Commit Graph

638 Commits

Author SHA1 Message Date
Ján Tomko
3f029fb531 LXC: Fix handling of RAM filesystem size units
Since 76b644c when the support for RAM filesystems was introduced,
libvirt accepted the following XML:
<source usage='1024' unit='KiB'/>

This was parsed correctly and internally stored in bytes, but it
was formatted as (with an extra 's'):
<source usage='1024' units='KiB'/>
When read again, this was treated as if the units were missing,
meaning libvirt was unable to parse its own XML correctly.

The usage attribute was documented as being in KiB, but it was not
scaled if the unit was missing. Transient domains still worked,
because this was balanced by an extra 'k' in the mount options.

This patch:
Changes the parser to use 'units' instead of 'unit', as the latter
was never documented (fixing persistent domains) and some programs
(libvirt-glib, libvirt-sandbox) already parse the 'units' attribute.

Removes the extra 'k' from the tmpfs mount options, which is needed
because now we parse our own XML correctly.

Changes the default input unit to KiB to match documentation, fixing:
https://bugzilla.redhat.com/show_bug.cgi?id=1015689
2013-10-09 17:44:45 +02:00
Daniel P. Berrange
999d72fbd5 Remove use of virConnectPtr from all remaining nwfilter code
The virConnectPtr is passed around loads of nwfilter code in
order to provide it as a parameter to the callback registered
by the virt drivers. None of the virt drivers use this param
though, so it serves no purpose.

Avoiding the need to pass a virConnectPtr means that the
nwfilterStateReload method no longer needs to open a bogus
QEMU driver connection. This addresses a race condition that
can lead to a crash on startup.

The nwfilter driver starts before the QEMU driver and registers
some callbacks with DBus to detect firewalld reload. If the
firewalld reload happens while the QEMU driver is still starting
up though, the nwfilterStateReload method will open a connection
to the partially initialized QEMU driver and cause a crash.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-10-07 14:19:10 +01:00
Daniel P. Berrange
8766e9b5a5 Avoid deleting NULL veth device name
If veth device allocation has a fatal error, the veths
array may contain NULL device names. Avoid calling the
virNetDevVethDelete function on such names.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-10-03 11:28:08 +01:00
Daniel P. Berrange
f5eae57086 Don't set netdev offline in container cleanup
During container cleanup there is a race where the kernel may
have destroyed the veth device before we try to set it offline.
This causes log error messages. Given that we're about to
delete the device entirely, setting it offline is pointless.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-10-03 11:25:20 +01:00
Chen Hanxiao
4b2b078a8b lxc: do cleanup when failed to bind fs as read-only
We forgot to do cleanup when lxcContainerMountFSTmpfs
failed to bind fs as read-only.

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2013-09-30 13:30:43 -06:00
Cédric Bosdonnat
bd773e74f0 LXC: workaround machined uncleaned data with containers running systemd.
The problem is described by [0] but its effect on libvirt is that
starting a container with a full distro running systemd after having
stopped it simply fails.

The container cleanup now calls the machined Terminate function to make
sure that everything is in order for the next run.

 [0]: https://bugs.freedesktop.org/show_bug.cgi?id=68370
2013-09-30 16:47:23 +01:00
Chen Hanxiao
cc5b920b24 lxc: fix a warning typo in virLXCControllerEventSend
s/becuase/because/

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-09-27 08:15:06 +02:00
Eric Blake
8de47efd3f maint: fix comment typos
* src/lxc/lxc_controller.c (virLXCControllerSetupDisk): Fix typo.
* src/lxc/lxc_driver.c (lxcDomainAttachDeviceDiskLive): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-09-26 15:40:34 -06:00
Chen Hanxiao
c82513acc2 LXC: free dst before lxcDomainAttachDeviceDiskLive returns
Free dst before lxcDomainAttachDeviceDiskLive returns

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-09-26 15:13:55 +02:00
Chen Hanxiao
9a08e2cbc6 LXC: Check the existence of dir before resolving symlinks
If a dir does not exist, raise an immediate error in logs
rather than letting virFileResolveAllLinks fail, since this
gives better error reporting to the user.

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-09-23 11:22:17 +01:00
Chen Hanxiao
0e618c6aff LXC: follow the unit style of /proc/meminfo
When FUSE is enabled, the LXC container is setup with
a custom /proc/meminfo file. This file uses "KB" as a
suffix, rather than "kB" which is the kernel's style.
Fix this inconsistency to avoid confusing apps.

