From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
linux-block@vger.kernel.org, linux-arch@vger.kernel.org,
hch@lst.de, jmoyer@redhat.com, avi@scylladb.com
Subject: Re: [PATCH 13/16] io_uring: add support for pre-mapped user IO buffers
Date: Wed, 9 Jan 2019 13:16:39 +0100 [thread overview]
Message-ID: <20190109121638.GE13779@lst.de> (raw)
In-Reply-To: <20190108165645.19311-14-axboe@kernel.dk>
> +static int io_setup_rw(int rw, struct io_kiocb *kiocb,
> + const struct io_uring_iocb *iocb, struct iovec **iovec,
> + struct iov_iter *iter, bool kaddr)
> {
> void __user *buf = (void __user *)(uintptr_t)iocb->addr;
> size_t ret;
>
> - ret = import_single_range(rw, buf, iocb->len, *iovec, iter);
> + if (!kaddr) {
> + ret = import_single_range(rw, buf, iocb->len, *iovec, iter);
> + } else {
> + struct io_ring_ctx *ctx = kiocb->ki_ctx;
> + struct io_mapped_ubuf *imu;
> + size_t len = iocb->len;
> + size_t offset;
> + int index;
> +
> + /* __io_submit_one() already validated the index */
> + index = array_index_nospec(kiocb->ki_index,
> + ctx->max_reqs);
> + imu = &ctx->user_bufs[index];
> + if ((unsigned long) iocb->addr < imu->ubuf ||
> + (unsigned long) iocb->addr + len > imu->ubuf + imu->len) {
> + ret = -EFAULT;
> + goto err;
> + }
> +
> + /*
> + * May not be a start of buffer, set size appropriately
> + * and advance us to the beginning.
> + */
> + offset = (unsigned long) iocb->addr - imu->ubuf;
> + iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs,
> + offset + len);
> + if (offset)
> + iov_iter_advance(iter, offset);
> + ret = 0;
> +
Please split this code in a separate helper.
> if (unlikely(!file->f_op->read_iter))
> goto out_fput;
>
> - ret = io_setup_rw(READ, iocb, &iovec, &iter);
> + ret = io_setup_rw(READ, kiocb, iocb, &iovec, &iter, kaddr);
And I'd personally just call that helper here based on the opcode and
avoid magic bool arguments.
> + down_write(¤t->mm->mmap_sem);
> + pret = get_user_pages(ubuf, nr_pages, 1, pages, NULL);
> + up_write(¤t->mm->mmap_sem);
This needs to be get_user_pages_longterm.
> + * We don't use the iovecs without fixed buffers being asked for.
> + * Error out if they don't match.
> + */
> + if (!(p->flags & IORING_SETUP_FIXEDBUFS) && iovecs)
> + return -EINVAL;
I don't think we need the IORING_SETUP_FIXEDBUFS flag at all, as a
non-zero iovecs pointer is enough of an indication.
next prev parent reply other threads:[~2019-01-09 12:16 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-08 16:56 [PATCHSET v1] io_uring IO interface Jens Axboe
2019-01-08 16:56 ` [PATCH 01/16] fs: add an iopoll method to struct file_operations Jens Axboe
2019-01-08 16:56 ` [PATCH 02/16] block: wire up block device iopoll method Jens Axboe
2019-01-08 16:56 ` [PATCH 03/16] block: add bio_set_polled() helper Jens Axboe
2019-01-10 9:43 ` Ming Lei
2019-01-10 16:05 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 04/16] iomap: wire up the iopoll method Jens Axboe
2019-01-08 16:56 ` [PATCH 05/16] Add io_uring IO interface Jens Axboe
2019-01-09 12:10 ` Christoph Hellwig
2019-01-09 15:53 ` Jens Axboe
2019-01-09 18:30 ` Christoph Hellwig
2019-01-09 20:07 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 06/16] io_uring: support for IO polling Jens Axboe
2019-01-09 12:11 ` Christoph Hellwig
2019-01-09 15:53 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 07/16] io_uring: add submission side request cache Jens Axboe
2019-01-08 16:56 ` [PATCH 08/16] fs: add fget_many() and fput_many() Jens Axboe
2019-01-08 16:56 ` [PATCH 09/16] io_uring: use fget/fput_many() for file references Jens Axboe
2019-01-08 16:56 ` [PATCH 10/16] io_uring: split kiocb init from allocation Jens Axboe
2019-01-09 12:12 ` Christoph Hellwig
2019-01-09 16:56 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 11/16] io_uring: batch io_kiocb allocation Jens Axboe
2019-01-09 12:13 ` Christoph Hellwig
2019-01-09 16:57 ` Jens Axboe
2019-01-09 19:03 ` Christoph Hellwig
2019-01-09 20:08 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 12/16] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-01-08 16:56 ` [PATCH 13/16] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-09 12:16 ` Christoph Hellwig [this message]
2019-01-09 17:06 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 14/16] io_uring: support kernel side submission Jens Axboe
2019-01-09 19:06 ` Christoph Hellwig
2019-01-09 20:49 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 15/16] io_uring: add submission polling Jens Axboe
2019-01-08 16:56 ` [PATCH 16/16] io_uring: add io_uring_event cache hit information Jens Axboe
2019-01-09 16:00 ` [PATCHSET v1] io_uring IO interface Matthew Wilcox
2019-01-09 16:27 ` Chris Mason
2019-01-12 21:29 [PATCHSET v3] " Jens Axboe
2019-01-12 21:30 ` [PATCH 13/16] io_uring: add support for pre-mapped user IO buffers Jens Axboe
[not found] <20190115025531.13985-1-axboe@kernel.dk>
2019-01-15 2:55 ` Jens Axboe
2019-01-16 10:53 ` Arnd Bergmann
2019-01-16 15:14 ` Jens Axboe
2019-01-16 15:32 ` Jens Axboe
2019-01-16 15:41 ` Arnd Bergmann
2019-01-16 15:47 ` 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 \
--in-reply-to=20190109121638.GE13779@lst.de \
--to=hch@lst.de \
--cc=avi@scylladb.com \
--cc=axboe@kernel.dk \
--cc=jmoyer@redhat.com \
--cc=linux-aio@kvack.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).