All the inet_* functions can be replaced with calls to the
virSocket APIs. Since many of the inet_* funtions are unsafe,
and the remainder are obsolete, forbid all future use of them
in libvirt.
The inet_pton and inet_ntop functions are obsolete, replaced
by getaddrinfo+getnameinfo with the AI_NUMERICHOST flag set.
These can be accessed via the virSocket APIs.
The bridge.c code had methods for fetching the IP address of
a bridge which used inet_ntop. Aside from the use of inet_ntop
these methods are broken, because a NIC can have multiple
addresses and this only returns one address. Since the methods
are never used, just remove them.
* src/conf/network_conf.c, src/nwfilter/nwfilter_learnipaddr.c:
Replace inet_pton and inet_ntop with virSocket APIs
* src/util/bridge.c, src/util/bridge.h: Remove unused methods
which called inet_ntop.
The virSocketParse method was not doing any error reporting
which meant the true cause of the problem was lost. Remove
all error reporting from callers, and push it into virSocketParse
* src/util/network.c: Add error reporting to virSocketParse
* src/conf/domain_conf.c, src/conf/network_conf.c,
src/network/bridge_driver.c: Remove error reporting in
callers of virSocketParse
The getnameinfo() function is more flexible than inet_ntop()
avoiding the need to if/else the code based on socket family.
Also make it support UNIX socket addrs and allow inclusion
of a port (service) address. Finally do proper error reporting
via normal APIs.
* src/conf/domain_conf.c, src/nwfilter/nwfilter_ebiptables_driver.c,
src/qemu/qemu_conf.c: Fix error handling with virSocketFormat
* src/util/network.c: Rewrite virSocketFormat to use getnameinfo
and cope with UNIX socket addrs.
The nwIPAddress was simply a wrapper about virSocketAddr.
Just use the latter directly, removing all the extra field
de-references from code & helper APIs for parsing/formatting.
Also remove all the redundant casts from strong types to
void * and then immediately back to strong types.
* src/conf/nwfilter_conf.h: Remove nwIPAddress
* src/conf/nwfilter_conf.c, src/nwfilter/nwfilter_ebiptables_driver.c:
Update to use virSocketAddr and remove void * casts.
Fix passing of address family to virSocketParseAddr
The virSocketParseAddr function was accepting any AF_* constant
and using that to set the ai_flags field in struct addrinfo.
This is invalid, since address families must go in the ai_family
field of the struct.
* src/util/network.c: Fix handling of address family
* src/conf/network_conf.c, src/network/bridge_driver.c: Pass
AF_UNSPEC instead of relying on it being 0.
Some operations on socket addresses need to know the length of
the sockaddr struct for the particular address family. This
info was being discarded when passing around virSocketAddr
instances. Turn it from a union into a struct containing
union+socklen_t fields, so length is always kept around.
* src/util/network.h: Add socklen_t field to virSocketAddr
* src/util/network.c, src/network/bridge_driver.c,
src/conf/domain_conf.c: Update to take account of new
struct definition.
Remove useless code in error path of getnameinfo()
If getnameinfo() with NI_NUMERICHOST set fails, there are no
grounds to expect inet_ntop to succeed, since these calls
are functionally equivalent. Remove useless inet_ntop code
in the getnameinfo() error path.
* daemon/remote.c, src/remote/remote_driver.c: Remove
calls to inet_ntop
Eric Blake [Wed, 20 Oct 2010 17:10:45 +0000 (11:10 -0600)]
maint: sort private sym lists
* src/libvirt_private.syms: Sort by header name, then within
header, and drop duplicate virNetworkDefParseNode,
virFileLinkPointsTo and virXPathBoolean.
The QEMU 0.13 release is finally out and from testing in RHEL-6
we know that its JSON and netdev features are now good enough
for us to use by default.
* src/qemu/qemu_conf.c: Enable JSON + netdev for QEMU >= 0.13
Matthias Bolte [Wed, 20 Oct 2010 12:28:45 +0000 (14:28 +0200)]
qemu: Exit on first error in qemuDomainGetMemoryParameters
There is no point in trying to fill params beyond the first error,
because when qemuDomainGetMemoryParameters returns -1 then the caller
cannot detect which values in params are valid.
John Morrissey [Wed, 20 Oct 2010 08:25:05 +0000 (10:25 +0200)]
Add process= support for 'qemu-kvm -name'
This sets the process name to the same value as the Windows title,
but since the name is limited to 16 chars only this is kept as a
configuration option and turned off by default
* src/qemu/qemu.conf src/qemu/qemu_conf.[ch]: hceck for support in the
QEmu help output, add the option in qemu conf file and augment
qemudBuildCommandLine to add it if switched on
* src/qemu/libvirtd_qemu.aug src/qemu/test_libvirtd_qemu.aug: augment
the augeas lenses accordingly
* tests/qemuhelptest.c: cope with the extra flag being detected now
Guido Günther [Fri, 15 Oct 2010 08:01:38 +0000 (10:01 +0200)]
Don't fail lxc domain start when memory controller support is missing
Debian stock kernel has CONFIG_CGROUP_MEM_RES_CTLR disabled due to the
overhead [1]. Allow to start containers if the corresponding files in
the cgroup filesystem are missing. This fixes Debian bug #566180 [2].
Fix symbol exports & remove duplicated libvirt_util.la linkage
The libvirt_util.la library was mistakenly linked into libvirtd
directly. Since libvirt_util.la is already linked to libvirt.so,
this resulted in libvirtd getting two copies of the code and
more critically 2 copies of static global variables.
Testing in turn exposed a issue with loadable modules. The
gnulib replacement functions are not exported to loadable
modules. Rather than trying to figure out the name sof all
gnulib functions & export them, just linkage all loadable
modules against libgnu.la statically.
* daemon/Makefile.am: Remove linkage of libvirt_util.la
and libvirt_driver.la
* src/Makefile.am: Link driver modules against libgnu.la
* src/libvirt.c: Don't try to load modules which were
compiled out
* src/libvirt_private.syms: Export all other internal
symbols that are required by drivers
Miloslav Trmač [Tue, 12 Oct 2010 11:23:55 +0000 (12:23 +0100)]
Audit SELinux label assignment.
A more natural auditing point would perhaps be
SELinuxSetSecurityProcessLabel, but this happens in the child after root
permissions are dropped, so the kernel would refuse the audit record.
Miloslav Trmač [Tue, 12 Oct 2010 11:22:03 +0000 (12:22 +0100)]
Audit VM start/stop/suspend/resume
Most operations are audited at the libvirtd level; auditing in
src/libvirt.c would result in two audit entries per operation (one in
the client, one in libvirtd).
The only exception is a domain stopping of its own will (e.g. because
the user clicks on "shutdown" inside the interface). There can often be
no client connected at the time the domain stops, so libvirtd does not
have any virConnectPtr object on which to attach an event watch. This
patch therefore adds auditing directly inside the qemu driver (other
drivers are not supported).
Integrate with libaudit.so for auditing of important operations.
libvirtd gains a couple of config entries for auditing. By
default it will enable auditing, if its enabled on the host.
It can be configured to force exit if auditing is disabled
on the host. It will can also send audit messages via libvirt
internal logging API
Places requiring audit reporting can use the VIR_AUDIT
macro to report data. This is a no-op unless auditing is
enabled
* autobuild.sh, mingw32-libvirt.spec.in: Disable audit
on mingw
* configure.ac: Add check for libaudit
* daemon/libvirtd.aug, daemon/libvirtd.conf,
daemon/test_libvirtd.aug, daemon/libvirtd.c: Add config
options to enable auditing
* include/libvirt/virterror.h, src/util/virterror.c: Add
VIR_FROM_AUDIT source
* libvirt.spec.in: Enable audit
* src/util/virtaudit.h, src/util/virtaudit.c: Simple internal
API for auditing messages
The statstest is xen specific. Instead of filling the code with
a huge number of #ifdef WITH_XEN, just make its entire compilation
conditional in the Makefile.am. Also ensure it links to the Xen
driver so that it builds when driver modules are enabled
* tests/Makefile.am: Make statstest xen conditional. Link to
xen driver
* tests/Makefile.am: Remove all conditionals
Eric Blake [Thu, 14 Oct 2010 22:17:18 +0000 (16:17 -0600)]
vcpu: improve support for setting xen vcpu counts
Tested with RHEL 5.6 (xendConfigVersion 2, where xend_internal
controls live domains and xm_internal controls inactive domains).
Hopefully this works with xendConfigVersion 3 (where xend_internal
controls everything).
* src/xen/xen_driver.c (xenUnifiedDomainSetVcpusFlags): Support
more flags.
(xenUnifiedGetMaxVcpus): Export.
* src/xen/xm_internal.h (xenXMDomainSetVcpusFlags): New prototype.
* src/xen/xend_internal.h (xenDaemonDomainSetVcpusFlags): Likewise.
* src/xen/xen_driver.h (xenUnifiedGetMaxVcpus): Likewise.
* src/xen/xm_internal.c (xenXMDomainSetVcpusFlags): New function.
* src/xen/xend_internal.c (xenDaemonDomainSetVcpusFlags): Likewise.
Eric Blake [Wed, 29 Sep 2010 21:58:47 +0000 (15:58 -0600)]
vcpu: improve vcpu support in qemu command line
* src/qemu/qemu_conf.c (qemuParseCommandLineSmp): Distinguish
between vcpus and maxvcpus, for new enough qemu.
* tests/qemuargv2xmltest.c (mymain): Add new test.
* tests/qemuxml2argvtest.c (mymain): Likewise.
* tests/qemuxml2xmltest.c (mymain): Likewise.
* tests/qemuxml2argvdata/qemuxml2argv-smp.args: New file.
Eric Blake [Wed, 29 Sep 2010 21:20:23 +0000 (15:20 -0600)]
vcpu: add virsh support
* tools/virsh.c (cmdSetvcpus): Add new flags. Let invalid
commands through to driver, to ease testing of hypervisor argument
validation.
(cmdMaxvcpus, cmdVcpucount): New commands.
(commands): Add new commands.
* tools/virsh.pod (setvcpus, vcpucount, maxvcpus): Document new
behavior.
Eric Blake [Wed, 29 Sep 2010 16:20:07 +0000 (10:20 -0600)]
vcpu: support maxvcpu in domain_conf
Although this patch adds a distinction between maximum vcpus and
current vcpus in the XML, the values should be identical for all
drivers at this point. Only in subsequent per-driver patches will
a distinction be made.
In general, virDomainGetInfo should prefer the current vcpus.
* src/conf/domain_conf.h (_virDomainDef): Adjust vcpus to unsigned
short, to match virDomainGetInfo limit. Add maxvcpus member.
* src/conf/domain_conf.c (virDomainDefParseXML)
(virDomainDefFormat): parse and print out vcpu details.
* src/xen/xend_internal.c (xenDaemonParseSxpr)
(xenDaemonFormatSxpr): Manage both vcpu numbers, and require them
to be equal for now.
* src/xen/xm_internal.c (xenXMDomainConfigParse)
(xenXMDomainConfigFormat): Likewise.
* src/phyp/phyp_driver.c (phypDomainDumpXML): Likewise.
* src/openvz/openvz_conf.c (openvzLoadDomains): Likewise.
* src/openvz/openvz_driver.c (openvzDomainDefineXML)
(openvzDomainCreateXML, openvzDomainSetVcpusInternal): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainDumpXML, vboxDomainDefineXML):
Likewise.
* src/xenapi/xenapi_driver.c (xenapiDomainDumpXML): Likewise.
* src/xenapi/xenapi_utils.c (createVMRecordFromXml): Likewise.
* src/esx/esx_vmx.c (esxVMX_ParseConfig, esxVMX_FormatConfig):
Likewise.
* src/qemu/qemu_conf.c (qemuBuildSmpArgStr)
(qemuParseCommandLineSmp, qemuParseCommandLine): Likewise.
* src/qemu/qemu_driver.c (qemudDomainHotplugVcpus): Likewise.
* src/opennebula/one_conf.c (xmlOneTemplate): Likewise.
Eric Blake [Mon, 27 Sep 2010 22:37:53 +0000 (16:37 -0600)]
vcpu: make old API trivially wrap to new API
Note - this wrapping is completely mechanical; the old API will
function identically, since the new API validates that the exact
same flags are provided by the old API. On a per-driver basis,
it may make sense to have the old API pass a different set of flags,
but that should be done in the per-driver patch that implements
the full range of flag support in the new API.
Eric Blake [Fri, 24 Sep 2010 22:48:45 +0000 (16:48 -0600)]
vcpu: add new public API
API agreed on in
https://www.redhat.com/archives/libvir-list/2010-September/msg00456.html,
but modified for enum names to be consistent with virDomainDeviceModifyFlags.
* include/libvirt/libvirt.h.in (virDomainVcpuFlags)
(virDomainSetVcpusFlags, virDomainGetVcpusFlags): New
declarations.
* src/libvirt_public.syms: Export new symbols.
Eric Blake [Mon, 27 Sep 2010 23:36:06 +0000 (17:36 -0600)]
vcpu: add current attribute to <vcpu> element
Syntax agreed on in
https://www.redhat.com/archives/libvir-list/2010-September/msg00476.html
<domain ...>
<vcpu current='x'>y</vcpu>
...
can now be used to specify 1 <= x <= y current vcpus, in relation
to the boot-time max of y vcpus. If current is omitted, then
current and max are assumed to be the same value.
* docs/schemas/domain.rng: Add new attribute.
* docs/formatdomain.html.in: Document it.
* tests/qemuxml2argvdata/qemuxml2argv-smp.xml: Add to
domainschematest.
* tests/xml2sexprdata/xml2sexpr-pv-vcpus.xml: Likewise.
Stefan Berger [Tue, 19 Oct 2010 15:35:58 +0000 (11:35 -0400)]
nwfilter: changes to rules in VM->host table
In the table built for traffic coming from the VM going to the host make the following changes:
- don't ACCEPT the packets but do a 'RETURN' and let the host-specific firewall rules in subsequent rules evaluate whether the traffic is allowed to enter
- use the '-m state' in the rules as everywhere else
Stefan Berger [Tue, 19 Oct 2010 14:23:51 +0000 (10:23 -0400)]
Introduce VIR_CLOSE to be used rather than close()
Since bugs due to double-closed file descriptors are difficult to track down in a multi-threaded system, I am introducing the VIR_CLOSE(fd) macro to help avoid mistakes here.
There are lots of places where close() is being used. In this patch I am only cleaning up usage of close() in src/conf where the problems were.
I also dare to declare close() as being deprecated in libvirt code base (HACKING).
Dan Kenigsberg [Tue, 19 Oct 2010 13:26:32 +0000 (15:26 +0200)]
root_squash: virFileOperation may fail with EPERM too
Over root-squashing nfs, when virFileOperation() is called as uid==0,
it may fail with EACCES, but also with EPERM, due to
virFileOperationNoFork()'s failed attemp to chown a writable file.
qemudDomainSaveFlag() should expect this case, too.
Dan Kenigsberg [Tue, 19 Oct 2010 13:22:57 +0000 (15:22 +0200)]
Run initgroups() in qemudOpenAsUID()
qemudOpenAsUID is intended to open a file with the credentials of a
specified uid. Current implementation fails if the file is accessible to
one of uid's groups but not owned by uid.
This patch replaces the supplementary group list that the child process
inherited from libvirtd with the default group list of uid.
Update docs for memory parameters and memtune command
* docs/formatdomain.html.in: Add memtune element details, added min_guarantee
* src/libvirt.c: Update virDomainGetMemoryParameters api description, make
it more clear that the user first needs to call the api to get the number
of parameters supported and then call again to get the values.
* tools/virsh.pod: Add usage of new command memtune in virsh manpage
The location of the socket below /var/lib/libvirt/qemu/channels makes
sense, to humans and selinux policy alike. However, that socket should
be accessible to vdsm, too.
Due to other (storage) reasons, vdsm is to join the "qemu" group. With
this patch, vdsm can look below /var/lib/libvirt/qemu and connect to the
socket.
The socket itself should be chmod'ed to allow qemu group read/write, but
that's for another project.
Eric Blake [Fri, 15 Oct 2010 13:38:49 +0000 (07:38 -0600)]
virsh: add support for accepting arbitrary argv
* tools/virsh.c (vshCmdOptType): Add VSH_OT_ARGV. Delete
unused VSH_OT_NONE.
(vshCmddefGetData): Special case new opt flag.
(vshCmddefHelp): Display help for argv.
(vshCommandOptArgv): New function.
