399 if (err == 0 && dsl_dir_is_clone(ds->ds_dir)) { 400 dsl_dataset_t *origin; 401 402 err = dsl_dataset_hold_obj(dp, 403 ds->ds_dir->dd_phys->dd_origin_obj, 404 FTAG, &origin); 405 if (err == 0) { 406 ds->ds_origin_txg = 407 origin->ds_phys->ds_creation_txg; 408 dsl_dataset_rele(origin, FTAG); 409 } 410 } 411 } else { 412 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 413 err = dsl_dataset_get_snapname(ds); 414 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 415 err = zap_count( 416 ds->ds_dir->dd_pool->dp_meta_objset, 417 ds->ds_phys->ds_userrefs_obj, 418 &ds->ds_userrefs); 419 } 420 } 421 422 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 423 /* 424 * In sync context, we're called with either no lock 425 * or with the write lock. If we're not syncing, 426 * we're always called with the read lock held. 427 */ 428 boolean_t need_lock = 429 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 430 dsl_pool_sync_context(dp); 431 432 if (need_lock) 433 rw_enter(&dp->dp_config_rwlock, RW_READER); 434 435 err = dsl_prop_get_ds(ds, 436 "refreservation", sizeof (uint64_t), 1, 437 &ds->ds_reserved, NULL); 438 if (err == 0) { 439 err = dsl_prop_get_ds(ds, 440 "refquota", sizeof (uint64_t), 1, 441 &ds->ds_quota, NULL); 442 } 443 444 if (need_lock) 445 rw_exit(&dp->dp_config_rwlock); 446 } else { 447 ds->ds_reserved = ds->ds_quota = 0; 448 } 449 450 if (err == 0) { 451 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 452 dsl_dataset_evict); 453 } 454 if (err || winner) { 455 bplist_close(&ds->ds_deadlist); 456 if (ds->ds_prev) 457 dsl_dataset_drop_ref(ds->ds_prev, ds); 458 dsl_dir_close(ds->ds_dir, ds); 459 mutex_destroy(&ds->ds_lock); 460 mutex_destroy(&ds->ds_recvlock); 461 mutex_destroy(&ds->ds_opening_lock); 462 mutex_destroy(&ds->ds_deadlist.bpl_lock); 463 rw_destroy(&ds->ds_rwlock); 464 cv_destroy(&ds->ds_exclusive_cv); 465 kmem_free(ds, sizeof (dsl_dataset_t)); 466 if (err) { 467 dmu_buf_rele(dbuf, tag); 468 return (err); 469 } 470 ds = winner; 471 } else { 472 ds->ds_fsid_guid = 473 unique_insert(ds->ds_phys->ds_fsid_guid); 474 } 475 } 476 ASSERT3P(ds->ds_dbuf, ==, dbuf); 477 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 478 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 479 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 480 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 481 mutex_enter(&ds->ds_lock); 482 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 483 mutex_exit(&ds->ds_lock); 484 dmu_buf_rele(ds->ds_dbuf, tag); 485 return (ENOENT); 486 } 487 mutex_exit(&ds->ds_lock); 488 *dsp = ds; 489 return (0); 490 } 491 492 static int 493 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 494 { 495 dsl_pool_t *dp = ds->ds_dir->dd_pool; 496 497 /* 498 * In syncing context we don't want the rwlock lock: there 499 * may be an existing writer waiting for sync phase to 500 * finish. We don't need to worry about such writers, since 501 * sync phase is single-threaded, so the writer can't be 502 * doing anything while we are active. 503 */ 504 if (dsl_pool_sync_context(dp)) { 505 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 506 return (0); 507 } 508 509 /* 510 * Normal users will hold the ds_rwlock as a READER until they 511 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 512 * drop their READER lock after they set the ds_owner field. 513 * 514 * If the dataset is being destroyed, the destroy thread will 515 * obtain a WRITER lock for exclusive access after it's done its 516 * open-context work and then change the ds_owner to 517 * dsl_reaper once destruction is assured. So threads 518 * may block here temporarily, until the "destructability" of 519 * the dataset is determined. 520 */ 521 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 522 mutex_enter(&ds->ds_lock); 523 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 524 rw_exit(&dp->dp_config_rwlock); 525 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 526 if (DSL_DATASET_IS_DESTROYED(ds)) { 527 mutex_exit(&ds->ds_lock); 528 dsl_dataset_drop_ref(ds, tag); 529 rw_enter(&dp->dp_config_rwlock, RW_READER); 530 return (ENOENT); 531 } 532 rw_enter(&dp->dp_config_rwlock, RW_READER); 533 } 534 mutex_exit(&ds->ds_lock); 535 return (0); 536 } 537 538 int 539 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 540 dsl_dataset_t **dsp) 541 { 542 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 543 544 if (err) 545 return (err); 546 return (dsl_dataset_hold_ref(*dsp, tag)); 547 } 548 549 int 550 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 551 void *tag, dsl_dataset_t **dsp) 552 { 553 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 554 if (err) 555 return (err); 556 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 557 dsl_dataset_rele(*dsp, tag); 558 *dsp = NULL; 559 return (EBUSY); 560 } 561 return (0); 562 } 563 564 int 565 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 566 { 567 dsl_dir_t *dd; 568 dsl_pool_t *dp; 569 const char *snapname; 570 uint64_t obj; 571 int err = 0; 572 573 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 574 if (err) 575 return (err); 576 577 dp = dd->dd_pool; 578 obj = dd->dd_phys->dd_head_dataset_obj; 579 rw_enter(&dp->dp_config_rwlock, RW_READER); 580 if (obj) 581 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 582 else 583 err = ENOENT; 584 if (err) 585 goto out; 586 587 err = dsl_dataset_hold_ref(*dsp, tag); 588 589 /* we may be looking for a snapshot */ 590 if (err == 0 && snapname != NULL) { 591 dsl_dataset_t *ds = NULL; 592 593 if (*snapname++ != '@') { 594 dsl_dataset_rele(*dsp, tag); 595 err = ENOENT; 596 goto out; 597 } 598 599 dprintf("looking for snapshot '%s'\n", snapname); 600 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 601 if (err == 0) 602 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 603 dsl_dataset_rele(*dsp, tag); 604 605 ASSERT3U((err == 0), ==, (ds != NULL)); 606 607 if (ds) { 608 mutex_enter(&ds->ds_lock); 609 if (ds->ds_snapname[0] == 0) 610 (void) strlcpy(ds->ds_snapname, snapname, 611 sizeof (ds->ds_snapname)); 612 mutex_exit(&ds->ds_lock); 613 err = dsl_dataset_hold_ref(ds, tag); 614 *dsp = err ? NULL : ds; 615 } 616 } 617 out: 618 rw_exit(&dp->dp_config_rwlock); 619 dsl_dir_close(dd, FTAG); 620 return (err); 621 } 622 623 int 624 dsl_dataset_own(const char *name, boolean_t inconsistentok, 625 void *tag, dsl_dataset_t **dsp) 626 { 627 int err = dsl_dataset_hold(name, tag, dsp); 628 if (err) 629 return (err); 630 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 631 dsl_dataset_rele(*dsp, tag); 632 return (EBUSY); 633 } 634 return (0); 635 } 636 637 void 638 dsl_dataset_name(dsl_dataset_t *ds, char *name) 639 { 640 if (ds == NULL) { 641 (void) strcpy(name, "mos"); 642 } else { 643 dsl_dir_name(ds->ds_dir, name); 644 VERIFY(0 == dsl_dataset_get_snapname(ds)); 645 if (ds->ds_snapname[0]) { 646 (void) strcat(name, "@"); 647 /* 648 * We use a "recursive" mutex so that we 649 * can call dprintf_ds() with ds_lock held. 650 */ 651 if (!MUTEX_HELD(&ds->ds_lock)) { 652 mutex_enter(&ds->ds_lock); 653 (void) strcat(name, ds->ds_snapname); 654 mutex_exit(&ds->ds_lock); 655 } else { 656 (void) strcat(name, ds->ds_snapname); 657 } 658 } 659 } 660 } 661 662 static int 663 dsl_dataset_namelen(dsl_dataset_t *ds) 664 { 665 int result; 666 667 if (ds == NULL) { 668 result = 3; /* "mos" */ 669 } else { 670 result = dsl_dir_namelen(ds->ds_dir); 671 VERIFY(0 == dsl_dataset_get_snapname(ds)); 672 if (ds->ds_snapname[0]) { 673 ++result; /* adding one for the @-sign */ 674 if (!MUTEX_HELD(&ds->ds_lock)) { 675 mutex_enter(&ds->ds_lock); 676 result += strlen(ds->ds_snapname); 677 mutex_exit(&ds->ds_lock); 678 } else { 679 result += strlen(ds->ds_snapname); 680 } 681 } 682 } 683 684 return (result); 685 } 686 687 void 688 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 689 { 690 dmu_buf_rele(ds->ds_dbuf, tag); 691 } 692 693 void 694 dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 695 { 696 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 697 rw_exit(&ds->ds_rwlock); 698 } 699 dsl_dataset_drop_ref(ds, tag); 700 } 701 702 void 703 dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 704 { 705 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 706 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 707 708 mutex_enter(&ds->ds_lock); 709 ds->ds_owner = NULL; 710 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 711 rw_exit(&ds->ds_rwlock); 712 cv_broadcast(&ds->ds_exclusive_cv); 713 } 714 mutex_exit(&ds->ds_lock); 715 if (ds->ds_dbuf) 716 dsl_dataset_drop_ref(ds, tag); 717 else 718 dsl_dataset_evict(ds->ds_dbuf, ds); 719 } 720 721 boolean_t 722 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 723 { 724 boolean_t gotit = FALSE; 725 726 mutex_enter(&ds->ds_lock); 727 if (ds->ds_owner == NULL && 728 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 729 ds->ds_owner = tag; 730 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 731 rw_exit(&ds->ds_rwlock); 732 gotit = TRUE; 733 } 734 mutex_exit(&ds->ds_lock); 735 return (gotit); 736 } 737 738 void 739 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 740 { 741 ASSERT3P(owner, ==, ds->ds_owner); 742 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 743 rw_enter(&ds->ds_rwlock, RW_WRITER); 744 } 745 746 uint64_t 747 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 748 uint64_t flags, dmu_tx_t *tx) 749 { 750 dsl_pool_t *dp = dd->dd_pool; 751 dmu_buf_t *dbuf; 752 dsl_dataset_phys_t *dsphys; 753 uint64_t dsobj; 754 objset_t *mos = dp->dp_meta_objset; 755 756 if (origin == NULL) 757 origin = dp->dp_origin_snap; 758 759 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 760 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 761 ASSERT(dmu_tx_is_syncing(tx)); 762 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 763 764 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 765 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 766 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 767 dmu_buf_will_dirty(dbuf, tx); 768 dsphys = dbuf->db_data; 769 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 770 dsphys->ds_dir_obj = dd->dd_object; 771 dsphys->ds_flags = flags; 772 dsphys->ds_fsid_guid = unique_create(); 773 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 774 sizeof (dsphys->ds_guid)); 775 dsphys->ds_snapnames_zapobj = 776 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 777 DMU_OT_NONE, 0, tx); 778 dsphys->ds_creation_time = gethrestime_sec(); 779 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 780 dsphys->ds_deadlist_obj = 781 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx); 782 783 if (origin) { 784 dsphys->ds_prev_snap_obj = origin->ds_object; 785 dsphys->ds_prev_snap_txg = 786 origin->ds_phys->ds_creation_txg; 787 dsphys->ds_used_bytes = 788 origin->ds_phys->ds_used_bytes; 789 dsphys->ds_compressed_bytes = 790 origin->ds_phys->ds_compressed_bytes; 791 dsphys->ds_uncompressed_bytes = 792 origin->ds_phys->ds_uncompressed_bytes; 793 dsphys->ds_bp = origin->ds_phys->ds_bp; 794 dsphys->ds_flags |= origin->ds_phys->ds_flags; 795 796 dmu_buf_will_dirty(origin->ds_dbuf, tx); 797 origin->ds_phys->ds_num_children++; 798 799 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 800 if (origin->ds_phys->ds_next_clones_obj == 0) { 801 origin->ds_phys->ds_next_clones_obj = 802 zap_create(mos, 803 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 804 } 805 VERIFY(0 == zap_add_int(mos, 806 origin->ds_phys->ds_next_clones_obj, 807 dsobj, tx)); 808 } 809 810 dmu_buf_will_dirty(dd->dd_dbuf, tx); 811 dd->dd_phys->dd_origin_obj = origin->ds_object; 812 } 813 814 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 815 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 816 817 dmu_buf_rele(dbuf, FTAG); 818 819 dmu_buf_will_dirty(dd->dd_dbuf, tx); 820 dd->dd_phys->dd_head_dataset_obj = dsobj; 821 822 return (dsobj); 823 } 824 825 uint64_t 826 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 827 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 828 { 829 dsl_pool_t *dp = pdd->dd_pool; 830 uint64_t dsobj, ddobj; 831 dsl_dir_t *dd; 832 833 ASSERT(lastname[0] != '@'); 834 835 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 836 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 837 838 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 839 840 dsl_deleg_set_create_perms(dd, tx, cr); 841 842 dsl_dir_close(dd, FTAG); 843 844 return (dsobj); 845 } 846 847 struct destroyarg { 848 dsl_sync_task_group_t *dstg; 849 char *snapname; 850 char *failed; 851 boolean_t defer; 852 }; 853 854 static int 855 dsl_snapshot_destroy_one(char *name, void *arg) 856 { 857 struct destroyarg *da = arg; 858 dsl_dataset_t *ds; 859 int err; 860 char *dsname; 861 862 dsname = kmem_asprintf("%s@%s", name, da->snapname); 863 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds); 864 strfree(dsname); 865 if (err == 0) { 866 struct dsl_ds_destroyarg *dsda; 867 868 dsl_dataset_make_exclusive(ds, da->dstg); 869 if (ds->ds_objset != NULL) { 870 dmu_objset_evict(ds->ds_objset); 871 ds->ds_objset = NULL; 872 } 873 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP); 874 dsda->ds = ds; 875 dsda->defer = da->defer; 876 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check, 877 dsl_dataset_destroy_sync, dsda, da->dstg, 0); 878 } else if (err == ENOENT) { 879 err = 0; 880 } else { 881 (void) strcpy(da->failed, name); 882 } 883 return (err); 884 } 885 886 /* 887 * Destroy 'snapname' in all descendants of 'fsname'. 