[PATCH 6/8] nvme-sysfs: add 'tls_keyring' attribute

[Hannes Reinecke <hare@kernel.org>]

Add a 'tls_keyring' attribute to display the contents of the
--keyring option from the connect string. Adding this attribute
allows us to recreate the original connect string from sysfs
settings.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
---
 drivers/nvme/host/sysfs.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index 62f03aa530c8..7a7a4ade59db 100644
--- a/drivers/nvme/host/sysfs.c
+++ b/drivers/nvme/host/sysfs.c
@@ -685,6 +685,16 @@ static ssize_t tls_configured_key_show(struct device *dev,
 	return sysfs_emit(buf, "%08x\n", key_serial(key));
 }
 static DEVICE_ATTR_RO(tls_configured_key);
+
+static ssize_t tls_keyring_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct key *keyring = ctrl->opts->keyring;
+
+	return sysfs_emit(buf, "%s\n", keyring->description);
+}
+static DEVICE_ATTR_RO(tls_keyring);
 #endif
 
 static struct attribute *nvme_dev_attrs[] = {
@@ -717,6 +727,7 @@ static struct attribute *nvme_dev_attrs[] = {
 #ifdef CONFIG_NVME_TCP_TLS
 	&dev_attr_tls_key.attr,
 	&dev_attr_tls_configured_key.attr,
+	&dev_attr_tls_keyring.attr,
 #endif
 	&dev_attr_adm_passthru_err_log_enabled.attr,
 	NULL
@@ -756,6 +767,10 @@ static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
 	    (!ctrl->opts || !ctrl->opts->tls_key ||
 	     strcmp(ctrl->opts->transport, "tcp")))
 		return 0;
+	if (a == &dev_attr_tls_keyring.attr &&
+	    (!ctrl->opts || !ctrl->opts->keyring ||
+	     strcmp(ctrl->opts->transport, "tcp")))
+		return 0;
 #endif
 
 	return a->mode;
-- 
2.35.3