Comment 7 for bug 1465749

If one sets user to root:
[root@node-4 radosgw]# grep user /etc/ceph/ceph.conf
user = root

Everything works fine:
root@node-4 radosgw]# lsof -p 32179 | grep log
radosgw 32179 root cwd DIR 253,1 4096 385044 /var/log/radosgw
radosgw 32179 root 3w REG 253,1 5680 384892 /var/log/radosgw/ceph-client.radosgw.gateway.log
[root@node-4 radosgw]# lsof -p 32179 | grep radosgw.gateway.log
radosgw 32179 root 3w REG 253,1 6665 384892 /var/log/radosgw/ceph-client.radosgw.gateway.log
[root@node-4 radosgw]# rm -rf /var/log/radosgw/ceph-client.radosgw.gateway.log
[root@node-4 radosgw]# kill -HUP 32179
[root@node-4 radosgw]# lsof -p 32179 | grep radosgw.gateway.log
radosgw 32179 root 3w REG 253,1 394 384892 /var/log/radosgw/ceph-client.radosgw.gateway.log