To make sure everything still compiles, we add a preliminary include
of forward.h to tests.h to make sure it is included in every test source
file. We'll clean up the tests.h includes in a later commit.
We also add a <errno.h> include to errno-list.h to keep test-errno-list.c
compiling. It'll be removed again when we clean up includes in src/basic.
Split out of #37344.
In various tools and services we have a per-system and per-user concept.
So far we sometimes used a boolean indicating whether we are in system
mode, or a reversed boolean indicating whether we are in user mode, or
the LookupScope enum used by the lookup path logic.
Let's address that, in introduce a common enum for this, we can use all
across the board.
This is mostly just search/replace, no actual code changes.
As suggested in
8b3ad3983f (r837345892)
The define is generalized and moved to path-lookup.h, where it seems to fit
better. This allows a recursive include to be removed and in general makes
things simpler.
Note that test-cgroup-mask, test-cgroup-unit-default and test-unit-name will now
report being skipped instead of reporting success if not run under systemd.
-------------------------------------------------------------------------------
Example Run:
foobar.service created below is a service unit file that has a non-existing key-value
pairing (foo = bar) and is thus, syntactically invalid.
maanya-goenka@debian:~/systemd (img-support)$ cat <<EOF>img/usr/lib/systemd/system/foobar.service
> [Unit]
> foo = bar
>
> [Service]
> ExecStart = /opt/script0.sh
> EOF
The failure to create foobar.service because of the recursive dependency searching and verification has been addressed
in a different PR: systemd-analyze: add option to return an error value when unit verification fails #20233
maanya-goenka@debian:~/systemd (img-support)$ sudo build/systemd-analyze verify --root=img/ foobar.service
/home/maanya-goenka/systemd/img/usr/lib/systemd/system/foobar.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
foobar.service: Failed to create foobar.service/start: Unit sysinit.target not found.
In a later commit we intend to move the slice logic to use proper
dependencies instead of a "UnitRef" object. This preparatory commit
drops direct use of the slice UnitRef object for a static inline
function UNIT_GET_SLICE() that is both easier to grok, and allows us to
easily replace its internal implementation later on.
In cgroup v2 we have protection tunables -- currently MemoryLow and
MemoryMin (there will be more in future for other resources, too). The
design of these protection tunables requires not only intermediate
cgroups to propagate protections, but also the units at the leaf of that
resource's operation to accept it (by setting MemoryLow or MemoryMin).
This makes sense from an low-level API design perspective, but it's a
good idea to also have a higher-level abstraction that can, by default,
propagate these resources to children recursively. In this patch, this
happens by having descendants set memory.low to N if their ancestor has
DefaultMemoryLow=N -- assuming they don't set a separate MemoryLow
value.
Any affected unit can opt out of this propagation by manually setting
`MemoryLow` to some value in its unit configuration. A unit can also
stop further propagation by setting `DefaultMemoryLow=` with no
argument. This removes further propagation in the subtree, but has no
effect on the unit itself (for that, use `MemoryLow=0`).
Our use case in production is simplifying the configuration of machines
which heavily rely on memory protection tunables, but currently require
tweaking a huge number of unit files to make that a reality. This
directive makes that significantly less fragile, and decreases the risk
of misconfiguration.
After this patch is merged, I will implement DefaultMemoryMin= using the
same principles.
