On 12/11/20 12:39 PM, Vladimir Sementsov-Ogievskiy wrote:
> Prepare to the following patch when bdrv_pad_request() will be able to
s/Prepare to/Prepare for/
> fail. Update the comments.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
> ---
> block/io.c | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> - if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) {
> + if (padded) {
> + /*
> + * Request was unaligned to request_alignment and therefore padded.
> + * We are going to do read-modify-write. User is not prepared to
> widened
> + * request intersections with other requests, so we serialize the
> + * request.
We are going to do read-modify-write, and must serialize the request to
prevent interactions of the widened region with other transactions.
Reviewed-by: Eric Blake <ebl...@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
