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Bug 492488

Summary: Driver core: make bus_find_device_by_name() more robust
Product: Red Hat Enterprise Linux 5 Reporter: Don Dutile (Red Hat) <ddutile>
Component: kernelAssignee: Don Dutile (Red Hat) <ddutile>
Status: CLOSED ERRATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: medium Docs Contact:
Priority: low    
Version: 5.4CC: dzickus, markmc, mgahagan, syeghiay
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-09-02 08:55:58 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
Posted patch none

Description Don Dutile (Red Hat) 2009-03-26 23:09:20 UTC 
Description of problem:
If one does the following, it fails on RHEL5:
  echo 0000:01:00.0 > /sys/bus/pci/devices/0000:01:00.0/driver/unbind 
with a bash echo write error.

This passes in upstream Linux (> 2.6.27).

Currently, the above is the instruction on how to unbind 
a PCI device so it can be pass-through to a KVM guest.

For user-scripting, it'd be prudent to make rhel5 & future
releases compatible when it comes to the API that does pass-through
for applications.

Version-Release number of selected component (if applicable):
5.3/5.4

How reproducible:
Always

Steps to Reproduce:
1. <as stated above>
2.
3.
  
Actual results:
error occurs, and PCI device is not unbound from the respective driver

Expected results:
no bash errors occur; PCI device is unbound from the respective driver

Additional info:
fix/patch is in upstream; 
commit id: 
   3ce24d8d93f8f9617841d0c8416174da7ee1b042
Description: same as this bz: 
   Driver core: make bus_find_device_by_name() more robust
Comment 1 Mark McLoughlin 2009-04-23 06:49:27 UTC 
The fix:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=3ce24d8d93

also requires sysfs_streq():

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=34990cf702
Comment 2 Don Dutile (Red Hat) 2009-04-23 21:43:10 UTC 
Created attachment 341028 [details]
Posted patch
Comment 4 Don Zickus 2009-05-06 17:17:15 UTC 
in kernel-2.6.18-144.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Please do NOT transition this bugzilla state to VERIFIED until our QE team
has sent specific instructions indicating when to do so.  However feel free
to provide a comment indicating that this fix has been verified.
Comment 7 errata-xmlrpc 2009-09-02 08:55:58 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 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-2009-1243.html