diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-05-26 19:20:18 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-05-27 00:30:53 -0700 |
| commit | 8a74ad60a546b13bd1096b2a61a7a5c6fd9ae17c (patch) | |
| tree | 3110e7e59883597b5d0f617e8507e15b8f965f3f /net/ipv4 | |
| parent | a56635a56f2afb3d22d9ce07e8f8d69537416b2d (diff) | |
net: fix lock_sock_bh/unlock_sock_bh
This new sock lock primitive was introduced to speedup some user context
socket manipulation. But it is unsafe to protect two threads, one using
regular lock_sock/release_sock, one using lock_sock_bh/unlock_sock_bh
This patch changes lock_sock_bh to be careful against 'owned' state.
If owned is found to be set, we must take the slow path.
lock_sock_bh() now returns a boolean to say if the slow path was taken,
and this boolean is used at unlock_sock_bh time to call the appropriate
unlock function.
After this change, BH are either disabled or enabled during the
lock_sock_bh/unlock_sock_bh protected section. This might be misleading,
so we rename these functions to lock_sock_fast()/unlock_sock_fast().
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/udp.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 9de6a698f91..b9d0d409516 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1063,10 +1063,11 @@ static unsigned int first_packet_length(struct sock *sk) spin_unlock_bh(&rcvq->lock); if (!skb_queue_empty(&list_kill)) { - lock_sock_bh(sk); + bool slow = lock_sock_fast(sk); + __skb_queue_purge(&list_kill); sk_mem_reclaim_partial(sk); - unlock_sock_bh(sk); + unlock_sock_fast(sk, slow); } return res; } @@ -1123,6 +1124,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, int peeked; int err; int is_udplite = IS_UDPLITE(sk); + bool slow; /* * Check any passed addresses @@ -1197,10 +1199,10 @@ out: return err; csum_copy_err: - lock_sock_bh(sk); + slow = lock_sock_fast(sk); if (!skb_kill_datagram(sk, skb, flags)) UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); - unlock_sock_bh(sk); + unlock_sock_fast(sk, slow); if (noblock) return -EAGAIN; @@ -1625,9 +1627,9 @@ int udp_rcv(struct sk_buff *skb) void udp_destroy_sock(struct sock *sk) { - lock_sock_bh(sk); + bool slow = lock_sock_fast(sk); udp_flush_pending_frames(sk); - unlock_sock_bh(sk); + unlock_sock_fast(sk, slow); } /* |