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4171 clean up spa_feature_*() interfaces
4172 implement extensible_dataset feature for use by other zpool features
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
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--- old/usr/src/uts/common/fs/zfs/dsl_pool.c
+++ new/usr/src/uts/common/fs/zfs/dsl_pool.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /*
22 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 24 * Copyright (c) 2013 Steven Hartland. All rights reserved.
25 25 */
26 26
27 27 #include <sys/dsl_pool.h>
28 28 #include <sys/dsl_dataset.h>
29 29 #include <sys/dsl_prop.h>
30 30 #include <sys/dsl_dir.h>
31 31 #include <sys/dsl_synctask.h>
32 32 #include <sys/dsl_scan.h>
33 33 #include <sys/dnode.h>
34 34 #include <sys/dmu_tx.h>
35 35 #include <sys/dmu_objset.h>
36 36 #include <sys/arc.h>
37 37 #include <sys/zap.h>
38 38 #include <sys/zio.h>
39 39 #include <sys/zfs_context.h>
40 40 #include <sys/fs/zfs.h>
41 41 #include <sys/zfs_znode.h>
42 42 #include <sys/spa_impl.h>
43 43 #include <sys/dsl_deadlist.h>
44 44 #include <sys/bptree.h>
45 45 #include <sys/zfeature.h>
46 46 #include <sys/zil_impl.h>
47 47 #include <sys/dsl_userhold.h>
48 48
49 49 /*
50 50 * ZFS Write Throttle
51 51 * ------------------
52 52 *
53 53 * ZFS must limit the rate of incoming writes to the rate at which it is able
54 54 * to sync data modifications to the backend storage. Throttling by too much
55 55 * creates an artificial limit; throttling by too little can only be sustained
56 56 * for short periods and would lead to highly lumpy performance. On a per-pool
57 57 * basis, ZFS tracks the amount of modified (dirty) data. As operations change
58 58 * data, the amount of dirty data increases; as ZFS syncs out data, the amount
59 59 * of dirty data decreases. When the amount of dirty data exceeds a
60 60 * predetermined threshold further modifications are blocked until the amount
61 61 * of dirty data decreases (as data is synced out).
62 62 *
63 63 * The limit on dirty data is tunable, and should be adjusted according to
64 64 * both the IO capacity and available memory of the system. The larger the
65 65 * window, the more ZFS is able to aggregate and amortize metadata (and data)
66 66 * changes. However, memory is a limited resource, and allowing for more dirty
67 67 * data comes at the cost of keeping other useful data in memory (for example
68 68 * ZFS data cached by the ARC).
69 69 *
70 70 * Implementation
71 71 *
72 72 * As buffers are modified dsl_pool_willuse_space() increments both the per-
73 73 * txg (dp_dirty_pertxg[]) and poolwide (dp_dirty_total) accounting of
74 74 * dirty space used; dsl_pool_dirty_space() decrements those values as data
75 75 * is synced out from dsl_pool_sync(). While only the poolwide value is
76 76 * relevant, the per-txg value is useful for debugging. The tunable
77 77 * zfs_dirty_data_max determines the dirty space limit. Once that value is
78 78 * exceeded, new writes are halted until space frees up.
79 79 *
80 80 * The zfs_dirty_data_sync tunable dictates the threshold at which we
81 81 * ensure that there is a txg syncing (see the comment in txg.c for a full
82 82 * description of transaction group stages).
83 83 *
84 84 * The IO scheduler uses both the dirty space limit and current amount of
85 85 * dirty data as inputs. Those values affect the number of concurrent IOs ZFS
86 86 * issues. See the comment in vdev_queue.c for details of the IO scheduler.
87 87 *
88 88 * The delay is also calculated based on the amount of dirty data. See the
89 89 * comment above dmu_tx_delay() for details.
90 90 */
91 91
92 92 /*
93 93 * zfs_dirty_data_max will be set to zfs_dirty_data_max_percent% of all memory,
94 94 * capped at zfs_dirty_data_max_max. It can also be overridden in /etc/system.
95 95 */
96 96 uint64_t zfs_dirty_data_max;
97 97 uint64_t zfs_dirty_data_max_max = 4ULL * 1024 * 1024 * 1024;
98 98 int zfs_dirty_data_max_percent = 10;
99 99
100 100 /*
101 101 * If there is at least this much dirty data, push out a txg.
102 102 */
103 103 uint64_t zfs_dirty_data_sync = 64 * 1024 * 1024;
104 104
105 105 /*
106 106 * Once there is this amount of dirty data, the dmu_tx_delay() will kick in
107 107 * and delay each transaction.
108 108 * This value should be >= zfs_vdev_async_write_active_max_dirty_percent.
109 109 */
110 110 int zfs_delay_min_dirty_percent = 60;
111 111
112 112 /*
113 113 * This controls how quickly the delay approaches infinity.
114 114 * Larger values cause it to delay less for a given amount of dirty data.
115 115 * Therefore larger values will cause there to be more dirty data for a
116 116 * given throughput.
117 117 *
118 118 * For the smoothest delay, this value should be about 1 billion divided
119 119 * by the maximum number of operations per second. This will smoothly
120 120 * handle between 10x and 1/10th this number.
121 121 *
122 122 * Note: zfs_delay_scale * zfs_dirty_data_max must be < 2^64, due to the
123 123 * multiply in dmu_tx_delay().
