RFC: should automounted file systems be exportable?

[Rick Macklem]

Edward Tomasz Napierala wrote:
> On 0511T2217, Rick Macklem wrote:
> > A recent bug was reported related to mountd and the
> > "automounted" flag.
> > 
> > Loosely related to this is the question...
> > Should automounted file systems be exportable?
> > 
> > I haven't tested it, but I suspect that it would be
> > broken and the NFS server will reply NFSERR_STALE
> > after the file system has been dismounted.
> > 
> > So, should I patch mountd so that it won't export
> > automounted file systems?
> 
> Exporting an automounted filesystem doesn't seem to make much sense,
> I agree, but I'm not sure if adding code to prevent it is such
> a good idea.  If the user asks for it, by putting it into exports(5),
> it's his fault; the only thing this code could add would be a more
> friendly error message.
> 
> 
So, how about having mountd generate a warning message in syslog(),
but allow it to proceed?
(Untested patch for this is attached.)

rick
ps: One other person emailed me suggesting that it should be doable and
    no one emailed that it should be restricted, so I figure that the "vote"
    favours a warning.
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