util-linux/mount-deprecated/fsprobe.c

142 lines
2.7 KiB
C

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdlib.h>
#include <blkid.h>
#include "blkdev.h"
#include "canonicalize.h"
#include "pathnames.h"
#include "fsprobe.h"
/*
* THIS IS DEPRECATED -- use blkid_evaluate_* API rather than this extra layer
*/
static blkid_cache blcache;
static blkid_probe blprobe;
void
fsprobe_init(void)
{
blcache = NULL;
blprobe = NULL;
}
void
fsprobe_exit(void)
{
if (blprobe)
blkid_free_probe(blprobe);
if (blcache)
blkid_put_cache(blcache);
}
/*
* Parses NAME=value, returns -1 on parse error, 0 success. The success is also
* when the 'spec' doesn't contain name=value pair (because the spec could be
* a devname too). In particular case the pointer 'name' is set to NULL.
*/
int
fsprobe_parse_spec(const char *spec, char **name, char **value)
{
*name = NULL;
*value = NULL;
if (strchr(spec, '='))
return blkid_parse_tag_string(spec, name, value);
return 0;
}
char *
fsprobe_get_devname_by_spec(const char *spec)
{
return blkid_evaluate_spec(spec, &blcache);
}
int
fsprobe_known_fstype(const char *fstype)
{
return blkid_known_fstype(fstype);
}
/* returns device LABEL, UUID, FSTYPE, ... by low-level
* probing interface
*/
static char *
fsprobe_get_value(const char *name, const char *devname, int *ambi)
{
int fd, rc;
const char *data = NULL;
if (!devname || !name)
return NULL;
fd = open(devname, O_RDONLY);
if (fd < 0)
return NULL;
if (!blprobe)
blprobe = blkid_new_probe();
if (!blprobe)
goto done;
if (blkid_probe_set_device(blprobe, fd, 0, 0))
goto done;
blkid_probe_enable_superblocks(blprobe, 1);
blkid_probe_set_superblocks_flags(blprobe,
BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID | BLKID_SUBLKS_TYPE);
rc = blkid_do_safeprobe(blprobe);
if (ambi)
*ambi = rc == -2 ? 1 : 0; /* ambivalent probing result */
if (!rc)
blkid_probe_lookup_value(blprobe, name, &data, NULL);
done:
close(fd);
return data ? strdup((char *) data) : NULL;
}
char *
fsprobe_get_label_by_devname(const char *devname)
{
return fsprobe_get_value("LABEL", devname, NULL);
}
char *
fsprobe_get_uuid_by_devname(const char *devname)
{
return fsprobe_get_value("UUID", devname, NULL);
}
char *
fsprobe_get_fstype_by_devname(const char *devname)
{
return fsprobe_get_value("TYPE", devname, NULL);
}
char *
fsprobe_get_fstype_by_devname_ambi(const char *devname, int *ambi)
{
return fsprobe_get_value("TYPE", devname, ambi);
}
char *
fsprobe_get_devname_by_uuid(const char *uuid)
{
return blkid_evaluate_tag("UUID", uuid, &blcache);
}
char *
fsprobe_get_devname_by_label(const char *label)
{
return blkid_evaluate_tag("LABEL", label, &blcache);
}