posix-timers: sys_timer_create: cleanup the error handling
Oleg Nesterov [Mon, 22 Sep 2008 21:42:49 +0000 (14:42 -0700)]
Cleanup.

- sys_timer_create() is big and complicated. The code above the "out:"
  label relies on the fact that "error" must be == 0. This is not very
  robust, make the code more explicit. Remove the unneeded initialization
  of error.

- If idr_get_new() succeeds (as it normally should), we check the returned
  value twice. Move the "-EAGAIN" check under "if (error)".

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: mingo@elte.hu
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/posix-timers.c

index c459b29..7be385f 100644 (file)
@@ -454,9 +454,8 @@ sys_timer_create(const clockid_t which_clock,
                 struct sigevent __user *timer_event_spec,
                 timer_t __user * created_timer_id)
 {
-       int error = 0;
        struct k_itimer *new_timer;
-       int new_timer_id;
+       int error, new_timer_id;
        struct task_struct *process;
        sigevent_t event;
        int it_id_set = IT_ID_NOT_SET;
@@ -478,9 +477,9 @@ sys_timer_create(const clockid_t which_clock,
        error = idr_get_new(&posix_timers_id, (void *) new_timer,
                            &new_timer_id);
        spin_unlock_irq(&idr_lock);
-       if (error == -EAGAIN)
-               goto retry;
-       else if (error) {
+       if (error) {
+               if (error == -EAGAIN)
+                       goto retry;
                /*
                 * Weird looking, but we return EAGAIN if the IDR is
                 * full (proper POSIX return value for this)
@@ -541,6 +540,8 @@ sys_timer_create(const clockid_t which_clock,
        new_timer->it_process = process;
        list_add(&new_timer->list, &current->signal->posix_timers);
        spin_unlock_irq(&current->sighand->siglock);
+
+       return 0;
        /*
         * In the case of the timer belonging to another task, after
         * the task is unlocked, the timer is owned by the other task
@@ -548,9 +549,7 @@ sys_timer_create(const clockid_t which_clock,
         * new_timer after the unlock call.
         */
 out:
-       if (error)
-               release_posix_timer(new_timer, it_id_set);
-
+       release_posix_timer(new_timer, it_id_set);
        return error;
 }