Bug 1827761

Summary:	After a system crash, VDO can report a slab journal block underflow
Product:	Red Hat Enterprise Linux 8	Reporter:	Andy Walsh <awalsh>
Component:	kmod-kvdo	Assignee:	corwin <corwin>
Status:	CLOSED ERRATA	QA Contact:	Filip Suba <fsuba>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	8.3	CC:	awalsh
Target Milestone:	rc	Flags:	pm-rhel: mirror+
Target Release:	8.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	6.2.3.91	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-11-04 02:01:47 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Andy Walsh 2020-04-24 17:59:55 UTC

Description of problem:
We have seen in our tests that when a system has crashed and recovered that there was a slab journal block underflow logged.

Version-Release number of selected component (if applicable):
kmod-kvdo-6.2.2.117

How reproducible:
Rare

Steps to Reproduce:
Cause a slab journal block underflow (unknown currently how to reproduce) by maybe crashing the system a whole bunch of times, but it is unclear what conditions specifically cause it.

Actual results:
[38918.224042] uds: kvdo1:physQ0: assertion "decrement of lock count for slab journal block 958 must not underflow" ((-adjustment <= lock->count)) failed at /var/lib/dkms/kvdo/6.2.2/build/kvdo/slabJournal.c:1129

Expected results:
A more clear message indicating what caused the underflow and by how much, and eventually no message at all.

Additional info:

Comment 3 Filip Suba 2020-08-21 08:57:46 UTC

Verified SanityOnly. Regression testing passed.

Comment 6 errata-xmlrpc 2020-11-04 02:01:47 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (kmod-kvdo bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:4551