Re: "simultaneous" mounts causing weird behavior

["H. Peter Anvin" <hpa@zytor.com>]

Matthew Mitchell wrote:
> 
> Yes, I know that mount can do that now.  But automount is spawning the
> second mount before the first one completes, no?  Still seems like there
> should be some sort of mutual exclusion around the lookup_mount call.  I
> realize our workload is kind of funny in that the processes effectively
> _try_ to synchronize their automount request.  
> 

autofs 3 relied on the mutural exclusion inherent in mount(2).  When
this was changed, it introduced a race condition in autofs 3.  I have
asked to add a mount flag to override this new behaviour; I don't know
if one was ever introduced or added to mount(8).

> Has any of this changed in the 4.0-pre autofs?  I haven't read through
> its source yet.

autofs 4 uses a different mutural exclusion strategy, so I would *think*
it would not be affected.

	-hpa