diff options
Diffstat (limited to 'drivers/md/dm-snap.h')
| -rw-r--r-- | drivers/md/dm-snap.h | 220 |
1 files changed, 0 insertions, 220 deletions
diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h deleted file mode 100644 index 93bce5d4974..00000000000 --- a/drivers/md/dm-snap.h +++ /dev/null @@ -1,220 +0,0 @@ -/* - * 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 "dm-bio-list.h" -#include <linux/blkdev.h> -#include <linux/workqueue.h> - -struct exception_table { - uint32_t hash_mask; - unsigned hash_shift; - 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; -}; - -struct dm_snapshot { - struct rw_semaphore lock; - struct dm_table *table; - - struct dm_dev *origin; - struct dm_dev *cow; - - /* List of snapshots per Origin */ - struct list_head list; - - /* Size of data blocks saved - must be a power of 2 */ - chunk_t chunk_size; - chunk_t chunk_mask; - chunk_t chunk_shift; - - /* You can't use a snapshot if this is 0 (e.g. if full) */ - int valid; - - /* Origin writes don't trigger exceptions until this is set */ - int active; - - /* Used for display of table */ - char type; - - /* The last percentage we notified */ - int last_percent; - - struct exception_table pending; - struct exception_table complete; - - /* - * pe_lock protects all pending_exception operations and access - * as well as the snapshot_bios list. - */ - spinlock_t pe_lock; - - /* The on disk metadata handler */ - struct exception_store store; - - struct kcopyd_client *kcopyd_client; - - /* Queue of snapshot writes for ksnapd to flush */ - struct bio_list queued_bios; - struct work_struct queued_bios_work; -}; - -/* - * 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. - */ -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_snapshot *s, sector_t sector) -{ - return (sector & ~s->chunk_mask) >> s->chunk_shift; -} - -static inline sector_t chunk_to_sector(struct dm_snapshot *s, chunk_t chunk) -{ - return chunk << s->chunk_shift; -} - -static inline int bdev_equal(struct block_device *lhs, struct block_device *rhs) -{ - /* - * There is only ever one instance of a particular block - * device so we can compare pointers safely. - */ - return lhs == rhs; -} - -#endif |
