net/appletalk: push down BKL into a atalk_dgram_ops

Making the BKL usage explicit in appletalk makes it more
obvious where it is used, reduces code size and helps
getting rid of the BKL in common code.

I did not analyse how to kill lock_kernel from appletalk
entirely, this will involve either proving that it's not
needed, or replacing with a proper mutex or spinlock,
after finding out which data structures are protected
by the lock.

Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 77 insertions, 28 deletions

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 7cd08b45c52b..31fca64d17a2 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1055,11 +1055,13 @@ static int atalk_release(struct socket *sock)
 {
         struct sock *sk = sock->sk;
 
+        lock_kernel();
         if (sk) {
                 sock_orphan(sk);
                 sock->sk = NULL;
                 atalk_destroy_socket(sk);
         }
+        unlock_kernel();
         return 0;
 }
 
@@ -1135,6 +1137,7 @@ static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
         struct sock *sk = sock->sk;
         struct atalk_sock *at = at_sk(sk);
+        int err;
 
         if (!sock_flag(sk, SOCK_ZAPPED) ||
             addr_len != sizeof(struct sockaddr_at))
@@ -1143,37 +1146,44 @@ static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
         if (addr->sat_family != AF_APPLETALK)
                 return -EAFNOSUPPORT;
 
+        lock_kernel();
         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
                 struct atalk_addr *ap = atalk_find_primary();
 
+                err = -EADDRNOTAVAIL;
                 if (!ap)
-                        return -EADDRNOTAVAIL;
+                        goto out;
 
                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
                 at->src_node = addr->sat_addr.s_node= ap->s_node;
         } else {
+                err = -EADDRNOTAVAIL;
                 if (!atalk_find_interface(addr->sat_addr.s_net,
                                           addr->sat_addr.s_node))
-                        return -EADDRNOTAVAIL;
+                        goto out;
 
                 at->src_net  = addr->sat_addr.s_net;
                 at->src_node = addr->sat_addr.s_node;
         }
 
         if (addr->sat_port == ATADDR_ANYPORT) {
-                int n = atalk_pick_and_bind_port(sk, addr);
+                err = atalk_pick_and_bind_port(sk, addr);
 
-                if (n < 0)
-                        return n;
+                if (err < 0)
+                        goto out;
         } else {
                 at->src_port = addr->sat_port;
 
+                err = -EADDRINUSE;
                 if (atalk_find_or_insert_socket(sk, addr))
-                        return -EADDRINUSE;
+                        goto out;
         }
 
         sock_reset_flag(sk, SOCK_ZAPPED);
-        return 0;
+        err = 0;
+out:
+        unlock_kernel();
+        return err;
 }
 
 /* Set the address we talk to */
@@ -1183,6 +1193,7 @@ static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
         struct sock *sk = sock->sk;
         struct atalk_sock *at = at_sk(sk);
         struct sockaddr_at *addr;
+        int err;
 
         sk->sk_state   = TCP_CLOSE;
         sock->state = SS_UNCONNECTED;
@@ -1207,12 +1218,15 @@ static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
 #endif
         }
 
+        lock_kernel();
+        err = -EBUSY;
         if (sock_flag(sk, SOCK_ZAPPED))
                 if (atalk_autobind(sk) < 0)
-                        return -EBUSY;
+                        goto out;
 
+        err = -ENETUNREACH;
         if (!atrtr_get_dev(&addr->sat_addr))
-                return -ENETUNREACH;
+                goto out;
 
         at->dest_port = addr->sat_port;
         at->dest_net  = addr->sat_addr.s_net;
@@ -1220,7 +1234,10 @@ static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
 
         sock->state  = SS_CONNECTED;
         sk->sk_state = TCP_ESTABLISHED;
-        return 0;
+        err = 0;
+out:
+        unlock_kernel();
+        return err;
 }
 
 /*
@@ -1233,17 +1250,21 @@ static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
         struct sockaddr_at sat;
         struct sock *sk = sock->sk;
         struct atalk_sock *at = at_sk(sk);
+        int err;
 
+        lock_kernel();
+        err = -ENOBUFS;
         if (sock_flag(sk, SOCK_ZAPPED))
                 if (atalk_autobind(sk) < 0)
-                        return -ENOBUFS;
+                        goto out;
 
         *uaddr_len = sizeof(struct sockaddr_at);
         memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
 
         if (peer) {
+                err = -ENOTCONN;
                 if (sk->sk_state != TCP_ESTABLISHED)
-                        return -ENOTCONN;
+                        goto out;
 
                 sat.sat_addr.s_net  = at->dest_net;
                 sat.sat_addr.s_node = at->dest_node;
@@ -1254,9 +1275,23 @@ static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
                 sat.sat_port        = at->src_port;
         }
 
