md: Cleanup after raid45->raid0 takeover

Problem:
After raid4->raid0 takeover operation, another takeover operation
(e.g raid0->raid10) results "kernel oops".
Root cause:
Variables 'degraded' in mddev structure is not cleared
on raid45->raid0 takeover.

This patch reset this variable.

Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 6e853c61d87..7d6f7f18a92 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3170,6 +3170,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
         mddev->layout = mddev->new_layout;
         mddev->chunk_sectors = mddev->new_chunk_sectors;
         mddev->delta_disks = 0;
+        mddev->degraded = 0;
         if (mddev->pers->sync_request == NULL) {
                 /* this is now an array without redundancy, so
                  * it must always be in_sync