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-09-23 11:01:07 +01:00
Peter Krempa
f9c7b32e5d lxc: Add metadata modification APIs 2013-09-17 09:42:50 +02:00
Peter Krempa
d79fe8b50b cgroup: Move [qemu|lxc]GetCpuBWStatus to vicgroup.c and refactor it
The function existed in two identical instances in lxc and qemu. Move it
to vircgroup.c and simplify it. Refactor the callers too.
2013-09-16 11:32:49 +02:00
Gao feng
1c7037cff4 LXC: don't try to mount selinux filesystem when user namespace enabled
Right now we mount selinuxfs even user namespace is enabled and
ignore the error. But we shouldn't ignore these errors when user
namespace is not enabled.

This patch skips mounting selinuxfs when user namespace enabled.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
2013-09-12 15:18:01 +01:00
Daniel P. Berrange
75235a52bc Ensure root filesystem is recursively mounted readonly
If the guest is configured with

    <filesystem type='mount'>
      <source dir='/'/>
      <target dir='/'/>
      <readonly/>
    </filesystem>

Then any submounts under / should also end up readonly, except
for those setup as basic mounts. eg if the user has /home on a
separate volume, they'd expect /home to be readonly, but we
should not touch the /sys, /proc, etc dirs we setup ourselves.

Users can selectively make sub-mounts read-write again by
simply listing them as new mounts without the <readonly>
flag set

    <filesystem type='mount'>
      <source dir='/home'/>
      <target dir='/home'/>
    </filesystem>

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-09-12 12:01:49 +01:00
Daniel P. Berrange
f27f5f7edd Move array of mounts out of lxcContainerMountBasicFS
Move the array of basic mounts out of the lxcContainerMountBasicFS
function, to a global variable. This is to allow it to be referenced
by other methods wanting to know what the basic mount paths are.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-09-12 11:52:12 +01:00
Gao feng
66e2adb2ba LXC: introduce lxcContainerUnmountForSharedRoot
Move the unmounting private or useless filesystems for
container to this function.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
2013-09-11 13:09:31 +01:00
Gao feng
4142bf46b8 LXC: umount the temporary filesystem created by libvirt
The devpts, dev and fuse filesystems are mounted temporarily.
there is no need to export them to container if container shares
the root directory with host.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
2013-09-11 13:09:31 +01:00
Hongwei Bi
46c9bce4c8 LXC: Free variable vroot in lxcDomainDetachDeviceHostdevUSBLive()
The variable vroot should be freed in label cleanup.
2013-09-09 10:40:13 +02:00
Chen Hanxiao
744fb50831 LXC: fix typos in lxc_container.c
Fix docs and error message typos in lxc_container.c

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
2013-09-06 12:14:00 +01:00
Gao feng
1583dfda7c LXC: Don't mount securityfs when user namespace enabled
Right now, securityfs is disallowed to be mounted in non-initial
user namespace, so we must avoid trying to mount securityfs in
a container which has user namespace enabled.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
2013-09-05 12:00:07 +01:00
Daniel P. Berrange
c13a2c282b Ensure that /dev exists in the container root filesystem
If booting a container with a root FS that isn't the host's
root, we must ensure that the /dev mount point exists.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-13 16:26:44 +01:00
Daniel P. Berrange
2d07f84302 Honour root prefix in lxcContainerMountFSBlockAuto
The lxcContainerMountFSBlockAuto method can be used to mount the
initial root filesystem, so it cannot assume a prefix of /.oldroot.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-13 14:04:28 +01:00
Dan Walsh
6807238d87 Ensure securityfs is mounted readonly in container
If securityfs is available on the host, we should ensure to
mount it read-only in the container. This will avoid systemd
trying to mount it during startup causing SELinux AVCs.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-08 14:25:50 +01:00
Michal Privoznik
1199edb1d4 Introduce max_queued_clients
This configuration knob lets user to set the length of queue of
connection requests waiting to be accept()-ed by the daemon. IOW, it
just controls the @backlog passed to listen:

  int listen(int sockfd, int backlog);
2013-08-05 11:03:01 +02:00
Daniel P. Berrange
1166eeba61 Fix crashing upgrading from older libvirts with running guests
If upgrading from a libvirt that is older than 1.0.5, we can
not assume that vm->def->resource is non-NULL. This bogus
assumption caused libvirtd to crash

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-02 15:32:26 +01:00
Daniel P. Berrange
2fe2470181 Enable support for systemd-machined in cgroups creation
Make the virCgroupNewMachine method try to use systemd-machined
first. If that fails, then fallback to using the traditional
cgroup setup code path.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-31 19:29:19 +01:00
Yuri Chornoivan
5b4c035b08 Fix minor typos in messages and docs
Signed-off-by: Eric Blake <eblake@redhat.com>
2013-07-30 07:07:33 -06:00
Daniel P. Berrange
35fe8d97c0 Set default partition in libvirtd instead of libvirt_lxc
By setting the default partition in libvirt_lxc it is not
visible when querying the live XML. Move setting of the
default partition into libvirtd virLXCProcessStart

