As same as normal directories, a cgroup cannot be removed if it
contains sub groups. This patch changes virCgroupRemove to remove
all descendant groups (subdirectories) of a target group before
removing the target group.
The handling is required when we run lxc with ns subsystem of cgroup.
Ns subsystem automatically creates child cgroups on every process
forks, but unfortunately the groups are not removed on process exits,
so we have to remove them by ourselves.
With this patch, such child (and descendant) groups are surely removed
at lxc shutdown, i.e., lxcVmCleanup which calls virCgroupRemove.
The switch from %lli to %lld in virCgroupGetValueI64 is intended,
as virCgroupGetValueU64 uses base 10 too, and virCgroupSetValueI64
uses %lld to format the number to string.
Parsing is stricter now and doesn't accept trailing characters
after the actual value anymore.
Invoking virDomainSetMemory() on lxc driver results in libvirtd
segfault when cgroups has not been configured on the host.
Ensure driver->cgroup is non-null before invoking
virCgroupForDomain(). To prevent similar segfaults in the future,
ensure driver parameter to virCgroupForDomain() is non-null before
dereferencing.
When getting the driver/domain cgroup it is possible to specify
whether it should be auto created. If auto-creation was turned
off, libvirt still mistakenly created its own top level cgroup
* src/util/cgroup.c: Honour autocreate flag for top level cgroup
In the scenario where the cgroups were mounted but the
particular group did not exist, and the caller had not
requested auto-creation, the code would fail to return
an error condition. This caused the lxc_controller to
think the cgroup existed, and it then later failed when
attempting to use it
* src/util/cgroup.c: Raise an error if the cgroup path does not
exist
A cgroup file returns integer value terminated with '\n' and remaining
it has sometimes harmful effects, for example it leads virStrToLong_ull
to fail.
* src/util/cgroup.c: strip out terminating \n when reading a value
The patch implements the missing memory control APIs for lxc, i.e.,
domainGetMaxMemory, domainSetMaxMemory, domainSetMemory, and improves
domainGetInfo to return proper amount of used memory via cgroup.
* src/libvirt_private.syms: Export virCgroupGetMemoryUsage
and add missing virCgroupSetMemory
* src/lxc/lxc_driver.c: Implement missing memory functions
* src/util/cgroup.c, src/util/cgroup.h: Add the function
to get used memory
* src/conf/domain_conf.c: Don't assume all virDomainObjPtr have
a non-NULL monitor_chr field in virDomainObjFormat.
* src/lxc/lxc_driver.c: Implement suspend/resume driver APis
* src/util/cgroup.c, src/util/cgroup.h: Support the 'freezer'
cgroup controller
* src/libvirt_private.syms: Export virCgroupSetFreezerState
and virCgroupGetFreezerState
