Re: Tar extract behaviour changed

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Wed, Oct 30, 2019 at 12:08:09PM +1100, matthew green wrote:
> nullfs is terrible.  i've always known it has the potential
> to double-cache some file when accessed on both sides.. but
> i recently had a problem where nullfs mounted system was
> stopping ffs from freeing deleted files.  i couldn't figure
> out where all my data was hiding.  eventually i unmounted
> the nullfs (which took a couple of minutes) and suddenly i
> had 80% of my disk back as unused.

It can't double-cache, since the data handling is always pushed through.
There are potentially bugs in the name cache invalidation, e.g. when it
holds a reference to the upper layer, it doesn't kill the reference as
usual when the vnode is unlinked in the lower layer. That said, none of
those really matter for this case.

Joerg