A.P. Lawrence

samba

If this isn't exactly what you wanted, please try our Search (there's a LOT of techy and non-techy stuff here about Linux, Unix, Mac OS X and just computers in general!):

From: Bela Lubkin <belal@caldera.com>
Subject: Re: Samba? streams leak
Date: Fri, 11 Oct 2002 08:36:17 GMT References: <Xns926797DEE445Bsniggle@216.166.71.231>

Someone calling himself "sniggle" wrote:

> Here's what I've got:
> 
> SCO 5.0.5
> oss459b (coff linker) patch
> oss497c (core os) patch
> oss499a (elf linker) patch
> oss505a (os supp) 
> oss505a (softmgr supp)
> oss600a (y2k)
> gcc from skunkware binaries
> mysql-3.23.49 (with FSU-pthreads-3.5c)
> apache 1.3.26
> 
> and finally
> samba 2.2.5 skunkware
> 
> and I've got a streams leak of about 2.2meg/week
> (lsof reports about 80 open handles of various types for 3 connections)
> 
> Stop samba, and streams leak stops.
> 
> I've tried several back versions of samba (224, 223a and 221 I built 
> myself) and they still leak. I've got a suspicion it's not really samba, 
> but something I've done incorrectly in applying the patches, or GCC or 
> something.

Someone asked me about this at GeoForum in Las Vegas; maybe even the
same person (he didn't introduce himself as "sniggle"...)

We tracked it down to a small OpenServer kernel bug that Samba was
triggering repeatedly.  The bug is fixed in OpenServer 5.0.7, but
meanwhile, a small patch to Samba causes it to stop triggering it.  I
believe a similar change may also be included in a newer version of
Samba (perhaps not out yet).

I don't have Samba source in front of me, but from my notes: find
source/lib/util_sock.c.  In its function print_socket_options(), notice
a loop where it prints out a bunch of information about socket options
using a Samba debug macro.  In effect, it says:

  loop over all options {
    DEBUGPRINT(5, "...", getsockopt(...))
  }

Either comment out this loop, or put at the top of the routine something
that says:

  if (DEBUGLEVEL < 5) return;   /* not the right variable name... */

The leak happens when Samba asks the kernel about socket options that
are not supported.  The loop calls getsockopt() with every possible
option (including some that the kernel doesn't support), and then
discards the data without using it at all, unless the debug level is
high.

I would appreciate it if some Samba hacker would reply to this,
translating my handwaving into an actual source-level patch...

> 4.  This all started when samba was upgraded to support XP. Does XP do 
> anything "funny" that could cause samba to leak on SCO?

I don't know Samba history, but I wouldn't be surprised to find that
this code (either the debug code to display all socket options, or
possibly _all_ knowledge of socket options) was added to deal with some
sort of XP peculiarity...

>Bela<

Enter your email address for automatic notification of new posts here
(be sure to whitelist 'feedburner.com' if you use spam filtering)

Need eyes on the ground at your customer's site?
Installation and light training Boston and New England
Reliable and experienced, punctual and professional.

/Bofcusm/1648.html copyright 1997-2004 Bela Lubkin All Rights Reserved

Have you tried Searching this site?

Unix/Linux/Mac OS X support by phone, email or on-site: Support Rates

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more. We appreciate comments and article submissions.

Publishing your articles here