genhd: send async notification on media change

Send an uevent to user space to indicate that a media change event has
occurred.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 7efa8bb25da9..863a8c0623ed 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -696,6 +696,27 @@ struct seq_operations diskstats_op = {
 	.show	= diskstats_show
 };
 
+static void media_change_notify_thread(struct work_struct *work)
+{
+	struct gendisk *gd = container_of(work, struct gendisk, async_notify);
+	char event[] = "MEDIA_CHANGE=1";
+	char *envp[] = { event, NULL };
+
+	/*
+	 * set enviroment vars to indicate which event this is for
+	 * so that user space will know to go check the media status.
+	 */
+	kobject_uevent_env(&gd->kobj, KOBJ_CHANGE, envp);
+	put_device(gd->driverfs_dev);
+}
+
+void genhd_media_change_notify(struct gendisk *disk)
+{
+	get_device(disk->driverfs_dev);
+	schedule_work(&disk->async_notify);
+}
+EXPORT_SYMBOL_GPL(genhd_media_change_notify);
+
 struct gendisk *alloc_disk(int minors)
 {
 	return alloc_disk_node(minors, -1);
@@ -725,6 +746,8 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
 		kobj_set_kset_s(disk,block_subsys);
 		kobject_init(&disk->kobj);
 		rand_initialize_disk(disk);
+		INIT_WORK(&disk->async_notify,
+			media_change_notify_thread);
 	}
 	return disk;
 }