drivers/md/dm-rq.h

   1 /*
   2  * Internal header file for device mapper
   3  *
   4  * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
   5  *
   6  * This file is released under the LGPL.
   7  */
   8
   9 #ifndef DM_RQ_INTERNAL_H
  10 #define DM_RQ_INTERNAL_H
  11
  12 #include <linux/bio.h>
  13 #include <linux/kthread.h>
  14
  15 #include "dm-stats.h"
  16
  17 struct mapped_device;
  18
  19 /*
  20  * One of these is allocated per request.
  21  */
  22 struct dm_rq_target_io {
  23         struct mapped_device *md;
  24         struct dm_target *ti;
  25         struct request *orig, *clone;
  26         struct kthread_work work;
  27         int error;
  28         union map_info info;
  29         struct dm_stats_aux stats_aux;
  30         unsigned long duration_jiffies;
  31         unsigned n_sectors;
  32 };
  33
  34 /*
  35  * For request-based dm - the bio clones we allocate are embedded in these
  36  * structs.
  37  *
  38  * We allocate these with bio_alloc_bioset, using the front_pad parameter when
  39  * the bioset is created - this means the bio has to come at the end of the
  40  * struct.
  41  */
  42 struct dm_rq_clone_bio_info {
  43         struct bio *orig;
  44         struct dm_rq_target_io *tio;
  45         struct bio clone;
  46 };
  47
  48 bool dm_use_blk_mq_default(void);
  49 bool dm_use_blk_mq(struct mapped_device *md);
  50
  51 int dm_old_init_request_queue(struct mapped_device *md);
  52 int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t);
  53 void dm_mq_cleanup_mapped_device(struct mapped_device *md);
  54
  55 void dm_start_queue(struct request_queue *q);
  56 void dm_stop_queue(struct request_queue *q);
  57
  58 void dm_mq_kick_requeue_list(struct mapped_device *md);
  59
  60 unsigned dm_get_reserved_rq_based_ios(void);
  61
  62 ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf);
  63 ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
  64                                                      const char *buf, size_t count);
  65
  66 #endif