From patchwork Tue Feb 9 00:54:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Simmons X-Patchwork-Id: 12076931 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=-16.8 required=3.0 tests=BAYES_00, 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 CF6D2C433DB for ; Tue, 9 Feb 2021 00:54:46 +0000 (UTC) Received: from pdx1-mailman02.dreamhost.com (pdx1-mailman02.dreamhost.com [64.90.62.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 826B364E77 for ; Tue, 9 Feb 2021 00:54:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 826B364E77 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lustre-devel-bounces@lists.lustre.org Received: from pdx1-mailman02.dreamhost.com (localhost [IPv6:::1]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 83AD730FACE; Mon, 8 Feb 2021 16:54:41 -0800 (PST) Received: from smtp4.ccs.ornl.gov (smtp4.ccs.ornl.gov [160.91.203.40]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 3B5E630F758 for ; Mon, 8 Feb 2021 16:54:31 -0800 (PST) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp4.ccs.ornl.gov (Postfix) with ESMTP id ECAD11006EBA; Mon, 8 Feb 2021 19:54:28 -0500 (EST) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id E7B394CC36; Mon, 8 Feb 2021 19:54:28 -0500 (EST) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Mon, 8 Feb 2021 19:54:21 -0500 Message-Id: <1612832067-1449-4-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1612832067-1449-1-git-send-email-jsimmons@infradead.org> References: <1612832067-1449-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH 3/9] lustre: obdclass: connect vs disconnect race X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wang Shilong , Lustre Development List MIME-Version: 1.0 Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" From: Wang Shilong There might be a possible race if setup (connect) and cleanup (disconnect) are tangled together(similar comments in osc_disconnect()): Thread1: Thread2: connecting class_cleanup ptlrpc_connect_interpret obd->obd_setup = 0 obd_import_event if (obd->obd_set_up) osc_init_grant() /*skipped*/ ptlrpc_activate_import.. And If RPC was waked up and send out before class_disconnect_exports(), It might hit divide zero crash in osc_announce_cached() because @cl_max_extent_pages is zero. The problem is we clear @obd_setup too early, It should be cleared when OBD is really shutdown. Fixes: cfd750 ("lustre: obdclass: obd_device improvement") WC-bug-id: https://jira.whamcloud.com/browse/LU-14283 Lustre-commit: 4f689a30fb5d870 ("LU-14283 obdclass: connect vs disconnect race") Signed-off-by: Wang Shilong Reviewed-on: https://review.whamcloud.com/41256 Reviewed-by: Sebastien Buisson Reviewed-by: Andreas Dilger Reviewed-by: John L. Hammond Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/obdclass/obd_config.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/fs/lustre/obdclass/obd_config.c b/fs/lustre/obdclass/obd_config.c index 09dee7b..8f062bb 100644 --- a/fs/lustre/obdclass/obd_config.c +++ b/fs/lustre/obdclass/obd_config.c @@ -467,10 +467,6 @@ static int class_cleanup(struct obd_device *obd, struct lustre_cfg *lcfg) } /* Leave this on forever */ obd->obd_stopping = 1; - /* function can't return error after that point, so clear setup flag - * as early as possible to avoid finding via obd_devs / hash - */ - obd->obd_set_up = 0; spin_unlock(&obd->obd_dev_lock); while (obd->obd_conn_inprogress > 0)