smc: fix sendpage() call

[ Upstream commit bda27ff5c4526f80a7620a94ecfe8dca153e3696 ]

The sendpage() call grabs the sock lock before calling the default
implementation - which tries to grab it once again.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 5a983c9bea53f82c58872bcfe04305a4265bc706..0132c08b06808ef91abd0ca07855a5d122d0b3cd 100644 (file)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1313,8 +1313,11 @@ static ssize_t smc_sendpage(struct socket *sock, struct page *page,
 
        smc = smc_sk(sk);
        lock_sock(sk);
-       if (sk->sk_state != SMC_ACTIVE)
+       if (sk->sk_state != SMC_ACTIVE) {
+               release_sock(sk);
                goto out;
+       }
+       release_sock(sk);
        if (smc->use_fallback)
                rc = kernel_sendpage(smc->clcsock, page, offset,
                                     size, flags);
@@ -1322,7 +1325,6 @@ static ssize_t smc_sendpage(struct socket *sock, struct page *page,
                rc = sock_no_sendpage(sock, page, offset, size, flags);
 
 out:
-       release_sock(sk);
        return rc;
 }