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 (EBUSY); 1288 1289 /* 1290 * This is really a dsl_dir thing, but check it here so that 1291 * we'll be less likely to leave this dataset inconsistent & 1292 * nearly destroyed. 1293 */ 1294 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1295 if (err) 1296 return (err); 1297 if (count != 0) 1298 return (EEXIST); 1299 1300 return (0); 1301 } 1302 1303 /* ARGSUSED */ 1304 static void 1305 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, 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 (EBUSY); 1384 1385 /* 1386 * If we made changes this txg, traverse_dsl_dataset won't find 1387 * them. Try again. 1388 */ 1389 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1390 return (EAGAIN); 1391 1392 if (dsl_dataset_is_snapshot(ds)) { 1393 /* 1394 * If this snapshot has an elevated user reference count, 1395 * we can't destroy it yet. 1396 */ 1397 if (ds->ds_userrefs > 0 && !dsda->releasing) 1398 return (EBUSY); 1399 1400 mutex_enter(&ds->ds_lock); 1401 /* 1402 * Can't delete a branch point. However, if we're destroying 1403 * a clone and removing its origin due to it having a user 1404 * hold count of 0 and having been marked for deferred destroy, 1405 * it's OK for the origin to have a single clone. 1406 */ 1407 if (ds->ds_phys->ds_num_children > 1408 (dsda->is_origin_rm ? 2 : 1)) { 1409 mutex_exit(&ds->ds_lock); 1410 return (EEXIST); 1411 } 1412 mutex_exit(&ds->ds_lock); 1413 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1414 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1415 } 1416 1417 /* XXX we should do some i/o error checking... */ 1418 return (0); 1419 } 1420 1421 struct refsarg { 1422 kmutex_t lock; 1423 boolean_t gone; 1424 kcondvar_t cv; 1425 }; 1426 1427 /* ARGSUSED */ 1428 static void 1429 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1430 { 1431 struct refsarg *arg = argv; 1432 1433 mutex_enter(&arg->lock); 1434 arg->gone = TRUE; 1435 cv_signal(&arg->cv); 1436 mutex_exit(&arg->lock); 1437 } 1438 1439 static void 1440 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1441 { 1442 struct refsarg arg; 1443 1444 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1445 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1446 arg.gone = FALSE; 1447 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1448 dsl_dataset_refs_gone); 1449 dmu_buf_rele(ds->ds_dbuf, tag); 1450 mutex_enter(&arg.lock); 1451 while (!arg.gone) 1452 cv_wait(&arg.cv, &arg.lock); 1453 ASSERT(arg.gone); 1454 mutex_exit(&arg.lock); 1455 ds->ds_dbuf = NULL; 1456 ds->ds_phys = NULL; 1457 mutex_destroy(&arg.lock); 1458 cv_destroy(&arg.cv); 1459 } 1460 1461 static void 1462 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1463 { 1464 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1465 uint64_t count; 1466 int err; 1467 1468 ASSERT(ds->ds_phys->ds_num_children >= 2); 1469 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1470 /* 1471 * The err should not be ENOENT, but a bug in a previous version 1472 * of the code could cause upgrade_clones_cb() to not set 1473 * ds_next_snap_obj when it should, leading to a missing entry. 1474 * If we knew that the pool was created after 1475 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1476 * ENOENT. However, at least we can check that we don't have 1477 * too many entries in the next_clones_obj even after failing to 1478 * remove this one. 1479 */ 1480 if (err != ENOENT) { 1481 VERIFY3U(err, ==, 0); 1482 } 1483 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1484 &count)); 1485 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1486 } 1487 1488 void 1489 dsl_dataset_destroy_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 1490 { 1491 struct dsl_ds_destroyarg *dsda = arg1; 1492 dsl_dataset_t *ds = dsda->ds; 1493 zio_t *zio; 1494 int err; 1495 int after_branch_point = FALSE; 1496 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1497 objset_t *mos = dp->dp_meta_objset; 1498 dsl_dataset_t *ds_prev = NULL; 1499 uint64_t obj; 1500 1501 ASSERT(ds->ds_owner); 1502 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1503 ASSERT(ds->ds_prev == NULL || 1504 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1505 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1506 1507 if (dsda->defer) { 1508 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1509 if (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1) { 1510 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1511 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1512 return; 1513 } 1514 } 1515 1516 /* signal any waiters that this dataset is going away */ 1517 mutex_enter(&ds->ds_lock); 1518 ds->ds_owner = dsl_reaper; 1519 cv_broadcast(&ds->ds_exclusive_cv); 1520 mutex_exit(&ds->ds_lock); 1521 1522 /* Remove our reservation */ 1523 if (ds->ds_reserved != 0) { 1524 uint64_t val = 0; 1525 dsl_dataset_set_reservation_sync(ds, &val, cr, tx); 1526 ASSERT3U(ds->ds_reserved, ==, 0); 1527 } 1528 1529 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1530 1531 dsl_pool_ds_destroyed(ds, tx); 1532 1533 obj = ds->ds_object; 1534 1535 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1536 if (ds->ds_prev) { 1537 ds_prev = ds->ds_prev; 1538 } else { 1539 VERIFY(0 == dsl_dataset_hold_obj(dp, 1540 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1541 } 1542 after_branch_point = 1543 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1544 1545 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1546 if (after_branch_point && 1547 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1548 remove_from_next_clones(ds_prev, obj, tx); 1549 if (ds->ds_phys->ds_next_snap_obj != 0) { 1550 VERIFY(0 == zap_add_int(mos, 1551 ds_prev->ds_phys->ds_next_clones_obj, 1552 ds->ds_phys->ds_next_snap_obj, tx)); 1553 } 1554 } 1555 if (after_branch_point && 1556 ds->ds_phys->ds_next_snap_obj == 0) { 1557 /* This clone is toast. */ 1558 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1559 ds_prev->ds_phys->ds_num_children--; 1560 1561 /* 1562 * If the clone's origin has no other clones, no 1563 * user holds, and has been marked for deferred 1564 * deletion, then we should have done the necessary 1565 * destroy setup for it. 1566 */ 1567 if (ds_prev->ds_phys->ds_num_children == 1 && 1568 ds_prev->ds_userrefs == 0 && 1569 DS_IS_DEFER_DESTROY(ds_prev)) { 1570 ASSERT3P(dsda->rm_origin, !=, NULL); 1571 } else { 1572 ASSERT3P(dsda->rm_origin, ==, NULL); 1573 } 1574 } else if (!after_branch_point) { 1575 ds_prev->ds_phys->ds_next_snap_obj = 1576 ds->ds_phys->ds_next_snap_obj; 1577 } 1578 } 1579 1580 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1581 1582 if (ds->ds_phys->ds_next_snap_obj != 0) { 1583 blkptr_t bp; 1584 dsl_dataset_t *ds_next; 1585 uint64_t itor = 0; 1586 uint64_t old_unique; 1587 int64_t used = 0, compressed = 0, uncompressed = 0; 1588 1589 VERIFY(0 == dsl_dataset_hold_obj(dp, 1590 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1591 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1592 1593 old_unique = dsl_dataset_unique(ds_next); 1594 1595 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1596 ds_next->ds_phys->ds_prev_snap_obj = 1597 ds->ds_phys->ds_prev_snap_obj; 1598 ds_next->ds_phys->ds_prev_snap_txg = 1599 ds->ds_phys->ds_prev_snap_txg; 1600 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1601 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1602 1603 /* 1604 * Transfer to our deadlist (which will become next's 1605 * new deadlist) any entries from next's current 1606 * deadlist which were born before prev, and free the 1607 * other entries. 1608 * 1609 * XXX we're doing this long task with the config lock held 1610 */ 1611 while (bplist_iterate(&ds_next->ds_deadlist, &itor, &bp) == 0) { 1612 if (bp.blk_birth <= ds->ds_phys->ds_prev_snap_txg) { 1613 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, 1614 &bp, tx)); 1615 if (ds_prev && !after_branch_point && 1616 bp.blk_birth > 1617 ds_prev->ds_phys->ds_prev_snap_txg) { 1618 ds_prev->ds_phys->ds_unique_bytes += 1619 bp_get_dasize(dp->dp_spa, &bp); 1620 } 1621 } else { 1622 used += bp_get_dasize(dp->dp_spa, &bp); 1623 compressed += BP_GET_PSIZE(&bp); 1624 uncompressed += BP_GET_UCSIZE(&bp); 1625 /* XXX check return value? */ 1626 (void) dsl_free(zio, dp, tx->tx_txg, 1627 &bp, NULL, NULL, ARC_NOWAIT); 1628 } 1629 } 1630 1631 ASSERT3U(used, ==, ds->ds_phys->ds_unique_bytes); 1632 1633 /* change snapused */ 1634 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1635 -used, -compressed, -uncompressed, tx); 1636 1637 /* free next's deadlist */ 1638 bplist_close(&ds_next->ds_deadlist); 1639 bplist_destroy(mos, ds_next->ds_phys->ds_deadlist_obj, tx); 1640 1641 /* set next's deadlist to our deadlist */ 1642 bplist_close(&ds->ds_deadlist); 1643 ds_next->ds_phys->ds_deadlist_obj = 1644 ds->ds_phys->ds_deadlist_obj; 1645 VERIFY(0 == bplist_open(&ds_next->ds_deadlist, mos, 1646 ds_next->ds_phys->ds_deadlist_obj)); 1647 ds->ds_phys->ds_deadlist_obj = 0; 1648 1649 if (ds_next->ds_phys->ds_next_snap_obj != 0) { 1650 /* 1651 * Update next's unique to include blocks which 1652 * were previously shared by only this snapshot 1653 * and it. Those blocks will be born after the 1654 * prev snap and before this snap, and will have 1655 * died after the next snap and before the one 1656 * after that (ie. be on the snap after next's 1657 * deadlist). 1658 * 1659 * XXX we're doing this long task with the 1660 * config lock held 1661 */ 1662 dsl_dataset_t *ds_after_next; 1663 uint64_t space; 1664 1665 VERIFY(0 == dsl_dataset_hold_obj(dp, 1666 ds_next->ds_phys->ds_next_snap_obj, 1667 FTAG, &ds_after_next)); 1668 1669 VERIFY(0 == 1670 bplist_space_birthrange(&ds_after_next->ds_deadlist, 1671 ds->ds_phys->ds_prev_snap_txg, 1672 ds->ds_phys->ds_creation_txg, &space)); 1673 ds_next->ds_phys->ds_unique_bytes += space; 1674 1675 dsl_dataset_rele(ds_after_next, FTAG); 1676 ASSERT3P(ds_next->ds_prev, ==, NULL); 1677 } else { 1678 ASSERT3P(ds_next->ds_prev, ==, ds); 1679 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1680 ds_next->ds_prev = NULL; 1681 if (ds_prev) { 1682 VERIFY(0 == dsl_dataset_get_ref(dp, 1683 ds->ds_phys->ds_prev_snap_obj, 1684 ds_next, &ds_next->ds_prev)); 1685 } 1686 1687 dsl_dataset_recalc_head_uniq(ds_next); 1688 1689 /* 1690 * Reduce the amount of our unconsmed refreservation 1691 * being charged to our parent by the amount of 1692 * new unique data we have gained. 1693 */ 1694 if (old_unique < ds_next->ds_reserved) { 1695 int64_t mrsdelta; 1696 uint64_t new_unique = 1697 ds_next->ds_phys->ds_unique_bytes; 1698 1699 ASSERT(old_unique <= new_unique); 1700 mrsdelta = MIN(new_unique - old_unique, 1701 ds_next->ds_reserved - old_unique); 1702 dsl_dir_diduse_space(ds->ds_dir, 1703 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1704 } 1705 } 1706 dsl_dataset_rele(ds_next, FTAG); 1707 } else { 1708 /* 1709 * There's no next snapshot, so this is a head dataset. 1710 * Destroy the deadlist. Unless it's a clone, the 1711 * deadlist should be empty. (If it's a clone, it's 1712 * safe to ignore the deadlist contents.) 1713 */ 1714 struct killarg ka; 1715 1716 ASSERT(after_branch_point || bplist_empty(&ds->ds_deadlist)); 1717 bplist_close(&ds->ds_deadlist); 1718 bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx); 1719 ds->ds_phys->ds_deadlist_obj = 0; 1720 1721 /* 1722 * Free everything that we point to (that's born after 1723 * the previous snapshot, if we are a clone) 1724 * 1725 * NB: this should be very quick, because we already 1726 * freed all the objects in open context. 1727 */ 1728 ka.ds = ds; 1729 ka.zio = zio; 1730 ka.tx = tx; 1731 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, 1732 TRAVERSE_POST, kill_blkptr, &ka); 1733 ASSERT3U(err, ==, 0); 1734 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1735 ds->ds_phys->ds_unique_bytes == 0); 1736 1737 if (ds->ds_prev != NULL) { 1738 dsl_dataset_rele(ds->ds_prev, ds); 1739 ds->ds_prev = ds_prev = NULL; 1740 } 1741 } 1742 1743 err = zio_wait(zio); 1744 ASSERT3U(err, ==, 0); 1745 1746 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1747 /* Erase the link in the dir */ 1748 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1749 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1750 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1751 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1752 ASSERT(err == 0); 1753 } else { 1754 /* remove from snapshot namespace */ 1755 dsl_dataset_t *ds_head; 1756 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1757 VERIFY(0 == dsl_dataset_hold_obj(dp, 1758 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1759 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1760 #ifdef ZFS_DEBUG 1761 { 1762 uint64_t val; 1763 1764 err = dsl_dataset_snap_lookup(ds_head, 1765 ds->ds_snapname, &val); 1766 ASSERT3U(err, ==, 0); 1767 ASSERT3U(val, ==, obj); 1768 } 1769 #endif 1770 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1771 ASSERT(err == 0); 1772 dsl_dataset_rele(ds_head, FTAG); 1773 } 1774 1775 if (ds_prev && ds->ds_prev != ds_prev) 1776 dsl_dataset_rele(ds_prev, FTAG); 1777 1778 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1779 spa_history_internal_log(LOG_DS_DESTROY, dp->dp_spa, tx, 1780 cr, "dataset = %llu", ds->ds_object); 1781 1782 if (ds->ds_phys->ds_next_clones_obj != 0) { 1783 uint64_t count; 1784 ASSERT(0 == zap_count(mos, 1785 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1786 VERIFY(0 == dmu_object_free(mos, 1787 ds->ds_phys->ds_next_clones_obj, tx)); 1788 } 1789 if (ds->ds_phys->ds_props_obj != 0) 1790 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1791 if (ds->ds_phys->ds_userrefs_obj != 0) 1792 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1793 dsl_dir_close(ds->ds_dir, ds); 1794 ds->ds_dir = NULL; 1795 dsl_dataset_drain_refs(ds, tag); 1796 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1797 1798 if (dsda->rm_origin) { 1799 /* 1800 * Remove the origin of the clone we just destroyed. 1801 */ 1802 struct dsl_ds_destroyarg ndsda = {0}; 1803 1804 ndsda.ds = dsda->rm_origin; 1805 dsl_dataset_destroy_sync(&ndsda, tag, cr, tx); 1806 } 1807 } 1808 1809 static int 1810 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1811 { 1812 uint64_t asize; 1813 1814 if (!dmu_tx_is_syncing(tx)) 1815 return (0); 1816 1817 /* 1818 * If there's an fs-only reservation, any blocks that might become 1819 * owned by the snapshot dataset must be accommodated by space 1820 * outside of the reservation. 1821 */ 1822 asize = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1823 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE)) 1824 return (ENOSPC); 1825 1826 /* 1827 * Propogate any reserved space for this snapshot to other 1828 * snapshot checks in this sync group. 1829 */ 1830 if (asize > 0) 1831 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 1832 1833 return (0); 1834 } 1835 1836 /* ARGSUSED */ 1837 int 1838 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 1839 { 1840 dsl_dataset_t *ds = arg1; 1841 const char *snapname = arg2; 1842 int err; 1843 uint64_t value; 1844 1845 /* 1846 * We don't allow multiple snapshots of the same txg. If there 1847 * is already one, try again. 1848 */ 1849 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 1850 return (EAGAIN); 1851 1852 /* 1853 * Check for conflicting name snapshot name. 1854 */ 1855 err = dsl_dataset_snap_lookup(ds, snapname, &value); 1856 if (err == 0) 1857 return (EEXIST); 1858 if (err != ENOENT) 1859 return (err); 1860 1861 /* 1862 * Check that the dataset's name is not too long. Name consists 1863 * of the dataset's length + 1 for the @-sign + snapshot name's length 1864 */ 1865 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 1866 return (ENAMETOOLONG); 1867 1868 err = dsl_dataset_snapshot_reserve_space(ds, tx); 1869 if (err) 1870 return (err); 1871 1872 ds->ds_trysnap_txg = tx->tx_txg; 1873 return (0); 1874 } 1875 1876 void 1877 dsl_dataset_snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 1878 { 1879 dsl_dataset_t *ds = arg1; 1880 const char *snapname = arg2; 1881 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1882 dmu_buf_t *dbuf; 1883 dsl_dataset_phys_t *dsphys; 1884 uint64_t dsobj, crtxg; 1885 objset_t *mos = dp->dp_meta_objset; 1886 int err; 1887 1888 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1889 1890 /* 1891 * The origin's ds_creation_txg has to be < TXG_INITIAL 1892 */ 1893 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 1894 crtxg = 1; 1895 else 1896 crtxg = tx->tx_txg; 1897 1898 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 1899 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 1900 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 1901 dmu_buf_will_dirty(dbuf, tx); 1902 dsphys = dbuf->db_data; 1903 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 1904 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 1905 dsphys->ds_fsid_guid = unique_create(); 1906 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 1907 sizeof (dsphys->ds_guid)); 1908 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 1909 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 1910 dsphys->ds_next_snap_obj = ds->ds_object; 1911 dsphys->ds_num_children = 1; 1912 dsphys->ds_creation_time = gethrestime_sec(); 1913 dsphys->ds_creation_txg = crtxg; 1914 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 1915 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes; 1916 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 1917 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 1918 dsphys->ds_flags = ds->ds_phys->ds_flags; 1919 dsphys->ds_bp = ds->ds_phys->ds_bp; 1920 dmu_buf_rele(dbuf, FTAG); 1921 1922 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 1923 if (ds->ds_prev) { 1924 uint64_t next_clones_obj = 1925 ds->ds_prev->ds_phys->ds_next_clones_obj; 1926 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 1927 ds->ds_object || 1928 ds->ds_prev->ds_phys->ds_num_children > 1); 1929 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 1930 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 1931 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1932 ds->ds_prev->ds_phys->ds_creation_txg); 1933 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 1934 } else if (next_clones_obj != 0) { 1935 remove_from_next_clones(ds->ds_prev, 1936 dsphys->ds_next_snap_obj, tx); 1937 VERIFY3U(0, ==, zap_add_int(mos, 1938 next_clones_obj, dsobj, tx)); 1939 } 1940 } 1941 1942 /* 1943 * If we have a reference-reservation on this dataset, we will 1944 * need to increase the amount of refreservation being charged 1945 * since our unique space is going to zero. 1946 */ 1947 if (ds->ds_reserved) { 1948 int64_t add = MIN(dsl_dataset_unique(ds), ds->ds_reserved); 1949 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 1950 add, 0, 0, tx); 1951 } 1952 1953 bplist_close(&ds->ds_deadlist); 1954 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1955 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 1956 ds->ds_phys->ds_prev_snap_obj = dsobj; 1957 ds->ds_phys->ds_prev_snap_txg = crtxg; 1958 ds->ds_phys->ds_unique_bytes = 0; 1959 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 1960 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1961 ds->ds_phys->ds_deadlist_obj = 1962 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx); 1963 VERIFY(0 == bplist_open(&ds->ds_deadlist, mos, 1964 ds->ds_phys->ds_deadlist_obj)); 1965 1966 dprintf("snap '%s' -> obj %llu\n", snapname, dsobj); 1967 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 1968 snapname, 8, 1, &dsobj, tx); 1969 ASSERT(err == 0); 1970 1971 if (ds->ds_prev) 1972 dsl_dataset_drop_ref(ds->ds_prev, ds); 1973 VERIFY(0 == dsl_dataset_get_ref(dp, 1974 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 1975 1976 dsl_pool_ds_snapshotted(ds, tx); 1977 1978 dsl_dir_snap_cmtime_update(ds->ds_dir); 1979 1980 spa_history_internal_log(LOG_DS_SNAPSHOT, dp->dp_spa, tx, cr, 1981 "dataset = %llu", dsobj); 1982 } 1983 1984 void 1985 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 1986 { 1987 ASSERT(dmu_tx_is_syncing(tx)); 1988 ASSERT(ds->ds_objset != NULL); 1989 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 1990 1991 /* 1992 * in case we had to change ds_fsid_guid when we opened it, 1993 * sync it out now. 1994 */ 1995 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1996 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 1997 1998 dsl_dir_dirty(ds->ds_dir, tx); 1999 dmu_objset_sync(ds->ds_objset, zio, tx); 2000 } 2001 2002 void 2003 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2004 { 2005 uint64_t refd, avail, uobjs, aobjs; 2006 2007 dsl_dir_stats(ds->ds_dir, nv); 2008 2009 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2010 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2011 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2012 2013 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2014 ds->ds_phys->ds_creation_time); 2015 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2016 ds->ds_phys->ds_creation_txg); 2017 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2018 ds->ds_quota); 2019 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2020 ds->ds_reserved); 2021 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2022 ds->ds_phys->ds_guid); 2023 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2024 dsl_dataset_unique(ds)); 2025 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2026 ds->ds_object); 2027 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, ds->ds_userrefs); 2028 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2029 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2030 2031 if (ds->ds_phys->ds_next_snap_obj) { 2032 /* 2033 * This is a snapshot; override the dd's space used with 2034 * our unique space and compression ratio. 2035 */ 2036 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2037 ds->ds_phys->ds_unique_bytes); 2038 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, 2039 ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2040 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2041 ds->ds_phys->ds_compressed_bytes)); 2042 } 2043 } 2044 2045 void 2046 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2047 { 2048 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2049 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2050 stat->dds_guid = ds->ds_phys->ds_guid; 2051 if (ds->ds_phys->ds_next_snap_obj) { 2052 stat->dds_is_snapshot = B_TRUE; 2053 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2054 } else { 2055 stat->dds_is_snapshot = B_FALSE; 2056 stat->dds_num_clones = 0; 2057 } 2058 2059 /* clone origin is really a dsl_dir thing... */ 2060 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2061 if (dsl_dir_is_clone(ds->ds_dir)) { 2062 dsl_dataset_t *ods; 2063 2064 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2065 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2066 dsl_dataset_name(ods, stat->dds_origin); 2067 dsl_dataset_drop_ref(ods, FTAG); 2068 } else { 2069 stat->dds_origin[0] = '\0'; 2070 } 2071 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2072 } 2073 2074 uint64_t 2075 dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2076 { 2077 return (ds->ds_fsid_guid); 2078 } 2079 2080 void 2081 dsl_dataset_space(dsl_dataset_t *ds, 2082 uint64_t *refdbytesp, uint64_t *availbytesp, 2083 uint64_t *usedobjsp, uint64_t *availobjsp) 2084 { 2085 *refdbytesp = ds->ds_phys->ds_used_bytes; 2086 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2087 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2088 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2089 if (ds->ds_quota != 0) { 2090 /* 2091 * Adjust available bytes according to refquota 2092 */ 2093 if (*refdbytesp < ds->ds_quota) 2094 *availbytesp = MIN(*availbytesp, 2095 ds->ds_quota - *refdbytesp); 2096 else 2097 *availbytesp = 0; 2098 } 2099 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2100 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2101 } 2102 2103 boolean_t 2104 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2105 { 2106 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2107 2108 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2109 dsl_pool_sync_context(dp)); 2110 if (ds->ds_prev == NULL) 2111 return (B_FALSE); 2112 if (ds->ds_phys->ds_bp.blk_birth > 2113 ds->ds_prev->ds_phys->ds_creation_txg) 2114 return (B_TRUE); 2115 return (B_FALSE); 2116 } 2117 2118 /* ARGSUSED */ 2119 static int 2120 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2121 { 2122 dsl_dataset_t *ds = arg1; 2123 char *newsnapname = arg2; 2124 dsl_dir_t *dd = ds->ds_dir; 2125 dsl_dataset_t *hds; 2126 uint64_t val; 2127 int err; 2128 2129 err = dsl_dataset_hold_obj(dd->dd_pool, 2130 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2131 if (err) 2132 return (err); 2133 2134 /* new name better not be in use */ 2135 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2136 dsl_dataset_rele(hds, FTAG); 2137 2138 if (err == 0) 2139 err = EEXIST; 2140 else if (err == ENOENT) 2141 err = 0; 2142 2143 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2144 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2145 err = ENAMETOOLONG; 2146 2147 return (err); 2148 } 2149 2150 static void 2151 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, 2152 cred_t *cr, dmu_tx_t *tx) 2153 { 2154 dsl_dataset_t *ds = arg1; 2155 const char *newsnapname = arg2; 2156 dsl_dir_t *dd = ds->ds_dir; 2157 objset_t *mos = dd->dd_pool->dp_meta_objset; 2158 dsl_dataset_t *hds; 2159 int err; 2160 2161 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2162 2163 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2164 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2165 2166 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2167 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2168 ASSERT3U(err, ==, 0); 2169 mutex_enter(&ds->ds_lock); 2170 (void) strcpy(ds->ds_snapname, newsnapname); 2171 mutex_exit(&ds->ds_lock); 2172 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2173 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2174 ASSERT3U(err, ==, 0); 2175 2176 spa_history_internal_log(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2177 cr, "dataset = %llu", ds->ds_object); 2178 dsl_dataset_rele(hds, FTAG); 2179 } 2180 2181 struct renamesnaparg { 2182 dsl_sync_task_group_t *dstg; 2183 char failed[MAXPATHLEN]; 2184 char *oldsnap; 2185 char *newsnap; 2186 }; 2187 2188 static int 2189 dsl_snapshot_rename_one(char *name, void *arg) 2190 { 2191 struct renamesnaparg *ra = arg; 2192 dsl_dataset_t *ds = NULL; 2193 char *cp; 2194 int err; 2195 2196 cp = name + strlen(name); 2197 *cp = '@'; 2198 (void) strcpy(cp + 1, ra->oldsnap); 2199 2200 /* 2201 * For recursive snapshot renames the parent won't be changing 2202 * so we just pass name for both the to/from argument. 2203 */ 2204 err = zfs_secpolicy_rename_perms(name, name, CRED()); 2205 if (err == ENOENT) { 2206 return (0); 2207 } else if (err) { 2208 (void) strcpy(ra->failed, name); 2209 return (err); 2210 } 2211 2212 #ifdef _KERNEL 2213 /* 2214 * For all filesystems undergoing rename, we'll need to unmount it. 2215 */ 2216 (void) zfs_unmount_snap(name, NULL); 2217 #endif 2218 err = dsl_dataset_hold(name, ra->dstg, &ds); 2219 *cp = '\0'; 2220 if (err == ENOENT) { 2221 return (0); 2222 } else if (err) { 2223 (void) strcpy(ra->failed, name); 2224 return (err); 2225 } 2226 2227 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2228 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2229 2230 return (0); 2231 } 2232 2233 static int 2234 dsl_recursive_rename(char *oldname, const char *newname) 2235 { 2236 int err; 2237 struct renamesnaparg *ra; 2238 dsl_sync_task_t *dst; 2239 spa_t *spa; 2240 char *cp, *fsname = spa_strdup(oldname); 2241 int len = strlen(oldname); 2242 2243 /* truncate the snapshot name to get the fsname */ 2244 cp = strchr(fsname, '@'); 2245 *cp = '\0'; 2246 2247 err = spa_open(fsname, &spa, FTAG); 2248 if (err) { 2249 kmem_free(fsname, len + 1); 2250 return (err); 2251 } 2252 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2253 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2254 2255 ra->oldsnap = strchr(oldname, '@') + 1; 2256 ra->newsnap = strchr(newname, '@') + 1; 2257 *ra->failed = '\0'; 2258 2259 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2260 DS_FIND_CHILDREN); 2261 kmem_free(fsname, len + 1); 2262 2263 if (err == 0) { 2264 err = dsl_sync_task_group_wait(ra->dstg); 2265 } 2266 2267 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2268 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2269 dsl_dataset_t *ds = dst->dst_arg1; 2270 if (dst->dst_err) { 2271 dsl_dir_name(ds->ds_dir, ra->failed); 2272 (void) strcat(ra->failed, "@"); 2273 (void) strcat(ra->failed, ra->newsnap); 2274 } 2275 dsl_dataset_rele(ds, ra->dstg); 2276 } 2277 2278 if (err) 2279 (void) strcpy(oldname, ra->failed); 2280 2281 dsl_sync_task_group_destroy(ra->dstg); 2282 kmem_free(ra, sizeof (struct renamesnaparg)); 2283 spa_close(spa, FTAG); 2284 return (err); 2285 } 2286 2287 static int 2288 dsl_valid_rename(char *oldname, void *arg) 2289 { 2290 int delta = *(int *)arg; 2291 2292 if (strlen(oldname) + delta >= MAXNAMELEN) 2293 return (ENAMETOOLONG); 2294 2295 return (0); 2296 } 2297 2298 #pragma weak dmu_objset_rename = dsl_dataset_rename 2299 int 2300 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive) 2301 { 2302 dsl_dir_t *dd; 2303 dsl_dataset_t *ds; 2304 const char *tail; 2305 int err; 2306 2307 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2308 if (err) 2309 return (err); 2310 /* 2311 * If there are more than 2 references there may be holds 2312 * hanging around that haven't been cleared out yet. 2313 */ 2314 if (dmu_buf_refcount(dd->dd_dbuf) > 2) 2315 txg_wait_synced(dd->dd_pool, 0); 2316 if (tail == NULL) { 2317 int delta = strlen(newname) - strlen(oldname); 2318 2319 /* if we're growing, validate child name lengths */ 2320 if (delta > 0) 2321 err = dmu_objset_find(oldname, dsl_valid_rename, 2322 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2323 2324 if (!err) 2325 err = dsl_dir_rename(dd, newname); 2326 dsl_dir_close(dd, FTAG); 2327 return (err); 2328 } 2329 if (tail[0] != '@') { 2330 /* the name ended in a nonexistent component */ 2331 dsl_dir_close(dd, FTAG); 2332 return (ENOENT); 2333 } 2334 2335 dsl_dir_close(dd, FTAG); 2336 2337 /* new name must be snapshot in same filesystem */ 2338 tail = strchr(newname, '@'); 2339 if (tail == NULL) 2340 return (EINVAL); 2341 tail++; 2342 if (strncmp(oldname, newname, tail - newname) != 0) 2343 return (EXDEV); 2344 2345 if (recursive) { 2346 err = dsl_recursive_rename(oldname, newname); 2347 } else { 2348 err = dsl_dataset_hold(oldname, FTAG, &ds); 2349 if (err) 2350 return (err); 2351 2352 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2353 dsl_dataset_snapshot_rename_check, 2354 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2355 2356 dsl_dataset_rele(ds, FTAG); 2357 } 2358 2359 return (err); 2360 } 2361 2362 struct promotenode { 2363 list_node_t link; 2364 dsl_dataset_t *ds; 2365 }; 2366 2367 struct promotearg { 2368 list_t shared_snaps, origin_snaps, clone_snaps; 2369 dsl_dataset_t *origin_origin, *origin_head; 2370 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2371 char *err_ds; 2372 }; 2373 2374 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2375 2376 /* ARGSUSED */ 2377 static int 2378 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2379 { 2380 dsl_dataset_t *hds = arg1; 2381 struct promotearg *pa = arg2; 2382 struct promotenode *snap = list_head(&pa->shared_snaps); 2383 dsl_dataset_t *origin_ds = snap->ds; 2384 int err; 2385 2386 /* Check that it is a real clone */ 2387 if (!dsl_dir_is_clone(hds->ds_dir)) 2388 return (EINVAL); 2389 2390 /* Since this is so expensive, don't do the preliminary check */ 2391 if (!dmu_tx_is_syncing(tx)) 2392 return (0); 2393 2394 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2395 return (EXDEV); 2396 2397 /* compute origin's new unique space */ 2398 snap = list_tail(&pa->clone_snaps); 2399 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2400 err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2401 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &pa->unique); 2402 if (err) 2403 return (err); 2404 2405 /* 2406 * Walk the snapshots that we are moving 2407 * 2408 * Compute space to transfer. Consider the incremental changes 2409 * to used for each snapshot: 2410 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2411 * So each snapshot gave birth to: 2412 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2413 * So a sequence would look like: 2414 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2415 * Which simplifies to: 2416 * uN + kN + kN-1 + ... + k1 + k0 2417 * Note however, if we stop before we reach the ORIGIN we get: 2418 * uN + kN + kN-1 + ... + kM - uM-1 2419 */ 2420 pa->used = origin_ds->ds_phys->ds_used_bytes; 2421 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2422 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2423 for (snap = list_head(&pa->shared_snaps); snap; 2424 snap = list_next(&pa->shared_snaps, snap)) { 2425 uint64_t val, dlused, dlcomp, dluncomp; 2426 dsl_dataset_t *ds = snap->ds; 2427 2428 /* Check that the snapshot name does not conflict */ 2429 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2430 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2431 if (err == 0) { 2432 err = EEXIST; 2433 goto out; 2434 } 2435 if (err != ENOENT) 2436 goto out; 2437 2438 /* The very first snapshot does not have a deadlist */ 2439 if (ds->ds_phys->ds_prev_snap_obj == 0) 2440 continue; 2441 2442 if (err = bplist_space(&ds->ds_deadlist, 2443 &dlused, &dlcomp, &dluncomp)) 2444 goto out; 2445 pa->used += dlused; 2446 pa->comp += dlcomp; 2447 pa->uncomp += dluncomp; 2448 } 2449 2450 /* 2451 * If we are a clone of a clone then we never reached ORIGIN, 2452 * so we need to subtract out the clone origin's used space. 2453 */ 2454 if (pa->origin_origin) { 2455 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes; 2456 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2457 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2458 } 2459 2460 /* Check that there is enough space here */ 2461 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2462 pa->used); 2463 if (err) 2464 return (err); 2465 2466 /* 2467 * Compute the amounts of space that will be used by snapshots 2468 * after the promotion (for both origin and clone). For each, 2469 * it is the amount of space that will be on all of their 2470 * deadlists (that was not born before their new origin). 2471 */ 2472 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2473 uint64_t space; 2474 2475 /* 2476 * Note, typically this will not be a clone of a clone, 2477 * so snap->ds->ds_origin_txg will be < TXG_INITIAL, so 2478 * these snaplist_space() -> bplist_space_birthrange() 2479 * calls will be fast because they do not have to 2480 * iterate over all bps. 2481 */ 2482 snap = list_head(&pa->origin_snaps); 2483 err = snaplist_space(&pa->shared_snaps, 2484 snap->ds->ds_origin_txg, &pa->cloneusedsnap); 2485 if (err) 2486 return (err); 2487 2488 err = snaplist_space(&pa->clone_snaps, 2489 snap->ds->ds_origin_txg, &space); 2490 if (err) 2491 return (err); 2492 pa->cloneusedsnap += space; 2493 } 2494 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2495 err = snaplist_space(&pa->origin_snaps, 2496 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2497 if (err) 2498 return (err); 2499 } 2500 2501 return (0); 2502 out: 2503 pa->err_ds = snap->ds->ds_snapname; 2504 return (err); 2505 } 2506 2507 static void 2508 dsl_dataset_promote_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2509 { 2510 dsl_dataset_t *hds = arg1; 2511 struct promotearg *pa = arg2; 2512 struct promotenode *snap = list_head(&pa->shared_snaps); 2513 dsl_dataset_t *origin_ds = snap->ds; 2514 dsl_dataset_t *origin_head; 2515 dsl_dir_t *dd = hds->ds_dir; 2516 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2517 dsl_dir_t *odd = NULL; 2518 uint64_t oldnext_obj; 2519 int64_t delta; 2520 2521 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2522 2523 snap = list_head(&pa->origin_snaps); 2524 origin_head = snap->ds; 2525 2526 /* 2527 * We need to explicitly open odd, since origin_ds's dd will be 2528 * changing. 