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Date:   Sun, 5 Dec 2021 22:58:10 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     linux-block@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 2/2] block: move direct_IO into our own read_iter handler
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On Fri, Dec 03, 2021 at 08:38:29AM -0700, Jens Axboe wrote:
> Don't call into generic_file_read_iter() if we know it's O_DIRECT, just
> set it up ourselves and call our own handler. This avoids an indirect call
> for O_DIRECT.
> 
> Fall back to filemap_read() if we fail.

Please also do it for the write side, having a partial ->direct_IO is a
really bad idea.