Currently, we mount via file descriptors using /proc/self/fd. This
works, but it means that in /proc/mounts and various other files,
the source of the mount will be listed as /proc/self/fd/xxx. For other
software that parses these files, /proc/self/fd/xxx doesn't mean anything,
or worse, it means the completely wrong thing, as it will refer to one of
their own file descriptors instead.
Let's improve the situation by using /proc/pid/fd instead. This allows
processes parsing /proc/mounts to do the right thing more often than not.
One scenario where even this doesn't work if when containers are involved,
as with the pid namespace unshared, even /proc/pid/fd will mean the wrong
thing, but it's no worse than /proc/self/fd which will always means the wrong
thing.
This also doesn't work if we mount via file descriptor and then exit, as the pid will
be gone, but it does work as long as the process that did the mount is alive, which
makes it useful for systemd-dissect --with for example if the program we run in the
image wants to parse /proc/mounts.
received
RFC4191 – Section 2.3 Route Information Option's Prf field:
If the Reserved (10) value is received, the Route Information Option MUST be ignored.
Salsa is the Debian git forge. In the package build environment test-path
always fails as we cannot set up cgroups and so the path unit fails to
start. Skip the test in that environment.
Unfortunately meson doesn't allow to skip individual tests by name.
