Re: [Qemu-devel] [PATCH v17 7/8] Implement new driver for block replication

[Changlong Xie <xiecl.fnst@cn.fujitsu.com>]

On 04/13/2016 09:02 PM, Stefan Hajnoczi wrote:
> On Mon, Apr 11, 2016 at 04:22:58PM +0800, Changlong Xie wrote:
>> +static coroutine_fn int replication_co_writev(BlockDriverState *bs,
>> +                                              int64_t sector_num,
>> +                                              int remaining_sectors,
>> +                                              QEMUIOVector *qiov)
>> +{
>> +    BDRVReplicationState *s = bs->opaque;
>> +    QEMUIOVector hd_qiov;
>> +    uint64_t bytes_done = 0;
>> +    BdrvChild *top = bs->file;
>> +    BdrvChild *base = s->secondary_disk;
>> +    BlockDriverState *target;
>> +    int ret, n;
>> +
>> +    ret = replication_get_io_status(s);
>> +    if (ret < 0) {
>> +        return ret;
>> +    }
>> +
>> +    if (ret == 0) {
>> +        ret = bdrv_co_writev(top->bs, sector_num,
>> +                             remaining_sectors, qiov);
>> +        return replication_return_value(s, ret);
>> +    }
>> +
>> +    /*
>> +     * Failover failed, only write to active disk if the sectors
>> +     * have already been allocated in active disk/hidden disk.
>> +     */
>> +    qemu_iovec_init(&hd_qiov, qiov->niov);
>> +    while (remaining_sectors > 0) {
>> +        ret = bdrv_is_allocated_above(top->bs, base->bs, sector_num,
>> +                                      remaining_sectors, &n);
>> +        if (ret < 0) {
>> +            return ret;
>> +        }
>> +
>> +        qemu_iovec_reset(&hd_qiov);
>> +        qemu_iovec_concat(&hd_qiov, qiov, bytes_done, n * BDRV_SECTOR_SIZE);
>> +
>> +        target = ret ? (top->bs) : (base->bs);
>> +        ret = bdrv_co_writev(target, sector_num, n, &hd_qiov);
>> +        if (ret < 0) {
>> +            return ret;
>> +        }
>> +
>> +        remaining_sectors -= n;
>> +        sector_num += n;
>> +        bytes_done += n * BDRV_SECTOR_SIZE;
>> +    }
>> +
>> +    return 0;
>
> qemu_iovec_destroy(&hd_qiov) is missing (also in error cases).

Yes, it's memory leak here.

Thanks
	-Xie

>