-/* Return true if it is easy to determine the file system type of the
- directory on which DIR_FD is open, and sorting dirents on inode numbers
- is known to improve traversal performance with that type of file system. */
+/* Linux-specific constants from coreutils' src/fs.h */
+# define S_MAGIC_TMPFS 0x1021994
+# define S_MAGIC_NFS 0x6969
+
+/* Return false if it is easy to determine the file system type of
+ the directory on which DIR_FD is open, and sorting dirents on
+ inode numbers is known not to improve traversal performance with
+ that type of file system. Otherwise, return true. */