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.
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.
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]
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 #include <sys/zfs_context.h>
27 #include <sys/spa_impl.h>
29 #include <sys/zio_checksum.h>
30 #include <sys/zio_compress.h>
32 #include <sys/dmu_tx.h>
35 #include <sys/vdev_impl.h>
36 #include <sys/metaslab.h>
37 #include <sys/uberblock_impl.h>
40 #include <sys/unique.h>
41 #include <sys/dsl_pool.h>
42 #include <sys/dsl_dir.h>
43 #include <sys/dsl_prop.h>
44 #include <sys/fs/zfs.h>
45 #include <sys/metaslab_impl.h>
46 #include <sys/sunddi.h>
53 * There are four basic locks for managing spa_t structures:
55 * spa_namespace_lock (global mutex)
57 * This lock must be acquired to do any of the following:
59 * - Lookup a spa_t by name
60 * - Add or remove a spa_t from the namespace
61 * - Increase spa_refcount from non-zero
62 * - Check if spa_refcount is zero
64 * - add/remove/attach/detach devices
65 * - Held for the duration of create/destroy/import/export
67 * It does not need to handle recursion. A create or destroy may
68 * reference objects (files or zvols) in other pools, but by
69 * definition they must have an existing reference, and will never need
70 * to lookup a spa_t by name.
72 * spa_refcount (per-spa refcount_t protected by mutex)
74 * This reference count keep track of any active users of the spa_t. The
75 * spa_t cannot be destroyed or freed while this is non-zero. Internally,
76 * the refcount is never really 'zero' - opening a pool implicitly keeps
77 * some references in the DMU. Internally we check against spa_minref, but
78 * present the image of a zero/non-zero value to consumers.
80 * spa_config_lock[] (per-spa array of rwlocks)
82 * This protects the spa_t from config changes, and must be held in
83 * the following circumstances:
85 * - RW_READER to perform I/O to the spa
86 * - RW_WRITER to change the vdev config
88 * The locking order is fairly straightforward:
90 * spa_namespace_lock -> spa_refcount
92 * The namespace lock must be acquired to increase the refcount from 0
93 * or to check if it is zero.
95 * spa_refcount -> spa_config_lock[]
97 * There must be at least one valid reference on the spa_t to acquire
100 * spa_namespace_lock -> spa_config_lock[]
102 * The namespace lock must always be taken before the config lock.
105 * The spa_namespace_lock can be acquired directly and is globally visible.
107 * The namespace is manipulated using the following functions, all of which
108 * require the spa_namespace_lock to be held.
110 * spa_lookup() Lookup a spa_t by name.
112 * spa_add() Create a new spa_t in the namespace.
114 * spa_remove() Remove a spa_t from the namespace. This also
115 * frees up any memory associated with the spa_t.
117 * spa_next() Returns the next spa_t in the system, or the
118 * first if NULL is passed.
120 * spa_evict_all() Shutdown and remove all spa_t structures in
123 * spa_guid_exists() Determine whether a pool/device guid exists.
125 * The spa_refcount is manipulated using the following functions:
127 * spa_open_ref() Adds a reference to the given spa_t. Must be
128 * called with spa_namespace_lock held if the
129 * refcount is currently zero.
131 * spa_close() Remove a reference from the spa_t. This will
132 * not free the spa_t or remove it from the
133 * namespace. No locking is required.
135 * spa_refcount_zero() Returns true if the refcount is currently
136 * zero. Must be called with spa_namespace_lock
139 * The spa_config_lock[] is an array of rwlocks, ordered as follows:
140 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
141 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
143 * To read the configuration, it suffices to hold one of these locks as reader.
144 * To modify the configuration, you must hold all locks as writer. To modify
145 * vdev state without altering the vdev tree's topology (e.g. online/offline),
146 * you must hold SCL_STATE and SCL_ZIO as writer.
148 * We use these distinct config locks to avoid recursive lock entry.
149 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
150 * block allocations (SCL_ALLOC), which may require reading space maps
151 * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
153 * The spa config locks cannot be normal rwlocks because we need the
154 * ability to hand off ownership. For example, SCL_ZIO is acquired
155 * by the issuing thread and later released by an interrupt thread.
