Re: [PATCH 4/4] multipath: delegate dangerous commands to multipathd

[Martin Wilck <mwilck@suse.com>]

On Thu, 2017-09-07 at 16:57 -0500, Benjamin Marzinski wrote:
> On Tue, Aug 29, 2017 at 12:05:36AM +0200, Martin Wilck wrote:
> > Some multipath commands are dangerous to run while multipathd is
> > running.
> > For example, "multipath -r" may apply a modified configuration to
> > the kernel,
> > while multipathd is still using the old configuration, leading to
> > inconsistent state between multipathd and the kernel.
> > 
> > It is safer to use equivalent multipathd client commands instead.
> > For now, do this only for "multipath -r", but other invocations
> > may be added in the future. Perhaps some day, all "multipath"
> > commands will be mapped to multipathd actions.
> 
> Thanks. I've been meaning to do something like this forever.

[...]

> +	if (execv(mpd_path, argv) == -1) {
> > +		condlog(0, "failed to execute multipathd: %s",
> > strerror(errno));
> > +		exit(1);
> > +	}
> 
> Why exec multipathd, instead of using the libmpathcmd api, like
> mpathpersist, libdmmp, and the multipathd client do?

Thanks for the review. I'll look into that, and your other suggestions.

Martin

-- 
Dr. Martin Wilck <mwilck@suse.com>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)

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