2529 */ 2530 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2531 NULL, FTAG, &odd)); 2532 2533 /* change origin's next snap */ 2534 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2535 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2536 snap = list_tail(&pa->clone_snaps); 2537 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2538 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2539 2540 /* change the origin's next clone */ 2541 if (origin_ds->ds_phys->ds_next_clones_obj) { 2542 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2543 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2544 origin_ds->ds_phys->ds_next_clones_obj, 2545 oldnext_obj, tx)); 2546 } 2547 2548 /* change origin */ 2549 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2550 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2551 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2552 hds->ds_origin_txg = origin_head->ds_origin_txg; 2553 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2554 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2555 origin_head->ds_origin_txg = origin_ds->ds_phys->ds_creation_txg; 2556 2557 /* move snapshots to this dir */ 2558 for (snap = list_head(&pa->shared_snaps); snap; 2559 snap = list_next(&pa->shared_snaps, snap)) { 2560 dsl_dataset_t *ds = snap->ds; 2561 2562 /* unregister props as dsl_dir is changing */ 2563 if (ds->ds_objset) { 2564 dmu_objset_evict(ds->ds_objset); 2565 ds->ds_objset = NULL; 2566 } 2567 /* move snap name entry */ 2568 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2569 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2570 ds->ds_snapname, tx)); 2571 VERIFY(0 == zap_add(dp->dp_meta_objset, 2572 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2573 8, 1, &ds->ds_object, tx)); 2574 /* change containing dsl_dir */ 2575 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2576 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2577 ds->ds_phys->ds_dir_obj = dd->dd_object; 2578 ASSERT3P(ds->ds_dir, ==, odd); 2579 dsl_dir_close(ds->ds_dir, ds); 2580 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2581 NULL, ds, &ds->ds_dir)); 2582 2583 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2584 } 2585 2586 /* 2587 * Change space accounting. 2588 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2589 * both be valid, or both be 0 (resulting in delta == 0). This 2590 * is true for each of {clone,origin} independently. 2591 */ 2592 2593 delta = pa->cloneusedsnap - 2594 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2595 ASSERT3S(delta, >=, 0); 2596 ASSERT3U(pa->used, >=, delta); 2597 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2598 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2599 pa->used - delta, pa->comp, pa->uncomp, tx); 2600 2601 delta = pa->originusedsnap - 2602 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2603 ASSERT3S(delta, <=, 0); 2604 ASSERT3U(pa->used, >=, -delta); 2605 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2606 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2607 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2608 2609 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2610 2611 /* log history record */ 2612 spa_history_internal_log(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2613 cr, "dataset = %llu", hds->ds_object); 2614 2615 dsl_dir_close(odd, FTAG); 2616 } 2617 2618 static char *snaplist_tag = "snaplist"; 2619 /* 2620 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2621 * (exclusive) and last_obj (inclusive). The list will be in reverse 2622 * order (last_obj will be the list_head()). If first_obj == 0, do all 2623 * snapshots back to this dataset's origin. 2624 */ 2625 static int 2626 snaplist_make(dsl_pool_t *dp, boolean_t own, 2627 uint64_t first_obj, uint64_t last_obj, list_t *l) 2628 { 2629 uint64_t obj = last_obj; 2630 2631 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2632 2633 list_create(l, sizeof (struct promotenode), 2634 offsetof(struct promotenode, link)); 2635 2636 while (obj != first_obj) { 2637 dsl_dataset_t *ds; 2638 struct promotenode *snap; 2639 int err; 2640 2641 if (own) { 2642 err = dsl_dataset_own_obj(dp, obj, 2643 0, snaplist_tag, &ds); 2644 if (err == 0) 2645 dsl_dataset_make_exclusive(ds, snaplist_tag); 2646 } else { 2647 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2648 } 2649 if (err == ENOENT) { 2650 /* lost race with snapshot destroy */ 2651 struct promotenode *last = list_tail(l); 2652 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2653 obj = last->ds->ds_phys->ds_prev_snap_obj; 2654 continue; 2655 } else if (err) { 2656 return (err); 2657 } 2658 2659 if (first_obj == 0) 2660 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2661 2662 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2663 snap->ds = ds; 2664 list_insert_tail(l, snap); 2665 obj = ds->ds_phys->ds_prev_snap_obj; 2666 } 2667 2668 return (0); 2669 } 2670 2671 static int 2672 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2673 { 2674 struct promotenode *snap; 2675 2676 *spacep = 0; 2677 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2678 uint64_t used; 2679 int err = bplist_space_birthrange(&snap->ds->ds_deadlist, 2680 mintxg, UINT64_MAX, &used); 2681 if (err) 2682 return (err); 2683 *spacep += used; 2684 } 2685 return (0); 2686 } 2687 2688 static void 2689 snaplist_destroy(list_t *l, boolean_t own) 2690 { 2691 struct promotenode *snap; 2692 2693 if (!l || !list_link_active(&l->list_head)) 2694 return; 2695 2696 while ((snap = list_tail(l)) != NULL) { 2697 list_remove(l, snap); 2698 if (own) 2699 dsl_dataset_disown(snap->ds, snaplist_tag); 2700 else 2701 dsl_dataset_rele(snap->ds, snaplist_tag); 2702 kmem_free(snap, sizeof (struct promotenode)); 2703 } 2704 list_destroy(l); 2705 } 2706 2707 /* 2708 * Promote a clone. Nomenclature note: 2709 * "clone" or "cds": the original clone which is being promoted 2710 * "origin" or "ods": the snapshot which is originally clone's origin 2711 * "origin head" or "ohds": the dataset which is the head 2712 * (filesystem/volume) for the origin 2713 * "origin origin": the origin of the origin's filesystem (typically 2714 * NULL, indicating that the clone is not a clone of a clone). 2715 */ 2716 int 2717 dsl_dataset_promote(const char *name, char *conflsnap) 2718 { 2719 dsl_dataset_t *ds; 2720 dsl_dir_t *dd; 2721 dsl_pool_t *dp; 2722 dmu_object_info_t doi; 2723 struct promotearg pa = { 0 }; 2724 struct promotenode *snap; 2725 int err; 2726 2727 err = dsl_dataset_hold(name, FTAG, &ds); 2728 if (err) 2729 return (err); 2730 dd = ds->ds_dir; 2731 dp = dd->dd_pool; 2732 2733 err = dmu_object_info(dp->dp_meta_objset, 2734 ds->ds_phys->ds_snapnames_zapobj, &doi); 2735 if (err) { 2736 dsl_dataset_rele(ds, FTAG); 2737 return (err); 2738 } 2739 2740 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 2741 dsl_dataset_rele(ds, FTAG); 2742 return (EINVAL); 2743 } 2744 2745 /* 2746 * We are going to inherit all the snapshots taken before our 2747 * origin (i.e., our new origin will be our parent's origin). 2748 * Take ownership of them so that we can rename them into our 2749 * namespace. 2750 */ 2751 rw_enter(&dp->dp_config_rwlock, RW_READER); 2752 2753 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 2754 &pa.shared_snaps); 2755 if (err != 0) 2756 goto out; 2757 2758 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 2759 if (err != 0) 2760 goto out; 2761 2762 snap = list_head(&pa.shared_snaps); 2763 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 2764 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 2765 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 2766 if (err != 0) 2767 goto out; 2768 2769 if (dsl_dir_is_clone(snap->ds->ds_dir)) { 2770 err = dsl_dataset_own_obj(dp, 2771 snap->ds->ds_dir->dd_phys->dd_origin_obj, 2772 0, FTAG, &pa.origin_origin); 2773 if (err != 0) 2774 goto out; 2775 } 2776 2777 out: 2778 rw_exit(&dp->dp_config_rwlock); 2779 2780 /* 2781 * Add in 128x the snapnames zapobj size, since we will be moving 2782 * a bunch of snapnames to the promoted ds, and dirtying their 2783 * bonus buffers. 2784 */ 2785 if (err == 0) { 2786 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 2787 dsl_dataset_promote_sync, ds, &pa, 2788 2 + 2 * doi.doi_physical_blks); 2789 if (err && pa.err_ds && conflsnap) 2790 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 2791 } 2792 2793 snaplist_destroy(&pa.shared_snaps, B_TRUE); 2794 snaplist_destroy(&pa.clone_snaps, B_FALSE); 2795 snaplist_destroy(&pa.origin_snaps, B_FALSE); 2796 if (pa.origin_origin) 2797 dsl_dataset_disown(pa.origin_origin, FTAG); 2798 dsl_dataset_rele(ds, FTAG); 2799 return (err); 2800 } 2801 2802 struct cloneswaparg { 2803 dsl_dataset_t *cds; /* clone dataset */ 2804 dsl_dataset_t *ohds; /* origin's head dataset */ 2805 boolean_t force; 2806 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 2807 }; 2808 2809 /* ARGSUSED */ 2810 static int 2811 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 2812 { 2813 struct cloneswaparg *csa = arg1; 2814 2815 /* they should both be heads */ 2816 if (dsl_dataset_is_snapshot(csa->cds) || 2817 dsl_dataset_is_snapshot(csa->ohds)) 2818 return (EINVAL); 2819 2820 /* the branch point should be just before them */ 2821 if (csa->cds->ds_prev != csa->ohds->ds_prev) 2822 return (EINVAL); 2823 2824 /* cds should be the clone (unless they are unrelated) */ 2825 if (csa->cds->ds_prev != NULL && 2826 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 2827 csa->ohds->ds_object != 2828 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 2829 return (EINVAL); 2830 2831 /* the clone should be a child of the origin */ 2832 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 2833 return (EINVAL); 2834 2835 /* ohds shouldn't be modified unless 'force' */ 2836 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 2837 return (ETXTBSY); 2838 2839 /* adjust amount of any unconsumed refreservation */ 2840 csa->unused_refres_delta = 2841 (int64_t)MIN(csa->ohds->ds_reserved, 2842 csa->ohds->ds_phys->ds_unique_bytes) - 2843 (int64_t)MIN(csa->ohds->ds_reserved, 2844 csa->cds->ds_phys->ds_unique_bytes); 2845 2846 if (csa->unused_refres_delta > 0 && 2847 csa->unused_refres_delta > 2848 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 2849 return (ENOSPC); 2850 2851 if (csa->ohds->ds_quota != 0 && 2852 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 2853 return (EDQUOT); 2854 2855 return (0); 2856 } 2857 2858 /* ARGSUSED */ 2859 static void 2860 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 2861 { 2862 struct cloneswaparg *csa = arg1; 2863 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 2864 2865 ASSERT(csa->cds->ds_reserved == 0); 2866 ASSERT(csa->ohds->ds_quota == 0 || 2867 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 2868 2869 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 2870 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 2871 2872 if (csa->cds->ds_objset != NULL) { 2873 dmu_objset_evict(csa->cds->ds_objset); 2874 csa->cds->ds_objset = NULL; 2875 } 2876 2877 if (csa->ohds->ds_objset != NULL) { 2878 dmu_objset_evict(csa->ohds->ds_objset); 2879 csa->ohds->ds_objset = NULL; 2880 } 2881 2882 /* 2883 * Reset origin's unique bytes, if it exists. 2884 */ 2885 if (csa->cds->ds_prev) { 2886 dsl_dataset_t *origin = csa->cds->ds_prev; 2887 dmu_buf_will_dirty(origin->ds_dbuf, tx); 2888 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2889 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2890 &origin->ds_phys->ds_unique_bytes)); 2891 } 2892 2893 /* swap blkptrs */ 2894 { 2895 blkptr_t tmp; 2896 tmp = csa->ohds->ds_phys->ds_bp; 2897 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 2898 csa->cds->ds_phys->ds_bp = tmp; 2899 } 2900 2901 /* set dd_*_bytes */ 2902 { 2903 int64_t dused, dcomp, duncomp; 2904 uint64_t cdl_used, cdl_comp, cdl_uncomp; 2905 uint64_t odl_used, odl_comp, odl_uncomp; 2906 2907 ASSERT3U(csa->cds->ds_dir->dd_phys-> 2908 dd_used_breakdown[DD_USED_SNAP], ==, 0); 2909 2910 VERIFY(0 == bplist_space(&csa->cds->ds_deadlist, &cdl_used, 2911 &cdl_comp, &cdl_uncomp)); 2912 VERIFY(0 == bplist_space(&csa->ohds->ds_deadlist, &odl_used, 2913 &odl_comp, &odl_uncomp)); 2914 2915 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used - 2916 (csa->ohds->ds_phys->ds_used_bytes + odl_used); 2917 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 2918 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 2919 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 2920 cdl_uncomp - 2921 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 2922 2923 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 2924 dused, dcomp, duncomp, tx); 2925 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 2926 -dused, -dcomp, -duncomp, tx); 2927 2928 /* 2929 * The difference in the space used by snapshots is the 2930 * difference in snapshot space due to the head's 2931 * deadlist (since that's the only thing that's 2932 * changing that affects the snapused). 2933 */ 2934 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist, 2935 csa->ohds->ds_origin_txg, UINT64_MAX, &cdl_used)); 2936 VERIFY(0 == bplist_space_birthrange(&csa->ohds->ds_deadlist, 2937 csa->ohds->ds_origin_txg, UINT64_MAX, &odl_used)); 2938 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 2939 DD_USED_HEAD, DD_USED_SNAP, tx); 2940 } 2941 2942 #define SWITCH64(x, y) \ 2943 { \ 2944 uint64_t __tmp = (x); \ 2945 (x) = (y); \ 2946 (y) = __tmp; \ 2947 } 2948 2949 /* swap ds_*_bytes */ 2950 SWITCH64(csa->ohds->ds_phys->ds_used_bytes, 2951 csa->cds->ds_phys->ds_used_bytes); 2952 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 2953 csa->cds->ds_phys->ds_compressed_bytes); 2954 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 2955 csa->cds->ds_phys->ds_uncompressed_bytes); 2956 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 2957 csa->cds->ds_phys->ds_unique_bytes); 2958 2959 /* apply any parent delta for change in unconsumed refreservation */ 2960 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 2961 csa->unused_refres_delta, 0, 0, tx); 2962 2963 /* swap deadlists */ 2964 bplist_close(&csa->cds->ds_deadlist); 2965 bplist_close(&csa->ohds->ds_deadlist); 2966 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 2967 csa->cds->ds_phys->ds_deadlist_obj); 2968 VERIFY(0 == bplist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 2969 csa->cds->ds_phys->ds_deadlist_obj)); 2970 VERIFY(0 == bplist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 2971 csa->ohds->ds_phys->ds_deadlist_obj)); 2972 2973 dsl_pool_ds_clone_swapped(csa->ohds, csa->cds, tx); 2974 } 2975 2976 /* 2977 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 2978 * recv" into an existing fs to swizzle the file system to the new 2979 * version, and by "zfs rollback". Can also be used to swap two 2980 * independent head datasets if neither has any snapshots. 2981 */ 2982 int 2983 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 2984 boolean_t force) 2985 { 2986 struct cloneswaparg csa; 2987 int error; 2988 2989 ASSERT(clone->ds_owner); 2990 ASSERT(origin_head->ds_owner); 2991 retry: 2992 /* Need exclusive access for the swap */ 2993 rw_enter(&clone->ds_rwlock, RW_WRITER); 2994 if (!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 2995 rw_exit(&clone->ds_rwlock); 2996 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 2997 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 2998 rw_exit(&origin_head->ds_rwlock); 2999 goto retry; 3000 } 3001 } 3002 csa.cds = clone; 3003 csa.ohds = origin_head; 3004 csa.force = force; 3005 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3006 dsl_dataset_clone_swap_check, 3007 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3008 return (error); 3009 } 3010 3011 /* 3012 * Given a pool name and a dataset object number in that pool, 3013 * return the name of that dataset. 3014 */ 3015 int 3016 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3017 { 3018 spa_t *spa; 3019 dsl_pool_t *dp; 3020 dsl_dataset_t *ds; 3021 int error; 3022 3023 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3024 return (error); 3025 dp = spa_get_dsl(spa); 3026 rw_enter(&dp->dp_config_rwlock, RW_READER); 3027 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3028 dsl_dataset_name(ds, buf); 3029 dsl_dataset_rele(ds, FTAG); 3030 } 3031 rw_exit(&dp->dp_config_rwlock); 3032 spa_close(spa, FTAG); 3033 3034 return (error); 3035 } 3036 3037 int 3038 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3039 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3040 { 3041 int error = 0; 3042 3043 ASSERT3S(asize, >, 0); 3044 3045 /* 3046 * *ref_rsrv is the portion of asize that will come from any 3047 * unconsumed refreservation space. 3048 */ 3049 *ref_rsrv = 0; 3050 3051 mutex_enter(&ds->ds_lock); 3052 /* 3053 * Make a space adjustment for reserved bytes. 