[Samba] secrets.tdb locking fun!

[Jeremy Allison]

On Fri, Jun 15, 2007 at 03:19:08PM +0100, Mac wrote:
> Hi all,
> 
> 	After much grief today, we'd like to support the 'TODO' note in
> source/lib/util_tdb.c  :-
> 
> /* TODO: If we time out waiting for a lock, it might
>  * be nice to use F_GETLK to get the pid of the
>  * process currently holding the lock and print that
>  * as part of the debugging message. -- mbp */
> 
> 
> It could have saved us a whole-sale restart of Samba if we could have
> more easily identified the process that was causing us to get loads and
> loads of:-
> 
> [2007/06/15 13:02:20, 0, pid=5430] tdb/tdbutil.c:tdb_log(783)
>   tdb(/usr/local/samba/private/secrets.tdb): tdb_lock failed on list 2 ltype=2 (Interrupted system call)
> [2007/06/15 13:02:20, 0, pid=5430] tdb/tdbutil.c:tdb_chainlock_with_timeout_internal(82)
>   tdb_chainlock_with_timeout_internal: alarm (10) timed out for key replay cache mutex in tdb /usr/local/samba/private/secrets.tdb
> 
> 
> We believe we did find it, but only by sending a SIGTERM to all 'smbd'
> processes and being left with 'smbd' proceses that didn't die.  (SIGKILL
> did remove them).

If you get an smbd in that state, can you attach to it with gdb and
get a stack backtrace so we can see where it was ?

Thanks,

	Jeremy.