124 124 */
125 125 uint64_t zfs_delay_scale = 1000 * 1000 * 1000 / 2000;
126 126
127 127
128 128 /*
129 129 * XXX someday maybe turn these into #defines, and you have to tune it on a
130 130 * per-pool basis using zfs.conf.
131 131 */
132 132
133 133
134 134 hrtime_t zfs_throttle_delay = MSEC2NSEC(10);
135 135 hrtime_t zfs_throttle_resolution = MSEC2NSEC(10);
136 136
137 137 int
138 138 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
139 139 {
140 140 uint64_t obj;
141 141 int err;
142 142
143 143 err = zap_lookup(dp->dp_meta_objset,
144 144 dp->dp_root_dir->dd_phys->dd_child_dir_zapobj,
145 145 name, sizeof (obj), 1, &obj);
146 146 if (err)
147 147 return (err);
148 148
149 149 return (dsl_dir_hold_obj(dp, obj, name, dp, ddp));
150 150 }
151 151
152 152 static dsl_pool_t *
153 153 dsl_pool_open_impl(spa_t *spa, uint64_t txg)
154 154 {
155 155 dsl_pool_t *dp;
156 156 blkptr_t *bp = spa_get_rootblkptr(spa);
157 157
158 158 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);
159 159 dp->dp_spa = spa;
160 160 dp->dp_meta_rootbp = *bp;
161 161 rrw_init(&dp->dp_config_rwlock, B_TRUE);
162 162 txg_init(dp, txg);
163 163
164 164 txg_list_create(&dp->dp_dirty_datasets,
165 165 offsetof(dsl_dataset_t, ds_dirty_link));
166 166 txg_list_create(&dp->dp_dirty_zilogs,
167 167 offsetof(zilog_t, zl_dirty_link));
168 168 txg_list_create(&dp->dp_dirty_dirs,
169 169 offsetof(dsl_dir_t, dd_dirty_link));
170 170 txg_list_create(&dp->dp_sync_tasks,
171 171 offsetof(dsl_sync_task_t, dst_node));
172 172
173 173 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
174 174 cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL);
175 175
176 176 dp->dp_vnrele_taskq = taskq_create("zfs_vn_rele_taskq", 1, minclsyspri,
177 177 1, 4, 0);
178 178
179 179 return (dp);
180 180 }
181 181
182 182 int
183 183 dsl_pool_init(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
184 184 {
185 185 int err;
186 186 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
187 187
188 188 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
189 189 &dp->dp_meta_objset);
190 190 if (err != 0)
191 191 dsl_pool_close(dp);
192 192 else
193 193 *dpp = dp;
194 194
195 195 return (err);
196 196 }
197 197
198 198 int
199 199 dsl_pool_open(dsl_pool_t *dp)
200 200 {
201 201 int err;
202 202 dsl_dir_t *dd;
203 203 dsl_dataset_t *ds;
204 204 uint64_t obj;
205 205
206 206 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
207 207 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
208 208 DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1,
209 209 &dp->dp_root_dir_obj);
210 210 if (err)
211 211 goto out;
212 212
213 213 err = dsl_dir_hold_obj(dp, dp->dp_root_dir_obj,
214 214 NULL, dp, &dp->dp_root_dir);
215 215 if (err)
216 216 goto out;
217 217
218 218 err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir);
219 219 if (err)
220 220 goto out;
221 221
222 222 if (spa_version(dp->dp_spa) >= SPA_VERSION_ORIGIN) {
223 223 err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd);
224 224 if (err)
225 225 goto out;
226 226 err = dsl_dataset_hold_obj(dp, dd->dd_phys->dd_head_dataset_obj,
227 227 FTAG, &ds);
228 228 if (err == 0) {
229 229 err = dsl_dataset_hold_obj(dp,
230 230 ds->ds_phys->ds_prev_snap_obj, dp,
231 231 &dp->dp_origin_snap);
232 232 dsl_dataset_rele(ds, FTAG);
233 233 }
234 234 dsl_dir_rele(dd, dp);
235 235 if (err)
236 236 goto out;
237 237 }
238 238
239 239 if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
240 240 err = dsl_pool_open_special_dir(dp, FREE_DIR_NAME,
241 241 &dp->dp_free_dir);
242 242 if (err)
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243 243 goto out;
244 244
245 245 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
246 246 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj);
247 247 if (err)
248 248 goto out;
249 249 VERIFY0(bpobj_open(&dp->dp_free_bpobj,
250 250 dp->dp_meta_objset, obj));
251 251 }
252 252
253 - if (spa_feature_is_active(dp->dp_spa,
254 - &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
253 + if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) {
255 254 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
256 255 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
257 256 &dp->dp_bptree_obj);
258 257 if (err != 0)
259 258 goto out;
260 259 }
261 260
262 - if (spa_feature_is_active(dp->dp_spa,
263 - &spa_feature_table[SPA_FEATURE_EMPTY_BPOBJ])) {
261 + if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_EMPTY_BPOBJ)) {
264 262 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
265 263 DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1,
266 264 &dp->dp_empty_bpobj);
267 265 if (err != 0)
268 266 goto out;
269 267 }
270 268
271 269 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
272 270 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1,
273 271 &dp->dp_tmp_userrefs_obj);
274 272 if (err == ENOENT)
275 273 err = 0;
276 274 if (err)
277 275 goto out;
278 276
279 277 err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg);
280 278
281 279 out:
282 280 rrw_exit(&dp->dp_config_rwlock, FTAG);
283 281 return (err);
284 282 }
285 283
286 284 void
287 285 dsl_pool_close(dsl_pool_t *dp)
288 286 {
289 287 /*
290 288 * Drop our references from dsl_pool_open().
