[PATCH 2/4] nvme: add host symbolic name

[Martin Belanger]

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

TP8010 introduces the 'host symbolic name' as an optional
parameter for explicit registration with a central discovery
controller.

Signed-off-by: Martin Belanger <martin.belanger at dell.com>
---
 drivers/nvme/host/core.c    | 14 ++++++++++++++
 drivers/nvme/host/fabrics.c | 17 +++++++++++++++--
 drivers/nvme/host/fabrics.h |  2 ++
 include/linux/nvme.h        |  2 ++
 4 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index cd34b92e8e9d..cf5d9984f8f6 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3404,6 +3404,16 @@ static ssize_t nvme_sysfs_show_hostnqn(struct device *dev,
 }
 static DEVICE_ATTR(hostnqn, S_IRUGO, nvme_sysfs_show_hostnqn, NULL);
 
+static ssize_t nvme_sysfs_show_hostsymname(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", ctrl->opts->host->symname);
+}
+static DEVICE_ATTR(hostsymname, S_IRUGO, nvme_sysfs_show_hostsymname, NULL);
+
 static ssize_t nvme_sysfs_show_hostid(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
@@ -3531,6 +3541,7 @@ static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_sqsize.attr,
 	&dev_attr_hostnqn.attr,
 	&dev_attr_hostid.attr,
+	&dev_attr_hostsymname.attr,
 	&dev_attr_ctrl_loss_tmo.attr,
 	&dev_attr_reconnect_delay.attr,
 	&dev_attr_fast_io_fail_tmo.attr,
@@ -3553,6 +3564,9 @@ static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
 		return 0;
 	if (a == &dev_attr_hostid.attr && !ctrl->opts)
 		return 0;
+	if (a == &dev_attr_hostsymname.attr &&
+	    (!ctrl->opts || (ctrl->opts->host->symname[0] == '\0')))
+		return 0;
 	if (a == &dev_attr_ctrl_loss_tmo.attr && !ctrl->opts)
 		return 0;
 	if (a == &dev_attr_reconnect_delay.attr && !ctrl->opts)
diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index 7ae041e2b3fb..040a6cce6afa 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -540,6 +540,7 @@ static const match_table_t opt_tokens = {
 	{ NVMF_OPT_HOST_TRADDR,		"host_traddr=%s"	},
 	{ NVMF_OPT_HOST_IFACE,		"host_iface=%s"		},
 	{ NVMF_OPT_HOST_ID,		"hostid=%s"		},
+	{ NVMF_OPT_SYMNAME,		"hostsymname=%s"	},
 	{ NVMF_OPT_DUP_CONNECT,		"duplicate_connect"	},
 	{ NVMF_OPT_DISABLE_SQFLOW,	"disable_sqflow"	},
 	{ NVMF_OPT_HDR_DIGEST,		"hdr_digest"		},
@@ -556,7 +557,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 		const char *buf)
 {
 	substring_t args[MAX_OPT_ARGS];
-	char *options, *o, *p;
+	char *options, *o, *p, *hostsymname = NULL;
 	int token, ret = 0;
 	size_t nqnlen  = 0;
 	int ctrl_loss_tmo = NVMF_DEF_CTRL_LOSS_TMO;
@@ -830,6 +831,13 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 		case NVMF_OPT_DISCOVERY:
 			opts->discovery_nqn = true;
 			break;
+		case NVMF_OPT_SYMNAME:
+			hostsymname = match_strdup(args);
+			if (!hostsymname) {
+				ret = -ENOMEM;
+				goto out;
+			}
+			break;
 		default:
 			pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
 				p);
@@ -864,8 +872,13 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 
 	uuid_copy(&opts->host->id, &hostid);
 
+	if (hostsymname)
+		strncpy(opts->host->symname, hostsymname,
+			sizeof(opts->host->symname) - 1);
+
 out:
 	kfree(options);
+	kfree(hostsymname);
 	return ret;
 }
 
@@ -957,7 +970,7 @@ EXPORT_SYMBOL_GPL(nvmf_free_options);
 				 NVMF_OPT_KATO | NVMF_OPT_HOSTNQN | \
 				 NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT |\
 				 NVMF_OPT_DISABLE_SQFLOW | NVMF_OPT_DISCOVERY |\
-				 NVMF_OPT_FAIL_FAST_TMO)
+				 NVMF_OPT_FAIL_FAST_TMO | NVMF_OPT_SYMNAME)
 
 static struct nvme_ctrl *
 nvmf_create_ctrl(struct device *dev, const char *buf)
diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
index c3203ff1c654..494e6dbe233a 100644
--- a/drivers/nvme/host/fabrics.h
+++ b/drivers/nvme/host/fabrics.h
@@ -38,6 +38,7 @@ struct nvmf_host {
 	struct list_head	list;
 	char			nqn[NVMF_NQN_SIZE];
 	uuid_t			id;
+	char			symname[NVMF_HOSTSYMNAME_SIZE+1];
 };
 
 /**
@@ -68,6 +69,7 @@ enum {
 	NVMF_OPT_FAIL_FAST_TMO	= 1 << 20,
 	NVMF_OPT_HOST_IFACE	= 1 << 21,
 	NVMF_OPT_DISCOVERY	= 1 << 22,
+	NVMF_OPT_SYMNAME	= 1 << 23,
 };
 
 /**
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 82567d493c51..3b47951342f4 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -16,6 +16,8 @@
 /* However the max length of a qualified name is another size */
 #define NVMF_NQN_SIZE		223
 
+#define NVMF_HOSTSYMNAME_SIZE	256
+
 #define NVMF_TRSVCID_SIZE	32
 #define NVMF_TRADDR_SIZE	256
 #define NVMF_TSAS_SIZE		256
-- 
2.34.1