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) 2013 by Delphix. All rights reserved.
24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25 * Copyright 2013 Saso Kiselkov. All rights reserved.
26 */
27
28 #include <sys/zfs_context.h>
29 #include <sys/spa_impl.h>
30 #include <sys/spa_boot.h>
31 #include <sys/zio.h>
32 #include <sys/zio_checksum.h>
33 #include <sys/zio_compress.h>
34 #include <sys/dmu.h>
35 #include <sys/dmu_tx.h>
36 #include <sys/zap.h>
37 #include <sys/zil.h>
38 #include <sys/vdev_impl.h>
39 #include <sys/metaslab.h>
40 #include <sys/uberblock_impl.h>
41 #include <sys/txg.h>
42 #include <sys/avl.h>
43 #include <sys/unique.h>
44 #include <sys/dsl_pool.h>
45 #include <sys/dsl_dir.h>
46 #include <sys/dsl_prop.h>
47 #include <sys/dsl_scan.h>
48 #include <sys/fs/zfs.h>
49 #include <sys/metaslab_impl.h>
50 #include <sys/arc.h>
51 #include <sys/ddt.h>
52 #include "zfs_prop.h"
53 #include <sys/zfeature.h>
54
55 /*
56 * SPA locking
57 *
58 * There are four basic locks for managing spa_t structures:
59 *
60 * spa_namespace_lock (global mutex)
61 *
62 * This lock must be acquired to do any of the following:
63 *
64 * - Lookup a spa_t by name
65 * - Add or remove a spa_t from the namespace
66 * - Increase spa_refcount from non-zero
67 * - Check if spa_refcount is zero
68 * - Rename a spa_t
69 * - add/remove/attach/detach devices
70 * - Held for the duration of create/destroy/import/export
71 *
72 * It does not need to handle recursion. A create or destroy may
73 * reference objects (files or zvols) in other pools, but by
74 * definition they must have an existing reference, and will never need
75 * to lookup a spa_t by name.
76 *
77 * spa_refcount (per-spa refcount_t protected by mutex)
78 *
79 * This reference count keep track of any active users of the spa_t. The
80 * spa_t cannot be destroyed or freed while this is non-zero. Internally,
81 * the refcount is never really 'zero' - opening a pool implicitly keeps
82 * some references in the DMU. Internally we check against spa_minref, but
83 * present the image of a zero/non-zero value to consumers.
84 *
85 * spa_config_lock[] (per-spa array of rwlocks)
86 *
87 * This protects the spa_t from config changes, and must be held in
88 * the following circumstances:
89 *
90 * - RW_READER to perform I/O to the spa
91 * - RW_WRITER to change the vdev config
92 *
93 * The locking order is fairly straightforward:
94 *
95 * spa_namespace_lock -> spa_refcount
96 *
97 * The namespace lock must be acquired to increase the refcount from 0
98 * or to check if it is zero.
99 *
100 * spa_refcount -> spa_config_lock[]
101 *
102 * There must be at least one valid reference on the spa_t to acquire
103 * the config lock.
104 *
105 * spa_namespace_lock -> spa_config_lock[]
106 *
107 * The namespace lock must always be taken before the config lock.
108 *
109 *
110 * The spa_namespace_lock can be acquired directly and is globally visible.
111 *
112 * The namespace is manipulated using the following functions, all of which
113 * require the spa_namespace_lock to be held.
114 *
115 * spa_lookup() Lookup a spa_t by name.
116 *
117 * spa_add() Create a new spa_t in the namespace.
118 *
119 * spa_remove() Remove a spa_t from the namespace. This also
120 * frees up any memory associated with the spa_t.
121 *
122 * spa_next() Returns the next spa_t in the system, or the
123 * first if NULL is passed.
124 *
125 * spa_evict_all() Shutdown and remove all spa_t structures in
126 * the system.
127 *
128 * spa_guid_exists() Determine whether a pool/device guid exists.
129 *
130 * The spa_refcount is manipulated using the following functions:
131 *
132 * spa_open_ref() Adds a reference to the given spa_t. Must be
133 * called with spa_namespace_lock held if the
134 * refcount is currently zero.
135 *
136 * spa_close() Remove a reference from the spa_t. This will
137 * not free the spa_t or remove it from the
138 * namespace. No locking is required.
139 *
140 * spa_refcount_zero() Returns true if the refcount is currently
141 * zero. Must be called with spa_namespace_lock
142 * held.
143 *
144 * The spa_config_lock[] is an array of rwlocks, ordered as follows:
145 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
146 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
147 *
148 * To read the configuration, it suffices to hold one of these locks as reader.
149 * To modify the configuration, you must hold all locks as writer. To modify
150 * vdev state without altering the vdev tree's topology (e.g. online/offline),
151 * you must hold SCL_STATE and SCL_ZIO as writer.
152 *
153 * We use these distinct config locks to avoid recursive lock entry.
154 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
155 * block allocations (SCL_ALLOC), which may require reading space maps
156 * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
157 *
158 * The spa config locks cannot be normal rwlocks because we need the
159 * ability to hand off ownership. For example, SCL_ZIO is acquired
160 * by the issuing thread and later released by an interrupt thread.
161 * They do, however, obey the usual write-wanted semantics to prevent
162 * writer (i.e. system administrator) starvation.
163 *
164 * The lock acquisition rules are as follows:
165 *
166 * SCL_CONFIG
167 * Protects changes to the vdev tree topology, such as vdev
168 * add/remove/attach/detach. Protects the dirty config list
169 * (spa_config_dirty_list) and the set of spares and l2arc devices.
170 *
171 * SCL_STATE
172 * Protects changes to pool state and vdev state, such as vdev
173 * online/offline/fault/degrade/clear. Protects the dirty state list
174 * (spa_state_dirty_list) and global pool state (spa_state).
175 *
176 * SCL_ALLOC
177 * Protects changes to metaslab groups and classes.
178 * Held as reader by metaslab_alloc() and metaslab_claim().
179 *
180 * SCL_ZIO
181 * Held by bp-level zios (those which have no io_vd upon entry)
182 * to prevent changes to the vdev tree. The bp-level zio implicitly
183 * protects all of its vdev child zios, which do not hold SCL_ZIO.
184 *
185 * SCL_FREE
186 * Protects changes to metaslab groups and classes.
187 * Held as reader by metaslab_free(). SCL_FREE is distinct from
188 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
189 * blocks in zio_done() while another i/o that holds either
190 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
191 *
192 * SCL_VDEV
193 * Held as reader to prevent changes to the vdev tree during trivial
194 * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the
195 * other locks, and lower than all of them, to ensure that it's safe
196 * to acquire regardless of caller context.
197 *
198 * In addition, the following rules apply:
199 *
200 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list.
201 * The lock ordering is SCL_CONFIG > spa_props_lock.
202 *
203 * (b) I/O operations on leaf vdevs. For any zio operation that takes
204 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
205 * or zio_write_phys() -- the caller must ensure that the config cannot
206 * cannot change in the interim, and that the vdev cannot be reopened.
207 * SCL_STATE as reader suffices for both.
208 *
209 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
210 *
211 * spa_vdev_enter() Acquire the namespace lock and the config lock
212 * for writing.