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-26 17:46:22 +01:00
John Ferlan
cefb97fb81 virStateDriver - Separate AutoStart from Initialize
Adjust these drivers to handle their Autostart functionality after each
of the drivers has gone through their Initialization functions
2013-07-26 09:30:53 -04:00
Daniel P. Berrange
5ec5a22493 Add 'controllers' arg to virCgroupNewDetect
When detecting cgroups we must honour any controllers
whitelist the driver may have.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-25 19:55:47 +01:00
Daniel P. Berrange
a45b99ead9 Introduce a more convenient virCgroupNewDetectMachine
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>
2013-07-25 19:47:30 +01:00
Daniel P. Berrange
f6c5f9077c Convert LXC driver to use virCgroupNewMachine
Convert the LXC driver code to use the new atomic API
for setup of cgroups

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-25 11:42:48 +01:00
Michal Privoznik
4e5f0dd2d3 virLXCMonitorClose: Unlock domain while closing monitor
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
2013-07-24 17:53:00 +02:00
John Ferlan
8134b37d34 lxc: Resolve Coverity warning
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.
2013-07-23 19:04:48 -04:00
Daniel P. Berrange
da704c8782 Create + setup cgroups atomically for LXC process
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>
2013-07-23 22:46:31 +01:00
Daniel P. Berrange
87b2e6fa84 Auto-detect existing cgroup placement
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>
2013-07-23 22:46:31 +01:00
Daniel P. Berrange
0d7f45aea7 Convert remainder of cgroups code to report errors
Convert the remaining methods in vircgroup.c to report errors
instead of returning errno values.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-22 13:09:58 +01:00
Daniel P. Berrange
3260fdfab0 Convert the virCgroupKill* APIs to report errors
Instead of returning errno values, change the virCgroupKill*
APIs to fully report errors.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-22 13:09:58 +01:00
Daniel P. Berrange
b64dabff27 Report full errors from virCgroupNew*
Instead of returning raw errno values, report full libvirt
errors in virCgroupNew* functions.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-22 13:09:58 +01:00
Daniel P. Berrange
3aac4e5632 LXC: Set default driver for image backed filesystems
If no explicit driver is set for an image backed filesystem,
set it to use the loop driver (if raw) or nbd driver (if
non-raw)

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-22 12:32:25 +01:00
Daniel P. Berrange
2e832b18d6 LXC: Fix some error reporting in filesystem setup
A couple of places in LXC setup for filesystems did not do
a "goto cleanup" after reporting errors. While fixing this,
also add in many more debug statements to aid troubleshooting

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-22 12:32:07 +01:00
Michal Privoznik
dbeb04a65c Introduce lxcDomObjFromDomain
Similarly to qemu driver, we can use a helper function to
lookup a domain instead of copying multiple lines around.
2013-07-18 14:16:54 +02:00
Michal Privoznik
eb150c86b4 Remove lxcDriverLock from almost everywhere
With the majority of fields in the virLXCDriverPtr struct
now immutable or self-locking, there is no need for practically
any methods to be using the LXC driver lock. Only a handful
of helper APIs now need it.
2013-07-18 14:16:54 +02:00
Michal Privoznik
2a82171aff lxc: Make activeUsbHostdevs use locks
The activeUsbHostdevs item in LXCDriver are lockable, but the lock has
to be called explicitly. Call the virObject(Un)Lock() in order to
achieve mutual exclusion once lxcDriverLock is removed.
2013-07-18 14:16:54 +02:00
Michal Privoznik
64ec738e58 Stop accessing driver->caps directly in LXC driver
The 'driver->caps' pointer can be changed on the fly. Accessing
it currently requires the global driver lock. Isolate this
access in a single helper, so a future patch can relax the
locking constraints.
2013-07-18 14:16:54 +02:00
Michal Privoznik
c86950533a lxc: switch to virCloseCallbacks API 2013-07-18 14:16:54 +02:00
Michal Privoznik
4deeb74d01 Introduce annotations for virLXCDriverPtr fields
Annotate the fields in virLXCDriverPtr to indicate the locking
rules for their use.
2013-07-18 14:16:54 +02:00
Michal Privoznik
29bed27eb4 lxc: Use atomic ops for driver->nactive 2013-07-18 14:16:54 +02:00
Michal Privoznik
7fca37554c Introduce a virLXCDriverConfigPtr object
Currently the virLXCDriverPtr struct contains an wide variety
of data with varying access needs. Move all the static config
data into a dedicated virLXCDriverConfigPtr object. The only
locking requirement is to hold the driver lock, while obtaining
an instance of virLXCDriverConfigPtr. Once a reference is held
on the config object, it can be used completely lockless since
it is immutable.

NB, not all APIs correctly hold the driver lock while getting
a reference to the config object in this patch. This is safe
for now since the config is never updated on the fly. Later
patches will address this fully.
2013-07-18 14:16:53 +02:00