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Commit ed07536e authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds
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[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: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarSteven Dickson <SteveD@redhat.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: default avatarNeil Brown <neilb@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
[ Fixed patch corruption by quilt, pointed out by Peter Zijlstra ]
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b9d85b08

include/net/sock.h

+19 −0
Original line number Diff line number Diff line
@@ -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)

kernel/lockdep.c

+1 −0
Original line number Diff line number Diff line
@@ -2645,6 +2645,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len) 
	}

	local_irq_restore(flags);

}

EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);



static void print_held_locks_bug(struct task_struct *curr)

{

net/core/sock.c

+5 −18
Original line number Diff line number Diff line
@@ -810,24 +810,11 @@ int sock_getsockopt(struct socket *sock, int level, int optname, 
 */

static void inline sock_lock_init(struct sock *sk)

{

	spin_lock_init(&sk->sk_lock.slock);

	sk->sk_lock.owner = NULL;

	init_waitqueue_head(&sk->sk_lock.wq);

	/*

	 * Make sure we are not reinitializing a held lock:

	 */

	debug_check_no_locks_freed((void *)&sk->sk_lock, sizeof(sk->sk_lock));



	/*

	 * Mark both the sk_lock and the sk_lock.slock as a

	 * per-address-family lock class:

	 */

	lockdep_set_class_and_name(&sk->sk_lock.slock,

	sock_lock_init_class_and_name(sk,

			af_family_slock_key_strings[sk->sk_family],

			af_family_slock_keys + sk->sk_family,

				   af_family_slock_key_strings[sk->sk_family]);

	lockdep_init_map(&sk->sk_lock.dep_map,

			af_family_key_strings[sk->sk_family],

			 af_family_keys + sk->sk_family, 0);

			af_family_keys + sk->sk_family);

}



/**

net/sunrpc/svcsock.c

+31 −0
Original line number Diff line number Diff line
@@ -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,

net/sunrpc/xprtsock.c

+31 −0
Original line number Diff line number Diff line
@@ -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);