From Fedora Project Wiki
High Level API Proposal
liblvm/liblvm.h
#include "error.h"
#include "handle.h"
#include "units.h"
#include "physical_volume.h"
/*
* lvm2_init
* Initialize LVM
*/
lvm_handle lvm_init(void);
/*
* lvm_load_config_file
* Load a lvm configuration file
*/
lvm_error_status lvm_load_config_file(lvm_handle h, const char *filename);
/*
* lvm_set_config_option
* Load an lvm config option into the existing configuration.
*
* The formation of the option parameter is similar to the names
* in /etc/lvm/lvm.conf.
* An option within a section is specified with a '/' between
* the section name and option. For example, the 'filter' option
* in the devices section is specified by 'devices/filter'
*/
lvm_error_status lvm_set_config_option(lvm_handle h, const char *option,
const char *value);
/*
* lvm_clear_config_option
*/
lvm_error_status lvm_clear_config_option(lvm_handle h, const char *option);
liblvm/handle.h
struct _lvm_handle {
char* config_file; /* default: NULL */
char** config_options; /* default: NULL */
char** config_values; /* default: NULL */
char* last_error_message; /* default: NULL */
};
typedef struct _lvm_handle lvm_handle;
liblvm/error.h
#include "handle.h"
enum _lvm_error_status {
NO_ERROR = 0,
INVALID_PV_NAME,
INVALID_PV_SIZE,
INVALID_DEV_SIZE,
INVALID_PE_SIZE,
INVALID_UUID,
INVALID_LABEL_SECTOR,
INVALID_METADATA_COPIES,
INVALID_METADATA_SIZE,
INVALID_PE_START,
INVALID_EXTENT_COUNT,
INVALID_EXTENT_SIZE,
/* more to come */
};
typedef enum _lvm_error_status lvm_error_status;
/*
* lvm_strerror
* Returns error string stored in the handle
*/
const char* lvm_strerror(lvm_handle h);
liblvm/physical_volume.h
#incldue "error.h"
#include "handle.h"
/*
* lvm physical volume information
*/
struct lvm_physical_volume {
char* pv_name;
char* vg_name;
uint64_t pv_size; /* units: use functions for conversions */
uint64_t dev_size; /* units */
uint64_t pe_size; /* units */
uint64_t total_pe;
uint64_t free_pe;
char* uuid;
};
/*
* private lvm pv object for physical volume creation and modification
*/
typedef struct lvm_pv_obj {
char* phys_vol;
uint64_t size;
int64_t labelsector;
int metadata_copies;
uint64_t metadata_size;
uint64_t pe_start;
uint32_t extent_count;
uint32_t extent_size;
const char* uuid;
} lvm_pv_obj_t;
/*
* lvm_pv_scan
* scans all supported LVM block devices in the system for physical volumes
* and gets attibutes of all physicalvolume
* returns: status
*/
lvm_error_status lvm_pv_scan(lvm_handle h,
struct LVM_PYSICAL_VOLUME** pv_return,
uint32_t* pv_count);
/*
* lvm_pv_get
* gets attibutes of one physicalvolume by volume path
* returns: status
*/
lvm_error_status lvm_pv_get(lvm_handle h,
struct lvm_physical_volume* pv_return,
const char* phys_vol_path);
/*
* lvm_pv_list
* gets attibutes of all physicalvolume by volume paths
* returns: status
*/
lvm_error_status lvm_pv_list(lvm_handle h,
struct lvm_physical_volume** pv_return,
const char** phys_vol_paths, uint32_t* pv_count);
/*
* lvm_pv_remove
* removes a physicalvolume by volume path
* returns: status
*/
