From patchwork Wed Sep 6 13:55:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13375669 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 B8C62EB8FD5 for ; Wed, 6 Sep 2023 13:55:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241271AbjIFNzr (ORCPT ); Wed, 6 Sep 2023 09:55:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241262AbjIFNzr (ORCPT ); Wed, 6 Sep 2023 09:55:47 -0400 Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50AA61B6; Wed, 6 Sep 2023 06:55:42 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=alibuda@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0VrU7-xt_1694008537; Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0VrU7-xt_1694008537) by smtp.aliyun-inc.com; Wed, 06 Sep 2023 21:55:39 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@linux.ibm.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org, "D. Wythe" Subject: [RFC net-next 1/2] net/smc: refactoring lgr pending lock Date: Wed, 6 Sep 2023 21:55:29 +0800 Message-Id: <1694008530-85087-2-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1694008530-85087-1-git-send-email-alibuda@linux.alibaba.com> References: <1694008530-85087-1-git-send-email-alibuda@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "D. Wythe" This patch replaces the locking and unlocking of lgr pending with a unified inline function, and since the granularity of lgr pending lock is within the lifecycle of init_info, which make it possible to record the lock state on init_info. So that other routines can unlock lgr pending lock safely. Signed-off-by: D. Wythe --- net/smc/af_smc.c | 24 ++++++++++++------------ net/smc/smc_core.h | 21 +++++++++++++++++++++ 2 files changed, 33 insertions(+), 12 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index bacdd97..52a987b 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1251,10 +1251,10 @@ static int smc_connect_rdma(struct smc_sock *smc, if (reason_code) return reason_code; - mutex_lock(&smc_client_lgr_pending); + smc_lgr_pending_lock(ini, &smc_client_lgr_pending); reason_code = smc_conn_create(smc, ini); if (reason_code) { - mutex_unlock(&smc_client_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_client_lgr_pending); return reason_code; } @@ -1346,7 +1346,7 @@ static int smc_connect_rdma(struct smc_sock *smc, if (reason_code) goto connect_abort; } - mutex_unlock(&smc_client_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_client_lgr_pending); smc_copy_sock_settings_to_clc(smc); smc->connect_nonblock = 0; @@ -1356,7 +1356,7 @@ static int smc_connect_rdma(struct smc_sock *smc, return 0; connect_abort: smc_conn_abort(smc, ini->first_contact_local); - mutex_unlock(&smc_client_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_client_lgr_pending); smc->connect_nonblock = 0; return reason_code; @@ -1413,10 +1413,10 @@ static int smc_connect_ism(struct smc_sock *smc, ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid; /* there is only one lgr role for SMC-D; use server lock */ - mutex_lock(&smc_server_lgr_pending); + smc_lgr_pending_lock(ini, &smc_server_lgr_pending); rc = smc_conn_create(smc, ini); if (rc) { - mutex_unlock(&smc_server_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_server_lgr_pending); return rc; } @@ -1443,7 +1443,7 @@ static int smc_connect_ism(struct smc_sock *smc, aclc->hdr.version, eid, ini); if (rc) goto connect_abort; - mutex_unlock(&smc_server_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_server_lgr_pending); smc_copy_sock_settings_to_clc(smc); smc->connect_nonblock = 0; @@ -1453,7 +1453,7 @@ static int smc_connect_ism(struct smc_sock *smc, return 0; connect_abort: smc_conn_abort(smc, ini->first_contact_local); - mutex_unlock(&smc_server_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_server_lgr_pending); smc->connect_nonblock = 0; return rc; @@ -2460,7 +2460,7 @@ static void smc_listen_work(struct work_struct *work) if (rc) goto out_decl; - mutex_lock(&smc_server_lgr_pending); + smc_lgr_pending_lock(ini, &smc_server_lgr_pending); smc_close_init(new_smc); smc_rx_init(new_smc); smc_tx_init(new_smc); @@ -2479,7 +2479,7 @@ static void smc_listen_work(struct work_struct *work) /* SMC-D does not need this lock any more */ if (ini->is_smcd) - mutex_unlock(&smc_server_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_server_lgr_pending); /* receive SMC Confirm CLC message */ memset(buf, 0, sizeof(*buf)); @@ -2510,7 +2510,7 @@ static void smc_listen_work(struct work_struct *work) ini->first_contact_local, ini); if (rc) goto out_unlock; - mutex_unlock(&smc_server_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_server_lgr_pending); } smc_conn_save_peer_info(new_smc, cclc); smc_listen_out_connected(new_smc); @@ -2518,7 +2518,7 @@ static void smc_listen_work(struct work_struct *work) goto out_free; out_unlock: - mutex_unlock(&smc_server_lgr_pending); + smc_lgr_pending_unlock(ini, &smc_server_lgr_pending); out_decl: smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0, proposal_version); diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 120027d..6f309a3 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -422,6 +422,8 @@ struct smc_init_info { u8 ism_offered_cnt; /* # of ISM devices offered */ u8 ism_selected; /* index of selected ISM dev*/ u8 smcd_version; + /* mutex holding for conn create */ + struct mutex *mutex; }; /* Find the connection associated with the given alert token in the link group. @@ -589,6 +591,25 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb); int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb); +static inline void smc_lgr_pending_lock(struct smc_init_info *ini, struct mutex *lock) +{ + if (unlikely(ini->mutex)) + pr_warn_once("smc: lgr pending deadlock dected."); + + mutex_lock(lock); + ini->mutex = lock; +} + +static inline void smc_lgr_pending_unlock(struct smc_init_info *ini, struct mutex *lock) +{ + /* already unlock it */ + if (!ini->mutex) + return; + + ini->mutex = NULL; + mutex_unlock(lock); +} + static inline struct smc_link_group *smc_get_lgr(struct smc_link *link) { return link->lgr;