nvme: split nvme_report_zones

Split multipath support out of nvme_report_zones into a separate helper
and simplify the non-multipath version as a result.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

drivers/nvme/host/core.c

@@ -2073,6 +2073,17 @@ int nvme_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, size_t len,
 EXPORT_SYMBOL_GPL(nvme_sec_submit);
 #endif /* CONFIG_BLK_SED_OPAL */
 
+#ifdef CONFIG_BLK_DEV_ZONED
+static int nvme_report_zones(struct gendisk *disk, sector_t sector,
+		unsigned int nr_zones, report_zones_cb cb, void *data)
+{
+	return nvme_ns_report_zones(disk->private_data, sector, nr_zones, cb,
+			data);
+}
+#else
+#define nvme_report_zones	NULL
+#endif /* CONFIG_BLK_DEV_ZONED */
+
 static const struct block_device_operations nvme_bdev_ops = {
 	.owner		= THIS_MODULE,
 	.ioctl		= nvme_ioctl,

drivers/nvme/host/multipath.c

@@ -349,6 +349,25 @@ static void nvme_ns_head_release(struct gendisk *disk, fmode_t mode)
 	nvme_put_ns_head(disk->private_data);
 }
 
+#ifdef CONFIG_BLK_DEV_ZONED
+static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector,
+		unsigned int nr_zones, report_zones_cb cb, void *data)
+{
+	struct nvme_ns_head *head = disk->private_data;
+	struct nvme_ns *ns;
+	int srcu_idx, ret = -EWOULDBLOCK;
+
+	srcu_idx = srcu_read_lock(&head->srcu);
+	ns = nvme_find_path(head);
+	if (ns)
+		ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data);
+	srcu_read_unlock(&head->srcu, srcu_idx);
+	return ret;
+}
+#else
+#define nvme_ns_head_report_zones	NULL
+#endif /* CONFIG_BLK_DEV_ZONED */
+
 const struct block_device_operations nvme_ns_head_ops = {
 	.owner		= THIS_MODULE,
 	.submit_bio	= nvme_ns_head_submit_bio,
@@ -356,7 +375,7 @@ const struct block_device_operations nvme_ns_head_ops = {
 	.release	= nvme_ns_head_release,
 	.ioctl		= nvme_ns_head_ioctl,
 	.getgeo		= nvme_getgeo,
-	.report_zones	= nvme_report_zones,
+	.report_zones	= nvme_ns_head_report_zones,
 	.pr_ops		= &nvme_pr_ops,
 };
 

drivers/nvme/host/nvme.h

@@ -810,17 +810,14 @@ static inline void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)
 #endif /* CONFIG_NVME_MULTIPATH */
 
 int nvme_revalidate_zones(struct nvme_ns *ns);
+int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
+		unsigned int nr_zones, report_zones_cb cb, void *data);
 #ifdef CONFIG_BLK_DEV_ZONED
 int nvme_update_zone_info(struct nvme_ns *ns, unsigned lbaf);
-int nvme_report_zones(struct gendisk *disk, sector_t sector,
-		      unsigned int nr_zones, report_zones_cb cb, void *data);
-
 blk_status_t nvme_setup_zone_mgmt_send(struct nvme_ns *ns, struct request *req,
 				       struct nvme_command *cmnd,
 				       enum nvme_zone_mgmt_action action);
 #else
-#define nvme_report_zones NULL
-
 static inline blk_status_t nvme_setup_zone_mgmt_send(struct nvme_ns *ns,
 		struct request *req, struct nvme_command *cmnd,
 		enum nvme_zone_mgmt_action action)

drivers/nvme/host/zns.c

@@ -171,8 +171,8 @@ static int nvme_zone_parse_entry(struct nvme_ns *ns,
 	return cb(&zone, idx, data);
 }
 
-static int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
-			unsigned int nr_zones, report_zones_cb cb, void *data)
+int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
+		unsigned int nr_zones, report_zones_cb cb, void *data)
 {
 	struct nvme_zone_report *report;
 	struct nvme_command c = { };
@@ -230,22 +230,6 @@ static int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
 	return ret;
 }
 
-int nvme_report_zones(struct gendisk *disk, sector_t sector,
-		      unsigned int nr_zones, report_zones_cb cb, void *data)
-{
-	struct nvme_ns_head *head = NULL;
-	struct nvme_ns *ns;
-	int srcu_idx, ret;
-
-	ns = nvme_get_ns_from_disk(disk, &head, &srcu_idx);
-	if (unlikely(!ns))
-		return -EWOULDBLOCK;
-	ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data);
-	nvme_put_ns_from_disk(head, srcu_idx);
-
-	return ret;
-}
-
 blk_status_t nvme_setup_zone_mgmt_send(struct nvme_ns *ns, struct request *req,
 		struct nvme_command *c, enum nvme_zone_mgmt_action action)
 {