Bug 210178

Summary: md: write behind feature does not work on big endian machines
Product: Red Hat Enterprise Linux 5 Reporter: Paul Clements <paul.clements>
Component: kernelAssignee: Doug Ledford <dledford>
Status: CLOSED ERRATA QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.0CC: dzickus
Target Milestone: ---   
Target Release: ---   
Hardware: ppc64   
OS: Linux   
Whiteboard:
Fixed In Version: RHBA-2008-0314 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2008-05-21 14:39:53 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:
Attachments:
Description Flags
patch none

Description Paul Clements 2006-10-10 16:33:19 UTC 
Description of problem:

There is a bug in the md driver. find_first_set_bit doesn't find the
least-significant bit on bigendian machines, so it is really wrong to use it.

ffs is closer, but takes an 'int' and we have a 'unsigned long'.  So use
ffz(~X) to convert a chunksize into a chunkshift.

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

kernel 2.6.17-1.2519.4.21.el5

Patch attached (patch is now in mainline).
Comment 1 Paul Clements 2006-10-10 16:33:19 UTC 
Created attachment 138158 [details]
patch
Comment 2 Linda Wang 2008-01-02 20:30:34 UTC 
patch posted 12/04/07.
Comment 4 Don Zickus 2008-01-08 20:45:49 UTC 
in 2.6.18-64.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5
Comment 6 Mike Gahagan 2008-04-02 21:29:06 UTC 
Confirmed the fix is in the -87.el5 kernel.
Comment 8 errata-xmlrpc 2008-05-21 14:39:53 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