[dm-devel] what's up with pp_balance_units?

[christophe varoqui]

You need to recheck with 0.4.5-pre1, as it is now allowed and encouraged
to have (null) prio callouts. Does that look good ?

        if (mask & DI_PRIO) {
                select_getprio(pp);

                if (!pp->getprio) {
                        pp->priority = 1;
                } else if (apply_format(pp->getprio, &buff[0], pp)) {
                        condlog(0, "error formatting prio callout
command");
                        pp->priority = -1;
                } else if (execute_program(buff, prio, 16)) {
                        condlog(0, "error calling out %s", buff);
                        pp->priority = -1;
                } else
                        pp->priority = atoi(prio);

                condlog(3, "prio = %u", pp->priority);
        }



struct path -> priority is now an "int", thanks for the report.

Regards,
cvaroqui

On jeu, 2005-04-28 at 17:52 -0400, k-ueda at ct.jp.nec.com wrote:
> Hi,
> 
> On Thu, 28 Apr 2005 22:36:20 +0200, christophe varoqui wrote:
> > It's not default because its code path is badly inefficient.
> 
> How about "don't use callout, and set same priority for all path"
> by defualt?  It's more efficient, I think.
> 
> And, I found a possible bug that pp->priority is defined as 
> "unsigned int" while it's used like "int".
> But, if you fix this bug, "/bin/false" doesn't work as callout
> because it always fails.
> So I think it will fit your policy to add a feature of
> "do not use callout" and use it by default.
> 
> 
> Bug in multipath-tools-0.4.4
> ============================
> If priority callout is "/bin/false", in devinfo(), execute_program()
> returns non-zero, since "/bin/false" exits by 1 even if "/bin/false"
> terminate normally.  So, pp->priority is set by "-1".
> 
> ---------------------------------------------------------------------
> libmultipath/discovery.c:477:
> 
>         /*
>          * get path prio
>          */
>         if (mask & DI_PRIO) {
>                 select_getprio(pp);
> 
>                 if (apply_format(pp->getprio, &buff[0], pp)) {
>                         condlog(0, "error formatting prio callout command");
>                         pp->priority = -1;
>                 } else if (execute_program(buff, prio, 16)) {
>                         condlog(0, "error calling out %s", buff);
>                         pp->priority = -1;
>                 } else
>                         pp->priority = atoi(prio);
> 
>                 condlog(3, "prio = %u", pp->priority);
>         }
> ---------------------------------------------------------------------
> 
> In coalesce_paths(), if "priority" of "struct path" is less than "0",
> the multipath which include the path isn't mapped.
> But this "if check" is always false even if it is set by "-1", since
> "priority" of "struct path" is declared with "unsigned int".
> Should it be declared with "int"?
> 
> ---------------------------------------------------------------
> multipath/main.c:713:
>                 if (pp1->priority < 0)
>                         mpp->action = ACT_NOTHING;
> 
> multipath/main.c:738:
>                         if (pp2->priority < 0)
>                                 mpp->action = ACT_NOTHING;
> ---------------------------------------------------------------
> 
> Regards,
> Ky (Kiyoshi Ueda)
> 
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-- 
christophe varoqui <christophe.varoqui at free.fr>