2 * Copyright (C) 2001 - 2003 Sistina Software
3 * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
5 * kcopyd provides a simple interface for copying an area of one
6 * block-device to one or more other block-devices, either synchronous
7 * or with an asynchronous completion notification.
9 * This file is released under the GPL.
12 #ifndef _LINUX_DM_KCOPYD_H
13 #define _LINUX_DM_KCOPYD_H
17 #include <linux/dm-io.h>
19 /* FIXME: make this configurable */
20 #define DM_KCOPYD_MAX_REGIONS 8
22 #define DM_KCOPYD_IGNORE_ERROR 1
25 * To use kcopyd you must first create a dm_kcopyd_client object.
27 struct dm_kcopyd_client
;
28 struct dm_kcopyd_client
*dm_kcopyd_client_create(void);
29 void dm_kcopyd_client_destroy(struct dm_kcopyd_client
*kc
);
32 * Submit a copy job to kcopyd. This is built on top of the
35 * read_err is a boolean,
36 * write_err is a bitset, with 1 bit for each destination region
38 typedef void (*dm_kcopyd_notify_fn
)(int read_err
, unsigned long write_err
,
41 int dm_kcopyd_copy(struct dm_kcopyd_client
*kc
, struct dm_io_region
*from
,
42 unsigned num_dests
, struct dm_io_region
*dests
,
43 unsigned flags
, dm_kcopyd_notify_fn fn
, void *context
);
46 * Prepare a callback and submit it via the kcopyd thread.
48 * dm_kcopyd_prepare_callback allocates a callback structure and returns it.
49 * It must not be called from interrupt context.
50 * The returned value should be passed into dm_kcopyd_do_callback.
52 * dm_kcopyd_do_callback submits the callback.
53 * It may be called from interrupt context.
54 * The callback is issued from the kcopyd thread.
56 void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client
*kc
,
57 dm_kcopyd_notify_fn fn
, void *context
);
58 void dm_kcopyd_do_callback(void *job
, int read_err
, unsigned long write_err
);
60 #endif /* __KERNEL__ */
61 #endif /* _LINUX_DM_KCOPYD_H */