Re: USB: on suspend to ram/disk all usb devices are replugged

Nigel Cunningham
2007-04-06T22:23:51Z

Hi.

On Mon, 2007-04-02 at 21:36 +0200, Pavel Machek wrote:
> Hi!
>
> > > But you're still likely to run into trouble if you unplug a storage
> > > device, move it to another system and write on it, then plug it back into
> > > the original system. The PLVM would somehow have to recognize that the
> > > data had been changed. I don't know a foolproof way of doing that.
> > >
> >
> > Mark the filesystem as in-use with a one-time UUID in the superblock at
> > mount time. If one moved the drive to another system it would require
> > an fsck to clear the UUID before the other system could use it; then
> > the original machine would refuse to use the drive when the UUID didn't
> > match on resume.
>
> You still need fs-specific code, I'm afraid... plus userland tool
> to reset signatures back.

You don't need userland to reset the signatures. More kernel code, sure.
But it doesn't _need_ to be userland.

Regards,

Nigel