Distribution:
gentoo with vanilla kernel 2.6.9

Hardware Environment:
x86: dual xeon 3.06ghz

Problem Description:
If I read large files (~180mB) from a network fs (nfs _and_ smb) which are not
yet cached, I get corrupt files (checked with md5sum, cmp and diff). But if I
read the file again just after the first reading (while it's still in the local
mem-cache) I get the files without any corruption. 
If I read the files from a local fs everything is fine.

Steps to reproduce:
Let's say /nfs is a directory the a nfs-server and /nfs/file has a size of 180mB.
Further let's say /local is a local directory and /local/sum.md5 contains the
_correct_ md5-sum of /nfs/file (built this directly on the server and
transferred it on an other way, so this file _is_ correct).
Now I do the following:
cd /local
cp /nfs/file .    # I see much transfer on eth0 while the file gets transferred
md5sum -c sum.md5 # Result: FAILED
rm file
cp /nfs/file .    # There's almost no load on eth0 as the file is still in the
local cache
md5sum -c sum.md5 # Result: OK

so it seems there's something wrong with the local file-buffer or something like
that...

Ok, I held this report short, but I'll attach a mail I sent on LKML which
contains much more details about what I checked...

Sincerly, 
 Thomas