Bug 442579 - Backport fix for possible data corruption in mark_buffer_dirty on SMP
Backport fix for possible data corruption in mark_buffer_dirty on SMP
Status: CLOSED ERRATA
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel (Show other bugs)
4.8
All Linux
medium Severity medium
: rc
: ---
Assigned To: Mikulas Patocka
Martin Jenner
http://git.kernel.org/?p=linux/kernel...
:
Depends On: 442577
Blocks: 461304
  Show dependency treegraph
 
Reported: 2008-04-15 12:50 EDT by Mikulas Patocka
Modified: 2009-05-18 15:32 EDT (History)
13 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Environment:
Last Closed: 2009-05-18 15:32:32 EDT
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
CRM:
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---


Attachments (Terms of Use)

  None (edit)
Description Mikulas Patocka 2008-04-15 12:50:20 EDT
+++ This bug was initially created as a clone of Bug #442577 +++

Description of problem:

Function mark_buffer_dirty() contains SMP-unsafe optimization. If CPU reorders
instructions in certain way, it may cause that modified data are not written and
filesystem corruption happens.

For discussion, see the thread at
http://www.uwsg.indiana.edu/hypermail/linux/kernel/0804.0/0854.html

There are several possible fixes with different performance and complexity (see
the thread), the one that went into upstream kernel is this:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=1be62dc190ebaca331038962c873e7967de6cc4b;hp=4ed919014eb2b591eb8fdd4dd00226a65faddef4

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

How reproducible:
Can't be reproduced, was found during source code review.
If data corruption because of this bug ever happened, it would be very hard to
link the corruption to this problem --- so maybe it would be better to fix the
bug preemtively.
Comment 1 RHEL Product and Program Management 2008-04-15 14:09:56 EDT
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 2 RHEL Product and Program Management 2008-09-03 09:10:23 EDT
Updating PM score.
Comment 3 Vivek Goyal 2008-09-12 15:58:05 EDT
Committed in 78.9.EL . RPMS are available at http://people.redhat.com/vgoyal/rhel4/
Comment 6 errata-xmlrpc 2009-05-18 15:32:32 EDT
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 therefore 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-2009-1024.html

Note You need to log in before you can comment on or make changes to this bug.