From: Hannes Reinecke <hare@suse.de>
Date: Wed, 22 Sep 2021 08:35:24 +0200
Subject: nvme: Add connect option 'discovery'
Patch-mainline: v5.16-rc1
Git-commit: 20e8b689c9088027b7495ffd6f80812c11ecc872
References: bsc#1192761

Add a connect option 'discovery' to specify that the connection
should be made to a discovery controller, not a normal I/O controller.
With discovery controllers supporting unique subsystem NQNs we
cannot easily distinguish by the subsystem NQN if this should be
a discovery connection, but we need this information to blank out
options not supported by discovery controllers.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/core.c    |    7 +++++++
 drivers/nvme/host/fabrics.c |    6 +++++-
 drivers/nvme/host/fabrics.h |    1 +
 3 files changed, 13 insertions(+), 1 deletion(-)

--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2978,6 +2978,13 @@ static int nvme_init_subsystem(struct nv
 	else
 		subsys->subtype = NVME_NQN_NVME;
 
+	if (nvme_discovery_ctrl(ctrl) && subsys->subtype != NVME_NQN_DISC) {
+		dev_err(ctrl->device,
+			"Subsystem %s is not a discovery controller",
+			subsys->subnqn);
+		kfree(subsys);
+		return -EINVAL;
+	}
 	subsys->awupf = le16_to_cpu(id->awupf);
 #ifdef CONFIG_NVME_MULTIPATH
 	subsys->iopolicy = NVME_IOPOLICY_NUMA;
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -620,6 +620,7 @@ static const match_table_t opt_tokens =
 	{ NVMF_OPT_NR_POLL_QUEUES,	"nr_poll_queues=%d"	},
 	{ NVMF_OPT_TOS,			"tos=%d"		},
 	{ NVMF_OPT_FAIL_FAST_TMO,	"fast_io_fail_tmo=%d"	},
+	{ NVMF_OPT_DISCOVERY,		"discovery"		},
 	{ NVMF_OPT_ERR,			NULL			}
 };
 
@@ -895,6 +896,9 @@ static int nvmf_parse_options(struct nvm
 			}
 			opts->tos = token;
 			break;
+		case NVMF_OPT_DISCOVERY:
+			opts->discovery_nqn = true;
+			break;
 		default:
 			pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
 				p);
@@ -1021,7 +1025,7 @@ EXPORT_SYMBOL_GPL(nvmf_free_options);
 #define NVMF_ALLOWED_OPTS	(NVMF_OPT_QUEUE_SIZE | NVMF_OPT_NR_IO_QUEUES | \
 				 NVMF_OPT_KATO | NVMF_OPT_HOSTNQN | \
 				 NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT |\
-				 NVMF_OPT_DISABLE_SQFLOW |\
+				 NVMF_OPT_DISABLE_SQFLOW | NVMF_OPT_DISCOVERY |\
 				 NVMF_OPT_FAIL_FAST_TMO)
 
 static struct nvme_ctrl *
--- a/drivers/nvme/host/fabrics.h
+++ b/drivers/nvme/host/fabrics.h
@@ -67,6 +67,7 @@ enum {
 	NVMF_OPT_TOS		= 1 << 19,
 	NVMF_OPT_FAIL_FAST_TMO	= 1 << 20,
 	NVMF_OPT_HOST_IFACE	= 1 << 21,
+	NVMF_OPT_DISCOVERY	= 1 << 22,
 };
 
 /**