block: get rid of on-stack plugging debug checks

We don't need them anymore, so kill:

- REQ_ON_PLUG checks in various places
- !rq_mergeable() check in plug merging

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

2 files changed, 0 insertions, 31 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 9e8e297374b..7369eeeafe2 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -569,8 +569,6 @@ int blk_get_queue(struct request_queue *q)
 
 static inline void blk_free_request(struct request_queue *q, struct request *rq)
 {
-        BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
-
         if (rq->cmd_flags & REQ_ELVPRIV)
                 elv_put_request(q, rq);
         mempool_free(rq, q->rq.rq_pool);
@@ -1110,14 +1108,6 @@ static bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
 {
         const int ff = bio->bi_rw & REQ_FAILFAST_MASK;
 
-        /*
-         * Debug stuff, kill later
-         */
-        if (!rq_mergeable(req)) {
-                blk_dump_rq_flags(req, "back");
-                return false;
-        }
-
         if (!ll_back_merge_fn(q, req, bio))
                 return false;
 
@@ -1141,14 +1131,6 @@ static bool bio_attempt_front_merge(struct request_queue *q,
         const int ff = bio->bi_rw & REQ_FAILFAST_MASK;
         sector_t sector;
 
-        /*
-         * Debug stuff, kill later
-         */
-        if (!rq_mergeable(req)) {
-                blk_dump_rq_flags(req, "front");
-                return false;
-        }
-
         if (!ll_front_merge_fn(q, req, bio))
                 return false;
 
@@ -1258,14 +1240,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 
         el_ret = elv_merge(q, &req, bio);
         if (el_ret == ELEVATOR_BACK_MERGE) {
-                BUG_ON(req->cmd_flags & REQ_ON_PLUG);
                 if (bio_attempt_back_merge(q, req, bio)) {
                         if (!attempt_back_merge(q, req))
                                 elv_merged_request(q, req, el_ret);
                         goto out_unlock;
                 }
         } else if (el_ret == ELEVATOR_FRONT_MERGE) {
-                BUG_ON(req->cmd_flags & REQ_ON_PLUG);
                 if (bio_attempt_front_merge(q, req, bio)) {
                         if (!attempt_front_merge(q, req))
                                 elv_merged_request(q, req, el_ret);
@@ -1320,10 +1300,6 @@ get_rq:
                         if (__rq->q != q)
                                 plug->should_sort = 1;
                 }
-                /*
-                 * Debug flag, kill later
-                 */
-                req->cmd_flags |= REQ_ON_PLUG;
                 list_add_tail(&req->queuelist, &plug->list);
                 drive_stat_acct(req, 1);
         } else {
@@ -2749,7 +2725,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
         while (!list_empty(&list)) {
                 rq = list_entry_rq(list.next);
                 list_del_init(&rq->queuelist);
-                BUG_ON(!(rq->cmd_flags & REQ_ON_PLUG));
                 BUG_ON(!rq->q);
                 if (rq->q != q) {
                         /*
@@ -2761,8 +2736,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
                         depth = 0;
                         spin_lock(q->queue_lock);
                 }
-                rq->cmd_flags &= ~REQ_ON_PLUG;
-
                 /*
                  * rq is already accounted, so use raw insert
                  */
diff --git a/block/elevator.c b/block/elevator.c
index 2a0b653c90f..b0b38ce0dcb 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -416,8 +416,6 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
         struct list_head *entry;
         int stop_flags;
 
-        BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
-
         if (q->last_merge == rq)
                 q->last_merge = NULL;
 
@@ -656,8 +654,6 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
 
         rq->q = q;
 
-        BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
-
         if (rq->cmd_flags & REQ_SOFTBARRIER) {
                 /* barriers are scheduling boundary, update end_sector */
                 if (rq->cmd_type == REQ_TYPE_FS ||