[Cluster-devel] [GFS2 Patch] GFS2: recovery stuck on transaction lock

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

Now in the -nmw tree. Thanks,

Steve.

On Wed, 2010-06-23 at 11:44 -0400, Bob Peterson wrote:
> Hi,
> 
> This patch fixes bugzilla bug #590878: GFS2: recovery stuck on
> transaction lock.  We set the frozen flag on the glock when we receive
> a completion that cannot be delivered due to blocked locks. At that
> point we check to see whether the first waiting holder has the noexp
> flag set. If the noexp lock is queued later, then we need to unfreeze
> the glock at that point in time, namely, in the glock work function.
> 
> This patch was originally written by Steve Whitehouse, but since
> he's on holiday, I'm submitting it.  It's been well tested with a
> complex recovery test called revolver.
> 
> Regards,
> 
> Bob Peterson
> Red Hat GFS
> 
> Signed-off-by: Steve Whitehouse <swhiteho@redhat.com> 
> Signed-off-by: Bob Peterson <rpeterso@redhat.com> 
> --
> diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
> index ddcdbf4..dbab3fd 100644
> --- a/fs/gfs2/glock.c
> +++ b/fs/gfs2/glock.c
> @@ -706,8 +706,18 @@ static void glock_work_func(struct work_struct *work)
>  {
>  	unsigned long delay = 0;
>  	struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
> +	struct gfs2_holder *gh;
>  	int drop_ref = 0;
>  
> +	if (unlikely(test_bit(GLF_FROZEN, &gl->gl_flags))) {
> +		spin_lock(&gl->gl_spin);
> +		gh = find_first_waiter(gl);
> +		if (gh && (gh->gh_flags & LM_FLAG_NOEXP) &&
> +		    test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
> +			set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
> +		spin_unlock(&gl->gl_spin);
> +	}
> +
>  	if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) {
>  		finish_xmote(gl, gl->gl_reply);
>  		drop_ref = 1;