Re: [linux-pm] Re: Hibernation considerations

Rafael J. Wysocki
2007-07-21T19:12:22Z

On Saturday, 21 July 2007 20:12, Miklos Szeredi wrote:
> > It seems that you could still potentially get a failure to freeze if one
> > FUSE process depends on another, and the one that is frozen second just
> > happens to be waiting on the one that is frozen first when it is frozen.
> > I admit that this situation is unlikely, and perhaps acceptable.
>
> It isn't all that unlikely. There's sshfs for example, that depends
> on a separate ssh process for transport.
>
> Oh, there are also userspace network transports, like tun/tap,
> nfqueue, etc. They could block any network filesystem (not just fuse)
> if frozen first, making the freezer fail.
>
> Hmm, wonder why this isn't affecting people with VPNs? Probably
> network mounts over VPN are rare, and ever rarer to have fs activity
> on them during suspend.
>
> Anyway, I think it's long overdue to stop thinking about how to "fix"
> fuse, and concentrate on fixing the underlying problem instead ;)

To conclude this branch of the thread, I have a patch in the works that may
help a bit with unfreezable FUSE filesystems and it only affects the freezer.
I'll post it when 2.6.23-rc1 is out, because it's on top of some other patches
that need to go first.

Greetings,
Rafael

--
"Premature optimization is the root of all evil." - Donald Knuth