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Date: Mon, 16 Apr 2018 23:58:00 -0700
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH] xfs: cap the length of deduplication requests
Message-ID: <20180417065800.GA2857@infradead.org>
References: <20180417051918.GD5203@magnolia>
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To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: xfs <linux-xfs@vger.kernel.org>, fstests <fstests@vger.kernel.org>

On Mon, Apr 16, 2018 at 10:19:18PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Since deduplication potentially has to read in all the pages in both
> files in order to compare the contents, cap the deduplication request
> length at MAX_RW_COUNT (roughly 2GB) so that we have /some/ upper bound
> on the request length and can't just lock up the kernel forever.  Found
> by running generic/304 after commit 1ddae54555b62 ("common/rc: add
> missing 'local' keywords").

Looks fine.  btrfs limits to 16MB, I guess we don't want to go that low?