888 */ 889 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy 890 int 891 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer) 892 { 893 int err; 894 struct destroyarg da; 895 dsl_sync_task_t *dst; 896 spa_t *spa; 897 898 err = spa_open(fsname, &spa, FTAG); 899 if (err) 900 return (err); 901 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 902 da.snapname = snapname; 903 da.failed = fsname; 904 da.defer = defer; 905 906 err = dmu_objset_find(fsname, 907 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN); 908 909 if (err == 0) 910 err = dsl_sync_task_group_wait(da.dstg); 911 912 for (dst = list_head(&da.dstg->dstg_tasks); dst; 913 dst = list_next(&da.dstg->dstg_tasks, dst)) { 914 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 915 dsl_dataset_t *ds = dsda->ds; 916 917 /* 918 * Return the file system name that triggered the error 919 */ 920 if (dst->dst_err) { 921 dsl_dataset_name(ds, fsname); 922 *strchr(fsname, '@') = '\0'; 923 } 924 ASSERT3P(dsda->rm_origin, ==, NULL); 925 dsl_dataset_disown(ds, da.dstg); 926 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 927 } 928 929 dsl_sync_task_group_destroy(da.dstg); 930 spa_close(spa, FTAG); 931 return (err); 932 } 933 934 static boolean_t 935 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 936 { 937 boolean_t might_destroy = B_FALSE; 938 939 mutex_enter(&ds->ds_lock); 940 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 941 DS_IS_DEFER_DESTROY(ds)) 942 might_destroy = B_TRUE; 943 mutex_exit(&ds->ds_lock); 944 945 return (might_destroy); 946 } 947 948 /* 949 * If we're removing a clone, and these three conditions are true: 950 * 1) the clone's origin has no other children 951 * 2) the clone's origin has no user references 952 * 3) the clone's origin has been marked for deferred destruction 953 * Then, prepare to remove the origin as part of this sync task group. 954 */ 955 static int 956 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 957 { 958 dsl_dataset_t *ds = dsda->ds; 959 dsl_dataset_t *origin = ds->ds_prev; 960 961 if (dsl_dataset_might_destroy_origin(origin)) { 962 char *name; 963 int namelen; 964 int error; 965 966 namelen = dsl_dataset_namelen(origin) + 1; 967 name = kmem_alloc(namelen, KM_SLEEP); 968 dsl_dataset_name(origin, name); 969 #ifdef _KERNEL 970 error = zfs_unmount_snap(name, NULL); 971 if (error) { 972 kmem_free(name, namelen); 973 return (error); 974 } 975 #endif 976 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 977 kmem_free(name, namelen); 978 if (error) 979 return (error); 980 dsda->rm_origin = origin; 981 dsl_dataset_make_exclusive(origin, tag); 982 983 if (origin->ds_objset != NULL) { 984 dmu_objset_evict(origin->ds_objset); 985 origin->ds_objset = NULL; 986 } 987 } 988 989 return (0); 990 } 991 992 /* 993 * ds must be opened as OWNER. On return (whether successful or not), 994 * ds will be closed and caller can no longer dereference it. 995 */ 996 int 997 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 998 { 999 int err; 1000 dsl_sync_task_group_t *dstg; 1001 objset_t *os; 1002 dsl_dir_t *dd; 1003 uint64_t obj; 1004 struct dsl_ds_destroyarg dsda = {0}; 1005 1006 dsda.ds = ds; 1007 1008 if (dsl_dataset_is_snapshot(ds)) { 1009 /* Destroying a snapshot is simpler */ 1010 dsl_dataset_make_exclusive(ds, tag); 1011 1012 if (ds->ds_objset != NULL) { 1013 dmu_objset_evict(ds->ds_objset); 1014 ds->ds_objset = NULL; 1015 } 1016 dsda.defer = defer; 1017 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1018 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1019 &dsda, tag, 0); 1020 ASSERT3P(dsda.rm_origin, ==, NULL); 1021 goto out; 1022 } else if (defer) { 1023 err = EINVAL; 1024 goto out; 1025 } 1026 1027 dd = ds->ds_dir; 1028 1029 /* 1030 * Check for errors and mark this ds as inconsistent, in 1031 * case we crash while freeing the objects. 1032 */ 1033 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, 1034 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1035 if (err) 1036 goto out; 1037 1038 err = dmu_objset_from_ds(ds, &os); 1039 if (err) 1040 goto out; 1041 1042 /* 1043 * remove the objects in open context, so that we won't 1044 * have too much to do in syncing context. 1045 */ 1046 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1047 ds->ds_phys->ds_prev_snap_txg)) { 1048 /* 1049 * Ignore errors, if there is not enough disk space 1050 * we will deal with it in dsl_dataset_destroy_sync(). 1051 */ 1052 (void) dmu_free_object(os, obj); 1053 } 1054 1055 /* 1056 * We need to sync out all in-flight IO before we try to evict 1057 * (the dataset evict func is trying to clear the cached entries 1058 * for this dataset in the ARC). 1059 */ 1060 txg_wait_synced(dd->dd_pool, 0); 1061 1062 /* 1063 * If we managed to free all the objects in open 1064 * context, the user space accounting should be zero. 1065 */ 1066 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1067 dmu_objset_userused_enabled(os)) { 1068 uint64_t count; 1069 1070 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || 1071 count == 0); 1072 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || 1073 count == 0); 1074 } 1075 1076 if (err != ESRCH) 1077 goto out; 1078 1079 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1080 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1081 rw_exit(&dd->dd_pool->dp_config_rwlock); 1082 1083 if (err) 1084 goto out; 1085 1086 if (ds->ds_objset) { 1087 /* 1088 * We need to sync out all in-flight IO before we try 1089 * to evict (the dataset evict func is trying to clear 1090 * the cached entries for this dataset in the ARC). 1091 */ 1092 txg_wait_synced(dd->dd_pool, 0); 1093 } 1094 1095 /* 1096 * Blow away the dsl_dir + head dataset. 1097 */ 1098 dsl_dataset_make_exclusive(ds, tag); 1099 if (ds->ds_objset) { 1100 dmu_objset_evict(ds->ds_objset); 1101 ds->ds_objset = NULL; 1102 } 1103 1104 /* 1105 * If we're removing a clone, we might also need to remove its 1106 * origin. 1107 */ 1108 do { 1109 dsda.need_prep = B_FALSE; 1110 if (dsl_dir_is_clone(dd)) { 1111 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1112 if (err) { 1113 dsl_dir_close(dd, FTAG); 1114 goto out; 1115 } 1116 } 1117 1118 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1119 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1120 dsl_dataset_destroy_sync, &dsda, tag, 0); 1121 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1122 dsl_dir_destroy_sync, dd, FTAG, 0); 1123 err = dsl_sync_task_group_wait(dstg); 1124 dsl_sync_task_group_destroy(dstg); 1125 1126 /* 1127 * We could be racing against 'zfs release' or 'zfs destroy -d' 1128 * on the origin snap, in which case we can get EBUSY if we 1129 * needed to destroy the origin snap but were not ready to 1130 * do so. 1131 */ 1132 if (dsda.need_prep) { 1133 ASSERT(err == EBUSY); 1134 ASSERT(dsl_dir_is_clone(dd)); 1135 ASSERT(dsda.rm_origin == NULL); 1136 } 1137 } while (dsda.need_prep); 1138 1139 if (dsda.rm_origin != NULL) 1140 dsl_dataset_disown(dsda.rm_origin, tag); 1141 1142 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1143 if (err) 1144 dsl_dir_close(dd, FTAG); 1145 out: 1146 dsl_dataset_disown(ds, tag); 1147 return (err); 1148 } 1149 1150 blkptr_t * 1151 dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1152 { 1153 return (&ds->ds_phys->ds_bp); 1154 } 1155 1156 void 1157 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1158 { 1159 ASSERT(dmu_tx_is_syncing(tx)); 1160 /* If it's the meta-objset, set dp_meta_rootbp */ 1161 if (ds == NULL) { 1162 tx->tx_pool->dp_meta_rootbp = *bp; 1163 } else { 1164 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1165 ds->ds_phys->ds_bp = *bp; 1166 } 1167 } 1168 1169 spa_t * 1170 dsl_dataset_get_spa(dsl_dataset_t *ds) 1171 { 1172 return (ds->ds_dir->dd_pool->dp_spa); 1173 } 1174 1175 void 1176 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1177 { 1178 dsl_pool_t *dp; 1179 1180 if (ds == NULL) /* this is the meta-objset */ 1181 return; 1182 1183 ASSERT(ds->ds_objset != NULL); 1184 1185 if (ds->ds_phys->ds_next_snap_obj != 0) 1186 panic("dirtying snapshot!"); 1187 1188 dp = ds->ds_dir->dd_pool; 1189 1190 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1191 /* up the hold count until we can be written out */ 1192 dmu_buf_add_ref(ds->ds_dbuf, ds); 1193 } 1194 } 1195 1196 /* 1197 * The unique space in the head dataset can be calculated by subtracting 1198 * the space used in the most recent snapshot, that is still being used 1199 * in this file system, from the space currently in use. To figure out 1200 * the space in the most recent snapshot still in use, we need to take 1201 * the total space used in the snapshot and subtract out the space that 1202 * has been freed up since the snapshot was taken. 1203 */ 1204 static void 1205 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1206 { 1207 uint64_t mrs_used; 1208 uint64_t dlused, dlcomp, dluncomp; 1209 1210 ASSERT(ds->ds_object == ds->ds_dir->dd_phys->dd_head_dataset_obj); 1211 1212 if (ds->ds_phys->ds_prev_snap_obj != 0) 1213 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes; 1214 else 1215 mrs_used = 0; 1216 1217 VERIFY(0 == bplist_space(&ds->ds_deadlist, &dlused, &dlcomp, 1218 &dluncomp)); 1219 1220 ASSERT3U(dlused, <=, mrs_used); 1221 ds->ds_phys->ds_unique_bytes = 1222 ds->ds_phys->ds_used_bytes - (mrs_used - dlused); 1223 1224 if (!DS_UNIQUE_IS_ACCURATE(ds) && 1225 spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1226 SPA_VERSION_UNIQUE_ACCURATE) 1227 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1228 } 1229 1230 static uint64_t 1231 dsl_dataset_unique(dsl_dataset_t *ds) 1232 { 1233 if (!DS_UNIQUE_IS_ACCURATE(ds) && !dsl_dataset_is_snapshot(ds)) 1234 dsl_dataset_recalc_head_uniq(ds); 1235 1236 return (ds->ds_phys->ds_unique_bytes); 1237 } 1238 1239 struct killarg { 1240 dsl_dataset_t *ds; 1241 zio_t *zio; 1242 dmu_tx_t *tx; 1243 }; 1244 1245 /* ARGSUSED */ 1246 static int 1247 kill_blkptr(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb, 1248 const dnode_phys_t *dnp, void *arg) 1249 { 1250 struct killarg *ka = arg; 1251 1252 if (bp == NULL) 1253 return (0); 1254 1255 if ((zb->zb_level == -1ULL && zb->zb_blkid != 0) || 1256 (zb->zb_object != 0 && dnp == NULL)) { 1257 /* 1258 * It's a block in the intent log. It has no 1259 * accounting, so just free it. 1260 */ 1261 VERIFY3U(0, ==, dsl_free(ka->zio, ka->tx->tx_pool, 1262 ka->tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT)); 1263 } else { 1264 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1265 (void) dsl_dataset_block_kill(ka->ds, bp, ka->zio, ka->tx); 1266 } 1267 1268 return (0); 1269 } 1270 1271 /* ARGSUSED */ 1272 static int 1273 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1274 { 1275 dsl_dataset_t *ds = arg1; 1276 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1277 uint64_t count; 1278 int err; 1279 1280 /* 1281 * Can't delete a head dataset if there are snapshots of it. 1282 * (Except if the only snapshots are from the branch we cloned 1283 * from.) 1284 */ 1285 if (ds->ds_prev != NULL && 1286 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1287 return (EINVAL); 1288 1289 /* 1290 * This is really a dsl_dir thing, but check it here so that 1291 * we'll be less likely to leave this dataset inconsistent & 1292 * nearly destroyed. 1293 */ 1294 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1295 if (err) 1296 return (err); 1297 if (count != 0) 1298 return (EEXIST); 1299 1300 return (0); 1301 } 1302 1303 /* ARGSUSED */ 1304 static void 1305 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 1306 { 1307 dsl_dataset_t *ds = arg1; 1308 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1309 1310 /* Mark it as inconsistent on-disk, in case we crash */ 1311 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1312 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1313 1314 spa_history_internal_log(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx, 1315 cr, "dataset = %llu", ds->ds_object); 1316 } 1317 1318 static int 1319 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1320 dmu_tx_t *tx) 1321 { 1322 dsl_dataset_t *ds = dsda->ds; 1323 dsl_dataset_t *ds_prev = ds->ds_prev; 1324 1325 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1326 struct dsl_ds_destroyarg ndsda = {0}; 1327 1328 /* 1329 * If we're not prepared to remove the origin, don't remove 1330 * the clone either. 1331 */ 1332 if (dsda->rm_origin == NULL) { 1333 dsda->need_prep = B_TRUE; 1334 return (EBUSY); 1335 } 1336 1337 ndsda.ds = ds_prev; 1338 ndsda.is_origin_rm = B_TRUE; 1339 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1340 } 1341 1342 /* 1343 * If we're not going to remove the origin after all, 1344 * undo the open context setup. 1345 */ 1346 if (dsda->rm_origin != NULL) { 1347 dsl_dataset_disown(dsda->rm_origin, tag); 1348 dsda->rm_origin = NULL; 1349 } 1350 1351 return (0); 1352 } 1353 1354 /* ARGSUSED */ 1355 int 1356 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1357 { 1358 struct dsl_ds_destroyarg *dsda = arg1; 1359 dsl_dataset_t *ds = dsda->ds; 1360 1361 /* we have an owner hold, so noone else can destroy us */ 1362 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1363 1364 /* 1365 * Only allow deferred destroy on pools that support it. 1366 * NOTE: deferred destroy is only supported on snapshots. 1367 */ 1368 if (dsda->defer) { 1369 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1370 SPA_VERSION_USERREFS) 1371 return (ENOTSUP); 1372 ASSERT(dsl_dataset_is_snapshot(ds)); 1373 return (0); 1374 } 1375 1376 /* 1377 * Can't delete a head dataset if there are snapshots of it. 1378 * (Except if the only snapshots are from the branch we cloned 1379 * from.) 1380 */ 1381 if (ds->ds_prev != NULL && 1382 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1383 return (EINVAL); 1384 1385 /* 1386 * If we made changes this txg, traverse_dsl_dataset won't find 1387 * them. Try again. 1388 */ 1389 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1390 return (EAGAIN); 1391 1392 if (dsl_dataset_is_snapshot(ds)) { 1393 /* 1394 * If this snapshot has an elevated user reference count, 1395 * we can't destroy it yet. 1396 */ 1397 if (ds->ds_userrefs > 0 && !dsda->releasing) 1398 return (EBUSY); 1399 1400 mutex_enter(&ds->ds_lock); 1401 /* 1402 * Can't delete a branch point. However, if we're destroying 1403 * a clone and removing its origin due to it having a user 1404 * hold count of 0 and having been marked for deferred destroy, 1405 * it's OK for the origin to have a single clone. 1406 */ 1407 if (ds->ds_phys->ds_num_children > 1408 (dsda->is_origin_rm ? 2 : 1)) { 1409 mutex_exit(&ds->ds_lock); 1410 return (EEXIST); 1411 } 1412 mutex_exit(&ds->ds_lock); 1413 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1414 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1415 } 1416 1417 /* XXX we should do some i/o error checking... */ 1418 return (0); 1419 } 1420 1421 struct refsarg { 1422 kmutex_t lock; 1423 boolean_t gone; 1424 kcondvar_t cv; 1425 }; 1426 1427 /* ARGSUSED */ 1428 static void 1429 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1430 { 1431 struct refsarg *arg = argv; 1432 1433 mutex_enter(&arg->lock); 1434 arg->gone = TRUE; 1435 cv_signal(&arg->cv); 1436 mutex_exit(&arg->lock); 1437 } 1438 1439 static void 1440 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1441 { 1442 struct refsarg arg; 1443 1444 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1445 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1446 arg.gone = FALSE; 1447 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1448 dsl_dataset_refs_gone); 1449 dmu_buf_rele(ds->ds_dbuf, tag); 1450 mutex_enter(&arg.lock); 1451 while (!arg.gone) 1452 cv_wait(&arg.cv, &arg.lock); 1453 ASSERT(arg.gone); 1454 mutex_exit(&arg.lock); 1455 ds->ds_dbuf = NULL; 1456 ds->ds_phys = NULL; 1457 mutex_destroy(&arg.lock); 1458 cv_destroy(&arg.cv); 1459 } 1460 1461 void 1462 dsl_dataset_destroy_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 1463 { 1464 struct dsl_ds_destroyarg *dsda = arg1; 1465 dsl_dataset_t *ds = dsda->ds; 1466 zio_t *zio; 1467 int err; 1468 int after_branch_point = FALSE; 1469 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1470 objset_t *mos = dp->dp_meta_objset; 1471 dsl_dataset_t *ds_prev = NULL; 1472 uint64_t obj; 1473 1474 ASSERT(ds->ds_owner); 1475 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1476 ASSERT(ds->ds_prev == NULL || 1477 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1478 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1479 1480 if (dsda->defer) { 1481 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1482 if (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1) { 1483 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1484 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1485 return; 1486 } 1487 } 1488 1489 /* signal any waiters that this dataset is going away */ 1490 mutex_enter(&ds->ds_lock); 1491 ds->ds_owner = dsl_reaper; 1492 cv_broadcast(&ds->ds_exclusive_cv); 1493 mutex_exit(&ds->ds_lock); 1494 1495 /* Remove our reservation */ 1496 if (ds->ds_reserved != 0) { 1497 uint64_t val = 0; 1498 dsl_dataset_set_reservation_sync(ds, &val, cr, tx); 1499 ASSERT3U(ds->ds_reserved, ==, 0); 1500 } 1501 1502 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1503 1504 dsl_pool_ds_destroyed(ds, tx); 1505 1506 obj = ds->ds_object; 1507 1508 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1509 if (ds->ds_prev) { 1510 ds_prev = ds->ds_prev; 1511 } else { 1512 VERIFY(0 == dsl_dataset_hold_obj(dp, 1513 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1514 } 1515 after_branch_point = 1516 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1517 1518 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1519 if (after_branch_point && 1520 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1521 VERIFY3U(0, ==, zap_remove_int(mos, 1522 ds_prev->ds_phys->ds_next_clones_obj, obj, tx)); 1523 if (ds->ds_phys->ds_next_snap_obj != 0) { 1524 VERIFY(0 == zap_add_int(mos, 1525 ds_prev->ds_phys->ds_next_clones_obj, 1526 ds->ds_phys->ds_next_snap_obj, tx)); 1527 } 1528 } 1529 if (after_branch_point && 1530 ds->ds_phys->ds_next_snap_obj == 0) { 1531 /* This clone is toast. */ 1532 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1533 ds_prev->ds_phys->ds_num_children--; 1534 1535 /* 1536 * If the clone's origin has no other clones, no 1537 * user holds, and has been marked for deferred 1538 * deletion, then we should have done the necessary 1539 * destroy setup for it. 1540 */ 1541 if (ds_prev->ds_phys->ds_num_children == 1 && 1542 ds_prev->ds_userrefs == 0 && 1543 DS_IS_DEFER_DESTROY(ds_prev)) { 1544 ASSERT3P(dsda->rm_origin, !=, NULL); 1545 } else { 1546 ASSERT3P(dsda->rm_origin, ==, NULL); 1547 } 1548 } else if (!after_branch_point) { 1549 ds_prev->ds_phys->ds_next_snap_obj = 1550 ds->ds_phys->ds_next_snap_obj; 1551 } 1552 } 1553 1554 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1555 1556 if (ds->ds_phys->ds_next_snap_obj != 0) { 1557 blkptr_t bp; 1558 dsl_dataset_t *ds_next; 1559 uint64_t itor = 0; 1560 uint64_t old_unique; 1561 int64_t used = 0, compressed = 0, uncompressed = 0; 1562 1563 VERIFY(0 == dsl_dataset_hold_obj(dp, 1564 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1565 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1566 1567 old_unique = dsl_dataset_unique(ds_next); 1568 1569 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1570 ds_next->ds_phys->ds_prev_snap_obj = 1571 ds->ds_phys->ds_prev_snap_obj; 1572 ds_next->ds_phys->ds_prev_snap_txg = 1573 ds->ds_phys->ds_prev_snap_txg; 1574 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1575 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1576 1577 /* 1578 * Transfer to our deadlist (which will become next's 1579 * new deadlist) any entries from next's current 1580 * deadlist which were born before prev, and free the 1581 * other entries. 1582 * 1583 * XXX we're doing this long task with the config lock held 1584 */ 1585 while (bplist_iterate(&ds_next->ds_deadlist, &itor, &bp) == 0) { 1586 if (bp.blk_birth <= ds->ds_phys->ds_prev_snap_txg) { 1587 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, 1588 &bp, tx)); 1589 if (ds_prev && !after_branch_point && 1590 bp.blk_birth > 1591 ds_prev->ds_phys->ds_prev_snap_txg) { 1592 ds_prev->ds_phys->ds_unique_bytes += 1593 bp_get_dasize(dp->dp_spa, &bp); 1594 } 1595 } else { 1596 used += bp_get_dasize(dp->dp_spa, &bp); 1597 compressed += BP_GET_PSIZE(&bp); 1598 uncompressed += BP_GET_UCSIZE(&bp); 1599 /* XXX check return value? */ 1600 (void) dsl_free(zio, dp, tx->tx_txg, 1601 &bp, NULL, NULL, ARC_NOWAIT); 1602 } 1603 } 1604 1605 ASSERT3U(used, ==, ds->ds_phys->ds_unique_bytes); 1606 1607 /* change snapused */ 1608 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1609 -used, -compressed, -uncompressed, tx); 1610 1611 /* free next's deadlist */ 1612 bplist_close(&ds_next->ds_deadlist); 1613 bplist_destroy(mos, ds_next->ds_phys->ds_deadlist_obj, tx); 1614 1615 /* set next's deadlist to our deadlist */ 1616 bplist_close(&ds->ds_deadlist); 1617 ds_next->ds_phys->ds_deadlist_obj = 1618 ds->ds_phys->ds_deadlist_obj; 1619 VERIFY(0 == bplist_open(&ds_next->ds_deadlist, mos, 1620 ds_next->ds_phys->ds_deadlist_obj)); 1621 ds->ds_phys->ds_deadlist_obj = 0; 1622 1623 if (ds_next->ds_phys->ds_next_snap_obj != 0) { 1624 /* 1625 * Update next's unique to include blocks which 1626 * were previously shared by only this snapshot 1627 * and it. Those blocks will be born after the 1628 * prev snap and before this snap, and will have 1629 * died after the next snap and before the one 1630 * after that (ie. be on the snap after next's 1631 * deadlist). 1632 * 1633 * XXX we're doing this long task with the 1634 * config lock held 1635 */ 1636 dsl_dataset_t *ds_after_next; 1637 uint64_t space; 1638 1639 VERIFY(0 == dsl_dataset_hold_obj(dp, 1640 ds_next->ds_phys->ds_next_snap_obj, 1641 FTAG, &ds_after_next)); 1642 1643 VERIFY(0 == 1644 bplist_space_birthrange(&ds_after_next->ds_deadlist, 1645 ds->ds_phys->ds_prev_snap_txg, 1646 ds->ds_phys->ds_creation_txg, &space)); 1647 ds_next->ds_phys->ds_unique_bytes += space; 1648 1649 dsl_dataset_rele(ds_after_next, FTAG); 1650 ASSERT3P(ds_next->ds_prev, ==, NULL); 1651 } else { 1652 ASSERT3P(ds_next->ds_prev, ==, ds); 1653 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1654 ds_next->ds_prev = NULL; 1655 if (ds_prev) { 1656 VERIFY(0 == dsl_dataset_get_ref(dp, 1657 ds->ds_phys->ds_prev_snap_obj, 1658 ds_next, &ds_next->ds_prev)); 1659 } 1660 1661 dsl_dataset_recalc_head_uniq(ds_next); 1662 1663 /* 1664 * Reduce the amount of our unconsmed refreservation 1665 * being charged to our parent by the amount of 1666 * new unique data we have gained. 1667 */ 1668 if (old_unique < ds_next->ds_reserved) { 1669 int64_t mrsdelta; 1670 uint64_t new_unique = 1671 ds_next->ds_phys->ds_unique_bytes; 1672 1673 ASSERT(old_unique <= new_unique); 1674 mrsdelta = MIN(new_unique - old_unique, 1675 ds_next->ds_reserved - old_unique); 1676 dsl_dir_diduse_space(ds->ds_dir, 1677 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1678 } 1679 } 1680 dsl_dataset_rele(ds_next, FTAG); 1681 } else { 1682 /* 1683 * There's no next snapshot, so this is a head dataset. 1684 * Destroy the deadlist. Unless it's a clone, the 1685 * deadlist should be empty. (If it's a clone, it's 1686 * safe to ignore the deadlist contents.) 1687 */ 1688 struct killarg ka; 1689 1690 ASSERT(after_branch_point || bplist_empty(&ds->ds_deadlist)); 1691 bplist_close(&ds->ds_deadlist); 1692 bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx); 1693 ds->ds_phys->ds_deadlist_obj = 0; 1694 1695 /* 1696 * Free everything that we point to (that's born after 1697 * the previous snapshot, if we are a clone) 1698 * 1699 * NB: this should be very quick, because we already 1700 * freed all the objects in open context. 1701 */ 1702 ka.ds = ds; 1703 ka.zio = zio; 1704 ka.tx = tx; 1705 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, 1706 TRAVERSE_POST, kill_blkptr, &ka); 1707 ASSERT3U(err, ==, 0); 1708 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1709 ds->ds_phys->ds_unique_bytes == 0); 1710 1711 if (ds->ds_prev != NULL) { 1712 dsl_dataset_rele(ds->ds_prev, ds); 1713 ds->ds_prev = ds_prev = NULL; 1714 } 1715 } 1716 1717 err = zio_wait(zio); 1718 ASSERT3U(err, ==, 0); 1719 1720 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1721 /* Erase the link in the dir */ 1722 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1723 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1724 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1725 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1726 ASSERT(err == 0); 1727 } else { 1728 /* remove from snapshot namespace */ 1729 dsl_dataset_t *ds_head; 1730 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1731 VERIFY(0 == dsl_dataset_hold_obj(dp, 1732 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1733 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1734 #ifdef ZFS_DEBUG 1735 { 1736 uint64_t val; 1737 1738 err = dsl_dataset_snap_lookup(ds_head, 1739 ds->ds_snapname, &val); 1740 ASSERT3U(err, ==, 0); 1741 ASSERT3U(val, ==, obj); 1742 } 1743 #endif 1744 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1745 ASSERT(err == 0); 1746 dsl_dataset_rele(ds_head, FTAG); 1747 } 1748 1749 if (ds_prev && ds->ds_prev != ds_prev) 1750 dsl_dataset_rele(ds_prev, FTAG); 1751 1752 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1753 spa_history_internal_log(LOG_DS_DESTROY, dp->dp_spa, tx, 1754 cr, "dataset = %llu", ds->ds_object); 1755 1756 if (ds->ds_phys->ds_next_clones_obj != 0) { 1757 uint64_t count; 1758 ASSERT(0 == zap_count(mos, 1759 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1760 VERIFY(0 == dmu_object_free(mos, 1761 ds->ds_phys->ds_next_clones_obj, tx)); 1762 } 1763 if (ds->ds_phys->ds_props_obj != 0) 1764 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1765 if (ds->ds_phys->ds_userrefs_obj != 0) 1766 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1767 dsl_dir_close(ds->ds_dir, ds); 1768 ds->ds_dir = NULL; 1769 dsl_dataset_drain_refs(ds, tag); 1770 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1771 1772 if (dsda->rm_origin) { 1773 /* 1774 * Remove the origin of the clone we just destroyed. 1775 */ 1776 struct dsl_ds_destroyarg ndsda = {0}; 1777 1778 ndsda.ds = dsda->rm_origin; 1779 dsl_dataset_destroy_sync(&ndsda, tag, cr, tx); 1780 } 1781 } 1782 1783 static int 1784 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1785 { 1786 uint64_t asize; 1787 1788 if (!dmu_tx_is_syncing(tx)) 1789 return (0); 1790 1791 /* 1792 * If there's an fs-only reservation, any blocks that might become 1793 * owned by the snapshot dataset must be accommodated by space 1794 * outside of the reservation. 1795 */ 1796 asize = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1797 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE)) 1798 return (ENOSPC); 1799 1800 /* 1801 * Propogate any reserved space for this snapshot to other 1802 * snapshot checks in this sync group. 1803 */ 1804 if (asize > 0) 1805 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 1806 1807 return (0); 1808 } 1809 1810 /* ARGSUSED */ 1811 int 1812 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 1813 { 1814 dsl_dataset_t *ds = arg1; 1815 const char *snapname = arg2; 1816 int err; 1817 uint64_t value; 1818 1819 /* 1820 * We don't allow multiple snapshots of the same txg. If there 1821 * is already one, try again. 1822 */ 1823 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 1824 return (EAGAIN); 1825 1826 /* 1827 * Check for conflicting name snapshot name. 1828 */ 1829 err = dsl_dataset_snap_lookup(ds, snapname, &value); 1830 if (err == 0) 1831 return (EEXIST); 1832 if (err != ENOENT) 1833 return (err); 1834 1835 /* 1836 * Check that the dataset's name is not too long. Name consists 1837 * of the dataset's length + 1 for the @-sign + snapshot name's length 1838 */ 1839 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 1840 return (ENAMETOOLONG); 1841 1842 err = dsl_dataset_snapshot_reserve_space(ds, tx); 1843 if (err) 1844 return (err); 1845 1846 ds->ds_trysnap_txg = tx->tx_txg; 1847 return (0); 1848 } 1849 1850 void 1851 dsl_dataset_snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 1852 { 1853 dsl_dataset_t *ds = arg1; 1854 const char *snapname = arg2; 1855 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1856 dmu_buf_t *dbuf; 1857 dsl_dataset_phys_t *dsphys; 1858 uint64_t dsobj, crtxg; 1859 objset_t *mos = dp->dp_meta_objset; 1860 int err; 1861 1862 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1863 1864 /* 1865 * The origin's ds_creation_txg has to be < TXG_INITIAL 1866 */ 1867 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 1868 crtxg = 1; 1869 else 1870 crtxg = tx->tx_txg; 1871 1872 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 1873 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 1874 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 1875 dmu_buf_will_dirty(dbuf, tx); 1876 dsphys = dbuf->db_data; 1877 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 1878 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 1879 dsphys->ds_fsid_guid = unique_create(); 1880 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 1881 sizeof (dsphys->ds_guid)); 1882 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 1883 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 1884 dsphys->ds_next_snap_obj = ds->ds_object; 1885 dsphys->ds_num_children = 1; 1886 dsphys->ds_creation_time = gethrestime_sec(); 1887 dsphys->ds_creation_txg = crtxg; 1888 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 1889 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes; 1890 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 1891 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 1892 dsphys->ds_flags = ds->ds_phys->ds_flags; 1893 dsphys->ds_bp = ds->ds_phys->ds_bp; 1894 dmu_buf_rele(dbuf, FTAG); 1895 1896 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 1897 if (ds->ds_prev) { 1898 uint64_t next_clones_obj = 1899 ds->ds_prev->ds_phys->ds_next_clones_obj; 1900 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 1901 ds->ds_object || 1902 ds->ds_prev->ds_phys->ds_num_children > 1); 1903 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 1904 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 1905 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1906 ds->ds_prev->ds_phys->ds_creation_txg); 1907 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 1908 } else if (next_clones_obj != 0) { 1909 VERIFY3U(0, ==, zap_remove_int(mos, 1910 next_clones_obj, dsphys->ds_next_snap_obj, tx)); 1911 VERIFY3U(0, ==, zap_add_int(mos, 1912 next_clones_obj, dsobj, tx)); 1913 } 1914 } 1915 1916 /* 1917 * If we have a reference-reservation on this dataset, we will 1918 * need to increase the amount of refreservation being charged 1919 * since our unique space is going to zero. 1920 */ 1921 if (ds->ds_reserved) { 1922 int64_t add = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1923 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 1924 add, 0, 0, tx); 1925 } 1926 1927 bplist_close(&ds->ds_deadlist); 1928 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1929 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 1930 ds->ds_phys->ds_prev_snap_obj = dsobj; 1931 ds->ds_phys->ds_prev_snap_txg = crtxg; 1932 ds->ds_phys->ds_unique_bytes = 0; 1933 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 1934 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1935 ds->ds_phys->ds_deadlist_obj = 1936 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx); 1937 VERIFY(0 == bplist_open(&ds->ds_deadlist, mos, 1938 ds->ds_phys->ds_deadlist_obj)); 1939 1940 dprintf("snap '%s' -> obj %llu\n", snapname, dsobj); 1941 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 1942 snapname, 8, 1, &dsobj, tx); 1943 ASSERT(err == 0); 1944 1945 if (ds->ds_prev) 1946 dsl_dataset_drop_ref(ds->ds_prev, ds); 1947 VERIFY(0 == dsl_dataset_get_ref(dp, 1948 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 1949 1950 dsl_pool_ds_snapshotted(ds, tx); 1951 1952 dsl_dir_snap_cmtime_update(ds->ds_dir); 1953 1954 spa_history_internal_log(LOG_DS_SNAPSHOT, dp->dp_spa, tx, cr, 1955 "dataset = %llu", dsobj); 1956 } 1957 1958 void 1959 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 1960 { 1961 ASSERT(dmu_tx_is_syncing(tx)); 1962 ASSERT(ds->ds_objset != NULL); 1963 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 1964 1965 /* 1966 * in case we had to change ds_fsid_guid when we opened it, 1967 * sync it out now. 1968 */ 1969 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1970 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 1971 1972 dsl_dir_dirty(ds->ds_dir, tx); 1973 dmu_objset_sync(ds->ds_objset, zio, tx); 1974 } 1975 1976 void 1977 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 1978 { 1979 uint64_t refd, avail, uobjs, aobjs; 1980 1981 dsl_dir_stats(ds->ds_dir, nv); 1982 1983 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 1984 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 1985 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 1986 1987 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 1988 ds->ds_phys->ds_creation_time); 1989 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 1990 ds->ds_phys->ds_creation_txg); 1991 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 1992 ds->ds_quota); 1993 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 1994 ds->ds_reserved); 1995 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 1996 ds->ds_phys->ds_guid); 1997 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 1998 dsl_dataset_unique(ds)); 1999 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2000 ds->ds_object); 2001 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, ds->ds_userrefs); 2002 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2003 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2004 2005 if (ds->ds_phys->ds_next_snap_obj) { 2006 /* 2007 * This is a snapshot; override the dd's space used with 2008 * our unique space and compression ratio. 2009 */ 2010 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2011 ds->ds_phys->ds_unique_bytes); 2012 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, 2013 ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2014 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2015 ds->ds_phys->ds_compressed_bytes)); 2016 } 2017 } 2018 2019 void 2020 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2021 { 2022 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2023 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2024 stat->dds_guid = ds->ds_phys->ds_guid; 2025 if (ds->ds_phys->ds_next_snap_obj) { 2026 stat->dds_is_snapshot = B_TRUE; 2027 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2028 } else { 2029 stat->dds_is_snapshot = B_FALSE; 2030 stat->dds_num_clones = 0; 2031 } 2032 2033 /* clone origin is really a dsl_dir thing... */ 2034 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2035 if (dsl_dir_is_clone(ds->ds_dir)) { 2036 dsl_dataset_t *ods; 2037 2038 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2039 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2040 dsl_dataset_name(ods, stat->dds_origin); 2041 dsl_dataset_drop_ref(ods, FTAG); 2042 } else { 2043 stat->dds_origin[0] = '\0'; 2044 } 2045 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2046 } 2047 2048 uint64_t 2049 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2050 { 2051 return (ds->ds_fsid_guid); 2052 } 2053 2054 void 2055 dsl_dataset_space(dsl_dataset_t *ds, 2056 uint64_t *refdbytesp, uint64_t *availbytesp, 2057 uint64_t *usedobjsp, uint64_t *availobjsp) 2058 { 2059 *refdbytesp = ds->ds_phys->ds_used_bytes; 2060 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2061 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2062 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2063 if (ds->ds_quota != 0) { 2064 /* 2065 * Adjust available bytes according to refquota 2066 */ 2067 if (*refdbytesp < ds->ds_quota) 2068 *availbytesp = MIN(*availbytesp, 2069 ds->ds_quota - *refdbytesp); 2070 else 2071 *availbytesp = 0; 2072 } 2073 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2074 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2075 } 2076 2077 boolean_t 2078 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2079 { 2080 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2081 2082 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2083 dsl_pool_sync_context(dp)); 2084 if (ds->ds_prev == NULL) 2085 return (B_FALSE); 2086 if (ds->ds_phys->ds_bp.blk_birth > 2087 ds->ds_prev->ds_phys->ds_creation_txg) 2088 return (B_TRUE); 2089 return (B_FALSE); 2090 } 2091 2092 /* ARGSUSED */ 2093 static int 2094 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2095 { 2096 dsl_dataset_t *ds = arg1; 2097 char *newsnapname = arg2; 2098 dsl_dir_t *dd = ds->ds_dir; 2099 dsl_dataset_t *hds; 2100 uint64_t val; 2101 int err; 2102 2103 err = dsl_dataset_hold_obj(dd->dd_pool, 2104 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2105 if (err) 2106 return (err); 2107 2108 /* new name better not be in use */ 2109 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2110 dsl_dataset_rele(hds, FTAG); 2111 2112 if (err == 0) 2113 err = EEXIST; 2114 else if (err == ENOENT) 2115 err = 0; 2116 2117 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2118 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2119 err = ENAMETOOLONG; 2120 2121 return (err); 2122 } 2123 2124 static void 2125 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, 2126 cred_t *cr, dmu_tx_t *tx) 2127 { 2128 dsl_dataset_t *ds = arg1; 2129 const char *newsnapname = arg2; 2130 dsl_dir_t *dd = ds->ds_dir; 2131 objset_t *mos = dd->dd_pool->dp_meta_objset; 2132 dsl_dataset_t *hds; 2133 int err; 2134 2135 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2136 2137 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2138 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2139 2140 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2141 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2142 ASSERT3U(err, ==, 0); 2143 mutex_enter(&ds->ds_lock); 2144 (void) strcpy(ds->ds_snapname, newsnapname); 2145 mutex_exit(&ds->ds_lock); 2146 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2147 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2148 ASSERT3U(err, ==, 0); 2149 2150 spa_history_internal_log(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2151 cr, "dataset = %llu", ds->ds_object); 2152 dsl_dataset_rele(hds, FTAG); 2153 } 2154 2155 struct renamesnaparg { 2156 dsl_sync_task_group_t *dstg; 2157 char failed[MAXPATHLEN]; 2158 char *oldsnap; 2159 char *newsnap; 2160 }; 2161 2162 static int 2163 dsl_snapshot_rename_one(char *name, void *arg) 2164 { 2165 struct renamesnaparg *ra = arg; 2166 dsl_dataset_t *ds = NULL; 2167 char *cp; 2168 int err; 2169 2170 cp = name + strlen(name); 2171 *cp = '@'; 2172 (void) strcpy(cp + 1, ra->oldsnap); 2173 2174 /* 2175 * For recursive snapshot renames the parent won't be changing 2176 * so we just pass name for both the to/from argument. 2177 */ 2178 err = zfs_secpolicy_rename_perms(name, name, CRED()); 2179 if (err == ENOENT) { 2180 return (0); 2181 } else if (err) { 2182 (void) strcpy(ra->failed, name); 2183 return (err); 2184 } 2185 2186 #ifdef _KERNEL 2187 /* 2188 * For all filesystems undergoing rename, we'll need to unmount it. 2189 */ 2190 (void) zfs_unmount_snap(name, NULL); 2191 #endif 2192 err = dsl_dataset_hold(name, ra->dstg, &ds); 2193 *cp = '\0'; 2194 if (err == ENOENT) { 2195 return (0); 2196 } else if (err) { 2197 (void) strcpy(ra->failed, name); 2198 return (err); 2199 } 2200 2201 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2202 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2203 2204 return (0); 2205 } 2206 2207 static int 2208 dsl_recursive_rename(char *oldname, const char *newname) 2209 { 2210 int err; 2211 struct renamesnaparg *ra; 2212 dsl_sync_task_t *dst; 2213 spa_t *spa; 2214 char *cp, *fsname = spa_strdup(oldname); 2215 int len = strlen(oldname); 2216 2217 /* truncate the snapshot name to get the fsname */ 2218 cp = strchr(fsname, '@'); 2219 *cp = '\0'; 2220 2221 err = spa_open(fsname, &spa, FTAG); 2222 if (err) { 2223 kmem_free(fsname, len + 1); 2224 return (err); 2225 } 2226 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2227 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2228 2229 ra->oldsnap = strchr(oldname, '@') + 1; 2230 ra->newsnap = strchr(newname, '@') + 1; 2231 *ra->failed = '\0'; 2232 2233 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2234 DS_FIND_CHILDREN); 2235 kmem_free(fsname, len + 1); 2236 2237 if (err == 0) { 2238 err = dsl_sync_task_group_wait(ra->dstg); 2239 } 2240 2241 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2242 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2243 dsl_dataset_t *ds = dst->dst_arg1; 2244 if (dst->dst_err) { 2245 dsl_dir_name(ds->ds_dir, ra->failed); 2246 (void) strcat(ra->failed, "@"); 2247 (void) strcat(ra->failed, ra->newsnap); 2248 } 2249 dsl_dataset_rele(ds, ra->dstg); 2250 } 2251 2252 if (err) 2253 (void) strcpy(oldname, ra->failed); 2254 2255 dsl_sync_task_group_destroy(ra->dstg); 2256 kmem_free(ra, sizeof (struct renamesnaparg)); 2257 spa_close(spa, FTAG); 2258 return (err); 2259 } 2260 2261 static int 2262 dsl_valid_rename(char *oldname, void *arg) 2263 { 2264 int delta = *(int *)arg; 2265 2266 if (strlen(oldname) + delta >= MAXNAMELEN) 2267 return (ENAMETOOLONG); 2268 2269 return (0); 2270 } 2271 2272 #pragma weak dmu_objset_rename = dsl_dataset_rename 2273 int 2274 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2275 { 2276 dsl_dir_t *dd; 2277 dsl_dataset_t *ds; 2278 const char *tail; 2279 int err; 2280 2281 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2282 if (err) 2283 return (err); 2284 /* 2285 * If there are more than 2 references there may be holds 2286 * hanging around that haven't been cleared out yet. 2287 */ 2288 if (dmu_buf_refcount(dd->dd_dbuf) > 2) 2289 txg_wait_synced(dd->dd_pool, 0); 2290 if (tail == NULL) { 2291 int delta = strlen(newname) - strlen(oldname); 2292 2293 /* if we're growing, validate child name lengths */ 2294 if (delta > 0) 2295 err = dmu_objset_find(oldname, dsl_valid_rename, 2296 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2297 2298 if (!err) 2299 err = dsl_dir_rename(dd, newname); 2300 dsl_dir_close(dd, FTAG); 2301 return (err); 2302 } 2303 if (tail[0] != '@') { 2304 /* the name ended in a nonexistent component */ 2305 dsl_dir_close(dd, FTAG); 2306 return (ENOENT); 2307 } 2308 2309 dsl_dir_close(dd, FTAG); 2310 2311 /* new name must be snapshot in same filesystem */ 2312 tail = strchr(newname, '@'); 2313 if (tail == NULL) 2314 return (EINVAL); 2315 tail++; 2316 if (strncmp(oldname, newname, tail - newname) != 0) 2317 return (EXDEV); 2318 2319 if (recursive) { 2320 err = dsl_recursive_rename(oldname, newname); 2321 } else { 2322 err = dsl_dataset_hold(oldname, FTAG, &ds); 2323 if (err) 2324 return (err); 2325 2326 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2327 dsl_dataset_snapshot_rename_check, 2328 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2329 2330 dsl_dataset_rele(ds, FTAG); 2331 } 2332 2333 return (err); 2334 } 2335 2336 struct promotenode { 2337 list_node_t link; 2338 dsl_dataset_t *ds; 2339 }; 2340 2341 struct promotearg { 2342 list_t shared_snaps, origin_snaps, clone_snaps; 2343 dsl_dataset_t *origin_origin, *origin_head; 2344 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2345 char *err_ds; 2346 }; 2347 2348 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2349 2350 /* ARGSUSED */ 2351 static int 2352 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2353 { 2354 dsl_dataset_t *hds = arg1; 2355 struct promotearg *pa = arg2; 2356 struct promotenode *snap = list_head(&pa->shared_snaps); 2357 dsl_dataset_t *origin_ds = snap->ds; 2358 int err; 2359 2360 /* Check that it is a real clone */ 2361 if (!dsl_dir_is_clone(hds->ds_dir)) 2362 return (EINVAL); 2363 2364 /* Since this is so expensive, don't do the preliminary check */ 2365 if (!dmu_tx_is_syncing(tx)) 2366 return (0); 2367 2368 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2369 return (EXDEV); 2370 2371 /* compute origin's new unique space */ 2372 snap = list_tail(&pa->clone_snaps); 2373 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2374 err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2375 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &pa->unique); 2376 if (err) 2377 return (err); 2378 2379 /* 2380 * Walk the snapshots that we are moving 2381 * 2382 * Compute space to transfer. Consider the incremental changes 2383 * to used for each snapshot: 2384 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2385 * So each snapshot gave birth to: 2386 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2387 * So a sequence would look like: 2388 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2389 * Which simplifies to: 2390 * uN + kN + kN-1 + ... + k1 + k0 2391 * Note however, if we stop before we reach the ORIGIN we get: 2392 * uN + kN + kN-1 + ... + kM - uM-1 2393 */ 2394 pa->used = origin_ds->ds_phys->ds_used_bytes; 2395 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2396 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2397 for (snap = list_head(&pa->shared_snaps); snap; 2398 snap = list_next(&pa->shared_snaps, snap)) { 2399 uint64_t val, dlused, dlcomp, dluncomp; 2400 dsl_dataset_t *ds = snap->ds; 2401 2402 /* Check that the snapshot name does not conflict */ 2403 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2404 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2405 if (err == 0) { 2406 err = EEXIST; 2407 goto out; 2408 } 2409 if (err != ENOENT) 2410 goto out; 2411 2412 /* The very first snapshot does not have a deadlist */ 2413 if (ds->ds_phys->ds_prev_snap_obj == 0) 2414 continue; 2415 2416 if (err = bplist_space(&ds->ds_deadlist, 2417 &dlused, &dlcomp, &dluncomp)) 2418 goto out; 2419 pa->used += dlused; 2420 pa->comp += dlcomp; 2421 pa->uncomp += dluncomp; 2422 } 2423 2424 /* 2425 * If we are a clone of a clone then we never reached ORIGIN, 2426 * so we need to subtract out the clone origin's used space. 2427 */ 2428 if (pa->origin_origin) { 2429 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes; 2430 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2431 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2432 } 2433 2434 /* Check that there is enough space here */ 2435 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2436 pa->used); 2437 if (err) 2438 return (err); 2439 2440 /* 2441 * Compute the amounts of space that will be used by snapshots 2442 * after the promotion (for both origin and clone). For each, 2443 * it is the amount of space that will be on all of their 2444 * deadlists (that was not born before their new origin). 