Re: FS: hardlinks on directories

Adam Sampson
2003-08-04T16:11:55Z

Stephan von Krawczynski <skraw@ithnet.com> writes:

> All that can handle symlinks already have the same problem
> nowadays. Where is the difference?

lstat() will tell you if a file is a symlink; if you only walk into
directories, then you're guaranteed not to get into a loop. If you've
got two hardlinks to a directory, how do you make that available in
stat() output, and how does a tree-walking program know which to walk
into? You could do the rsync trick of keeping track of every
device-inode pair you've seen to detect hardlinks, but that's horribly
non-space-efficient on large directories -- particularly bad for
backups.

I could imagine this functionality maybe being useful for system
administrators, but with normal Unixish userspace, it doesn't strike
me as a good idea to give users the ability to create hardlinks to
directories.

--
Adam Sampson <azz@us-lot.org> <http://offog.org/>