156 * They do, however, obey the usual write-wanted semantics to prevent
157 * writer (i.e. system administrator) starvation.
159 * The lock acquisition rules are as follows:
162 * Protects changes to the vdev tree topology, such as vdev
163 * add/remove/attach/detach. Protects the dirty config list
164 * (spa_config_dirty_list) and the set of spares and l2arc devices.
167 * Protects changes to pool state and vdev state, such as vdev
168 * online/offline/fault/degrade/clear. Protects the dirty state list
169 * (spa_state_dirty_list) and global pool state (spa_state).
172 * Protects changes to metaslab groups and classes.
173 * Held as reader by metaslab_alloc() and metaslab_claim().
176 * Held by bp-level zios (those which have no io_vd upon entry)
177 * to prevent changes to the vdev tree. The bp-level zio implicitly
178 * protects all of its vdev child zios, which do not hold SCL_ZIO.
181 * Protects changes to metaslab groups and classes.
182 * Held as reader by metaslab_free(). SCL_FREE is distinct from
183 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
184 * blocks in zio_done() while another i/o that holds either
185 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
188 * Held as reader to prevent changes to the vdev tree during trivial
189 * inquiries such as bp_get_dasize(). SCL_VDEV is distinct from the
190 * other locks, and lower than all of them, to ensure that it's safe
191 * to acquire regardless of caller context.
193 * In addition, the following rules apply:
195 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list.
196 * The lock ordering is SCL_CONFIG > spa_props_lock.
198 * (b) I/O operations on leaf vdevs. For any zio operation that takes
199 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
200 * or zio_write_phys() -- the caller must ensure that the config cannot
201 * cannot change in the interim, and that the vdev cannot be reopened.
202 * SCL_STATE as reader suffices for both.
204 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
206 * spa_vdev_enter() Acquire the namespace lock and the config lock
209 * spa_vdev_exit() Release the config lock, wait for all I/O
210 * to complete, sync the updated configs to the
211 * cache, and release the namespace lock.
213 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
214 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
215 * locking is, always, based on spa_namespace_lock and spa_config_lock[].
217 * spa_rename() is also implemented within this file since is requires
218 * manipulation of the namespace.
221 static avl_tree_t spa_namespace_avl;
222 kmutex_t spa_namespace_lock;
223 static kcondvar_t spa_namespace_cv;
224 static int spa_active_count;
225 int spa_max_replication_override = SPA_DVAS_PER_BP;
227 static kmutex_t spa_spare_lock;
228 static avl_tree_t spa_spare_avl;
229 static kmutex_t spa_l2cache_lock;
230 static avl_tree_t spa_l2cache_avl;
232 kmem_cache_t *spa_buffer_pool;
236 /* Everything except dprintf is on by default in debug builds */
237 int zfs_flags = ~ZFS_DEBUG_DPRINTF;
243 * zfs_recover can be set to nonzero to attempt to recover from
244 * otherwise-fatal errors, typically caused by on-disk corruption. When
245 * set, calls to zfs_panic_recover() will turn into warning messages.
251 * ==========================================================================
253 * ==========================================================================
256 spa_config_lock_init(spa_t *spa)
258 for (int i = 0; i < SCL_LOCKS; i++) {
259 spa_config_lock_t *scl = &spa->spa_config_lock[i];
260 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
261 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
262 refcount_create(&scl->scl_count);
263 scl->scl_writer = NULL;
264 scl->scl_write_wanted = 0;
269 spa_config_lock_destroy(spa_t *spa)
271 for (int i = 0; i < SCL_LOCKS; i++) {
272 spa_config_lock_t *scl = &spa->spa_config_lock[i];
273 mutex_destroy(&scl->scl_lock);
274 cv_destroy(&scl->scl_cv);
275 refcount_destroy(&scl->scl_count);
276 ASSERT(scl->scl_writer == NULL);
277 ASSERT(scl->scl_write_wanted == 0);
282 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
284 for (int i = 0; i < SCL_LOCKS; i++) {
285 spa_config_lock_t *scl = &spa->spa_config_lock[i];
286 if (!(locks & (1 << i)))
288 mutex_enter(&scl->scl_lock);
289 if (rw == RW_READER) {
290 if (scl->scl_writer || scl->scl_write_wanted) {
291 mutex_exit(&scl->scl_lock);
292 spa_config_exit(spa, locks ^ (1 << i), tag);
296 ASSERT(scl->scl_writer != curthread);
297 if (!refcount_is_zero(&scl->scl_count)) {
298 mutex_exit(&scl->scl_lock);
299 spa_config_exit(spa, locks ^ (1 << i), tag);
302 scl->scl_writer = curthread;
304 (void) refcount_add(&scl->scl_count, tag);
305 mutex_exit(&scl->scl_lock);
311 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
313 for (int i = 0; i < SCL_LOCKS; i++) {
314 spa_config_lock_t *scl = &spa->spa_config_lock[i];
315 if (!(locks & (1 << i)))
317 mutex_enter(&scl->scl_lock);
318 if (rw == RW_READER) {
319 while (scl->scl_writer || scl->scl_write_wanted) {
320 cv_wait(&scl->scl_cv, &scl->scl_lock);
323 ASSERT(scl->scl_writer != curthread);
324 while (!refcount_is_zero(&scl->scl_count)) {
325 scl->scl_write_wanted++;
326 cv_wait(&scl->scl_cv, &scl->scl_lock);
327 scl->scl_write_wanted--;
329 scl->scl_writer = curthread;
331 (void) refcount_add(&scl->scl_count, tag);
332 mutex_exit(&scl->scl_lock);
337 spa_config_exit(spa_t *spa, int locks, void *tag)
339 for (int i = SCL_LOCKS - 1; i >= 0; i--) {
340 spa_config_lock_t *scl = &spa->spa_config_lock[i];
341 if (!(locks & (1 << i)))
343 mutex_enter(&scl->scl_lock);
344 ASSERT(!refcount_is_zero(&scl->scl_count));
345 if (refcount_remove(&scl->scl_count, tag) == 0) {
346 ASSERT(scl->scl_writer == NULL ||
347 scl->scl_writer == curthread);
348 scl->scl_writer = NULL; /* OK in either case */
349 cv_broadcast(&scl->scl_cv);
351 mutex_exit(&scl->scl_lock);
356 spa_config_held(spa_t *spa, int locks, krw_t rw)
360 for (int i = 0; i < SCL_LOCKS; i++) {
361 spa_config_lock_t *scl = &spa->spa_config_lock[i];
362 if (!(locks & (1 << i)))
364 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
365 (rw == RW_WRITER && scl->scl_writer == curthread))
366 locks_held |= 1 << i;
373 * ==========================================================================
374 * SPA namespace functions
375 * ==========================================================================
379 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held.
380 * Returns NULL if no matching spa_t is found.
383 spa_lookup(const char *name)
385 static spa_t search; /* spa_t is large; don't allocate on stack */
391 ASSERT(MUTEX_HELD(&spa_namespace_lock));
394 * If it's a full dataset name, figure out the pool name and
397 cp = strpbrk(name, "/@");
403 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
404 spa = avl_find(&spa_namespace_avl, &search, &where);
413 * Create an uninitialized spa_t with the given name. Requires
414 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already
415 * exist by calling spa_lookup() first.
418 spa_add(const char *name, const char *altroot)
421 spa_config_dirent_t *dp;
423 ASSERT(MUTEX_HELD(&spa_namespace_lock));
425 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
427 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
428 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
429 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
430 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
431 mutex_init(&spa->spa_sync_bplist.bpl_lock, NULL, MUTEX_DEFAULT, NULL);
432 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
433 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
435 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
436 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
437 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
439 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
440 spa->spa_state = POOL_STATE_UNINITIALIZED;
441 spa->spa_freeze_txg = UINT64_MAX;
442 spa->spa_final_txg = UINT64_MAX;
444 refcount_create(&spa->spa_refcount);
445 spa_config_lock_init(spa);
447 avl_add(&spa_namespace_avl, spa);
449 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
452 * Set the alternate root, if there is one.
455 spa->spa_root = spa_strdup(altroot);
460 * Every pool starts with the default cachefile
462 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
463 offsetof(spa_config_dirent_t, scd_link));
465 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
466 dp->scd_path = spa_strdup(spa_config_path);
467 list_insert_head(&spa->spa_config_list, dp);
473 * Removes a spa_t from the namespace, freeing up any memory used. Requires
474 * spa_namespace_lock. This is called only after the spa_t has been closed and
478 spa_remove(spa_t *spa)
480 spa_config_dirent_t *dp;
482 ASSERT(MUTEX_HELD(&spa_namespace_lock));
483 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
485 avl_remove(&spa_namespace_avl, spa);
486 cv_broadcast(&spa_namespace_cv);
489 spa_strfree(spa->spa_root);
493 while ((dp = list_head(&spa->spa_config_list)) != NULL) {
494 list_remove(&spa->spa_config_list, dp);
495 if (dp->scd_path != NULL)
496 spa_strfree(dp->scd_path);
497 kmem_free(dp, sizeof (spa_config_dirent_t));
500 list_destroy(&spa->spa_config_list);
502 spa_config_set(spa, NULL);
504 refcount_destroy(&spa->spa_refcount);
506 spa_config_lock_destroy(spa);
508 cv_destroy(&spa->spa_async_cv);
509 cv_destroy(&spa->spa_scrub_io_cv);
510 cv_destroy(&spa->spa_suspend_cv);
512 mutex_destroy(&spa->spa_async_lock);
513 mutex_destroy(&spa->spa_scrub_lock);
514 mutex_destroy(&spa->spa_errlog_lock);
515 mutex_destroy(&spa->spa_errlist_lock);
516 mutex_destroy(&spa->spa_sync_bplist.bpl_lock);
517 mutex_destroy(&spa->spa_history_lock);
518 mutex_destroy(&spa->spa_props_lock);
519 mutex_destroy(&spa->spa_suspend_lock);
521 kmem_free(spa, sizeof (spa_t));
525 * Given a pool, return the next pool in the namespace, or NULL if there is
526 * none. If 'prev' is NULL, return the first pool.
529 spa_next(spa_t *prev)
531 ASSERT(MUTEX_HELD(&spa_namespace_lock));
534 return (AVL_NEXT(&spa_namespace_avl, prev));
536 return (avl_first(&spa_namespace_avl));
540 * ==========================================================================
541 * SPA refcount functions
542 * ==========================================================================
546 * Add a reference to the given spa_t. Must have at least one reference, or
547 * have the namespace lock held.
550 spa_open_ref(spa_t *spa, void *tag)
552 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
553 MUTEX_HELD(&spa_namespace_lock));
554 (void) refcount_add(&spa->spa_refcount, tag);
558 * Remove a reference to the given spa_t. Must have at least one reference, or
559 * have the namespace lock held.
562 spa_close(spa_t *spa, void *tag)
564 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
565 MUTEX_HELD(&spa_namespace_lock));
566 (void) refcount_remove(&spa->spa_refcount, tag);
570 * Check to see if the spa refcount is zero. Must be called with
571 * spa_namespace_lock held. We really compare against spa_minref, which is the
572 * number of references acquired when opening a pool
575 spa_refcount_zero(spa_t *spa)
577 ASSERT(MUTEX_HELD(&spa_namespace_lock));
579 return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
583 * ==========================================================================
584 * SPA spare and l2cache tracking
585 * ==========================================================================
589 * Hot spares and cache devices are tracked using the same code below,
590 * for 'auxiliary' devices.
593 typedef struct spa_aux {
601 spa_aux_compare(const void *a, const void *b)
603 const spa_aux_t *sa = a;
604 const spa_aux_t *sb = b;
606 if (sa->aux_guid < sb->aux_guid)
608 else if (sa->aux_guid > sb->aux_guid)
615 spa_aux_add(vdev_t *vd, avl_tree_t *avl)
621 search.aux_guid = vd->vdev_guid;
622 if ((aux = avl_find(avl, &search, &where)) != NULL) {
625 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
626 aux->aux_guid = vd->vdev_guid;
628 avl_insert(avl, aux, where);
633 spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
639 search.aux_guid = vd->vdev_guid;
640 aux = avl_find(avl, &search, &where);
644 if (--aux->aux_count == 0) {
645 avl_remove(avl, aux);
646 kmem_free(aux, sizeof (spa_aux_t));
647 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
648 aux->aux_pool = 0ULL;
653 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
655 spa_aux_t search, *found;
657 search.aux_guid = guid;
658 found = avl_find(avl, &search, NULL);
662 *pool = found->aux_pool;
669 *refcnt = found->aux_count;
674 return (found != NULL);
678 spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
680 spa_aux_t search, *found;
683 search.aux_guid = vd->vdev_guid;
684 found = avl_find(avl, &search, &where);
685 ASSERT(found != NULL);
686 ASSERT(found->aux_pool == 0ULL);
688 found->aux_pool = spa_guid(vd->vdev_spa);
692 * Spares are tracked globally due to the following constraints:
694 * - A spare may be part of multiple pools.
