__d_move(): fold manipulations with ->d_child/->d_subdirs

list_del() + list_add() is a slightly pessimised list_move()
list_del() + INIT_LIST_HEAD() is a slightly pessimised list_del_init()

Interleaving those makes the resulting code even worse.  And harder to follow...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 5 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 22107630fc03..86afdf1376ac 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2506,8 +2506,6 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
                            d_hash(dentry->d_parent, dentry->d_name.hash));
         }
 
-        list_del(&dentry->d_u.d_child);
-        list_del(&target->d_u.d_child);
 
         /* Switch the names.. */
         switch_names(dentry, target);
@@ -2517,15 +2515,15 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
         if (IS_ROOT(dentry)) {
                 dentry->d_parent = target->d_parent;
                 target->d_parent = target;
-                INIT_LIST_HEAD(&target->d_u.d_child);
+                list_del_init(&target->d_u.d_child);
         } else {
                 swap(dentry->d_parent, target->d_parent);
 
                 /* And add them back to the (new) parent lists */
-                list_add(&target->d_u.d_child, &target->d_parent->d_subdirs);
+                list_move(&target->d_u.d_child, &target->d_parent->d_subdirs);
         }
 
-        list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+        list_move(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
 
         write_seqcount_end(&target->d_seq);
         write_seqcount_end(&dentry->d_seq);