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-rw-r--r--Documentation/device-mapper/cache.txt9
-rw-r--r--drivers/md/dm-cache-metadata.c133
-rw-r--r--drivers/md/dm-cache-metadata.h10
-rw-r--r--drivers/md/dm-cache-policy-internal.h10
-rw-r--r--drivers/md/dm-cache-policy-mq.c8
-rw-r--r--drivers/md/dm-cache-policy.h4
-rw-r--r--drivers/md/dm-cache-target.c204
7 files changed, 320 insertions, 58 deletions
diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt
index 68c0f517c60e..82960cffbad3 100644
--- a/Documentation/device-mapper/cache.txt
+++ b/Documentation/device-mapper/cache.txt
@@ -221,6 +221,7 @@ Status
<#read hits> <#read misses> <#write hits> <#write misses>
<#demotions> <#promotions> <#dirty> <#features> <features>*
<#core args> <core args>* <policy name> <#policy args> <policy args>*
+<cache metadata mode>
metadata block size : Fixed block size for each metadata block in
sectors
@@ -251,8 +252,12 @@ core args : Key/value pairs for tuning the core
e.g. migration_threshold
policy name : Name of the policy
#policy args : Number of policy arguments to follow (must be even)
-policy args : Key/value pairs
- e.g. sequential_threshold
+policy args : Key/value pairs e.g. sequential_threshold
+cache metadata mode : ro if read-only, rw if read-write
+ In serious cases where even a read-only mode is deemed unsafe
+ no further I/O will be permitted and the status will just
+ contain the string 'Fail'. The userspace recovery tools
+ should then be used.
Messages
--------
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index c1c010498a21..20cc36b01b77 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -39,6 +39,8 @@
enum superblock_flag_bits {
/* for spotting crashes that would invalidate the dirty bitset */
CLEAN_SHUTDOWN,
+ /* metadata must be checked using the tools */
+ NEEDS_CHECK,
};
/*
@@ -107,6 +109,7 @@ struct dm_cache_metadata {
struct dm_disk_bitset discard_info;
struct rw_semaphore root_lock;
+ unsigned long flags;
dm_block_t root;
dm_block_t hint_root;
dm_block_t discard_root;
@@ -129,6 +132,14 @@ struct dm_cache_metadata {
* buffer before the superblock is locked and updated.
*/
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
+
+ /*
+ * Set if a transaction has to be aborted but the attempt to roll
+ * back to the previous (good) transaction failed. The only
+ * metadata operation permissible in this state is the closing of
+ * the device.
+ */
+ bool fail_io:1;
};
/*-------------------------------------------------------------------
@@ -527,6 +538,7 @@ static unsigned long clear_clean_shutdown(unsigned long flags)
static void read_superblock_fields(struct dm_cache_metadata *cmd,
struct cache_disk_superblock *disk_super)
{
+ cmd->flags = le32_to_cpu(disk_super->flags);
cmd->root = le64_to_cpu(disk_super->mapping_root);
cmd->hint_root = le64_to_cpu(disk_super->hint_root);
cmd->discard_root = le64_to_cpu(disk_super->discard_root);
@@ -625,6 +637,7 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
if (mutator)
update_flags(disk_super, mutator);
+ disk_super->flags = cpu_to_le32(cmd->flags);
disk_super->mapping_root = cpu_to_le64(cmd->root);
disk_super->hint_root = cpu_to_le64(cmd->hint_root);
disk_super->discard_root = cpu_to_le64(cmd->discard_root);
@@ -693,6 +706,7 @@ static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
cmd->cache_blocks = 0;
cmd->policy_hint_size = policy_hint_size;
cmd->changed = true;
+ cmd->fail_io = false;
r = __create_persistent_data_objects(cmd, may_format_device);
if (r) {
@@ -796,7 +810,8 @@ void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
list_del(&cmd->list);
mutex_unlock(&table_lock);
- __destroy_persistent_data_objects(cmd);
+ if (!cmd->fail_io)
+ __destroy_persistent_data_objects(cmd);
kfree(cmd);
}
}
@@ -848,13 +863,26 @@ static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
return 0;
}
+#define WRITE_LOCK(cmd) \
+ if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \
+ return -EINVAL; \
+ down_write(&cmd->root_lock)
+
+#define WRITE_LOCK_VOID(cmd) \
+ if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \
+ return; \
+ down_write(&cmd->root_lock)
+
+#define WRITE_UNLOCK(cmd) \
+ up_write(&cmd->root_lock)
+
int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
{
int r;
bool clean;
__le64 null_mapping = pack_value(0, 0);
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
__dm_bless_for_disk(&null_mapping);
if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
@@ -880,7 +908,7 @@ int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
cmd->changed = true;
out:
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -891,7 +919,7 @@ int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = dm_bitset_resize(&cmd->discard_info,
cmd->discard_root,
from_dblock(cmd->discard_nr_blocks),
@@ -903,7 +931,7 @@ int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
}
cmd->changed = true;
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -946,9 +974,9 @@ int dm_cache_set_discard(struct dm_cache_metadata *cmd,
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __discard(cmd, dblock, discard);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1020,9 +1048,9 @@ int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __remove(cmd, cblock);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1048,9 +1076,9 @@ int dm_cache_insert_mapping(struct dm_cache_metadata *cmd,
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __insert(cmd, cblock, oblock);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1234,9 +1262,9 @@ int dm_cache_set_dirty(struct dm_cache_metadata *cmd,
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __dirty(cmd, cblock, dirty);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1252,9 +1280,9 @@ void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
struct dm_cache_statistics *stats)
{
- down_write(&cmd->root_lock);
+ WRITE_LOCK_VOID(cmd);
cmd->stats = *stats;
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
}
int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
@@ -1263,7 +1291,7 @@ int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
clear_clean_shutdown);
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __commit_transaction(cmd, mutator);
if (r)
goto out;
@@ -1271,7 +1299,7 @@ int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
r = __begin_transaction(cmd);
out:
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1376,9 +1404,9 @@ int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = write_hints(cmd, policy);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1387,3 +1415,70 @@ int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
{
return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
}
+
+void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
+{
+ WRITE_LOCK_VOID(cmd);
+ dm_bm_set_read_only(cmd->bm);
+ WRITE_UNLOCK(cmd);
+}
+
+void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
+{
+ WRITE_LOCK_VOID(cmd);
+ dm_bm_set_read_write(cmd->bm);
+ WRITE_UNLOCK(cmd);
+}
+
+int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
+{
+ int r;
+ struct dm_block *sblock;
+ struct cache_disk_superblock *disk_super;
+
+ /*
+ * We ignore fail_io for this function.
+ */
+ down_write(&cmd->root_lock);
+ set_bit(NEEDS_CHECK, &cmd->flags);
+
+ r = superblock_lock(cmd, &sblock);
+ if (r) {
+ DMERR("couldn't read superblock");
+ goto out;
+ }
+
+ disk_super = dm_block_data(sblock);
+ disk_super->flags = cpu_to_le32(cmd->flags);
+
+ dm_bm_unlock(sblock);
+
+out:
+ up_write(&cmd->root_lock);
+ return r;
+}
+
+bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd)
+{
+ bool needs_check;
+
+ down_read(&cmd->root_lock);
+ needs_check = !!test_bit(NEEDS_CHECK, &cmd->flags);
+ up_read(&cmd->root_lock);
+
+ return needs_check;
+}
+
+int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
+{
+ int r;
+
+ WRITE_LOCK(cmd);
+ __destroy_persistent_data_objects(cmd);
+ r = __create_persistent_data_objects(cmd, false);
+ if (r)
+ cmd->fail_io = true;
+ WRITE_UNLOCK(cmd);
+
+ return r;
+}
diff --git a/drivers/md/dm-cache-metadata.h b/drivers/md/dm-cache-metadata.h
index 4ecc403be283..2ffee21f318d 100644
--- a/drivers/md/dm-cache-metadata.h
+++ b/drivers/md/dm-cache-metadata.h
@@ -102,6 +102,10 @@ struct dm_cache_statistics {
void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
struct dm_cache_statistics *stats);
+
+/*
+ * 'void' because it's no big deal if it fails.
