Backports fails to compile with 'refcount_t {aka struct refcount_struct}' has no member named 'counter'

Answer

There are certain patch ranges within kernels 4.4 and 4.9 that need a modification so backports can build, the reason why we cannot fix it in backports is that we cannot track and differentiate between patch versions of the same 'major.minor' version of kernel. To fix this issue, move the function kobject_has_children from linux/kobject.h to drivers/base/core.c in your kernel source, rebuild the kernel and then rebuild backports.