This makes it possible to update a home record (and blob directory) of a
home area that's either completely absent (i.e. on a USB stick that's
unplugged) or just inaccessible due to lack of authentication
This bypasses authentication (i.e. user_record_authenticate) if the
volume key was loaded from the keyring and no secret section is
provided.
This also changes Update() and Resize() to always try and load the
volume key from the keyring. This makes the secret section optional for
these methods while still letting them function (as long as the home
area is active)
Introduces new extended variants of the various incarnations of
Create and Update, which take a map of filenames to FDs. This map is
then used to populate the bulk directory.
FDs are used to prevent the client from abusing homed's blob directory
permissions (everything is made world-readable by homed) to open files
that they normally aren't allowed to open. Passing along an FD ensures
that the client has read access to the file it wants homed to make
world-readable.
Internally, homework uses the map to overwrite the system blob dir.
Later, homework's existing blob dir reconciliation logic will propagate
the new contents from the system blob dir into the embedded blob
dir
This returns an FD that can be used to temporarily inhibit the automatic
locking on system suspend behavior of homed. As long as the FD is open,
LockAllHomes() won't lock that home directory on suspend. This allows
desktop environments to implement custom more complicated behavior
Let's explicitly deactivate all home dirs on shutdown, in order to
properly synchronizing unmounting and avoiding blocking devices.
Previously, we'd rely on automatic deactivation when home directories
become unused. However, that scheme is asynchronous, and ongoing
deactviations might conflicts with attempts to unmount /home. Let's fix
that by providing an explicit service systemd-homed-activate.service
whose only job is to have a ExecStop= line that explicitly deactivates
all home directories on shutdown. This service can the be ordered after
home.mount and similar, ensuring that we'll first deactivate all homes
before deactivating /home itself during shutdown.
This is kept separate from systemd-homed.service so that it is possible
to restart systemd-homed.service without deactivating all home
directories.
Fixes: #16842
These arguments contain UserRecord structures serialized to JSON,
however only the "secret" part of it, not a whole user record. We do
this since the secret part is conceptually part of the user record and
in some contexts we need a user record in full with both secret and
non-secret part, and in others just the secret and in other just the
non-secret part, but we want to keep this in memory in the same logic.
Hence, let's rename the arguments where we expect a user record
consisting only of the secret part to "secret".