213 *
214 * spa_vdev_exit() Release the config lock, wait for all I/O
215 * to complete, sync the updated configs to the
216 * cache, and release the namespace lock.
217 *
218 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
219 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
220 * locking is, always, based on spa_namespace_lock and spa_config_lock[].
221 *
222 * spa_rename() is also implemented within this file since it requires
223 * manipulation of the namespace.
224 */
225
226 static avl_tree_t spa_namespace_avl;
227 kmutex_t spa_namespace_lock;
228 static kcondvar_t spa_namespace_cv;
229 static int spa_active_count;
230 int spa_max_replication_override = SPA_DVAS_PER_BP;
231
232 static kmutex_t spa_spare_lock;
233 static avl_tree_t spa_spare_avl;
234 static kmutex_t spa_l2cache_lock;
235 static avl_tree_t spa_l2cache_avl;
236
237 kmem_cache_t *spa_buffer_pool;
238 int spa_mode_global;
239
240 #ifdef ZFS_DEBUG
241 /* Everything except dprintf and spa is on by default in debug builds */
242 int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA);
243 #else
244 int zfs_flags = 0;
245 #endif
246
247 /*
248 * zfs_recover can be set to nonzero to attempt to recover from
249 * otherwise-fatal errors, typically caused by on-disk corruption. When
250 * set, calls to zfs_panic_recover() will turn into warning messages.
251 */
252 int zfs_recover = 0;
253
254 /*
255 * Expiration time in milliseconds. This value has two meanings. First it is
256 * used to determine when the spa_deadman() logic should fire. By default the
257 * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds.
258 * Secondly, the value determines if an I/O is considered "hung". Any I/O that
259 * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting
260 * in a system panic.
261 */
262 uint64_t zfs_deadman_synctime_ms = 1000000ULL;
263
264 /*
265 * Check time in milliseconds. This defines the frequency at which we check
266 * for hung I/O.
267 */
268 uint64_t zfs_deadman_checktime_ms = 5000ULL;
269
270 /*
271 * Override the zfs deadman behavior via /etc/system. By default the
272 * deadman is enabled except on VMware and sparc deployments.
273 */
274 int zfs_deadman_enabled = -1;
275
276 /*
277 * The worst case is single-sector max-parity RAID-Z blocks, in which
278 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
279 * times the size; so just assume that. Add to this the fact that
280 * we can have up to 3 DVAs per bp, and one more factor of 2 because
281 * the block may be dittoed with up to 3 DVAs by ddt_sync(). All together,
282 * the worst case is:
283 * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24
284 */
285 int spa_asize_inflation = 24;
286
287 /*
288 * ==========================================================================
289 * SPA config locking
290 * ==========================================================================
291 */
292 static void
293 spa_config_lock_init(spa_t *spa)
294 {
295 for (int i = 0; i < SCL_LOCKS; i++) {
296 spa_config_lock_t *scl = &spa->spa_config_lock[i];
297 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
298 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
299 refcount_create_untracked(&scl->scl_count);
300 scl->scl_writer = NULL;
301 scl->scl_write_wanted = 0;
302 }
303 }
304
305 static void
306 spa_config_lock_destroy(spa_t *spa)
307 {
308 for (int i = 0; i < SCL_LOCKS; i++) {
309 spa_config_lock_t *scl = &spa->spa_config_lock[i];
310 mutex_destroy(&scl->scl_lock);
311 cv_destroy(&scl->scl_cv);
312 refcount_destroy(&scl->scl_count);
313 ASSERT(scl->scl_writer == NULL);
314 ASSERT(scl->scl_write_wanted == 0);
315 }
316 }
317
318 int
319 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
320 {
321 for (int i = 0; i < SCL_LOCKS; i++) {
322 spa_config_lock_t *scl = &spa->spa_config_lock[i];
323 if (!(locks & (1 << i)))
324 continue;
325 mutex_enter(&scl->scl_lock);
326 if (rw == RW_READER) {
327 if (scl->scl_writer || scl->scl_write_wanted) {
328 mutex_exit(&scl->scl_lock);
329 spa_config_exit(spa, locks ^ (1 << i), tag);
330 return (0);
331 }
332 } else {
333 ASSERT(scl->scl_writer != curthread);
334 if (!refcount_is_zero(&scl->scl_count)) {
335 mutex_exit(&scl->scl_lock);
336 spa_config_exit(spa, locks ^ (1 << i), tag);
337 return (0);
338 }
339 scl->scl_writer = curthread;
340 }
341 (void) refcount_add(&scl->scl_count, tag);
342 mutex_exit(&scl->scl_lock);
343 }
344 return (1);
345 }
346
347 void
348 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
349 {
350 int wlocks_held = 0;
351
352 ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY);
353
354 for (int i = 0; i < SCL_LOCKS; i++) {
355 spa_config_lock_t *scl = &spa->spa_config_lock[i];
356 if (scl->scl_writer == curthread)
357 wlocks_held |= (1 << i);
358 if (!(locks & (1 << i)))
359 continue;
360 mutex_enter(&scl->scl_lock);
361 if (rw == RW_READER) {
362 while (scl->scl_writer || scl->scl_write_wanted) {
363 cv_wait(&scl->scl_cv, &scl->scl_lock);
364 }
365 } else {
366 ASSERT(scl->scl_writer != curthread);
367 while (!refcount_is_zero(&scl->scl_count)) {
368 scl->scl_write_wanted++;
369 cv_wait(&scl->scl_cv, &scl->scl_lock);
370 scl->scl_write_wanted--;
371 }
372 scl->scl_writer = curthread;
373 }
374 (void) refcount_add(&scl->scl_count, tag);
375 mutex_exit(&scl->scl_lock);
376 }
377 ASSERT(wlocks_held <= locks);
378 }
379
380 void
381 spa_config_exit(spa_t *spa, int locks, void *tag)
382 {
383 for (int i = SCL_LOCKS - 1; i >= 0; i--) {
384 spa_config_lock_t *scl = &spa->spa_config_lock[i];
385 if (!(locks & (1 << i)))
386 continue;
387 mutex_enter(&scl->scl_lock);
388 ASSERT(!refcount_is_zero(&scl->scl_count));
389 if (refcount_remove(&scl->scl_count, tag) == 0) {
390 ASSERT(scl->scl_writer == NULL ||
391 scl->scl_writer == curthread);
392 scl->scl_writer = NULL; /* OK in either case */
393 cv_broadcast(&scl->scl_cv);
394 }
395 mutex_exit(&scl->scl_lock);
396 }
397 }
398
399 int
400 spa_config_held(spa_t *spa, int locks, krw_t rw)
401 {
402 int locks_held = 0;
403
404 for (int i = 0; i < SCL_LOCKS; i++) {
405 spa_config_lock_t *scl = &spa->spa_config_lock[i];
406 if (!(locks & (1 << i)))
407 continue;
408 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
409 (rw == RW_WRITER && scl->scl_writer == curthread))
410 locks_held |= 1 << i;
411 }
412
413 return (locks_held);
414 }
415
416 /*
417 * ==========================================================================
418 * SPA namespace functions
419 * ==========================================================================
420 */
421
422 /*
423 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held.
424 * Returns NULL if no matching spa_t is found.
425 */
426 spa_t *
427 spa_lookup(const char *name)
428 {
429 static spa_t search; /* spa_t is large; don't allocate on stack */
430 spa_t *spa;
431 avl_index_t where;
432 char *cp;
433
434 ASSERT(MUTEX_HELD(&spa_namespace_lock));
435
436 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
437
438 /*
439 * If it's a full dataset name, figure out the pool name and
440 * just use that.
441 */
442 cp = strpbrk(search.spa_name, "/@");
443 if (cp != NULL)
444 *cp = '\0';
445
446 spa = avl_find(&spa_namespace_avl, &search, &where);
447
448 return (spa);
449 }
450
451 /*
452 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms.
453 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues
454 * looking for potentially hung I/Os.
455 */
456 void
457 spa_deadman(void *arg)
458 {
459 spa_t *spa = arg;
460
461 /*
462 * Disable the deadman timer if the pool is suspended.
463 */
464 if (spa_suspended(spa)) {
465 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
466 return;
467 }
468
469 zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu",
470 (gethrtime() - spa->spa_sync_starttime) / NANOSEC,
471 ++spa->spa_deadman_calls);
472 if (zfs_deadman_enabled)
473 vdev_deadman(spa->spa_root_vdev);
474 }
475
476 /*
477 * Create an uninitialized spa_t with the given name. Requires
478 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already
479 * exist by calling spa_lookup() first.
480 */
481 spa_t *
482 spa_add(const char *name, nvlist_t *config, const char *altroot)
483 {
484 spa_t *spa;
485 spa_config_dirent_t *dp;
486 cyc_handler_t hdlr;
487 cyc_time_t when;
488
489 ASSERT(MUTEX_HELD(&spa_namespace_lock));
490
491 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
492
493 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
494 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
495 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
496 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
497 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL);
498 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
499 mutex_init(&spa->spa_cksum_tmpls_lock, NULL, MUTEX_DEFAULT, NULL);
500 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
501 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
502 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL);
503 mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL);
504
505 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
506 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL);
507 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
508 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
509
510 for (int t = 0; t < TXG_SIZE; t++)
511 bplist_create(&spa->spa_free_bplist[t]);
512
513 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
514 spa->spa_state = POOL_STATE_UNINITIALIZED;
515 spa->spa_freeze_txg = UINT64_MAX;
516 spa->spa_final_txg = UINT64_MAX;
517 spa->spa_load_max_txg = UINT64_MAX;
518 spa->spa_proc = &p0;
519 spa->spa_proc_state = SPA_PROC_NONE;
520
521 hdlr.cyh_func = spa_deadman;
522 hdlr.cyh_arg = spa;
523 hdlr.cyh_level = CY_LOW_LEVEL;
524
525 spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms);
526
527 /*
528 * This determines how often we need to check for hung I/Os after
529 * the cyclic has already fired. Since checking for hung I/Os is
530 * an expensive operation we don't want to check too frequently.
531 * Instead wait for 5 seconds before checking again.
532 */
533 when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms);
534 when.cyt_when = CY_INFINITY;
535 mutex_enter(&cpu_lock);
536 spa->spa_deadman_cycid = cyclic_add(&hdlr, &when);
537 mutex_exit(&cpu_lock);
538
539 refcount_create(&spa->spa_refcount);
540 spa_config_lock_init(spa);
541
542 avl_add(&spa_namespace_avl, spa);
543
544 /*
545 * Set the alternate root, if there is one.
546 */
547 if (altroot) {
548 spa->spa_root = spa_strdup(altroot);
549 spa_active_count++;
550 }
551
552 /*
553 * Every pool starts with the default cachefile
554 */
555 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
556 offsetof(spa_config_dirent_t, scd_link));
557
558 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
559 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
560 list_insert_head(&spa->spa_config_list, dp);
561
562 VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME,
563 KM_SLEEP) == 0);
564
565 if (config != NULL) {
566 nvlist_t *features;
567
568 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
569 &features) == 0) {
570 VERIFY(nvlist_dup(features, &spa->spa_label_features,
571 0) == 0);
572 }
573
574 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
575 }
576
577 if (spa->spa_label_features == NULL) {
578 VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME,
579 KM_SLEEP) == 0);
580 }
581
582 spa->spa_iokstat = kstat_create("zfs", 0, name,
583 "disk", KSTAT_TYPE_IO, 1, 0);
584 if (spa->spa_iokstat) {
585 spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock;
586 kstat_install(spa->spa_iokstat);
587 }
588
589 spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0);
590
591 return (spa);
592 }
593
594 /*
595 * Removes a spa_t from the namespace, freeing up any memory used. Requires
596 * spa_namespace_lock. This is called only after the spa_t has been closed and
597 * deactivated.
598 */
599 void
600 spa_remove(spa_t *spa)
601 {
602 spa_config_dirent_t *dp;
603
604 ASSERT(MUTEX_HELD(&spa_namespace_lock));
605 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
606
607 nvlist_free(spa->spa_config_splitting);
608
609 avl_remove(&spa_namespace_avl, spa);
610 cv_broadcast(&spa_namespace_cv);
611
612 if (spa->spa_root) {
613 spa_strfree(spa->spa_root);
614 spa_active_count--;
615 }
616
617 while ((dp = list_head(&spa->spa_config_list)) != NULL) {
618 list_remove(&spa->spa_config_list, dp);
619 if (dp->scd_path != NULL)
620 spa_strfree(dp->scd_path);
621 kmem_free(dp, sizeof (spa_config_dirent_t));
622 }
623
624 list_destroy(&spa->spa_config_list);
625
626 nvlist_free(spa->spa_label_features);
627 nvlist_free(spa->spa_load_info);
628 spa_config_set(spa, NULL);
629
630 mutex_enter(&cpu_lock);
631 if (spa->spa_deadman_cycid != CYCLIC_NONE)
632 cyclic_remove(spa->spa_deadman_cycid);
633 mutex_exit(&cpu_lock);
634 spa->spa_deadman_cycid = CYCLIC_NONE;
635
636 refcount_destroy(&spa->spa_refcount);
637
638 spa_config_lock_destroy(spa);
639
640 kstat_delete(spa->spa_iokstat);
641 spa->spa_iokstat = NULL;
642
643 for (int t = 0; t < TXG_SIZE; t++)
644 bplist_destroy(&spa->spa_free_bplist[t]);
645
646 zio_checksum_templates_free(spa);
647
648 cv_destroy(&spa->spa_async_cv);
649 cv_destroy(&spa->spa_proc_cv);
650 cv_destroy(&spa->spa_scrub_io_cv);
651 cv_destroy(&spa->spa_suspend_cv);
652
653 mutex_destroy(&spa->spa_async_lock);
654 mutex_destroy(&spa->spa_errlist_lock);
655 mutex_destroy(&spa->spa_errlog_lock);
656 mutex_destroy(&spa->spa_history_lock);
657 mutex_destroy(&spa->spa_proc_lock);
658 mutex_destroy(&spa->spa_props_lock);
659 mutex_destroy(&spa->spa_cksum_tmpls_lock);
660 mutex_destroy(&spa->spa_scrub_lock);
661 mutex_destroy(&spa->spa_suspend_lock);
662 mutex_destroy(&spa->spa_vdev_top_lock);
663 mutex_destroy(&spa->spa_iokstat_lock);
664
665 kmem_free(spa, sizeof (spa_t));
666 }
667
668 /*
669 * Given a pool, return the next pool in the namespace, or NULL if there is
670 * none. If 'prev' is NULL, return the first pool.
671 */
672 spa_t *
673 spa_next(spa_t *prev)
674 {
675 ASSERT(MUTEX_HELD(&spa_namespace_lock));
676
677 if (prev)
678 return (AVL_NEXT(&spa_namespace_avl, prev));
679 else
680 return (avl_first(&spa_namespace_avl));
681 }
682
683 /*
684 * ==========================================================================
685 * SPA refcount functions
686 * ==========================================================================
687 */
688
689 /*
690 * Add a reference to the given spa_t. Must have at least one reference, or
691 * have the namespace lock held.
692 */
693 void
694 spa_open_ref(spa_t *spa, void *tag)
695 {
696 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
697 MUTEX_HELD(&spa_namespace_lock));
698 (void) refcount_add(&spa->spa_refcount, tag);
699 }
700
701 /*
702 * Remove a reference to the given spa_t. Must have at least one reference, or
703 * have the namespace lock held.
704 */
705 void
706 spa_close(spa_t *spa, void *tag)
707 {
708 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
709 MUTEX_HELD(&spa_namespace_lock));
710 (void) refcount_remove(&spa->spa_refcount, tag);
711 }
712
713 /*
714 * Check to see if the spa refcount is zero. Must be called with
715 * spa_namespace_lock held. We really compare against spa_minref, which is the
716 * number of references acquired when opening a pool
717 */
718 boolean_t
719 spa_refcount_zero(spa_t *spa)
720 {
721 ASSERT(MUTEX_HELD(&spa_namespace_lock));
722
723 return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
724 }
725
726 /*
727 * ==========================================================================
728 * SPA spare and l2cache tracking
729 * ==========================================================================
730 */
731
732 /*
733 * Hot spares and cache devices are tracked using the same code below,
734 * for 'auxiliary' devices.
735 */
736
737 typedef struct spa_aux {
738 uint64_t aux_guid;
739 uint64_t aux_pool;
740 avl_node_t aux_avl;
741 int aux_count;
742 } spa_aux_t;
743
744 static int
745 spa_aux_compare(const void *a, const void *b)
746 {
747 const spa_aux_t *sa = a;
748 const spa_aux_t *sb = b;
749
750 if (sa->aux_guid < sb->aux_guid)
751 return (-1);
752 else if (sa->aux_guid > sb->aux_guid)
753 return (1);
754 else
755 return (0);
756 }
757
758 void
759 spa_aux_add(vdev_t *vd, avl_tree_t *avl)
760 {
761 avl_index_t where;
762 spa_aux_t search;
763 spa_aux_t *aux;
764
765 search.aux_guid = vd->vdev_guid;
766 if ((aux = avl_find(avl, &search, &where)) != NULL) {
767 aux->aux_count++;
768 } else {
769 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
770 aux->aux_guid = vd->vdev_guid;
771 aux->aux_count = 1;
772 avl_insert(avl, aux, where);
773 }
774 }
775
776 void
777 spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
778 {
779 spa_aux_t search;
780 spa_aux_t *aux;
781 avl_index_t where;
782
783 search.aux_guid = vd->vdev_guid;
784 aux = avl_find(avl, &search, &where);
785
786 ASSERT(aux != NULL);
787
788 if (--aux->aux_count == 0) {
789 avl_remove(avl, aux);
790 kmem_free(aux, sizeof (spa_aux_t));
791 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
792 aux->aux_pool = 0ULL;
793 }
794 }
795
796 boolean_t
797 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
798 {
799 spa_aux_t search, *found;
800
801 search.aux_guid = guid;
802 found = avl_find(avl, &search, NULL);
803
804 if (pool) {
805 if (found)
806 *pool = found->aux_pool;
807 else
808 *pool = 0ULL;
809 }
810
811 if (refcnt) {
812 if (found)
813 *refcnt = found->aux_count;
814 else
815 *refcnt = 0;
816 }
817
818 return (found != NULL);
819 }
820
821 void
822 spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
823 {
824 spa_aux_t search, *found;
825 avl_index_t where;
826
827 search.aux_guid = vd->vdev_guid;
828 found = avl_find(avl, &search, &where);
829 ASSERT(found != NULL);
830 ASSERT(found->aux_pool == 0ULL);
831
832 found->aux_pool = spa_guid(vd->vdev_spa);
833 }
834
835 /*
836 * Spares are tracked globally due to the following constraints:
837 *
838 * - A spare may be part of multiple pools.
839 * - A spare may be added to a pool even if it's actively in use within
840 * another pool.
841 * - A spare in use in any pool can only be the source of a replacement if
842 * the target is a spare in the same pool.
843 *
844 * We keep track of all spares on the system through the use of a reference
845 * counted AVL tree. When a vdev is added as a spare, or used as a replacement
846 * spare, then we bump the reference count in the AVL tree. In addition, we set
847 * the 'vdev_isspare' member to indicate that the device is a spare (active or
848 * inactive). When a spare is made active (used to replace a device in the
849 * pool), we also keep track of which pool its been made a part of.
850 *
851 * The 'spa_spare_lock' protects the AVL tree. These functions are normally
852 * called under the spa_namespace lock as part of vdev reconfiguration. The
853 * separate spare lock exists for the status query path, which does not need to
854 * be completely consistent with respect to other vdev configuration changes.
855 */
856
857 static int
858 spa_spare_compare(const void *a, const void *b)
859 {
860 return (spa_aux_compare(a, b));
861 }
862
863 void
864 spa_spare_add(vdev_t *vd)
865 {
866 mutex_enter(&spa_spare_lock);
867 ASSERT(!vd->vdev_isspare);
868 spa_aux_add(vd, &spa_spare_avl);
869 vd->vdev_isspare = B_TRUE;
870 mutex_exit(&spa_spare_lock);
871 }
872
873 void
874 spa_spare_remove(vdev_t *vd)
875 {
876 mutex_enter(&spa_spare_lock);
877 ASSERT(vd->vdev_isspare);
878 spa_aux_remove(vd, &spa_spare_avl);
879 vd->vdev_isspare = B_FALSE;
880 mutex_exit(&spa_spare_lock);
881 }
882
883 boolean_t
884 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
885 {
886 boolean_t found;
887
888 mutex_enter(&spa_spare_lock);
889 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
890 mutex_exit(&spa_spare_lock);
891
892 return (found);
893 }
894
895 void
896 spa_spare_activate(vdev_t *vd)
897 {
898 mutex_enter(&spa_spare_lock);
899 ASSERT(vd->vdev_isspare);
900 spa_aux_activate(vd, &spa_spare_avl);
901 mutex_exit(&spa_spare_lock);
902 }
903
904 /*
905 * Level 2 ARC devices are tracked globally for the same reasons as spares.
906 * Cache devices currently only support one pool per cache device, and so
907 * for these devices the aux reference count is currently unused beyond 1.
908 */
909
910 static int
911 spa_l2cache_compare(const void *a, const void *b)
912 {
913 return (spa_aux_compare(a, b));
914 }
915
916 void
917 spa_l2cache_add(vdev_t *vd)
918 {
919 mutex_enter(&spa_l2cache_lock);
920 ASSERT(!vd->vdev_isl2cache);
921 spa_aux_add(vd, &spa_l2cache_avl);
922 vd->vdev_isl2cache = B_TRUE;
923 mutex_exit(&spa_l2cache_lock);
924 }
925
926 void
927 spa_l2cache_remove(vdev_t *vd)
928 {
929 mutex_enter(&spa_l2cache_lock);
930 ASSERT(vd->vdev_isl2cache);
931 spa_aux_remove(vd, &spa_l2cache_avl);
932 vd->vdev_isl2cache = B_FALSE;
933 mutex_exit(&spa_l2cache_lock);
934 }
935
936 boolean_t
937 spa_l2cache_exists(uint64_t guid, uint64_t *pool)
938 {
939 boolean_t found;
940
941 mutex_enter(&spa_l2cache_lock);
942 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
943 mutex_exit(&spa_l2cache_lock);
944
945 return (found);
946 }
947
948 void
949 spa_l2cache_activate(vdev_t *vd)
950 {
951 mutex_enter(&spa_l2cache_lock);
952 ASSERT(vd->vdev_isl2cache);
953 spa_aux_activate(vd, &spa_l2cache_avl);
954 mutex_exit(&spa_l2cache_lock);
955 }
956
957 /*
958 * ==========================================================================
959 * SPA vdev locking
960 * ==========================================================================
961 */
962
963 /*
964 * Lock the given spa_t for the purpose of adding or removing a vdev.
965 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
966 * It returns the next transaction group for the spa_t.
967 */
968 uint64_t
969 spa_vdev_enter(spa_t *spa)
970 {
971 mutex_enter(&spa->spa_vdev_top_lock);
972 mutex_enter(&spa_namespace_lock);
973 return (spa_vdev_config_enter(spa));
974 }
975
976 /*
977 * Internal implementation for spa_vdev_enter(). Used when a vdev
978 * operation requires multiple syncs (i.e. removing a device) while
979 * keeping the spa_namespace_lock held.
980 */
981 uint64_t
982 spa_vdev_config_enter(spa_t *spa)
983 {
984 ASSERT(MUTEX_HELD(&spa_namespace_lock));
985
986 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
987
988 return (spa_last_synced_txg(spa) + 1);
989 }
990
991 /*
992 * Used in combination with spa_vdev_config_enter() to allow the syncing
993 * of multiple transactions without releasing the spa_namespace_lock.
994 */
995 void
996 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
997 {
998 ASSERT(MUTEX_HELD(&spa_namespace_lock));
999
1000 int config_changed = B_FALSE;
1001
1002 ASSERT(txg > spa_last_synced_txg(spa));
1003
1004 spa->spa_pending_vdev = NULL;
1005
1006 /*
1007 * Reassess the DTLs.
1008 */
1009 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
1010
1011 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
1012 config_changed = B_TRUE;
1013 spa->spa_config_generation++;
1014 }
1015
1016 /*
1017 * Verify the metaslab classes.
1018 */
1019 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
1020 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
1021
1022 spa_config_exit(spa, SCL_ALL, spa);
1023
1024 /*
1025 * Panic the system if the specified tag requires it. This
1026 * is useful for ensuring that configurations are updated
1027 * transactionally.
1028 */
1029 if (zio_injection_enabled)
1030 zio_handle_panic_injection(spa, tag, 0);
1031
1032 /*
1033 * Note: this txg_wait_synced() is important because it ensures
1034 * that there won't be more than one config change per txg.
1035 * This allows us to use the txg as the generation number.
1036 */
1037 if (error == 0)
1038 txg_wait_synced(spa->spa_dsl_pool, txg);
1039
1040 if (vd != NULL) {
1041 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL);
1042 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1043 vdev_free(vd);
1044 spa_config_exit(spa, SCL_ALL, spa);
1045 }
1046
1047 /*
1048 * If the config changed, update the config cache.
1049 */
1050 if (config_changed)
1051 spa_config_sync(spa, B_FALSE, B_TRUE);
1052 }
1053
1054 /*
1055 * Unlock the spa_t after adding or removing a vdev. Besides undoing the
1056 * locking of spa_vdev_enter(), we also want make sure the transactions have
1057 * synced to disk, and then update the global configuration cache with the new
1058 * information.
1059 */
1060 int
1061 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
1062 {
1063 spa_vdev_config_exit(spa, vd, txg, error, FTAG);
1064 mutex_exit(&spa_namespace_lock);
1065 mutex_exit(&spa->spa_vdev_top_lock);
1066
1067 return (error);
1068 }
1069
1070 /*
1071 * Lock the given spa_t for the purpose of changing vdev state.
1072 */
1073 void
1074 spa_vdev_state_enter(spa_t *spa, int oplocks)
1075 {
1076 int locks = SCL_STATE_ALL | oplocks;
1077
1078 /*
1079 * Root pools may need to read of the underlying devfs filesystem
1080 * when opening up a vdev. Unfortunately if we're holding the
1081 * SCL_ZIO lock it will result in a deadlock when we try to issue
1082 * the read from the root filesystem. Instead we "prefetch"
1083 * the associated vnodes that we need prior to opening the
1084 * underlying devices and cache them so that we can prevent
1085 * any I/O when we are doing the actual open.
1086 */
1087 if (spa_is_root(spa)) {
1088 int low = locks & ~(SCL_ZIO - 1);
1089 int high = locks & ~low;
1090
1091 spa_config_enter(spa, high, spa, RW_WRITER);
1092 vdev_hold(spa->spa_root_vdev);
1093 spa_config_enter(spa, low, spa, RW_WRITER);
1094 } else {
1095 spa_config_enter(spa, locks, spa, RW_WRITER);
1096 }
1097 spa->spa_vdev_locks = locks;
1098 }
1099
1100 int
1101 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
1102 {
1103 boolean_t config_changed = B_FALSE;
1104
1105 if (vd != NULL || error == 0)
1106 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
1107 0, 0, B_FALSE);
1108
1109 if (vd != NULL) {
1110 vdev_state_dirty(vd->vdev_top);
1111 config_changed = B_TRUE;
1112 spa->spa_config_generation++;
1113 }
1114
1115 if (spa_is_root(spa))
1116 vdev_rele(spa->spa_root_vdev);
1117
1118 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1119 spa_config_exit(spa, spa->spa_vdev_locks, spa);
1120
1121 /*
1122 * If anything changed, wait for it to sync. This ensures that,
1123 * from the system administrator's perspective, zpool(1M) commands
1124 * are synchronous. This is important for things like zpool offline:
1125 * when the command completes, you expect no further I/O from ZFS.
1126 */
1127 if (vd != NULL)
1128 txg_wait_synced(spa->spa_dsl_pool, 0);
1129
1130 /*
1131 * If the config changed, update the config cache.
