Noticed that the expected "not supported" error is dropped when
invoking 'virsh snapshot-list dom' on a Xen installation running
the libxl driver
virsh snapshot-list test
error: Invalid snapshot: virDomainSnapshotFree
The error is overwritten by a call to virDomainSnapshotFree
in cleanup code within cmdSnapshotList. Prevent overwritting
the real error by not calling virDomainSnapshotFree with a NULL
virDomainSnapshotPtr.
If the app has provided a whitelist of controllers to be used,
we skip detecting its mount point. We still, however, fill in
the placement info which later confuses the machine name
validation code. Skip detecting placement if the controller
mount point is not set
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When a VM has an 'emulator' child cgroup present, we must
strip off that suffix when detecting the cgroup for a
machine
Rename the virCgroupIsValidMachineGroup method to
virCgroupValidateMachineGroup to make a bit clearer
that this isn't simply a boolean check, it will make
changes to the object.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virCgroupIsValidMachine does not need to be called from
outside the cgroups file now, so make it static.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Instead of requiring drivers to use a combination of calls
to virCgroupNewDetect and virCgroupIsValidMachine, combine
the two into virCgroupNewDetectMachine
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
since sizeof(int) != sizeof(long long) on 32bit archs.
This unbreaks virdbustest which otherwise fails like:
(gdb) bt
#0 __strlen_sse2_bsf () at ../sysdeps/i386/i686/multiarch/strlen-sse2-bsf.S:50
#1 0x405907d2 in ?? () from /lib/i386-linux-gnu/libdbus-1.so.3
#2 0x4057c140 in ?? () from /lib/i386-linux-gnu/libdbus-1.so.3
#3 0x4057e7ec in dbus_message_iter_append_basic () from /lib/i386-linux-gnu/libdbus-1.so.3
#4 0x400742ec in virDBusMessageIterEncode (args=0xbfd4b8f0 "k\321\004\b.", types=0x804d260 "",
rootiter=0xbfd4b844) at util/virdbus.c:560
#5 virDBusMessageEncodeArgs (msg=msg@entry=0x893c278, types=types@entry=0x804d25c "sais",
args=args@entry=0xbfd4b8d8 "r\320\004\b\003") at util/virdbus.c:921
#6 0x40075917 in virDBusMessageEncode (msg=0x893c278, types=0x804d25c "sais") at util/virdbus.c:959
#7 0x0804a4a1 in testMessageArray (args=0x0) at virdbustest.c:195
#8 0x0804c404 in virtTestRun (title=title@entry=0x804cfcb "Test message array ",
nloops=nloops@entry=1, body=body@entry=0x804a3f0 <testMessageArray>, data=data@entry=0x0)
at testutils.c:168
#9 0x08049346 in mymain () at virdbustest.c:384
#10 0x0804cb2e in virtTestMain (argc=argc@entry=1, argv=argv@entry=0xbfd4bb24,
func=func@entry=0x80492c0 <mymain>) at testutils.c:764
#11 0x080491af in main (argc=1, argv=0xbfd4bb24) at virdbustest.c:393
Reuse the XML files in storagevolxml2xmlin.
(This requires changing a few backing files to /dev/null,
since virStorageBackendCreateQemuImgCmd checks for its
presence)
Both virStoragePoolFree and virStorageVolFree reset the last error,
which might lead to the cryptic message:
An error occurred, but the cause is unknown
When the volume wasn't found, virStorageVolFree was called with NULL,
leading to an error:
invalid storage volume pointer in virStorageVolFree
This patch changes it to:
Storage volume not found: no storage vol with matching name 'tomato'
Add protection such that the virCgroupRemove and
virCgroupKill* do not do anything to the root cgroup.
Killing all PIDs in the root cgroup does not end well.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Instead of requiring one API call to create a cgroup and
another to add a task to it, introduce a new API
virCgroupNewMachine which does both jobs at once. This
will facilitate the later code to talk to systemd to
achieve this job which is also atomic.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There's a race in lxc driver causing a deadlock. If a domain is
destroyed immediately after started, the deadlock can occur. When domain
is started, the even loop tries to connect to the monitor. If the
connecting succeeds, virLXCProcessMonitorInitNotify() is called with
@mon->client locked. The first thing that callee does, is
virObjectLock(vm). So the order of locking is: 1) @mon->client, 2) @vm.
