[PATCH 2/2] xen: Add alias to autoload backend drivers

[Bastian Blank <waldi@debian.org>]

All the Xen backend drivers are assigned to a special bus type
xen-backend. This allows userspace to load the modules on request.

This patch defines xen-backend:* aliases on the modules and exports this
names through modalias and uevent.

Signed-off-by: Bastian Blank <waldi@debian.org>
---
 drivers/block/xen-blkback/blkback.c       |    1 +
 drivers/net/xen-netback/netback.c         |    1 +
 drivers/xen/xenbus/xenbus_probe.c         |    3 ++-
 drivers/xen/xenbus/xenbus_probe_backend.c |    3 +++
 4 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 5cf2993..ed62008 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -824,3 +824,4 @@ static int __init xen_blkif_init(void)
 module_init(xen_blkif_init);
 
 MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:vbd");
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 0e4851b..fd00f25 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1743,3 +1743,4 @@ failed_init:
 module_init(netback_init);
 
 MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:vif");
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 2ed0b04..bd2f90c 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -393,7 +393,8 @@ static ssize_t devtype_show(struct device *dev,
 static ssize_t modalias_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "xen:%s\n", to_xenbus_device(dev)->devicetype);
+	return sprintf(buf, "%s:%s\n", dev->bus->name,
+		       to_xenbus_device(dev)->devicetype);
 }
 
 struct device_attribute xenbus_dev_attrs[] = {
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index ec510e5..60adf91 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -107,6 +107,9 @@ static int xenbus_uevent_backend(struct device *dev,
 	if (xdev == NULL)
 		return -ENODEV;
 
+	if (add_uevent_var(env, "MODALIAS=xen-backend:%s", xdev->devicetype))
+		return -ENOMEM;
+
 	/* stuff we want to pass to /sbin/hotplug */
 	if (add_uevent_var(env, "XENBUS_TYPE=%s", xdev->devicetype))
 		return -ENOMEM;
-- 
1.7.5.4