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1/*
2 * Copyright (C) 2005-2007 Red Hat GmbH
3 *
4 * A target that delays reads and/or writes and can send
5 * them to different devices.
6 *
7 * This file is released under the GPL.
8 */
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/blkdev.h>
13#include <linux/bio.h>
14#include <linux/slab.h>
15
16#include <linux/device-mapper.h>
17
18#define DM_MSG_PREFIX "delay"
19
20struct delay_c {
21 struct timer_list delay_timer;
22 struct mutex timer_lock;
23 struct work_struct flush_expired_bios;
24 struct list_head delayed_bios;
25 atomic_t may_delay;
26 mempool_t *delayed_pool;
27
28 struct dm_dev *dev_read;
29 sector_t start_read;
30 unsigned read_delay;
31 unsigned reads;
32
33 struct dm_dev *dev_write;
34 sector_t start_write;
35 unsigned write_delay;
36 unsigned writes;
37};
38
39struct dm_delay_info {
40 struct delay_c *context;
41 struct list_head list;
42 struct bio *bio;
43 unsigned long expires;
44};
45
46static DEFINE_MUTEX(delayed_bios_lock);
47
48static struct workqueue_struct *kdelayd_wq;
49static struct kmem_cache *delayed_cache;
50
51static void handle_delayed_timer(unsigned long data)
52{
53 struct delay_c *dc = (struct delay_c *)data;
54
55 queue_work(kdelayd_wq, &dc->flush_expired_bios);
56}
57
58static void queue_timeout(struct delay_c *dc, unsigned long expires)
59{
60 mutex_lock(&dc->timer_lock);
61
62 if (!timer_pending(&dc->delay_timer) || expires < dc->delay_timer.expires)
63 mod_timer(&dc->delay_timer, expires);
64
65 mutex_unlock(&dc->timer_lock);
66}
67
68static void flush_bios(struct bio *bio)
69{
70 struct bio *n;
71
72 while (bio) {
73 n = bio->bi_next;
74 bio->bi_next = NULL;
75 generic_make_request(bio);
76 bio = n;
77 }
78}
79
80static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all)
81{
82 struct dm_delay_info *delayed, *next;
83 unsigned long next_expires = 0;
84 int start_timer = 0;
85 struct bio_list flush_bios = { };
86
87 mutex_lock(&delayed_bios_lock);
88 list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
89 if (flush_all || time_after_eq(jiffies, delayed->expires)) {
90 list_del(&delayed->list);
91 bio_list_add(&flush_bios, delayed->bio);
92 if ((bio_data_dir(delayed->bio) == WRITE))
93 delayed->context->writes--;
94 else
95 delayed->context->reads--;
96 mempool_free(delayed, dc->delayed_pool);
97 continue;
98 }
99
100 if (!start_timer) {
101 start_timer = 1;
102 next_expires = delayed->expires;
103 } else
104 next_expires = min(next_expires, delayed->expires);
105 }
106
107 mutex_unlock(&delayed_bios_lock);
108
109 if (start_timer)
110 queue_timeout(dc, next_expires);
111
112 return bio_list_get(&flush_bios);
113}
114
115static void flush_expired_bios(struct work_struct *work)
116{
117 struct delay_c *dc;
118
119 dc = container_of(work, struct delay_c, flush_expired_bios);
120 flush_bios(flush_delayed_bios(dc, 0));
121}
122
123/*
124 * Mapping parameters:
125 * <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
126 *
127 * With separate write parameters, the first set is only used for reads.
128 * Delays are specified in milliseconds.
129 */
130static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
131{
132 struct delay_c *dc;
133 unsigned long long tmpll;
134
135 if (argc != 3 && argc != 6) {
136 ti->error = "requires exactly 3 or 6 arguments";
137 return -EINVAL;
138 }
139
140 dc = kmalloc(sizeof(*dc), GFP_KERNEL);
141 if (!dc) {
142 ti->error = "Cannot allocate context";
143 return -ENOMEM;
144 }
145
146 dc->reads = dc->writes = 0;
147
148 if (sscanf(argv[1], "%llu", &tmpll) != 1) {
149 ti->error = "Invalid device sector";
150 goto bad;
151 }
152 dc->start_read = tmpll;
153
154 if (sscanf(argv[2], "%u", &dc->read_delay) != 1) {
155 ti->error = "Invalid delay";
156 goto bad;
157 }
158
159 if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
160 &dc->dev_read)) {
161 ti->error = "Device lookup failed";
162 goto bad;
163 }
164
165 dc->dev_write = NULL;
166 if (argc == 3)
167 goto out;
168
169 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
170 ti->error = "Invalid write device sector";
171 goto bad_dev_read;
172 }
173 dc->start_write = tmpll;
174
175 if (sscanf(argv[5], "%u", &dc->write_delay) != 1) {
176 ti->error = "Invalid write delay";
177 goto bad_dev_read;
178 }
179
180 if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table),
181 &dc->dev_write)) {
182 ti->error = "Write device lookup failed";
183 goto bad_dev_read;
184 }
185
186out:
187 dc->delayed_pool = mempool_create_slab_pool(128, delayed_cache);
188 if (!dc->delayed_pool) {
189 DMERR("Couldn't create delayed bio pool.");
190 goto bad_dev_write;
191 }
192
193 setup_timer(&dc->delay_timer, handle_delayed_timer, (unsigned long)dc);
194
195 INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
196 INIT_LIST_HEAD(&dc->delayed_bios);
197 mutex_init(&dc->timer_lock);
198 atomic_set(&dc->may_delay, 1);
199
200 ti->num_flush_requests = 1;
201 ti->num_discard_requests = 1;
202 ti->private = dc;
203 return 0;
204
205bad_dev_write:
206 if (dc->dev_write)
207 dm_put_device(ti, dc->dev_write);
208bad_dev_read:
209 dm_put_device(ti, dc->dev_read);
210bad:
211 kfree(dc);
212 return -EINVAL;
213}
214
215static void delay_dtr(struct dm_target *ti)
216{
217 struct delay_c *dc = ti->private;
218
219 flush_workqueue(kdelayd_wq);
220
221 dm_put_device(ti, dc->dev_read);
222
223 if (dc->dev_write)
224 dm_put_device(ti, dc->dev_write);
225
226 mempool_destroy(dc->delayed_pool);
227 kfree(dc);
228}
229
230static int delay_bio(struct delay_c *dc, int delay, struct bio *bio)
231{
232 struct dm_delay_info *delayed;
233 unsigned long expires = 0;
234
235 if (!delay || !atomic_read(&dc->may_delay))
236 return 1;
237
238 delayed = mempool_alloc(dc->delayed_pool, GFP_NOIO);
239
240 delayed->context = dc;
241 delayed->bio = bio;
242 delayed->expires = expires = jiffies + (delay * HZ / 1000);
243
244 mutex_lock(&delayed_bios_lock);
245
246 if (bio_data_dir(bio) == WRITE)
247 dc->writes++;
248 else
249 dc->reads++;
250
251 list_add_tail(&delayed->list, &dc->delayed_bios);
252
253 mutex_unlock(&delayed_bios_lock);
254
255 queue_timeout(dc, expires);
256
257 return 0;
258}
259
260static void delay_presuspend(struct dm_target *ti)
261{
262 struct delay_c *dc = ti->private;
263
264 atomic_set(&dc->may_delay, 0);
265 del_timer_sync(&dc->delay_timer);
266 flush_bios(flush_delayed_bios(dc, 1));
267}
268
269static void delay_resume(struct dm_target *ti)
270{
271 struct delay_c *dc = ti->private;
272
273 atomic_set(&dc->may_delay, 1);
274}
275
276static int delay_map(struct dm_target *ti, struct bio *bio,
277 union map_info *map_context)
278{
279 struct delay_c *dc = ti->private;
280
281 if ((bio_data_dir(bio) == WRITE) && (dc->dev_write)) {
282 bio->bi_bdev = dc->dev_write->bdev;
283 if (bio_sectors(bio))
284 bio->bi_sector = dc->start_write +
285 dm_target_offset(ti, bio->bi_sector);
286
287 return delay_bio(dc, dc->write_delay, bio);
288 }
289
290 bio->bi_bdev = dc->dev_read->bdev;
291 bio->bi_sector = dc->start_read + dm_target_offset(ti, bio->bi_sector);
292
293 return delay_bio(dc, dc->read_delay, bio);
294}
295
296static int delay_status(struct dm_target *ti, status_type_t type,
297 char *result, unsigned maxlen)
298{
299 struct delay_c *dc = ti->private;
300 int sz = 0;
301
302 switch (type) {
303 case STATUSTYPE_INFO:
304 DMEMIT("%u %u", dc->reads, dc->writes);
305 break;
306
307 case STATUSTYPE_TABLE:
308 DMEMIT("%s %llu %u", dc->dev_read->name,
309 (unsigned long long) dc->start_read,
310 dc->read_delay);
311 if (dc->dev_write)
312 DMEMIT(" %s %llu %u", dc->dev_write->name,
313 (unsigned long long) dc->start_write,
314 dc->write_delay);
315 break;
316 }
317
318 return 0;
319}
320
321static int delay_iterate_devices(struct dm_target *ti,
322 iterate_devices_callout_fn fn, void *data)
323{
324 struct delay_c *dc = ti->private;
325 int ret = 0;
326
327 ret = fn(ti, dc->dev_read, dc->start_read, ti->len, data);
328 if (ret)
329 goto out;
330
331 if (dc->dev_write)
332 ret = fn(ti, dc->dev_write, dc->start_write, ti->len, data);
333
334out:
335 return ret;
336}
337
338static struct target_type delay_target = {
339 .name = "delay",
340 .version = {1, 1, 0},
341 .module = THIS_MODULE,
342 .ctr = delay_ctr,
343 .dtr = delay_dtr,
344 .map = delay_map,
345 .presuspend = delay_presuspend,
346 .resume = delay_resume,
347 .status = delay_status,
348 .iterate_devices = delay_iterate_devices,
349};
350
351static int __init dm_delay_init(void)
352{
353 int r = -ENOMEM;
354
355 kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
356 if (!kdelayd_wq) {
357 DMERR("Couldn't start kdelayd");
358 goto bad_queue;
359 }
360
361 delayed_cache = KMEM_CACHE(dm_delay_info, 0);
362 if (!delayed_cache) {
363 DMERR("Couldn't create delayed bio cache.");
364 goto bad_memcache;
365 }
366
367 r = dm_register_target(&delay_target);
368 if (r < 0) {
369 DMERR("register failed %d", r);
370 goto bad_register;
371 }
372
373 return 0;
374
375bad_register:
376 kmem_cache_destroy(delayed_cache);
377bad_memcache:
378 destroy_workqueue(kdelayd_wq);
379bad_queue:
380 return r;
381}
382
383static void __exit dm_delay_exit(void)
384{
385 dm_unregister_target(&delay_target);
386 kmem_cache_destroy(delayed_cache);
387 destroy_workqueue(kdelayd_wq);
388}
389
390/* Module hooks */
391module_init(dm_delay_init);
392module_exit(dm_delay_exit);
393
394MODULE_DESCRIPTION(DM_NAME " delay target");
395MODULE_AUTHOR("Heinz Mauelshagen <mauelshagen@redhat.com>");
396MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/kthread.h>
17
18#include <linux/device-mapper.h>
19
20#define DM_MSG_PREFIX "delay"
21
22struct delay_class {
23 struct dm_dev *dev;
24 sector_t start;
25 unsigned int delay;
26 unsigned int ops;
27};
28
29struct delay_c {
30 struct timer_list delay_timer;
31 struct mutex process_bios_lock; /* hold while removing bios to be processed from list */
32 spinlock_t delayed_bios_lock; /* hold on all accesses to delayed_bios list */
33 struct workqueue_struct *kdelayd_wq;
34 struct work_struct flush_expired_bios;
35 struct list_head delayed_bios;
36 struct task_struct *worker;
37 bool may_delay;
38
39 struct delay_class read;
40 struct delay_class write;
41 struct delay_class flush;
42
43 int argc;
44};
45
46struct dm_delay_info {
47 struct delay_c *context;
48 struct delay_class *class;
49 struct list_head list;
50 unsigned long expires;
51};
52
53static void handle_delayed_timer(struct timer_list *t)
54{
55 struct delay_c *dc = from_timer(dc, t, delay_timer);
56
57 queue_work(dc->kdelayd_wq, &dc->flush_expired_bios);
58}
59
60static void queue_timeout(struct delay_c *dc, unsigned long expires)
61{
62 timer_reduce(&dc->delay_timer, expires);
63}
64
65static inline bool delay_is_fast(struct delay_c *dc)
66{
67 return !!dc->worker;
68}
69
70static void flush_bios(struct bio *bio)
71{
72 struct bio *n;
73
74 while (bio) {
75 n = bio->bi_next;
76 bio->bi_next = NULL;
77 dm_submit_bio_remap(bio, NULL);
78 bio = n;
79 }
80}
81
82static void flush_delayed_bios(struct delay_c *dc, bool flush_all)
83{
84 struct dm_delay_info *delayed, *next;
85 struct bio_list flush_bio_list;
86 LIST_HEAD(local_list);
87 unsigned long next_expires = 0;
88 bool start_timer = false;
89 bio_list_init(&flush_bio_list);
90
91 mutex_lock(&dc->process_bios_lock);
92 spin_lock(&dc->delayed_bios_lock);
93 list_replace_init(&dc->delayed_bios, &local_list);
94 spin_unlock(&dc->delayed_bios_lock);
95 list_for_each_entry_safe(delayed, next, &local_list, list) {
96 cond_resched();
97 if (flush_all || time_after_eq(jiffies, delayed->expires)) {
98 struct bio *bio = dm_bio_from_per_bio_data(delayed,
99 sizeof(struct dm_delay_info));
100 list_del(&delayed->list);
101 bio_list_add(&flush_bio_list, bio);
102 delayed->class->ops--;
103 continue;
104 }
105
106 if (!delay_is_fast(dc)) {
107 if (!start_timer) {
108 start_timer = true;
109 next_expires = delayed->expires;
110 } else {
111 next_expires = min(next_expires, delayed->expires);
112 }
113 }
114 }
115 spin_lock(&dc->delayed_bios_lock);
116 list_splice(&local_list, &dc->delayed_bios);
117 spin_unlock(&dc->delayed_bios_lock);
118 mutex_unlock(&dc->process_bios_lock);
119
120 if (start_timer)
121 queue_timeout(dc, next_expires);
122
123 flush_bios(bio_list_get(&flush_bio_list));
124}
125
126static int flush_worker_fn(void *data)
127{
128 struct delay_c *dc = data;
129
130 while (!kthread_should_stop()) {
131 flush_delayed_bios(dc, false);
132 spin_lock(&dc->delayed_bios_lock);
133 if (unlikely(list_empty(&dc->delayed_bios))) {
134 set_current_state(TASK_INTERRUPTIBLE);
135 spin_unlock(&dc->delayed_bios_lock);
136 schedule();
137 } else {
138 spin_unlock(&dc->delayed_bios_lock);
139 cond_resched();
140 }
141 }
142
143 return 0;
144}
145
146static void flush_expired_bios(struct work_struct *work)
147{
148 struct delay_c *dc;
149
150 dc = container_of(work, struct delay_c, flush_expired_bios);
151 flush_delayed_bios(dc, false);
152}
153
154static void delay_dtr(struct dm_target *ti)
155{
156 struct delay_c *dc = ti->private;
157
158 if (dc->kdelayd_wq) {
159 timer_shutdown_sync(&dc->delay_timer);
160 destroy_workqueue(dc->kdelayd_wq);
161 }
162
163 if (dc->read.dev)
164 dm_put_device(ti, dc->read.dev);
165 if (dc->write.dev)
166 dm_put_device(ti, dc->write.dev);
167 if (dc->flush.dev)
168 dm_put_device(ti, dc->flush.dev);
169 if (dc->worker)
170 kthread_stop(dc->worker);
171
172 mutex_destroy(&dc->process_bios_lock);
173
174 kfree(dc);
175}
176
177static int delay_class_ctr(struct dm_target *ti, struct delay_class *c, char **argv)
178{
179 int ret;
180 unsigned long long tmpll;
181 char dummy;
182
183 if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
184 ti->error = "Invalid device sector";
185 return -EINVAL;
186 }
187 c->start = tmpll;
188
189 if (sscanf(argv[2], "%u%c", &c->delay, &dummy) != 1) {
190 ti->error = "Invalid delay";
191 return -EINVAL;
192 }
193
194 ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &c->dev);
195 if (ret) {
196 ti->error = "Device lookup failed";
197 return ret;
198 }
199
200 return 0;
201}
202
203/*
204 * Mapping parameters:
205 * <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
206 *
207 * With separate write parameters, the first set is only used for reads.
