1/*
2 * Internal header file for device mapper
3 *
4 * Copyright (C) 2001, 2002 Sistina Software
5 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
6 *
7 * This file is released under the LGPL.
8 */
9
10#ifndef DM_INTERNAL_H
11#define DM_INTERNAL_H
12
13#include <linux/fs.h>
14#include <linux/device-mapper.h>
15#include <linux/list.h>
16#include <linux/blkdev.h>
17#include <linux/hdreg.h>
18#include <linux/completion.h>
19#include <linux/kobject.h>
20
21#include "dm-stats.h"
22
23/*
24 * Suspend feature flags
25 */
26#define DM_SUSPEND_LOCKFS_FLAG		(1 << 0)
27#define DM_SUSPEND_NOFLUSH_FLAG		(1 << 1)
28
29/*
30 * Status feature flags
31 */
32#define DM_STATUS_NOFLUSH_FLAG		(1 << 0)
33
34/*
35 * Type of table and mapped_device's mempool
36 */
37#define DM_TYPE_NONE			0
38#define DM_TYPE_BIO_BASED		1
39#define DM_TYPE_REQUEST_BASED		2
40#define DM_TYPE_MQ_REQUEST_BASED	3
41
42/*
43 * List of devices that a metadevice uses and should open/close.
44 */
45struct dm_dev_internal {
46	struct list_head list;
47	atomic_t count;
48	struct dm_dev *dm_dev;
49};
50
51struct dm_table;
52struct dm_md_mempools;
53
54/*-----------------------------------------------------------------
55 * Internal table functions.
56 *---------------------------------------------------------------*/
57void dm_table_destroy(struct dm_table *t);
58void dm_table_event_callback(struct dm_table *t,
59			     void (*fn)(void *), void *context);
60struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
61struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
62bool dm_table_has_no_data_devices(struct dm_table *table);
63int dm_calculate_queue_limits(struct dm_table *table,
64			      struct queue_limits *limits);
65void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
66			       struct queue_limits *limits);
67struct list_head *dm_table_get_devices(struct dm_table *t);
68void dm_table_presuspend_targets(struct dm_table *t);
69void dm_table_presuspend_undo_targets(struct dm_table *t);
70void dm_table_postsuspend_targets(struct dm_table *t);
71int dm_table_resume_targets(struct dm_table *t);
72int dm_table_any_congested(struct dm_table *t, int bdi_bits);
73unsigned dm_table_get_type(struct dm_table *t);
74struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
75bool dm_table_request_based(struct dm_table *t);
76bool dm_table_mq_request_based(struct dm_table *t);
77void dm_table_free_md_mempools(struct dm_table *t);
78struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
79
80int dm_queue_merge_is_compulsory(struct request_queue *q);
81
82void dm_lock_md_type(struct mapped_device *md);
83void dm_unlock_md_type(struct mapped_device *md);
84void dm_set_md_type(struct mapped_device *md, unsigned type);
85unsigned dm_get_md_type(struct mapped_device *md);
86struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
87
88int dm_setup_md_queue(struct mapped_device *md);
89
90/*
91 * To check the return value from dm_table_find_target().
92 */
93#define dm_target_is_valid(t) ((t)->table)
94
95/*
96 * To check whether the target type is bio-based or not (request-based).
97 */
98#define dm_target_bio_based(t) ((t)->type->map != NULL)
99
100/*
101 * To check whether the target type is request-based or not (bio-based).
102 */
103#define dm_target_request_based(t) (((t)->type->map_rq != NULL) || \
104				    ((t)->type->clone_and_map_rq != NULL))
105
106/*
107 * To check whether the target type is a hybrid (capable of being
108 * either request-based or bio-based).
109 */
110#define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
111
112/*-----------------------------------------------------------------
113 * A registry of target types.
114 *---------------------------------------------------------------*/
115int dm_target_init(void);
116void dm_target_exit(void);
117struct target_type *dm_get_target_type(const char *name);
118void dm_put_target_type(struct target_type *tt);
119int dm_target_iterate(void (*iter_func)(struct target_type *tt,
120					void *param), void *param);
121
122int dm_split_args(int *argc, char ***argvp, char *input);
123
124/*
125 * Is this mapped_device being deleted?
126 */
127int dm_deleting_md(struct mapped_device *md);
128
129/*
130 * Is this mapped_device suspended?
131 */
132int dm_suspended_md(struct mapped_device *md);
133
134/*
135 * Internal suspend and resume methods.
136 */
137int dm_suspended_internally_md(struct mapped_device *md);
138void dm_internal_suspend_fast(struct mapped_device *md);
139void dm_internal_resume_fast(struct mapped_device *md);
140void dm_internal_suspend_noflush(struct mapped_device *md);
141void dm_internal_resume(struct mapped_device *md);
142
143/*
144 * Test if the device is scheduled for deferred remove.
145 */
146int dm_test_deferred_remove_flag(struct mapped_device *md);
147
148/*
149 * Try to remove devices marked for deferred removal.
150 */
151void dm_deferred_remove(void);
152
153/*
154 * The device-mapper can be driven through one of two interfaces;
155 * ioctl or filesystem, depending which patch you have applied.
156 */
157int dm_interface_init(void);
158void dm_interface_exit(void);
159
160/*
161 * sysfs interface
162 */
163struct dm_kobject_holder {
164	struct kobject kobj;
165	struct completion completion;
166};
167
168static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
169{
170	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
171}
172
173int dm_sysfs_init(struct mapped_device *md);
174void dm_sysfs_exit(struct mapped_device *md);
175struct kobject *dm_kobject(struct mapped_device *md);
176struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
177
178/*
179 * The kobject helper
180 */
181void dm_kobject_release(struct kobject *kobj);
182
183/*
184 * Targets for linear and striped mappings
185 */
186int dm_linear_init(void);
187void dm_linear_exit(void);
188
189int dm_stripe_init(void);
190void dm_stripe_exit(void);
191
192/*
193 * mapped_device operations
194 */
195void dm_destroy(struct mapped_device *md);
196void dm_destroy_immediate(struct mapped_device *md);
197int dm_open_count(struct mapped_device *md);
198int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
199int dm_cancel_deferred_remove(struct mapped_device *md);
200int dm_request_based(struct mapped_device *md);
201sector_t dm_get_size(struct mapped_device *md);
202struct request_queue *dm_get_md_queue(struct mapped_device *md);
203int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
204			struct dm_dev **result);
205void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
206struct dm_stats *dm_get_stats(struct mapped_device *md);
207
208int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
209		      unsigned cookie);
210
211void dm_internal_suspend(struct mapped_device *md);
212void dm_internal_resume(struct mapped_device *md);
213
214bool dm_use_blk_mq(struct mapped_device *md);
215
216int dm_io_init(void);
217void dm_io_exit(void);
218
219int dm_kcopyd_init(void);
220void dm_kcopyd_exit(void);
221
222/*
223 * Mempool operations
224 */
225struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type,
226					    unsigned integrity, unsigned per_bio_data_size);
227void dm_free_md_mempools(struct dm_md_mempools *pools);
228
229/*
230 * Helpers that are used by DM core
231 */
232unsigned dm_get_reserved_bio_based_ios(void);
233unsigned dm_get_reserved_rq_based_ios(void);
234
235static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
236{
237	return !maxlen || strlen(result) + 1 >= maxlen;
238}
239
240ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf);
241ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
242						     const char *buf, size_t count);
243
244#endif
245