From: Jens Axboe <axboe@kernel.dk>
To: Pavel Begunkov <asml.silence@gmail.com>,
Stefan Metzmacher <metze@samba.org>,
io-uring@vger.kernel.org, Josh Triplett <josh@joshtriplett.org>
Cc: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH v2 0/4] open/accept directly into io_uring fixed file table
Date: Tue, 17 Aug 2021 08:57:13 -0600 [thread overview]
Message-ID: <ab450460-1faa-dea1-f8a3-894a42461597@kernel.dk> (raw)
In-Reply-To: <78e2d63a-5d3a-6334-8177-11646d4ec261@gmail.com>
On 8/17/21 3:33 AM, Pavel Begunkov wrote:
> On 8/16/21 4:45 PM, Stefan Metzmacher wrote:
>> Hi Pavel,
>>
>>> The behaviour is controlled by setting sqe->file_index, where 0 implies
>>> the old behaviour. If non-zero value is specified, then it will behave
>>> as described and place the file into a fixed file slot
>>> sqe->file_index - 1. A file table should be already created, the slot
>>> should be valid and empty, otherwise the operation will fail.
>>>
>>> Note 1: we can't use IOSQE_FIXED_FILE to switch between modes, because
>>> accept takes a file, and it already uses the flag with a different
>>> meaning.
>>
>> Would it be hard to support IOSQE_FIXED_FILE for the dirfd of openat*, renameat, unlinkat, statx?
>> (And mkdirat, linkat, symlinkat when they arrive)
>> renameat and linkat might be trickier as they take two dirfds, but it
>> would make the feature more complete and useful.
>
> Good idea. There is nothing blocking on the io_uring side, but
> the fs part may get ugly, e.g. too intrusive. We definitely need
> to take a look
Indeed, the io_uring side is trivial, but the VFS interface would
require a lot of man handling... That's why I didn't add support for
fixed files originally.
--
Jens Axboe
prev parent reply other threads:[~2021-08-17 14:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-13 16:43 [PATCH v2 0/4] open/accept directly into io_uring fixed file table Pavel Begunkov
2021-08-13 16:43 ` [PATCH v2 1/4] net: add accept helper not installing fd Pavel Begunkov
2021-08-13 16:43 ` [PATCH v2 2/4] io_uring: openat directly into fixed fd table Pavel Begunkov
2021-08-13 16:43 ` [PATCH v2 3/4] io_uring: hand code io_accept() fd installing Pavel Begunkov
2021-08-13 16:43 ` [PATCH v2 4/4] io_uring: accept directly into fixed file table Pavel Begunkov
2021-08-13 19:00 ` [PATCH v2 0/4] open/accept directly into io_uring " Josh Triplett
2021-08-14 12:50 ` Pavel Begunkov
2021-08-14 23:03 ` Jens Axboe
2021-08-15 3:42 ` Josh Triplett
2021-08-15 15:05 ` Jens Axboe
2021-08-15 15:12 ` Jens Axboe
2021-08-15 13:00 ` Pavel Begunkov
2021-08-15 3:31 ` Josh Triplett
2021-08-15 10:48 ` Pavel Begunkov
2021-08-15 14:23 ` Pavel Begunkov
2021-08-16 15:45 ` Stefan Metzmacher
2021-08-17 9:33 ` Pavel Begunkov
2021-08-17 14:57 ` Jens Axboe [this message]
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