[NETLINK]: Switch cb_lock spinlock to mutex and allow to override it

[powerpc.git] / net / netlink / af_netlink.c

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 2cbf168..ec16c9b 100644 (file)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -56,6 +56,7 @@
 #include <linux/types.h>
 #include <linux/audit.h>
 #include <linux/selinux.h>
+#include <linux/mutex.h>
 
 #include <net/sock.h>
 #include <net/scm.h>
@@ -76,7 +77,8 @@ struct netlink_sock {
        unsigned long           state;
        wait_queue_head_t       wait;
        struct netlink_callback *cb;
-       spinlock_t              cb_lock;
+       struct mutex            *cb_mutex;
+       struct mutex            cb_def_mutex;
        void                    (*data_ready)(struct sock *sk, int bytes);
        struct module           *module;
 };
@@ -108,6 +110,7 @@ struct netlink_table {
        unsigned long *listeners;
        unsigned int nl_nonroot;
        unsigned int groups;
+       struct mutex *cb_mutex;
        struct module *module;
        int registered;
 };
@@ -370,7 +373,8 @@ static struct proto netlink_proto = {
        .obj_size = sizeof(struct netlink_sock),
 };
 
-static int __netlink_create(struct socket *sock, int protocol)
+static int __netlink_create(struct socket *sock, struct mutex *cb_mutex,
+                           int protocol)
 {
        struct sock *sk;
        struct netlink_sock *nlk;
@@ -384,7 +388,8 @@ static int __netlink_create(struct socket *sock, int protocol)
        sock_init_data(sock, sk);
 
        nlk = nlk_sk(sk);
-       spin_lock_init(&nlk->cb_lock);
+       nlk->cb_mutex = cb_mutex ? : &nlk->cb_def_mutex;
+       mutex_init(nlk->cb_mutex);
        init_waitqueue_head(&nlk->wait);
 
        sk->sk_destruct = netlink_sock_destruct;
@@ -395,6 +400,7 @@ static int __netlink_create(struct socket *sock, int protocol)
 static int netlink_create(struct socket *sock, int protocol)
 {
        struct module *module = NULL;
+       struct mutex *cb_mutex;
        struct netlink_sock *nlk;
        int err = 0;
 
@@ -417,9 +423,10 @@ static int netlink_create(struct socket *sock, int protocol)
        if (nl_table[protocol].registered &&
            try_module_get(nl_table[protocol].module))
                module = nl_table[protocol].module;
+       cb_mutex = nl_table[protocol].cb_mutex;
        netlink_unlock_table();
 
-       if ((err = __netlink_create(sock, protocol)) < 0)
+       if ((err = __netlink_create(sock, cb_mutex, protocol)) < 0)
                goto out_module;
 
        nlk = nlk_sk(sock->sk);
@@ -444,14 +451,14 @@ static int netlink_release(struct socket *sock)
        sock_orphan(sk);
        nlk = nlk_sk(sk);
 
-       spin_lock(&nlk->cb_lock);
+       mutex_lock(nlk->cb_mutex);
        if (nlk->cb) {
                if (nlk->cb->done)
                        nlk->cb->done(nlk->cb);
                netlink_destroy_callback(nlk->cb);
                nlk->cb = NULL;
        }
-       spin_unlock(&nlk->cb_lock);
+       mutex_unlock(nlk->cb_mutex);
 
        /* OK. Socket is unlinked, and, therefore,
           no new packets will arrive */
@@ -1266,7 +1273,7 @@ static void netlink_data_ready(struct sock *sk, int len)
 struct sock *
 netlink_kernel_create(int unit, unsigned int groups,
                      void (*input)(struct sock *sk, int len),
-                     struct module *module)
+                     struct mutex *cb_mutex, struct module *module)
 {
        struct socket *sock;
        struct sock *sk;
@@ -1281,7 +1288,7 @@ netlink_kernel_create(int unit, unsigned int groups,
        if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
                return NULL;
 
-       if (__netlink_create(sock, unit) < 0)
+       if (__netlink_create(sock, cb_mutex, unit) < 0)
                goto out_sock_release;
 
        if (groups < 32)
@@ -1305,6 +1312,7 @@ netlink_kernel_create(int unit, unsigned int groups,
        netlink_table_grab();
        nl_table[unit].groups = groups;
        nl_table[unit].listeners = listeners;
+       nl_table[unit].cb_mutex = cb_mutex;
        nl_table[unit].module = module;
        nl_table[unit].registered = 1;
        netlink_table_ungrab();
@@ -1347,7 +1355,7 @@ static int netlink_dump(struct sock *sk)
        if (!skb)
                goto errout;
 
-       spin_lock(&nlk->cb_lock);
+       mutex_lock(nlk->cb_mutex);
 
        cb = nlk->cb;
        if (cb == NULL) {
@@ -1358,7 +1366,7 @@ static int netlink_dump(struct sock *sk)
        len = cb->dump(skb, cb);
 
        if (len > 0) {
-               spin_unlock(&nlk->cb_lock);
+               mutex_unlock(nlk->cb_mutex);
                skb_queue_tail(&sk->sk_receive_queue, skb);
                sk->sk_data_ready(sk, len);
                return 0;
@@ -1376,13 +1384,13 @@ static int netlink_dump(struct sock *sk)
        if (cb->done)
                cb->done(cb);
        nlk->cb = NULL;
-       spin_unlock(&nlk->cb_lock);
+       mutex_unlock(nlk->cb_mutex);
 
        netlink_destroy_callback(cb);
        return 0;
 
 errout_skb:
-       spin_unlock(&nlk->cb_lock);
+       mutex_unlock(nlk->cb_mutex);
        kfree_skb(skb);
 errout:
        return err;
@@ -1414,15 +1422,15 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
        }
        nlk = nlk_sk(sk);
        /* A dump or destruction is in progress... */
-       spin_lock(&nlk->cb_lock);
+       mutex_lock(nlk->cb_mutex);
        if (nlk->cb || sock_flag(sk, SOCK_DEAD)) {
-               spin_unlock(&nlk->cb_lock);
+               mutex_unlock(nlk->cb_mutex);
                netlink_destroy_callback(cb);
                sock_put(sk);
                return -EBUSY;
        }
        nlk->cb = cb;
-       spin_unlock(&nlk->cb_lock);
+       mutex_unlock(nlk->cb_mutex);
 
        netlink_dump(sk);
        sock_put(sk);