3054 */ 3055 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3056 ASSERT3U(*used, >=, 3057 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3058 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3059 *ref_rsrv = 3060 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3061 } 3062 3063 if (!check_quota || ds->ds_quota == 0) { 3064 mutex_exit(&ds->ds_lock); 3065 return (0); 3066 } 3067 /* 3068 * If they are requesting more space, and our current estimate 3069 * is over quota, they get to try again unless the actual 3070 * on-disk is over quota and there are no pending changes (which 3071 * may free up space for us). 3072 */ 3073 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) { 3074 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota) 3075 error = ERESTART; 3076 else 3077 error = EDQUOT; 3078 } 3079 mutex_exit(&ds->ds_lock); 3080 3081 return (error); 3082 } 3083 3084 /* ARGSUSED */ 3085 static int 3086 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3087 { 3088 dsl_dataset_t *ds = arg1; 3089 uint64_t *quotap = arg2; 3090 uint64_t new_quota = *quotap; 3091 3092 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3093 return (ENOTSUP); 3094 3095 if (new_quota == 0) 3096 return (0); 3097 3098 if (new_quota < ds->ds_phys->ds_used_bytes || 3099 new_quota < ds->ds_reserved) 3100 return (ENOSPC); 3101 3102 return (0); 3103 } 3104 3105 /* ARGSUSED */ 3106 void 3107 dsl_dataset_set_quota_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3108 { 3109 dsl_dataset_t *ds = arg1; 3110 uint64_t *quotap = arg2; 3111 uint64_t new_quota = *quotap; 3112 3113 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3114 3115 ds->ds_quota = new_quota; 3116 3117 dsl_dir_prop_set_uint64_sync(ds->ds_dir, "refquota", new_quota, cr, tx); 3118 3119 spa_history_internal_log(LOG_DS_REFQUOTA, ds->ds_dir->dd_pool->dp_spa, 3120 tx, cr, "%lld dataset = %llu ", 3121 (longlong_t)new_quota, ds->ds_object); 3122 } 3123 3124 int 3125 dsl_dataset_set_quota(const char *dsname, uint64_t quota) 3126 { 3127 dsl_dataset_t *ds; 3128 int err; 3129 3130 err = dsl_dataset_hold(dsname, FTAG, &ds); 3131 if (err) 3132 return (err); 3133 3134 if (quota != ds->ds_quota) { 3135 /* 3136 * If someone removes a file, then tries to set the quota, we 3137 * want to make sure the file freeing takes effect. 3138 */ 3139 txg_wait_open(ds->ds_dir->dd_pool, 0); 3140 3141 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3142 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3143 ds, "a, 0); 3144 } 3145 dsl_dataset_rele(ds, FTAG); 3146 return (err); 3147 } 3148 3149 static int 3150 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3151 { 3152 dsl_dataset_t *ds = arg1; 3153 uint64_t *reservationp = arg2; 3154 uint64_t new_reservation = *reservationp; 3155 uint64_t unique; 3156 3157 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3158 SPA_VERSION_REFRESERVATION) 3159 return (ENOTSUP); 3160 3161 if (dsl_dataset_is_snapshot(ds)) 3162 return (EINVAL); 3163 3164 /* 3165 * If we are doing the preliminary check in open context, the 3166 * space estimates may be inaccurate. 3167 */ 3168 if (!dmu_tx_is_syncing(tx)) 3169 return (0); 3170 3171 mutex_enter(&ds->ds_lock); 3172 unique = dsl_dataset_unique(ds); 3173 mutex_exit(&ds->ds_lock); 3174 3175 if (MAX(unique, new_reservation) > MAX(unique, ds->ds_reserved)) { 3176 uint64_t delta = MAX(unique, new_reservation) - 3177 MAX(unique, ds->ds_reserved); 3178 3179 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3180 return (ENOSPC); 3181 if (ds->ds_quota > 0 && 3182 new_reservation > ds->ds_quota) 3183 return (ENOSPC); 3184 } 3185 3186 return (0); 3187 } 3188 3189 /* ARGSUSED */ 3190 static void 3191 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, cred_t *cr, 3192 dmu_tx_t *tx) 3193 { 3194 dsl_dataset_t *ds = arg1; 3195 uint64_t *reservationp = arg2; 3196 uint64_t new_reservation = *reservationp; 3197 uint64_t unique; 3198 int64_t delta; 3199 3200 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3201 3202 mutex_enter(&ds->ds_dir->dd_lock); 3203 mutex_enter(&ds->ds_lock); 3204 unique = dsl_dataset_unique(ds); 3205 delta = MAX(0, (int64_t)(new_reservation - unique)) - 3206 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3207 ds->ds_reserved = new_reservation; 3208 mutex_exit(&ds->ds_lock); 3209 3210 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3211 mutex_exit(&ds->ds_dir->dd_lock); 3212 dsl_dir_prop_set_uint64_sync(ds->ds_dir, "refreservation", 3213 new_reservation, cr, tx); 3214 3215 spa_history_internal_log(LOG_DS_REFRESERV, 3216 ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu", 3217 (longlong_t)new_reservation, ds->ds_object); 3218 } 3219 3220 int 3221 dsl_dataset_set_reservation(const char *dsname, uint64_t reservation) 3222 { 3223 dsl_dataset_t *ds; 3224 int err; 3225 3226 err = dsl_dataset_hold(dsname, FTAG, &ds); 3227 if (err) 3228 return (err); 3229 3230 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3231 dsl_dataset_set_reservation_check, 3232 dsl_dataset_set_reservation_sync, ds, &reservation, 0); 3233 dsl_dataset_rele(ds, FTAG); 3234 return (err); 3235 } 3236 3237 struct dsl_ds_holdarg { 3238 dsl_sync_task_group_t *dstg; 3239 char *htag; 3240 char *snapname; 3241 boolean_t recursive; 3242 boolean_t gotone; 3243 boolean_t temphold; 3244 char failed[MAXPATHLEN]; 3245 }; 3246 3247 static int 3248 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3249 { 3250 dsl_dataset_t *ds = arg1; 3251 struct dsl_ds_holdarg *ha = arg2; 3252 char *htag = ha->htag; 3253 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3254 int error = 0; 3255 3256 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3257 return (ENOTSUP); 3258 3259 if (!dsl_dataset_is_snapshot(ds)) 3260 return (EINVAL); 3261 3262 /* tags must be unique */ 3263 mutex_enter(&ds->ds_lock); 3264 if (ds->ds_phys->ds_userrefs_obj) { 3265 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3266 8, 1, tx); 3267 if (error == 0) 3268 error = EEXIST; 3269 else if (error == ENOENT) 3270 error = 0; 3271 } 3272 mutex_exit(&ds->ds_lock); 3273 3274 return (error); 3275 } 3276 3277 static void 3278 dsl_dataset_user_hold_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx) 3279 { 3280 dsl_dataset_t *ds = arg1; 3281 struct dsl_ds_holdarg *ha = arg2; 3282 char *htag = ha->htag; 3283 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3284 objset_t *mos = dp->dp_meta_objset; 3285 time_t now = gethrestime_sec(); 3286 uint64_t zapobj; 3287 3288 mutex_enter(&ds->ds_lock); 3289 if (ds->ds_phys->ds_userrefs_obj == 0) { 3290 /* 3291 * This is the first user hold for this dataset. Create 3292 * the userrefs zap object. 3293 */ 3294 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3295 zapobj = ds->ds_phys->ds_userrefs_obj = 3296 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3297 } else { 3298 zapobj = ds->ds_phys->ds_userrefs_obj; 3299 } 3300 ds->ds_userrefs++; 3301 mutex_exit(&ds->ds_lock); 3302 3303 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3304 3305 if (ha->temphold) { 3306 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3307 htag, &now, tx)); 3308 } 3309 3310 spa_history_internal_log(LOG_DS_USER_HOLD, 3311 dp->dp_spa, tx, cr, "<%s> temp = %d dataset = %llu", htag, 3312 (int)ha->temphold, ds->ds_object); 3313 } 3314 3315 static int 3316 dsl_dataset_user_hold_one(char *dsname, void *arg) 3317 { 3318 struct dsl_ds_holdarg *ha = arg; 3319 dsl_dataset_t *ds; 3320 int error; 3321 char *name; 3322 3323 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3324 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3325 error = dsl_dataset_hold(name, ha->dstg, &ds); 3326 strfree(name); 3327 if (error == 0) { 3328 ha->gotone = B_TRUE; 3329 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3330 dsl_dataset_user_hold_sync, ds, ha, 0); 3331 } else if (error == ENOENT && ha->recursive) { 3332 error = 0; 3333 } else { 3334 (void) strcpy(ha->failed, dsname); 3335 } 3336 return (error); 3337 } 3338 3339 int 3340 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3341 boolean_t recursive, boolean_t temphold) 3342 { 3343 struct dsl_ds_holdarg *ha; 3344 dsl_sync_task_t *dst; 3345 spa_t *spa; 3346 int error; 3347 3348 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3349 3350 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3351 3352 error = spa_open(dsname, &spa, FTAG); 3353 if (error) { 3354 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3355 return (error); 3356 } 3357 3358 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3359 ha->htag = htag; 3360 ha->snapname = snapname; 3361 ha->recursive = recursive; 3362 ha->temphold = temphold; 3363 if (recursive) { 3364 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3365 ha, DS_FIND_CHILDREN); 3366 } else { 3367 error = dsl_dataset_user_hold_one(dsname, ha); 3368 } 3369 if (error == 0) 3370 error = dsl_sync_task_group_wait(ha->dstg); 3371 3372 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3373 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3374 dsl_dataset_t *ds = dst->dst_arg1; 