kern/42241: Problems with AIO and Samba

[stadtkind2%gmx.de@localhost]

>Number:         42241
>Category:       kern
>Synopsis:       Problems with AIO and Samba
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Oct 28 11:00:01 +0000 2009
>Originator:     Stefan Krüger
>Release:        NetBSD 5.0.1
>Organization:
>Environment:
NetBSD localhost 5.0.1 NetBSD 5.0.1 (GENERIC) #0: Thu Jul 30 01:39:11 UTC 2009  
builds%b8.netbsd.org@localhost:/home/builds/ab/netbsd-5-0-1-RELEASE/i386/200907292356Z-obj/home/builds/ab/netbsd-5-0-1-RELEASE/src/sys/arch/i386/compile/GENERIC
 i386
>Description:
As already written in 
http://mail-index.netbsd.org/tech-kern/2009/10/27/msg006371.html , Samba 
compilied with AIO support and aio read/write enabled in smb.conf doesn't work 
correctly. The connection is dropped after some time (randomly with normal 
usage, pretty fast with Bart's Stuff Test 5, see "How to repeat").

A quick testrun produced a 46M ktrace.out file (120M "decoded" with kdump), 
which showed nothing suspicious IMHO

Running smbd with '-i' makes Samba quit during the test (I see a SIGTERM in 
ktrace), running it daemonized '-D' just spawns a new child it seems.

Mounting the share on FreeBSD (via mount_smbfs) and running fsx (File system 
exerciser, can be found in FreeBSDs src/tools/regression/fsx/ directory) on it 
works w/o any problems though...
>How-To-Repeat:
(Re)compile Samba with the following line

CONFIGURE_ARGS+=        --with-aio-support

added to pkgsrc/net/samba/Makefile

Edit smb.conf to include

aio read size = 4096
aio write size = 4096

Connect to the AIO enabled Samba share on Windows and run Bart's Stuff Test 5 ( 
http://www.nu2.nu/bst/ ) on it to trigger the problem easily
>Fix: