Merge tag 'omapdrm-fixes-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba...

[karo-tx-linux.git] / drivers / md / dm-cache-metadata.c

diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index cbd568a3a5790aeed73b1b423a004759d8f63e8d..4ead4ba606562b0c33d750064660a4effe0594ea 100644 (file)
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -120,6 +120,12 @@ struct dm_cache_metadata {
        unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
        size_t policy_hint_size;
        struct dm_cache_statistics stats;
+
+       /*
+        * Reading the space map root can fail, so we read it into this
+        * buffer before the superblock is locked and updated.
+        */
+       __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
 };
 
 /*-------------------------------------------------------------------
@@ -260,11 +266,31 @@ static void __setup_mapping_info(struct dm_cache_metadata *cmd)
        }
 }
 
+static int __save_sm_root(struct dm_cache_metadata *cmd)
+{
+       int r;
+       size_t metadata_len;
+
+       r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
+       if (r < 0)
+               return r;
+
+       return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
+                              metadata_len);
+}
+
+static void __copy_sm_root(struct dm_cache_metadata *cmd,
+                          struct cache_disk_superblock *disk_super)
+{
+       memcpy(&disk_super->metadata_space_map_root,
+              &cmd->metadata_space_map_root,
+              sizeof(cmd->metadata_space_map_root));
+}
+
 static int __write_initial_superblock(struct dm_cache_metadata *cmd)
 {
        int r;
        struct dm_block *sblock;
-       size_t metadata_len;
        struct cache_disk_superblock *disk_super;
        sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
 
@@ -272,12 +298,16 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd)
        if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
                bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
 
-       r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
+       r = dm_tm_pre_commit(cmd->tm);
        if (r < 0)
                return r;
 
-       r = dm_tm_pre_commit(cmd->tm);
-       if (r < 0)
+       /*
+        * dm_sm_copy_root() can fail.  So we need to do it before we start
+        * updating the superblock.
+        */
+       r = __save_sm_root(cmd);
+       if (r)
                return r;
 
        r = superblock_lock_zero(cmd, &sblock);
@@ -293,10 +323,7 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd)
        memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
        disk_super->policy_hint_size = 0;
 
-       r = dm_sm_copy_root(cmd->metadata_sm, &disk_super->metadata_space_map_root,
-                           metadata_len);
-       if (r < 0)
-               goto bad_locked;
+       __copy_sm_root(cmd, disk_super);
 
        disk_super->mapping_root = cpu_to_le64(cmd->root);
        disk_super->hint_root = cpu_to_le64(cmd->hint_root);
@@ -313,10 +340,6 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd)
        disk_super->write_misses = cpu_to_le32(0);
 
        return dm_tm_commit(cmd->tm, sblock);
-
-bad_locked:
-       dm_bm_unlock(sblock);
-       return r;
 }
 
 static int __format_metadata(struct dm_cache_metadata *cmd)
@@ -530,8 +553,9 @@ 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)
@@ -559,7 +583,6 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
                                flags_mutator mutator)
 {
        int r;
-       size_t metadata_len;
        struct cache_disk_superblock *disk_super;
        struct dm_block *sblock;
 
@@ -577,8 +600,8 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
        if (r < 0)
                return r;
 
-       r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
-       if (r < 0)
+       r = __save_sm_root(cmd);
+       if (r)
                return r;
 
        r = superblock_lock(cmd, &sblock);
@@ -605,13 +628,7 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
        disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
        disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
        disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
-
-       r = dm_sm_copy_root(cmd->metadata_sm, &disk_super->metadata_space_map_root,
-                           metadata_len);
-       if (r < 0) {
-               dm_bm_unlock(sblock);
-               return r;
-       }
+       __copy_sm_root(cmd, disk_super);
 
        return dm_tm_commit(cmd->tm, sblock);
 }
@@ -1228,22 +1245,12 @@ static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *po
        return 0;
 }
 
-int dm_cache_begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
+static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint)
 {
+       struct dm_cache_metadata *cmd = context;
+       __le32 value = cpu_to_le32(hint);
        int r;
 
-       down_write(&cmd->root_lock);
-       r = begin_hints(cmd, policy);
-       up_write(&cmd->root_lock);
-
-       return r;
-}
-
-static int save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
-                    uint32_t hint)
-{
-       int r;
-       __le32 value = cpu_to_le32(hint);
        __dm_bless_for_disk(&value);
 
        r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
@@ -1253,16 +1260,25 @@ static int save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
        return r;
 }
 
-int dm_cache_save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
-                      uint32_t hint)
+static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
 {
        int r;
 
-       if (!hints_array_initialized(cmd))
-               return 0;
+       r = begin_hints(cmd, policy);
+       if (r) {
+               DMERR("begin_hints failed");
+               return r;
+       }
+
+       return policy_walk_mappings(policy, save_hint, cmd);
+}
+
+int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
+{
+       int r;
 
        down_write(&cmd->root_lock);
-       r = save_hint(cmd, cblock, hint);
+       r = write_hints(cmd, policy);
        up_write(&cmd->root_lock);
 
        return r;