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) 2012 by Delphix. All rights reserved.
24 */
25
26 #include <sys/dsl_pool.h>
27 #include <sys/dsl_dataset.h>
28 #include <sys/dsl_prop.h>
29 #include <sys/dsl_dir.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/dsl_scan.h>
32 #include <sys/dnode.h>
33 #include <sys/dmu_tx.h>
34 #include <sys/dmu_objset.h>
35 #include <sys/arc.h>
36 #include <sys/zap.h>
37 #include <sys/zio.h>
38 #include <sys/zfs_context.h>
39 #include <sys/fs/zfs.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/spa_impl.h>
42 #include <sys/dsl_deadlist.h>
43 #include <sys/bptree.h>
44 #include <sys/zfeature.h>
45
46 int zfs_no_write_throttle = 0;
47 int zfs_write_limit_shift = 3; /* 1/8th of physical memory */
48 int zfs_txg_synctime_ms = 1000; /* target millisecs to sync a txg */
49
50 uint64_t zfs_write_limit_min = 32 << 20; /* min write limit is 32MB */
51 uint64_t zfs_write_limit_max = 0; /* max data payload per txg */
52 uint64_t zfs_write_limit_inflated = 0;
53 uint64_t zfs_write_limit_override = 0;
54
55 kmutex_t zfs_write_limit_lock;
56
57 static pgcnt_t old_physmem = 0;
58
59 int
60 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
61 {
62 uint64_t obj;
63 int err;
64
65 err = zap_lookup(dp->dp_meta_objset,
66 dp->dp_root_dir->dd_phys->dd_child_dir_zapobj,
67 name, sizeof (obj), 1, &obj);
68 if (err)
69 return (err);
70
71 return (dsl_dir_open_obj(dp, obj, name, dp, ddp));
72 }
73
74 static dsl_pool_t *
75 dsl_pool_open_impl(spa_t *spa, uint64_t txg)
76 {
77 dsl_pool_t *dp;
78 blkptr_t *bp = spa_get_rootblkptr(spa);
79
80 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);
81 dp->dp_spa = spa;
82 dp->dp_meta_rootbp = *bp;
83 rw_init(&dp->dp_config_rwlock, NULL, RW_DEFAULT, NULL);
84 dp->dp_write_limit = zfs_write_limit_min;
85 txg_init(dp, txg);
86
87 txg_list_create(&dp->dp_dirty_datasets,
88 offsetof(dsl_dataset_t, ds_dirty_link));
89 txg_list_create(&dp->dp_dirty_dirs,
90 offsetof(dsl_dir_t, dd_dirty_link));
91 txg_list_create(&dp->dp_sync_tasks,
92 offsetof(dsl_sync_task_group_t, dstg_node));
93 list_create(&dp->dp_synced_datasets, sizeof (dsl_dataset_t),
94 offsetof(dsl_dataset_t, ds_synced_link));
95
96 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
97
98 dp->dp_vnrele_taskq = taskq_create("zfs_vn_rele_taskq", 1, minclsyspri,
99 1, 4, 0);
100
101 return (dp);
102 }
103
104 int
105 dsl_pool_init(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
106 {
107 int err;
108 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
109
110 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
111 &dp->dp_meta_objset);
112 if (err != 0)
113 dsl_pool_close(dp);
114 else
115 *dpp = dp;
116
117 return (err);
118 }
119
120 int
121 dsl_pool_open(dsl_pool_t *dp)
122 {
123 int err;
124 dsl_dir_t *dd;
125 dsl_dataset_t *ds;
126 uint64_t obj;
127
128 ASSERT(!dmu_objset_is_dirty_anywhere(dp->dp_meta_objset));
129
130 rw_enter(&dp->dp_config_rwlock, RW_WRITER);
131 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
132 DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1,
133 &dp->dp_root_dir_obj);
134 if (err)
135 goto out;
136
137 err = dsl_dir_open_obj(dp, dp->dp_root_dir_obj,
138 NULL, dp, &dp->dp_root_dir);
139 if (err)
140 goto out;
141
142 err = dsl_pool_open_special_dir(dp, MOS_DIR_NAME, &dp->dp_mos_dir);
143 if (err)
144 goto out;
145
146 if (spa_version(dp->dp_spa) >= SPA_VERSION_ORIGIN) {
147 err = dsl_pool_open_special_dir(dp, ORIGIN_DIR_NAME, &dd);
148 if (err)
149 goto out;
150 err = dsl_dataset_hold_obj(dp, dd->dd_phys->dd_head_dataset_obj,
151 FTAG, &ds);
