NFS lockup when copying a "special" file

[Sean McNeil]

On Thu, 2006-07-13 at 22:30 +0300, Ruslan Ermilov wrote:
> On Thu, Jul 13, 2006 at 09:09:02PM +0200, Oliver Lehmann wrote:
> > Sean McNeil wrote:
> > 
> > >
> > > I used to have a similar problem and tracked it down to my NIC and
> > > hardware checksums.  Would this happen to be an if_re device?  Can you
> > > give ifconfig info and if hardware checksums are on, try your test with
> > > them turned off (RXCSUM and TXCSUM).  You can try different combos of
> > > these if turning off both helps.
> > 
> > Yeah, it is indeed an on-board if_re:
> > 
> > re0: <RealTek 8169S Single-chip Gigabit Ethernet> port 0xe800-0xe8ff mem 0xcfffff00-0xcfffffff irq 16 at device 11.0 on pci0
> > miibus0: <MII bus> on re0
> > rgephy0: <RTL8169S/8110S media interface> on miibus0
> > rgephy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseTX, 1000baseTX-FDX, auto
> > re0: Ethernet address: 00:11:09:cf:e2:e1
> > re0: [FAST]
> > 
> > 
> > olivleh1 at kartoffel olivleh1> ifconfig
> > re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
> >         options=18<VLAN_MTU,VLAN_HWTAGGING>
> >         inet6 fe80::211:9ff:fecf:e2e1%re0 prefixlen 64 scopeid 0x1 
> >         inet 10.0.1.51 netmask 0xffffff00 broadcast 10.0.1.255
> >         ether 00:11:09:cf:e2:e1
> >         media: Ethernet autoselect (100baseTX <full-duplex>)
> >         status: active
> > plip0: flags=108810<POINTOPOINT,SIMPLEX,MULTICAST,NEEDSGIANT> mtu 1500
> > lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
> >         inet6 ::1 prefixlen 128 
> >         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 
> >         inet 127.0.0.1 netmask 0xff000000 
> > 
> > olivleh1 at kartoffel olivleh1> uname -a
> > FreeBSD kartoffel.salatschuessel.net 6.1-STABLE FreeBSD 6.1-STABLE #0: Fri Jul  7 18:40:18 CEST 2006     olivleh1 at kartoffel.salatschuessel.net:/usr/obj/amd64-athlon64-6.1/usr/src/sys/KARTOFFEL  amd64
> > 
> > How can I disable checksum offloading?
> > 
> The re(4) driver has them disabled by default, though manpage is silent
> about this.
> 
> : revision 1.37
> : date: 2005/01/05 00:06:15;  author: cognet;  state: Exp;  lines: +2 -2
> : Disable checksum offloading by default. It seems to produce corrupted packets
> : with some revisions of the chip (particularly when using multiple TX
> : descriptors).
> : 
> : MFC after:      1 week

ethereal is a good tool to get a better understanding of what is going
on here.