diff options
Diffstat (limited to 'uts/common/fs/zfs/spa_misc.c')
| -rw-r--r-- | uts/common/fs/zfs/spa_misc.c | 1672 |
1 files changed, 1672 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/spa_misc.c b/uts/common/fs/zfs/spa_misc.c new file mode 100644 index 000000000000..1b54afb0be5e --- /dev/null +++ b/uts/common/fs/zfs/spa_misc.c @@ -0,0 +1,1672 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + */ + +#include <sys/zfs_context.h> +#include <sys/spa_impl.h> +#include <sys/zio.h> +#include <sys/zio_checksum.h> +#include <sys/zio_compress.h> +#include <sys/dmu.h> +#include <sys/dmu_tx.h> +#include <sys/zap.h> +#include <sys/zil.h> +#include <sys/vdev_impl.h> +#include <sys/metaslab.h> +#include <sys/uberblock_impl.h> +#include <sys/txg.h> +#include <sys/avl.h> +#include <sys/unique.h> +#include <sys/dsl_pool.h> +#include <sys/dsl_dir.h> +#include <sys/dsl_prop.h> +#include <sys/dsl_scan.h> +#include <sys/fs/zfs.h> +#include <sys/metaslab_impl.h> +#include <sys/arc.h> +#include <sys/ddt.h> +#include "zfs_prop.h" + +/* + * SPA locking + * + * There are four basic locks for managing spa_t structures: + * + * spa_namespace_lock (global mutex) + * + * This lock must be acquired to do any of the following: + * + * - Lookup a spa_t by name + * - Add or remove a spa_t from the namespace + * - Increase spa_refcount from non-zero + * - Check if spa_refcount is zero + * - Rename a spa_t + * - add/remove/attach/detach devices + * - Held for the duration of create/destroy/import/export + * + * It does not need to handle recursion. A create or destroy may + * reference objects (files or zvols) in other pools, but by + * definition they must have an existing reference, and will never need + * to lookup a spa_t by name. + * + * spa_refcount (per-spa refcount_t protected by mutex) + * + * This reference count keep track of any active users of the spa_t. The + * spa_t cannot be destroyed or freed while this is non-zero. Internally, + * the refcount is never really 'zero' - opening a pool implicitly keeps + * some references in the DMU. Internally we check against spa_minref, but + * present the image of a zero/non-zero value to consumers. + * + * spa_config_lock[] (per-spa array of rwlocks) + * + * This protects the spa_t from config changes, and must be held in + * the following circumstances: + * + * - RW_READER to perform I/O to the spa + * - RW_WRITER to change the vdev config + * + * The locking order is fairly straightforward: + * + * spa_namespace_lock -> spa_refcount + * + * The namespace lock must be acquired to increase the refcount from 0 + * or to check if it is zero. + * + * spa_refcount -> spa_config_lock[] + * + * There must be at least one valid reference on the spa_t to acquire + * the config lock. + * + * spa_namespace_lock -> spa_config_lock[] + * + * The namespace lock must always be taken before the config lock. + * + * + * The spa_namespace_lock can be acquired directly and is globally visible. + * + * The namespace is manipulated using the following functions, all of which + * require the spa_namespace_lock to be held. + * + * spa_lookup() Lookup a spa_t by name. + * + * spa_add() Create a new spa_t in the namespace. + * + * spa_remove() Remove a spa_t from the namespace. This also + * frees up any memory associated with the spa_t. + * + * spa_next() Returns the next spa_t in the system, or the + * first if NULL is passed. + * + * spa_evict_all() Shutdown and remove all spa_t structures in + * the system. + * + * spa_guid_exists() Determine whether a pool/device guid exists. + * + * The spa_refcount is manipulated using the following functions: + * + * spa_open_ref() Adds a reference to the given spa_t. Must be + * called with spa_namespace_lock held if the + * refcount is currently zero. + * + * spa_close() Remove a reference from the spa_t. This will + * not free the spa_t or remove it from the + * namespace. No locking is required. + * + * spa_refcount_zero() Returns true if the refcount is currently + * zero. Must be called with spa_namespace_lock + * held. + * + * The spa_config_lock[] is an array of rwlocks, ordered as follows: + * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV. + * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}(). + * + * To read the configuration, it suffices to hold one of these locks as reader. + * To modify the configuration, you must hold all locks as writer. To modify + * vdev state without altering the vdev tree's topology (e.g. online/offline), + * you must hold SCL_STATE and SCL_ZIO as writer. + * + * We use these distinct config locks to avoid recursive lock entry. + * For example, spa_sync() (which holds SCL_CONFIG as reader) induces + * block allocations (SCL_ALLOC), which may require reading space maps + * from disk (dmu_read() -> zio_read() -> SCL_ZIO). + * + * The spa config locks cannot be normal rwlocks because we need the + * ability to hand off ownership. For example, SCL_ZIO is acquired + * by the issuing thread and later released by an interrupt thread. + * They do, however, obey the usual write-wanted semantics to prevent + * writer (i.e. system administrator) starvation. + * + * The lock acquisition rules are as follows: + * + * SCL_CONFIG + * Protects changes to the vdev tree topology, such as vdev + * add/remove/attach/detach. Protects the dirty config list + * (spa_config_dirty_list) and the set of spares and l2arc devices. + * + * SCL_STATE + * Protects changes to pool state and vdev state, such as vdev + * online/offline/fault/degrade/clear. Protects the dirty state list + * (spa_state_dirty_list) and global pool state (spa_state). + * + * SCL_ALLOC + * Protects changes to metaslab groups and classes. + * Held as reader by metaslab_alloc() and metaslab_claim(). + * + * SCL_ZIO + * Held by bp-level zios (those which have no io_vd upon entry) + * to prevent changes to the vdev tree. The bp-level zio implicitly + * protects all of its vdev child zios, which do not hold SCL_ZIO. + * + * SCL_FREE + * Protects changes to metaslab groups and classes. + * Held as reader by metaslab_free(). SCL_FREE is distinct from + * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free + * blocks in zio_done() while another i/o that holds either + * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete. + * + * SCL_VDEV + * Held as reader to prevent changes to the vdev tree during trivial + * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the + * other locks, and lower than all of them, to ensure that it's safe + * to acquire regardless of caller context. + * + * In addition, the following rules apply: + * + * (a) spa_props_lock protects pool properties, spa_config and spa_config_list. + * The lock ordering is SCL_CONFIG > spa_props_lock. + * + * (b) I/O operations on leaf vdevs. For any zio operation that takes + * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(), + * or zio_write_phys() -- the caller must ensure that the config cannot + * cannot change in the interim, and that the vdev cannot be reopened. + * SCL_STATE as reader suffices for both. + * + * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit(). + * + * spa_vdev_enter() Acquire the namespace lock and the config lock + * for writing. + * + * spa_vdev_exit() Release the config lock, wait for all I/O + * to complete, sync the updated configs to the + * cache, and release the namespace lock. + * + * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit(). + * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual + * locking is, always, based on spa_namespace_lock and spa_config_lock[]. + * + * spa_rename() is also implemented within this file since is requires + * manipulation of the namespace. + */ + +static avl_tree_t spa_namespace_avl; +kmutex_t spa_namespace_lock; +static kcondvar_t spa_namespace_cv; +static int spa_active_count; +int spa_max_replication_override = SPA_DVAS_PER_BP; + +static kmutex_t spa_spare_lock; +static avl_tree_t spa_spare_avl; +static kmutex_t spa_l2cache_lock; +static avl_tree_t spa_l2cache_avl; + +kmem_cache_t *spa_buffer_pool; +int spa_mode_global; + +#ifdef ZFS_DEBUG +/* Everything except dprintf is on by default in debug builds */ +int zfs_flags = ~ZFS_DEBUG_DPRINTF; +#else +int zfs_flags = 0; +#endif + +/* + * zfs_recover can be set to nonzero to attempt to recover from + * otherwise-fatal errors, typically caused by on-disk corruption. When + * set, calls to zfs_panic_recover() will turn into warning messages. + */ +int zfs_recover = 0; + + +/* + * ========================================================================== + * SPA config locking + * ========================================================================== + */ +static void +spa_config_lock_init(spa_t *spa) +{ + for (int i = 0; i < SCL_LOCKS; i++) { + spa_config_lock_t *scl = &spa->spa_config_lock[i]; + mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL); + refcount_create(&scl->scl_count); + scl->scl_writer = NULL; + scl->scl_write_wanted = 0; + } +} + +static void +spa_config_lock_destroy(spa_t *spa) +{ + for (int i = 0; i < SCL_LOCKS; i++) { + spa_config_lock_t *scl = &spa->spa_config_lock[i]; + mutex_destroy(&scl->scl_lock); + cv_destroy(&scl->scl_cv); + refcount_destroy(&scl->scl_count); + ASSERT(scl->scl_writer == NULL); + ASSERT(scl->scl_write_wanted == 0); + } +} + +int +spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw) +{ + for (int i = 0; i < SCL_LOCKS; i++) { + spa_config_lock_t *scl = &spa->spa_config_lock[i]; + if (!(locks & (1 << i))) + continue; + mutex_enter(&scl->scl_lock); + if (rw == RW_READER) { + if (scl->scl_writer || scl->scl_write_wanted) { + mutex_exit(&scl->scl_lock); + spa_config_exit(spa, locks ^ (1 << i), tag); + return (0); + } + } else { + ASSERT(scl->scl_writer != curthread); + if (!refcount_is_zero(&scl->scl_count)) { + mutex_exit(&scl->scl_lock); + spa_config_exit(spa, locks ^ (1 << i), tag); + return (0); + } + scl->scl_writer = curthread; + } + (void) refcount_add(&scl->scl_count, tag); + mutex_exit(&scl->scl_lock); + } + return (1); +} + +void +spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw) +{ + int wlocks_held = 0; + + for (int i = 0; i < SCL_LOCKS; i++) { + spa_config_lock_t *scl = &spa->spa_config_lock[i]; + if (scl->scl_writer == curthread) + wlocks_held |= (1 << i); + if (!(locks & (1 << i))) + continue; + mutex_enter(&scl->scl_lock); + if (rw == RW_READER) { + while (scl->scl_writer || scl->scl_write_wanted) { + cv_wait(&scl->scl_cv, &scl->scl_lock); + } + } else { + ASSERT(scl->scl_writer != curthread); + while (!refcount_is_zero(&scl->scl_count)) { + scl->scl_write_wanted++; + cv_wait(&scl->scl_cv, &scl->scl_lock); + scl->scl_write_wanted--; + } + scl->scl_writer = curthread; + } + (void) refcount_add(&scl->scl_count, tag); + mutex_exit(&scl->scl_lock); + } + ASSERT(wlocks_held <= locks); +} + +void +spa_config_exit(spa_t *spa, int locks, void *tag) +{ + for (int i = SCL_LOCKS - 1; i >= 0; i--) { + spa_config_lock_t *scl = &spa->spa_config_lock[i]; + if (!(locks & (1 << i))) + continue; + mutex_enter(&scl->scl_lock); + ASSERT(!refcount_is_zero(&scl->scl_count)); + if (refcount_remove(&scl->scl_count, tag) == 0) { + ASSERT(scl->scl_writer == NULL || + scl->scl_writer == curthread); + scl->scl_writer = NULL; /* OK in either case */ + cv_broadcast(&scl->scl_cv); + } + mutex_exit(&scl->scl_lock); + } +} + +int +spa_config_held(spa_t *spa, int locks, krw_t rw) +{ + int locks_held = 0; + + for (int i = 0; i < SCL_LOCKS; i++) { + spa_config_lock_t *scl = &spa->spa_config_lock[i]; + if (!(locks & (1 << i))) + continue; + if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) || + (rw == RW_WRITER && scl->scl_writer == curthread)) + locks_held |= 1 << i; + } + + return (locks_held); +} + +/* + * ========================================================================== + * SPA namespace functions + * ========================================================================== + */ + +/* + * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held. + * Returns NULL if no matching spa_t is found. + */ +spa_t * +spa_lookup(const char *name) +{ + static spa_t search; /* spa_t is large; don't allocate on stack */ + spa_t *spa; + avl_index_t where; + char c; + char *cp; + + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + /* + * If it's a full dataset name, figure out the pool name and + * just use that. + */ + cp = strpbrk(name, "/@"); + if (cp) { + c = *cp; + *cp = '\0'; + } + + (void) strlcpy(search.spa_name, name, sizeof (search.spa_name)); + spa = avl_find(&spa_namespace_avl, &search, &where); + + if (cp) + *cp = c; + + return (spa); +} + +/* + * Create an uninitialized spa_t with the given name. Requires + * spa_namespace_lock. The caller must ensure that the spa_t doesn't already + * exist by calling spa_lookup() first. + */ +spa_t * +spa_add(const char *name, nvlist_t *config, const char *altroot) +{ + spa_t *spa; + spa_config_dirent_t *dp; + + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP); + + mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL); + + cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL); + cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL); + cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL); + cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL); + + for (int t = 0; t < TXG_SIZE; t++) + bplist_create(&spa->spa_free_bplist[t]); + + (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name)); + spa->spa_state = POOL_STATE_UNINITIALIZED; + spa->spa_freeze_txg = UINT64_MAX; + spa->spa_final_txg = UINT64_MAX; + spa->spa_load_max_txg = UINT64_MAX; + spa->spa_proc = &p0; + spa->spa_proc_state = SPA_PROC_NONE; + + refcount_create(&spa->spa_refcount); + spa_config_lock_init(spa); + + avl_add(&spa_namespace_avl, spa); + + /* + * Set the alternate root, if there is one. + */ + if (altroot) { + spa->spa_root = spa_strdup(altroot); + spa_active_count++; + } + + /* + * Every pool starts with the default cachefile + */ + list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t), + offsetof(spa_config_dirent_t, scd_link)); + + dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP); + dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path); + list_insert_head(&spa->spa_config_list, dp); + + VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME, + KM_SLEEP) == 0); + + if (config != NULL) + VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0); + + return (spa); +} + +/* + * Removes a spa_t from the namespace, freeing up any memory used. Requires + * spa_namespace_lock. This is called only after the spa_t has been closed and + * deactivated. + */ +void +spa_remove(spa_t *spa) +{ + spa_config_dirent_t *dp; + + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED); + + nvlist_free(spa->spa_config_splitting); + + avl_remove(&spa_namespace_avl, spa); + cv_broadcast(&spa_namespace_cv); + + if (spa->spa_root) { + spa_strfree(spa->spa_root); + spa_active_count--; + } + + while ((dp = list_head(&spa->spa_config_list)) != NULL) { + list_remove(&spa->spa_config_list, dp); + if (dp->scd_path != NULL) + spa_strfree(dp->scd_path); + kmem_free(dp, sizeof (spa_config_dirent_t)); + } + + list_destroy(&spa->spa_config_list); + + nvlist_free(spa->spa_load_info); + spa_config_set(spa, NULL); + + refcount_destroy(&spa->spa_refcount); + + spa_config_lock_destroy(spa); + + for (int t = 0; t < TXG_SIZE; t++) + bplist_destroy(&spa->spa_free_bplist[t]); + + cv_destroy(&spa->spa_async_cv); + cv_destroy(&spa->spa_proc_cv); + cv_destroy(&spa->spa_scrub_io_cv); + cv_destroy(&spa->spa_suspend_cv); + + mutex_destroy(&spa->spa_async_lock); + mutex_destroy(&spa->spa_errlist_lock); + mutex_destroy(&spa->spa_errlog_lock); + mutex_destroy(&spa->spa_history_lock); + mutex_destroy(&spa->spa_proc_lock); + mutex_destroy(&spa->spa_props_lock); + mutex_destroy(&spa->spa_scrub_lock); + mutex_destroy(&spa->spa_suspend_lock); + mutex_destroy(&spa->spa_vdev_top_lock); + + kmem_free(spa, sizeof (spa_t)); +} + +/* + * Given a pool, return the next pool in the namespace, or NULL if there is + * none. If 'prev' is NULL, return the first pool. + */ +spa_t * +spa_next(spa_t *prev) +{ + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + if (prev) + return (AVL_NEXT(&spa_namespace_avl, prev)); + else + return (avl_first(&spa_namespace_avl)); +} + +/* + * ========================================================================== + * SPA refcount functions + * ========================================================================== + */ + +/* + * Add a reference to the given spa_t. Must have at least one reference, or + * have the namespace lock held. + */ +void +spa_open_ref(spa_t *spa, void *tag) +{ + ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref || + MUTEX_HELD(&spa_namespace_lock)); + (void) refcount_add(&spa->spa_refcount, tag); +} + +/* + * Remove a reference to the given spa_t. Must have at least one reference, or + * have the namespace lock held. + */ +void +spa_close(spa_t *spa, void *tag) +{ + ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref || + MUTEX_HELD(&spa_namespace_lock)); + (void) refcount_remove(&spa->spa_refcount, tag); +} + +/* + * Check to see if the spa refcount is zero. Must be called with + * spa_namespace_lock held. We really compare against spa_minref, which is the + * number of references acquired when opening a pool + */ +boolean_t +spa_refcount_zero(spa_t *spa) +{ + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + return (refcount_count(&spa->spa_refcount) == spa->spa_minref); +} + +/* + * ========================================================================== + * SPA spare and l2cache tracking + * ========================================================================== + */ + +/* + * Hot spares and cache devices are tracked using the same code below, + * for 'auxiliary' devices. + */ + +typedef struct spa_aux { + uint64_t aux_guid; + uint64_t aux_pool; + avl_node_t aux_avl; + int aux_count; +} spa_aux_t; + +static int +spa_aux_compare(const void *a, const void *b) +{ + const spa_aux_t *sa = a; + const spa_aux_t *sb = b; + + if (sa->aux_guid < sb->aux_guid) + return (-1); + else if (sa->aux_guid > sb->aux_guid) + return (1); + else + return (0); +} + +void +spa_aux_add(vdev_t *vd, avl_tree_t *avl) +{ + avl_index_t where; + spa_aux_t search; + spa_aux_t *aux; + + search.aux_guid = vd->vdev_guid; + if ((aux = avl_find(avl, &search, &where)) != NULL) { + aux->aux_count++; + } else { + aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP); + aux->aux_guid = vd->vdev_guid; + aux->aux_count = 1; + avl_insert(avl, aux, where); + } +} + +void +spa_aux_remove(vdev_t *vd, avl_tree_t *avl) +{ + spa_aux_t search; + spa_aux_t *aux; + avl_index_t where; + + search.aux_guid = vd->vdev_guid; + aux = avl_find(avl, &search, &where); + + ASSERT(aux != NULL); + + if (--aux->aux_count == 0) { + avl_remove(avl, aux); + kmem_free(aux, sizeof (spa_aux_t)); + } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) { + aux->aux_pool = 0ULL; + } +} + +boolean_t +spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl) +{ + spa_aux_t search, *found; + + search.aux_guid = guid; + found = avl_find(avl, &search, NULL); + + if (pool) { + if (found) + *pool = found->aux_pool; + else + *pool = 0ULL; + } + + if (refcnt) { + if (found) + *refcnt = found->aux_count; + else + *refcnt = 0; + } + + return (found != NULL); +} + +void +spa_aux_activate(vdev_t *vd, avl_tree_t *avl) +{ + spa_aux_t search, *found; + avl_index_t where; + + search.aux_guid = vd->vdev_guid; + found = avl_find(avl, &search, &where); + ASSERT(found != NULL); + ASSERT(found->aux_pool == 0ULL); + + found->aux_pool = spa_guid(vd->vdev_spa); +} + +/* + * Spares are tracked globally due to the following constraints: + * + * - A spare may be part of multiple pools. + * - A spare may be added to a pool even if it's actively in use within + * another pool. + * - A spare in use in any pool can only be the source of a replacement if + * the target is a spare in the same pool. + * + * We keep track of all spares on the system through the use of a reference + * counted AVL tree. When a vdev is added as a spare, or used as a replacement + * spare, then we bump the reference count in the AVL tree. In addition, we set + * the 'vdev_isspare' member to indicate that the device is a spare (active or + * inactive). When a spare is made active (used to replace a device in the + * pool), we also keep track of which