291 289 *
292 290 * Since we held the origin_snap from "syncing" context (which
293 291 * includes pool-opening context), it actually only got a "ref"
294 292 * and not a hold, so just drop that here.
295 293 */
296 294 if (dp->dp_origin_snap)
297 295 dsl_dataset_rele(dp->dp_origin_snap, dp);
298 296 if (dp->dp_mos_dir)
299 297 dsl_dir_rele(dp->dp_mos_dir, dp);
300 298 if (dp->dp_free_dir)
301 299 dsl_dir_rele(dp->dp_free_dir, dp);
302 300 if (dp->dp_root_dir)
303 301 dsl_dir_rele(dp->dp_root_dir, dp);
304 302
305 303 bpobj_close(&dp->dp_free_bpobj);
306 304
307 305 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
308 306 if (dp->dp_meta_objset)
309 307 dmu_objset_evict(dp->dp_meta_objset);
310 308
311 309 txg_list_destroy(&dp->dp_dirty_datasets);
312 310 txg_list_destroy(&dp->dp_dirty_zilogs);
313 311 txg_list_destroy(&dp->dp_sync_tasks);
314 312 txg_list_destroy(&dp->dp_dirty_dirs);
315 313
316 314 arc_flush(dp->dp_spa);
317 315 txg_fini(dp);
318 316 dsl_scan_fini(dp);
319 317 rrw_destroy(&dp->dp_config_rwlock);
320 318 mutex_destroy(&dp->dp_lock);
321 319 taskq_destroy(dp->dp_vnrele_taskq);
322 320 if (dp->dp_blkstats)
323 321 kmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
324 322 kmem_free(dp, sizeof (dsl_pool_t));
325 323 }
326 324
327 325 dsl_pool_t *
328 326 dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg)
329 327 {
330 328 int err;
331 329 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
332 330 dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
333 331 objset_t *os;
334 332 dsl_dataset_t *ds;
335 333 uint64_t obj;
336 334
337 335 rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
338 336
339 337 /* create and open the MOS (meta-objset) */
340 338 dp->dp_meta_objset = dmu_objset_create_impl(spa,
341 339 NULL, &dp->dp_meta_rootbp, DMU_OST_META, tx);
342 340
343 341 /* create the pool directory */
344 342 err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
345 343 DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx);
346 344 ASSERT0(err);
347 345
348 346 /* Initialize scan structures */
349 347 VERIFY0(dsl_scan_init(dp, txg));
350 348
351 349 /* create and open the root dir */
352 350 dp->dp_root_dir_obj = dsl_dir_create_sync(dp, NULL, NULL, tx);
353 351 VERIFY0(dsl_dir_hold_obj(dp, dp->dp_root_dir_obj,
354 352 NULL, dp, &dp->dp_root_dir));
355 353
356 354 /* create and open the meta-objset dir */
357 355 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, MOS_DIR_NAME, tx);
358 356 VERIFY0(dsl_pool_open_special_dir(dp,
359 357 MOS_DIR_NAME, &dp->dp_mos_dir));
360 358
361 359 if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
362 360 /* create and open the free dir */
363 361 (void) dsl_dir_create_sync(dp, dp->dp_root_dir,
364 362 FREE_DIR_NAME, tx);
365 363 VERIFY0(dsl_pool_open_special_dir(dp,
366 364 FREE_DIR_NAME, &dp->dp_free_dir));
367 365
368 366 /* create and open the free_bplist */
369 367 obj = bpobj_alloc(dp->dp_meta_objset, SPA_MAXBLOCKSIZE, tx);
370 368 VERIFY(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
371 369 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx) == 0);
372 370 VERIFY0(bpobj_open(&dp->dp_free_bpobj,
373 371 dp->dp_meta_objset, obj));
374 372 }
375 373
376 374 if (spa_version(spa) >= SPA_VERSION_DSL_SCRUB)
377 375 dsl_pool_create_origin(dp, tx);
378 376
379 377 /* create the root dataset */
380 378 obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx);
381 379
382 380 /* create the root objset */
383 381 VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG, &ds));
384 382 os = dmu_objset_create_impl(dp->dp_spa, ds,
385 383 dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx);
386 384 #ifdef _KERNEL
387 385 zfs_create_fs(os, kcred, zplprops, tx);
388 386 #endif
389 387 dsl_dataset_rele(ds, FTAG);
390 388
391 389 dmu_tx_commit(tx);
392 390
393 391 rrw_exit(&dp->dp_config_rwlock, FTAG);
394 392
395 393 return (dp);
396 394 }
397 395
398 396 /*
399 397 * Account for the meta-objset space in its placeholder dsl_dir.
