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.
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Jens Axboe <axboe@xxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
---
io_uring/rsrc.c | 34 ++++++----------------------------
1 file changed, 6 insertions(+), 28 deletions(-)
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index d46f72a5ef73..b6451f8bc5d5 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1030,9 +1030,8 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
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 ubuf, unsigned long len, int *npages)
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);
--
2.40.1
