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/*
* 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.
* Copyright (c) 2011 by Delphix. All rights reserved.
* Copyright 2011 Nexenta Systems, Inc. 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;
SYSCTL_DECL(_vfs_zfs);
TUNABLE_INT("vfs.zfs.recover", &zfs_recover);
SYSCTL_INT(_vfs_zfs, OID_AUTO, recover, CTLFLAG_RDTUN, &zfs_recover, 0,
"Try to recover from otherwise-fatal errors.");
/*
* ==========================================================================
* 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
zfs_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_config_guid' to handle
* this case.
*/
if (spa->spa_root_vdev != NULL)
return (spa->spa_root_vdev->vdev_guid);
else
return (spa->spa_config_guid);
}
uint64_t
spa_load_guid(spa_t *spa)
{
/*
* This is a GUID that exists solely as a reference for the
* purposes of the arc. It is generated at load time, and
* is never written to persistent storage.
*/
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_sysinit();
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);
}
boolean_t
spa_debug_enabled(spa_t *spa)
{
return (spa->spa_debug);
}