Btrfs: remove unneeded field / smaller extent_map structure

We don't need to have an unsigned int field in the extent_map struct
to tell us whether the extent map is in the inode's extent_map tree or
not. We can use the rb_node struct field and the RB_CLEAR_NODE and
RB_EMPTY_NODE macros to achieve the same task.

This reduces sizeof(struct extent_map) from 152 bytes to 144 bytes (on a
64 bits system).

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index fbe501d3bd01..2c9fbe3b6eec 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2763,7 +2763,7 @@ __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
 
         if (em_cached && *em_cached) {
                 em = *em_cached;
-                if (em->in_tree && start >= em->start &&
+                if (extent_map_in_tree(em) && start >= em->start &&
                     start < extent_map_end(em)) {
                         atomic_inc(&em->refs);
                         return em;