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, 2016 by Delphix. All rights reserved. 24 * Copyright (c) 2013 Steven Hartland. All rights reserved. 25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 26 * Copyright (c) 2014 Integros [integros.com] 27 * Copyright 2016 Nexenta Systems, Inc. All rights reserved. 28 */ 29 30 #include <sys/dsl_pool.h> 31 #include <sys/dsl_dataset.h> 32 #include <sys/dsl_prop.h> 33 #include <sys/dsl_dir.h> 34 #include <sys/dsl_synctask.h> 35 #include <sys/dsl_scan.h> 36 #include <sys/dnode.h> 37 #include <sys/dmu_tx.h> 38 #include <sys/dmu_objset.h> 39 #include <sys/arc.h> 40 #include <sys/zap.h> 41 #include <sys/zio.h> 42 #include <sys/zfs_context.h> 43 #include <sys/fs/zfs.h> 44 #include <sys/zfs_znode.h> 45 #include <sys/spa_impl.h> 46 #include <sys/dsl_deadlist.h> 47 #include <sys/bptree.h> 48 #include <sys/zfeature.h> 49 #include <sys/zil_impl.h> 50 #include <sys/dsl_userhold.h> 51 52 #if defined(__FreeBSD__) && defined(_KERNEL) 53 #include <sys/types.h> 54 #include <sys/sysctl.h> 55 #endif 56 57 /* 58 * ZFS Write Throttle 59 * ------------------ 60 * 61 * ZFS must limit the rate of incoming writes to the rate at which it is able 62 * to sync data modifications to the backend storage. Throttling by too much 63 * creates an artificial limit; throttling by too little can only be sustained 64 * for short periods and would lead to highly lumpy performance. On a per-pool 65 * basis, ZFS tracks the amount of modified (dirty) data. As operations change 66 * data, the amount of dirty data increases; as ZFS syncs out data, the amount 67 * of dirty data decreases. When the amount of dirty data exceeds a 68 * predetermined threshold further modifications are blocked until the amount 69 * of dirty data decreases (as data is synced out). 70 * 71 * The limit on dirty data is tunable, and should be adjusted according to 72 * both the IO capacity and available memory of the system. The larger the 73 * window, the more ZFS is able to aggregate and amortize metadata (and data) 74 * changes. However, memory is a limited resource, and allowing for more dirty 75 * data comes at the cost of keeping other useful data in memory (for example 76 * ZFS data cached by the ARC). 77 * 78 * Implementation 79 * 80 * As buffers are modified dsl_pool_willuse_space() increments both the per- 81 * txg (dp_dirty_pertxg[]) and poolwide (dp_dirty_total) accounting of 82 * dirty space used; dsl_pool_dirty_space() decrements those values as data 83 * is synced out from dsl_pool_sync(). While only the poolwide value is 84 * relevant, the per-txg value is useful for debugging. The tunable 85 * zfs_dirty_data_max determines the dirty space limit. Once that value is 86 * exceeded, new writes are halted until space frees up. 87 * 88 * The zfs_dirty_data_sync tunable dictates the threshold at which we 89 * ensure that there is a txg syncing (see the comment in txg.c for a full 90 * description of transaction group stages). 91 * 92 * The IO scheduler uses both the dirty space limit and current amount of 93 * dirty data as inputs. Those values affect the number of concurrent IOs ZFS 94 * issues. See the comment in vdev_queue.c for details of the IO scheduler. 95 * 96 * The delay is also calculated based on the amount of dirty data. See the 97 * comment above dmu_tx_delay() for details. 98 */ 99 100 /* 101 * zfs_dirty_data_max will be set to zfs_dirty_data_max_percent% of all memory, 102 * capped at zfs_dirty_data_max_max. It can also be overridden in /etc/system. 103 */ 104 uint64_t zfs_dirty_data_max; 105 uint64_t zfs_dirty_data_max_max = 4ULL * 1024 * 1024 * 1024; 106 int zfs_dirty_data_max_percent = 10; 107 108 /* 109 * If there is at least this much dirty data, push out a txg. 110 */ 111 uint64_t zfs_dirty_data_sync = 64 * 1024 * 1024; 112 113 /* 114 * Once there is this amount of dirty data, the dmu_tx_delay() will kick in 115 * and delay each transaction. 116 * This value should be >= zfs_vdev_async_write_active_max_dirty_percent. 117 */ 118 int zfs_delay_min_dirty_percent = 60; 119 120 /* 121 * This controls how quickly the delay approaches infinity. 122 * Larger values cause it to delay more for a given amount of dirty data. 123 * Therefore larger values will cause there to be less dirty data for a 124 * given throughput. 125 * 126 * For the smoothest delay, this value should be about 1 billion divided 127 * by the maximum number of operations per second. This will smoothly 128 * handle between 10x and 1/10th this number. 129 * 130 * Note: zfs_delay_scale * zfs_dirty_data_max must be < 2^64, due to the 131 * multiply in dmu_tx_delay(). 