[PATCH] CTDB PID file fixes (bug 12287)

[Amitay Isaacs]

On Fri, Oct 14, 2016 at 12:55 PM, Martin Schwenke <martin at meltin.net> wrote:

> On Thu, 13 Oct 2016 14:21:46 +0200, Volker Lendecke <vl at samba.org>
> wrote:
>
> > Martin Schwenke <martin at meltin.net> writes:
> >
> > > 3 patches to improve CTDB PID file handling in ctdbd_wrapper.
> > >
> > > The 1st patch is an additional patch for bug 12287, so will be
> > > backported.
> > >
> > > The others can just go into master and won't need a backport.
> >
> > The third one seems RHEL-specific. At least Ubuntu gives an error
> > message:
> >
> > vlendec at sn-devel-144:~/autobuild/samba-autobuild$ ps -h -q 1 -o comm
> > error: unsupported SysV option
> >
> > Usage:
> >  ps [options]
> >
> >  Try 'ps --help <simple|list|output|threads|misc|all>'
> >    or 'ps --help <s|l|o|t|m|a>'
> >     for additional help text.
> >
> > For more details see ps(1).
> >
> > So to get the rest in I had to drop patch 3/3.
>
> Thanks for catching this!
>
> My hand testing and testing on RHEL 6.8 all seemed to work.  On closer
> examination, there were warnings being printed when ps was used with
> the -h option.
>
> The options available in different versions are bizarre!
>
> * Debian testing has a variant of 3.3.12.  This supports both the -q
>   and -h options.
>
> * Ubuntu 14.04.5 has a variant of 3.3.9.  This supports the -h option
>   but not -q.  This makes sense because -q was added in 3.3.10 (around
>   June 2015).
>
> * RHEL 6.8 has a variant of 3.2.8.  This supports the -q option but not
>   -h.  It looks like it contains a backport of -q.
>
> I used -q because the -p option is an idiot.  With -p you are always
> going to get a single process.  However, "ps -p 1" walks every
> process' subdirectory in /proc/, collects the desired information and
> then filters it to print information about just the one process.  While
> I understand the benefits of re-usable code, I don't understand why
> this can't be a special case...
>
> Updated patch attached.  Please review and maybe push...
>
> peace & happiness,
> martin
>

Pushed to autobuild.

Amitay.