btrfs-progs: backref: add list_first_pref helper

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

diff --git a/backref.c b/backref.c
index 127951c..305cd05 100644 (file)
--- a/backref.c
+++ b/backref.c
@@ -130,6 +130,11 @@ struct __prelim_ref {
        u64 wanted_disk_byte;
 };
 
+static struct __prelim_ref *list_first_pref(struct list_head *head)
+{
+       return list_first_entry(head, struct __prelim_ref, list);
+}
+
 struct pref_state {
        struct list_head pending;
 };
@@ -803,8 +808,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
        __merge_refs(&prefstate, 2);
 
        while (!list_empty(&prefstate.pending)) {
-               ref = list_first_entry(&prefstate.pending,
-                                      struct __prelim_ref, list);
+               ref = list_first_pref(&prefstate.pending);
                WARN_ON(ref->count < 0);
                if (roots && ref->count && ref->root_id && ref->parent == 0) {
                        /* no parent == root of tree */
@@ -854,8 +858,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 out:
        btrfs_free_path(path);
        while (!list_empty(&prefstate.pending)) {
-               ref = list_first_entry(&prefstate.pending,
-                                      struct __prelim_ref, list);
+               ref = list_first_pref(&prefstate.pending);
                list_del(&ref->list);
                kfree(ref);
        }