[PATCH 2/8] block: Introduce the blk_rq_is_seq_zone_write() function

[Bart Van Assche <bvanassche@acm.org>]

Introduce a function that makes it easy to verify whether a write
request is for a sequential write required or sequential write preferred
zone.

Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 include/linux/blk-mq.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 6735db1ad24d..29f834e5c3a9 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -1167,6 +1167,24 @@ static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
 	return disk_zone_is_seq(rq->q->disk, blk_rq_pos(rq));
 }
 
+/**
+ * blk_rq_is_seq_zone_write() - Whether @rq is a write request for a sequential zone.
+ * @rq: Request to examine.
+ *
+ * In this context sequential zone means either a sequential write required or
+ * to a sequential write preferred zone.
+ */
+static inline bool blk_rq_is_seq_zone_write(struct request *rq)
+{
+	switch (req_op(rq)) {
+	case REQ_OP_WRITE:
+	case REQ_OP_WRITE_ZEROES:
+		return blk_rq_zone_is_seq(rq);
+	default:
+		return false;
+	}
+}
+
 bool blk_req_needs_zone_write_lock(struct request *rq);
 bool blk_req_zone_write_trylock(struct request *rq);
 void __blk_req_zone_write_lock(struct request *rq);
@@ -1197,6 +1215,11 @@ static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
 	return !blk_req_zone_is_write_locked(rq);
 }
 #else /* CONFIG_BLK_DEV_ZONED */
+static inline bool blk_rq_is_seq_zone_write(struct request *rq)
+{
+	return false;
+}
+
 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
 {
 	return false;