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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 192E9C28CC0 for ; Thu, 30 May 2019 03:10:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA7A0244AF for ; Thu, 30 May 2019 03:10:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559185809; bh=1gA9nvV+E5omLZsPBciMnJafgqO9Z+E19ZOC8VTwvw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MIiKY6nHbIhFSRisfapkETcNXVYzGxZ6hO/XxZtNPwtQ/DJr2DFL5aBVhr6wopA5s h+7nCWKYC8M/jAf9R0qxmK/q5mrUaqpPYuRUFWZssiRlkwrO6PSG+vE8yo3gGEUUAi iD+yynXDM6C0WPvVc8mFv74tV0cyV5q1nyXg9QKg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727967AbfE3DKJ (ORCPT ); Wed, 29 May 2019 23:10:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:46330 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727732AbfE3DKI (ORCPT ); Wed, 29 May 2019 23:10:08 -0400 Received: from localhost (ip67-88-213-2.z213-88-67.customer.algx.net [67.88.213.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2575524482; Thu, 30 May 2019 03:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559185808; bh=1gA9nvV+E5omLZsPBciMnJafgqO9Z+E19ZOC8VTwvw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EKXhs8F0jPHWT93dh/e1NfC7RafBQ0JmLxisPAKiDGcFHcf16vylcRlJiEpGPmE5R 0C+Rk02aULZqENyp5N84WbS70BP8AIHZgvp8Qit5xCitRviLUhhD6eecPRTtbwllUJ SY3BPLKCfG6mm/lg7aP5ruV9UCUGlXP+0N4R0kR0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Abhi Das , Andreas Gruenbacher , Sasha Levin Subject: [PATCH 5.1 049/405] gfs2: fix race between gfs2_freeze_func and unmount Date: Wed, 29 May 2019 20:00:47 -0700 Message-Id: <20190530030543.313272702@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030540.291644921@linuxfoundation.org> References: <20190530030540.291644921@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 8f91821990fd6f170a5dca79697a441181a41b16 ] As part of the freeze operation, gfs2_freeze_func() is left blocking on a request to hold the sd_freeze_gl in SH. This glock is held in EX by the gfs2_freeze() code. A subsequent call to gfs2_unfreeze() releases the EXclusively held sd_freeze_gl, which allows gfs2_freeze_func() to acquire it in SH and resume its operation. gfs2_unfreeze(), however, doesn't wait for gfs2_freeze_func() to complete. If a umount is issued right after unfreeze, it could result in an inconsistent filesystem because some journal data (statfs update) isn't written out. Refer to commit 24972557b12c for a more detailed explanation of how freeze/unfreeze work. This patch causes gfs2_unfreeze() to wait for gfs2_freeze_func() to complete before returning to the user. Signed-off-by: Abhi Das Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin --- fs/gfs2/incore.h | 1 + fs/gfs2/super.c | 8 +++++--- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index cdf07b408f54c..539e8dc5a3f6c 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -621,6 +621,7 @@ enum { SDF_SKIP_DLM_UNLOCK = 8, SDF_FORCE_AIL_FLUSH = 9, SDF_AIL1_IO_ERROR = 10, + SDF_FS_FROZEN = 11, }; enum gfs2_freeze_state { diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index ca71163ff7cfd..360206704a14c 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -973,8 +973,7 @@ void gfs2_freeze_func(struct work_struct *work) if (error) { printk(KERN_INFO "GFS2: couldn't get freeze lock : %d\n", error); gfs2_assert_withdraw(sdp, 0); - } - else { + } else { atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN); error = thaw_super(sb); if (error) { @@ -987,6 +986,8 @@ void gfs2_freeze_func(struct work_struct *work) gfs2_glock_dq_uninit(&freeze_gh); } deactivate_super(sb); + clear_bit_unlock(SDF_FS_FROZEN, &sdp->sd_flags); + wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN); return; } @@ -1029,6 +1030,7 @@ static int gfs2_freeze(struct super_block *sb) msleep(1000); } error = 0; + set_bit(SDF_FS_FROZEN, &sdp->sd_flags); out: mutex_unlock(&sdp->sd_freeze_mutex); return error; @@ -1053,7 +1055,7 @@ static int gfs2_unfreeze(struct super_block *sb) gfs2_glock_dq_uninit(&sdp->sd_freeze_gh); mutex_unlock(&sdp->sd_freeze_mutex); - return 0; + return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE); } /** -- 2.20.1