nvmet: add nvmet_req_bio put helper for backends

In current code there exists two backends which are using inline bio
optimization, that adds a duplicate code for freeing the bio.

For Zoned Block Device backend we also use the same optimzation and it
will lead to having duplicate code in the three backends: generic
bdev, passsthru, and generic zns.

Add a helper function to avoid duplicate code and update the respective
backends.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/io-cmd-bdev.c

@@ -164,8 +164,7 @@ static void nvmet_bio_done(struct bio *bio)
 	struct nvmet_req *req = bio->bi_private;
 
 	nvmet_req_complete(req, blk_to_nvme_status(req, bio->bi_status));
-	if (bio != &req->b.inline_bio)
-		bio_put(bio);
+	nvmet_req_bio_put(req, bio);
 }
 
 #ifdef CONFIG_BLK_DEV_INTEGRITY

drivers/nvme/target/nvmet.h

@@ -632,4 +632,10 @@ static inline void nvmet_req_cns_error_complete(struct nvmet_req *req)
 	nvmet_req_complete(req, NVME_SC_INVALID_FIELD | NVME_SC_DNR);
 }
 
+static inline void nvmet_req_bio_put(struct nvmet_req *req, struct bio *bio)
+{
+	if (bio != &req->b.inline_bio)
+		bio_put(bio);
+}
+
 #endif /* _NVMET_H */

drivers/nvme/target/passthru.c

@@ -206,8 +206,7 @@ static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
 	for_each_sg(req->sg, sg, req->sg_cnt, i) {
 		if (bio_add_pc_page(rq->q, bio, sg_page(sg), sg->length,
 				    sg->offset) < sg->length) {
-			if (bio != &req->p.inline_bio)
-				bio_put(bio);
+			nvmet_req_bio_put(req, bio);
 			return -EINVAL;
 		}
 	}