dm mpath: fix check for null mpio in end_io fn

The mpio dereference should be moved below the BUG_ON NULL test
in multipath_end_io().

spatch with a semantic match was used to found this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index d778563a4ffd..573bd04591bf 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1309,13 +1309,14 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
 {
         struct multipath *m = ti->private;
         struct dm_mpath_io *mpio = map_context->ptr;
-        struct pgpath *pgpath = mpio->pgpath;
+        struct pgpath *pgpath;
         struct path_selector *ps;
         int r;
 
         BUG_ON(!mpio);
 
         r  = do_end_io(m, clone, error, mpio);
+        pgpath = mpio->pgpath;
         if (pgpath) {
                 ps = &pgpath->pg->ps;
                 if (ps->type->end_io)