freebsd-nq/module/zfs/spa_errlog.c

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/*
* 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) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013, 2014 by Delphix. All rights reserved.
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*/
/*
* Routines to manage the on-disk persistent error log.
*
* Each pool stores a log of all logical data errors seen during normal
* operation. This is actually the union of two distinct logs: the last log,
* and the current log. All errors seen are logged to the current log. When a
* scrub completes, the current log becomes the last log, the last log is thrown
* out, and the current log is reinitialized. This way, if an error is somehow
* corrected, a new scrub will show that that it no longer exists, and will be
* deleted from the log when the scrub completes.
*
* The log is stored using a ZAP object whose key is a string form of the
* zbookmark_phys tuple (objset, object, level, blkid), and whose contents is an
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* optional 'objset:object' human-readable string describing the data. When an
* error is first logged, this string will be empty, indicating that no name is
* known. This prevents us from having to issue a potentially large amount of
* I/O to discover the object name during an error path. Instead, we do the
* calculation when the data is requested, storing the result so future queries
* will be faster.
*
* This log is then shipped into an nvlist where the key is the dataset name and
* the value is the object name. Userland is then responsible for uniquifying
* this list and displaying it to the user.
*/
#include <sys/dmu_tx.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/zap.h>
#include <sys/zio.h>
/*
* Convert a bookmark to a string.
*/
static void
bookmark_to_name(zbookmark_phys_t *zb, char *buf, size_t len)
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{
(void) snprintf(buf, len, "%llx:%llx:%llx:%llx",
(u_longlong_t)zb->zb_objset, (u_longlong_t)zb->zb_object,
(u_longlong_t)zb->zb_level, (u_longlong_t)zb->zb_blkid);
}
/*
* Convert a string to a bookmark
*/
#ifdef _KERNEL
static void
name_to_bookmark(char *buf, zbookmark_phys_t *zb)
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{
zb->zb_objset = zfs_strtonum(buf, &buf);
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ASSERT(*buf == ':');
zb->zb_object = zfs_strtonum(buf + 1, &buf);
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ASSERT(*buf == ':');
zb->zb_level = (int)zfs_strtonum(buf + 1, &buf);
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ASSERT(*buf == ':');
zb->zb_blkid = zfs_strtonum(buf + 1, &buf);
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ASSERT(*buf == '\0');
}
#endif
/*
* Log an uncorrectable error to the persistent error log. We add it to the
* spa's list of pending errors. The changes are actually synced out to disk
* during spa_errlog_sync().
*/
void
Native Encryption for ZFS on Linux This change incorporates three major pieces: The first change is a keystore that manages wrapping and encryption keys for encrypted datasets. These commands mostly involve manipulating the new DSL Crypto Key ZAP Objects that live in the MOS. Each encrypted dataset has its own DSL Crypto Key that is protected with a user's key. This level of indirection allows users to change their keys without re-encrypting their entire datasets. The change implements the new subcommands "zfs load-key", "zfs unload-key" and "zfs change-key" which allow the user to manage their encryption keys and settings. In addition, several new flags and properties have been added to allow dataset creation and to make mounting and unmounting more convenient. The second piece of this patch provides the ability to encrypt, decyrpt, and authenticate protected datasets. Each object set maintains a Merkel tree of Message Authentication Codes that protect the lower layers, similarly to how checksums are maintained. This part impacts the zio layer, which handles the actual encryption and generation of MACs, as well as the ARC and DMU, which need to be able to handle encrypted buffers and protected data. The last addition is the ability to do raw, encrypted sends and receives. The idea here is to send raw encrypted and compressed data and receive it exactly as is on a backup system. This means that the dataset on the receiving system is protected using the same user key that is in use on the sending side. By doing so, datasets can be efficiently backed up to an untrusted system without fear of data being compromised. Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Jorgen Lundman <lundman@lundman.net> Signed-off-by: Tom Caputi <tcaputi@datto.com> Closes #494 Closes #5769
2017-08-14 17:36:48 +00:00
spa_log_error(spa_t *spa, const zbookmark_phys_t *zb)
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{
spa_error_entry_t search;
spa_error_entry_t *new;
avl_tree_t *tree;
avl_index_t where;
/*
* If we are trying to import a pool, ignore any errors, as we won't be
* writing to the pool any time soon.
*/
if (spa_load_state(spa) == SPA_LOAD_TRYIMPORT)
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return;
mutex_enter(&spa->spa_errlist_lock);
/*
* If we have had a request to rotate the log, log it to the next list
* instead of the current one.
