"nsenter -a" doesn't migrate the specified process into the target
cgroup (it really should). Thus the cgroup will remain in a cgroup
that is (due to cgroup ns) outside our visibility. The kernel will
report the cgroup path of such cgroups as starting with "/../". Detect
that and print a reasonably error message instead of trying to resolve
that.
Follow-up for 9e615117da
We'll typically send signals to all remaining processes in the following
cases:
1. pid1 (in initrd) when transitioning from initrd to sysroot: SIGTERM
2. pid1 (in sysroot) before transitioning back to initrd (exitrd): SIGTERM + SIGKILL
3. systemd-shutdown (in exitrd): SIGTERM + SIGKILL
'warn_rootfs' is set to true only when we're not in initrd and we're
sending SIGKILL, which means the second case. So, we want to emit the
warning when the root of the storage daemon IS the same as that of pid1,
rather than the other way around.
The condition is spuriously reversed in the offending commit.
systemd's own cgroup hierarchy is special to us, we use it to actually
manage processes. Because of that many calls tha apply to cgroups are
only ever called with the SYSTEMD_CGROUP_CONTROLLER as controller
argument. Let's hence remove the argument altogether.
This in particular touches the kill and xattr routines.
This changes no behaviour, we just drop an argument that is always set
to the same value anyway.
This is preparation to eventually getting rid of the cgroupvs1, because
on cgroupvs2 the cgroup paths do not change for different controllers,
there's only a single hierarchy there.
Add a new boolean for units, SurviveFinalKillSignal=yes/no. Units that
set it will not have their process receive the final sigterm/sigkill in
the shutdown phase.
This is implemented by checking if a process is part of a cgroup marked
with a user.survive_final_kill_signal xattr (or a trusted xattr if we
can't set a user one, which were added only in kernel v5.7 and are not
supported in CentOS 8).
The name "def.h" originates from before the rule of "no needless abbreviations"
was established. Let's rename the file to clarify that it contains a collection
of various semi-related constants.
I changed imports of util.h to initrd-util.h, or added an import of
initrd-util.h, to keep compilation working. It turns out that many files didn't
import util.h directly.
When viewing the patch, don't be confused by git rename detection logic:
a new .c file is added and two functions moved into it.
The variable is not useful outside of the loop (it'll always be null
after the loop is finished), so we can declare it inline in the loop.
This saves one variable declaration and reduces the chances that somebody
tries to use the variable outside of the loop.
For consistency, 'de' is used everywhere for the var name.
Lennart Poettering
Mike Yuan
Frantisek Sumsal
Luca Boccassi
Zbigniew Jędrzejewski-Szmek
Yu Watanabe