+
+bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) {
+ bool changed = false;
+ const char* const* i;
+
+ assert(timestamp);
+
+ if (paths == NULL)
+ return false;
+
+ STRV_FOREACH(i, paths) {
+ struct stat stats;
+ usec_t u;
+
+ if (stat(*i, &stats) < 0)
+ continue;
+
+ u = timespec_load(&stats.st_mtim);
+
+ /* first check */
+ if (*timestamp >= u)
+ continue;
+
+ log_debug("timestamp of '%s' changed", *i);
+
+ /* update timestamp */
+ if (update) {
+ *timestamp = u;
+ changed = true;
+ } else
+ return true;
+ }
+
+ return changed;
+}
+
+int fsck_exists(const char *fstype) {
+ _cleanup_free_ char *p = NULL, *d = NULL;
+ const char *checker;
+ int r;
+
+ checker = strjoina("fsck.", fstype);
+
+ r = find_binary(checker, true, &p);
+ if (r < 0)
+ return r;
+
+ /* An fsck that is linked to /bin/true is a non-existent
+ * fsck */
+
+ r = readlink_malloc(p, &d);
+ if (r >= 0 &&
+ (path_equal(d, "/bin/true") ||
+ path_equal(d, "/usr/bin/true") ||
+ path_equal(d, "/dev/null")))
+ return -ENOENT;
+
+ return 0;
+}
+
+char *prefix_root(const char *root, const char *path) {
+ char *n, *p;
+ size_t l;
+
+ /* If root is passed, prefixes path with it. Otherwise returns
+ * it as is. */
+
+ assert(path);
+
+ /* First, drop duplicate prefixing slashes from the path */
+ while (path[0] == '/' && path[1] == '/')
+ path++;
+
+ if (isempty(root) || path_equal(root, "/"))
+ return strdup(path);
+
+ l = strlen(root) + 1 + strlen(path) + 1;
+
+ n = new(char, l);
+ if (!n)
+ return NULL;
+
+ p = stpcpy(n, root);
+
+ while (p > n && p[-1] == '/')
+ p--;
+
+ if (path[0] != '/')
+ *(p++) = '/';
+
+ strcpy(p, path);
+ return n;
+}