summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorMike Snitzer <snitzer@redhat.com>2018-08-02 16:08:52 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-09 20:01:21 +0200
commitd08b58b5c3ca41fa65a03a7c11398d48bf803079 (patch)
tree35c47241db70409529ee57aa692fbdb49a446d58 /drivers
parent9a3f8fd5bd75b8bc96e435cc973c2cd9e25c6c17 (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')
-rw-r--r--drivers/md/dm-cache-metadata.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 6937ca42be8c..a184c9830ca5 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -344,7 +344,7 @@ 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);
@@ -659,6 +659,7 @@ 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);