dm exception store: separate type from instance

Introduce struct dm_exception_store_type.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index bb9f33d5daa2..aed1f1172f9e 100644
--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -37,11 +37,15 @@ struct dm_snap_exception {
  * Abstraction to handle the meta/layout of exception stores (the
  * COW device).
  */
-struct dm_exception_store {
+struct dm_exception_store;
+struct dm_exception_store_type {
+        int (*ctr) (struct dm_exception_store *store,
+                    unsigned argc, char **argv);
+
         /*
          * Destroys this object when you've finished with it.
          */
-        void (*destroy) (struct dm_exception_store *store);
+        void (*dtr) (struct dm_exception_store *store);
 
         /*
          * The target shouldn't read the COW device until this is
@@ -81,8 +85,13 @@ struct dm_exception_store {
         void (*fraction_full) (struct dm_exception_store *store,
                                sector_t *numerator,
                                sector_t *denominator);
+};
+
+struct dm_exception_store {
+        struct dm_exception_store_type type;
 
         struct dm_snapshot *snap;
+
         void *context;
 };