There's an odd bug somewhere with ext4..

but before I begin, first let me be clear.

This bug exists and is quite impossible to replicate.

The bug relates to having "two" entries with the same name in a folder. (I've seen something like this before with ext3 to which I filed but this was actually quite some time ago and wouldn't recall the details.. It had a cloned pathname, whether it was two files or what I don't recall.. but this seemed all refreshed to me in a very similar situation today with ext4 involving ln

the following was done which eventually led to creating two entries with the same name

cd /usr/src
tar was used to extract an xz tarball

The ln command was then issued as follows (there were 2 or 3 prior ln commands issued before this. whether this helped set conditions or not that I don't know)

ln -s linux-3.17~rc5 linux

ls -la ->  (no bash ls aliases)

lrwxrwxrwx  1 root  root         5 Oct 19 12:20 linux_3.17~rc5 -> linux
drwxr-xr-x 22 wlake wlake     4096 Oct 19 12:18 linux-3.17~rc5

coreutils is 8.23-2,
libc6:amd64 is 2.19-11  

I did not delete the outcome of the problem, so if anyone wants to take a shot at it I can try commands I otherwise didn't.

Now I won't reply to questions like, did I check my "bash aliases", sane filesystem checks, hardware failure(dmesg show anything?), all turn out positive.

So what went wrong? It's certainly not distro, hardware, or anything "special", it's really got to be either kernel/ext4 or somewhere along the lines with it concerning libc.. 

fwiw, "stat <name>" does show the inode for the "link" and in order for me to get a stat on the directory, "stat *" is used.  The good news is the inodes are different telling me there's a sane record for it.. 

 .. but afaict this is a bug in the ext4 driver and it would be great if this can be looked into

thanks