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

/*
 * No copyright is claimed.  This code is in the public domain; do with
 * it what you wish.
 */
#ifndef UTIL_LINUX_LOOPDEV_H
#define UTIL_LINUX_LOOPDEV_H

#include <stdbool.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 */

	bool		done;		/* scanning done */
	bool		default_check;  /* 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>) */
	dev_t		devno;		/* loop device devno from /sys */
	mode_t		mode;		/* fd mode O_{RDONLY,RDWR} */
	uint64_t	blocksize;	/* used by loopcxt_setup_device() */

	int		flags;		/* LOOPDEV_FL_* flags */
	bool		has_info;	/* .info contains data */
	bool		extra_check;	/* unusual stuff for iterator */
	bool		info_failed;	/* LOOP_GET_STATUS ioctl failed */
	bool		control_ok;	/* /dev/loop-control success */
	bool		is_lost;	/* device in /sys, but missing in /dev */

	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_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 dev_t loopcxt_get_devno(struct loopdev_cxt *lc);
extern int loopdev_has_backing_file(const char *device);
extern int loopcxt_is_lost(struct loopdev_cxt *lc);
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_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);
int loopcxt_set_refname(struct loopdev_cxt *lc, const char *refname);

extern char *loopcxt_get_backing_file(struct loopdev_cxt *lc);
extern char *loopcxt_get_refname(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
faeb1b64 KZ	1	/*
	2	* No copyright is claimed. This code is in the public domain; do with
	3	* it what you wish.
	4	*/
10ee5932 KZ	5	#ifndef UTIL_LINUX_LOOPDEV_H
	6	#define UTIL_LINUX_LOOPDEV_H
	7
63d79371	8	#include <stdbool.h>
fd7f0718 KZ	9	#include "sysfs.h"
fd7f0718 KZ	10
10ee5932 KZ	11	/*
	12	* loop_info.lo_encrypt_type
	13	*/
	14	#define LO_CRYPT_NONE 0
	15	#define LO_CRYPT_XOR 1
	16	#define LO_CRYPT_DES 2
	17	#define LO_CRYPT_CRYPTOAPI 18
	18
	19	#define LOOP_SET_FD 0x4C00
	20	#define LOOP_CLR_FD 0x4C01
	21	/*
	22	* Obsolete (kernel < 2.6)
	23	*
	24	* #define LOOP_SET_STATUS 0x4C02
	25	* #define LOOP_GET_STATUS 0x4C03
	26	*/
	27	#define LOOP_SET_STATUS64 0x4C04
	28	#define LOOP_GET_STATUS64 0x4C05
	29	/* #define LOOP_CHANGE_FD 0x4C06 */
	30	#define LOOP_SET_CAPACITY 0x4C07
64c3bb3c	31	#define LOOP_SET_DIRECT_IO 0x4C08
a1a41597	32	#define LOOP_SET_BLOCK_SIZE 0x4C09
10ee5932	33
0b14bf7a KZ	34	/* /dev/loop-control interface */
	35	#ifndef LOOP_CTL_ADD
	36	# define LOOP_CTL_ADD 0x4C80
	37	# define LOOP_CTL_REMOVE 0x4C81
	38	# define LOOP_CTL_GET_FREE 0x4C82
	39	#endif
	40
10ee5932 KZ	41	/*
	42	* loop_info.lo_flags
	43	*/
	44	enum {
	45	LO_FLAGS_READ_ONLY = 1,
	46	LO_FLAGS_USE_AOPS = 2,
916bf85e KZ	47	LO_FLAGS_AUTOCLEAR = 4, /* kernel >= 2.6.25 */
916bf85e KZ	48	LO_FLAGS_PARTSCAN = 8, /* kernel >= 3.2 */
faeef4d2	49	LO_FLAGS_DIRECT_IO = 16, /* kernel >= 4.2 */
10ee5932 KZ	50	};
	51
	52	#define LO_NAME_SIZE 64
	53	#define LO_KEY_SIZE 32
	54
	55	/*
a5c523a0	56	* Linux LOOP_{SET,GET}_STATUS64 ioctl struct
10ee5932 KZ	57	*/
	58	struct loop_info64 {
	59	uint64_t lo_device;
	60	uint64_t lo_inode;
	61	uint64_t lo_rdevice;
	62	uint64_t lo_offset;
	63	uint64_t lo_sizelimit; /* bytes, 0 == max available */
	64	uint32_t lo_number;
	65	uint32_t lo_encrypt_type;
	66	uint32_t lo_encrypt_key_size;
	67	uint32_t lo_flags;
	68	uint8_t lo_file_name[LO_NAME_SIZE];
	69	uint8_t lo_crypt_name[LO_NAME_SIZE];
	70	uint8_t lo_encrypt_key[LO_KEY_SIZE];
	71	uint64_t lo_init[2];
	72	};
	73
d5fd456c	74	#ifndef LOOP_CONFIGURE
a61955ba KZ	75	/*
	76	* Since Linux v5.8-rc1 (commit 3448914e8cc550ba792d4ccc74471d1ca4293aae)
