[sheepdog] [PATCH] sheep: update node in cluster driver

[MORITA Kazutaka]

At Fri, 31 May 2013 21:45:31 +0800,
Liu Yuan wrote:
> 
> On 05/31/2013 08:52 PM, MORITA Kazutaka wrote:
> > At Fri, 31 May 2013 18:35:59 +0800,
> > Liu Yuan wrote:
> >>
> >> diff --git a/sheep/group.c b/sheep/group.c
> >> index b9399ee..f74ef10 100644
> >> --- a/sheep/group.c
> >> +++ b/sheep/group.c
> >> @@ -1242,6 +1242,7 @@ void update_node_size(struct sd_node *node)
> >>  	int idx = get_node_idx(cur_vinfo, node);
> >>  	assert(idx != -1);
> >>  	cur_vinfo->nodes[idx].space = node->space;
> >> +	sys->cdrv->update_node(node);
> >>  }
> > 
> > The current cluster driver model is:
> > 
> >  - Sheep triggers a node event with a cluster driver interface.
> >  - The cluster driver updates its internal state, and invokes a
> >    callback to notify the change to sheep.
> > 
> > In that sense, this fix is a bit weird to me.
> > 
> > I think a better fix is:
> > 
> >  1. make SD_OP_REWEIGHT a local request.
> >  2. call cdrv->update_node() in cluster_reweight().
> >  3. order the update_node event with other nonblocking events and call
> >     sd_update_node() as a callback of the update_node event.
> >  4. call update_node_size() and kick_node_recover() in sd_update_node()
> > 
> > Then, we can remove a SD_OP_UPDATE_SIZE operation and FIXME in the
> > local driver.
> > 
> > That being said, the current fix also looks correct to me (except the
> > local driver), so I'm fine with merging this code without changes.
> > 
> 
> Yeah, your fix looks better integrated but this patch win as a simpler
> with less change approach and the node can be updated inside a ordered
> notify event. Local driver just a test driver so there is nothing to worry.
> 
> That said, I'd like to merge my fix for 0.6.0 and prepare a another
> patch as you described.

Okay, I've applied this patch, thanks!

Kazutaka