Eric Blake [Fri, 15 Oct 2010 19:34:24 +0000 (13:34 -0600)]
docs: document how to disable memballoon
https://bugzilla.redhat.com/show_bug.cgi?id=623903 documents a qemu
bug that causes libvirt to hang if virt-manager happens to be
querying balloon info when a guest is paused. Until the qemu bug
is fixed, people need to know how to avoid the issue.
This introduces new attribute to filesystem element
to support customizable access mode for mount type.
Valid accessmode are: passthrough, mapped and squash.
did previously not cut off existing (ssh) connections but only prevented newly initiated ones. The attached patch allows to cut off existing connections as well, thus enforcing what the filter is showing.
I had only tested with a configuration where the physical interface is connected to the bridge where the filters are applied. This patch now also solves a filtering problem where the physical interface is not connected to the bridge, but the bridge is given an IP address and the host routes between bridge and physical interface. Here the filters drop non-allowed traffic on the outgoing side on the host.
Eric Blake [Wed, 13 Oct 2010 22:14:58 +0000 (16:14 -0600)]
build: fix mingw build
* .gnulib: Update to latest, for termios fix.
* configure.ac (AC_CHECK_HEADERS): Drop redundent check.
* bootstrap: Synchronize from upstream.
Reported by Daniel P. Berrange.
Jiri Denemark [Wed, 13 Oct 2010 13:51:50 +0000 (15:51 +0200)]
qemu: Prohibit migration of guests with host devices
Explicitly raising a nice error in the case user tries to migrate a
guest with assigned host devices is much better than waiting for a
mysterious error with no clue for the reason.
Jiri Denemark [Wed, 13 Oct 2010 10:26:22 +0000 (12:26 +0200)]
cpu: Use vendor in baseline CPU only if all hosts use it
When only some host CPUs given to cpuBaseline contain <vendor> element,
baseline CPU should not contain it. Otherwise the result would not be
compatible with the host CPUs without vendor. CPU vendors are still
taken into account when computing baseline CPU, it's just removed from
the result.
Jiri Denemark [Wed, 13 Oct 2010 09:42:19 +0000 (11:42 +0200)]
cpu: Fix vendor for recent CPU models
Recent CPU models were specified using invalid vendor element
<vendor>NAME</vendor>, which was silently ignored due to a bug in the
code which was parsing it.
Eric Blake [Wed, 13 Oct 2010 17:09:40 +0000 (11:09 -0600)]
memory: fix remote protocol compilation
'make -C src rpcgen' is supposed to be idempotent. But commit f928f43b7b mistakently manually edited a generated file rather
than fixing the upstream file.
* src/remote/remote_protocol.x (remote_memory_param_value): Use
correct spelling of enum values.
* src/remote/remote_protocol.c: Regenerate.
This enables support for nested SVM using the regular CPU
model/features block. If the CPU model or features include
'svm', then the '-enable-nesting' flag will be added to the
QEMU command line. Latest out of tree patches for nested
'vmx', no longer require the '-enable-nesting' flag. They
instead just look at the cpu features. Several of the models
already include svm support, but QEMU was just masking out
the svm bit silently. So this will enable SVM on such
models
* src/qemu/qemu_conf.h: flag for -enable-nesting
* src/qemu/qemu_conf.c: Use -enable-nesting if VMX or SVM are in
the CPUID
* src/cpu/cpu.h, src/cpu/cpu.c: API to check for a named feature
* src/cpu/cpu_x86.c: x86 impl of feature check
* src/libvirt_private.syms: Add cpuHasFeature
* src/qemuhelptest.c: Add nesting flag where required
Fix Xen SEXPR generation to properly quote strings containing ()
* src/xen/sexpr.c: Ensure () are escaped in sexpr2string
* tests/sexpr2xmldata/sexpr2xml-boot-grub.sexpr,
tests/sexpr2xmldata/sexpr2xml-boot-grub.xml,
tests/xml2sexprdata/xml2sexpr-boot-grub.sexpr,
tests/xml2sexprdata/xml2sexpr-boot-grub.xml: Data files to
check escaping
* tests/sexpr2xmltest.c, tests/xml2sexprtest.c: Add boot-grub
escaping test case
Stefan Berger [Wed, 13 Oct 2010 14:33:26 +0000 (10:33 -0400)]
nwfilter: resolve deadlock between VM ops and filter update
This is from a bug report and conversation on IRC where Soren reported that while a filter update is occurring on one or more VMs (due to a rule having been edited for example), a deadlock can occur when a VM referencing a filter is started.
