Re: [PATCH] block: nbd: Fix dirty bitmap context name

[Nir Soffer]

On Thu, Dec 19, 2019 at 5:55 PM Nir Soffer <address@hidden> wrote:
>
> On Thu, Dec 19, 2019 at 5:17 PM Vladimir Sementsov-Ogievskiy
> <address@hidden> wrote:
...
> > Note also, that client may use NBD_OPT_LIST_META_CONTEXT with query
> > "qemu:dirty-bitmap:", to get list of all exported bitmaps.
>
> This is another option, I did not try to use this yet. We can use the single
> exported bitmap and fail if we get more than one. This is probably better
> than changing the entire stack to support bitmap name.

I went with this option for now, getting the single bitmap published by qemu.
https://gerrit.ovirt.org/c/105861/2/common/ovirt_imageio_common/nbd.py

This way I can work with current libvirt, and I don't care about the name of
the bitmap.

Practically this will break if libvirt will configure another dirty
bitmap, but it is fine.
Using API that promise list with unknown bitmap name is the same as API
returning only one bitmap. Libvirt cannot change it now since it will break
existing users :-)