ceph: fix d_revalidate oopsen on NFS exports

can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 099a586..ebafa65 100644 (file)
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -993,7 +993,7 @@ static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
        struct inode *dir;
 
-       if (nd->flags & LOOKUP_RCU)
+       if (nd && nd->flags & LOOKUP_RCU)
                return -ECHILD;
 
        dir = dentry->d_parent->d_inode;