xref: /illumos-gate/usr/src/uts/common/fs/zfs/spa.c

/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * This file contains all the routines used when modifying on-disk SPA state.
 * This includes opening, importing, destroying, exporting a pool, and syncing a
 * pool.
 */

#include <sys/zfs_context.h>
#include <sys/fm/fs/zfs.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/dmu_traverse.h>
#include <sys/dmu_objset.h>
#include <sys/unique.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_prop.h>
#include <sys/dsl_synctask.h>
#include <sys/fs/zfs.h>
#include <sys/callb.h>
#include <sys/systeminfo.h>
#include <sys/sunddi.h>

int zio_taskq_threads = 8;

/*
 * ==========================================================================
 * SPA state manipulation (open/create/destroy/import/export)
 * ==========================================================================
 */

static int
spa_error_entry_compare(const void *a, const void *b)
{
	spa_error_entry_t *sa = (spa_error_entry_t *)a;
	spa_error_entry_t *sb = (spa_error_entry_t *)b;
	int ret;

	ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
	    sizeof (zbookmark_t));

	if (ret < 0)
		return (-1);
	else if (ret > 0)
		return (1);
	else
		return (0);
}

/*
 * Utility function which retrieves copies of the current logs and
 * re-initializes them in the process.
 */
void
spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
{
	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));

	bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
	bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));

	avl_create(&spa->spa_errlist_scrub,
	    spa_error_entry_compare, sizeof (spa_error_entry_t),
	    offsetof(spa_error_entry_t, se_avl));
	avl_create(&spa->spa_errlist_last,
	    spa_error_entry_compare, sizeof (spa_error_entry_t),
	    offsetof(spa_error_entry_t, se_avl));
}

/*
 * Activate an uninitialized pool.
 */
static void
spa_activate(spa_t *spa)
{
	int t;

	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);

	spa->spa_state = POOL_STATE_ACTIVE;

	spa->spa_normal_class = metaslab_class_create();

	for (t = 0; t < ZIO_TYPES; t++) {
		spa->spa_zio_issue_taskq[t] = taskq_create("spa_zio_issue",
		    zio_taskq_threads, maxclsyspri, 50, INT_MAX,
		    TASKQ_PREPOPULATE);
		spa->spa_zio_intr_taskq[t] = taskq_create("spa_zio_intr",
		    zio_taskq_threads, maxclsyspri, 50, INT_MAX,
		    TASKQ_PREPOPULATE);
	}

	rw_init(&spa->spa_traverse_lock, NULL, RW_DEFAULT, NULL);

	mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&spa->spa_config_cache_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_config_lock.scl_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);

	list_create(&spa->spa_dirty_list, sizeof (vdev_t),
	    offsetof(vdev_t, vdev_dirty_node));

	txg_list_create(&spa->spa_vdev_txg_list,
	    offsetof(struct vdev, vdev_txg_node));

	avl_create(&spa->spa_errlist_scrub,
	    spa_error_entry_compare, sizeof (spa_error_entry_t),
	    offsetof(spa_error_entry_t, se_avl));
	avl_create(&spa->spa_errlist_last,
	    spa_error_entry_compare, sizeof (spa_error_entry_t),
	    offsetof(spa_error_entry_t, se_avl));
}

/*
 * Opposite of spa_activate().
 */
static void
spa_deactivate(spa_t *spa)
{
	int t;

	ASSERT(spa->spa_sync_on == B_FALSE);
	ASSERT(spa->spa_dsl_pool == NULL);
	ASSERT(spa->spa_root_vdev == NULL);

	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);

	txg_list_destroy(&spa->spa_vdev_txg_list);

	list_destroy(&spa->spa_dirty_list);

	rw_destroy(&spa->spa_traverse_lock);

	for (t = 0; t < ZIO_TYPES; t++) {
		taskq_destroy(spa->spa_zio_issue_taskq[t]);
		taskq_destroy(spa->spa_zio_intr_taskq[t]);
		spa->spa_zio_issue_taskq[t] = NULL;
		spa->spa_zio_intr_taskq[t] = NULL;
	}

	metaslab_class_destroy(spa->spa_normal_class);
	spa->spa_normal_class = NULL;

