Re: [Qemu-devel] [PATCH v4] Stop VM on ENOSPC error.

[Ian Jackson]

Gleb Natapov writes ("Re: [Qemu-devel] [PATCH v4] Stop VM on ENOSPC error."):
> On Tue, Jan 20, 2009 at 02:01:21PM +0000, Ian Jackson wrote:
> > Are we sure that the ide layer is the right place to do this ?
> > Perhaps it would be better to do it in block.c.  That way it would
> > seamlessly affect scsi too and other kinds of weird block devices
> > on other platforms.
...
> I thought about it and I see only two places where this can be done. In
> ide/scsi/pv-block layer or in individual block implementations
> (qcow,raw, etc). The problem doing it in generic block.c layer is that
> how should it handle errors during blocking writes? It can't return
> error to the caller and it can't wait inside the function. Doing this in
> the ide layer allows for error handling flexibility that this patch
> provides.

Hrm, yes, I see.

We could abolish the blocking calls.  Or rather, we could say that a
device emulation which wants the stop-on-enospc behaviour must never
make the blocking calls.

That way there would still have to be some additional complexity in
ide.c and scsi.c but only the minimum necessary.

Ian.