[PATCH v3 3/5] pid: use pid_has_task() in __change_pid()

[Christian Brauner]

Replace hlist_empty() with the new pid_has_task() helper which is more
idiomatic, easier to grep for, and unifies how callers perform this
check.

Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Reviewed-by: Oleg Nesterov <oleg@xxxxxxxxxx>
---
/* pidfd selftests */
passed

/* v1 */
patch not present

/* v2 */
Link: https://lore.kernel.org/r/20191016153606.2326-3-christian.brauner@xxxxxxxxxx
patch introduced

/* v2 */
- Oleg Nesterov <oleg@xxxxxxxxxx>:
  - s/task_alive/pid_has_task/g
---
 kernel/pid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/pid.c b/kernel/pid.c
index 0a9f2e437217..124d40b239b1 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -299,7 +299,7 @@ static void __change_pid(struct task_struct *task, enum pid_type type,
 	*pid_ptr = new;
 
 	for (tmp = PIDTYPE_MAX; --tmp >= 0; )
-		if (!hlist_empty(&pid->tasks[tmp]))
+		if (pid_has_task(pid, tmp))
 			return;
 
 	free_pid(pid);
-- 
2.23.0