This is a debugging feature. It's sometimes incredibly useful to be able
to run a second instance of homed that operates on another dir than
/home/.
Specifically, if you build homed from the source tree you can now run an
instance of it pretty reasonably directly from the build tree via:
sudo SYSTEMD_HOME_DEBUG_SUFFIX=foo SYSTEMD_HOMEWORK_PATH=$(pwd)/build/systemd-homework SYSTEMD_HOME_ROOT=/home/foo ./build/systemd-homed
And then talk to it via
sudo SYSTEMD_HOME_DEBUG_SUFFIX=foo homectl …
(you might need to tweak your dbus policy for this to work fully though)
The pin fd keeps the mount busy, ensuring that unmount requests need to
go through us.
Note that this doesn't change too much IRL, since a logged in user
generally has processes keeping the home dir busy anyway. However, in
some corner cases it is safer to protect from accidental unmounts this
way. (e.g. if user manually called "homectl activate" first).
Currently, when Xen PV domains are nested within a hypervisor which is
detected through CPUID (such as VMware), the detected hypervisor might
not be Xen, because we don't check for Xen until after the CPUID check.
This change moves the Xen check before CPUID checks to fix the issue,
and moves Dom0 checking to detect_vm_xen so that we keep ignoring Xen
when we are in Dom0.
Register a LINUX_EFI_INITRD_MEDIA_GUID DevicePath with a LoadFile2Protocol interface and serve the initrd to a supported Linux kernel (Version 5.8+)
Leave the x86 code for older kernels in place until supported kernels become more mainstream
Let's use the underlying Linux API directly, instead of
opendir()/readdir(). This makes it possible for us to do a single memory
allocation for all directory entries in common cases, instead of one for
each entry.
glibc 2.30 (Aug 2019) added a wrapper for getdents64(). For older
versions let's define our own.
(This syscall exists since Linux 2.4, hence should be safe to use for
us)
Using kernel types __u32 is fine for headers shared by the kernel, but
if we define something in userspace and only use it in userspace, in our
own .c files, let's stick to userspace fixed-length types.
