[Qemu-devel] Re: [PATCH 2/3] Introduce do_snapshot_blkdev() and monitor command to handle it.

[Jes Sorensen <Jes.Sorensen@redhat.com>]

On 12/15/10 17:55, Kevin Wolf wrote:
>> +int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
>> +{
>> +    const char *device = qdict_get_str(qdict, "device");
>> +    const char *filename = qdict_get_try_str(qdict, "snapshot_file");
>> +    const char *format = qdict_get_try_str(qdict, "format");
>> +    const char format_qcow2[] = "qcow2";
>> +    BlockDriverState *bs;
>> +    BlockDriver *drv, *proto_drv;
>> +    int ret = 0;
>> +    int flags;
>> +
>> +    bs = bdrv_find(device);
>> +    if (!bs) {
>> +        qerror_report(QERR_DEVICE_NOT_FOUND, device);
>> +        ret = -1;
>> +        goto out;
>> +    }
>> +
>> +    if (!format) {
>> +        format = format_qcow2;
>> +    }
>> +
>> +    drv = bdrv_find_format(format);
>> +    if (!drv) {
>> +        qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
>> +        ret = -1;
>> +        goto out;
>> +    }
>> +
>> +    proto_drv = bdrv_find_protocol(filename);
>> +    if (!proto_drv) {
>> +        qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
>> +        ret = -1;
>> +        goto out;
>> +    }
>> +
>> +    ret = bdrv_img_create(filename, format, bs->filename,
>> +                          bs->drv->format_name, NULL, -1, bs->open_flags);
>> +    if (ret) {
>> +        goto out;
>> +    }
>> +
>> +    qemu_aio_flush();
>> +    bdrv_flush(bs);
>> +
>> +    flags = bs->open_flags;
>> +    bdrv_close(bs);
>> +    ret = bdrv_open(bs, filename, flags, drv);
>> +    /*
>> +     * If reopening the image file we just created fails, we really
>> +     * are in trouble :(
>> +     */
>> +    assert(ret == 0);
>> +out:
>> +    if (ret) {
>> +        ret = 1;
> 
> I seem to remember that errors are always -1 for monitor commands.

I mapped it after something else, but admitted I cannot remember where -
can someone clarify?

Cheers,
Jes