[1/1] : Thaws refrigerated bdi flusher threads before invoking kthread_stop on them

Commit Message

Dasgupta, Romit Nov. 12, 2009, 11:52 a.m. UTC

None

Patch

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 5a37e20..5a9ab6f 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -603,11 +603,15 @@  static void bdi_wb_shutdown(struct backing_dev_info *bdi)
 	bdi_remove_from_list(bdi);
 
 	/*
+	 * Force unfreeze of bdi threads before stopping it, otherwise
+	 * it would never exit if it is stuck in the refrigerator.
 	 * Finally, kill the kernel threads. We don't need to be RCU
 	 * safe anymore, since the bdi is gone from visibility.
 	 */
-	list_for_each_entry(wb, &bdi->wb_list, list)
+	list_for_each_entry(wb, &bdi->wb_list, list) {
+		wb->task->flags &= ~PF_FROZEN;
 		kthread_stop(wb->task);
+	}
 }
 
 void bdi_unregister(struct backing_dev_info *bdi)