	77	*/
	78	# define LOOP_CONFIGURE 0x4C0A
d5fd456c SK	79	struct loop_config {
	80	uint32_t fd;
	81	uint32_t block_size;
	82	struct loop_info64 info;
	83	uint64_t __reserved[8];
	84	};
	85	#endif
	86
10ee5932 KZ	87	#define LOOPDEV_MAJOR 7 /* loop major number */
	88	#define LOOPDEV_DEFAULT_NNODES 8 /* default number of loop devices */
	89
	90	struct loopdev_iter {
	91	FILE proc; / /proc/partitions */
e4062c72	92	DIR sysblock; / /sys/block */
10ee5932 KZ	93	int ncur; /* current position */
	94	int minors; / ary of minor numbers (when scan whole /dev) */
	95	int nminors; /* number of items in minors /
	96	int ct_perm; /* count permission problems */
	97	int ct_succ; /* count number of detected devices */
	98
63d79371 ZJS	99	bool done; /* scanning done */
63d79371 ZJS	100	bool default_check; /* check first LOOPDEV_NLOOPS */
10ee5932 KZ	101	int flags; /* LOOPITER_FL_* flags */
	102	};
	103
	104	enum {
	105	LOOPITER_FL_FREE = (1 << 0),
	106	LOOPITER_FL_USED = (1 << 1)
	107	};
	108
	109	/*
	110	* handler for work with loop devices
	111	*/
	112	struct loopdev_cxt {
	113	char device[128]; /* device path (e.g. /dev/loop<N>) */
	114	char filename; / backing file for loopcxt_set_... */
	115	int fd; /* open(/dev/looo<N>) */
a6ca0456	116	dev_t devno; /* loop device devno from /sys */
ced1142d	117	mode_t mode; /* fd mode O_{RDONLY,RDWR} */
75d239ff	118	uint64_t blocksize; /* used by loopcxt_setup_device() */
10ee5932 KZ	119
10ee5932 KZ	120	int flags; /* LOOPDEV_FL_* flags */
63d79371 ZJS	121	bool has_info; /* .info contains data */
	122	bool extra_check; /* unusual stuff for iterator */
	123	bool info_failed; /* LOOP_GET_STATUS ioctl failed */
	124	bool control_ok; /* /dev/loop-control success */
	125	bool is_lost; /* device in /sys, but missing in /dev */
10ee5932	126
7604f85f	127	struct path_cxt sysfs; / pointer to /sys/dev/block/<maj:min>/ */
db8f7815	128	struct loop_config config; /* for GET/SET ioctl */
10ee5932 KZ	129	struct loopdev_iter iter; /* scans /sys or /dev for used/free devices */
	130	};
	131
7604f85f	132	#define UL_LOOPDEVCXT_EMPTY { .fd = -1 }
6219c25e	133
10ee5932 KZ	134	/*
	135	* loopdev_cxt.flags
	136	*/
	137	enum {
10ee5932 KZ	138	LOOPDEV_FL_OFFSET = (1 << 4),
	139	LOOPDEV_FL_NOSYSFS = (1 << 5),
	140	LOOPDEV_FL_NOIOCTL = (1 << 6),
0b14bf7a KZ	141	LOOPDEV_FL_DEVSUBDIR = (1 << 7),
0b14bf7a KZ	142	LOOPDEV_FL_CONTROL = (1 << 8), /* system with /dev/loop-control */
c7e0925d	143	LOOPDEV_FL_SIZELIMIT = (1 << 9)
10ee5932 KZ	144	};
	145
	146	/*
	147	* High-level
	148	*/
59d749c3 KZ	149	extern int loopmod_supports_partscan(void);
59d749c3 KZ	150
10ee5932 KZ	151	extern int is_loopdev(const char *device);
10ee5932 KZ	152	extern int loopdev_is_autoclear(const char *device);
6c224de1	153
10ee5932	154	extern char loopdev_get_backing_file(const char device);
a6ca0456	155	extern dev_t loopcxt_get_devno(struct loopdev_cxt *lc);
14bb8e3c	156	extern int loopdev_has_backing_file(const char *device);
a6ca0456	157	extern int loopcxt_is_lost(struct loopdev_cxt *lc);
10ee5932	158	extern int loopdev_is_used(const char device, const char filename,
74a4705a	159	uint64_t offset, uint64_t sizelimit, int flags);
10ee5932	160	extern char loopdev_find_by_backing_file(const char filename,
74a4705a	161	uint64_t offset, uint64_t sizelimit, int flags);
10ee5932 KZ	162	extern int loopcxt_find_unused(struct loopdev_cxt *lc);
10ee5932 KZ	163	extern int loopdev_delete(const char *device);
d5688130	164	extern int loopdev_count_by_backing_file(const char filename, char *loopdev);
10ee5932 KZ	165
	166	/*
	167	* Low-level
	168	*/
