[linux-2.6-block.git] / include / linux / dm-kcopyd.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * 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 int throttle;
	unsigned int num_io_jobs;
	unsigned int io_period;
	unsigned int total_period;
	unsigned int 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 int long write_err,
				    void *context);

void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
		    unsigned int num_dests, struct dm_io_region *dests,
		    unsigned int 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 int long write_err);

void dm_kcopyd_zero(struct dm_kcopyd_client *kc,
		    unsigned int num_dests, struct dm_io_region *dests,
		    unsigned int flags, dm_kcopyd_notify_fn fn, void *context);

#endif	/* __KERNEL__ */
#endif	/* _LINUX_DM_KCOPYD_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0-only */
	2	/*
	3	* Copyright (C) 2001 - 2003 Sistina Software
	4	* Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
	5	*
	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.
	9	*
	10	* This file is released under the GPL.
	11	*/
	12
	13	#ifndef _LINUX_DM_KCOPYD_H
	14	#define _LINUX_DM_KCOPYD_H
	15
	16	#ifdef __KERNEL__
	17
	18	#include <linux/dm-io.h>
	19
	20	/* FIXME: make this configurable */
	21	#define DM_KCOPYD_MAX_REGIONS 8
	22
	23	#define DM_KCOPYD_IGNORE_ERROR 1
	24	#define DM_KCOPYD_WRITE_SEQ 2
	25
	26	struct dm_kcopyd_throttle {
	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;
	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
	48	/*
	49	* To use kcopyd you must first create a dm_kcopyd_client object.
	50	* throttle can be NULL if you don't want any throttling.
	51	*/
	52	struct dm_kcopyd_client;
	53	struct dm_kcopyd_client dm_kcopyd_client_create(struct dm_kcopyd_throttle throttle);
	54	void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
	55	void dm_kcopyd_client_flush(struct dm_kcopyd_client *kc);
	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	*/
	64	typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned int long write_err,
	65	void *context);
	66
	67	void dm_kcopyd_copy(struct dm_kcopyd_client kc, struct dm_io_region from,
	68	unsigned int num_dests, struct dm_io_region *dests,
	69	unsigned int flags, dm_kcopyd_notify_fn fn, void *context);
	70
	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);
	84	void dm_kcopyd_do_callback(void *job, int read_err, unsigned int long write_err);
	85
	86	void dm_kcopyd_zero(struct dm_kcopyd_client *kc,
	87	unsigned int num_dests, struct dm_io_region *dests,
	88	unsigned int flags, dm_kcopyd_notify_fn fn, void *context);
	89
	90	#endif /* __KERNEL__ */
	91	#endif /* _LINUX_DM_KCOPYD_H */