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3bd94003 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
1da177e4 | 2 | /* |
eb69aca5 HM |
3 | * Copyright (C) 2001 - 2003 Sistina Software |
4 | * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved. | |
1da177e4 | 5 | * |
eb69aca5 HM |
6 | * kcopyd provides a simple interface for copying an area of one |
7 | * block-device to one or more other block-devices, either synchronous | |
8 | * or with an asynchronous completion notification. | |
1da177e4 | 9 | * |
eb69aca5 | 10 | * This file is released under the GPL. |
1da177e4 LT |
11 | */ |
12 | ||
eb69aca5 HM |
13 | #ifndef _LINUX_DM_KCOPYD_H |
14 | #define _LINUX_DM_KCOPYD_H | |
15 | ||
16 | #ifdef __KERNEL__ | |
1da177e4 | 17 | |
a765e20e | 18 | #include <linux/dm-io.h> |
1da177e4 LT |
19 | |
20 | /* FIXME: make this configurable */ | |
eb69aca5 | 21 | #define DM_KCOPYD_MAX_REGIONS 8 |
1da177e4 | 22 | |
eb69aca5 | 23 | #define DM_KCOPYD_IGNORE_ERROR 1 |
b73c67c2 | 24 | #define DM_KCOPYD_WRITE_SEQ 2 |
1da177e4 | 25 | |
df5d2e90 | 26 | struct dm_kcopyd_throttle { |
86a3238c HM |
27 | unsigned int throttle; |
28 | unsigned int num_io_jobs; | |
29 | unsigned int io_period; | |
30 | unsigned int total_period; | |
31 | unsigned int last_jiffies; | |
df5d2e90 MP |
32 | }; |
33 | ||
34 | /* | |
35 | * kcopyd clients that want to support throttling must pass an initialised | |
36 | * dm_kcopyd_throttle struct into dm_kcopyd_client_create(). | |
37 | * Two or more clients may share the same instance of this struct between | |
38 | * them if they wish to be throttled as a group. | |
39 | * | |
40 | * This macro also creates a corresponding module parameter to configure | |
41 | * the amount of throttling. | |
42 | */ | |
43 | #define DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(name, description) \ | |
44 | static struct dm_kcopyd_throttle dm_kcopyd_throttle = { 100, 0, 0, 0, 0 }; \ | |
45 | module_param_named(name, dm_kcopyd_throttle.throttle, uint, 0644); \ | |
46 | MODULE_PARM_DESC(name, description) | |
47 | ||
1da177e4 | 48 | /* |
eb69aca5 | 49 | * To use kcopyd you must first create a dm_kcopyd_client object. |
df5d2e90 | 50 | * throttle can be NULL if you don't want any throttling. |
1da177e4 | 51 | */ |
eb69aca5 | 52 | struct dm_kcopyd_client; |
df5d2e90 | 53 | struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle); |
eb69aca5 | 54 | void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc); |
293128b1 | 55 | void dm_kcopyd_client_flush(struct dm_kcopyd_client *kc); |
1da177e4 LT |
56 | |
57 | /* | |
58 | * Submit a copy job to kcopyd. This is built on top of the | |
59 | * previous three fns. | |
60 | * | |
61 | * read_err is a boolean, | |
62 | * write_err is a bitset, with 1 bit for each destination region | |
63 | */ | |
86a3238c | 64 | typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned int long write_err, |
eb69aca5 | 65 | void *context); |
1da177e4 | 66 | |
7209049d | 67 | void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, |
86a3238c HM |
68 | unsigned int num_dests, struct dm_io_region *dests, |
69 | unsigned int flags, dm_kcopyd_notify_fn fn, void *context); | |
1da177e4 | 70 | |
a6e50b40 MP |
71 | /* |
72 | * Prepare a callback and submit it via the kcopyd thread. | |
73 | * | |
74 | * dm_kcopyd_prepare_callback allocates a callback structure and returns it. | |
75 | * It must not be called from interrupt context. | |
76 | * The returned value should be passed into dm_kcopyd_do_callback. | |
77 | * | |
78 | * dm_kcopyd_do_callback submits the callback. | |
79 | * It may be called from interrupt context. | |
80 | * The callback is issued from the kcopyd thread. | |
81 | */ | |
82 | void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc, | |
83 | dm_kcopyd_notify_fn fn, void *context); | |
86a3238c | 84 | void dm_kcopyd_do_callback(void *job, int read_err, unsigned int long write_err); |
a6e50b40 | 85 | |
7209049d | 86 | void dm_kcopyd_zero(struct dm_kcopyd_client *kc, |
86a3238c HM |
87 | unsigned int num_dests, struct dm_io_region *dests, |
88 | unsigned int flags, dm_kcopyd_notify_fn fn, void *context); | |
7f069653 | 89 | |
eb69aca5 HM |
90 | #endif /* __KERNEL__ */ |
91 | #endif /* _LINUX_DM_KCOPYD_H */ |