From: Mike Christie michael.christie@oracle.com
[ Upstream commit bb42856bfd54fda1cbc7c470fcf5db1596938f4f ]
During qedi shutdown we need to stop the iSCSI layer from sending new nops as pings and from responding to target ones and make sure there is no running connection cleanups. Commit d1f2ce77638d ("scsi: qedi: Fix host removal with running sessions") converted the driver to use the libicsi helper to drive session removal, so the above issues could be handled. The problem is that during system shutdown iscsid will not be running so when we try to remove the root session we will hang waiting for userspace to reply.
Add a helper that will drive the destruction of sessions like these during system shutdown.
Link: https://lore.kernel.org/r/20220616222738.5722-5-michael.christie@oracle.com Tested-by: Nilesh Javali njavali@marvell.com Reviewed-by: Nilesh Javali njavali@marvell.com Signed-off-by: Mike Christie michael.christie@oracle.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/scsi_transport_iscsi.c | 49 +++++++++++++++++++++++++++++ include/scsi/scsi_transport_iscsi.h | 1 + 2 files changed, 50 insertions(+)
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 671a03b80c30..f46ae5391758 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2360,6 +2360,55 @@ static void iscsi_cleanup_conn_work_fn(struct work_struct *work) ISCSI_DBG_TRANS_CONN(conn, "cleanup done.\n"); }
+static int iscsi_iter_force_destroy_conn_fn(struct device *dev, void *data) +{ + struct iscsi_transport *transport; + struct iscsi_cls_conn *conn; + + if (!iscsi_is_conn_dev(dev)) + return 0; + + conn = iscsi_dev_to_conn(dev); + transport = conn->transport; + + if (READ_ONCE(conn->state) != ISCSI_CONN_DOWN) + iscsi_if_stop_conn(conn, STOP_CONN_TERM); + + transport->destroy_conn(conn); + return 0; +} + +/** + * iscsi_force_destroy_session - destroy a session from the kernel + * @session: session to destroy + * + * Force the destruction of a session from the kernel. This should only be + * used when userspace is no longer running during system shutdown. + */ +void iscsi_force_destroy_session(struct iscsi_cls_session *session) +{ + struct iscsi_transport *transport = session->transport; + unsigned long flags; + + WARN_ON_ONCE(system_state == SYSTEM_RUNNING); + + spin_lock_irqsave(&sesslock, flags); + if (list_empty(&session->sess_list)) { + spin_unlock_irqrestore(&sesslock, flags); + /* + * Conn/ep is already freed. Session is being torn down via + * async path. For shutdown we don't care about it so return. + */ + return; + } + spin_unlock_irqrestore(&sesslock, flags); + + device_for_each_child(&session->dev, NULL, + iscsi_iter_force_destroy_conn_fn); + transport->destroy_session(session); +} +EXPORT_SYMBOL_GPL(iscsi_force_destroy_session); + void iscsi_free_session(struct iscsi_cls_session *session) { ISCSI_DBG_TRANS_SESSION(session, "Freeing session\n"); diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h index 3ecf9702287b..0f2f149ad916 100644 --- a/include/scsi/scsi_transport_iscsi.h +++ b/include/scsi/scsi_transport_iscsi.h @@ -441,6 +441,7 @@ extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *t, int dd_size, unsigned int target_id); +extern void iscsi_force_destroy_session(struct iscsi_cls_session *session); extern void iscsi_remove_session(struct iscsi_cls_session *session); extern void iscsi_free_session(struct iscsi_cls_session *session); extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,