From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 A1371C43331 for ; Wed, 13 Nov 2019 02:19:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 773BD2084E for ; Wed, 13 Nov 2019 02:19:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573611592; bh=H98E+O2rGiNbR2/s9wKrb2qi+Flmw69WX72yGfxD1Vk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zeVsZHVHM15ea43YrIA1rVg4kTmwkTDl55N3fpusY/UKTQTXM2mTsdEATmremxYH0 os3IuecuraaVZeCecEc8DAHNJS6DbzJ1CJIt61SanhnfnunbHYbAt2jp61qhFR7ZYr AM3msQUG6cc19x3WzeHYhnulDHZyEkBef98USFeI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729513AbfKMCTv (ORCPT ); Tue, 12 Nov 2019 21:19:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:46432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728871AbfKMBzF (ORCPT ); Tue, 12 Nov 2019 20:55:05 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 43E8A222CD; Wed, 13 Nov 2019 01:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573610105; bh=H98E+O2rGiNbR2/s9wKrb2qi+Flmw69WX72yGfxD1Vk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XUDZZuFu7RLPU6x+4NIgmwo6NJVZmUlk21/0NF5L2lZMvVtcvutO97tcqNx2AAK+S Wz2UeUUXRsI0ZgbOHc2h4rVYNV/N7SomWrhdrO6OpiX21gT0LzQxxfGbz8TYMDln8g 4vqAE2tkWVSAt0nshqQlZQOA9mr4WQ0HyNNkfMLw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tim Smith , Mark Syms , Bob Peterson , Sasha Levin , cluster-devel@redhat.com Subject: [PATCH AUTOSEL 4.19 164/209] GFS2: Flush the GFS2 delete workqueue before stopping the kernel threads Date: Tue, 12 Nov 2019 20:49:40 -0500 Message-Id: <20191113015025.9685-164-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191113015025.9685-1-sashal@kernel.org> References: <20191113015025.9685-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tim Smith [ Upstream commit 1eb8d7387908022951792a46fa040ad3942b3b08 ] Flushing the workqueue can cause operations to happen which might call gfs2_log_reserve(), or get stuck waiting for locks taken by such operations. gfs2_log_reserve() can io_schedule(). If this happens, it will never wake because the only thing which can wake it is gfs2_logd() which was already stopped. This causes umount of a gfs2 filesystem to wedge permanently if, for example, the umount immediately follows a large delete operation. When this occured, the following stack trace was obtained from the umount command [] flush_workqueue+0x1c8/0x520 [] gfs2_make_fs_ro+0x69/0x160 [gfs2] [] gfs2_put_super+0xa9/0x1c0 [gfs2] [] generic_shutdown_super+0x6f/0x100 [] kill_block_super+0x27/0x70 [] gfs2_kill_sb+0x71/0x80 [gfs2] [] deactivate_locked_super+0x3b/0x70 [] deactivate_super+0x59/0x60 [] cleanup_mnt+0x58/0x80 [] __cleanup_mnt+0x12/0x20 [] task_work_run+0x7d/0xa0 [] exit_to_usermode_loop+0x73/0x98 [] syscall_return_slowpath+0x41/0x50 [] int_ret_from_sys_call+0x25/0x8f [] 0xffffffffffffffff Signed-off-by: Tim Smith Signed-off-by: Mark Syms Signed-off-by: Bob Peterson Signed-off-by: Sasha Levin --- fs/gfs2/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index c212893534ed6..a971862b186e3 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -854,10 +854,10 @@ static int gfs2_make_fs_ro(struct gfs2_sbd *sdp) if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) return error; + flush_workqueue(gfs2_delete_workqueue); kthread_stop(sdp->sd_quotad_process); kthread_stop(sdp->sd_logd_process); - flush_workqueue(gfs2_delete_workqueue); gfs2_quota_sync(sdp->sd_vfs, 0); gfs2_statfs_sync(sdp->sd_vfs, 0); -- 2.20.1