[PATCH 4/4] nvme-fabrics: add explicit deregistration on disconnect.

[Martin Belanger <nitram_67@hotmail.com>]

From: Martin Belanger <martin.belanger@dell.com>

Per TP8010, a host explicitly registered with a Discovery
Controller (DC) must deregister on disconnect. This patch
sends a DIM PDU to DCs to deregister the host on disconnect.

Signed-off-by: Martin Belanger <martin.belanger@dell.com>
---
 drivers/nvme/host/tcp.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 970b7df574a4..804d927b4b81 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2176,6 +2176,16 @@ static void nvme_tcp_teardown_ctrl(struct nvme_ctrl *ctrl, bool shutdown)
 
 static void nvme_tcp_delete_ctrl(struct nvme_ctrl *ctrl)
 {
+	if (ctrl->opts->explicit_registration &&
++	    ((ctrl->dctype == NVME_DCTYPE_DDC) ||
+	     (ctrl->dctype == NVME_DCTYPE_CDC))) {
+		/* Deregister from discovery controller */
+		union nvmf_tsas tsas = {.tcp.sectype = NVMF_TCP_SECTYPE_NONE};
+
+		nvmf_disc_info_mgmt(ctrl, NVME_TAS_DEREGISTER, NVMF_TRTYPE_TCP,
+				    nvme_get_adrfam(ctrl), "", &tsas);
+	}
+
 	nvme_tcp_teardown_ctrl(ctrl, true);
 }
 
-- 
2.34.1