[PATCH 4/4] utrace_set_events: use goto to return -EALREADY

[Oleg Nesterov]

utrace_set_events() is not trivial, and imho it has too much
"unlock + return" cases. Change the code to use goto, this also
lessens the source and compiled code a bit.

---

 kernel/utrace.c |   19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

--- kstub/kernel/utrace.c~4_cleanup_ealready    2010-08-14 04:30:29.000000000 
+0200
+++ kstub/kernel/utrace.c       2010-08-14 04:30:29.000000000 +0200
@@ -524,7 +524,7 @@ int utrace_set_events(struct task_struct
 {
        struct utrace *utrace;
        unsigned long old_flags, old_utrace_flags;
-       int ret;
+       int ret = -EALREADY;
 
        /*
         * We just ignore the internal bit, so callers can use
@@ -542,15 +542,11 @@ int utrace_set_events(struct task_struct
        /* If ->death or ->reap is true we must see exit_state != 0. */
        if (target->exit_state) {
                if (utrace->death) {
-                       if ((old_flags & ~events) &  _UTRACE_DEATH_EVENTS) {
-                               spin_unlock(&utrace->lock);
-                               return -EALREADY;
-                       }
+                       if ((old_flags & ~events) &  _UTRACE_DEATH_EVENTS)
+                               goto unlock;
                } else if (utrace->reap) {
-                       if ((old_flags ^ events) & UTRACE_EVENT(REAP)) {
-                               spin_unlock(&utrace->lock);
-                               return -EALREADY;
-                       }
+                       if ((old_flags ^ events) & UTRACE_EVENT(REAP))
+                               goto unlock;
                }
        }
 
@@ -568,8 +564,7 @@ int utrace_set_events(struct task_struct
                read_lock(&tasklist_lock);
                if (unlikely(target->exit_state)) {
                        read_unlock(&tasklist_lock);
-                       spin_unlock(&utrace->lock);
-                       return -EALREADY;
+                       goto unlock;
                }
                target->utrace_flags |= events;
                read_unlock(&tasklist_lock);
@@ -597,7 +592,7 @@ int utrace_set_events(struct task_struct
                if (utrace->reporting == engine)
                        ret = -EINPROGRESS;
        }
-
+unlock:
        spin_unlock(&utrace->lock);
 
        return ret;