bio_get_first_bvec(prev_rq->bio, &pb);
else
bio_get_first_bvec(prev, &pb);
- if (pb.bv_offset)
+ if (pb.bv_offset & queue_virt_boundary(q))
return true;
/*
/* Zero-sector (unknown) and one-sector granularities are the same. */
granularity = max(q->limits.discard_granularity >> 9, 1U);
- max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+ max_discard_sectors = min(q->limits.max_discard_sectors,
+ bio_allowed_max_sectors(q));
max_discard_sectors -= max_discard_sectors % granularity;
if (unlikely(!max_discard_sectors)) {
part_stat_unlock();
}
}
+/*
+ * Two cases of handling DISCARD merge:
+ * If max_discard_segments > 1, the driver takes every bio
+ * as a range and send them to controller together. The ranges
+ * needn't to be contiguous.
+ * Otherwise, the bios/requests will be handled as same as
+ * others which should be contiguous.
+ */
+static inline bool blk_discard_mergable(struct request *req)
+{
+ if (req_op(req) == REQ_OP_DISCARD &&
+ queue_max_discard_segments(req->q) > 1)
+ return true;
+ return false;
+}
+
+enum elv_merge blk_try_req_merge(struct request *req, struct request *next)
+{
+ if (blk_discard_mergable(req))
+ return ELEVATOR_DISCARD_MERGE;
+ else if (blk_rq_pos(req) + blk_rq_sectors(req) == blk_rq_pos(next))
+ return ELEVATOR_BACK_MERGE;
+
+ return ELEVATOR_NO_MERGE;
+}
/*
* For non-mq, this has to be called with the request spinlock acquired.
if (req_op(req) != req_op(next))
return NULL;
- /*
- * not contiguous
- */
- if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
- return NULL;
-
if (rq_data_dir(req) != rq_data_dir(next)
|| req->rq_disk != next->rq_disk
|| req_no_special_merge(next))
* counts here. Handle DISCARDs separately, as they
* have separate settings.
*/
- if (req_op(req) == REQ_OP_DISCARD) {
+
+ switch (blk_try_req_merge(req, next)) {
+ case ELEVATOR_DISCARD_MERGE:
if (!req_attempt_discard_merge(q, req, next))
return NULL;
- } else if (!ll_merge_requests_fn(q, req, next))
+ break;
+ case ELEVATOR_BACK_MERGE:
+ if (!ll_merge_requests_fn(q, req, next))
+ return NULL;
+ break;
+ default:
return NULL;
+ }
/*
* If failfast settings disagree or any of the two is already
enum elv_merge blk_try_merge(struct request *rq, struct bio *bio)
{
- if (req_op(rq) == REQ_OP_DISCARD &&
- queue_max_discard_segments(rq->q) > 1)
+ if (blk_discard_mergable(rq))
return ELEVATOR_DISCARD_MERGE;
else if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector)
return ELEVATOR_BACK_MERGE;