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Date:   Wed, 11 Dec 2019 18:21:55 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Linux-MM <linux-mm@kvack.org>,
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        Chris Mason <clm@fb.com>, Dave Chinner <david@fromorbit.com>,
        Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCHSET v3 0/5] Support for RWF_UNCACHED
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On Wed, Dec 11, 2019 at 07:03:40PM -0700, Jens Axboe wrote:
> Tested and cleaned a bit, and added truncate protection through
> inode_dio_begin()/inode_dio_end().
> 
> https://git.kernel.dk/cgit/linux-block/commit/?h=buffered-uncached&id=6dac80bc340dabdcbfb4230b9331e52510acca87
> 
> This is much faster than the previous page cache dance, and I _think_
> we're ok as long as we block truncate and hole punching.

What about races between UNCACHED and regular buffered IO?  Seems like
we might end up sending overlapping writes to the device?