[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>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 730899ce5162..03684e702d13 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -746,6 +746,25 @@ static inline int sk_stream_wmem_schedule(struct sock *sk, int size)
  */
 #define sock_owned_by_user(sk)  ((sk)->sk_lock.owner)
 
+/*
+ * Macro so as to not evaluate some arguments when
+ * lockdep is not enabled.
+ *
+ * Mark both the sk_lock and the sk_lock.slock as a
+ * per-address-family lock class.
+ */
+#define sock_lock_init_class_and_name(sk, sname, skey, name, key)       \
+do {                                                                    \
+        sk->sk_lock.owner = NULL;                                       \
+        init_waitqueue_head(&sk->sk_lock.wq);                           \
+        spin_lock_init(&(sk)->sk_lock.slock);                           \
+        debug_check_no_locks_freed((void *)&(sk)->sk_lock,              \
+                        sizeof((sk)->sk_lock));                         \
+        lockdep_set_class_and_name(&(sk)->sk_lock.slock,                \
+                        (skey), (sname));                               \
+        lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);     \
+} while (0)
+
 extern void FASTCALL(lock_sock_nested(struct sock *sk, int subclass));
 
 static inline void lock_sock(struct sock *sk)