dsl_dataset.c revision 226676
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011 by Delphix. All rights reserved. 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/zfs_onexit.h> 42#include <sys/zvol.h> 43#include <sys/dsl_scan.h> 44#include <sys/dsl_deadlist.h> 45 46static char *dsl_reaper = "the grim reaper"; 47 48static dsl_checkfunc_t dsl_dataset_destroy_begin_check; 49static dsl_syncfunc_t dsl_dataset_destroy_begin_sync; 50static dsl_syncfunc_t dsl_dataset_set_reservation_sync; 51 52#define SWITCH64(x, y) \ 53 { \ 54 uint64_t __tmp = (x); \ 55 (x) = (y); \ 56 (y) = __tmp; \ 57 } 58 59#define DS_REF_MAX (1ULL << 62) 60 61#define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE 62 63#define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper) 64 65 66/* 67 * Figure out how much of this delta should be propogated to the dsl_dir 68 * layer. If there's a refreservation, that space has already been 69 * partially accounted for in our ancestors. 70 */ 71static int64_t 72parent_delta(dsl_dataset_t *ds, int64_t delta) 73{ 74 uint64_t old_bytes, new_bytes; 75 76 if (ds->ds_reserved == 0) 77 return (delta); 78 79 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 80 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved); 81 82 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta)); 83 return (new_bytes - old_bytes); 84} 85 86void 87dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx) 88{ 89 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 90 int compressed = BP_GET_PSIZE(bp); 91 int uncompressed = BP_GET_UCSIZE(bp); 92 int64_t delta; 93 94 dprintf_bp(bp, "ds=%p", ds); 95 96 ASSERT(dmu_tx_is_syncing(tx)); 97 /* It could have been compressed away to nothing */ 98 if (BP_IS_HOLE(bp)) 99 return; 100 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE); 101 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES); 102 if (ds == NULL) { 103 /* 104 * Account for the meta-objset space in its placeholder 105 * dsl_dir. 106 */ 107 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */ 108 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 109 used, compressed, uncompressed, tx); 110 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 111 return; 112 } 113 dmu_buf_will_dirty(ds->ds_dbuf, tx); 114 115 mutex_enter(&ds->ds_dir->dd_lock); 116 mutex_enter(&ds->ds_lock); 117 delta = parent_delta(ds, used); 118 ds->ds_phys->ds_used_bytes += used; 119 ds->ds_phys->ds_compressed_bytes += compressed; 120 ds->ds_phys->ds_uncompressed_bytes += uncompressed; 121 ds->ds_phys->ds_unique_bytes += used; 122 mutex_exit(&ds->ds_lock); 123 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta, 124 compressed, uncompressed, tx); 125 dsl_dir_transfer_space(ds->ds_dir, used - delta, 126 DD_USED_REFRSRV, DD_USED_HEAD, tx); 127 mutex_exit(&ds->ds_dir->dd_lock); 128} 129 130int 131dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx, 132 boolean_t async) 133{ 134 if (BP_IS_HOLE(bp)) 135 return (0); 136 137 ASSERT(dmu_tx_is_syncing(tx)); 138 ASSERT(bp->blk_birth <= tx->tx_txg); 139 140 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp); 141 int compressed = BP_GET_PSIZE(bp); 142 int uncompressed = BP_GET_UCSIZE(bp); 143 144 ASSERT(used > 0); 145 if (ds == NULL) { 146 /* 147 * Account for the meta-objset space in its placeholder 148 * dataset. 149 */ 150 dsl_free(tx->tx_pool, tx->tx_txg, bp); 151 152 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD, 153 -used, -compressed, -uncompressed, tx); 154 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx); 155 return (used); 156 } 157 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool); 158 159 ASSERT(!dsl_dataset_is_snapshot(ds)); 160 dmu_buf_will_dirty(ds->ds_dbuf, tx); 161 162 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) { 163 int64_t delta; 164 165 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object); 166 dsl_free(tx->tx_pool, tx->tx_txg, bp); 167 168 mutex_enter(&ds->ds_dir->dd_lock); 169 mutex_enter(&ds->ds_lock); 170 ASSERT(ds->ds_phys->ds_unique_bytes >= used || 171 !DS_UNIQUE_IS_ACCURATE(ds)); 172 delta = parent_delta(ds, -used); 173 ds->ds_phys->ds_unique_bytes -= used; 174 mutex_exit(&ds->ds_lock); 175 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, 176 delta, -compressed, -uncompressed, tx); 177 dsl_dir_transfer_space(ds->ds_dir, -used - delta, 178 DD_USED_REFRSRV, DD_USED_HEAD, tx); 179 mutex_exit(&ds->ds_dir->dd_lock); 180 } else { 181 dprintf_bp(bp, "putting on dead list: %s", ""); 182 if (async) { 183 /* 184 * We are here as part of zio's write done callback, 185 * which means we're a zio interrupt thread. We can't 186 * call dsl_deadlist_insert() now because it may block 187 * waiting for I/O. Instead, put bp on the deferred 188 * queue and let dsl_pool_sync() finish the job. 189 */ 190 bplist_append(&ds->ds_pending_deadlist, bp); 191 } else { 192 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx); 193 } 194 ASSERT3U(ds->ds_prev->ds_object, ==, 195 ds->ds_phys->ds_prev_snap_obj); 196 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0); 197 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */ 198 if (ds->ds_prev->ds_phys->ds_next_snap_obj == 199 ds->ds_object && bp->blk_birth > 200 ds->ds_prev->ds_phys->ds_prev_snap_txg) { 201 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 202 mutex_enter(&ds->ds_prev->ds_lock); 203 ds->ds_prev->ds_phys->ds_unique_bytes += used; 204 mutex_exit(&ds->ds_prev->ds_lock); 205 } 206 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) { 207 dsl_dir_transfer_space(ds->ds_dir, used, 208 DD_USED_HEAD, DD_USED_SNAP, tx); 209 } 210 } 211 mutex_enter(&ds->ds_lock); 212 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used); 213 ds->ds_phys->ds_used_bytes -= used; 214 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed); 215 ds->ds_phys->ds_compressed_bytes -= compressed; 216 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed); 217 ds->ds_phys->ds_uncompressed_bytes -= uncompressed; 218 mutex_exit(&ds->ds_lock); 219 220 return (used); 221} 222 223uint64_t 224dsl_dataset_prev_snap_txg(dsl_dataset_t *ds) 225{ 226 uint64_t trysnap = 0; 227 228 if (ds == NULL) 229 return (0); 230 /* 231 * The snapshot creation could fail, but that would cause an 232 * incorrect FALSE return, which would only result in an 233 * overestimation of the amount of space that an operation would 234 * consume, which is OK. 235 * 236 * There's also a small window where we could miss a pending 237 * snapshot, because we could set the sync task in the quiescing 238 * phase. So this should only be used as a guess. 239 */ 240 if (ds->ds_trysnap_txg > 241 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa)) 242 trysnap = ds->ds_trysnap_txg; 243 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap)); 244} 245 246boolean_t 247dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp, 248 uint64_t blk_birth) 249{ 250 if (blk_birth <= dsl_dataset_prev_snap_txg(ds)) 251 return (B_FALSE); 252 253 ddt_prefetch(dsl_dataset_get_spa(ds), bp); 254 255 return (B_TRUE); 256} 257 258/* ARGSUSED */ 259static void 260dsl_dataset_evict(dmu_buf_t *db, void *dsv) 261{ 262 dsl_dataset_t *ds = dsv; 263 264 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds)); 265 266 unique_remove(ds->ds_fsid_guid); 267 268 if (ds->ds_objset != NULL) 269 dmu_objset_evict(ds->ds_objset); 270 271 if (ds->ds_prev) { 272 dsl_dataset_drop_ref(ds->ds_prev, ds); 273 ds->ds_prev = NULL; 274 } 275 276 bplist_destroy(&ds->ds_pending_deadlist); 277 if (db != NULL) { 278 dsl_deadlist_close(&ds->ds_deadlist); 279 } else { 280 ASSERT(ds->ds_deadlist.dl_dbuf == NULL); 281 ASSERT(!ds->ds_deadlist.dl_oldfmt); 282 } 283 if (ds->ds_dir) 284 dsl_dir_close(ds->ds_dir, ds); 285 286 ASSERT(!list_link_active(&ds->ds_synced_link)); 287 288 if (mutex_owned(&ds->ds_lock)) 289 mutex_exit(&ds->ds_lock); 290 mutex_destroy(&ds->ds_lock); 291 mutex_destroy(&ds->ds_recvlock); 292 if (mutex_owned(&ds->ds_opening_lock)) 293 mutex_exit(&ds->ds_opening_lock); 294 mutex_destroy(&ds->ds_opening_lock); 295 rw_destroy(&ds->ds_rwlock); 296 cv_destroy(&ds->ds_exclusive_cv); 297 298 kmem_free(ds, sizeof (dsl_dataset_t)); 299} 300 301static int 302dsl_dataset_get_snapname(dsl_dataset_t *ds) 303{ 304 dsl_dataset_phys_t *headphys; 305 int err; 306 dmu_buf_t *headdbuf; 307 dsl_pool_t *dp = ds->ds_dir->dd_pool; 308 objset_t *mos = dp->dp_meta_objset; 309 310 if (ds->ds_snapname[0]) 311 return (0); 312 if (ds->ds_phys->ds_next_snap_obj == 0) 313 return (0); 314 315 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj, 316 FTAG, &headdbuf); 317 if (err) 318 return (err); 319 headphys = headdbuf->db_data; 320 err = zap_value_search(dp->dp_meta_objset, 321 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname); 322 dmu_buf_rele(headdbuf, FTAG); 323 return (err); 324} 325 326static int 327dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value) 328{ 329 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 330 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 331 matchtype_t mt; 332 int err; 333 334 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 335 mt = MT_FIRST; 336 else 337 mt = MT_EXACT; 338 339 err = zap_lookup_norm(mos, snapobj, name, 8, 1, 340 value, mt, NULL, 0, NULL); 341 if (err == ENOTSUP && mt == MT_FIRST) 342 err = zap_lookup(mos, snapobj, name, 8, 1, value); 343 return (err); 344} 345 346static int 347dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx) 348{ 349 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 350 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj; 351 matchtype_t mt; 352 int err; 353 354 dsl_dir_snap_cmtime_update(ds->ds_dir); 355 356 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET) 357 mt = MT_FIRST; 358 else 359 mt = MT_EXACT; 360 361 err = zap_remove_norm(mos, snapobj, name, mt, tx); 362 if (err == ENOTSUP && mt == MT_FIRST) 363 err = zap_remove(mos, snapobj, name, tx); 364 return (err); 365} 366 367static int 368dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag, 369 dsl_dataset_t **dsp) 370{ 371 objset_t *mos = dp->dp_meta_objset; 372 dmu_buf_t *dbuf; 373 dsl_dataset_t *ds; 374 int err; 375 dmu_object_info_t doi; 376 377 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 378 dsl_pool_sync_context(dp)); 379 380 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf); 381 if (err) 382 return (err); 383 384 /* Make sure dsobj has the correct object type. */ 385 dmu_object_info_from_db(dbuf, &doi); 386 if (doi.doi_type != DMU_OT_DSL_DATASET) 387 return (EINVAL); 388 389 ds = dmu_buf_get_user(dbuf); 390 if (ds == NULL) { 391 dsl_dataset_t *winner; 392 393 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP); 394 ds->ds_dbuf = dbuf; 395 ds->ds_object = dsobj; 396 ds->ds_phys = dbuf->db_data; 397 398 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL); 399 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL); 400 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL); 401 rw_init(&ds->ds_rwlock, 0, 0, 0); 402 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL); 403 404 bplist_create(&ds->ds_pending_deadlist); 405 dsl_deadlist_open(&ds->ds_deadlist, 406 mos, ds->ds_phys->ds_deadlist_obj); 407 408 if (err == 0) { 409 err = dsl_dir_open_obj(dp, 410 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir); 411 } 412 if (err) { 413 mutex_destroy(&ds->ds_lock); 414 mutex_destroy(&ds->ds_recvlock); 415 mutex_destroy(&ds->ds_opening_lock); 416 rw_destroy(&ds->ds_rwlock); 417 cv_destroy(&ds->ds_exclusive_cv); 418 bplist_destroy(&ds->ds_pending_deadlist); 419 dsl_deadlist_close(&ds->ds_deadlist); 420 kmem_free(ds, sizeof (dsl_dataset_t)); 421 dmu_buf_rele(dbuf, tag); 422 return (err); 423 } 424 425 if (!dsl_dataset_is_snapshot(ds)) { 426 ds->ds_snapname[0] = '\0'; 427 if (ds->ds_phys->ds_prev_snap_obj) { 428 err = dsl_dataset_get_ref(dp, 429 ds->ds_phys->ds_prev_snap_obj, 430 ds, &ds->ds_prev); 431 } 432 } else { 433 if (zfs_flags & ZFS_DEBUG_SNAPNAMES) 434 err = dsl_dataset_get_snapname(ds); 435 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) { 436 err = zap_count( 437 ds->ds_dir->dd_pool->dp_meta_objset, 438 ds->ds_phys->ds_userrefs_obj, 439 &ds->ds_userrefs); 440 } 441 } 442 443 if (err == 0 && !dsl_dataset_is_snapshot(ds)) { 444 /* 445 * In sync context, we're called with either no lock 446 * or with the write lock. If we're not syncing, 447 * we're always called with the read lock held. 448 */ 449 boolean_t need_lock = 450 !RW_WRITE_HELD(&dp->dp_config_rwlock) && 451 dsl_pool_sync_context(dp); 452 453 if (need_lock) 454 rw_enter(&dp->dp_config_rwlock, RW_READER); 455 456 err = dsl_prop_get_ds(ds, 457 "refreservation", sizeof (uint64_t), 1, 458 &ds->ds_reserved, NULL); 459 if (err == 0) { 460 err = dsl_prop_get_ds(ds, 461 "refquota", sizeof (uint64_t), 1, 462 &ds->ds_quota, NULL); 463 } 464 465 if (need_lock) 466 rw_exit(&dp->dp_config_rwlock); 467 } else { 468 ds->ds_reserved = ds->ds_quota = 0; 469 } 470 471 if (err == 0) { 472 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys, 473 dsl_dataset_evict); 474 } 475 if (err || winner) { 476 bplist_destroy(&ds->ds_pending_deadlist); 477 dsl_deadlist_close(&ds->ds_deadlist); 478 if (ds->ds_prev) 479 dsl_dataset_drop_ref(ds->ds_prev, ds); 480 dsl_dir_close(ds->ds_dir, ds); 481 mutex_destroy(&ds->ds_lock); 482 mutex_destroy(&ds->ds_recvlock); 483 mutex_destroy(&ds->ds_opening_lock); 484 rw_destroy(&ds->ds_rwlock); 485 cv_destroy(&ds->ds_exclusive_cv); 486 kmem_free(ds, sizeof (dsl_dataset_t)); 487 if (err) { 488 dmu_buf_rele(dbuf, tag); 489 return (err); 490 } 491 ds = winner; 492 } else { 493 ds->ds_fsid_guid = 494 unique_insert(ds->ds_phys->ds_fsid_guid); 495 } 496 } 497 ASSERT3P(ds->ds_dbuf, ==, dbuf); 498 ASSERT3P(ds->ds_phys, ==, dbuf->db_data); 499 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 || 500 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN || 501 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap); 502 mutex_enter(&ds->ds_lock); 503 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) { 504 mutex_exit(&ds->ds_lock); 505 dmu_buf_rele(ds->ds_dbuf, tag); 506 return (ENOENT); 507 } 508 mutex_exit(&ds->ds_lock); 509 *dsp = ds; 510 return (0); 511} 512 513static int 514dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag) 515{ 516 dsl_pool_t *dp = ds->ds_dir->dd_pool; 517 518 /* 519 * In syncing context we don't want the rwlock lock: there 520 * may be an existing writer waiting for sync phase to 521 * finish. We don't need to worry about such writers, since 522 * sync phase is single-threaded, so the writer can't be 523 * doing anything while we are active. 524 */ 525 if (dsl_pool_sync_context(dp)) { 526 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 527 return (0); 528 } 529 530 /* 531 * Normal users will hold the ds_rwlock as a READER until they 532 * are finished (i.e., call dsl_dataset_rele()). "Owners" will 533 * drop their READER lock after they set the ds_owner field. 