[NET] ifb: set separate lockdep classes for queue locks

[safe/jmp/linux-2.6] / drivers / net / ifb.c

diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index 15949d3..af233b5 100644 (file)
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -35,6 +35,7 @@
 #include <linux/moduleparam.h>
 #include <net/pkt_sched.h>
 #include <net/net_namespace.h>
+#include <linux/lockdep.h>
 
 #define TX_TIMEOUT  (2*HZ)
 
@@ -227,6 +228,16 @@ static struct rtnl_link_ops ifb_link_ops __read_mostly = {
 module_param(numifbs, int, 0);
 MODULE_PARM_DESC(numifbs, "Number of ifb devices");
 
+/*
+ * dev_ifb->queue_lock is usually taken after dev->ingress_lock,
+ * reversely to e.g. qdisc_lock_tree(). It should be safe until
+ * ifb doesn't take dev->queue_lock with dev_ifb->ingress_lock.
+ * But lockdep should know that ifb has different locks from dev.
+ */
+static struct lock_class_key ifb_queue_lock_key;
+static struct lock_class_key ifb_ingress_lock_key;
+
+
 static int __init ifb_init_one(int index)
 {
        struct net_device *dev_ifb;
@@ -246,6 +257,10 @@ static int __init ifb_init_one(int index)
        err = register_netdevice(dev_ifb);
        if (err < 0)
                goto err;
+
+       lockdep_set_class(&dev_ifb->queue_lock, &ifb_queue_lock_key);
+       lockdep_set_class(&dev_ifb->ingress_lock, &ifb_ingress_lock_key);
+
        return 0;
 
 err: