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-rw-r--r--drivers/md/dm-exception-store.h58
1 files changed, 49 insertions, 9 deletions
diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index bb9f33d5daa..0a2e6e7f67b 100644
--- 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 */