target/pscsi: Don't leak scsi_host if hba is VIRTUAL_HOST

commit 5a7125c6 upstream.

See https://bugzilla.redhat.com/show_bug.cgi?id=1025672

We need to put() the reference to the scsi host that we got in
pscsi_configure_device(). In VIRTUAL_HOST mode it is associated with
the dev_virt, not the hba_virt.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>

drivers/target/target_core_pscsi.c

@@ -567,6 +567,7 @@ static struct se_device *pscsi_create_virtdevice(
 					" pdv_host_id: %d\n", pdv->pdv_host_id);
 				return ERR_PTR(-EINVAL);
 			}
+			pdv->pdv_lld_host = sh;
 		}
 	} else {
 		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
@@ -653,6 +654,8 @@ static void pscsi_free_device(void *p)
 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
 		    (phv->phv_lld_host != NULL))
 			scsi_host_put(phv->phv_lld_host);
+		else if (pdv->pdv_lld_host)
+			scsi_host_put(pdv->pdv_lld_host);
 
 		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
 			scsi_device_put(sd);

drivers/target/target_core_pscsi.h

@@ -45,6 +45,7 @@ struct pscsi_dev_virt {
 	int	pdv_lun_id;
 	struct block_device *pdv_bd;
 	struct scsi_device *pdv_sd;
+	struct Scsi_Host *pdv_lld_host;
 	struct se_hba *pdv_se_hba;
 } ____cacheline_aligned;