[linux-2.6-block.git] / drivers / md / dm-delay.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005-2007 Red Hat GmbH
 *
 * A target that delays reads and/or writes and can send
 * them to different devices.
 *
 * This file is released under the GPL.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/slab.h>

#include <linux/device-mapper.h>

#define DM_MSG_PREFIX "delay"

struct delay_class {
	struct dm_dev *dev;
	sector_t start;
	unsigned int delay;
	unsigned int ops;
};

struct delay_c {
	struct timer_list delay_timer;
	struct mutex timer_lock;
	struct workqueue_struct *kdelayd_wq;
	struct work_struct flush_expired_bios;
	struct list_head delayed_bios;
	atomic_t may_delay;

	struct delay_class read;
	struct delay_class write;
	struct delay_class flush;

	int argc;
};

struct dm_delay_info {
	struct delay_c *context;
	struct delay_class *class;
	struct list_head list;
	unsigned long expires;
};

static DEFINE_MUTEX(delayed_bios_lock);

static void handle_delayed_timer(struct timer_list *t)
{
	struct delay_c *dc = from_timer(dc, t, delay_timer);

	queue_work(dc->kdelayd_wq, &dc->flush_expired_bios);
}

static void queue_timeout(struct delay_c *dc, unsigned long expires)
{
	mutex_lock(&dc->timer_lock);

	if (!timer_pending(&dc->delay_timer) || expires < dc->delay_timer.expires)
		mod_timer(&dc->delay_timer, expires);

	mutex_unlock(&dc->timer_lock);
}

static void flush_bios(struct bio *bio)
{
	struct bio *n;

	while (bio) {
		n = bio->bi_next;
		bio->bi_next = NULL;
		dm_submit_bio_remap(bio, NULL);
		bio = n;
	}
}

static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all)
{
	struct dm_delay_info *delayed, *next;
	unsigned long next_expires = 0;
	unsigned long start_timer = 0;
	struct bio_list flush_bios = { };

	mutex_lock(&delayed_bios_lock);
	list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
		if (flush_all || time_after_eq(jiffies, delayed->expires)) {
			struct bio *bio = dm_bio_from_per_bio_data(delayed,
						sizeof(struct dm_delay_info));
			list_del(&delayed->list);
			bio_list_add(&flush_bios, bio);
			delayed->class->ops--;
			continue;
		}

		if (!start_timer) {
			start_timer = 1;
			next_expires = delayed->expires;
		} else
			next_expires = min(next_expires, delayed->expires);
	}
	mutex_unlock(&delayed_bios_lock);

	if (start_timer)
		queue_timeout(dc, next_expires);

	return bio_list_get(&flush_bios);
}

static void flush_expired_bios(struct work_struct *work)
{
	struct delay_c *dc;

	dc = container_of(work, struct delay_c, flush_expired_bios);
	flush_bios(flush_delayed_bios(dc, 0));
}

static void delay_dtr(struct dm_target *ti)
{
	struct delay_c *dc = ti->private;

	if (dc->kdelayd_wq)
		destroy_workqueue(dc->kdelayd_wq);

	if (dc->read.dev)
		dm_put_device(ti, dc->read.dev);
	if (dc->write.dev)
		dm_put_device(ti, dc->write.dev);
	if (dc->flush.dev)
		dm_put_device(ti, dc->flush.dev);

	mutex_destroy(&dc->timer_lock);

	kfree(dc);
}

static int delay_class_ctr(struct dm_target *ti, struct delay_class *c, char **argv)
{
	int ret;
	unsigned long long tmpll;
	char dummy;

	if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
		ti->error = "Invalid device sector";
		return -EINVAL;
	}
	c->start = tmpll;

	if (sscanf(argv[2], "%u%c", &c->delay, &dummy) != 1) {
		ti->error = "Invalid delay";
		return -EINVAL;
	}

