The patch titled
Subject: io_uring: rsrc: delegate VMA file-backed check to GUP
has been added to the -mm mm-unstable branch. Its filename is
io_uring-rsrc-delegate-vma-file-backed-check-to-gup.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/io_uring-rsrc-delegate-vma-file-backed-check-to-gup.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Subject: io_uring: rsrc: delegate VMA file-backed check to GUP
Date: Wed, 17 May 2023 20:25:42 +0100
Now that the GUP explicitly checks FOLL_LONGTERM pin_user_pages() for
broken file-backed mappings in "mm/gup: disallow FOLL_LONGTERM GUP-nonfast
writing to file-backed mappings", there is no need to explicitly check VMAs
for this condition, so simply remove this logic from io_uring altogether.
Link: https://lkml.kernel.org/r/e4a4efbda9cd12df71e0ed81796dc630231a1ef2.1684350871.git.lstoakes@xxxxxxxxx
Signed-off-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Jens Axboe <axboe@xxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
io_uring/rsrc.c | 34 ++++++----------------------------
1 file changed, 6 insertions(+), 28 deletions(-)
--- a/io_uring/rsrc.c~io_uring-rsrc-delegate-vma-file-backed-check-to-gup
+++ a/io_uring/rsrc.c
@@ -1030,9 +1030,8 @@ static int io_buffer_account_pin(struct
struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
{
unsigned long start, end, nr_pages;
- struct vm_area_struct **vmas = NULL;
struct page **pages = NULL;
- int i, pret, ret = -ENOMEM;
+ int pret, ret = -ENOMEM;
end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
start = ubuf >> PAGE_SHIFT;
@@ -1042,45 +1041,24 @@ struct page **io_pin_pages(unsigned long
if (!pages)
goto done;
- vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
- GFP_KERNEL);
- if (!vmas)
- goto done;
-
ret = 0;
mmap_read_lock(current->mm);
pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
- pages, vmas);
- if (pret == nr_pages) {
- /* 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))
- continue;
- if (vma->vm_file &&
- !is_file_hugepages(vma->vm_file)) {
- ret = -EOPNOTSUPP;
- break;
- }
- }
+ pages, NULL);
+ if (pret == nr_pages)
*npages = nr_pages;
- } else {
+ else
ret = pret < 0 ? pret : -EFAULT;
- }
+
mmap_read_unlock(current->mm);
if (ret) {
- /*
- * if we did partial map, or found file backed vmas,
- * release any pages we did get
- */
+ /* if we did partial map, release any pages we did get */
if (pret > 0)
unpin_user_pages(pages, pret);
goto done;
}
ret = 0;
done:
- kvfree(vmas);
if (ret < 0) {
kvfree(pages);
pages = ERR_PTR(ret);
_
Patches currently in -mm which might be from lstoakes@xxxxxxxxx are
mm-mmap-separate-writenotify-and-dirty-tracking-logic.patch
mm-gup-disallow-foll_longterm-gup-nonfast-writing-to-file-backed-mappings.patch
mm-gup-disallow-foll_longterm-gup-fast-writing-to-file-backed-mappings.patch
mm-gup-add-missing-gup_must_unshare-check-to-gup_huge_pgd.patch
mm-gup-remove-unused-vmas-parameter-from-get_user_pages.patch
mm-gup-remove-unused-vmas-parameter-from-pin_user_pages_remote.patch
mm-gup-remove-vmas-parameter-from-get_user_pages_remote.patch
io_uring-rsrc-delegate-vma-file-backed-check-to-gup.patch
mm-gup-remove-vmas-parameter-from-pin_user_pages.patch
mm-gup-remove-vmas-array-from-internal-gup-functions.patch
