"readdir" pseudo file security

Hello

Reiser4 with pseudo files enabled has a security issue. You can read contents of any directory if you have "+x" access to it, for example if "a" is a directory:

cat a/metas/readdir

will list directory contents even if you don't have read permissions to "a". This patch adds setup_mode() method to reiser4 pseudo_plugin structure which allows for more granular setting of permissions depending on given "host" object permissions. Patch is available at:

http://kem.p.lodz.pl/~peter/reiser4/reiser4_secure_readdir.patch

Regards

Piotr Neuman

ps. thanks go (as usually ;) to Nikita Danilov...