132 */ 133 uint64_t zfs_delay_scale = 1000 * 1000 * 1000 / 2000; 134 135 136 #if defined(__FreeBSD__) && defined(_KERNEL) 137 138 extern int zfs_vdev_async_write_active_max_dirty_percent; 139 140 SYSCTL_DECL(_vfs_zfs); 141 142 SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, dirty_data_max, CTLFLAG_RWTUN, 143 &zfs_dirty_data_max, 0, 144 "The maximum amount of dirty data in bytes after which new writes are " 145 "halted until space becomes available"); 146 147 SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, dirty_data_max_max, CTLFLAG_RDTUN, 148 &zfs_dirty_data_max_max, 0, 149 "The absolute cap on dirty_data_max when auto calculating"); 150 151 static int sysctl_zfs_dirty_data_max_percent(SYSCTL_HANDLER_ARGS); 152 SYSCTL_PROC(_vfs_zfs, OID_AUTO, dirty_data_max_percent, 153 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RWTUN, 0, sizeof(int), 154 sysctl_zfs_dirty_data_max_percent, "I", 155 "The percent of physical memory used to auto calculate dirty_data_max"); 156 157 SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, dirty_data_sync, CTLFLAG_RWTUN, 158 &zfs_dirty_data_sync, 0, 159 "Force a txg if the number of dirty buffer bytes exceed this value"); 160 161 static int sysctl_zfs_delay_min_dirty_percent(SYSCTL_HANDLER_ARGS); 162 /* No zfs_delay_min_dirty_percent tunable due to limit requirements */ 163 SYSCTL_PROC(_vfs_zfs, OID_AUTO, delay_min_dirty_percent, 164 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, sizeof(int), 165 sysctl_zfs_delay_min_dirty_percent, "I", 166 "The limit of outstanding dirty data before transations are delayed"); 167 168 static int sysctl_zfs_delay_scale(SYSCTL_HANDLER_ARGS); 169 /* No zfs_delay_scale tunable due to limit requirements */ 170 SYSCTL_PROC(_vfs_zfs, OID_AUTO, delay_scale, 171 CTLTYPE_U64 | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, sizeof(uint64_t), 172 sysctl_zfs_delay_scale, "QU", 173 "Controls how quickly the delay approaches infinity"); 174 175 static int 176 sysctl_zfs_dirty_data_max_percent(SYSCTL_HANDLER_ARGS) 177 { 178 int val, err; 179 180 val = zfs_dirty_data_max_percent; 181 err = sysctl_handle_int(oidp, &val, 0, req); 182 if (err != 0 || req->newptr == NULL) 183 return (err); 184 185 if (val < 0 || val > 100) 186 return (EINVAL); 187 188 zfs_dirty_data_max_percent = val; 189 190 return (0); 191 } 192 193 static int 194 sysctl_zfs_delay_min_dirty_percent(SYSCTL_HANDLER_ARGS) 195 { 196 int val, err; 197 198 val = zfs_delay_min_dirty_percent; 199 err = sysctl_handle_int(oidp, &val, 0, req); 200 if (err != 0 || req->newptr == NULL) 201 return (err); 202 203 if (val < zfs_vdev_async_write_active_max_dirty_percent) 204 return (EINVAL); 205 206 zfs_delay_min_dirty_percent = val; 207 208 return (0); 209 } 210 211 static int 212 sysctl_zfs_delay_scale(SYSCTL_HANDLER_ARGS) 213 { 214 uint64_t val; 215 int err; 216 217 val = zfs_delay_scale; 218 err = sysctl_handle_64(oidp, &val, 0, req); 219 if (err != 0 || req->newptr == NULL) 220 return (err); 221 222 if (val > UINT64_MAX / zfs_dirty_data_max) 223 return (EINVAL); 224 225 zfs_delay_scale = val; 226 227 return (0); 228 } 229 #endif 230 231 hrtime_t zfs_throttle_delay = MSEC2NSEC(10); 232 hrtime_t zfs_throttle_resolution = MSEC2NSEC(10); 233 234 int 235 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp) 236 { 237 uint64_t obj; 238 int err; 239 240 err = zap_lookup(dp->dp_meta_objset, 241 dsl_dir_phys(dp->dp_root_dir)->dd_child_dir_zapobj, 242 name, sizeof (obj), 1, &obj); 243 if (err) 244 return (err); 245 246 return (dsl_dir_hold_obj(dp, obj, name, dp, ddp)); 247 } 248 249 static dsl_pool_t * 250 dsl_pool_open_impl(spa_t *spa, uint64_t txg) 251 { 252 dsl_pool_t *dp; 253 blkptr_t *bp = spa_get_rootblkptr(spa); 254 255 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP); 256 dp->dp_spa = spa; 257 dp->dp_meta_rootbp = *bp; 258 rrw_init(&dp->dp_config_rwlock, B_TRUE); 259 txg_init(dp, txg); 260 261 txg_list_create(&dp->dp_dirty_datasets, 262 offsetof(dsl_dataset_t, ds_dirty_link)); 263 txg_list_create(&dp->dp_dirty_zilogs, 264 offsetof(zilog_t, zl_dirty_link)); 265 txg_list_create(&dp->dp_dirty_dirs, 266 offsetof(dsl_dir_t, dd_dirty_link)); 267 txg_list_create(&dp->dp_sync_tasks, 268 offsetof(dsl_sync_task_t, dst_node)); 269 270 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL); 271 cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL); 272 273 dp->dp_vnrele_taskq = taskq_create("zfs_vn_rele_taskq", 1, minclsyspri, 274 1, 4, 0); 275 276 return (dp); 277 } 278 279 int 280 dsl_pool_init(spa_t *spa, uint64_t txg, dsl_pool_t **dpp) 281 { 282 int err; 283 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg); 284 285 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp, 286 &dp->dp_meta_objset); 