spa_config.c revision fa9e4066f08beec538e775443c5be79dd423fcab
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#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>
/*
* Pool configuration repository.
*
* The configuration for all pools, in addition to being stored on disk, is
* stored in /kernel/drv/zpool.cache as a packed nvlist. The kernel maintains
* this list as pools are created, destroyed, or modified.
*
* We have a single nvlist which holds all the configuration information. When
* the module loads, we read this information from the 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_dir = ZPOOL_CACHE_DIR;
/*
* 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)
{
vnode_t *vp;
void *buf = NULL;
vattr_t vattr;
ssize_t resid;
nvlist_t *nvlist, *child;
nvpair_t *nvpair;
spa_t *spa;
char pathname[128];
/*
* Open the configuration file.
*/
(void) snprintf(pathname, sizeof (pathname), "./%s/%s", spa_config_dir,
ZPOOL_CACHE_FILE);
if (vn_openat(pathname, UIO_SYSSPACE, FREAD | FOFFMAX, 0, &vp, 0, 0,
rootdir) != 0)
return;
/*
* Read the nvlist from the file.
*/
if (VOP_GETATTR(vp, &vattr, 0, kcred) != 0)
goto out;
buf = kmem_alloc(vattr.va_size, KM_SLEEP);
if (vn_rdwr(UIO_READ, vp, buf, vattr.va_size, 0, UIO_SYSSPACE,
0, RLIM64_INFINITY, kcred, &resid) != 0)
goto out;
if (resid != 0)
goto out;
/*
* Unpack the nvlist.
*/
if (nvlist_unpack(buf, vattr.va_size, &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));
/*
* 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, vattr.va_size);
(void) VOP_CLOSE(vp, FREAD | FOFFMAX, 1, 0, kcred);
VN_RELE(vp);
}
/*
* Synchronize all pools to disk. This must be called with the namespace lock
* held.
*/
void
spa_config_sync(void)
{
spa_t *spa = NULL;
nvlist_t *config;
size_t buflen;
char *buf;
vnode_t *vp;
int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX;
char pathname[128];
char pathname2[128];
ASSERT(MUTEX_HELD(&spa_namespace_lock));
VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, 0) == 0);
/*
* Add all known pools to the configuration list, ignoring those with
* alternate root paths.
*/
spa = NULL;
while ((spa = spa_next(spa)) != NULL) {
mutex_enter(&spa->spa_config_cache_lock);
if (spa->spa_config && spa->spa_name && spa->spa_root == NULL)
VERIFY(nvlist_add_nvlist(config, spa->spa_name,
spa->spa_config) == 0);
mutex_exit(&spa->spa_config_cache_lock);
}
/*
* Pack the configuration into a buffer.
*/
VERIFY(nvlist_size(config, &buflen, NV_ENCODE_XDR) == 0);
buf = kmem_alloc(buflen, KM_SLEEP);
VERIFY(nvlist_pack(config, &buf, &buflen, NV_ENCODE_XDR, 0) == 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(pathname, sizeof (pathname), "%s/%s", spa_config_dir,
ZPOOL_CACHE_TMP);
if (vn_open(pathname, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) != 0)
goto out;
if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
0, RLIM64_INFINITY, kcred, NULL) == 0 &&
VOP_FSYNC(vp, FSYNC, kcred) == 0) {
(void) snprintf(pathname2, sizeof (pathname2), "%s/%s",
spa_config_dir, ZPOOL_CACHE_FILE);
(void) vn_rename(pathname, pathname2, UIO_SYSSPACE);
}
(void) VOP_CLOSE(vp, oflags, 1, 0, kcred);
VN_RELE(vp);
out:
(void) vn_remove(pathname, UIO_SYSSPACE, RMFILE);
spa_config_generation++;
kmem_free(buf, buflen);
nvlist_free(config);
}
/*
* Sigh. Inside a local zone, we don't have access to /kernel/drv/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;
if (*generation == spa_config_generation)
return (NULL);
VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, 0) == 0);
spa = NULL;
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_config_cache_lock);
VERIFY(nvlist_add_nvlist(pools, spa_name(spa),
spa->spa_config) == 0);
mutex_exit(&spa->spa_config_cache_lock);
}
}
mutex_exit(&spa_namespace_lock);
*generation = spa_config_generation;
return (pools);
}
void
spa_config_set(spa_t *spa, nvlist_t *config)
{
mutex_enter(&spa->spa_config_cache_lock);
if (spa->spa_config != NULL)
nvlist_free(spa->spa_config);
spa->spa_config = config;
mutex_exit(&spa->spa_config_cache_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;
if (vd == NULL)
vd = rvd;
/*
* If txg is -1, report the current value of spa->spa_config_txg.
* If txg is any other non-zero value, update spa->spa_config_txg.
*/
if (txg == -1ULL)
txg = spa->spa_config_txg;
else if (txg != 0 && vd == rvd)
spa->spa_config_txg = txg;
VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, 0) == 0);
VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
UBERBLOCK_VERSION) == 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);
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);
vd = vd->vdev_top; /* label contains top config */
}
nvroot = vdev_config_generate(vd, getstats);
VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
nvlist_free(nvroot);
return (config);
}