On Thu, 2018-03-29 at 08:04 +0200, Hannes Reinecke wrote: > > > The only way I see to avoid this is to try calling open(O_EXCL) on > > the > > path device in "multipath -u". So far we've avoided that because > > it's > > not completely race-free. But we're not talking about a race here, > > but > > a situation where some entity grabbed a device before pivot-root. > > So we could attempt open(O_EXCL) only in the "is maybe a valid > > path" > > case, and only return "maybe" if that open succeeds. Otherwise we'd > > return "no", as we already checked that the device isn't currently > > part of a multipath map. > > > > Ho-hum. > > Watch out when you do this; systemd will generate another event > whenever you close this fd, and suddenly you find yourself in a > middle > of an event storm ... Thanks for mentioning that. Udev listens for inotify events for "close after write". We will do the test with O_RDONLY|O_EXCL, so no event should be generated. Moreover, events should only occur if udev is watching the device, which shouldn't be the case while an event is processed (but I'm not 100% certain about that). Anyway, I'll test this. Cheers, Martin -- Dr. Martin Wilck <mwilck@xxxxxxxx>, Tel. +49 (0)911 74053 2107 SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
