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Diffstat (limited to 'drivers/md/dm-exception-store.h')
-rw-r--r--drivers/md/dm-exception-store.h62
1 files changed, 48 insertions, 14 deletions
diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index 8a223a48802c..e8dfa06af3ba 100644
--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -26,7 +26,7 @@ typedef sector_t chunk_t;
* of chunks that follow contiguously. Remaining bits hold the number of the
* chunk within the device.
*/
-struct dm_snap_exception {
+struct dm_exception {
struct list_head hash_list;
chunk_t old_chunk;
@@ -64,17 +64,34 @@ struct dm_exception_store_type {
* Find somewhere to store the next exception.
*/
int (*prepare_exception) (struct dm_exception_store *store,
- struct dm_snap_exception *e);
+ struct dm_exception *e);
/*
* Update the metadata with this exception.
*/
void (*commit_exception) (struct dm_exception_store *store,
- struct dm_snap_exception *e,
+ struct dm_exception *e,
void (*callback) (void *, int success),
void *callback_context);
/*
+ * Returns 0 if the exception store is empty.
+ *
+ * If there are exceptions still to be merged, sets
+ * *last_old_chunk and *last_new_chunk to the most recent
+ * still-to-be-merged chunk and returns the number of
+ * consecutive previous ones.
+ */
+ int (*prepare_merge) (struct dm_exception_store *store,
+ chunk_t *last_old_chunk, chunk_t *last_new_chunk);
+
+ /*
+ * Clear the last n exceptions.
+ * nr_merged must be <= the value returned by prepare_merge.
+ */
+ int (*commit_merge) (struct dm_exception_store *store, int nr_merged);
+
+ /*
* The snapshot is invalid, note this in the metadata.
*/
void (*drop_snapshot) (struct dm_exception_store *store);
@@ -86,19 +103,19 @@ struct dm_exception_store_type {
/*
* Return how full the snapshot is.
*/
- void (*fraction_full) (struct dm_exception_store *store,
- sector_t *numerator,
- sector_t *denominator);
+ void (*usage) (struct dm_exception_store *store,
+ sector_t *total_sectors, sector_t *sectors_allocated,
+ sector_t *metadata_sectors);
/* For internal device-mapper use only. */
struct list_head list;
};
+struct dm_snapshot;
+
struct dm_exception_store {
struct dm_exception_store_type *type;
- struct dm_target *ti;
-
- struct dm_dev *cow;
+ struct dm_snapshot *snap;
/* Size of data blocks saved - must be a power of 2 */
unsigned chunk_size;
@@ -109,6 +126,11 @@ struct dm_exception_store {
};
/*
+ * Obtain the cow device used by a given snapshot.
+ */
+struct dm_dev *dm_snap_cow(struct dm_snapshot *snap);
+
+/*
* Funtions to manipulate consecutive chunks
*/
# if defined(CONFIG_LBDAF) || (BITS_PER_LONG == 64)
@@ -120,18 +142,25 @@ static inline chunk_t dm_chunk_number(chunk_t chunk)
return chunk & (chunk_t)((1ULL << DM_CHUNK_NUMBER_BITS) - 1ULL);
}
-static inline unsigned dm_consecutive_chunk_count(struct dm_snap_exception *e)
+static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e)
{
return e->new_chunk >> DM_CHUNK_NUMBER_BITS;
}
-static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
+static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e)
{
e->new_chunk += (1ULL << DM_CHUNK_NUMBER_BITS);
BUG_ON(!dm_consecutive_chunk_count(e));
}
+static inline void dm_consecutive_chunk_count_dec(struct dm_exception *e)
+{
+ BUG_ON(!dm_consecutive_chunk_count(e));
+
+ e->new_chunk -= (1ULL << DM_CHUNK_NUMBER_BITS);
+}
+
# else
# define DM_CHUNK_CONSECUTIVE_BITS 0
@@ -140,12 +169,16 @@ static inline chunk_t dm_chunk_number(chunk_t chunk)
return chunk;
}
-static inline unsigned dm_consecutive_chunk_count(struct dm_snap_exception *e)
+static inline unsigned dm_consecutive_chunk_count(struct dm_exception *e)
{
return 0;
}
-static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
+static inline void dm_consecutive_chunk_count_inc(struct dm_exception *e)
+{
+}
+
+static inline void dm_consecutive_chunk_count_dec(struct dm_exception *e)
{
}
@@ -162,7 +195,7 @@ static inline sector_t get_dev_size(struct block_device *bdev)
static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
sector_t sector)
{
- return (sector & ~store->chunk_mask) >> store->chunk_shift;
+ return sector >> store->chunk_shift;
}
int dm_exception_store_type_register(struct dm_exception_store_type *type);
@@ -173,6 +206,7 @@ int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
char **error);
int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
+ struct dm_snapshot *snap,
unsigned *args_used,
struct dm_exception_store **store);
void dm_exception_store_destroy(struct dm_exception_store *store);