From 9ed28556a388fdb894bdf9bd64c05cf6e7783ba3 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Thu, 22 Nov 2018 10:26:37 +0100 Subject: [PATCH] net/smc: allow fallback after clc timeouts If connection initialization fails for the LLC CONFIRM LINK or the LLC ADD LINK step, fallback to TCP should be enabled. Thus the negative return code -EAGAIN should switch to a positive timeout reason code in these cases, and the internal CLC socket should not have a set sk_err. Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/af_smc.c | 8 ++++---- net/smc/smc_clc.c | 9 +++++++-- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index d9b1a0e..66836cf 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -336,7 +336,7 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc) rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc), SMC_CLC_DECLINE); - return rc; + return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc; } if (link->llc_confirm_rc) @@ -364,7 +364,7 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc) rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc), SMC_CLC_DECLINE); - return rc; + return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc; } /* send add link reject message, only one link supported for now */ @@ -966,7 +966,7 @@ static int smc_serv_conf_first_link(struct smc_sock *smc) rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc), SMC_CLC_DECLINE); - return rc; + return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc; } if (link->llc_confirm_resp_rc) @@ -987,7 +987,7 @@ static int smc_serv_conf_first_link(struct smc_sock *smc) rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc), SMC_CLC_DECLINE); - return rc; + return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc; } smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time); diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c index 7278ec0..62043d6 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -297,7 +297,11 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen, } if (clc_sk->sk_err) { reason_code = -clc_sk->sk_err; - smc->sk.sk_err = clc_sk->sk_err; + if (clc_sk->sk_err == EAGAIN && + expected_type == SMC_CLC_DECLINE) + clc_sk->sk_err = 0; /* reset for fallback usage */ + else + smc->sk.sk_err = clc_sk->sk_err; goto out; } if (!len) { /* peer has performed orderly shutdown */ @@ -306,7 +310,8 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen, goto out; } if (len < 0) { - smc->sk.sk_err = -len; + if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE) + smc->sk.sk_err = -len; reason_code = len; goto out; } -- 2.7.4