Follow-up for 19a44dfe45
If a drop-in is set from upper level, e.g. global unit_type.d/,
even if a unit is masked, its dropin_paths would still be partially
populated. However, unit_need_daemon_reload() would always
compare u->dropin_paths with empty strv in case of masked units,
resulting in it always returning true. Instead, let's ignore
dropins entirely here.
Fixes#33672
Currently, we only follow merged units for unit_load_dropin() call.
But if the unit is an alias, we should always perform operations
on the "canonical" unit.
Use the new function `hashmap_ensure_replace()` where we're using
`hashmap_ensure_allocated()` and `hashmap_ensure_replace()`.
Signed-off-by: Matteo Croce <teknoraver@meta.com>
Since the introduction of CGroupRuntime, there's no need
to call *_reset_accounting in unit_new(), hence make those
static. While at it, refrain from hardcoding default values
in cgroup_runtime_new(), but call the corresponding funcs.
This also corrects the default value of io_accounting_base.
Fixes#33482
No functional change, just deduplicate default values
in cgroup_runtime_free() and remove pointless call in
unit_free() (at the time it's called the CGRuntime has
been destroyed already).
The purpose of the check is to prevent leaking API VFS fds
from host into a mount namespace/container. When mountns
is not used at all, the check is pointless and causes
inconvenience. E.g. file managers might need to be spawned
under those directories, and they surely won't run in mountns.
Suggested in https://github.com/systemd/systemd/pull/33454#issuecomment-2186351467Fixes#33361
DynamicUser= enables PrivateTmp= implicitly to avoid files owned by reusable uids
leaking into the host. Change it to instead create a fully private tmpfs instance
instead, which also ensures the same result, since it has less impactful semantics
with respect to PrivateTmp=yes, which links the mount namespace to the host's /tmp
instead. If a user specifies PrivateTmp manually, let the existing behaviour
unchanged to ensure backward compatibility is not broken.
This reverts commit 1e1225614c.
This was an incomplete workaround of the race. Now that
we stop generating mount units for credential mounts,
the logic could be dropped.
While at it, the duplicate log of "Unit entered failed state"
is dropped. Since the state change would be logged by each
unit type already, before calling unit_notify().
Currently, Unit.freezer_state is always initialized to
FREEZER_RUNNING. While realizing cgroups for frozen units
was disabled in 7923e9493c,
the commit only checked for freezer_state of the unit inself,
meaning that newly-loaded units might be started and the kernel
would hang pid1 when trying to spawn sd-executor into sub-cgroup.
This can be easily reproduced by the following:
```console
# systemd-run --slice=test.slice sleep infinity
# systemctl freeze test.slice
# systemd-run --slice=test.slice sleep infinity
```
Therefore, let's correctly initialize Unit.freezer_state
based on the parent slice.
We can only do a debug log from the library, so let's add that. Callers
probably want to provide some hint when that happens, but it's very unlikely so
not worth coding in every caller.
And drop the now-unnecessary handling in unit_dequeue_rewatch_pids().
Otherwise, if a service unit that requests LogNamespace= stopped before
systemd-journald@.service is started, logs generated by the service will be
lost, as systemd-journald@.socket is stopped and
systemd-journald@.service will never started.
To prevent the issue, let's introduce another implicit dependency to
a oneshot service that explicitly synchronizes a namespaced journal file
when the log namespace is not needed anymore.
Fixes#32604.
- drop unnecessary SYNTHETIC_ERRNO() when the logger does not propagate
error code,
- drop unnecessary '%m' in error message when the error code is
specified with SYNTHETIC_ERRNO(),
- add missing full stop at the end of log message,
- use RET_GATHER(),
- add missing ", ignoring.",
- upeercase the first letter, etc., etc...
This changes the executor to systematically send handoff timestamps to
the service manager if a socket for that is supplied. This drops the
code that did this via Type=exec messages, and reverts that part to the
old behaviour before 93cb78aee2.
Benefits of this approach:
1. We can collect the handoff for any command we fork off, regardless
if it's ExecStart= something else, regardless whether it's Type=exec,
Type=simple or some any other service type, regardless of the unit
type.
2. We collect both CLOCK_REALTIME and CLOCK_MONOTONIC, as we do for the
other process timestamps.
