Bug 796673

Summary: cifs: problem writing files to win2k3 with jumbo frames enabled
Product: Red Hat Enterprise Linux 6 Reporter: Michal <m.myszko>
Component: kernelAssignee: Jeff Layton <jlayton>
Status: CLOSED INSUFFICIENT_DATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: high Docs Contact:
Priority: unspecified    
Version: 6.2CC: agospoda, sprabhu, steved
Target Milestone: rc   
Target Release: 6.2   
Hardware: x86_64   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2012-03-22 15:17:28 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
scr none

Description Michal 2012-02-23 12:56:29 UTC
Description of problem:

I'm coping one file from one share on windows 2003 do another share on another windows 2003

Comment 1 Michal 2012-02-23 12:57:41 UTC
Created attachment 565296 [details]
scr

view of coping

Comment 3 Michal 2012-02-23 13:42:08 UTC
This occurs only when MTU is 9000, if it is 1500 everything is ok

Comment 4 Jeff Layton 2012-02-23 14:56:33 UTC
Interesting.

cifs.ko is more or less a "consumer" of the socket layer. It generally doesn't
much care what sort of MTU you have.

The screenshot shows that attempts to send on the socket are failing with an
-EAGAIN error.

Speculation:

Perhaps the server is shrinking the receive window such that we can't send to
it and not opening it back up in a timely fashion?

Either way, a binary capture of the traffic between client and server would be
interesting. If you need help collecting that, please open a support case with
Red Hat so our support people can assist you.

Comment 5 Jeff Layton 2012-03-22 15:16:01 UTC
No response in

Comment 6 Jeff Layton 2012-03-22 15:17:28 UTC
No response in almost a month and there's very little info to go on. If you're still seeing this problem, what would probably be best is to open a case with
RH support and have them help you gather some more info to help narrow down the
cause.