From patchwork Mon Jul 12 06:08:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 474293 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C76A9C07E99 for ; Mon, 12 Jul 2021 06:42:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B13026113B for ; Mon, 12 Jul 2021 06:42:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235179AbhGLGpP (ORCPT ); Mon, 12 Jul 2021 02:45:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:39704 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238954AbhGLGob (ORCPT ); Mon, 12 Jul 2021 02:44:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5845961008; Mon, 12 Jul 2021 06:40:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626072027; bh=MZzqfv3cG0jwKxocEjfCzBeR/+AZnBvF9fr5yZCQoZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WrR3LkDYM5URW0O+q9tfj6gqDyf9efacARuTq/xXRLBSPgNAxcr/bSzoImOCfuVKU 4SGN1zF4tGpz8PAsbU35Ey7r7keF3T4fdarqitfNNWwzhmrzkxj82o+WzwTtoPQJNS EipH4sJgyPxvzuWyvC9USXbe4w6MQRbGNHpO0tjc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Md Haris Iqbal , Gioh Kim , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.10 322/593] RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading its stats Date: Mon, 12 Jul 2021 08:08:02 +0200 Message-Id: <20210712060921.052077478@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060843.180606720@linuxfoundation.org> References: <20210712060843.180606720@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Md Haris Iqbal [ Upstream commit 41db63a7efe1c8c2dd282c1849a6ebfbbedbaf67 ] When get_next_path_min_inflight is called to select the next path, it iterates over the list of available rtrs_clt_sess (paths). It then reads the number of inflight IOs for that path to select one which has the least inflight IO. But it may so happen that rtrs_clt_sess (path) is no longer in the connected state because closing or error recovery paths can change the status of the rtrs_clt_Sess. For example, the client sent the heart-beat and did not get the response, it would change the session status and stop IO processing. The added checking of this patch can prevent accessing the broken path and generating duplicated error messages. It is ok if the status is changed after checking the status because the error recovery path does not free memory and only tries to reconnection. And also it is ok if the session is closed after checking the status because closing the session changes the session status and flush all IO beforing free memory. If the session is being accessed for IO processing, the closing session will wait. Fixes: 6a98d71daea18 ("RDMA/rtrs: client: main functionality") Link: https://lore.kernel.org/r/20210528113018.52290-13-jinpu.wang@ionos.com Signed-off-by: Md Haris Iqbal Reviewed-by: Gioh Kim Signed-off-by: Gioh Kim Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/ulp/rtrs/rtrs-clt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c index 7db550ba25d7..7d7dcc0a0458 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c @@ -811,6 +811,9 @@ static struct rtrs_clt_sess *get_next_path_min_inflight(struct path_it *it) int inflight; list_for_each_entry_rcu(sess, &clt->paths_list, s.entry) { + if (unlikely(READ_ONCE(sess->state) != RTRS_CLT_CONNECTED)) + continue; + if (unlikely(!list_empty(raw_cpu_ptr(sess->mp_skip_entry)))) continue;