+static inline bool lu_name_is_temp_file(const char *name, int namelen,
+ bool dot_prefix, int suffixlen)
+{
+ int lower = 0;
+ int upper = 0;
+ int digit = 0;
+ int len = suffixlen;
+
+ if (dot_prefix && name[0] != '.')
+ return false;
+
+ if (namelen < dot_prefix + suffixlen + 2 ||
+ name[namelen - suffixlen - 1] != '.')
+ return false;
+
+ while (len) {
+ lower += islower(name[namelen - len]);
+ upper += isupper(name[namelen - len]);
+ digit += isdigit(name[namelen - len]);
+ len--;
+ }
+ /* mktemp() filename suffixes will have a mix of upper- and lower-case
+ * letters and/or numbers, not all numbers, or all upper or lower-case.
+ * About 0.07% of randomly-generated names will slip through,
+ * but this avoids 99.93% of cross-MDT renames for those files.
+ */
+ if ((digit >= suffixlen - 1 && !isdigit(name[namelen - suffixlen])) ||
+ upper == suffixlen || lower == suffixlen)
+ return false;
+
+ return true;
+}
+
+static inline bool lu_name_is_backup_file(const char *name, int namelen,
+ int *suffixlen)
+{
+ if (namelen > 1 &&
+ name[namelen - 2] != '.' && name[namelen - 1] == '~') {
+ if (suffixlen)
+ *suffixlen = 1;
+ return true;
+ }
+
+ if (namelen > 4 && name[namelen - 4] == '.' &&
+ (!strncasecmp(name + namelen - 3, "bak", 3) ||
+ !strncasecmp(name + namelen - 3, "sav", 3))) {
+ if (suffixlen)
+ *suffixlen = 4;
+ return true;
+ }
+
+ if (namelen > 5 && name[namelen - 5] == '.' &&
+ !strncasecmp(name + namelen - 4, "orig", 4)) {
+ if (suffixlen)
+ *suffixlen = 5;
+ return true;
+ }
+
+ return false;
+}
+