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Message-ID: <184c0b11-4f97-5872-5b25-ffd99eb6185d@redhat.com>
Date:   Tue, 16 May 2023 10:28:16 +0200
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Subject: Re: [PATCH v5 4/6] io_uring: rsrc: delegate VMA file-backed check to
 GUP
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To:     Lorenzo Stoakes <lstoakes@gmail.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Matthew Wilcox <willy@infradead.org>, Jens Axboe <axboe@kernel.dk>,
        Pavel Begunkov <asml.silence@gmail.com>,
        io-uring@vger.kernel.org, Jason Gunthorpe <jgg@ziepe.ca>,
        John Hubbard <jhubbard@nvidia.com>
References: <cover.1684097001.git.lstoakes@gmail.com>
 <642128d50f5423b3331e3108f8faf6b8ac0d957e.1684097002.git.lstoakes@gmail.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <642128d50f5423b3331e3108f8faf6b8ac0d957e.1684097002.git.lstoakes@gmail.com>
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On 14.05.23 23:26, Lorenzo Stoakes wrote:
> Now that the GUP explicitly checks FOLL_LONGTERM pin_user_pages() for
> broken file-backed mappings in "mm/gup: disallow FOLL_LONGTERM GUP-nonfast
> writing to file-backed mappings", there is no need to explicitly check VMAs
> for this condition, so simply remove this logic from io_uring altogether.
> 

Worth adding "Note that this change will make iouring fixed buffers work 
on MAP_PRIVATE file mappings."

I'll run my test cases with this series and expect no surprises :)


Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb