Re: [Qemu-block] [PATCH] qcow2: Check the L1 table parameters from all internal snapshots

[Kevin Wolf]

Am 09.02.2018 um 16:11 hat Alberto Garcia geschrieben:
> On Fri 09 Feb 2018 04:03:31 PM CET, Kevin Wolf wrote:
> > How about we move the check to bdrv_open() as proposed, but make it
> > conditional so that it's skipped with BDRV_O_CHECK and then add a way
> > to fix the situation with qemu-img check -r?
> 
> That was one of the alternatives that I was considering, but you can't
> really fix a broken L1 table pointer, can you?
> 
> What you can probably do is allow deleting the snapshot, but 'qemu-img
> snapshot' doesn't use BDRV_O_CHECK. We'd have to change that, look for a
> new flag or think of some other alternative.
> 
> Or, perhaps more easily, make 'qemu-img check' delete all corrupted
> snapshots.

Yes, the latter is what I was thinking of. Of course, that would require
a new -r option because it would be a destructive operation.

Maybe it would even be worth making such destructive operations
interactive so that the user has to explicitly confirm each snapshot
that we delete. Not sure though.

Kevin