400 398 */
401 399 void
402 400 dsl_pool_mos_diduse_space(dsl_pool_t *dp,
403 401 int64_t used, int64_t comp, int64_t uncomp)
404 402 {
405 403 ASSERT3U(comp, ==, uncomp); /* it's all metadata */
406 404 mutex_enter(&dp->dp_lock);
407 405 dp->dp_mos_used_delta += used;
408 406 dp->dp_mos_compressed_delta += comp;
409 407 dp->dp_mos_uncompressed_delta += uncomp;
410 408 mutex_exit(&dp->dp_lock);
411 409 }
412 410
413 411 static int
414 412 deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
415 413 {
416 414 dsl_deadlist_t *dl = arg;
417 415 dsl_deadlist_insert(dl, bp, tx);
418 416 return (0);
419 417 }
420 418
421 419 static void
422 420 dsl_pool_sync_mos(dsl_pool_t *dp, dmu_tx_t *tx)
423 421 {
424 422 zio_t *zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
425 423 dmu_objset_sync(dp->dp_meta_objset, zio, tx);
426 424 VERIFY0(zio_wait(zio));
427 425 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");
428 426 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
429 427 }
430 428
431 429 static void
432 430 dsl_pool_dirty_delta(dsl_pool_t *dp, int64_t delta)
433 431 {
434 432 ASSERT(MUTEX_HELD(&dp->dp_lock));
435 433
436 434 if (delta < 0)
437 435 ASSERT3U(-delta, <=, dp->dp_dirty_total);
438 436
439 437 dp->dp_dirty_total += delta;
440 438
441 439 /*
442 440 * Note: we signal even when increasing dp_dirty_total.
443 441 * This ensures forward progress -- each thread wakes the next waiter.
444 442 */
445 443 if (dp->dp_dirty_total <= zfs_dirty_data_max)
446 444 cv_signal(&dp->dp_spaceavail_cv);
447 445 }
448 446
449 447 void
450 448 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
451 449 {
452 450 zio_t *zio;
453 451 dmu_tx_t *tx;
454 452 dsl_dir_t *dd;
455 453 dsl_dataset_t *ds;
456 454 objset_t *mos = dp->dp_meta_objset;
457 455 list_t synced_datasets;
458 456
459 457 list_create(&synced_datasets, sizeof (dsl_dataset_t),
460 458 offsetof(dsl_dataset_t, ds_synced_link));
461 459
462 460 tx = dmu_tx_create_assigned(dp, txg);
463 461
464 462 /*
465 463 * Write out all dirty blocks of dirty datasets.
466 464 */
467 465 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
468 466 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) {
469 467 /*
470 468 * We must not sync any non-MOS datasets twice, because
471 469 * we may have taken a snapshot of them. However, we
472 470 * may sync newly-created datasets on pass 2.
473 471 */
474 472 ASSERT(!list_link_active(&ds->ds_synced_link));
475 473 list_insert_tail(&synced_datasets, ds);
476 474 dsl_dataset_sync(ds, zio, tx);
477 475 }
478 476 VERIFY0(zio_wait(zio));
479 477
480 478 /*
481 479 * We have written all of the accounted dirty data, so our
482 480 * dp_space_towrite should now be zero. However, some seldom-used
483 481 * code paths do not adhere to this (e.g. dbuf_undirty(), also
484 482 * rounding error in dbuf_write_physdone).
485 483 * Shore up the accounting of any dirtied space now.
486 484 */
487 485 dsl_pool_undirty_space(dp, dp->dp_dirty_pertxg[txg & TXG_MASK], txg);
488 486
489 487 /*
490 488 * After the data blocks have been written (ensured by the zio_wait()
491 489 * above), update the user/group space accounting.
492 490 */
493 491 for (ds = list_head(&synced_datasets); ds != NULL;
494 492 ds = list_next(&synced_datasets, ds)) {
495 493 dmu_objset_do_userquota_updates(ds->ds_objset, tx);
496 494 }
497 495
498 496 /*
499 497 * Sync the datasets again to push out the changes due to
500 498 * userspace updates. This must be done before we process the
501 499 * sync tasks, so that any snapshots will have the correct
502 500 * user accounting information (and we won't get confused
503 501 * about which blocks are part of the snapshot).
504 502 */
505 503 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
506 504 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) {
507 505 ASSERT(list_link_active(&ds->ds_synced_link));
508 506 dmu_buf_rele(ds->ds_dbuf, ds);
509 507 dsl_dataset_sync(ds, zio, tx);
510 508 }
511 509 VERIFY0(zio_wait(zio));
512 510
513 511 /*
514 512 * Now that the datasets have been completely synced, we can
515 513 * clean up our in-memory structures accumulated while syncing:
516 514 *
517 515 * - move dead blocks from the pending deadlist to the on-disk deadlist
518 516 * - release hold from dsl_dataset_dirty()
519 517 */
520 518 while ((ds = list_remove_head(&synced_datasets)) != NULL) {
521 519 objset_t *os = ds->ds_objset;
522 520 bplist_iterate(&ds->ds_pending_deadlist,
523 521 deadlist_enqueue_cb, &ds->ds_deadlist, tx);
524 522 ASSERT(!dmu_objset_is_dirty(os, txg));
525 523 dmu_buf_rele(ds->ds_dbuf, ds);
526 524 }
527 525 while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)) != NULL) {
528 526 dsl_dir_sync(dd, tx);
529 527 }
530 528
531 529 /*
532 530 * The MOS's space is accounted for in the pool/$MOS
533 531 * (dp_mos_dir). We can't modify the mos while we're syncing
534 532 * it, so we remember the deltas and apply them here.
