[SCM] Samba Shared Repository - branch master updated - release-4-0-0alpha8-494-geba2eb4

[Jeremy Allison]

On Tue, Jul 21, 2009 at 08:22:46AM +0200, Stefan (metze) Metzmacher wrote:
> Hi Jeremy,
> 
> >     Move the initialization of smbd_server_conn from smbd/process,
> >     after the accept and fork, to smbd_init_globals(), so it's
> >     done immediately on server startup. This is needed as some
> >     messages are sent to all active smbd processes (including
> >     the master listening daemon). If it gets a message that
> >     forces it to scan it's current connections (ie. conn_find())
> >     then it discovers that sconn->smb1.tcons.Connections dereferences
> >     null (as sconn == NULL in the parent) and crashes. Yes,
> >     I could fix all cases where sconn is used and explicitly
> >     check for NULL but this fix is easier. It means that
> >     the smbd_event_context() is initialized in the master
> >     daemon and then re-initialized after fork, but that
> >     should be being done correctly in every fork call anyway.
> >     Without this change the previous fix 6a9e0039100b57f9626e87defec6720c476b9789
> >     still panics in the reproducible test case for bug
> >     6564, as this is one case where such a message
> >     (MSG_SMB_CONF_UPDATED) is sent to the parent. Metze
> >     please check. This change passes valgrind.
> >     Jeremy.
> 
> I think it is thte wrong approach, smbd_server_connection represents
> the state of a connected client/a smbd child process.
> I added it so that we strictly separate code that runs in the parent
> from code that runs in the child.
> 
> I'd really like to understand what the problem is.
> From reading the code I can't find where we hit any panic.

Oh, I thought the above description was good enough, sorry :-).

> Can you send me the backtrace please?

Sure, I'll reproduce and send it. I'm glad you're looking
at it, it's an ugly fix but I couldn't see an elegant way
of fixing it without filling the code with "if (!sconn) return"
statements everywhere.

Jeremy.