/*
- * dm-snapshot.c
- *
* Copyright (C) 2001-2002 Sistina Software (UK) Limited.
*
* This file is released under the GPL.
#ifndef DM_SNAPSHOT_H
#define DM_SNAPSHOT_H
-#include "dm.h"
+#include <linux/device-mapper.h>
+#include "dm-exception-store.h"
#include "dm-bio-list.h"
#include <linux/blkdev.h>
#include <linux/workqueue.h>
struct list_head *table;
};
-/*
- * The snapshot code deals with largish chunks of the disk at a
- * time. Typically 32k - 512k.
- */
-typedef sector_t chunk_t;
-
-/*
- * An exception is used where an old chunk of data has been
- * replaced by a new one.
- * If chunk_t is 64 bits in size, the top 8 bits of new_chunk hold the number
- * of chunks that follow contiguously. Remaining bits hold the number of the
- * chunk within the device.
- */
-struct dm_snap_exception {
- struct list_head hash_list;
-
- chunk_t old_chunk;
- chunk_t new_chunk;
-};
-
-/*
- * Funtions to manipulate consecutive chunks
- */
-# if defined(CONFIG_LBD) || (BITS_PER_LONG == 64)
-# define DM_CHUNK_CONSECUTIVE_BITS 8
-# define DM_CHUNK_NUMBER_BITS 56
-
-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)
-{
- return e->new_chunk >> DM_CHUNK_NUMBER_BITS;
-}
-
-static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
-{
- e->new_chunk += (1ULL << DM_CHUNK_NUMBER_BITS);
-
- BUG_ON(!dm_consecutive_chunk_count(e));
-}
-
-# else
-# define DM_CHUNK_CONSECUTIVE_BITS 0
-
-static inline chunk_t dm_chunk_number(chunk_t chunk)
-{
- return chunk;
-}
-
-static inline unsigned dm_consecutive_chunk_count(struct dm_snap_exception *e)
-{
- return 0;
-}
-
-static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
-{
-}
-
-# endif
-
-/*
- * Abstraction to handle the meta/layout of exception stores (the
- * COW device).
- */
-struct exception_store {
-
- /*
- * Destroys this object when you've finished with it.
- */
- void (*destroy) (struct exception_store *store);
-
- /*
- * The target shouldn't read the COW device until this is
- * called.
- */
- int (*read_metadata) (struct exception_store *store);
-
- /*
- * Find somewhere to store the next exception.
- */
- int (*prepare_exception) (struct exception_store *store,
- struct dm_snap_exception *e);
-
- /*
- * Update the metadata with this exception.
- */
- void (*commit_exception) (struct exception_store *store,
- struct dm_snap_exception *e,
- void (*callback) (void *, int success),
- void *callback_context);
-
- /*
- * The snapshot is invalid, note this in the metadata.
- */
- void (*drop_snapshot) (struct exception_store *store);
-
- /*
- * Return how full the snapshot is.
- */
- void (*fraction_full) (struct exception_store *store,
- sector_t *numerator,
- sector_t *denominator);
-
- struct dm_snapshot *snap;
- void *context;
-};
-
#define DM_TRACKED_CHUNK_HASH_SIZE 16
#define DM_TRACKED_CHUNK_HASH(x) ((unsigned long)(x) & \
(DM_TRACKED_CHUNK_HASH_SIZE - 1))
/* Used for display of table */
char type;
- /* The last percentage we notified */
- int last_percent;
-
mempool_t *pending_pool;
+ atomic_t pending_exceptions_count;
+
struct exception_table pending;
struct exception_table complete;
spinlock_t pe_lock;
/* The on disk metadata handler */
- struct exception_store store;
+ struct dm_exception_store store;
struct dm_kcopyd_client *kcopyd_client;
struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
};
-/*
- * Used by the exception stores to load exceptions hen
- * initialising.
- */
-int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new);
-
-/*
- * Constructor and destructor for the default persistent
- * store.
- */
-int dm_create_persistent(struct exception_store *store);
-
-int dm_create_transient(struct exception_store *store);
-
/*
* Return the number of sectors in the device.
*/