From patchwork Wed Oct 16 05:11:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 11192357 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AC0E51668 for ; Wed, 16 Oct 2019 05:11:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96B2E2067D for ; Wed, 16 Oct 2019 05:11:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732706AbfJPFLI (ORCPT ); Wed, 16 Oct 2019 01:11:08 -0400 Received: from mail105.syd.optusnet.com.au ([211.29.132.249]:55830 "EHLO mail105.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730411AbfJPFLI (ORCPT ); Wed, 16 Oct 2019 01:11:08 -0400 Received: from dread.disaster.area (pa49-181-198-88.pa.nsw.optusnet.com.au [49.181.198.88]) by mail105.syd.optusnet.com.au (Postfix) with ESMTPS id 28579362207; Wed, 16 Oct 2019 16:11:02 +1100 (AEDT) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.2) (envelope-from ) id 1iKbaP-0003aq-Gc; Wed, 16 Oct 2019 16:11:01 +1100 Received: from dave by discord.disaster.area with local (Exim 4.92) (envelope-from ) id 1iKbaP-0003IH-Cq; Wed, 16 Oct 2019 16:11:01 +1100 From: Dave Chinner To: linux-xfs@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH] iomap: iomap that extends beyond EOF should be marked dirty Date: Wed, 16 Oct 2019 16:11:01 +1100 Message-Id: <20191016051101.12620-1-david@fromorbit.com> X-Mailer: git-send-email 2.23.0.rc1 MIME-Version: 1.0 X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.2 cv=D+Q3ErZj c=1 sm=1 tr=0 a=ocld+OpnWJCUTqzFQA3oTA==:117 a=ocld+OpnWJCUTqzFQA3oTA==:17 a=XobE76Q3jBoA:10 a=20KFwNOVAAAA:8 a=S-1eUNTvgfi6r5ippUoA:9 a=-LxSyIH3IyFY79c0:21 a=rj11tZLffgg5wOKJ:21 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Dave Chinner When doing a direct IO that spans the current EOF, and there are written blocks beyond EOF that extend beyond the current write, the only metadata update that needs to be done is a file size extension. However, we don't mark such iomaps as IOMAP_F_DIRTY to indicate that there is IO completion metadata updates required, and hence we may fail to correctly sync file size extensions made in IO completion when O_DSYNC writes are beingt used and the hardware supports FUA. Hence when setting IOMAP_F_DIRTY, we need to also take into account whether the iomap spans the current EOF. If it does, then we need to mark it dirty so that IO completion will call generic_write_sync() to flush the inode size update to stable storage correctly. Signed-off-by: Dave Chinner --- fs/ext4/inode.c | 9 ++++++++- fs/xfs/xfs_iomap.c | 8 ++++++++ include/linux/iomap.h | 2 ++ 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 516faa280ced..e9dc52537e5b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3523,9 +3523,16 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, return ret; } + /* + * Writes that span EOF might trigger an IO size update on completion, + * so consider them to be dirty for the purposes of O_DSYNC even if + * there is no other metadata changes being made or are pending here. + */ iomap->flags = 0; - if (ext4_inode_datasync_dirty(inode)) + if (ext4_inode_datasync_dirty(inode) || + offset + length > i_size_read(inode)) iomap->flags |= IOMAP_F_DIRTY; + iomap->bdev = inode->i_sb->s_bdev; iomap->dax_dev = sbi->s_daxdev; iomap->offset = (u64)first_block << blkbits; diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index f780e223b118..38be06f19ea2 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -722,6 +722,14 @@ xfs_file_iomap_begin_delay( xfs_trim_extent(&imap, cmap.br_startoff, cmap.br_blockcount); shared = true; } + + /* + * Writes that span EOF might trigger an IO size update on completion, + * so consider them to be dirty for the purposes of O_DSYNC even if + * there is no other metadata changes being made or are pending here. + */ + if (offset + count > i_size_read(inode)) + iomap->flags |= IOMAP_F_DIRTY; error = xfs_bmbt_to_iomap(ip, iomap, &imap, shared); out_unlock: xfs_iunlock(ip, XFS_ILOCK_EXCL); diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 7aa5d6117936..24bd227d59f9 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -32,6 +32,8 @@ struct vm_fault; * * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access * written data and requires fdatasync to commit them to persistent storage. + * This needs to take into account metadata changes that *may* be made at IO + * completion, such as file size updates from direct IO. */ #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ #define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */