blk-mq: add support for carrying internal tag information in blk_qc_t

axboe · axboe · commit fd2d332677c6 · 2017-01-17T10:04:09.000-07:00
No functional change in this patch, just in preparation for having
two types of tags available to the block layer for a single request.

Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
Reviewed-by: Omar Sandoval &lt;osandov@fb.com&gt;
diff --git a/block/blk-mq.c b/block/blk-mq.c
@@ -1308,6 +1308,11 @@ static struct request *blk_mq_map_request(struct request_queue *q,
 	return rq;
 }
 
+static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq)
+{
+	return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false);
+}
+
 static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie)
 {
 	int ret;
@@ -1318,7 +1323,7 @@ static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie)
 		.list = NULL,
 		.last = 1
 	};
-	blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);
+	blk_qc_t new_cookie = request_to_qc_t(hctx, rq);
 
 	if (blk_mq_hctx_stopped(hctx))
 		goto insert;
@@ -1387,7 +1392,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
 	wbt_track(&rq->issue_stat, wb_acct);
 
-	cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
+	cookie = request_to_qc_t(data.hctx, rq);
 
 	if (unlikely(is_flush_fua)) {
 		blk_mq_bio_to_request(rq, bio);
@@ -1496,7 +1501,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
 
 	wbt_track(&rq->issue_stat, wb_acct);
 
-	cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
+	cookie = request_to_qc_t(data.hctx, rq);
 
 	if (unlikely(is_flush_fua)) {
 		blk_mq_bio_to_request(rq, bio);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
@@ -232,29 +232,41 @@ static inline bool op_is_sync(unsigned int op)
 }
 
 typedef unsigned int blk_qc_t;
-#define BLK_QC_T_NONE	-1U
-#define BLK_QC_T_SHIFT	16
+#define BLK_QC_T_NONE		-1U
+#define BLK_QC_T_SHIFT		16
+#define BLK_QC_T_INTERNAL	(1U << 31)
 
 static inline bool blk_qc_t_valid(blk_qc_t cookie)
 {
 	return cookie != BLK_QC_T_NONE;
 }
 
-static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)
+static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
+				       bool internal)
 {
-	return tag | (queue_num << BLK_QC_T_SHIFT);
+	blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
+
+	if (internal)
+		ret |= BLK_QC_T_INTERNAL;
+
+	return ret;
 }
 
 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
 {
-	return cookie >> BLK_QC_T_SHIFT;
+	return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
 }
 
 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
 {
 	return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
 }
 
+static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
+{
+	return (cookie & BLK_QC_T_INTERNAL) != 0;
+}
+
 struct blk_issue_stat {
 	u64 time;
 };

Original file line number	Diff line number	Diff line change
`@@ -232,29 +232,41 @@ static inline bool op_is_sync(unsigned int op)`
`232`	`232`	`}`
`233`	`233`
`234`	`234`	`typedef unsigned int blk_qc_t;`
`235`		`-#define BLK_QC_T_NONE -1U`
`236`		`-#define BLK_QC_T_SHIFT 16`
	`235`	`+#define BLK_QC_T_NONE -1U`
	`236`	`+#define BLK_QC_T_SHIFT 16`
	`237`	`+#define BLK_QC_T_INTERNAL (1U << 31)`
`237`	`238`
`238`	`239`	`static inline bool blk_qc_t_valid(blk_qc_t cookie)`
`239`	`240`	`{`
`240`	`241`	`return cookie != BLK_QC_T_NONE;`
`241`	`242`	`}`
`242`	`243`
`243`		`-static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)`
	`244`	`+static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,`
	`245`	`+ bool internal)`
`244`	`246`	`{`
`245`		`- return tag \| (queue_num << BLK_QC_T_SHIFT);`
	`247`	`+ blk_qc_t ret = tag \| (queue_num << BLK_QC_T_SHIFT);`
	`248`	`+`
	`249`	`+ if (internal)`
	`250`	`+ ret \|= BLK_QC_T_INTERNAL;`
	`251`	`+`
	`252`	`+ return ret;`
`246`	`253`	`}`
`247`	`254`
`248`	`255`	`static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)`
`249`	`256`	`{`
`250`		`- return cookie >> BLK_QC_T_SHIFT;`
	`257`	`+ return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;`
`251`	`258`	`}`
`252`	`259`
`253`	`260`	`static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)`
`254`	`261`	`{`
`255`	`262`	`return cookie & ((1u << BLK_QC_T_SHIFT) - 1);`
`256`	`263`	`}`
`257`	`264`
	`265`	`+static inline bool blk_qc_t_is_internal(blk_qc_t cookie)`
	`266`	`+{`
	`267`	`+ return (cookie & BLK_QC_T_INTERNAL) != 0;`
	`268`	`+}`
	`269`	`+`
`258`	`270`	`struct blk_issue_stat {`
`259`	`271`	`u64 time;`
`260`	`272`	`};`