$ du -s .
du: fts_read: No such file or directory

This is a rather surprising outcome.

This is happening on an MS-DOS filesystem.  (Kernel is dated August 6.)

"du -s *" works fine; there is no subdirectory that causes trouble.

ktrace says:

  1226 du       RET   getdents 0
  1226 du       CALL  lseek(4,0,0,0,0)
  1226 du       RET   lseek 0
  1226 du       CALL  close(4)
  1226 du       RET   close 0
  1226 du       CALL  open(0xbdbd025b,0,0x804b000)
  1226 du       NAMI  ".."
  1226 du       RET   open -1 errno 2 No such file or directory
  1226 du       CALL  write(2,0xbfbfde60,4)
  1226 du       GIO   fd 2 wrote 4 bytes
       "du: "
  1226 du       RET   write 4
  1226 du       CALL  write(2,0xbfbfde80,8)
  1226 du       GIO   fd 2 wrote 8 bytes
       "fts_read"
  1226 du       RET   write 8
  1226 du       CALL  write(2,0xbdbcc9d2,2)
  1226 du       GIO   fd 2 wrote 2 bytes
       ": "
  1226 du       RET   write 2

I have no clue how that can happen.  Needless to say, there is indeed a ".."
entry.

-s