	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &c->dev);
	if (ret) {
		ti->error = "Device lookup failed";
		return ret;
	}

	return 0;
}

/*
 * Mapping parameters:
 *    <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
 *
 * With separate write parameters, the first set is only used for reads.
 * Offsets are specified in sectors.
 * Delays are specified in milliseconds.
 */
static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
	struct delay_c *dc;
	int ret;

	if (argc != 3 && argc != 6 && argc != 9) {
		ti->error = "Requires exactly 3, 6 or 9 arguments";
		return -EINVAL;
	}

	dc = kzalloc(sizeof(*dc), GFP_KERNEL);
	if (!dc) {
		ti->error = "Cannot allocate context";
		return -ENOMEM;
	}

	ti->private = dc;
	timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
	INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
	INIT_LIST_HEAD(&dc->delayed_bios);
	mutex_init(&dc->timer_lock);
	atomic_set(&dc->may_delay, 1);
	dc->argc = argc;

	ret = delay_class_ctr(ti, &dc->read, argv);
	if (ret)
		goto bad;

	if (argc == 3) {
		ret = delay_class_ctr(ti, &dc->write, argv);
		if (ret)
			goto bad;
		ret = delay_class_ctr(ti, &dc->flush, argv);
		if (ret)
			goto bad;
		goto out;
	}

	ret = delay_class_ctr(ti, &dc->write, argv + 3);
	if (ret)
		goto bad;
	if (argc == 6) {
		ret = delay_class_ctr(ti, &dc->flush, argv + 3);
		if (ret)
			goto bad;
		goto out;
	}

	ret = delay_class_ctr(ti, &dc->flush, argv + 6);
	if (ret)
		goto bad;

out:
	dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
	if (!dc->kdelayd_wq) {
		ret = -EINVAL;
		DMERR("Couldn't start kdelayd");
		goto bad;
	}

	ti->num_flush_bios = 1;
	ti->num_discard_bios = 1;
	ti->accounts_remapped_io = true;
	ti->per_io_data_size = sizeof(struct dm_delay_info);
	return 0;

bad:
	delay_dtr(ti);
	return ret;
}

static int delay_bio(struct delay_c *dc, struct delay_class *c, struct bio *bio)
{
	struct dm_delay_info *delayed;
	unsigned long expires = 0;

	if (!c->delay || !atomic_read(&dc->may_delay))
		return DM_MAPIO_REMAPPED;

	delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));

	delayed->context = dc;
	delayed->expires = expires = jiffies + msecs_to_jiffies(c->delay);

	mutex_lock(&delayed_bios_lock);
	c->ops++;
	list_add_tail(&delayed->list, &dc->delayed_bios);
	mutex_unlock(&delayed_bios_lock);

	queue_timeout(dc, expires);

	return DM_MAPIO_SUBMITTED;
}

static void delay_presuspend(struct dm_target *ti)
{
	struct delay_c *dc = ti->private;

	atomic_set(&dc->may_delay, 0);
	del_timer_sync(&dc->delay_timer);
	flush_bios(flush_delayed_bios(dc, 1));
}

static void delay_resume(struct dm_target *ti)
{
	struct delay_c *dc = ti->private;

	atomic_set(&dc->may_delay, 1);
}

static int delay_map(struct dm_target *ti, struct bio *bio)
{
	struct delay_c *dc = ti->private;
	struct delay_class *c;
	struct dm_delay_info *delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));

	if (bio_data_dir(bio) == WRITE) {
		if (unlikely(bio->bi_opf & REQ_PREFLUSH))
			c = &dc->flush;
		else
			c = &dc->write;
	} else {
		c = &dc->read;
	}
	delayed->class = c;
	bio_set_dev(bio, c->dev->bdev);
	bio->bi_iter.bi_sector = c->start + dm_target_offset(ti, bio->bi_iter.bi_sector);

	return delay_bio(dc, c, bio);
}

#define DMEMIT_DELAY_CLASS(c) \
	DMEMIT("%s %llu %u", (c)->dev->name, (unsigned long long)(c)->start, (c)->delay)

static void delay_status(struct dm_target *ti, status_type_t type,
			 unsigned int status_flags, char *result, unsigned int maxlen)
{
	struct delay_c *dc = ti->private;
	int sz = 0;

	switch (type) {
	case STATUSTYPE_INFO:
		DMEMIT("%u %u %u", dc->read.ops, dc->write.ops, dc->flush.ops);
		break;

	case STATUSTYPE_TABLE:
		DMEMIT_DELAY_CLASS(&dc->read);
		if (dc->argc >= 6) {
			DMEMIT(" ");
			DMEMIT_DELAY_CLASS(&dc->write);
		}
		if (dc->argc >= 9) {
			DMEMIT(" ");
			DMEMIT_DELAY_CLASS(&dc->flush);
		}
		break;

	case STATUSTYPE_IMA:
		*result = '\0';
		break;
	}
}

static int delay_iterate_devices(struct dm_target *ti,
				 iterate_devices_callout_fn fn, void *data)
{
	struct delay_c *dc = ti->private;
	int ret = 0;

	ret = fn(ti, dc->read.dev, dc->read.start, ti->len, data);
	if (ret)
		goto out;
	ret = fn(ti, dc->write.dev, dc->write.start, ti->len, data);
	if (ret)
		goto out;
	ret = fn(ti, dc->flush.dev, dc->flush.start, ti->len, data);
	if (ret)
		goto out;

out:
	return ret;
}

static struct target_type delay_target = {
	.name	     = "delay",
	.version     = {1, 3, 0},
	.features    = DM_TARGET_PASSES_INTEGRITY,
	.module      = THIS_MODULE,
	.ctr	     = delay_ctr,
	.dtr	     = delay_dtr,
	.map	     = delay_map,
	.presuspend  = delay_presuspend,
	.resume	     = delay_resume,
	.status	     = delay_status,
	.iterate_devices = delay_iterate_devices,
};

static int __init dm_delay_init(void)
{
	int r;

	r = dm_register_target(&delay_target);
	if (r < 0) {
		DMERR("register failed %d", r);
		goto bad_register;
	}

	return 0;

bad_register:
	return r;
}

static void __exit dm_delay_exit(void)
{
	dm_unregister_target(&delay_target);
}

/* Module hooks */
module_init(dm_delay_init);
module_exit(dm_delay_exit);

MODULE_DESCRIPTION(DM_NAME " delay target");
MODULE_AUTHOR("Heinz Mauelshagen <mauelshagen@redhat.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
3bd94003	1	// SPDX-License-Identifier: GPL-2.0-only
26b9f228 HM	2	/*
	3	* Copyright (C) 2005-2007 Red Hat GmbH
	4	*
	5	* A target that delays reads and/or writes and can send
	6	* them to different devices.
	7	*
	8	* This file is released under the GPL.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/init.h>
	13	#include <linux/blkdev.h>
	14	#include <linux/bio.h>
	15	#include <linux/slab.h>
	16
586e80e6 MP	17	#include <linux/device-mapper.h>
586e80e6 MP	18
26b9f228 HM	19	#define DM_MSG_PREFIX "delay"
26b9f228 HM	20
3876ac76 MP	21	struct delay_class {
	22	struct dm_dev *dev;
	23	sector_t start;
86a3238c HM	24	unsigned int delay;
86a3238c HM	25	unsigned int ops;
3876ac76 MP	26	};
3876ac76 MP	27
26b9f228 HM	28	struct delay_c {
26b9f228 HM	29	struct timer_list delay_timer;
ac818646	30	struct mutex timer_lock;
718822c1	31	struct workqueue_struct *kdelayd_wq;
26b9f228 HM	32	struct work_struct flush_expired_bios;
	33	struct list_head delayed_bios;
	34	atomic_t may_delay;
26b9f228	35
3876ac76 MP	36	struct delay_class read;
3876ac76 MP	37	struct delay_class write;
cda6b5ab	38	struct delay_class flush;
26b9f228	39
3876ac76	40	int argc;
26b9f228 HM	41	};
26b9f228 HM	42
028867ac	43	struct dm_delay_info {
26b9f228	44	struct delay_c *context;
3876ac76	45	struct delay_class *class;
26b9f228	46	struct list_head list;
26b9f228 HM	47	unsigned long expires;
	48	};
	49
	50	static DEFINE_MUTEX(delayed_bios_lock);
	51
8376d3c1	52	static void handle_delayed_timer(struct timer_list *t)
26b9f228	53	{
8376d3c1	54	struct delay_c *dc = from_timer(dc, t, delay_timer);
26b9f228	55
718822c1	56	queue_work(dc->kdelayd_wq, &dc->flush_expired_bios);
26b9f228 HM	57	}
	58
	59	static void queue_timeout(struct delay_c *dc, unsigned long expires)
	60	{
ac818646	61	mutex_lock(&dc->timer_lock);
26b9f228 HM	62
	63	if (!timer_pending(&dc->delay_timer) \|\| expires < dc->delay_timer.expires)
	64	mod_timer(&dc->delay_timer, expires);
	65
ac818646	66	mutex_unlock(&dc->timer_lock);
26b9f228 HM	67	}
	68
	69	static void flush_bios(struct bio *bio)
	70	{
	71	struct bio *n;
	72
	73	while (bio) {
	74	n = bio->bi_next;
	75	bio->bi_next = NULL;
b7f8dff0	76	dm_submit_bio_remap(bio, NULL);
26b9f228 HM	77	bio = n;
	78	}
	79	}
	80
	81	static struct bio flush_delayed_bios(struct delay_c dc, int flush_all)
	82	{
028867ac	83	struct dm_delay_info delayed, next;
26b9f228	84	unsigned long next_expires = 0;
3876ac76	85	unsigned long start_timer = 0;
051814c6	86	struct bio_list flush_bios = { };
26b9f228 HM	87
	88	mutex_lock(&delayed_bios_lock);
	89	list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
	90	if (flush_all \|\| time_after_eq(jiffies, delayed->expires)) {
42065460 MP	91	struct bio *bio = dm_bio_from_per_bio_data(delayed,
42065460 MP	92	sizeof(struct dm_delay_info));
26b9f228	93	list_del(&delayed->list);
42065460	94	bio_list_add(&flush_bios, bio);
3876ac76	95	delayed->class->ops--;
26b9f228 HM	96	continue;
	97	}
	98
	99	if (!start_timer) {
	100	start_timer = 1;
	101	next_expires = delayed->expires;
	102	} else
	103	next_expires = min(next_expires, delayed->expires);
	104	}
26b9f228 HM	105	mutex_unlock(&delayed_bios_lock);
	106
	107	if (start_timer)
	108	queue_timeout(dc, next_expires);
	109
	110	return bio_list_get(&flush_bios);
	111	}
	112
	113	static void flush_expired_bios(struct work_struct *work)
	114	{
	115	struct delay_c *dc;
	116
	117	dc = container_of(work, struct delay_c, flush_expired_bios);
	118	flush_bios(flush_delayed_bios(dc, 0));
	119	}
	120
3876ac76 MP	121	static void delay_dtr(struct dm_target *ti)
	122	{
	123	struct delay_c *dc = ti->private;
	124
81bc6d15 MP	125	if (dc->kdelayd_wq)
81bc6d15 MP	126	destroy_workqueue(dc->kdelayd_wq);
3876ac76 MP	127
	128	if (dc->read.dev)
	129	dm_put_device(ti, dc->read.dev);
	130	if (dc->write.dev)
	131	dm_put_device(ti, dc->write.dev);
cda6b5ab MP	132	if (dc->flush.dev)
cda6b5ab MP	133	dm_put_device(ti, dc->flush.dev);
3876ac76 MP	134
	135	mutex_destroy(&dc->timer_lock);
	136
	137	kfree(dc);
	138	}
	139
	140	static int delay_class_ctr(struct dm_target ti, struct delay_class c, char **argv)
	141	{
	142	int ret;
	143	unsigned long long tmpll;
	144	char dummy;
	145
ef87bfc2	146	if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1 \|\| tmpll != (sector_t)tmpll) {
3876ac76 MP	147	ti->error = "Invalid device sector";
	148	return -EINVAL;
	149	}
	150	c->start = tmpll;
	151
	152	if (sscanf(argv[2], "%u%c", &c->delay, &dummy) != 1) {
	153	ti->error = "Invalid delay";
	154	return -EINVAL;
	155	}
	156
	157	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &c->dev);
	158	if (ret) {
	159	ti->error = "Device lookup failed";
	160	return ret;
	161	}
	162
	163	return 0;
	164	}
	165
26b9f228 HM	166	/*
	167	* Mapping parameters:
	168	* <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
	169	*
	170	* With separate write parameters, the first set is only used for reads.
f49e869a	171	* Offsets are specified in sectors.
26b9f228 HM	172	* Delays are specified in milliseconds.
	173	*/
	174	static int delay_ctr(struct dm_target ti, unsigned int argc, char *argv)
	175	{
	176	struct delay_c *dc;
e80d1c80	177	int ret;
26b9f228	178
cda6b5ab MP	179	if (argc != 3 && argc != 6 && argc != 9) {
cda6b5ab MP	180	ti->error = "Requires exactly 3, 6 or 9 arguments";
26b9f228 HM	181	return -EINVAL;
	182	}
	183
3876ac76	184	dc = kzalloc(sizeof(*dc), GFP_KERNEL);
26b9f228 HM	185	if (!dc) {
	186	ti->error = "Cannot allocate context";
	187	return -ENOMEM;
	188	}
	189
3876ac76 MP	190	ti->private = dc;
	191	timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
	192	INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
	193	INIT_LIST_HEAD(&dc->delayed_bios);
	194	mutex_init(&dc->timer_lock);
	195	atomic_set(&dc->may_delay, 1);
	196	dc->argc = argc;
26b9f228	197
3876ac76 MP	198	ret = delay_class_ctr(ti, &dc->read, argv);
3876ac76 MP	199	if (ret)
26b9f228	200	goto bad;
26b9f228	201
3876ac76 MP	202	if (argc == 3) {
3876ac76 MP	203	ret = delay_class_ctr(ti, &dc->write, argv);
cda6b5ab MP	204	if (ret)
	205	goto bad;
	206	ret = delay_class_ctr(ti, &dc->flush, argv);
3876ac76 MP	207	if (ret)
3876ac76 MP	208	goto bad;
26b9f228	209	goto out;
26b9f228	210	}
26b9f228	211
3876ac76 MP	212	ret = delay_class_ctr(ti, &dc->write, argv + 3);
	213	if (ret)
	214	goto bad;
cda6b5ab MP	215	if (argc == 6) {
	216	ret = delay_class_ctr(ti, &dc->flush, argv + 3);
	217	if (ret)
	218	goto bad;
	219	goto out;
	220	}
	221
	222	ret = delay_class_ctr(ti, &dc->flush, argv + 6);
	223	if (ret)
	224	goto bad;
26b9f228 HM	225
26b9f228 HM	226	out:
718822c1 MP	227	dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
718822c1 MP	228	if (!dc->kdelayd_wq) {
3876ac76	229	ret = -EINVAL;
718822c1	230	DMERR("Couldn't start kdelayd");
3876ac76	231	goto bad;
718822c1 MP	232	}
718822c1 MP	233
55a62eef AK	234	ti->num_flush_bios = 1;
55a62eef AK	235	ti->num_discard_bios = 1;
c3573421	236	ti->accounts_remapped_io = true;
30187e1d	237	ti->per_io_data_size = sizeof(struct dm_delay_info);
26b9f228 HM	238	return 0;
	239
	240	bad:
3876ac76	241	delay_dtr(ti);
e80d1c80	242	return ret;
26b9f228 HM	243	}
26b9f228 HM	244
3876ac76	245	static int delay_bio(struct delay_c dc, struct delay_class c, struct bio *bio)
26b9f228	246	{
028867ac	247	struct dm_delay_info *delayed;
26b9f228 HM	248	unsigned long expires = 0;
26b9f228 HM	249
3876ac76	250	if (!c->delay \|\| !atomic_read(&dc->may_delay))
340c9ec0	251	return DM_MAPIO_REMAPPED;
26b9f228	252
42065460	253	delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
26b9f228 HM	254
26b9f228 HM	255	delayed->context = dc;
3876ac76	256	delayed->expires = expires = jiffies + msecs_to_jiffies(c->delay);
26b9f228 HM	257
26b9f228 HM	258	mutex_lock(&delayed_bios_lock);
3876ac76	259	c->ops++;
26b9f228	260	list_add_tail(&delayed->list, &dc->delayed_bios);
