diff options
Diffstat (limited to 'include/loopdev.h')
| -rw-r--r-- | include/loopdev.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/include/loopdev.h b/include/loopdev.h new file mode 100644 index 0000000..903adc4 --- /dev/null +++ b/include/loopdev.h @@ -0,0 +1,226 @@ +/* + * 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 "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 */ |