287 if (err != 0) 288 dsl_pool_close(dp); 289 else 290 *dpp = dp; 291 292 return (err); 293 } 294 295 int 296 dsl_pool_open(dsl_pool_t *dp) 297 { 298 int err; 299 dsl_dir_t *dd; 300 dsl_dataset_t *ds; 301 uint64_t obj; 302 303 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); 304 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 305 DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1, 306 &dp->dp_root_dir_obj); 307 if (err) 308 goto out; 309 310 err = dsl_dir_hold_obj(dp, dp->dp_root_dir_obj, 311 NULL, dp, &dp->dp_root_dir); 312 if (err) 313 goto out; 314 315 err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir); 316 if (err) 317 goto out; 318 319 if (spa_version(dp->dp_spa) >= SPA_VERSION_ORIGIN) { 320 err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd); 321 if (err) 322 goto out; 323 err = dsl_dataset_hold_obj(dp, 324 dsl_dir_phys(dd)->dd_head_dataset_obj, FTAG, &ds); 325 if (err == 0) { 326 err = dsl_dataset_hold_obj(dp, 327 dsl_dataset_phys(ds)->ds_prev_snap_obj, dp, 328 &dp->dp_origin_snap); 329 dsl_dataset_rele(ds, FTAG); 330 } 331 dsl_dir_rele(dd, dp); 332 if (err) 333 goto out; 334 } 335 336 if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) { 337 err = dsl_pool_open_special_dir(dp, FREE_DIR_NAME, 338 &dp->dp_free_dir); 339 if (err) 340 goto out; 341 342 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 343 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj); 344 if (err) 345 goto out; 346 VERIFY0(bpobj_open(&dp->dp_free_bpobj, 347 dp->dp_meta_objset, obj)); 348 } 349 350 /* 351 * Note: errors ignored, because the leak dir will not exist if we 352 * have not encountered a leak yet. 353 */ 354 (void) dsl_pool_open_special_dir(dp, LEAK_DIR_NAME, 355 &dp->dp_leak_dir); 356 357 if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) { 358 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 359 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1, 360 &dp->dp_bptree_obj); 361 if (err != 0) 362 goto out; 363 } 364 365 if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_EMPTY_BPOBJ)) { 366 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 367 DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1, 368 &dp->dp_empty_bpobj); 369 if (err != 0) 370 goto out; 371 } 372 373 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 374 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1, 375 &dp->dp_tmp_userrefs_obj); 376 if (err == ENOENT) 377 err = 0; 378 if (err) 379 goto out; 380 381 err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg); 382 383 out: 384 rrw_exit(&dp->dp_config_rwlock, FTAG); 385 return (err); 386 } 387 388 void 389 dsl_pool_close(dsl_pool_t *dp) 390 { 391 /* 392 * Drop our references from dsl_pool_open(). 393 * 394 * Since we held the origin_snap from "syncing" context (which 395 * includes pool-opening context), it actually only got a "ref" 396 * and not a hold, so just drop that here. 397 */ 398 if (dp->dp_origin_snap) 399 dsl_dataset_rele(dp->dp_origin_snap, dp); 400 if (dp->dp_mos_dir) 401 dsl_dir_rele(dp->dp_mos_dir, dp); 402 if (dp->dp_free_dir) 403 dsl_dir_rele(dp->dp_free_dir, dp); 404 if (dp->dp_leak_dir) 405 dsl_dir_rele(dp->dp_leak_dir, dp); 406 if (dp->dp_root_dir) 407 dsl_dir_rele(dp->dp_root_dir, dp); 408 409 bpobj_close(&dp->dp_free_bpobj); 410 411 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */ 412 if (dp->dp_meta_objset) 413 dmu_objset_evict(dp->dp_meta_objset); 414 415 txg_list_destroy(&dp->dp_dirty_datasets); 416 txg_list_destroy(&dp->dp_dirty_zilogs); 417 txg_list_destroy(&dp->dp_sync_tasks); 418 txg_list_destroy(&dp->dp_dirty_dirs); 419 420 /* 421 * We can't set retry to TRUE since we're explicitly specifying 422 * a spa to flush. This is good enough; any missed buffers for 423 * this spa won't cause trouble, and they'll eventually fall 424 * out of the ARC just like any other unused buffer. 425 */ 426 arc_flush(dp->dp_spa, FALSE); 427 428 txg_fini(dp); 429 dsl_scan_fini(dp); 430 dmu_buf_user_evict_wait(); 431 432 rrw_destroy(&dp->dp_config_rwlock); 433 mutex_destroy(&dp->dp_lock); 434 cv_destroy(&dp->dp_spaceavail_cv); 435 taskq_destroy(dp->dp_vnrele_taskq); 436 if (dp->dp_blkstats) 437 kmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); 438 kmem_free(dp, sizeof (dsl_pool_t)); 439 } 440 441 dsl_pool_t * 442 dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg) 443 { 444 int err; 445 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg); 446 dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg); 447 objset_t *os; 448 dsl_dataset_t *ds; 449 uint64_t obj; 450 451 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); 452 453 /* create and open the MOS (meta-objset) */ 454 dp->dp_meta_objset = dmu_objset_create_impl(spa, 455 NULL, &dp->dp_meta_rootbp, DMU_OST_META, tx); 456 457 /* create the pool directory */ 458 err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 459 DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx); 460 ASSERT0(err); 461 462 /* Initialize scan structures */ 463 VERIFY0(dsl_scan_init(dp, txg)); 464 465 /* create and open the root dir */ 466 dp->dp_root_dir_obj = dsl_dir_create_sync(dp, NULL, NULL, tx); 467 VERIFY0(dsl_dir_hold_obj(dp, dp->dp_root_dir_obj, 468 NULL, dp, &dp->dp_root_dir)); 469 470 /* create and open the meta-objset dir */ 471 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, MOS_DIR_NAME, tx); 472 VERIFY0(dsl_pool_open_special_dir(dp, 473 MOS_DIR_NAME, &dp->dp_mos_dir)); 474 475 if (spa_version(spa) >= SPA_VERSION_DEADLISTS) { 476 /* create and open the free dir */ 477 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, 478 FREE_DIR_NAME, tx); 479 VERIFY0(dsl_pool_open_special_dir(dp, 480 FREE_DIR_NAME, &dp->dp_free_dir)); 481 482 /* create and open the free_bplist */ 483 obj = bpobj_alloc(dp->dp_meta_objset, SPA_OLD_MAXBLOCKSIZE, tx); 484 VERIFY(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 485 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx) == 0); 486 VERIFY0(bpobj_open(&dp->dp_free_bpobj, 487 dp->dp_meta_objset, obj)); 488 } 489 490 if (spa_version(spa) >= SPA_VERSION_DSL_SCRUB) 491 dsl_pool_create_origin(dp, tx); 492 493 /* create the root dataset */ 494 obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx); 495 496 /* create the root objset */ 497 VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG, &ds)); 498 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG); 499 os = dmu_objset_create_impl(dp->dp_spa, ds, 500 dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx); 501 rrw_exit(&ds->ds_bp_rwlock, FTAG); 502 #ifdef _KERNEL 503 zfs_create_fs(os, kcred, zplprops, tx); 504 #endif 505 dsl_dataset_rele(ds, FTAG); 506 507 dmu_tx_commit(tx); 508 509 rrw_exit(&dp->dp_config_rwlock, FTAG); 510 511 return (dp); 512 } 513 514 /* 515 * Account for the meta-objset space in its placeholder dsl_dir. 516 */ 517 void 518 dsl_pool_mos_diduse_space(dsl_pool_t *dp, 519 int64_t used, int64_t comp, int64_t uncomp) 520 { 521 ASSERT3U(comp, ==, uncomp); /* it's all metadata */ 522 mutex_enter(&dp->dp_lock); 523 dp->dp_mos_used_delta += used; 524 dp->dp_mos_compressed_delta += comp; 525 dp->dp_mos_uncompressed_delta += uncomp; 526 mutex_exit(&dp->dp_lock); 527 } 528 529 static void 530 dsl_pool_sync_mos(dsl_pool_t *dp, dmu_tx_t *tx) 531 { 532 zio_t *zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 533 dmu_objset_sync(dp->dp_meta_objset, zio, tx); 534 VERIFY0(zio_wait(zio)); 535 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", ""); 536 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); 537 } 538 539 static void 540 dsl_pool_dirty_delta(dsl_pool_t *dp, int64_t delta) 541 { 542 ASSERT(MUTEX_HELD(&dp->dp_lock)); 543 544 if (delta < 0) 545 ASSERT3U(-delta, <=, dp->dp_dirty_total); 546 547 dp->dp_dirty_total += delta; 548 549 /* 550 * Note: we signal even when increasing dp_dirty_total. 551 * This ensures forward progress -- each thread wakes the next waiter. 552 */ 553 if (dp->dp_dirty_total <= zfs_dirty_data_max) 554 cv_signal(&dp->dp_spaceavail_cv); 555 } 556 557 void 558 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg) 559 { 560 zio_t *zio; 561 dmu_tx_t *tx; 562 dsl_dir_t *dd; 563 dsl_dataset_t *ds; 564 objset_t *mos = dp->dp_meta_objset; 565 list_t synced_datasets; 566 567 list_create(&synced_datasets, sizeof (dsl_dataset_t), 568 offsetof(dsl_dataset_t, ds_synced_link)); 569 570 tx = dmu_tx_create_assigned(dp, txg); 571 572 /* 573 * Write out all dirty blocks of dirty datasets. 574 */ 575 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 576 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) { 577 /* 578 * We must not sync any non-MOS datasets twice, because 579 * we may have taken a snapshot of them. However, we 580 * may sync newly-created datasets on pass 2. 581 */ 582 ASSERT(!list_link_active(&ds->ds_synced_link)); 583 list_insert_tail(&synced_datasets, ds); 584 dsl_dataset_sync(ds, zio, tx); 585 } 586 VERIFY0(zio_wait(zio)); 587 588 /* 589 * We have written all of the accounted dirty data, so our 590 * dp_space_towrite should now be zero. However, some seldom-used 591 * code paths do not adhere to this (e.g. dbuf_undirty(), also 592 * rounding error in dbuf_write_physdone). 