[thirdparty/util-linux.git] / include / loopdev.h

#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];
};

#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_info64	info;	/* 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_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 */
Commit	Line	Data
10ee5932 KZ	1	#ifndef UTIL_LINUX_LOOPDEV_H
	2	#define UTIL_LINUX_LOOPDEV_H
	3
fd7f0718 KZ	4	#include "sysfs.h"
fd7f0718 KZ	5
10ee5932 KZ	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
64c3bb3c	26	#define LOOP_SET_DIRECT_IO 0x4C08
a1a41597	27	#define LOOP_SET_BLOCK_SIZE 0x4C09
10ee5932	28
0b14bf7a KZ	29	/* /dev/loop-control interface */
	30	#ifndef LOOP_CTL_ADD
	31	# define LOOP_CTL_ADD 0x4C80
	32	# define LOOP_CTL_REMOVE 0x4C81
	33	# define LOOP_CTL_GET_FREE 0x4C82
	34	#endif
	35
10ee5932 KZ	36	/*
	37	* loop_info.lo_flags
	38	*/
	39	enum {
	40	LO_FLAGS_READ_ONLY = 1,
	41	LO_FLAGS_USE_AOPS = 2,
916bf85e KZ	42	LO_FLAGS_AUTOCLEAR = 4, /* kernel >= 2.6.25 */
916bf85e KZ	43	LO_FLAGS_PARTSCAN = 8, /* kernel >= 3.2 */
faeef4d2	44	LO_FLAGS_DIRECT_IO = 16, /* kernel >= 4.2 */
10ee5932 KZ	45	};
	46
	47	#define LO_NAME_SIZE 64
	48	#define LO_KEY_SIZE 32
	49
	50	/*
a5c523a0	51	* Linux LOOP_{SET,GET}_STATUS64 ioctl struct
10ee5932 KZ	52	*/
	53	struct loop_info64 {
	54	uint64_t lo_device;
	55	uint64_t lo_inode;
	56	uint64_t lo_rdevice;
	57	uint64_t lo_offset;
	58	uint64_t lo_sizelimit; /* bytes, 0 == max available */
	59	uint32_t lo_number;
	60	uint32_t lo_encrypt_type;
	61	uint32_t lo_encrypt_key_size;
	62	uint32_t lo_flags;
	63	uint8_t lo_file_name[LO_NAME_SIZE];
	64	uint8_t lo_crypt_name[LO_NAME_SIZE];
	65	uint8_t lo_encrypt_key[LO_KEY_SIZE];
	66	uint64_t lo_init[2];
	67	};
	68
	69	#define LOOPDEV_MAJOR 7 /* loop major number */
	70	#define LOOPDEV_DEFAULT_NNODES 8 /* default number of loop devices */
	71
	72	struct loopdev_iter {
	73	FILE proc; / /proc/partitions */
e4062c72	74	DIR sysblock; / /sys/block */
10ee5932 KZ	75	int ncur; /* current position */
	76	int minors; / ary of minor numbers (when scan whole /dev) */
	77	int nminors; /* number of items in minors /
	78	int ct_perm; /* count permission problems */
	79	int ct_succ; /* count number of detected devices */
	80
9feec79c KZ	81	unsigned int done:1; /* scanning done */
9feec79c KZ	82	unsigned int default_check:1;/* check first LOOPDEV_NLOOPS */
10ee5932 KZ	83	int flags; /* LOOPITER_FL_* flags */
	84	};
	85
	86	enum {
	87	LOOPITER_FL_FREE = (1 << 0),
	88	LOOPITER_FL_USED = (1 << 1)
	89	};
	90
	91	/*
	92	* handler for work with loop devices
	93	*/
	94	struct loopdev_cxt {
	95	char device[128]; /* device path (e.g. /dev/loop<N>) */
	96	char filename; / backing file for loopcxt_set_... */
	97	int fd; /* open(/dev/looo<N>) */
fd7f0718	98	int mode; /* fd mode O_{RDONLY,RDWR} */
75d239ff	99	uint64_t blocksize; /* used by loopcxt_setup_device() */