208 * Offsets are specified in sectors.
209 * Delays are specified in milliseconds.
210 */
211static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
212{
213 struct delay_c *dc;
214 int ret;
215 unsigned int max_delay;
216
217 if (argc != 3 && argc != 6 && argc != 9) {
218 ti->error = "Requires exactly 3, 6 or 9 arguments";
219 return -EINVAL;
220 }
221
222 dc = kzalloc(sizeof(*dc), GFP_KERNEL);
223 if (!dc) {
224 ti->error = "Cannot allocate context";
225 return -ENOMEM;
226 }
227
228 ti->private = dc;
229 INIT_LIST_HEAD(&dc->delayed_bios);
230 mutex_init(&dc->process_bios_lock);
231 spin_lock_init(&dc->delayed_bios_lock);
232 dc->may_delay = true;
233 dc->argc = argc;
234
235 ret = delay_class_ctr(ti, &dc->read, argv);
236 if (ret)
237 goto bad;
238 max_delay = dc->read.delay;
239
240 if (argc == 3) {
241 ret = delay_class_ctr(ti, &dc->write, argv);
242 if (ret)
243 goto bad;
244 ret = delay_class_ctr(ti, &dc->flush, argv);
245 if (ret)
246 goto bad;
247 goto out;
248 }
249
250 ret = delay_class_ctr(ti, &dc->write, argv + 3);
251 if (ret)
252 goto bad;
253 max_delay = max(max_delay, dc->write.delay);
254
255 if (argc == 6) {
256 ret = delay_class_ctr(ti, &dc->flush, argv + 3);
257 if (ret)
258 goto bad;
259 goto out;
260 }
261
262 ret = delay_class_ctr(ti, &dc->flush, argv + 6);
263 if (ret)
264 goto bad;
265 max_delay = max(max_delay, dc->flush.delay);
266
267out:
268 if (max_delay < 50) {
269 /*
270 * In case of small requested delays, use kthread instead of
271 * timers and workqueue to achieve better latency.
272 */
273 dc->worker = kthread_run(&flush_worker_fn, dc, "dm-delay-flush-worker");
274 if (IS_ERR(dc->worker)) {
275 ret = PTR_ERR(dc->worker);
276 dc->worker = NULL;
277 goto bad;
278 }
279 } else {
280 timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
281 INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
282 dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
283 if (!dc->kdelayd_wq) {
284 ret = -EINVAL;
285 DMERR("Couldn't start kdelayd");
286 goto bad;
287 }
288 }
289
290 ti->num_flush_bios = 1;
291 ti->num_discard_bios = 1;
292 ti->accounts_remapped_io = true;
293 ti->per_io_data_size = sizeof(struct dm_delay_info);
294 return 0;
295
296bad:
297 delay_dtr(ti);
298 return ret;
299}
300
301static int delay_bio(struct delay_c *dc, struct delay_class *c, struct bio *bio)
302{
303 struct dm_delay_info *delayed;
304 unsigned long expires = 0;
305
306 if (!c->delay)
307 return DM_MAPIO_REMAPPED;
308
309 delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
310
311 delayed->context = dc;
312 delayed->expires = expires = jiffies + msecs_to_jiffies(c->delay);
313
314 spin_lock(&dc->delayed_bios_lock);
315 if (unlikely(!dc->may_delay)) {
316 spin_unlock(&dc->delayed_bios_lock);
317 return DM_MAPIO_REMAPPED;
318 }
319 c->ops++;
320 list_add_tail(&delayed->list, &dc->delayed_bios);
321 spin_unlock(&dc->delayed_bios_lock);
322
323 if (delay_is_fast(dc))
