Bug 137067 - nbd loses request structures, eventually hangs system
Summary: nbd loses request structures, eventually hangs system
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel   
(Show other bugs)
Version: 4.0
Hardware: All Linux
Target Milestone: ---
: ---
Assignee: Kiersten (Kerri) Anderson
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2004-10-25 17:13 UTC by Paul Clements
Modified: 2007-11-30 22:07 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2005-01-13 17:58:21 UTC
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
nbd patch (2.41 KB, patch)
2004-10-25 17:16 UTC, Paul Clements
no flags Details | Diff

Description Paul Clements 2004-10-25 17:13:42 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040116

Description of problem:
A bug in the nbd driver causes struct requests to be lost, which over
time will cause the system to livelock (kernel debugger trace shows
CPU spinning trying to get a request, which nbd never releases). The
patch to fix this problem is now in mainline, and is attached to this
bug report.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. perform I/O over nbd while periodically breaking the nbd connection
and re-establishing it

Actual Results:  system livelocks

Expected Results:  system should continue working normally

Additional info:

Comment 1 Paul Clements 2004-10-25 17:16:28 UTC
Created attachment 105733 [details]
nbd patch

Comment 2 Bill Nottingham 2004-10-26 16:19:29 UTC
At what point was this patch added to mainline?

Comment 3 Paul Clements 2004-10-26 16:53:14 UTC
~2.6.8 -- I don't have a pristine 2.6.8 sitting in front of me, but it
was around that time, may have been slightly before or after

Comment 7 Kiersten (Kerri) Anderson 2004-10-28 22:07:23 UTC
The patch has already been applied to the RHEL4 B2 kernel when we
updated to the 2.6.9 base, so will be in the B2 release kernel when

Comment 8 Jay Turner 2005-01-13 17:58:21 UTC
Closing out.  Please reopen if the problem is still present with recent code.

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