From: Stefan Metzmacher <metze@samba.org>
To: Pavel Begunkov <asml.silence@gmail.com>,
Jens Axboe <axboe@kernel.dk>,
Alexander Viro <viro@zeniv.linux.org.uk>,
io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/3] io_uring: add splice(2) support
Date: Mon, 17 Feb 2020 16:54:14 +0100 [thread overview]
Message-ID: <033a6560-df47-39a2-871b-13f2d84bb1ec@samba.org> (raw)
In-Reply-To: <b44a4692-f43c-e625-3eb7-cc4e12041f48@gmail.com>
[-- Attachment #1.1: Type: text/plain, Size: 1251 bytes --]
Am 17.02.20 um 16:40 schrieb Pavel Begunkov:
> On 2/17/2020 6:18 PM, Stefan Metzmacher wrote:
>> Hi Pavel,
>>
>>> +static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>>> +{
>>> + struct io_splice* sp = &req->splice;
>>> + unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
>>> + int ret;
>>> +
>>> + if (req->flags & REQ_F_NEED_CLEANUP)
>>> + return 0;
>>> +
>>> + sp->file_in = NULL;
>>> + sp->off_in = READ_ONCE(sqe->off_in);
>>> + sp->off_out = READ_ONCE(sqe->off);
>>> + sp->len = READ_ONCE(sqe->len);
>>> + sp->flags = READ_ONCE(sqe->splice_flags);
>>> +
>>> + if (unlikely(READ_ONCE(sqe->ioprio) || (sp->flags & ~valid_flags)))
>>> + return -EINVAL;
>>
>> Why is ioprio not supported?
>
> Because there is no way to set it without changing much of splice code.
> It may be added later
>
> BTW, it seems, only opcodes cares about ioprio are read*/write*.
> recv*() and send*() don't reject it, but never use.
I guess it's more like a hint, so should we just ignore it until
it's passed down? Otherwise applications need to do some logic to
find out if they can pass a value or not.
I'm not sure what's better, but I think it needs to be discussed...
metze
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2020-02-17 15:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-15 22:05 [PATCH v2 0/3] " Pavel Begunkov
2020-02-15 22:05 ` [PATCH v2 1/3] splice: make do_splice public Pavel Begunkov
2020-02-15 22:05 ` [PATCH v2 2/3] io_uring: add interface for getting files Pavel Begunkov
2020-02-15 22:05 ` [PATCH v2 3/3] io_uring: add splice(2) support Pavel Begunkov
2020-02-17 15:18 ` Stefan Metzmacher
2020-02-17 15:40 ` Pavel Begunkov
2020-02-17 15:54 ` Stefan Metzmacher [this message]
2020-02-17 15:59 ` Pavel Begunkov
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 \
--in-reply-to=033a6560-df47-39a2-871b-13f2d84bb1ec@samba.org \
--to=metze@samba.org \
--cc=asml.silence@gmail.com \
--cc=axboe@kernel.dk \
--cc=io-uring@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/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
all inboxes | Powered by JetHome®