/*
* 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, 2020 by Delphix. All rights reserved.
* Copyright 2017 Joyent, Inc.
* Copyright (c) 2021, Colm Buckley <colm@tuatha.org>
*/
#include <sys/spa.h>
#include <sys/file.h>
#include <sys/fm/fs/zfs.h>
#include <sys/spa_impl.h>
#include <sys/nvpair.h>
#include <sys/fs/zfs.h>
#include <sys/vdev_impl.h>
#include <sys/zfs_ioctl.h>
#include <sys/systeminfo.h>
#include <sys/sunddi.h>
#include <sys/zfeature.h>
#include <sys/zfs_file.h>
#include <sys/zfs_context.h>
#ifdef _KERNEL
#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_write_cachefile(), 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.
*/
char *spa_config_path = ZPOOL_CACHE;
#ifdef _KERNEL
static int zfs_autoimport_disable = B_TRUE;
#endif
/*
* 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;
zfs_file_t *fp;
zfs_file_attr_t zfa;
uint64_t fsize;
int err;
#ifdef _KERNEL
if (zfs_autoimport_disable)
return;
#endif
/*
* Open the configuration file.
*/
pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
(void) snprintf(pathname, MAXPATHLEN, "%s", spa_config_path);
err = zfs_file_open(pathname, O_RDONLY, 0, &fp);
#ifdef __FreeBSD__
if (err)
err = zfs_file_open(ZPOOL_CACHE_BOOT, O_RDONLY, 0, &fp);
#endif
kmem_free(pathname, MAXPATHLEN);
if (err)
return;
if (zfs_file_getattr(fp, &zfa))
goto out;
fsize = zfa.zfa_size;
buf = kmem_alloc(fsize, KM_SLEEP);
/*
* Read the nvlist from the file.
*/
if (zfs_file_read(fp, buf, fsize, NULL) < 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);
zfs_file_close(fp);
}
static int
spa_config_remove(spa_config_dirent_t *dp)
{
int error = 0;
/*
* Remove the cache file. If zfs_file_unlink() in not supported by the
* platform fallback to truncating the file which is functionally
* equivalent.
*/
error = zfs_file_unlink(dp->scd_path);
if (error == EOPNOTSUPP) {
int flags = O_RDWR | O_TRUNC;
zfs_file_t *fp;
error = zfs_file_open(dp->scd_path, flags, 0644, &fp);
if (error == 0) {
(void) zfs_file_fsync(fp, O_SYNC);
(void) zfs_file_close(fp);
}
}
return (error);
}
static int
spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
{
size_t buflen;
char *buf;
int oflags = O_RDWR | O_TRUNC | O_CREAT | O_LARGEFILE;
char *temp;
int err;
zfs_file_t *fp;
/*
* If the nvlist is empty (NULL), then remove the old cachefile.
*/
if (nvl == NULL) {
err = spa_config_remove(dp);
if (err == ENOENT)
err = 0;
return (err);
}
/*
* Pack the configuration into a buffer.
*/
buf = fnvlist_pack(nvl, &buflen);
temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
/*
* Write the configuration to disk. Due to the complexity involved
* in performing a rename and remove from within the kernel the file
* is instead truncated and overwritten in place. This way we always
* have a consistent view of the data or a zero length file.
*/
err = zfs_file_open(dp->scd_path, oflags, 0644, &fp);
if (err == 0) {
err = zfs_file_write(fp, buf, buflen, NULL);
if (err == 0)
err = zfs_file_fsync(fp, O_SYNC);
zfs_file_close(fp);
if (err)
(void) spa_config_remove(dp);
}
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 explicit import
* would be required.
*/
void
spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent)
{
spa_config_dirent_t *dp, *tdp;
nvlist_t *nvl;
char *pool_name;
boolean_t ccw_failure;
int error = 0;
ASSERT(MUTEX_HELD(&spa_namespace_lock));
if (!(spa_mode_global & SPA_MODE_WRITE))
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 == 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();
if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME)
pool_name = fnvlist_lookup_string(
spa->spa_config, ZPOOL_CONFIG_POOL_NAME);
else
pool_name = spa_name(spa);
fnvlist_add_nvlist(nvl, pool_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) {
(void) zfs_ereport_post(
FM_EREPORT_ZFS_CONFIG_CACHE_WRITE,
target, NULL, NULL, NULL, 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, 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);
if (spa->spa_config != NULL && spa->spa_config != config)
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;
char *pool_name;
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;
/*
* Originally, users had to handle spa namespace collisions by either
* exporting the already imported pool or by specifying a new name for
* the pool with a conflicting name. In the case of root pools from
* virtual guests, neither approach to collision resolution is
* reasonable. This is addressed by extending the new name syntax with
* an option to specify that the new name is temporary. When specified,
* ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us
* to use the previous name, which we do below.
*/
if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) {
VERIFY0(nvlist_lookup_string(spa->spa_config,
ZPOOL_CONFIG_POOL_NAME, &pool_name));
} else
pool_name = spa_name(spa);
config = fnvlist_alloc();
fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, pool_name);
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));
fnvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA, spa->spa_errata);
if (spa->spa_comment != NULL)
fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT,
spa->spa_comment);
if (spa->spa_compatibility != NULL)
fnvlist_add_string(config, ZPOOL_CONFIG_COMPATIBILITY,
spa->spa_compatibility);
hostid = spa_get_hostid(spa);
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];
/*
* Explicitly skip vdevs that are indirect or
* log vdevs that are being removed. The reason
* is that both of those can have vdev_ms_array
* set to 0 and we wouldn't want to change their
* metaslab size nor call vdev_expand() on them.
*/
if (!vdev_is_concrete(tvd) ||
(tvd->vdev_islog && tvd->vdev_removing))
continue;
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_write_cachefile(spa, B_FALSE,
what != SPA_CONFIG_UPDATE_POOL);
}
if (what == SPA_CONFIG_UPDATE_POOL)
spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
}
EXPORT_SYMBOL(spa_config_load);
EXPORT_SYMBOL(spa_all_configs);
EXPORT_SYMBOL(spa_config_set);
EXPORT_SYMBOL(spa_config_generate);
EXPORT_SYMBOL(spa_config_update);
#ifdef __linux__
/* string sysctls require a char array on FreeBSD */
ZFS_MODULE_PARAM(zfs_spa, spa_, config_path, STRING, ZMOD_RD,
"SPA config file (/etc/zfs/zpool.cache)");
#endif
ZFS_MODULE_PARAM(zfs, zfs_, autoimport_disable, INT, ZMOD_RW,
"Disable pool import at module load");
