Bug 814102
| Summary: | mirroring starts anyway with "existing" mode and a non-existing target | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Shaolong Hu <shu> | |
| Component: | qemu-kvm | Assignee: | Jeff Cody <jcody> | |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> | |
| Severity: | medium | Docs Contact: | ||
| Priority: | urgent | |||
| Version: | 6.3 | CC: | abaron, acathrow, bsarathy, chetan, dyasny, jpallich, juzhang, michen, minovotn, mkenneth, pbonzini, tburke, virt-maint | |
| Target Milestone: | rc | Keywords: | ZStream | |
| Target Release: | --- | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | qemu-kvm-0.12.1.2-2.297.el6 | Doc Type: | Bug Fix | |
| Doc Text: |
A mirroring operation set to "existing" mode was executed even when a target did not exist. Consequently, snapshot-related operations could not be performed because the block device was in use by the mirroring job. Now, a mirror block job is not created if the target bdrv_open() call fails, so mirroring does not start when the target does not exist.
|
Story Points: | --- | |
| Clone Of: | ||||
| : | 861905 (view as bug list) | Environment: | ||
| Last Closed: | 2013-02-21 13:07:34 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: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 844627, 861905, 864962 | |||
I am able to partially reproduce this on qemu-kvm-0.12.1.2-2.295.el6. When I attempt to mirror to a non-existent target while in existing mode, I do get a valid error back:
{"error": {"class": "OpenFileFailed", "desc": "Could not open '/tmp/sn1'", "data": {"filename": "/tmp/sn1"}}}
However, I am still seeing item 4 from comment #1, when trying to subsequently perform a snapshot on the device:
{ "execute": "transaction", "arguments":
{'actions': [
{ 'type': 'blockdev-snapshot-sync', 'data' :
{ 'device': 'virtio0', 'snapshot-file': '/tmp/f16-snap1.qcow2' } }
] } }
{"error": {"class": "DeviceInUse", "desc": "Device 'virtio0' is in use", "data": {"device": "virtio0"}}}
The 'DeviceInUse' condition after a failed mirroring attempt happens because the block job is created (which sets the BDS to be 'in use'), but on failure of opening the BDS, the block job is not cleaned up. The simple solution would be to just not start the block job if opening the BDS fails. Verified on qemu-kvm-rhev-0.12.1.2-2.337.el6.x86_64:
1.{ "execute": "qmp_capabilities" }
{"return": {}}
2.{ "execute": "__com.redhat_drive-mirror", "arguments": { "device": "drive-virtio-disk0", "target": "/root/sn1", "format": "qcow2", "mode": "existing" } }
{"error": {"class": "OpenFileFailed", "desc": "Could not open '/root/sn1': No such file or directory", "data": {"filename": "/root/sn1", "__com.redhat_error_message": "No such file or directory"}}}
3.{ "execute": "blockdev-snapshot-sync", "arguments": { "device": "drive-virtio-disk0", "snapshot-file": "/root/sn1", "format": "qcow2" } }
{"return": {}}
4.(qemu) info block
drive-virtio-disk0: removable=0 io-status=ok file=/root/sn1 backing_file=RHEL6.4 ro=0 drv=qcow2 encrypted=0
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. http://rhn.redhat.com/errata/RHBA-2013-0543.html |
Description of problem: -------------------------- mirroring with "existing" mode and a non-existing target starts anyway. Version-Release number of selected component (if applicable): -------------------------------------------------------------- qemu-kvm-rhev-0.12.1.2-2.278.el6.x86_64 How reproducible: ------------------ 100% Steps to Reproduce: 1.boot guest with QMP 2.in QMP connection, /root/sn1 does not exist: { "execute" : "__com.redhat_drive-mirror", "arguments" : { "device" : "drive-virtio-disk0", "target" : "/root/sn1", "format": "qcow2", "mode": "existing", "full" : false } } 3.mirror starts: (qemu) info block-jobs Type mirror, device drive-virtio-disk0: Completed 0 of 0 bytes, speed limit 0 bytes/s (qemu) info block-jobs Type mirror, device drive-virtio-disk0: Completed 0 of 0 bytes, speed limit 0 bytes/s 4.following snapshot related operation complains block device in use.