From patchwork Mon Jul 12 06:07:46 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: 475756 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 EA50DC07E9C for ; Mon, 12 Jul 2021 07:12:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA8AA610CA for ; Mon, 12 Jul 2021 07:12:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242977AbhGLHP0 (ORCPT ); Mon, 12 Jul 2021 03:15:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:48022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240067AbhGLHOA (ORCPT ); Mon, 12 Jul 2021 03:14:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8CA0D61151; Mon, 12 Jul 2021 07:11:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626073861; bh=ZHPtdMtLw+LRQMoNHxOGGo1Ztxl6VU7JJPy7gPvtOSA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cm8cKMckuf2PgEad02UpJ/gJmRoN6BwxKVHL77AOqk35k0lO/EoA7+6mw9nh2xvl0 GxRLmCr491TFmTsGM8R8PfAs7K3R/YeM+WFYxjFV7ILe8Ojkup2KtdJ2BL3MrCn60L lo50biayHLvs2M7hOulsDr0Y4H/ddXar8hDxx4VU= 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 5.12 383/700] RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading its stats Date: Mon, 12 Jul 2021 08:07:46 +0200 Message-Id: <20210712061017.119323222@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@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 959ba0462ef0..cb6f5c7610a0 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c @@ -805,6 +805,9 @@ 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;