[dm-devel] [PATCH 4/7] multipathd: add "del maps" multipathd command

[Benjamin Marzinski]

On Thu, Jun 18, 2020 at 08:37:20PM +0000, Martin Wilck wrote:
> On Wed, 2020-06-17 at 19:24 -0500, Benjamin Marzinski wrote:
> > This will flush all multipath devices.
> > 
> > Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> > ---
> >  libmultipath/devmapper.c  |  7 +++++--
> >  libmultipath/devmapper.h  |  2 +-
> >  multipath/main.c          |  2 +-
> >  multipathd/cli.c          |  1 +
> >  multipathd/cli_handlers.c | 19 +++++++++++++++++++
> >  multipathd/cli_handlers.h |  1 +
> >  multipathd/main.c         |  3 ++-
> >  multipathd/main.h         |  1 +
> >  8 files changed, 31 insertions(+), 5 deletions(-)
> > 
> > diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
> > index 682c0038..a5e0d298 100644
> > --- a/libmultipath/devmapper.c
> > +++ b/libmultipath/devmapper.c
> > @@ -991,7 +991,7 @@ dm_flush_map_nopaths(const char * mapname, int
> > deferred_remove)
> >  
> >  #endif
> >  
> > -int dm_flush_maps (int retries)
> > +int dm_flush_maps (int need_suspend, int retries)
> >  {
> >  	int r = 1;
> >  	struct dm_task *dmt;
> > @@ -1014,7 +1014,10 @@ int dm_flush_maps (int retries)
> >  
> >  	r = 0;
> >  	do {
> > -		r |= dm_suspend_and_flush_map(names->name, retries);
> > +		if (need_suspend)
> > +			r |= dm_suspend_and_flush_map(names->name,
> > retries);
> > +		else
> > +			r |= dm_flush_map(names->name);
> 
> This is fine, but considering the previous discussion, I'd prefer to
> get rid of need_suspend and dm_suspend_and_flush_map() entirely. It
> would simplify the _dm_flush_map code path significantly.
> 
> As we determined that we use the suspend/resume only in multipath
> anyway, we could add it there in the "non-delegated" code path.

I'm confused. dm_flush_maps() is also called in the non-delegated code
path, where it uses the dm_suspend_and_flush_map(). Are you proposing
an alternative version of dm_flush_maps() for multipath?

-Ben

> Thanks,
> Martin
> 
> -- 
> Dr. Martin Wilck <mwilck at suse.com>, Tel. +49 (0)911 74053 2107
> SUSE  Software Solutions Germany GmbH
> HRB 36809, AG Nürnberg GF: Felix
> Imendörffer
>