The amount of available space in a filesystem is not exactly
the advertise amount. Things like indirect blocks or metadata
may use up some of this space. Reserving it to avoid reaching
full capacity by default.

This value is configurable from the CDIConfig object spec,
both globally and per-storageclass.

The default value is 0.055, or "5.5% of the space is
reserved". This value was chosen because some filesystems
reserve 5% of the space as overhead for the root user and
this space doubles as reservation for the worst case
behaviour for unclear space usage. I've chosen a value
that is slightly higher.

This validation is only necessary because we use sparse
images instead of fallocated ones, which was done to have
reasonable alerts regarding space usage from various
storage providers.

---

Update CDIConfig filesystemOverhead status, validate, and
pass the final value to importer/upload pods.

Only the status values controlled by the config controller
are used, and it's filled out for all available storage
classes in the cluster.

Use this value in Validate calls to ensure that some of the
space is reserved for the filesystem overhead to guard from
accidents.

Caveats:

Doesn't use Default: to define the default of 0.055, instead
it is hard-coded in reconcile. It seems like we can't use a
default value.

Validates the per-storageClass values in reconcile, and
doesn't reject bad values.

Signed-off-by: Maya Rashish <mrashish@redhat.com>

Signed-off-by: Maya Rashish <mrashish@redhat.com>

Signed-off-by: Maya Rashish <mrashish@redhat.com>

Intended to help with flakes, but didn't make a difference.
Probably still worth doing.

Signed-off-by: Maya Rashish <mrashish@redhat.com>

Signed-off-by: Maya Rashish <mrashish@redhat.com>

Note that this change isn't expected to make a difference, as we
check if the targetStorageClass is nil later on and have the same
behaviour, but this is probably more correct API usage.

Signed-off-by: Maya Rashish <mrashish@redhat.com>

Signed-off-by: Maya Rashish <mrashish@redhat.com>

Wait for all of them, not just the last one.

Signed-off-by: Maya Rashish <mrashish@redhat.com>