Bug 895882
Summary: | invalid domain pointer error occurs when use domain object from snapshot object 's getdomain method | ||
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Product: | Red Hat Enterprise Linux 6 | Reporter: | hongming <honzhang> |
Component: | libvirt | Assignee: | Jiri Denemark <jdenemar> |
Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> |
Severity: | high | Docs Contact: | |
Priority: | high | ||
Version: | 6.4 | CC: | acathrow, ajia, cwei, dallan, dyuan, gsun, jdenemar, mzhan |
Target Milestone: | rc | Keywords: | ZStream |
Target Release: | --- | ||
Hardware: | Unspecified | ||
OS: | Unspecified | ||
Whiteboard: | |||
Fixed In Version: | libvirt-0.10.2-19.el6 | Doc Type: | Bug Fix |
Doc Text: |
Cause: Python bindings for libvirt contained incorrect implementation of
getDomain() and getConnect() methods in virDomainSnapshot class.
Consequence: An application using these methods may fail or crash.
Fix: Python bindings now provide proper domain() and connect() accessors that
fetch python objects stored internally within virDomainSnapshot instance. For
backward compatibility, getDomain() and getConnect() methods call these
accessors.
Result: An application using either of these methods works as expected.
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Story Points: | --- |
Clone Of: | Environment: | ||
Last Closed: | 2013-11-21 08:39:59 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: | 915348 |
Description
hongming
2013-01-16 08:23:07 UTC
The bus is also reproducible upstream, although the python client segfaults there rather than reporting invalid pointers. In any case, we have a nasty bug in python bindings. virDomainSnapshotGetDomain() API (called as snapshot.getDomain() in python) returns the domain object but does not increment its reference counter. However, we just take it and wrap it as virDomain object in python and once the object is deleted, it calls virDomainFree. And virDomainFree is called once more when the snapshot object is deleted (as it holds a reference to the domain). Thus, before creating a virDomain object from the domain pointer returned by virDomainSnapshotGetDomain, we need to call virDomainRef to increment its reference counter. Unfortunately, it seems virDomainSnapshotGetDomain API is not the only one affected and we have similar bugs in other APIs too. Fixed upstream by v1.0.2-rc1-6-g7b35fd7: commit 7b35fd718d2156224797ace08f752dfbb9884520 Author: Jiri Denemark <jdenemar> Date: Wed Jan 23 12:14:57 2013 +0100 python: Fix bindings for virDomainSnapshotGet{Domain,Connect} https://bugzilla.redhat.com/show_bug.cgi?id=895882 virDomainSnapshot.getDomain() and virDomainSnapshot.getConnect() wrappers around virDomainSnapshotGet{Domain,Connect} were not supposed to be ever implemented. The class should contain proper domain() and connect() accessors that fetch python objects stored internally within the class. While domain() was already provided, connect() was missing. This patch adds connect() method to virDomainSnapshot class and reimplements getDomain() and getConnect() methods as aliases to domain() and connect() for backward compatibility. Verify it as follows. The result is expected. # rpm -q libvirt-python libvirt-python-0.10.2-19.el6.x86_64 # virsh snapshot-list kvm-rhel6.4-x86_64-qcow2-virtio Name Creation Time State ------------------------------------------------------------ 1373349897 2013-07-09 02:04:57 -0400 running 1373349908 2013-07-09 02:05:08 -0400 running # cat snapshot.py import libvirt def snapshot(): con = libvirt.open('') dom = con.lookupByName('kvm-rhel6.4-x86_64-qcow2-virtio') snapshot_list = dom.listAllSnapshots(0) print "snapshot object list:%s" % snapshot_list domain = snapshot_list[0].getDomain() domain_name = domain.name() print "domain name:%s" % domain_name if __name__=='__main__': snapshot() # python snapshot.py snapshot object list:[<libvirt.virDomainSnapshot instance at 0x7fb2cb9a0e18>, <libvirt.virDomainSnapshot instance at 0x7fb2cb9a0e60>] domain name:kvm-rhel6.4-x86_64-qcow2-virtio # cat snapshot1.py #!/usr/bin/env python import libvirt def snapshot(): con = libvirt.open('') dom = con.lookupByName('kvm-rhel6.4-x86_64-qcow2-virtio') snapshot_list = dom.listAllSnapshots(0) print "snapshot object list: %s" % snapshot_list for snapshot_item in snapshot_list: domain = snapshot_item.getDomain() print "domain name: %s " % domain.name() if __name__=='__main__': snapshot() # python snapshot1.py snapshot object list: [<libvirt.virDomainSnapshot instance at 0x7fa941a7ae60>, <libvirt.virDomainSnapshot instance at 0x7fa941a7aea8>] domain name: kvm-rhel6.4-x86_64-qcow2-virtio domain name: kvm-rhel6.4-x86_64-qcow2-virtio 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-2013-1581.html |