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>
This commit is contained in:
Tejun Heo 2022-08-27 19:04:34 -10:00 committed by Greg Kroah-Hartman
parent b52c2379c3
commit cf2dc9db93

View file

@ -554,31 +554,28 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma)
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;
}