Bug 430542

Summary:	If write back cache used scsi layer is not sending sync cache to disk
Product:	Red Hat Enterprise Linux 5	Reporter:	Mike Christie <mchristi>
Component:	kernel	Assignee:	Mike Christie <mchristi>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Red Hat Kernel QE team <kernel-qe>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	5.2	CC:	bdonahue, coughlan, emcnabb
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:	2012-06-27 09:27:15 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:	430557, 533192

Description Mike Christie 2008-01-28 18:03:35 UTC

Description of problem:

SCSI layer should be sending sync cache to disk when removing or shutting down
disk if write cache is enabled.


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


How reproducible:


Steps to Reproduce:
1. echo 1 > /sys/block/sdX/device/delete
2.
3.
  
Actual results:

Do not see a sync cache command being sent by the scsi layer.

Expected results:

Should see a "Synchronizing SCSI cache" message in the log, and a sync cache
command in a trace.


Additional info:

Comment 2 RHEL Program Management 2008-01-28 18:56:34 UTC

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 3 Mike Christie 2008-01-28 19:03:04 UTC

(In reply to comment #0)
> Steps to Reproduce:
> 1. echo 1 > /sys/block/sdX/device/delete

Bad test example. This does not seem to work on 5.1 either.

If you reboot or shutdown the system though, the sync cache would get sent in
5.1 and RHEL4, but does not in 5.2.

It looks like there is a reordering of some driver model or scsi device teardown
code.

Comment 5 RHEL Program Management 2008-01-28 19:16:45 UTC

This bugzilla has Keywords: Regression.  

Since no regressions are allowed between releases, 
it is also being proposed as a blocker for this release.  

Please resolve ASAP.

Comment 6 Mike Christie 2008-01-28 21:14:58 UTC

For 5.2, we just do not print out the cache sync message during reboot/shutdown.
It still gets sent and executed.

For all RHEL5 kernels, we do not send the cache sync when manually removing a
device like with "echo 1 > /sys/block/sdX/device/delete".

So there is no regression.

We should send the cache sync during manual removal, but it is too late to fix
this, so I am putting this bug up for 5.3.

Comment 7 RHEL Program Management 2008-01-28 21:16:56 UTC

This bugzilla has Keywords: Regression.  

Since no regressions are allowed between releases, 
it is also being proposed as a blocker for this release.  

Please resolve ASAP.

Comment 8 RHEL Program Management 2008-01-30 22:57:10 UTC

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 9 RHEL Program Management 2008-01-30 23:17:16 UTC

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 10 RHEL Program Management 2008-01-30 23:37:29 UTC

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 13 RHEL Program Management 2008-01-31 04:47:06 UTC

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 16 Tom Coughlan 2008-10-28 18:40:32 UTC

This did not make 5.3, due to a lack of resources. Proposing for 5.4.

Comment 17 RHEL Program Management 2009-02-16 15:34:09 UTC

Updating PM score.

Comment 19 RHEL Program Management 2009-09-25 17:41:50 UTC

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.