695 * - A spare may be added to a pool even if it's actively in use within
697 * - A spare in use in any pool can only be the source of a replacement if
698 * the target is a spare in the same pool.
700 * We keep track of all spares on the system through the use of a reference
701 * counted AVL tree. When a vdev is added as a spare, or used as a replacement
702 * spare, then we bump the reference count in the AVL tree. In addition, we set
703 * the 'vdev_isspare' member to indicate that the device is a spare (active or
704 * inactive). When a spare is made active (used to replace a device in the
705 * pool), we also keep track of which pool its been made a part of.
707 * The 'spa_spare_lock' protects the AVL tree. These functions are normally
708 * called under the spa_namespace lock as part of vdev reconfiguration. The
709 * separate spare lock exists for the status query path, which does not need to
710 * be completely consistent with respect to other vdev configuration changes.
714 spa_spare_compare(const void *a, const void *b)
716 return (spa_aux_compare(a, b));
720 spa_spare_add(vdev_t *vd)
722 mutex_enter(&spa_spare_lock);
723 ASSERT(!vd->vdev_isspare);
724 spa_aux_add(vd, &spa_spare_avl);
725 vd->vdev_isspare = B_TRUE;
726 mutex_exit(&spa_spare_lock);
730 spa_spare_remove(vdev_t *vd)
732 mutex_enter(&spa_spare_lock);
733 ASSERT(vd->vdev_isspare);
734 spa_aux_remove(vd, &spa_spare_avl);
735 vd->vdev_isspare = B_FALSE;
736 mutex_exit(&spa_spare_lock);
740 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
744 mutex_enter(&spa_spare_lock);
745 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
746 mutex_exit(&spa_spare_lock);
752 spa_spare_activate(vdev_t *vd)
754 mutex_enter(&spa_spare_lock);
755 ASSERT(vd->vdev_isspare);
756 spa_aux_activate(vd, &spa_spare_avl);
757 mutex_exit(&spa_spare_lock);
761 * Level 2 ARC devices are tracked globally for the same reasons as spares.
762 * Cache devices currently only support one pool per cache device, and so
763 * for these devices the aux reference count is currently unused beyond 1.
767 spa_l2cache_compare(const void *a, const void *b)
769 return (spa_aux_compare(a, b));
773 spa_l2cache_add(vdev_t *vd)
775 mutex_enter(&spa_l2cache_lock);
776 ASSERT(!vd->vdev_isl2cache);
777 spa_aux_add(vd, &spa_l2cache_avl);
778 vd->vdev_isl2cache = B_TRUE;
779 mutex_exit(&spa_l2cache_lock);
783 spa_l2cache_remove(vdev_t *vd)
785 mutex_enter(&spa_l2cache_lock);
786 ASSERT(vd->vdev_isl2cache);
787 spa_aux_remove(vd, &spa_l2cache_avl);
788 vd->vdev_isl2cache = B_FALSE;
789 mutex_exit(&spa_l2cache_lock);
793 spa_l2cache_exists(uint64_t guid, uint64_t *pool)
797 mutex_enter(&spa_l2cache_lock);
798 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
799 mutex_exit(&spa_l2cache_lock);
805 spa_l2cache_activate(vdev_t *vd)
807 mutex_enter(&spa_l2cache_lock);
808 ASSERT(vd->vdev_isl2cache);
809 spa_aux_activate(vd, &spa_l2cache_avl);
810 mutex_exit(&spa_l2cache_lock);
814 spa_l2cache_space_update(vdev_t *vd, int64_t space, int64_t alloc)
816 vdev_space_update(vd, space, alloc, B_FALSE);
820 * ==========================================================================
822 * ==========================================================================
826 * Lock the given spa_t for the purpose of adding or removing a vdev.
