1/*
 2 * Copyright (C) 2017 Red Hat. All rights reserved.
 3 *
 4 * This file is released under the GPL.
 5 */
 6
 7#ifndef DM_CACHE_BACKGROUND_WORK_H
 8#define DM_CACHE_BACKGROUND_WORK_H
 9
10#include <linux/vmalloc.h>
11#include "dm-cache-policy.h"
12
13/*----------------------------------------------------------------*/
14
15struct background_work;
16struct background_tracker;
17
18/*
19 * FIXME: discuss lack of locking in all methods.
20 */
21struct background_tracker *btracker_create(unsigned max_work);
22void btracker_destroy(struct background_tracker *b);
23
24unsigned btracker_nr_writebacks_queued(struct background_tracker *b);
25unsigned btracker_nr_demotions_queued(struct background_tracker *b);
26
27/*
28 * returns -EINVAL iff the work is already queued.  -ENOMEM if the work
29 * couldn't be queued for another reason.
30 */
31int btracker_queue(struct background_tracker *b,
32		   struct policy_work *work,
33		   struct policy_work **pwork);
34
35/*
36 * Returns -ENODATA if there's no work.
37 */
38int btracker_issue(struct background_tracker *b, struct policy_work **work);
39void btracker_complete(struct background_tracker *b,
40		       struct policy_work *op);
41bool btracker_promotion_already_present(struct background_tracker *b,
42					dm_oblock_t oblock);
43
44/*----------------------------------------------------------------*/
45
46#endif