[linux-cifs-client] Corrupted data on write to Windows 2003 Server

[Danny Sung]

When copying a file from linux to windows, I noticed corrupted data 
whenever my data size is larger than about 100-200MB.  I ran a few 
tests, using 'dd', writing a 1GB file with varying block sizes (1, 10, 
50, 100, and 200 megs).   Each one reported a different md5 when reading 
back.  Only the 200 MB block size was successful, but it may have been a 
fluke... I need to run the test a few more times.

The actual number of bytes in the destination file is correct.  But 
running 'cmp' afterwards, I discovered that the destination ends up 
being 0 padded after a certain point.  The exact spot seems to wander, 
but it appears to be around the 800-900MB mark for these files.

I don't get any error messages or anything from the actual 'dd' command. 
  The only message I get is a kernel message saying: "CIFS VFS: No 
writable handles for inode", which I suppose explains it all.  But it'd 
be nice if the user commands reported some sort of failure.

I don't suppose there are any mount options I can give to cifs to make 
it do more checking or retries or anything?  Or how do I actually 
prevent the "no writable handles" problem?

Of course, if I use rsync, that seems to get around the problem.  But it 
seems kind dumb to have to do that for mounted filesystems. =P



Linux system: Fedora Core 5
Linux aeolus.eng.lantronix.com 2.6.18-1.2200.fc5smp #1 SMP Sat Oct 14 
17:15:35 EDT 2006 i686 i686 i386 GNU/Linux


Windows System: Windows Server 2003 R2 Standard w/ SP1

mount options:  cifs (rw,mand)

I don't think this uses samba since cifs is a kernel module, but just in 
case, my samba version is: 3.0.23c

Thanks for any assistance,
Danny

---
Please ignore the following disclaimer, not the message. =)
**********************************************************************
This e-mail is the property of Lantronix. It is intended only for the person or entity to which it is addressed and may contain information that is privileged, confidential, or otherwise protected from disclosure. Distribution or copying of this e-mail, or the information contained herein, to anyone other than the intended recipient is prohibited.