324 wake_up_process(dc->worker);
325 else
326 queue_timeout(dc, expires);
327
328 return DM_MAPIO_SUBMITTED;
329}
330
331static void delay_presuspend(struct dm_target *ti)
332{
333 struct delay_c *dc = ti->private;
334
335 spin_lock(&dc->delayed_bios_lock);
336 dc->may_delay = false;
337 spin_unlock(&dc->delayed_bios_lock);
338
339 if (!delay_is_fast(dc))
340 timer_delete(&dc->delay_timer);
341 flush_delayed_bios(dc, true);
342}
343
344static void delay_resume(struct dm_target *ti)
345{
346 struct delay_c *dc = ti->private;
347
348 dc->may_delay = true;
349}
350
351static int delay_map(struct dm_target *ti, struct bio *bio)
352{
353 struct delay_c *dc = ti->private;
354 struct delay_class *c;
355 struct dm_delay_info *delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
356
357 if (bio_data_dir(bio) == WRITE) {
358 if (unlikely(bio->bi_opf & REQ_PREFLUSH))
359 c = &dc->flush;
360 else
361 c = &dc->write;
362 } else {
363 c = &dc->read;
364 }
365 delayed->class = c;
366 bio_set_dev(bio, c->dev->bdev);
367 bio->bi_iter.bi_sector = c->start + dm_target_offset(ti, bio->bi_iter.bi_sector);
368
369 return delay_bio(dc, c, bio);
370}
371
372#define DMEMIT_DELAY_CLASS(c) \
373 DMEMIT("%s %llu %u", (c)->dev->name, (unsigned long long)(c)->start, (c)->delay)
374
375static void delay_status(struct dm_target *ti, status_type_t type,
376 unsigned int status_flags, char *result, unsigned int maxlen)
377{
378 struct delay_c *dc = ti->private;
379 int sz = 0;
380
381 switch (type) {
382 case STATUSTYPE_INFO:
383 DMEMIT("%u %u %u", dc->read.ops, dc->write.ops, dc->flush.ops);
384 break;
385
386 case STATUSTYPE_TABLE:
387 DMEMIT_DELAY_CLASS(&dc->read);
388 if (dc->argc >= 6) {
389 DMEMIT(" ");
390 DMEMIT_DELAY_CLASS(&dc->write);
391 }
392 if (dc->argc >= 9) {
393 DMEMIT(" ");
394 DMEMIT_DELAY_CLASS(&dc->flush);
395 }
396 break;
397
398 case STATUSTYPE_IMA:
399 *result = '\0';
400 break;
401 }
402}
403
404static int delay_iterate_devices(struct dm_target *ti,
405 iterate_devices_callout_fn fn, void *data)
406{
407 struct delay_c *dc = ti->private;
408 int ret = 0;
409
410 ret = fn(ti, dc->read.dev, dc->read.start, ti->len, data);
411 if (ret)
412 goto out;
413 ret = fn(ti, dc->write.dev, dc->write.start, ti->len, data);
414 if (ret)
415 goto out;
416 ret = fn(ti, dc->flush.dev, dc->flush.start, ti->len, data);
417 if (ret)
418 goto out;
419
420out:
421 return ret;
422}
423
424static struct target_type delay_target = {
425 .name = "delay",
426 .version = {1, 4, 0},
427 .features = DM_TARGET_PASSES_INTEGRITY,
428 .module = THIS_MODULE,
429 .ctr = delay_ctr,
430 .dtr = delay_dtr,
431 .map = delay_map,
432 .presuspend = delay_presuspend,
433 .resume = delay_resume,
434 .status = delay_status,
435 .iterate_devices = delay_iterate_devices,
436};
437module_dm(delay);
438
439MODULE_DESCRIPTION(DM_NAME " delay target");
440MODULE_AUTHOR("Heinz Mauelshagen <mauelshagen@redhat.com>");
441MODULE_LICENSE("GPL");