From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Teigland Date: Thu, 21 Jan 2010 09:30:20 -0600 Subject: [Ocfs2-devel] [PATCH] ocfs2: fix __ocfs2_cluster_lock() dead lock In-Reply-To: <4B4E1BA8.3060408@oracle.com> References: <201001060835.o067n0EO000623@rcsinet13.oracle.com> <20100107020005.GC20095@mail.oracle.com> <20100109180521.GA5148@laptop.oracle.com> <20100112015946.GE20285@mail.oracle.com> <20100113032049.GA4045@laptop.oracle.com> <20100113075752.GA23372@mail.oracle.com> <4B4E1BA8.3060408@oracle.com> Message-ID: <20100121153020.GA12304@redhat.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com On Wed, Jan 13, 2010 at 11:14:48AM -0800, Sunil Mushran wrote: > Joel Becker wrote: > >On Wed, Jan 13, 2010 at 11:20:49AM +0800, Wengang Wang wrote: > >>before update_holders, the lock could be DCed(since no BUSY flag set by > >>here). > >> > >>and even after update_holders, the lock could be DCed too. > >> > >>so that we get ocfs2_cluster_lock()(with holders increased) returned > >>sucessfully > >>but actually we don't hold the dlm lock. --thus more than one node is > >>considering that they have the (EX) lock. > > > > You make a good point. I don't like the solution you propose, > >though. Another flag that's almost the same? Eww! There's got to be a > >better way. > > I don't see how we can resolve this without another flag. It could > be a mirror image of the PENDING flag. PENDING takes care of the gap > between BUSY set and calling dlm_lock(). This flag has to take care > of the gap between BUSY clear and inc_holders. > > Am working on improving Wengang's patch. I'm afraid I lost track of which patches I should be trying. Is there something that we expect should solve the known problems, even if it's not a final version? Dave