[Ocfs2-devel] [PATCH] ocfs2: force clean refmap when doing local recovery cleanup

[Sunil Mushran]

I see no need for a separate function. Just do....

 } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
    if (test_bit(node, res->refmap))
          dlm_lockres_clear_refmap_bit(dlm, res, node);
}



On Thu, Aug 1, 2013 at 5:05 AM, Xue jiufei <xuejiufei at huawei.com> wrote:

> Function dlm_do_local_recovery_cleanup() should force clean refmap if
> the owner of lockres is UNKNOWN. Otherwise node may hang when umounting
> filesystems.
> Here's the situation:
>
>         Node1                                    Node2
> dlmlock()
>   -> dlm_get_lock_resource()
> send DLM_MASTER_REQUEST_MSG to
> other nodes.
>
>                                        trying to master this lockres,
>                                        return MAYBE.
>
> selected as the master of lockresA,
> set mle->master to Node1,
> and do assert_master,
> send DLM_ASSERT_MASTER_MSG to Node2.
>                                        Node 2 has interest on lockresA
>                                        and return
>                                        DLM_ASSERT_RESPONSE_MASTERY_REF
>                                        then something happened and
>                                        Node2 crashed.
>
> receiving DLM_ASSERT_RESPONSE_MASTERY_REF,
> set Node2 into refmap, and keep sending
> DLM_ASSERT_MASTER_MSG to other nodes
>
> o2hb found node2 down, calling
> dlm_hb_node_down()
> --> dlm_do_local_recovery_cleanup()
> the master of lockresA is still UNKNOWN,
> no need to call dlm_free_dead_locks().
>
> set the master of lockresA to Node1, but
> Node2 stills remains in refmap.
>
> when Node1 umount, it found that the refmap of lockresA is not empty
> and attempted to migrate it to Node2, But Node2 is already down,
> so umount hang, trying to migrate lockresA again and again.
>
> Signed-off-by: joyce <xuejiufei at huawei.com>
> ---
>  fs/ocfs2/dlm/dlmrecovery.c |   18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
> index 773bd32..7b4413d 100644
> --- a/fs/ocfs2/dlm/dlmrecovery.c
> +++ b/fs/ocfs2/dlm/dlmrecovery.c
> @@ -2191,6 +2191,21 @@ static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
>         }
>  }
>
> +static void dlm_force_clean_refmap(struct dlm_ctxt *dlm,
> +               struct dlm_lock_resource *res, u16 dead_node)
> +{
> +       assert_spin_locked(&dlm->spinlock);
> +       assert_spin_locked(&res->spinlock);
> +
> +       if (test_bit(dead_node, res->refmap)) {
> +               mlog(0, "%s:%.*s: dead node %u had a ref, but had "
> +                               "no locks and had not purged before
> dying\n",
> +                               dlm->name, res->lockname.len,
> +                               res->lockname.name, dead_node);
> +               dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
> +       }
> +}
> +
>  static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
>                                 struct dlm_lock_resource *res, u8
> dead_node)
>  {
> @@ -2328,7 +2343,8 @@ static void dlm_do_local_recovery_cleanup(struct
> dlm_ctxt *dlm, u8 dead_node)
>                         } else if (res->owner == dlm->node_num) {
>                                 dlm_free_dead_locks(dlm, res, dead_node);
>                                 __dlm_lockres_calc_usage(dlm, res);
> -                       }
> +                       } else if (res->owner ==
> DLM_LOCK_RES_OWNER_UNKNOWN)
> +                               dlm_force_clean_refmap(dlm, res,
> dead_node);
>                         spin_unlock(&res->spinlock);
>                 }
>         }
> --
> 1.7.9.7
>
>
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> Ocfs2-devel at oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
>
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