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Date: Mon, 29 Aug 2016 08:57:41 -0400
From: "Theodore Ts'o" <tytso@mit.edu>
To: Christoph Hellwig <hch@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>,
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Subject: Re: [PATCH v2 2/9] ext2: tell DAX the size of allocation holes
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On Mon, Aug 29, 2016 at 12:41:16AM -0700, Christoph Hellwig wrote:
> 
> We're going to move forward killing buffer_heads in XFS.  I think ext4
> would dramatically benefit from this a well, as would ext2 (although I
> think all that DAX work in ext2 is a horrible idea to start with).

It's been on my todo list.  The only reason why I haven't done it yet
is because I knew you were working on a solution, and I didn't want to
do things one way for buffered I/O, and a different way for Direct
I/O, and disentangling the DIO code and the different assumptions of
how different file systems interact with the DIO code is a *mess*.

It may have gotten better more recently, but a few years ago I took a
look at it and backed slowly away.....

						- Ted