1 files changed, 61 insertions, 0 deletions

diff --git a/drivers/md/dm-hw-handler.h b/drivers/md/dm-hw-handler.h
new file mode 100644
index 000000000000..15f5629e231a
--- /dev/null
+++ b/drivers/md/dm-hw-handler.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the GPL.
+ *
+ * Multipath hardware handler registration.
+ */
+
+#ifndef DM_HW_HANDLER_H
+#define DM_HW_HANDLER_H
+
+#include <linux/device-mapper.h>
+
+#include "dm-mpath.h"
+
+struct hw_handler_type;
+struct hw_handler {
+        struct hw_handler_type *type;
+        void *context;
+};
+
+/*
+ * Constructs a hardware handler object, takes custom arguments
+ */
+/* Information about a hardware handler type */
+struct hw_handler_type {
+        char *name;
+        struct module *module;
+
+        int (*create) (struct hw_handler *handler, unsigned int argc,
+                       char **argv);
+        void (*destroy) (struct hw_handler *hwh);
+
+        void (*pg_init) (struct hw_handler *hwh, unsigned bypassed,
+                         struct path *path);
+        unsigned (*error) (struct hw_handler *hwh, struct bio *bio);
+        int (*status) (struct hw_handler *hwh, status_type_t type,
+                       char *result, unsigned int maxlen);
+};
+
+/* Register a hardware handler */
+int dm_register_hw_handler(struct hw_handler_type *type);
+
+/* Unregister a hardware handler */
+int dm_unregister_hw_handler(struct hw_handler_type *type);
+
+/* Returns a registered hardware handler type */
+struct hw_handler_type *dm_get_hw_handler(const char *name);
+
+/* Releases a hardware handler  */
+void dm_put_hw_handler(struct hw_handler_type *hwht);
+
+/* Default err function */
+unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio);
+
+/* Error flags for err and dm_pg_init_complete */
+#define MP_FAIL_PATH 1
+#define MP_BYPASS_PG 2
+#define MP_ERROR_IO  4  /* Don't retry this I/O */
+
+#endif