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gerrit.twrp.me / android_bootable_recovery / 87c7bac9c9a2875feb8cf67284f3530fc371c468 / . / libblkid / loopdev.h
blob: 6efa0c78f777885028a665bdd92d5eb6da31b27f [file] [log] [blame]
bigbiff bigbiffe60683a2013-02-22 20:55:50 -0500[diff] [blame]1#ifndef UTIL_LINUX_LOOPDEV_H
2#define UTIL_LINUX_LOOPDEV_H
3
4#include "sysfs.h"
5
6/*
7 * loop_info.lo_encrypt_type
8 */
9#define LO_CRYPT_NONE 0
10#define LO_CRYPT_XOR 1
11#define LO_CRYPT_DES 2
12#define LO_CRYPT_CRYPTOAPI 18
13
14#define LOOP_SET_FD 0x4C00
15#define LOOP_CLR_FD 0x4C01
16/*
17 * Obsolete (kernel < 2.6)
18 *
19 * #define LOOP_SET_STATUS 0x4C02
20 * #define LOOP_GET_STATUS 0x4C03
21 */
22#define LOOP_SET_STATUS64 0x4C04
23#define LOOP_GET_STATUS64 0x4C05
24/* #define LOOP_CHANGE_FD 0x4C06 */
25#define LOOP_SET_CAPACITY 0x4C07
26
27/* /dev/loop-control interface */
28#ifndef LOOP_CTL_ADD
29# define LOOP_CTL_ADD 0x4C80
30# define LOOP_CTL_REMOVE 0x4C81
31# define LOOP_CTL_GET_FREE 0x4C82
32#endif
33
34/*
35 * loop_info.lo_flags
36 */
37enum {
38 LO_FLAGS_READ_ONLY = 1,
39 LO_FLAGS_USE_AOPS = 2,
40 LO_FLAGS_AUTOCLEAR = 4, /* kernel >= 2.6.25 */
41 LO_FLAGS_PARTSCAN = 8, /* kernel >= 3.2 */
42};
43
44#define LO_NAME_SIZE 64
45#define LO_KEY_SIZE 32
46
47/*
48 * Linux LOOP_{SET,GET}_STATUS64 ioclt struct
49 */
50struct loop_info64 {
51 uint64_t lo_device;
52 uint64_t lo_inode;
53 uint64_t lo_rdevice;
54 uint64_t lo_offset;
55 uint64_t lo_sizelimit; /* bytes, 0 == max available */
56 uint32_t lo_number;
57 uint32_t lo_encrypt_type;
58 uint32_t lo_encrypt_key_size;
59 uint32_t lo_flags;
60 uint8_t lo_file_name[LO_NAME_SIZE];
61 uint8_t lo_crypt_name[LO_NAME_SIZE];
62 uint8_t lo_encrypt_key[LO_KEY_SIZE];
63 uint64_t lo_init[2];
64};
65
66#define LOOPDEV_MAJOR 7 /* loop major number */
67#define LOOPDEV_DEFAULT_NNODES 8 /* default number of loop devices */
68
69struct loopdev_iter {
70 FILE *proc; /* /proc/partitions */
71 DIR *sysblock; /* /sys/block */
72 int ncur; /* current position */
73 int *minors; /* ary of minor numbers (when scan whole /dev) */
74 int nminors; /* number of items in *minors */
75 int ct_perm; /* count permission problems */
76 int ct_succ; /* count number of detected devices */
77
78 unsigned int done:1; /* scanning done */
79 unsigned int default_check:1;/* check first LOOPDEV_NLOOPS */
80 int flags; /* LOOPITER_FL_* flags */
81};
82
83enum {
84 LOOPITER_FL_FREE = (1 << 0),
85 LOOPITER_FL_USED = (1 << 1)
86};
87
88/*
89 * handler for work with loop devices
90 */
91struct loopdev_cxt {
92 char device[128]; /* device path (e.g. /dev/loop<N>) */
93 char *filename; /* backing file for loopcxt_set_... */
94 int fd; /* open(/dev/looo<N>) */
95 int mode; /* fd mode O_{RDONLY,RDWR} */
96
97 int flags; /* LOOPDEV_FL_* flags */
98 unsigned int has_info:1; /* .info contains data */
99 unsigned int extra_check:1; /* unusual stuff for iterator */
100 unsigned int debug:1; /* debug mode ON/OFF */
101 unsigned int info_failed:1; /* LOOP_GET_STATUS ioctl failed */
102
103 struct sysfs_cxt sysfs; /* pointer to /sys/dev/block/<maj:min>/ */
104 struct loop_info64 info; /* for GET/SET ioctl */
105 struct loopdev_iter iter; /* scans /sys or /dev for used/free devices */
106};
107
108#define UL_LOOPDEVCXT_EMPTY { .fd = -1, .sysfs = UL_SYSFSCXT_EMPTY }
109
110/*
111 * loopdev_cxt.flags
112 */
113enum {
114 LOOPDEV_FL_RDONLY = (1 << 0), /* open(/dev/loop) mode; default */
