Re: [PATCH 3/3] Add timeout feature

Dave Chinner
2008-07-08T23:10:43Z

On Mon, Jul 07, 2008 at 01:07:31PM +0200, Pavel Machek wrote:
> Hi!
>
> > I still disagree with this whole patch. There is not reason to let
> > the freeze request timeout - an auto-unfreezing will only confuse the
> > hell out of the caller. The only reason where the current XFS freeze
> > call can hang and this would be theoretically useful is when the
>
> What happens when someone dirties so much data that vm swaps out
> whatever process that frozen the filesystem?

a) you can't dirty a frozen filesystem - by definition a frozen
filesystem is a *clean filesystem* and *cannot be dirtied*.
b) Swap doesn't write through the filesystem
c) you can still read from a frozen filesystem to page your
executableѕ in.
d) if dirtying another unfrozen filesystem swaps out your
application so it can't run, then there's a major VM bug.
Regardless, until the app completes it is relying on the
filesystem being frozen, so it better remain frozen....

> I though that was why the timeout was there...

Not that I know of.

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com