tracefs is a special-purpose filesystem in Linux used for tracing filesystem and kernel operations.
This was added to the kernel back in 2015 to replace debugfs. For security reasons, some system do not mount debugfs at all. Tracefs reduces the attack surface by allowing to trace without mounting debugfs. Additionally it provides features not supported by debugfs (such as calls for mkdir and rmdir
Debian and Arch Linux both enable this by default.
RHEL 8 and later, they enable tracefs by default.
Signed-off-by: John Titor <50095635+JohnRTitor@users.noreply.github.com>
Closes#381822
Apparently, I swapped `path` and `tmpfiles-type` in
2be50b1efe. Sorry about that 🫠
Also giving
`systemd.tmpfiles.settings.<config-name>.<path>.<tmpfiles-type>.type` a
better default in the manual than `‹name›`, i.e. `‹tmpfiles-type›` so
that it corresponds to the placeholders in the attribute path.
We default this option to null ; which is different
from upstream which defaults this to true.
Defaulting this to true leads to log-spam in /dev/kmesg
and thus in our opinion is a bad default https://github.com/systemd/systemd/issues/15324
We need to take the "top" mount instead of any mount, which is the last
line printed by findmnt. Additionally, make the regex more strict, so we
don't select mount options ending in ro (like `errors=remount-ro` from
ext4, or overlay paths ending in 'ro') and accidentally leave the Nix
store RW after boot.
Prior to this change a service failure would occur when this tmpfiles
service did not finish fast enough and receive a SIGTERM from systemd.
Additionally, `initrd-nixos-activation` is already ordered with
`After=initrd-switch-root.target`.
By default, systemd-repart refuses to act on empty disk devices, i.e.
those without any existing partition table for safety reasons.
This behaviour can be customized via the `--empty` flag, which we now
expose via the module system. This makes to partition empty disks
on first boot.
These daemons should not be stopped, as they're foundational to a
proper functioning of the system. When switching configurations, they
only need a restart instead of that stop/start cycle.