26b9f228 HM	261	mutex_unlock(&delayed_bios_lock);
	262
	263	queue_timeout(dc, expires);
	264
340c9ec0	265	return DM_MAPIO_SUBMITTED;
26b9f228 HM	266	}
	267
	268	static void delay_presuspend(struct dm_target *ti)
	269	{
	270	struct delay_c *dc = ti->private;
	271
	272	atomic_set(&dc->may_delay, 0);
	273	del_timer_sync(&dc->delay_timer);
	274	flush_bios(flush_delayed_bios(dc, 1));
	275	}
	276
	277	static void delay_resume(struct dm_target *ti)
	278	{
	279	struct delay_c *dc = ti->private;
	280
	281	atomic_set(&dc->may_delay, 1);
	282	}
	283
7de3ee57	284	static int delay_map(struct dm_target ti, struct bio bio)
26b9f228 HM	285	{
26b9f228 HM	286	struct delay_c *dc = ti->private;
3876ac76 MP	287	struct delay_class *c;
3876ac76 MP	288	struct dm_delay_info *delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
26b9f228	289
3876ac76	290	if (bio_data_dir(bio) == WRITE) {
cda6b5ab MP	291	if (unlikely(bio->bi_opf & REQ_PREFLUSH))
	292	c = &dc->flush;
	293	else
	294	c = &dc->write;
3876ac76 MP	295	} else {
3876ac76 MP	296	c = &dc->read;
26b9f228	297	}
3876ac76 MP	298	delayed->class = c;
3876ac76 MP	299	bio_set_dev(bio, c->dev->bdev);
e86f2b00	300	bio->bi_iter.bi_sector = c->start + dm_target_offset(ti, bio->bi_iter.bi_sector);
26b9f228	301
3876ac76	302	return delay_bio(dc, c, bio);
26b9f228 HM	303	}
26b9f228 HM	304
3876ac76 MP	305	#define DMEMIT_DELAY_CLASS(c) \
	306	DMEMIT("%s %llu %u", (c)->dev->name, (unsigned long long)(c)->start, (c)->delay)
	307
fd7c092e	308	static void delay_status(struct dm_target *ti, status_type_t type,
86a3238c	309	unsigned int status_flags, char *result, unsigned int maxlen)
26b9f228 HM	310	{
	311	struct delay_c *dc = ti->private;
	312	int sz = 0;
	313
	314	switch (type) {
	315	case STATUSTYPE_INFO:
cda6b5ab	316	DMEMIT("%u %u %u", dc->read.ops, dc->write.ops, dc->flush.ops);
26b9f228 HM	317	break;
	318
	319	case STATUSTYPE_TABLE:
3876ac76 MP	320	DMEMIT_DELAY_CLASS(&dc->read);
	321	if (dc->argc >= 6) {
	322	DMEMIT(" ");
	323	DMEMIT_DELAY_CLASS(&dc->write);
	324	}
cda6b5ab MP	325	if (dc->argc >= 9) {
	326	DMEMIT(" ");
	327	DMEMIT_DELAY_CLASS(&dc->flush);
	328	}
26b9f228	329	break;
8ec45662 TS	330
	331	case STATUSTYPE_IMA:
	332	*result = '\0';
	333	break;
26b9f228	334	}
26b9f228 HM	335	}
26b9f228 HM	336
af4874e0 MS	337	static int delay_iterate_devices(struct dm_target *ti,
	338	iterate_devices_callout_fn fn, void *data)
	339	{
	340	struct delay_c *dc = ti->private;
	341	int ret = 0;
	342
3876ac76 MP	343	ret = fn(ti, dc->read.dev, dc->read.start, ti->len, data);
	344	if (ret)
	345	goto out;
	346	ret = fn(ti, dc->write.dev, dc->write.start, ti->len, data);
af4874e0 MS	347	if (ret)
af4874e0 MS	348	goto out;
cda6b5ab MP	349	ret = fn(ti, dc->flush.dev, dc->flush.start, ti->len, data);
	350	if (ret)
	351	goto out;
af4874e0 MS	352
	353	out:
	354	return ret;
	355	}
	356
26b9f228 HM	357	static struct target_type delay_target = {
26b9f228 HM	358	.name = "delay",
c3573421	359	.version = {1, 3, 0},
e2460f2a	360	.features = DM_TARGET_PASSES_INTEGRITY,
26b9f228 HM	361	.module = THIS_MODULE,
	362	.ctr = delay_ctr,
	363	.dtr = delay_dtr,
	364	.map = delay_map,
	365	.presuspend = delay_presuspend,
	366	.resume = delay_resume,
	367	.status = delay_status,
af4874e0	368	.iterate_devices = delay_iterate_devices,
26b9f228 HM	369	};
	370
	371	static int __init dm_delay_init(void)
	372	{
42065460	373	int r;
26b9f228 HM	374
	375	r = dm_register_target(&delay_target);
	376	if (r < 0) {
	377	DMERR("register failed %d", r);
	378	goto bad_register;
	379	}
	380
	381	return 0;
	382
	383	bad_register:
26b9f228 HM	384	return r;
	385	}
	386
	387	static void __exit dm_delay_exit(void)
	388	{
10d3bd09	389	dm_unregister_target(&delay_target);
26b9f228 HM	390	}
	391
	392	/* Module hooks */
	393	module_init(dm_delay_init);
	394	module_exit(dm_delay_exit);
	395
	396	MODULE_DESCRIPTION(DM_NAME " delay target");
	397	MODULE_AUTHOR("Heinz Mauelshagen <mauelshagen@redhat.com>");
	398	MODULE_LICENSE("GPL");