diff options
| author | Mike Snitzer <snitzer@redhat.com> | 2018-08-02 16:08:52 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-09 20:04:33 +0200 |
| commit | 75ae059e856946a47f600c9ee1cd60dba006c6d3 (patch) | |
| tree | 91db119f914060f2ceebdd38f587e4ce999004ec | |
| parent | 15898df477269c981dc1ae5afa39e1bb65e1db0a (diff) | |
dm cache metadata: save in-core policy_hint_size to on-disk superblock
commit fd2fa95416188a767a63979296fa3e169a9ef5ec upstream.
policy_hint_size starts as 0 during __write_initial_superblock(). It
isn't until the policy is loaded that policy_hint_size is set in-core
(cmd->policy_hint_size). But it never got recorded in the on-disk
superblock because __commit_transaction() didn't deal with transfering
the in-core cmd->policy_hint_size to the on-disk superblock.
The in-core cmd->policy_hint_size gets initialized by metadata_open()'s
__begin_transaction_flags() which re-reads all superblock fields.
Because the superblock's policy_hint_size was never properly stored, when
the cache was created, hints_array_available() would always return false
when re-activating a previously created cache. This means
__load_mappings() always considered the hints invalid and never made use
of the hints (these hints served to optimize).
Another detremental side-effect of this oversight is the cache_check
utility would fail with: "invalid hint width: 0"
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/dm-cache-metadata.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index d3c55d7754af..905badc6cb17 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -337,7 +337,7 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd) disk_super->version = cpu_to_le32(MAX_CACHE_VERSION); memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name)); memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version)); - disk_super->policy_hint_size = 0; + disk_super->policy_hint_size = cpu_to_le32(0); __copy_sm_root(cmd, disk_super); @@ -652,6 +652,7 @@ static int __commit_transaction(struct dm_cache_metadata *cmd, disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]); disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]); disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]); + disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size); disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits); disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses); |