[PATCH] lockdep: annotate nfs/nfsd in-kernel sockets

Stick NFS sockets in their own class to avoid some lockdep warnings.  NFS
sockets are never exposed to user-space, and will hence not trigger certain
code paths that would otherwise pose deadlock scenarios.

[akpm@osdl.org: cleanups]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Steven Dickson <SteveD@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: Neil Brown <neilb@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
[ Fixed patch corruption by quilt, pointed out by Peter Zijlstra ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 62 insertions, 0 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 1c68956824e3..99f54fb6d669 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -85,6 +85,35 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req);
  */
 static int svc_conn_age_period = 6*60;
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key svc_key[2];
+static struct lock_class_key svc_slock_key[2];
+
+static inline void svc_reclassify_socket(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	BUG_ON(sk->sk_lock.owner != NULL);
+	switch (sk->sk_family) {
+	case AF_INET:
+		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
+		    &svc_slock_key[0], "sk_lock-AF_INET-NFSD", &svc_key[0]);
+		break;
+
+	case AF_INET6:
+		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
+		    &svc_slock_key[1], "sk_lock-AF_INET6-NFSD", &svc_key[1]);
+		break;
+
+	default:
+		BUG();
+	}
+}
+#else
+static inline void svc_reclassify_socket(struct socket *sock)
+{
+}
+#endif
+
 /*
  * Queue up an idle server thread.  Must have pool->sp_lock held.
  * Note: this is really a stack rather than a queue, so that we only
@@ -1557,6 +1586,8 @@ svc_create_socket(struct svc_serv *serv, int protocol, struct sockaddr_in *sin)
 	if ((error = sock_create_kern(PF_INET, type, protocol, &sock)) < 0)
 		return error;
 
+	svc_reclassify_socket(sock);
+
 	if (type == SOCK_STREAM)
 		sock->sk->sk_reuse = 1; /* allow address reuse */
 	error = kernel_bind(sock, (struct sockaddr *) sin,
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index cfe3c15be948..2fc4a3123261 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1058,6 +1058,35 @@ static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
 	return err;
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key xs_key[2];
+static struct lock_class_key xs_slock_key[2];
+
+static inline void xs_reclassify_socket(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	BUG_ON(sk->sk_lock.owner != NULL);
+	switch (sk->sk_family) {
+	case AF_INET:
+		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFS",
+			&xs_slock_key[0], "sk_lock-AF_INET-NFS", &xs_key[0]);
+		break;
+
+	case AF_INET6:
+		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFS",
+			&xs_slock_key[1], "sk_lock-AF_INET6-NFS", &xs_key[1]);
+		break;
+
+	default:
+		BUG();
+	}
+}
+#else
+static inline void xs_reclassify_socket(struct socket *sock)
+{
+}
+#endif
+
 /**
  * xs_udp_connect_worker - set up a UDP socket
  * @work: RPC transport to connect
@@ -1081,6 +1110,7 @@ static void xs_udp_connect_worker(struct work_struct *work)
 		dprintk("RPC:      can't create UDP transport socket (%d).\n", -err);
 		goto out;
 	}
+	xs_reclassify_socket(sock);
 
 	if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
 		sock_release(sock);
@@ -1165,6 +1195,7 @@ static void xs_tcp_connect_worker(struct work_struct *work)
 			dprintk("RPC:      can't create TCP transport socket (%d).\n", -err);
 			goto out;
 		}
+		xs_reclassify_socket(sock);
 
 		if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
 			sock_release(sock);