nvmet: Add drvdata field to struct nvmet_ctrl

Allow a target driver to attach private data to a target controller by
adding the new field drvdata to struct nvmet_ctrl.

Signed-off-by: Damien Le Moal <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Tested-by: Rick Wertenbroek <[email protected]>
Tested-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Keith Busch <[email protected]>

Author: damien-lemoal

drivers/nvme/target/nvmet.h

@@ -238,6 +238,8 @@ struct nvmet_ctrl {
 	struct nvmet_subsys	*subsys;
 	struct nvmet_sq		**sqs;
 
+	void			*drvdata;
+
 	bool			reset_tbkas;
 
 	struct mutex		lock;