dm: introduce merge_bvec_fn

Introduce a bvec merge function for device mapper devices
for dynamic size restrictions.

This code ensures the requested biovec lies within a single
target and then calls a target-specific function to check
against any constraints imposed by underlying devices.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index b03c41b..28c2940 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -256,9 +256,9 @@
 #define DM_DEV_SET_GEOMETRY	_IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
 
 #define DM_VERSION_MAJOR	4
-#define DM_VERSION_MINOR	13
+#define DM_VERSION_MINOR	14
 #define DM_VERSION_PATCHLEVEL	0
-#define DM_VERSION_EXTRA	"-ioctl (2007-10-18)"
+#define DM_VERSION_EXTRA	"-ioctl (2008-04-23)"
 
 /* Status bits */
 #define DM_READONLY_FLAG	(1 << 0) /* In/Out */