Commit 34ed8d0d authored by Lorenzo Stoakes's avatar Lorenzo Stoakes Committed by Andrew Morton
Browse files

io_uring: rsrc: delegate VMA file-backed check to GUP 

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@gmail.com


Signed-off-by: default avatarLorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJens Axboe <axboe@kernel.dk>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent ca5e8632

io_uring/rsrc.c

+6 −28
Original line number Diff line number Diff line
@@ -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);