2445 */ 2446 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2447 uint64_t space; 2448 2449 /* 2450 * Note, typically this will not be a clone of a clone, 2451 * so snap->ds->ds_origin_txg will be < TXG_INITIAL, so 2452 * these snaplist_space() -> bplist_space_birthrange() 2453 * calls will be fast because they do not have to 2454 * iterate over all bps. 2455 */ 2456 snap = list_head(&pa->origin_snaps); 2457 err = snaplist_space(&pa->shared_snaps, 2458 snap->ds->ds_origin_txg, &pa->cloneusedsnap); 2459 if (err) 2460 return (err); 2461 2462 err = snaplist_space(&pa->clone_snaps, 2463 snap->ds->ds_origin_txg, &space); 2464 if (err) 2465 return (err); 2466 pa->cloneusedsnap += space; 2467 } 2468 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2469 err = snaplist_space(&pa->origin_snaps, 2470 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2471 if (err) 2472 return (err); 2473 } 2474 2475 return (0); 2476 out: 2477 pa->err_ds = snap->ds->ds_snapname; 2478 return (err); 2479 } 2480 2481 static void 2482 dsl_dataset_promote_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2483 { 2484 dsl_dataset_t *hds = arg1; 2485 struct promotearg *pa = arg2; 2486 struct promotenode *snap = list_head(&pa->shared_snaps); 2487 dsl_dataset_t *origin_ds = snap->ds; 2488 dsl_dataset_t *origin_head; 2489 dsl_dir_t *dd = hds->ds_dir; 2490 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2491 dsl_dir_t *odd = NULL; 2492 uint64_t oldnext_obj; 2493 int64_t delta; 2494 2495 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2496 2497 snap = list_head(&pa->origin_snaps); 2498 origin_head = snap->ds; 2499 2500 /* 2501 * We need to explicitly open odd, since origin_ds's dd will be 2502 * changing. 2503 */ 2504 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2505 NULL, FTAG, &odd)); 2506 2507 /* change origin's next snap */ 2508 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2509 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2510 snap = list_tail(&pa->clone_snaps); 2511 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2512 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2513 2514 /* change the origin's next clone */ 2515 if (origin_ds->ds_phys->ds_next_clones_obj) { 2516 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2517 origin_ds->ds_phys->ds_next_clones_obj, 2518 origin_ds->ds_phys->ds_next_snap_obj, tx)); 2519 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2520 origin_ds->ds_phys->ds_next_clones_obj, 2521 oldnext_obj, tx)); 2522 } 2523 2524 /* change origin */ 2525 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2526 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2527 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2528 hds->ds_origin_txg = origin_head->ds_origin_txg; 2529 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2530 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2531 origin_head->ds_origin_txg = origin_ds->ds_phys->ds_creation_txg; 2532 2533 /* move snapshots to this dir */ 2534 for (snap = list_head(&pa->shared_snaps); snap; 2535 snap = list_next(&pa->shared_snaps, snap)) { 2536 dsl_dataset_t *ds = snap->ds; 2537 2538 /* unregister props as dsl_dir is changing */ 2539 if (ds->ds_objset) { 2540 dmu_objset_evict(ds->ds_objset); 2541 ds->ds_objset = NULL; 2542 } 2543 /* move snap name entry */ 2544 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2545 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2546 ds->ds_snapname, tx)); 2547 VERIFY(0 == zap_add(dp->dp_meta_objset, 2548 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2549 8, 1, &ds->ds_object, tx)); 2550 /* change containing dsl_dir */ 2551 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2552 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2553 ds->ds_phys->ds_dir_obj = dd->dd_object; 2554 ASSERT3P(ds->ds_dir, ==, odd); 2555 dsl_dir_close(ds->ds_dir, ds); 2556 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2557 NULL, ds, &ds->ds_dir)); 2558 2559 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2560 } 2561 2562 /* 2563 * Change space accounting. 2564 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2565 * both be valid, or both be 0 (resulting in delta == 0). This 2566 * is true for each of {clone,origin} independently. 2567 */ 2568 2569 delta = pa->cloneusedsnap - 2570 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2571 ASSERT3S(delta, >=, 0); 2572 ASSERT3U(pa->used, >=, delta); 2573 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2574 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2575 pa->used - delta, pa->comp, pa->uncomp, tx); 2576 2577 delta = pa->originusedsnap - 2578 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2579 ASSERT3S(delta, <=, 0); 2580 ASSERT3U(pa->used, >=, -delta); 2581 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2582 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2583 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2584 2585 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2586 2587 /* log history record */ 2588 spa_history_internal_log(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2589 cr, "dataset = %llu", hds->ds_object); 2590 2591 dsl_dir_close(odd, FTAG); 2592 } 2593 2594 static char *snaplist_tag = "snaplist"; 2595 /* 2596 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2597 * (exclusive) and last_obj (inclusive). The list will be in reverse 2598 * order (last_obj will be the list_head()). If first_obj == 0, do all 2599 * snapshots back to this dataset's origin. 2600 */ 2601 static int 2602 snaplist_make(dsl_pool_t *dp, boolean_t own, 2603 uint64_t first_obj, uint64_t last_obj, list_t *l) 2604 { 2605 uint64_t obj = last_obj; 2606 2607 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2608 2609 list_create(l, sizeof (struct promotenode), 2610 offsetof(struct promotenode, link)); 2611 2612 while (obj != first_obj) { 2613 dsl_dataset_t *ds; 2614 struct promotenode *snap; 2615 int err; 2616 2617 if (own) { 2618 err = dsl_dataset_own_obj(dp, obj, 2619 0, snaplist_tag, &ds); 2620 if (err == 0) 2621 dsl_dataset_make_exclusive(ds, snaplist_tag); 2622 } else { 2623 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2624 } 2625 if (err == ENOENT) { 2626 /* lost race with snapshot destroy */ 2627 struct promotenode *last = list_tail(l); 2628 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2629 obj = last->ds->ds_phys->ds_prev_snap_obj; 2630 continue; 2631 } else if (err) { 2632 return (err); 2633 } 2634 2635 if (first_obj == 0) 2636 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2637 2638 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2639 snap->ds = ds; 2640 list_insert_tail(l, snap); 2641 obj = ds->ds_phys->ds_prev_snap_obj; 2642 } 2643 2644 return (0); 2645 } 2646 2647 static int 2648 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2649 { 2650 struct promotenode *snap; 2651 2652 *spacep = 0; 2653 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2654 uint64_t used; 2655 int err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2656 mintxg, UINT64_MAX, &used); 2657 if (err) 2658 return (err); 2659 *spacep += used; 2660 } 2661 return (0); 2662 } 2663 2664 static void 2665 snaplist_destroy(list_t *l, boolean_t own) 2666 { 2667 struct promotenode *snap; 2668 2669 if (!l || !list_link_active(&l->list_head)) 2670 return; 2671 2672 while ((snap = list_tail(l)) != NULL) { 2673 list_remove(l, snap); 2674 if (own) 2675 dsl_dataset_disown(snap->ds, snaplist_tag); 2676 else 2677 dsl_dataset_rele(snap->ds, snaplist_tag); 2678 kmem_free(snap, sizeof (struct promotenode)); 2679 } 2680 list_destroy(l); 2681 } 2682 2683 /* 2684 * Promote a clone. Nomenclature note: 2685 * "clone" or "cds": the original clone which is being promoted 2686 * "origin" or "ods": the snapshot which is originally clone's origin 2687 * "origin head" or "ohds": the dataset which is the head 2688 * (filesystem/volume) for the origin 2689 * "origin origin": the origin of the origin's filesystem (typically 2690 * NULL, indicating that the clone is not a clone of a clone). 2691 */ 2692 int 2693 dsl_dataset_promote(const char *name, char *conflsnap) 2694 { 2695 dsl_dataset_t *ds; 2696 dsl_dir_t *dd; 2697 dsl_pool_t *dp; 2698 dmu_object_info_t doi; 2699 struct promotearg pa = { 0 }; 2700 struct promotenode *snap; 2701 int err; 2702 2703 err = dsl_dataset_hold(name, FTAG, &ds); 2704 if (err) 2705 return (err); 2706 dd = ds->ds_dir; 2707 dp = dd->dd_pool; 2708 2709 err = dmu_object_info(dp->dp_meta_objset, 2710 ds->ds_phys->ds_snapnames_zapobj, &doi); 2711 if (err) { 2712 dsl_dataset_rele(ds, FTAG); 2713 return (err); 2714 } 2715 2716 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 2717 dsl_dataset_rele(ds, FTAG); 2718 return (EINVAL); 2719 } 2720 2721 /* 2722 * We are going to inherit all the snapshots taken before our 2723 * origin (i.e., our new origin will be our parent's origin). 2724 * Take ownership of them so that we can rename them into our 2725 * namespace. 2726 */ 2727 rw_enter(&dp->dp_config_rwlock, RW_READER); 2728 2729 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 2730 &pa.shared_snaps); 2731 if (err != 0) 2732 goto out; 2733 2734 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 2735 if (err != 0) 2736 goto out; 2737 2738 snap = list_head(&pa.shared_snaps); 2739 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 2740 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 2741 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 2742 if (err != 0) 2743 goto out; 2744 2745 if (dsl_dir_is_clone(snap->ds->ds_dir)) { 2746 err = dsl_dataset_own_obj(dp, 2747 snap->ds->ds_dir->dd_phys->dd_origin_obj, 2748 0, FTAG, &pa.origin_origin); 2749 if (err != 0) 2750 goto out; 2751 } 2752 2753 out: 2754 rw_exit(&dp->dp_config_rwlock); 2755 2756 /* 2757 * Add in 128x the snapnames zapobj size, since we will be moving 2758 * a bunch of snapnames to the promoted ds, and dirtying their 2759 * bonus buffers. 2760 */ 2761 if (err == 0) { 2762 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 2763 dsl_dataset_promote_sync, ds, &pa, 2764 2 + 2 * doi.doi_physical_blks); 2765 if (err && pa.err_ds && conflsnap) 2766 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 2767 } 2768 2769 snaplist_destroy(&pa.shared_snaps, B_TRUE); 2770 snaplist_destroy(&pa.clone_snaps, B_FALSE); 2771 snaplist_destroy(&pa.origin_snaps, B_FALSE); 2772 if (pa.origin_origin) 2773 dsl_dataset_disown(pa.origin_origin, FTAG); 2774 dsl_dataset_rele(ds, FTAG); 2775 return (err); 2776 } 2777 2778 struct cloneswaparg { 2779 dsl_dataset_t *cds; /* clone dataset */ 2780 dsl_dataset_t *ohds; /* origin's head dataset */ 2781 boolean_t force; 2782 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 2783 }; 2784 2785 /* ARGSUSED */ 2786 static int 2787 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 2788 { 2789 struct cloneswaparg *csa = arg1; 2790 2791 /* they should both be heads */ 2792 if (dsl_dataset_is_snapshot(csa->cds) || 2793 dsl_dataset_is_snapshot(csa->ohds)) 2794 return (EINVAL); 2795 2796 /* the branch point should be just before them */ 2797 if (csa->cds->ds_prev != csa->ohds->ds_prev) 2798 return (EINVAL); 2799 2800 /* cds should be the clone (unless they are unrelated) */ 2801 if (csa->cds->ds_prev != NULL && 2802 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 2803 csa->ohds->ds_object != 2804 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 2805 return (EINVAL); 2806 2807 /* the clone should be a child of the origin */ 2808 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 2809 return (EINVAL); 2810 2811 /* ohds shouldn't be modified unless 'force' */ 2812 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 2813 return (ETXTBSY); 2814 2815 /* adjust amount of any unconsumed refreservation */ 2816 csa->unused_refres_delta = 2817 (int64_t)MIN(csa->ohds->ds_reserved, 2818 csa->ohds->ds_phys->ds_unique_bytes) - 2819 (int64_t)MIN(csa->ohds->ds_reserved, 2820 csa->cds->ds_phys->ds_unique_bytes); 2821 2822 if (csa->unused_refres_delta > 0 && 2823 csa->unused_refres_delta > 2824 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 2825 return (ENOSPC); 2826 2827 return (0); 2828 } 2829 2830 /* ARGSUSED */ 2831 static void 2832 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2833 { 2834 struct cloneswaparg *csa = arg1; 2835 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 2836 2837 ASSERT(csa->cds->ds_reserved == 0); 2838 ASSERT(csa->cds->ds_quota == csa->ohds->ds_quota); 2839 2840 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 2841 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 2842 2843 if (csa->cds->ds_objset != NULL) { 2844 dmu_objset_evict(csa->cds->ds_objset); 2845 csa->cds->ds_objset = NULL; 2846 } 2847 2848 if (csa->ohds->ds_objset != NULL) { 2849 dmu_objset_evict(csa->ohds->ds_objset); 2850 csa->ohds->ds_objset = NULL; 2851 } 2852 2853 /* 2854 * Reset origin's unique bytes, if it exists. 