Tell pg_init_fn whether PG is already bypassed, and if it is and the
function fails, insist that the path gets failed.
--- diff/drivers/md/dm-hw-handler.h	2004-10-29 15:39:19.000000000 +0100
+++ source/drivers/md/dm-hw-handler.h	2004-10-29 15:39:50.000000000 +0100
@@ -25,8 +25,8 @@
 typedef int (*hwh_ctr_fn) (struct hw_handler *hwh, unsigned arc, char **argv);
 typedef void (*hwh_dtr_fn) (struct hw_handler *hwh);
 
-typedef void (*hwh_pg_init_fn) (struct hw_handler *hwh, struct path *path,
-				struct block_device *bdev);
+typedef void (*hwh_pg_init_fn) (struct hw_handler *hwh, unsigned bypassed,
+				struct path *path, struct block_device *bdev);
 typedef unsigned (*hwh_err_fn) (struct hw_handler *hwh, struct bio *bio);
 typedef	int (*hwh_status_fn) (struct hw_handler *hwh,
 			      status_type_t type,
--- diff/drivers/md/dm-mpath.c	2004-10-29 15:39:44.000000000 +0100
+++ source/drivers/md/dm-mpath.c	2004-10-29 15:39:50.000000000 +0100
@@ -313,7 +313,7 @@
 	struct multipath *m = (struct multipath *) data;
 	struct hw_handler *hwh = &m->hw_handler;
 	struct path *path;
-	unsigned init_required, must_queue;
+	unsigned init_required, must_queue, bypassed;
 	unsigned long flags;
 
 	spin_lock_irqsave(&m->lock, flags);
@@ -322,6 +322,7 @@
 		__choose_path(m);
 
 	path = m->current_path;
+	bypassed = path->pg->bypass;
 	must_queue = m->queue_io;
 
 	init_required = m->pg_init_required;
@@ -331,7 +332,7 @@
 	spin_unlock_irqrestore(&m->lock, flags);
 
 	if (init_required)
-		hwh->type->pg_init(hwh, path, path->dev->bdev);
+		hwh->type->pg_init(hwh, bypassed, path, path->dev->bdev);
 
 	if (path && must_queue)
 		return;
@@ -772,6 +773,10 @@
 	struct multipath *m = pg->m;
 	unsigned long flags;
 
+	/* We insist on failing the path if the PG is already bypassed. */
+	if (err_flags && pg->bypass)
+		err_flags |= MP_FAIL_PATH;
+
 	if (err_flags & MP_FAIL_PATH)
 		fail_path(path);