Commit 9cebcf7b authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/rsrc: clean up io_coalesce_buffer() 



We don't need special handling for the first page in
io_coalesce_buffer(), move it inside the loop.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: default avatarAnuj Gupta <anuj20.g@samsung.com>
Link: https://lore.kernel.org/r/ad698cddc1eadb3d92a7515e95bb13f79420323d.1745083025.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ea769256

io_uring/rsrc.c

+22 −25
Original line number Diff line number Diff line
@@ -685,37 +685,34 @@ static bool io_coalesce_buffer(struct page ***pages, int *nr_pages, 
				struct io_imu_folio_data *data)

{

	struct page **page_array = *pages, **new_array = NULL;

	int nr_pages_left = *nr_pages, i, j;

	int nr_folios = data->nr_folios;

	unsigned nr_pages_left = *nr_pages;

	unsigned nr_folios = data->nr_folios;

	unsigned i, j;



	/* Store head pages only*/

	new_array = kvmalloc_array(nr_folios, sizeof(struct page *),

					GFP_KERNEL);

	new_array = kvmalloc_array(nr_folios, sizeof(struct page *), GFP_KERNEL);

	if (!new_array)

		return false;



	new_array[0] = compound_head(page_array[0]);

	/*

	 * The pages are bound to the folio, it doesn't

	 * actually unpin them but drops all but one reference,

	 * which is usually put down by io_buffer_unmap().

	 */

	if (data->nr_pages_head > 1)

		unpin_user_folio(page_folio(new_array[0]), data->nr_pages_head - 1);



	j = data->nr_pages_head;

	nr_pages_left -= data->nr_pages_head;

	for (i = 1; i < nr_folios; i++) {

		unsigned int nr_unpin;



		new_array[i] = page_array[j];

		nr_unpin = min_t(unsigned int, nr_pages_left - 1,

					data->nr_pages_mid - 1);

		if (nr_unpin)

			unpin_user_folio(page_folio(new_array[i]), nr_unpin);

		j += data->nr_pages_mid;

		nr_pages_left -= data->nr_pages_mid;

	for (i = 0, j = 0; i < nr_folios; i++) {

		struct page *p = compound_head(page_array[j]);

		struct folio *folio = page_folio(p);

		unsigned int nr;



		WARN_ON_ONCE(i > 0 && p != page_array[j]);



		nr = i ? data->nr_pages_mid : data->nr_pages_head;

		nr = min(nr, nr_pages_left);

		/* Drop all but one ref, the entire folio will remain pinned. */

		if (nr > 1)

			unpin_user_folio(folio, nr - 1);

		j += nr;

		nr_pages_left -= nr;

		new_array[i] = p;

	}



	WARN_ON_ONCE(j != *nr_pages);



	kvfree(page_array);

	*pages = new_array;

	*nr_pages = nr_folios;