diff options
| author | Hans Wippel <hwippel@linux.ibm.com> | 2019-02-07 15:56:17 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-02-07 18:06:18 -0800 |
| commit | 62c7139f3ed011379fbbef832b4b15e3c10b355f (patch) | |
| tree | 6e95eaae911df9dfc3463d26fe6af865d6eff5e0 /net | |
| parent | a225d2cd88d3303e7c6d1481578a4f23d5f92350 (diff) | |
| download | lwn-62c7139f3ed011379fbbef832b4b15e3c10b355f.tar.gz lwn-62c7139f3ed011379fbbef832b4b15e3c10b355f.zip | |
net/smc: unlock LGR pending lock earlier for SMC-D
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@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/smc/af_smc.c | 14 |
1 files 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); } |