[DLM] compat patch

Here's a patch which add 32/64 bit compat to the DLM IOs and tidies the
structures for alignment.

As it causes an ABI change I had few qualms about adding the extra flag for
"is64bit" as it simply uses a byte that would have been padding.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/include/linux/dlm_device.h b/include/linux/dlm_device.h
index f8ba198..2a2dd18 100644
--- a/include/linux/dlm_device.h
+++ b/include/linux/dlm_device.h
@@ -18,35 +18,37 @@
 #define DLM_USER_LVB_LEN	32
 
 /* Version of the device interface */
-#define DLM_DEVICE_VERSION_MAJOR 4
+#define DLM_DEVICE_VERSION_MAJOR 5
 #define DLM_DEVICE_VERSION_MINOR 0
 #define DLM_DEVICE_VERSION_PATCH 0
 
 /* struct passed to the lock write */
 struct dlm_lock_params {
 	__u8 mode;
+	__u8 namelen;
 	__u16 flags;
 	__u32 lkid;
 	__u32 parent;
-	__u8 namelen;
         void __user *castparam;
 	void __user *castaddr;
 	void __user *bastparam;
         void __user *bastaddr;
 	struct dlm_lksb __user *lksb;
 	char lvb[DLM_USER_LVB_LEN];
-	char name[1];
+	char name[0];
 };
 
 struct dlm_lspace_params {
 	__u32 flags;
 	__u32 minor;
-	char name[1];
+	char name[0];
 };
 
 struct dlm_write_request {
 	__u32 version[3];
 	__u8 cmd;
+	__u8 is64bit;
+	__u8 unused[2];
 
 	union  {
 		struct dlm_lock_params   lock;
@@ -63,6 +65,7 @@
 	struct dlm_lksb __user * user_lksb;
 	struct dlm_lksb lksb;
 	__u8 bast_mode;
+	__u8 unused[3];
 	/* Offsets may be zero if no data is present */
 	__u32 lvb_offset;
 };