Commit 1545f137 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Correctly check against BIO_MAX_PAGES 



bch_bio_max_sectors() was checking against BIO_MAX_PAGES as if the limit
was for the total bytes in the bio, not the number of segments.

Signed-off-by: default avatarKent Overstreet <koverstreet@google.com>
parent bca97ada

drivers/md/bcache/io.c

+4 −5
Original line number Diff line number Diff line
@@ -158,8 +158,10 @@ static unsigned bch_bio_max_sectors(struct bio *bio) 
{

	unsigned ret = bio_sectors(bio);

	struct request_queue *q = bdev_get_queue(bio->bi_bdev);

	unsigned max_segments = min_t(unsigned, BIO_MAX_PAGES,

				      queue_max_segments(q));

	struct bio_vec *bv, *end = bio_iovec(bio) +

		min_t(int, bio_segments(bio), queue_max_segments(q));

		min_t(int, bio_segments(bio), max_segments);



	struct bvec_merge_data bvm = {

		.bi_bdev	= bio->bi_bdev,
@@ -171,7 +173,7 @@ static unsigned bch_bio_max_sectors(struct bio *bio) 
	if (bio->bi_rw & REQ_DISCARD)

		return min(ret, q->limits.max_discard_sectors);



	if (bio_segments(bio) > queue_max_segments(q) ||

	if (bio_segments(bio) > max_segments ||

	    q->merge_bvec_fn) {

		ret = 0;
@@ -183,9 +185,6 @@ static unsigned bch_bio_max_sectors(struct bio *bio) 
			ret		+= bv->bv_len >> 9;

			bvm.bi_size	+= bv->bv_len;

		}



		if (ret >= (BIO_MAX_PAGES * PAGE_SIZE) >> 9)

			return (BIO_MAX_PAGES * PAGE_SIZE) >> 9;

	}



	ret = min(ret, queue_max_sectors(q));