Commit Graph

66 Commits

Author SHA1 Message Date
Daniel P. Berrange
aedd46e7e3 Add support for systemd cgroup mount
Systemd uses a named cgroup mount for tracking processes. Add
it as another type of controller, albeit one which we have to
special case in a number of places. In particular we must
never create/delete directories there, nor add tasks. Essentially
the systemd mount is to be considered read-only for libvirt.

With this change both the virCgroupDetectPlacement and
virCgroupCopyPlacement methods must be invoked. The copy
placement method will copy setup for resource controllers
only. The detect placement method will probe for any
named controllers, or resource controllers not already
setup.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-31 19:27:19 +01:00
Daniel P. Berrange
d64e852b5a Remove obsolete cgroups creation apis
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>
2013-07-23 22:46:31 +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
7a1e691711 Convert 'int i' to 'size_t i' in tests/ files
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-10 17:40:13 +01:00
Viktor Mihajlovski
eb21408f44 cgroups: Do not enforce nonexistent controllers
Currently, the controllers argument to virCgroupDetect acts both as
a result filter and a required controller specification, which is
a bit overloaded. If both functionalities are needed, it would be
better to have them seperated into a filter and a requirement mask.
The only situation where it is used today is to ensure that only
CPU related controllers are used for the VCPU directories. But here
we clearly do not want to enforce the existence of cpu, cpuacct and
specifically not cpuset at the same time.
This commit changes the semantics of controllers to "filter only".
Should a required mask ever be needed, more work will have to be done.

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
2013-05-24 12:11:24 +02:00
Osier Yang
bb3ea8416b tests/: Remove the whitespace before ";" 2013-05-21 23:41:45 +08:00
Michal Privoznik
e60b9783e1 Adapt to VIR_STRDUP and VIR_STRNDUP in tests/* 2013-05-10 11:54:29 +02:00
Michal Privoznik
7c9a2d88cd virutil: Move string related functions to virstring.c
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
2013-05-02 16:56:55 +02:00
Daniel P. Berrange
f3662737b1 Do proper escaping of cgroup resource partitions
If a user cgroup name begins with "cgroup.", "_" or with any of
the controllers from /proc/cgroups followed by a dot, then they
need to be prefixed with a single underscore. eg if there is
an object "cpu.service", then this would end up as "_cpu.service"
in the cgroup filesystem tree, however, "waldo.service" would
stay "waldo.service", at least as long as nobody comes up with
a cgroup controller called "waldo".

Since we require a '.XXXX' suffix on all partitions, there is
no scope for clashing with the kernel 'tasks' and 'release_agent'
files.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-26 13:52:02 +01:00
Daniel P. Berrange
9ddfe7eea6 Ensure all cgroup partitions have a suffix of ".partition"
If the partition named passed in the XML does not already have
a suffix, ensure it gets a '.partition' added to each component.
The exceptions are /machine, /user and /system which do not need
to have a suffix, since they are fixed partitions at the top
level.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-26 13:52:02 +01:00
Daniel P. Berrange
824e86e723 Change VM cgroup suffix from '{lxc,qemu}.libvirt' to 'libvirt-{lxc,qemu}'
Recently we changed to create VM cgroups with the naming pattern
$VMNAME.$DRIVER.libvirt. Following discussions with the systemd
community it was decided that only having a single '.' in the
names is preferrable. So this changes the naming scheme to be
$VMNAME.libvirt-$DRIVER. eg for LXC 'mycontainer.libvirt-lxc' or
for KVM 'myvm.libvirt-qemu'.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-26 13:52:02 +01:00
Daniel P. Berrange
83336118db Track symlinks for co-mounted cgroup controllers
If a cgroup controller is co-mounted with another, eg

   /sys/fs/cgroup/cpu,cpuacct

Then it is a requirement that there exist symlinks at

   /sys/fs/cgroup/cpu
   /sys/fs/cgroup/cpuacct

pointing to the real mount point. Add support to virCgroupPtr
to detect and track these symlinks

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-15 17:35:32 +01:00
Daniel P. Berrange
767596bdb4 Remove non-functional code for setting up non-root cgroups
The virCgroupNewDriver method had a 'bool privileged' param.
If a false value was ever passed in, it would simply not
work, since non-root users don't have any privileges to create
new cgroups. Just delete this broken code entirely and make
the QEMU driver skip cgroup setup in non-privileged mode

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-15 17:35:31 +01:00
Daniel P. Berrange
aa8604dd45 Add a new virCgroupNewPartition for setting up resource partitions
A resource partition is an absolute cgroup path, ignoring the
current process placement. Expose a virCgroupNewPartition API
for constructing such cgroups

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-15 17:35:31 +01:00
Daniel P. Berrange
8d1c141a8d Refactor cgroups internal data structures
Currently the virCgroupPtr struct contains 3 pieces of
information

 - path - path of the cgroup, relative to current process'
   cgroup placement
 - placement - current process' placement in each controller
 - mounts - mount point of each controller

When reading/writing cgroup settings, the path & placement
strings are combined to form the file path. This approach
only works if we assume all cgroups will be relative to
the current process' cgroup placement.

To allow support for managing cgroups at any place in the
heirarchy a change is needed. The 'placement' data should
reflect the absolute path to the cgroup, and the 'path'
value should no longer be used to form the paths to the
cgroup attribute files.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-15 17:35:31 +01:00
Daniel P. Berrange
d14524701a Add a test suite for cgroups functionality
Some aspects of the cgroups setup / detection code are quite subtle
and easy to break. It would greatly benefit from unit testing, but
this is difficult because the test suite won't have privileges to
play around with cgroups. The solution is to use monkey patching
via LD_PRELOAD to override the fopen, open, mkdir, access functions
to redirect access of cgroups files to some magic stubs in the
test suite.

Using this we provide custom content for the /proc/cgroup and
/proc/self/mounts files which report a fixed cgroup setup. We
then override open/mkdir/access so that access to the cgroups
filesystem gets redirected into files in a temporary directory
tree in the test suite build dir.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-15 17:35:31 +01:00