X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=ipc%2Fnamespace.c;h=9171d948751e72c6c0c8fa1b8e60688ba4384a0c;hb=ba1eb95cf3cc666769afe42eaa15a3a34ae82f94;hp=1b967655eb350eba0c4308998e376a8d3a719c72;hpb=f3aafa6c2535d36542a6dfc8647cd2fdb5999648;p=linux-2.6-omap-h63xx.git

diff --git a/ipc/namespace.c b/ipc/namespace.c
index 1b967655eb3..9171d948751 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -20,10 +20,20 @@ static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
 	if (ns == NULL)
 		return ERR_PTR(-ENOMEM);
 
+	atomic_inc(&nr_ipc_ns);
+
 	sem_init_ns(ns);
 	msg_init_ns(ns);
 	shm_init_ns(ns);
 
+	/*
+	 * msgmni has already been computed for the new ipc ns.
+	 * Thus, do the ipcns creation notification before registering that
+	 * new ipcns in the chain.
+	 */
+	ipcns_notify(IPCNS_CREATED);
+	register_ipcns_notifier(ns);
+
 	kref_init(&ns->kref);
 	return ns;
 }
@@ -79,8 +89,24 @@ void free_ipc_ns(struct kref *kref)
 	struct ipc_namespace *ns;
 
 	ns = container_of(kref, struct ipc_namespace, kref);
+	/*
+	 * Unregistering the hotplug notifier at the beginning guarantees
+	 * that the ipc namespace won't be freed while we are inside the
+	 * callback routine. Since the blocking_notifier_chain_XXX routines
+	 * hold a rw lock on the notifier list, unregister_ipcns_notifier()
+	 * won't take the rw lock before blocking_notifier_call_chain() has
+	 * released the rd lock.
+	 */
+	unregister_ipcns_notifier(ns);
 	sem_exit_ns(ns);
 	msg_exit_ns(ns);
 	shm_exit_ns(ns);
 	kfree(ns);
+	atomic_dec(&nr_ipc_ns);
+
+	/*
+	 * Do the ipcns removal notification after decrementing nr_ipc_ns in
+	 * order to have a correct value when recomputing msgmni.
+	 */
+	ipcns_notify(IPCNS_REMOVED);
 }