From: Jens Axboe <axboe@kernel.dk>
To: Andy Lutomirski <luto@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
linux-aio@kvack.org, linux-block@vger.kernel.org,
Jeff Moyer <jmoyer@redhat.com>, Avi Kivity <avi@scylladb.com>,
Linux API <linux-api@vger.kernel.org>,
linux-man <linux-man@vger.kernel.org>
Subject: Re: [PATCH 05/18] Add io_uring IO interface
Date: Thu, 31 Jan 2019 09:37:42 -0700 [thread overview]
Message-ID: <58f458d1-f2fd-5d7c-974a-06b35701d92d@kernel.dk> (raw)
In-Reply-To: <CALCETrVwHcWcJB4r=14=uB2NHGasW+rRRWVoun6-UY_t3+AU2A@mail.gmail.com>
On 1/30/19 10:11 PM, Andy Lutomirski wrote:
>>>> On Jan 28, 2019, at 5:20 PM, Jens Axboe <axboe@kernel.dk> wrote:
>>>>
>>>> On 1/28/19 5:47 PM, Andy Lutomirski wrote:
>>>> On Mon, Jan 28, 2019 at 6:57 AM Christoph Hellwig <hch@lst.de> wrote:
>>>>
>>>> [please make sure linux-api and linux-man are CCed on new syscalls
>>>> so that we get API experts to review them]
>>>
>>>>> +static int io_import_iovec(struct io_ring_ctx *ctx, int rw,
>>>>> + const struct io_uring_sqe *sqe,
>>>>> + struct iovec **iovec, struct iov_iter *iter)
>>>>> +{
>>>>> + void __user *buf = u64_to_user_ptr(sqe->addr);
>>>>> +
>>>>> +#ifdef CONFIG_COMPAT
>>>>> + if (ctx->compat)
>>>>> + return compat_import_iovec(rw, buf, sqe->len, UIO_FASTIOV,
>>>>> + iovec, iter);
>>>>> +#endif
>>>>
>>>> I think we can just check in_compat_syscall() here, which means we
>>>> can kill the ->compat member, and the separate compat version of the
>>>> setup syscall.
>>>
>>> Since this whole API is new, I don't suppose you could introduce a
>>> struct iovec64 or similar and just make the ABI be identical for
>>> 64-bit and 32-bit code?
>>
>> Sure, that would be straight forward. Is there a strong reason to do
>> so outside of "that would be nice"? It's not like it's a huge amount
>> of code.
>
> Here are some minor-ish benefits:
>
> - It avoids having a code path that is only used with 32 bit code on
> 64 bit kernels and is therefore rarely tested. (In this particular
> case, the code path doesn't diverge much, but for most compat
> syscalls, it's almost an entirely separate implementation of the main
> syscall code.)
>
> - It makes life easier for tools like strace.
>
> - It minimizes the chance of making a giant mess on x32, which isn't
> really native or compat.
Not really anything major here, at least not to the extent that
suffering the pain of having a different iovec for this is warranted.