1132 */
1133 if (config_changed) {
1134 mutex_enter(&spa_namespace_lock);
1135 spa_config_sync(spa, B_FALSE, B_TRUE);
1136 mutex_exit(&spa_namespace_lock);
1137 }
1138
1139 return (error);
1140 }
1141
1142 /*
1143 * ==========================================================================
1144 * Miscellaneous functions
1145 * ==========================================================================
1146 */
1147
1148 void
1149 spa_activate_mos_feature(spa_t *spa, const char *feature)
1150 {
1151 (void) nvlist_add_boolean(spa->spa_label_features, feature);
1152 vdev_config_dirty(spa->spa_root_vdev);
1153 }
1154
1155 void
1156 spa_deactivate_mos_feature(spa_t *spa, const char *feature)
1157 {
1158 (void) nvlist_remove_all(spa->spa_label_features, feature);
1159 vdev_config_dirty(spa->spa_root_vdev);
1160 }
1161
1162 /*
1163 * Rename a spa_t.
1164 */
1165 int
1166 spa_rename(const char *name, const char *newname)
1167 {
1168 spa_t *spa;
1169 int err;
1170
1171 /*
1172 * Lookup the spa_t and grab the config lock for writing. We need to
1173 * actually open the pool so that we can sync out the necessary labels.
1174 * It's OK to call spa_open() with the namespace lock held because we
1175 * allow recursive calls for other reasons.
1176 */
1177 mutex_enter(&spa_namespace_lock);
1178 if ((err = spa_open(name, &spa, FTAG)) != 0) {
1179 mutex_exit(&spa_namespace_lock);
1180 return (err);
1181 }
1182
1183 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1184
1185 avl_remove(&spa_namespace_avl, spa);
1186 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1187 avl_add(&spa_namespace_avl, spa);
1188
1189 /*
1190 * Sync all labels to disk with the new names by marking the root vdev
1191 * dirty and waiting for it to sync. It will pick up the new pool name
1192 * during the sync.
1193 */
1194 vdev_config_dirty(spa->spa_root_vdev);
1195
1196 spa_config_exit(spa, SCL_ALL, FTAG);
1197
1198 txg_wait_synced(spa->spa_dsl_pool, 0);
1199
1200 /*
1201 * Sync the updated config cache.
1202 */
1203 spa_config_sync(spa, B_FALSE, B_TRUE);
1204
1205 spa_close(spa, FTAG);
1206
1207 mutex_exit(&spa_namespace_lock);
1208
1209 return (0);
1210 }
1211
1212 /*
1213 * Return the spa_t associated with given pool_guid, if it exists. If
1214 * device_guid is non-zero, determine whether the pool exists *and* contains
1215 * a device with the specified device_guid.
1216 */
1217 spa_t *
1218 spa_by_guid(uint64_t pool_guid, uint64_t device_guid)
1219 {
1220 spa_t *spa;
1221 avl_tree_t *t = &spa_namespace_avl;
1222
1223 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1224
1225 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1226 if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1227 continue;
1228 if (spa->spa_root_vdev == NULL)
1229 continue;
1230 if (spa_guid(spa) == pool_guid) {
1231 if (device_guid == 0)
1232 break;
1233
1234 if (vdev_lookup_by_guid(spa->spa_root_vdev,
1235 device_guid) != NULL)
1236 break;
1237
1238 /*
1239 * Check any devices we may be in the process of adding.
1240 */
1241 if (spa->spa_pending_vdev) {
1242 if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1243 device_guid) != NULL)
1244 break;
1245 }
1246 }
1247 }
1248
1249 return (spa);
1250 }
1251
1252 /*
1253 * Determine whether a pool with the given pool_guid exists.
1254 */
1255 boolean_t
1256 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1257 {
1258 return (spa_by_guid(pool_guid, device_guid) != NULL);
1259 }
1260
1261 char *
1262 spa_strdup(const char *s)
1263 {
1264 size_t len;
1265 char *new;
1266
1267 len = strlen(s);
1268 new = kmem_alloc(len + 1, KM_SLEEP);
1269 bcopy(s, new, len);
1270 new[len] = '\0';
1271
1272 return (new);
1273 }
1274
1275 void
1276 spa_strfree(char *s)
1277 {
1278 kmem_free(s, strlen(s) + 1);
1279 }
1280
1281 uint64_t
1282 spa_get_random(uint64_t range)
1283 {
1284 uint64_t r;
1285
1286 ASSERT(range != 0);
1287
1288 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1289
1290 return (r % range);
1291 }
1292
1293 uint64_t
1294 spa_generate_guid(spa_t *spa)
1295 {
1296 uint64_t guid = spa_get_random(-1ULL);
1297
1298 if (spa != NULL) {
1299 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1300 guid = spa_get_random(-1ULL);
1301 } else {
1302 while (guid == 0 || spa_guid_exists(guid, 0))
1303 guid = spa_get_random(-1ULL);
1304 }
1305
1306 return (guid);
1307 }
1308
1309 void
1310 sprintf_blkptr(char *buf, const blkptr_t *bp)
1311 {
1312 char type[256];
1313 char *checksum = NULL;
1314 char *compress = NULL;
1315
1316 if (bp != NULL) {
1317 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) {
1318 dmu_object_byteswap_t bswap =
1319 DMU_OT_BYTESWAP(BP_GET_TYPE(bp));
1320 (void) snprintf(type, sizeof (type), "bswap %s %s",
1321 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ?
1322 "metadata" : "data",
1323 dmu_ot_byteswap[bswap].ob_name);
1324 } else {
1325 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name,
1326 sizeof (type));
1327 }
1328 checksum = zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name;
1329 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name;
1330 }
1331
1332 SPRINTF_BLKPTR(snprintf, ' ', buf, bp, type, checksum, compress);
1333 }
1334
1335 void
1336 spa_freeze(spa_t *spa)
1337 {
1338 uint64_t freeze_txg = 0;
1339
1340 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1341 if (spa->spa_freeze_txg == UINT64_MAX) {
1342 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1343 spa->spa_freeze_txg = freeze_txg;
1344 }
1345 spa_config_exit(spa, SCL_ALL, FTAG);
1346 if (freeze_txg != 0)
1347 txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1348 }
1349
1350 void
1351 zfs_panic_recover(const char *fmt, ...)
1352 {
1353 va_list adx;
1354
1355 va_start(adx, fmt);
1356 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1357 va_end(adx);
1358 }
1359
1360 /*
1361 * This is a stripped-down version of strtoull, suitable only for converting
1362 * lowercase hexadecimal numbers that don't overflow.