827 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
828 * It returns the next transaction group for the spa_t.
831 spa_vdev_enter(spa_t *spa)
833 mutex_enter(&spa_namespace_lock);
835 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
837 return (spa_last_synced_txg(spa) + 1);
841 * Unlock the spa_t after adding or removing a vdev. Besides undoing the
842 * locking of spa_vdev_enter(), we also want make sure the transactions have
843 * synced to disk, and then update the global configuration cache with the new
847 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
849 int config_changed = B_FALSE;
851 ASSERT(txg > spa_last_synced_txg(spa));
853 spa->spa_pending_vdev = NULL;
858 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
861 * If the config changed, notify the scrub thread that it must restart.
863 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
864 dsl_pool_scrub_restart(spa->spa_dsl_pool);
865 config_changed = B_TRUE;
868 spa_config_exit(spa, SCL_ALL, spa);
871 * Note: this txg_wait_synced() is important because it ensures
872 * that there won't be more than one config change per txg.
873 * This allows us to use the txg as the generation number.
876 txg_wait_synced(spa->spa_dsl_pool, txg);
879 ASSERT(!vd->vdev_detached || vd->vdev_dtl_smo.smo_object == 0);
880 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
882 spa_config_exit(spa, SCL_ALL, spa);
886 * If the config changed, update the config cache.
889 spa_config_sync(spa, B_FALSE, B_TRUE);
891 mutex_exit(&spa_namespace_lock);
897 * Lock the given spa_t for the purpose of changing vdev state.
900 spa_vdev_state_enter(spa_t *spa)
902 spa_config_enter(spa, SCL_STATE_ALL, spa, RW_WRITER);
906 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
909 vdev_state_dirty(vd->vdev_top);
911 spa_config_exit(spa, SCL_STATE_ALL, spa);
914 * If anything changed, wait for it to sync. This ensures that,
915 * from the system administrator's perspective, zpool(1M) commands
916 * are synchronous. This is important for things like zpool offline:
917 * when the command completes, you expect no further I/O from ZFS.
920 txg_wait_synced(spa->spa_dsl_pool, 0);
926 * ==========================================================================
927 * Miscellaneous functions
928 * ==========================================================================
935 spa_rename(const char *name, const char *newname)
941 * Lookup the spa_t and grab the config lock for writing. We need to
942 * actually open the pool so that we can sync out the necessary labels.
943 * It's OK to call spa_open() with the namespace lock held because we
944 * allow recursive calls for other reasons.
946 mutex_enter(&spa_namespace_lock);
947 if ((err = spa_open(name, &spa, FTAG)) != 0) {
948 mutex_exit(&spa_namespace_lock);
952 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
954 avl_remove(&spa_namespace_avl, spa);
955 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
956 avl_add(&spa_namespace_avl, spa);
959 * Sync all labels to disk with the new names by marking the root vdev
960 * dirty and waiting for it to sync. It will pick up the new pool name
963 vdev_config_dirty(spa->spa_root_vdev);
965 spa_config_exit(spa, SCL_ALL, FTAG);
967 txg_wait_synced(spa->spa_dsl_pool, 0);
970 * Sync the updated config cache.
972 spa_config_sync(spa, B_FALSE, B_TRUE);
974 spa_close(spa, FTAG);
976 mutex_exit(&spa_namespace_lock);
983 * Determine whether a pool with given pool_guid exists. If device_guid is
984 * non-zero, determine whether the pool exists *and* contains a device with the
985 * specified device_guid.
988 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
991 avl_tree_t *t = &spa_namespace_avl;
993 ASSERT(MUTEX_HELD(&spa_namespace_lock));
995 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
996 if (spa->spa_state == POOL_STATE_UNINITIALIZED)
998 if (spa->spa_root_vdev == NULL)
1000 if (spa_guid(spa) == pool_guid) {
1001 if (device_guid == 0)
1004 if (vdev_lookup_by_guid(spa->spa_root_vdev,
1005 device_guid) != NULL)
1009 * Check any devices we may be in the process of adding.