2855 */ 2856 if (csa->cds->ds_prev) { 2857 dsl_dataset_t *origin = csa->cds->ds_prev; 2858 dmu_buf_will_dirty(origin->ds_dbuf, tx); 2859 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2860 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2861 &origin->ds_phys->ds_unique_bytes)); 2862 } 2863 2864 /* swap blkptrs */ 2865 { 2866 blkptr_t tmp; 2867 tmp = csa->ohds->ds_phys->ds_bp; 2868 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 2869 csa->cds->ds_phys->ds_bp = tmp; 2870 } 2871 2872 /* set dd_*_bytes */ 2873 { 2874 int64_t dused, dcomp, duncomp; 2875 uint64_t cdl_used, cdl_comp, cdl_uncomp; 2876 uint64_t odl_used, odl_comp, odl_uncomp; 2877 2878 ASSERT3U(csa->cds->ds_dir->dd_phys-> 2879 dd_used_breakdown[DD_USED_SNAP], ==, 0); 2880 2881 VERIFY(0 == bplist_space(&csa->cds->ds_deadlist, &cdl_used, 2882 &cdl_comp, &cdl_uncomp)); 2883 VERIFY(0 == bplist_space(&csa->ohds->ds_deadlist, &odl_used, 2884 &odl_comp, &odl_uncomp)); 2885 2886 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used - 2887 (csa->ohds->ds_phys->ds_used_bytes + odl_used); 2888 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 2889 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 2890 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 2891 cdl_uncomp - 2892 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 2893 2894 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 2895 dused, dcomp, duncomp, tx); 2896 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 2897 -dused, -dcomp, -duncomp, tx); 2898 2899 /* 2900 * The difference in the space used by snapshots is the 2901 * difference in snapshot space due to the head's 2902 * deadlist (since that's the only thing that's 2903 * changing that affects the snapused). 2904 */ 2905 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2906 csa->ohds->ds_origin_txg, UINT64_MAX, &cdl_used)); 2907 VERIFY(0 == bplist_space_birthrange(&csa->ohds->ds_deadlist, 2908 csa->ohds->ds_origin_txg, UINT64_MAX, &odl_used)); 2909 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 2910 DD_USED_HEAD, DD_USED_SNAP, tx); 2911 } 2912 2913 #define SWITCH64(x, y) \ 2914 { \ 2915 uint64_t __tmp = (x); \ 2916 (x) = (y); \ 2917 (y) = __tmp; \ 2918 } 2919 2920 /* swap ds_*_bytes */ 2921 SWITCH64(csa->ohds->ds_phys->ds_used_bytes, 2922 csa->cds->ds_phys->ds_used_bytes); 2923 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 2924 csa->cds->ds_phys->ds_compressed_bytes); 2925 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 2926 csa->cds->ds_phys->ds_uncompressed_bytes); 2927 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 2928 csa->cds->ds_phys->ds_unique_bytes); 2929 2930 /* apply any parent delta for change in unconsumed refreservation */ 2931 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 2932 csa->unused_refres_delta, 0, 0, tx); 2933 2934 /* swap deadlists */ 2935 bplist_close(&csa->cds->ds_deadlist); 2936 bplist_close(&csa->ohds->ds_deadlist); 2937 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 2938 csa->cds->ds_phys->ds_deadlist_obj); 2939 VERIFY(0 == bplist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 2940 csa->cds->ds_phys->ds_deadlist_obj)); 2941 VERIFY(0 == bplist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 2942 csa->ohds->ds_phys->ds_deadlist_obj)); 2943 2944 dsl_pool_ds_clone_swapped(csa->ohds, csa->cds, tx); 2945 } 2946 2947 /* 2948 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 2949 * recv" into an existing fs to swizzle the file system to the new 2950 * version, and by "zfs rollback". Can also be used to swap two 2951 * independent head datasets if neither has any snapshots. 2952 */ 2953 int 2954 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 2955 boolean_t force) 2956 { 2957 struct cloneswaparg csa; 2958 int error; 2959 2960 ASSERT(clone->ds_owner); 2961 ASSERT(origin_head->ds_owner); 2962 retry: 2963 /* Need exclusive access for the swap */ 2964 rw_enter(&clone->ds_rwlock, RW_WRITER); 2965 if (!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 2966 rw_exit(&clone->ds_rwlock); 2967 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 2968 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 2969 rw_exit(&origin_head->ds_rwlock); 2970 goto retry; 2971 } 2972 } 2973 csa.cds = clone; 2974 csa.ohds = origin_head; 2975 csa.force = force; 2976 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 2977 dsl_dataset_clone_swap_check, 2978 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 2979 return (error); 2980 } 2981 2982 /* 2983 * Given a pool name and a dataset object number in that pool, 2984 * return the name of that dataset. 2985 */ 2986 int 2987 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 2988 { 2989 spa_t *spa; 2990 dsl_pool_t *dp; 2991 dsl_dataset_t *ds; 2992 int error; 2993 2994 if ((error = spa_open(pname, &spa, FTAG)) != 0) 2995 return (error); 2996 dp = spa_get_dsl(spa); 2997 rw_enter(&dp->dp_config_rwlock, RW_READER); 2998 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 2999 dsl_dataset_name(ds, buf); 3000 dsl_dataset_rele(ds, FTAG); 3001 } 3002 rw_exit(&dp->dp_config_rwlock); 3003 spa_close(spa, FTAG); 3004 3005 return (error); 3006 } 3007 3008 int 3009 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3010 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3011 { 3012 int error = 0; 3013 3014 ASSERT3S(asize, >, 0); 3015 3016 /* 3017 * *ref_rsrv is the portion of asize that will come from any 3018 * unconsumed refreservation space. 3019 */ 3020 *ref_rsrv = 0; 3021 3022 mutex_enter(&ds->ds_lock); 3023 /* 3024 * Make a space adjustment for reserved bytes. 3025 */ 3026 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3027 ASSERT3U(*used, >=, 3028 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3029 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3030 *ref_rsrv = 3031 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3032 } 3033 3034 if (!check_quota || ds->ds_quota == 0) { 3035 mutex_exit(&ds->ds_lock); 3036 return (0); 3037 } 3038 /* 3039 * If they are requesting more space, and our current estimate 3040 * is over quota, they get to try again unless the actual 3041 * on-disk is over quota and there are no pending changes (which 3042 * may free up space for us). 3043 */ 3044 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) { 3045 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota) 3046 error = ERESTART; 3047 else 3048 error = EDQUOT; 3049 } 3050 mutex_exit(&ds->ds_lock); 3051 3052 return (error); 3053 } 3054 3055 /* ARGSUSED */ 3056 static int 3057 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3058 { 3059 dsl_dataset_t *ds = arg1; 3060 uint64_t *quotap = arg2; 3061 uint64_t new_quota = *quotap; 3062 3063 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3064 return (ENOTSUP); 3065 3066 if (new_quota == 0) 3067 return (0); 3068 3069 if (new_quota < ds->ds_phys->ds_used_bytes || 3070 new_quota < ds->ds_reserved) 3071 return (ENOSPC); 3072 3073 return (0); 3074 } 3075 3076 /* ARGSUSED */ 3077 void 3078 dsl_dataset_set_quota_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3079 { 3080 dsl_dataset_t *ds = arg1; 3081 uint64_t *quotap = arg2; 3082 uint64_t new_quota = *quotap; 3083 3084 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3085 3086 ds->ds_quota = new_quota; 3087 3088 dsl_dir_prop_set_uint64_sync(ds->ds_dir, "refquota", new_quota, cr, tx); 3089 3090 spa_history_internal_log(LOG_DS_REFQUOTA, ds->ds_dir->dd_pool->dp_spa, 3091 tx, cr, "%lld dataset = %llu ", 3092 (longlong_t)new_quota, ds->ds_object); 3093 } 3094 3095 int 3096 dsl_dataset_set_quota(const char *dsname, uint64_t quota) 3097 { 3098 dsl_dataset_t *ds; 3099 int err; 3100 3101 err = dsl_dataset_hold(dsname, FTAG, &ds); 3102 if (err) 3103 return (err); 3104 3105 if (quota != ds->ds_quota) { 3106 /* 3107 * If someone removes a file, then tries to set the quota, we 3108 * want to make sure the file freeing takes effect. 3109 */ 3110 txg_wait_open(ds->ds_dir->dd_pool, 0); 3111 3112 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3113 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3114 ds, "a, 0); 3115 } 3116 dsl_dataset_rele(ds, FTAG); 3117 return (err); 3118 } 3119 3120 static int 3121 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3122 { 3123 dsl_dataset_t *ds = arg1; 3124 uint64_t *reservationp = arg2; 3125 uint64_t new_reservation = *reservationp; 3126 uint64_t unique; 3127 3128 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3129 SPA_VERSION_REFRESERVATION) 3130 return (ENOTSUP); 3131 3132 if (dsl_dataset_is_snapshot(ds)) 3133 return (EINVAL); 3134 3135 /* 3136 * If we are doing the preliminary check in open context, the 3137 * space estimates may be inaccurate. 3138 */ 3139 if (!dmu_tx_is_syncing(tx)) 3140 return (0); 3141 3142 mutex_enter(&ds->ds_lock); 3143 unique = dsl_dataset_unique(ds); 3144 mutex_exit(&ds->ds_lock); 3145 3146 if (MAX(unique, new_reservation) > MAX(unique, ds->ds_reserved)) { 3147 uint64_t delta = MAX(unique, new_reservation) - 3148 MAX(unique, ds->ds_reserved); 3149 3150 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3151 return (ENOSPC); 3152 if (ds->ds_quota > 0 && 3153 new_reservation > ds->ds_quota) 3154 return (ENOSPC); 3155 } 3156 3157 return (0); 3158 } 3159 3160 /* ARGSUSED */ 3161 static void 3162 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, cred_t *cr, 3163 dmu_tx_t *tx) 3164 { 3165 dsl_dataset_t *ds = arg1; 3166 uint64_t *reservationp = arg2; 3167 uint64_t new_reservation = *reservationp; 3168 uint64_t unique; 3169 int64_t delta; 3170 3171 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3172 3173 mutex_enter(&ds->ds_dir->dd_lock); 3174 mutex_enter(&ds->ds_lock); 3175 unique = dsl_dataset_unique(ds); 3176 delta = MAX(0, (int64_t)(new_reservation - unique)) - 3177 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3178 ds->ds_reserved = new_reservation; 3179 mutex_exit(&ds->ds_lock); 3180 3181 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3182 mutex_exit(&ds->ds_dir->dd_lock); 3183 dsl_dir_prop_set_uint64_sync(ds->ds_dir, "refreservation", 3184 new_reservation, cr, tx); 3185 3186 spa_history_internal_log(LOG_DS_REFRESERV, 3187 ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu", 3188 (longlong_t)new_reservation, ds->ds_object); 3189 } 3190 3191 int 3192 dsl_dataset_set_reservation(const char *dsname, uint64_t reservation) 3193 { 3194 dsl_dataset_t *ds; 3195 int err; 3196 3197 err = dsl_dataset_hold(dsname, FTAG, &ds); 3198 if (err) 3199 return (err); 3200 3201 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3202 dsl_dataset_set_reservation_check, 3203 dsl_dataset_set_reservation_sync, ds, &reservation, 0); 3204 dsl_dataset_rele(ds, FTAG); 3205 return (err); 3206 } 3207 3208 struct dsl_ds_holdarg { 3209 dsl_sync_task_group_t *dstg; 3210 char *htag; 3211 char *snapname; 3212 boolean_t recursive; 3213 boolean_t gotone; 3214 boolean_t temphold; 3215 char failed[MAXPATHLEN]; 3216 }; 3217 3218 static int 3219 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3220 { 3221 dsl_dataset_t *ds = arg1; 3222 struct dsl_ds_holdarg *ha = arg2; 3223 char *htag = ha->htag; 3224 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3225 int error = 0; 3226 3227 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3228 return (ENOTSUP); 3229 3230 if (!dsl_dataset_is_snapshot(ds)) 3231 return (EINVAL); 3232 3233 /* tags must be unique */ 3234 mutex_enter(&ds->ds_lock); 3235 if (ds->ds_phys->ds_userrefs_obj) { 3236 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3237 8, 1, tx); 3238 if (error == 0) 3239 error = EEXIST; 3240 else if (error == ENOENT) 3241 error = 0; 3242 } 3243 mutex_exit(&ds->ds_lock); 3244 3245 return (error); 3246 } 3247 3248 static void 3249 dsl_dataset_user_hold_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3250 { 3251 dsl_dataset_t *ds = arg1; 3252 struct dsl_ds_holdarg *ha = arg2; 3253 char *htag = ha->htag; 3254 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3255 objset_t *mos = dp->dp_meta_objset; 3256 time_t now = gethrestime_sec(); 3257 uint64_t zapobj; 3258 3259 mutex_enter(&ds->ds_lock); 3260 if (ds->ds_phys->ds_userrefs_obj == 0) { 3261 /* 3262 * This is the first user hold for this dataset. Create 3263 * the userrefs zap object. 