On Thu, May 30, 2013 at 5:37 AM, Fam Zheng <f...@redhat.com> wrote:
> On Mon, 04/29 09:42, Stefan Hajnoczi wrote:
>> +
>> +static void coroutine_fn backup_run(void *opaque)
>> +{
>> + BackupBlockJob *job = opaque;
>> + BlockDriverState *bs = job->common.bs;
>> + assert(bs);
>> +
>> + int64_t start, end;
>> +
>> + start = 0;
>> + end = DIV_ROUND_UP(bdrv_getlength(bs) / BDRV_SECTOR_SIZE,
>> + BACKUP_BLOCKS_PER_CLUSTER);
>> +
>> + job->bitmap = hbitmap_alloc(end, 0);
>> +
>> + DPRINTF("backup_run start %s %" PRId64 " %" PRId64 "\n",
>> + bdrv_get_device_name(bs), start, end);
>> +
>> + int ret = 0;
>> +
>> + for (; start < end; start++) {
>> + if (block_job_is_cancelled(&job->common)) {
>> + ret = -1;
>> + break;
>> + }
>> +
>> + /* we need to yield so that qemu_aio_flush() returns.
>> + * (without, VM does not reboot)
>> + */
>> + if (job->common.speed) {
>> + uint64_t delay_ns = ratelimit_calculate_delay(
>> + &job->limit, job->sectors_read);
>> + job->sectors_read = 0;
>> + block_job_sleep_ns(&job->common, rt_clock, delay_ns);
>> + } else {
>> + block_job_sleep_ns(&job->common, rt_clock, 0);
>> + }
>> +
>> + if (block_job_is_cancelled(&job->common)) {
>> + ret = -1;
>> + break;
>> + }
>> +
>> + if (hbitmap_get(job->bitmap, start)) {
>> + continue; /* already copied */
>> + }
>> +
>> + DPRINTF("backup_run loop C%" PRId64 "\n", start);
>> +
>> + /**
>> + * This triggers a cluster copy
>> + * Note: avoid direct call to brdv_co_backup_cow, because
>> + * this does not call tracked_request_begin()
>> + */
>> + ret = bdrv_co_backup(bs, start*BACKUP_BLOCKS_PER_CLUSTER, 1);
>> + if (ret < 0) {
>> + break;
>> + }
>> + /* Publish progress */
>> + job->common.offset += BACKUP_CLUSTER_SIZE;
>> + }
>> +
>> + /* wait until pending backup_do_cow()calls have completed */
>> + qemu_co_rwlock_wrlock(&job->rwlock);
>> + qemu_co_rwlock_unlock(&job->rwlock);
>> +
>> + hbitmap_free(job->bitmap);
>> +
>> + bdrv_delete(job->target);
>> +
>> + DPRINTF("backup_run complete %d\n", ret);
>> + block_job_completed(&job->common, ret);
>> +}
>
> What will ret value be when the source block is not aligned to cluster
> size?
Good catch, will fix.
Stefan