593 * Shore up the accounting of any dirtied space now. 594 */ 595 dsl_pool_undirty_space(dp, dp->dp_dirty_pertxg[txg & TXG_MASK], txg); 596 597 /* 598 * Update the long range free counter after 599 * we're done syncing user data 600 */ 601 mutex_enter(&dp->dp_lock); 602 ASSERT(spa_sync_pass(dp->dp_spa) == 1 || 603 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] == 0); 604 dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] = 0; 605 mutex_exit(&dp->dp_lock); 606 607 /* 608 * After the data blocks have been written (ensured by the zio_wait() 609 * above), update the user/group space accounting. 610 */ 611 for (ds = list_head(&synced_datasets); ds != NULL; 612 ds = list_next(&synced_datasets, ds)) { 613 dmu_objset_do_userquota_updates(ds->ds_objset, tx); 614 } 615 616 /* 617 * Sync the datasets again to push out the changes due to 618 * userspace updates. This must be done before we process the 619 * sync tasks, so that any snapshots will have the correct 620 * user accounting information (and we won't get confused 621 * about which blocks are part of the snapshot). 622 */ 623 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED); 624 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) { 625 ASSERT(list_link_active(&ds->ds_synced_link)); 626 dmu_buf_rele(ds->ds_dbuf, ds); 627 dsl_dataset_sync(ds, zio, tx); 628 } 629 VERIFY0(zio_wait(zio)); 630 631 /* 632 * Now that the datasets have been completely synced, we can 633 * clean up our in-memory structures accumulated while syncing: 634 * 635 * - move dead blocks from the pending deadlist to the on-disk deadlist 636 * - release hold from dsl_dataset_dirty() 637 */ 638 while ((ds = list_remove_head(&synced_datasets)) != NULL) { 639 dsl_dataset_sync_done(ds, tx); 640 } 641 while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)) != NULL) { 642 dsl_dir_sync(dd, tx); 643 } 644 645 /* 646 * The MOS's space is accounted for in the pool/$MOS 647 * (dp_mos_dir). We can't modify the mos while we're syncing 648 * it, so we remember the deltas and apply them here. 649 */ 650 if (dp->dp_mos_used_delta != 0 || dp->dp_mos_compressed_delta != 0 || 651 dp->dp_mos_uncompressed_delta != 0) { 652 dsl_dir_diduse_space(dp->dp_mos_dir, DD_USED_HEAD, 653 dp->dp_mos_used_delta, 654 dp->dp_mos_compressed_delta, 655 dp->dp_mos_uncompressed_delta, tx); 656 dp->dp_mos_used_delta = 0; 657 dp->dp_mos_compressed_delta = 0; 658 dp->dp_mos_uncompressed_delta = 0; 659 } 660 661 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL || 662 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) { 663 dsl_pool_sync_mos(dp, tx); 664 } 665 666 /* 667 * If we modify a dataset in the same txg that we want to destroy it, 668 * its dsl_dir's dd_dbuf will be dirty, and thus have a hold on it. 669 * dsl_dir_destroy_check() will fail if there are unexpected holds. 670 * Therefore, we want to sync the MOS (thus syncing the dd_dbuf 671 * and clearing the hold on it) before we process the sync_tasks. 672 * The MOS data dirtied by the sync_tasks will be synced on the next 673 * pass. 674 */ 675 if (!txg_list_empty(&dp->dp_sync_tasks, txg)) { 676 dsl_sync_task_t *dst; 677 /* 678 * No more sync tasks should have been added while we 679 * were syncing. 680 */ 681 ASSERT3U(spa_sync_pass(dp->dp_spa), ==, 1); 682 while ((dst = txg_list_remove(&dp->dp_sync_tasks, txg)) != NULL) 683 dsl_sync_task_sync(dst, tx); 684 } 685 686 dmu_tx_commit(tx); 687 688 DTRACE_PROBE2(dsl_pool_sync__done, dsl_pool_t *dp, dp, uint64_t, txg); 689 } 690 691 void 692 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg) 693 { 694 zilog_t *zilog; 695 696 while (zilog = txg_list_head(&dp->dp_dirty_zilogs, txg)) { 697 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 698 /* 699 * We don't remove the zilog from the dp_dirty_zilogs 700 * list until after we've cleaned it. This ensures that 701 * callers of zilog_is_dirty() receive an accurate 702 * answer when they are racing with the spa sync thread. 703 */ 704 zil_clean(zilog, txg); 705 (void) txg_list_remove_this(&dp->dp_dirty_zilogs, zilog, txg); 706 ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg)); 707 dmu_buf_rele(ds->ds_dbuf, zilog); 708 } 709 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg)); 710 } 711 712 /* 713 * TRUE if the current thread is the tx_sync_thread or if we 714 * are being called from SPA context during pool initialization. 715 */ 716 int 717 dsl_pool_sync_context(dsl_pool_t *dp) 718 { 719 return (curthread == dp->dp_tx.tx_sync_thread || 720 spa_is_initializing(dp->dp_spa)); 721 } 722 723 uint64_t 724 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree) 725 { 726 uint64_t space, resv; 727 728 /* 729 * If we're trying to assess whether it's OK to do a free, 730 * cut the reservation in half to allow forward progress 731 * (e.g. make it possible to rm(1) files from a full pool). 732 */ 733 space = spa_get_dspace(dp->dp_spa); 734 resv = spa_get_slop_space(dp->dp_spa); 735 if (netfree) 736 resv >>= 1; 737 738 return (space - resv); 739 } 740 741 boolean_t 742 dsl_pool_need_dirty_delay(dsl_pool_t *dp) 743 { 744 uint64_t delay_min_bytes = 745 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100; 746 boolean_t rv; 747 748 mutex_enter(&dp->dp_lock); 749 if (dp->dp_dirty_total > zfs_dirty_data_sync) 750 txg_kick(dp); 751 rv = (dp->dp_dirty_total > delay_min_bytes); 752 mutex_exit(&dp->dp_lock); 753 return (rv); 754 } 755 756 void 757 dsl_pool_dirty_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx) 758 { 759 if (space > 0) { 760 mutex_enter(&dp->dp_lock); 761 dp->dp_dirty_pertxg[tx->tx_txg & TXG_MASK] += space; 762 dsl_pool_dirty_delta(dp, space); 763 mutex_exit(&dp->dp_lock); 764 } 765 } 766 767 void 768 dsl_pool_undirty_space(dsl_pool_t *dp, int64_t space, uint64_t txg) 769 { 770 ASSERT3S(space, >=, 0); 771 if (space == 0) 772 return; 773 mutex_enter(&dp->dp_lock); 774 if (dp->dp_dirty_pertxg[txg & TXG_MASK] < space) { 775 /* XXX writing something we didn't dirty? */ 776 space = dp->dp_dirty_pertxg[txg & TXG_MASK]; 777 } 778 ASSERT3U(dp->dp_dirty_pertxg[txg & TXG_MASK], >=, space); 779 dp->dp_dirty_pertxg[txg & TXG_MASK] -= space; 780 ASSERT3U(dp->dp_dirty_total, >=, space); 781 dsl_pool_dirty_delta(dp, -space); 782 mutex_exit(&dp->dp_lock); 783 } 784 785 /* ARGSUSED */ 786 static int 787 upgrade_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) 788 { 789 dmu_tx_t *tx = arg; 790 dsl_dataset_t *ds, *prev = NULL; 791 int err; 792 793 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); 794 if (err) 795 return (err); 796 797 while (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) { 798 err = dsl_dataset_hold_obj(dp, 799 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev); 800 if (err) { 801 dsl_dataset_rele(ds, FTAG); 802 return (err); 803 } 804 805 if (dsl_dataset_phys(prev)->ds_next_snap_obj != ds->ds_object) 806 break; 807 dsl_dataset_rele(ds, FTAG); 808 ds = prev; 809 prev = NULL; 810 } 811 812 if (prev == NULL) { 813 prev = dp->dp_origin_snap; 814 815 /* 816 * The $ORIGIN can't have any data, or the accounting 817 * will be wrong. 818 */ 819 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG); 820 ASSERT0(dsl_dataset_phys(prev)->ds_bp.blk_birth); 821 rrw_exit(&ds->ds_bp_rwlock, FTAG); 822 823 /* The origin doesn't get attached to itself */ 824 if (ds->ds_object == prev->ds_object) { 825 dsl_dataset_rele(ds, FTAG); 826 return (0); 827 } 828 829 dmu_buf_will_dirty(ds->ds_dbuf, tx); 830 dsl_dataset_phys(ds)->ds_prev_snap_obj = prev->ds_object; 831 dsl_dataset_phys(ds)->ds_prev_snap_txg = 832 dsl_dataset_phys(prev)->ds_creation_txg; 833 834 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx); 835 dsl_dir_phys(ds->ds_dir)->dd_origin_obj = prev->ds_object; 836 837 dmu_buf_will_dirty(prev->ds_dbuf, tx); 838 dsl_dataset_phys(prev)->ds_num_children++; 839 840 if (dsl_dataset_phys(ds)->ds_next_snap_obj == 0) { 841 ASSERT(ds->ds_prev == NULL); 842 VERIFY0(dsl_dataset_hold_obj(dp, 843 dsl_dataset_phys(ds)->ds_prev_snap_obj, 844 ds, &ds->ds_prev)); 845 } 846 } 847 848 ASSERT3U(dsl_dir_phys(ds->ds_dir)->dd_origin_obj, ==, prev->ds_object); 849 ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_obj, ==, prev->ds_object); 850 851 if (dsl_dataset_phys(prev)->ds_next_clones_obj == 0) { 852 dmu_buf_will_dirty(prev->ds_dbuf, tx); 853 dsl_dataset_phys(prev)->ds_next_clones_obj = 854 zap_create(dp->dp_meta_objset, 855 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx); 856 } 857 VERIFY0(zap_add_int(dp->dp_meta_objset, 858 dsl_dataset_phys(prev)->ds_next_clones_obj, ds->ds_object, tx)); 859 860 dsl_dataset_rele(ds, FTAG); 861 if (prev != dp->dp_origin_snap) 862 dsl_dataset_rele(prev, FTAG); 863 return (0); 864 } 865 866 void 867 dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx) 868 { 869 ASSERT(dmu_tx_is_syncing(tx)); 870 ASSERT(dp->dp_origin_snap != NULL); 871 872 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, upgrade_clones_cb, 873 tx, DS_FIND_CHILDREN | DS_FIND_SERIALIZE)); 874 } 875 876 /* ARGSUSED */ 877 static int 878 upgrade_dir_clones_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg) 879 { 880 dmu_tx_t *tx = arg; 881 objset_t *mos = dp->dp_meta_objset; 882 883 if (dsl_dir_phys(ds->ds_dir)->dd_origin_obj != 0) { 884 dsl_dataset_t *origin; 885 886 VERIFY0(dsl_dataset_hold_obj(dp, 887 dsl_dir_phys(ds->ds_dir)->dd_origin_obj, FTAG, &origin)); 888 889 if (dsl_dir_phys(origin->ds_dir)->dd_clones == 0) { 890 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx); 891 dsl_dir_phys(origin->ds_dir)->dd_clones = 892 zap_create(mos, DMU_OT_DSL_CLONES, DMU_OT_NONE, 893 0, tx); 894 } 895 896 VERIFY0(zap_add_int(dp->dp_meta_objset, 897 dsl_dir_phys(origin->ds_dir)->dd_clones, 898 ds->ds_object, tx)); 899 900 dsl_dataset_rele(origin, FTAG); 901 } 902 return (0); 903 } 904 905 void 906 dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx) 907 { 908 ASSERT(dmu_tx_is_syncing(tx)); 909 uint64_t obj; 910 911 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, FREE_DIR_NAME, tx); 912 VERIFY0(dsl_pool_open_special_dir(dp, 913 FREE_DIR_NAME, &dp->dp_free_dir)); 914 915 /* 916 * We can't use bpobj_alloc(), because spa_version() still 917 * returns the old version, and we need a new-version bpobj with 918 * subobj support. So call dmu_object_alloc() directly. 919 */ 920 obj = dmu_object_alloc(dp->dp_meta_objset, DMU_OT_BPOBJ, 921 SPA_OLD_MAXBLOCKSIZE, DMU_OT_BPOBJ_HDR, sizeof (bpobj_phys_t), tx); 922 VERIFY0(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, 923 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx)); 924 VERIFY0(bpobj_open(&dp->dp_free_bpobj, dp->dp_meta_objset, obj)); 925 926 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, 927 upgrade_dir_clones_cb, tx, DS_FIND_CHILDREN | DS_FIND_SERIALIZE)); 928 } 929 930 void 931 dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx) 932 { 933 uint64_t dsobj; 934 dsl_dataset_t *ds; 935 936 ASSERT(dmu_tx_is_syncing(tx)); 937 ASSERT(dp->dp_origin_snap == NULL); 938 ASSERT(rrw_held(&dp->dp_config_rwlock, RW_WRITER)); 939 940 /* create the origin dir, ds, & snap-ds */ 941 dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME, 942 NULL, 0, kcred, tx); 943 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); 944 dsl_dataset_snapshot_sync_impl(ds, ORIGIN_DIR_NAME, tx); 945 VERIFY0(dsl_dataset_hold_obj(dp, dsl_dataset_phys(ds)->ds_prev_snap_obj, 946 dp, &dp->dp_origin_snap)); 947 dsl_dataset_rele(ds, FTAG); 948 } 949 950 taskq_t * 951 dsl_pool_vnrele_taskq(dsl_pool_t *dp) 952 { 953 return (dp->dp_vnrele_taskq); 954 } 955 956 /* 957 * Walk through the pool-wide zap object of temporary snapshot user holds 958 * and release them. 959 */ 960 void 961 dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp) 962 { 963 zap_attribute_t za; 964 zap_cursor_t zc; 965 objset_t *mos = dp->dp_meta_objset; 966 uint64_t zapobj = dp->dp_tmp_userrefs_obj; 967 nvlist_t *holds; 968 969 if (zapobj == 0) 970 return; 971 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 972 973 holds = fnvlist_alloc(); 974 975 for (zap_cursor_init(&zc, mos, zapobj); 976 zap_cursor_retrieve(&zc, &za) == 0; 977 zap_cursor_advance(&zc)) { 978 char *htag; 979 nvlist_t *tags; 980 981 htag = strchr(za.za_name, '-'); 982 *htag = '\0'; 983 ++htag; 984 if (nvlist_lookup_nvlist(holds, za.za_name, &tags) != 0) { 985 tags = fnvlist_alloc(); 986 fnvlist_add_boolean(tags, htag); 987 fnvlist_add_nvlist(holds, za.za_name, tags); 988 fnvlist_free(tags); 989 } else { 990 fnvlist_add_boolean(tags, htag); 991 } 992 } 993 dsl_dataset_user_release_tmp(dp, holds); 994 fnvlist_free(holds); 995 zap_cursor_fini(&zc); 996 } 997 998 /* 999 * Create the pool-wide zap object for storing temporary snapshot holds. 1000 */ 1001 void 1002 dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx) 1003 { 1004 objset_t *mos = dp->dp_meta_objset; 1005 1006 ASSERT(dp->dp_tmp_userrefs_obj == 0); 1007 ASSERT(dmu_tx_is_syncing(tx)); 1008 1009 dp->dp_tmp_userrefs_obj = zap_create_link(mos, DMU_OT_USERREFS, 1010 DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, tx); 1011 } 1012 1013 static int 1014 dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj, 1015 const char *tag, uint64_t now, dmu_tx_t *tx, boolean_t holding) 1016 { 1017 objset_t *mos = dp->dp_meta_objset; 1018 uint64_t zapobj = dp->dp_tmp_userrefs_obj; 1019 char *name; 1020 int error; 1021 1022 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS); 1023 ASSERT(dmu_tx_is_syncing(tx)); 1024 1025 /* 1026 * If the pool was created prior to SPA_VERSION_USERREFS, the 1027 * zap object for temporary holds might not exist yet. 1028 */ 1029 if (zapobj == 0) { 1030 if (holding) { 1031 dsl_pool_user_hold_create_obj(dp, tx); 1032 zapobj = dp->dp_tmp_userrefs_obj; 1033 } else { 1034 return (SET_ERROR(ENOENT)); 1035 } 1036 } 1037 1038 name = kmem_asprintf("%llx-%s", (u_longlong_t)dsobj, tag); 1039 if (holding) 1040 error = zap_add(mos, zapobj, name, 8, 1, &now, tx); 1041 else 1042 error = zap_remove(mos, zapobj, name, tx); 1043 strfree(name); 1044 1045 return (error); 1046 } 1047 1048 /* 1049 * Add a temporary hold for the given dataset object and tag. 1050 */ 1051 int 1052 dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag, 1053 uint64_t now, dmu_tx_t *tx) 1054 { 1055 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE)); 1056 } 1057 1058 /* 1059 * Release a temporary hold for the given dataset object and tag. 1060 */ 1061 int 1062 dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj, const char *tag, 1063 dmu_tx_t *tx) 1064 { 1065 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, 0, 1066 tx, B_FALSE)); 1067 } 1068 1069 /* 1070 * DSL Pool Configuration Lock 1071 * 1072 * The dp_config_rwlock protects against changes to DSL state (e.g. dataset 1073 * creation / destruction / rename / property setting). It must be held for 1074 * read to hold a dataset or dsl_dir. I.e. you must call 1075 * dsl_pool_config_enter() or dsl_pool_hold() before calling 1076 * dsl_{dataset,dir}_hold{_obj}. In most circumstances, the dp_config_rwlock 1077 * must be held continuously until all datasets and dsl_dirs are released. 1078 * 1079 * The only exception to this rule is that if a "long hold" is placed on 1080 * a dataset, then the dp_config_rwlock may be dropped while the dataset 1081 * is still held. The long hold will prevent the dataset from being 1082 * destroyed -- the destroy will fail with EBUSY. A long hold can be 1083 * obtained by calling dsl_dataset_long_hold(), or by "owning" a dataset 1084 * (by calling dsl_{dataset,objset}_{try}own{_obj}). 1085 * 1086 * Legitimate long-holders (including owners) should be long-running, cancelable 1087 * tasks that should cause "zfs destroy" to fail. This includes DMU 1088 * consumers (i.e. a ZPL filesystem being mounted or ZVOL being open), 1089 * "zfs send", and "zfs diff". There are several other long-holders whose 1090 * uses are suboptimal (e.g. "zfs promote", and zil_suspend()). 1091 * 1092 * The usual formula for long-holding would be: 1093 * dsl_pool_hold() 1094 * dsl_dataset_hold() 1095 * ... perform checks ... 1096 * dsl_dataset_long_hold() 1097 * dsl_pool_rele() 1098 * ... perform long-running task ... 1099 * dsl_dataset_long_rele() 1100 * dsl_dataset_rele() 1101 * 1102 * Note that when the long hold is released, the dataset is still held but 1103 * the pool is not held. The dataset may change arbitrarily during this time 1104 * (e.g. it could be destroyed). Therefore you shouldn't do anything to the 1105 * dataset except release it. 1106 * 1107 * User-initiated operations (e.g. ioctls, zfs_ioc_*()) are either read-only 1108 * or modifying operations. 1109 * 1110 * Modifying operations should generally use dsl_sync_task(). The synctask 1111 * infrastructure enforces proper locking strategy with respect to the 1112 * dp_config_rwlock. See the comment above dsl_sync_task() for details. 1113 * 1114 * Read-only operations will manually hold the pool, then the dataset, obtain 1115 * information from the dataset, then release the pool and dataset. 1116 * dmu_objset_{hold,rele}() are convenience routines that also do the pool 1117 * hold/rele. 1118 */ 1119 1120 int 1121 dsl_pool_hold(const char *name, void *tag, dsl_pool_t **dp) 1122 { 1123 spa_t *spa; 1124 int error; 1125 1126 error = spa_open(name, &spa, tag); 1127 if (error == 0) { 1128 *dp = spa_get_dsl(spa); 1129 dsl_pool_config_enter(*dp, tag); 1130 } 1131 return (error); 1132 } 1133 1134 void 1135 dsl_pool_rele(dsl_pool_t *dp, void *tag) 1136 { 1137 dsl_pool_config_exit(dp, tag); 1138 spa_close(dp->dp_spa, tag); 1139 } 1140 1141 void 1142 dsl_pool_config_enter(dsl_pool_t *dp, void *tag) 1143 { 1144 /* 1145 * We use a "reentrant" reader-writer lock, but not reentrantly. 1146 * 1147 * The rrwlock can (with the track_all flag) track all reading threads, 1148 * which is very useful for debugging which code path failed to release 1149 * the lock, and for verifying that the *current* thread does hold 1150 * the lock. 1151 * 1152 * (Unlike a rwlock, which knows that N threads hold it for 1153 * read, but not *which* threads, so rw_held(RW_READER) returns TRUE 1154 * if any thread holds it for read, even if this thread doesn't). 1155 */ 1156 ASSERT(!rrw_held(&dp->dp_config_rwlock, RW_READER)); 1157 rrw_enter(&dp->dp_config_rwlock, RW_READER, tag); 1158 } 1159 1160 void 1161 dsl_pool_config_enter_prio(dsl_pool_t *dp, void *tag) 1162 { 1163 ASSERT(!rrw_held(&dp->dp_config_rwlock, RW_READER)); 1164 rrw_enter_read_prio(&dp->dp_config_rwlock, tag); 1165 } 1166 1167 void 1168 dsl_pool_config_exit(dsl_pool_t *dp, void *tag) 1169 { 1170 rrw_exit(&dp->dp_config_rwlock, tag); 1171 } 1172 1173 boolean_t 1174 dsl_pool_config_held(dsl_pool_t *dp) 1175 { 1176 return (RRW_LOCK_HELD(&dp->dp_config_rwlock)); 1177 } 1178 1179 boolean_t 1180 dsl_pool_config_held_writer(dsl_pool_t *dp) 1181 { 1182 return (RRW_WRITE_HELD(&dp->dp_config_rwlock)); 1183 } 1184
Indexes created Wed Jun 10 00:26:05 UTC 2026