[Samba] mount.cifs: regular freezes with s3fs

[steve]

cifs-utils-5.6
samba Version 4.0.0rc3
openSUSE 12.2
LAN of XP, w7 and Linux clients under Samba4 DC and s3fs fileserver

Hi
I am testing the possibility of migrating from nfs to cifs to serve our 
Linux clients.

Currently we mount the samba shares, e.g. the home directory, using nfs.

The test setup is that instead of:
mount -t nfs hh1:/home2 /home2 -osec=rw,krb5
I changed to:
mount -t cifs //hh1/home2 /home2 -osec=rw,sec=krb5,multiuser

This works fine for console logins, but is very slow (unusable) for 
graphical logins to either LXDE or XFCE.

The login sometimes works:
Kerberos: AS-REQ steve3 at HH3.SITE from ipv4:192.168.1.41:57380 for 
krbtgt/HH3.SITE at HH3.SITE
Kerberos: Client sent patypes: 149
Kerberos: Looking for PKINIT pa-data -- steve3 at HH3.SITE
Kerberos: Looking for ENC-TS pa-data -- steve3 at HH3.SITE
Kerberos: No preauth found, returning PREAUTH-REQUIRED -- steve3 at HH3.SITE
Kerberos: AS-REQ steve3 at HH3.SITE from ipv4:192.168.1.41:41237 for 
krbtgt/HH3.SITE at HH3.SITE
Kerberos: Client sent patypes: encrypted-timestamp, 149
Kerberos: Looking for PKINIT pa-data -- steve3 at HH3.SITE
Kerberos: Looking for ENC-TS pa-data -- steve3 at HH3.SITE
Kerberos: ENC-TS Pre-authentication succeeded -- steve3 at HH3.SITE using 
arcfour-hmac-md5
Kerberos: AS-REQ authtime: 2012-10-18T09:57:33 starttime: unset endtime: 
2012-10-18T19:57:33 renew till: 2012-10-19T09:55:48
Kerberos: Client supported enctypes: aes256-cts-hmac-sha1-96, 
aes128-cts-hmac-sha1-96, des3-cbc-sha1, arcfour-hmac-md5, using 
arcfour-hmac-md5/arcfour-hmac-md5
Kerberos: Requested flags: renewable, forwardable
Kerberos: TGS-REQ steve3 at HH3.SITE from ipv4:192.168.1.41:50790 for 
host/hh7.hh3.site at HH3.SITE [canonicalize, renewable, forwardable]
Kerberos: TGS-REQ authtime: 2012-10-18T09:57:33 starttime: 
2012-10-18T09:57:33 endtime: 2012-10-18T10:02:33 renew till: 
2012-10-19T09:55:48
Kerberos: TGS-REQ steve3 at HH3.SITE from ipv4:192.168.1.41:44350 for 
cifs/hh1 at HH3.SITE [canonicalize, renewable, forwardable]
Kerberos: TGS-REQ authtime: 2012-10-18T09:57:33 starttime: 
2012-10-18T09:57:33 endtime: 2012-10-18T19:57:33 renew till: 
2012-10-19T09:55:48

But then as soon as we open the file manager (or do anything else) it 
freezes for as long as 5 minutes, before it makes another cifs request 
and comes alive for a while:

Terminating connection - 'wbsrv_call_loop: tstream_read_pdu_blob_recv() 
- NT_STATUS_CONNECTION_DISCONNECTED'
single_terminate: reason[wbsrv_call_loop: tstream_read_pdu_blob_recv() - 
NT_STATUS_CONNECTION_DISCONNECTED]
Kerberos: TGS-REQ steve3 at HH3.SITE from ipv4:192.168.1.41:58872 for 
cifs/hh1 at HH3.SITE [canonicalize, renewable, forwardable]
Kerberos: TGS-REQ authtime: 2012-10-18T09:57:33 starttime: 
2012-10-18T09:59:58 endtime: 2012-10-18T19:57:33 renew till: 
2012-10-19T09:55:48

It is then OK for a few minutes more until it freezes again until the 
next cifs request etc etc. . .

This sometimes occurs in the samba log but with different files each time:
usr/local/samba/sbin/smbd: Oplock break failed for file 
home/steve3/.cache/openbox/openbox.log -- replying anyway

Here is the test smb.conf:

# Global parameters
[global]
         workgroup = MARINA
         realm = hh3.site
         netbios name = HH1
         server role = active directory domain controller
         dns forwarder = 192.168.1.1
         idmap_ldb:use rfc2307 = Yes
         unix extensions = Yes
         panic action = /home/steve/samba-master/selftest/gdb_backtrace %d

[netlogon]
         path = /usr/local/samba/var/locks/sysvol/hh3.site/scripts
         read only = No

[sysvol]
         path = /usr/local/samba/var/locks/sysvol
         read only = No

[home2]
         path = /home2
         read only = No

Here is the wireshark of a login and a 'cifs freeze'.
https://dl.dropbox.com/u/45150875/cifs-freeze

Please note that this works fine for the same user and data with both 
nfs3 and nfs4.

Any help most grateful.
Cheers,
Steve