Re: [Qemu-devel] [PATCH 0/5] NBD reconnect: preliminary refactoring

[Vladimir Sementsov-Ogievskiy]

17.05.2018 16:48, Eric Blake wrote:
> On 05/17/2018 04:54 AM, Vladimir Sementsov-Ogievskiy wrote:
> > What about patches 1-4?
>
> Still on my list to review (I'm first trying to post an updated 
> proposal on the libvirt list for managing incremental backups); but on 
> first glance, the idea of being able to reconnect instead of 
> permanently switching to EIO failures on first error seems reasonable.

It relates to the same case as CMD_CACHE. We need to start guest over 
new empty disk with backing = r-o nbd server (backup). Guest is already 
running, disconnect will lead to data loss (not very significant, we can 
retry, starting from the same backup), so ability to reconnect may help.



> > 07.05.2018 18:44, Vladimir Sementsov-Ogievskiy wrote:
> > > Hi all!
> > >
> > > Here are some preliminary refactoring patches, before NBD reconnect
> > > series.
> > >
> > > Vladimir Sementsov-Ogievskiy (5):
> > >    block/nbd-client: split channel errors from export errors
> > >    block/nbd: move connection code from block/nbd to block/nbd-client
> > >    block/nbd-client: split connection from initialization
> > >    block/nbd-client: fix nbd_reply_chunk_iter_receive
> > >    block/nbd-client: don't check ioc
> > >
> > >   block/nbd-client.h |   2 +-
> > >   block/nbd-client.c | 163 
> > > ++++++++++++++++++++++++++++++++++-------------------
> > >   block/nbd.c        |  41 +-------------
> > >   3 files changed, 107 insertions(+), 99 deletions(-)


--
Best regards,
Vladimir