From: Peter Zijlstra 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. Signed-off-by: Peter Zijlstra Signed-off-by: Steven Dickson Acked-by: Ingo Molnar Cc: Trond Myklebust Acked-by: Neil Brown Cc: "David S. Miller" Signed-off-by: Andrew Morton --- include/net/sock.h | 19 +++++++++++++++++++ kernel/lockdep.c | 1 + net/core/sock.c | 23 +++++------------------ net/sunrpc/svcsock.c | 33 +++++++++++++++++++++++++++++++++ net/sunrpc/xprtsock.c | 33 +++++++++++++++++++++++++++++++++ 5 files changed, 91 insertions(+), 18 deletions(-) diff -puN include/net/sock.h~lockdep-annotate-nfs-nfsd-in-kernel-sockets include/net/sock.h --- a/include/net/sock.h~lockdep-annotate-nfs-nfsd-in-kernel-sockets +++ a/include/net/sock.h @@ -745,6 +745,25 @@ static inline int sk_stream_wmem_schedul */ #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) diff -puN kernel/lockdep.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets kernel/lockdep.c --- a/kernel/lockdep.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets +++ a/kernel/lockdep.c @@ -2644,6 +2644,7 @@ void debug_check_no_locks_freed(const vo } local_irq_restore(flags); } +EXPORT_SYMBOL_GPL(debug_check_no_locks_freed); static void print_held_locks_bug(struct task_struct *curr) { diff -puN net/core/sock.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets net/core/sock.c --- a/net/core/sock.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets +++ a/net/core/sock.c @@ -806,24 +806,11 @@ lenout: */ 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, - 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); + sock_lock_init_class_and_name(sk, + af_family_slock_key_strings[sk->sk_family], + af_family_slock_keys + sk->sk_family, + af_family_key_strings[sk->sk_family], + af_family_keys + sk->sk_family); } /** diff -puN net/sunrpc/svcsock.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets net/sunrpc/svcsock.c --- a/net/sunrpc/svcsock.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets +++ a/net/sunrpc/svcsock.c @@ -85,6 +85,37 @@ static struct cache_deferred_req *svc_de */ 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 +1588,8 @@ svc_create_socket(struct svc_serv *serv, 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 -puN net/sunrpc/xprtsock.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets net/sunrpc/xprtsock.c --- a/net/sunrpc/xprtsock.c~lockdep-annotate-nfs-nfsd-in-kernel-sockets +++ a/net/sunrpc/xprtsock.c @@ -1058,6 +1058,37 @@ static int xs_bindresvport(struct rpc_xp 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 * @args: RPC transport to connect @@ -1080,6 +1111,7 @@ static void xs_udp_connect_worker(void * 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); @@ -1163,6 +1195,7 @@ static void xs_tcp_connect_worker(void * 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); _