dm cache metadata: do not allow the data block size to change

[android-x86/kernel.git] / drivers / md / dm-cache-metadata.c

diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 1af7255..de737ba 100644 (file)
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -384,6 +384,15 @@ static int __open_metadata(struct dm_cache_metadata *cmd)
 
        disk_super = dm_block_data(sblock);
 
+       /* Verify the data block size hasn't changed */
+       if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) {
+               DMERR("changing the data block size (from %u to %llu) is not supported",
+                     le32_to_cpu(disk_super->data_block_size),
+                     (unsigned long long)cmd->data_block_size);
+               r = -EINVAL;
+               goto bad;
+       }
+
        r = __check_incompat_features(disk_super, cmd);
        if (r < 0)
                goto bad;
@@ -511,8 +520,9 @@ static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
        disk_super = dm_block_data(sblock);
        update_flags(disk_super, mutator);
        read_superblock_fields(cmd, disk_super);
+       dm_bm_unlock(sblock);
 
-       return dm_bm_flush_and_unlock(cmd->bm, sblock);
+       return dm_bm_flush(cmd->bm);
 }
 
 static int __begin_transaction(struct dm_cache_metadata *cmd)