534 * 535 * If the dataset is being destroyed, the destroy thread will 536 * obtain a WRITER lock for exclusive access after it's done its 537 * open-context work and then change the ds_owner to 538 * dsl_reaper once destruction is assured. So threads 539 * may block here temporarily, until the "destructability" of 540 * the dataset is determined. 541 */ 542 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock)); 543 mutex_enter(&ds->ds_lock); 544 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) { 545 rw_exit(&dp->dp_config_rwlock); 546 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock); 547 if (DSL_DATASET_IS_DESTROYED(ds)) { 548 mutex_exit(&ds->ds_lock); 549 dsl_dataset_drop_ref(ds, tag); 550 rw_enter(&dp->dp_config_rwlock, RW_READER); 551 return (ENOENT); 552 } 553 /* 554 * The dp_config_rwlock lives above the ds_lock. And 555 * we need to check DSL_DATASET_IS_DESTROYED() while 556 * holding the ds_lock, so we have to drop and reacquire 557 * the ds_lock here. 558 */ 559 mutex_exit(&ds->ds_lock); 560 rw_enter(&dp->dp_config_rwlock, RW_READER); 561 mutex_enter(&ds->ds_lock); 562 } 563 mutex_exit(&ds->ds_lock); 564 return (0); 565} 566 567int 568dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag, 569 dsl_dataset_t **dsp) 570{ 571 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp); 572 573 if (err) 574 return (err); 575 return (dsl_dataset_hold_ref(*dsp, tag)); 576} 577 578int 579dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok, 580 void *tag, dsl_dataset_t **dsp) 581{ 582 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp); 583 if (err) 584 return (err); 585 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 586 dsl_dataset_rele(*dsp, tag); 587 *dsp = NULL; 588 return (EBUSY); 589 } 590 return (0); 591} 592 593int 594dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp) 595{ 596 dsl_dir_t *dd; 597 dsl_pool_t *dp; 598 const char *snapname; 599 uint64_t obj; 600 int err = 0; 601 602 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname); 603 if (err) 604 return (err); 605 606 dp = dd->dd_pool; 607 obj = dd->dd_phys->dd_head_dataset_obj; 608 rw_enter(&dp->dp_config_rwlock, RW_READER); 609 if (obj) 610 err = dsl_dataset_get_ref(dp, obj, tag, dsp); 611 else 612 err = ENOENT; 613 if (err) 614 goto out; 615 616 err = dsl_dataset_hold_ref(*dsp, tag); 617 618 /* we may be looking for a snapshot */ 619 if (err == 0 && snapname != NULL) { 620 dsl_dataset_t *ds = NULL; 621 622 if (*snapname++ != '@') { 623 dsl_dataset_rele(*dsp, tag); 624 err = ENOENT; 625 goto out; 626 } 627 628 dprintf("looking for snapshot '%s'\n", snapname); 629 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj); 630 if (err == 0) 631 err = dsl_dataset_get_ref(dp, obj, tag, &ds); 632 dsl_dataset_rele(*dsp, tag); 633 634 ASSERT3U((err == 0), ==, (ds != NULL)); 635 636 if (ds) { 637 mutex_enter(&ds->ds_lock); 638 if (ds->ds_snapname[0] == 0) 639 (void) strlcpy(ds->ds_snapname, snapname, 640 sizeof (ds->ds_snapname)); 641 mutex_exit(&ds->ds_lock); 642 err = dsl_dataset_hold_ref(ds, tag); 643 *dsp = err ? NULL : ds; 644 } 645 } 646out: 647 rw_exit(&dp->dp_config_rwlock); 648 dsl_dir_close(dd, FTAG); 649 return (err); 650} 651 652int 653dsl_dataset_own(const char *name, boolean_t inconsistentok, 654 void *tag, dsl_dataset_t **dsp) 655{ 656 int err = dsl_dataset_hold(name, tag, dsp); 657 if (err) 658 return (err); 659 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) { 660 dsl_dataset_rele(*dsp, tag); 661 return (EBUSY); 662 } 663 return (0); 664} 665 666void 667dsl_dataset_name(dsl_dataset_t *ds, char *name) 668{ 669 if (ds == NULL) { 670 (void) strcpy(name, "mos"); 671 } else { 672 dsl_dir_name(ds->ds_dir, name); 673 VERIFY(0 == dsl_dataset_get_snapname(ds)); 674 if (ds->ds_snapname[0]) { 675 (void) strcat(name, "@"); 676 /* 677 * We use a "recursive" mutex so that we 678 * can call dprintf_ds() with ds_lock held. 679 */ 680 if (!MUTEX_HELD(&ds->ds_lock)) { 681 mutex_enter(&ds->ds_lock); 682 (void) strcat(name, ds->ds_snapname); 683 mutex_exit(&ds->ds_lock); 684 } else { 685 (void) strcat(name, ds->ds_snapname); 686 } 687 } 688 } 689} 690 691static int 692dsl_dataset_namelen(dsl_dataset_t *ds) 693{ 694 int result; 695 696 if (ds == NULL) { 697 result = 3; /* "mos" */ 698 } else { 699 result = dsl_dir_namelen(ds->ds_dir); 700 VERIFY(0 == dsl_dataset_get_snapname(ds)); 701 if (ds->ds_snapname[0]) { 702 ++result; /* adding one for the @-sign */ 703 if (!MUTEX_HELD(&ds->ds_lock)) { 704 mutex_enter(&ds->ds_lock); 705 result += strlen(ds->ds_snapname); 706 mutex_exit(&ds->ds_lock); 707 } else { 708 result += strlen(ds->ds_snapname); 709 } 710 } 711 } 712 713 return (result); 714} 715 716void 717dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag) 718{ 719 dmu_buf_rele(ds->ds_dbuf, tag); 720} 721 722void 723dsl_dataset_rele(dsl_dataset_t *ds, void *tag) 724{ 725 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) { 726 rw_exit(&ds->ds_rwlock); 727 } 728 dsl_dataset_drop_ref(ds, tag); 729} 730 731void 732dsl_dataset_disown(dsl_dataset_t *ds, void *tag) 733{ 734 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) || 735 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL)); 736 737 mutex_enter(&ds->ds_lock); 738 ds->ds_owner = NULL; 739 if (RW_WRITE_HELD(&ds->ds_rwlock)) { 740 rw_exit(&ds->ds_rwlock); 741 cv_broadcast(&ds->ds_exclusive_cv); 742 } 743 mutex_exit(&ds->ds_lock); 744 if (ds->ds_dbuf) 745 dsl_dataset_drop_ref(ds, tag); 746 else 747 dsl_dataset_evict(NULL, ds); 748} 749 750boolean_t 751dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag) 752{ 753 boolean_t gotit = FALSE; 754 755 mutex_enter(&ds->ds_lock); 756 if (ds->ds_owner == NULL && 757 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) { 758 ds->ds_owner = tag; 759 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) 760 rw_exit(&ds->ds_rwlock); 761 gotit = TRUE; 762 } 763 mutex_exit(&ds->ds_lock); 764 return (gotit); 765} 766 767void 768dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner) 769{ 770 ASSERT3P(owner, ==, ds->ds_owner); 771 if (!RW_WRITE_HELD(&ds->ds_rwlock)) 772 rw_enter(&ds->ds_rwlock, RW_WRITER); 773} 774 775uint64_t 776dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin, 777 uint64_t flags, dmu_tx_t *tx) 778{ 779 dsl_pool_t *dp = dd->dd_pool; 780 dmu_buf_t *dbuf; 781 dsl_dataset_phys_t *dsphys; 782 uint64_t dsobj; 783 objset_t *mos = dp->dp_meta_objset; 784 785 if (origin == NULL) 786 origin = dp->dp_origin_snap; 787 788 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp); 789 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0); 790 ASSERT(dmu_tx_is_syncing(tx)); 791 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0); 792 793 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 794 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 795 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 796 dmu_buf_will_dirty(dbuf, tx); 797 dsphys = dbuf->db_data; 798 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 799 dsphys->ds_dir_obj = dd->dd_object; 800 dsphys->ds_flags = flags; 801 dsphys->ds_fsid_guid = unique_create(); 802 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 803 sizeof (dsphys->ds_guid)); 804 dsphys->ds_snapnames_zapobj = 805 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP, 806 DMU_OT_NONE, 0, tx); 807 dsphys->ds_creation_time = gethrestime_sec(); 808 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg; 809 810 if (origin == NULL) { 811 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx); 812 } else { 813 dsl_dataset_t *ohds; 814 815 dsphys->ds_prev_snap_obj = origin->ds_object; 816 dsphys->ds_prev_snap_txg = 817 origin->ds_phys->ds_creation_txg; 818 dsphys->ds_used_bytes = 819 origin->ds_phys->ds_used_bytes; 820 dsphys->ds_compressed_bytes = 821 origin->ds_phys->ds_compressed_bytes; 822 dsphys->ds_uncompressed_bytes = 823 origin->ds_phys->ds_uncompressed_bytes; 824 dsphys->ds_bp = origin->ds_phys->ds_bp; 825 dsphys->ds_flags |= origin->ds_phys->ds_flags; 826 827 dmu_buf_will_dirty(origin->ds_dbuf, tx); 828 origin->ds_phys->ds_num_children++; 829 830 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 831 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds)); 832 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist, 833 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx); 834 dsl_dataset_rele(ohds, FTAG); 835 836 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) { 837 if (origin->ds_phys->ds_next_clones_obj == 0) { 838 origin->ds_phys->ds_next_clones_obj = 839 zap_create(mos, 840 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 841 } 842 VERIFY(0 == zap_add_int(mos, 843 origin->ds_phys->ds_next_clones_obj, 844 dsobj, tx)); 845 } 846 847 dmu_buf_will_dirty(dd->dd_dbuf, tx); 848 dd->dd_phys->dd_origin_obj = origin->ds_object; 849 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 850 if (origin->ds_dir->dd_phys->dd_clones == 0) { 851 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); 852 origin->ds_dir->dd_phys->dd_clones = 853 zap_create(mos, 854 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 855 } 856 VERIFY3U(0, ==, zap_add_int(mos, 857 origin->ds_dir->dd_phys->dd_clones, dsobj, tx)); 858 } 859 } 860 861 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 862 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 863 864 dmu_buf_rele(dbuf, FTAG); 865 866 dmu_buf_will_dirty(dd->dd_dbuf, tx); 867 dd->dd_phys->dd_head_dataset_obj = dsobj; 868 869 return (dsobj); 870} 871 872uint64_t 873dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname, 874 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx) 875{ 876 dsl_pool_t *dp = pdd->dd_pool; 877 uint64_t dsobj, ddobj; 878 dsl_dir_t *dd; 879 880 ASSERT(lastname[0] != '@'); 881 882 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx); 883 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd)); 884 885 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx); 886 887 dsl_deleg_set_create_perms(dd, tx, cr); 888 889 dsl_dir_close(dd, FTAG); 890 891 /* 892 * If we are creating a clone, make sure we zero out any stale 893 * data from the origin snapshots zil header. 894 */ 895 if (origin != NULL) { 896 dsl_dataset_t *ds; 897 objset_t *os; 898 899 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 900 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os)); 901 bzero(&os->os_zil_header, sizeof (os->os_zil_header)); 902 dsl_dataset_dirty(ds, tx); 903 dsl_dataset_rele(ds, FTAG); 904 } 905 906 return (dsobj); 907} 908 909struct destroyarg { 910 dsl_sync_task_group_t *dstg; 911 char *snapname; 912 char *failed; 913 boolean_t defer; 914}; 915 916static int 917dsl_snapshot_destroy_one(const char *name, void *arg) 918{ 919 struct destroyarg *da = arg; 920 dsl_dataset_t *ds; 921 int err; 922 char *dsname; 923 924 dsname = kmem_asprintf("%s@%s", name, da->snapname); 925 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds); 926 strfree(dsname); 927 if (err == 0) { 928 struct dsl_ds_destroyarg *dsda; 929 930 dsl_dataset_make_exclusive(ds, da->dstg); 931 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP); 932 dsda->ds = ds; 933 dsda->defer = da->defer; 934 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check, 935 dsl_dataset_destroy_sync, dsda, da->dstg, 0); 936 } else if (err == ENOENT) { 937 err = 0; 938 } else { 939 (void) strcpy(da->failed, name); 940 } 941 return (err); 942} 943 944/* 945 * Destroy 'snapname' in all descendants of 'fsname'. 946 */ 947#pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy 948int 949dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer) 950{ 951 int err; 952 struct destroyarg da; 953 dsl_sync_task_t *dst; 954 spa_t *spa; 955 956 err = spa_open(fsname, &spa, FTAG); 957 if (err) 958 return (err); 959 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 960 da.snapname = snapname; 961 da.failed = fsname; 962 da.defer = defer; 963 964 err = dmu_objset_find(fsname, 965 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN); 966 967 if (err == 0) 968 err = dsl_sync_task_group_wait(da.dstg); 969 970 for (dst = list_head(&da.dstg->dstg_tasks); dst; 971 dst = list_next(&da.dstg->dstg_tasks, dst)) { 972 struct dsl_ds_destroyarg *dsda = dst->dst_arg1; 973 dsl_dataset_t *ds = dsda->ds; 974 975 /* 976 * Return the file system name that triggered the error 977 */ 978 if (dst->dst_err) { 979 dsl_dataset_name(ds, fsname); 980 *strchr(fsname, '@') = '\0'; 981 } 982 ASSERT3P(dsda->rm_origin, ==, NULL); 983 dsl_dataset_disown(ds, da.dstg); 984 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg)); 985 } 986 987 dsl_sync_task_group_destroy(da.dstg); 988 spa_close(spa, FTAG); 989 return (err); 990} 991 992static boolean_t 993dsl_dataset_might_destroy_origin(dsl_dataset_t *ds) 994{ 995 boolean_t might_destroy = B_FALSE; 996 997 mutex_enter(&ds->ds_lock); 998 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 && 999 DS_IS_DEFER_DESTROY(ds)) 1000 might_destroy = B_TRUE; 1001 mutex_exit(&ds->ds_lock); 1002 1003 return (might_destroy); 1004} 1005 1006/* 1007 * If we're removing a clone, and these three conditions are true: 1008 * 1) the clone's origin has no other children 1009 * 2) the clone's origin has no user references 1010 * 3) the clone's origin has been marked for deferred destruction 1011 * Then, prepare to remove the origin as part of this sync task group. 1012 */ 1013static int 1014dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag) 1015{ 1016 dsl_dataset_t *ds = dsda->ds; 1017 dsl_dataset_t *origin = ds->ds_prev; 1018 1019 if (dsl_dataset_might_destroy_origin(origin)) { 1020 char *name; 1021 int namelen; 1022 int error; 1023 1024 namelen = dsl_dataset_namelen(origin) + 1; 1025 name = kmem_alloc(namelen, KM_SLEEP); 1026 dsl_dataset_name(origin, name); 1027#ifdef _KERNEL 1028 error = zfs_unmount_snap(name, NULL); 1029 if (error) { 1030 kmem_free(name, namelen); 1031 return (error); 1032 } 1033#endif 1034 error = dsl_dataset_own(name, B_TRUE, tag, &origin); 1035 kmem_free(name, namelen); 1036 if (error) 1037 return (error); 1038 dsda->rm_origin = origin; 1039 dsl_dataset_make_exclusive(origin, tag); 1040 } 1041 1042 return (0); 1043} 1044 1045/* 1046 * ds must be opened as OWNER. On return (whether successful or not), 1047 * ds will be closed and caller can no longer dereference it. 1048 */ 1049int 1050dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer) 1051{ 1052 int err; 1053 dsl_sync_task_group_t *dstg; 1054 objset_t *os; 1055 dsl_dir_t *dd; 1056 uint64_t obj; 1057 struct dsl_ds_destroyarg dsda = { 0 }; 1058 dsl_dataset_t dummy_ds = { 0 }; 1059 1060 dsda.ds = ds; 1061 1062 if (dsl_dataset_is_snapshot(ds)) { 1063 /* Destroying a snapshot is simpler */ 1064 dsl_dataset_make_exclusive(ds, tag); 1065 1066 dsda.defer = defer; 1067 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 1068 dsl_dataset_destroy_check, dsl_dataset_destroy_sync, 1069 &dsda, tag, 0); 1070 ASSERT3P(dsda.rm_origin, ==, NULL); 1071 goto out; 1072 } else if (defer) { 1073 err = EINVAL; 1074 goto out; 1075 } 1076 1077 dd = ds->ds_dir; 1078 dummy_ds.ds_dir = dd; 1079 dummy_ds.ds_object = ds->ds_object; 1080 1081 /* 1082 * Check for errors and mark this ds as inconsistent, in 1083 * case we crash while freeing the objects. 1084 */ 1085 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check, 1086 dsl_dataset_destroy_begin_sync, ds, NULL, 0); 1087 if (err) 1088 goto out; 1089 1090 err = dmu_objset_from_ds(ds, &os); 1091 if (err) 1092 goto out; 1093 1094 /* 1095 * remove the objects in open context, so that we won't 1096 * have too much to do in syncing context. 1097 */ 1098 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE, 1099 ds->ds_phys->ds_prev_snap_txg)) { 1100 /* 1101 * Ignore errors, if there is not enough disk space 1102 * we will deal with it in dsl_dataset_destroy_sync(). 1103 */ 1104 (void) dmu_free_object(os, obj); 1105 } 1106 if (err != ESRCH) 1107 goto out; 1108 1109 /* 1110 * Only the ZIL knows how to free log blocks. 1111 */ 1112 zil_destroy(dmu_objset_zil(os), B_FALSE); 1113 1114 /* 1115 * Sync out all in-flight IO. 1116 */ 1117 txg_wait_synced(dd->dd_pool, 0); 1118 1119 /* 1120 * If we managed to free all the objects in open 1121 * context, the user space accounting should be zero. 1122 */ 1123 if (ds->ds_phys->ds_bp.blk_fill == 0 && 1124 dmu_objset_userused_enabled(os)) { 1125 uint64_t count; 1126 1127 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 || 1128 count == 0); 1129 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 || 1130 count == 0); 1131 } 1132 1133 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER); 1134 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd); 1135 rw_exit(&dd->dd_pool->dp_config_rwlock); 1136 1137 if (err) 1138 goto out; 1139 1140 /* 1141 * Blow away the dsl_dir + head dataset. 1142 */ 1143 dsl_dataset_make_exclusive(ds, tag); 1144 /* 1145 * If we're removing a clone, we might also need to remove its 1146 * origin. 1147 */ 1148 do { 1149 dsda.need_prep = B_FALSE; 1150 if (dsl_dir_is_clone(dd)) { 1151 err = dsl_dataset_origin_rm_prep(&dsda, tag); 1152 if (err) { 1153 dsl_dir_close(dd, FTAG); 1154 goto out; 1155 } 1156 } 1157 1158 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool); 1159 dsl_sync_task_create(dstg, dsl_dataset_destroy_check, 1160 dsl_dataset_destroy_sync, &dsda, tag, 0); 1161 dsl_sync_task_create(dstg, dsl_dir_destroy_check, 1162 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0); 1163 err = dsl_sync_task_group_wait(dstg); 1164 dsl_sync_task_group_destroy(dstg); 1165 1166 /* 1167 * We could be racing against 'zfs release' or 'zfs destroy -d' 1168 * on the origin snap, in which case we can get EBUSY if we 1169 * needed to destroy the origin snap but were not ready to 1170 * do so. 1171 */ 1172 if (dsda.need_prep) { 1173 ASSERT(err == EBUSY); 1174 ASSERT(dsl_dir_is_clone(dd)); 1175 ASSERT(dsda.rm_origin == NULL); 1176 } 1177 } while (dsda.need_prep); 1178 1179 if (dsda.rm_origin != NULL) 1180 dsl_dataset_disown(dsda.rm_origin, tag); 1181 1182 /* if it is successful, dsl_dir_destroy_sync will close the dd */ 1183 if (err) 1184 dsl_dir_close(dd, FTAG); 1185out: 1186 dsl_dataset_disown(ds, tag); 1187 return (err); 1188} 1189 1190blkptr_t * 1191dsl_dataset_get_blkptr(dsl_dataset_t *ds) 1192{ 1193 return (&ds->ds_phys->ds_bp); 1194} 1195 1196void 1197dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx) 1198{ 1199 ASSERT(dmu_tx_is_syncing(tx)); 1200 /* If it's the meta-objset, set dp_meta_rootbp */ 1201 if (ds == NULL) { 1202 tx->tx_pool->dp_meta_rootbp = *bp; 1203 } else { 1204 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1205 ds->ds_phys->ds_bp = *bp; 1206 } 1207} 1208 1209spa_t * 1210dsl_dataset_get_spa(dsl_dataset_t *ds) 1211{ 1212 return (ds->ds_dir->dd_pool->dp_spa); 1213} 1214 1215void 1216dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx) 1217{ 1218 dsl_pool_t *dp; 1219 1220 if (ds == NULL) /* this is the meta-objset */ 1221 return; 1222 1223 ASSERT(ds->ds_objset != NULL); 1224 1225 if (ds->ds_phys->ds_next_snap_obj != 0) 1226 panic("dirtying snapshot!"); 1227 1228 dp = ds->ds_dir->dd_pool; 1229 1230 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) { 1231 /* up the hold count until we can be written out */ 1232 dmu_buf_add_ref(ds->ds_dbuf, ds); 1233 } 1234} 1235 1236/* 1237 * The unique space in the head dataset can be calculated by subtracting 1238 * the space used in the most recent snapshot, that is still being used 1239 * in this file system, from the space currently in use. To figure out 1240 * the space in the most recent snapshot still in use, we need to take 1241 * the total space used in the snapshot and subtract out the space that 1242 * has been freed up since the snapshot was taken. 1243 */ 1244static void 1245dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds) 1246{ 1247 uint64_t mrs_used; 1248 uint64_t dlused, dlcomp, dluncomp; 1249 1250 ASSERT(!dsl_dataset_is_snapshot(ds)); 1251 1252 if (ds->ds_phys->ds_prev_snap_obj != 0) 1253 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes; 1254 else 1255 mrs_used = 0; 1256 1257 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp); 1258 1259 ASSERT3U(dlused, <=, mrs_used); 1260 ds->ds_phys->ds_unique_bytes = 1261 ds->ds_phys->ds_used_bytes - (mrs_used - dlused); 1262 1263 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >= 1264 SPA_VERSION_UNIQUE_ACCURATE) 1265 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 1266} 1267 1268struct killarg { 1269 dsl_dataset_t *ds; 1270 dmu_tx_t *tx; 1271}; 1272 1273/* ARGSUSED */ 1274static int 1275kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf, 1276 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 1277{ 1278 struct killarg *ka = arg; 1279 dmu_tx_t *tx = ka->tx; 1280 1281 if (bp == NULL) 1282 return (0); 1283 1284 if (zb->zb_level == ZB_ZIL_LEVEL) { 1285 ASSERT(zilog != NULL); 1286 /* 1287 * It's a block in the intent log. It has no 1288 * accounting, so just free it. 1289 */ 1290 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp); 1291 } else { 1292 ASSERT(zilog == NULL); 1293 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg); 1294 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE); 1295 } 1296 1297 return (0); 1298} 1299 1300/* ARGSUSED */ 1301static int 1302dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx) 1303{ 1304 dsl_dataset_t *ds = arg1; 1305 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1306 uint64_t count; 1307 int err; 1308 1309 /* 1310 * Can't delete a head dataset if there are snapshots of it. 1311 * (Except if the only snapshots are from the branch we cloned 1312 * from.) 1313 */ 1314 if (ds->ds_prev != NULL && 1315 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1316 return (EBUSY); 1317 1318 /* 1319 * This is really a dsl_dir thing, but check it here so that 1320 * we'll be less likely to leave this dataset inconsistent & 1321 * nearly destroyed. 1322 */ 1323 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count); 1324 if (err) 1325 return (err); 1326 if (count != 0) 1327 return (EEXIST); 1328 1329 return (0); 1330} 1331 1332/* ARGSUSED */ 1333static void 1334dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx) 1335{ 1336 dsl_dataset_t *ds = arg1; 1337 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1338 1339 /* Mark it as inconsistent on-disk, in case we crash */ 1340 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1341 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT; 1342 1343 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx, 1344 "dataset = %llu", ds->ds_object); 1345} 1346 1347static int 1348dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag, 1349 dmu_tx_t *tx) 1350{ 1351 dsl_dataset_t *ds = dsda->ds; 1352 dsl_dataset_t *ds_prev = ds->ds_prev; 1353 1354 if (dsl_dataset_might_destroy_origin(ds_prev)) { 1355 struct dsl_ds_destroyarg ndsda = {0}; 1356 1357 /* 1358 * If we're not prepared to remove the origin, don't remove 1359 * the clone either. 1360 */ 1361 if (dsda->rm_origin == NULL) { 1362 dsda->need_prep = B_TRUE; 1363 return (EBUSY); 1364 } 1365 1366 ndsda.ds = ds_prev; 1367 ndsda.is_origin_rm = B_TRUE; 1368 return (dsl_dataset_destroy_check(&ndsda, tag, tx)); 1369 } 1370 1371 /* 1372 * If we're not going to remove the origin after all, 1373 * undo the open context setup. 1374 */ 1375 if (dsda->rm_origin != NULL) { 1376 dsl_dataset_disown(dsda->rm_origin, tag); 1377 dsda->rm_origin = NULL; 1378 } 1379 1380 return (0); 1381} 1382 1383/* 1384 * If you add new checks here, you may need to add 1385 * additional checks to the "temporary" case in 1386 * snapshot_check() in dmu_objset.c. 1387 */ 1388/* ARGSUSED */ 1389int 1390dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx) 1391{ 1392 struct dsl_ds_destroyarg *dsda = arg1; 1393 dsl_dataset_t *ds = dsda->ds; 1394 1395 /* we have an owner hold, so noone else can destroy us */ 1396 ASSERT(!DSL_DATASET_IS_DESTROYED(ds)); 1397 1398 /* 1399 * Only allow deferred destroy on pools that support it. 1400 * NOTE: deferred destroy is only supported on snapshots. 1401 */ 1402 if (dsda->defer) { 1403 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 1404 SPA_VERSION_USERREFS) 1405 return (ENOTSUP); 1406 ASSERT(dsl_dataset_is_snapshot(ds)); 1407 return (0); 1408 } 1409 1410 /* 1411 * Can't delete a head dataset if there are snapshots of it. 1412 * (Except if the only snapshots are from the branch we cloned 1413 * from.) 1414 */ 1415 if (ds->ds_prev != NULL && 1416 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) 1417 return (EBUSY); 1418 1419 /* 1420 * If we made changes this txg, traverse_dsl_dataset won't find 1421 * them. Try again. 1422 */ 1423 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg) 1424 return (EAGAIN); 1425 1426 if (dsl_dataset_is_snapshot(ds)) { 1427 /* 1428 * If this snapshot has an elevated user reference count, 1429 * we can't destroy it yet. 1430 */ 1431 if (ds->ds_userrefs > 0 && !dsda->releasing) 1432 return (EBUSY); 1433 1434 mutex_enter(&ds->ds_lock); 1435 /* 1436 * Can't delete a branch point. However, if we're destroying 1437 * a clone and removing its origin due to it having a user 1438 * hold count of 0 and having been marked for deferred destroy, 1439 * it's OK for the origin to have a single clone. 1440 */ 1441 if (ds->ds_phys->ds_num_children > 1442 (dsda->is_origin_rm ? 2 : 1)) { 1443 mutex_exit(&ds->ds_lock); 1444 return (EEXIST); 1445 } 1446 mutex_exit(&ds->ds_lock); 1447 } else if (dsl_dir_is_clone(ds->ds_dir)) { 1448 return (dsl_dataset_origin_check(dsda, arg2, tx)); 1449 } 1450 1451 /* XXX we should do some i/o error checking... */ 1452 return (0); 1453} 1454 1455struct refsarg { 1456 kmutex_t lock; 1457 boolean_t gone; 1458 kcondvar_t cv; 1459}; 1460 1461/* ARGSUSED */ 1462static void 1463dsl_dataset_refs_gone(dmu_buf_t *db, void *argv) 1464{ 1465 struct refsarg *arg = argv; 1466 1467 mutex_enter(&arg->lock); 1468 arg->gone = TRUE; 1469 cv_signal(&arg->cv); 1470 mutex_exit(&arg->lock); 1471} 1472 1473static void 1474dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag) 1475{ 1476 struct refsarg arg; 1477 1478 bzero(&arg, sizeof(arg)); 1479 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL); 1480 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL); 1481 arg.gone = FALSE; 1482 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys, 1483 dsl_dataset_refs_gone); 1484 dmu_buf_rele(ds->ds_dbuf, tag); 1485 mutex_enter(&arg.lock); 1486 while (!arg.gone) 1487 cv_wait(&arg.cv, &arg.lock); 1488 ASSERT(arg.gone); 1489 mutex_exit(&arg.lock); 1490 ds->ds_dbuf = NULL; 1491 ds->ds_phys = NULL; 1492 mutex_destroy(&arg.lock); 1493 cv_destroy(&arg.cv); 1494} 1495 1496static void 1497remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx) 1498{ 1499 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1500 uint64_t count; 1501 int err; 1502 1503 ASSERT(ds->ds_phys->ds_num_children >= 2); 1504 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx); 1505 /* 1506 * The err should not be ENOENT, but a bug in a previous version 1507 * of the code could cause upgrade_clones_cb() to not set 1508 * ds_next_snap_obj when it should, leading to a missing entry. 1509 * If we knew that the pool was created after 1510 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't 1511 * ENOENT. However, at least we can check that we don't have 1512 * too many entries in the next_clones_obj even after failing to 1513 * remove this one. 1514 */ 1515 if (err != ENOENT) { 1516 VERIFY3U(err, ==, 0); 1517 } 1518 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj, 1519 &count)); 1520 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2); 1521} 1522 1523static void 1524dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx) 1525{ 1526 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 1527 zap_cursor_t zc; 1528 zap_attribute_t za; 1529 1530 /* 1531 * If it is the old version, dd_clones doesn't exist so we can't 1532 * find the clones, but deadlist_remove_key() is a no-op so it 1533 * doesn't matter. 1534 */ 1535 if (ds->ds_dir->dd_phys->dd_clones == 0) 1536 return; 1537 1538 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones); 1539 zap_cursor_retrieve(&zc, &za) == 0; 1540 zap_cursor_advance(&zc)) { 1541 dsl_dataset_t *clone; 1542 1543 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool, 1544 za.za_first_integer, FTAG, &clone)); 1545 if (clone->ds_dir->dd_origin_txg > mintxg) { 1546 dsl_deadlist_remove_key(&clone->ds_deadlist, 1547 mintxg, tx); 1548 dsl_dataset_remove_clones_key(clone, mintxg, tx); 1549 } 1550 dsl_dataset_rele(clone, FTAG); 1551 } 1552 zap_cursor_fini(&zc); 1553} 1554 1555struct process_old_arg { 1556 dsl_dataset_t *ds; 1557 dsl_dataset_t *ds_prev; 1558 boolean_t after_branch_point; 1559 zio_t *pio; 1560 uint64_t used, comp, uncomp; 1561}; 1562 1563static int 1564process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) 1565{ 1566 struct process_old_arg *poa = arg; 1567 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool; 1568 1569 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) { 1570 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx); 1571 if (poa->ds_prev && !poa->after_branch_point && 1572 bp->blk_birth > 1573 poa->ds_prev->ds_phys->ds_prev_snap_txg) { 1574 poa->ds_prev->ds_phys->ds_unique_bytes += 1575 bp_get_dsize_sync(dp->dp_spa, bp); 1576 } 1577 } else { 1578 poa->used += bp_get_dsize_sync(dp->dp_spa, bp); 1579 poa->comp += BP_GET_PSIZE(bp); 1580 poa->uncomp += BP_GET_UCSIZE(bp); 1581 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp); 1582 } 1583 return (0); 1584} 1585 1586static void 1587process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev, 1588 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx) 1589{ 1590 struct process_old_arg poa = { 0 }; 1591 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1592 objset_t *mos = dp->dp_meta_objset; 1593 1594 ASSERT(ds->ds_deadlist.dl_oldfmt); 1595 ASSERT(ds_next->ds_deadlist.dl_oldfmt); 1596 1597 poa.ds = ds; 1598 poa.ds_prev = ds_prev; 1599 poa.after_branch_point = after_branch_point; 1600 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 1601 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj, 1602 process_old_cb, &poa, tx)); 1603 VERIFY3U(zio_wait(poa.pio), ==, 0); 1604 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes); 1605 1606 /* change snapused */ 1607 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1608 -poa.used, -poa.comp, -poa.uncomp, tx); 1609 1610 /* swap next's deadlist to our deadlist */ 1611 dsl_deadlist_close(&ds->ds_deadlist); 1612 dsl_deadlist_close(&ds_next->ds_deadlist); 1613 SWITCH64(ds_next->ds_phys->ds_deadlist_obj, 1614 ds->ds_phys->ds_deadlist_obj); 1615 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 1616 dsl_deadlist_open(&ds_next->ds_deadlist, mos, 1617 ds_next->ds_phys->ds_deadlist_obj); 1618} 1619 1620void 1621dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx) 1622{ 1623 struct dsl_ds_destroyarg *dsda = arg1; 1624 dsl_dataset_t *ds = dsda->ds; 1625 int err; 1626 int after_branch_point = FALSE; 1627 dsl_pool_t *dp = ds->ds_dir->dd_pool; 1628 objset_t *mos = dp->dp_meta_objset; 1629 dsl_dataset_t *ds_prev = NULL; 1630 boolean_t wont_destroy; 1631 uint64_t obj; 1632 1633 wont_destroy = (dsda->defer && 1634 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1)); 1635 1636 ASSERT(ds->ds_owner || wont_destroy); 1637 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1); 1638 ASSERT(ds->ds_prev == NULL || 1639 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object); 1640 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg); 1641 1642 if (wont_destroy) { 1643 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1644 dmu_buf_will_dirty(ds->ds_dbuf, tx); 1645 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY; 1646 return; 1647 } 1648 1649 /* signal any waiters that this dataset is going away */ 1650 mutex_enter(&ds->ds_lock); 1651 ds->ds_owner = dsl_reaper; 1652 cv_broadcast(&ds->ds_exclusive_cv); 1653 mutex_exit(&ds->ds_lock); 1654 1655 /* Remove our reservation */ 1656 if (ds->ds_reserved != 0) { 1657 dsl_prop_setarg_t psa; 1658 uint64_t value = 0; 1659 1660 dsl_prop_setarg_init_uint64(&psa, "refreservation", 1661 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED), 1662 &value); 1663 psa.psa_effective_value = 0; /* predict default value */ 1664 1665 dsl_dataset_set_reservation_sync(ds, &psa, tx); 1666 ASSERT3U(ds->ds_reserved, ==, 0); 1667 } 1668 1669 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 1670 1671 dsl_scan_ds_destroyed(ds, tx); 1672 1673 obj = ds->ds_object; 1674 1675 if (ds->ds_phys->ds_prev_snap_obj != 0) { 1676 if (ds->ds_prev) { 1677 ds_prev = ds->ds_prev; 1678 } else { 1679 VERIFY(0 == dsl_dataset_hold_obj(dp, 1680 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev)); 1681 } 1682 after_branch_point = 1683 (ds_prev->ds_phys->ds_next_snap_obj != obj); 1684 1685 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx); 1686 if (after_branch_point && 1687 ds_prev->ds_phys->ds_next_clones_obj != 0) { 1688 remove_from_next_clones(ds_prev, obj, tx); 1689 if (ds->ds_phys->ds_next_snap_obj != 0) { 1690 VERIFY(0 == zap_add_int(mos, 1691 ds_prev->ds_phys->ds_next_clones_obj, 1692 ds->ds_phys->ds_next_snap_obj, tx)); 1693 } 1694 } 1695 if (after_branch_point && 1696 ds->ds_phys->ds_next_snap_obj == 0) { 1697 /* This clone is toast. */ 1698 ASSERT(ds_prev->ds_phys->ds_num_children > 1); 1699 ds_prev->ds_phys->ds_num_children--; 1700 1701 /* 1702 * If the clone's origin has no other clones, no 1703 * user holds, and has been marked for deferred 1704 * deletion, then we should have done the necessary 1705 * destroy setup for it. 1706 */ 1707 if (ds_prev->ds_phys->ds_num_children == 1 && 1708 ds_prev->ds_userrefs == 0 && 1709 DS_IS_DEFER_DESTROY(ds_prev)) { 1710 ASSERT3P(dsda->rm_origin, !=, NULL); 1711 } else { 1712 ASSERT3P(dsda->rm_origin, ==, NULL); 1713 } 1714 } else if (!after_branch_point) { 1715 ds_prev->ds_phys->ds_next_snap_obj = 1716 ds->ds_phys->ds_next_snap_obj; 1717 } 1718 } 1719 1720 if (dsl_dataset_is_snapshot(ds)) { 1721 dsl_dataset_t *ds_next; 1722 uint64_t old_unique; 1723 uint64_t used = 0, comp = 0, uncomp = 0; 1724 1725 VERIFY(0 == dsl_dataset_hold_obj(dp, 1726 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next)); 1727 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj); 1728 1729 old_unique = ds_next->ds_phys->ds_unique_bytes; 1730 1731 dmu_buf_will_dirty(ds_next->ds_dbuf, tx); 1732 ds_next->ds_phys->ds_prev_snap_obj = 1733 ds->ds_phys->ds_prev_snap_obj; 1734 ds_next->ds_phys->ds_prev_snap_txg = 1735 ds->ds_phys->ds_prev_snap_txg; 1736 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 1737 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0); 1738 1739 1740 if (ds_next->ds_deadlist.dl_oldfmt) { 1741 process_old_deadlist(ds, ds_prev, ds_next, 1742 after_branch_point, tx); 1743 } else { 1744 /* Adjust prev's unique space. */ 1745 if (ds_prev && !after_branch_point) { 1746 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1747 ds_prev->ds_phys->ds_prev_snap_txg, 1748 ds->ds_phys->ds_prev_snap_txg, 1749 &used, &comp, &uncomp); 1750 ds_prev->ds_phys->ds_unique_bytes += used; 1751 } 1752 1753 /* Adjust snapused. */ 1754 dsl_deadlist_space_range(&ds_next->ds_deadlist, 1755 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 1756 &used, &comp, &uncomp); 1757 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP, 1758 -used, -comp, -uncomp, tx); 1759 1760 /* Move blocks to be freed to pool's free list. */ 1761 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist, 1762 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg, 1763 tx); 1764 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, 1765 DD_USED_HEAD, used, comp, uncomp, tx); 1766 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx); 1767 1768 /* Merge our deadlist into next's and free it. */ 1769 dsl_deadlist_merge(&ds_next->ds_deadlist, 1770 ds->ds_phys->ds_deadlist_obj, tx); 1771 } 1772 dsl_deadlist_close(&ds->ds_deadlist); 1773 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1774 1775 /* Collapse range in clone heads */ 1776 dsl_dataset_remove_clones_key(ds, 1777 ds->ds_phys->ds_creation_txg, tx); 1778 1779 if (dsl_dataset_is_snapshot(ds_next)) { 1780 dsl_dataset_t *ds_nextnext; 1781 1782 /* 1783 * Update next's unique to include blocks which 1784 * were previously shared by only this snapshot 1785 * and it. Those blocks will be born after the 1786 * prev snap and before this snap, and will have 1787 * died after the next snap and before the one 1788 * after that (ie. be on the snap after next's 1789 * deadlist). 1790 */ 1791 VERIFY(0 == dsl_dataset_hold_obj(dp, 1792 ds_next->ds_phys->ds_next_snap_obj, 1793 FTAG, &ds_nextnext)); 1794 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist, 1795 ds->ds_phys->ds_prev_snap_txg, 1796 ds->ds_phys->ds_creation_txg, 1797 &used, &comp, &uncomp); 1798 ds_next->ds_phys->ds_unique_bytes += used; 1799 dsl_dataset_rele(ds_nextnext, FTAG); 1800 ASSERT3P(ds_next->ds_prev, ==, NULL); 1801 1802 /* Collapse range in this head. */ 1803 dsl_dataset_t *hds; 1804 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 1805 ds->ds_dir->dd_phys->dd_head_dataset_obj, 1806 FTAG, &hds)); 1807 dsl_deadlist_remove_key(&hds->ds_deadlist, 1808 ds->ds_phys->ds_creation_txg, tx); 1809 dsl_dataset_rele(hds, FTAG); 1810 1811 } else { 1812 ASSERT3P(ds_next->ds_prev, ==, ds); 1813 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next); 1814 ds_next->ds_prev = NULL; 1815 if (ds_prev) { 1816 VERIFY(0 == dsl_dataset_get_ref(dp, 1817 ds->ds_phys->ds_prev_snap_obj, 1818 ds_next, &ds_next->ds_prev)); 1819 } 1820 1821 dsl_dataset_recalc_head_uniq(ds_next); 1822 1823 /* 1824 * Reduce the amount of our unconsmed refreservation 1825 * being charged to our parent by the amount of 1826 * new unique data we have gained. 1827 */ 1828 if (old_unique < ds_next->ds_reserved) { 1829 int64_t mrsdelta; 1830 uint64_t new_unique = 1831 ds_next->ds_phys->ds_unique_bytes; 1832 1833 ASSERT(old_unique <= new_unique); 1834 mrsdelta = MIN(new_unique - old_unique, 1835 ds_next->ds_reserved - old_unique); 1836 dsl_dir_diduse_space(ds->ds_dir, 1837 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx); 1838 } 1839 } 1840 dsl_dataset_rele(ds_next, FTAG); 1841 } else { 1842 /* 1843 * There's no next snapshot, so this is a head dataset. 1844 * Destroy the deadlist. Unless it's a clone, the 1845 * deadlist should be empty. (If it's a clone, it's 1846 * safe to ignore the deadlist contents.) 1847 */ 1848 struct killarg ka; 1849 1850 dsl_deadlist_close(&ds->ds_deadlist); 1851 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx); 1852 ds->ds_phys->ds_deadlist_obj = 0; 1853 1854 /* 1855 * Free everything that we point to (that's born after 1856 * the previous snapshot, if we are a clone) 1857 * 1858 * NB: this should be very quick, because we already 1859 * freed all the objects in open context. 1860 */ 1861 ka.ds = ds; 1862 ka.tx = tx; 1863 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg, 1864 TRAVERSE_POST, kill_blkptr, &ka); 1865 ASSERT3U(err, ==, 0); 1866 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || 1867 ds->ds_phys->ds_unique_bytes == 0); 1868 1869 if (ds->ds_prev != NULL) { 1870 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 1871 VERIFY3U(0, ==, zap_remove_int(mos, 1872 ds->ds_prev->ds_dir->dd_phys->dd_clones, 1873 ds->ds_object, tx)); 1874 } 1875 dsl_dataset_rele(ds->ds_prev, ds); 1876 ds->ds_prev = ds_prev = NULL; 1877 } 1878 } 1879 1880 /* 1881 * This must be done after the dsl_traverse(), because it will 1882 * re-open the objset. 1883 */ 1884 if (ds->ds_objset) { 1885 dmu_objset_evict(ds->ds_objset); 1886 ds->ds_objset = NULL; 1887 } 1888 1889 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) { 1890 /* Erase the link in the dir */ 1891 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 1892 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0; 1893 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0); 1894 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx); 1895 ASSERT(err == 0); 1896 } else { 1897 /* remove from snapshot namespace */ 1898 dsl_dataset_t *ds_head; 1899 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0); 1900 VERIFY(0 == dsl_dataset_hold_obj(dp, 1901 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head)); 1902 VERIFY(0 == dsl_dataset_get_snapname(ds)); 1903#ifdef ZFS_DEBUG 1904 { 1905 uint64_t val; 1906 1907 err = dsl_dataset_snap_lookup(ds_head, 1908 ds->ds_snapname, &val); 1909 ASSERT3U(err, ==, 0); 1910 ASSERT3U(val, ==, obj); 1911 } 1912#endif 1913 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx); 1914 ASSERT(err == 0); 1915 dsl_dataset_rele(ds_head, FTAG); 1916 } 1917 1918 if (ds_prev && ds->ds_prev != ds_prev) 1919 dsl_dataset_rele(ds_prev, FTAG); 1920 1921 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx); 1922 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx, 1923 "dataset = %llu", ds->ds_object); 1924 1925 if (ds->ds_phys->ds_next_clones_obj != 0) { 1926 uint64_t count; 1927 ASSERT(0 == zap_count(mos, 1928 ds->ds_phys->ds_next_clones_obj, &count) && count == 0); 1929 VERIFY(0 == dmu_object_free(mos, 1930 ds->ds_phys->ds_next_clones_obj, tx)); 1931 } 1932 if (ds->ds_phys->ds_props_obj != 0) 1933 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx)); 1934 if (ds->ds_phys->ds_userrefs_obj != 0) 1935 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx)); 1936 dsl_dir_close(ds->ds_dir, ds); 1937 ds->ds_dir = NULL; 1938 dsl_dataset_drain_refs(ds, tag); 1939 VERIFY(0 == dmu_object_free(mos, obj, tx)); 1940 1941 if (dsda->rm_origin) { 1942 /* 1943 * Remove the origin of the clone we just destroyed. 1944 */ 1945 struct dsl_ds_destroyarg ndsda = {0}; 1946 1947 ndsda.ds = dsda->rm_origin; 1948 dsl_dataset_destroy_sync(&ndsda, tag, tx); 1949 } 1950} 1951 1952static int 1953dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx) 1954{ 1955 uint64_t asize; 1956 1957 if (!dmu_tx_is_syncing(tx)) 1958 return (0); 1959 1960 /* 1961 * If there's an fs-only reservation, any blocks that might become 1962 * owned by the snapshot dataset must be accommodated by space 1963 * outside of the reservation. 1964 */ 1965 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds)); 1966 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 1967 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 1968 return (ENOSPC); 1969 1970 /* 1971 * Propogate any reserved space for this snapshot to other 1972 * snapshot checks in this sync group. 1973 */ 1974 if (asize > 0) 1975 dsl_dir_willuse_space(ds->ds_dir, asize, tx); 1976 1977 return (0); 1978} 1979 1980int 1981dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx) 1982{ 1983 dsl_dataset_t *ds = arg1; 1984 const char *snapname = arg2; 1985 int err; 1986 uint64_t value; 1987 1988 /* 1989 * We don't allow multiple snapshots of the same txg. If there 1990 * is already one, try again. 1991 */ 1992 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg) 1993 return (EAGAIN); 1994 1995 /* 1996 * Check for conflicting name snapshot name. 1997 */ 1998 err = dsl_dataset_snap_lookup(ds, snapname, &value); 1999 if (err == 0) 2000 return (EEXIST); 2001 if (err != ENOENT) 2002 return (err); 2003 2004 /* 2005 * Check that the dataset's name is not too long. Name consists 2006 * of the dataset's length + 1 for the @-sign + snapshot name's length 2007 */ 2008 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN) 2009 return (ENAMETOOLONG); 2010 2011 err = dsl_dataset_snapshot_reserve_space(ds, tx); 2012 if (err) 2013 return (err); 2014 2015 ds->ds_trysnap_txg = tx->tx_txg; 2016 return (0); 2017} 2018 2019void 2020dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2021{ 2022 dsl_dataset_t *ds = arg1; 2023 const char *snapname = arg2; 2024 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2025 dmu_buf_t *dbuf; 2026 dsl_dataset_phys_t *dsphys; 2027 uint64_t dsobj, crtxg; 2028 objset_t *mos = dp->dp_meta_objset; 2029 int err; 2030 2031 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock)); 2032 2033 /* 2034 * The origin's ds_creation_txg has to be < TXG_INITIAL 2035 */ 2036 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0) 2037 crtxg = 1; 2038 else 2039 crtxg = tx->tx_txg; 2040 2041 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0, 2042 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx); 2043 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf)); 2044 dmu_buf_will_dirty(dbuf, tx); 2045 dsphys = dbuf->db_data; 2046 bzero(dsphys, sizeof (dsl_dataset_phys_t)); 2047 dsphys->ds_dir_obj = ds->ds_dir->dd_object; 2048 dsphys->ds_fsid_guid = unique_create(); 2049 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid, 2050 sizeof (dsphys->ds_guid)); 2051 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj; 2052 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg; 2053 dsphys->ds_next_snap_obj = ds->ds_object; 2054 dsphys->ds_num_children = 1; 2055 dsphys->ds_creation_time = gethrestime_sec(); 2056 dsphys->ds_creation_txg = crtxg; 2057 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj; 2058 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes; 2059 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes; 2060 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes; 2061 dsphys->ds_flags = ds->ds_phys->ds_flags; 2062 dsphys->ds_bp = ds->ds_phys->ds_bp; 2063 dmu_buf_rele(dbuf, FTAG); 2064 2065 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0); 2066 if (ds->ds_prev) { 2067 uint64_t next_clones_obj = 2068 ds->ds_prev->ds_phys->ds_next_clones_obj; 2069 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj == 2070 ds->ds_object || 2071 ds->ds_prev->ds_phys->ds_num_children > 1); 2072 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) { 2073 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx); 2074 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==, 2075 ds->ds_prev->ds_phys->ds_creation_txg); 2076 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj; 2077 } else if (next_clones_obj != 0) { 2078 remove_from_next_clones(ds->ds_prev, 2079 dsphys->ds_next_snap_obj, tx); 2080 VERIFY3U(0, ==, zap_add_int(mos, 2081 next_clones_obj, dsobj, tx)); 2082 } 2083 } 2084 2085 /* 2086 * If we have a reference-reservation on this dataset, we will 2087 * need to increase the amount of refreservation being charged 2088 * since our unique space is going to zero. 2089 */ 2090 if (ds->ds_reserved) { 2091 int64_t delta; 2092 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 2093 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved); 2094 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, 2095 delta, 0, 0, tx); 2096 } 2097 2098 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2099 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu", 2100 ds->ds_dir->dd_myname, snapname, dsobj, 2101 ds->ds_phys->ds_prev_snap_txg); 2102 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist, 2103 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx); 2104 dsl_deadlist_close(&ds->ds_deadlist); 2105 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj); 2106 dsl_deadlist_add_key(&ds->ds_deadlist, 2107 ds->ds_phys->ds_prev_snap_txg, tx); 2108 2109 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg); 2110 ds->ds_phys->ds_prev_snap_obj = dsobj; 2111 ds->ds_phys->ds_prev_snap_txg = crtxg; 2112 ds->ds_phys->ds_unique_bytes = 0; 2113 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE) 2114 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE; 2115 2116 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj, 2117 snapname, 8, 1, &dsobj, tx); 2118 ASSERT(err == 0); 2119 2120 if (ds->ds_prev) 2121 dsl_dataset_drop_ref(ds->ds_prev, ds); 2122 VERIFY(0 == dsl_dataset_get_ref(dp, 2123 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 2124 2125 dsl_scan_ds_snapshotted(ds, tx); 2126 2127 dsl_dir_snap_cmtime_update(ds->ds_dir); 2128 2129 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx, 2130 "dataset = %llu", dsobj); 2131} 2132 2133void 2134dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx) 2135{ 2136 ASSERT(dmu_tx_is_syncing(tx)); 2137 ASSERT(ds->ds_objset != NULL); 2138 ASSERT(ds->ds_phys->ds_next_snap_obj == 0); 2139 2140 /* 2141 * in case we had to change ds_fsid_guid when we opened it, 2142 * sync it out now. 2143 */ 2144 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2145 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid; 2146 2147 dsl_dir_dirty(ds->ds_dir, tx); 2148 dmu_objset_sync(ds->ds_objset, zio, tx); 2149} 2150 2151void 2152dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv) 2153{ 2154 uint64_t refd, avail, uobjs, aobjs, ratio; 2155 2156 dsl_dir_stats(ds->ds_dir, nv); 2157 2158 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs); 2159 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail); 2160 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd); 2161 2162 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION, 2163 ds->ds_phys->ds_creation_time); 2164 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG, 2165 ds->ds_phys->ds_creation_txg); 2166 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA, 2167 ds->ds_quota); 2168 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION, 2169 ds->ds_reserved); 2170 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID, 2171 ds->ds_phys->ds_guid); 2172 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE, 2173 ds->ds_phys->ds_unique_bytes); 2174 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID, 2175 ds->ds_object); 2176 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, 2177 ds->ds_userrefs); 2178 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY, 2179 DS_IS_DEFER_DESTROY(ds) ? 1 : 0); 2180 2181 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 : 2182 (ds->ds_phys->ds_uncompressed_bytes * 100 / 2183 ds->ds_phys->ds_compressed_bytes); 2184 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio); 2185 2186 if (ds->ds_phys->ds_next_snap_obj) { 2187 /* 2188 * This is a snapshot; override the dd's space used with 2189 * our unique space and compression ratio. 2190 */ 2191 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED, 2192 ds->ds_phys->ds_unique_bytes); 2193 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio); 2194 } 2195} 2196 2197void 2198dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat) 2199{ 2200 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg; 2201 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT; 2202 stat->dds_guid = ds->ds_phys->ds_guid; 2203 if (ds->ds_phys->ds_next_snap_obj) { 2204 stat->dds_is_snapshot = B_TRUE; 2205 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1; 2206 } else { 2207 stat->dds_is_snapshot = B_FALSE; 2208 stat->dds_num_clones = 0; 2209 } 2210 2211 /* clone origin is really a dsl_dir thing... */ 2212 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER); 2213 if (dsl_dir_is_clone(ds->ds_dir)) { 2214 dsl_dataset_t *ods; 2215 2216 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool, 2217 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods)); 2218 dsl_dataset_name(ods, stat->dds_origin); 2219 dsl_dataset_drop_ref(ods, FTAG); 2220 } else { 2221 stat->dds_origin[0] = '\0'; 2222 } 2223 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock); 2224} 2225 2226uint64_t 2227dsl_dataset_fsid_guid(dsl_dataset_t *ds) 2228{ 2229 return (ds->ds_fsid_guid); 2230} 2231 2232void 2233dsl_dataset_space(dsl_dataset_t *ds, 2234 uint64_t *refdbytesp, uint64_t *availbytesp, 2235 uint64_t *usedobjsp, uint64_t *availobjsp) 2236{ 2237 *refdbytesp = ds->ds_phys->ds_used_bytes; 2238 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE); 2239 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) 2240 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes; 2241 if (ds->ds_quota != 0) { 2242 /* 2243 * Adjust available bytes according to refquota 2244 */ 2245 if (*refdbytesp < ds->ds_quota) 2246 *availbytesp = MIN(*availbytesp, 2247 ds->ds_quota - *refdbytesp); 2248 else 2249 *availbytesp = 0; 2250 } 2251 *usedobjsp = ds->ds_phys->ds_bp.blk_fill; 2252 *availobjsp = DN_MAX_OBJECT - *usedobjsp; 2253} 2254 2255boolean_t 2256dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds) 2257{ 2258 dsl_pool_t *dp = ds->ds_dir->dd_pool; 2259 2260 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) || 2261 dsl_pool_sync_context(dp)); 2262 if (ds->ds_prev == NULL) 2263 return (B_FALSE); 2264 if (ds->ds_phys->ds_bp.blk_birth > 2265 ds->ds_prev->ds_phys->ds_creation_txg) { 2266 objset_t *os, *os_prev; 2267 /* 2268 * It may be that only the ZIL differs, because it was 2269 * reset in the head. Don't count that as being 2270 * modified. 2271 */ 2272 if (dmu_objset_from_ds(ds, &os) != 0) 2273 return (B_TRUE); 2274 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0) 2275 return (B_TRUE); 2276 return (bcmp(&os->os_phys->os_meta_dnode, 2277 &os_prev->os_phys->os_meta_dnode, 2278 sizeof (os->os_phys->os_meta_dnode)) != 0); 2279 } 2280 return (B_FALSE); 2281} 2282 2283/* ARGSUSED */ 2284static int 2285dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx) 2286{ 2287 dsl_dataset_t *ds = arg1; 2288 char *newsnapname = arg2; 2289 dsl_dir_t *dd = ds->ds_dir; 2290 dsl_dataset_t *hds; 2291 uint64_t val; 2292 int err; 2293 2294 err = dsl_dataset_hold_obj(dd->dd_pool, 2295 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds); 2296 if (err) 2297 return (err); 2298 2299 /* new name better not be in use */ 2300 err = dsl_dataset_snap_lookup(hds, newsnapname, &val); 2301 dsl_dataset_rele(hds, FTAG); 2302 2303 if (err == 0) 2304 err = EEXIST; 2305 else if (err == ENOENT) 2306 err = 0; 2307 2308 /* dataset name + 1 for the "@" + the new snapshot name must fit */ 2309 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN) 2310 err = ENAMETOOLONG; 2311 2312 return (err); 2313} 2314 2315static void 2316dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2317{ 2318 char oldname[MAXPATHLEN], newname[MAXPATHLEN]; 2319 dsl_dataset_t *ds = arg1; 2320 const char *newsnapname = arg2; 2321 dsl_dir_t *dd = ds->ds_dir; 2322 objset_t *mos = dd->dd_pool->dp_meta_objset; 2323 dsl_dataset_t *hds; 2324 int err; 2325 2326 ASSERT(ds->ds_phys->ds_next_snap_obj != 0); 2327 2328 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool, 2329 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds)); 2330 2331 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2332 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx); 2333 ASSERT3U(err, ==, 0); 2334 dsl_dataset_name(ds, oldname); 2335 mutex_enter(&ds->ds_lock); 2336 (void) strcpy(ds->ds_snapname, newsnapname); 2337 mutex_exit(&ds->ds_lock); 2338 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj, 2339 ds->ds_snapname, 8, 1, &ds->ds_object, tx); 2340 ASSERT3U(err, ==, 0); 2341 dsl_dataset_name(ds, newname); 2342#ifdef _KERNEL 2343 zvol_rename_minors(oldname, newname); 2344#endif 2345 2346 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx, 2347 "dataset = %llu", ds->ds_object); 2348 dsl_dataset_rele(hds, FTAG); 2349} 2350 2351struct renamesnaparg { 2352 dsl_sync_task_group_t *dstg; 2353 char failed[MAXPATHLEN]; 2354 char *oldsnap; 2355 char *newsnap; 2356}; 2357 2358static int 2359dsl_snapshot_rename_one(const char *name, void *arg) 2360{ 2361 struct renamesnaparg *ra = arg; 2362 dsl_dataset_t *ds = NULL; 2363 char *snapname; 2364 int err; 2365 2366 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap); 2367 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed)); 2368 2369 /* 2370 * For recursive snapshot renames the parent won't be changing 2371 * so we just pass name for both the to/from argument. 2372 */ 2373 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED()); 2374 if (err != 0) { 2375 strfree(snapname); 2376 return (err == ENOENT ? 0 : err); 2377 } 2378 2379#ifdef _KERNEL 2380 /* 2381 * For all filesystems undergoing rename, we'll need to unmount it. 2382 */ 2383 (void) zfs_unmount_snap(snapname, NULL); 2384#endif 2385 err = dsl_dataset_hold(snapname, ra->dstg, &ds); 2386 strfree(snapname); 2387 if (err != 0) 2388 return (err == ENOENT ? 0 : err); 2389 2390 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check, 2391 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0); 2392 2393 return (0); 2394} 2395 2396static int 2397dsl_recursive_rename(char *oldname, const char *newname) 2398{ 2399 int err; 2400 struct renamesnaparg *ra; 2401 dsl_sync_task_t *dst; 2402 spa_t *spa; 2403 char *cp, *fsname = spa_strdup(oldname); 2404 int len = strlen(oldname) + 1; 2405 2406 /* truncate the snapshot name to get the fsname */ 2407 cp = strchr(fsname, '@'); 2408 *cp = '\0'; 2409 2410 err = spa_open(fsname, &spa, FTAG); 2411 if (err) { 2412 kmem_free(fsname, len); 2413 return (err); 2414 } 2415 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP); 2416 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 2417 2418 ra->oldsnap = strchr(oldname, '@') + 1; 2419 ra->newsnap = strchr(newname, '@') + 1; 2420 *ra->failed = '\0'; 2421 2422 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra, 2423 DS_FIND_CHILDREN); 2424 kmem_free(fsname, len); 2425 2426 if (err == 0) { 2427 err = dsl_sync_task_group_wait(ra->dstg); 2428 } 2429 2430 for (dst = list_head(&ra->dstg->dstg_tasks); dst; 2431 dst = list_next(&ra->dstg->dstg_tasks, dst)) { 2432 dsl_dataset_t *ds = dst->dst_arg1; 2433 if (dst->dst_err) { 2434 dsl_dir_name(ds->ds_dir, ra->failed); 2435 (void) strlcat(ra->failed, "@", sizeof (ra->failed)); 2436 (void) strlcat(ra->failed, ra->newsnap, 2437 sizeof (ra->failed)); 2438 } 2439 dsl_dataset_rele(ds, ra->dstg); 2440 } 2441 2442 if (err) 2443 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed)); 2444 2445 dsl_sync_task_group_destroy(ra->dstg); 2446 kmem_free(ra, sizeof (struct renamesnaparg)); 2447 spa_close(spa, FTAG); 2448 return (err); 2449} 2450 2451static int 2452dsl_valid_rename(const char *oldname, void *arg) 2453{ 2454 int delta = *(int *)arg; 2455 2456 if (strlen(oldname) + delta >= MAXNAMELEN) 2457 return (ENAMETOOLONG); 2458 2459 return (0); 2460} 2461 2462#pragma weak dmu_objset_rename = dsl_dataset_rename 2463int 2464dsl_dataset_rename(char *oldname, const char *newname, int flags) 2465{ 2466 dsl_dir_t *dd; 2467 dsl_dataset_t *ds; 2468 const char *tail; 2469 int err; 2470 2471 err = dsl_dir_open(oldname, FTAG, &dd, &tail); 2472 if (err) 2473 return (err); 2474 2475 if (tail == NULL) { 2476 int delta = strlen(newname) - strlen(oldname); 2477 2478 /* if we're growing, validate child name lengths */ 2479 if (delta > 0) 2480 err = dmu_objset_find(oldname, dsl_valid_rename, 2481 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS); 2482 2483 if (err == 0) 2484 err = dsl_dir_rename(dd, newname, flags); 2485 dsl_dir_close(dd, FTAG); 2486 return (err); 2487 } 2488 2489 if (tail[0] != '@') { 2490 /* the name ended in a nonexistent component */ 2491 dsl_dir_close(dd, FTAG); 2492 return (ENOENT); 2493 } 2494 2495 dsl_dir_close(dd, FTAG); 2496 2497 /* new name must be snapshot in same filesystem */ 2498 tail = strchr(newname, '@'); 2499 if (tail == NULL) 2500 return (EINVAL); 2501 tail++; 2502 if (strncmp(oldname, newname, tail - newname) != 0) 2503 return (EXDEV); 2504 2505 if (flags & ZFS_RENAME_RECURSIVE) { 2506 err = dsl_recursive_rename(oldname, newname); 2507 } else { 2508 err = dsl_dataset_hold(oldname, FTAG, &ds); 2509 if (err) 2510 return (err); 2511 2512 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 2513 dsl_dataset_snapshot_rename_check, 2514 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1); 2515 2516 dsl_dataset_rele(ds, FTAG); 2517 } 2518 2519 return (err); 2520} 2521 2522struct promotenode { 2523 list_node_t link; 2524 dsl_dataset_t *ds; 2525}; 2526 2527struct promotearg { 2528 list_t shared_snaps, origin_snaps, clone_snaps; 2529 dsl_dataset_t *origin_origin; 2530 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap; 2531 char *err_ds; 2532}; 2533 2534static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep); 2535static boolean_t snaplist_unstable(list_t *l); 2536 2537static int 2538dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx) 2539{ 2540 dsl_dataset_t *hds = arg1; 2541 struct promotearg *pa = arg2; 2542 struct promotenode *snap = list_head(&pa->shared_snaps); 2543 dsl_dataset_t *origin_ds = snap->ds; 2544 int err; 2545 uint64_t unused; 2546 2547 /* Check that it is a real clone */ 2548 if (!dsl_dir_is_clone(hds->ds_dir)) 2549 return (EINVAL); 2550 2551 /* Since this is so expensive, don't do the preliminary check */ 2552 if (!dmu_tx_is_syncing(tx)) 2553 return (0); 2554 2555 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) 2556 return (EXDEV); 2557 2558 /* compute origin's new unique space */ 2559 snap = list_tail(&pa->clone_snaps); 2560 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2561 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2562 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, 2563 &pa->unique, &unused, &unused); 2564 2565 /* 2566 * Walk the snapshots that we are moving 2567 * 2568 * Compute space to transfer. Consider the incremental changes 2569 * to used for each snapshot: 2570 * (my used) = (prev's used) + (blocks born) - (blocks killed) 2571 * So each snapshot gave birth to: 2572 * (blocks born) = (my used) - (prev's used) + (blocks killed) 2573 * So a sequence would look like: 2574 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0) 2575 * Which simplifies to: 2576 * uN + kN + kN-1 + ... + k1 + k0 2577 * Note however, if we stop before we reach the ORIGIN we get: 2578 * uN + kN + kN-1 + ... + kM - uM-1 2579 */ 2580 pa->used = origin_ds->ds_phys->ds_used_bytes; 2581 pa->comp = origin_ds->ds_phys->ds_compressed_bytes; 2582 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes; 2583 for (snap = list_head(&pa->shared_snaps); snap; 2584 snap = list_next(&pa->shared_snaps, snap)) { 2585 uint64_t val, dlused, dlcomp, dluncomp; 2586 dsl_dataset_t *ds = snap->ds; 2587 2588 /* Check that the snapshot name does not conflict */ 2589 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2590 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val); 2591 if (err == 0) { 2592 err = EEXIST; 2593 goto out; 2594 } 2595 if (err != ENOENT) 2596 goto out; 2597 2598 /* The very first snapshot does not have a deadlist */ 2599 if (ds->ds_phys->ds_prev_snap_obj == 0) 2600 continue; 2601 2602 dsl_deadlist_space(&ds->ds_deadlist, 2603 &dlused, &dlcomp, &dluncomp); 2604 pa->used += dlused; 2605 pa->comp += dlcomp; 2606 pa->uncomp += dluncomp; 2607 } 2608 2609 /* 2610 * If we are a clone of a clone then we never reached ORIGIN, 2611 * so we need to subtract out the clone origin's used space. 