drivers/md/dm-cache-background-tracker.h

   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
  15 struct background_work;
  16 struct background_tracker;
  17
  18 /*
  19  * FIXME: discuss lack of locking in all methods.
  20  */
  21 struct background_tracker *btracker_create(unsigned max_work);
  22 void btracker_destroy(struct background_tracker *b);
  23
  24 unsigned btracker_nr_writebacks_queued(struct background_tracker *b);
  25 unsigned 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  */
  31 int 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  */
  38 int btracker_issue(struct background_tracker *b, struct policy_work **work);
  39 void btracker_complete(struct background_tracker *b,
  40                        struct policy_work *op);
  41 bool btracker_promotion_already_present(struct background_tracker *b,
  42                                         dm_oblock_t oblock);
  43
  44 /*----------------------------------------------------------------*/
  45
  46 #endif