[dm-devel] [PATCH 10/11] libmpathpersist: add linker version script

[Martin Wilck]

On Thu, 2020-09-24 at 23:00 -0500, Benjamin Marzinski wrote:
> On Thu, Sep 24, 2020 at 03:36:43PM +0200, mwilck at suse.com wrote:
> > 
> > --- /dev/null
> > +++ b/libmpathpersist/libmpathpersist.version
> > @@ -0,0 +1,20 @@
> > +LIBMPATHPERSIST_0.8.4.0 {
> 
> I have a question about this version. Do you plan on bumping this
> each
> time a new release is tagged? It seems like we only ever want to
> change
> the version if we actually change the ABI. Or is 0.8.4 just because
> that's the relesae where we started this?

That was the idea, yes. And the last digit is because we'll have to
bump it between releases from Christophe. It makes sense for
libmultipath's rapidly changing ABI; much less so for libmpathcmd and
libmpathpersist, which are meant to be stable. I am open for discussing
these numbers; if you prefer, we might as well use LIBMPATHPERSIST_1.0.

I admit I haven't thought about what would happen once Christophe makes
a new release. Probably, nothing - afaics it's impossible to add a new
version without any new symbols, and *renaming* an existing version is
bad; it would introduce artificial incompatibility. 

So libmultipath from multipath-tools 0.8.5 would still have a 0.8.4.x
ABI; only the first change after 0.8.5 would get a 0.8.5.1 number. Hm.

Again, I'm open for discussion here. We might as well choose to not tie
the ABI version to the libmultipath version at all, and simply start at
0.1 or whatevever for libmultipath. After all, looking up the ABI
version in the commit history will be simple enough.

Martin