535 533 */
536 534 if (dp->dp_mos_used_delta != 0 || dp->dp_mos_compressed_delta != 0 ||
537 535 dp->dp_mos_uncompressed_delta != 0) {
538 536 dsl_dir_diduse_space(dp->dp_mos_dir, DD_USED_HEAD,
539 537 dp->dp_mos_used_delta,
540 538 dp->dp_mos_compressed_delta,
541 539 dp->dp_mos_uncompressed_delta, tx);
542 540 dp->dp_mos_used_delta = 0;
543 541 dp->dp_mos_compressed_delta = 0;
544 542 dp->dp_mos_uncompressed_delta = 0;
545 543 }
546 544
547 545 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL ||
548 546 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) {
549 547 dsl_pool_sync_mos(dp, tx);
550 548 }
551 549
552 550 /*
553 551 * If we modify a dataset in the same txg that we want to destroy it,
554 552 * its dsl_dir's dd_dbuf will be dirty, and thus have a hold on it.
555 553 * dsl_dir_destroy_check() will fail if there are unexpected holds.
556 554 * Therefore, we want to sync the MOS (thus syncing the dd_dbuf
557 555 * and clearing the hold on it) before we process the sync_tasks.
558 556 * The MOS data dirtied by the sync_tasks will be synced on the next
559 557 * pass.
560 558 */
561 559 if (!txg_list_empty(&dp->dp_sync_tasks, txg)) {
562 560 dsl_sync_task_t *dst;
563 561 /*
564 562 * No more sync tasks should have been added while we
565 563 * were syncing.
566 564 */
567 565 ASSERT3U(spa_sync_pass(dp->dp_spa), ==, 1);
568 566 while ((dst = txg_list_remove(&dp->dp_sync_tasks, txg)) != NULL)
569 567 dsl_sync_task_sync(dst, tx);
570 568 }
571 569
572 570 dmu_tx_commit(tx);
573 571
574 572 DTRACE_PROBE2(dsl_pool_sync__done, dsl_pool_t *dp, dp, uint64_t, txg);
575 573 }
576 574
577 575 void
578 576 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
579 577 {
580 578 zilog_t *zilog;
581 579
582 580 while (zilog = txg_list_remove(&dp->dp_dirty_zilogs, txg)) {
583 581 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
584 582 zil_clean(zilog, txg);
585 583 ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg));
586 584 dmu_buf_rele(ds->ds_dbuf, zilog);
587 585 }
588 586 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg));
589 587 }
590 588
591 589 /*
592 590 * TRUE if the current thread is the tx_sync_thread or if we
593 591 * are being called from SPA context during pool initialization.
594 592 */
595 593 int
596 594 dsl_pool_sync_context(dsl_pool_t *dp)
597 595 {
598 596 return (curthread == dp->dp_tx.tx_sync_thread ||
599 597 spa_is_initializing(dp->dp_spa));
600 598 }
601 599
602 600 uint64_t
603 601 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)
604 602 {
605 603 uint64_t space, resv;
606 604
607 605 /*
608 606 * Reserve about 1.6% (1/64), or at least 32MB, for allocation
609 607 * efficiency.
610 608 * XXX The intent log is not accounted for, so it must fit
611 609 * within this slop.
612 610 *
613 611 * If we're trying to assess whether it's OK to do a free,
614 612 * cut the reservation in half to allow forward progress
615 613 * (e.g. make it possible to rm(1) files from a full pool).
616 614 */
617 615 space = spa_get_dspace(dp->dp_spa);
618 616 resv = MAX(space >> 6, SPA_MINDEVSIZE >> 1);
619 617 if (netfree)
620 618 resv >>= 1;
621 619
622 620 return (space - resv);
623 621 }
624 622
625 623 boolean_t
626 624 dsl_pool_need_dirty_delay(dsl_pool_t *dp)
627 625 {
628 626 uint64_t delay_min_bytes =
629 627 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100;
630 628 boolean_t rv;
631 629
632 630 mutex_enter(&dp->dp_lock);
633 631 if (dp->dp_dirty_total > zfs_dirty_data_sync)
634 632 txg_kick(dp);
635 633 rv = (dp->dp_dirty_total > delay_min_bytes);
636 634 mutex_exit(&dp->dp_lock);
637 635 return (rv);
638 636 }
639 637
640 638 void
641 639 dsl_pool_dirty_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
642 640 {
643 641 if (space > 0) {
644 642 mutex_enter(&dp->dp_lock);
645 643 dp->dp_dirty_pertxg[tx->tx_txg & TXG_MASK] += space;
646 644 dsl_pool_dirty_delta(dp, space);
647 645 mutex_exit(&dp->dp_lock);
648 646 }
649 647 }
650 648
651 649 void
652 650 dsl_pool_undirty_space(dsl_pool_t *dp, int64_t space, uint64_t txg)
653 651 {
654 652 ASSERT3S(space, >=, 0);
655 653 if (space == 0)
656 654 return;
657 655 mutex_enter(&dp->dp_lock);
658 656 if (dp->dp_dirty_pertxg[txg & TXG_MASK] < space) {
659 657 /* XXX writing something we didn't dirty? */
660 658 space = dp->dp_dirty_pertxg[txg & TXG_MASK];
661 659 }
662 660 ASSERT3U(dp->dp_dirty_pertxg[txg & TXG_MASK], >=, space);
663 661 dp->dp_dirty_pertxg[txg & TXG_MASK] -= space;
664 662 ASSERT3U(dp->dp_dirty_total, >=, space);
665 663 dsl_pool_dirty_delta(dp, -space);
666 664 mutex_exit(&dp->dp_lock);
667 665 }
668 666
669 667 /* ARGSUSED */
670 668 static int
671 669 upgrade_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
672 670 {
673 671 dmu_tx_t *tx = arg;
674 672 dsl_dataset_t *ds, *prev = NULL;
675 673 int err;
676 674
677 675 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
678 676 if (err)
679 677 return (err);
680 678
681 679 while (ds->ds_phys->ds_prev_snap_obj != 0) {
682 680 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
683 681 FTAG, &prev);
684 682 if (err) {
685 683 dsl_dataset_rele(ds, FTAG);
686 684 return (err);
687 685 }
688 686
689 687 if (prev->ds_phys->ds_next_snap_obj != ds->ds_object)
690 688 break;
691 689 dsl_dataset_rele(ds, FTAG);
692 690 ds = prev;
693 691 prev = NULL;
694 692 }
695 693
696 694 if (prev == NULL) {
697 695 prev = dp->dp_origin_snap;
698 696
699 697 /*
700 698 * The $ORIGIN can't have any data, or the accounting
701 699 * will be wrong.
