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