consolidate compat lookup_dcookie()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/dcookies.c b/fs/dcookies.c
index f08375b..ab5954b 100644
--- a/fs/dcookies.c
+++ b/fs/dcookies.c
@@ -25,6 +25,7 @@
 #include <linux/dcookies.h>
 #include <linux/mutex.h>
 #include <linux/path.h>
+#include <linux/compat.h>
 #include <asm/uaccess.h>
 
 /* The dcookies are allocated from a kmem_cache and
@@ -202,6 +203,17 @@
 	return err;
 }
 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(lookup_dcookie, u32, w0, u32, w1, char __user *, buf, size_t, len)
+{
+#ifdef __BIG_ENDIAN
+	return sys_lookup_dcookie(((u64)w0 << 32) | w1, buf, len);
+#else
+	return sys_lookup_dcookie(((u64)w1 << 32) | w0, buf, len);
+#endif
+}
+#endif
+
 static int dcookie_init(void)
 {
 	struct list_head * d;