[linux-cifs-client] [patch] Increase send time out on a socket long enough inorder to eliminate any timeouts on large sends

[Shirish Pargaonkar]

On Thu, Jul 23, 2009 at 7:05 AM, Jeff Layton<jlayton at redhat.com> wrote:
> On Wed, 22 Jul 2009 20:14:38 -0500
> Shirish Pargaonkar <shirishpargaonkar at gmail.com> wrote:
>
>> Inspite of a set of data integrity patches in cifs last yer, there
>> still persist errors
>> caused due to timeouts resulting in sending incomplete data and
>> hence data integrity errors.
>>
>> The proposed socket send timeout is large enough to elminate that possibility.
>
> On what evidence do you base the above statement? Who's to say that 30s
> is long enough if someone has a high-latency enough connection?
>
>> The tests with this patches have resulted in elminating data integrity errors on
>> an 80 hours test runs which otherwise manifest in matter of hours of a test run.
>>
>
> Also, can you give some details about these data integrity errors? Were
> writes failing? If so, were they not reported at fsync or close?

The errors logged by cifs client were like this
This is what I had seen last year when the patches were developed.
The entire write could not be sent because of socket timeout, other thread
fills in rest of the 56K write so that second 56K is not responded and client
logs 'No response for cmd'.
The longer timeout seems to be long enough for server to receive entire
smbwrite (56K).

May 12 05:17:09 voyBCSsles11-rc3 kernel:  CIFS VFS: server not responding
May 12 05:17:09 voyBCSsles11-rc3 kernel:  CIFS VFS: No response for cmd 50 mid
20646
May 12 05:17:09 voyBCSsles11-rc3 kernel:  CIFS VFS: No response to cmd 47 mid
20647
May 12 05:17:09 voyBCSsles11-rc3 kernel:  CIFS VFS: Write2 ret -11, wrote 0
May 12 05:17:11 voyBCSsles11-rc3 kernel:  CIFS VFS: Write2 ret -9, wrote 0
May 12 05:17:39 voyBCSsles11-rc3 kernel:  CIFS VFS: server not responding
May 12 05:17:39 voyBCSsles11-rc3 kernel:  CIFS VFS: No response for cmd 50 mid
21347
May 12 05:17:39 voyBCSsles11-rc3 kernel:  CIFS VFS: No response to cmd 47 mid
21348
May 12 05:17:39 voyBCSsles11-rc3 kernel:  CIFS VFS: Write2 ret -11, wrote 0
May 12 05:17:39 voyBCSsles11-rc3 kernel:  CIFS VFS: Write2 ret -9, wrote 0
May 12 05:18:09 voyBCSsles11-rc3 kernel:  CIFS VFS: server not responding
May 12 05:18:09 voyBCSsles11-rc3 kernel:  CIFS VFS: No response to cmd 46 mid
24859
May 12 05:18:09 voyBCSsles11-rc3 kernel:  CIFS VFS: Send error in read = -11
May 12 05:18:09 voyBCSsles11-rc3 kernel:  CIFS VFS: No response for cmd 50 mid
24858


>
> My suspicion is that the main problem here is the default of "soft" for
> CIFS mounts. It's well known that that's a recipe for data corruption
> with NFS and there's no reason why it wouldn't be the same for CIFS.
>
> Instead of this patch, how about doing a patch that fixes the
> hard/soft mount options for CIFS and see whether you can still
> reproduce the data corruption with a hard mount?
>
> --
> Jeff Layton <jlayton at redhat.com>
>