From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: [[PATCH stable <3.12]] xen-netback: fix refcnt unbalance for 3.11 and earlier versions Date: Thu, 28 Nov 2013 13:13:46 +0000 Message-ID: <20131128131346.GK12187@zion.uk.xensource.com> References: <1385642889-11513-1-git-send-email-wei.liu2@citrix.com> <1385644133.20209.11.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Wei Liu , , , , , Konrad Wilk , David Vrabel To: Ian Campbell Return-path: Content-Disposition: inline In-Reply-To: <1385644133.20209.11.camel@kazak.uk.xensource.com> Sender: stable-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, Nov 28, 2013 at 01:08:53PM +0000, Ian Campbell wrote: > On Thu, 2013-11-28 at 12:48 +0000, Wei Liu wrote: > > With the introduction of "xen-netback: Don't destroy the netdev until > > the vif is shut down" (upstream commit id 279f438e36), vif disconnect > > and free are separated. However in the backported verion reference > > counting code was not correctly modified, and the reset of vif->tx_irq > > was lost. If frontend goes through vif life cycle more than once the > > reference counting is skewed. > > > > This patch adds back the missing tx_irq reset line. It also moves > > several lines of the reference counting code to vif_free, so the moved > > code corresponds to the counterpart in vif_alloc, thus the reference > > counting is balanced. > > Is this a requirement of the bugfix or just to make reasoning about > things easier? > The latter. Wei.