scsi: iscsi: Fail session and connection on transport registration failure

If the transport cannot be registered, the session/connection creation
needs to be failed early to let the initiator know.  Otherwise, the system
will have an outstanding connection that cannot be used nor removed by
open-iscsi. The result is similar to the error below, triggered by
injecting a failure in the transport's registration path.

openiscsi reports success:

root@debian-vm:~#  iscsiadm -m node -T iqn:lun1 -p 127.0.0.1 -l
Logging in to [iface: default, target: iqn:lun1, portal: 127.0.0.1,3260]
Login to [iface: default, target: iqn:lun1, portal:127.0.0.1,3260] successful.

But cannot remove the session afterwards, since the kernel is in an
inconsistent state.

root@debian-vm:~#  iscsiadm -m node -T iqn:lun1 -p 127.0.0.1 -u
iscsiadm: No matching sessions found

Link: https://lore.kernel.org/r/20200106185817.640331-4-krisman@collabora.com
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 271afea654e2ba2390ae98181adc65271f6f15dc..dfc726fa34e34f5206101fdda0a84b2a9c3a7592 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -2093,7 +2093,12 @@ int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
                                         "could not register session's dev\n");
                goto release_ida;
        }
-       transport_register_device(&session->dev);
+       err = transport_register_device(&session->dev);
+       if (err) {
+               iscsi_cls_session_printk(KERN_ERR, session,
+                                        "could not register transport's dev\n");
+               goto release_dev;
+       }
 
        spin_lock_irqsave(&sesslock, flags);
        list_add(&session->sess_list, &sesslist);
@@ -2103,6 +2108,8 @@ int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
        ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n");
        return 0;
 
+release_dev:
+       device_del(&session->dev);
 release_ida:
        if (session->ida_used)
                ida_simple_remove(&iscsi_sess_ida, session->target_id);
@@ -2263,7 +2270,12 @@ iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
                                         "register connection's dev\n");
                goto release_parent_ref;
        }
-       transport_register_device(&conn->dev);
+       err = transport_register_device(&conn->dev);
+       if (err) {
+               iscsi_cls_session_printk(KERN_ERR, session, "could not "
+                                        "register transport's dev\n");
+               goto release_conn_ref;
+       }
 
        spin_lock_irqsave(&connlock, flags);
        list_add(&conn->conn_list, &connlist);
@@ -2272,6 +2284,8 @@ iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
        ISCSI_DBG_TRANS_CONN(conn, "Completed conn creation\n");
        return conn;
 
+release_conn_ref:
+       put_device(&conn->dev);
 release_parent_ref:
        put_device(&session->dev);
 free_conn: