/**
* mnt_fs_match_source:
* @fs: filesystem
* @source: tag or path (device or so)
* @cache: tags/paths cache or NULL
*
* Possible are four attempts:
* 1) compare @source with @fs->source
* 2) compare realpath(@source) with @fs->source
* 3) compare realpath(@source) with realpath(@fs->source)
* 4) compare realpath(@source) with evaluated tag from @fs->source
*
* The 2nd, 3rd and 4th attempts are not performed when @cache is NULL. The
* 2nd and 3rd attempts are not performed if @fs->source is tag.
*
* Returns: 1 if @fs source is equal to @source else 0.
*/
int mnt_fs_match_source(mnt_fs *fs, const char *source, mnt_cache *cache)
{
char *cn;
const char *src, *t, *v;
if (!fs || !source || !fs->source)
return 0;
/* 1) native paths/tags */
if (!strcmp(source, fs->source))
return 1;
if (!cache)
return 0;
if (fs->flags & (MNT_FS_NET | MNT_FS_PSEUDO))
return 0;
cn = mnt_resolve_spec(source, cache);
if (!cn)
return 0;
/* 2) canonicalized and native */
src = mnt_fs_get_srcpath(fs);
if (src && !strcmp(cn, src))
return 1;
/* 3) canonicalized and canonicalized */
if (src) {
src = mnt_resolve_path(src, cache);
if (src && !strcmp(cn, src))
return 1;
}
if (src || mnt_fs_get_tag(fs, &t, &v))
/* src path does not match and tag is not defined */
return 0;
/* read @source's tags to the cache */
if (mnt_cache_read_tags(cache, cn) < 0) {
if (errno == EACCES) {
/* we don't have permissions to read TAGs from
* @source, but can translate @fs tag to devname.
*
* (because libblkid uses udev symlinks and this is
* accessible for non-root uses)
*/
char *x = mnt_resolve_tag(t, v, cache);
if (x && !strcmp(x, cn))
return 1;
}
return 0;
}
/* 4) has the @source a tag that matches with tag from @fs ? */
if (mnt_cache_device_has_tag(cache, cn, t, v))
return 1;
return 0;
}
/**
* mnt_resolve_spec:
* @spec: path or tag
* @cache: paths cache
*
* Returns: canonicalized path or NULL. The result has to be
* deallocated by free() if @cache is NULL.
*/
char *mnt_resolve_spec(const char *spec, struct libmnt_cache *cache)
{
char *cn = NULL;
char *t = NULL, *v = NULL;
if (!spec)
return NULL;
if (blkid_parse_tag_string(spec, &t, &v) == 0 && mnt_valid_tagname(t))
cn = mnt_resolve_tag(t, v, cache);
else
cn = mnt_resolve_path(spec, cache);
free(t);
free(v);
return cn;
}
/*
* This function works like mnt_resolve_tag(), but it's able to read UUiD/LABEL
* from regular swap files too (according to entries in /proc/swaps). Note that
* mnt_resolve_tag() and mnt_resolve_spec() works with system visible block
* devices only.
*/
static char *swapoff_resolve_tag(const char *name, const char *value,
struct libmnt_cache *cache)
{
char *path;
struct libmnt_table *tb;
struct libmnt_iter *itr;
struct libmnt_fs *fs;
/* this is usual case for block devices (and it's really fast as it uses
* udev /dev/disk/by-* symlinks by default */
path = mnt_resolve_tag(name, value, cache);
if (path)
return path;
/* try regular files from /proc/swaps */
tb = get_swaps();
if (!tb)
return NULL;
itr = mnt_new_iter(MNT_ITER_BACKWARD);
if (!itr)
err(EXIT_FAILURE, _("failed to initialize libmount iterator"));
while (tb && mnt_table_next_fs(tb, itr, &fs) == 0) {
blkid_probe pr = NULL;
const char *src = mnt_fs_get_source(fs);
const char *type = mnt_fs_get_swaptype(fs);
const char *data = NULL;
if (!src || !type || strcmp(type, "file") != 0)
continue;
pr = get_swap_prober(src);
if (!pr)
continue;
blkid_probe_lookup_value(pr, name, &data, NULL);
if (data && strcmp(data, value) == 0)
path = xstrdup(src);
blkid_free_probe(pr);
if (path)
break;
}
mnt_free_iter(itr);
return path;
}
/**
* mnt_resolve_spec:
* @spec: path or tag
* @cache: paths cache
*
* Returns: canonicalized path or NULL. The result has to be
* deallocated by free() if @cache is NULL.
*/
char *mnt_resolve_spec(const char *spec, struct libmnt_cache *cache)
{
char *cn = NULL;
if (!spec)
return NULL;
if (strchr(spec, '=')) {
char *tag, *val;
if (!blkid_parse_tag_string(spec, &tag, &val)) {
cn = mnt_resolve_tag(tag, val, cache);
free(tag);
free(val);
}
} else
cn = mnt_resolve_path(spec, cache);
return cn;
}
