Re: [Qemu-devel] [PATCH V2 4/4] block: Optionally block drivers to optionally reopen images after snapshot creation.

[Benoît Canet]

Le Tuesday 29 Jan 2013 à 14:30:39 (+0100), Kevin Wolf a écrit :
> Am 29.01.2013 14:09, schrieb Benoît Canet:
> > Le Tuesday 29 Jan 2013 à 13:22:12 (+0100), Kevin Wolf a écrit :
> >> Am 28.01.2013 18:04, schrieb Benoît Canet:
> >>> Protocols like quorum will be able to queue multiple reopens.
> >>>
> >>> Signed-off-by: Benoit Canet <address@hidden>
> >>
> >> -EPARSE for the subject line.
> >>
> >> Also, what's the difference between this and a normal reopen?
> > 
> > With this patch protocols like quorum can do something like :
> > 
> > +static int quorum_snapshot_reopen(BlockDriverState *bs, int bdrv_flags,
> > +                                  Error **errp)
> > +{
> > +    BDRVQuorumState *s = bs->file->opaque;
> > +    int i, ret = -1;
> > +    Error *local_err = NULL;
> > +    BlockReopenQueue *queue = NULL;
> > +
> > +    for (i = 0; i < s->total; i++) {
> > +        queue = bdrv_reopen_queue(queue, s->bs[i], bdrv_flags);
> > +    }
> > +
> > +    ret = bdrv_reopen_multiple(queue, &local_err);
> > +    if (local_err != NULL) {
> > +        error_propagate(errp, local_err);
> > +    }
> > +    return ret;
> > +}
> > 
> > It allows to handle the reopening of multiple bs without duplicating a part 
> > of
> > bdrv_reopen_multiple's code.
> 
> Have a look at VMDK to see how it's supposed to be done.

ok,
Thanks

> 
> Kevin
>