From: Pavel Begunkov <[email protected]>
To: [email protected]
Cc: Jens Axboe <[email protected]>
Subject: Re: [PATCH for-next 1/1] io_uring/rsrc: don't mix different mappings in reg
Date: Mon, 20 Feb 2023 14:16:30 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <813cdd2d15c3c471bf06c6c93a0a35315d08a3ad.1676902351.git.asml.silence@gmail.com>
On 2/20/23 14:13, Pavel Begunkov wrote:
> If two or more mappings go back to back to each other they can be passed
> into io_uring to be registered as a single registered buffer. That would
> even work if mappings came from different sources, e.g. it's possible to
> mix in this way anon pages and pages from shmem or hugetlb. That is not
> a problem but it'd rather be less prone if we forbid such mixing.
The commit title got botched, let me rename and resend it.
> Cc: <[email protected]>
> Signed-off-by: Pavel Begunkov <[email protected]>
> ---
> io_uring/rsrc.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
> index a59fc02de598..70d7f94670f9 100644
> --- a/io_uring/rsrc.c
> +++ b/io_uring/rsrc.c
> @@ -1162,18 +1162,19 @@ struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
> pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
> pages, vmas);
> if (pret == nr_pages) {
> + struct file *file = vmas[0]->vm_file;
> +
> /* don't support file backed memory */
> for (i = 0; i < nr_pages; i++) {
> - struct vm_area_struct *vma = vmas[i];
> -
> - if (vma_is_shmem(vma))
> + if (vmas[i]->vm_file != file)
> + break;
> + if (!file)
> continue;
> - if (vma->vm_file &&
> - !is_file_hugepages(vma->vm_file)) {
> - ret = -EOPNOTSUPP;
> + if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file))
> break;
> - }
> }
> + if (i != nr_pages)
> + ret = -EOPNOTSUPP;
> *npages = nr_pages;
> } else {
> ret = pret < 0 ? pret : -EFAULT;
--
Pavel Begunkov
prev parent reply other threads:[~2023-02-20 14:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-20 14:13 [PATCH for-next 1/1] io_uring/rsrc: don't mix different mappings in reg Pavel Begunkov
2023-02-20 14:16 ` Pavel Begunkov [this message]
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