Users LOCKED OUT (was :Re: printing, locking, etc in 2.2.0)

[Andrew Bartlett]

Andrew Bartlett wrote:
> 
> Sorry about the incomplete e-mail, my mouse slipped...
> 
> Andrew Bartlett wrote:
> >
> > Jeremy Allison wrote:
> > >
> > > Andrew Bartlett wrote:
> > > >
> > > > My installation of last nights CVS, plus my pam patch (irrelevent for
> > > > this particular code path) also shows:
> > > >
> > > > May 23 09:44:42 jessie smbd[15437]: art14 (192.168.29.10) closed
> > > > connection to service webbc
> > > > May 23 09:44:42 jessie smbd[15417]: too many connections - rejected
> > > >
> > > > My theroy is that process 15437 is locking at least part of
> > > > connections.tdb, and that this code in connections.c:claim_connection()
> > > > is then failing:
> > > >
> > > >         if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0)
> > > >                 ret = False;
> > > >
> > > > Can this happen?  Should it be fixed?  Note that we have never had
> > > > connection limits at our site.  In any case, it has only happend once
> > > > (that I have seen), and is certainly not critical.
> > >
> > > Hmmm. That's a concern. I've checked over the code, and
> > > the tdb_store should block until it gets a lock, even if
> > > it's in competition with another smbd.
> > >
> > > I've added some tdb_errstr() calls to smbd/connection.c
> > > so we can see what's going on if any tdb calls fail.
> > >
> >
> > Unfortunetly we seem to have hit a bigger bug in this area, while
> > previously I had only seen one line in the logfile to indicate the
> > problem, this time I herd it by mobile...  Only about 8 studnets + staff
> > were able to log into the server, with the remainder locked out with the
> 'too many connections - rejected' message.
> >
> > I've cvs updated and installed, causing the problem to 'go away'
> because it also restarted samba.  I'll see what the error is if we ever
> get it again.
> 
> In the meantime, i have the connections.tdb, all 8MB of it.  I wonder if
> this is some internal limit?  Note that we have NO error handling for
> the delete case, a failure doesn't rate the slightest mention.  Could
> the be an issue?
> 
> Anyway, is there somebody who would like to analyze the tdb?
> 
> Andrew Bartlett
> 

Well I now have some errors:

I think this log message -

> May 25 17:05:06 jessie smbd[4761]: claim_connection: tdb_store failed with error IO Error. 

may be related to this on one of the computers (noted in an e-mail from
one of the IT teachers at the College):

> The following problems have come to light since 4pm today:-
>
> 1- ART16 had the following blue screen (I think on shutdown?)
>
>                      NETWORK ERROR
>
>          YOU HAVE NO SPACE AVAILABLE ON THE SERVER.
>
> This computer is on the student network.
>

I can't prove the link between the two, and art16 (Win98SE) did show a
valid logoff

> May 25 16:54:50 jessie smbd[4623]: art16 (192.168.29.58) closed connection to service thomsm1 
> May 25 16:54:50 jessie PAM_unix[4623]: (samba) session closed for user thomsm1

but there is only one error in the logs, beside some workgroup/browse
sync issues.

In any case, why do we get an IO error?  Also note that the lack of a
'max connections' error message indicates that is is being called from
the reply.c code (setting up the record for this smbd) not the per-share
code (service.c).

There is plenty of space free on the disks, and the system is RedHat
6.2, kernel 2.2.19

Andrew Bartlett

-- 
Andrew Bartlett
abartlet at pcug.org.au