From patchwork Wed Oct 16 06:06:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 11192423 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 79F8B18A6 for ; Wed, 16 Oct 2019 06:06:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6329B2067D for ; Wed, 16 Oct 2019 06:06:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732165AbfJPGGJ (ORCPT ); Wed, 16 Oct 2019 02:06:09 -0400 Received: from mail105.syd.optusnet.com.au ([211.29.132.249]:54049 "EHLO mail105.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726421AbfJPGGJ (ORCPT ); Wed, 16 Oct 2019 02:06:09 -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 695B33636FC; Wed, 16 Oct 2019 17:06:05 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.2) (envelope-from ) id 1iKcRg-0003xB-1l; Wed, 16 Oct 2019 17:06:04 +1100 Date: Wed, 16 Oct 2019 17:06:04 +1100 From: Dave Chinner To: linux-xfs@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v2] iomap: iomap that extends beyond EOF should be marked dirty Message-ID: <20191016060604.GH16973@dread.disaster.area> References: <20191016051101.12620-1-david@fromorbit.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191016051101.12620-1-david@fromorbit.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.2 cv=FNpr/6gs c=1 sm=1 tr=0 a=ocld+OpnWJCUTqzFQA3oTA==:117 a=ocld+OpnWJCUTqzFQA3oTA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=XobE76Q3jBoA:10 a=20KFwNOVAAAA:8 a=5vzvWiW_mgQDgNkobbgA:9 a=aYwfINTa6weEsN5u:21 a=hBXOXyVhz2Bli8Yj:21 a=CjuIK1q_8ugA:10 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 being 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 Reviewed-by: Christoph Hellwig --- V2: put the XFS code in the right function, tested on non-FUA capable hardware, too. fs/ext4/inode.c | 9 ++++++++- fs/xfs/xfs_iomap.c | 7 +++++++ include/linux/iomap.h | 2 ++ 3 files changed, 17 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..32993c2acbd9 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -1049,6 +1049,13 @@ xfs_file_iomap_begin( trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap); out_finish: + /* + * 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 pending or have been made here. + */ + if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode)) + iomap->flags |= IOMAP_F_DIRTY; return xfs_bmbt_to_iomap(ip, iomap, &imap, shared); out_found: 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 */