+ */
void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
struct dm_cache_statistics *stats);
@@ -133,6 +137,12 @@ int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *
*/
int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result);
+bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd);
+int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd);
+void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd);
+void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd);
+int dm_cache_metadata_abort(struct dm_cache_metadata *cmd);
+
/*----------------------------------------------------------------*/
#endif /* DM_CACHE_METADATA_H */
diff --git a/drivers/md/dm-cache-policy-internal.h b/drivers/md/dm-cache-policy-internal.h
index 9dc05a52369e..ccbe852d5362 100644
--- a/drivers/md/dm-cache-policy-internal.h
+++ b/drivers/md/dm-cache-policy-internal.h
@@ -89,13 +89,15 @@ static inline void policy_tick(struct dm_cache_policy *p)
return p->tick(p);
}
-static inline int policy_emit_config_values(struct dm_cache_policy *p, char *result, unsigned maxlen)
+static inline int policy_emit_config_values(struct dm_cache_policy *p, char *result,
+ unsigned maxlen, ssize_t *sz_ptr)
{
- ssize_t sz = 0;
+ ssize_t sz = *sz_ptr;
if (p->emit_config_values)
- return p->emit_config_values(p, result, maxlen);
+ return p->emit_config_values(p, result, maxlen, sz_ptr);
- DMEMIT("0");
+ DMEMIT("0 ");
+ *sz_ptr = sz;
return 0;
}
diff --git a/drivers/md/dm-cache-policy-mq.c b/drivers/md/dm-cache-policy-mq.c
index 7cbae125879c..084eec653321 100644
--- a/drivers/md/dm-cache-policy-mq.c
+++ b/drivers/md/dm-cache-policy-mq.c
@@ -1323,22 +1323,24 @@ static int mq_set_config_value(struct dm_cache_policy *p,
return 0;
}
-static int mq_emit_config_values(struct dm_cache_policy *p, char *result, unsigned maxlen)
+static int mq_emit_config_values(struct dm_cache_policy *p, char *result,
+ unsigned maxlen, ssize_t *sz_ptr)
{
- ssize_t sz = 0;
+ ssize_t sz = *sz_ptr;
struct mq_policy *mq = to_mq_policy(p);
DMEMIT("10 random_threshold %u "
"sequential_threshold %u "
"discard_promote_adjustment %u "
"read_promote_adjustment %u "
- "write_promote_adjustment %u",
+ "write_promote_adjustment %u ",
mq->tracker.thresholds[PATTERN_RANDOM],
mq->tracker.thresholds[PATTERN_SEQUENTIAL],
mq->discard_promote_adjustment,
mq->read_promote_adjustment,
mq->write_promote_adjustment);
+ *sz_ptr = sz;
return 0;
}
diff --git a/drivers/md/dm-cache-policy.h b/drivers/md/dm-cache-policy.h
index 6106ca3aa350..74709129d856 100644
--- a/drivers/md/dm-cache-policy.h
+++ b/drivers/md/dm-cache-policy.h
@@ -208,8 +208,8 @@ struct dm_cache_policy {
/*
* Configuration.
*/
- int (*emit_config_values)(struct dm_cache_policy *p,
- char *result, unsigned maxlen);
+ int (*emit_config_values)(struct dm_cache_policy *p, char *result,
+ unsigned maxlen, ssize_t *sz_ptr);
int (*set_config_value)(struct dm_cache_policy *p,
const char *key, const char *value);
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 6d36ed3c46a0..dae0321ebfa9 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -150,12 +150,10 @@ static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio)
#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT)
#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
-/*
- * FIXME: the cache is read/write for the time being.