1363 */
1364 uint64_t
1365 strtonum(const char *str, char **nptr)
1366 {
1367 uint64_t val = 0;
1368 char c;
1369 int digit;
1370
1371 while ((c = *str) != '\0') {
1372 if (c >= '0' && c <= '9')
1373 digit = c - '0';
1374 else if (c >= 'a' && c <= 'f')
1375 digit = 10 + c - 'a';
1376 else
1377 break;
1378
1379 val *= 16;
1380 val += digit;
1381
1382 str++;
1383 }
1384
1385 if (nptr)
1386 *nptr = (char *)str;
1387
1388 return (val);
1389 }
1390
1391 /*
1392 * ==========================================================================
1393 * Accessor functions
1394 * ==========================================================================
1395 */
1396
1397 boolean_t
1398 spa_shutting_down(spa_t *spa)
1399 {
1400 return (spa->spa_async_suspended);
1401 }
1402
1403 dsl_pool_t *
1404 spa_get_dsl(spa_t *spa)
1405 {
1406 return (spa->spa_dsl_pool);
1407 }
1408
1409 boolean_t
1410 spa_is_initializing(spa_t *spa)
1411 {
1412 return (spa->spa_is_initializing);
1413 }
1414
1415 blkptr_t *
1416 spa_get_rootblkptr(spa_t *spa)
1417 {
1418 return (&spa->spa_ubsync.ub_rootbp);
1419 }
1420
1421 void
1422 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1423 {
1424 spa->spa_uberblock.ub_rootbp = *bp;
1425 }
1426
1427 void
1428 spa_altroot(spa_t *spa, char *buf, size_t buflen)
1429 {
1430 if (spa->spa_root == NULL)
1431 buf[0] = '\0';
1432 else
1433 (void) strncpy(buf, spa->spa_root, buflen);
1434 }
1435
1436 int
1437 spa_sync_pass(spa_t *spa)
1438 {
1439 return (spa->spa_sync_pass);
1440 }
1441
1442 char *
1443 spa_name(spa_t *spa)
1444 {
1445 return (spa->spa_name);
1446 }
1447
1448 uint64_t
1449 spa_guid(spa_t *spa)
1450 {
1451 dsl_pool_t *dp = spa_get_dsl(spa);
1452 uint64_t guid;
1453
1454 /*
1455 * If we fail to parse the config during spa_load(), we can go through
1456 * the error path (which posts an ereport) and end up here with no root
1457 * vdev. We stash the original pool guid in 'spa_config_guid' to handle
1458 * this case.
1459 */
1460 if (spa->spa_root_vdev == NULL)
1461 return (spa->spa_config_guid);
1462
1463 guid = spa->spa_last_synced_guid != 0 ?
1464 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid;
1465
1466 /*
1467 * Return the most recently synced out guid unless we're
1468 * in syncing context.
1469 */
1470 if (dp && dsl_pool_sync_context(dp))
1471 return (spa->spa_root_vdev->vdev_guid);
1472 else
1473 return (guid);
1474 }
1475
1476 uint64_t
1477 spa_load_guid(spa_t *spa)
1478 {
1479 /*
1480 * This is a GUID that exists solely as a reference for the
1481 * purposes of the arc. It is generated at load time, and
1482 * is never written to persistent storage.
1483 */
1484 return (spa->spa_load_guid);
1485 }
1486
1487 uint64_t
1488 spa_last_synced_txg(spa_t *spa)
1489 {
1490 return (spa->spa_ubsync.ub_txg);
1491 }
1492
1493 uint64_t
1494 spa_first_txg(spa_t *spa)
1495 {
1496 return (spa->spa_first_txg);
1497 }
1498
1499 uint64_t
1500 spa_syncing_txg(spa_t *spa)
1501 {
1502 return (spa->spa_syncing_txg);
1503 }
1504
1505 pool_state_t
1506 spa_state(spa_t *spa)
1507 {
1508 return (spa->spa_state);
1509 }
1510
1511 spa_load_state_t
1512 spa_load_state(spa_t *spa)
1513 {
1514 return (spa->spa_load_state);
1515 }
1516
1517 uint64_t
1518 spa_freeze_txg(spa_t *spa)
1519 {
1520 return (spa->spa_freeze_txg);
1521 }
1522
1523 /* ARGSUSED */
1524 uint64_t
1525 spa_get_asize(spa_t *spa, uint64_t lsize)
1526 {
1527 return (lsize * spa_asize_inflation);
1528 }
1529
1530 uint64_t
1531 spa_get_dspace(spa_t *spa)
1532 {
1533 return (spa->spa_dspace);
1534 }
1535
1536 void
1537 spa_update_dspace(spa_t *spa)
1538 {
1539 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1540 ddt_get_dedup_dspace(spa);
1541 }
1542
1543 /*
1544 * Return the failure mode that has been set to this pool. The default
1545 * behavior will be to block all I/Os when a complete failure occurs.
1546 */
1547 uint8_t
1548 spa_get_failmode(spa_t *spa)
1549 {
1550 return (spa->spa_failmode);
1551 }
1552
1553 boolean_t
1554 spa_suspended(spa_t *spa)
1555 {
1556 return (spa->spa_suspended);
1557 }
1558
1559 uint64_t
1560 spa_version(spa_t *spa)
1561 {
1562 return (spa->spa_ubsync.ub_version);
1563 }
1564
1565 boolean_t
1566 spa_deflate(spa_t *spa)
1567 {
1568 return (spa->spa_deflate);
1569 }
1570
1571 metaslab_class_t *
1572 spa_normal_class(spa_t *spa)
1573 {
1574 return (spa->spa_normal_class);
1575 }
1576
1577 metaslab_class_t *
1578 spa_log_class(spa_t *spa)
1579 {
1580 return (spa->spa_log_class);
1581 }
1582
1583 int
1584 spa_max_replication(spa_t *spa)
1585 {
1586 /*
1587 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1588 * handle BPs with more than one DVA allocated. Set our max
1589 * replication level accordingly.
1590 */
1591 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1592 return (1);
1593 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1594 }
1595
1596 int
1597 spa_prev_software_version(spa_t *spa)
1598 {
1599 return (spa->spa_prev_software_version);
1600 }
1601
1602 uint64_t
1603 spa_deadman_synctime(spa_t *spa)
1604 {
1605 return (spa->spa_deadman_synctime);
1606 }
1607
1608 uint64_t
1609 dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1610 {
1611 uint64_t asize = DVA_GET_ASIZE(dva);
1612 uint64_t dsize = asize;
1613
1614 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1615
1616 if (asize != 0 && spa->spa_deflate) {
1617 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1618 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1619 }
1620
1621 return (dsize);
1622 }
1623
1624 uint64_t
1625 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1626 {
1627 uint64_t dsize = 0;
1628
1629 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1630 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1631
1632 return (dsize);
1633 }
1634
1635 uint64_t
1636 bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1637 {
1638 uint64_t dsize = 0;
1639
1640 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1641
1642 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1643 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1644
1645 spa_config_exit(spa, SCL_VDEV, FTAG);
1646
1647 return (dsize);
1648 }
1649
1650 /*
1651 * ==========================================================================
1652 * Initialization and Termination
1653 * ==========================================================================
1654 */
1655
1656 static int
1657 spa_name_compare(const void *a1, const void *a2)
1658 {
1659 const spa_t *s1 = a1;
1660 const spa_t *s2 = a2;
1661 int s;
1662
1663 s = strcmp(s1->spa_name, s2->spa_name);
1664 if (s > 0)
1665 return (1);
1666 if (s < 0)
1667 return (-1);
1668 return (0);
1669 }
1670
1671 int
1672 spa_busy(void)
1673 {
1674 return (spa_active_count);
1675 }
1676
1677 void
1678 spa_boot_init()
1679 {
1680 spa_config_load();
1681 }
1682
1683 void
1684 spa_init(int mode)
1685 {
1686 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1687 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1688 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1689 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1690
1691 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1692 offsetof(spa_t, spa_avl));
1693
1694 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1695 offsetof(spa_aux_t, aux_avl));
1696
1697 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1698 offsetof(spa_aux_t, aux_avl));
1699
1700 spa_mode_global = mode;
1701
1702 #ifdef _KERNEL
1703 spa_arch_init();
1704 #else
1705 if (spa_mode_global != FREAD && dprintf_find_string("watch")) {
1706 arc_procfd = open("/proc/self/ctl", O_WRONLY);
1707 if (arc_procfd == -1) {
1708 perror("could not enable watchpoints: "
1709 "opening /proc/self/ctl failed: ");
1710 } else {
1711 arc_watch = B_TRUE;
1712 }
1713 }
1714 #endif
1715
1716 refcount_init();
1717 unique_init();
1718 range_tree_init();
1719 zio_init();
1720 dmu_init();
1721 zil_init();
1722 vdev_cache_stat_init();
1723 zfs_prop_init();
1724 zpool_prop_init();
1725 zpool_feature_init();
1726 spa_config_load();
1727 l2arc_start();
1728 }
1729
1730 void
1731 spa_fini(void)
1732 {
1733 l2arc_stop();
1734
1735 spa_evict_all();
1736
1737 vdev_cache_stat_fini();
1738 zil_fini();
1739 dmu_fini();
1740 zio_fini();
1741 range_tree_fini();
1742 unique_fini();
1743 refcount_fini();
1744
1745 avl_destroy(&spa_namespace_avl);
1746 avl_destroy(&spa_spare_avl);
1747 avl_destroy(&spa_l2cache_avl);
1748
1749 cv_destroy(&spa_namespace_cv);
1750 mutex_destroy(&spa_namespace_lock);
1751 mutex_destroy(&spa_spare_lock);
1752 mutex_destroy(&spa_l2cache_lock);
1753 }
1754
1755 /*
1756 * Return whether this pool has slogs. No locking needed.
