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1/*
2 * Copyright (C) 2001 - 2003 Sistina Software
3 * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
4 *
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.
8 *
9 * This file is released under the GPL.
10 */
11
12#ifndef _LINUX_DM_KCOPYD_H
13#define _LINUX_DM_KCOPYD_H
14
15#ifdef __KERNEL__
16
17#include <linux/dm-io.h>
18
19/* FIXME: make this configurable */
20#define DM_KCOPYD_MAX_REGIONS 8
21
22#define DM_KCOPYD_IGNORE_ERROR 1
23
24/*
25 * To use kcopyd you must first create a dm_kcopyd_client object.
26 */
27struct dm_kcopyd_client;
28struct dm_kcopyd_client *dm_kcopyd_client_create(void);
29void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
30
31/*
32 * Submit a copy job to kcopyd. This is built on top of the
33 * previous three fns.
34 *
35 * read_err is a boolean,
36 * write_err is a bitset, with 1 bit for each destination region
37 */
38typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err,
39 void *context);
40
41int 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);
44
45/*
46 * Prepare a callback and submit it via the kcopyd thread.
47 *
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.
51 *
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.
55 */
56void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc,
57 dm_kcopyd_notify_fn fn, void *context);
58void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err);
59
60int dm_kcopyd_zero(struct dm_kcopyd_client *kc,
61 unsigned num_dests, struct dm_io_region *dests,
62 unsigned flags, dm_kcopyd_notify_fn fn, void *context);
63
64#endif /* __KERNEL__ */
65#endif /* _LINUX_DM_KCOPYD_H */