btrfs: convert btrfs_get_global_root to use a switch statement

Use a switch statement instead of an endless chain of if statements
to make the code a little cleaner.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4d34799..c53c82c 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1172,25 +1172,28 @@ static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
                .offset = 0,
        };
 
-       if (objectid == BTRFS_ROOT_TREE_OBJECTID)
+       switch (objectid) {
+       case BTRFS_ROOT_TREE_OBJECTID:
                return btrfs_grab_root(fs_info->tree_root);
-       if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
+       case BTRFS_EXTENT_TREE_OBJECTID:
                return btrfs_grab_root(btrfs_global_root(fs_info, &key));
-       if (objectid == BTRFS_CHUNK_TREE_OBJECTID)
+       case BTRFS_CHUNK_TREE_OBJECTID:
                return btrfs_grab_root(fs_info->chunk_root);
-       if (objectid == BTRFS_DEV_TREE_OBJECTID)
+       case BTRFS_DEV_TREE_OBJECTID:
                return btrfs_grab_root(fs_info->dev_root);
-       if (objectid == BTRFS_CSUM_TREE_OBJECTID)
+       case BTRFS_CSUM_TREE_OBJECTID:
                return btrfs_grab_root(btrfs_global_root(fs_info, &key));
-       if (objectid == BTRFS_QUOTA_TREE_OBJECTID)
+       case BTRFS_QUOTA_TREE_OBJECTID:
                return btrfs_grab_root(fs_info->quota_root);
-       if (objectid == BTRFS_UUID_TREE_OBJECTID)
+       case BTRFS_UUID_TREE_OBJECTID:
                return btrfs_grab_root(fs_info->uuid_root);
-       if (objectid == BTRFS_BLOCK_GROUP_TREE_OBJECTID)
+       case BTRFS_BLOCK_GROUP_TREE_OBJECTID:
                return btrfs_grab_root(fs_info->block_group_root);
-       if (objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
+       case BTRFS_FREE_SPACE_TREE_OBJECTID:
                return btrfs_grab_root(btrfs_global_root(fs_info, &key));
-       return NULL;
+       default:
+               return NULL;
+       }
 }
 
 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,