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#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>
#ifdef HAVE_BLKID_BLKID_H
#include <blkid/blkid.h>
#else
#include <blkid.h>
#endif
#include "blkdev.h"
#include "canonicalize.h"
#include "pathnames.h"
#include "fsprobe.h"
static blkid_cache blcache;
#ifdef HAVE_LIBBLKID_INTERNAL
/* ask kernel developers why we need such ugly open() method... */
static int
open_device(const char *devname)
{
int retries = 0;
do {
int fd = open(devname, O_RDONLY);
if (fd >= 0)
return fd;
if (errno != ENOMEDIUM)
break;
if (retries >= CRDOM_NOMEDIUM_RETRIES)
break;
++retries;
sleep(3);
} while(1);
return -1;
}
#endif
/*
* 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)
{
char *name, *value;
if (!spec)
return NULL;
if (fsprobe_parse_spec(spec, &name, &value) != 0)
return NULL; /* parse error */
if (name) {
char *nspec = NULL;
if (!strcmp(name,"LABEL"))
nspec = fsprobe_get_devname_by_label(value);
else if (!strcmp(name,"UUID"))
nspec = fsprobe_get_devname_by_uuid(value);
free(name);
free(value);
return nspec;
}
return canonicalize_path(spec);
}
void
fsprobe_init(void)
{
blcache = NULL;
}
int
fsprobe_known_fstype(const char *fstype)
{
return blkid_known_fstype(fstype);
}
#ifdef HAVE_LIBBLKID_INTERNAL
/*
* libblkid from util-linux-ng
* -- recommended
*/
static blkid_probe blprobe;
void
fsprobe_exit(void)
{
if (blprobe)
blkid_free_probe(blprobe);
if (blcache)
blkid_put_cache(blcache);
}
/* 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_device(devname);
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);
}
#else /* !HAVE_LIBBLKID_INTERNAL */
/*
* Classic libblkid (from e2fsprogs) without blkid_evaluate_tag()
* -- deprecated
*/
#define BLKID_EMPTY_CACHE "/dev/null"
void
fsprobe_exit(void)
{
if (blcache)
blkid_put_cache(blcache);
}
char *
fsprobe_get_devname_by_uuid(const char *uuid)
{
if (!blcache)
blkid_get_cache(&blcache, NULL);
return blkid_get_devname(blcache, "UUID", uuid);
}
char *
fsprobe_get_devname_by_label(const char *label)
{
if (!blcache)
blkid_get_cache(&blcache, NULL);
return blkid_get_devname(blcache, "LABEL", label);
}
char *
fsprobe_get_fstype_by_devname(const char *devname)
{
blkid_cache c;
char *tp;
if (blcache)
return blkid_get_tag_value(blcache, "TYPE", devname);
/* The cache is not initialized yet. Use empty cache rather than waste
* time with /etc/blkid.tab. It seems that probe FS is faster than
* parse the cache file. -- kzak (17-May-2007)
*/
blkid_get_cache(&c, BLKID_EMPTY_CACHE);
tp = blkid_get_tag_value(c, "TYPE", devname);
blkid_put_cache(c);
return tp;
}
char *
fsprobe_get_fstype_by_devname_ambi(const char *devname, int *ambi)
{
if (ambi)
*ambi = 0;
return fsprobe_get_fstype_by_devname(devname);
}
char *
fsprobe_get_label_by_devname(const char *devname)
{
if (!blcache)
blkid_get_cache(&blcache, NULL);
return blkid_get_tag_value(blcache, "LABEL", devname);
}
char *
fsprobe_get_uuid_by_devname(const char *devname)
{
if (!blcache)
blkid_get_cache(&blcache, NULL);
return blkid_get_tag_value(blcache, "UUID", devname);
}
#endif /* !HAVE_LIBBLKID_INTERNAL */
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