Re: [PATCH][re-post] vmbus: fix subchannel removal

[Sasha Levin]

On Wed, Jan 09, 2019 at 08:56:06PM +0000, Dexuan Cui wrote:
> The changes to split ring allocation from open/close, broke
> the cleanup of subchannels. This resulted in problems using
> uio on network devices because the subchannel was left behind
> when the network device was unbound.
>
> The cause was in the disconnect logic which used list splice
> to move the subchannel list into a local variable. This won't
> work because the subchannel list is needed later during the
> process of the rescind messages (relid2channel).
>
> The fix is to just leave the subchannel list in place
> which is what the original code did. The list is cleaned
> up later when the host rescind is processed.
>
> Without the fix, we have a lot of "hang" issues in netvsc when we
> try to change the NIC's MTU, set the number of channels, etc.
>
> Fixes: ae6935ed7d42 ("vmbus: split ring buffer allocation from open")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>

Queued, thank you.

--
Thanks,
Sasha