Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH][for-linus] io_uring: Fix mm_fault with READ/WRITE_FIXED
To:     Pavel Begunkov <asml.silence@gmail.com>,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
References: <a30b1e934506227b4740b6030dd77e7e233a58c2.1572207237.git.asml.silence@gmail.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <e70202d3-53c1-db48-f95b-0334f11178d1@kernel.dk>
Date:   Sun, 27 Oct 2019 21:28:36 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.9.0
MIME-Version: 1.0
In-Reply-To: <a30b1e934506227b4740b6030dd77e7e233a58c2.1572207237.git.asml.silence@gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 10/27/19 2:15 PM, Pavel Begunkov wrote:
> Commit fb5ccc98782f ("io_uring: Fix broken links with offloading")
> itroduced a regression with unconditionally taking mm even for
> READ/WRITE_FIXED operations.
> 
> Return the logic handling it back. mm-faulted requests will go through
> the generic submission path, so honoring links and drains, but will
> fail further on req->has_user check.

I thought about this a bit, and I think we should just defer this to
the next release and mark it stable for 5.4. I'll do that, thanks.

-- 
Jens Axboe