nvmet: add helper to report invalid opcode

In the NVMeOF block device backend, file backend, and passthru backend
we reject and report the commands if opcode is not handled.

Add an helper and use it in block device backend to keep the code
and error message uniform.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/core.c

@@ -82,6 +82,15 @@ inline u16 errno_to_nvme_status(struct nvmet_req *req, int errno)
 	return status;
 }
 
+u16 nvmet_report_invalid_opcode(struct nvmet_req *req)
+{
+	pr_debug("unhandled cmd %d on qid %d\n", req->cmd->common.opcode,
+		 req->sq->qid);
+
+	req->error_loc = offsetof(struct nvme_common_command, opcode);
+	return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+}
+
 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
 		const char *subsysnqn);
 

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

@@ -449,9 +449,6 @@ u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 		req->execute = nvmet_bdev_execute_write_zeroes;
 		return 0;
 	default:
-		pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
-		       req->sq->qid);
-		req->error_loc = offsetof(struct nvme_common_command, opcode);
-		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+		return nvmet_report_invalid_opcode(req);
 	}
 }

drivers/nvme/target/nvmet.h

@@ -589,6 +589,7 @@ nvmet_req_passthru_ctrl(struct nvmet_req *req)
 }
 
 u16 errno_to_nvme_status(struct nvmet_req *req, int errno);
+u16 nvmet_report_invalid_opcode(struct nvmet_req *req);
 
 /* Convert a 32-bit number to a 16-bit 0's based number */
 static inline __le16 to0based(u32 a)