From: Geliang Tang <tanggeliang@kylinos.cn>

This patch defines a new nvmet_fabrics_ops named nvmet_mptcp_ops, which
is almost identical to nvmet_tcp_ops except for the .type field.

It is registered in nvmet_tcp_init() and unregistered in nvmet_tcp_exit().

This new nvmet_fabrics_ops is selected in nvmet_tcp_done_recv_pdu() based
on the protocol type.

A MODULE_ALIAS for "nvmet-transport-4" is also added.

v2:
 - use trtype instead of tsas (Hannes).

v3:
 - check mptcp protocol from disc_addr.trtype instead of passing a
parameter (Hannes).

v4:
 - check CONFIG_MPTCP.

Cc: Hannes Reinecke <hare@suse.de>
Co-developed-by: zhenwei pi <zhenwei.pi@linux.dev>
Signed-off-by: zhenwei pi <zhenwei.pi@linux.dev>
Co-developed-by: Hui Zhu <zhuhui@kylinos.cn>
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
Co-developed-by: Gang Yan <yangang@kylinos.cn>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 drivers/nvme/target/configfs.c |  1 +
 drivers/nvme/target/tcp.c      | 41 +++++++++++++++++++++++++++++++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 3088e044dbcb..4b7498ffb102 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -38,6 +38,7 @@ static struct nvmet_type_name_map nvmet_transport[] = {
 	{ NVMF_TRTYPE_RDMA,	"rdma" },
 	{ NVMF_TRTYPE_FC,	"fc" },
 	{ NVMF_TRTYPE_TCP,	"tcp" },
+	{ NVMF_TRTYPE_MPTCP,	"mptcp" },
 	{ NVMF_TRTYPE_PCI,	"pci" },
 	{ NVMF_TRTYPE_LOOP,	"loop" },
 };
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 8471b14a7ee8..1ca9fbbaea92 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -222,6 +222,9 @@ static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
 
 static struct workqueue_struct *nvmet_tcp_wq;
 static const struct nvmet_fabrics_ops nvmet_tcp_ops;
+#ifdef CONFIG_MPTCP
+static const struct nvmet_fabrics_ops nvmet_mptcp_ops;
+#endif
 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
 static void nvmet_tcp_free_cmd_buffers(struct nvmet_tcp_cmd *cmd);
 
@@ -1037,6 +1040,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 {
 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
 	struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
+	const struct nvmet_fabrics_ops *ops;
 	struct nvmet_req *req;
 	int ret;
 
@@ -1077,7 +1081,15 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 	req = &queue->cmd->req;
 	memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
 
-	if (unlikely(!nvmet_req_init(req, &queue->nvme_sq, &nvmet_tcp_ops))) {
+	if (queue->sock->sk->sk_protocol == IPPROTO_TCP)
+		ops = &nvmet_tcp_ops;
+#ifdef CONFIG_MPTCP
+	else if (queue->sock->sk->sk_protocol == IPPROTO_MPTCP)
+		ops = &nvmet_mptcp_ops;
+#endif
+	else
+		return -EINVAL;
+	if (unlikely(!nvmet_req_init(req, &queue->nvme_sq, ops))) {
 		pr_err("failed cmd %p id %d opcode %d, data_len: %d, status: %04x\n",
 			req->cmd, req->cmd->common.command_id,
 			req->cmd->common.opcode,
@@ -2264,6 +2276,21 @@ static const struct nvmet_fabrics_ops nvmet_tcp_ops = {
 	.host_traddr		= nvmet_tcp_host_port_addr,
 };
 
+#ifdef CONFIG_MPTCP
+static const struct nvmet_fabrics_ops nvmet_mptcp_ops = {
+	.owner			= THIS_MODULE,
+	.type			= NVMF_TRTYPE_MPTCP,
+	.msdbd			= 1,
+	.add_port		= nvmet_tcp_add_port,
+	.remove_port		= nvmet_tcp_remove_port,
+	.queue_response		= nvmet_tcp_queue_response,
+	.delete_ctrl		= nvmet_tcp_delete_ctrl,
+	.install_queue		= nvmet_tcp_install_queue,
+	.disc_traddr		= nvmet_tcp_disc_port_addr,
+	.host_traddr		= nvmet_tcp_host_port_addr,
+};
+#endif
+
 static int __init nvmet_tcp_init(void)
 {
 	int ret;
@@ -2277,6 +2304,14 @@ static int __init nvmet_tcp_init(void)
 	if (ret)
 		goto err;
 
+#ifdef CONFIG_MPTCP
+	ret = nvmet_register_transport(&nvmet_mptcp_ops);
+	if (ret) {
+		nvmet_unregister_transport(&nvmet_tcp_ops);
+		goto err;
+	}
+#endif
+
 	return 0;
 err:
 	destroy_workqueue(nvmet_tcp_wq);
@@ -2287,6 +2322,9 @@ static void __exit nvmet_tcp_exit(void)
 {
 	struct nvmet_tcp_queue *queue;
 
+#ifdef CONFIG_MPTCP
+	nvmet_unregister_transport(&nvmet_mptcp_ops);
+#endif
 	nvmet_unregister_transport(&nvmet_tcp_ops);
 
 	flush_workqueue(nvmet_wq);
@@ -2306,3 +2344,4 @@ module_exit(nvmet_tcp_exit);
 MODULE_DESCRIPTION("NVMe target TCP transport driver");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
+MODULE_ALIAS("nvmet-transport-4"); /* 4 == NVMF_TRTYPE_MPTCP */
-- 
2.51.0