posix-timers: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/posix-timers.c

@@ -552,24 +552,22 @@ SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
 		return -EAGAIN;
 
 	spin_lock_init(&new_timer->it_lock);
- retry:
-	if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
-		error = -EAGAIN;
-		goto out;
-	}
+
+	idr_preload(GFP_KERNEL);
 	spin_lock_irq(&idr_lock);
-	error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
+	error = idr_alloc(&posix_timers_id, new_timer, 0, 0, GFP_NOWAIT);
 	spin_unlock_irq(&idr_lock);
-	if (error) {
-		if (error == -EAGAIN)
-			goto retry;
+	idr_preload_end();
+	if (error < 0) {
 		/*
 		 * Weird looking, but we return EAGAIN if the IDR is
 		 * full (proper POSIX return value for this)
 		 */
-		error = -EAGAIN;
+		if (error == -ENOSPC)
+			error = -EAGAIN;
 		goto out;
 	}
+	new_timer_id = error;
 
 	it_id_set = IT_ID_SET;
 	new_timer->it_id = (timer_t) new_timer_id;