driver core: set up ownership of class devices in sysfs

Plumb in get_ownership() callback for devices belonging to a class so that
they can be created with uid/gid different from global root. This will
allow network devices in a container to belong to container's root and not
global root.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index df3e1a44707a..276c7e3f754c 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -866,10 +866,19 @@ static const void *device_namespace(struct kobject *kobj)
         return ns;
 }
 
+static void device_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
+{
+        struct device *dev = kobj_to_dev(kobj);
+
+        if (dev->class && dev->class->get_ownership)
+                dev->class->get_ownership(dev, uid, gid);
+}
+
 static struct kobj_type device_ktype = {
         .release        = device_release,
         .sysfs_ops      = &dev_sysfs_ops,
         .namespace      = device_namespace,
+        .get_ownership  = device_get_ownership,
 };