10ee5932 KZ	100
10ee5932 KZ	101	int flags; /* LOOPDEV_FL_* flags */
9feec79c KZ	102	unsigned int has_info:1; /* .info contains data */
9feec79c KZ	103	unsigned int extra_check:1; /* unusual stuff for iterator */
6c224de1	104	unsigned int info_failed:1; /* LOOP_GET_STATUS ioctl failed */
663bf040	105	unsigned int control_ok:1; /* /dev/loop-control success */
10ee5932	106
7604f85f	107	struct path_cxt sysfs; / pointer to /sys/dev/block/<maj:min>/ */
10ee5932 KZ	108	struct loop_info64 info; /* for GET/SET ioctl */
	109	struct loopdev_iter iter; /* scans /sys or /dev for used/free devices */
	110	};
	111
7604f85f	112	#define UL_LOOPDEVCXT_EMPTY { .fd = -1 }
6219c25e	113
10ee5932 KZ	114	/*
	115	* loopdev_cxt.flags
	116	*/
	117	enum {
fd7f0718	118	LOOPDEV_FL_RDONLY = (1 << 0), /* open(/dev/loop) mode; default */
10ee5932 KZ	119	LOOPDEV_FL_RDWR = (1 << 1), /* necessary for loop setup only */
	120	LOOPDEV_FL_OFFSET = (1 << 4),
	121	LOOPDEV_FL_NOSYSFS = (1 << 5),
	122	LOOPDEV_FL_NOIOCTL = (1 << 6),
0b14bf7a KZ	123	LOOPDEV_FL_DEVSUBDIR = (1 << 7),
0b14bf7a KZ	124	LOOPDEV_FL_CONTROL = (1 << 8), /* system with /dev/loop-control */
c7e0925d	125	LOOPDEV_FL_SIZELIMIT = (1 << 9)
10ee5932 KZ	126	};
	127
	128	/*
	129	* High-level
	130	*/
59d749c3 KZ	131	extern int loopmod_supports_partscan(void);
59d749c3 KZ	132
10ee5932 KZ	133	extern int is_loopdev(const char *device);
10ee5932 KZ	134	extern int loopdev_is_autoclear(const char *device);
6c224de1	135
10ee5932 KZ	136	extern char loopdev_get_backing_file(const char device);
10ee5932 KZ	137	extern int loopdev_is_used(const char device, const char filename,
74a4705a	138	uint64_t offset, uint64_t sizelimit, int flags);
10ee5932	139	extern char loopdev_find_by_backing_file(const char filename,
74a4705a	140	uint64_t offset, uint64_t sizelimit, int flags);
10ee5932 KZ	141	extern int loopcxt_find_unused(struct loopdev_cxt *lc);
10ee5932 KZ	142	extern int loopdev_delete(const char *device);
d5688130	143	extern int loopdev_count_by_backing_file(const char filename, char *loopdev);
10ee5932 KZ	144
	145	/*
	146	* Low-level
	147	*/
defa0710 KZ	148	extern int loopcxt_init(struct loopdev_cxt *lc, int flags)
defa0710 KZ	149	__attribute__ ((warn_unused_result));
10ee5932 KZ	150	extern void loopcxt_deinit(struct loopdev_cxt *lc);
10ee5932 KZ	151
defa0710 KZ	152	extern int loopcxt_set_device(struct loopdev_cxt lc, const char device)
defa0710 KZ	153	__attribute__ ((warn_unused_result));
c7e0925d	154	extern int loopcxt_has_device(struct loopdev_cxt *lc);
3cb2413b	155	extern int loopcxt_add_device(struct loopdev_cxt *lc);
10ee5932 KZ	156	extern char loopcxt_strdup_device(struct loopdev_cxt lc);
10ee5932 KZ	157	extern const char loopcxt_get_device(struct loopdev_cxt lc);
c8ea3514	158	extern struct loop_info64 loopcxt_get_info(struct loopdev_cxt lc);
