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Linux kernel mirror (for testing)
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linux
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 mutex suspend_lock;
33
34 struct mutex table_devices_lock;
35 struct list_head table_devices;
36
37 /*
38 * The current mapping (struct dm_table *).
39 * Use dm_get_live_table{_fast} or take suspend_lock for
40 * dereference.
41 */
42 void __rcu *map;
43
44 unsigned long flags;
45
46 /* Protect queue and type against concurrent access. */
47 struct mutex type_lock;
48 enum dm_queue_mode type;
49
50 int numa_node_id;
51 struct request_queue *queue;
52
53 atomic_t holders;
54 atomic_t open_count;
55
56 struct dm_target *immutable_target;
57 struct target_type *immutable_target_type;
58
59 char name[16];
60 struct gendisk *disk;
61 struct dax_device *dax_dev;
62
63 /*
64 * A list of ios that arrived while we were suspended.
65 */
66 struct work_struct work;
67 wait_queue_head_t wait;
68 atomic_t pending[2];
69 spinlock_t deferred_lock;
70 struct bio_list deferred;
71
72 void *interface_ptr;
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 * io objects are allocated from here.
88 */
89 struct bio_set io_bs;
90 struct bio_set bs;
91
92 /*
93 * Processing queue (flush)
94 */
95 struct workqueue_struct *wq;
96
97 /*
98 * freeze/thaw support require holding onto a super block
99 */
100 struct super_block *frozen_sb;
101
102 /* forced geometry settings */
103 struct hd_geometry geometry;
104
105 /* kobject and completion */
106 struct dm_kobject_holder kobj_holder;
107
108 struct block_device *bdev;
109
110 /* zero-length flush that will be cloned and submitted to targets */
111 struct bio flush_bio;
112
113 struct dm_stats stats;
114
115 struct kthread_worker kworker;
116 struct task_struct *kworker_task;
117
118 /* for request-based merge heuristic in dm_request_fn() */
119 unsigned seq_rq_merge_deadline_usecs;
120 int last_rq_rw;
121 sector_t last_rq_pos;
122 ktime_t last_rq_start_time;
123
124 /* for blk-mq request-based DM support */
125 struct blk_mq_tag_set *tag_set;
126 bool use_blk_mq:1;
127 bool init_tio_pdu:1;
128
129 struct srcu_struct io_barrier;
130};
131
132int md_in_flight(struct mapped_device *md);
133void disable_write_same(struct mapped_device *md);
134void disable_write_zeroes(struct mapped_device *md);
135
136static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
137{
138 return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
139}
140
141unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
142
143static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
144{
145 return !maxlen || strlen(result) + 1 >= maxlen;
146}
147
148extern atomic_t dm_global_event_nr;
149extern wait_queue_head_t dm_global_eventq;
150void dm_issue_global_event(void);
151
152#endif