On Tue, 06/05 13:22, Stefan Hajnoczi wrote:
> On Tue, Jun 05, 2018 at 04:07:10PM +0800, Fam Zheng wrote:
> > The implementation is similar to the 'qemu-img convert'. In the
> > beginning of the job, offloaded copy is attempted. If it fails, further
> > I/O will go through the existing bounce buffer code path.
> >
> > Signed-off-by: Fam Zheng <f...@redhat.com>
>
> Nice, this has become much more readable.
>
> > +/* Copy range to target and return the bytes copied. If error occured,
> > return a
> > + * negative error number. */
> > +static int backup_cow_with_offload(BackupBlockJob *job,
>
> coroutine_fn
Will try to remember this better. :)
>
> > + int64_t start,
> > + int64_t end,
> > + bool is_write_notifier)
> > +{
> > + int ret;
> > + int nr_clusters;
> > + BlockBackend *blk = job->common.blk;
> > + int nbytes;
> > +
> > + assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size));
> > + nbytes = MIN(job->copy_range_size, end - start);
> > + nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size);
> > + hbitmap_reset(job->copy_bitmap, start / job->cluster_size,
> > + nr_clusters);
> > + ret = blk_co_copy_range(blk, start, job->target, start, nbytes,
> > + is_write_notifier ? BDRV_REQ_NO_SERIALISING :
> > 0);
> > + if (ret < 0) {
> > + job->use_copy_range = false;
>
> This is not necessary since backup_do_cow() also sets it to false. This
> function doesn't need to know about job->use_copy_range.
Yes, will fix.
Fam
