dm ioctl: introduce flag indicating uevent was generated

Set a new DM_UEVENT_GENERATED_FLAG when returning from ioctls to
indicate that a uevent was actually generated.  This tells the userspace
caller that it may need to wait for the event to be processed.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 7199846364e9..d21e1284604f 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2618,18 +2618,19 @@ out:
 /*-----------------------------------------------------------------
  * Event notification.
  *---------------------------------------------------------------*/
-void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
+int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
                        unsigned cookie)
 {
         char udev_cookie[DM_COOKIE_LENGTH];
         char *envp[] = { udev_cookie, NULL };
 
         if (!cookie)
-                kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
+                return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
         else {
                 snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
                          DM_COOKIE_ENV_VAR_NAME, cookie);
-                kobject_uevent_env(&disk_to_dev(md->disk)->kobj, action, envp);
+                return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
+                                          action, envp);
         }
 }