block: get rid of on-stack plugging debug checks
Jens Axboe [Fri, 20 May 2011 18:52:16 +0000 (20:52 +0200)]
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>

block/blk-core.c
block/elevator.c
include/linux/blk_types.h

index 9e8e297..7369eee 100644 (file)
@@ -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
                 */
index 2a0b653..b0b38ce 100644 (file)
@@ -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 ||
index be50d9e..2a7cea5 100644 (file)
@@ -151,7 +151,6 @@ enum rq_flag_bits {
        __REQ_IO_STAT,          /* account I/O stat */
        __REQ_MIXED_MERGE,      /* merge of different types, fail separately */
        __REQ_SECURE,           /* secure discard (used with __REQ_DISCARD) */
-       __REQ_ON_PLUG,          /* on plug list */
        __REQ_NR_BITS,          /* stops here */
 };
 
@@ -192,6 +191,5 @@ enum rq_flag_bits {
 #define REQ_IO_STAT            (1 << __REQ_IO_STAT)
 #define REQ_MIXED_MERGE                (1 << __REQ_MIXED_MERGE)
 #define REQ_SECURE             (1 << __REQ_SECURE)
-#define REQ_ON_PLUG            (1 << __REQ_ON_PLUG)
 
 #endif /* __LINUX_BLK_TYPES_H */