tcp: Fix recvmsg MSG_PEEK influence of blocking behavior.

Vito Caputo noticed that tcp_recvmsg() returns immediately from
partial reads when MSG_PEEK is used.  In particular, this means that
SO_RCVLOWAT is not respected.

Simply remove the test.  And this matches the behavior of several
other systems, including BSD.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 2 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index eccb7165a80c..c5aca0bb116a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1374,8 +1374,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                             sk->sk_state == TCP_CLOSE ||
                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
                             !timeo ||
-                            signal_pending(current) ||
-                            (flags & MSG_PEEK))
+                            signal_pending(current))
                                 break;
                 } else {
                         if (sock_flag(sk, SOCK_DONE))