702 700 */
703 701 ASSERT0(prev->ds_phys->ds_bp.blk_birth);
704 702
705 703 /* The origin doesn't get attached to itself */
706 704 if (ds->ds_object == prev->ds_object) {
707 705 dsl_dataset_rele(ds, FTAG);
708 706 return (0);
709 707 }
710 708
711 709 dmu_buf_will_dirty(ds->ds_dbuf, tx);
712 710 ds->ds_phys->ds_prev_snap_obj = prev->ds_object;
713 711 ds->ds_phys->ds_prev_snap_txg = prev->ds_phys->ds_creation_txg;
714 712
715 713 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
716 714 ds->ds_dir->dd_phys->dd_origin_obj = prev->ds_object;
717 715
718 716 dmu_buf_will_dirty(prev->ds_dbuf, tx);
719 717 prev->ds_phys->ds_num_children++;
720 718
721 719 if (ds->ds_phys->ds_next_snap_obj == 0) {
722 720 ASSERT(ds->ds_prev == NULL);
723 721 VERIFY0(dsl_dataset_hold_obj(dp,
724 722 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
725 723 }
726 724 }
727 725
728 726 ASSERT3U(ds->ds_dir->dd_phys->dd_origin_obj, ==, prev->ds_object);
729 727 ASSERT3U(ds->ds_phys->ds_prev_snap_obj, ==, prev->ds_object);
730 728
731 729 if (prev->ds_phys->ds_next_clones_obj == 0) {
732 730 dmu_buf_will_dirty(prev->ds_dbuf, tx);
733 731 prev->ds_phys->ds_next_clones_obj =
734 732 zap_create(dp->dp_meta_objset,
735 733 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
736 734 }
737 735 VERIFY0(zap_add_int(dp->dp_meta_objset,
738 736 prev->ds_phys->ds_next_clones_obj, ds->ds_object, tx));
739 737
740 738 dsl_dataset_rele(ds, FTAG);
741 739 if (prev != dp->dp_origin_snap)
742 740 dsl_dataset_rele(prev, FTAG);
743 741 return (0);
744 742 }
745 743
746 744 void
747 745 dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx)
748 746 {
749 747 ASSERT(dmu_tx_is_syncing(tx));
750 748 ASSERT(dp->dp_origin_snap != NULL);
751 749
752 750 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, upgrade_clones_cb,
753 751 tx, DS_FIND_CHILDREN));
754 752 }
755 753
756 754 /* ARGSUSED */
757 755 static int
758 756 upgrade_dir_clones_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
759 757 {
760 758 dmu_tx_t *tx = arg;
761 759 objset_t *mos = dp->dp_meta_objset;
762 760
763 761 if (ds->ds_dir->dd_phys->dd_origin_obj != 0) {
764 762 dsl_dataset_t *origin;
765 763
766 764 VERIFY0(dsl_dataset_hold_obj(dp,
767 765 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin));
768 766
769 767 if (origin->ds_dir->dd_phys->dd_clones == 0) {
770 768 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
771 769 origin->ds_dir->dd_phys->dd_clones = zap_create(mos,
772 770 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
773 771 }
774 772
775 773 VERIFY0(zap_add_int(dp->dp_meta_objset,
776 774 origin->ds_dir->dd_phys->dd_clones, ds->ds_object, tx));
777 775
778 776 dsl_dataset_rele(origin, FTAG);
779 777 }
780 778 return (0);
781 779 }
782 780
783 781 void
784 782 dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx)
785 783 {
786 784 ASSERT(dmu_tx_is_syncing(tx));
787 785 uint64_t obj;
788 786
789 787 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, FREE_DIR_NAME, tx);
790 788 VERIFY0(dsl_pool_open_special_dir(dp,
791 789 FREE_DIR_NAME, &dp->dp_free_dir));
792 790
793 791 /*
794 792 * We can't use bpobj_alloc(), because spa_version() still
795 793 * returns the old version, and we need a new-version bpobj with
796 794 * subobj support. So call dmu_object_alloc() directly.
