[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>

1 files changed, 15 insertions, 6 deletions

diff --git a/include/linux/dlm_device.h b/include/linux/dlm_device.h
index c2735cab2ebf..f7b9b57348a8 100644
--- a/include/linux/dlm_device.h
+++ b/include/linux/dlm_device.h
@@ -2,7 +2,7 @@
 *******************************************************************************
 **
 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
-**  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
 **
 **  This copyrighted material is made available to anyone wishing to use,
 **  modify, copy, or redistribute it subject to the terms and conditions
@@ -18,21 +18,24 @@
 #define DLM_USER_LVB_LEN	32
 
 /* Version of the device interface */
-#define DLM_DEVICE_VERSION_MAJOR 5
-#define DLM_DEVICE_VERSION_MINOR 1
+#define DLM_DEVICE_VERSION_MAJOR 6
+#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;
+	__u16 unused;
+	__u32 flags;
 	__u32 lkid;
 	__u32 parent;
-        void __user *castparam;
+	__u64 xid;
+	__u64 timeout;
+	void __user *castparam;
 	void __user *castaddr;
 	void __user *bastparam;
-        void __user *bastaddr;
+	void __user *bastaddr;
 	struct dlm_lksb __user *lksb;
 	char lvb[DLM_USER_LVB_LEN];
 	char name[0];
@@ -62,9 +65,15 @@ struct dlm_write_request {
 	} i;
 };
 
+struct dlm_device_version {
+	__u32 version[3];
+};
+
 /* struct read from the "device" fd,
    consists mainly of userspace pointers for the library to use */
+
 struct dlm_lock_result {
+	__u32 version[3];
 	__u32 length;
 	void __user * user_astaddr;
 	void __user * user_astparam;