1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/dsl_pool.h> 27 #include <sys/dsl_dataset.h> 28 #include <sys/dsl_dir.h> 29 #include <sys/dsl_synctask.h> 30 #include <sys/dmu_tx.h> 31 #include <sys/dmu_objset.h> 32 #include <sys/arc.h> 33 #include <sys/zap.h> 34 #include <sys/zio.h> 35 #include <sys/zfs_context.h> 36 #include <sys/fs/zfs.h> 37 #include <sys/zfs_znode.h> 38 #include <sys/spa_impl.h> 39 40 int zfs_no_write_throttle = 0; 41 int zfs_write_limit_shift = 3; /* 1/8th of physical memory */ 42 int zfs_txg_synctime = 5; /* target secs to sync a txg */ 43 44 uint64_t zfs_write_limit_min = 32 << 20; /* min write limit is 32MB */ 45 uint64_t zfs_write_limit_max = 0; /* max data payload per txg */ 46 uint64_t zfs_write_limit_inflated = 0; 47 uint64_t zfs_write_limit_override = 0; 48 49 kmutex_t zfs_write_limit_lock; 50 51 static pgcnt_t old_physmem = 0; 52 53 static int 54 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp) 55 { 56 uint64_t obj; 57 int err; 58 59 err = zap_lookup(dp->dp_meta_objset, 60 dp->dp_root_dir->dd_phys->dd_child_dir_zapobj, 61 name, sizeof (obj), 1, &obj); 62 if (err) 63 return (err); 64 65 return (dsl_dir_open_obj(dp, obj, name, dp, ddp)); 66 } 67 68 static dsl_pool_t * 69 dsl_pool_open_impl(spa_t *spa, uint64_t txg) 70 { 71 dsl_pool_t *dp; 72 blkptr_t *bp = spa_get_rootblkptr(spa); 73 74 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP); 75 dp->dp_spa = spa; 76 dp->dp_meta_rootbp = *bp; 77 rw_init(&dp->dp_config_rwlock, NULL, RW_DEFAULT, NULL); 78 dp->dp_write_limit = zfs_write_limit_min; 79 txg_init(dp, txg); 80 81 txg_list_create(&dp->dp_dirty_datasets, 82 offsetof(dsl_dataset_t, ds_dirty_link)); 83 txg_list_create(&dp->dp_dirty_dirs, 84 offsetof(dsl_dir_t, dd_dirty_link)); 85 txg_list_create(&dp->dp_sync_tasks, 86 offsetof(dsl_sync_task_group_t, dstg_node)); 87 list_create(&dp->dp_synced_datasets, sizeof (dsl_dataset_t), 88 offsetof(dsl_dataset_t, ds_synced_link)); 89 90 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL); 91 mutex_init(&dp->dp_scrub_cancel_lock, NULL, MUTEX_DEFAULT, NULL); 92 93 dp->dp_vnrele_taskq = taskq_create("zfs_vn_rele_taskq", 1, minclsyspri, 94 1, 4, 0); 95 96 return (dp); 97 } 98 99 int 100 dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp) 101 { 102 int err; 103 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg); 104 dsl_dir_t *dd; 105 dsl_dataset_t *ds; 106 107 rw_enter(&dp->dp_config_rwlock, RW_WRITER); 108 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp, 109 &dp->dp_meta_objset); 110 if (err) 111 goto out; 112 113 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 114 DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1, 115 &dp->dp_root_dir_obj); 116 if (err) 117 goto out; 118 119 err = dsl_dir_open_obj(dp, dp->dp_root_dir_obj, 120 NULL, dp, &dp->dp_root_dir); 121 if (err) 122 goto out; 123 124 err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir); 125 if (err) 126 goto out; 127 128 if (spa_version(spa) >= SPA_VERSION_ORIGIN) { 129 err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd); 130 if (err) 131 goto out; 132 err = dsl_dataset_hold_obj(dp, dd->dd_phys->dd_head_dataset_obj, 133 FTAG, &ds); 134 if (err == 0) { 135 err = dsl_dataset_hold_obj(dp, 136 ds->ds_phys->ds_prev_snap_obj, dp, 