[PATCH v3 3/9] block: Introduce blk_rq_is_seq_zoned_write()

[Bart Van Assche <bvanassche@xxxxxxx>]

Introduce the function blk_rq_is_seq_zoned_write(). This function will
be used in later patches to preserve the order of zoned writes for which
the order needs to be preserved.

Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 block/blk-zoned.c      | 22 +++++++++++++++++++---
 include/linux/blk-mq.h |  6 ++++++
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 4640b75ae66f..78c39fc505bc 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -52,15 +52,31 @@ const char *blk_zone_cond_str(enum blk_zone_cond zone_cond)
 }
 EXPORT_SYMBOL_GPL(blk_zone_cond_str);
 
+/**
+ * blk_rq_is_seq_zoned_write() - Check if @rq requires write serialization.
+ * @rq: Request to examine.
+ *
+ * Note: REQ_OP_ZONE_APPEND requests do not require serialization.
+ */
+bool blk_rq_is_seq_zoned_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;
+	}
+}
+EXPORT_SYMBOL_GPL(blk_rq_is_seq_zoned_write);
+
 /*
  * Return true if a request is a write requests that needs zone write locking.
  */
 bool blk_req_needs_zone_write_lock(struct request *rq)
 {
 	return rq->q->disk->seq_zones_wlock &&
-		(req_op(rq) == REQ_OP_WRITE ||
-		 req_op(rq) == REQ_OP_WRITE_ZEROES) &&
-		blk_rq_zone_is_seq(rq);
+		blk_rq_is_seq_zoned_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 06caacd77ed6..e498b85bc470 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -1164,6 +1164,7 @@ static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
 	return disk_zone_is_seq(rq->q->disk, blk_rq_pos(rq));
 }
 
+bool blk_rq_is_seq_zoned_write(struct request *rq);
 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);
@@ -1194,6 +1195,11 @@ 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_zoned_write(struct request *rq)
+{
+	return false;
+}
+
 static inline bool blk_req_needs_zone_write_lock(struct request *rq)
 {
 	return false;