[dm-devel] [PATCH] multipath: return failure on an invalid remove command

[Benjamin Marzinski]

On Wed, Mar 30, 2022 at 12:50:00PM +0000, Martin Wilck wrote:
> On Tue, 2022-03-29 at 22:21 -0500, Benjamin Marzinski wrote:
> > When "multipath -f" is run on a device that doesn't exist or isn't a
> > multipath device, the command will not remove any device, but it will
> > still return success.  Multiple functions rely on _dm_flush_map()
> > returning success when called with name that doesn't match any
> > multipath device. So before calling _dm_flush_map(), call
> > dm_is_mpath(),
> > to check if the device exists and is a multipath device, and return
> > failure if it's not.
> > 
> > Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> > ---
> >  multipath/main.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/multipath/main.c b/multipath/main.c
> > index d09f62db..e865309d 100644
> > --- a/multipath/main.c
> > +++ b/multipath/main.c
> > @@ -1060,6 +1060,11 @@ main (int argc, char *argv[])
> >         if (retries < 0)
> >                 retries = conf->remove_retries;
> >         if (cmd == CMD_FLUSH_ONE) {
> > +               if (dm_is_mpath(dev) != 1) {
> > +                       condlog(0, "failed removing \"%s\"", dev);
> 
> Could we provide a more meaningful error message here?
> (As you're the native speaker - shouldn't it rather be "failed to
> remove"?)

Sure. I'll clean that up.

-Ben

> 
> Otherwise, ack.
> 
> Martin
> 
> 
> > +                       r = RTVL_FAIL;
> > +                       goto out;
> > +               }
> >                 r = dm_suspend_and_flush_map(dev, retries) ?
> >                     RTVL_FAIL : RTVL_OK;
> >                 goto out;