Re: [Qemu-devel] [PATCH] block: use drained section around bdrv_snapshot_delete

[Kevin Wolf <kwolf@redhat.com>]

[ Cc: qemu-block ]

Am 17.12.2015 um 02:55 hat Fam Zheng geschrieben:
> On Wed, 12/16 19:33, Paolo Bonzini wrote:
> > Do not use bdrv_drain, since by itself it does not guarantee
> > anything.
> > 
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Thanks, applied to the block branch.

Kevin

> >  block/snapshot.c | 23 ++++++++++++++---------
> >  1 file changed, 14 insertions(+), 9 deletions(-)
> > 
> > diff --git a/block/snapshot.c b/block/snapshot.c
> > index 6e9fa8d..2d86b88 100644
> > --- a/block/snapshot.c
> > +++ b/block/snapshot.c
> > @@ -229,6 +229,8 @@ int bdrv_snapshot_delete(BlockDriverState *bs,
> >                           Error **errp)
> >  {
> >      BlockDriver *drv = bs->drv;
> > +    int ret;
> > +
> >      if (!drv) {
> >          error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
> >          return -ENOMEDIUM;
> > @@ -239,18 +241,21 @@ int bdrv_snapshot_delete(BlockDriverState *bs,
> >      }
> >  
> >      /* drain all pending i/o before deleting snapshot */
> > -    bdrv_drain(bs);
> > +    bdrv_drained_begin(bs);
> >  
> >      if (drv->bdrv_snapshot_delete) {
> > -        return drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp);
> > +        ret = drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp);
> > +    } else if (bs->file) {
> > +        ret = bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp);
> > +    } else {
> > +        error_setg(errp, "Block format '%s' used by device '%s' "
> > +                   "does not support internal snapshot deletion",
> > +                   drv->format_name, bdrv_get_device_name(bs));
> > +        ret = -ENOTSUP;
> >      }
> > -    if (bs->file) {
> > -        return bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp);
> > -    }
> > -    error_setg(errp, "Block format '%s' used by device '%s' "
> > -               "does not support internal snapshot deletion",
> > -               drv->format_name, bdrv_get_device_name(bs));
> > -    return -ENOTSUP;
> > +
> > +    bdrv_drained_end(bs);
> > +    return ret;
> >  }
> >  
> >  int bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
> > -- 
> > 2.5.0
> > 
> > 
> 
> Reviewed-by: Fam Zheng <famz@redhat.com>
>