Bug 185459

Summary: kernel dm snapshots: fix invalidation
Product: Red Hat Enterprise Linux 4 Reporter: Alasdair Kergon <agk>
Component: kernelAssignee: Alasdair Kergon <agk>
Status: CLOSED ERRATA QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.0CC: jbaron, mbroz
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: RHSA-2006-0575 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2006-08-10 22:44:19 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 181409    

Description Alasdair Kergon 2006-03-14 22:16:14 UTC
When a snapshot becomes invalid, s->valid is set to 0.  In this state, a
snapshot can no longer be accessed.
 
When s->lock is acquired, before doing anything else, s->valid must be checked
to ensure the snapshot remains valid.
 
This patch eliminates some races (that may cause panics) by adding some
missing checks.  At the same time, some unnecessary levels of indentation are
removed and snapshot invalidation is moved into a single function that always
generates a device-mapper event.

Comment 2 Jason Baron 2006-03-28 17:59:08 UTC
committed in stream u4 build 34.9. A test kernel with this patch is available
from http://people.redhat.com/~jbaron/rhel4/


Comment 6 Red Hat Bugzilla 2006-08-10 22:44:19 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/RHSA-2006-0575.html