1011 if (spa->spa_pending_vdev) {
1012 if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1013 device_guid) != NULL)
1019 return (spa != NULL);
1023 spa_strdup(const char *s)
1029 new = kmem_alloc(len + 1, KM_SLEEP);
1037 spa_strfree(char *s)
1039 kmem_free(s, strlen(s) + 1);
1043 spa_get_random(uint64_t range)
1049 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1055 sprintf_blkptr(char *buf, int len, const blkptr_t *bp)
1060 (void) snprintf(buf, len, "<NULL>");
1064 if (BP_IS_HOLE(bp)) {
1065 (void) snprintf(buf, len, "<hole>");
1069 (void) snprintf(buf, len, "[L%llu %s] %llxL/%llxP ",
1070 (u_longlong_t)BP_GET_LEVEL(bp),
1071 dmu_ot[BP_GET_TYPE(bp)].ot_name,
1072 (u_longlong_t)BP_GET_LSIZE(bp),
1073 (u_longlong_t)BP_GET_PSIZE(bp));
1075 for (d = 0; d < BP_GET_NDVAS(bp); d++) {
1076 const dva_t *dva = &bp->blk_dva[d];
1077 (void) snprintf(buf + strlen(buf), len - strlen(buf),
1078 "DVA[%d]=<%llu:%llx:%llx> ", d,
1079 (u_longlong_t)DVA_GET_VDEV(dva),
1080 (u_longlong_t)DVA_GET_OFFSET(dva),
1081 (u_longlong_t)DVA_GET_ASIZE(dva));
1084 (void) snprintf(buf + strlen(buf), len - strlen(buf),
1085 "%s %s %s %s birth=%llu fill=%llu cksum=%llx:%llx:%llx:%llx",
1086 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name,
1087 zio_compress_table[BP_GET_COMPRESS(bp)].ci_name,
1088 BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",
1089 BP_IS_GANG(bp) ? "gang" : "contiguous",
1090 (u_longlong_t)bp->blk_birth,
1091 (u_longlong_t)bp->blk_fill,
1092 (u_longlong_t)bp->blk_cksum.zc_word[0],
1093 (u_longlong_t)bp->blk_cksum.zc_word[1],
1094 (u_longlong_t)bp->blk_cksum.zc_word[2],
1095 (u_longlong_t)bp->blk_cksum.zc_word[3]);
1099 spa_freeze(spa_t *spa)
1101 uint64_t freeze_txg = 0;
1103 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1104 if (spa->spa_freeze_txg == UINT64_MAX) {
1105 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1106 spa->spa_freeze_txg = freeze_txg;
1108 spa_config_exit(spa, SCL_ALL, FTAG);
1109 if (freeze_txg != 0)
1110 txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1114 zfs_panic_recover(const char *fmt, ...)
1119 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1124 * ==========================================================================
1125 * Accessor functions
1126 * ==========================================================================
1130 spa_shutting_down(spa_t *spa)
1132 return (spa->spa_async_suspended);
1136 spa_get_dsl(spa_t *spa)
1138 return (spa->spa_dsl_pool);
1142 spa_get_rootblkptr(spa_t *spa)
1144 return (&spa->spa_ubsync.ub_rootbp);
1148 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1150 spa->spa_uberblock.ub_rootbp = *bp;
1154 spa_altroot(spa_t *spa, char *buf, size_t buflen)
1156 if (spa->spa_root == NULL)
1159 (void) strncpy(buf, spa->spa_root, buflen);
1163 spa_sync_pass(spa_t *spa)
1165 return (spa->spa_sync_pass);
1169 spa_name(spa_t *spa)
1171 return (spa->spa_name);
1175 spa_guid(spa_t *spa)
1178 * If we fail to parse the config during spa_load(), we can go through
1179 * the error path (which posts an ereport) and end up here with no root
1180 * vdev. We stash the original pool guid in 'spa_load_guid' to handle
1183 if (spa->spa_root_vdev != NULL)
1184 return (spa->spa_root_vdev->vdev_guid);
1186 return (spa->spa_load_guid);
1190 spa_last_synced_txg(spa_t *spa)
1192 return (spa->spa_ubsync.ub_txg);
1196 spa_first_txg(spa_t *spa)
1198 return (spa->spa_first_txg);
1202 spa_state(spa_t *spa)
1204 return (spa->spa_state);
1208 spa_freeze_txg(spa_t *spa)
1210 return (spa->spa_freeze_txg);
1214 * Return how much space is allocated in the pool (ie. sum of all asize)
1217 spa_get_alloc(spa_t *spa)
1219 return (spa->spa_root_vdev->vdev_stat.vs_alloc);
1223 * Return how much (raid-z inflated) space there is in the pool.