lvm_error_status lvm_pv_remove(lvm_handle h, const char* phys_vol_path);
/*
* lvm_pv_create
* creates a physicalvolume object model with accessors and mutators
*/
/*
* usage example:
* lvm_pv_obj_t *pv = lvm_pv_obj_create("/dev/sda1");
* lvm_pv_obj_set_zero(pv, 1);
* lvm_pv_obj_set_uuid(pv "WDhaBn-bSGn-EW98-DkI7-M8zB-R4S9-BPkFqS");
* status = lvm_pv_create(handle, pv);
*/
lvm_pv_obj_t* lvm_pv_obj_create(const char* phys_vol);
/* accessors */
lvm_error_status lvm_pv_obj_set_volume(lvm_pv_obj_t* pv_obj,
const char* phys_vol);
lvm_error_status lvm_pv_obj_set_size(lvm_pv_obj_t* pv_obj, uint64t size);
lvm_error_status lvm_pv_obj_set_labelsector(lvm_pv_obj_t* pv_obj,
int64_t labelsector);
lvm_error_status lvm_pv_obj_set_metadata_copies(lvm_pv_obj_t* pv_obj,
int metadata_copies);
lvm_error_status lvm_pv_obj_set_metadata_size(lvm_pv_obj_t* pv_obj,
uint64_t metadata_size);
lvm_error_status lvm_pv_obj_set_pe_start(lvm_pv_obj_t* pv_obj,
uint64_t pe_start);
lvm_error_status lvm_pv_obj_set_extent_count(lvm_pv_obj_t* pv_obj,
uint32_t extent_count);
lvm_error_status lvm_pv_obj_set_extent_size(lvm_pv_obj_t* pv_obj,
uint32_t extent_size);
lvm_error_status lvm_pv_obj_set_uuid(lvm_pv_obj_t* pv_obj, const char* uuid);
lvm_error_status lvm_pv_obj_set_volume(lvm_pv_obj_t* pv_obj,
const char* phys_vol);
/* mutators */
uint64_t lvm_pv_obj_get_size(lvm_pv_obj_t* pv_obj);
int64_t lvm_pv_obj_get_labelsector(lvm_pv_obj_t* pv_obj);
int lvm_pv_obj_get_metadata_copies(lvm_pv_obj_t* pv_obj);
uint64_t lvm_pv_obj_get_metadata_size(lvm_pv_obj_t* pv_obj);
uint64_t lvm_pv_obj_get_pe_start(lvm_pv_obj_t* pv_obj);
uint32_t lvm_pv_obj_get_extent_count(lvm_pv_obj_t* pv_obj);
uint32_t lvm_pv_obj_get_extent_size(lvm_pv_obj_t* pv_obj);
const char* lvm_pv_obj_get_uuid(lvm_pv_obj_t* pv_obj);
const char* lvm_error_status lvm_pv_obj_get_volume(lvm_pv_obj_t* pv_obj);
lvm_error_status lvm_pv_create(lvm_handle h, lvm_pv_obj_t* pv_obj, int zero);
/*
* lvm_pv_change
* changes physicalvolume parameters
*/
lvm_error_status lvm_pv_obj_get(const char* phys_vol,
lvm_pv_obj_t* pv_obj_return);
lvm_error_status lvm_pv_change(lvm_handle h, lvm_pv_obj_t* pv_obj);
/*
* lvm_pv_restore_from
* restore physicalvolume parameters, use lvm_pv_change afterwards
*/
lvm_error_status lvm_pv_obj_restore_from(const char* uuid,
lvm_pv_obj_t* pv_obj_return,
const char* restore_file);
/*
* lvm_pv_fsck
*/
lvm_error_status lvm_pv_fsck(const char* phys_vol, int64_t labelsector);
liblvm/units.h
enum lvm_unit_type {
TYPE_UNITS = 0,
TYPE_BYTES,
TYPE_KILO_BYTE,
TYPE_KIBI_BYTE,
TYPE_GIGA_BYTE,
TYPE_GIBI_BYTE,
TYPE_TERA_BYTE,
TYPE_TEBI_BYTE,
TYPE_PETA_BYTE,
TYPE_PEBI_BYTE,
TYPE_EXA_BYTE,
TYPE_EXBI_BYTE
};
uint64_t lvm_unit_convert(uint64_t value,
enum lvm_unit_type from_type,
enum lvm_unit_type to_type);
uint64_t lvm_units_to_bytes(uint64_t units) {
return lvm_unit_convert(units, TYPE_UNITS, TYPE_BYTES);
}
uint64_t lvm_bytes_to_units(uint64_t bytes) {
return lvm_unit_convert(units, TYPE_BYTES, TYPE_UNITS);
}
static const char* lvm_unit_string(uint64_t units, enum lvm_unit_type type);