From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Teigland <teigland@redhat.com>
Date: Fri, 16 Oct 2009 11:33:33 -0500
Subject: [Cluster-devel] Re: gfs2-utils: master - gfs_controld: Remove
	three unused functions
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On Fri, Oct 16, 2009 at 05:01:18PM +0100, Steven Whitehouse wrote:
> Hi,
> 
> On Fri, 2009-10-16 at 10:59 -0500, David Teigland wrote:
> > On Fri, Oct 16, 2009 at 03:56:05PM +0100, Steven Whitehouse wrote:
> > > Hi,
> > > 
> > > On Wed, 2009-10-14 at 12:53 -0500, David Teigland wrote:
> > > > On Wed, Oct 14, 2009 at 02:55:04PM +0000, Steven Whitehouse wrote:
> > > > > gfs_controld: Remove three unused functions
> > > > > 
> > > > > These functions are not called from anywhere and appear
> > > > > to be left over from earlier times.
> > > > 
> > > > They were just added, but in translating the dlm_controld patch to
> > > > gfs_controld I missed the bits that called them (both in
> > > > cluster.git/STABLE3 and gfs2-utils.git)  I'll reapply this bit with the
> > > > bits that are missing.
> > > > 
> > > > Dave
> > > > 
> > > 
> > > I'm not sure I understand the purpose of this code. Is there more to
> > > come yet?
> > > 
> > > The function find_mg_id() still seems to be unused. So far as I can
> > > figure out the purpose of the new code seems to be to maintain two
> > > timestamps: cluster_add_time whose sole purpose seems to be to check
> > > against cg->create_time but I'm not quite sure why, and
> > > cluster_remove_time which seems to not do anything at all at the moment.
> > > 
> > > I can't get any clues from dlm_controld because cluster_remove_time
> > > seems to be unused there as well,
> > 
> > Right, cluster_add_time is used, but cluster_remove_time isn't, although
> > it can be very useful to know for debugging.
> > 
> > Dave
> > 
> Yes, but used for what exactly? What is the purpose of this bit of code?

This bit about cluster_add_time?

+       /* a node's start can't match a change if the node joined the cluster
+          more recently than the change was created */
+
+       node = get_node_history(mg, hd->nodeid);
+       if (!node) {
+               log_group(mg, "match_change %d:%u skip cg %u no node history",
+                         hd->nodeid, seq, cg->seq);
+               return 0;
+       }
+
+       if (node->cluster_add_time > cg->create_time) {
+               log_group(mg, "match_change %d:%u skip cg %u created %llu "
+                         "cluster add %llu", hd->nodeid, seq, cg->seq,
+                         (unsigned long long)cg->create_time,
+                         (unsigned long long)node->cluster_add_time);
+               return 0;
+       }

The commit gave a brief summary and pointed to this other commit for the
long description of the problems with sorting out events after partitions
and merges:

http://git.fedorahosted.org/git/cluster.git?p=cluster.git;a=commitdiff;h=bcc5fdef8473d99399c624a7bc15423a2af645c1