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=-9.1 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 21805C282CE for ; Wed, 22 May 2019 19:23:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E920E21880 for ; Wed, 22 May 2019 19:23:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553027; bh=2exSR2Nnkhck0kqyrIIIcnFhOeWL/t1JxLNownjldOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ewUsbzC/+o3xr4ynhlRamNAeUR+md5gcNTw8QTQhzSu2tZXq/NkSpQP/I/s8HqpH5 W57B7ytHkV3lUagQqOHi6qCCOZqHNwQ4WZe7ybK3jD4x3wpHSPqIg7+zmdT2X9A6ce q4SpRRG29PS5wGQuHTwwaBxI5iTva9sOPnaeKJUU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730974AbfEVTXp (ORCPT ); Wed, 22 May 2019 15:23:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:44672 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730235AbfEVTXp (ORCPT ); Wed, 22 May 2019 15:23:45 -0400 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 B987B21850; Wed, 22 May 2019 19:23:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553024; bh=2exSR2Nnkhck0kqyrIIIcnFhOeWL/t1JxLNownjldOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TPudtTCB/5H8v0DS9B9dVLlB1b2rm/fjBIRGz89aB7aRkAMbVDQrr7adFfTzicsYL 4VpNqY7ldG452bfKGSjbEVA4n7JO5UwcXywYCRP/7qpFbRmAoGhEdZs+QNA5pHsS5C Ip7AazUqI4t6uqpwtCOGgc34PnmJhjv8Wt8jw0qI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Abhi Das , Andreas Gruenbacher , Sasha Levin , cluster-devel@redhat.com Subject: [PATCH AUTOSEL 5.0 005/317] gfs2: fix race between gfs2_freeze_func and unmount Date: Wed, 22 May 2019 15:18:26 -0400 Message-Id: <20190522192338.23715-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190522192338.23715-1-sashal@kernel.org> References: <20190522192338.23715-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Abhi Das [ 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 e10e0b0a7cd58..e1a33d2881213 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