Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 9 Jan 2019 19:20:50 -0500
From:   Sasha Levin <sashal@kernel.org>
To:     Dexuan Cui <decui@microsoft.com>
Cc:     "'gregkh@linuxfoundation.org'" <gregkh@linuxfoundation.org>,
        'Stephen Hemminger' <stephen@networkplumber.org>,
        Sasha Levin <Alexander.Levin@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        KY Srinivasan <kys@microsoft.com>,
        "'devel@linuxdriverproject.org'" <devel@linuxdriverproject.org>,
        "'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>,
        Michael Kelley <mikelley@microsoft.com>,
        "'marcelo.cerri@canonical.com'" <marcelo.cerri@canonical.com>,
        "'apw@canonical.com'" <apw@canonical.com>,
        "'olaf@aepfle.de'" <olaf@aepfle.de>,
        vkuznets <vkuznets@redhat.com>,
        "'jasowang@redhat.com'" <jasowang@redhat.com>,
        'Dan B' <dan@structuredgrid.net>
Subject: Re: [PATCH][re-post] vmbus: fix subchannel removal
Message-ID: <20190110002050.GL166797@sasha-vm>
References: <PU1P153MB0169D32ECDF37A2DB55AD485BF8B0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Disposition: inline
In-Reply-To: <PU1P153MB0169D32ECDF37A2DB55AD485BF8B0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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@vger.kernel.org
>Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
>Signed-off-by: Dexuan Cui <decui@microsoft.com>

Queued, thank you.

--
Thanks,
Sasha