Let's make our units more robust to being added to an initrd:
1. systemd-boot-update only makes sense if sd-boot is available in /usr/
to copy into the ESP. This is generally not the case in initrds, and
even if it was, we shouldn't update the ESP from the initrd, but from
the host instead.
2. The rfkill services save/restore rfkill state, but that information
is only available once /var/ is mounted, which generally happens
after the initrd transition.
3. utmp management is partly in /var/, and legacy anyway, hence don't
bother with it in the initrd.
Follow-up for 123c0e24dd.
Note, the entry was originally added for IdeaPad Flex 5 in
21b589a155.
Then, a bug introduced by 19db450f3a.
But, when it was fixed by 738a195bd5,
the glob becomes too stricter, and another variant was added by
123c0e24dd.
Follow-up for 017a7ba4f4
Before this commit, when a unit that is restarting propagates stop
to other units, it can also depend on them, which results in
job type conflict and thus failure to pull in the dependencies.
So, let's introduce a new dependency atom UNIT_ATOM_PROPAGATE_STOP_GRACEFUL,
and use it for PropagatesStopTo=. It will enqueue a restart job if
there's already a start job, which meets the ultimate goal and avoids
job type conflict.
Fixes#26839
This extends the test framework a bit, and allows adding additional
initrds to the qemu invocation, which we use here to place credentials
in the new /run/systemd/@initrd/ credentials dir which are then passed
to the host.
Let's unify these very similar functions, and port them to the new
mount_credentials_fs() call.
While we are at it, if we detect that the credentials dir already is a
mount point, remount it writable so that we can actually write to it.
Let's add two new helpers: mount_credentials_fs() and
credentials_fs_mount_flags(). The former mounts a file system suitable
for storing of unencrypted credentials at runtime (i.e. a ramfs or
tmpfs). The latter determines the right mount flags to use for such a
mount.
Both functions mostly just take code from execute.c, but make two
changes:
1. If the kernel supports it we'll use a tmpfs with the new "noswap"
mount option instead of ramfs. Was added in kernel 6.4, hence is very
recent, but tmpfs is so much less crappy than ramfs, hence worth it.
2. We'll set MS_NOSYMFOLLOW on the mounts if supported. These file
systems should only contain regulra files, hence no need to allow
symlinks.
Let's hook up one more thing with credentials: the machine ID to use
when none is initialized yet.
This requires some reordering of initialization steps in PID 1: we need
to import credentials first, and only then initialize the machine ID.
This is just like read_credential() but also looks into the encrypted
credential directory, not just the regular one.
Normally, we decrypt credentials at the moment we pass them to services.
From service PoV all credentials are hence decrypted credentials.
However, when we want to access credentials in a generator this logic
does not apply: here we have the regular and the encrypted credentials
directory. So far we didn't attempt to make use of credentials in
generators hence.
Let's address and add helper that looks into both directories, and talks
to the TPM if necessary to decrypt the credentials.
When the credential dir is backed by an fs that supports ACLs we must be
more careful with adjusting the 'x' bit of the directory, as any chmod()
call on the dir will reset the mask entry of the ACL entirely which we
don't want. Hence, do a manual set of ACL changes, that only add/drop
the 'x' bit but otherwise leave the ACL as it is.
This matters if we use tmpfs rather than ramfs to store credentials.
This log message is shown pretty regular at boot in various scenarios
(such as CI builds), and it's not a reason for any concern, it's just the
immediate effect of explicit configuration. Hence let's downgrade from
LOG_NOTICE to LOG_INFO so that it is still usually in the boot output,
but not particularly highlighted, since there's really no reason to.
