2 stable fixes for dm-cache and 1 3.19 DM core fix:
- Fix potential for dm-cache metadata corruption via stale metadata
buffers being used when switching an inactive cache table to active;
this could occur due to each table having it's own bufio client rather
than sharing the client between tables.
- Fix dm-cache target to properly account for discard IO while
suspending otherwise IO quiescing could complete prematurely.
- Fix DM core's handling of multiple internal suspends by maintaining an
'internal_suspend_count' and only resuming the device when this count
drops to zero.
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Merge tag 'dm-3.19-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer:
"Two stable fixes for dm-cache and one 3.19 DM core fix:
- fix potential for dm-cache metadata corruption via stale metadata
buffers being used when switching an inactive cache table to
active; this could occur due to each table having it's own bufio
client rather than sharing the client between tables.
- fix dm-cache target to properly account for discard IO while
suspending otherwise IO quiescing could complete prematurely.
- fix DM core's handling of multiple internal suspends by maintaining
an 'internal_suspend_count' and only resuming the device when this
count drops to zero"
* tag 'dm-3.19-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm: fix handling of multiple internal suspends
dm cache: fix problematic dual use of a single migration count variable
dm cache: share cache-metadata object across inactive and active DM tables
This commit is contained in:
Linus Torvalds
commit
bfc835b571
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@ -94,6 +94,9 @@ struct cache_disk_superblock {
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} __packed;
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struct dm_cache_metadata {
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atomic_t ref_count;
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struct list_head list;
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struct block_device *bdev;
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struct dm_block_manager *bm;
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struct dm_space_map *metadata_sm;
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@ -669,10 +672,10 @@ static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags)
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/*----------------------------------------------------------------*/
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struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
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sector_t data_block_size,
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bool may_format_device,
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size_t policy_hint_size)
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static struct dm_cache_metadata *metadata_open(struct block_device *bdev,
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sector_t data_block_size,
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bool may_format_device,
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size_t policy_hint_size)
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{
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int r;
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struct dm_cache_metadata *cmd;
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@ -683,6 +686,7 @@ struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
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return NULL;
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}
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atomic_set(&cmd->ref_count, 1);
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init_rwsem(&cmd->root_lock);
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cmd->bdev = bdev;
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cmd->data_block_size = data_block_size;
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@ -705,10 +709,95 @@ struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
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return cmd;
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}
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/*
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* We keep a little list of ref counted metadata objects to prevent two
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* different target instances creating separate bufio instances. This is
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* an issue if a table is reloaded before the suspend.
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*/
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static DEFINE_MUTEX(table_lock);
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static LIST_HEAD(table);
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static struct dm_cache_metadata *lookup(struct block_device *bdev)
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{
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struct dm_cache_metadata *cmd;
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list_for_each_entry(cmd, &table, list)
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if (cmd->bdev == bdev) {
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atomic_inc(&cmd->ref_count);
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return cmd;
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}
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return NULL;
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}
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static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev,
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sector_t data_block_size,
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bool may_format_device,
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size_t policy_hint_size)
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{
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struct dm_cache_metadata *cmd, *cmd2;
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mutex_lock(&table_lock);
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cmd = lookup(bdev);
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mutex_unlock(&table_lock);
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if (cmd)
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return cmd;
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cmd = metadata_open(bdev, data_block_size, may_format_device, policy_hint_size);
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if (cmd) {
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mutex_lock(&table_lock);
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cmd2 = lookup(bdev);
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if (cmd2) {
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mutex_unlock(&table_lock);
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__destroy_persistent_data_objects(cmd);
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kfree(cmd);
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return cmd2;
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}
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list_add(&cmd->list, &table);
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mutex_unlock(&table_lock);
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}
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return cmd;
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}
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static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size)
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{
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if (cmd->data_block_size != data_block_size) {
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DMERR("data_block_size (%llu) different from that in metadata (%llu)\n",
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(unsigned long long) data_block_size,
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(unsigned long long) cmd->data_block_size);
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return false;
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}
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return true;
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}
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struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
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sector_t data_block_size,
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bool may_format_device,
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size_t policy_hint_size)
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{
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struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size,
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may_format_device, policy_hint_size);
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if (cmd && !same_params(cmd, data_block_size)) {
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dm_cache_metadata_close(cmd);
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return NULL;
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}
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return cmd;
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}
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void dm_cache_metadata_close(struct dm_cache_metadata *cmd)
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{
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__destroy_persistent_data_objects(cmd);
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kfree(cmd);
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if (atomic_dec_and_test(&cmd->ref_count)) {
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mutex_lock(&table_lock);
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list_del(&cmd->list);
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mutex_unlock(&table_lock);
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__destroy_persistent_data_objects(cmd);
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kfree(cmd);
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}
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}
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/*
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@ -221,7 +221,13 @@ struct cache {
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struct list_head need_commit_migrations;
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sector_t migration_threshold;
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wait_queue_head_t migration_wait;
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atomic_t nr_migrations;
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atomic_t nr_allocated_migrations;
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/*
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* The number of in flight migrations that are performing
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* background io. eg, promotion, writeback.
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*/
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atomic_t nr_io_migrations;
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wait_queue_head_t quiescing_wait;
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atomic_t quiescing;
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@ -258,7 +264,6 @@ struct cache {
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struct dm_deferred_set *all_io_ds;
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mempool_t *migration_pool;
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struct dm_cache_migration *next_migration;
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struct dm_cache_policy *policy;
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unsigned policy_nr_args;
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@ -350,10 +355,31 @@ static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell *cel
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dm_bio_prison_free_cell(cache->prison, cell);
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}
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static struct dm_cache_migration *alloc_migration(struct cache *cache)
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{
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struct dm_cache_migration *mg;
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mg = mempool_alloc(cache->migration_pool, GFP_NOWAIT);
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if (mg) {
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mg->cache = cache;
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atomic_inc(&mg->cache->nr_allocated_migrations);
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}
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return mg;
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}
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static void free_migration(struct dm_cache_migration *mg)
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{
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if (atomic_dec_and_test(&mg->cache->nr_allocated_migrations))
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wake_up(&mg->cache->migration_wait);
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mempool_free(mg, mg->cache->migration_pool);
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}
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static int prealloc_data_structs(struct cache *cache, struct prealloc *p)
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{
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if (!p->mg) {
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p->mg = mempool_alloc(cache->migration_pool, GFP_NOWAIT);
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p->mg = alloc_migration(cache);
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if (!p->mg)
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return -ENOMEM;
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}
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@ -382,7 +408,7 @@ static void prealloc_free_structs(struct cache *cache, struct prealloc *p)
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free_prison_cell(cache, p->cell1);
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if (p->mg)
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mempool_free(p->mg, cache->migration_pool);
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free_migration(p->mg);
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}
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static struct dm_cache_migration *prealloc_get_migration(struct prealloc *p)
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@ -854,24 +880,14 @@ static void remap_to_origin_then_cache(struct cache *cache, struct bio *bio,
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* Migration covers moving data from the origin device to the cache, or
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* vice versa.
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*--------------------------------------------------------------*/
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static void free_migration(struct dm_cache_migration *mg)
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static void inc_io_migrations(struct cache *cache)
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{
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mempool_free(mg, mg->cache->migration_pool);
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atomic_inc(&cache->nr_io_migrations);
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}
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static void inc_nr_migrations(struct cache *cache)
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static void dec_io_migrations(struct cache *cache)
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{
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atomic_inc(&cache->nr_migrations);
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}
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static void dec_nr_migrations(struct cache *cache)
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{
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atomic_dec(&cache->nr_migrations);
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/*
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* Wake the worker in case we're suspending the target.
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*/
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wake_up(&cache->migration_wait);
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atomic_dec(&cache->nr_io_migrations);
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}
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static void __cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell,
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@ -894,11 +910,10 @@ static void cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell,
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wake_worker(cache);
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}
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static void cleanup_migration(struct dm_cache_migration *mg)
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static void free_io_migration(struct dm_cache_migration *mg)
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{
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struct cache *cache = mg->cache;
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dec_io_migrations(mg->cache);
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free_migration(mg);
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dec_nr_migrations(cache);
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}
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static void migration_failure(struct dm_cache_migration *mg)
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@ -923,7 +938,7 @@ static void migration_failure(struct dm_cache_migration *mg)
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cell_defer(cache, mg->new_ocell, true);
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}
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cleanup_migration(mg);
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free_io_migration(mg);
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}
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static void migration_success_pre_commit(struct dm_cache_migration *mg)
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@ -934,7 +949,7 @@ static void migration_success_pre_commit(struct dm_cache_migration *mg)
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if (mg->writeback) {
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clear_dirty(cache, mg->old_oblock, mg->cblock);
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cell_defer(cache, mg->old_ocell, false);
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cleanup_migration(mg);
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free_io_migration(mg);
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return;
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} else if (mg->demote) {
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@ -944,14 +959,14 @@ static void migration_success_pre_commit(struct dm_cache_migration *mg)
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mg->old_oblock);
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if (mg->promote)
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cell_defer(cache, mg->new_ocell, true);
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cleanup_migration(mg);
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free_io_migration(mg);
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return;
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}
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} else {
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if (dm_cache_insert_mapping(cache->cmd, mg->cblock, mg->new_oblock)) {
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DMWARN_LIMIT("promotion failed; couldn't update on disk metadata");
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policy_remove_mapping(cache->policy, mg->new_oblock);
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cleanup_migration(mg);
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free_io_migration(mg);
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return;
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}
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}
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@ -984,7 +999,7 @@ static void migration_success_post_commit(struct dm_cache_migration *mg)
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} else {
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if (mg->invalidate)
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policy_remove_mapping(cache->policy, mg->old_oblock);
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cleanup_migration(mg);
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free_io_migration(mg);
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}
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} else {
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@ -999,7 +1014,7 @@ static void migration_success_post_commit(struct dm_cache_migration *mg)
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bio_endio(mg->new_ocell->holder, 0);
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cell_defer(cache, mg->new_ocell, false);
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}
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cleanup_migration(mg);
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free_io_migration(mg);
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}
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}
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@ -1251,7 +1266,7 @@ static void promote(struct cache *cache, struct prealloc *structs,
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mg->new_ocell = cell;
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mg->start_jiffies = jiffies;
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inc_nr_migrations(cache);
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inc_io_migrations(cache);
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quiesce_migration(mg);
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}
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@ -1275,7 +1290,7 @@ static void writeback(struct cache *cache, struct prealloc *structs,
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mg->new_ocell = NULL;
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mg->start_jiffies = jiffies;
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inc_nr_migrations(cache);
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inc_io_migrations(cache);
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quiesce_migration(mg);
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}
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@ -1302,7 +1317,7 @@ static void demote_then_promote(struct cache *cache, struct prealloc *structs,
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mg->new_ocell = new_ocell;
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mg->start_jiffies = jiffies;
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inc_nr_migrations(cache);
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inc_io_migrations(cache);
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quiesce_migration(mg);
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}
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@ -1330,7 +1345,7 @@ static void invalidate(struct cache *cache, struct prealloc *structs,
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mg->new_ocell = NULL;
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mg->start_jiffies = jiffies;
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inc_nr_migrations(cache);
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inc_io_migrations(cache);
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quiesce_migration(mg);
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}
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@ -1412,7 +1427,7 @@ static void process_discard_bio(struct cache *cache, struct prealloc *structs,
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static bool spare_migration_bandwidth(struct cache *cache)
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{
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sector_t current_volume = (atomic_read(&cache->nr_migrations) + 1) *
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sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) *
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cache->sectors_per_block;
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return current_volume < cache->migration_threshold;
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}
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@ -1764,7 +1779,7 @@ static void stop_quiescing(struct cache *cache)
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static void wait_for_migrations(struct cache *cache)
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{
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wait_event(cache->migration_wait, !atomic_read(&cache->nr_migrations));
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wait_event(cache->migration_wait, !atomic_read(&cache->nr_allocated_migrations));
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}
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static void stop_worker(struct cache *cache)
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@ -1876,9 +1891,6 @@ static void destroy(struct cache *cache)
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{
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unsigned i;
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if (cache->next_migration)
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mempool_free(cache->next_migration, cache->migration_pool);
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if (cache->migration_pool)
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mempool_destroy(cache->migration_pool);
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@ -2424,7 +2436,8 @@ static int cache_create(struct cache_args *ca, struct cache **result)
|
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INIT_LIST_HEAD(&cache->quiesced_migrations);
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INIT_LIST_HEAD(&cache->completed_migrations);
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INIT_LIST_HEAD(&cache->need_commit_migrations);
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atomic_set(&cache->nr_migrations, 0);
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atomic_set(&cache->nr_allocated_migrations, 0);
|
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atomic_set(&cache->nr_io_migrations, 0);
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init_waitqueue_head(&cache->migration_wait);
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||||
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init_waitqueue_head(&cache->quiescing_wait);
|
||||
|
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@ -2487,8 +2500,6 @@ static int cache_create(struct cache_args *ca, struct cache **result)
|
|||
goto bad;
|
||||
}
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cache->next_migration = NULL;
|
||||
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cache->need_tick_bio = true;
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||||
cache->sized = false;
|
||||
cache->invalidate = false;
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||||
|
|
|
|||
|
|
@ -206,6 +206,9 @@ struct mapped_device {
|
|||
/* zero-length flush that will be cloned and submitted to targets */
|
||||
struct bio flush_bio;
|
||||
|
||||
/* the number of internal suspends */
|
||||
unsigned internal_suspend_count;
|
||||
|
||||
struct dm_stats stats;
|
||||
};
|
||||
|
||||
|
|
@ -2928,7 +2931,7 @@ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_fla
|
|||
{
|
||||
struct dm_table *map = NULL;
|
||||
|
||||
if (dm_suspended_internally_md(md))
|
||||
if (md->internal_suspend_count++)
|
||||
return; /* nested internal suspend */
|
||||
|
||||
if (dm_suspended_md(md)) {
|
||||
|
|
@ -2953,7 +2956,9 @@ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_fla
|
|||
|
||||
static void __dm_internal_resume(struct mapped_device *md)
|
||||
{
|
||||
if (!dm_suspended_internally_md(md))
|
||||
BUG_ON(!md->internal_suspend_count);
|
||||
|
||||
if (--md->internal_suspend_count)
|
||||
return; /* resume from nested internal suspend */
|
||||
|
||||
if (dm_suspended_md(md))
|
||||
|
|
|
|||
Loading…
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