Turns this:
r = -errno;
log_error_errno(errno, "foo");
into this:
r = log_error_errno(errno, "foo");
and this:
r = log_error_errno(errno, "foo");
return r;
into this:
return log_error_errno(errno, "foo");
Make sure we always check conditions before checking whether the unit
type is supported in unit_start(), since condition checks are "clean
errors", while "not supported" errors are fatal.
This cleans up the boot output of systemd in containers, where a lot of
NOTSUPP lines were shown befor this fix.
This partially reverts 8ff4d2ab0d which
reorder the checks.
Introduce a proper enum, and don't pass around string ids anymore. This
simplifies things quite a bit, and makes virtualization detection more
similar to architecture detection.
.nspawn fiels are simple settings files that may accompany container
images and directories and contain settings otherwise passed on the
nspawn command line. This provides an efficient way to attach execution
data directly to containers.
This funciton is exposed via CanStart on the bus, and should be as
accurate as possible. Hence: make sure to return false for units of unit
types not supported on the system, and for unit types where
configuration failed to load.
Also see #1105.
The following details are passed:
- unit: the primary name of the unit upon which the action was
invoked (i.e. after resolving any aliases);
- verb: one of 'start', 'stop', 'reload', 'restart', 'try-restart',
'reload-or-restart', 'reload-or-try-restart', 'kill',
'reset-failed', or 'set-property', corresponding to the
systemctl verb used to invoke the action.
Typical use of these details in a polkit policy rule might be:
// Allow alice to manage example.service;
// fall back to implicit authorization otherwise.
polkit.addRule(function(action, subject) {
if (action.id == "org.freedesktop.systemd1.manage-units" &&
action.lookup("unit") == "example.service" &&
subject.user == "alice") {
return polkit.Result.YES;
}
});
We also supply a custom polkit message that includes the unit's name and
the requested operation.
Extra details for an action can be supplied when calling polkit's
CheckAuthorization method. Details are a list of key/value string pairs.
Custom policy can use these details when making authorization decisions.
Delegation to unpriviliged processes is safe in the unified hierarchy,
hence allow it. This has the benefit of permitting "systemd --user"
instances to further partition their resources between user services.
Let's move the actual cgroup part of it into a new separate function
manager_get_unit_by_pid_cgroup(), and then make
manager_get_unit_by_pid() just a wrapper that also checks the two pid
hashmaps.
Then, let's make sure the various calls that want to deliver events to
the owners of a PID check both hashmaps and the cgroup and deliver the
event to *each* of them. OTOH make sure bus calls like GetUnitByPID()
continue to check the PID hashmaps first and the cgroup only as
fallback.
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.
When the user wants to explicitly send our own PID a signal, then do so.
Don't follow up SIGABRT with a SIGHUP if send_sighup is enabled. At that
point the process should have segfaulted, hence there's no point in
following up with a SIGHUP.
Send only termination signals to ourselves, never KILL or ABRT signals.
Always say when we ignore errors. Cast calls whose return value we
knowingly ingore to (void). Use "bool" where we actually mean a boolean,
even if we return it as an int later on.
It's cheaper that going to cgroupfs, and also usually the better choice
since it's not racy and can map PIDs even if they were moved to a
different unit.
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.
The legacy cgroup hierarchy does not support reliable empty
notifications in containers and if there are left-over subgroups in a
cgroup. This makes it hard to correctly wait for them running empty, and
thus we previously disabled this logic entirely.
With this change we explicitly check for the container case, and whether
the unit is a "delegation" unit (i.e. one where programs may create
their own subgroups). If we are neither in a container, nor operating on
a delegation unit cgroup empty notifications become reliable and thus we
start waiting for the empty notifications again.
This doesn't really fix the general problem around cgroup notifications
but reduces the effect around it.
(This also reorders #include lines by their focus, as suggsted in
CODING_STYLE. We have to add "virt.h", so let's do that at the right
place.)
Also see #317.
Rework the "service is good" check, to only check the cgroup state if we
really need to instead of always.
This allows us to suppress going to the cgroupfs for an empty check for
the majority of services.
No functional change.
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
Related to the TODO item to replace FOREACH_WORD_QUOTED with it.
Tested by setting `JoinControllers=cpu,cpuacct,memory net_cls,blkio' in
/etc/systemd/system.conf, rebooting the system with the patched binaries
and checking that the desired setup was created by inspecting the
entries under /sys/fs/cgroup.
No regressions observed in test cases.
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.
Related to the TODO item to replace FOREACH_WORD_QUOTED with it.
Tested by setting `CPUAfinity=0 1' (and other similar settings) in
/etc/systemd/system.conf, booting the system with the patched binaries
(and also using `systemctl daemon-reload` to reconfigure) and checking
that /proc/1/status indicates only CPUs 0 and 1 are allowed for PID 1.
No regressions observed in test cases.
We store the properties for transient units in drop-ins anyway, and
units don't have to have fragment files, hence don't bother with them,
and don't create them.