pool its been made a part of. + * + * The 'spa_spare_lock' protects the AVL tree. These functions are normally + * called under the spa_namespace lock as part of vdev reconfiguration. The + * separate spare lock exists for the status query path, which does not need to + * be completely consistent with respect to other vdev configuration changes. + */ + +static int +spa_spare_compare(const void *a, const void *b) +{ + return (spa_aux_compare(a, b)); +} + +void +spa_spare_add(vdev_t *vd) +{ + mutex_enter(&spa_spare_lock); + ASSERT(!vd->vdev_isspare); + spa_aux_add(vd, &spa_spare_avl); + vd->vdev_isspare = B_TRUE; + mutex_exit(&spa_spare_lock); +} + +void +spa_spare_remove(vdev_t *vd) +{ + mutex_enter(&spa_spare_lock); + ASSERT(vd->vdev_isspare); + spa_aux_remove(vd, &spa_spare_avl); + vd->vdev_isspare = B_FALSE; + mutex_exit(&spa_spare_lock); +} + +boolean_t +spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt) +{ + boolean_t found; + + mutex_enter(&spa_spare_lock); + found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl); + mutex_exit(&spa_spare_lock); + + return (found); +} + +void +spa_spare_activate(vdev_t *vd) +{ + mutex_enter(&spa_spare_lock); + ASSERT(vd->vdev_isspare); + spa_aux_activate(vd, &spa_spare_avl); + mutex_exit(&spa_spare_lock); +} + +/* + * Level 2 ARC devices are tracked globally for the same reasons as spares. + * Cache devices currently only support one pool per cache device, and so + * for these devices the aux reference count is currently unused beyond 1. + */ + +static int +spa_l2cache_compare(const void *a, const void *b) +{ + return (spa_aux_compare(a, b)); +} + +void +spa_l2cache_add(vdev_t *vd) +{ + mutex_enter(&spa_l2cache_lock); + ASSERT(!vd->vdev_isl2cache); + spa_aux_add(vd, &spa_l2cache_avl); + vd->vdev_isl2cache = B_TRUE; + mutex_exit(&spa_l2cache_lock); +} + +void +spa_l2cache_remove(vdev_t *vd) +{ + mutex_enter(&spa_l2cache_lock); + ASSERT(vd->vdev_isl2cache); + spa_aux_remove(vd, &spa_l2cache_avl); + vd->vdev_isl2cache = B_FALSE; + mutex_exit(&spa_l2cache_lock); +} + +boolean_t +spa_l2cache_exists(uint64_t guid, uint64_t *pool) +{ + boolean_t found; + + mutex_enter(&spa_l2cache_lock); + found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl); + mutex_exit(&spa_l2cache_lock); + + return (found); +} + +void +spa_l2cache_activate(vdev_t *vd) +{ + mutex_enter(&spa_l2cache_lock); + ASSERT(vd->vdev_isl2cache); + spa_aux_activate(vd, &spa_l2cache_avl); + mutex_exit(&spa_l2cache_lock); +} + +/* + * ========================================================================== + * SPA vdev locking + * ========================================================================== + */ + +/* + * Lock the given spa_t for the purpose of adding or removing a vdev. + * Grabs the global spa_namespace_lock plus the spa config lock for writing. + * It returns the next transaction group for the spa_t. + */ +uint64_t +spa_vdev_enter(spa_t *spa) +{ + mutex_enter(&spa->spa_vdev_top_lock); + mutex_enter(&spa_namespace_lock); + return (spa_vdev_config_enter(spa)); +} + +/* + * Internal implementation for spa_vdev_enter(). Used when a vdev + * operation requires multiple syncs (i.e. removing a device) while + * keeping the spa_namespace_lock held. + */ +uint64_t +spa_vdev_config_enter(spa_t *spa) +{ + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); + + return (spa_last_synced_txg(spa) + 1); +} + +/* + * Used in combination with spa_vdev_config_enter() to allow the syncing + * of multiple transactions without releasing the spa_namespace_lock. + */ +void +spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag) +{ + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + int config_changed = B_FALSE; + + ASSERT(txg > spa_last_synced_txg(spa)); + + spa->spa_pending_vdev = NULL; + + /* + * Reassess the DTLs. + */ + vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE); + + if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) { + config_changed = B_TRUE; + spa->spa_config_generation++; + } + + /* + * Verify the metaslab classes. + */ + ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0); + ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0); + + spa_config_exit(spa, SCL_ALL, spa); + + /* + * Panic the system if the specified tag requires it. This + * is useful for ensuring that configurations are updated + * transactionally. + */ + if (zio_injection_enabled) + zio_handle_panic_injection(spa, tag, 0); + + /* + * Note: this txg_wait_synced() is important because it ensures + * that there won't be more than one config change per txg. + * This allows us to use the txg as the generation number. + */ + if (error == 0) + txg_wait_synced(spa->spa_dsl_pool, txg); + + if (vd != NULL) { + ASSERT(!vd->vdev_detached || vd->vdev_dtl_smo.smo_object == 0); + spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); + vdev_free(vd); + spa_config_exit(spa, SCL_ALL, spa); + } + + /* + * If the config changed, update the config cache. + */ + if (config_changed) + spa_config_sync(spa, B_FALSE, B_TRUE); +} + +/* + * Unlock the spa_t after adding or removing a vdev. Besides undoing the + * locking of spa_vdev_enter(), we also want make sure the transactions have + * synced to disk, and then update the global configuration cache with the new + * information. + */ +int +spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error) +{ + spa_vdev_config_exit(spa, vd, txg, error, FTAG); + mutex_exit(&spa_namespace_lock); + mutex_exit(&spa->spa_vdev_top_lock); + + return (error); +} + +/* + * Lock the given spa_t for the purpose of changing vdev state. + */ +void +spa_vdev_state_enter(spa_t *spa, int oplocks) +{ + int locks = SCL_STATE_ALL | oplocks; + + /* + * Root pools may need to read of the underlying devfs filesystem + * when opening up a vdev. Unfortunately if we're holding the + * SCL_ZIO lock it will result in a deadlock when we try to issue + * the read from the root filesystem. Instead we "prefetch" + * the associated vnodes that we need prior to opening the + * underlying devices and cache them so that we can prevent + * any I/O when we are doing the actual open. + */ + if (spa_is_root(spa)) { + int low = locks & ~(SCL_ZIO - 1); + int high = locks & ~low; + + spa_config_enter(spa, high, spa, RW_WRITER); + vdev_hold(spa->spa_root_vdev); + spa_config_enter(spa, low, spa, RW_WRITER); + } else { + spa_config_enter(spa, locks, spa, RW_WRITER); + } + spa->spa_vdev_locks = locks; +} + +int +spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error) +{ + boolean_t config_changed = B_FALSE; + + if (vd != NULL || error == 0) + vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev, + 0, 0, B_FALSE); + + if (vd != NULL) { + vdev_state_dirty(vd->vdev_top); + config_changed = B_TRUE; + spa->spa_config_generation++; + } + + if (spa_is_root(spa)) + vdev_rele(spa->spa_root_vdev); + + ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL); + spa_config_exit(spa, spa->spa_vdev_locks, spa); + + /* + * If anything changed, wait for it to sync. This ensures that, + * from the system administrator's perspective, zpool(1M) commands + * are synchronous. This is important for things like zpool offline: + * when the command completes, you expect no further I/O from ZFS. + */ + if (vd != NULL) + txg_wait_synced(spa->spa_dsl_pool, 0); + + /* + * If the config changed, update the config cache. + */ + if (config_changed) { + mutex_enter(&spa_namespace_lock); + spa_config_sync(spa, B_FALSE, B_TRUE); + mutex_exit(&spa_namespace_lock); + } + + return (error); +} + +/* + * ========================================================================== + * Miscellaneous functions + * ========================================================================== + */ + +/* + * Rename a spa_t. + */ +int +spa_rename(const char *name, const char *newname) +{ + spa_t *spa; + int err; + + /* + * Lookup the spa_t and grab the config lock for writing. We need to + * actually open the pool so that we can sync out the necessary labels. + * It's OK to call spa_open() with the namespace lock held because we + * allow recursive calls for other reasons. + */ + mutex_enter(&spa_namespace_lock); + if ((err = spa_open(name, &spa, FTAG)) != 0) { + mutex_exit(&spa_namespace_lock); + return (err); + } + + spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); + + avl_remove(&spa_namespace_avl, spa); + (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name)); + avl_add(&spa_namespace_avl, spa); + + /* + * Sync all labels to disk with the new names by marking the root vdev + * dirty and waiting for it to sync. It will pick up the new pool name + * during the sync. + */ + vdev_config_dirty(spa->spa_root_vdev); + + spa_config_exit(spa, SCL_ALL, FTAG); + + txg_wait_synced(spa->spa_dsl_pool, 0); + + /* + * Sync the updated config cache. + */ + spa_config_sync(spa, B_FALSE, B_TRUE); + + spa_close(spa, FTAG); + + mutex_exit(&spa_namespace_lock); + + return (0); +} + +/* + * Return the spa_t associated with given pool_guid, if it exists. If + * device_guid is non-zero, determine whether the pool exists *and* contains + * a device with the specified device_guid. + */ +spa_t * +spa_by_guid(uint64_t pool_guid, uint64_t device_guid) +{ + spa_t *spa; + avl_tree_t *t = &spa_namespace_avl; + + ASSERT(MUTEX_HELD(&spa_namespace_lock)); + + for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) { + if (spa->spa_state == POOL_STATE_UNINITIALIZED) + continue; + if (spa->spa_root_vdev == NULL) + continue; + if (spa_guid(spa) == pool_guid) { + if (device_guid == 0) + break; + + if (vdev_lookup_by_guid(spa->spa_root_vdev, + device_guid) != NULL) + break; + + /* + * Check any devices we may be in the process of adding. + */ + if (spa->spa_pending_vdev) { + if (vdev_lookup_by_guid(spa->spa_pending_vdev, + device_guid) != NULL) + break; + } + } + } + + return (spa); +} + +/* + * Determine whether a pool with the given pool_guid exists. + */ +boolean_t +spa_guid_exists(uint64_t pool_guid, uint64_t device_guid) +{ + return (spa_by_guid(pool_guid, device_guid) != NULL); +} + +char * +spa_strdup(const char *s) +{ + size_t len; + char *new; + + len = strlen(s); + new = kmem_alloc(len + 1, KM_SLEEP); + bcopy(s, new, len); + new[len] = '\0'; + + return (new); +} + +void +spa_strfree(char *s) +{ + kmem_free(s, strlen(s) + 1); +} + +uint64_t +spa_get_random(uint64_t range) +{ + uint64_t r; + + ASSERT(range != 0); + + (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t)); + + return (r % range); +} + +uint64_t +spa_generate_guid(spa_t *spa) +{ + uint64_t guid = spa_get_random(-1ULL); + + if (spa != NULL) { + while (guid == 0 || spa_guid_exists(spa_guid(spa), guid)) + guid = spa_get_random(-1ULL); + } else { + while (guid == 0 || spa_guid_exists(guid, 0)) + guid = spa_get_random(-1ULL); + } + + return (guid); +} + +void +sprintf_blkptr(char *buf, const blkptr_t *bp) +{ + char *type = NULL; + char *checksum = NULL; + char *compress = NULL; + + if (bp != NULL) { + type = dmu_ot[BP_GET_TYPE(bp)].ot_name; + checksum = zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name; + compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name; + } + + SPRINTF_BLKPTR(snprintf, ' ', buf, bp, type, checksum, compress); +} + +void +spa_freeze(spa_t *spa) +{ + uint64_t freeze_txg = 0; + + spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); + if (spa->spa_freeze_txg == UINT64_MAX) { + freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE; + spa->spa_freeze_txg = freeze_txg; + } + spa_config_exit(spa, SCL_ALL, FTAG); + if (freeze_txg != 0) + txg_wait_synced(spa_get_dsl(spa), freeze_txg); +} + +void +zfs_panic_recover(const char *fmt, ...) +{ + va_list adx; + + va_start(adx, fmt); + vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx); + va_end(adx); +} + +/* + * This is a stripped-down version of strtoull, suitable only for converting + * lowercase hexidecimal numbers that don't overflow. + */ +uint64_t +strtonum(const char *str, char **nptr) +{ + uint64_t val = 0; + char c; + int digit; + + while ((c = *str) != '\0') { + if (c >= '0' && c <= '9') + digit = c - '0'; + else if (c >= 'a' && c <= 'f') + digit = 10 + c - 'a'; + else + break; + + val *= 16; + val += digit; + + str++; + } + + if (nptr) + *nptr = (char *)str; + + return (val); +} + +/* + * ========================================================================== + * Accessor functions + * ========================================================================== + */ + +boolean_t +spa_shutting_down(spa_t *spa) +{ + return (spa->spa_async_suspended); +} + +dsl_pool_t * +spa_get_dsl(spa_t *spa) +{ + return (spa->spa_dsl_pool); +} + +blkptr_t * +spa_get_rootblkptr(spa_t *spa) +{ + return (&spa->spa_ubsync.ub_rootbp); +} + +void +spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp) +{ + spa->spa_uberblock.ub_rootbp = *bp; +} + +void +spa_altroot(spa_t *spa, char *buf, size_t buflen) +{ + if (spa->spa_root == NULL) + buf[0] = '\0'; + else + (void) strncpy(buf, spa->spa_root, buflen); +} + +int +spa_sync_pass(spa_t *spa) +{ + return (spa->spa_sync_pass); +} + +char * +spa_name(spa_t *spa) +{ + return (spa->spa_name); +} + +uint64_t +spa_guid(spa_t *spa) +{ + /* + * If we fail to parse the config during spa_load(), we can go through + * the error path (which posts an ereport) and end up here with no root + * vdev. We stash the original pool guid in 'spa_load_guid' to handle + * this case. + */ + if (spa->spa_root_vdev != NULL) + return (spa->spa_root_vdev->vdev_guid); + else + return (spa->spa_load_guid); +} + +uint64_t +spa_last_synced_txg(spa_t *spa) +{ + return (spa->spa_ubsync.ub_txg); +} + +uint64_t +spa_first_txg(spa_t *spa) +{ + return (spa->spa_first_txg); +} + +uint64_t +spa_syncing_txg(spa_t *spa) +{ + return (spa->spa_syncing_txg); +} + +pool_state_t +spa_state(spa_t *spa) +{ + return (spa->spa_state); +} + +spa_load_state_t +spa_load_state(spa_t *spa) +{ + return (spa->spa_load_state); +} + +uint64_t +spa_freeze_txg(spa_t *spa) +{ + return (spa->spa_freeze_txg); +} + +/* ARGSUSED */ +uint64_t +spa_get_asize(spa_t *spa, uint64_t lsize) +{ + /* + * The worst case is single-sector max-parity RAID-Z blocks, in which + * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1) + * times the size; so just assume that. Add to this the fact that + * we can have up to 3 DVAs per bp, and one more factor of 2 because + * the block may be dittoed with up to 3 DVAs by ddt_sync(). + */ + return (lsize * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2); +} + +uint64_t +spa_get_dspace(spa_t *spa) +{ + return (spa->spa_dspace); +} + +void +spa_update_dspace(spa_t *spa) +{ + spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) + + ddt_get_dedup_dspace(spa); +} + +/* + * Return the failure mode that has been set to this pool. The default + * behavior will be to block all I/Os when a complete failure occurs. + */ +uint8_t +spa_get_failmode(spa_t *spa) +{ + return (spa->spa_failmode); +} + +boolean_t +spa_suspended(spa_t *spa) +{ + return (spa->spa_suspended); +} + +uint64_t +spa_version(spa_t *spa) +{ + return (spa->spa_ubsync.ub_version); +} + +boolean_t +spa_deflate(spa_t *spa) +{ + return (spa->spa_deflate); +} + +metaslab_class_t * +spa_normal_class(spa_t *spa) +{ + return (spa->spa_normal_class); +} + +metaslab_class_t * +spa_log_class(spa_t *spa) +{ + return (spa->spa_log_class); +} + +int +spa_max_replication(spa_t *spa) +{ + /* + * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to + * handle BPs with more than one DVA allocated. Set our max + * replication level accordingly. + */ + if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS) + return (1); + return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override)); +} + +int +spa_prev_software_version(spa_t *spa) +{ + return (spa->spa_prev_software_version); +} + +uint64_t +dva_get_dsize_sync(spa_t *spa, const dva_t *dva) +{ + uint64_t asize = DVA_GET_ASIZE(dva); + uint64_t dsize = asize; + + ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); + + if (asize != 0 && spa->spa_deflate) { + vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); + dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio; + } + + return (dsize); +} + +uint64_t +bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp) +{ + uint64_t dsize = 0; + + for (int d = 0; d < SPA_DVAS_PER_BP; d++) + dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); + + return (dsize); +} + +uint64_t +bp_get_dsize(spa_t *spa, const blkptr_t *bp) +{ + uint64_t dsize = 0; + + spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); + + for (int d = 0; d < SPA_DVAS_PER_BP; d++) + dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); + + spa_config_exit(spa, SCL_VDEV, FTAG); + + return (dsize); +} + +/* + * ========================================================================== + * Initialization and Termination + * ========================================================================== + */ + +static int +spa_name_compare(const void *a1, const void *a2) +{ + const spa_t *s1 = a1; + const spa_t *s2 = a2; + int s; + + s = strcmp(s1->spa_name, s2->spa_name); + if (s > 0) + return (1); + if (s < 0) + return (-1); + return (0); +} + +int +spa_busy(void) +{ + return (spa_active_count); +} + +void +spa_boot_init() +{ + spa_config_load(); +} + +void +spa_init(int mode) +{ + mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL); + + avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t), + offsetof(spa_t, spa_avl)); + + avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t), + offsetof(spa_aux_t, aux_avl)); + + avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t), + offsetof(spa_aux_t, aux_avl)); + + spa_mode_global = mode; + + refcount_init(); + unique_init(); + zio_init(); + dmu_init(); + zil_init(); + vdev_cache_stat_init(); + zfs_prop_init(); + zpool_prop_init(); + spa_config_load(); + l2arc_start(); +} + +void +spa_fini(void) +{ + l2arc_stop(); + + spa_evict_all(); + + vdev_cache_stat_fini(); + zil_fini(); + dmu_fini(); + zio_fini(); + unique_fini(); + refcount_fini(); + + avl_destroy(&spa_namespace_avl); + avl_destroy(&spa_spare_avl); + avl_destroy(&spa_l2cache_avl); + + cv_destroy(&spa_namespace_cv); + mutex_destroy(&spa_namespace_lock); + mutex_destroy(&spa_spare_lock); + mutex_destroy(&spa_l2cache_lock); +} + +/* + * Return whether this pool has slogs. No locking needed. + * It's not a problem if the wrong answer is returned as it's only for + * performance and not correctness + */ +boolean_t +spa_has_slogs(spa_t *spa) +{ + return (spa->spa_log_class->mc_rotor != NULL); +} + +spa_log_state_t +spa_get_log_state(spa_t *spa) +{ + return (spa->spa_log_state); +} + +void +spa_set_log_state(spa_t *spa, spa_log_state_t state) +{ + spa->spa_log_state = state; +} + +boolean_t +spa_is_root(spa_t *spa) +{ + return (spa->spa_is_root); +} + +boolean_t +spa_writeable(spa_t *spa) +{ + return (!!(spa->spa_mode & FWRITE)); +} + +int +spa_mode(spa_t *spa) +{ + return (spa->spa_mode); +} + +uint64_t +spa_bootfs(spa_t *spa) +{ + return (spa->spa_bootfs); +} + +uint64_t +spa_delegation(spa_t *spa) +{ + return (spa->spa_delegation); +} + +objset_t * +spa_meta_objset(spa_t *spa) +{ + return (spa->spa_meta_objset); +} + +enum zio_checksum +spa_dedup_checksum(spa_t *spa) +{ + return (spa->spa_dedup_checksum); +} + +/* + * Reset pool scan stat per scan pass (or reboot). + */ +void +spa_scan_stat_init(spa_t *spa) +{ + /* data not stored on disk */ + spa->spa_scan_pass_start = gethrestime_sec(); + spa->spa_scan_pass_exam = 0; + vdev_scan_stat_init(spa->spa_root_vdev); +} + +/* + * Get scan stats for zpool status reports + */ +int +spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps) +{ + dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL; + + if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE) + return (ENOENT); + bzero(ps, sizeof (pool_scan_stat_t)); + + /* data stored on disk */ + ps->pss_func = scn->scn_phys.scn_func; + ps->pss_start_time = scn->scn_phys.scn_start_time; + ps->pss_end_time = scn->scn_phys.scn_end_time; + ps->pss_to_examine = scn->scn_phys.scn_to_examine; + ps->pss_examined = scn->scn_phys.scn_examined; + ps->pss_to_process = scn->scn_phys.scn_to_process; + ps->pss_processed = scn->scn_phys.scn_processed; + ps->pss_errors = scn->scn_phys.scn_errors; + ps->pss_state = scn->scn_phys.scn_state; + + /* data not stored on disk */ + ps->pss_pass_start = spa->spa_scan_pass_start; + ps->pss_pass_exam = spa->spa_scan_pass_exam; + + return (0); +} |