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Bug 965636

Summary:	streaming with no backing file should not do anything
Product:	Red Hat Enterprise Linux 7	Reporter:	Paolo Bonzini <pbonzini>
Component:	qemu-kvm	Assignee:	Hanna Czenczek <hreitz>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.0	CC:	acathrow, areis, bsarathy, hhuang, juzhang, mkenneth, pbonzini, shu, tpoitras, virt-maint
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	qemu-kvm-1.5.3-34.el7	Doc Type:	Bug Fix
Doc Text:	Previously, streaming an image without a backing file would waste time copying the whole image onto itself. Now, if you attempt to stream an image that does not have a backup file, the streaming job ends immediately.	Story Points:	---
Clone Of:	808114	Environment:
Last Closed:	2014-06-13 12:04:24 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:	808114
Bug Blocks:	806280, 1080820

Description Paolo Bonzini 2013-05-21 12:59:16 UTC

+++ This bug was initially created as a clone of Bug #808114 +++

Description of problem:
Streaming an image with no backing file wastes time copying the whole image onto itself.

Version-Release number of selected component (if applicable):
qemu-kvm 267rhev

How reproducible:
100%

Steps to Reproduce:
1. install to qcow2
2. start QEMU
3. do block_stream virtio0
  
Actual results:
Streaming job runs

Expected results:
Streaming job ends immediately

Additional info:
Also related, streaming should not even start if the image format does not support bdrv_change_backing_file.

--- Additional comment from juzhang on 2012-03-30 23:05:27 EDT ---

Can reproduce with qemu-kvm-267.el6ev.

1.boot guest with qcow2
2.block_stream virtio0
3.info block-jobs

Resutls
(qemu) info block-jobs 
Streaming device virtio0: Completed 12817137664 of 21474836480 bytes, speed limit 0 bytes/s

--- Additional comment from Ademar de Souza Reis Jr. on 2012-09-26 20:48:35 EDT ---

Deferring to 6.5 due to capacity. If a customer reports it, we'll consider it of higher priority. Nevertheless, if a patch is available it's for sure welcome in 6.4.

--- Additional comment from Ludek Smid on 2013-03-07 09:38:57 EST ---

Since the release flag was set to ? after the qa_ack and pm_ack flags were set to + (was likely set for the previous release), the qa_ack and pm_ack flags have been reset to ? by the bugbot (pm-rhel). This action ensures the proper review by Product Management.

Comment 2 Miroslav Rezanina 2014-01-08 12:43:38 UTC

Fix included in qemu-kvm-1.5.3-34.el7

Comment 4 Shaolong Hu 2014-01-24 05:22:42 UTC

Verified on qemu-kvm-rhev-1.5.3-39.el7.x86_64:


after issue block stream, job complete immediately, log shows in QMP connection:

{"timestamp": {"seconds": 1390540852, "microseconds": 646379}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "drive-virtio-disk0", "len": 0, "offset": 0, "speed": 0, "type": "stream"}}

Comment 6 Ludek Smid 2014-06-13 12:04:24 UTC

This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.