issue reported on python-rtslib-2.1.fb39-1.el7.noarch:

targetcli ls
o- / ......................................................................................................................... [...]
  o- backstores .............................................................................................................. [...]
  | o- block .................................................................................................. [Storage Objects: 0]
  | o- fileio ................................................................................................. [Storage Objects: 1]
  | | o- target1-lun1 ......................................................... [./target1-lun1.img (200.0MiB) write-back activated]
  | o- pscsi .................................................................................................. [Storage Objects: 0]
  | o- ramdisk ................................................................................................ [Storage Objects: 0]
  o- iscsi ............................................................................................................ [Targets: 1]
  | o- iqn.2009-10.com.redhat:storage-1 .................................................................................. [TPGs: 1]
  |   o- tpg1 .................................................................................................. [gen-acls, no-auth]
  |     o- acls .......................................................................................................... [ACLs: 1]
  |     | o- iqn.1994-05.com.redhat:test .......................................................................... [Mapped LUNs: 1]
  |     |   o- mapped_lun1 ......................................................................... [lun1 fileio/target1-lun1 (rw)]
  |     o- luns .......................................................................................................... [LUNs: 1]
  |     | o- lun1 ....................................................................... [fileio/target1-lun1 (./target1-lun1.img)]
  |     o- portals .................................................................................................... [Portals: 1]
  |       o- [::0]:3260 ....................................................................................................... [OK]
  o- loopback ......................................................................................................... [Targets: 0]
  o- vhost ............................................................................................................ [Targets: 0]


service targetcli restart
Redirecting to /bin/systemctl restart  targetcli.service
Job for targetcli.service failed. See 'systemctl status targetcli.service' and 'journalctl -xn' for details.

systemctl status targetcli.service -l
targetcli.service - Restore LIO kernel target configuration
   Loaded: loaded (/usr/lib/systemd/system/targetcli.service; enabled)
   Active: failed (Result: exit-code) since Thu 2013-10-03 05:14:09 EDT; 11s ago
  Process: 4536 ExecStop=/usr/bin/targetcli clearconfig confirm=true (code=exited, status=0/SUCCESS)
  Process: 4545 ExecStart=/usr/bin/targetcli restoreconfig clear_existing=true (code=exited, status=1/FAILURE)

Verified on python-rtslib-2.1.fb40-1.el7, targetcli-2.1.fb30-1.el7.

I repeated the same steps as in comment#3 and service was able to restart properly.

# service targetcli restart

# targetcli ls
o- / ......................................................................................................................... [...]
  o- backstores .............................................................................................................. [...]
  | o- block .................................................................................................. [Storage Objects: 0]
  | o- fileio ................................................................................................. [Storage Objects: 1]
  | | o- target1-lun1 ......................................................... [./target1-lun1.img (200.0MiB) write-back activated]
  | o- pscsi .................................................................................................. [Storage Objects: 0]
  | o- ramdisk ................................................................................................ [Storage Objects: 0]
  o- iscsi ............................................................................................................ [Targets: 1]
  | o- iqn.2009-10.com.redhat:storage-1 .................................................................................. [TPGs: 1]
  |   o- tpg1 .................................................................................................. [gen-acls, no-auth]
  |     o- acls .......................................................................................................... [ACLs: 1]
  |     | o- storage-iqn .......................................................... [(iqn.1994-05.com.redhat:test) , Mapped LUNs: 1]
  |     |   o- mapped_lun1 ......................................................................... [lun1 fileio/target1-lun1 (rw)]
  |     o- luns .......................................................................................................... [LUNs: 1]
  |     | o- lun1 ....................................................................... [fileio/target1-lun1 (./target1-lun1.img)]
  |     o- portals .................................................................................................... [Portals: 1]
  |       o- [::0]:3260 ....................................................................................................... [OK]
  o- loopback ......................................................................................................... [Targets: 0]

This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.