From: Gulam Mohamed gulam.mohamed@oracle.com
commit 9e67600ed6b8565da4b85698ec659b5879a6c1c6 upstream.
A kernel panic was observed due to a timing issue between the sync thread and the initiator processing a login response from the target. The session reopen can be invoked both from the session sync thread when iscsid restarts and from iscsid through the error handler. Before the initiator receives the response to a login, another reopen request can be sent from the error handler/sync session. When the initial login response is subsequently processed, the connection has been closed and the socket has been released.
To fix this a new connection state, ISCSI_CONN_BOUND, is added:
- Set the connection state value to ISCSI_CONN_DOWN upon iscsi_if_ep_disconnect() and iscsi_if_stop_conn()
- Set the connection state to the newly created value ISCSI_CONN_BOUND after bind connection (transport->bind_conn())
- In iscsi_set_param(), return -ENOTCONN if the connection state is not either ISCSI_CONN_BOUND or ISCSI_CONN_UP
Link: https://lore.kernel.org/r/20210325093248.284678-1-gulam.mohamed@oracle.com Reviewed-by: Mike Christie michael.christie@oracle.com Signed-off-by: Gulam Mohamed gulam.mohamed@oracle.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Hanjun Guo guohanjun@huawei.com --- drivers/scsi/scsi_transport_iscsi.c | 14 +++++++++++++- include/scsi/scsi_transport_iscsi.h | 1 + 2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index c520239..cb7b74a0 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2480,6 +2480,7 @@ static void iscsi_if_stop_conn(struct iscsi_cls_conn *conn, int flag) */ mutex_lock(&conn_mutex); conn->transport->stop_conn(conn, flag); + conn->state = ISCSI_CONN_DOWN; mutex_unlock(&conn_mutex);
} @@ -2906,6 +2907,13 @@ int iscsi_session_event(struct iscsi_cls_session *session, default: err = transport->set_param(conn, ev->u.set_param.param, data, ev->u.set_param.len); + if ((conn->state == ISCSI_CONN_BOUND) || + (conn->state == ISCSI_CONN_UP)) { + err = transport->set_param(conn, ev->u.set_param.param, + data, ev->u.set_param.len); + } else { + return -ENOTCONN; + } }
return err; @@ -2965,6 +2973,7 @@ static int iscsi_if_ep_disconnect(struct iscsi_transport *transport, mutex_lock(&conn->ep_mutex); conn->ep = NULL; mutex_unlock(&conn->ep_mutex); + conn->state = ISCSI_CONN_DOWN; }
transport->ep_disconnect(ep); @@ -3732,6 +3741,8 @@ static int iscsi_logout_flashnode_sid(struct iscsi_transport *transport, ev->r.retcode = transport->bind_conn(session, conn, ev->u.b_conn.transport_eph, ev->u.b_conn.is_leading); + if (!ev->r.retcode) + conn->state = ISCSI_CONN_BOUND; mutex_unlock(&conn_mutex);
if (ev->r.retcode || !transport->ep_connect) @@ -3971,7 +3982,8 @@ static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param, \ static const char *const connection_state_names[] = { [ISCSI_CONN_UP] = "up", [ISCSI_CONN_DOWN] = "down", - [ISCSI_CONN_FAILED] = "failed" + [ISCSI_CONN_FAILED] = "failed", + [ISCSI_CONN_BOUND] = "bound" };
static ssize_t show_conn_state(struct device *dev, diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h index 8a26a2f..fc5a398 100644 --- a/include/scsi/scsi_transport_iscsi.h +++ b/include/scsi/scsi_transport_iscsi.h @@ -193,6 +193,7 @@ enum iscsi_connection_state { ISCSI_CONN_UP = 0, ISCSI_CONN_DOWN, ISCSI_CONN_FAILED, + ISCSI_CONN_BOUND, };
struct iscsi_cls_conn {