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 19:55:55 +0200 |
| commit | b7227e6044be9e0a0617346cd54baa384298b18b (patch) | |
| tree | 45f1cfbf6723e788e8dce8e0c1623bbdccbee012 /drivers/md | |
| parent | 3bef88257145fd4f8abf0c0f92ecdeafbd96739e (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>
Diffstat (limited to 'drivers/md')
| -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 4a4e9c75fc4c..98f58eeb7dc5 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -362,7 +362,7 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd) disk_super->version = cpu_to_le32(cmd->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); @@ -700,6 +700,7 @@ 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); |