NFSv4: Fix an oops in nfs4_fill_super

The mount statistics patches introduced a call to nfs_free_iostats that is
not only redundant, but actually causes an oops.

Also fix a memory leak due to the lack of a call to nfs_free_iostats on
unmount.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/nfs/iostat.h b/fs/nfs/iostat.h
index 7a7495153317..6350ecbde589 100644
--- a/fs/nfs/iostat.h
+++ b/fs/nfs/iostat.h
@@ -156,7 +156,8 @@ static inline struct nfs_iostats *nfs_alloc_iostats(void)
 
 static inline void nfs_free_iostats(struct nfs_iostats *stats)
 {
-        free_percpu(stats);
+        if (stats != NULL)
+                free_percpu(stats);
 }
 
 #endif