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Subject: Re: [RFC] iomap: fix race between readahead and direct write
To:     "Darrick J. Wong" <darrick.wong@oracle.com>,
        Jan Kara <jack@suse.cz>
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        <yi.zhang@huawei.com>
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From:   "yukuai (C)" <yukuai3@huawei.com>
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Date:   Sun, 19 Jan 2020 09:25:16 +0800
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On 2020/1/18 0:24, Darrick J. Wong wrote:
> Does the problem go away if you apply[1]?  If I understand the race
> correctly, marking the extents unwritten and leaving them that way until
> after we've written the disk should eliminate the exposure vector...?:)

Thank you for your response.

The patch [1] fixed the stale data exposure problem which was tested by
generic/042. I'm afarid it's completely a diffrent case for generic/418.

In generic/418, direct write wrote some data to disk successfully, while
buffer read left the correspond page uptodate with 0 content in
pagecache.

Thanks!
Yu Kuai