[dm-devel] [PATCH 71/74] multipath: use update_pathvec_from_dm()

[Martin Wilck]

On Sun, 2020-07-19 at 21:57 -0500, Benjamin Marzinski wrote:
> On Thu, Jul 09, 2020 at 12:51:42PM +0200, mwilck at suse.com wrote:
> > From: Martin Wilck <mwilck at suse.com>
> > 
> > The multipath-specific function update_paths() can now be replaced
> > with
> > a call to update_pathvec_from_dm().
> > 
> > Signed-off-by: Martin Wilck <mwilck at suse.com>
> > ---
> >  multipath/main.c | 67 +++-----------------------------------------
> > ----
> >  1 file changed, 3 insertions(+), 64 deletions(-)
> > 
> > diff --git a/multipath/main.c b/multipath/main.c
> > index 8a2a6f7..435c5d5 100644
> > --- a/multipath/main.c
> > +++ b/multipath/main.c
> > 
> >  static int
> >  get_dm_mpvec (enum mpath_cmds cmd, vector curmp, vector pathvec,
> > char * refwwid)
> >  {
> > @@ -273,13 +216,8 @@ get_dm_mpvec (enum mpath_cmds cmd, vector
> > curmp, vector pathvec, char * refwwid)
> >  		condlog(3, "status = %s", status);
> >  
> >  		disassemble_map(pathvec, params, mpp);
> > -
> > -		/*
> > -		 * disassemble_map() can add new paths to pathvec.
> > -		 * If not in "fast list mode", we need to fetch
> > information
> > -		 * about them
> > -		 */
> > -		update_paths(mpp, (cmd == CMD_LIST_SHORT));
> > +		update_pathvec_from_dm(pathvec, mpp,
> > +				       (cmd == CMD_LIST_SHORT ? 0 :
> > DI_ALL));
> 
> I personally don't think that "multipath -l" should be opening the
> path
> fd. Checking sysfs seems like the limit of what we want to do for
> fast
> listing. So, I would prefer
> 
> update_pathvec_from_dm(pathvec, mpp,
> 		       (cmd == CMD_LIST_SHORT ? DI_NOIO : DI_ALL));
> 
> That will make pathinfo exit early.

Good suggestion. But then I need to avoid rerunning pathinfo() for
already scanned paths in update_pathvec_from_dm(). Will do.

Regards
Martin