scsi: iscsi: Add iscsi_cls_conn refcount helpers

[ Upstream commit b1d19e8c92cfb0ded180ef3376c20e130414e067 ] There are a couple places where we could free the iscsi_cls_conn while it's still in use. This adds some helpers to get/put a refcount on the struct and converts an exiting user. Subsequent commits will then use the helpers to fix 2 bugs in the eh code. Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Lee Duncan <[email protected]> Signed-off-by: Mike Christie <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
NobUser · Jul 20, 2021 · 83bd5f1 · 83bd5f1
1 parent 1fa1489
commit 83bd5f1
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Showing 3 changed files with 16 additions and 5 deletions.
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
@@ -1384,7 +1384,6 @@ void iscsi_session_failure(struct iscsi_session *session,
 			   enum iscsi_err err)
 {
 	struct iscsi_conn *conn;
-	struct device *dev;
 
 	spin_lock_bh(&session->frwd_lock);
 	conn = session->leadconn;
@@ -1393,10 +1392,8 @@ void iscsi_session_failure(struct iscsi_session *session,
 		return;
 	}
 
-	dev = get_device(&conn->cls_conn->dev);
+	iscsi_get_conn(conn->cls_conn);
 	spin_unlock_bh(&session->frwd_lock);
-	if (!dev)
-	        return;
 	/*
 	 * if the host is being removed bypass the connection
 	 * recovery initialization because we are going to kill
@@ -1406,7 +1403,7 @@ void iscsi_session_failure(struct iscsi_session *session,
 		iscsi_conn_error_event(conn->cls_conn, err);
 	else
 		iscsi_conn_failure(conn, err);
-	put_device(dev);
+	iscsi_put_conn(conn->cls_conn);
 }
 EXPORT_SYMBOL_GPL(iscsi_session_failure);
 

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
@@ -2327,6 +2327,18 @@ int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
 }
 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
 
+void iscsi_put_conn(struct iscsi_cls_conn *conn)
+{
+	put_device(&conn->dev);
+}
+EXPORT_SYMBOL_GPL(iscsi_put_conn);
+
+void iscsi_get_conn(struct iscsi_cls_conn *conn)
+{
+	get_device(&conn->dev);
+}
+EXPORT_SYMBOL_GPL(iscsi_get_conn);
+
 /*
  * iscsi interface functions
  */

diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
@@ -437,6 +437,8 @@ extern void iscsi_free_session(struct iscsi_cls_session *session);
 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 						int dd_size, uint32_t cid);
+extern void iscsi_put_conn(struct iscsi_cls_conn *conn);
+extern void iscsi_get_conn(struct iscsi_cls_conn *conn);
 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 extern void iscsi_block_session(struct iscsi_cls_session *session);