115 LOOPDEV_FL_RDWR = (1 << 1), /* necessary for loop setup only */
116 LOOPDEV_FL_OFFSET = (1 << 4),
117 LOOPDEV_FL_NOSYSFS = (1 << 5),
118 LOOPDEV_FL_NOIOCTL = (1 << 6),
119 LOOPDEV_FL_DEVSUBDIR = (1 << 7),
120 LOOPDEV_FL_CONTROL = (1 << 8), /* system with /dev/loop-control */
121 LOOPDEV_FL_SIZELIMIT = (1 << 9)
122};
123
124/*
125 * High-level
126 */
127extern int loopmod_supports_partscan(void);
128
129extern int is_loopdev(const char *device);
130extern int loopdev_is_autoclear(const char *device);
131
132extern char *loopdev_get_backing_file(const char *device);
133extern int loopdev_is_used(const char *device, const char *filename,
134 uint64_t offset, int flags);
135extern char *loopdev_find_by_backing_file(const char *filename,
136 uint64_t offset, int flags);
137extern int loopcxt_find_unused(struct loopdev_cxt *lc);
138extern int loopdev_delete(const char *device);
139extern int loopdev_count_by_backing_file(const char *filename, char **loopdev);
140
141/*
142 * Low-level
143 */
144extern int loopcxt_init(struct loopdev_cxt *lc, int flags)
145 __attribute__ ((warn_unused_result));
146extern void loopcxt_deinit(struct loopdev_cxt *lc);
147extern void loopcxt_enable_debug(struct loopdev_cxt *lc, int enable);
148
149extern int loopcxt_set_device(struct loopdev_cxt *lc, const char *device)
150 __attribute__ ((warn_unused_result));
151extern int loopcxt_has_device(struct loopdev_cxt *lc);
152extern char *loopcxt_strdup_device(struct loopdev_cxt *lc);
153extern const char *loopcxt_get_device(struct loopdev_cxt *lc);
154extern struct sysfs_cxt *loopcxt_get_sysfs(struct loopdev_cxt *lc);
155extern struct loop_info64 *loopcxt_get_info(struct loopdev_cxt *lc);
156
157extern int loopcxt_get_fd(struct loopdev_cxt *lc);
158extern int loopcxt_set_fd(struct loopdev_cxt *lc, int fd, int mode);
159
160extern int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags);
161extern int loopcxt_deinit_iterator(struct loopdev_cxt *lc);
162extern int loopcxt_next(struct loopdev_cxt *lc);
163
164extern int loopcxt_setup_device(struct loopdev_cxt *lc);
165extern int loopcxt_delete_device(struct loopdev_cxt *lc);
166
167int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset);
168int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit);
169int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags);
170int loopcxt_set_backing_file(struct loopdev_cxt *lc, const char *filename);
171
172extern char *loopcxt_get_backing_file(struct loopdev_cxt *lc);
173extern int loopcxt_get_backing_devno(struct loopdev_cxt *lc, dev_t *devno);
174extern int loopcxt_get_backing_inode(struct loopdev_cxt *lc, ino_t *ino);
175extern int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset);
176extern int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size);
177extern int loopcxt_get_encrypt_type(struct loopdev_cxt *lc, uint32_t *type);
178extern const char *loopcxt_get_crypt_name(struct loopdev_cxt *lc);
179extern int loopcxt_is_autoclear(struct loopdev_cxt *lc);
180extern int loopcxt_is_readonly(struct loopdev_cxt *lc);
181extern int loopcxt_is_partscan(struct loopdev_cxt *lc);
182extern int loopcxt_find_by_backing_file(struct loopdev_cxt *lc,
183 const char *filename,
184 uint64_t offset, int flags);
185
186extern int loopcxt_is_used(struct loopdev_cxt *lc,
187 struct stat *st,
188 const char *backing_file,
189 uint64_t offset,
190 int flags);
191
192#endif /* UTIL_LINUX_LOOPDEV_H */