fd7f0718	159
10ee5932	160	extern int loopcxt_get_fd(struct loopdev_cxt *lc);
fd7f0718	161	extern int loopcxt_set_fd(struct loopdev_cxt *lc, int fd, int mode);
10ee5932 KZ	162
	163	extern int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags);
	164	extern int loopcxt_deinit_iterator(struct loopdev_cxt *lc);
	165	extern int loopcxt_next(struct loopdev_cxt *lc);
	166
	167	extern int loopcxt_setup_device(struct loopdev_cxt *lc);
	168	extern int loopcxt_delete_device(struct loopdev_cxt *lc);
9fcc8936 KZ	169
	170	extern int loopcxt_ioctl_status(struct loopdev_cxt *lc);
	171	extern int loopcxt_ioctl_capacity(struct loopdev_cxt *lc);
	172	extern int loopcxt_ioctl_dio(struct loopdev_cxt *lc, unsigned long use_dio);
	173	extern int loopcxt_ioctl_blocksize(struct loopdev_cxt *lc, uint64_t blocksize);
10ee5932 KZ	174
	175	int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset);
	176	int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit);
75d239ff	177	int loopcxt_set_blocksize(struct loopdev_cxt *lc, uint64_t blocksize);
10ee5932 KZ	178	int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags);
10ee5932 KZ	179	int loopcxt_set_backing_file(struct loopdev_cxt lc, const char filename);
10ee5932 KZ	180
10ee5932 KZ	181	extern char loopcxt_get_backing_file(struct loopdev_cxt lc);
6c224de1 KZ	182	extern int loopcxt_get_backing_devno(struct loopdev_cxt lc, dev_t devno);
6c224de1 KZ	183	extern int loopcxt_get_backing_inode(struct loopdev_cxt lc, ino_t ino);
10ee5932	184	extern int loopcxt_get_offset(struct loopdev_cxt lc, uint64_t offset);
a1a41597	185	extern int loopcxt_get_blocksize(struct loopdev_cxt lc, uint64_t blocksize);
10ee5932	186	extern int loopcxt_get_sizelimit(struct loopdev_cxt lc, uint64_t size);
6c224de1 KZ	187	extern int loopcxt_get_encrypt_type(struct loopdev_cxt lc, uint32_t type);
6c224de1 KZ	188	extern const char loopcxt_get_crypt_name(struct loopdev_cxt lc);
10ee5932	189	extern int loopcxt_is_autoclear(struct loopdev_cxt *lc);
fd7f0718	190	extern int loopcxt_is_readonly(struct loopdev_cxt *lc);
faeef4d2	191	extern int loopcxt_is_dio(struct loopdev_cxt *lc);
59d749c3	192	extern int loopcxt_is_partscan(struct loopdev_cxt *lc);
10ee5932 KZ	193	extern int loopcxt_find_by_backing_file(struct loopdev_cxt *lc,
10ee5932 KZ	194	const char *filename,
74a4705a SB	195	uint64_t offset, uint64_t sizelimit,
74a4705a SB	196	int flags);
c444a71b KZ	197	extern int loopcxt_find_overlap(struct loopdev_cxt *lc,
	198	const char *filename,
	199	uint64_t offset, uint64_t sizelimit);
10ee5932	200
6c224de1 KZ	201	extern int loopcxt_is_used(struct loopdev_cxt *lc,
	202	struct stat *st,
	203	const char *backing_file,
	204	uint64_t offset,
74a4705a	205	uint64_t sizelimit,
6c224de1 KZ	206	int flags);
6c224de1 KZ	207
10ee5932	208	#endif /* UTIL_LINUX_LOOPDEV_H */