[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;