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Date: Fri, 21 Dec 2018 12:30:11 +0100
From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, hch@lst.de,
        viro@zeniv.linux.org.uk
Subject: Re: [PATCH 16/22] block: add BIO_HOLD_PAGES flag
Message-ID: <20181221113011.GE7319@lst.de>
References: <20181218154230.3120-1-axboe@kernel.dk> <20181218154230.3120-17-axboe@kernel.dk>
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On Tue, Dec 18, 2018 at 08:42:24AM -0700, Jens Axboe wrote:
> For user mapped IO, we do get_user_pages() upfront, and then do a
> put_page() on each page at end_io time to release the page reference. In
> preparation for having permanently mapped pages, add a BIO_HOLD_PAGES
> flag that tells us not to release the pages, the caller will do that.
> 
> Signed-off-by: Jens Axboe <axboe@kernel.dk>

This looks sensible, but I'm not sure it makes sense on its own.
The changes are a lot more obvious if merged into the next patch.