+        err = 0;
         sat.sat_family = AF_APPLETALK;
         memcpy(uaddr, &sat, sizeof(sat));
-        return 0;
+
+out:
+        unlock_kernel();
+        return err;
+}
+
+static unsigned int atalk_poll(struct file *file, struct socket *sock,
+                           poll_table *wait)
+{
+        int err;
+        lock_kernel();
+        err = datagram_poll(file, sock, wait);
+        unlock_kernel();
+        return err;
 }
 
 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
@@ -1564,23 +1599,28 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
         if (len > DDP_MAXSZ)
                 return -EMSGSIZE;
 
+        lock_kernel();
         if (usat) {
+                err = -EBUSY;
                 if (sock_flag(sk, SOCK_ZAPPED))
                         if (atalk_autobind(sk) < 0)
-                                return -EBUSY;
+                                goto out;
 
+                err = -EINVAL;
                 if (msg->msg_namelen < sizeof(*usat) ||
                     usat->sat_family != AF_APPLETALK)
-                        return -EINVAL;
+                        goto out;
 
+                err = -EPERM;
                 /* netatalk didn't implement this check */
                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
                     !sock_flag(sk, SOCK_BROADCAST)) {
-                        return -EPERM;
+                        goto out;
                 }
         } else {
+                err = -ENOTCONN;
                 if (sk->sk_state != TCP_ESTABLISHED)
-                        return -ENOTCONN;
+                        goto out;
                 usat = &local_satalk;
                 usat->sat_family      = AF_APPLETALK;
                 usat->sat_port        = at->dest_port;
@@ -1604,8 +1644,9 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
 
                 rt = atrtr_find(&at_hint);
         }
+        err = ENETUNREACH;
         if (!rt)
-                return -ENETUNREACH;
+                goto out;
 
         dev = rt->dev;
 
@@ -1615,7 +1656,7 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
         size += dev->hard_header_len;
         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
         if (!skb)
-                return err;
+                goto out;
 
         skb->sk = sk;
         skb_reserve(skb, ddp_dl->header_length);
@@ -1638,7 +1679,8 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
         if (err) {
                 kfree_skb(skb);
-                return -EFAULT;
+                err = -EFAULT;
+                goto out;
         }
 
         if (sk->sk_no_check == 1)
@@ -1677,7 +1719,8 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
                         rt = atrtr_find(&at_lo);
                         if (!rt) {
                                 kfree_skb(skb);
-                                return -ENETUNREACH;
+                                err = -ENETUNREACH;
+                                goto out;
                         }
                         dev = rt->dev;
                         skb->dev = dev;
@@ -1697,7 +1740,9 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
         }
         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
 
-        return len;
+out:
+        unlock_kernel();
+        return err ? : len;
 }
 
 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
@@ -1709,10 +1754,13 @@ static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
         int copied = 0;
         int offset = 0;
         int err = 0;
-        struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
+        struct sk_buff *skb;
+
+        lock_kernel();
+        skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
                                                 flags & MSG_DONTWAIT, &err);
         if (!skb)
-                return err;
+                goto out;
 
         /* FIXME: use skb->cb to be able to use shared skbs */
         ddp = ddp_hdr(skb);
@@ -1740,6 +1788,9 @@ static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
         }
 
         skb_free_datagram(sk, skb);     /* Free the datagram. */
+
+out:
+        unlock_kernel();
         return err ? : copied;
 }
 
@@ -1830,7 +1881,7 @@ static const struct net_proto_family atalk_family_ops = {
         .owner          = THIS_MODULE,
 };
 
-static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
+static const struct proto_ops atalk_dgram_ops = {
         .family         = PF_APPLETALK,
         .owner          = THIS_MODULE,
         .release        = atalk_release,
@@ -1839,7 +1890,7 @@ static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
         .socketpair     = sock_no_socketpair,
         .accept         = sock_no_accept,
         .getname        = atalk_getname,
-        .poll           = datagram_poll,
+        .poll           = atalk_poll,
         .ioctl          = atalk_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = atalk_compat_ioctl,
@@ -1854,8 +1905,6 @@ static const struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
         .sendpage       = sock_no_sendpage,
 };
 
-SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
-
 static struct notifier_block ddp_notifier = {
         .notifier_call  = ddp_device_event,
 };