| /* |
| * Copyright (C) 2001 - 2003 Sistina Software |
| * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved. |
| * |
| * kcopyd provides a simple interface for copying an area of one |
| * block-device to one or more other block-devices, either synchronous |
| * or with an asynchronous completion notification. |
| * |
| * This file is released under the GPL. |
| */ |
| |
| #ifndef _LINUX_DM_KCOPYD_H |
| #define _LINUX_DM_KCOPYD_H |
| |
| #ifdef __KERNEL__ |
| |
| #include <linux/dm-io.h> |
| |
| /* FIXME: make this configurable */ |
| #define DM_KCOPYD_MAX_REGIONS 8 |
| |
| #define DM_KCOPYD_IGNORE_ERROR 1 |
| #define DM_KCOPYD_WRITE_SEQ 2 |
| |
| struct dm_kcopyd_throttle { |
| unsigned throttle; |
| unsigned num_io_jobs; |
| unsigned io_period; |
| unsigned total_period; |
| unsigned last_jiffies; |
| }; |
| |
| /* |
| * kcopyd clients that want to support throttling must pass an initialised |
| * dm_kcopyd_throttle struct into dm_kcopyd_client_create(). |
| * Two or more clients may share the same instance of this struct between |
| * them if they wish to be throttled as a group. |
| * |
| * This macro also creates a corresponding module parameter to configure |
| * the amount of throttling. |
| */ |
| #define DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(name, description) \ |
| static struct dm_kcopyd_throttle dm_kcopyd_throttle = { 100, 0, 0, 0, 0 }; \ |
| module_param_named(name, dm_kcopyd_throttle.throttle, uint, 0644); \ |
| MODULE_PARM_DESC(name, description) |
| |
| /* |
| * To use kcopyd you must first create a dm_kcopyd_client object. |
| * throttle can be NULL if you don't want any throttling. |
| */ |
| struct dm_kcopyd_client; |
| struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle); |
| void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc); |
| void dm_kcopyd_client_flush(struct dm_kcopyd_client *kc); |
| |
| /* |
| * Submit a copy job to kcopyd. This is built on top of the |
| * previous three fns. |
| * |
| * read_err is a boolean, |
| * write_err is a bitset, with 1 bit for each destination region |
| */ |
| typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err, |
| void *context); |
| |
| void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, |
| unsigned num_dests, struct dm_io_region *dests, |
| unsigned flags, dm_kcopyd_notify_fn fn, void *context); |
| |
| /* |
| * Prepare a callback and submit it via the kcopyd thread. |
| * |
| * dm_kcopyd_prepare_callback allocates a callback structure and returns it. |
| * It must not be called from interrupt context. |
| * The returned value should be passed into dm_kcopyd_do_callback. |
| * |
| * dm_kcopyd_do_callback submits the callback. |
| * It may be called from interrupt context. |
| * The callback is issued from the kcopyd thread. |
| */ |
| void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc, |
| dm_kcopyd_notify_fn fn, void *context); |
| void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err); |
| |
| void dm_kcopyd_zero(struct dm_kcopyd_client *kc, |
| unsigned num_dests, struct dm_io_region *dests, |
| unsigned flags, dm_kcopyd_notify_fn fn, void *context); |
| |
| #endif /* __KERNEL__ */ |
| #endif /* _LINUX_DM_KCOPYD_H */ |