static int dir_to_device(const char *spec, dev_t *dev)
{
struct libmnt_table *tb = mnt_new_table_from_file("/proc/self/mountinfo");
struct libmnt_fs *fs;
struct libmnt_cache *cache;
int rc = -1;
if (!tb) {
/*
* Fallback. Traditional way to detect mountpoints. This way
* is independent on /proc, but not able to detect bind mounts.
*/
struct stat pst, st;
char buf[PATH_MAX], *cn;
int len;
if (stat(spec, &st) != 0)
return -1;
cn = mnt_resolve_path(spec, NULL); /* canonicalize */
len = snprintf(buf, sizeof(buf), "%s/..", cn ? cn : spec);
free(cn);
if (len < 0 || (size_t) len + 1 > sizeof(buf))
return -1;
if (stat(buf, &pst) !=0)
return -1;
if ((st.st_dev != pst.st_dev) ||
(st.st_dev == pst.st_dev && st.st_ino == pst.st_ino)) {
*dev = st.st_dev;
return 0;
}
return -1;
}
/* to canonicalize all necessary paths */
cache = mnt_new_cache();
mnt_table_set_cache(tb, cache);
fs = mnt_table_find_target(tb, spec, MNT_ITER_BACKWARD);
if (fs && mnt_fs_get_target(fs)) {
*dev = mnt_fs_get_devno(fs);
rc = 0;
}
mnt_free_table(tb);
mnt_free_cache(cache);
return rc;
}
static int dir_to_device(struct mountpoint_control *ctl)
{
struct libmnt_table *tb = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
struct libmnt_fs *fs;
struct libmnt_cache *cache;
int rc = -1;
if (!tb) {
/*
* Fallback. Traditional way to detect mountpoints. This way
* is independent on /proc, but not able to detect bind mounts.
*/
struct stat pst;
char buf[PATH_MAX], *cn;
int len;
cn = mnt_resolve_path(ctl->path, NULL); /* canonicalize */
len = snprintf(buf, sizeof(buf), "%s/..", cn ? cn : ctl->path);
free(cn);
if (len < 0 || (size_t) len >= sizeof(buf))
return -1;
if (stat(buf, &pst) !=0)
return -1;
if ((ctl->st.st_dev != pst.st_dev) ||
(ctl->st.st_dev == pst.st_dev && ctl->st.st_ino == pst.st_ino)) {
ctl->dev = ctl->st.st_dev;
return 0;
}
return -1;
}
/* to canonicalize all necessary paths */
cache = mnt_new_cache();
mnt_table_set_cache(tb, cache);
mnt_unref_cache(cache);
fs = mnt_table_find_target(tb, ctl->path, MNT_ITER_BACKWARD);
if (fs && mnt_fs_get_target(fs)) {
ctl->dev = mnt_fs_get_devno(fs);
rc = 0;
}
mnt_unref_table(tb);
return rc;
}