797 795 */
798 796 obj = dmu_object_alloc(dp->dp_meta_objset, DMU_OT_BPOBJ,
799 797 SPA_MAXBLOCKSIZE, DMU_OT_BPOBJ_HDR, sizeof (bpobj_phys_t), tx);
800 798 VERIFY0(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
801 799 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx));
802 800 VERIFY0(bpobj_open(&dp->dp_free_bpobj, dp->dp_meta_objset, obj));
803 801
804 802 VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
805 803 upgrade_dir_clones_cb, tx, DS_FIND_CHILDREN));
806 804 }
807 805
808 806 void
809 807 dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx)
810 808 {
811 809 uint64_t dsobj;
812 810 dsl_dataset_t *ds;
813 811
814 812 ASSERT(dmu_tx_is_syncing(tx));
815 813 ASSERT(dp->dp_origin_snap == NULL);
816 814 ASSERT(rrw_held(&dp->dp_config_rwlock, RW_WRITER));
817 815
818 816 /* create the origin dir, ds, & snap-ds */
819 817 dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME,
820 818 NULL, 0, kcred, tx);
821 819 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
822 820 dsl_dataset_snapshot_sync_impl(ds, ORIGIN_DIR_NAME, tx);
823 821 VERIFY0(dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
824 822 dp, &dp->dp_origin_snap));
825 823 dsl_dataset_rele(ds, FTAG);
826 824 }
827 825
828 826 taskq_t *
829 827 dsl_pool_vnrele_taskq(dsl_pool_t *dp)
830 828 {
831 829 return (dp->dp_vnrele_taskq);
832 830 }
833 831
834 832 /*
835 833 * Walk through the pool-wide zap object of temporary snapshot user holds
836 834 * and release them.
837 835 */
838 836 void
839 837 dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp)
840 838 {
841 839 zap_attribute_t za;
842 840 zap_cursor_t zc;
843 841 objset_t *mos = dp->dp_meta_objset;
844 842 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
845 843 nvlist_t *holds;
846 844
847 845 if (zapobj == 0)
848 846 return;
849 847 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
850 848
851 849 holds = fnvlist_alloc();
852 850
853 851 for (zap_cursor_init(&zc, mos, zapobj);
854 852 zap_cursor_retrieve(&zc, &za) == 0;
855 853 zap_cursor_advance(&zc)) {
856 854 char *htag;
857 855 nvlist_t *tags;
858 856
859 857 htag = strchr(za.za_name, '-');
860 858 *htag = '\0';
861 859 ++htag;
862 860 if (nvlist_lookup_nvlist(holds, za.za_name, &tags) != 0) {
863 861 tags = fnvlist_alloc();
864 862 fnvlist_add_boolean(tags, htag);
865 863 fnvlist_add_nvlist(holds, za.za_name, tags);
866 864 fnvlist_free(tags);
867 865 } else {
868 866 fnvlist_add_boolean(tags, htag);
869 867 }
870 868 }
871 869 dsl_dataset_user_release_tmp(dp, holds);
872 870 fnvlist_free(holds);
873 871 zap_cursor_fini(&zc);
874 872 }
875 873
876 874 /*
877 875 * Create the pool-wide zap object for storing temporary snapshot holds.
878 876 */
879 877 void
880 878 dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx)
881 879 {
882 880 objset_t *mos = dp->dp_meta_objset;
883 881
884 882 ASSERT(dp->dp_tmp_userrefs_obj == 0);
885 883 ASSERT(dmu_tx_is_syncing(tx));
886 884
887 885 dp->dp_tmp_userrefs_obj = zap_create_link(mos, DMU_OT_USERREFS,
888 886 DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, tx);
889 887 }
890 888
891 889 static int
892 890 dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj,
893 891 const char *tag, uint64_t now, dmu_tx_t *tx, boolean_t holding)
894 892 {
895 893 objset_t *mos = dp->dp_meta_objset;
896 894 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
897 895 char *name;
898 896 int error;
899 897
900 898 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
901 899 ASSERT(dmu_tx_is_syncing(tx));
902 900
903 901 /*
904 902 * If the pool was created prior to SPA_VERSION_USERREFS, the
905 903 * zap object for temporary holds might not exist yet.
906 904 */
907 905 if (zapobj == 0) {
908 906 if (holding) {
909 907 dsl_pool_user_hold_create_obj(dp, tx);
910 908 zapobj = dp->dp_tmp_userrefs_obj;
911 909 } else {
912 910 return (SET_ERROR(ENOENT));
913 911 }
914 912 }
915 913
916 914 name = kmem_asprintf("%llx-%s", (u_longlong_t)dsobj, tag);
917 915 if (holding)
918 916 error = zap_add(mos, zapobj, name, 8, 1, &now, tx);
919 917 else
920 918 error = zap_remove(mos, zapobj, name, tx);
921 919 strfree(name);
922 920
923 921 return (error);
924 922 }
925 923
926 924 /*
927 925 * Add a temporary hold for the given dataset object and tag.
928 926 */
929 927 int
930 928 dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
931 929 uint64_t now, dmu_tx_t *tx)
932 930 {
933 931 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE));
934 932 }
935 933
936 934 /*
937 935 * Release a temporary hold for the given dataset object and tag.