1757 * It's not a problem if the wrong answer is returned as it's only for
1758 * performance and not correctness
1759 */
1760 boolean_t
1761 spa_has_slogs(spa_t *spa)
1762 {
1763 return (spa->spa_log_class->mc_rotor != NULL);
1764 }
1765
1766 spa_log_state_t
1767 spa_get_log_state(spa_t *spa)
1768 {
1769 return (spa->spa_log_state);
1770 }
1771
1772 void
1773 spa_set_log_state(spa_t *spa, spa_log_state_t state)
1774 {
1775 spa->spa_log_state = state;
1776 }
1777
1778 boolean_t
1779 spa_is_root(spa_t *spa)
1780 {
1781 return (spa->spa_is_root);
1782 }
1783
1784 boolean_t
1785 spa_writeable(spa_t *spa)
1786 {
1787 return (!!(spa->spa_mode & FWRITE));
1788 }
1789
1790 static int
1791 activate_salted_cksum_check(zfeature_info_t *feature, dmu_tx_t *tx)
1792 {
1793 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1794
1795 if (!spa_feature_is_active(spa, feature))
1796 return (0);
1797 else
1798 return (SET_ERROR(EBUSY));
1799 }
1800
1801 static void
1802 activate_salted_cksum_sync(zfeature_info_t *feature, dmu_tx_t *tx)
1803 {
1804 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1805
1806 spa_feature_incr(spa, feature, tx);
1807 /*
1808 * This is the first salted checksum that's been activated, so
1809 * create the persistent checksum salt object now.
1810 */
1811 if (spa->spa_cksum_salt_obj == 0) {
1812 spa->spa_cksum_salt_obj = zap_create_link(spa->spa_meta_objset,
1813 DMU_OTN_ZAP_METADATA, DMU_POOL_DIRECTORY_OBJECT,
1814 DMU_POOL_CHECKSUM_SALT, tx);
1815 VERIFY3U(zap_add(spa->spa_meta_objset,
1816 spa->spa_cksum_salt_obj, DMU_POOL_CHECKSUM_SALT, 1,
1817 sizeof (spa->spa_cksum_salt.zcs_bytes),
1818 spa->spa_cksum_salt.zcs_bytes, tx), ==, 0);
1819 }
1820 }
1821
1822 /*
1823 * Activates a feature associated with a salted checksum. You must call this
1824 * function instead of calling spa_feature_incr() directly, because we may
1825 * also need to sync the MOS object holding the checksum salt.
1826 * Arguments:
1827 * spa Pool on which to activate the salted checksum feature.
1828 * feature Salted checksum algorithm feature to activate (see
1829 * spa_feature_table).
1830 */
1831 int
1832 spa_activate_salted_cksum(spa_t *spa, struct zfeature_info *feature)
1833 {
1834 int err;
1835
1836 /* EBUSY here indicates that the feature is already active */
1837 err = dsl_sync_task(spa_name(spa),
1838 (dsl_checkfunc_t *)activate_salted_cksum_check,
1839 (dsl_syncfunc_t *)activate_salted_cksum_sync, feature, 2);
1840
1841 if (err != 0 && err != EBUSY)
1842 return (err);
1843 else
1844 return (0);
1845 }
1846
1847 int
1848 spa_mode(spa_t *spa)
1849 {
1850 return (spa->spa_mode);
1851 }
1852
1853 uint64_t
1854 spa_bootfs(spa_t *spa)
1855 {
1856 return (spa->spa_bootfs);
1857 }
1858
1859 uint64_t
1860 spa_delegation(spa_t *spa)
1861 {
1862 return (spa->spa_delegation);
1863 }
1864
1865 objset_t *
1866 spa_meta_objset(spa_t *spa)
1867 {
1868 return (spa->spa_meta_objset);
1869 }
1870
1871 enum zio_checksum
1872 spa_dedup_checksum(spa_t *spa)
1873 {
1874 return (spa->spa_dedup_checksum);
1875 }
1876
1877 /*
1878 * Reset pool scan stat per scan pass (or reboot).
1879 */
1880 void
1881 spa_scan_stat_init(spa_t *spa)
1882 {
1883 /* data not stored on disk */
1884 spa->spa_scan_pass_start = gethrestime_sec();
1885 spa->spa_scan_pass_exam = 0;
1886 vdev_scan_stat_init(spa->spa_root_vdev);
1887 }
1888
1889 /*
1890 * Get scan stats for zpool status reports
1891 */
1892 int
1893 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps)
1894 {
1895 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL;
1896
1897 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE)
1898 return (SET_ERROR(ENOENT));
1899 bzero(ps, sizeof (pool_scan_stat_t));
1900
1901 /* data stored on disk */
1902 ps->pss_func = scn->scn_phys.scn_func;
1903 ps->pss_start_time = scn->scn_phys.scn_start_time;
1904 ps->pss_end_time = scn->scn_phys.scn_end_time;
1905 ps->pss_to_examine = scn->scn_phys.scn_to_examine;
1906 ps->pss_examined = scn->scn_phys.scn_examined;
1907 ps->pss_to_process = scn->scn_phys.scn_to_process;
1908 ps->pss_processed = scn->scn_phys.scn_processed;
1909 ps->pss_errors = scn->scn_phys.scn_errors;
1910 ps->pss_state = scn->scn_phys.scn_state;
1911
1912 /* data not stored on disk */
1913 ps->pss_pass_start = spa->spa_scan_pass_start;
1914 ps->pss_pass_exam = spa->spa_scan_pass_exam;
1915
1916 return (0);
1917 }
1918
1919 boolean_t
1920 spa_debug_enabled(spa_t *spa)
1921 {
1922 return (spa->spa_debug);
1923 }