From: Hans Wippel <hwippel@xxxxxxxxxxxxx>
If SMC client and server connections are both established at the same
time, smc_connect_ism() cannot send a CLC confirm message while
smc_listen_work() is waiting for one due to lock contention. This can
result in timeouts in smc_clc_wait_msg() and failed SMC connections.
In case of SMC-D, the LGR pending lock is not needed while
smc_listen_work() is waiting for the CLC confirm message. So, this patch
releases the lock earlier for SMC-D to avoid the locking issue.
Signed-off-by: Hans Wippel <hwippel@xxxxxxxxxxxxx>
Signed-off-by: Ursula Braun <ubraun@xxxxxxxxxxxxx>
---
net/smc/af_smc.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 60ccc8f50368..cf49ed05007b 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1287,24 +1287,28 @@ static void smc_listen_work(struct work_struct *work)
return;
}
+ /* SMC-D does not need this lock any more */
+ if (ism_supported)
+ mutex_unlock(&smc_create_lgr_pending);
+
/* receive SMC Confirm CLC message */
reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
SMC_CLC_CONFIRM, CLC_WAIT_TIME);
if (reason_code) {
- mutex_unlock(&smc_create_lgr_pending);
+ if (!ism_supported)
+ mutex_unlock(&smc_create_lgr_pending);
smc_listen_decline(new_smc, reason_code, local_contact);
return;
}
/* finish worker */
if (!ism_supported) {
- if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) {
- mutex_unlock(&smc_create_lgr_pending);
+ rc = smc_listen_rdma_finish(new_smc, &cclc, local_contact);
+ mutex_unlock(&smc_create_lgr_pending);
+ if (rc)
return;
- }
}
smc_conn_save_peer_info(new_smc, &cclc);
- mutex_unlock(&smc_create_lgr_pending);
smc_listen_out_connected(new_smc);
}
--
2.16.4
