[PATCH v3 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. Simplify blk_req_needs_zone_write_lock() by using the new function.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 block/blk-zoned.c      | 14 +-------------
 include/linux/blk-mq.h | 25 ++++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 38cd840d8838..9da8cf1bb378 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -57,19 +57,7 @@ EXPORT_SYMBOL_GPL(blk_zone_cond_str);
  */
 bool blk_req_needs_zone_write_lock(struct request *rq)
 {
-	if (!rq->q->seq_zones_wlock)
-		return false;
-
-	if (blk_rq_is_passthrough(rq))
-		return false;
-
-	switch (req_op(rq)) {
-	case REQ_OP_WRITE_ZEROES:
-	case REQ_OP_WRITE:
-		return blk_rq_zone_is_seq(rq);
-	default:
-		return false;
-	}
+	return rq->q->seq_zones_wlock && blk_rq_is_seq_zone_write(rq);
 }
 EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
 
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 909d47e34b7c..ccfcac9db879 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -1129,13 +1129,31 @@ static inline unsigned int blk_rq_zone_no(struct request *rq)
  * @rq: Request pointer.
  *
  * Return: true if and only if blk_rq_pos(@rq) refers either to a sequential
- * write required or a sequential write preferred zone.
+ * write required or to a sequential write preferred zone.
  */
 static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
 {
 	return blk_queue_zone_is_seq(rq->q, 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);
@@ -1166,6 +1184,11 @@ 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;