From 9515066f6edd15c1527ee5756d4dcdf22e23fa33 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 3 Jul 2006 00:25:12 -0700
Subject: [PATCH] --- yaml --- r: 31825 b: refs/heads/master c:
 a09785a2414afb261d9f719d544742af4300df22 h: refs/heads/master i:   31823:
 b86668ece16df4bdc2342c5c93257c97454aa7c4 v: v3

---
 [refs]                      |  2 +-
 trunk/include/net/af_unix.h |  3 +++
 trunk/net/unix/af_unix.c    | 12 +++++++++++-
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 4cde954fd00d..0258576fd392 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: da21f24dd73954c2ed0cd39a698e2c9916c05d71
+refs/heads/master: a09785a2414afb261d9f719d544742af4300df22
diff --git a/trunk/include/net/af_unix.h b/trunk/include/net/af_unix.h
index 5ba72d95280c..2fec827c8801 100644
--- a/trunk/include/net/af_unix.h
+++ b/trunk/include/net/af_unix.h
@@ -67,6 +67,9 @@ struct unix_skb_parms {
 #define unix_state_rlock(s)	spin_lock(&unix_sk(s)->lock)
 #define unix_state_runlock(s)	spin_unlock(&unix_sk(s)->lock)
 #define unix_state_wlock(s)	spin_lock(&unix_sk(s)->lock)
+#define unix_state_wlock_nested(s) \
+				spin_lock_nested(&unix_sk(s)->lock, \
+				SINGLE_DEPTH_NESTING)
 #define unix_state_wunlock(s)	spin_unlock(&unix_sk(s)->lock)
 
 #ifdef __KERNEL__
diff --git a/trunk/net/unix/af_unix.c b/trunk/net/unix/af_unix.c
index aca650109425..e9a287bc3142 100644
--- a/trunk/net/unix/af_unix.c
+++ b/trunk/net/unix/af_unix.c
@@ -565,6 +565,14 @@ static struct proto unix_proto = {
 	.obj_size = sizeof(struct unix_sock),
 };
 
+/*
+ * AF_UNIX sockets do not interact with hardware, hence they
+ * dont trigger interrupts - so it's safe for them to have
+ * bh-unsafe locking for their sk_receive_queue.lock. Split off
+ * this special lock-class by reinitializing the spinlock key:
+ */
+static struct lock_class_key af_unix_sk_receive_queue_lock_key;
+
 static struct sock * unix_create1(struct socket *sock)
 {
 	struct sock *sk = NULL;
@@ -580,6 +588,8 @@ static struct sock * unix_create1(struct socket *sock)
 	atomic_inc(&unix_nr_socks);
 
 	sock_init_data(sock,sk);
+	lockdep_set_class(&sk->sk_receive_queue.lock,
+				&af_unix_sk_receive_queue_lock_key);
 
 	sk->sk_write_space	= unix_write_space;
 	sk->sk_max_ack_backlog	= sysctl_unix_max_dgram_qlen;
@@ -1045,7 +1055,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 		goto out_unlock;
 	}
 
-	unix_state_wlock(sk);
+	unix_state_wlock_nested(sk);
 
 	if (sk->sk_state != st) {
 		unix_state_wunlock(sk);