137 &dp->dp_origin_snap); 138 dsl_dataset_rele(ds, FTAG); 139 } 140 dsl_dir_close(dd, dp); 141 if (err) 142 goto out; 143 } 144 145 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 146 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1, 147 &dp->dp_tmp_userrefs_obj); 148 if (err == ENOENT) 149 err = 0; 150 if (err) 151 goto out; 152 153 /* get scrub status */ 154 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 155 DMU_POOL_SCRUB_FUNC, sizeof (uint32_t), 1, 156 &dp->dp_scrub_func); 157 if (err == 0) { 158 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 159 DMU_POOL_SCRUB_QUEUE, sizeof (uint64_t), 1, 160 &dp->dp_scrub_queue_obj); 161 if (err) 162 goto out; 163 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 164 DMU_POOL_SCRUB_MIN_TXG, sizeof (uint64_t), 1, 165 &dp->dp_scrub_min_txg); 166 if (err) 167 goto out; 168 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 169 DMU_POOL_SCRUB_MAX_TXG, sizeof (uint64_t), 1, 170 &dp->dp_scrub_max_txg); 171 if (err) 172 goto out; 173 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 174 DMU_POOL_SCRUB_BOOKMARK, sizeof (uint64_t), 175 sizeof (dp->dp_scrub_bookmark) / sizeof (uint64_t), 176 &dp->dp_scrub_bookmark); 177 if (err) 178 goto out; 179 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 180 DMU_POOL_SCRUB_DDT_BOOKMARK, sizeof (uint64_t), 181 sizeof (dp->dp_scrub_ddt_bookmark) / sizeof (uint64_t), 182 &dp->dp_scrub_ddt_bookmark); 183 if (err && err != ENOENT) 184 goto out; 185 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 186 DMU_POOL_SCRUB_DDT_CLASS_MAX, sizeof (uint64_t), 1, 187 &dp->dp_scrub_ddt_class_max); 188 if (err && err != ENOENT) 189 goto out; 190 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 191 DMU_POOL_SCRUB_ERRORS, sizeof (uint64_t), 1, 192 &spa->spa_scrub_errors); 193 if (err) 194 goto out; 195 if (spa_version(spa) < SPA_VERSION_DSL_SCRUB) { 196 /* 197 * A new-type scrub was in progress on an old 198 * pool. Restart from the beginning, since the 199 * old software may have changed the pool in the 200 * meantime. 201 */ 202 dsl_pool_scrub_restart(dp); 203 } 204 } else { 205 /* 206 * It's OK if there is no scrub in progress (and if 207 * there was an I/O error, ignore it). 208 */ 209 err = 0; 210 } 211 212 out: 213 rw_exit(&dp->dp_config_rwlock); 214 if (err) 215 dsl_pool_close(dp); 216 else 217 *dpp = dp; 218 219 return (err); 220 } 221 222 void 223 dsl_pool_close(dsl_pool_t *dp) 224 { 225 /* drop our references from dsl_pool_open() */ 226 227 /* 228 * Since we held the origin_snap from "syncing" context (which 229 * includes pool-opening context), it actually only got a "ref" 230 * and not a hold, so just drop that here. 231 */ 232 if (dp->dp_origin_snap) 233 dsl_dataset_drop_ref(dp->dp_origin_snap, dp); 234 if (dp->dp_mos_dir) 235 dsl_dir_close(dp->dp_mos_dir, dp); 236 if (dp->dp_root_dir) 237 dsl_dir_close(dp->dp_root_dir, dp); 238 239 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */ 240 if (dp->dp_meta_objset) 241 dmu_objset_evict(dp->dp_meta_objset); 242 243 txg_list_destroy(&dp->dp_dirty_datasets); 244 txg_list_destroy(&dp->dp_dirty_dirs); 245 list_destroy(&dp->dp_synced_datasets); 246 247 arc_flush(dp->dp_spa); 248 txg_fini(dp); 249 rw_destroy(&dp->dp_config_rwlock); 250 