nvme-tcp: add nvme-tcp pdu size build protection

Make sure that we don't somehow mess up the wire structures in the spec.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kkch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/tcp.c

@@ -2694,6 +2694,15 @@ static struct nvmf_transport_ops nvme_tcp_transport = {
 
 static int __init nvme_tcp_init_module(void)
 {
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_hdr) != 8);
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_cmd_pdu) != 72);
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_data_pdu) != 24);
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_rsp_pdu) != 24);
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_r2t_pdu) != 24);
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_icreq_pdu) != 128);
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_icresp_pdu) != 128);
+	BUILD_BUG_ON(sizeof(struct nvme_tcp_term_pdu) != 24);
+
 	nvme_tcp_wq = alloc_workqueue("nvme_tcp_wq",
 			WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
 	if (!nvme_tcp_wq)