Am 15.04.2014 um 15:28 hat Jeff Cody geschrieben: > Some block drivers have multiple BlockDriver instances with identical > format_name fields (e.g. gluster, nbd). In those cases, the > protocol_name is usually the more unique identifier (e.g. gluster+tcp). > > Both qemu-img and qemu will use bdrv_iterate_format() to list the > supported formats when a help option is invoked. When just the > format_name is used, redundant listings of formats occur (e.g., > "Supported formats: ... gluster gluster gluster gluster ... "). > > If we prefer the protocol_name over the format_name (when the > protocol name exists), then that provides a more informative > help message: > > "Supported formats: ... gluster gluster+tcp gluster+unix > gluster+rdma ... " > > Signed-off-by: Jeff Cody <jc...@redhat.com>
On the other hand, it means that you can't take any driver name from here as use it as -drive driver=... value any more. The good thing is that most drivers stay in the list, so if anyone was checking the list to query whether a given driver can be used, it would still work after this patch. gluster/nbd/sheepdog all have a BlockDriver with a plain gluster/nbd/sheepdog protocol_name. The one driver that may cause trouble is vvfat, which would be changed to fat in the output. Not sure if we care. Let's wait a bit for more comments on this change before we apply it. I'm not against it per se, but it's not obviously good either. Kevin
