btrfs: remove unnecessary extent map initializations

When allocating an extent map, we use kmem_cache_zalloc() which guarantees
the returned memory is initialized to zeroes, therefore it's pointless
to initialize the generation and flags of the extent map to zero again.

Remove those initializations, as they are pointless and slightly increase
the object text size.

Before removing them:

   $ size fs/btrfs/extent_map.o
      text	   data	    bss	    dec	    hex	filename
      9241	    274	     24	   9539	   2543	fs/btrfs/extent_map.o

After removing them:

   $ size fs/btrfs/extent_map.o
      text	   data	    bss	    dec	    hex	filename
      9209	    274	     24	   9507	   2523	fs/btrfs/extent_map.o

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 2e6dc5a772f45b6850d8f6689f7436b70da3185b..6b7eee92d9810fb9f13649648c7cbb777c31907a 100644 (file)
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -55,9 +55,7 @@ struct extent_map *alloc_extent_map(void)
        if (!em)
                return NULL;
        RB_CLEAR_NODE(&em->rb_node);
-       em->flags = 0;
        em->compress_type = BTRFS_COMPRESS_NONE;
-       em->generation = 0;
        refcount_set(&em->refs, 1);
        INIT_LIST_HEAD(&em->list);
        return em;