net/smc: serialize connection creation in all cases

If a link group for a new server connection exists already, the mutex
serializing the determination of link groups is given up early.
The coming registration of memory regions benefits from the serialization
as well, if the mutex is held till connection creation is finished.
This patch postpones the unlocking of the link group creation mutex.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 6793d73..120a7b9 100644 (file)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -779,11 +779,6 @@ static void smc_listen_work(struct work_struct *work)
        mutex_lock(&smc_create_lgr_pending);
        local_contact = smc_conn_create(new_smc, peeraddr.sin_addr.s_addr,
                                        smcibdev, ibport, &pclc.lcl, 0);
-       if (local_contact == SMC_REUSE_CONTACT)
-               /* lock no longer needed, free it due to following
-                * smc_clc_wait_msg() call
-                */
-               mutex_unlock(&smc_create_lgr_pending);
        if (local_contact < 0) {
                rc = local_contact;
                if (rc == -ENOMEM)
@@ -853,8 +848,7 @@ out_connected:
        if (newsmcsk->sk_state == SMC_INIT)
                newsmcsk->sk_state = SMC_ACTIVE;
 enqueue:
-       if (local_contact == SMC_FIRST_CONTACT)
-               mutex_unlock(&smc_create_lgr_pending);
+       mutex_unlock(&smc_create_lgr_pending);
        lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
        if (lsmc->sk.sk_state == SMC_LISTEN) {
                smc_accept_enqueue(&lsmc->sk, newsmcsk);