Bug 1437797

Summary: Volume's format should be updated automatically after it is wiped
Product: Red Hat Enterprise Linux 7 Reporter: lijuan men <lmen>
Component: libvirtAssignee: John Ferlan <jferlan>
Status: CLOSED ERRATA QA Contact: jiyan <jiyan>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 7.4CC: dyuan, rbalakri, xuzhang, yisun
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: libvirt-3.7.0-1.el7 Doc Type: No Doc Update
Doc Text:
undefined
Story Points: ---
Clone Of: Environment:
Last Closed: 2018-04-10 10:42:33 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description lijuan men 2017-03-31 08:34:39 UTC
Description of problem:
Volume's format should be updated automatically after it is wiped

Version-Release number of selected component (if applicable):
libvirt-3.1.0-2.el7.x86_64
qemu-kvm-rhev-2.8.0-6.el7.x86_64


How reproducible:
100%

Steps to Reproduce:

1.create a volume(format is qcow2) in the default pool

[root@lmen1 ~]# virsh vol-dumpxml abc.qcow2 default
<volume type='file'>
  <name>abc.qcow2</name>
  <key>/var/lib/libvirt/images/abc.qcow2</key>
  <source>
  </source>
 ...
    <path>/var/lib/libvirt/images/abc.qcow2</path>
  ***  <format type='qcow2'/> ***
    <permissions>
  ...
  </target>
</volume>


2.wipe the volume
[root@lmen1 ~]# virsh vol-wipe abc.qcow2 default
Vol abc.qcow2 wiped

3.check the format before refreshing the pool
[root@lmen1 ~]# virsh vol-dumpxml abc.qcow2 default
<volume type='file'>
  <name>abc.qcow2</name>
  <key>/var/lib/libvirt/images/abc.qcow2</key>
...
    <path>/var/lib/libvirt/images/abc.qcow2</path>
 ***   <format type='qcow2'/> ***
    <permissions>
...
  </target>
</volume>

4.check the format after refreshing the pool
[root@lmen1 ~]# virsh pool-refresh default
Pool default refreshed

[root@lmen1 ~]# virsh vol-dumpxml abc.qcow2 default
<volume type='file'>
  <name>abc.qcow2</name>
  <key>/var/lib/libvirt/images/abc.qcow2</key>
 ...
    <path>/var/lib/libvirt/images/abc.qcow2</path>
  ***    <format type='raw'/>   ***
    <permissions>
 ...
  </target>
</volume>

Actual results:
Volume's format is not updated automatically

Expected results:
Volume's format should be updated automatically


Additional info:

Comment 2 John Ferlan 2017-08-24 22:32:24 UTC
I've posted a couple patches upstream for review, see:

https://www.redhat.com/archives/libvir-list/2017-August/msg00739.html

Testing showed the following results:

# virsh vol-create-as default bz 10M --format qcow2
Vol bz created


# virsh vol-dumpxml bz default | grep format
    <format type='qcow2'/>
# virsh vol-wipe bz default
Vol bz wiped

# virsh vol-dumpxml bz default | grep format
    <format type='raw'/>
# virsh vol-delete bz default
Vol bz deleted

#

NB: For each test pass (without changes and with changes) the vol sizes were:

"After create":

  <capacity unit='bytes'>10485760</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>196616</physical>

"After refresh" (either algorithm, including doing pool refresh):

  <capacity unit='bytes'>200704</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>200704</physical>

So that did not change

Comment 3 John Ferlan 2017-08-30 19:37:07 UTC
Pushed the change upstream:

commit d16f803d780f63b8899df04b624d5acfd6939541
Author: John Ferlan <jferlan>
Date:   Thu Aug 24 18:19:14 2017 -0400

    storage: Use virStorageBackendRefreshVolTargetUpdate after wipeVol
    
...
    
    Rather than using refreshVol which essentially only updates the
    allocation, capacity, and permissions for the volume, but not
    the format which does get updated in a pool refresh - let's use
    the same helper that pool refresh uses in order to update the
    volume target.


