/**
* mnt_resolve_tag:
* @token: tag name
* @value: tag value
* @cache: for results or NULL
*
* Returns: device name or NULL in case of error. The result has to be
* deallocated by free() if @cache is NULL.
*/
char *mnt_resolve_tag(const char *token, const char *value,
struct libmnt_cache *cache)
{
char *p = NULL;
/*DBG(CACHE, ul_debugobj(cache, "resolving tag token=%s value=%s",
token, value));*/
if (!token || !value)
return NULL;
if (cache)
p = (char *) cache_find_tag(cache, token, value);
if (!p) {
/* returns newly allocated string */
p = blkid_evaluate_tag(token, value, cache ? &cache->bc : NULL);
if (p && cache &&
cache_add_tag(cache, token, value, p, 0))
goto error;
}
return p;
error:
free(p);
return NULL;
}
/**
* mnt_cache_read_tags
* @cache: pointer to struct libmnt_cache instance
* @devname: path device
*
* Reads @devname LABEL and UUID to the @cache.
*
* Returns: 0 if at least one tag was added, 1 if no tag was added or
* negative number in case of error.
*/
int mnt_cache_read_tags(struct libmnt_cache *cache, const char *devname)
{
blkid_probe pr;
size_t i, ntags = 0;
int rc;
const char *tags[] = { "LABEL", "UUID", "TYPE", "PARTUUID", "PARTLABEL" };
const char *blktags[] = { "LABEL", "UUID", "TYPE", "PART_ENTRY_UUID", "PART_ENTRY_NAME" };
if (!cache || !devname)
return -EINVAL;
DBG(CACHE, ul_debugobj(cache, "tags for %s requested", devname));
/* check if device is already cached */
for (i = 0; i < cache->nents; i++) {
struct mnt_cache_entry *e = &cache->ents[i];
if (!(e->flag & MNT_CACHE_TAGREAD))
continue;
if (strcmp(e->value, devname) == 0)
/* tags have already been read */
return 0;
}
pr = blkid_new_probe_from_filename(devname);
if (!pr)
return -1;
blkid_probe_enable_superblocks(pr, 1);
blkid_probe_set_superblocks_flags(pr,
BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID |
BLKID_SUBLKS_TYPE);
blkid_probe_enable_partitions(pr, 1);
blkid_probe_set_partitions_flags(pr, BLKID_PARTS_ENTRY_DETAILS);
rc = blkid_do_safeprobe(pr);
if (rc)
goto error;
DBG(CACHE, ul_debugobj(cache, "reading tags for: %s", devname));
for (i = 0; i < ARRAY_SIZE(tags); i++) {
const char *data;
char *dev;
if (cache_find_tag_value(cache, devname, tags[i])) {
DBG(CACHE, ul_debugobj(cache,
"\ntag %s already cached", tags[i]));
continue;
}
if (blkid_probe_lookup_value(pr, blktags[i], &data, NULL))
continue;
dev = strdup(devname);
if (!dev)
goto error;
if (cache_add_tag(cache, tags[i], data, dev,
MNT_CACHE_TAGREAD)) {
free(dev);
goto error;
}
ntags++;
}
DBG(CACHE, ul_debugobj(cache, "\tread %zd tags", ntags));
blkid_free_probe(pr);
return ntags ? 0 : 1;
error:
blkid_free_probe(pr);
return rc < 0 ? rc : -1;
}
/**
* mnt_cache_read_tags
* @cache: pointer to struct libmnt_cache instance
* @devname: path device
*
* Reads @devname LABEL and UUID to the @cache.
*
* Returns: 0 if at least one tag was added, 1 if no tag was added or
* negative number in case of error.
*/
int mnt_cache_read_tags(struct libmnt_cache *cache, const char *devname)
{
size_t i, ntags = 0;
int rc;
const char *tags[] = { "LABEL", "UUID", "TYPE" };
assert(cache);
assert(devname);
if (!cache || !devname)
return -EINVAL;
DBG(CACHE, mnt_debug_h(cache, "tags for %s requested", devname));
/* check is device is already cached */
for (i = 0; i < cache->nents; i++) {
struct mnt_cache_entry *e = &cache->ents[i];
if (!(e->flag & MNT_CACHE_TAGREAD))
continue;
if (strcmp(e->value, devname) == 0)
/* tags has been already read */
return 0;
}
rc = cache_get_probe(cache, devname, NULL);
if (rc)
return rc;
blkid_probe_enable_superblocks(cache->pr, 1);
blkid_probe_set_superblocks_flags(cache->pr,
BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID |
BLKID_SUBLKS_TYPE);
if (blkid_do_safeprobe(cache->pr))
goto error;
DBG(CACHE, mnt_debug_h(cache, "reading tags for: %s", devname));
for (i = 0; i < ARRAY_SIZE(tags); i++) {
const char *data;
char *dev;
if (cache_find_tag_value(cache, devname, tags[i])) {
DBG(CACHE, mnt_debug_h(cache,
"\ntag %s already cached", tags[i]));
continue;
}
if (blkid_probe_lookup_value(cache->pr, tags[i], &data, NULL))
continue;
dev = strdup(devname);
if (!dev)
goto error;
if (cache_add_tag(cache, tags[i], data, dev,
MNT_CACHE_TAGREAD)) {
free(dev);
goto error;
}
ntags++;
}
DBG(CACHE, mnt_debug_h(cache, "\tread %zd tags", ntags));
return ntags ? 0 : 1;
error:
return -1;
}
