drivers/md/dm-core.h

   1 /*
   2  * Internal header file _only_ for device mapper core
   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_CORE_INTERNAL_H
  10 #define DM_CORE_INTERNAL_H
  11
  12 #include <linux/kthread.h>
  13 #include <linux/ktime.h>
  14 #include <linux/genhd.h>
  15 #include <linux/blk-mq.h>
  16 #include <linux/keyslot-manager.h>
  17
  18 #include <trace/events/block.h>
  19
  20 #include "dm.h"
  21
  22 #define DM_RESERVED_MAX_IOS             1024
  23
  24 struct dm_kobject_holder {
  25         struct kobject kobj;
  26         struct completion completion;
  27 };
  28
  29 /*
  30  * DM core internal structures used directly by dm.c, dm-rq.c and dm-table.c.
  31  * DM targets must _not_ deference a mapped_device or dm_table to directly
  32  * access their members!
  33  */
  34
  35 struct mapped_device {
  36         struct mutex suspend_lock;
  37
  38         struct mutex table_devices_lock;
  39         struct list_head table_devices;
  40
  41         /*
  42          * The current mapping (struct dm_table *).
  43          * Use dm_get_live_table{_fast} or take suspend_lock for
  44          * dereference.
  45          */
  46         void __rcu *map;
  47
  48         unsigned long flags;
  49
  50         /* Protect queue and type against concurrent access. */
  51         struct mutex type_lock;
  52         enum dm_queue_mode type;
  53
  54         int numa_node_id;
  55         struct request_queue *queue;
  56
  57         atomic_t holders;
  58         atomic_t open_count;
  59
  60         struct dm_target *immutable_target;
  61         struct target_type *immutable_target_type;
  62
  63         char name[16];
  64         struct gendisk *disk;
  65         struct dax_device *dax_dev;
  66
  67         /*
  68          * A list of ios that arrived while we were suspended.
  69          */
  70         struct work_struct work;
  71         wait_queue_head_t wait;
  72         spinlock_t deferred_lock;
  73         struct bio_list deferred;
  74
  75         void *interface_ptr;
  76
  77         /*
  78          * Event handling.
  79          */
  80         wait_queue_head_t eventq;
  81         atomic_t event_nr;
  82         atomic_t uevent_seq;
  83         struct list_head uevent_list;
  84         spinlock_t uevent_lock; /* Protect access to uevent_list */
  85
  86         /* the number of internal suspends */
  87         unsigned internal_suspend_count;
  88
  89         /*
  90          * io objects are allocated from here.
  91          */
  92         struct bio_set io_bs;
  93         struct bio_set bs;
  94
  95         /*
  96          * Processing queue (flush)
  97          */
  98         struct workqueue_struct *wq;
  99
 100         /* forced geometry settings */
 101         struct hd_geometry geometry;
 102
 103         /* kobject and completion */
 104         struct dm_kobject_holder kobj_holder;
 105
 106         int swap_bios;
 107         struct semaphore swap_bios_semaphore;
 108         struct mutex swap_bios_lock;
 109
 110         struct dm_stats stats;
 111
 112         /* for blk-mq request-based DM support */
 113         struct blk_mq_tag_set *tag_set;
 114         bool init_tio_pdu:1;
 115
 116         struct srcu_struct io_barrier;
 117 };
 118
 119 void disable_discard(struct mapped_device *md);
 120 void disable_write_same(struct mapped_device *md);
 121 void disable_write_zeroes(struct mapped_device *md);
 122
 123 static inline sector_t dm_get_size(struct mapped_device *md)
 124 {
 125         return get_capacity(md->disk);
 126 }
 127
 128 static inline struct dm_stats *dm_get_stats(struct mapped_device *md)
 129 {
 130         return &md->stats;
 131 }
 132
 133 #define DM_TABLE_MAX_DEPTH 16
 134
 135 struct dm_table {
 136         struct mapped_device *md;
 137         enum dm_queue_mode type;
 138
 139         /* btree table */
 140         unsigned int depth;
 141         unsigned int counts[DM_TABLE_MAX_DEPTH]; /* in nodes */
 142         sector_t *index[DM_TABLE_MAX_DEPTH];
 143
 144         unsigned int num_targets;
 145         unsigned int num_allocated;
 146         sector_t *highs;
 147         struct dm_target *targets;
 148
 149         struct target_type *immutable_target_type;
 150
 151         bool integrity_supported:1;
 152         bool singleton:1;
 153         unsigned integrity_added:1;
 154
 155         /*
 156          * Indicates the rw permissions for the new logical
 157          * device.  This should be a combination of FMODE_READ
 158          * and FMODE_WRITE.
 159          */
 160         fmode_t mode;
 161
 162         /* a list of devices used by this table */
 163         struct list_head devices;
 164
 165         /* events get handed up using this callback */
 166         void (*event_fn)(void *);
 167         void *event_context;
 168
 169         struct dm_md_mempools *mempools;
 170
 171 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 172         struct blk_keyslot_manager *ksm;
 173 #endif
 174 };
 175
 176 static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
 177 {
 178         return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
 179 }
 180
 181 unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
 182
 183 static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
 184 {
 185         return !maxlen || strlen(result) + 1 >= maxlen;
 186 }
 187
 188 extern atomic_t dm_global_event_nr;
 189 extern wait_queue_head_t dm_global_eventq;
 190 void dm_issue_global_event(void);
 191
 192 #endif