3. It's entirely backwards compatible, as this doesn't change the
protocol between service manager and executor, but just extends it.
I didn't know that this helper existed… It is very similar to strdup_to_full(),
but all callers can actually be replaced by strdup_to(), which has more fitting
semantics.
Let's inform the the supervisor about various happenings of our service
manager, specifically the boot milestones we reach.
We so far have only a singular READY=1 message, to inform about bootup
completion. But sometimes it is interesting to have something for
finegrained, in particular something that indicates optional components
that have been activated.
Usecase for this: in a later PR I intend to introduce a generic
"ssh.target" that is supposed to be activated when SSH becomes available
on a host. A supervisor (i.e. a VMM/hypervisor/container mgr/…) can
watch for that, and know two things:
1. that SSH is generally available in the system
2. when it is available
In order to not flood the supervisor with events I only send these out
for target units. We could open this up later, in theory, but I think it
makes sense to tell people instead to define clear milestone target
units if they want a supervisor to be able to track system state.
Though, when unit_prepare_exec() is called, the unit should always
have the cgroup runtime context 'crt'. So, I think we can insert assert().
But, for consistency with other places that call unit_get_cgroup_runtime(),
here use the simple non-NULL check for 'crt' instead of using assert().
Follow-up for 9cc545447e.
Fixes CID#1534667.
This refactors the Unit structure a bit: all cgroup-related state fields
are moved to a new structure CGroupRuntime, which is only allocated as
we realize a cgroup.
This is both a nice cleanup and should make unit structures considerably
smaller that have no cgroup associated, because never realized or
because they belong to a unit type that doesn#t have cgroups anyway.
This makes things nicely symmetric:
ExecContext → static user configuration about execution
ExecRuntime → dynamic user state of execution
CGroupContext → static user configuration about cgroups
CGroupRuntime → dynamic user state of cgroups
And each time the XyzContext is part of the unit type structures such as
Service or Slice that need it, but the runtime object is only allocated
when a unit is started.
Previously, unit_{start,stop,reload} would call the low-level cgroup
unfreeze function whenever a unit was started, stopped, or reloaded. It
did so with no error checking. This call would ultimately recurse up the
cgroup tree, and unfreeze all the parent cgroups of the unit, unless an
error occurred (in which case I have no idea what would happen...)
After the freeze/thaw rework in a previous commit, this can no longer
work. If we recursively thaw the parent cgroups of the unit, there may
be sibling units marked as PARENT_FROZEN which will no longer actually
have frozen parents. Fixing this is a lot more complicated than simply
disallowing start/stop/reload on a frozen unit
Fixes https://github.com/systemd/systemd/issues/15849
This commit overhauls the way freeze/thaw works recursively:
First, it introduces new FreezerActions that are like the existing
FREEZE and THAW but indicate that the action was initiated by a parent
unit. We also refactored the code to pass these FreezerActions through
the whole call stack so that we can make use of them. FreezerState was
extended similarly, to be able to differentiate between a unit that's
frozen manually and a unit that's frozen because a parent is frozen.
Next, slices were changed to check recursively that all their child
units can be frozen before it attempts to freeze them. This is different
from the previous behavior, that would just check if the unit's type
supported freezing at all. This cleans up the code, and also ensures
that the behavior of slices corresponds to the unit's actual ability
to be frozen
Next, we make it so that if you FREEZE a slice, it'll PARENT_FREEZE
all of its children. Similarly, if you THAW a slice it will PARENT_THAW
its children.
Finally, we use the new states available to us to refactor the code
that actually does the cgroup freezing. The code now looks at the unit's
existing freezer state and the action being requested, and decides what
next state is most appropriate. Then it puts the unit in that state.
For instance, a RUNNING unit with a request to PARENT_FREEZE will
put the unit into the PARENT_FREEZING state. As another example, a
FROZEN unit who's parent is also FROZEN will transition to
PARENT_FROZEN in response to a request to THAW.
Fixes https://github.com/systemd/systemd/issues/30640
Fixes https://github.com/systemd/systemd/issues/15850
Mike Yuan
Luca Boccassi
Matteo Croce
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Yu Watanabe
Adrian Vovk