mutex_destroy(&dp->dp_lock); 251 mutex_destroy(&dp->dp_scrub_cancel_lock); 252 taskq_destroy(dp->dp_vnrele_taskq); 253 if (dp->dp_blkstats) 254 kmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); 255 kmem_free(dp, sizeof (dsl_pool_t)); 256 } 257 258 dsl_pool_t * 259 dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg) 260 { 261 int err; 262 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg); 263 dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg); 264 objset_t *os; 265 dsl_dataset_t *ds; 266 uint64_t dsobj; 267 268 /* create and open the MOS (meta-objset) */ 269 dp->dp_meta_objset = dmu_objset_create_impl(spa, 270 NULL, &dp->dp_meta_rootbp, DMU_OST_META, tx); 271 272 /* create the pool directory */ 273 err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 274 DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx); 275 ASSERT3U(err, ==, 0); 276 277 /* create and open the root dir */ 278 dp->dp_root_dir_obj = dsl_dir_create_sync(dp, NULL, NULL, tx); 279 VERIFY(0 == dsl_dir_open_obj(dp, dp->dp_root_dir_obj, 280 NULL, dp, &dp->dp_root_dir)); 281 282 /* create and open the meta-objset dir */ 283 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, MOS_DIR_NAME, tx); 284 VERIFY(0 == dsl_pool_open_special_dir(dp, 285 MOS_DIR_NAME, &dp->dp_mos_dir)); 286 287 if (spa_version(spa) >= SPA_VERSION_DSL_SCRUB) 288 dsl_pool_create_origin(dp, tx); 289 290 /* create the root dataset */ 291 dsobj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx); 292 293 /* create the root objset */ 294 VERIFY(0 == dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 295 os = dmu_objset_create_impl(dp->dp_spa, ds, 296 dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx); 297 #ifdef _KERNEL 298 zfs_create_fs(os, kcred, zplprops, tx); 299 #endif 300 dsl_dataset_rele(ds, FTAG); 301 302 dmu_tx_commit(tx); 303 304 return (dp); 305 } 306 307 void 308 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg) 309 { 310 zio_t *zio; 311 dmu_tx_t *tx; 312 dsl_dir_t *dd; 313 dsl_dataset_t *ds; 314 dsl_sync_task_group_t *dstg; 315 objset_t *mos = dp->dp_meta_objset; 316 hrtime_t start, write_time; 317 uint64_t data_written; 318 int err; 319 320 tx = dmu_tx_create_assigned(dp, txg); 321 322 dp->dp_read_overhead = 0; 323 start = gethrtime(); 324 325 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 326 while (ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) { 327 /* 328 * We must not sync any non-MOS datasets twice, because 329 * we may have taken a snapshot of them. However, we 330 * may sync newly-created datasets on pass 2. 331 */ 332 ASSERT(!list_link_active(&ds->ds_synced_link)); 333 list_insert_tail(&dp->dp_synced_datasets, ds); 334 dsl_dataset_sync(ds, zio, tx); 335 } 336 DTRACE_PROBE(pool_sync__1setup); 337 err = zio_wait(zio); 338 339 write_time = gethrtime() - start; 340 ASSERT(err == 0); 341 DTRACE_PROBE(pool_sync__2rootzio); 342 343 for (ds = list_head(&dp->dp_synced_datasets); ds; 344 ds = list_next(&dp->dp_synced_datasets, ds)) 345 dmu_objset_do_userquota_callbacks(ds->ds_objset, tx); 346 347 /* 348 * Sync the datasets again to push out the changes due to 349 * userquota updates. This must be done before we process the 350 * sync tasks, because that could cause a snapshot of a dataset 351 * whose ds_bp will be rewritten when we do this 2nd sync. 352 */ 353 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 354 while (ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) { 355 ASSERT(list_link_active(&ds->ds_synced_link)); 356 dmu_buf_rele(ds->ds_dbuf, ds); 357 dsl_dataset_sync(ds, zio, tx); 358 } 359 err = zio_wait(zio); 360 361 /* 362 * If anything was added to a deadlist during a zio done callback, 363 * it had to be put on the deferred queue. Enqueue it for real now. 364 */ 365 for (ds = list_head(&dp->dp_synced_datasets); ds; 366 ds = list_next(&dp->dp_synced_datasets, ds)) 367 bplist_sync(&ds->ds_deadlist, 368 bplist_enqueue_cb, &ds->ds_deadlist, tx); 369 370 while (dstg = txg_list_remove(&dp->dp_sync_tasks, txg)) { 371 /* 372 * No more sync tasks should have been added while we 373 * were syncing. 374 */ 375 ASSERT(spa_sync_pass(dp->dp_spa) == 1); 376 dsl_sync_task_group_sync(dstg, tx); 377 } 378 DTRACE_PROBE(pool_sync__3task); 379 380 start = gethrtime(); 381 while (dd = txg_list_remove(&dp->dp_dirty_dirs, txg)) 382 dsl_dir_sync(dd, tx); 383 write_time += gethrtime() - start; 384 385 if (spa_sync_pass(dp->dp_spa) == 1) 386 dsl_pool_scrub_sync(dp, tx); 387 388 start = gethrtime(); 389 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL || 390 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) { 391 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 392 dmu_objset_sync(mos, zio, tx); 393 err = zio_wait(zio); 394 ASSERT(err == 0); 395 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", ""); 396 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); 397 } 398 write_time += gethrtime() - start; 399 DTRACE_PROBE2(pool_sync__4io, hrtime_t, write_time, 400 hrtime_t, dp->dp_read_overhead); 401 write_time -= dp->dp_read_overhead; 402 403 dmu_tx_commit(tx); 404 405 data_written = dp->dp_space_towrite[txg & TXG_MASK]; 406 dp->dp_space_towrite[txg & TXG_MASK] = 0; 407 ASSERT(dp->dp_tempreserved[txg & TXG_MASK] == 0); 408 409 /* 410 * If the write limit max has not been explicitly set, set it 411 * to a fraction of available physical memory (default 1/8th). 412 * Note that we must inflate the limit because the spa 413 * inflates write sizes to account for data replication. 414 * Check this each sync phase to catch changing memory size. 415 */ 416 if (physmem != old_physmem && zfs_write_limit_shift) { 417 mutex_enter(&zfs_write_limit_lock); 418 old_physmem = physmem; 419 zfs_write_limit_max = ptob(physmem) >> zfs_write_limit_shift; 420 zfs_write_limit_inflated = MAX(zfs_write_limit_min, 421 spa_get_asize(dp->dp_spa, zfs_write_limit_max)); 422 mutex_exit(&zfs_write_limit_lock); 423 } 424 425 /* 426 * Attempt to keep the sync time consistent by adjusting the 427 * amount of write traffic allowed into each transaction group. 