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

[Shirish S Pargaonkar]

linux-cifs-client-bounces+shirishp=us.ibm.com at lists.samba.org wrote on
12/08/2006 01:24:24 PM:

> 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.
>
> _______________________________________________
> linux-cifs-client mailing list
> linux-cifs-client at lists.samba.org
> https://lists.samba.org/mailman/listinfo/linux-cifs-client

This patch to cifs.ko should fix the problem, and you do not have to cifs
mount with forcedirectio

http://master.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff_plain;h=cb876f451455b6187a7d69de2c112c45ec4b7f99


Regards,

Shirish
-------------- next part --------------
HTML attachment scrubbed and removed