Using autoconf check define fmode_t typedef if undefined.

module/zfs/include/sys/blkdev.h

@@ -7,6 +7,10 @@
 #include <linux/elevator.h>
 #include "zfs_config.h"
 
+#ifndef HAVE_FMODE_T
+typedef unsigned __bitwise__ fmode_t;
+#endif /* HAVE_FMODE_T */
+
 #ifndef HAVE_BLK_FETCH_REQUEST
 static inline struct request *
 blk_fetch_request(struct request_queue *q)

module/zfs/zvol.c

@@ -681,10 +681,6 @@ zvol_remove(zvol_state_t *zv_remove)
 	list_remove(&zvol_state_list, zv_remove);
 }
 
-#ifndef HAVE_BDEV_BLOCK_DEVICE_OPERATIONS
-typedef unsigned __bitwise__ fmode_t;
-#endif /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
-
 static int
 zvol_open(struct block_device *bdev, fmode_t flag)
 {