--
Jens Axboe
next prev parent reply other threads:[~2019-01-31 16:37 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-23 15:35 [PATCHSET v7] io_uring IO interface Jens Axboe
2019-01-23 15:35 ` [PATCH 01/18] fs: add an iopoll method to struct file_operations Jens Axboe
2019-01-28 14:25 ` Christoph Hellwig
2019-01-28 16:13 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 02/18] block: wire up block device iopoll method Jens Axboe
2019-01-23 15:35 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe
2019-01-28 14:26 ` Christoph Hellwig
2019-01-23 15:35 ` [PATCH 04/18] iomap: wire up the iopoll method Jens Axboe
2019-01-23 15:35 ` [PATCH 05/18] Add io_uring IO interface Jens Axboe
2019-01-28 14:57 ` Christoph Hellwig
2019-01-28 16:26 ` Jens Axboe
2019-01-28 16:34 ` Christoph Hellwig
2019-01-28 19:32 ` Jens Axboe
2019-01-28 18:25 ` Jens Axboe
2019-01-29 6:30 ` Christoph Hellwig
2019-01-29 11:58 ` Arnd Bergmann
2019-01-29 15:20 ` Jens Axboe
2019-01-29 16:18 ` Arnd Bergmann
2019-01-29 16:19 ` Jens Axboe
2019-01-29 16:26 ` Arnd Bergmann
2019-01-29 16:28 ` Jens Axboe
2019-01-29 16:46 ` Arnd Bergmann
2019-01-29 0:47 ` Andy Lutomirski
2019-01-29 1:20 ` Jens Axboe
2019-01-29 6:45 ` Christoph Hellwig
2019-01-29 12:05 ` Arnd Bergmann
2019-01-31 5:11 ` Andy Lutomirski
2019-01-31 16:37 ` Jens Axboe [this message]
2019-01-23 15:35 ` [PATCH 06/18] io_uring: add fsync support Jens Axboe
2019-01-23 15:35 ` [PATCH 07/13] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-23 15:35 ` [PATCH 07/18] io_uring: support for IO polling Jens Axboe
2019-01-28 15:02 ` Christoph Hellwig
2019-01-28 16:46 ` Jens Axboe
2019-01-29 6:27 ` Christoph Hellwig
2019-01-29 13:20 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 08/18] fs: add fget_many() and fput_many() Jens Axboe
2019-01-28 14:29 ` Christoph Hellwig
2019-01-28 16:48 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 08/13] io_uring: add file set registration Jens Axboe
2019-01-23 15:35 ` [PATCH 09/13] io_uring: add submission polling Jens Axboe
2019-01-28 15:09 ` Christoph Hellwig
2019-01-28 17:05 ` Jens Axboe
2019-01-29 6:29 ` Christoph Hellwig
2019-01-29 13:21 ` Jens Axboe
2019-01-28 21:13 ` Jeff Moyer
2019-01-28 21:28 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 09/18] io_uring: use fget/fput_many() for file references Jens Axboe
2019-01-23 15:35 ` [PATCH 10/13] io_uring: add io_kiocb ref count Jens Axboe
2019-01-23 15:35 ` [PATCH 10/18] io_uring: batch io_kiocb allocation Jens Axboe
2019-01-23 15:35 ` [PATCH 11/18] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-01-28 14:31 ` Christoph Hellwig
2019-01-28 16:54 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 11/13] io_uring: add support for IORING_OP_POLL Jens Axboe
2019-01-23 15:35 ` [PATCH 12/18] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-23 15:35 ` [PATCH 12/13] io_uring: allow workqueue item to handle multiple buffered requests Jens Axboe
2019-01-23 15:35 ` [PATCH 13/18] io_uring: add file set registration Jens Axboe
2019-01-23 15:35 ` [PATCH 13/13] io_uring: add io_uring_event cache hit information Jens Axboe
2019-01-23 15:35 ` [PATCH 14/18] io_uring: add submission polling Jens Axboe
2019-01-23 15:35 ` [PATCH 15/18] io_uring: add io_kiocb ref count Jens Axboe
2019-01-23 15:35 ` [PATCH 16/18] io_uring: add support for IORING_OP_POLL Jens Axboe
2019-01-23 15:35 ` [PATCH 17/18] io_uring: allow workqueue item to handle multiple buffered requests Jens Axboe
2019-01-23 15:35 ` [PATCH 18/18] io_uring: add io_uring_event cache hit information Jens Axboe
[not found] <20190128213538.13486-1-axboe@kernel.dk>
[not found] ` <20190128213538.13486-6-axboe@kernel.dk>
[not found] ` <CAG48ez0vDqDH4ks7q4L3F+xt-4kVQrN1yw34QwFAmwQyy27FTw@mail.gmail.com>
[not found] ` <e9326a77-54c5-e2b8-d9e5-663261462597@kernel.dk>
[not found] ` <CAG48ez17NW0GJVRC6dFcHZTgQifFz5og1XCUbXkHKhr6f=j74Q@mail.gmail.com>
[not found] ` <05cb18f7a97a6151c305cdb7240c4abc995aed59.camel@fb.com>
[not found] ` <CAG48ez09iOOnPz83b6HxktYHTfouS2GD6i3PfQEjp8WCp+3-VA@mail.gmail.com>
2019-02-01 17:23 ` [PATCH 05/18] Add io_uring IO interface Jann Horn
2019-02-01 18:05 ` Al Viro
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