[PATCH] [v2] blk-mq: use BLK_MQ_NO_TAG for no tag

[Xianting Tian]

Replace various magic -1 constants for tags with BLK_MQ_NO_TAG.
And move the definition of BLK_MQ_NO_TAG from 'block/blk-mq-tag.h'
to 'include/linux/blk-mq.h'

Signed-off-by: Xianting Tian <tian.xiant...@h3c.com>
---
 block/blk-core.c       | 4 ++--
 block/blk-mq-sched.c   | 2 +-
 block/blk-mq-tag.h     | 6 ------
 include/linux/blk-mq.h | 8 +++++++-
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index d9d632639..c7eaf7504 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -116,8 +116,8 @@ void blk_rq_init(struct request_queue *q, struct request 
*rq)
        rq->__sector = (sector_t) -1;
        INIT_HLIST_NODE(&rq->hash);
        RB_CLEAR_NODE(&rq->rb_node);
-       rq->tag = -1;
-       rq->internal_tag = -1;
+       rq->tag = BLK_MQ_NO_TAG;
+       rq->internal_tag = BLK_MQ_NO_TAG;
        rq->start_time_ns = ktime_get_ns();
        rq->part = NULL;
        refcount_set(&rq->ref, 1);
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index a19cdf159..439481f59 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -522,7 +522,7 @@ void blk_mq_sched_insert_request(struct request *rq, bool 
at_head,
                goto run;
        }
 
-       WARN_ON(e && (rq->tag != -1));
+       WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG));
 
        if (blk_mq_sched_bypass_insert(hctx, !!e, rq)) {
                /*
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index b1acac518..8fc48aa72 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -45,12 +45,6 @@ static inline struct sbq_wait_state *bt_wait_ptr(struct 
sbitmap_queue *bt,
        return sbq_wait_ptr(bt, &hctx->wait_index);
 }
 
-enum {
-       BLK_MQ_NO_TAG           = -1U,
-       BLK_MQ_TAG_MIN          = 1,
-       BLK_MQ_TAG_MAX          = BLK_MQ_NO_TAG - 1,
-};
-
 extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
 extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
 
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 9d2d5ad36..2499d8aae 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -209,6 +209,12 @@ enum hctx_type {
        HCTX_MAX_TYPES,
 };
 
+enum {
+       BLK_MQ_NO_TAG           = -1U,
+       BLK_MQ_TAG_MIN          = 1,
+       BLK_MQ_TAG_MAX          = BLK_MQ_NO_TAG - 1,
+};
+
 /**
  * struct blk_mq_tag_set - tag set that can be shared between request queues
  * @map:          One or more ctx -> hctx mappings. One map exists for each
@@ -569,7 +575,7 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq)
 static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx,
                struct request *rq)
 {
-       if (rq->tag != -1)
+       if (rq->tag != BLK_MQ_NO_TAG)
                return rq->tag | (hctx->queue_num << BLK_QC_T_SHIFT);
 
        return rq->internal_tag | (hctx->queue_num << BLK_QC_T_SHIFT) |
-- 
2.17.1