This complements the previous PRs to implement more volume features:
directory volumes control their permissions, SELinux labels, etc.
Overlay mounts support additional parent relationship.
Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>
Do not do string lookups in repetitive calls. We do not support changing SELinux status during runtime, so once we read this we can assume status does not change.
Also avoid unneeded FS writes when appropriate label is already set on file.
Signed-off-by: Dmitry Sharshakov <dmitry.sharshakov@siderolabs.com>
Part of: #9127
Label executables and processes, build, load and manage SELinux policy, enable audit support.
Labeling filesystems, devices and runtime files will be done in further changes, see the full PR.
Signed-off-by: Dmitry Sharshakov <dmitry.sharshakov@siderolabs.com>
