Bug 358821 - DLM: block dlm_recv in recovery transition
Summary: DLM: block dlm_recv in recovery transition
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel
Version: 5.1
Hardware: All
OS: Linux
low
low
Target Milestone: ---
: ---
Assignee: David Teigland
QA Contact: Cluster QE
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2007-10-30 18:36 UTC by David Teigland
Modified: 2008-05-21 14:59 UTC (History)
2 users (show)

Fixed In Version: RHBA-2008-0314
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2008-05-21 14:59:47 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2008:0314 0 normal SHIPPED_LIVE Updated kernel packages for Red Hat Enterprise Linux 5.2 2008-05-20 18:43:34 UTC

Description David Teigland 2007-10-30 18:36:49 UTC
Description of problem:

Introduce a per-lockspace rwsem that's held in read mode by dlm_recv
threads while working in the dlm.  This allows dlm_recv activity to be
suspended when the lockspace transitions to, from and between recovery
cycles.

The specific bug prompting this change is one where an in-progress
recovery cycle is aborted by a new recovery cycle.  While dlm_recv was
processing a recovery message, the recovery cycle was aborted and
dlm_recoverd began cleaning up.  dlm_recv decremented recover_locks_count
on an rsb after dlm_recoverd had reset it to zero.  This is fixed by
suspending dlm_recv (taking write lock on the rwsem) before aborting the
current recovery.

The transitions to/from normal and recovery modes are simplified by using
this new ability to block dlm_recv.  The switch from normal to recovery
mode means dlm_recv goes from processing locking messages, to saving them
for later, and vice versa.  Races are avoided by blocking dlm_recv when
setting the flag that switches between modes.

Upstream commit
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=c36258b5925e6cf6bf72904635100593573bfcff

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


How reproducible:


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Comment 2 RHEL Program Management 2007-11-29 16:45:40 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 3 Don Zickus 2007-12-17 19:37:13 UTC
in 2.6.18-61.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Comment 6 errata-xmlrpc 2008-05-21 14:59:47 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2008-0314.html



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