Merge branch 'omap-pool'

[linux-2.6-omap-h63xx.git] / drivers / md / dm-exception-store.h

diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index bb9f33d5daa2169127d96fd9ebfcbe41d1cc819b..0a2e6e7f67b3c5b6ac4c4cbd7dc2ca6811eaa30c 100644 (file)
--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -37,11 +37,18 @@ 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 {
+       const char *name;
+       struct module *module;
+
+       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
@@ -72,8 +79,9 @@ struct dm_exception_store {
         */
        void (*drop_snapshot) (struct dm_exception_store *store);
 
-       int (*status) (struct dm_exception_store *store, status_type_t status,
-                      char *result, unsigned int maxlen);
+       unsigned (*status) (struct dm_exception_store *store,
+                           status_type_t status, char *result,
+                           unsigned maxlen);
 
        /*
         * Return how full the snapshot is.
@@ -82,7 +90,21 @@ struct dm_exception_store {
                               sector_t *numerator,
                               sector_t *denominator);
 
-       struct dm_snapshot *snap;
+       /* For internal device-mapper use only. */
+       struct list_head list;
+};
+
+struct dm_exception_store {
+       struct dm_exception_store_type *type;
+       struct dm_target *ti;
+
+       struct dm_dev *cow;
+
+       /* Size of data blocks saved - must be a power of 2 */
+       chunk_t chunk_size;
+       chunk_t chunk_mask;
+       chunk_t chunk_shift;
+
        void *context;
 };
 
@@ -129,6 +151,28 @@ static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
 
 #  endif
 
+/*
+ * Return the number of sectors in the device.
+ */
+static inline sector_t get_dev_size(struct block_device *bdev)
+{
+       return bdev->bd_inode->i_size >> SECTOR_SHIFT;
+}
+
+static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
+                                     sector_t sector)
+{
+       return (sector & ~store->chunk_mask) >> store->chunk_shift;
+}
+
+int dm_exception_store_type_register(struct dm_exception_store_type *type);
+int dm_exception_store_type_unregister(struct dm_exception_store_type *type);
+
+int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
+                             unsigned *args_used,
+                             struct dm_exception_store **store);
+void dm_exception_store_destroy(struct dm_exception_store *store);
+
 int dm_exception_store_init(void);
 void dm_exception_store_exit(void);
 
@@ -141,8 +185,4 @@ void dm_persistent_snapshot_exit(void);
 int dm_transient_snapshot_init(void);
 void dm_transient_snapshot_exit(void);
 
-int dm_create_persistent(struct dm_exception_store *store);
-
-int dm_create_transient(struct dm_exception_store *store);
-
 #endif /* _LINUX_DM_EXCEPTION_STORE */