While dealing with some disk corruption, I managed to create some
directories which appeared, to ls, to be fine, but would fail
the empty_dir test in fs/ext2/namei.c:553. To be precise, line 572,
where it does "strcmp(".", de->name). It seems that de->name[1] was
not '\0'. Of course, de->name_len was 1, so ls produced fine
results, but the test failed.
e2fsck 1.02 (I know, I know) does not detect or correct this problem,
but ext2fs doesn't like it. I don't know which of the two is considered
to have the bug, but one of them does.
The bug is definitely in the kernel, since names in directories are not
null-terminated. (If a directory name is a multiple of 4
bytes long, there's not even any room for the null termination
character.)
At the same time, because the 2.0 kernel is doing this, I will be fixing
e2fsprogs to make sure the directory names are null terminated.
Thanks for reporting the bug!
- Ted