I'm assuming that it's fine if a _const_ or _pure_ function
calls assert. It is assumed that the assert won't trigger,
and even if it does, it can only trigger on the first call
with a given set of parameters, and we don't care if the
compiler moves the order of calls.

This was needed with log_struct_unit() but log_notice_unit() adds it
anyway.

When a trigger unit wants to know if a stop is queued for it, we should
just check precisely that and do not check whether it is actually
stopped already. This is because we use these checks usually from state
change calls where the state variables are not updated yet.

This change splits unit_pending_inactive() into two calls
unit_inactive_or_pending() and unit_stop_pending(). The former checks
state and pending jobs, the latter only pending jobs.

Let's better be safe than sorry.

Instead of having explicit type-specific callbacks that inform the
triggering unit when a triggered unit changes state, make this generic
so that state changes are forwarded betwee any triggered and triggering
unit.

Also, get rid of UnitRef references from automount, timer, path units,
to the units they trigger and rely exclsuively on UNIT_TRIGGER type
dendencies.

Session objects will now get the .session suffix, user objects the .user
suffix, nspawn containers the .nspawn suffix.

This also changes the user cgroups to be named after the numeric UID
rather than the username, since this allows us the parse these paths
standalone without requiring access to the cgroup file system.

This also changes the mapping of instanced units to cgroups. Instead of
mapping foo@bar.service to the cgroup path /user/foo@.service/bar we
will now map it to /user/foo@.service/foo@bar.service, in order to
ensure that all our objects are properly suffixed in the tree.

Before, we would initialize many fields twice: first
by filling the structure with zeros, and then a second
time with the real values. We can let the compiler do
the job for us, avoiding one copy.

A downside of this patch is that text gets slightly
bigger. This is because all zero() calls are effectively
inlined:

$ size build/.libs/systemd
         text    data     bss     dec     hex filename
before 897737  107300    2560 1007597   f5fed build/.libs/systemd
after  897873  107300    2560 1007733   f6075 build/.libs/systemd

… actually less than 1‰.

A few asserts that the parameter is not null had to be removed. I
don't think this changes much, because first, it is quite unlikely
for the assert to fail, and second, an immediate SEGV is almost as
good as an assert.

Instead of outputting "5h 55s 50ms 3us" we'll now output "5h
55.050003s". Also, while outputting the accuracy is configurable.

Basically we now try use "dot notation" for all time values > 1min. For
>= 1s we use 's' as unit, otherwise for >= 1ms we use 'ms' as unit, and
finally 'us'.

This should give reasonably values in most cases.

You can write much more than just one line with this call (and we
frequently do), so let's correct the naming.

Requesites are not supposed to be auto-started afterall, they are just
checks, so don't try to be smarter here than appropriate.

Based on a patch from Michal Schmidt.

Previously, it would set all caps, but it should drop them all, anything
else makes little sense.

Also, document that this works as it does, and what to do in order to
assign all caps to the bounding set.

https://bugzilla.redhat.com/show_bug.cgi?id=914705

There are very few differences in the implementations of the kill method in the
unit types that have one. Let's unify them.

This does not yet unify unit_kill() with unit_kill_context().

Installation of a deserialized job may fail (though purely in theory),
so increase the running job counter only when succeeding.

All active units will call unit_notify() during coldplug, so we just
make sure we're counting from zero again and get the correct result for
n_on_console.

For n_running_jobs we likewise reset it to zero and then count
the running jobs as we encounter them in deserialization.

unit_notify is fired in deserelization code (particulary in
service_set_state). Units passed in random order, and there is possibility,
that unit with StopWhenUnneeded=yes passed before it actual dependecies. In
that case unit will be stopped as unneeded, because deps in UNIT_INACTIVE state
yet.

So, reuse similar logic (unit.c:1421) to avoid this race

Take advantage of the fact that almost all callers want to pass unit
description as the last parameter. Those who don't can use the more
flexible manager_status_printf().

unit_status_printf() checks the state of the manager, not of the unit
as such. Move it to manager.c and rename it to manager_status_printf().

Temporarily keep unit_status_printf as a wrapper macro.

This introduces a new static list of known attributes and their special
semantics. This means that cgroup attribute values can now be
automatically translated from user to kernel notation for command line
set settings, too.

This also adds proper support for multi-line attributes.

It is not really necessary to have a hard requirement dependency on
systemd-journald.socket in almost every unit. The socket gets pulled
into boot via at least two ways:
 sockets.target -> systemd-journald.socket
 sysinit.target -> systemd-journald.service -> systemd-journald.socket

So just assume something pulled the socket in and drop the automatic
requirement dependencies on it.

"systemctl stop systemd-journald.socket" will now not take the whole
system down with it.

Also split out some fileio functions to fileio.c and provide a SELinux
aware pendant in fileio-label.c

see https://bugzilla.redhat.com/show_bug.cgi?id=881577

In commit 246aa6dd (core: add bus API and systemctl commands for altering
cgroup parameters during runtime), when rewriting unit_add_one_default_cgroup
to prefered style, the check of strduped b->controller was incorrectly
changed to check the containing structure. Correct it.

For all unit files foobar.service we will now read
foobar.service.d/*.conf, too. This may be used to override certain unit
settings without having to edit unit files directly.

This makes it really easy to change specific settings for services
without having to edit any unit file:

mkdir /etc/systemd/system/avahi-daemon.service.d/
echo -e '[Service]\nNice=99' > /etc/systemd/system/avahi-daemon.service.d/nice.conf
systemctl daemon-reload

Information which unit a log entry pertains to enables systemctl
status to display more log messages.