Bug 682151

Summary:	guest can not reboot after hot remove in used virtio block device
Product:	Red Hat Enterprise Linux 5	Reporter:	Shirley Zhou <szhou>
Component:	kernel	Assignee:	Red Hat Kernel Manager <kernel-mgr>
Status:	CLOSED WORKSFORME	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	5.7	CC:	juzhang, mshao, xfu
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-06-10 04:30:27 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:	580948

Description Shirley Zhou 2011-03-04 10:21:05 UTC

Description of problem:
dd file to attached virtio disk, and hot remove this virtio disk, because this disk is in use, so it can not be removed. After that, guest can not be reboot in guest.

Version-Release number of selected component (if applicable):
guest kernel:kernel-2.6.18-238.5.1.el5
host qemu:qemu-kvm-0.12.1.2-2.113.el6_0.8.x86_64

How reproducible:
100%

Steps to Reproduce:
1.start qemu rhel5.6.z guest, one boot disk, one virtio data disk
2.login guest, make partition and make file sytem on this data disk, and mount this disk to /mnt
3. dd big file to /mnt
#dd if=/dev/urandom of=/mnt/test bs=1M count=2048 conv=fsync
4. before dd finish, hot remove this disk via qemu monitor
#(qemu) device_del $device_id
5. excute reboot command in guest
  
Actual results:
after step5, reboot message broadcast, but guest keep running, not restart.

Expected results:
guest can be reboot ok

Additional info:

Tried on RHEL6.1 guest, can be reboot ok after step 5.

Comment 1 FuXiangChun 2011-06-09 11:10:32 UTC

tested on

host info:
# uname -r
2.6.32-156.el6.x86_64
#rpm -qa|grep kvm
qemu-kvm-0.12.1.2-2.164.el6.x86_64

guest info:
# uname -r
2.6.18-267.el5

steps to test:

1./usr/libexec/qemu-kvm -m 4G -smp 2 -usbdevice tablet -drive file=rhel5.7-64,if=none,id=drive-virtio0,werror=stop,rerror=stop,cache=none -boot c -device virtio-blk-pci,drive=drive-virtio0,id=virtio-blk-pci0 -drive file=/root/2.qcow2,if=none,id=drive-virtio0-1,format=qcow2,cache=none -device virtio-blk-pci,drive=drive-virtio0-1,id=virtio-blk-pci0-1 -netdev tap,id=hostnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,mac=02:00:ff:3F:2f:1f,bus=pci.0 -uuid `uuidgen` -name rhel57 -cdrom /dev/sr0 -monitor stdio -vnc :1

2. format a new disk and mount it in guest 
mkfs -t ext3 /dev/vdb in guest
mount /dev/vdb /mnt/

3.dd if=/dev/urandom of=/mnt/test bs=1M count=2048 conv=fsync
4.(qemu) device_del virtio-blk-pci0-1

5. reboot guest in guest

result:
guest can be reboot.

Based on above ,this bug can not be reproduced.

Comment 2 juzhang 2011-06-10 04:30:27 UTC

According to comment1, close this issue as worksforeme,if anybody hit this issue again,please re-open it.