pid_eins, 1 month ago

This is such a bad bad API compat breakage:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e81cd5a983bb35dabd38ee472cf3fea1c63e0f23

It's used all over the place in userspace. In systemd we use it:

1. to detect if a block device has partition scanning off or on
2. In our udev test suite, to validate devices are in order
3. udev rules use it for some feature checks (in older versions of systemd).

And it's even a frickin documented userspace API:

https://www.kernel.org/doc/html/v5.5/block/capability.html

So much about that nonsensical "we don't break userspace" kernel mantra.