2 files changed, 34 insertions, 0 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 67b2a2b00286..8dc73c489a17 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1571,6 +1571,12 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
                 goto fault;
         }
 
+        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
+                reason = FAILURE_SESSION_IN_RECOVERY;
+                sc->result = DID_REQUEUE;
+                goto fault;
+        }
+
         if (iscsi_check_cmdsn_window_closed(conn)) {
                 reason = FAILURE_WINDOW_CLOSED;
                 goto reject;
@@ -1810,6 +1816,33 @@ static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
         }
 }
 
+/**
+ * iscsi_suspend_queue - suspend iscsi_queuecommand
+ * @conn: iscsi conn to stop queueing IO on
+ *
+ * This grabs the session lock to make sure no one is in
+ * xmit_task/queuecommand, and then sets suspend to prevent
+ * new commands from being queued. This only needs to be called
+ * by offload drivers that need to sync a path like ep disconnect
+ * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
+ * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
+ */
+void iscsi_suspend_queue(struct iscsi_conn *conn)
+{
+        spin_lock_bh(&conn->session->lock);
+        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+        spin_unlock_bh(&conn->session->lock);
+}
+EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
+
+/**
+ * iscsi_suspend_tx - suspend iscsi_data_xmit
+ * @conn: iscsi conn tp stop processing IO on.
+ *
+ * This function sets the suspend bit to prevent iscsi_data_xmit
+ * from sending new IO, and if work is queued on the xmit thread
+ * it will wait for it to be completed.
+ */
 void iscsi_suspend_tx(struct iscsi_conn *conn)
 {
         struct Scsi_Host *shost = conn->session->host;
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 439c8b75cb69..887e57e3e223 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -390,6 +390,7 @@ extern void iscsi_session_failure(struct iscsi_session *session,
 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
                                 enum iscsi_param param, char *buf);
 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
+extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 
 #define iscsi_conn_printk(prefix, _c, fmt, a...) \