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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 151E6C04AAC for ; Mon, 20 May 2019 12:30:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D386220675 for ; Mon, 20 May 2019 12:30:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558355450; bh=Y8pn0klUBCj5HAGh+Ju8aJxxSJY616eLJ6p9gRpf8b4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Fu8bYafP4Ez9pHv2XBI273ykV3JJDrNOb1je55LSgut4mxcAVsZ6wBga+XTMEgRUM w1gTNfo3ddNC1Scdk3xTozRpyP4KXSWPRjfCTYh0uw3JFjS+PomC2+rc3se7o3jrQL ba8jQOrty3STfUAFaQz6Xxc+muGTP8nfv5kOFJJ8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390170AbfETMau (ORCPT ); Mon, 20 May 2019 08:30:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:47050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390150AbfETMan (ORCPT ); Mon, 20 May 2019 08:30:43 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 F17E520675; Mon, 20 May 2019 12:30:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558355442; bh=Y8pn0klUBCj5HAGh+Ju8aJxxSJY616eLJ6p9gRpf8b4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bG6mCGeHfajWWUnXuL6VTG0wlznq8/WMEt4uLk3gaJIhlR0VuzdlWeTxNoYtnEcnt bNPfHRLLvHJNqkwYIidG5QGJlxRRykYYbCj39yeEGNuPnF3KMVHfr+4c488+1NYf5d q7IewBH8P8ZcsJI0d6laScxvnOMk+BMQDUJulX/o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukas Czerner , Theodore Tso , stable@kernel.org Subject: [PATCH 5.0 103/123] ext4: fix data corruption caused by overlapping unaligned and aligned IO Date: Mon, 20 May 2019 14:14:43 +0200 Message-Id: <20190520115251.893061163@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190520115245.439864225@linuxfoundation.org> References: <20190520115245.439864225@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lukas Czerner commit 57a0da28ced8707cb9f79f071a016b9d005caf5a upstream. Unaligned AIO must be serialized because the zeroing of partial blocks of unaligned AIO can result in data corruption in case it's overlapping another in flight IO. Currently we wait for all unwritten extents before we submit unaligned AIO which protects data in case of unaligned AIO is following overlapping IO. However if a unaligned AIO is followed by overlapping aligned AIO we can still end up corrupting data. To fix this, we must make sure that the unaligned AIO is the only IO in flight by waiting for unwritten extents conversion not just before the IO submission, but right after it as well. This problem can be reproduced by xfstest generic/538 Signed-off-by: Lukas Czerner Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/file.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -264,6 +264,13 @@ ext4_file_write_iter(struct kiocb *iocb, } ret = __generic_file_write_iter(iocb, from); + /* + * Unaligned direct AIO must be the only IO in flight. Otherwise + * overlapping aligned IO after unaligned might result in data + * corruption. + */ + if (ret == -EIOCBQUEUED && unaligned_aio) + ext4_unwritten_wait(inode); inode_unlock(inode); if (ret > 0)