152 if (err == 0) {
153 err = dsl_dataset_hold_obj(dp,
154 ds->ds_phys->ds_prev_snap_obj, dp,
155 &dp->dp_origin_snap);
156 dsl_dataset_rele(ds, FTAG);
157 }
158 dsl_dir_close(dd, dp);
159 if (err)
160 goto out;
161 }
162
163 if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) {
164 err = dsl_pool_open_special_dir(dp, FREE_DIR_NAME,
165 &dp->dp_free_dir);
166 if (err)
167 goto out;
168
169 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
170 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj);
171 if (err)
172 goto out;
173 VERIFY0(bpobj_open(&dp->dp_free_bpobj,
174 dp->dp_meta_objset, obj));
175 }
176
177 if (spa_feature_is_active(dp->dp_spa,
178 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
179 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
180 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
181 &dp->dp_bptree_obj);
182 if (err != 0)
183 goto out;
184 }
185
186 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
187 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1,
188 &dp->dp_tmp_userrefs_obj);
189 if (err == ENOENT)
190 err = 0;
191 if (err)
192 goto out;
193
194 err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg);
195
196 out:
197 rw_exit(&dp->dp_config_rwlock);
198 return (err);
199 }
200
201 void
202 dsl_pool_close(dsl_pool_t *dp)
203 {
204 /* drop our references from dsl_pool_open() */
205
206 /*
207 * Since we held the origin_snap from "syncing" context (which
208 * includes pool-opening context), it actually only got a "ref"
209 * and not a hold, so just drop that here.
210 */
211 if (dp->dp_origin_snap)
212 dsl_dataset_drop_ref(dp->dp_origin_snap, dp);
213 if (dp->dp_mos_dir)
214 dsl_dir_close(dp->dp_mos_dir, dp);
215 if (dp->dp_free_dir)
216 dsl_dir_close(dp->dp_free_dir, dp);
217 if (dp->dp_root_dir)
218 dsl_dir_close(dp->dp_root_dir, dp);
219
220 bpobj_close(&dp->dp_free_bpobj);
221
222 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
223 if (dp->dp_meta_objset)
224 dmu_objset_evict(dp->dp_meta_objset);
225
226 txg_list_destroy(&dp->dp_dirty_datasets);
227 txg_list_destroy(&dp->dp_sync_tasks);
228 txg_list_destroy(&dp->dp_dirty_dirs);
229 list_destroy(&dp->dp_synced_datasets);
230
231 arc_flush(dp->dp_spa);
232 txg_fini(dp);
233 dsl_scan_fini(dp);
234 rw_destroy(&dp->dp_config_rwlock);
235 mutex_destroy(&dp->dp_lock);
236 taskq_destroy(dp->dp_vnrele_taskq);
237 if (dp->dp_blkstats)
238 kmem_free(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
239 kmem_free(dp, sizeof (dsl_pool_t));
240 }
241
242 dsl_pool_t *
243 dsl_pool_create(spa_t *spa, nvlist_t *zplprops, uint64_t txg)
244 {
245 int err;
246 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
247 dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
248 objset_t *os;
249 dsl_dataset_t *ds;
250 uint64_t obj;
251
252 /* create and open the MOS (meta-objset) */
253 dp->dp_meta_objset = dmu_objset_create_impl(spa,
254 NULL, &dp->dp_meta_rootbp, DMU_OST_META, tx);
255
256 /* create the pool directory */
257 err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
258 DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx);
259 ASSERT0(err);
260
261 /* Initialize scan structures */
262 VERIFY0(dsl_scan_init(dp, txg));
263
264 /* create and open the root dir */
265 dp->dp_root_dir_obj = dsl_dir_create_sync(dp, NULL, NULL, tx);
266 VERIFY(0 == dsl_dir_open_obj(dp, dp->dp_root_dir_obj,
267 NULL, dp, &dp->dp_root_dir));
268
269 /* create and open the meta-objset dir */
270 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, MOS_DIR_NAME, tx);
271 VERIFY(0 == dsl_pool_open_special_dir(dp,
272 MOS_DIR_NAME, &dp->dp_mos_dir));
273
274 if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
275 /* create and open the free dir */
276 (void) dsl_dir_create_sync(dp, dp->dp_root_dir,
277 FREE_DIR_NAME, tx);
278 VERIFY(0 == dsl_pool_open_special_dir(dp,
279 FREE_DIR_NAME, &dp->dp_free_dir));
280
281 /* create and open the free_bplist */
282 obj = bpobj_alloc(dp->dp_meta_objset, SPA_MAXBLOCKSIZE, tx);
283 VERIFY(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
284 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx) == 0);
285 VERIFY0(bpobj_open(&dp->dp_free_bpobj,
286 dp->dp_meta_objset, obj));
287 }
288
289 if (spa_version(spa) >= SPA_VERSION_DSL_SCRUB)
290 dsl_pool_create_origin(dp, tx);
291
292 /* create the root dataset */
293 obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, 0, tx);
294
295 /* create the root objset */
296 VERIFY(0 == dsl_dataset_hold_obj(dp, obj, FTAG, &ds));
297 os = dmu_objset_create_impl(dp->dp_spa, ds,
298 dsl_dataset_get_blkptr(ds), DMU_OST_ZFS, tx);
299 #ifdef _KERNEL
300 zfs_create_fs(os, kcred, zplprops, tx);
301 #endif
302 dsl_dataset_rele(ds, FTAG);
303
304 dmu_tx_commit(tx);
305
306 return (dp);
307 }
308
309 static int
310 deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
311 {
312 dsl_deadlist_t *dl = arg;
313 dsl_pool_t *dp = dmu_objset_pool(dl->dl_os);
314 rw_enter(&dp->dp_config_rwlock, RW_READER);
315 dsl_deadlist_insert(dl, bp, tx);
316 rw_exit(&dp->dp_config_rwlock);
317 return (0);
318 }
319
320 void
321 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
322 {
323 zio_t *zio;
324 dmu_tx_t *tx;
325 dsl_dir_t *dd;
326 dsl_dataset_t *ds;
327 dsl_sync_task_group_t *dstg;
328 objset_t *mos = dp->dp_meta_objset;
329 hrtime_t start, write_time;
330 uint64_t data_written;
331 int err;
332
333 /*
334 * We need to copy dp_space_towrite() before doing
335 * dsl_sync_task_group_sync(), because
336 * dsl_dataset_snapshot_reserve_space() will increase
337 * dp_space_towrite but not actually write anything.
338 */
339 data_written = dp->dp_space_towrite[txg & TXG_MASK];
340
341 tx = dmu_tx_create_assigned(dp, txg);
342
343 dp->dp_read_overhead = 0;
344 start = gethrtime();
345
346 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
347 while (ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) {
348 /*
349 * We must not sync any non-MOS datasets twice, because
350 * we may have taken a snapshot of them. However, we
351 * may sync newly-created datasets on pass 2.
352 */
353 ASSERT(!list_link_active(&ds->ds_synced_link));
354 list_insert_tail(&dp->dp_synced_datasets, ds);
355 dsl_dataset_sync(ds, zio, tx);
356 }
357 DTRACE_PROBE(pool_sync__1setup);
358 err = zio_wait(zio);
359
360 write_time = gethrtime() - start;
361 ASSERT(err == 0);
362 DTRACE_PROBE(pool_sync__2rootzio);
363
364 for (ds = list_head(&dp->dp_synced_datasets); ds;
365 ds = list_next(&dp->dp_synced_datasets, ds))
366 dmu_objset_do_userquota_updates(ds->ds_objset, tx);
367
368 /*
369 * Sync the datasets again to push out the changes due to
370 * userspace updates. This must be done before we process the
371 * sync tasks, because that could cause a snapshot of a dataset
372 * whose ds_bp will be rewritten when we do this 2nd sync.
373 */
374 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
375 while (ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) {
376 ASSERT(list_link_active(&ds->ds_synced_link));
377 dmu_buf_rele(ds->ds_dbuf, ds);
378 dsl_dataset_sync(ds, zio, tx);
379 }
380 err = zio_wait(zio);
381
382 /*
383 * Move dead blocks from the pending deadlist to the on-disk
384 * deadlist.