- */
enum cache_metadata_mode {
CM_WRITE, /* metadata may be changed */
CM_READ_ONLY, /* metadata may not be changed */
+ CM_FAIL
};
enum cache_io_mode {
@@ -385,6 +383,8 @@ struct prealloc {
struct dm_bio_prison_cell *cell2;
};
+static enum cache_metadata_mode get_cache_mode(struct cache *cache);
+
static void wake_worker(struct cache *cache)
{
queue_work(cache->wq, &cache->worker);
@@ -699,6 +699,9 @@ static void save_stats(struct cache *cache)
{
struct dm_cache_statistics stats;
+ if (get_cache_mode(cache) >= CM_READ_ONLY)
+ return;
+
stats.read_hits = atomic_read(&cache->stats.read_hit);
stats.read_misses = atomic_read(&cache->stats.read_miss);
stats.write_hits = atomic_read(&cache->stats.write_hit);
@@ -958,6 +961,84 @@ static void remap_to_origin_then_cache(struct cache *cache, struct bio *bio,
}
/*----------------------------------------------------------------
+ * Failure modes
+ *--------------------------------------------------------------*/
+static enum cache_metadata_mode get_cache_mode(struct cache *cache)
+{
+ return cache->features.mode;
+}
+
+static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mode)
+{
+ const char *descs[] = {
+ "write",
+ "read-only",
+ "fail"
+ };
+
+ dm_table_event(cache->ti->table);
+ DMINFO("switching cache to %s mode", descs[(int)mode]);
+}
+
+static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode)
+{
+ bool needs_check = dm_cache_metadata_needs_check(cache->cmd);
+ enum cache_metadata_mode old_mode = get_cache_mode(cache);
+
+ if (new_mode == CM_WRITE && needs_check) {
+ DMERR("unable to switch cache to write mode until repaired.");
+ if (old_mode != new_mode)
+ new_mode = old_mode;
+ else
+ new_mode = CM_READ_ONLY;
+ }
+
+ /* Never move out of fail mode */
+ if (old_mode == CM_FAIL)
+ new_mode = CM_FAIL;
+
+ switch (new_mode) {
+ case CM_FAIL:
+ case CM_READ_ONLY:
+ dm_cache_metadata_set_read_only(cache->cmd);
+ break;
+
+ case CM_WRITE:
+ dm_cache_metadata_set_read_write(cache->cmd);
+ break;
+ }
+
+ cache->features.mode = new_mode;
+
+ if (new_mode != old_mode)
+ notify_mode_switch(cache, new_mode);
+}
+
+static void abort_transaction(struct cache *cache)
+{
+ if (get_cache_mode(cache) >= CM_READ_ONLY)
+ return;
+
+ if (dm_cache_metadata_set_needs_check(cache->cmd)) {
+ DMERR("failed to set 'needs_check' flag in metadata");
+ set_cache_mode(cache, CM_FAIL);
+ }
+
+ DMERR_LIMIT("aborting current metadata transaction");
+ if (dm_cache_metadata_abort(cache->cmd)) {
+ DMERR("failed to abort metadata transaction");
+ set_cache_mode(cache, CM_FAIL);
+ }
+}
+
+static void metadata_operation_failed(struct cache *cache, const char *op, int r)
+{
+ DMERR_LIMIT("metadata operation '%s' failed: error = %d", op, r);
+ abort_transaction(cache);
+ set_cache_mode(cache, CM_READ_ONLY);
+}
+
+/*----------------------------------------------------------------
* Migration processing
*
* Migration covers moving data from the origin device to the cache, or
@@ -1063,6 +1144,7 @@ static void migration_failure(struct dm_cache_migration *mg)
static void migration_success_pre_commit(struct dm_cache_migration *mg)
{
+ int r;
unsigned long flags;
struct cache *cache = mg->cache;
@@ -1073,8 +1155,10 @@ static void migration_success_pre_commit(struct dm_cache_migration *mg)
return;
} else if (mg->demote) {
- if (dm_cache_remove_mapping(cache->cmd, mg->cblock)) {
+ r = dm_cache_remove_mapping(cache->cmd, mg->cblock);
+ if (r) {
DMWARN_LIMIT("demotion failed; couldn't update on disk metadata");
+ metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
policy_force_mapping(cache->policy, mg->new_oblock,
mg->old_oblock);
if (mg->promote)
@@ -1083,8 +1167,10 @@ static void migration_success_pre_commit(struct dm_cache_migration *mg)
return;
}
} else {
- if (dm_cache_insert_mapping(cache->cmd, mg->cblock, mg->new_oblock)) {
+ r = dm_cache_insert_mapping(cache->cmd, mg->cblock, mg->new_oblock);
+ if (r) {
DMWARN_LIMIT("promotion failed; couldn't update on disk metadata");
+ metadata_operation_failed(cache, "dm_cache_insert_mapping", r);
policy_remove_mapping(cache->policy, mg->new_oblock);
free_io_migration(mg);
return;
@@ -1812,15 +1898,32 @@ static int need_commit_due_to_time(struct cache *cache)
jiffies > cache->last_commit_jiffies + COMMIT_PERIOD;
}
+/*
+ * A non-zero return indicates read_only or fail_io mode.
