[mirror_ubuntu-bionic-kernel.git] / include / linux / dm-kcopyd.h

/*
 * 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

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);

/*
 * 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);

int 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);

int 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 */
Commit	Line	Data
	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	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
	46	/*
	47	* To use kcopyd you must first create a dm_kcopyd_client object.
	48	* throttle can be NULL if you don't want any throttling.
	49	*/
	50	struct dm_kcopyd_client;
	51	struct dm_kcopyd_client dm_kcopyd_client_create(struct dm_kcopyd_throttle throttle);
	52	void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
	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	*/
	61	typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err,
	62	void *context);
	63
	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);
	67
	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
	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
	87	#endif /* __KERNEL__ */
	88	#endif /* _LINUX_DM_KCOPYD_H */