Re: FS: hardlinks on directories

viro
2003-08-05T16:46:51Z

Egads... OK, here comes:
a) if you have real loops in directory graph (directory being
its own descendent), determining whether rename() will make it disconnected
becomes hell; it's completely infeasible.
b) if you allow multiple paths from root, preventing loops creation
upon rename() also becomes hell.

Forget about VFS, on-disk structures, etc. - just think in terms
of oriented graphs and operations on them; that's the price you'd have
to pay with any implementation and it's *big*.