Date: Fri, 22 Sep 2006 11:29:28 -0700 From: Chuck Swiger <cswiger@mac.com> To: Robert Joosten <robert@ml.erje.net> Cc: questions@freebsd.org Subject: Re: 6.1 and NFS Message-ID: <186AD616-6739-41EF-88F1-4F8B9BD417BC@mac.com> In-Reply-To: <20060922180202.GB918@iphouse.com> References: <C87B42D9-AF83-4DFC-9E13-53FCD874A444@obmail.net> <20060921182252.GA24321@xor.obsecurity.org> <20060921214316.GD673@iphouse.com> <6180D198-A44B-46D0-8A0B-FC5D3ACA115C@mac.com> <20060922180202.GB918@iphouse.com>
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On Sep 22, 2006, at 11:02 AM, Robert Joosten wrote:
>>> Hmmm, is there a way to run pxe-boxes without rpc.lockd and then
>>> still
>>> able to run adduser and so on ?
>> Safely? No. But then, flock() doesn't work via NFS even if
>> rpc.lockd is running, so you aren't any worse off.
>
> flock() .. hmm yeah, I discoverd trouble with sendmail as well, it
> rings
> my bell. At least I know where to look for digging in the code finding
> clues about why.
>
> You say flock() doesn't work with rpc.lockd running.
At least at one point, flock() used against an NFS-mount filesystem
would simply return as if the call was successful, but no locking was
done. Whether rpc.lockd is running or not would have no impact.
> I observed running a pxe client running fbsd 5.[45] being served by
> nfs-box running 5 (and 4
> nowadays because of asr0 trouble due to geom) having disabled
> rpc.lockd
> the box doens't let me run adduser, but with rpc.lockd enabled it's
> fine
> with 'em. Is that strange or am I missing (some) insight about this
> matter?
That's interesting. Are you getting a "could not lock the passwd
file: EOPNOTSUPP" failure with rpc.lockd not enabled? I suspect that
the pw_lock() code in libutil ought to use O_EXLOCK in the open()
call rather than calling flock() separately:
[EOPNOTSUPP] O_SHLOCK or O_EXLOCK is specified but the
underlying
file system does not support locking.
...?
--
-Chuck
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