/*

 * 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 2009 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#include <sys/spa.h>

#include <sys/spa_impl.h>

#include <sys/nvpair.h>

#include <sys/uio.h>

#include <sys/fs/zfs.h>

#include <sys/vdev_impl.h>

#include <sys/zfs_ioctl.h>

#include <sys/utsname.h>

#include <sys/systeminfo.h>

#include <sys/sunddi.h>

#ifdef _KERNEL

#include <sys/kobj.h>

#include <sys/zone.h>

#endif

/*

 * Pool configuration repository.

 *

 * Pool configuration is stored as a packed nvlist on the filesystem.  By

 * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot

 * (when the ZFS module is loaded).  Pools can also have the 'cachefile'

 * property set that allows them to be stored in an alternate location until

 * the control of external software.

 *

 * For each cache file, we have a single nvlist which holds all the

 * configuration information.  When the module loads, we read this information

 * from /etc/zfs/zpool.cache and populate the SPA namespace.  This namespace is

 * maintained independently in spa.c.  Whenever the namespace is modified, or

 * the configuration of a pool is changed, we call spa_config_sync(), which

 * walks through all the active pools and writes the configuration to disk.

 */

static uint64_t spa_config_generation = 1;

/*

 * This can be overridden in userland to preserve an alternate namespace for

 * userland pools when doing testing.

 */

const char *spa_config_path = ZPOOL_CACHE;

/*

 * Called when the module is first loaded, this routine loads the configuration

 * file into the SPA namespace.  It does not actually open or load the pools; it

 * only populates the namespace.

 */

void

spa_config_load(void)

{

	void *buf = NULL;

	nvlist_t *nvlist, *child;

	nvpair_t *nvpair;

	spa_t *spa;

	char *pathname;

	struct _buf *file;

	uint64_t fsize;

	/*

	 * Open the configuration file.

	 */

	pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);

	(void) snprintf(pathname, MAXPATHLEN, "%s%s",

	    (rootdir != NULL) ? "./" : "", spa_config_path);

	file = kobj_open_file(pathname);

	kmem_free(pathname, MAXPATHLEN);

	if (file == (struct _buf *)-1)

		return;

	if (kobj_get_filesize(file, &fsize) != 0)

		goto out;

	buf = kmem_alloc(fsize, KM_SLEEP);

	/*

	 * Read the nvlist from the file.

	 */

	if (kobj_read_file(file, buf, fsize, 0) < 0)

		goto out;

	/*

	 * Unpack the nvlist.

	 */

	if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0)

		goto out;

	/*

	 * Iterate over all elements in the nvlist, creating a new spa_t for

	 * each one with the specified configuration.

	 */

	mutex_enter(&spa_namespace_lock);

	nvpair = NULL;

	while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) {

		if (nvpair_type(nvpair) != DATA_TYPE_NVLIST)

			continue;

		VERIFY(nvpair_value_nvlist(nvpair, &child) == 0);

		if (spa_lookup(nvpair_name(nvpair)) != NULL)

			continue;

		spa = spa_add(nvpair_name(nvpair), NULL);

		/*

		 * We blindly duplicate the configuration here.  If it's

		 * invalid, we will catch it when the pool is first opened.

		 */

		VERIFY(nvlist_dup(child, &spa->spa_config, 0) == 0);

	}

	mutex_exit(&spa_namespace_lock);

	nvlist_free(nvlist);

out:

	if (buf != NULL)

		kmem_free(buf, fsize);

	kobj_close_file(file);

}

static void

spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)

{

	size_t buflen;

	char *buf;

	vnode_t *vp;

	int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;

	char *temp;

	/*

	 * If the nvlist is empty (NULL), then remove the old cachefile.

	 */

	if (nvl == NULL) {

		(void) vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);

		return;

	}

	/*

	 * Pack the configuration into a buffer.