	/*
	 * If this was part of an import or the open otherwise failed, we may
	 * still have errors left in the queues.  Empty them just in case.
	 */
	spa_errlog_drain(spa);

	avl_destroy(&spa->spa_errlist_scrub);
	avl_destroy(&spa->spa_errlist_last);

	spa->spa_state = POOL_STATE_UNINITIALIZED;
}

/*
 * Verify a pool configuration, and construct the vdev tree appropriately.  This
 * will create all the necessary vdevs in the appropriate layout, with each vdev
 * in the CLOSED state.  This will prep the pool before open/creation/import.
 * All vdev validation is done by the vdev_alloc() routine.
 */
static int
spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
    uint_t id, int atype)
{
	nvlist_t **child;
	uint_t c, children;
	int error;

	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
		return (error);

	if ((*vdp)->vdev_ops->vdev_op_leaf)
		return (0);

	if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
	    &child, &children) != 0) {
		vdev_free(*vdp);
		*vdp = NULL;
		return (EINVAL);
	}

	for (c = 0; c < children; c++) {
		vdev_t *vd;
		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
		    atype)) != 0) {
			vdev_free(*vdp);
			*vdp = NULL;
			return (error);
		}
	}

	ASSERT(*vdp != NULL);

	return (0);
}

/*
 * Opposite of spa_load().
 */
static void
spa_unload(spa_t *spa)
{
	int i;

	/*
	 * Stop async tasks.
	 */
	spa_async_suspend(spa);

	/*
	 * Stop syncing.
	 */
	if (spa->spa_sync_on) {
		txg_sync_stop(spa->spa_dsl_pool);
		spa->spa_sync_on = B_FALSE;
	}

	/*
	 * Wait for any outstanding prefetch I/O to complete.
	 */
	spa_config_enter(spa, RW_WRITER, FTAG);
	spa_config_exit(spa, FTAG);

	/*
	 * Close the dsl pool.
	 */
	if (spa->spa_dsl_pool) {
		dsl_pool_close(spa->spa_dsl_pool);
		spa->spa_dsl_pool = NULL;
	}

	/*
	 * Close all vdevs.
	 */
	if (spa->spa_root_vdev)
		vdev_free(spa->spa_root_vdev);
	ASSERT(spa->spa_root_vdev == NULL);

	for (i = 0; i < spa->spa_nspares; i++)
		vdev_free(spa->spa_spares[i]);
	if (spa->spa_spares) {
		kmem_free(spa->spa_spares, spa->spa_nspares * sizeof (void *));
		spa->spa_spares = NULL;
	}
	if (spa->spa_sparelist) {
		nvlist_free(spa->spa_sparelist);
		spa->spa_sparelist = NULL;
	}

	spa->spa_async_suspended = 0;
}

/*
 * Load (or re-load) the current list of vdevs describing the active spares for
 * this pool.  When this is called, we have some form of basic information in
 * 'spa_sparelist'.  We parse this into vdevs, try to open them, and then
 * re-generate a more complete list including status information.
 */
static void
spa_load_spares(spa_t *spa)
{
	nvlist_t **spares;
	uint_t nspares;
	int i;
	vdev_t *vd, *tvd;

	/*
	 * First, close and free any existing spare vdevs.
	 */
	for (i = 0; i < spa->spa_nspares; i++) {
		vd = spa->spa_spares[i];

		/* Undo the call to spa_activate() below */
		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid)) != NULL &&
		    tvd->vdev_isspare)
			spa_spare_remove(tvd);
		vdev_close(vd);
		vdev_free(vd);
	}

	if (spa->spa_spares)
		kmem_free(spa->spa_spares, spa->spa_nspares * sizeof (void *));

	if (spa->spa_sparelist == NULL)
		nspares = 0;
	else
		VERIFY(nvlist_lookup_nvlist_array(spa->spa_sparelist,
		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);

	spa->spa_nspares = (int)nspares;
	spa->spa_spares = NULL;

	if (nspares == 0)
		return;

	/*
	 * Construct the array of vdevs, opening them to get status in the
	 * process.   For each spare, there is potentially two different vdev_t
	 * structures associated with it: one in the list of spares (used only
	 * for basic validation purposes) and one in the active vdev
	 * configuration (if it's spared in).  During this phase we open and
	 * validate each vdev on the spare list.  If the vdev also exists in the
	 * active configuration, then we also mark this vdev as an active spare.
	 */
	spa->spa_spares = kmem_alloc(nspares * sizeof (void *), KM_SLEEP);
	for (i = 0; i < spa->spa_nspares; i++) {
		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
		    VDEV_ALLOC_SPARE) == 0);
		ASSERT(vd != NULL);

		spa->spa_spares[i] = vd;

		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid)) != NULL) {
			if (!tvd->vdev_isspare)
				spa_spare_add(tvd);

			/*
			 * We only mark the spare active if we were successfully
			 * able to load the vdev.  Otherwise, importing a pool
			 * with a bad active spare would result in strange
			 * behavior, because multiple pool would think the spare
			 * is actively in use.
			 *
			 * There is a vulnerability here to an equally bizarre
			 * circumstance, where a dead active spare is later
			 * brought back to life (onlined or otherwise).  Given
			 * the rarity of this scenario, and the extra complexity
			 * it adds, we ignore the possibility.
			 */
			if (!vdev_is_dead(tvd))
				spa_spare_activate(tvd);
		}

		if (vdev_open(vd) != 0)
			continue;

		vd->vdev_top = vd;
		(void) vdev_validate_spare(vd);
	}

	/*
	 * Recompute the stashed list of spares, with status information
	 * this time.
	 */
	VERIFY(nvlist_remove(spa->spa_sparelist, ZPOOL_CONFIG_SPARES,
	    DATA_TYPE_NVLIST_ARRAY) == 0);

	spares = kmem_alloc(spa->spa_nspares * sizeof (void *), KM_SLEEP);
	for (i = 0; i < spa->spa_nspares; i++)
		spares[i] = vdev_config_generate(spa, spa->spa_spares[i],
		    B_TRUE, B_TRUE);
	VERIFY(nvlist_add_nvlist_array(spa->spa_sparelist, ZPOOL_CONFIG_SPARES,
	    spares, spa->spa_nspares) == 0);
	for (i = 0; i < spa->spa_nspares; i++)
		nvlist_free(spares[i]);
	kmem_free(spares, spa->spa_nspares * sizeof (void *));
}

static int
load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
{
	dmu_buf_t *db;
	char *packed = NULL;
	size_t nvsize = 0;
	int error;
	*value = NULL;

	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
	nvsize = *(uint64_t *)db->db_data;
	dmu_buf_rele(db, FTAG);

	packed = kmem_alloc(nvsize, KM_SLEEP);
	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed);
	if (error == 0)
		error = nvlist_unpack(packed, nvsize, value, 0);
	kmem_free(packed, nvsize);

	return (error);
}

/*
 * Load an existing storage pool, using the pool's builtin spa_config as a
 * source of configuration information.
 */
static int
spa_load(spa_t *spa, nvlist_t *config, spa_load_state_t state, int mosconfig)
{
	int error = 0;
	nvlist_t *nvroot = NULL;
	vdev_t *rvd;
	uberblock_t *ub = &spa->spa_uberblock;
	uint64_t config_cache_txg = spa->spa_config_txg;
	uint64_t pool_guid;
	uint64_t version;
	zio_t *zio;

	spa->spa_load_state = state;

	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot) ||
	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid)) {
		error = EINVAL;
		goto out;
	}

	/*
	 * Versioning wasn't explicitly added to the label until later, so if
	 * it's not present treat it as the initial version.
	 */
	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION, &version) != 0)
		version = ZFS_VERSION_INITIAL;

	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
	    &spa->spa_config_txg);

	if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
	    spa_guid_exists(pool_guid, 0)) {
		error = EEXIST;
		goto out;
	}

	spa->spa_load_guid = pool_guid;

	/*
	 * Parse the configuration into a vdev tree.  We explicitly set the
	 * value that will be returned by spa_version() since parsing the
	 * configuration requires knowing the version number.
	 */
	spa_config_enter(spa, RW_WRITER, FTAG);
	spa->spa_ubsync.ub_version = version;
	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_LOAD);
	spa_config_exit(spa, FTAG);

	if (error != 0)
		goto out;

	ASSERT(spa->spa_root_vdev == rvd);
	ASSERT(spa_guid(spa) == pool_guid);

	/*
	 * Try to open all vdevs, loading each label in the process.
	 */
	if (vdev_open(rvd) != 0) {
		error = ENXIO;
		goto out;