CRED: Pass credentials through dentry_open()

Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.

The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index a5e14e8..632a50b 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -226,7 +226,8 @@
 
 	nfs4_save_user(&uid, &gid);
 
-	filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY);
+	filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY,
+			   current_cred());
 	status = PTR_ERR(filp);
 	if (IS_ERR(filp))
 		goto out;