The problem is caused by the two locking sequences of
qemu driver, qemu domain, filter # for the VM start operation
filter, qemu_driver, qemu_domain # for the filter update operation
that obviously don't lock in the same order. The problem is the 2nd lock sequence. Here the qemu_driver lock is being grabbed in qemu_driver:qemudVMFilterRebuild()
The following solution is based on the idea of trying to re-arrange the 2nd sequence of locks as follows:
qemu_driver, filter, qemu_driver, qemu_domain
and making the qemu driver recursively lockable so that a second lock can occur, this would then lead to the following net-locking sequence
qemu_driver, filter, qemu_domain
where the 2nd qemu_driver lock has been ( logically ) eliminated.
The 2nd part of the idea is that the sequence of locks (filter, qemu_domain) and (qemu_domain, filter) becomes interchangeable if all code paths where filter AND qemu_domain are locked have a preceding qemu_domain lock that basically blocks their concurrent execution
So, the following code paths exist towards qemu_driver:qemudVMFilterRebuild where we now want to put a qemu_driver lock in front of the filter lock.
Qemu is not the only driver using the nwfilter driver, but also the UML driver calls into it. Therefore qemuVMFilterRebuild() can be exchanged with umlVMFilterRebuild() along with the driver lock of qemu_driver that can now be a uml_driver. Further, since UML and Qemu domains can be running on the same machine, the triggering of a rebuild of the filter can touch both types of drivers and their domains.
In the patch below I am now extending each nwfilter callback driver with functions for locking and unlocking the (VM) driver (UML, QEMU) and introduce new functions for locking all registered callback drivers and unlocking them. Then I am distributing the lock-all-cbdrivers/unlock-all-cbdrivers call into the above call paths. The last shown callpath starting with nwfilterDriverStart() is problematic since it is initialize before the Qemu and UML drives are and thus a lock in the path would result in a NULL pointer attempted to be locked -- the call to virNWFilterTriggerVMFilterRebuild() is never called, so we never lock either the qemu_driver or the uml_driver in that path. Therefore, only the first 3 paths now receive calls to lock and unlock all callback drivers. Now that the locks are distributed where it matters I can remove the qemu_driver and uml_driver lock from qemudVMFilterRebuild() and umlVMFilterRebuild() and not requiring the recursive locks.
For now I want to put this out as an RFC patch. I have tested it by 'stretching' the critical section after the define/undefine functions each lock the filter so I can (easily) concurrently execute another VM operation (suspend,start). That code is in this patch and if you want you can de-activate it. It seems to work ok and operations are being blocked while the update is being done.
I still also want to verify the other assumption above that locking filter and qemu_domain always has a preceding qemu_driver lock.
Lai Jiangshan [Tue, 12 Oct 2010 07:14:01 +0000 (15:14 +0800)]
virsh: rework command parsing
Old virsh command parsing mashes all the args back into a string and
miss the quotes, this patches fix it. It is also needed for introducing
qemu-monitor-command which is very useful.
This patches uses the new vshCommandParser abstraction and adds
vshCommandArgvParse() for arguments vector, so we don't need
to mash arguments vector into a command sting.
And the usage was changed:
old:
virsh [options] [commands]
Lai Jiangshan [Tue, 12 Oct 2010 07:13:39 +0000 (15:13 +0800)]
virsh: better handling the boolean option
in old code the following commands are equivalent:
virsh # dumpxml --update-cpu=vm1
virsh # dumpxml --update-cpu vm1
because the old code split the option argument into 2 parts:
--update-cpu=vm1 is split into update-cpu and vm1,
and update-cpu is a boolean option, so the parser takes vm1 as another
argument, very strange.
after this patch applied, the first one will become illegal.
To achieve this, we don't parse/check options when parsing command sting,
but check options when parsing a command argument. And the argument is
not split when parsing command sting.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Eric Blake [Tue, 12 Oct 2010 17:24:00 +0000 (11:24 -0600)]
virsh: poison raw allocation routines
* tools/virsh.c (malloc, calloc, realloc, strdup): Enforce that
within this file, we use the safe vsh wrappers instead.
(cmdNodeListDevices, cmdSnapshotCreate, main): Fix violations of
this policy.