Hi,

This is a request for comments on GoboHide, a patch developed as part
of the GoboLinux project. Its purpose is to hide directories and
symlinks from the filesystem, while still allowing them to be
reachable and executed. The big motif came from the fact that Gobo
doesn't use the traditional *NIX hierarchy of directories, but still
needed to maintain backwards compatibility with it.

The implementation itself is pretty simple: it has a private linked
list of inodes registered by the super-user to be hidden from
readdir(), which is done by skipping their copy on filldir(). This
list can be manipulated in order to add, remove and list its contents,
and these operations are performed through an ioctl() interface.

Until recently, the support on filesystems was done by introducing a
few hooks at their readdir() implementation, and after a cleanup this
check was merged into the VFS, allowing a less intrusive
implementation.

The function names chosen are probably not the best ones, as we were
still keeping the patch tied to the Gobo kernel, but of course we're
open to new suggestions. Also, while we pretty much understand that
this feature might not fit a place mainline due to its nature of
hiding things, we'd really like to hear from you to make it a better
patch.

The gobohide tool can be used in order to test it:
http://gobolinux.org/download/gobohide/GoboHide-0.09.tar.bz2


Thanks in advance for taking your time,

Lucas && Felipe