defa0710 KZ	169	extern int loopcxt_init(struct loopdev_cxt *lc, int flags)
defa0710 KZ	170	__attribute__ ((warn_unused_result));
10ee5932 KZ	171	extern void loopcxt_deinit(struct loopdev_cxt *lc);
10ee5932 KZ	172
defa0710 KZ	173	extern int loopcxt_set_device(struct loopdev_cxt lc, const char device)
defa0710 KZ	174	__attribute__ ((warn_unused_result));
c7e0925d	175	extern int loopcxt_has_device(struct loopdev_cxt *lc);
3cb2413b	176	extern int loopcxt_add_device(struct loopdev_cxt *lc);
10ee5932 KZ	177	extern char loopcxt_strdup_device(struct loopdev_cxt lc);
10ee5932 KZ	178	extern const char loopcxt_get_device(struct loopdev_cxt lc);
c8ea3514	179	extern struct loop_info64 loopcxt_get_info(struct loopdev_cxt lc);
fd7f0718	180
10ee5932 KZ	181	extern int loopcxt_get_fd(struct loopdev_cxt *lc);
	182
	183	extern int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags);
	184	extern int loopcxt_deinit_iterator(struct loopdev_cxt *lc);
	185	extern int loopcxt_next(struct loopdev_cxt *lc);
	186
	187	extern int loopcxt_setup_device(struct loopdev_cxt *lc);
	188	extern int loopcxt_delete_device(struct loopdev_cxt *lc);
9fcc8936 KZ	189
	190	extern int loopcxt_ioctl_status(struct loopdev_cxt *lc);
	191	extern int loopcxt_ioctl_capacity(struct loopdev_cxt *lc);
	192	extern int loopcxt_ioctl_dio(struct loopdev_cxt *lc, unsigned long use_dio);
	193	extern int loopcxt_ioctl_blocksize(struct loopdev_cxt *lc, uint64_t blocksize);
10ee5932 KZ	194
	195	int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset);
	196	int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit);
75d239ff	197	int loopcxt_set_blocksize(struct loopdev_cxt *lc, uint64_t blocksize);
10ee5932 KZ	198	int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags);
10ee5932 KZ	199	int loopcxt_set_backing_file(struct loopdev_cxt lc, const char filename);
db8f7815	200	int loopcxt_set_refname(struct loopdev_cxt lc, const char refname);
10ee5932 KZ	201
10ee5932 KZ	202	extern char loopcxt_get_backing_file(struct loopdev_cxt lc);
db8f7815	203	extern char loopcxt_get_refname(struct loopdev_cxt lc);
6c224de1 KZ	204	extern int loopcxt_get_backing_devno(struct loopdev_cxt lc, dev_t devno);
6c224de1 KZ	205	extern int loopcxt_get_backing_inode(struct loopdev_cxt lc, ino_t ino);
10ee5932	206	extern int loopcxt_get_offset(struct loopdev_cxt lc, uint64_t offset);
a1a41597	207	extern int loopcxt_get_blocksize(struct loopdev_cxt lc, uint64_t blocksize);
10ee5932	208	extern int loopcxt_get_sizelimit(struct loopdev_cxt lc, uint64_t size);
6c224de1 KZ	209	extern int loopcxt_get_encrypt_type(struct loopdev_cxt lc, uint32_t type);
6c224de1 KZ	210	extern const char loopcxt_get_crypt_name(struct loopdev_cxt lc);
10ee5932	211	extern int loopcxt_is_autoclear(struct loopdev_cxt *lc);
fd7f0718	212	extern int loopcxt_is_readonly(struct loopdev_cxt *lc);
faeef4d2	213	extern int loopcxt_is_dio(struct loopdev_cxt *lc);
59d749c3	214	extern int loopcxt_is_partscan(struct loopdev_cxt *lc);
10ee5932 KZ	215	extern int loopcxt_find_by_backing_file(struct loopdev_cxt *lc,
10ee5932 KZ	216	const char *filename,
74a4705a SB	217	uint64_t offset, uint64_t sizelimit,
74a4705a SB	218	int flags);
c444a71b KZ	219	extern int loopcxt_find_overlap(struct loopdev_cxt *lc,
	220	const char *filename,
	221	uint64_t offset, uint64_t sizelimit);
10ee5932	222
6c224de1 KZ	223	extern int loopcxt_is_used(struct loopdev_cxt *lc,
	224	struct stat *st,
	225	const char *backing_file,
	226	uint64_t offset,
74a4705a	227	uint64_t sizelimit,
6c224de1 KZ	228	int flags);
6c224de1 KZ	229
10ee5932	230	#endif /* UTIL_LINUX_LOOPDEV_H */