	 */

	VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0);

	buf = kmem_alloc(buflen, KM_SLEEP);

	temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);

	VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR,

	    KM_SLEEP) == 0);

	/*

	 * Write the configuration to disk.  We need to do the traditional

	 * 'write to temporary file, sync, move over original' to make sure we

	 * always have a consistent view of the data.

	 */

	(void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path);

	if (vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) == 0) {

		if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,

		    0, RLIM64_INFINITY, kcred, NULL) == 0 &&

		    VOP_FSYNC(vp, FSYNC, kcred, NULL) == 0) {

			(void) vn_rename(temp, dp->scd_path, UIO_SYSSPACE);

		}

		(void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);

		VN_RELE(vp);

	}

	(void) vn_remove(temp, UIO_SYSSPACE, RMFILE);

	kmem_free(buf, buflen);

	kmem_free(temp, MAXPATHLEN);

}

/*

 * Synchronize pool configuration to disk.  This must be called with the

 * namespace lock held.

 */

void

spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)

{

	spa_config_dirent_t *dp, *tdp;

	nvlist_t *nvl;

	ASSERT(MUTEX_HELD(&spa_namespace_lock));

	if (rootdir == NULL || !(spa_mode_global & FWRITE))

		return;

	/*

	 * Iterate over all cachefiles for the pool, past or present.  When the

	 * cachefile is changed, the new one is pushed onto this list, allowing

	 * us to update previous cachefiles that no longer contain this pool.

	 */

	for (dp = list_head(&target->spa_config_list); dp != NULL;

	    dp = list_next(&target->spa_config_list, dp)) {

		spa_t *spa = NULL;

		if (dp->scd_path == NULL)

			continue;

		/*

		 * Iterate over all pools, adding any matching pools to 'nvl'.

		 */

		nvl = NULL;

		while ((spa = spa_next(spa)) != NULL) {

			if (spa == target && removing)

				continue;

			mutex_enter(&spa->spa_props_lock);

			tdp = list_head(&spa->spa_config_list);

			if (spa->spa_config == NULL ||

			    tdp->scd_path == NULL ||

			    strcmp(tdp->scd_path, dp->scd_path) != 0) {

				mutex_exit(&spa->spa_props_lock);

				continue;

			}

			if (nvl == NULL)

				VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME,

				    KM_SLEEP) == 0);

			VERIFY(nvlist_add_nvlist(nvl, spa->spa_name,

			    spa->spa_config) == 0);

			mutex_exit(&spa->spa_props_lock);

		}

		spa_config_write(dp, nvl);

		nvlist_free(nvl);

	}

	/*

	 * Remove any config entries older than the current one.

	 */

	dp = list_head(&target->spa_config_list);

	while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) {

		list_remove(&target->spa_config_list, tdp);

		if (tdp->scd_path != NULL)

			spa_strfree(tdp->scd_path);

		kmem_free(tdp, sizeof (spa_config_dirent_t));

	}

	spa_config_generation++;

	if (postsysevent)

		spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC);

}

/*

 * Sigh.  Inside a local zone, we don't have access to /etc/zfs/zpool.cache,

 * and we don't want to allow the local zone to see all the pools anyway.

 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration

 * information for all pool visible within the zone.

 */

nvlist_t *

spa_all_configs(uint64_t *generation)

{

	nvlist_t *pools;

	spa_t *spa = NULL;

	if (*generation == spa_config_generation)

		return (NULL);

	VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0);

	mutex_enter(&spa_namespace_lock);

	while ((spa = spa_next(spa)) != NULL) {

		if (INGLOBALZONE(curproc) ||

		    zone_dataset_visible(spa_name(spa), NULL)) {

			mutex_enter(&spa->spa_props_lock);

			VERIFY(nvlist_add_nvlist(pools, spa_name(spa),

			    spa->spa_config) == 0);

			mutex_exit(&spa->spa_props_lock);

		}

	}

	*generation = spa_config_generation;

	mutex_exit(&spa_namespace_lock);

	return (pools);

}

void

spa_config_set(spa_t *spa, nvlist_t *config)

{

	mutex_enter(&spa->spa_props_lock);

	if (spa->spa_config != NULL)

		nvlist_free(spa->spa_config);

	spa->spa_config = config;

	mutex_exit(&spa->spa_props_lock);

}

/*

 * Generate the pool's configuration based on the current in-core state.

