Bug 687042

Summary:	virtio_blk: Export device serial id attribute
Product:	Red Hat Enterprise Linux 6	Reporter:	Vivek Goyal <vgoyal>
Component:	kernel	Assignee:	Vivek Goyal <vgoyal>
Status:	CLOSED DUPLICATE	QA Contact:	Red Hat Kernel QE team <kernel-qe>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	6.2	CC:	chellwig, jzhenyon, msnitzer, 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:	2011-08-04 16:59:00 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Bug Depends On:	688604, 710349
Bug Blocks:

Description Vivek Goyal 2011-03-15 14:47:33 UTC

Description of problem:

In kdump (kexec-tools) we are introducing better features for device identification so that we reduce the probably of dumping on wrong device in
second kernel which can possibly happen due to device renaming issues. (see bz 682244).

Kexec-tools will use scsi_id in host and save the unique id of device. Will need similar mechanism for virtio blk devices in guest. Though it is not
clear whether device renumbering will happen for virtio blk devices or not
but having a common mechanism does not hurt.

There is a upstream patch to report serial id of block device and there
is an associated fix. (Thanks to mike snitzer for the background). We need
to backport those fixes.

commit a5eb9e4ff18a33e43557d44b205f953b0c1efade
Author: Ryan Harper <ryanh.com>
Date:   Wed Jun 23 22:19:57 2010 -0500

    virtio_blk: Add 'serial' attribute to virtio-blk devices (v2)

commit e4c4776dea9fd0295ebb3b215599d52938d6d7a3
Author: Mike Snitzer <snitzer>
Date:   Sat Oct 9 12:12:13 2010 +1030

    virtio-blk: fix request leak.
    
    Must drop reference taken by blk_make_request().

There seems to be a qemu patch also which makes sure a serial id is generated
for the disk. Shall have to make sure that 6.2 qemu has that patch.

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Comment 2 Vivek Goyal 2011-03-16 22:01:16 UTC

looks like following is upstream qemu-kvm commit to make this work in guest.

commit 2930b313dd602d67a568815b0b031b824916cec9
Author: john cooper <john.cooper>
Date:   Fri Jul 2 13:44:25 2010 -0400

    Add virtio disk identification support
    
    This patch adds the final missing bits for support of
    passing a serial/id string to a virtio-blk guest driver.
    
    The guest-side component already exists in the virtio
    driver, and has recently been reworked by Ryan to export
    a /sys interface for retrieval of the id from guest userland.
    
    Signed-off-by: john cooper <john.cooper>
    Signed-off-by: Kevin Wolf <kwolf>

Comment 3 Vivek Goyal 2011-03-17 13:36:52 UTC

Opened a qemu-kvm bz 688604 to track qemu-kvm changes required to make this work.

Comment 4 RHEL Program Management 2011-04-04 02:35:28 UTC

Since RHEL 6.1 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.

Comment 8 Vivek Goyal 2011-08-04 16:58:14 UTC

Ok, looks like that Amit Shah already committed the patches through bz 694553 in kernel. Closing this bz as duplicate.

Comment 9 Vivek Goyal 2011-08-04 16:59:00 UTC


*** This bug has been marked as a duplicate of bug 694553 ***