385 */
386 for (ds = list_head(&dp->dp_synced_datasets); ds;
387 ds = list_next(&dp->dp_synced_datasets, ds)) {
388 bplist_iterate(&ds->ds_pending_deadlist,
389 deadlist_enqueue_cb, &ds->ds_deadlist, tx);
390 }
391
392 while (dstg = txg_list_remove(&dp->dp_sync_tasks, txg)) {
393 /*
394 * No more sync tasks should have been added while we
395 * were syncing.
396 */
397 ASSERT(spa_sync_pass(dp->dp_spa) == 1);
398 dsl_sync_task_group_sync(dstg, tx);
399 }
400 DTRACE_PROBE(pool_sync__3task);
401
402 start = gethrtime();
403 while (dd = txg_list_remove(&dp->dp_dirty_dirs, txg))
404 dsl_dir_sync(dd, tx);
405 write_time += gethrtime() - start;
406
407 start = gethrtime();
408 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL ||
409 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) {
410 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
411 dmu_objset_sync(mos, zio, tx);
412 err = zio_wait(zio);
413 ASSERT(err == 0);
414 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");
415 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
416 }
417 write_time += gethrtime() - start;
418 DTRACE_PROBE2(pool_sync__4io, hrtime_t, write_time,
419 hrtime_t, dp->dp_read_overhead);
420 write_time -= dp->dp_read_overhead;
421
422 dmu_tx_commit(tx);
423
424 dp->dp_space_towrite[txg & TXG_MASK] = 0;
425 ASSERT(dp->dp_tempreserved[txg & TXG_MASK] == 0);
426
427 /*
428 * If the write limit max has not been explicitly set, set it
429 * to a fraction of available physical memory (default 1/8th).
430 * Note that we must inflate the limit because the spa
431 * inflates write sizes to account for data replication.
432 * Check this each sync phase to catch changing memory size.
433 */
434 if (physmem != old_physmem && zfs_write_limit_shift) {
435 mutex_enter(&zfs_write_limit_lock);
436 old_physmem = physmem;
437 zfs_write_limit_max = ptob(physmem) >> zfs_write_limit_shift;
438 zfs_write_limit_inflated = MAX(zfs_write_limit_min,
439 spa_get_asize(dp->dp_spa, zfs_write_limit_max));
440 mutex_exit(&zfs_write_limit_lock);
441 }
442
443 /*
444 * Attempt to keep the sync time consistent by adjusting the
445 * amount of write traffic allowed into each transaction group.
446 * Weight the throughput calculation towards the current value:
447 * thru = 3/4 old_thru + 1/4 new_thru
448 *
449 * Note: write_time is in nanosecs, so write_time/MICROSEC
450 * yields millisecs
451 */
452 ASSERT(zfs_write_limit_min > 0);
453 if (data_written > zfs_write_limit_min / 8 && write_time > MICROSEC) {
454 uint64_t throughput = data_written / (write_time / MICROSEC);
455
456 if (dp->dp_throughput)
457 dp->dp_throughput = throughput / 4 +
458 3 * dp->dp_throughput / 4;
459 else
460 dp->dp_throughput = throughput;
461 dp->dp_write_limit = MIN(zfs_write_limit_inflated,
462 MAX(zfs_write_limit_min,
463 dp->dp_throughput * zfs_txg_synctime_ms));
464 }
465 }
466
467 void
468 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
469 {
470 dsl_dataset_t *ds;
471 objset_t *os;
472
473 while (ds = list_head(&dp->dp_synced_datasets)) {
474 list_remove(&dp->dp_synced_datasets, ds);
475 os = ds->ds_objset;
476 zil_clean(os->os_zil, txg);
477 ASSERT(!dmu_objset_is_dirty(os, txg));
478 dmu_buf_rele(ds->ds_dbuf, ds);
479 }
480 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg));
481 }
482
483 /*
484 * TRUE if the current thread is the tx_sync_thread or if we
485 * are being called from SPA context during pool initialization.
486 */
487 int
488 dsl_pool_sync_context(dsl_pool_t *dp)
489 {
490 return (curthread == dp->dp_tx.tx_sync_thread ||
491 spa_is_initializing(dp->dp_spa));
492 }
493
494 uint64_t
495 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)
496 {
497 uint64_t space, resv;
498
499 /*
500 * Reserve about 1.6% (1/64), or at least 32MB, for allocation
501 * efficiency.
502 * XXX The intent log is not accounted for, so it must fit
503 * within this slop.
504 *
505 * If we're trying to assess whether it's OK to do a free,
506 * cut the reservation in half to allow forward progress
507 * (e.g. make it possible to rm(1) files from a full pool).
508 */
509 space = spa_get_dspace(dp->dp_spa);
510 resv = MAX(space >> 6, SPA_MINDEVSIZE >> 1);
511 if (netfree)
512 resv >>= 1;
513
514 return (space - resv);
515 }
516
517 int
518 dsl_pool_tempreserve_space(dsl_pool_t *dp, uint64_t space, dmu_tx_t *tx)
519 {
520 uint64_t reserved = 0;
521 uint64_t write_limit = (zfs_write_limit_override ?
522 zfs_write_limit_override : dp->dp_write_limit);
523
524 if (zfs_no_write_throttle) {
525 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK],
526 space);
527 return (0);
528 }
529
530 /*
531 * Check to see if we have exceeded the maximum allowed IO for
532 * this transaction group. We can do this without locks since
533 * a little slop here is ok. Note that we do the reserved check
534 * with only half the requested reserve: this is because the
535 * reserve requests are worst-case, and we really don't want to
536 * throttle based off of worst-case estimates.
537 */
538 if (write_limit > 0) {
539 reserved = dp->dp_space_towrite[tx->tx_txg & TXG_MASK]
540 + dp->dp_tempreserved[tx->tx_txg & TXG_MASK] / 2;
541
542 if (reserved && reserved > write_limit)
543 return (ERESTART);
544 }
545
546 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], space);
547
548 /*
549 * If this transaction group is over 7/8ths capacity, delay
550 * the caller 1 clock tick. This will slow down the "fill"
551 * rate until the sync process can catch up with us.
552 */
553 if (reserved && reserved > (write_limit - (write_limit >> 3)))
554 txg_delay(dp, tx->tx_txg, 1);
555
556 return (0);
557 }
558
559 void
560 dsl_pool_tempreserve_clear(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
561 {
562 ASSERT(dp->dp_tempreserved[tx->tx_txg & TXG_MASK] >= space);
563 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], -space);
564 }
565
566 void
567 dsl_pool_memory_pressure(dsl_pool_t *dp)
568 {
569 uint64_t space_inuse = 0;
570 int i;
571
572 if (dp->dp_write_limit == zfs_write_limit_min)
573 return;
574
575 for (i = 0; i < TXG_SIZE; i++) {
576 space_inuse += dp->dp_space_towrite[i];
577 space_inuse += dp->dp_tempreserved[i];
578 }
579 dp->dp_write_limit = MAX(zfs_write_limit_min,
580 MIN(dp->dp_write_limit, space_inuse / 4));
581 }
582
583 void
584 dsl_pool_willuse_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
585 {
586 if (space > 0) {
587 mutex_enter(&dp->dp_lock);
588 dp->dp_space_towrite[tx->tx_txg & TXG_MASK] += space;
589 mutex_exit(&dp->dp_lock);
590 }
591 }
592
593 /* ARGSUSED */
594 static int
595 upgrade_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
596 {
597 dmu_tx_t *tx = arg;
598 dsl_dataset_t *ds, *prev = NULL;
599 int err;
600 dsl_pool_t *dp = spa_get_dsl(spa);
601
602 err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
603 if (err)
604 return (err);
605
606 while (ds->ds_phys->ds_prev_snap_obj != 0) {
607 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
608 FTAG, &prev);
609 if (err) {
610 dsl_dataset_rele(ds, FTAG);
611 return (err);
612 }
613
614 if (prev->ds_phys->ds_next_snap_obj != ds->ds_object)
615 break;
616 dsl_dataset_rele(ds, FTAG);
617 ds = prev;
618 prev = NULL;
619 }
620
621 if (prev == NULL) {
622 prev = dp->dp_origin_snap;
623
624 /*
625 * The $ORIGIN can't have any data, or the accounting
626 * will be wrong.
627 */
628 ASSERT(prev->ds_phys->ds_bp.blk_birth == 0);
629
630 /* The origin doesn't get attached to itself */
631 if (ds->ds_object == prev->ds_object) {
632 dsl_dataset_rele(ds, FTAG);
633 return (0);
634 }
635
636 dmu_buf_will_dirty(ds->ds_dbuf, tx);
637 ds->ds_phys->ds_prev_snap_obj = prev->ds_object;
638 ds->ds_phys->ds_prev_snap_txg = prev->ds_phys->ds_creation_txg;
639
640 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
641 ds->ds_dir->dd_phys->dd_origin_obj = prev->ds_object;
642
643 dmu_buf_will_dirty(prev->ds_dbuf, tx);
644 prev->ds_phys->ds_num_children++;
645
646 if (ds->ds_phys->ds_next_snap_obj == 0) {
647 ASSERT(ds->ds_prev == NULL);
648 VERIFY(0 == dsl_dataset_hold_obj(dp,
649 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
650 }
651 }
652
653 ASSERT(ds->ds_dir->dd_phys->dd_origin_obj == prev->ds_object);
654 ASSERT(ds->ds_phys->ds_prev_snap_obj == prev->ds_object);
655
656 if (prev->ds_phys->ds_next_clones_obj == 0) {
657 dmu_buf_will_dirty(prev->ds_dbuf, tx);
658 prev->ds_phys->ds_next_clones_obj =
659 zap_create(dp->dp_meta_objset,
660 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
661 }
662 VERIFY(0 == zap_add_int(dp->dp_meta_objset,
663 prev->ds_phys->ds_next_clones_obj, ds->ds_object, tx));
664
665 dsl_dataset_rele(ds, FTAG);
666 if (prev != dp->dp_origin_snap)
667 dsl_dataset_rele(prev, FTAG);
668 return (0);
669 }
670
671 void
672 dsl_pool_upgrade_clones(dsl_pool_t *dp, dmu_tx_t *tx)
673 {
674 ASSERT(dmu_tx_is_syncing(tx));
675 ASSERT(dp->dp_origin_snap != NULL);
676
677 VERIFY0(dmu_objset_find_spa(dp->dp_spa, NULL, upgrade_clones_cb,
678 tx, DS_FIND_CHILDREN));
679 }
680
681 /* ARGSUSED */
682 static int
683 upgrade_dir_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
684 {
685 dmu_tx_t *tx = arg;
686 dsl_dataset_t *ds;
687 dsl_pool_t *dp = spa_get_dsl(spa);
688 objset_t *mos = dp->dp_meta_objset;
689
690 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
691
692 if (ds->ds_dir->dd_phys->dd_origin_obj) {
693 dsl_dataset_t *origin;
694
695 VERIFY0(dsl_dataset_hold_obj(dp,
696 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin));
697
698 if (origin->ds_dir->dd_phys->dd_clones == 0) {
699 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
700 origin->ds_dir->dd_phys->dd_clones = zap_create(mos,
701 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
702 }
703
704 VERIFY0(zap_add_int(dp->dp_meta_objset,
705 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
706
707 dsl_dataset_rele(origin, FTAG);
708 }
709
710 dsl_dataset_rele(ds, FTAG);
711 return (0);
712 }
713
714 void
715 dsl_pool_upgrade_dir_clones(dsl_pool_t *dp, dmu_tx_t *tx)
716 {
717 ASSERT(dmu_tx_is_syncing(tx));
718 uint64_t obj;
719
720 (void) dsl_dir_create_sync(dp, dp->dp_root_dir, FREE_DIR_NAME, tx);
721 VERIFY(0 == dsl_pool_open_special_dir(dp,
722 FREE_DIR_NAME, &dp->dp_free_dir));
723
724 /*
725 * We can't use bpobj_alloc(), because spa_version() still
726 * returns the old version, and we need a new-version bpobj with
727 * subobj support. So call dmu_object_alloc() directly.
