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android-review.linaro.org / kernel / hikey-linaro / bf7ef8f2d57cd1f5f1846dd58ff9309efad58252 / . / drivers / md / dm-core.h
blob: 40ceba1fe8be28d77ccf82af75a3f0e0eac09499 [file] [log] [blame]
Mike Snitzer4cc96132016-05-12 16:28:10 -0400[diff] [blame]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/blk-mq.h>
15
16#include <trace/events/block.h>
17
18#include "dm.h"
19
20#define DM_RESERVED_MAX_IOS 1024
21
22struct dm_kobject_holder {
23 struct kobject kobj;
24 struct completion completion;
25};
26
27/*
28 * DM core internal structure that used directly by dm.c and dm-rq.c
29 * DM targets must _not_ deference a mapped_device to directly access its members!
30 */
31struct mapped_device {
32 struct srcu_struct io_barrier;
33 struct mutex suspend_lock;
34
35 /*
36 * The current mapping (struct dm_table *).
37 * Use dm_get_live_table{_fast} or take suspend_lock for
38 * dereference.
39 */
40 void __rcu *map;
41
42 struct list_head table_devices;
43 struct mutex table_devices_lock;
44
45 unsigned long flags;
46
47 struct request_queue *queue;
48 int numa_node_id;
49
50 unsigned type;
51 /* Protect queue and type against concurrent access. */
52 struct mutex type_lock;
53
54 atomic_t holders;
55 atomic_t open_count;
56
57 struct dm_target *immutable_target;
58 struct target_type *immutable_target_type;
59
60 struct gendisk *disk;
61 char name[16];
62
63 void *interface_ptr;
64
65 /*
66 * A list of ios that arrived while we were suspended.
67 */
68 atomic_t pending[2];
69 wait_queue_head_t wait;
70 struct work_struct work;
71 spinlock_t deferred_lock;
72 struct bio_list deferred;
73
74 /*
75 * Event handling.
76 */
77 wait_queue_head_t eventq;
78 atomic_t event_nr;
79 atomic_t uevent_seq;
80 struct list_head uevent_list;
81 spinlock_t uevent_lock; /* Protect access to uevent_list */
82
83 /* the number of internal suspends */
84 unsigned internal_suspend_count;
85
86 /*
87 * Processing queue (flush)
88 */
89 struct workqueue_struct *wq;
90
91 /*
92 * io objects are allocated from here.
93 */
94 mempool_t *io_pool;
95 mempool_t *rq_pool;
96
97 struct bio_set *bs;
98
99 /*
100 * freeze/thaw support require holding onto a super block
101 */
102 struct super_block *frozen_sb;
103
104 /* forced geometry settings */
105 struct hd_geometry geometry;
106
107 struct block_device *bdev;
108
109 /* kobject and completion */
110 struct dm_kobject_holder kobj_holder;
111
112 /* zero-length flush that will be cloned and submitted to targets */
113 struct bio flush_bio;
114
115 struct dm_stats stats;
116
117 struct kthread_worker kworker;
118 struct task_struct *kworker_task;
119
120 /* for request-based merge heuristic in dm_request_fn() */
121 unsigned seq_rq_merge_deadline_usecs;
122 int last_rq_rw;
123 sector_t last_rq_pos;
124 ktime_t last_rq_start_time;
125
126 /* for blk-mq request-based DM support */
127 struct blk_mq_tag_set *tag_set;
128 bool use_blk_mq:1;
129 bool init_tio_pdu:1;
130};
131
132void dm_init_md_queue(struct mapped_device *md);
133void dm_init_normal_md_queue(struct mapped_device *md);
134int md_in_flight(struct mapped_device *md);
135void disable_write_same(struct mapped_device *md);
136
137static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
138{
139 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
140}
141
142unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
143
144static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
145{
146 return !maxlen || strlen(result) + 1 >= maxlen;
147}
148
149#endif