block: improve the gap check in __bio_add_pc_page (320ea869) · Commits · 戴 / test

If we can add more data into an existing segment we do not create a gap per definition, so move the check for a gap after the attempt to merge into the segment. Signed-off-by:

Christoph Hellwig <hch@lst.de> Reviewed-by:

Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

block/bio.c

+7 −7

Original line number	Diff line number	Diff line
		@@ -710,18 +710,18 @@ static int __bio_add_pc_page(struct request_queue q, struct bio bio,
		goto done;
		}

		/*
		* If the queue doesn't support SG gaps and adding this
		* offset would create a gap, disallow it.
		*/
		if (bvec_gap_to_prev(q, bvec, offset))
		return 0;

		if (page_is_mergeable(bvec, page, len, offset, &same_page) &&
		can_add_page_to_seg(q, bvec, page, len, offset)) {
		bvec->bv_len += len;
		goto done;
		}

		/*
		* If the queue doesn't support SG gaps and adding this segment
		* would create a gap, disallow it.
		*/
		if (bvec_gap_to_prev(q, bvec, offset))
		return 0;
		}

		if (bio_full(bio, len))

Admin message