2612 */ 2613 if (pa->origin_origin) { 2614 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes; 2615 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes; 2616 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes; 2617 } 2618 2619 /* Check that there is enough space here */ 2620 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir, 2621 pa->used); 2622 if (err) 2623 return (err); 2624 2625 /* 2626 * Compute the amounts of space that will be used by snapshots 2627 * after the promotion (for both origin and clone). For each, 2628 * it is the amount of space that will be on all of their 2629 * deadlists (that was not born before their new origin). 2630 */ 2631 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2632 uint64_t space; 2633 2634 /* 2635 * Note, typically this will not be a clone of a clone, 2636 * so dd_origin_txg will be < TXG_INITIAL, so 2637 * these snaplist_space() -> dsl_deadlist_space_range() 2638 * calls will be fast because they do not have to 2639 * iterate over all bps. 2640 */ 2641 snap = list_head(&pa->origin_snaps); 2642 err = snaplist_space(&pa->shared_snaps, 2643 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap); 2644 if (err) 2645 return (err); 2646 2647 err = snaplist_space(&pa->clone_snaps, 2648 snap->ds->ds_dir->dd_origin_txg, &space); 2649 if (err) 2650 return (err); 2651 pa->cloneusedsnap += space; 2652 } 2653 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) { 2654 err = snaplist_space(&pa->origin_snaps, 2655 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap); 2656 if (err) 2657 return (err); 2658 } 2659 2660 return (0); 2661out: 2662 pa->err_ds = snap->ds->ds_snapname; 2663 return (err); 2664} 2665 2666static void 2667dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx) 2668{ 2669 dsl_dataset_t *hds = arg1; 2670 struct promotearg *pa = arg2; 2671 struct promotenode *snap = list_head(&pa->shared_snaps); 2672 dsl_dataset_t *origin_ds = snap->ds; 2673 dsl_dataset_t *origin_head; 2674 dsl_dir_t *dd = hds->ds_dir; 2675 dsl_pool_t *dp = hds->ds_dir->dd_pool; 2676 dsl_dir_t *odd = NULL; 2677 uint64_t oldnext_obj; 2678 int64_t delta; 2679 2680 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)); 2681 2682 snap = list_head(&pa->origin_snaps); 2683 origin_head = snap->ds; 2684 2685 /* 2686 * We need to explicitly open odd, since origin_ds's dd will be 2687 * changing. 2688 */ 2689 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object, 2690 NULL, FTAG, &odd)); 2691 2692 /* change origin's next snap */ 2693 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx); 2694 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj; 2695 snap = list_tail(&pa->clone_snaps); 2696 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object); 2697 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object; 2698 2699 /* change the origin's next clone */ 2700 if (origin_ds->ds_phys->ds_next_clones_obj) { 2701 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx); 2702 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2703 origin_ds->ds_phys->ds_next_clones_obj, 2704 oldnext_obj, tx)); 2705 } 2706 2707 /* change origin */ 2708 dmu_buf_will_dirty(dd->dd_dbuf, tx); 2709 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object); 2710 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj; 2711 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg; 2712 dmu_buf_will_dirty(odd->dd_dbuf, tx); 2713 odd->dd_phys->dd_origin_obj = origin_ds->ds_object; 2714 origin_head->ds_dir->dd_origin_txg = 2715 origin_ds->ds_phys->ds_creation_txg; 2716 2717 /* change dd_clone entries */ 2718 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2719 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2720 odd->dd_phys->dd_clones, hds->ds_object, tx)); 2721 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2722 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2723 hds->ds_object, tx)); 2724 2725 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, 2726 pa->origin_origin->ds_dir->dd_phys->dd_clones, 2727 origin_head->ds_object, tx)); 2728 if (dd->dd_phys->dd_clones == 0) { 2729 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset, 2730 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx); 2731 } 2732 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset, 2733 dd->dd_phys->dd_clones, origin_head->ds_object, tx)); 2734 2735 } 2736 2737 /* move snapshots to this dir */ 2738 for (snap = list_head(&pa->shared_snaps); snap; 2739 snap = list_next(&pa->shared_snaps, snap)) { 2740 dsl_dataset_t *ds = snap->ds; 2741 2742 /* unregister props as dsl_dir is changing */ 2743 if (ds->ds_objset) { 2744 dmu_objset_evict(ds->ds_objset); 2745 ds->ds_objset = NULL; 2746 } 2747 /* move snap name entry */ 2748 VERIFY(0 == dsl_dataset_get_snapname(ds)); 2749 VERIFY(0 == dsl_dataset_snap_remove(origin_head, 2750 ds->ds_snapname, tx)); 2751 VERIFY(0 == zap_add(dp->dp_meta_objset, 2752 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname, 2753 8, 1, &ds->ds_object, tx)); 2754 2755 /* change containing dsl_dir */ 2756 dmu_buf_will_dirty(ds->ds_dbuf, tx); 2757 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object); 2758 ds->ds_phys->ds_dir_obj = dd->dd_object; 2759 ASSERT3P(ds->ds_dir, ==, odd); 2760 dsl_dir_close(ds->ds_dir, ds); 2761 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object, 2762 NULL, ds, &ds->ds_dir)); 2763 2764 /* move any clone references */ 2765 if (ds->ds_phys->ds_next_clones_obj && 2766 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) { 2767 zap_cursor_t zc; 2768 zap_attribute_t za; 2769 2770 for (zap_cursor_init(&zc, dp->dp_meta_objset, 2771 ds->ds_phys->ds_next_clones_obj); 2772 zap_cursor_retrieve(&zc, &za) == 0; 2773 zap_cursor_advance(&zc)) { 2774 dsl_dataset_t *cnds; 2775 uint64_t o; 2776 2777 if (za.za_first_integer == oldnext_obj) { 2778 /* 2779 * We've already moved the 2780 * origin's reference. 2781 */ 2782 continue; 2783 } 2784 2785 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, 2786 za.za_first_integer, FTAG, &cnds)); 2787 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj; 2788 2789 VERIFY3U(zap_remove_int(dp->dp_meta_objset, 2790 odd->dd_phys->dd_clones, o, tx), ==, 0); 2791 VERIFY3U(zap_add_int(dp->dp_meta_objset, 2792 dd->dd_phys->dd_clones, o, tx), ==, 0); 2793 dsl_dataset_rele(cnds, FTAG); 2794 } 2795 zap_cursor_fini(&zc); 2796 } 2797 2798 ASSERT3U(dsl_prop_numcb(ds), ==, 0); 2799 } 2800 2801 /* 2802 * Change space accounting. 2803 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either 2804 * both be valid, or both be 0 (resulting in delta == 0). This 2805 * is true for each of {clone,origin} independently. 2806 */ 2807 2808 delta = pa->cloneusedsnap - 2809 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2810 ASSERT3S(delta, >=, 0); 2811 ASSERT3U(pa->used, >=, delta); 2812 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx); 2813 dsl_dir_diduse_space(dd, DD_USED_HEAD, 2814 pa->used - delta, pa->comp, pa->uncomp, tx); 2815 2816 delta = pa->originusedsnap - 2817 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP]; 2818 ASSERT3S(delta, <=, 0); 2819 ASSERT3U(pa->used, >=, -delta); 2820 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx); 2821 dsl_dir_diduse_space(odd, DD_USED_HEAD, 2822 -pa->used - delta, -pa->comp, -pa->uncomp, tx); 2823 2824 origin_ds->ds_phys->ds_unique_bytes = pa->unique; 2825 2826 /* log history record */ 2827 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx, 2828 "dataset = %llu", hds->ds_object); 2829 2830 dsl_dir_close(odd, FTAG); 2831} 2832 2833static char *snaplist_tag = "snaplist"; 2834/* 2835 * Make a list of dsl_dataset_t's for the snapshots between first_obj 2836 * (exclusive) and last_obj (inclusive). The list will be in reverse 2837 * order (last_obj will be the list_head()). If first_obj == 0, do all 2838 * snapshots back to this dataset's origin. 2839 */ 2840static int 2841snaplist_make(dsl_pool_t *dp, boolean_t own, 2842 uint64_t first_obj, uint64_t last_obj, list_t *l) 2843{ 2844 uint64_t obj = last_obj; 2845 2846 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock)); 2847 2848 list_create(l, sizeof (struct promotenode), 2849 offsetof(struct promotenode, link)); 2850 2851 while (obj != first_obj) { 2852 dsl_dataset_t *ds; 2853 struct promotenode *snap; 2854 int err; 2855 2856 if (own) { 2857 err = dsl_dataset_own_obj(dp, obj, 2858 0, snaplist_tag, &ds); 2859 if (err == 0) 2860 dsl_dataset_make_exclusive(ds, snaplist_tag); 2861 } else { 2862 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds); 2863 } 2864 if (err == ENOENT) { 2865 /* lost race with snapshot destroy */ 2866 struct promotenode *last = list_tail(l); 2867 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj); 2868 obj = last->ds->ds_phys->ds_prev_snap_obj; 2869 continue; 2870 } else if (err) { 2871 return (err); 2872 } 2873 2874 if (first_obj == 0) 2875 first_obj = ds->ds_dir->dd_phys->dd_origin_obj; 2876 2877 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP); 2878 snap->ds = ds; 2879 list_insert_tail(l, snap); 2880 obj = ds->ds_phys->ds_prev_snap_obj; 2881 } 2882 2883 return (0); 2884} 2885 2886static int 2887snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep) 2888{ 2889 struct promotenode *snap; 2890 2891 *spacep = 0; 2892 for (snap = list_head(l); snap; snap = list_next(l, snap)) { 2893 uint64_t used, comp, uncomp; 2894 dsl_deadlist_space_range(&snap->ds->ds_deadlist, 2895 mintxg, UINT64_MAX, &used, &comp, &uncomp); 2896 *spacep += used; 2897 } 2898 return (0); 2899} 2900 2901static void 2902snaplist_destroy(list_t *l, boolean_t own) 2903{ 2904 struct promotenode *snap; 2905 2906 if (!l || !list_link_active(&l->list_head)) 2907 return; 2908 2909 while ((snap = list_tail(l)) != NULL) { 2910 list_remove(l, snap); 2911 if (own) 2912 dsl_dataset_disown(snap->ds, snaplist_tag); 2913 else 2914 dsl_dataset_rele(snap->ds, snaplist_tag); 2915 kmem_free(snap, sizeof (struct promotenode)); 2916 } 2917 list_destroy(l); 2918} 2919 2920/* 2921 * Promote a clone. Nomenclature note: 2922 * "clone" or "cds": the original clone which is being promoted 2923 * "origin" or "ods": the snapshot which is originally clone's origin 2924 * "origin head" or "ohds": the dataset which is the head 2925 * (filesystem/volume) for the origin 2926 * "origin origin": the origin of the origin's filesystem (typically 2927 * NULL, indicating that the clone is not a clone of a clone). 2928 */ 2929int 2930dsl_dataset_promote(const char *name, char *conflsnap) 2931{ 2932 dsl_dataset_t *ds; 2933 dsl_dir_t *dd; 2934 dsl_pool_t *dp; 2935 dmu_object_info_t doi; 2936 struct promotearg pa = { 0 }; 2937 struct promotenode *snap; 2938 int err; 2939 2940 err = dsl_dataset_hold(name, FTAG, &ds); 2941 if (err) 2942 return (err); 2943 dd = ds->ds_dir; 2944 dp = dd->dd_pool; 2945 2946 err = dmu_object_info(dp->dp_meta_objset, 2947 ds->ds_phys->ds_snapnames_zapobj, &doi); 2948 if (err) { 2949 dsl_dataset_rele(ds, FTAG); 2950 return (err); 2951 } 2952 2953 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) { 2954 dsl_dataset_rele(ds, FTAG); 2955 return (EINVAL); 2956 } 2957 2958 /* 2959 * We are going to inherit all the snapshots taken before our 2960 * origin (i.e., our new origin will be our parent's origin). 2961 * Take ownership of them so that we can rename them into our 2962 * namespace. 2963 */ 2964 rw_enter(&dp->dp_config_rwlock, RW_READER); 2965 2966 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj, 2967 &pa.shared_snaps); 2968 if (err != 0) 2969 goto out; 2970 2971 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps); 2972 if (err != 0) 2973 goto out; 2974 2975 snap = list_head(&pa.shared_snaps); 2976 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj); 2977 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj, 2978 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps); 2979 if (err != 0) 2980 goto out; 2981 2982 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) { 2983 err = dsl_dataset_hold_obj(dp, 2984 snap->ds->ds_dir->dd_phys->dd_origin_obj, 2985 FTAG, &pa.origin_origin); 2986 if (err != 0) 2987 goto out; 2988 } 2989 2990out: 2991 rw_exit(&dp->dp_config_rwlock); 2992 2993 /* 2994 * Add in 128x the snapnames zapobj size, since we will be moving 2995 * a bunch of snapnames to the promoted ds, and dirtying their 2996 * bonus buffers. 2997 */ 2998 if (err == 0) { 2999 err = dsl_sync_task_do(dp, dsl_dataset_promote_check, 3000 dsl_dataset_promote_sync, ds, &pa, 3001 2 + 2 * doi.doi_physical_blocks_512); 3002 if (err && pa.err_ds && conflsnap) 3003 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN); 3004 } 3005 3006 snaplist_destroy(&pa.shared_snaps, B_TRUE); 3007 snaplist_destroy(&pa.clone_snaps, B_FALSE); 3008 snaplist_destroy(&pa.origin_snaps, B_FALSE); 3009 if (pa.origin_origin) 3010 dsl_dataset_rele(pa.origin_origin, FTAG); 3011 dsl_dataset_rele(ds, FTAG); 3012 return (err); 3013} 3014 3015struct cloneswaparg { 3016 dsl_dataset_t *cds; /* clone dataset */ 3017 dsl_dataset_t *ohds; /* origin's head dataset */ 3018 boolean_t force; 3019 int64_t unused_refres_delta; /* change in unconsumed refreservation */ 3020}; 3021 3022/* ARGSUSED */ 3023static int 3024dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx) 3025{ 3026 struct cloneswaparg *csa = arg1; 3027 3028 /* they should both be heads */ 3029 if (dsl_dataset_is_snapshot(csa->cds) || 3030 dsl_dataset_is_snapshot(csa->ohds)) 3031 return (EINVAL); 3032 3033 /* the branch point should be just before them */ 3034 if (csa->cds->ds_prev != csa->ohds->ds_prev) 3035 return (EINVAL); 3036 3037 /* cds should be the clone (unless they are unrelated) */ 3038 if (csa->cds->ds_prev != NULL && 3039 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap && 3040 csa->ohds->ds_object != 3041 csa->cds->ds_prev->ds_phys->ds_next_snap_obj) 3042 return (EINVAL); 3043 3044 /* the clone should be a child of the origin */ 3045 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir) 3046 return (EINVAL); 3047 3048 /* ohds shouldn't be modified unless 'force' */ 3049 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds)) 3050 return (ETXTBSY); 3051 3052 /* adjust amount of any unconsumed refreservation */ 3053 csa->unused_refres_delta = 3054 (int64_t)MIN(csa->ohds->ds_reserved, 3055 csa->ohds->ds_phys->ds_unique_bytes) - 3056 (int64_t)MIN(csa->ohds->ds_reserved, 3057 csa->cds->ds_phys->ds_unique_bytes); 3058 3059 if (csa->unused_refres_delta > 0 && 3060 csa->unused_refres_delta > 3061 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE)) 3062 return (ENOSPC); 3063 3064 if (csa->ohds->ds_quota != 0 && 3065 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota) 3066 return (EDQUOT); 3067 3068 return (0); 3069} 3070 3071/* ARGSUSED */ 3072static void 3073dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3074{ 3075 struct cloneswaparg *csa = arg1; 3076 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool; 3077 3078 ASSERT(csa->cds->ds_reserved == 0); 3079 ASSERT(csa->ohds->ds_quota == 0 || 3080 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota); 3081 3082 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx); 3083 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx); 3084 3085 if (csa->cds->ds_objset != NULL) { 3086 dmu_objset_evict(csa->cds->ds_objset); 3087 csa->cds->ds_objset = NULL; 3088 } 3089 3090 if (csa->ohds->ds_objset != NULL) { 3091 dmu_objset_evict(csa->ohds->ds_objset); 3092 csa->ohds->ds_objset = NULL; 3093 } 3094 3095 /* 3096 * Reset origin's unique bytes, if it exists. 3097 */ 3098 if (csa->cds->ds_prev) { 3099 dsl_dataset_t *origin = csa->cds->ds_prev; 3100 uint64_t comp, uncomp; 3101 3102 dmu_buf_will_dirty(origin->ds_dbuf, tx); 3103 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3104 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX, 3105 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp); 3106 } 3107 3108 /* swap blkptrs */ 3109 { 3110 blkptr_t tmp; 3111 tmp = csa->ohds->ds_phys->ds_bp; 3112 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp; 3113 csa->cds->ds_phys->ds_bp = tmp; 3114 } 3115 3116 /* set dd_*_bytes */ 3117 { 3118 int64_t dused, dcomp, duncomp; 3119 uint64_t cdl_used, cdl_comp, cdl_uncomp; 3120 uint64_t odl_used, odl_comp, odl_uncomp; 3121 3122 ASSERT3U(csa->cds->ds_dir->dd_phys-> 3123 dd_used_breakdown[DD_USED_SNAP], ==, 0); 3124 3125 dsl_deadlist_space(&csa->cds->ds_deadlist, 3126 &cdl_used, &cdl_comp, &cdl_uncomp); 3127 dsl_deadlist_space(&csa->ohds->ds_deadlist, 3128 &odl_used, &odl_comp, &odl_uncomp); 3129 3130 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used - 3131 (csa->ohds->ds_phys->ds_used_bytes + odl_used); 3132 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp - 3133 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp); 3134 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes + 3135 cdl_uncomp - 3136 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp); 3137 3138 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD, 3139 dused, dcomp, duncomp, tx); 3140 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD, 3141 -dused, -dcomp, -duncomp, tx); 3142 3143 /* 3144 * The difference in the space used by snapshots is the 3145 * difference in snapshot space due to the head's 3146 * deadlist (since that's the only thing that's 3147 * changing that affects the snapused). 3148 */ 3149 dsl_deadlist_space_range(&csa->cds->ds_deadlist, 3150 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3151 &cdl_used, &cdl_comp, &cdl_uncomp); 3152 dsl_deadlist_space_range(&csa->ohds->ds_deadlist, 3153 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX, 3154 &odl_used, &odl_comp, &odl_uncomp); 3155 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used, 3156 DD_USED_HEAD, DD_USED_SNAP, tx); 3157 } 3158 3159 /* swap ds_*_bytes */ 3160 SWITCH64(csa->ohds->ds_phys->ds_used_bytes, 3161 csa->cds->ds_phys->ds_used_bytes); 3162 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes, 3163 csa->cds->ds_phys->ds_compressed_bytes); 3164 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes, 3165 csa->cds->ds_phys->ds_uncompressed_bytes); 3166 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes, 3167 csa->cds->ds_phys->ds_unique_bytes); 3168 3169 /* apply any parent delta for change in unconsumed refreservation */ 3170 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV, 3171 csa->unused_refres_delta, 0, 0, tx); 3172 3173 /* 3174 * Swap deadlists. 3175 */ 3176 dsl_deadlist_close(&csa->cds->ds_deadlist); 3177 dsl_deadlist_close(&csa->ohds->ds_deadlist); 3178 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj, 3179 csa->cds->ds_phys->ds_deadlist_obj); 3180 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset, 3181 csa->cds->ds_phys->ds_deadlist_obj); 3182 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset, 3183 csa->ohds->ds_phys->ds_deadlist_obj); 3184 3185 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx); 3186} 3187 3188/* 3189 * Swap 'clone' with its origin head datasets. Used at the end of "zfs 3190 * recv" into an existing fs to swizzle the file system to the new 3191 * version, and by "zfs rollback". Can also be used to swap two 3192 * independent head datasets if neither has any snapshots. 3193 */ 3194int 3195dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head, 3196 boolean_t force) 3197{ 3198 struct cloneswaparg csa; 3199 int error; 3200 3201 ASSERT(clone->ds_owner); 3202 ASSERT(origin_head->ds_owner); 3203retry: 3204 /* 3205 * Need exclusive access for the swap. If we're swapping these 3206 * datasets back after an error, we already hold the locks. 3207 */ 3208 if (!RW_WRITE_HELD(&clone->ds_rwlock)) 3209 rw_enter(&clone->ds_rwlock, RW_WRITER); 3210 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) && 3211 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) { 3212 rw_exit(&clone->ds_rwlock); 3213 rw_enter(&origin_head->ds_rwlock, RW_WRITER); 3214 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) { 3215 rw_exit(&origin_head->ds_rwlock); 3216 goto retry; 3217 } 3218 } 3219 csa.cds = clone; 3220 csa.ohds = origin_head; 3221 csa.force = force; 3222 error = dsl_sync_task_do(clone->ds_dir->dd_pool, 3223 dsl_dataset_clone_swap_check, 3224 dsl_dataset_clone_swap_sync, &csa, NULL, 9); 3225 return (error); 3226} 3227 3228/* 3229 * Given a pool name and a dataset object number in that pool, 3230 * return the name of that dataset. 3231 */ 3232int 3233dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf) 3234{ 3235 spa_t *spa; 3236 dsl_pool_t *dp; 3237 dsl_dataset_t *ds; 3238 int error; 3239 3240 if ((error = spa_open(pname, &spa, FTAG)) != 0) 3241 return (error); 3242 dp = spa_get_dsl(spa); 3243 rw_enter(&dp->dp_config_rwlock, RW_READER); 3244 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) { 3245 dsl_dataset_name(ds, buf); 3246 dsl_dataset_rele(ds, FTAG); 3247 } 3248 rw_exit(&dp->dp_config_rwlock); 3249 spa_close(spa, FTAG); 3250 3251 return (error); 3252} 3253 3254int 3255dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota, 3256 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv) 3257{ 3258 int error = 0; 3259 3260 ASSERT3S(asize, >, 0); 3261 3262 /* 3263 * *ref_rsrv is the portion of asize that will come from any 3264 * unconsumed refreservation space. 3265 */ 3266 *ref_rsrv = 0; 3267 3268 mutex_enter(&ds->ds_lock); 3269 /* 3270 * Make a space adjustment for reserved bytes. 3271 */ 3272 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) { 3273 ASSERT3U(*used, >=, 3274 ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3275 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes); 3276 *ref_rsrv = 3277 asize - MIN(asize, parent_delta(ds, asize + inflight)); 3278 } 3279 3280 if (!check_quota || ds->ds_quota == 0) { 3281 mutex_exit(&ds->ds_lock); 3282 return (0); 3283 } 3284 /* 3285 * If they are requesting more space, and our current estimate 3286 * is over quota, they get to try again unless the actual 3287 * on-disk is over quota and there are no pending changes (which 3288 * may free up space for us). 3289 */ 3290 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) { 3291 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota) 3292 error = ERESTART; 3293 else 3294 error = EDQUOT; 3295 } 3296 mutex_exit(&ds->ds_lock); 3297 3298 return (error); 3299} 3300 3301/* ARGSUSED */ 3302static int 3303dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx) 3304{ 3305 dsl_dataset_t *ds = arg1; 3306 dsl_prop_setarg_t *psa = arg2; 3307 int err; 3308 3309 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA) 3310 return (ENOTSUP); 3311 3312 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3313 return (err); 3314 3315 if (psa->psa_effective_value == 0) 3316 return (0); 3317 3318 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes || 3319 psa->psa_effective_value < ds->ds_reserved) 3320 return (ENOSPC); 3321 3322 return (0); 3323} 3324 3325extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *); 3326 3327void 3328dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3329{ 3330 dsl_dataset_t *ds = arg1; 3331 dsl_prop_setarg_t *psa = arg2; 3332 uint64_t effective_value = psa->psa_effective_value; 3333 3334 dsl_prop_set_sync(ds, psa, tx); 3335 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3336 3337 if (ds->ds_quota != effective_value) { 3338 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3339 ds->ds_quota = effective_value; 3340 3341 spa_history_log_internal(LOG_DS_REFQUOTA, 3342 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ", 3343 (longlong_t)ds->ds_quota, ds->ds_object); 3344 } 3345} 3346 3347int 3348dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota) 3349{ 3350 dsl_dataset_t *ds; 3351 dsl_prop_setarg_t psa; 3352 int err; 3353 3354 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a); 3355 3356 err = dsl_dataset_hold(dsname, FTAG, &ds); 3357 if (err) 3358 return (err); 3359 3360 /* 3361 * If someone removes a file, then tries to set the quota, we 3362 * want to make sure the file freeing takes effect. 3363 */ 3364 txg_wait_open(ds->ds_dir->dd_pool, 0); 3365 3366 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3367 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync, 3368 ds, &psa, 0); 3369 3370 dsl_dataset_rele(ds, FTAG); 3371 return (err); 3372} 3373 3374static int 3375dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx) 3376{ 3377 dsl_dataset_t *ds = arg1; 3378 dsl_prop_setarg_t *psa = arg2; 3379 uint64_t effective_value; 3380 uint64_t unique; 3381 int err; 3382 3383 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < 3384 SPA_VERSION_REFRESERVATION) 3385 return (ENOTSUP); 3386 3387 if (dsl_dataset_is_snapshot(ds)) 3388 return (EINVAL); 3389 3390 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0) 3391 return (err); 3392 3393 effective_value = psa->psa_effective_value; 3394 3395 /* 3396 * If we are doing the preliminary check in open context, the 3397 * space estimates may be inaccurate. 3398 */ 3399 if (!dmu_tx_is_syncing(tx)) 3400 return (0); 3401 3402 mutex_enter(&ds->ds_lock); 3403 if (!DS_UNIQUE_IS_ACCURATE(ds)) 3404 dsl_dataset_recalc_head_uniq(ds); 3405 unique = ds->ds_phys->ds_unique_bytes; 3406 mutex_exit(&ds->ds_lock); 3407 3408 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) { 3409 uint64_t delta = MAX(unique, effective_value) - 3410 MAX(unique, ds->ds_reserved); 3411 3412 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) 3413 return (ENOSPC); 3414 if (ds->ds_quota > 0 && 3415 effective_value > ds->ds_quota) 3416 return (ENOSPC); 3417 } 3418 3419 return (0); 3420} 3421 3422static void 3423dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3424{ 3425 dsl_dataset_t *ds = arg1; 3426 dsl_prop_setarg_t *psa = arg2; 3427 uint64_t effective_value = psa->psa_effective_value; 3428 uint64_t unique; 3429 int64_t delta; 3430 3431 dsl_prop_set_sync(ds, psa, tx); 3432 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa); 3433 3434 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3435 3436 mutex_enter(&ds->ds_dir->dd_lock); 3437 mutex_enter(&ds->ds_lock); 3438 ASSERT(DS_UNIQUE_IS_ACCURATE(ds)); 3439 unique = ds->ds_phys->ds_unique_bytes; 3440 delta = MAX(0, (int64_t)(effective_value - unique)) - 3441 MAX(0, (int64_t)(ds->ds_reserved - unique)); 3442 ds->ds_reserved = effective_value; 3443 mutex_exit(&ds->ds_lock); 3444 3445 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx); 3446 mutex_exit(&ds->ds_dir->dd_lock); 3447 3448 spa_history_log_internal(LOG_DS_REFRESERV, 3449 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu", 3450 (longlong_t)effective_value, ds->ds_object); 3451} 3452 3453int 3454dsl_dataset_set_reservation(const char *dsname, zprop_source_t source, 3455 uint64_t reservation) 3456{ 3457 dsl_dataset_t *ds; 3458 dsl_prop_setarg_t psa; 3459 int err; 3460 3461 dsl_prop_setarg_init_uint64(&psa, "refreservation", source, 3462 &reservation); 3463 3464 err = dsl_dataset_hold(dsname, FTAG, &ds); 3465 if (err) 3466 return (err); 3467 3468 err = dsl_sync_task_do(ds->ds_dir->dd_pool, 3469 dsl_dataset_set_reservation_check, 3470 dsl_dataset_set_reservation_sync, ds, &psa, 0); 3471 3472 dsl_dataset_rele(ds, FTAG); 3473 return (err); 3474} 3475 3476typedef struct zfs_hold_cleanup_arg { 3477 dsl_pool_t *dp; 3478 uint64_t dsobj; 3479 char htag[MAXNAMELEN]; 3480} zfs_hold_cleanup_arg_t; 3481 3482static void 3483dsl_dataset_user_release_onexit(void *arg) 3484{ 3485 zfs_hold_cleanup_arg_t *ca = arg; 3486 3487 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag, 3488 B_TRUE); 3489 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t)); 3490} 3491 3492void 3493dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag, 3494 minor_t minor) 3495{ 3496 zfs_hold_cleanup_arg_t *ca; 3497 3498 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP); 3499 ca->dp = ds->ds_dir->dd_pool; 3500 ca->dsobj = ds->ds_object; 3501 (void) strlcpy(ca->htag, htag, sizeof (ca->htag)); 3502 VERIFY3U(0, ==, zfs_onexit_add_cb(minor, 3503 dsl_dataset_user_release_onexit, ca, NULL)); 3504} 3505 3506/* 3507 * If you add new checks here, you may need to add 3508 * additional checks to the "temporary" case in 3509 * snapshot_check() in dmu_objset.c. 3510 */ 3511static int 3512dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx) 3513{ 3514 dsl_dataset_t *ds = arg1; 3515 struct dsl_ds_holdarg *ha = arg2; 3516 char *htag = ha->htag; 3517 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3518 int error = 0; 3519 3520 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3521 return (ENOTSUP); 3522 3523 if (!dsl_dataset_is_snapshot(ds)) 3524 return (EINVAL); 3525 3526 /* tags must be unique */ 3527 mutex_enter(&ds->ds_lock); 3528 if (ds->ds_phys->ds_userrefs_obj) { 3529 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag, 3530 8, 1, tx); 3531 if (error == 0) 3532 error = EEXIST; 3533 else if (error == ENOENT) 3534 error = 0; 3535 } 3536 mutex_exit(&ds->ds_lock); 3537 3538 if (error == 0 && ha->temphold && 3539 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) 3540 error = E2BIG; 3541 3542 return (error); 3543} 3544 3545void 3546dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx) 3547{ 3548 dsl_dataset_t *ds = arg1; 3549 struct dsl_ds_holdarg *ha = arg2; 3550 char *htag = ha->htag; 3551 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3552 objset_t *mos = dp->dp_meta_objset; 3553 uint64_t now = gethrestime_sec(); 3554 uint64_t zapobj; 3555 3556 mutex_enter(&ds->ds_lock); 3557 if (ds->ds_phys->ds_userrefs_obj == 0) { 3558 /* 3559 * This is the first user hold for this dataset. Create 3560 * the userrefs zap object. 