+ */
+static int commit(struct cache *cache, bool clean_shutdown)
+{
+ int r;
+
+ if (get_cache_mode(cache) >= CM_READ_ONLY)
+ return -EINVAL;
+
+ atomic_inc(&cache->stats.commit_count);
+ r = dm_cache_commit(cache->cmd, clean_shutdown);
+ if (r)
+ metadata_operation_failed(cache, "dm_cache_commit", r);
+
+ return r;
+}
+
static int commit_if_needed(struct cache *cache)
{
int r = 0;
if ((cache->commit_requested || need_commit_due_to_time(cache)) &&
dm_cache_changed_this_transaction(cache->cmd)) {
- atomic_inc(&cache->stats.commit_count);
+ r = commit(cache, false);
cache->commit_requested = false;
- r = dm_cache_commit(cache->cmd, false);
cache->last_commit_jiffies = jiffies;
}
@@ -1988,8 +2091,10 @@ static void process_invalidation_request(struct cache *cache, struct invalidatio
r = policy_remove_cblock(cache->policy, to_cblock(begin));
if (!r) {
r = dm_cache_remove_mapping(cache->cmd, to_cblock(begin));
- if (r)
+ if (r) {
+ metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
break;
+ }
} else if (r == -ENODATA) {
/* harmless, already unmapped */
@@ -2133,12 +2238,6 @@ static void do_worker(struct work_struct *ws)
if (commit_if_needed(cache)) {
process_deferred_flush_bios(cache, false);
process_migrations(cache, &cache->need_commit_migrations, migration_failure);
-
- /*
- * FIXME: rollback metadata or just go into a
- * failure mode and error everything
- */
-
} else {
process_deferred_flush_bios(cache, true);
process_migrations(cache, &cache->need_commit_migrations,
@@ -2711,6 +2810,12 @@ static int cache_create(struct cache_args *ca, struct cache **result)
goto bad;
}
cache->cmd = cmd;
+ set_cache_mode(cache, CM_WRITE);
+ if (get_cache_mode(cache) != CM_WRITE) {
+ *error = "Unable to get write access to metadata, please check/repair metadata.";
+ r = -EINVAL;
+ goto bad;
+ }
if (passthrough_mode(&cache->features)) {
bool all_clean;
@@ -3043,11 +3148,16 @@ static int write_dirty_bitset(struct cache *cache)
{
unsigned i, r;
+ if (get_cache_mode(cache) >= CM_READ_ONLY)
+ return -EINVAL;
+
for (i = 0; i < from_cblock(cache->cache_size); i++) {
r = dm_cache_set_dirty(cache->cmd, to_cblock(i),
is_dirty(cache, to_cblock(i)));
- if (r)
+ if (r) {
+ metadata_operation_failed(cache, "dm_cache_set_dirty", r);
return r;
+ }
}
return 0;
@@ -3057,18 +3167,40 @@ static int write_discard_bitset(struct cache *cache)
{
unsigned i, r;
+ if (get_cache_mode(cache) >= CM_READ_ONLY)
+ return -EINVAL;
+
r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size,
cache->discard_nr_blocks);
if (r) {
DMERR("could not resize on-disk discard bitset");
+ metadata_operation_failed(cache, "dm_cache_discard_bitset_resize", r);
return r;
}
for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) {
r = dm_cache_set_discard(cache->cmd, to_dblock(i),
is_discarded(cache, to_dblock(i)));
- if (r)
+ if (r) {
+ metadata_operation_failed(cache, "dm_cache_set_discard", r);
return r;
+ }
+ }
+
+ return 0;
+}
+
+static int write_hints(struct cache *cache)
+{
+ int r;
+
+ if (get_cache_mode(cache) >= CM_READ_ONLY)
+ return -EINVAL;
+
+ r = dm_cache_write_hints(cache->cmd, cache->policy);
+ if (r) {
+ metadata_operation_failed(cache, "dm_cache_write_hints", r);
+ return r;
}
return 0;
@@ -3091,7 +3223,7 @@ static bool sync_metadata(struct cache *cache)
save_stats(cache);
- r3 = dm_cache_write_hints(cache->cmd, cache->policy);
+ r3 = write_hints(cache);
if (r3)
DMERR("could not write hints");
@@ -3100,9 +3232,9 @@ static bool sync_metadata(struct cache *cache)
* set the clean shutdown flag. This will effectively force every
* dirty bit to be set on reload.
