Root shares like this

[all]
        path = /
        read only = No

do not work any more, if the latest Samba updates are installed (tested with
samba-4.1.22-21.1 on openSUSE 13.2, but Leap and Factory and other versions
using Samba <= 4.3.3 may affected too). Accessing a directory under root (like
/home) fails with NT_STATUS_ACCESS_DENIED.

[2015/12/26 10:49:54.414714,  2] ../source3/smbd/vfs.c:1234(check_reduced_name)
  check_reduced_name: Bad access attempt: home is a symlink outside the share
path
  conn_rootdir =/
  resolved_name=/home
[2015/12/26 10:49:54.414803,  3]
../source3/smbd/filename.c:1404(filename_convert_internal)
  filename_convert_internal: check_name failed for name home with
NT_STATUS_ACCESS_DENIED

The bug is already fixed upstream:

https://bugzilla.samba.org/show_bug.cgi?id=11647