Commit 776617db authored May 03, 2023 by Tobias Holl Committed by Jens Axboe May 03, 2023

io_uring/rsrc: check for nonconsecutive pages



Pages that are from the same folio do not necessarily need to be
consecutive. In that case, we cannot consolidate them into a single bvec
entry. Before applying the huge page optimization from commit 57bebf80
("io_uring/rsrc: optimise registered huge pages"), check that the memory
is actually consecutive.

Cc: stable@vger.kernel.org
Fixes: 57bebf80 ("io_uring/rsrc: optimise registered huge pages")
Signed-off-by: Tobias Holl <tobias@tholl.xyz>
[axboe: formatting]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 3c85cc43

io_uring/rsrc.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1117,7 +1117,12 @@ static int io_sqe_buffer_register(struct io_ring_ctx ctx, struct iovec iov,
		if (nr_pages > 1) {
		folio = page_folio(pages[0]);
		for (i = 1; i < nr_pages; i++) {
		if (page_folio(pages[i]) != folio) {
		/*
		* Pages must be consecutive and on the same folio for
		* this to work
		*/
		if (page_folio(pages[i]) != folio \|\|
		pages[i] != pages[i - 1] + 1) {
		folio = NULL;
		break;
		}