dm table: add immutable feature
Introduce DM_TARGET_IMMUTABLE to indicate that the target type cannot be mixed
with any other target type, and once loaded into a device, it cannot be
replaced with a table containing a different type.
The thin provisioning pool device will use this.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index cc58e2d..98f34b8 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -173,6 +173,13 @@
#define dm_target_always_writeable(type) \
((type)->features & DM_TARGET_ALWAYS_WRITEABLE)
+/*
+ * Any device that contains a table with an instance of this target may never
+ * have tables containing any different target type.
+ */
+#define DM_TARGET_IMMUTABLE 0x00000004
+#define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)
+
struct dm_target {
struct dm_table *table;
struct target_type *type;
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 0cb8eff..75fd557 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -267,9 +267,9 @@
#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 21
+#define DM_VERSION_MINOR 22
#define DM_VERSION_PATCHLEVEL 0
-#define DM_VERSION_EXTRA "-ioctl (2011-07-06)"
+#define DM_VERSION_EXTRA "-ioctl (2011-10-19)"
/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */