+ /**
+ * Try to get the real path to the device, in case it is a
+ * symbolic link for instance
+ */
+ if (realpath(usource, real_path) != NULL) {
+ usource = real_path;
+
+ ptr = strrchr(real_path, '/');
+ if (ptr && strncmp(ptr, "/dm-", 4) == 0 && isdigit(*(ptr + 4))) {
+ snprintf(path, sizeof(path), "/sys/block/%s/dm/name", ptr+1);
+ if ((f = fopen(path, "r"))) {
+ /* read "<name>\n" from sysfs */
+ if (fgets(name, sizeof(name), f) && (sz = strlen(name)) > 1) {
+ name[sz - 1] = '\0';
+ snprintf(real_path, sizeof(real_path), "/dev/mapper/%s", name);
+ }
+ fclose(f);
+ }
+ }
+ }
+