From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Matthew Bobrowski <mbobrowski@mbobrowski.org>,
Jan Kara <jack@suse.cz>, Ritesh Harjani <riteshh@linux.ibm.com>,
Theodore Ts'o <tytso@mit.edu>, Sasha Levin <sashal@kernel.org>,
linux-ext4@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 042/134] ext4: iomap that extends beyond EOF should be marked dirty
Date: Wed, 11 Dec 2019 10:10:18 -0500 [thread overview]
Message-ID: <20191211151150.19073-42-sashal@kernel.org> (raw)
In-Reply-To: <20191211151150.19073-1-sashal@kernel.org>
From: Matthew Bobrowski <mbobrowski@mbobrowski.org>
[ Upstream commit 2e9b51d78229d5145725a481bb5464ebc0a3f9b2 ]
This patch addresses what Dave Chinner had discovered and fixed within
commit: 7684e2c4384d. This changes does not have any user visible
impact for ext4 as none of the current users of ext4_iomap_begin()
that extend files depend on IOMAP_F_DIRTY.
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: Matthew Bobrowski <mbobrowski@mbobrowski.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/8b43ee9ee94bee5328da56ba0909b7d2229ef150.1572949325.git.mbobrowski@mbobrowski.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext4/inode.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 207b8c23e53d9..02313f10e8897 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3523,8 +3523,14 @@ retry:
return ret;
}
+ /*
+ * Writes that span EOF might trigger an I/O 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;
--
2.20.1
next prev parent reply other threads:[~2019-12-11 16:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191211151150.19073-1-sashal@kernel.org>
2019-12-11 15:10 ` [PATCH AUTOSEL 5.4 041/134] ext4: update direct I/O read lock pattern for IOCB_NOWAIT Sasha Levin
2019-12-11 15:10 ` Sasha Levin [this message]
2019-12-11 15:10 ` [PATCH AUTOSEL 5.4 043/134] jbd2: Fix statistics for the number of logged blocks Sasha Levin
2019-12-11 15:10 ` [PATCH AUTOSEL 5.4 077/134] ext4: fix a bug in ext4_wait_for_tail_page_commit Sasha Levin
2019-12-11 15:11 ` [PATCH AUTOSEL 5.4 089/134] ext4: work around deleting a file with i_nlink == 0 safely Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191211151150.19073-42-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=jack@suse.cz \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mbobrowski@mbobrowski.org \
--cc=riteshh@linux.ibm.com \
--cc=stable@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).