@@ -553,9 +553,7 @@ static bool req_no_special_merge(struct request *req)
static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
struct request *next)
{
- int total_phys_segments;
- unsigned int seg_size =
- req->biotail->bi_seg_back_size + next->bio->bi_seg_front_size;
+ int total_phys_segments = 0;
/*
* First check if the either of the requests are re-queued
@@ -574,17 +572,27 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
blk_rq_get_max_sectors(req, blk_rq_pos(req)))
return 0;
- total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
- if (blk_phys_contig_segment(q, req->biotail, next->bio)) {
- if (req->nr_phys_segments == 1)
- req->bio->bi_seg_front_size = seg_size;
- if (next->nr_phys_segments == 1)
- next->biotail->bi_seg_back_size = seg_size;
- total_phys_segments--;
- }
+ /*
+ * If the requests aren't carrying any data payloads, we don't need
+ * to look at the segment count
+ */
+ if (bio_has_data(next->bio)) {
+ total_phys_segments = req->nr_phys_segments +
+ next->nr_phys_segments;
+ if (blk_phys_contig_segment(q, req->biotail, next->bio)) {
+ unsigned int seg_size = req->biotail->bi_seg_back_size +
+ next->bio->bi_seg_front_size;
+
+ if (req->nr_phys_segments == 1)
+ req->bio->bi_seg_front_size = seg_size;
+ if (next->nr_phys_segments == 1)
+ next->biotail->bi_seg_back_size = seg_size;
+ total_phys_segments--;
+ }
- if (total_phys_segments > queue_max_segments(q))
- return 0;
+ if (total_phys_segments > queue_max_segments(q))
+ return 0;
+ }
if (blk_integrity_merge_rq(q, req, next) == false)
return 0;