3375 3376 if (dst->dst_err) { 3377 dsl_dataset_name(ds, ha->failed); 3378 *strchr(ha->failed, '@') = '\0'; 3379 } 3380 dsl_dataset_rele(ds, ha->dstg); 3381 } 3382 3383 if (error == 0 && recursive && !ha->gotone) 3384 error = ENOENT; 3385 3386 if (error) 3387 (void) strcpy(dsname, ha->failed); 3388 3389 dsl_sync_task_group_destroy(ha->dstg); 3390 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3391 spa_close(spa, FTAG); 3392 return (error); 3393 } 3394 3395 struct dsl_ds_releasearg { 3396 dsl_dataset_t *ds; 3397 const char *htag; 3398 boolean_t own; /* do we own or just hold ds? */ 3399 }; 3400 3401 static int 3402 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3403 boolean_t *might_destroy) 3404 { 3405 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3406 uint64_t zapobj; 3407 uint64_t tmp; 3408 int error; 3409 3410 *might_destroy = B_FALSE; 3411 3412 mutex_enter(&ds->ds_lock); 3413 zapobj = ds->ds_phys->ds_userrefs_obj; 3414 if (zapobj == 0) { 3415 /* The tag can't possibly exist */ 3416 mutex_exit(&ds->ds_lock); 3417 return (ESRCH); 3418 } 3419 3420 /* Make sure the tag exists */ 3421 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3422 if (error) { 3423 mutex_exit(&ds->ds_lock); 3424 if (error == ENOENT) 3425 error = ESRCH; 3426 return (error); 3427 } 3428 3429 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3430 DS_IS_DEFER_DESTROY(ds)) 3431 *might_destroy = B_TRUE; 3432 3433 mutex_exit(&ds->ds_lock); 3434 return (0); 3435 } 3436 3437 static int 3438 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3439 { 3440 struct dsl_ds_releasearg *ra = arg1; 3441 dsl_dataset_t *ds = ra->ds; 3442 boolean_t might_destroy; 3443 int error; 3444 3445 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3446 return (ENOTSUP); 3447 3448 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3449 if (error) 3450 return (error); 3451 3452 if (might_destroy) { 3453 struct dsl_ds_destroyarg dsda = {0}; 3454 3455 if (dmu_tx_is_syncing(tx)) { 3456 /* 3457 * If we're not prepared to remove the snapshot, 3458 * we can't allow the release to happen right now. 3459 */ 3460 if (!ra->own) 3461 return (EBUSY); 3462 if (ds->ds_objset) { 3463 dmu_objset_evict(ds->ds_objset); 3464 ds->ds_objset = NULL; 3465 } 3466 } 3467 dsda.ds = ds; 3468 dsda.releasing = B_TRUE; 3469 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3470 } 3471 3472 return (0); 3473 } 3474 3475 static void 3476 dsl_dataset_user_release_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx) 3477 { 3478 struct dsl_ds_releasearg *ra = arg1; 3479 dsl_dataset_t *ds = ra->ds; 3480 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3481 objset_t *mos = dp->dp_meta_objset; 3482 uint64_t zapobj; 3483 uint64_t dsobj = ds->ds_object; 3484 uint64_t refs; 3485 int error; 3486 3487 mutex_enter(&ds->ds_lock); 3488 ds->ds_userrefs--; 3489 refs = ds->ds_userrefs; 3490 mutex_exit(&ds->ds_lock); 3491 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3492 VERIFY(error == 0 || error == ENOENT); 3493 zapobj = ds->ds_phys->ds_userrefs_obj; 3494 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3495 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3496 DS_IS_DEFER_DESTROY(ds)) { 3497 struct dsl_ds_destroyarg dsda = {0}; 3498 3499 ASSERT(ra->own); 3500 dsda.ds = ds; 3501 dsda.releasing = B_TRUE; 3502 /* We already did the destroy_check */ 3503 dsl_dataset_destroy_sync(&dsda, tag, cr, tx); 3504 } 3505 3506 spa_history_internal_log(LOG_DS_USER_RELEASE, 3507 dp->dp_spa, tx, cr, "<%s> %lld dataset = %llu", 3508 ra->htag, (longlong_t)refs, dsobj); 3509 } 3510 3511 static int 3512 dsl_dataset_user_release_one(char *dsname, void *arg) 3513 { 3514 struct dsl_ds_holdarg *ha = arg; 3515 struct dsl_ds_releasearg *ra; 3516 dsl_dataset_t *ds; 3517 int error; 3518 void *dtag = ha->dstg; 3519 char *name; 3520 boolean_t own = B_FALSE; 3521 boolean_t might_destroy; 3522 3523 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3524 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3525 error = dsl_dataset_hold(name, dtag, &ds); 3526 strfree(name); 3527 if (error == ENOENT && ha->recursive) 3528 return (0); 3529 (void) strcpy(ha->failed, dsname); 3530 if (error) 3531 return (error); 3532 3533 ha->gotone = B_TRUE; 3534 3535 ASSERT(dsl_dataset_is_snapshot(ds)); 3536 3537 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3538 if (error) { 3539 dsl_dataset_rele(ds, dtag); 3540 return (error); 3541 } 3542 3543 if (might_destroy) { 3544 #ifdef _KERNEL 3545 error = zfs_unmount_snap(name, NULL); 3546 if (error) { 3547 dsl_dataset_rele(ds, dtag); 3548 return (error); 3549 } 3550 #endif 3551 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3552 dsl_dataset_rele(ds, dtag); 3553 return (EBUSY); 3554 } else { 3555 own = B_TRUE; 3556 dsl_dataset_make_exclusive(ds, dtag); 3557 } 3558 } 3559 3560 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3561 ra->ds = ds; 3562 ra->htag = ha->htag; 3563 ra->own = own; 3564 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3565 dsl_dataset_user_release_sync, ra, dtag, 0); 3566 3567 return (0); 3568 } 3569 3570 int 3571 dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3572 boolean_t recursive) 3573 { 3574 struct dsl_ds_holdarg *ha; 3575 dsl_sync_task_t *dst; 3576 spa_t *spa; 3577 int error; 3578 3579 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3580 3581 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3582 3583 error = spa_open(dsname, &spa, FTAG); 3584 if (error) { 3585 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3586 return (error); 3587 } 3588 3589 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3590 ha->htag = htag; 3591 ha->snapname = snapname; 3592 ha->recursive = recursive; 3593 if (recursive) { 3594 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3595 ha, DS_FIND_CHILDREN); 3596 } else { 3597 error = dsl_dataset_user_release_one(dsname, ha); 3598 } 3599 if (error == 0) 3600 error = dsl_sync_task_group_wait(ha->dstg); 3601 3602 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3603 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3604 struct dsl_ds_releasearg *ra = dst->dst_arg1; 3605 dsl_dataset_t *ds = ra->ds; 3606 3607 if (dst->dst_err) 3608 dsl_dataset_name(ds, ha->failed); 3609 3610 if (ra->own) 3611 dsl_dataset_disown(ds, ha->dstg); 3612 else 3613 dsl_dataset_rele(ds, ha->dstg); 3614 3615 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 3616 } 3617 3618 if (error == 0 && recursive && !ha->gotone) 3619 error = ENOENT; 3620 3621 if (error) 3622 (void) strcpy(dsname, ha->failed); 3623 3624 dsl_sync_task_group_destroy(ha->dstg); 3625 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3626 spa_close(spa, FTAG); 3627 return (error); 3628 } 3629 3630 /* 3631 * Called at spa_load time to release a stale temporary user hold. 3632 */ 3633 int 3634 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag) 3635 { 3636 dsl_dataset_t *ds; 3637 char *snap; 3638 char *name; 3639 int namelen; 3640 int error; 3641 3642 rw_enter(&dp->dp_config_rwlock, RW_READER); 3643 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 3644 rw_exit(&dp->dp_config_rwlock); 3645 if (error) 3646 return (error); 3647 namelen = dsl_dataset_namelen(ds)+1; 3648 name = kmem_alloc(namelen, KM_SLEEP); 3649 dsl_dataset_name(ds, name); 3650 dsl_dataset_rele(ds, FTAG); 3651 3652 snap = strchr(name, '@'); 3653 *snap = '\0'; 3654 ++snap; 3655 return (dsl_dataset_user_release(name, snap, htag, B_FALSE)); 3656 } 3657 3658 int 3659 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 3660 { 3661 dsl_dataset_t *ds; 3662 int err; 3663 3664 err = dsl_dataset_hold(dsname, FTAG, &ds); 3665 if (err) 3666 return (err); 3667 3668 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 3669 if (ds->ds_phys->ds_userrefs_obj != 0) { 3670 zap_attribute_t *za; 3671 zap_cursor_t zc; 3672 3673 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 3674 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 3675 ds->ds_phys->ds_userrefs_obj); 3676 zap_cursor_retrieve(&zc, za) == 0; 3677 zap_cursor_advance(&zc)) { 3678 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 3679 za->za_first_integer)); 3680 } 3681 zap_cursor_fini(&zc); 3682 kmem_free(za, sizeof (zap_attribute_t)); 3683 } 3684 dsl_dataset_rele(ds, FTAG); 3685 return (0); 3686 } 3687 3688 /* 3689 * Note, this fuction is used as the callback for dmu_objset_find(). We 3690 * always return 0 so that we will continue to find and process 3691 * inconsistent datasets, even if we encounter an error trying to 3692 * process one of them. 3693 */ 3694 /* ARGSUSED */ 3695 int 3696 dsl_destroy_inconsistent(char *dsname, void *arg) 3697 { 3698 dsl_dataset_t *ds; 3699 3700 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 3701 if (DS_IS_INCONSISTENT(ds)) 3702 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 3703 else 3704 dsl_dataset_disown(ds, FTAG); 3705 } 3706 return (0); 3707 } 3708