UBI: fix ubi_wl_flush

The flush function should finish all the pending jobs. But if
somebody else is doing a work, this function should wait and let
it finish.

This patche uses rw semaphore for synchronization purpose - it
just looks quite convinient.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index ea9a6990a4dc..994233d6e1e3 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -355,6 +355,7 @@ struct ubi_device {
         } prot;
         spinlock_t wl_lock;
         struct mutex move_mutex;
+        struct rw_semaphore work_sem;
         int wl_scheduled;
         struct ubi_wl_entry **lookuptbl;
         unsigned long long abs_ec;