gfs2: eliminate GIF_ORDERED in favor of list_empty

In several places, we used the GIF_ORDERED inode flag to determine
if an inode was on the ordered writes list. However, since we always
held the sd_ordered_lock spin_lock during the manipulation, we can
just as easily check list_empty(&ip->i_ordered) instead.
This allows us to keep more than one ordered writes list to make
journal writing improvements.

This patch eliminates GIF_ORDERED in favor of checking list_empty.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

fs/gfs2/main.c

@@ -39,6 +39,7 @@ static void gfs2_init_inode_once(void *foo)
 	atomic_set(&ip->i_sizehint, 0);
 	init_rwsem(&ip->i_rw_mutex);
 	INIT_LIST_HEAD(&ip->i_trunc_list);
+	INIT_LIST_HEAD(&ip->i_ordered);
 	ip->i_qadata = NULL;
 	gfs2_holder_mark_uninitialized(&ip->i_rgd_gh);
 	memset(&ip->i_res, 0, sizeof(ip->i_res));