However, if there's another thread executing virDomainDestroy on the
very same domain, the first thing done here is locking the @vm. Then,
the corresponding libvirt_lxc process is killed and monitor is closed
via calling virLXCMonitorClose(). This callee tries to lock @mon->client
too. So the order is reversed to the first case. This situation results
in deadlock and unresponsive libvirtd (since the eventloop is involved).
The proper solution is to unlock the @vm in virLXCMonitorClose prior
entering virNetClientClose(). See the backtrace as follows:
Thread 25 (Thread 0x7f1b7c9b8700 (LWP 16312)):
0 0x00007f1b80539714 in __lll_lock_wait () from /lib64/libpthread.so.0
1 0x00007f1b8053516c in _L_lock_516 () from /lib64/libpthread.so.0
2 0x00007f1b80534fbb in pthread_mutex_lock () from /lib64/libpthread.so.0
3 0x00007f1b82a637cf in virMutexLock (m=0x7f1b3c0038d0) at util/virthreadpthread.c:85
4 0x00007f1b82a4ccf2 in virObjectLock (anyobj=0x7f1b3c0038c0) at util/virobject.c:320
5 0x00007f1b82b861f6 in virNetClientCloseInternal (client=0x7f1b3c0038c0, reason=3) at rpc/virnetclient.c:696
6 0x00007f1b82b862f5 in virNetClientClose (client=0x7f1b3c0038c0) at rpc/virnetclient.c:721
7 0x00007f1b6ee12500 in virLXCMonitorClose (mon=0x7f1b3c007210) at lxc/lxc_monitor.c:216
8 0x00007f1b6ee129f0 in virLXCProcessCleanup (driver=0x7f1b68100240, vm=0x7f1b680ceb70, reason=VIR_DOMAIN_SHUTOFF_DESTROYED) at lxc/lxc_process.c:174
9 0x00007f1b6ee14106 in virLXCProcessStop (driver=0x7f1b68100240, vm=0x7f1b680ceb70, reason=VIR_DOMAIN_SHUTOFF_DESTROYED) at lxc/lxc_process.c:710
10 0x00007f1b6ee1aa36 in lxcDomainDestroyFlags (dom=0x7f1b5c002560, flags=0) at lxc/lxc_driver.c:1291
11 0x00007f1b6ee1ab1a in lxcDomainDestroy (dom=0x7f1b5c002560) at lxc/lxc_driver.c:1321
12 0x00007f1b82b05be5 in virDomainDestroy (domain=0x7f1b5c002560) at libvirt.c:2303
13 0x00007f1b835a7e85 in remoteDispatchDomainDestroy (server=0x7f1b857419d0, client=0x7f1b8574ae40, msg=0x7f1b8574acf0, rerr=0x7f1b7c9b7c30, args=0x7f1b5c004a50) at remote_dispatch.h:3143
14 0x00007f1b835a7d78 in remoteDispatchDomainDestroyHelper (server=0x7f1b857419d0, client=0x7f1b8574ae40, msg=0x7f1b8574acf0, rerr=0x7f1b7c9b7c30, args=0x7f1b5c004a50, ret=0x7f1b5c0029e0) at remote_dispatch.h:3121
15 0x00007f1b82b93704 in virNetServerProgramDispatchCall (prog=0x7f1b8573af90, server=0x7f1b857419d0, client=0x7f1b8574ae40, msg=0x7f1b8574acf0) at rpc/virnetserverprogram.c:435
16 0x00007f1b82b93263 in virNetServerProgramDispatch (prog=0x7f1b8573af90, server=0x7f1b857419d0, client=0x7f1b8574ae40, msg=0x7f1b8574acf0) at rpc/virnetserverprogram.c:305
17 0x00007f1b82b8c0f6 in virNetServerProcessMsg (srv=0x7f1b857419d0, client=0x7f1b8574ae40, prog=0x7f1b8573af90, msg=0x7f1b8574acf0) at rpc/virnetserver.c:163
18 0x00007f1b82b8c1da in virNetServerHandleJob (jobOpaque=0x7f1b8574dca0, opaque=0x7f1b857419d0) at rpc/virnetserver.c:184
19 0x00007f1b82a64158 in virThreadPoolWorker (opaque=0x7f1b8573cb10) at util/virthreadpool.c:144
20 0x00007f1b82a63ae5 in virThreadHelper (data=0x7f1b8574b9f0) at util/virthreadpthread.c:161
21 0x00007f1b80532f4a in start_thread () from /lib64/libpthread.so.0
22 0x00007f1b7fc4f20d in clone () from /lib64/libc.so.6
Thread 1 (Thread 0x7f1b83546740 (LWP 16297)):
0 0x00007f1b80539714 in __lll_lock_wait () from /lib64/libpthread.so.0
1 0x00007f1b8053516c in _L_lock_516 () from /lib64/libpthread.so.0
2 0x00007f1b80534fbb in pthread_mutex_lock () from /lib64/libpthread.so.0
3 0x00007f1b82a637cf in virMutexLock (m=0x7f1b680ceb80) at util/virthreadpthread.c:85
4 0x00007f1b82a4ccf2 in virObjectLock (anyobj=0x7f1b680ceb70) at util/virobject.c:320
5 0x00007f1b6ee13bd7 in virLXCProcessMonitorInitNotify (mon=0x7f1b3c007210, initpid=4832, vm=0x7f1b680ceb70) at lxc/lxc_process.c:601
6 0x00007f1b6ee11fd3 in virLXCMonitorHandleEventInit (prog=0x7f1b3c001f10, client=0x7f1b3c0038c0, evdata=0x7f1b8574a7d0, opaque=0x7f1b3c007210) at lxc/lxc_monitor.c:109
7 0x00007f1b82b8a196 in virNetClientProgramDispatch (prog=0x7f1b3c001f10, client=0x7f1b3c0038c0, msg=0x7f1b3c003928) at rpc/virnetclientprogram.c:259
8 0x00007f1b82b87030 in virNetClientCallDispatchMessage (client=0x7f1b3c0038c0) at rpc/virnetclient.c:1019
9 0x00007f1b82b876bb in virNetClientCallDispatch (client=0x7f1b3c0038c0) at rpc/virnetclient.c:1140
10 0x00007f1b82b87d41 in virNetClientIOHandleInput (client=0x7f1b3c0038c0) at rpc/virnetclient.c:1312
11 0x00007f1b82b88f51 in virNetClientIncomingEvent (sock=0x7f1b3c0044e0, events=1, opaque=0x7f1b3c0038c0) at rpc/virnetclient.c:1832
12 0x00007f1b82b9e1c8 in virNetSocketEventHandle (watch=3321, fd=54, events=1, opaque=0x7f1b3c0044e0) at rpc/virnetsocket.c:1695
13 0x00007f1b82a272cf in virEventPollDispatchHandles (nfds=21, fds=0x7f1b8574ded0) at util/vireventpoll.c:498
14 0x00007f1b82a27af2 in virEventPollRunOnce () at util/vireventpoll.c:645
15 0x00007f1b82a25a61 in virEventRunDefaultImpl () at util/virevent.c:273
16 0x00007f1b82b8e97e in virNetServerRun (srv=0x7f1b857419d0) at rpc/virnetserver.c:1097
17 0x00007f1b8359db6b in main (argc=2, argv=0x7ffff98dbaa8) at libvirtd.c:1512
The avail_vcpu bitmap has to be allocated before it can be used (using
the maximum allowed value for that). Then for each available VCPU the
bit in the mask has to be set (libxl_bitmap_set takes a bit position
as an argument, not the number of bits to set).
Without this, I would always only get one VCPU for guests created
through libvirt/libxl.
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
virCgroupAvailable() implementation calls getmntent_r
without checking if HAVE_GETMNTENT_R is defined, so it fails
to build on platforms without getmntent_r support.
Make virCgroupAvailable() just return false without
HAVE_GETMNTENT_R.
link_addr detection in configure always reports that
link_addr is missing because it uses link_addr(NULL, NULL) in
AC_LINK_IFELSE check with limited set of headers that doesn't
define NULL.
Fix by replacing 'NULL' with just '0'.
Function qemuOpenFile() haven't had any idea about seclabels applied
to VMs only, so in case the seclabel differed from the "user:group"
from configuration, there might have been issues with opening files.
Make qemuOpenFile() VM-aware, but only optionally, passing NULL
argument means skipping VM seclabel info completely.
However, all current qemuOpenFile() calls look like they should use VM
seclabel info in case there is any, so convert these calls as well.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=869053
Parsing 'user:group' is useful even outside the DAC security driver,
so expose the most abstract function which has no DAC security driver
bits in itself.
Since PCI bridges, PCIe bridges, PCIe switches, and PCIe root ports
all share the same namespace, they are all defined as controllers of
type='pci' in libvirt (but with a differing model attribute). Each of
these controllers has a certain connection type upstream, allows
certain connection types downstream, and each can either allow a
single downstream connection at slot 0, or connections from slot 1 -
31.
Right now, we only support the pci-root and pci-bridge devices, both
of which only allow PCI devices to connect, and both which have usable
slots 1 - 31. In preparation for adding other types of controllers
that have different capabilities, this patch 1) adds info to the
qemuDomainPCIAddressBus object to indicate the capabilities, 2) sets
those capabilities appropriately for pci-root and pci-bridge devices,
and 3) validates that the controller being connected to is the proper
type when allocating slots or validating that a user-selected slot is
appropriate for a device..
Having this infrastructure in place will make it much easier to add
support for the other PCI controller types.
While it would be possible to do all the necessary checking by just
storing the controller model in the qemyuDomainPCIAddressBus, it
greatly simplifies all the validation code to also keep a "flags",
"minSlot" and "maxSlot" for each - that way we can just check those
attributes rather than requiring a nearly identical switch statement
everywhere we need to validate compatibility.
You may notice many places where the flags are seemingly hard-coded to
QEMU_PCI_CONNECT_HOTPLUGGABLE | QEMU_PCI_CONNECT_TYPE_PCI
This is currently the correct value for all PCI devices, and in the
future will be the default, with small bits of code added to change to
the flags for the few devices which are the exceptions to this rule.
Finally, there are a few places with "FIXME" comments. Note that these
aren't indicating places that are broken according to the currently
supported devices, they are places that will need fixing when support
for new PCI controller models is added.
To assure that there was no regression in the auto-allocation of PCI
addresses or auto-creation of integrated pci-root, ide, and usb
controllers, a new test case (pci-bridge-many-disks) has been added to
both the qemuxml2argv and qemuxml2xml tests. This new test defines a
domain with several dozen virtio disks but no pci-root or
pci-bridges. The .args file of the new test case was created using
libvirt sources from before this patch, and the test still passes
after this patch has been applied.
Although these two enums are named ..._LAST, they really had the value
of ..._SIZE. This patch changes their values so that, e.g.,
QEMU_PCI_ADDRESS_SLOT_LAST really is the slot number of the last slot
on a PCI bus.
The implicit IDE, USB, and video controllers provided by the PIIX3
chipset in the pc-* machinetypes are not present on other
machinetypes, so we shouldn't be doing the special checking for
them. This patch places those validation checks into a separate
function that is only called for machine types that have a PIIX3 chip
(which happens to be the i440fx-based pc-* machine types).
One qemuxml2argv test data file had to be changed - the
pseries-usb-multi test had included a piix3-usb-uhci device, which was
being placed at a specific address, and also had slot 2 auto reserved
for a video device, but the pseries virtual machine doesn't actually
have a PIIX3 chip, so even if there was a piix3-usb-uhci driver for
it, the device wouldn't need to reside at slot 1 function 2. I just
changed the .argv file to have the generic slot info for the two
devices that results when the special PIIX3 code isn't executed.
qemuDomainPCIAddressBus was an array of QEMU_PCI_ADDRESS_SLOT_LAST
uint8_t's, which worked fine as long as every PCI bus was
identical. In the future, some PCI busses will allow connecting PCI
devices, and some will allow PCIe devices; also some will only allow
connection of a single device, while others will allow connecting 31
devices.
In order to keep track of that information for each bus, we need to
turn qemuDomainPCIAddressBus into a struct, for now with just one
member:
uint8_t slots[QEMU_PCI_ADDRESS_SLOT_LAST];
Additional members will come in later patches.
The item in qemuDomainPCIAddresSet that contains the array of
qemuDomainPCIAddressBus is now called "buses" to be more consistent
with the already existing "nbuses" (and with the new "slots" array).
Thanks to a lack of coordination between kernel and glibc folks,
it has been impossible to mix code using <linux/in.h> and
<net/in.h> for some time now (see for example commit c308a9a).
On at least RHEL 6, <linux/if_bridge.h> tries to use the kernel
side, and fails due to our desire to use the glibc side elsewhere:
In file included from /usr/include/linux/if_bridge.h:17,
from util/virnetdevbridge.c:42:
/usr/include/linux/in6.h:31: error: redefinition of ‘struct in6_addr’
/usr/include/linux/in6.h:48: error: redefinition of ‘struct sockaddr_in6’
/usr/include/linux/in6.h:56: error: redefinition of ‘struct ipv6_mreq’
Thankfully, the kernel layout of these structs is ABI-compatible,
they only differ in the type system presented to the C compiler.
While there are other versions of kernel headers that avoid the
problem, it is easier to just work around the issue than to expect
all developers to upgrade to working kernel headers.
* src/util/virnetdevbridge.c (includes): Coerce the kernel version
of in.h to not collide with the normal version.
Signed-off-by: Eric Blake <eblake@redhat.com>
dbus 1.2.24 (on RHEL 6) lacks DBUS_TYPE_UNIX_FD; but as we aren't
trying to pass one of those anyways, we can just drop support for
it in our wrapper. Solves this build error introduced in commit
834c9c94:
CC libvirt_util_la-virdbus.lo
util/virdbus.c:242: error: 'DBUS_TYPE_UNIX_FD' undeclared here (not in a function)
* src/util/virdbus.c (virDBusBasicTypes): Drop support for unix fds.
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit id '4421e257' strdup'd devAlias, but didn't free
Running qemuhotplugtest under valgrind resulted in the following:
==7375== 9 bytes in 1 blocks are definitely lost in loss record 11 of 70
==7375== at 0x4A0887C: malloc (vg_replace_malloc.c:270)
==7375== by 0x37C1085D71: strdup (strdup.c:42)
==7375== by 0x4CBBD5F: virStrdup (virstring.c:554)
==7375== by 0x4CFF9CB: virDomainEventDeviceRemovedNew (domain_event.c:1174)
==7375== by 0x427791: qemuDomainRemoveChrDevice (qemu_hotplug.c:2508)
==7375== by 0x42C65D: qemuDomainDetachChrDevice (qemu_hotplug.c:3357)
==7375== by 0x41C94F: testQemuHotplug (qemuhotplugtest.c:115)
==7375== by 0x41D817: virtTestRun (testutils.c:168)
==7375== by 0x41C400: mymain (qemuhotplugtest.c:322)
==7375== by 0x41DF3A: virtTestMain (testutils.c:764)
==7375== by 0x37C1021A04: (below main) (libc-start.c:225)
Commit 'c8695053' resulted in the following:
Coverity error seen in the output:
ERROR: REVERSE_INULL
FUNCTION: lxcProcessAutoDestroy
Due to the 'dom' being checked before 'dom->persistent' since 'dom'
is already dereferenced prior to that.
Currently the LXC driver creates the VM's cgroup prior to
forking, and then libvirt_lxc moves the child process
into the cgroup. This won't work with systemd whose APIs
do the creation of cgroups + attachment of processes atomically.
Fortunately we simply move the entire cgroups setup into
the libvirt_lxc child process. We make it take place before
fork'ing into the background, so by the time virCommandRun
returns in the LXC driver, the cgroup is guaranteed to be
present.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the QEMU driver creates the VM's cgroup prior to
forking, and then uses a virCommand hook to move the child
into the cgroup. This won't work with systemd whose APIs
do the creation of cgroups + attachment of processes atomically.
