autofs problem

[Daniel Braniss]

> On 15 Feb 2016, at 23:41, Edward Tomasz Napierała <trasz at FreeBSD.org> wrote:
> 
> On 0214T1655, Daniel Braniss wrote:
>> Hi,
>> I’m converting our (very) old am-utils maps to use the new autofs,
>> so I wrote a python script that queries the am-utils map, and ‘generates’
>> one that autofs likes.
>> so autofs_master has:
>> …
>> /cs	auto_cs
>> 
>> auto_cs is a python script and is executable.
>> 
>> at the moment I’m stuck with what am-utils  type=link
>> so I’m using -fstype=nullfs :/cs/some-path, but before this can work I need
>> to trigger autofs with the /cs/some-path, so before the script returns I do a
>> 	os.stat('/cs/some-path')
>> but this returns an error, mainly because it is not caught by autofs!
>> doing the same in the command line works, and later the nullfs too, (i’m afraid
>> of what the auto unmount will do later, but that’s another issue)
>> 
>> is this by design? or is there some better way?
> 
> It's by design - basically, autofs(4) has code to explicitly disable triggering
> by anything running with the same SID (session id) as the automountd(8).  This
> is to prevent some obvious (and some less than obvious and quite hard to debug)
> deadlocks.  Thus, any script ran by automountd(8) works as if the autofs mounts
> "weren't there".
> 
> You might be able to work around this by somehow calling setsid() from
> the Python script before triggering.

bingo!, that did it

thanks,
	danny