Introduce "lockspace_handle" variable.

Unload the handle when unloading the module. The handle will be loaded when
clustered arguments are supplied, in some of the next patches.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 drivers/md/dm-exception-store.h |    4 ++++
 drivers/md/dm-snap.c            |   13 +++++++++++++
 2 files changed, 17 insertions(+)

Index: linux-2.6.31-fast/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.31-fast.orig/drivers/md/dm-snap.c	2009-10-16 21:52:48.000000000 +0200
+++ linux-2.6.31-fast/drivers/md/dm-snap.c	2009-10-19 12:07:40.000000000 +0200
@@ -23,6 +23,10 @@
 
 #include "dm-exception-store.h"
 
+#ifdef CLUSTER_SNAPSHOTS
+#include "dm-cluster-locking.h"
+#endif
+
 #define DM_MSG_PREFIX "snapshots"
 
 /*
@@ -49,6 +53,10 @@
 #define DM_TRACKED_CHUNK_HASH(x)	((unsigned long)(x) & \
 					 (DM_TRACKED_CHUNK_HASH_SIZE - 1))
 
+#ifdef CLUSTER_SNAPSHOTS
+static void *lockspace_handle = NULL;
+#endif
+
 struct dm_exception_table {
 	uint32_t hash_mask;
 	unsigned hash_shift;
@@ -2023,6 +2031,11 @@ bad_register_snapshot_target:
 
 static void __exit dm_snapshot_exit(void)
 {
+#ifdef CLUSTER_SNAPSHOTS
+	if (lockspace_handle)
+		dm_cluster_lock_exit(lockspace_handle);
+#endif
+
 	dm_unregister_target(&snapshot_target);
 	dm_unregister_target(&origin_target);
 	dm_unregister_target(&merge_target);
Index: linux-2.6.31-fast/drivers/md/dm-exception-store.h
===================================================================
--- linux-2.6.31-fast.orig/drivers/md/dm-exception-store.h	2009-10-16 21:51:55.000000000 +0200
+++ linux-2.6.31-fast/drivers/md/dm-exception-store.h	2009-10-19 12:05:53.000000000 +0200
@@ -13,6 +13,10 @@
 #include <linux/blkdev.h>
 #include <linux/device-mapper.h>
 
+#if defined(CONFIG_DM_CLUSTER_LOCKING) || (defined(CONFIG_DM_SNAPSHOT_MODULE) && defined(CONFIG_DM_CLUSTER_LOCKING_MODULE))
+#define CLUSTER_SNAPSHOTS
+#endif
+
 /*
  * The snapshot code deals with largish chunks of the disk at a
  * time. Typically 32k - 512k.