Re: [Qemu-devel] [PATCH 00/16] block: Get rid of bdrv_swap()

[Alberto Garcia]

On Thu 17 Sep 2015 03:48:04 PM CEST, Kevin Wolf <address@hidden> wrote:

> bdrv_swap() has always been an ugly hack that we would rather have
> avoided.  When it was introduced, we simply didn't have the
> infrastructure to update pointers instead of transplanting the
> contents of BDS object, so we grudgingly added bdrv_swap() as a quick
> solution.  Meanwhile, most of the infrastructure exists and this
> series implements the final step necessary to implement the required
> functionality in a less adventurous way.

I didn't have the chance to debug this further, but with this series if
I make a snapshot of a device with ongoing I/O I get lots of errors in
the guest:

Buffer I/O error on device vda1, logical block 3801549
end_request: I/O error, dev vda, sector 7604516
[...]

The drive is attached with -drive if=virtio,file=foo.qcow2,node-name=bar

Berto