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util-linux/include/loopdev.h

222 lines
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#ifndef UTIL_LINUX_LOOPDEV_H
#define UTIL_LINUX_LOOPDEV_H
#include "sysfs.h"
/*
* loop_info.lo_encrypt_type
*/
#define LO_CRYPT_NONE 0
#define LO_CRYPT_XOR 1
#define LO_CRYPT_DES 2
#define LO_CRYPT_CRYPTOAPI 18
#define LOOP_SET_FD 0x4C00
#define LOOP_CLR_FD 0x4C01
/*
* Obsolete (kernel < 2.6)
*
* #define LOOP_SET_STATUS 0x4C02
* #define LOOP_GET_STATUS 0x4C03
*/
#define LOOP_SET_STATUS64 0x4C04
#define LOOP_GET_STATUS64 0x4C05
/* #define LOOP_CHANGE_FD 0x4C06 */
#define LOOP_SET_CAPACITY 0x4C07
#define LOOP_SET_DIRECT_IO 0x4C08
#define LOOP_SET_BLOCK_SIZE 0x4C09
/* /dev/loop-control interface */
#ifndef LOOP_CTL_ADD
# define LOOP_CTL_ADD 0x4C80
# define LOOP_CTL_REMOVE 0x4C81
# define LOOP_CTL_GET_FREE 0x4C82
#endif
/*
* loop_info.lo_flags
*/
enum {
LO_FLAGS_READ_ONLY = 1,
LO_FLAGS_USE_AOPS = 2,
LO_FLAGS_AUTOCLEAR = 4, /* kernel >= 2.6.25 */
LO_FLAGS_PARTSCAN = 8, /* kernel >= 3.2 */
LO_FLAGS_DIRECT_IO = 16, /* kernel >= 4.2 */
};
#define LO_NAME_SIZE 64
#define LO_KEY_SIZE 32
/*
* Linux LOOP_{SET,GET}_STATUS64 ioctl struct
*/
struct loop_info64 {
uint64_t lo_device;
uint64_t lo_inode;
uint64_t lo_rdevice;
uint64_t lo_offset;
uint64_t lo_sizelimit; /* bytes, 0 == max available */
uint32_t lo_number;
uint32_t lo_encrypt_type;
uint32_t lo_encrypt_key_size;
uint32_t lo_flags;
uint8_t lo_file_name[LO_NAME_SIZE];
uint8_t lo_crypt_name[LO_NAME_SIZE];
uint8_t lo_encrypt_key[LO_KEY_SIZE];
uint64_t lo_init[2];
};
#ifndef LOOP_CONFIGURE
/*
* Since Linux v5.8-rc1 (commit 3448914e8cc550ba792d4ccc74471d1ca4293aae)
*/
# define LOOP_CONFIGURE 0x4C0A
struct loop_config {
uint32_t fd;
uint32_t block_size;
struct loop_info64 info;
uint64_t __reserved[8];
};
#endif
#define LOOPDEV_MAJOR 7 /* loop major number */
#define LOOPDEV_DEFAULT_NNODES 8 /* default number of loop devices */
struct loopdev_iter {
FILE *proc; /* /proc/partitions */
DIR *sysblock; /* /sys/block */
int ncur; /* current position */
int *minors; /* ary of minor numbers (when scan whole /dev) */
int nminors; /* number of items in *minors */
int ct_perm; /* count permission problems */
int ct_succ; /* count number of detected devices */
unsigned int done:1; /* scanning done */
unsigned int default_check:1;/* check first LOOPDEV_NLOOPS */
int flags; /* LOOPITER_FL_* flags */
};
enum {
LOOPITER_FL_FREE = (1 << 0),
LOOPITER_FL_USED = (1 << 1)
};
/*
* handler for work with loop devices
*/
struct loopdev_cxt {
char device[128]; /* device path (e.g. /dev/loop<N>) */
char *filename; /* backing file for loopcxt_set_... */
int fd; /* open(/dev/looo<N>) */
int mode; /* fd mode O_{RDONLY,RDWR} */
uint64_t blocksize; /* used by loopcxt_setup_device() */
int flags; /* LOOPDEV_FL_* flags */
unsigned int has_info:1; /* .info contains data */
unsigned int extra_check:1; /* unusual stuff for iterator */
unsigned int info_failed:1; /* LOOP_GET_STATUS ioctl failed */
unsigned int control_ok:1; /* /dev/loop-control success */
struct path_cxt *sysfs; /* pointer to /sys/dev/block/<maj:min>/ */
struct loop_config config; /* for GET/SET ioctl */
struct loopdev_iter iter; /* scans /sys or /dev for used/free devices */
};
#define UL_LOOPDEVCXT_EMPTY { .fd = -1 }
/*
* loopdev_cxt.flags
*/
enum {
LOOPDEV_FL_RDONLY = (1 << 0), /* open(/dev/loop) mode; default */
LOOPDEV_FL_RDWR = (1 << 1), /* necessary for loop setup only */
LOOPDEV_FL_OFFSET = (1 << 4),
LOOPDEV_FL_NOSYSFS = (1 << 5),
LOOPDEV_FL_NOIOCTL = (1 << 6),
LOOPDEV_FL_DEVSUBDIR = (1 << 7),
LOOPDEV_FL_CONTROL = (1 << 8), /* system with /dev/loop-control */
LOOPDEV_FL_SIZELIMIT = (1 << 9)
};
/*
* High-level
*/
extern int loopmod_supports_partscan(void);
extern int is_loopdev(const char *device);
extern int loopdev_is_autoclear(const char *device);
extern char *loopdev_get_backing_file(const char *device);
extern int loopdev_has_backing_file(const char *device);
extern int loopdev_is_used(const char *device, const char *filename,
uint64_t offset, uint64_t sizelimit, int flags);
extern char *loopdev_find_by_backing_file(const char *filename,
uint64_t offset, uint64_t sizelimit, int flags);
extern int loopcxt_find_unused(struct loopdev_cxt *lc);
extern int loopdev_delete(const char *device);
extern int loopdev_count_by_backing_file(const char *filename, char **loopdev);
/*
* Low-level
*/
extern int loopcxt_init(struct loopdev_cxt *lc, int flags)
__attribute__ ((warn_unused_result));
extern void loopcxt_deinit(struct loopdev_cxt *lc);
extern int loopcxt_set_device(struct loopdev_cxt *lc, const char *device)
__attribute__ ((warn_unused_result));
extern int loopcxt_has_device(struct loopdev_cxt *lc);
extern int loopcxt_add_device(struct loopdev_cxt *lc);
extern char *loopcxt_strdup_device(struct loopdev_cxt *lc);
extern const char *loopcxt_get_device(struct loopdev_cxt *lc);
extern struct loop_info64 *loopcxt_get_info(struct loopdev_cxt *lc);
extern int loopcxt_get_fd(struct loopdev_cxt *lc);
extern int loopcxt_set_fd(struct loopdev_cxt *lc, int fd, int mode);
extern int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags);
extern int loopcxt_deinit_iterator(struct loopdev_cxt *lc);
extern int loopcxt_next(struct loopdev_cxt *lc);
extern int loopcxt_setup_device(struct loopdev_cxt *lc);
extern int loopcxt_delete_device(struct loopdev_cxt *lc);
extern int loopcxt_ioctl_status(struct loopdev_cxt *lc);
extern int loopcxt_ioctl_capacity(struct loopdev_cxt *lc);
extern int loopcxt_ioctl_dio(struct loopdev_cxt *lc, unsigned long use_dio);
extern int loopcxt_ioctl_blocksize(struct loopdev_cxt *lc, uint64_t blocksize);
int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset);
int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit);
int loopcxt_set_blocksize(struct loopdev_cxt *lc, uint64_t blocksize);
int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags);
int loopcxt_set_backing_file(struct loopdev_cxt *lc, const char *filename);
extern char *loopcxt_get_backing_file(struct loopdev_cxt *lc);
extern int loopcxt_get_backing_devno(struct loopdev_cxt *lc, dev_t *devno);
extern int loopcxt_get_backing_inode(struct loopdev_cxt *lc, ino_t *ino);
extern int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset);
extern int loopcxt_get_blocksize(struct loopdev_cxt *lc, uint64_t *blocksize);
extern int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size);
extern int loopcxt_get_encrypt_type(struct loopdev_cxt *lc, uint32_t *type);
extern const char *loopcxt_get_crypt_name(struct loopdev_cxt *lc);
extern int loopcxt_is_autoclear(struct loopdev_cxt *lc);
extern int loopcxt_is_readonly(struct loopdev_cxt *lc);
extern int loopcxt_is_dio(struct loopdev_cxt *lc);
extern int loopcxt_is_partscan(struct loopdev_cxt *lc);
extern int loopcxt_find_by_backing_file(struct loopdev_cxt *lc,
const char *filename,
uint64_t offset, uint64_t sizelimit,
int flags);
extern int loopcxt_find_overlap(struct loopdev_cxt *lc,
const char *filename,
uint64_t offset, uint64_t sizelimit);
extern int loopcxt_is_used(struct loopdev_cxt *lc,
struct stat *st,
const char *backing_file,
uint64_t offset,
uint64_t sizelimit,
int flags);
#endif /* UTIL_LINUX_LOOPDEV_H */