block: Move bio merge related functions into blk-merge.c

It's better to move bio merge related functions into blk-merge.c,
which contains all merge related functions.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 0 insertions, 156 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 10c08ac50697..11661f5b64d6 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -643,162 +643,6 @@ void blk_put_request(struct request *req)
 }
 EXPORT_SYMBOL(blk_put_request);
 
-static void blk_account_io_merge_bio(struct request *req)
-{
-	if (!blk_do_io_stat(req))
-		return;
-
-	part_stat_lock();
-	part_stat_inc(req->part, merges[op_stat_group(req_op(req))]);
-	part_stat_unlock();
-}
-
-bool bio_attempt_back_merge(struct request *req, struct bio *bio,
-		unsigned int nr_segs)
-{
-	const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
-
-	if (!ll_back_merge_fn(req, bio, nr_segs))
-		return false;
-
-	trace_block_bio_backmerge(req->q, req, bio);
-	rq_qos_merge(req->q, req, bio);
-
-	if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
-		blk_rq_set_mixed_merge(req);
-
-	req->biotail->bi_next = bio;
-	req->biotail = bio;
-	req->__data_len += bio->bi_iter.bi_size;
-
-	bio_crypt_free_ctx(bio);
-
-	blk_account_io_merge_bio(req);
-	return true;
-}
-
-bool bio_attempt_front_merge(struct request *req, struct bio *bio,
-		unsigned int nr_segs)
-{
-	const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
-
-	if (!ll_front_merge_fn(req, bio, nr_segs))
-		return false;
-
-	trace_block_bio_frontmerge(req->q, req, bio);
-	rq_qos_merge(req->q, req, bio);
-
-	if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
-		blk_rq_set_mixed_merge(req);
-
-	bio->bi_next = req->bio;
-	req->bio = bio;
-
-	req->__sector = bio->bi_iter.bi_sector;
-	req->__data_len += bio->bi_iter.bi_size;
-
-	bio_crypt_do_front_merge(req, bio);
-
-	blk_account_io_merge_bio(req);
-	return true;
-}
-
-bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
-		struct bio *bio)
-{
-	unsigned short segments = blk_rq_nr_discard_segments(req);
-
-	if (segments >= queue_max_discard_segments(q))
-		goto no_merge;
-	if (blk_rq_sectors(req) + bio_sectors(bio) >
-	    blk_rq_get_max_sectors(req, blk_rq_pos(req)))
-		goto no_merge;
-
-	rq_qos_merge(q, req, bio);
-
-	req->biotail->bi_next = bio;
-	req->biotail = bio;
-	req->__data_len += bio->bi_iter.bi_size;
-	req->nr_phys_segments = segments + 1;
-
-	blk_account_io_merge_bio(req);
-	return true;
-no_merge:
-	req_set_nomerge(q, req);
-	return false;
-}
-
-/**
- * blk_attempt_plug_merge - try to merge with %current's plugged list
- * @q: request_queue new bio is being queued at
- * @bio: new bio being queued
- * @nr_segs: number of segments in @bio
- * @same_queue_rq: pointer to &struct request that gets filled in when
- * another request associated with @q is found on the plug list
- * (optional, may be %NULL)
- *
- * Determine whether @bio being queued on @q can be merged with a request
- * on %current's plugged list.  Returns %true if merge was successful,
- * otherwise %false.
- *
- * Plugging coalesces IOs from the same issuer for the same purpose without
- * going through @q->queue_lock.  As such it's more of an issuing mechanism
- * than scheduling, and the request, while may have elvpriv data, is not
- * added on the elevator at this point.  In addition, we don't have
- * reliable access to the elevator outside queue lock.  Only check basic
- * merging parameters without querying the elevator.
- *
- * Caller must ensure !blk_queue_nomerges(q) beforehand.
- */
-bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
-		unsigned int nr_segs, struct request **same_queue_rq)
-{
-	struct blk_plug *plug;
-	struct request *rq;
-	struct list_head *plug_list;
-
-	plug = blk_mq_plug(q, bio);
-	if (!plug)
-		return false;
-
-	plug_list = &plug->mq_list;
-
-	list_for_each_entry_reverse(rq, plug_list, queuelist) {
-		bool merged = false;
-
-		if (rq->q == q && same_queue_rq) {
-			/*
-			 * Only blk-mq multiple hardware queues case checks the
-			 * rq in the same queue, there should be only one such
-			 * rq in a queue
-			 **/
-			*same_queue_rq = rq;
-		}
-
-		if (rq->q != q || !blk_rq_merge_ok(rq, bio))
-			continue;
-
-		switch (blk_try_merge(rq, bio)) {
-		case ELEVATOR_BACK_MERGE:
-			merged = bio_attempt_back_merge(rq, bio, nr_segs);
-			break;
-		case ELEVATOR_FRONT_MERGE:
-			merged = bio_attempt_front_merge(rq, bio, nr_segs);
-			break;
-		case ELEVATOR_DISCARD_MERGE:
-			merged = bio_attempt_discard_merge(q, rq, bio);
-			break;
-		default:
-			break;
-		}
-
-		if (merged)
-			return true;
-	}
-
-	return false;
-}
-
 static void handle_bad_sector(struct bio *bio, sector_t maxsector)
 {
 	char b[BDEVNAME_SIZE];