938 936 */
939 937 int
940 938 dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
941 939 dmu_tx_t *tx)
942 940 {
943 941 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, NULL,
944 942 tx, B_FALSE));
945 943 }
946 944
947 945 /*
948 946 * DSL Pool Configuration Lock
949 947 *
950 948 * The dp_config_rwlock protects against changes to DSL state (e.g. dataset
951 949 * creation / destruction / rename / property setting). It must be held for
952 950 * read to hold a dataset or dsl_dir. I.e. you must call
953 951 * dsl_pool_config_enter() or dsl_pool_hold() before calling
954 952 * dsl_{dataset,dir}_hold{_obj}. In most circumstances, the dp_config_rwlock
955 953 * must be held continuously until all datasets and dsl_dirs are released.
956 954 *
957 955 * The only exception to this rule is that if a "long hold" is placed on
958 956 * a dataset, then the dp_config_rwlock may be dropped while the dataset
959 957 * is still held. The long hold will prevent the dataset from being
960 958 * destroyed -- the destroy will fail with EBUSY. A long hold can be
961 959 * obtained by calling dsl_dataset_long_hold(), or by "owning" a dataset
962 960 * (by calling dsl_{dataset,objset}_{try}own{_obj}).
963 961 *
964 962 * Legitimate long-holders (including owners) should be long-running, cancelable
965 963 * tasks that should cause "zfs destroy" to fail. This includes DMU
966 964 * consumers (i.e. a ZPL filesystem being mounted or ZVOL being open),
967 965 * "zfs send", and "zfs diff". There are several other long-holders whose
968 966 * uses are suboptimal (e.g. "zfs promote", and zil_suspend()).
969 967 *
970 968 * The usual formula for long-holding would be:
971 969 * dsl_pool_hold()
972 970 * dsl_dataset_hold()
973 971 * ... perform checks ...
974 972 * dsl_dataset_long_hold()
975 973 * dsl_pool_rele()
976 974 * ... perform long-running task ...
977 975 * dsl_dataset_long_rele()
978 976 * dsl_dataset_rele()
979 977 *
980 978 * Note that when the long hold is released, the dataset is still held but
981 979 * the pool is not held. The dataset may change arbitrarily during this time
982 980 * (e.g. it could be destroyed). Therefore you shouldn't do anything to the
983 981 * dataset except release it.
984 982 *
985 983 * User-initiated operations (e.g. ioctls, zfs_ioc_*()) are either read-only
986 984 * or modifying operations.
987 985 *
988 986 * Modifying operations should generally use dsl_sync_task(). The synctask
989 987 * infrastructure enforces proper locking strategy with respect to the
990 988 * dp_config_rwlock. See the comment above dsl_sync_task() for details.
991 989 *
992 990 * Read-only operations will manually hold the pool, then the dataset, obtain
993 991 * information from the dataset, then release the pool and dataset.
994 992 * dmu_objset_{hold,rele}() are convenience routines that also do the pool
995 993 * hold/rele.
996 994 */
997 995
998 996 int
999 997 dsl_pool_hold(const char *name, void *tag, dsl_pool_t **dp)
1000 998 {
1001 999 spa_t *spa;
1002 1000 int error;
1003 1001
1004 1002 error = spa_open(name, &spa, tag);
1005 1003 if (error == 0) {
1006 1004 *dp = spa_get_dsl(spa);
1007 1005 dsl_pool_config_enter(*dp, tag);
1008 1006 }
1009 1007 return (error);
1010 1008 }
1011 1009
1012 1010 void
1013 1011 dsl_pool_rele(dsl_pool_t *dp, void *tag)
1014 1012 {
1015 1013 dsl_pool_config_exit(dp, tag);
1016 1014 spa_close(dp->dp_spa, tag);
1017 1015 }
1018 1016
1019 1017 void
1020 1018 dsl_pool_config_enter(dsl_pool_t *dp, void *tag)
1021 1019 {
1022 1020 /*
1023 1021 * We use a "reentrant" reader-writer lock, but not reentrantly.
1024 1022 *
1025 1023 * The rrwlock can (with the track_all flag) track all reading threads,
1026 1024 * which is very useful for debugging which code path failed to release
1027 1025 * the lock, and for verifying that the *current* thread does hold
1028 1026 * the lock.
1029 1027 *
1030 1028 * (Unlike a rwlock, which knows that N threads hold it for
1031 1029 * read, but not *which* threads, so rw_held(RW_READER) returns TRUE
1032 1030 * if any thread holds it for read, even if this thread doesn't).
1033 1031 */
1034 1032 ASSERT(!rrw_held(&dp->dp_config_rwlock, RW_READER));
1035 1033 rrw_enter(&dp->dp_config_rwlock, RW_READER, tag);
1036 1034 }
1037 1035
1038 1036 void
1039 1037 dsl_pool_config_exit(dsl_pool_t *dp, void *tag)
1040 1038 {
1041 1039 rrw_exit(&dp->dp_config_rwlock, tag);
1042 1040 }
1043 1041
1044 1042 boolean_t
1045 1043 dsl_pool_config_held(dsl_pool_t *dp)
1046 1044 {
1047 1045 return (RRW_LOCK_HELD(&dp->dp_config_rwlock));
1048 1046 }
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