Driver core: show drivers in /sys/module/

Show the drivers, which belong to the module:
  $ ls -l /sys/module/usbcore/drivers/
  hub -> ../../../bus/usb/drivers/hub
  usb -> ../../../bus/usb/drivers/usb
  usbfs -> ../../../bus/usb/drivers/usbfs

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/module.h

@@ -264,6 +264,7 @@ struct module
  struct module_attribute *modinfo_attrs;
  const char *version;
  const char *srcversion;
+ struct kobject *drivers_dir;
 
  /* Exported symbols */
  const struct kernel_symbol *syms;

kernel/module.c

@@ -1086,22 +1086,35 @@ static int mod_sysfs_setup(struct module *mod,
  goto out;
  kobj_set_kset_s(&mod->mkobj, module_subsys);
  mod->mkobj.mod = mod;
- err = kobject_register(&mod->mkobj.kobj);
+
+ /* delay uevent until full sysfs population */
+ kobject_init(&mod->mkobj.kobj);
+ err = kobject_add(&mod->mkobj.kobj);
  if (err)
  goto out;
 
+ mod->drivers_dir = kobject_add_dir(&mod->mkobj.kobj, "drivers");
+ if (!mod->drivers_dir)
+ goto out_unreg;
+
  err = module_param_sysfs_setup(mod, kparam, num_params);
  if (err)
- goto out_unreg;
+ goto out_unreg_drivers;
 
  err = module_add_modinfo_attrs(mod);
  if (err)
- goto out_unreg;
+ goto out_unreg_param;
 
+ kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
  return 0;
 
+out_unreg_drivers:
+ kobject_unregister(mod->drivers_dir);
+out_unreg_param:
+ module_param_sysfs_remove(mod);
 out_unreg:
- kobject_unregister(&mod->mkobj.kobj);
+ kobject_del(&mod->mkobj.kobj);
+ kobject_put(&mod->mkobj.kobj);
 out:
  return err;
 }
@@ -1110,6 +1123,7 @@ static void mod_kobject_remove(struct module *mod)
 {
  module_remove_modinfo_attrs(mod);
  module_param_sysfs_remove(mod);
+ kobject_unregister(mod->drivers_dir);
 
  kobject_unregister(&mod->mkobj.kobj);
 }
@@ -2275,11 +2289,14 @@ void print_modules(void)
 
 void module_add_driver(struct module *mod, struct device_driver *drv)
 {
+ int no_warn;
+
  if (!mod || !drv)
  return;
 
- /* Don't check return code; this call is idempotent */
- sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
+ /* Don't check return codes; these calls are idempotent */
+ no_warn = sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
+ no_warn = sysfs_create_link(mod->drivers_dir, &drv->kobj, drv->name);
 }
 EXPORT_SYMBOL(module_add_driver);
 
@@ -2288,6 +2305,8 @@ void module_remove_driver(struct device_driver *drv)
  if (!drv)
  return;
  sysfs_remove_link(&drv->kobj, "module");
+ if (drv->owner && drv->owner->drivers_dir)
+ sysfs_remove_link(drv->owner->drivers_dir, drv->name);
 }
 EXPORT_SYMBOL(module_remove_driver);