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
41/*
42 * List of devices that a metadevice uses and should open/close.
43 */
44struct dm_dev_internal {
45	struct list_head list;
46	atomic_t count;
47	struct dm_dev *dm_dev;
48};
49
50struct dm_table;
51struct dm_md_mempools;
52
53/*-----------------------------------------------------------------
54 * Internal table functions.
55 *---------------------------------------------------------------*/
56void dm_table_destroy(struct dm_table *t);
57void dm_table_event_callback(struct dm_table *t,
58			     void (*fn)(void *), void *context);
59struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
60struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
61bool dm_table_has_no_data_devices(struct dm_table *table);
62int dm_calculate_queue_limits(struct dm_table *table,
63			      struct queue_limits *limits);
64void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
65			       struct queue_limits *limits);
66struct list_head *dm_table_get_devices(struct dm_table *t);
67void dm_table_presuspend_targets(struct dm_table *t);
68void dm_table_postsuspend_targets(struct dm_table *t);
69int dm_table_resume_targets(struct dm_table *t);
70int dm_table_any_congested(struct dm_table *t, int bdi_bits);
71int dm_table_any_busy_target(struct dm_table *t);
72unsigned dm_table_get_type(struct dm_table *t);
73struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
74bool dm_table_request_based(struct dm_table *t);
75void dm_table_free_md_mempools(struct dm_table *t);
76struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
77
78int dm_queue_merge_is_compulsory(struct request_queue *q);
79
80void dm_lock_md_type(struct mapped_device *md);
81void dm_unlock_md_type(struct mapped_device *md);
82void dm_set_md_type(struct mapped_device *md, unsigned type);
83unsigned dm_get_md_type(struct mapped_device *md);
84struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
85
86int dm_setup_md_queue(struct mapped_device *md);
87
88/*
89 * To check the return value from dm_table_find_target().
90 */
91#define dm_target_is_valid(t) ((t)->table)
92
93/*
94 * To check whether the target type is bio-based or not (request-based).
95 */
96#define dm_target_bio_based(t) ((t)->type->map != NULL)
97
98/*
99 * To check whether the target type is request-based or not (bio-based).
100 */
101#define dm_target_request_based(t) ((t)->type->map_rq != NULL)
102
103/*
104 * To check whether the target type is a hybrid (capable of being
105 * either request-based or bio-based).
106 */
107#define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
108
109/*-----------------------------------------------------------------
110 * A registry of target types.
111 *---------------------------------------------------------------*/
112int dm_target_init(void);
113void dm_target_exit(void);
114struct target_type *dm_get_target_type(const char *name);
115void dm_put_target_type(struct target_type *tt);
116int dm_target_iterate(void (*iter_func)(struct target_type *tt,
117					void *param), void *param);
118
119int dm_split_args(int *argc, char ***argvp, char *input);
120
121/*
122 * Is this mapped_device being deleted?
123 */
124int dm_deleting_md(struct mapped_device *md);
125
126/*
127 * Is this mapped_device suspended?
128 */
129int dm_suspended_md(struct mapped_device *md);
130
131/*
132 * Test if the device is scheduled for deferred remove.
133 */
134int dm_test_deferred_remove_flag(struct mapped_device *md);
135
136/*
137 * Try to remove devices marked for deferred removal.
138 */
139void dm_deferred_remove(void);
140
141/*
142 * The device-mapper can be driven through one of two interfaces;
143 * ioctl or filesystem, depending which patch you have applied.
144 */
145int dm_interface_init(void);
146void dm_interface_exit(void);
147
148/*
149 * sysfs interface
150 */
151struct dm_kobject_holder {
152	struct kobject kobj;
153	struct completion completion;
154};
155
156static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
157{
158	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
159}
160
161int dm_sysfs_init(struct mapped_device *md);
162void dm_sysfs_exit(struct mapped_device *md);
163struct kobject *dm_kobject(struct mapped_device *md);
164struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
165
166/*
167 * The kobject helper
168 */
169void dm_kobject_release(struct kobject *kobj);
170
171/*
172 * Targets for linear and striped mappings
173 */
174int dm_linear_init(void);
175void dm_linear_exit(void);
176
177int dm_stripe_init(void);
178void dm_stripe_exit(void);
179
180/*
181 * mapped_device operations
182 */
183void dm_destroy(struct mapped_device *md);
184void dm_destroy_immediate(struct mapped_device *md);
185int dm_open_count(struct mapped_device *md);
186int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
187int dm_cancel_deferred_remove(struct mapped_device *md);
188int dm_request_based(struct mapped_device *md);
189sector_t dm_get_size(struct mapped_device *md);
190struct request_queue *dm_get_md_queue(struct mapped_device *md);
191int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
192			struct dm_dev **result);
193void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
194struct dm_stats *dm_get_stats(struct mapped_device *md);
195
196int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
197		      unsigned cookie);
198
199void dm_internal_suspend(struct mapped_device *md);
200void dm_internal_resume(struct mapped_device *md);
201
202int dm_io_init(void);
203void dm_io_exit(void);
204
205int dm_kcopyd_init(void);
206void dm_kcopyd_exit(void);
207
208/*
209 * Mempool operations
210 */
211struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size);
212void dm_free_md_mempools(struct dm_md_mempools *pools);
213
214/*
215 * Helpers that are used by DM core
216 */
217unsigned dm_get_reserved_bio_based_ios(void);
218unsigned dm_get_reserved_rq_based_ios(void);
219
220static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
221{
222	return !maxlen || strlen(result) + 1 >= maxlen;
223}
224
225#endif
226