3561 */ 3562 dmu_buf_will_dirty(ds->ds_dbuf, tx); 3563 zapobj = ds->ds_phys->ds_userrefs_obj = 3564 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); 3565 } else { 3566 zapobj = ds->ds_phys->ds_userrefs_obj; 3567 } 3568 ds->ds_userrefs++; 3569 mutex_exit(&ds->ds_lock); 3570 3571 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx)); 3572 3573 if (ha->temphold) { 3574 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object, 3575 htag, &now, tx)); 3576 } 3577 3578 spa_history_log_internal(LOG_DS_USER_HOLD, 3579 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag, 3580 (int)ha->temphold, ds->ds_object); 3581} 3582 3583static int 3584dsl_dataset_user_hold_one(const char *dsname, void *arg) 3585{ 3586 struct dsl_ds_holdarg *ha = arg; 3587 dsl_dataset_t *ds; 3588 int error; 3589 char *name; 3590 3591 /* alloc a buffer to hold dsname@snapname plus terminating NULL */ 3592 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3593 error = dsl_dataset_hold(name, ha->dstg, &ds); 3594 strfree(name); 3595 if (error == 0) { 3596 ha->gotone = B_TRUE; 3597 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check, 3598 dsl_dataset_user_hold_sync, ds, ha, 0); 3599 } else if (error == ENOENT && ha->recursive) { 3600 error = 0; 3601 } else { 3602 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3603 } 3604 return (error); 3605} 3606 3607int 3608dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag, 3609 boolean_t temphold) 3610{ 3611 struct dsl_ds_holdarg *ha; 3612 int error; 3613 3614 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3615 ha->htag = htag; 3616 ha->temphold = temphold; 3617 error = dsl_sync_task_do(ds->ds_dir->dd_pool, 3618 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync, 3619 ds, ha, 0); 3620 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3621 3622 return (error); 3623} 3624 3625int 3626dsl_dataset_user_hold(char *dsname, char *snapname, char *htag, 3627 boolean_t recursive, boolean_t temphold, int cleanup_fd) 3628{ 3629 struct dsl_ds_holdarg *ha; 3630 dsl_sync_task_t *dst; 3631 spa_t *spa; 3632 int error; 3633 minor_t minor = 0; 3634 3635 if (cleanup_fd != -1) { 3636 /* Currently we only support cleanup-on-exit of tempholds. */ 3637 if (!temphold) 3638 return (EINVAL); 3639 error = zfs_onexit_fd_hold(cleanup_fd, &minor); 3640 if (error) 3641 return (error); 3642 } 3643 3644 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3645 3646 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3647 3648 error = spa_open(dsname, &spa, FTAG); 3649 if (error) { 3650 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3651 if (cleanup_fd != -1) 3652 zfs_onexit_fd_rele(cleanup_fd); 3653 return (error); 3654 } 3655 3656 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3657 ha->htag = htag; 3658 ha->snapname = snapname; 3659 ha->recursive = recursive; 3660 ha->temphold = temphold; 3661 3662 if (recursive) { 3663 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one, 3664 ha, DS_FIND_CHILDREN); 3665 } else { 3666 error = dsl_dataset_user_hold_one(dsname, ha); 3667 } 3668 if (error == 0) 3669 error = dsl_sync_task_group_wait(ha->dstg); 3670 3671 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3672 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3673 dsl_dataset_t *ds = dst->dst_arg1; 3674 3675 if (dst->dst_err) { 3676 dsl_dataset_name(ds, ha->failed); 3677 *strchr(ha->failed, '@') = '\0'; 3678 } else if (error == 0 && minor != 0 && temphold) { 3679 /* 3680 * If this hold is to be released upon process exit, 3681 * register that action now. 3682 */ 3683 dsl_register_onexit_hold_cleanup(ds, htag, minor); 3684 } 3685 dsl_dataset_rele(ds, ha->dstg); 3686 } 3687 3688 if (error == 0 && recursive && !ha->gotone) 3689 error = ENOENT; 3690 3691 if (error) 3692 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3693 3694 dsl_sync_task_group_destroy(ha->dstg); 3695 3696 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3697 spa_close(spa, FTAG); 3698 if (cleanup_fd != -1) 3699 zfs_onexit_fd_rele(cleanup_fd); 3700 return (error); 3701} 3702 3703struct dsl_ds_releasearg { 3704 dsl_dataset_t *ds; 3705 const char *htag; 3706 boolean_t own; /* do we own or just hold ds? */ 3707}; 3708 3709static int 3710dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag, 3711 boolean_t *might_destroy) 3712{ 3713 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset; 3714 uint64_t zapobj; 3715 uint64_t tmp; 3716 int error; 3717 3718 *might_destroy = B_FALSE; 3719 3720 mutex_enter(&ds->ds_lock); 3721 zapobj = ds->ds_phys->ds_userrefs_obj; 3722 if (zapobj == 0) { 3723 /* The tag can't possibly exist */ 3724 mutex_exit(&ds->ds_lock); 3725 return (ESRCH); 3726 } 3727 3728 /* Make sure the tag exists */ 3729 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp); 3730 if (error) { 3731 mutex_exit(&ds->ds_lock); 3732 if (error == ENOENT) 3733 error = ESRCH; 3734 return (error); 3735 } 3736 3737 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 && 3738 DS_IS_DEFER_DESTROY(ds)) 3739 *might_destroy = B_TRUE; 3740 3741 mutex_exit(&ds->ds_lock); 3742 return (0); 3743} 3744 3745static int 3746dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx) 3747{ 3748 struct dsl_ds_releasearg *ra = arg1; 3749 dsl_dataset_t *ds = ra->ds; 3750 boolean_t might_destroy; 3751 int error; 3752 3753 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS) 3754 return (ENOTSUP); 3755 3756 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy); 3757 if (error) 3758 return (error); 3759 3760 if (might_destroy) { 3761 struct dsl_ds_destroyarg dsda = {0}; 3762 3763 if (dmu_tx_is_syncing(tx)) { 3764 /* 3765 * If we're not prepared to remove the snapshot, 3766 * we can't allow the release to happen right now. 3767 */ 3768 if (!ra->own) 3769 return (EBUSY); 3770 } 3771 dsda.ds = ds; 3772 dsda.releasing = B_TRUE; 3773 return (dsl_dataset_destroy_check(&dsda, tag, tx)); 3774 } 3775 3776 return (0); 3777} 3778 3779static void 3780dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx) 3781{ 3782 struct dsl_ds_releasearg *ra = arg1; 3783 dsl_dataset_t *ds = ra->ds; 3784 dsl_pool_t *dp = ds->ds_dir->dd_pool; 3785 objset_t *mos = dp->dp_meta_objset; 3786 uint64_t zapobj; 3787 uint64_t dsobj = ds->ds_object; 3788 uint64_t refs; 3789 int error; 3790 3791 mutex_enter(&ds->ds_lock); 3792 ds->ds_userrefs--; 3793 refs = ds->ds_userrefs; 3794 mutex_exit(&ds->ds_lock); 3795 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx); 3796 VERIFY(error == 0 || error == ENOENT); 3797 zapobj = ds->ds_phys->ds_userrefs_obj; 3798 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx)); 3799 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 && 3800 DS_IS_DEFER_DESTROY(ds)) { 3801 struct dsl_ds_destroyarg dsda = {0}; 3802 3803 ASSERT(ra->own); 3804 dsda.ds = ds; 3805 dsda.releasing = B_TRUE; 3806 /* We already did the destroy_check */ 3807 dsl_dataset_destroy_sync(&dsda, tag, tx); 3808 } 3809 3810 spa_history_log_internal(LOG_DS_USER_RELEASE, 3811 dp->dp_spa, tx, "<%s> %lld dataset = %llu", 3812 ra->htag, (longlong_t)refs, dsobj); 3813} 3814 3815static int 3816dsl_dataset_user_release_one(const char *dsname, void *arg) 3817{ 3818 struct dsl_ds_holdarg *ha = arg; 3819 struct dsl_ds_releasearg *ra; 3820 dsl_dataset_t *ds; 3821 int error; 3822 void *dtag = ha->dstg; 3823 char *name; 3824 boolean_t own = B_FALSE; 3825 boolean_t might_destroy; 3826 3827 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */ 3828 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3829 error = dsl_dataset_hold(name, dtag, &ds); 3830 strfree(name); 3831 if (error == ENOENT && ha->recursive) 3832 return (0); 3833 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3834 if (error) 3835 return (error); 3836 3837 ha->gotone = B_TRUE; 3838 3839 ASSERT(dsl_dataset_is_snapshot(ds)); 3840 3841 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy); 3842 if (error) { 3843 dsl_dataset_rele(ds, dtag); 3844 return (error); 3845 } 3846 3847 if (might_destroy) { 3848#ifdef _KERNEL 3849 name = kmem_asprintf("%s@%s", dsname, ha->snapname); 3850 error = zfs_unmount_snap(name, NULL); 3851 strfree(name); 3852 if (error) { 3853 dsl_dataset_rele(ds, dtag); 3854 return (error); 3855 } 3856#endif 3857 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) { 3858 dsl_dataset_rele(ds, dtag); 3859 return (EBUSY); 3860 } else { 3861 own = B_TRUE; 3862 dsl_dataset_make_exclusive(ds, dtag); 3863 } 3864 } 3865 3866 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP); 3867 ra->ds = ds; 3868 ra->htag = ha->htag; 3869 ra->own = own; 3870 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check, 3871 dsl_dataset_user_release_sync, ra, dtag, 0); 3872 3873 return (0); 3874} 3875 3876int 3877dsl_dataset_user_release(char *dsname, char *snapname, char *htag, 3878 boolean_t recursive) 3879{ 3880 struct dsl_ds_holdarg *ha; 3881 dsl_sync_task_t *dst; 3882 spa_t *spa; 3883 int error; 3884 3885top: 3886 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP); 3887 3888 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed)); 3889 3890 error = spa_open(dsname, &spa, FTAG); 3891 if (error) { 3892 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3893 return (error); 3894 } 3895 3896 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa)); 3897 ha->htag = htag; 3898 ha->snapname = snapname; 3899 ha->recursive = recursive; 3900 if (recursive) { 3901 error = dmu_objset_find(dsname, dsl_dataset_user_release_one, 3902 ha, DS_FIND_CHILDREN); 3903 } else { 3904 error = dsl_dataset_user_release_one(dsname, ha); 3905 } 3906 if (error == 0) 3907 error = dsl_sync_task_group_wait(ha->dstg); 3908 3909 for (dst = list_head(&ha->dstg->dstg_tasks); dst; 3910 dst = list_next(&ha->dstg->dstg_tasks, dst)) { 3911 struct dsl_ds_releasearg *ra = dst->dst_arg1; 3912 dsl_dataset_t *ds = ra->ds; 3913 3914 if (dst->dst_err) 3915 dsl_dataset_name(ds, ha->failed); 3916 3917 if (ra->own) 3918 dsl_dataset_disown(ds, ha->dstg); 3919 else 3920 dsl_dataset_rele(ds, ha->dstg); 3921 3922 kmem_free(ra, sizeof (struct dsl_ds_releasearg)); 3923 } 3924 3925 if (error == 0 && recursive && !ha->gotone) 3926 error = ENOENT; 3927 3928 if (error && error != EBUSY) 3929 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed)); 3930 3931 dsl_sync_task_group_destroy(ha->dstg); 3932 kmem_free(ha, sizeof (struct dsl_ds_holdarg)); 3933 spa_close(spa, FTAG); 3934 3935 /* 3936 * We can get EBUSY if we were racing with deferred destroy and 3937 * dsl_dataset_user_release_check() hadn't done the necessary 3938 * open context setup. We can also get EBUSY if we're racing 3939 * with destroy and that thread is the ds_owner. Either way 3940 * the busy condition should be transient, and we should retry 3941 * the release operation. 3942 */ 3943 if (error == EBUSY) 3944 goto top; 3945 3946 return (error); 3947} 3948 3949/* 3950 * Called at spa_load time (with retry == B_FALSE) to release a stale 3951 * temporary user hold. Also called by the onexit code (with retry == B_TRUE). 3952 */ 3953int 3954dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag, 3955 boolean_t retry) 3956{ 3957 dsl_dataset_t *ds; 3958 char *snap; 3959 char *name; 3960 int namelen; 3961 int error; 3962 3963 do { 3964 rw_enter(&dp->dp_config_rwlock, RW_READER); 3965 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 3966 rw_exit(&dp->dp_config_rwlock); 3967 if (error) 3968 return (error); 3969 namelen = dsl_dataset_namelen(ds)+1; 3970 name = kmem_alloc(namelen, KM_SLEEP); 3971 dsl_dataset_name(ds, name); 3972 dsl_dataset_rele(ds, FTAG); 3973 3974 snap = strchr(name, '@'); 3975 *snap = '\0'; 3976 ++snap; 3977 error = dsl_dataset_user_release(name, snap, htag, B_FALSE); 3978 kmem_free(name, namelen); 3979 3980 /* 3981 * The object can't have been destroyed because we have a hold, 3982 * but it might have been renamed, resulting in ENOENT. Retry 3983 * if we've been requested to do so. 3984 * 3985 * It would be nice if we could use the dsobj all the way 3986 * through and avoid ENOENT entirely. But we might need to 3987 * unmount the snapshot, and there's currently no way to lookup 3988 * a vfsp using a ZFS object id. 3989 */ 3990 } while ((error == ENOENT) && retry); 3991 3992 return (error); 3993} 3994 3995int 3996dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp) 3997{ 3998 dsl_dataset_t *ds; 3999 int err; 4000 4001 err = dsl_dataset_hold(dsname, FTAG, &ds); 4002 if (err) 4003 return (err); 4004 4005 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP)); 4006 if (ds->ds_phys->ds_userrefs_obj != 0) { 4007 zap_attribute_t *za; 4008 zap_cursor_t zc; 4009 4010 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 4011 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, 4012 ds->ds_phys->ds_userrefs_obj); 4013 zap_cursor_retrieve(&zc, za) == 0; 4014 zap_cursor_advance(&zc)) { 4015 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name, 4016 za->za_first_integer)); 4017 } 4018 zap_cursor_fini(&zc); 4019 kmem_free(za, sizeof (zap_attribute_t)); 4020 } 4021 dsl_dataset_rele(ds, FTAG); 4022 return (0); 4023} 4024 4025/* 4026 * Note, this fuction is used as the callback for dmu_objset_find(). We 4027 * always return 0 so that we will continue to find and process 4028 * inconsistent datasets, even if we encounter an error trying to 4029 * process one of them. 4030 */ 4031/* ARGSUSED */ 4032int 4033dsl_destroy_inconsistent(const char *dsname, void *arg) 4034{ 4035 dsl_dataset_t *ds; 4036 4037 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) { 4038 if (DS_IS_INCONSISTENT(ds)) 4039 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE); 4040 else 4041 dsl_dataset_disown(ds, FTAG); 4042 } 4043 return (0); 4044} 4045