 * We infer whether to generate a complete config or just one top-level config

 * based on whether vd is the root vdev.

 */

nvlist_t *

spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)

{

	nvlist_t *config, *nvroot;

	vdev_t *rvd = spa->spa_root_vdev;

	unsigned long hostid = 0;

	boolean_t locked = B_FALSE;

	if (vd == NULL) {

		vd = rvd;

		locked = B_TRUE;

		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);

	}

	ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) ==

	    (SCL_CONFIG | SCL_STATE));

	/*

	 * If txg is -1, report the current value of spa->spa_config_txg.

	 */

	if (txg == -1ULL)

		txg = spa->spa_config_txg;

	VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0);

	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,

	    spa_version(spa)) == 0);

	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,

	    spa_name(spa)) == 0);

	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,

	    spa_state(spa)) == 0);

	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,

	    txg) == 0);

	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,

	    spa_guid(spa)) == 0);

#ifdef	_KERNEL

	hostid = zone_get_hostid(NULL);

#else	/* _KERNEL */

	/*

	 * We're emulating the system's hostid in userland, so we can't use

	 * zone_get_hostid().

	 */

	(void) ddi_strtoul(hw_serial, NULL, 10, &hostid);

#endif	/* _KERNEL */

	if (hostid != 0) {

		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,

		    hostid) == 0);

	}

	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,

	    utsname.nodename) == 0);

	if (vd != rvd) {

		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,

		    vd->vdev_top->vdev_guid) == 0);

		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID,

		    vd->vdev_guid) == 0);

		if (vd->vdev_isspare)

			VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE,

			    1ULL) == 0);

		if (vd->vdev_islog)

			VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG,

			    1ULL) == 0);

		vd = vd->vdev_top;		/* label contains top config */

	}

	/*

	 * Add the top-level config.  We even add this on pools which

	 * don't support holes in the namespace as older pools will

	 * just ignore it.

	 */

	vdev_top_config_generate(spa, config);

	nvroot = vdev_config_generate(spa, vd, getstats, B_FALSE, B_FALSE);

	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);

	nvlist_free(nvroot);

	if (locked)

		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);

	return (config);

}

/*

 * Update all disk labels, generate a fresh config based on the current

 * in-core state, and sync the global config cache (do not sync the config

 * cache if this is a booting rootpool).

 */

void

spa_config_update(spa_t *spa, int what)

{

	vdev_t *rvd = spa->spa_root_vdev;

	uint64_t txg;

	int c;

	ASSERT(MUTEX_HELD(&spa_namespace_lock));

	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);

	txg = spa_last_synced_txg(spa) + 1;

	if (what == SPA_CONFIG_UPDATE_POOL) {

		vdev_config_dirty(rvd);

	} else {

		/*

		 * If we have top-level vdevs that were added but have

		 * not yet been prepared for allocation, do that now.

		 * (It's safe now because the config cache is up to date,

		 * so it will be able to translate the new DVAs.)

		 * See comments in spa_vdev_add() for full details.

		 */

		for (c = 0; c < rvd->vdev_children; c++) {

			vdev_t *tvd = rvd->vdev_child[c];

			if (tvd->vdev_ms_array == 0)

				vdev_metaslab_set_size(tvd);

			vdev_expand(tvd, txg);

		}

	}

	spa_config_exit(spa, SCL_ALL, FTAG);

	/*

	 * Wait for the mosconfig to be regenerated and synced.

	 */

	txg_wait_synced(spa->spa_dsl_pool, txg);

	/*

	 * Update the global config cache to reflect the new mosconfig.

	 */

	if (!spa->spa_is_root)

		spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);

	if (what == SPA_CONFIG_UPDATE_POOL)

		spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);

}