From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Whitehouse Date: Wed, 12 Mar 2014 14:47:40 +0000 Subject: [Cluster-devel] [GFS2 PATCH] GFS2: Adjust lock reference count In-Reply-To: <1205189675.13171627.1394634740946.JavaMail.zimbra@redhat.com> References: <1205189675.13171627.1394634740946.JavaMail.zimbra@redhat.com> Message-ID: <1394635660.2729.60.camel@menhir> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, On Wed, 2014-03-12 at 10:32 -0400, Bob Peterson wrote: > Hi, > > This patch closes a small timing window whereby a request to hold the > transaction glock can get stuck. The problem is that after the DLM has > granted the lock, it can get into a state whereby it doesn't transition > the glock to a held state, due to not having requeued the glock state > machine to finish the transition. > > Steve: Feel free to adjust the patch description as you see fit. > I'm not feeling very creative at the moment. > > Regards, > > Bob Peterson > Red Hat File Systems > I updated the description, and also converted the atomic_inc to lockref - I guess that you didn't compile test this one. Anyway, that should sort it out I think, so I've added it to the tree now, since we know that the fix is needed, Steve. > Signed-off-by: Bob Peterson > --- > fs/gfs2/glock.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c > index 52f7478..67ac456 100644 > --- a/fs/gfs2/glock.c > +++ b/fs/gfs2/glock.c > @@ -1047,9 +1047,13 @@ int gfs2_glock_nq(struct gfs2_holder *gh) > > spin_lock(&gl->gl_spin); > add_to_queue(gh); > - if ((LM_FLAG_NOEXP & gh->gh_flags) && > - test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) > + if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) && > + test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) { > set_bit(GLF_REPLY_PENDING, &gl->gl_flags); > + atomic_inc(&gl->gl_ref); > + if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) > + atomic_dec(&gl->gl_ref); > + } > run_queue(gl, 1); > spin_unlock(&gl->gl_spin); > >