*/
- r4 = dm_cache_commit(cache->cmd, !r1 && !r2 && !r3);
+ r4 = commit(cache, !r1 && !r2 && !r3);
if (r4)
- DMERR("could not write cache metadata. Data loss may occur.");
+ DMERR("could not write cache metadata.");
return !r1 && !r2 && !r3 && !r4;
}
@@ -3118,7 +3250,8 @@ static void cache_postsuspend(struct dm_target *ti)
requeue_deferred_cells(cache);
stop_quiescing(cache);
- (void) sync_metadata(cache);
+ if (get_cache_mode(cache) == CM_WRITE)
+ (void) sync_metadata(cache);
}
static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
@@ -3257,6 +3390,7 @@ static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size)
r = dm_cache_resize(cache->cmd, new_size);
if (r) {
DMERR("could not resize cache metadata");
+ metadata_operation_failed(cache, "dm_cache_resize", r);
return r;
}
@@ -3295,6 +3429,7 @@ static int cache_preresume(struct dm_target *ti)
load_mapping, cache);
if (r) {
DMERR("could not load cache mappings");
+ metadata_operation_failed(cache, "dm_cache_load_mappings", r);
return r;
}
@@ -3315,6 +3450,7 @@ static int cache_preresume(struct dm_target *ti)
r = dm_cache_load_discards(cache->cmd, load_discard, &li);
if (r) {
DMERR("could not load origin discards");
+ metadata_operation_failed(cache, "dm_cache_load_discards", r);
return r;
}
set_discard_range(&li);
@@ -3342,7 +3478,7 @@ static void cache_resume(struct dm_target *ti)
* <#demotions> <#promotions> <#dirty>
* <#features> <features>*
* <#core args> <core args>
- * <policy name> <#policy args> <policy args>*
+ * <policy name> <#policy args> <policy args>* <cache metadata mode>
*/
static void cache_status(struct dm_target *ti, status_type_t type,
unsigned status_flags, char *result, unsigned maxlen)
@@ -3358,13 +3494,15 @@ static void cache_status(struct dm_target *ti, status_type_t type,
switch (type) {
case STATUSTYPE_INFO:
- /* Commit to ensure statistics aren't out-of-date */
- if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) {
- r = dm_cache_commit(cache->cmd, false);
- if (r)
- DMERR("could not commit metadata for accurate status");
+ if (get_cache_mode(cache) == CM_FAIL) {
+ DMEMIT("Fail");
+ break;
}
+ /* Commit to ensure statistics aren't out-of-date */
+ if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
+ (void) commit(cache, false);
+
r = dm_cache_get_free_metadata_block_count(cache->cmd,
&nr_free_blocks_metadata);
if (r) {
@@ -3413,11 +3551,16 @@ static void cache_status(struct dm_target *ti, status_type_t type,
DMEMIT("%s ", dm_cache_policy_get_name(cache->policy));
if (sz < maxlen) {
- r = policy_emit_config_values(cache->policy, result + sz, maxlen - sz);
+ r = policy_emit_config_values(cache->policy, result, maxlen, &sz);
if (r)
DMERR("policy_emit_config_values returned %d", r);
}
+ if (get_cache_mode(cache) == CM_READ_ONLY)
+ DMEMIT("ro ");
+ else
+ DMEMIT("rw ");
+
break;
case STATUSTYPE_TABLE:
@@ -3573,6 +3716,11 @@ static int cache_message(struct dm_target *ti, unsigned argc, char **argv)
if (!argc)
return -EINVAL;
+ if (get_cache_mode(cache) >= CM_READ_ONLY) {
+ DMERR("unable to service cache target messages in READ_ONLY or FAIL mode");
+ return -EOPNOTSUPP;
+ }
+
if (!strcasecmp(argv[0], "invalidate_cblocks"))
return process_invalidate_cblocks_message(cache, argc - 1, (const char **) argv + 1);
@@ -3646,7 +3794,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
static struct target_type cache_target = {
.name = "cache",
- .version = {1, 6, 0},
+ .version = {1, 7, 0},
.module = THIS_MODULE,
.ctr = cache_ctr,
.dtr = cache_dtr,
generated by cgit (git 2.34.1) at 2024-06-26 11:17:57 +0000