*
* If that didn't work we will try to read the mount id from
* /proc/self/fdinfo/<fd>. This is almost as good as
- * name_to_handle_at(), however, does not return the the
+ * name_to_handle_at(), however, does not return the
* opaque file handle. The opaque file handle is pretty useful
* to detect the root directory, which we should always
* consider a mount point. Hence we use this only as
/* flags can be AT_SYMLINK_FOLLOW or 0 */
int path_is_mount_point(const char *t, int flags) {
_cleanup_close_ int fd = -1;
- _cleanup_free_ char *parent = NULL;
+ _cleanup_free_ char *canonical = NULL, *parent = NULL;
int r;
assert(t);
if (path_equal(t, "/"))
return 1;
- r = path_get_parent(t, &parent);
+ /* we need to resolve symlinks manually, we can't just rely on
+ * fd_is_mount_point() to do that for us; if we have a structure like
+ * /bin -> /usr/bin/ and /usr is a mount point, then the parent that we
+ * look at needs to be /usr, not /. */
+ if (flags & AT_SYMLINK_FOLLOW) {
+ canonical = canonicalize_file_name(t);
+ if (!canonical)
+ return -errno;
+ }
+
+ r = path_get_parent(canonical ?: t, &parent);
if (r < 0)
return r;
if (fd < 0)
return -errno;
- return fd_is_mount_point(fd, basename(t), flags);
+ return fd_is_mount_point(fd, basename(canonical ?: t), flags);
}
int path_is_read_only_fs(const char *path) {