On Sun, Aug 12, 2018 at 10:16:48AM +0200, J. Hannken-Illjes wrote: > While creating a snapshot "/mount0" lookup "/mount0/file", it will block > as "/mount0" is suspended. The lookup holds a lock on "/". > > Now snapshot "/ "and trying to suspend "/" will block as the lookup > has the root vnode locked.
This scenario is not the same as the one I asked about, which was: performing a snapshot of filesystem mounted on /mount0 using /dev/fss0 and a snapshot of filesystem mounted on /mount1 using /dev/fss1 while the first one is still active. Is there some deadlock in this case? But you also raise a deadlock scenario for which there is no protection in currentn code. I already experienced it in the past and it would be fair to return EGAIN rather than letting the administrator set a snapshot that will kill the system later. -- Emmanuel Dreyfus m...@netbsd.org
