blk: pass from_schedule to non-request unplug functions.

This will allow md/raid to know why the unplug was called,
and will be able to act according - if !from_schedule it
is safe to perform tasks which could themselves schedule.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 8f998e0..f385b03 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -629,7 +629,7 @@
 				   struct mddev *mddev);
 extern void md_trim_bio(struct bio *bio, int offset, int size);
 
-extern void md_unplug(struct blk_plug_cb *cb);
+extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
 static inline int mddev_check_plugged(struct mddev *mddev)
 {
 	return !!blk_check_plugged(md_unplug, mddev,