Christoph Hellwig wrote:

 o files as directories
   - O_DIRECTORY opens succeed on all files on reiser4.  Besides breaking
     .htaccess handling in apache and glibc compilation this also renders
     this flag entirely useless and opens up the races it tries to
     prevent against cmpletely useless

Ouch.

I would definitely classify this as a security hole, since userland 
definitely uses O_DIRECTORY to avoid races.

	Jeff