3264 */ 3265 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3266 zapobj = ds->ds_phys->ds_userrefs_obj = 3267 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3268 } else { 3269 zapobj = ds->ds_phys->ds_userrefs_obj; 3270 } 3271 ds->ds_userrefs++; 3272 mutex_exit(&ds->ds_lock); 3273 3274 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3275 3276 if (ha->temphold) { 3277 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3278 htag, &now, tx)); 3279 } 3280 3281 spa_history_internal_log(LOG_DS_USER_HOLD, 3282 dp->dp_spa, tx, cr, "<%s> temp = %d dataset = %llu", htag, 3283 (int)ha->temphold, ds->ds_object); 3284 } 3285 3286 static int 3287 dsl_dataset_user_hold_one(char *dsname, void *arg) 3288 { 3289 struct dsl_ds_holdarg *ha = arg; 3290 dsl_dataset_t *ds; 3291 int error; 3292 char *name; 3293 3294 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3295 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3296 error = dsl_dataset_hold(name, ha->dstg, &ds); 3297 strfree(name); 3298 if (error == 0) { 3299 ha->gotone = B_TRUE; 3300 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3301 dsl_dataset_user_hold_sync, ds, ha, 0); 3302 } else if (error == ENOENT && ha->recursive) { 3303 error = 0; 3304 } else { 3305 (void) strcpy(ha->failed, dsname); 3306 } 3307 return (error); 3308 } 3309 3310 int 3311 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3312 boolean_t recursive, boolean_t temphold) 3313 { 3314 struct dsl_ds_holdarg *ha; 3315 dsl_sync_task_t *dst; 3316 spa_t *spa; 3317 int error; 3318 3319 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3320 3321 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3322 3323 error = spa_open(dsname, &spa, FTAG); 3324 if (error) { 3325 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3326 return (error); 3327 } 3328 3329 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3330 ha->htag = htag; 3331 ha->snapname = snapname; 3332 ha->recursive = recursive; 3333 ha->temphold = temphold; 3334 if (recursive) { 3335 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3336 ha, DS_FIND_CHILDREN); 3337 } else { 3338 error = dsl_dataset_user_hold_one(dsname, ha); 3339 } 3340 if (error == 0) 3341 error = dsl_sync_task_group_wait(ha->dstg); 3342 3343 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3344 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3345 dsl_dataset_t *ds = dst->dst_arg1; 3346 3347 if (dst->dst_err) { 3348 dsl_dataset_name(ds, ha->failed); 3349 *strchr(ha->failed, '@') = '\0'; 3350 } 3351 dsl_dataset_rele(ds, ha->dstg); 3352 } 3353 3354 if (error == 0 && recursive && !ha->gotone) 3355 error = ENOENT; 3356 3357 if (error) 3358 (void) strcpy(dsname, ha->failed); 3359 3360 dsl_sync_task_group_destroy(ha->dstg); 3361 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3362 spa_close(spa, FTAG); 3363 return (error); 3364 } 3365 3366 struct dsl_ds_releasearg { 3367 dsl_dataset_t *ds; 3368 const char *htag; 3369 boolean_t own; /* do we own or just hold ds? */ 3370 }; 3371 3372 static int 3373 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3374 boolean_t *might_destroy) 3375 { 3376 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3377 uint64_t zapobj; 3378 uint64_t tmp; 3379 int error; 3380 3381 *might_destroy = B_FALSE; 3382 3383 mutex_enter(&ds->ds_lock); 3384 zapobj = ds->ds_phys->ds_userrefs_obj; 3385 if (zapobj == 0) { 3386 /* The tag can't possibly exist */ 3387 mutex_exit(&ds->ds_lock); 3388 return (ESRCH); 3389 } 3390 3391 /* Make sure the tag exists */ 3392 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3393 if (error) { 3394 mutex_exit(&ds->ds_lock); 3395 if (error == ENOENT) 3396 error = ESRCH; 3397 return (error); 3398 } 3399 3400 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3401 DS_IS_DEFER_DESTROY(ds)) 3402 *might_destroy = B_TRUE; 3403 3404 mutex_exit(&ds->ds_lock); 3405 return (0); 3406 } 3407 3408 static int 3409 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3410 { 3411 struct dsl_ds_releasearg *ra = arg1; 3412 dsl_dataset_t *ds = ra->ds; 3413 boolean_t might_destroy; 3414 int error; 3415 3416 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3417 return (ENOTSUP); 3418 3419 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3420 if (error) 3421 return (error); 3422 3423 if (might_destroy) { 3424 struct dsl_ds_destroyarg dsda = {0}; 3425 3426 if (dmu_tx_is_syncing(tx)) { 3427 /* 3428 * If we're not prepared to remove the snapshot, 3429 * we can't allow the release to happen right now. 3430 */ 3431 if (!ra->own) 3432 return (EBUSY); 3433 if (ds->ds_objset) { 3434 dmu_objset_evict(ds->ds_objset); 3435 ds->ds_objset = NULL; 3436 } 3437 } 3438 dsda.ds = ds; 3439 dsda.releasing = B_TRUE; 3440 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3441 } 3442 3443 return (0); 3444 } 3445 3446 static void 3447 dsl_dataset_user_release_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 3448 { 3449 struct dsl_ds_releasearg *ra = arg1; 3450 dsl_dataset_t *ds = ra->ds; 3451 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3452 objset_t *mos = dp->dp_meta_objset; 3453 uint64_t zapobj; 3454 uint64_t dsobj = ds->ds_object; 3455 uint64_t refs; 3456 int error; 3457 3458 mutex_enter(&ds->ds_lock); 3459 ds->ds_userrefs--; 3460 refs = ds->ds_userrefs; 3461 mutex_exit(&ds->ds_lock); 3462 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3463 VERIFY(error == 0 || error == ENOENT); 3464 zapobj = ds->ds_phys->ds_userrefs_obj; 3465 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3466 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3467 DS_IS_DEFER_DESTROY(ds)) { 3468 struct dsl_ds_destroyarg dsda = {0}; 3469 3470 ASSERT(ra->own); 3471 dsda.ds = ds; 3472 dsda.releasing = B_TRUE; 3473 /* We already did the destroy_check */ 3474 dsl_dataset_destroy_sync(&dsda, tag, cr, tx); 3475 } 3476 3477 spa_history_internal_log(LOG_DS_USER_RELEASE, 3478 dp->dp_spa, tx, cr, "<%s> %lld dataset = %llu", 3479 ra->htag, (longlong_t)refs, dsobj); 3480 } 3481 3482 static int 3483 dsl_dataset_user_release_one(char *dsname, void *arg) 3484 { 3485 struct dsl_ds_holdarg *ha = arg; 3486 struct dsl_ds_releasearg *ra; 3487 dsl_dataset_t *ds; 3488 int error; 3489 void *dtag = ha->dstg; 3490 char *name; 3491 boolean_t own = B_FALSE; 3492 boolean_t might_destroy; 3493 3494 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3495 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3496 error = dsl_dataset_hold(name, dtag, &ds); 3497 strfree(name); 3498 if (error == ENOENT && ha->recursive) 3499 return (0); 3500 (void) strcpy(ha->failed, dsname); 3501 if (error) 3502 return (error); 3503 3504 ha->gotone = B_TRUE; 3505 3506 ASSERT(dsl_dataset_is_snapshot(ds)); 3507 3508 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3509 if (error) { 3510 dsl_dataset_rele(ds, dtag); 3511 return (error); 3512 } 3513 3514 if (might_destroy) { 3515 #ifdef _KERNEL 3516 error = zfs_unmount_snap(name, NULL); 3517 if (error) { 3518 dsl_dataset_rele(ds, dtag); 3519 return (error); 3520 } 3521 #endif 3522 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3523 dsl_dataset_rele(ds, dtag); 3524 return (EBUSY); 3525 } else { 3526 own = B_TRUE; 3527 dsl_dataset_make_exclusive(ds, dtag); 3528 } 3529 } 3530 3531 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3532 ra->ds = ds; 3533 ra->htag = ha->htag; 3534 ra->own = own; 3535 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3536 dsl_dataset_user_release_sync, ra, dtag, 0); 3537 3538 return (0); 3539 } 3540 3541 int 3542 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3543 boolean_t recursive) 3544 { 3545 struct dsl_ds_holdarg *ha; 3546 dsl_sync_task_t *dst; 3547 spa_t *spa; 3548 int error; 3549 3550 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3551 3552 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3553 3554 error = spa_open(dsname, &spa, FTAG); 3555 if (error) { 3556 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3557 return (error); 3558 } 3559 3560 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3561 ha->htag = htag; 3562 ha->snapname = snapname; 3563 ha->recursive = recursive; 3564 if (recursive) { 3565 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3566 ha, DS_FIND_CHILDREN); 3567 } else { 3568 error = dsl_dataset_user_release_one(dsname, ha); 3569 } 3570 if (error == 0) 3571 error = dsl_sync_task_group_wait(ha->dstg); 3572 3573 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3574 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3575 struct dsl_ds_releasearg *ra = dst->dst_arg1; 3576 dsl_dataset_t *ds = ra->ds; 3577 3578 if (dst->dst_err) 3579 dsl_dataset_name(ds, ha->failed); 3580 3581 if (ra->own) 3582 dsl_dataset_disown(ds, ha->dstg); 3583 else 3584 dsl_dataset_rele(ds, ha->dstg); 3585 3586 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 3587 } 3588 3589 if (error == 0 && recursive && !ha->gotone) 3590 error = ENOENT; 3591 3592 if (error) 3593 (void) strcpy(dsname, ha->failed); 3594 3595 dsl_sync_task_group_destroy(ha->dstg); 3596 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3597 spa_close(spa, FTAG); 3598 return (error); 3599 } 3600 3601 /* 3602 * Called at spa_load time to release a stale temporary user hold. 3603 */ 3604 int 3605 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag) 3606 { 3607 dsl_dataset_t *ds; 3608 char *snap; 3609 char *name; 3610 int namelen; 3611 int error; 3612 3613 rw_enter(&dp->dp_config_rwlock, RW_READER); 3614 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 3615 rw_exit(&dp->dp_config_rwlock); 3616 if (error) 3617 return (error); 3618 namelen = dsl_dataset_namelen(ds)+1; 3619 name = kmem_alloc(namelen, KM_SLEEP); 3620 dsl_dataset_name(ds, name); 3621 dsl_dataset_rele(ds, FTAG); 3622 3623 snap = strchr(name, '@'); 3624 *snap = '\0'; 3625 ++snap; 3626 return (dsl_dataset_user_release(name, snap, htag, B_FALSE)); 3627 } 3628 3629 int 3630 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 3631 { 3632 dsl_dataset_t *ds; 3633 int err; 3634 3635 err = dsl_dataset_hold(dsname, FTAG, &ds); 3636 if (err) 3637 return (err); 3638 3639 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 3640 if (ds->ds_phys->ds_userrefs_obj != 0) { 3641 zap_attribute_t *za; 3642 zap_cursor_t zc; 3643 3644 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 3645 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 3646 ds->ds_phys->ds_userrefs_obj); 3647 zap_cursor_retrieve(&zc, za) == 0; 3648 zap_cursor_advance(&zc)) { 3649 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 3650 za->za_first_integer)); 3651 } 3652 zap_cursor_fini(&zc); 3653 kmem_free(za, sizeof (zap_attribute_t)); 3654 } 3655 dsl_dataset_rele(ds, FTAG); 3656 return (0); 3657 } 3658 3659 /* 3660 * Note, this fuction is used as the callback for dmu_objset_find(). We 3661 * always return 0 so that we will continue to find and process 3662 * inconsistent datasets, even if we encounter an error trying to 3663 * process one of them. 3664 */ 3665 /* ARGSUSED */ 3666 int 3667 dsl_destroy_inconsistent(char *dsname, void *arg) 3668 { 3669 dsl_dataset_t *ds; 3670 3671 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 3672 if (DS_IS_INCONSISTENT(ds)) 3673 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 3674 else 3675 dsl_dataset_disown(ds, FTAG); 3676 } 3677 return (0); 3678 } 3679