> On Feb 15, 2016, at 2:43 AM, Toshiaki Makita <makita.toshiaki@xxxxxxxxxxxxx> wrote: > > On 2016/02/13 0:40, Chuck Lever wrote: >> Hi- > > Hi, > >>> On Feb 12, 2016, at 1:41 AM, Toshiaki Makita <makita.toshiaki@xxxxxxxxxxxxx> wrote: >>> >>> statd calls atexit(statd_unregister) to unregister statd service on exit, >>> which actually has a side-effect that ha_callout() unregisters statd >>> service even when the child callout process exits on execl() failure. >>> >>> Certain clustering software's deployment script adds -H option with its >>> specified file non-existent, when it is configured not to use callout. >>> In other words, -H seems to be used no matter if callout is needed or not, >>> but when callout is unnecessary, the specified callout program is not >>> deployed. >>> This causes statd not to work once a lock is requested by its NFS client, >>> as execl() in ha_callout() results in ENOENT and exit() of the child >>> process calls exit-handler statd_unregister(). Eventually, the NFS client >>> gets stuck with messages "lockd: cannot monitor xxx" on the NFS server. >>> >>> Although this may not be an expected way of using -H option, it would be >>> better if statd could continue to work even in that situation. Also, >>> execl() could fail for other reasons like ENFILE and EIO, where statd >>> service should not be unregistered as well. >>> Call _exit(), which does not call any exit-handlers, instead of exit() to >>> take care of those situations and make statd more reliable. >> >> OK, but I think the explanation could be simpler? It doesn't >> seem like a matter of "it would be better if" but more like >> "a forked child must not unregister the statd RPC server." >> In other words, this seems like a real bug to me, not an >> enhancement. > > Thank you for your feedback. > > Here is a simpler one. > If it looks fine to you, I'll send v2 with your Reviewed-by. Looks good, thanks for the update. > --- > > -Although this may not be an expected way of using -H option, it would be > -better if statd could continue to work even in that situation. Also, > -execl() could fail for other reasons like ENFILE and EIO, where statd > -service should not be unregistered as well. > -Call _exit(), which does not call any exit-handlers, instead of exit() to > -take care of those situations and make statd more reliable. > > +Also, execl() could fail for other reasons like ENFILE or EIO as well. > + > +A forked child must not unregister the statd RPC server, so use > +_exit(), which does not call any exit-handlers, instead of exit(). > > --- > Regards, > Toshiaki Makita -- Chuck Lever -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
