Re: [patch] Minor PAGG attach/detach semantic change for 2.6.11

Ok; so I think this matches what you were suggested.  We unsubscribe the
subscriber that knows about the failure.  For other subscribers, they now
get cleaned up in copy_process when the fork fails.

The changes to __pnotify_fork are just comment changes.

I'll run some tests against this but my tests won't catch this type of
thing, at least not yet.


diff -Narup -x linux/.pc linux-orig/kernel/fork.c linux/kernel/fork.c
--- linux-orig/kernel/fork.c	2005-10-04 09:01:09.105780000 -0500
+++ linux/kernel/fork.c	2005-10-04 09:19:14.548775980 -0500
@@ -1086,7 +1086,7 @@ static task_t *copy_process(unsigned lon
 	if (sigismember(&current->pending.signal, SIGKILL)) {
 		write_unlock_irq(&tasklist_lock);
 		retval = -EINTR;
-		goto bad_fork_cleanup_pnotify;
+		goto bad_fork_cleanup_namespace;
 	}
 
 	/* CLONE_PARENT re-uses the old parent */
@@ -1172,9 +1172,8 @@ fork_out:
 		return ERR_PTR(retval);
 	return p;
 
-bad_fork_cleanup_pnotify:
-	pnotify_exit(p);
 bad_fork_cleanup_namespace:
+	pnotify_exit(p);
 	exit_namespace(p);
 bad_fork_cleanup_keys:
 	exit_keys(p);
diff -Narup -x linux/.pc linux-orig/kernel/pnotify.c linux/kernel/pnotify.c
--- linux-orig/kernel/pnotify.c	2005-09-30 16:05:56.548237000 -0500
+++ linux/kernel/pnotify.c	2005-10-04 09:22:02.585499338 -0500
@@ -458,10 +458,10 @@ __pnotify_fork(struct task_struct *to_ta
 						  from_subscriber->events);
 		if (!to_subscriber) {
 			/* Failed to get memory.
-			 * we don't force __pnotify_exit to run here because
-			 * the child is in-consturction and not running yet.
 			 * We don't need a write lock on the subscriber
 			 * list because the child is in construction.
+			 * pnotify_exit is run in copy_process for failed
+			 * forks and will clean up the other subscribers.
 			 */
 			pnotify_unsubscribe(to_task);
 			up_read(&from_task->pnotify_subscriber_list_sem);
@@ -474,8 +474,8 @@ __pnotify_fork(struct task_struct *to_ta
 			/* Propagates to copy_process as a fork failure.
 			 * Since the child is in consturction, we don't
 			 * need a write lock on the subscriber list.
-			 * __pnotify_exit isn't run because the child
-			 * never got running, exit doesn't make sense.
+			 * pnotify_exit is run in copy_process for failed
+			 * forks and will clean up the other subscribers.
 			 */
 			pnotify_unsubscribe(to_task);
 			up_read(&from_task->pnotify_subscriber_list_sem);