kernfs: Refactor kernfs_get_open_node()

Factor out commont part. This is cleaner and should help with future
changes. No functional changes.

Tested-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220828050440.734579-4-tj@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 6437f7c..7060a2a 100644 (file)
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -554,31 +554,28 @@ out_unlock:
 static int kernfs_get_open_node(struct kernfs_node *kn,
                                struct kernfs_open_file *of)
 {
-       struct kernfs_open_node *on, *new_on = NULL;
+       struct kernfs_open_node *on;
        struct mutex *mutex;
 
        mutex = kernfs_open_file_mutex_lock(kn);
        on = kernfs_deref_open_node_locked(kn);
 
-       if (on) {
-               list_add_tail(&of->list, &on->files);
-               mutex_unlock(mutex);
-               return 0;
-       } else {
+       if (!on) {
                /* not there, initialize a new one */
-               new_on = kmalloc(sizeof(*new_on), GFP_KERNEL);
-               if (!new_on) {
+               on = kmalloc(sizeof(*on), GFP_KERNEL);
+               if (!on) {
                        mutex_unlock(mutex);
                        return -ENOMEM;
                }
-               atomic_set(&new_on->event, 1);
-               init_waitqueue_head(&new_on->poll);
-               INIT_LIST_HEAD(&new_on->files);
-               list_add_tail(&of->list, &new_on->files);
-               rcu_assign_pointer(kn->attr.open, new_on);
+               atomic_set(&on->event, 1);
+               init_waitqueue_head(&on->poll);
+               INIT_LIST_HEAD(&on->files);
+               rcu_assign_pointer(kn->attr.open, on);
        }
-       mutex_unlock(mutex);
 
+       list_add_tail(&of->list, &on->files);
+
+       mutex_unlock(mutex);
        return 0;
 }