1226 spa_get_space(spa_t *spa)
1228 return (spa->spa_root_vdev->vdev_stat.vs_space);
1232 * Return the amount of raid-z-deflated space in the pool.
1235 spa_get_dspace(spa_t *spa)
1237 if (spa->spa_deflate)
1238 return (spa->spa_root_vdev->vdev_stat.vs_dspace);
1240 return (spa->spa_root_vdev->vdev_stat.vs_space);
1245 spa_get_asize(spa_t *spa, uint64_t lsize)
1248 * For now, the worst case is 512-byte RAID-Z blocks, in which
1249 * case the space requirement is exactly 2x; so just assume that.
1250 * Add to this the fact that we can have up to 3 DVAs per bp, and
1251 * we have to multiply by a total of 6x.
1257 * Return the failure mode that has been set to this pool. The default
1258 * behavior will be to block all I/Os when a complete failure occurs.
1261 spa_get_failmode(spa_t *spa)
1263 return (spa->spa_failmode);
1267 spa_suspended(spa_t *spa)
1269 return (spa->spa_suspended);
1273 spa_version(spa_t *spa)
1275 return (spa->spa_ubsync.ub_version);
1279 spa_max_replication(spa_t *spa)
1282 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1283 * handle BPs with more than one DVA allocated. Set our max
1284 * replication level accordingly.
1286 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1288 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1292 bp_get_dasize(spa_t *spa, const blkptr_t *bp)
1296 if (!spa->spa_deflate)
1297 return (BP_GET_ASIZE(bp));
1299 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1300 for (i = 0; i < SPA_DVAS_PER_BP; i++) {
1302 vdev_lookup_top(spa, DVA_GET_VDEV(&bp->blk_dva[i]));
1304 sz += (DVA_GET_ASIZE(&bp->blk_dva[i]) >>
1305 SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1307 spa_config_exit(spa, SCL_VDEV, FTAG);
1312 * ==========================================================================
1313 * Initialization and Termination
1314 * ==========================================================================
1318 spa_name_compare(const void *a1, const void *a2)
1320 const spa_t *s1 = a1;
1321 const spa_t *s2 = a2;
1324 s = strcmp(s1->spa_name, s2->spa_name);
1335 return (spa_active_count);
1347 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1348 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1349 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1350 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1352 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1353 offsetof(spa_t, spa_avl));
1355 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1356 offsetof(spa_aux_t, aux_avl));
1358 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1359 offsetof(spa_aux_t, aux_avl));
1361 spa_mode_global = mode;
1368 vdev_cache_stat_init();
1382 vdev_cache_stat_fini();
1389 avl_destroy(&spa_namespace_avl);
1390 avl_destroy(&spa_spare_avl);
1391 avl_destroy(&spa_l2cache_avl);
1393 cv_destroy(&spa_namespace_cv);
1394 mutex_destroy(&spa_namespace_lock);
1395 mutex_destroy(&spa_spare_lock);
1396 mutex_destroy(&spa_l2cache_lock);
1400 * Return whether this pool has slogs. No locking needed.
1401 * It's not a problem if the wrong answer is returned as it's only for
1402 * performance and not correctness
1405 spa_has_slogs(spa_t *spa)
1407 return (spa->spa_log_class->mc_rotor != NULL);
1411 * Return whether this pool is the root pool.
1414 spa_is_root(spa_t *spa)
1416 return (spa->spa_is_root);
1420 spa_writeable(spa_t *spa)
1422 return (!!(spa->spa_mode & FWRITE));
1426 spa_mode(spa_t *spa)
1428 return (spa->spa_mode);