*/
if (spa->spa_scrub_active || spa->spa_scrub_finished)
tree = &spa->spa_errlist_scrub;
else
tree = &spa->spa_errlist_last;
search.se_bookmark = *zb;
if (avl_find(tree, &search, &where) != NULL) {
mutex_exit(&spa->spa_errlist_lock);
return;
}
new = kmem_zalloc(sizeof (spa_error_entry_t), KM_SLEEP);
new->se_bookmark = *zb;
avl_insert(tree, new, where);
mutex_exit(&spa->spa_errlist_lock);
}
/*
* Return the number of errors currently in the error log. This is actually the
* sum of both the last log and the current log, since we don't know the union
* of these logs until we reach userland.
*/
uint64_t
spa_get_errlog_size(spa_t *spa)
{
uint64_t total = 0, count;
mutex_enter(&spa->spa_errlog_lock);
if (spa->spa_errlog_scrub != 0 &&
zap_count(spa->spa_meta_objset, spa->spa_errlog_scrub,
&count) == 0)
total += count;
if (spa->spa_errlog_last != 0 && !spa->spa_scrub_finished &&
zap_count(spa->spa_meta_objset, spa->spa_errlog_last,
&count) == 0)
total += count;
mutex_exit(&spa->spa_errlog_lock);
mutex_enter(&spa->spa_errlist_lock);
total += avl_numnodes(&spa->spa_errlist_last);
total += avl_numnodes(&spa->spa_errlist_scrub);
mutex_exit(&spa->spa_errlist_lock);
return (total);
}
#ifdef _KERNEL
static int
process_error_log(spa_t *spa, uint64_t obj, void *addr, size_t *count)
{
zap_cursor_t zc;
zap_attribute_t za;
zbookmark_phys_t zb;
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if (obj == 0)
return (0);
for (zap_cursor_init(&zc, spa->spa_meta_objset, obj);
zap_cursor_retrieve(&zc, &za) == 0;
zap_cursor_advance(&zc)) {
if (*count == 0) {
zap_cursor_fini(&zc);
return (SET_ERROR(ENOMEM));
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}
name_to_bookmark(za.za_name, &zb);
if (copyout(&zb, (char *)addr +
(*count - 1) * sizeof (zbookmark_phys_t),
sizeof (zbookmark_phys_t)) != 0) {
zap_cursor_fini(&zc);
return (SET_ERROR(EFAULT));
}
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*count -= 1;
}
zap_cursor_fini(&zc);
return (0);
}
static int
process_error_list(avl_tree_t *list, void *addr, size_t *count)
{
spa_error_entry_t *se;
for (se = avl_first(list); se != NULL; se = AVL_NEXT(list, se)) {
if (*count == 0)
return (SET_ERROR(ENOMEM));
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if (copyout(&se->se_bookmark, (char *)addr +
(*count - 1) * sizeof (zbookmark_phys_t),
sizeof (zbookmark_phys_t)) != 0)
return (SET_ERROR(EFAULT));
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*count -= 1;
}
return (0);
}
#endif
/*
* Copy all known errors to userland as an array of bookmarks. This is
* actually a union of the on-disk last log and current log, as well as any
* pending error requests.
*
* Because the act of reading the on-disk log could cause errors to be
* generated, we have two separate locks: one for the error log and one for the
* in-core error lists. We only need the error list lock to log and error, so
* we grab the error log lock while we read the on-disk logs, and only pick up
* the error list lock when we are finished.
*/
int
spa_get_errlog(spa_t *spa, void *uaddr, size_t *count)
{
int ret = 0;
#ifdef _KERNEL
mutex_enter(&spa->spa_errlog_lock);
ret = process_error_log(spa, spa->spa_errlog_scrub, uaddr, count);
if (!ret && !spa->spa_scrub_finished)
ret = process_error_log(spa, spa->spa_errlog_last, uaddr,
count);
mutex_enter(&spa->spa_errlist_lock);
if (!ret)
ret = process_error_list(&spa->spa_errlist_scrub, uaddr,
count);
if (!ret)
ret = process_error_list(&spa->spa_errlist_last, uaddr,
count);
mutex_exit(&spa->spa_errlist_lock);
mutex_exit(&spa->spa_errlog_lock);
#endif
return (ret);
}
/*
* Called when a scrub completes. This simply set a bit which tells which AVL
* tree to add new errors. spa_errlog_sync() is responsible for actually
* syncing the changes to the underlying objects.
*/
void
spa_errlog_rotate(spa_t *spa)
{
mutex_enter(&spa->spa_errlist_lock);
spa->spa_scrub_finished = B_TRUE;
mutex_exit(&spa->spa_errlist_lock);
}
/*
* Discard any pending errors from the spa_t. Called when unloading a faulted
* pool, as the errors encountered during the open cannot be synced to disk.
*/
void
spa_errlog_drain(spa_t *spa)
{
spa_error_entry_t *se;
void *cookie;
mutex_enter(&spa->spa_errlist_lock);
cookie = NULL;
while ((se = avl_destroy_nodes(&spa->spa_errlist_last,
&cookie)) != NULL)
kmem_free(se, sizeof (spa_error_entry_t));
cookie = NULL;
while ((se = avl_destroy_nodes(&spa->spa_errlist_scrub,
&cookie)) != NULL)
kmem_free(se, sizeof (spa_error_entry_t));
mutex_exit(&spa->spa_errlist_lock);
}
/*
* Process a list of errors into the current on-disk log.
*/
static void
sync_error_list(spa_t *spa, avl_tree_t *t, uint64_t *obj, dmu_tx_t *tx)
{
spa_error_entry_t *se;
char buf[64];
void *cookie;
if (avl_numnodes(t) != 0) {
/* create log if necessary */
if (*obj == 0)
*obj = zap_create(spa->spa_meta_objset,
DMU_OT_ERROR_LOG, DMU_OT_NONE,
0, tx);
/* add errors to the current log */
for (se = avl_first(t); se != NULL; se = AVL_NEXT(t, se)) {
char *name = se->se_name ? se->se_name : "";
bookmark_to_name(&se->se_bookmark, buf, sizeof (buf));
(void) zap_update(spa->spa_meta_objset,
*obj, buf, 1, strlen(name) + 1, name, tx);
}
/* purge the error list */
cookie = NULL;
while ((se = avl_destroy_nodes(t, &cookie)) != NULL)
kmem_free(se, sizeof (spa_error_entry_t));
}
}
/*
* Sync the error log out to disk. This is a little tricky because the act of
* writing the error log requires the spa_errlist_lock. So, we need to lock the
* error lists, take a copy of the lists, and then reinitialize them. Then, we
* drop the error list lock and take the error log lock, at which point we
* do the errlog processing. Then, if we encounter an I/O error during this
* process, we can successfully add the error to the list. Note that this will
* result in the perpetual recycling of errors, but it is an unlikely situation
* and not a performance critical operation.
*/
void
spa_errlog_sync(spa_t *spa, uint64_t txg)
{
dmu_tx_t *tx;
avl_tree_t scrub, last;
int scrub_finished;
mutex_enter(&spa->spa_errlist_lock);
/*
* Bail out early under normal circumstances.
*/
if (avl_numnodes(&spa->spa_errlist_scrub) == 0 &&
avl_numnodes(&spa->spa_errlist_last) == 0 &&
!spa->spa_scrub_finished) {
mutex_exit(&spa->spa_errlist_lock);
return;
}
spa_get_errlists(spa, &last, &scrub);
scrub_finished = spa->spa_scrub_finished;
spa->spa_scrub_finished = B_FALSE;
mutex_exit(&spa->spa_errlist_lock);
mutex_enter(&spa->spa_errlog_lock);
tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
/*
* Sync out the current list of errors.
*/
sync_error_list(spa, &last, &spa->spa_errlog_last, tx);
/*
* Rotate the log if necessary.
*/
if (scrub_finished) {
if (spa->spa_errlog_last != 0)
VERIFY(dmu_object_free(spa->spa_meta_objset,
spa->spa_errlog_last, tx) == 0);
spa->spa_errlog_last = spa->spa_errlog_scrub;
spa->spa_errlog_scrub = 0;
sync_error_list(spa, &scrub, &spa->spa_errlog_last, tx);
}
/*
* Sync out any pending scrub errors.
*/
sync_error_list(spa, &scrub, &spa->spa_errlog_scrub, tx);
/*
* Update the MOS to reflect the new values.
*/
(void) zap_update(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_ERRLOG_LAST, sizeof (uint64_t), 1,
&spa->spa_errlog_last, tx);
(void) zap_update(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
DMU_POOL_ERRLOG_SCRUB, sizeof (uint64_t), 1,
&spa->spa_errlog_scrub, tx);
dmu_tx_commit(tx);
mutex_exit(&spa->spa_errlog_lock);
}
#if defined(_KERNEL) && defined(HAVE_SPL)
/* error handling */
EXPORT_SYMBOL(spa_log_error);
EXPORT_SYMBOL(spa_get_errlog_size);
EXPORT_SYMBOL(spa_get_errlog);
EXPORT_SYMBOL(spa_errlog_rotate);
EXPORT_SYMBOL(spa_errlog_drain);
EXPORT_SYMBOL(spa_errlog_sync);
EXPORT_SYMBOL(spa_get_errlists);
#endif