[DLM] dlm_device interface changes [3/6]

Change the user/kernel device interface used by libdlm:
- Add ability for userspace to check the version of the interface.  libdlm
  can now adapt to different versions of the kernel interface.
- Increase the size of the flags passed in a lock request so all possible
  flags can be used from userspace.
- Add an opaque "xid" value for each lock.  This "transaction id" will be
  used later to associate locks with each other during deadlock detection.
- Add a "timeout" value for each lock.  This is used along with the
  DLM_LKF_TIMEOUT flag.

Also, remove a fragment of unused code in device_read().

This patch requires updating libdlm which is backward compatible with
older kernels.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/dlm/lock.h b/fs/dlm/lock.h
index 6b5b71f..99ab463 100644
--- a/fs/dlm/lock.h
+++ b/fs/dlm/lock.h
@@ -38,9 +38,11 @@
 int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc);
 
 int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua, int mode,
-	uint32_t flags, void *name, unsigned int namelen, uint32_t parent_lkid);
+	uint32_t flags, void *name, unsigned int namelen,
+	unsigned long timeout_cs);
 int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
-	int mode, uint32_t flags, uint32_t lkid, char *lvb_in);
+	int mode, uint32_t flags, uint32_t lkid, char *lvb_in,
+	unsigned long timeout_cs);
 int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
 	uint32_t flags, uint32_t lkid, char *lvb_in);
 int dlm_user_cancel(struct dlm_ls *ls,  struct dlm_user_args *ua_tmp,