[Samba] [PATCH] Do not close winbind socket during use

Tue Jul 9 09:33:40 MDT 2013

Hi Andrew,

Am 03.07.2013 09:44, schrieb Andrew Bartlett:
> On Thu, 2013-06-27 at 11:42 +1000, Andrew Bartlett wrote:
>> On Wed, 2013-06-26 at 20:39 +1000, Andrew Bartlett wrote:
>>> On Mon, 2013-06-24 at 15:26 +0000, Philippe.Simonet at swisscom.com wrote:
>>>> Hi Andrew, and by putting more num-callers : 
>>>>
>>>> valgrind --num-callers=50 samba -i -M single
>>>
>>> Thanks for getting me that.  I've managed to reproduce it here, but not
>>> under valgrind, and only when I hack the code to force a timeout.  At
>>> least this should help me figure out why we process the winbind socket
>>> close, which is the crux of this issue.
>>
>> I think I've found the cause of the issue you are hitting.  There is
>> still another issue with the nested event loop in the krb5 libs, but
>> these two patches should help significantly.
>>
>> As you have had more luck than I in reproducing this in a unaltered
>> setting, please let me know if this helps.
>>
>> Patches are for git master, but may apply to 4.0 as well.
> 
> G'Day,
> 
> The original reporter has confirmed to me that this removes the segfault
> for him.  It changes it to a 105 sec hang, (due to the winbind client
> trying for 5 second at at a time many times). 
> 
> Can I get a review on it so we can rid master and eventually 4.0 of this
> nasty crash?

I've looked through this patches and have some improvements.
The main problem is that we're not sure wbsrv_call_loop() is called again
on the terminated connection, when the last pending request is finished.
That's why I remember all broken connections and try to clean them up
before accepting a new connection or processing any new request on any
connection.
This way we're sure the connection gets removed eventually.

I'm currently running some autobuild with the attached patches,
they might also fix the current flakey crashes, e.g.
https://git.samba.org/autobuild.flakey/2013-07-08-0055/samba.stderr

metze
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