md: add support for raising dm events.

dm uses scheduled work to raise events to user-space.
So allow md device to have work_structs and schedule them on an error.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 6e7e3495f6e4..c88b04745e85 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -318,6 +318,7 @@ struct mddev_s
         struct bio *barrier;
         atomic_t flush_pending;
         struct work_struct barrier_work;
+        struct work_struct event_work;  /* used by dm to report failure event */
 };