/*
* 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 2011 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2011, 2015 by Delphix. All rights reserved.
*/
#include <sys/spa.h>
#include <sys/fm/fs/zfs.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>
#include <sys/zfeature.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;
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;
child = fnvpair_value_nvlist(nvpair);
if (spa_lookup(nvpair_name(nvpair)) != NULL)
continue;
(void) spa_add(nvpair_name(nvpair), child, NULL);
}
mutex_exit(&spa_namespace_lock);
nvlist_free(nvlist);
out:
if (buf != NULL)
kmem_free(buf, fsize);
kobj_close_file(file);
}
static int
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;
int err;
/*
* If the nvlist is empty (NULL), then remove the old cachefile.
*/
if (nvl == NULL) {
err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
return (err);
}
/*
* Pack the configuration into a buffer.
*/
buf = fnvlist_pack(nvl, &buflen);
temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
/*
* 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);
err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0);
if (err == 0) {
err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE,
0, RLIM64_INFINITY, kcred, NULL);
if (err == 0)
err = VOP_FSYNC(vp, FSYNC, kcred, NULL);
if (err == 0)
err = 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);
fnvlist_pack_free(buf, buflen);
kmem_free(temp, MAXPATHLEN);
return (err);
}
/*
* Synchronize pool configuration to disk. This must be called with the
* namespace lock held. Synchronizing the pool cache is typically done after
* the configuration has been synced to the MOS. This exposes a window where
* the MOS config will have been updated but the cache file has not. If
* the system were to crash at that instant then the cached config may not
* contain the correct information to open the pool and an explicity import
* would be required.
*/
void
spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
{
spa_config_dirent_t *dp, *tdp;
nvlist_t *nvl;
boolean_t ccw_failure;
int error;
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.
*/
ccw_failure = B_FALSE;
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) {
/*
* Skip over our own pool if we're about to remove
* ourselves from the spa namespace or any pool that
* is readonly. Since we cannot guarantee that a
* readonly pool would successfully import upon reboot,
* we don't allow them to be written to the cache file.
*/
if ((spa == target && removing) ||
!spa_writeable(spa))
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)
nvl = fnvlist_alloc();
fnvlist_add_nvlist(nvl, spa->spa_name,
spa->spa_config);
mutex_exit(&spa->spa_props_lock);
}
error = spa_config_write(dp, nvl);
if (error != 0)
ccw_failure = B_TRUE;
nvlist_free(nvl);
}
if (ccw_failure) {
/*
* Keep trying so that configuration data is
* written if/when any temporary filesystem
* resource issues are resolved.
*/
if (target->spa_ccw_fail_time == 0) {
zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE,
target, NULL, NULL, 0, 0);
}
target->spa_ccw_fail_time = gethrtime();
spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE);
} else {
/*
* Do not rate limit future attempts to update
* the config cache.
*/
target->spa_ccw_fail_time = 0;
}
/*
* 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);
pools = fnvlist_alloc();
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);
fnvlist_add_nvlist(pools, spa_name(spa),
spa->spa_config);
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);
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;
uint64_t split_guid;
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;
config = fnvlist_alloc();
fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, spa_name(spa));
fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa));
fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg);
fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa));
if (spa->spa_comment != NULL) {
fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT,
spa->spa_comment);
}
#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) {
fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid);
}
fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname.nodename);
int config_gen_flags = 0;
if (vd != rvd) {
fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
vd->vdev_top->vdev_guid);
fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID,
vd->vdev_guid);
if (vd->vdev_isspare) {
fnvlist_add_uint64(config,
ZPOOL_CONFIG_IS_SPARE, 1ULL);
}
if (vd->vdev_islog) {
fnvlist_add_uint64(config,
ZPOOL_CONFIG_IS_LOG, 1ULL);
}
vd = vd->vdev_top; /* label contains top config */
} else {
/*
* Only add the (potentially large) split information
* in the mos config, and not in the vdev labels
*/
if (spa->spa_config_splitting != NULL)
fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT,
spa->spa_config_splitting);
fnvlist_add_boolean(config,
ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS);
config_gen_flags |= VDEV_CONFIG_MOS;
}
/*
* Add the top-level config. We even add this on pools which
* don't support holes in the namespace.
*/
vdev_top_config_generate(spa, config);
/*
* If we're splitting, record the original pool's guid.
*/
if (spa->spa_config_splitting != NULL &&
nvlist_lookup_uint64(spa->spa_config_splitting,
ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) {
fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID,
split_guid);
}
nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags);
fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot);
nvlist_free(nvroot);
/*
* Store what's necessary for reading the MOS in the label.
*/
fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
spa->spa_label_features);
if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
ddt_histogram_t *ddh;
ddt_stat_t *dds;
ddt_object_t *ddo;
ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
ddt_get_dedup_histogram(spa, ddh);
fnvlist_add_uint64_array(config,
ZPOOL_CONFIG_DDT_HISTOGRAM,
(uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t));
kmem_free(ddh, sizeof (ddt_histogram_t));
ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP);
ddt_get_dedup_object_stats(spa, ddo);
fnvlist_add_uint64_array(config,
ZPOOL_CONFIG_DDT_OBJ_STATS,
(uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t));
kmem_free(ddo, sizeof (ddt_object_t));
dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP);
ddt_get_dedup_stats(spa, dds);
fnvlist_add_uint64_array(config,
ZPOOL_CONFIG_DDT_STATS,
(uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t));
kmem_free(dds, sizeof (ddt_stat_t));
}
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);
}