$ git describe d16f803d780f63b8899df04b624d5acfd6939541
v3.7.0-rc1-13-gd16f803
$

Comment 5 jiyan 2017-09-09 11:11:10 UTC
Test env components:
libvirt-3.7.0-2.el7.x86_64
qemu-kvm-rhev-2.9.0-16.el7_4.6.x86_64
kernel-3.10.0-709.el7.x86_64

Test scenarios:
Scenario-1: Wipe a volume without backing file
1. Prepare a volume named '1.qcow2' in 'default' pool, and display the dumpxml file info of the volume
# virsh pool-list --all |grep default
 default              active     yes   

# qemu-img info /var/lib/libvirt/images/1.qcow2 --backing-chain
image: /var/lib/libvirt/images/1.qcow2
file format: qcow2
virtual size: 1.0G (1073741824 bytes)
disk size: 196K
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false

# virsh vol-list default |grep 1.qcow2
 1.qcow2              /var/lib/libvirt/images/1.qcow2  

# virsh vol-dumpxml 1.qcow2 default
  ...
  <capacity unit='bytes'>1073741824</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>196624</physical>
  ...
    <path>/var/lib/libvirt/images/1.qcow2</path>
    <format type='qcow2'/>
  ...

2. Wipe the volume and then check the dumpxml file info of the volume
# virsh vol-wipe 1.qcow2 default
Vol 1.qcow2 wiped

# virsh vol-dumpxml 1.qcow2 default
  ...
  <capacity unit='bytes'>200704</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>200704</physical>
  ...
    <path>/var/lib/libvirt/images/1.qcow2</path>
    <format type='raw'/>
  ...

3. Check the dumpxml file info of the volume after refreshing the pool
# virsh pool-refresh default
Pool default refreshed

# virsh vol-dumpxml 1.qcow2 default
  ...
  <capacity unit='bytes'>200704</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>200704</physical>
  ...
    <path>/var/lib/libvirt/images/1.qcow2</path>
    <format type='raw'/>
  ...

Scenario-2: Wipe a volume with backing file
1. Prepare a volume named '2.qcow2' in 'default' pool with backing file named '1.qcow2', and display the dumpxml file info of the volume
# virsh pool-list --all |grep default
 default              active     yes  

# qemu-img info /var/lib/libvirt/images/2.qcow2 --backing-chain
image: /var/lib/libvirt/images/2.qcow2
file format: qcow2
virtual size: 1.0G (1073741824 bytes)
disk size: 196K
cluster_size: 65536
backing file: 1.qcow2 (actual path: /var/lib/libvirt/images/1.qcow2)
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false

image: /var/lib/libvirt/images/1.qcow2
file format: qcow2
virtual size: 1.0G (1073741824 bytes)
disk size: 196K
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false

# virsh vol-list default |grep 2.qcow2
 2.qcow2              /var/lib/libvirt/images/2.qcow2    

# virsh vol-dumpxml 2.qcow2 default
  ...
  <capacity unit='bytes'>1073741824</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>196624</physical>
  <target>
    <path>/var/lib/libvirt/images/2.qcow2</path>
    <format type='qcow2'/>
  </target>
  ...
  <backingStore>
    <path>/var/lib/libvirt/images/1.qcow2</path>
    <format type='qcow2'/>
  </backingStore>
  ...

2. Wipe the volume and then check the dumpxml file info of the volume
# virsh vol-wipe 2.qcow2 default
Vol 2.qcow2 wiped

# virsh vol-dumpxml 2.qcow2 default
  ...
  <capacity unit='bytes'>200704</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>200704</physical>
  <target>
    <path>/var/lib/libvirt/images/2.qcow2</path>
    <format type='raw'/>
  </target>
  <backingStore>
    <path>/var/lib/libvirt/images/1.qcow2</path>
    <format type='qcow2'/>
  </backingStore>
  ...

3. Check the dumpxml file info of the volume after refreshing the pool
Note: Backing file is not supported for file format 'raw'.
# virsh pool-refresh default
Pool default refreshed

# virsh vol-dumpxml 2.qcow2 default
  ...
  <capacity unit='bytes'>200704</capacity>
  <allocation unit='bytes'>200704</allocation>
  <physical unit='bytes'>200704</physical>
  <target>
    <path>/var/lib/libvirt/images/2.qcow2</path>
    <format type='raw'/>
  </target>
  ...

All the results are as expected, move this bug to be verified.

Comment 9 errata-xmlrpc 2018-04-10 10:42:33 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2018:0704