Commit 4aebe859 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: use memcpy_from_bvec in __blk_queue_bounce 



Rewrite the actual bounce buffering loop in __blk_queue_bounce to that
the memcpy_to_bvec helper can be used to perform the data copies.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727055646.118787-14-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d24920e2

block/bounce.c

+7 −12
Original line number Diff line number Diff line
@@ -239,24 +239,19 @@ void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) 
	 * because the 'bio' is single-page bvec.

	 */

	for (i = 0, to = bio->bi_io_vec; i < bio->bi_vcnt; to++, i++) {

		struct page *page = to->bv_page;

		struct page *bounce_page;



		if (!PageHighMem(page))

		if (!PageHighMem(to->bv_page))

			continue;



		to->bv_page = mempool_alloc(&page_pool, GFP_NOIO);

		inc_zone_page_state(to->bv_page, NR_BOUNCE);

		bounce_page = mempool_alloc(&page_pool, GFP_NOIO);

		inc_zone_page_state(bounce_page, NR_BOUNCE);



		if (rw == WRITE) {

			char *vto, *vfrom;



			flush_dcache_page(page);



			vto = page_address(to->bv_page) + to->bv_offset;

			vfrom = kmap_atomic(page) + to->bv_offset;

			memcpy(vto, vfrom, to->bv_len);

			kunmap_atomic(vfrom);

			flush_dcache_page(to->bv_page);

			memcpy_from_bvec(page_address(bounce_page), to);

		}

		to->bv_page = bounce_page;

	}



	trace_block_bio_bounce(*bio_orig);