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authorArnd Bergmann <arnd@arndb.de>2011-01-22 23:44:59 +0100
committerArnd Bergmann <arnd@arndb.de>2011-03-05 10:55:45 +0100
commit77b2283604bdd7053494a97b0e2fee97148206c6 (patch)
tree4d5c54156d64fd80de765cc18dc7e4a68b5ec5e1 /net/x25/af_x25.c
parent788257d6101d986ac8f2741aaa35974af47f574c (diff)
x25: remove the BKL
This replaces all instances of lock_kernel in x25 with lock_sock, taking care to release the socket lock around sleeping functions (sock_alloc_send_skb and skb_recv_datagram). It is not clear whether this is a correct solution, but it seem to be what other protocols do in the same situation. Includes a fix suggested by Eric Dumazet. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Hendry <andrew.hendry@gmail.com> Cc: linux-x25@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Eric Dumazet <eric.dumazet@gmail.com>
Diffstat (limited to 'net/x25/af_x25.c')
-rw-r--r--net/x25/af_x25.c58
1 files changed, 18 insertions, 40 deletions
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index ad96ee90fe27..4680b1e4c79c 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -40,7 +40,6 @@
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
-#include <linux/smp_lock.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/net.h>
@@ -432,15 +431,6 @@ void x25_destroy_socket_from_timer(struct sock *sk)
sock_put(sk);
}
-static void x25_destroy_socket(struct sock *sk)
-{
- sock_hold(sk);
- lock_sock(sk);
- __x25_destroy_socket(sk);
- release_sock(sk);
- sock_put(sk);
-}
-
/*
* Handling for system calls applied via the various interfaces to a
* X.25 socket object.
@@ -647,18 +637,19 @@ static int x25_release(struct socket *sock)
struct sock *sk = sock->sk;
struct x25_sock *x25;
- lock_kernel();
if (!sk)
- goto out;
+ return 0;
x25 = x25_sk(sk);
+ sock_hold(sk);
+ lock_sock(sk);
switch (x25->state) {
case X25_STATE_0:
case X25_STATE_2:
x25_disconnect(sk, 0, 0, 0);
- x25_destroy_socket(sk);
+ __x25_destroy_socket(sk);
goto out;
case X25_STATE_1:
@@ -678,7 +669,8 @@ static int x25_release(struct socket *sock)
sock_orphan(sk);
out:
- unlock_kernel();
+ release_sock(sk);
+ sock_put(sk);
return 0;
}
@@ -1085,7 +1077,7 @@ static int x25_sendmsg(struct kiocb *iocb, struct socket *sock,
size_t size;
int qbit = 0, rc = -EINVAL;
- lock_kernel();
+ lock_sock(sk);
if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
goto out;
@@ -1148,7 +1140,9 @@ static int x25_sendmsg(struct kiocb *iocb, struct socket *sock,
size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
+ release_sock(sk);
skb = sock_alloc_send_skb(sk, size, noblock, &rc);
+ lock_sock(sk);
if (!skb)
goto out;
X25_SKB_CB(skb)->flags = msg->msg_flags;
@@ -1231,26 +1225,10 @@ static int x25_sendmsg(struct kiocb *iocb, struct socket *sock,
len++;
}
- /*
- * lock_sock() is currently only used to serialize this x25_kick()
- * against input-driven x25_kick() calls. It currently only blocks
- * incoming packets for this socket and does not protect against
- * any other socket state changes and is not called from anywhere
- * else. As x25_kick() cannot block and as long as all socket
- * operations are BKL-wrapped, we don't need take to care about
- * purging the backlog queue in x25_release().
- *
- * Using lock_sock() to protect all socket operations entirely
- * (and making the whole x25 stack SMP aware) unfortunately would
- * require major changes to {send,recv}msg and skb allocation methods.
- * -> 2.5 ;)
- */
- lock_sock(sk);
x25_kick(sk);
- release_sock(sk);
rc = len;
out:
- unlock_kernel();
+ release_sock(sk);
return rc;
out_kfree_skb:
kfree_skb(skb);
@@ -1271,7 +1249,7 @@ static int x25_recvmsg(struct kiocb *iocb, struct socket *sock,
unsigned char *asmptr;
int rc = -ENOTCONN;
- lock_kernel();
+ lock_sock(sk);
/*
* This works for seqpacket too. The receiver has ordered the queue for
* us! We do one quick check first though
@@ -1300,8 +1278,10 @@ static int x25_recvmsg(struct kiocb *iocb, struct socket *sock,
msg->msg_flags |= MSG_OOB;
} else {
/* Now we can treat all alike */
+ release_sock(sk);
skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
flags & MSG_DONTWAIT, &rc);
+ lock_sock(sk);
if (!skb)
goto out;
@@ -1338,14 +1318,12 @@ static int x25_recvmsg(struct kiocb *iocb, struct socket *sock,
msg->msg_namelen = sizeof(struct sockaddr_x25);
- lock_sock(sk);
x25_check_rbuf(sk);
- release_sock(sk);
rc = copied;
out_free_dgram:
skb_free_datagram(sk, skb);
out:
- unlock_kernel();
+ release_sock(sk);
return rc;
}
@@ -1581,18 +1559,18 @@ out_cud_release:
case SIOCX25CALLACCPTAPPRV: {
rc = -EINVAL;
- lock_kernel();
+ lock_sock(sk);
if (sk->sk_state != TCP_CLOSE)
break;
clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
- unlock_kernel();
+ release_sock(sk);
rc = 0;
break;
}
case SIOCX25SENDCALLACCPT: {
rc = -EINVAL;
- lock_kernel();
+ lock_sock(sk);
if (sk->sk_state != TCP_ESTABLISHED)
break;
/* must call accptapprv above */
@@ -1600,7 +1578,7 @@ out_cud_release:
break;
x25_write_internal(sk, X25_CALL_ACCEPTED);
x25->state = X25_STATE_3;
- unlock_kernel();
+ release_sock(sk);
rc = 0;
break;
}