[Cluster-devel] fixing cpg names in 3.0.8?

[David Teigland]

On Tue, Jan 12, 2010 at 04:00:20PM +0000, Christine Caulfield wrote:
> On 12/01/10 16:24, David Teigland wrote:
> >I just discovered that the cpg group names that fenced, dlm_controld and
> >gfs_controld use in cluster3 include a nul within the name length.  This
> >can happen because cpg names have both a string part and a length part,
> >and the length is currently being set to strlen + 1 instead of strlen.
> >It's harmless since all the code is making the same mistake, but it's an
> >obvious flaw.
> >
> >You can easily see this by the trailing \x00 from corosync-cpgtool,
> >
> >fenced:default\x00
> >
> >If we fixed the length of the names, it would break internode
> >compatibility between 3.0.7 and 3.0.8 releases, e.g.
> >
> >"fenced:default\x00" and "fenced:default" are two different groups.
> >
> >AFAIK we're not yet guaranteeing rolling upgrade compatibility from one
> >3.0 release to the next, so I think I should go ahead and fix this, unless
> >anyone feels strongly otherwise?
> 
> 
> I'm sure we've seen this before. Oh well I'll repeat my opinion anyway.
> 
> I don't think it's a flaw and I don't see that it needs to be "fixed". 
> It's just the way things happen. What benefits accrue from changing it ?

Good point, it isn't a flaw per se, we just have inconsistent usages of
that api (ocfs_controld, at least, sets length to strlen).  There's
something to be said for consistency, but you've convinced me it's not
worth changing.

How about making corosync-cpgtool default to the -e behavior, and making
-e = escape unprintable characters in group name ?

Dave