Move the world out of /zfs/ and seperate out module build tree

1 files changed, 1410 insertions, 0 deletions

diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c
new file mode 100644
index 000000000..36046e6df
--- /dev/null
+++ b/module/zfs/spa_misc.c
@@ -0,0 +1,1410 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#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/fs/zfs.h>
+#include <sys/metaslab_impl.h>
+#include <sys/sunddi.h>
+#include <sys/arc.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_dasize().  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;
+
+#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)
+{
+	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) {
+			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);
+	}
+}
+
+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, 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_async_root_lock, NULL, MUTEX_DEFAULT, NULL);
+	mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
+	mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
+	mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
+	mutex_init(&spa->spa_sync_bplist.bpl_lock, NULL, MUTEX_DEFAULT, NULL);
+	mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
+	mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
+
+	cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
+	cv_init(&spa->spa_async_root_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);
+
+	(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;
+
+	refcount_create(&spa->spa_refcount);
+	spa_config_lock_init(spa);
+
+	avl_add(&spa_namespace_avl, spa);
+
+	mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
+
+	/*
+	 * 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 = spa_strdup(spa_config_path);
+	list_insert_head(&spa->spa_config_list, dp);
+
+	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);
+
+	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);
+
+	spa_config_set(spa, NULL);
+
+	refcount_destroy(&spa->spa_refcount);
+
+	spa_config_lock_destroy(spa);
+
+	cv_destroy(&spa->spa_async_cv);
+	cv_destroy(&spa->spa_async_root_cv);
+	cv_destroy(&spa->spa_scrub_io_cv);
+	cv_destroy(&spa->spa_suspend_cv);
+
+	mutex_destroy(&spa->spa_async_lock);
+	mutex_destroy(&spa->spa_async_root_lock);
+	mutex_destroy(&spa->spa_scrub_lock);
+	mutex_destroy(&spa->spa_errlog_lock);
+	mutex_destroy(&spa->spa_errlist_lock);
+	mutex_destroy(&spa->spa_sync_bplist.bpl_lock);
+	mutex_destroy(&spa->spa_history_lock);
+	mutex_destroy(&spa->spa_props_lock);
+	mutex_destroy(&spa->spa_suspend_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);
+}
+
+void
+spa_l2cache_space_update(vdev_t *vd, int64_t space, int64_t alloc)
+{
+	vdev_space_update(vd, space, alloc, B_FALSE);
+}
+
+/*
+ * ==========================================================================
+ * 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_namespace_lock);
+
+	spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
+
+	return (spa_last_synced_txg(spa) + 1);
+}
+
+/*
+ * 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)
+{
+	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 the config changed, notify the scrub thread that it must restart.
+	 */
+	if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
+		dsl_pool_scrub_restart(spa->spa_dsl_pool);
+		config_changed = B_TRUE;
+	}
+
+	spa_config_exit(spa, SCL_ALL, spa);
+
+	/*
+	 * 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_object == 0);
+		vdev_free(vd);
+	}
+
+	/*
+	 * If the config changed, update the config cache.
+	 */
+	if (config_changed)
+		spa_config_sync(spa, B_FALSE, B_TRUE);
+
+	mutex_exit(&spa_namespace_lock);
+
+	return (error);
+}
+
+/*
+ * Lock the given spa_t for the purpose of changing vdev state.
+ */
+void
+spa_vdev_state_enter(spa_t *spa)
+{
+	spa_config_enter(spa, SCL_STATE_ALL, spa, RW_WRITER);
+}
+
+int
+spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
+{
+	if (vd != NULL)
+		vdev_state_dirty(vd->vdev_top);
+
+	spa_config_exit(spa, SCL_STATE_ALL, spa);
+
+	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);
+}
+
+
+/*
+ * Determine whether a pool with given pool_guid exists.  If device_guid is
+ * non-zero, determine whether the pool exists *and* contains a device with the
+ * specified device_guid.
+ */
+boolean_t
+spa_guid_exists(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 != 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);
+}
+
+void
+sprintf_blkptr(char *buf, int len, const blkptr_t *bp)
+{
+	int d;
+
+	if (bp == NULL) {
+		(void) snprintf(buf, len, "<NULL>");
+		return;
+	}
+
+	if (BP_IS_HOLE(bp)) {
+		(void) snprintf(buf, len, "<hole>");
+		return;
+	}
+
+	(void) snprintf(buf, len, "[L%llu %s] %llxL/%llxP ",
+	    (u_longlong_t)BP_GET_LEVEL(bp),
+	    dmu_ot[BP_GET_TYPE(bp)].ot_name,
+	    (u_longlong_t)BP_GET_LSIZE(bp),
+	    (u_longlong_t)BP_GET_PSIZE(bp));
+
+	for (d = 0; d < BP_GET_NDVAS(bp); d++) {
+		const dva_t *dva = &bp->blk_dva[d];
+		(void) snprintf(buf + strlen(buf), len - strlen(buf),
+		    "DVA[%d]=<%llu:%llx:%llx> ", d,
+		    (u_longlong_t)DVA_GET_VDEV(dva),
+		    (u_longlong_t)DVA_GET_OFFSET(dva),
+		    (u_longlong_t)DVA_GET_ASIZE(dva));
+	}
+
+	(void) snprintf(buf + strlen(buf), len - strlen(buf),
+	    "%s %s %s %s birth=%llu fill=%llu cksum=%llx:%llx:%llx:%llx",
+	    zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name,
+	    zio_compress_table[BP_GET_COMPRESS(bp)].ci_name,
+	    BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",
+	    BP_IS_GANG(bp) ? "gang" : "contiguous",
+	    (u_longlong_t)bp->blk_birth,
+	    (u_longlong_t)bp->blk_fill,
+	    (u_longlong_t)bp->blk_cksum.zc_word[0],
+	    (u_longlong_t)bp->blk_cksum.zc_word[1],
+	    (u_longlong_t)bp->blk_cksum.zc_word[2],
+	    (u_longlong_t)bp->blk_cksum.zc_word[3]);
+}
+
+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);
+}
+
+/*
+ * ==========================================================================
+ * 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);
+}
+
+pool_state_t
+spa_state(spa_t *spa)
+{
+	return (spa->spa_state);
+}
+
+uint64_t
+spa_freeze_txg(spa_t *spa)
+{
+	return (spa->spa_freeze_txg);
+}
+
+/*
+ * Return how much space is allocated in the pool (ie. sum of all asize)
+ */
+uint64_t
+spa_get_alloc(spa_t *spa)
+{
+	return (spa->spa_root_vdev->vdev_stat.vs_alloc);
+}
+
+/*
+ * Return how much (raid-z inflated) space there is in the pool.
+ */
+uint64_t
+spa_get_space(spa_t *spa)
+{
+	return (spa->spa_root_vdev->vdev_stat.vs_space);
+}
+
+/*
+ * Return the amount of raid-z-deflated space in the pool.
+ */
+uint64_t
+spa_get_dspace(spa_t *spa)
+{
+	if (spa->spa_deflate)
+		return (spa->spa_root_vdev->vdev_stat.vs_dspace);
+	else
+		return (spa->spa_root_vdev->vdev_stat.vs_space);
+}
+
+/* ARGSUSED */
+uint64_t
+spa_get_asize(spa_t *spa, uint64_t lsize)
+{
+	/*
+	 * For now, the worst case is 512-byte RAID-Z blocks, in which
+	 * case the space requirement is exactly 2x; so just assume that.
+	 * Add to this the fact that we can have up to 3 DVAs per bp, and
+	 * we have to multiply by a total of 6x.
+	 */
+	return (lsize * 6);
+}
+
+/*
+ * 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);
+}
+
+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));
+}
+
+uint64_t
+bp_get_dasize(spa_t *spa, const blkptr_t *bp)
+{
+	int sz = 0, i;
+
+	if (!spa->spa_deflate)
+		return (BP_GET_ASIZE(bp));
+
+	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
+	for (i = 0; i < SPA_DVAS_PER_BP; i++) {
+		vdev_t *vd =
+		    vdev_lookup_top(spa, DVA_GET_VDEV(&bp->blk_dva[i]));
+		if (vd)
+			sz += (DVA_GET_ASIZE(&bp->blk_dva[i]) >>
+			    SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
+	}
+	spa_config_exit(spa, SCL_VDEV, FTAG);
+	return (sz);
+}
+
+/*
+ * ==========================================================================
+ * 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 = 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);
+}
+
+/*
+ * Return whether this pool is the root pool.
+ */
+boolean_t
+spa_is_root(spa_t *spa)
+{
+	return (spa->spa_is_root);
+}