728 */
729 obj = dmu_object_alloc(dp->dp_meta_objset, DMU_OT_BPOBJ,
730 SPA_MAXBLOCKSIZE, DMU_OT_BPOBJ_HDR, sizeof (bpobj_phys_t), tx);
731 VERIFY0(zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
732 DMU_POOL_FREE_BPOBJ, sizeof (uint64_t), 1, &obj, tx));
733 VERIFY0(bpobj_open(&dp->dp_free_bpobj,
734 dp->dp_meta_objset, obj));
735
736 VERIFY0(dmu_objset_find_spa(dp->dp_spa, NULL,
737 upgrade_dir_clones_cb, tx, DS_FIND_CHILDREN));
738 }
739
740 void
741 dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx)
742 {
743 uint64_t dsobj;
744 dsl_dataset_t *ds;
745
746 ASSERT(dmu_tx_is_syncing(tx));
747 ASSERT(dp->dp_origin_snap == NULL);
748
749 /* create the origin dir, ds, & snap-ds */
750 rw_enter(&dp->dp_config_rwlock, RW_WRITER);
751 dsobj = dsl_dataset_create_sync(dp->dp_root_dir, ORIGIN_DIR_NAME,
752 NULL, 0, kcred, tx);
753 VERIFY(0 == dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
754 dsl_dataset_snapshot_sync(ds, ORIGIN_DIR_NAME, tx);
755 VERIFY(0 == dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
756 dp, &dp->dp_origin_snap));
757 dsl_dataset_rele(ds, FTAG);
758 rw_exit(&dp->dp_config_rwlock);
759 }
760
761 taskq_t *
762 dsl_pool_vnrele_taskq(dsl_pool_t *dp)
763 {
764 return (dp->dp_vnrele_taskq);
765 }
766
767 /*
768 * Walk through the pool-wide zap object of temporary snapshot user holds
769 * and release them.
770 */
771 void
772 dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp)
773 {
774 zap_attribute_t za;
775 zap_cursor_t zc;
776 objset_t *mos = dp->dp_meta_objset;
777 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
778
779 if (zapobj == 0)
780 return;
781 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
782
783 for (zap_cursor_init(&zc, mos, zapobj);
784 zap_cursor_retrieve(&zc, &za) == 0;
785 zap_cursor_advance(&zc)) {
786 char *htag;
787 uint64_t dsobj;
788
789 htag = strchr(za.za_name, '-');
790 *htag = '\0';
791 ++htag;
792 dsobj = strtonum(za.za_name, NULL);
793 (void) dsl_dataset_user_release_tmp(dp, dsobj, htag, B_FALSE);
794 }
795 zap_cursor_fini(&zc);
796 }
797
798 /*
799 * Create the pool-wide zap object for storing temporary snapshot holds.
800 */
801 void
802 dsl_pool_user_hold_create_obj(dsl_pool_t *dp, dmu_tx_t *tx)
803 {
804 objset_t *mos = dp->dp_meta_objset;
805
806 ASSERT(dp->dp_tmp_userrefs_obj == 0);
807 ASSERT(dmu_tx_is_syncing(tx));
808
809 dp->dp_tmp_userrefs_obj = zap_create_link(mos, DMU_OT_USERREFS,
810 DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_TMP_USERREFS, tx);
811 }
812
813 static int
814 dsl_pool_user_hold_rele_impl(dsl_pool_t *dp, uint64_t dsobj,
815 const char *tag, uint64_t *now, dmu_tx_t *tx, boolean_t holding)
816 {
817 objset_t *mos = dp->dp_meta_objset;
818 uint64_t zapobj = dp->dp_tmp_userrefs_obj;
819 char *name;
820 int error;
821
822 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
823 ASSERT(dmu_tx_is_syncing(tx));
824
825 /*
826 * If the pool was created prior to SPA_VERSION_USERREFS, the
827 * zap object for temporary holds might not exist yet.
828 */
829 if (zapobj == 0) {
830 if (holding) {
831 dsl_pool_user_hold_create_obj(dp, tx);
832 zapobj = dp->dp_tmp_userrefs_obj;
833 } else {
834 return (ENOENT);
835 }
836 }
837
838 name = kmem_asprintf("%llx-%s", (u_longlong_t)dsobj, tag);
839 if (holding)
840 error = zap_add(mos, zapobj, name, 8, 1, now, tx);
841 else
842 error = zap_remove(mos, zapobj, name, tx);
843 strfree(name);
844
845 return (error);
846 }
847
848 /*
849 * Add a temporary hold for the given dataset object and tag.
850 */
851 int
852 dsl_pool_user_hold(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
853 uint64_t *now, dmu_tx_t *tx)
854 {
855 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, now, tx, B_TRUE));
856 }
857
858 /*
859 * Release a temporary hold for the given dataset object and tag.
860 */
861 int
862 dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj, const char *tag,
863 dmu_tx_t *tx)
864 {
865 return (dsl_pool_user_hold_rele_impl(dp, dsobj, tag, NULL,
866 tx, B_FALSE));
867 }