1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2005-2007 Red Hat GmbH
17 #include <linux/device-mapper.h>
19 #define DM_MSG_PREFIX "delay"
24 	unsigned int delay;  member
36 	struct delay_class read;  member
56 	queue_work(dc->kdelayd_wq, &dc->flush_expired_bios);  in handle_delayed_timer()
61 	mutex_lock(&dc->timer_lock);  in queue_timeout()
63 	if (!timer_pending(&dc->delay_timer) || expires < dc->delay_timer.expires)  in queue_timeout()
64 		mod_timer(&dc->delay_timer, expires);  in queue_timeout()
66 	mutex_unlock(&dc->timer_lock);  in queue_timeout()
74 		n = bio->bi_next;  in flush_bios()
75 		bio->bi_next = NULL;  in flush_bios()
89 	list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {  in flush_delayed_bios()
90 		if (flush_all || time_after_eq(jiffies, delayed->expires)) {  in flush_delayed_bios()
93 			list_del(&delayed->list);  in flush_delayed_bios()
95 			delayed->class->ops--;  in flush_delayed_bios()
101 			next_expires = delayed->expires;  in flush_delayed_bios()
103 			next_expires = min(next_expires, delayed->expires);  in flush_delayed_bios()
123 	struct delay_c *dc = ti->private;  in delay_dtr()
125 	if (dc->kdelayd_wq)  in delay_dtr()
126 		destroy_workqueue(dc->kdelayd_wq);  in delay_dtr()
128 	if (dc->read.dev)  in delay_dtr()
129 		dm_put_device(ti, dc->read.dev);  in delay_dtr()
130 	if (dc->write.dev)  in delay_dtr()
131 		dm_put_device(ti, dc->write.dev);  in delay_dtr()
132 	if (dc->flush.dev)  in delay_dtr()
133 		dm_put_device(ti, dc->flush.dev);  in delay_dtr()
135 	mutex_destroy(&dc->timer_lock);  in delay_dtr()
147 		ti->error = "Invalid device sector";  in delay_class_ctr()
148 		return -EINVAL;  in delay_class_ctr()
150 	c->start = tmpll;  in delay_class_ctr()
152 	if (sscanf(argv[2], "%u%c", &c->delay, &dummy) != 1) {  in delay_class_ctr()
153 		ti->error = "Invalid delay";  in delay_class_ctr()
154 		return -EINVAL;  in delay_class_ctr()
157 	ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &c->dev);  in delay_class_ctr()
159 		ti->error = "Device lookup failed";  in delay_class_ctr()
168  *    <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
180 		ti->error = "Requires exactly 3, 6 or 9 arguments";  in delay_ctr()
181 		return -EINVAL;  in delay_ctr()
186 		ti->error = "Cannot allocate context";  in delay_ctr()
187 		return -ENOMEM;  in delay_ctr()
190 	ti->private = dc;  in delay_ctr()
191 	timer_setup(&dc->delay_timer, handle_delayed_timer, 0);  in delay_ctr()
192 	INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);  in delay_ctr()
193 	INIT_LIST_HEAD(&dc->delayed_bios);  in delay_ctr()
194 	mutex_init(&dc->timer_lock);  in delay_ctr()
195 	dc->may_delay = true;  in delay_ctr()
196 	dc->argc = argc;  in delay_ctr()
198 	ret = delay_class_ctr(ti, &dc->read, argv);  in delay_ctr()
203 		ret = delay_class_ctr(ti, &dc->write, argv);  in delay_ctr()
206 		ret = delay_class_ctr(ti, &dc->flush, argv);  in delay_ctr()
212 	ret = delay_class_ctr(ti, &dc->write, argv + 3);  in delay_ctr()
216 		ret = delay_class_ctr(ti, &dc->flush, argv + 3);  in delay_ctr()
222 	ret = delay_class_ctr(ti, &dc->flush, argv + 6);  in delay_ctr()
227 	dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);  in delay_ctr()
228 	if (!dc->kdelayd_wq) {  in delay_ctr()
229 		ret = -EINVAL;  in delay_ctr()
234 	ti->num_flush_bios = 1;  in delay_ctr()
235 	ti->num_discard_bios = 1;  in delay_ctr()
236 	ti->accounts_remapped_io = true;  in delay_ctr()
237 	ti->per_io_data_size = sizeof(struct dm_delay_info);  in delay_ctr()
250 	if (!c->delay)  in delay_bio()
255 	delayed->context = dc;  in delay_bio()
256 	delayed->expires = expires = jiffies + msecs_to_jiffies(c->delay);  in delay_bio()
259 	if (unlikely(!dc->may_delay)) {  in delay_bio()
263 	c->ops++;  in delay_bio()
264 	list_add_tail(&delayed->list, &dc->delayed_bios);  in delay_bio()
274 	struct delay_c *dc = ti->private;  in delay_presuspend()
277 	dc->may_delay = false;  in delay_presuspend()
280 	del_timer_sync(&dc->delay_timer);  in delay_presuspend()
286 	struct delay_c *dc = ti->private;  in delay_resume()
288 	dc->may_delay = true;  in delay_resume()
293 	struct delay_c *dc = ti->private;  in delay_map()
298 		if (unlikely(bio->bi_opf & REQ_PREFLUSH))  in delay_map()
299 			c = &dc->flush;  in delay_map()
301 			c = &dc->write;  in delay_map()
303 		c = &dc->read;  in delay_map()
305 	delayed->class = c;  in delay_map()
306 	bio_set_dev(bio, c->dev->bdev);  in delay_map()
307 	bio->bi_iter.bi_sector = c->start + dm_target_offset(ti, bio->bi_iter.bi_sector);  in delay_map()
313 	DMEMIT("%s %llu %u", (c)->dev->name, (unsigned long long)(c)->start, (c)->delay)
318 	struct delay_c *dc = ti->private;  in delay_status()
323 		DMEMIT("%u %u %u", dc->read.ops, dc->write.ops, dc->flush.ops);  in delay_status()
327 		DMEMIT_DELAY_CLASS(&dc->read);  in delay_status()
328 		if (dc->argc >= 6) {  in delay_status()
330 			DMEMIT_DELAY_CLASS(&dc->write);  in delay_status()
332 		if (dc->argc >= 9) {  in delay_status()
334 			DMEMIT_DELAY_CLASS(&dc->flush);  in delay_status()
347 	struct delay_c *dc = ti->private;  in delay_iterate_devices()
350 	ret = fn(ti, dc->read.dev, dc->read.start, ti->len, data);  in delay_iterate_devices()
353 	ret = fn(ti, dc->write.dev, dc->write.start, ti->len, data);  in delay_iterate_devices()
356 	ret = fn(ti, dc->flush.dev, dc->flush.start, ti->len, data);  in delay_iterate_devices()
365 	.name	     = "delay",
377 module_dm(delay);
379 MODULE_DESCRIPTION(DM_NAME " delay target");