---

yaml
---
r: 43838
b: refs/heads/master
c: 45cbcd7
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a3d77d35be6f416a250c528c3ed5c70013a915e8
+refs/heads/master: 45cbcd798354251b99694086af9d57c99e89bb43

trunk/drivers/md/dm.c

@@ -482,9 +482,13 @@ static int clone_endio(struct bio *bio, unsigned int done, int error)
 		r = endio(tio->ti, bio, error, &tio->info);
 		if (r < 0)
 			error = r;
-		else if (r > 0)
-			/* the target wants another shot at the io */
+		else if (r == DM_ENDIO_INCOMPLETE)
+			/* The target will handle the io */
 			return 1;
+		else if (r) {
+			DMWARN("unimplemented target endio return value: %d", r);
+			BUG();
+		}
 	}
 
 	dec_pending(tio->io, error);
@@ -542,7 +546,7 @@ static void __map_bio(struct dm_target *ti, struct bio *clone,
 	atomic_inc(&tio->io->io_count);
 	sector = clone->bi_sector;
 	r = ti->type->map(ti, clone, &tio->info);
-	if (r > 0) {
+	if (r == DM_MAPIO_REMAPPED) {
 		/* the bio has been remapped so dispatch it */
 
 		blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone,
@@ -560,6 +564,9 @@ static void __map_bio(struct dm_target *ti, struct bio *clone,
 		clone->bi_private = md->bs;
 		bio_put(clone);
 		free_tio(md, tio);
+	} else if (r) {
+		DMWARN("unimplemented target map return value: %d", r);
+		BUG();
 	}
 }
 

trunk/drivers/md/dm.h

@@ -32,6 +32,17 @@
 
 #define SECTOR_SHIFT 9
 
+/*
+ * Definitions of return values from target end_io function.
+ */
+#define DM_ENDIO_INCOMPLETE	1
+
+/*
+ * Definitions of return values from target map function.
+ */
+#define DM_MAPIO_SUBMITTED	0
+#define DM_MAPIO_REMAPPED	1
+
 /*
  * Suspend feature flags
  */

trunk/include/linux/device-mapper.h

@@ -39,7 +39,7 @@ typedef void (*dm_dtr_fn) (struct dm_target *ti);
  * The map function must return:
  * < 0: error
  * = 0: The target will handle the io by resubmitting it later
- * > 0: simple remap complete
+ * = 1: simple remap complete
  */
 typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
 			  union map_info *map_context);