Fortunately we have a handshake taking place between the
QEMU driver and the child process prior to QEMU being exec()d,
which was introduced to allow setup of disk locking. By good
fortune this synchronization point can be used to enable the
QEMU driver to do atomic setup of cgroups removing the use
of the hook script.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virCgroupNewDomainDriver and virCgroupNewDriver methods
are obsolete now that we can auto-detect existing cgroup
placement. Delete them to reduce code bloat.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Use the new virCgroupNewDetect function to determine cgroup
placement of existing running VMs. This will allow the legacy
cgroups creation APIs to be removed entirely
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add virCgroupIsValidMachine API to check whether an auto
detected cgroup is valid for a machine. This lets us
check if a VM has just been placed into some generic
shared cgroup, or worse, the root cgroup
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add a virCgroupNewDetect API which is used to initialize a
cgroup object with the placement of an arbitrary process.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If systemd machine does not exist, return -2 instead of -1,
so that applications don't need to repeat the tedious error
checking code
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Current code for handling dbus errors only works for errors
received from the remote application itself. We must also
handle errors emitted by the bus itself, for example, when
it fails to spawn the target service.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add a privileged field to storageDriverState
Use the privileged value in order to generate a connection which could
be passed to the various storage backend drivers.
In particular, the iSCSI driver will need a connect in order to perform
pool authentication using the 'chap' secrets and the RBD driver utilizes
the connection during pool refresh for pools using 'ceph' secrets.
For now that connection will be to be to qemu driver until a mechanism
is devised to get a connection to just the secret driver without qemu.
Update virStorageBackendRBDOpenRADOSConn() to use the internal API to the
secret driver in order to get the secret value instead of the external
virSecretGetValue() path. Without the flag VIR_SECRET_GET_VALUE_INTERNAL_CALL
there is no way to get the value of private secret.
This also requires ensuring there is a connection which wasn't true for
for the refreshPool() path calls from storageDriverAutostart() prior to
adding support for the connection to a qemu driver. It seems calls to
virSecretLookupByUUIDString() and virSecretLookupByUsage() from the
refreshPool() path would have failed with no way to find the secret - that is
theoretically speaking since the 'conn' was NULL the failure would have been
"failed to find the secret".
Although the XML for CHAP authentication with plain "password"
was introduced long ago, the function was never implemented. This
patch replaces the login/password mechanism by following the
'ceph' (or RBD) model of using a 'username' with a 'secret' which
has the authentication information.
This patch performs the authentication during startPool() processing
of pools with an authType of VIR_STORAGE_POOL_AUTH_CHAP specified
for iSCSI pools.
There are two types of CHAP configurations supported for iSCSI
authentication:
* Initiator Authentication
Forward, one-way; The initiator is authenticated by the target.
* Target Authentication
Reverse, Bi-directional, mutual, two-way; The target is authenticated
by the initiator; This method also requires Initiator Authentication
This only supports the "Initiator Authentication". (I don't have any
enterprise iSCSI env for testing, only have a iSCSI target setup with
tgtd, which doesn't support "Target Authentication").
"Discovery authentication" is not supported by tgt yet too. So this only
setup the session authentication by executing 3 iscsiadm commands, E.g:
% iscsiadm -m node --target "iqn.2013-05.test:iscsi.foo" --name \
"node.session.auth.authmethod" -v "CHAP" --op update
% iscsiadm -m node --target "iqn.2013-05.test:iscsi.foo" --name \
"node.session.auth.username" -v "Jim" --op update
% iscsiadm -m node --target "iqn.2013-05.test:iscsi.foo" --name \
"node.session.auth.password" -v "Jimsecret" --op update
During qemuTranslateDiskSourcePool() execution, if the srcpool has been
defined with authentication information, then for iSCSI pools copy the
authentication and host information to virDomainDiskDef.
Due to a goto statement missed when refactoring in 2771f8b74c
when acquiring of a domain job failed the error path was not taken. This
resulted into a crash afterwards as an extra reference was removed from a
domain object leading to it being freed. An attempt to list the domains
leaded to a crash of the daemon afterwards.
https://bugzilla.redhat.com/show_bug.cgi?id=928672