428 * Weight the throughput calculation towards the current value: 429 * thru = 3/4 old_thru + 1/4 new_thru 430 */ 431 ASSERT(zfs_write_limit_min > 0); 432 if (data_written > zfs_write_limit_min / 8 && write_time > 0) { 433 uint64_t throughput = (data_written * NANOSEC) / write_time; 434 if (dp->dp_throughput) 435 dp->dp_throughput = throughput / 4 + 436 3 * dp->dp_throughput / 4; 437 else 438 dp->dp_throughput = throughput; 439 dp->dp_write_limit = MIN(zfs_write_limit_inflated, 440 MAX(zfs_write_limit_min, 441 dp->dp_throughput * zfs_txg_synctime)); 442 } 443 } 444 445 void 446 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg) 447 { 448 dsl_dataset_t *ds; 449 objset_t *os; 450 451 while (ds = list_head(&dp->dp_synced_datasets)) { 452 list_remove(&dp->dp_synced_datasets, ds); 453 os = ds->ds_objset; 454 zil_clean(os->os_zil); 455 ASSERT(!dmu_objset_is_dirty(os, txg)); 456 dmu_buf_rele(ds->ds_dbuf, ds); 457 } 458 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg)); 459 } 460 461 /* 462 * TRUE if the current thread is the tx_sync_thread or if we 463 * are being called from SPA context during pool initialization. 464 */ 465 int 466 dsl_pool_sync_context(dsl_pool_t *dp) 467 { 468 return (curthread == dp->dp_tx.tx_sync_thread || 469 spa_get_dsl(dp->dp_spa) == NULL); 470 } 471 472 uint64_t 473 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree) 474 { 475 uint64_t space, resv; 476 477 /* 478 * Reserve about 1.6% (1/64), or at least 32MB, for allocation 479 * efficiency. 480 * XXX The intent log is not accounted for, so it must fit 481 * within this slop. 482 * 483 * If we're trying to assess whether it's OK to do a free, 484 * cut the reservation in half to allow forward progress 485 * (e.g. make it possible to rm(1) files from a full pool). 486 */ 487 space = spa_get_dspace(dp->dp_spa); 488 resv = MAX(space >> 6, SPA_MINDEVSIZE >> 1); 489 if (netfree) 490 resv >>= 1; 491 492 return (space - resv); 493 } 494 495 int 496 dsl_pool_tempreserve_space(dsl_pool_t *dp, uint64_t space, dmu_tx_t *tx) 497 { 498 uint64_t reserved = 0; 499 uint64_t write_limit = (zfs_write_limit_override ? 500 zfs_write_limit_override : dp->dp_write_limit); 501 502 if (zfs_no_write_throttle) { 503 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], 504 space); 505 return (0); 506 } 507 508 /* 509 * Check to see if we have exceeded the maximum allowed IO for 510 * this transaction group. We can do this without locks since 511 * a little slop here is ok. Note that we do the reserved check 512 * with only half the requested reserve: this is because the 513 * reserve requests are worst-case, and we really don't want to 514 * throttle based off of worst-case estimates. 515 */ 516 if (write_limit > 0) { 517 reserved = dp->dp_space_towrite[tx->tx_txg & TXG_MASK] 518 + dp->dp_tempreserved[tx->tx_txg & TXG_MASK] / 2; 519 520 if (reserved && reserved > write_limit) 521 return (ERESTART); 522 } 523 524 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], space); 525 526 /* 527 * If this transaction group is over 7/8ths capacity, delay 528 * the caller 1 clock tick. This will slow down the "fill" 529 * rate until the sync process can catch up with us. 530 */ 531 if (reserved && reserved > (write_limit - (write_limit >> 3))) 532 txg_delay(dp, tx->tx_txg, 1); 533 534 return (0); 535 } 536 537 void 538 dsl_pool_tempreserve_clear(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx) 539 { 540 ASSERT(dp->dp_tempreserved[tx->tx_txg & TXG_MASK] >= space); 541 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], -space); 542 } 543 544 void 545 dsl_pool_memory_pressure(dsl_pool_t *dp) 546 { 547 uint64_t space_inuse = 0; 548 int i; 549 550 if (dp->dp_write_limit == zfs_write_limit_min) 551 return; 552 553 for (i = 0; i < TXG_SIZE; i++) { 554 space_inuse += dp->dp_space_towrite[i]; 555 space_inuse += dp->dp_tempreserved[i]; 556 } 557 dp->dp_write_limit = MAX(zfs_write_limit_min, 558 MIN(dp->dp_write_limit, space_inuse / 4)); 559 } 560 561 void 562 dsl_pool_willuse_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx) 563 { 564 if (space > 0) { 565 mutex_enter(&dp->dp_lock); 566 dp->dp_space_towrite[tx->tx_txg & TXG_MASK] += space; 567 mutex_exit(&dp->dp_lock); 568 } 569 } 570 571 /* ARGSUSED */ 572 static int 573 upgrade_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg) 574 { 575 dmu_tx_t *tx = arg; 576 dsl_dataset_t *ds, *prev = NULL; 577 int err; 578 dsl_pool_t *dp = spa_get_dsl(spa); 579 580 err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds); 581 if (err) 582 return (err); 583 584 while (ds->ds_phys->ds_prev_snap_obj != 0) { 585 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj, 586 FTAG, &prev); 587 if (err) { 588 dsl_dataset_rele(ds, FTAG); 589 return (err); 590 } 591 592 if (prev->ds_phys->ds_next_snap_obj != ds->ds_object) 593 break; 594 dsl_dataset_rele(ds, FTAG); 595 ds = prev; 596 prev = NULL; 597 } 598 599 if (prev == NULL) { 600 prev = dp->dp_origin_snap; 601 602 /* 603 * The $ORIGIN can't have any data, or the accounting 604 * will be wrong. 605 */ 606 ASSERT(prev->ds_phys->ds_bp.blk_birth == 0); 607 608 /* The origin doesn't get attached to itself */ 609 if (ds->ds_object == prev->ds_object) { 610 dsl_dataset_rele(ds, FTAG); 611 return (0); 612 } 613 614 dmu_buf_will_dirty(ds->ds_dbuf, tx); 615 ds->ds_phys->ds_prev_snap_obj = prev->ds_object; 616 ds->ds_phys->ds_prev_snap_txg = prev->ds_phys->ds_creation_txg; 617 618 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 619 ds->ds_dir->dd_phys->dd_origin_obj = prev->ds_object; 620 621 dmu_buf_will_dirty(prev->ds_dbuf, tx); 622 prev->ds_phys->ds_num_children++; 623 624 if (ds->ds_phys->ds_next_snap_obj == 0) { 625 ASSERT(ds->ds_prev == NULL); 626 VERIFY(0 == dsl_dataset_hold_obj(dp, 627 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev)); 628 } 629 } 630 631 ASSERT(ds->ds_dir->dd_phys->dd_origin_obj == prev->ds_object); 632 ASSERT(ds->ds_phys->ds_prev_snap_obj == prev->ds_object); 633 634 if (prev->ds_phys->ds_next_clones_obj == 0) { 635 dmu_buf_will_dirty(prev->ds_dbuf, tx); 636 prev->ds_phys->ds_next_clones_obj = 637 zap_create(dp->dp_meta_objset, 638 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 639 } 640 VERIFY(0 == zap_add_int(dp->dp_meta_objset, 641 prev->ds_phys->ds_next_clones_obj, ds->ds_object, tx)); 642 643 dsl_dataset_rele(ds, FTAG); 644 if (prev != dp->dp_origin_snap) 645 dsl_dataset_rele(prev, FTAG); 646 return (0); 647 } 648 649 void 650 dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx) 651 { 652 ASSERT(dmu_tx_is_syncing(tx)); 653 ASSERT(dp->dp_origin_snap != NULL); 654 655 VERIFY3U(0, ==, dmu_objset_find_spa(dp->dp_spa, NULL, upgrade_clones_cb, 656 tx, DS_FIND_CHILDREN)); 657 } 658 659 void 660 dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx) 661 { 662 uint64_t dsobj; 663 dsl_dataset_t *ds; 664 665 ASSERT(dmu_tx_is_syncing(tx)); 666 ASSERT(dp->dp_origin_snap == NULL); 667 668 /* create the origin dir, ds, & snap-ds */ 669 rw_enter(&dp->dp_config_rwlock, RW_WRITER); 670 dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME, 671 NULL, 0, kcred, tx); 672 VERIFY(0 == dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 673 dsl_dataset_snapshot_sync(ds, ORIGIN_DIR_NAME, kcred, tx); 674 VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj, 675 dp, &dp->dp_origin_snap)); 676 dsl_dataset_rele(ds, FTAG); 677 rw_exit(&dp->dp_config_rwlock); 678 } 679 680 taskq_t * 681 dsl_pool_vnrele_taskq(dsl_pool_t *dp) 682 { 683 return (dp->dp_vnrele_taskq); 684 } 685 686 /* 687 * Walk through the pool-wide zap object of temporary snapshot user holds 688 * and release them. 689 */ 690 void 691 dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp) 692 { 693 zap_attribute_t za; 694 zap_cursor_t zc; 695 objset_t *mos = dp->dp_meta_objset; 696 uint64_t zapobj = dp->dp_tmp_userrefs_obj; 697 698 if (zapobj == 0) 699 return; 700 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 701 702 for (zap_cursor_init(&zc, mos, zapobj); 703 zap_cursor_retrieve(&zc, &za) == 0; 704 zap_cursor_advance(&zc)) { 705 char *htag; 706 uint64_t dsobj; 707 708 htag = strchr(za.za_name, '-'); 709 *htag = '\0'; 710 ++htag; 711 dsobj = strtonum(za.za_name, NULL); 712 (void) dsl_dataset_user_release_tmp(dp, dsobj, htag); 713 } 714 zap_cursor_fini(&zc); 715 } 716 717 /* 718 * Create the pool-wide zap object for storing temporary snapshot holds. 719 */ 720 void 721 dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx) 722 { 723 objset_t *mos = dp->dp_meta_objset; 724 725 ASSERT(dp->dp_tmp_userrefs_obj == 0); 726 ASSERT(dmu_tx_is_syncing(tx)); 727 728 dp->dp_tmp_userrefs_obj = zap_create(mos, DMU_OT_USERREFS, 729 DMU_OT_NONE, 0, tx); 730 731 VERIFY(zap_add(mos, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, 732 sizeof (uint64_t), 1, &dp->dp_tmp_userrefs_obj, tx) == 0); 733 } 734 735 static int 736 dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj, 737 const char *tag, uint64_t *now, dmu_tx_t *tx, boolean_t holding) 738 { 739 objset_t *mos = dp->dp_meta_objset; 740 uint64_t zapobj = dp->dp_tmp_userrefs_obj; 741 char *name; 742 int error; 743 744 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 745 ASSERT(dmu_tx_is_syncing(tx)); 746 747 /* 748 * If the pool was created prior to SPA_VERSION_USERREFS, the 749 * zap object for temporary holds might not exist yet. 750 */ 751 if (zapobj == 0) { 752 if (holding) { 753 dsl_pool_user_hold_create_obj(dp, tx); 754 zapobj = dp->dp_tmp_userrefs_obj; 755 } else { 756 return (ENOENT); 757 } 758 } 759 760 name = kmem_asprintf("%llx-%s", (u_longlong_t)dsobj, tag); 761 if (holding) 762 error = zap_add(mos, zapobj, name, 8, 1, now, tx); 763 else 764 error = zap_remove(mos, zapobj, name, tx); 765 strfree(name); 766 767 return (error); 768 } 769 770 /* 771 * Add a temporary hold for the given dataset object and tag. 772 */ 773 int 774 dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag, 775 uint64_t *now, dmu_tx_t *tx) 776 { 777 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE)); 778 } 779 780 /* 781 * Release a temporary hold for the given dataset object and tag. 782 */ 783 int 784 dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj, const char *tag, 785 dmu_tx_t *tx) 786 { 787 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, NULL, 788 tx, B_FALSE)); 789 } 790