On Tue, Nov 19, 2013 at 06:07:29PM +0100, Paolo Bonzini wrote:
> @@ -2761,14 +2761,19 @@ static int coroutine_fn
> bdrv_co_do_write_zeroes(BlockDriverState *bs,
> while (nb_sectors > 0 && !ret) {
> int num = nb_sectors;
>
> - /* align request */
> - if (bs->bl.write_zeroes_alignment &&
> - num >= bs->bl.write_zeroes_alignment &&
> - sector_num % bs->bl.write_zeroes_alignment) {
> - if (num > bs->bl.write_zeroes_alignment) {
> + /* Align request. Block drivers can expect the "bulk" of the request
> + * to be aligned.
> + */
> + if (bs->bl.write_zeroes_alignment
> + && num > bs->bl.write_zeroes_alignment) {
Here '>' is used...
> + if (sector_num % bs->bl.write_zeroes_alignment != 0) {
> + /* Make a small request up to the first aligned sector. */
> num = bs->bl.write_zeroes_alignment;
> + num -= sector_num % bs->bl.write_zeroes_alignment;
> + } else if (num >= bs->bl.write_zeroes_alignment) {
...but here '>=' is used.
The == case here cannot happen. Did you mean '>=' in both places?
