On Wed, Nov 23, 2016 at 10:39:12AM +0000, Olaf Hering wrote:
> The guest sends discard requests as u64 sector/count pairs, but the
> block layer operates internally with s64/s32 pairs. The conversion
> leads to IO errors in the guest, the discard request is not processed.
>
> domU.cfg:
> 'vdev=xvda, format=qcow2, backendtype=qdisk, target=/x.qcow2'
> domU:
> mkfs.ext4 -F /dev/xvda
> Discarding device blocks: failed - Input/output error
>
> Fix this by splitting the request into chunks of BDRV_REQUEST_MAX_SECTORS.
> Add input range checking to avoid overflow.
>
> Fixes f313520 ("xen_disk: add discard support")
>
> Signed-off-by: Olaf Hering <[email protected]>
Acked-by: Anthony PERARD <[email protected]>
--
Anthony PERARD
