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/moduleparam.h>
17 #include <linux/blkdev.h>
18 #include <linux/backing-dev.h>
19 #include <linux/hdreg.h>
20 #include <linux/completion.h>
21 #include <linux/kobject.h>
22 #include <linux/refcount.h>
23 
24 #include "dm-stats.h"
25 
26 /*
27  * Suspend feature flags
28  */
29 #define DM_SUSPEND_LOCKFS_FLAG		(1 << 0)
30 #define DM_SUSPEND_NOFLUSH_FLAG		(1 << 1)
31 
32 /*
33  * Status feature flags
34  */
35 #define DM_STATUS_NOFLUSH_FLAG		(1 << 0)
36 
37 /*
38  * List of devices that a metadevice uses and should open/close.
39  */
40 struct dm_dev_internal {
41 	struct list_head list;
42 	refcount_t count;
43 	struct dm_dev *dm_dev;
44 };
45 
46 struct dm_table;
47 struct dm_md_mempools;
48 
49 /*-----------------------------------------------------------------
50  * Internal table functions.
51  *---------------------------------------------------------------*/
52 void dm_table_event_callback(struct dm_table *t,
53 			     void (*fn)(void *), void *context);
54 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
55 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
56 bool dm_table_has_no_data_devices(struct dm_table *table);
57 int dm_calculate_queue_limits(struct dm_table *table,
58 			      struct queue_limits *limits);
59 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
60 			       struct queue_limits *limits);
61 struct list_head *dm_table_get_devices(struct dm_table *t);
62 void dm_table_presuspend_targets(struct dm_table *t);
63 void dm_table_presuspend_undo_targets(struct dm_table *t);
64 void dm_table_postsuspend_targets(struct dm_table *t);
65 int dm_table_resume_targets(struct dm_table *t);
66 enum dm_queue_mode dm_table_get_type(struct dm_table *t);
67 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
68 struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
69 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
70 bool dm_table_bio_based(struct dm_table *t);
71 bool dm_table_request_based(struct dm_table *t);
72 void dm_table_free_md_mempools(struct dm_table *t);
73 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
74 bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,
75 			   int *blocksize);
76 int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
77 			   sector_t start, sector_t len, void *data);
78 
79 void dm_lock_md_type(struct mapped_device *md);
80 void dm_unlock_md_type(struct mapped_device *md);
81 void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type);
82 enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
83 struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
84 
85 int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
86 
87 /*
88  * To check whether the target type is bio-based or not (request-based).
89  */
90 #define dm_target_bio_based(t) ((t)->type->map != NULL)
91 
92 /*
93  * To check whether the target type is request-based or not (bio-based).
94  */
95 #define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
96 
97 /*
98  * To check whether the target type is a hybrid (capable of being
99  * either request-based or bio-based).
100  */
101 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
102 
103 /*-----------------------------------------------------------------
104  * A registry of target types.
105  *---------------------------------------------------------------*/
106 int dm_target_init(void);
107 void dm_target_exit(void);
108 struct target_type *dm_get_target_type(const char *name);
109 void dm_put_target_type(struct target_type *tt);
110 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
111 					void *param), void *param);
112 
113 int dm_split_args(int *argc, char ***argvp, char *input);
114 
115 /*
116  * Is this mapped_device being deleted?
117  */
118 int dm_deleting_md(struct mapped_device *md);
119 
120 /*
121  * Is this mapped_device suspended?
122  */
123 int dm_suspended_md(struct mapped_device *md);
124 
125 /*
126  * Internal suspend and resume methods.
127  */
128 int dm_suspended_internally_md(struct mapped_device *md);
129 void dm_internal_suspend_fast(struct mapped_device *md);
130 void dm_internal_resume_fast(struct mapped_device *md);
131 void dm_internal_suspend_noflush(struct mapped_device *md);
132 void dm_internal_resume(struct mapped_device *md);
133 
134 /*
135  * Test if the device is scheduled for deferred remove.
136  */
137 int dm_test_deferred_remove_flag(struct mapped_device *md);
138 
139 /*
140  * Try to remove devices marked for deferred removal.
141  */
142 void dm_deferred_remove(void);
143 
144 /*
145  * The device-mapper can be driven through one of two interfaces;
146  * ioctl or filesystem, depending which patch you have applied.
147  */
148 int dm_interface_init(void);
149 void dm_interface_exit(void);
150 
151 /*
152  * sysfs interface
153  */
154 int dm_sysfs_init(struct mapped_device *md);
155 void dm_sysfs_exit(struct mapped_device *md);
156 struct kobject *dm_kobject(struct mapped_device *md);
157 struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
158 
159 /*
160  * The kobject helper
161  */
162 void dm_kobject_release(struct kobject *kobj);
163 
164 /*
165  * Targets for linear and striped mappings
166  */
167 int dm_linear_init(void);
168 void dm_linear_exit(void);
169 
170 int dm_stripe_init(void);
171 void dm_stripe_exit(void);
172 
173 /*
174  * mapped_device operations
175  */
176 void dm_destroy(struct mapped_device *md);
177 void dm_destroy_immediate(struct mapped_device *md);
178 int dm_open_count(struct mapped_device *md);
179 int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
180 int dm_cancel_deferred_remove(struct mapped_device *md);
181 int dm_request_based(struct mapped_device *md);
182 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
183 			struct dm_dev **result);
184 void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
185 
186 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
187 		      unsigned cookie);
188 
189 void dm_internal_suspend(struct mapped_device *md);
190 void dm_internal_resume(struct mapped_device *md);
191 
192 int dm_io_init(void);
193 void dm_io_exit(void);
194 
195 int dm_kcopyd_init(void);
196 void dm_kcopyd_exit(void);
197 
198 /*
199  * Mempool operations
200  */
201 struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
202 					    unsigned integrity, unsigned per_bio_data_size,
203 					    unsigned min_pool_size);
204 void dm_free_md_mempools(struct dm_md_mempools *pools);
205 
206 /*
207  * Various helpers
208  */
209 unsigned dm_get_reserved_bio_based_ios(void);
210 
211 #endif
212