public inbox for [email protected]
 help / color / mirror / Atom feed
From: Jens Axboe <[email protected]>
To: Pavel Begunkov <[email protected]>, [email protected]
Subject: Re: [PATCH] io_uring: make OP_CLOSE consistent direct open
Date: Fri, 24 Sep 2021 14:25:46 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On 9/24/21 2:21 PM, Pavel Begunkov wrote:
> On 9/24/21 9:19 PM, Jens Axboe wrote:
>> On 9/24/21 2:11 PM, Pavel Begunkov wrote:
>>> On 9/24/21 9:06 PM, Jens Axboe wrote:
>>>> On 9/24/21 1:57 PM, Jens Axboe wrote:
>>>>> On 9/24/21 1:04 PM, Pavel Begunkov wrote:
>>>>>> From recently open/accept are now able to manipulate fixed file table,
>>>>>> but it's inconsistent that close can't. Close the gap, keep API same as
>>>>>> with open/accept, i.e. via sqe->file_slot.
>>>>>
>>>>> I really think we should do this for 5.15 to make the API a bit more
>>>>> sane from the user point of view, folks definitely expect being able
>>>>> to use IORING_OP_CLOSE with a fixed file that they got with IORING_OP_OPEN,
>>>>> for example.
>>>>>
>>>>> How about this small tweak, basically making it follow the same rules
>>>>> as other commands that do fixed files:
>>>>>
>>>>> 1) Require IOSQE_FIXED_FILE to be set for a direct close. sqe->file_index
>>>>>    will be the descriptor to close in that case. If sqe->fd is set, we
>>>>>    -EINVAL the request.
>>>>>
>>>>> 2) If IOSQE_FIXED_FILE isn't set, it's a normal close. As before, if
>>>>>    sqe->file_index is set and IOSQE_FIXED_FILE isn't, then we -EINVAL
>>>>>    the request.
>>>>>
>>>>> Basically this incremental on top of yours.
>>>>
>>>> Hmm, we don't require that for open or accept. Why not? Seems a bit
>>>> counter intuitive. But maybe it's better we do this one as-is, and then
>>>
>>> Accept takes a fd as an argument and so IOSQE_FIXED_FILE already applies
>>> to it and can't be used as described. Close is just made consistent with
>>> the rest.
>>
>> What I'm saying is why don't we make IOSQE_FIXED_FILE for open/accept
>> consistent as well?
> 
> The flag is already used for accept but for a different purpose 
> 
> 
> [IORING_OP_ACCEPT] = {
> 	.needs_file		= 1,
> 
> if (io_op_defs[req->opcode].needs_file) {
> 	req->file = io_file_get(ctx, req, READ_ONCE(sqe->fd),
> 				(sqe_flags & IOSQE_FIXED_FILE));

Oh yeah, I guess that won't fly then. Let's just go with this one then,
at least there's an explanation for it and they are consistent in using
->file_index to gate it.

-- 
Jens Axboe


  reply	other threads:[~2021-09-24 20:25 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-24 19:04 [PATCH] io_uring: make OP_CLOSE consistent direct open Pavel Begunkov
2021-09-24 19:57 ` Jens Axboe
2021-09-24 20:06   ` Jens Axboe
2021-09-24 20:11     ` Pavel Begunkov
2021-09-24 20:19       ` Jens Axboe
2021-09-24 20:21         ` Pavel Begunkov
2021-09-24 20:25           ` Jens Axboe [this message]
2021-09-24 19:58 ` Jens Axboe
2021-09-24 19:59   ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox