btrfs: use smaller type for btrfs_path lowest_level

The level is 0..7, we can use smaller type. The size of btrfs_path is now
136 bytes from 144, which is +2 objects that fit into a 4k slab.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e5f9b96..09ee92d 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -598,7 +598,7 @@ struct btrfs_path {
        int locks[BTRFS_MAX_LEVEL];
        u8 reada;
        /* keep some upper locks as we walk down */
-       int lowest_level;
+       u8 lowest_level;
 
        /*
         * set by btrfs_split_item, tells search_slot to keep all locks