In the unified hierarchy delegating controller access is safe, hence
make sure to enable all controllers for the "payload" subcgroup if we
create it, so that the container will have all controllers enabled the
nspawn service itself has.
If the controller managed by systemd cannot found in /proc/$PID/cgroup,
return ENODATA, the usual error for cases where the data being looked
for does not exist, even if the process does.
Previously, on the legacy hierarchy a non-existing cgroup was considered
identical to an empty one, but the unified hierarchy the check for a
non-existing one returned ENOENT.
This simply factors out the uid validation checks from parse_uid() and
uses them everywhere. This simply verifies that the passed UID is
neither 64bit -1 nor 32bit -1.
This adds a new PID_TO_PTR() macro, plus PTR_TO_PID() and makes use of
it wherever we maintain processes in a hash table. Previously we
sometimes used LONG_TO_PTR() and other times ULONG_TO_PTR() for that,
hence let's make this more explicit and clean up things.
This patch set adds full support the new unified cgroup hierarchy logic
of modern kernels.
A new kernel command line option "systemd.unified_cgroup_hierarchy=1" is
added. If specified the unified hierarchy is mounted to /sys/fs/cgroup
instead of a tmpfs. No further hierarchies are mounted. The kernel
command line option defaults to off. We can turn it on by default as
soon as the kernel's APIs regarding this are stabilized (but even then
downstream distros might want to turn this off, as this will break any
tools that access cgroupfs directly).
It is possibly to choose for each boot individually whether the unified
or the legacy hierarchy is used. nspawn will by default provide the
legacy hierarchy to containers if the host is using it, and the unified
otherwise. However it is possible to run containers with the unified
hierarchy on a legacy host and vice versa, by setting the
$UNIFIED_CGROUP_HIERARCHY environment variable for nspawn to 1 or 0,
respectively.
The unified hierarchy provides reliable cgroup empty notifications for
the first time, via inotify. To make use of this we maintain one
manager-wide inotify fd, and each cgroup to it.
This patch also removes cg_delete() which is unused now.
On kernel 4.2 only the "memory" controller is compatible with the
unified hierarchy, hence that's the only controller systemd exposes when
booted in unified heirarchy mode.
This introduces a new enum for enumerating supported controllers, plus a
related enum for the mask bits mapping to it. The core is changed to
make use of this everywhere.
This moves PID 1 into a new "init.scope" implicit scope unit in the root
slice. This is necessary since on the unified hierarchy cgroups may
either contain subgroups or processes but not both. PID 1 hence has to
move out of the root cgroup (strictly speaking the root cgroup is the
only one where processes and subgroups are still allowed, but in order
to support containers nicey, we move PID 1 into the new scope in all
cases.) This new unit is also used on legacy hierarchy setups. It's
actually pretty useful on all systems, as it can then be used to filter
journal messages coming from PID 1, and so on.
The root slice ("-.slice") is now implicitly created and started (and
does not require a unit file on disk anymore), since
that's where "init.scope" is located and the slice needs to be started
before the scope can.
To check whether we are in unified or legacy hierarchy mode we use
statfs() on /sys/fs/cgroup. If the .f_type field reports tmpfs we are in
legacy mode, if it reports cgroupfs we are in unified mode.
This patch set carefuly makes sure that cgls and cgtop continue to work
as desired.
When invoking nspawn as a service it will implicitly create two
subcgroups in the cgroup it is using, one to move the nspawn process
into, the other to move the actual container processes into. This is
done because of the requirement that cgroups may either contain
processes or other subgroups.
In all cases where the function (or cg_is_empty_recursive()) ignoring
the calling process is actually wrong, as a process keeps a cgroup busy
regardless if its the current one or another. Hence, let's simplify
things and drop the "ignore_self" parameter.
When mcstransd* is running non-raw functions will return translated SELinux
context. Problem is that libselinux will cache this information and in the
future it will return same context even though mcstransd maybe not running at
that time. If you then check with such context against SELinux policy then
selinux_check_access may fail depending on whether mcstransd is running or not.
To workaround this problem/bug in libselinux, we should always get raw context
instead. Most users will not notice because result of access check is logged
only in debug mode.
* SELinux context translation service, which will translates labels to human
readable form
Make use of it in config_parse_cpu_affinity2.
Tested by tweaking the `CPUAffinity' setting in /etc/systemd/system.conf
and reloading the daemon to confirm it is working as expected.
No regressions observed in test cases.
Refactor allocation of the result string to the top, since it is
currently done in both branches of the condition.
Remove unreachable code checking for EXTRACT_DONT_COALESCE_SEPARATORS
when state == SEPARATOR (the only place where SEPARATOR is assigned to
state follows a check for EXTRACT_DONT_COALESCE_SEPARATORS that jumps to
the end of the function.)
Tested by running test-util successfully.
Follow up to: 206644aede
This covers the case where an argument is an empty string, such as ''.
Instead of allocating the empty string in the individual conditions when
state == VALUE, just always allocate it at the end of state == START, at
which point we know we will have an argument.
Tested that test-util keeps passing after the refactor.
Follow up to: 14e685c29d
In preparation of the unified cgroup support, let's clean up cgtop:
a) rework time code to be based on "nsec_t" rather than "struct timespec"
b) Introduce long option --order= for selecting ordering
c) count number of processes only in the main hierarchy, don't bother
with the controller hierarchies. We don't allow orthogonal
hierarchies in systemd anymore, hence there's no point to check the
other hierarchies.
d) Deal with non-monotonic cpuacct values (see #749)
e) When sorting groups, don't do prefix compare when ordering by number
of tasks, since this is not accumulative for all children.
f) Actually make --cpu without parameter work
g) Don't output control characters when we get them as input.
Fixes#749.
Let's add a way to get the type-specific D-Bus interface of a unit from
either its type or name to src/basic/unit-name.[ch]. That way we can
share it with the client side, where it is useful in tools like cgls or
machinectl.
Also ports over machinectl to make use of this.
Apparently, sendfile() does not work between fifos and ttys, but
splice() does, hence let's optionally fall back to that. This is useful
to implement the fallback pager this way.
This reverts commit d4d00020d6. The idea of
the commit is broken and needs to be reworked. We really cannot reduce
the bus-addresses to a single address. We always will have systemd with
native clients and legacy clients at the same time, so we also need both
addresses at the same time.
refcnt.h only exists for cases where objects are simultaneously handled
by different threads. Otherwise it should not be used. The only case
where this applies is sd_bus, really, and pretty much none of our APIs,
since we do not claim thread-safety for them.
Some of the operations machined/machinectl implement are also very
useful when applied to the host system (such as machinectl login,
machinectl shell or machinectl status), hence introduce a pseudo-machine
by the name of ".host" in machined that refers to the host system, and
may be used top execute operations on the host system with.
This copies the pseudo-image ".host" machined already implements for
image related commands.
(This commit also adds a PK privilege for opening a PTY in a container,
which was previously not accessible for non-root.)
When enumerating machines from /run, and when accepting machine names
for operations, be more strict and always validate.
Note that these checks are strictly speaking unnecessary, since
enumeration happens only on the trusted /run...
