Re: [PATCH] xen-blkback: Switch to closed state after releasing the backing device

From: Valentin Vidic
Date: Wed Sep 05 2018 - 12:28:09 EST


On Wed, Sep 05, 2018 at 01:35:15PM +0200, Valentin Vidic wrote:
> > AFAICT, this will cause the backend to never switch to 'Closed' state
> > until the toolstack sets online to 0, which is not good IMO.
> >
> > If for example a frontend decides to close a device, the backend will
> > stay in state 'Closing' until the toolstack actually removes the disk
> > by setting online to 0.
> >
> > This will prevent resetting blk connections, as blkback will refuse to
> > switch to state XenbusStateInitWait unless it's at XenbusStateClosed
> > (see the XenbusStateInitialising case in frontend_changed), which will
> > never be reached with your patch.

Would it be possible to call xen_vbd_free before the state change?

case XenbusStateClosed:
xen_blkif_disconnect(be->blkif);
xen_vbd_free(&be->blkif->vbd);
xenbus_switch_state(dev, XenbusStateClosed);

--
Valentin