From patchwork Wed Mar 2 13:16:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 12765982 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82CF9C43219 for ; Wed, 2 Mar 2022 13:16:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242097AbiCBNQ7 (ORCPT ); Wed, 2 Mar 2022 08:16:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241136AbiCBNQ6 (ORCPT ); Wed, 2 Mar 2022 08:16:58 -0500 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DB4DC3C2C; Wed, 2 Mar 2022 05:16:13 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0V632axy_1646226970; Received: from localhost(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0V632axy_1646226970) by smtp.aliyun-inc.com(127.0.0.1); Wed, 02 Mar 2022 21:16:11 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH net v2 2/2] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error cause by server Date: Wed, 2 Mar 2022 21:16:08 +0800 Message-Id: <1646226968-2315-3-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1646226968-2315-2-git-send-email-alibuda@linux.alibaba.com> References: <1646226968-2315-1-git-send-email-alibuda@linux.alibaba.com> <1646226968-2315-2-git-send-email-alibuda@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: "D. Wythe" The problem of SMC_CLC_DECL_ERR_REGRMB on the server is very clear. Based on the fact that whether a new SMC connection can be accepted or not depends on not only the limit of conn nums, but also the available entries of rtoken. Since the rtoken release is trigger by peer, while the conn nums is decrease by local, tons of thing can happen in this time difference. This only thing that needs to be mentioned is that now all connection creations are completely protected by smc_server_lgr_pending lock, it's enough to check only the available entries in rtokens_used_mask. Fixes: cd6851f30386 ("smc: remote memory buffers (RMBs)") Signed-off-by: D. Wythe --- net/smc/smc_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index f8c9675..be7d704 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1864,7 +1864,8 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) (ini->smcd_version == SMC_V2 || lgr->vlan_id == ini->vlan_id) && (role == SMC_CLNT || ini->is_smcd || - lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) { + (lgr->conns_num < SMC_RMBS_PER_LGR_MAX && + !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) { /* link group found */ ini->first_contact_local = 0; conn->lgr = lgr;