[PATCH] cleanup + fix bounce end_io handling

Andrew found out that bounce end_io handling did not work for him, so I
fixed the bug (not consistent checking of bi_size). I cleaned it up and
moved the bi_size checking out of bounce_end_io() (the main worker) and
into the individual bi_end_io() handlers instead. Please apply to make
highmem bouncing work again.

mm/highmem.c

@@ -291,16 +291,12 @@ static inline void copy_to_high_bio_irq(struct bio *to, struct bio *from)
 	}
 }
 
-static inline int bounce_end_io(struct bio *bio, unsigned int bytes_done,
-				int error, mempool_t *pool)
+static void bounce_end_io(struct bio *bio, mempool_t *pool)
 {
 	struct bio *bio_orig = bio->bi_private;
 	struct bio_vec *bvec, *org_vec;
 	int i;
 
-	if (bio->bi_size)
-		return 1;
-
 	if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
 		goto out_eio;
 
@@ -318,43 +314,54 @@ static inline int bounce_end_io(struct bio *bio, unsigned int bytes_done,
 	}
 
 out_eio:
-	bio_endio(bio_orig, bytes_done, error);
+	bio_endio(bio_orig, bio_orig->bi_size, 0);
 	bio_put(bio);
-	return 0;
 }
 
-static int bounce_end_io_write(struct bio *bio, unsigned int bytes_done,
-			       int error)
+static int bounce_end_io_write(struct bio *bio, unsigned int bytes_done,int err)
 {
-	return bounce_end_io(bio, bytes_done, error, page_pool);
+	if (bio->bi_size)
+		return 1;
+
+	bounce_end_io(bio, page_pool);
+	return 0;
 }
 
-static int bounce_end_io_write_isa(struct bio *bio, unsigned int bytes_done,
-				   int error)
+static int bounce_end_io_write_isa(struct bio *bio, unsigned int bytes_done, int err)
 {
-	return bounce_end_io(bio, bytes_done, error, isa_page_pool);
+	if (bio->bi_size)
+		return 1;
+
+	bounce_end_io(bio, isa_page_pool);
+	return 0;
 }
 
-static inline int __bounce_end_io_read(struct bio *bio, unsigned int done,
-				       int error, mempool_t *pool)
+static inline void __bounce_end_io_read(struct bio *bio, mempool_t *pool)
 {
 	struct bio *bio_orig = bio->bi_private;
 
 	if (test_bit(BIO_UPTODATE, &bio->bi_flags))
 		copy_to_high_bio_irq(bio_orig, bio);
 
-	return bounce_end_io(bio, done, error, pool);
+	bounce_end_io(bio, pool);
 }
 
 static int bounce_end_io_read(struct bio *bio, unsigned int bytes_done, int err)
 {
-	return __bounce_end_io_read(bio, bytes_done, err, page_pool);
+	if (bio->bi_size)
+		return 1;
+
+	__bounce_end_io_read(bio, page_pool);
+	return 0;
 }
 
-static int bounce_end_io_read_isa(struct bio *bio, unsigned int bytes_done,
-				  int err)
+static int bounce_end_io_read_isa(struct bio *bio, unsigned int bytes_done, int err)
 {
-	return __bounce_end_io_read(bio, bytes_done, err, isa_page_pool);
+	if (bio->bi_size)
+		return 1;
+
+	__bounce_end_io_read(bio, isa_page_pool);
+	return 0;
 }
 
 void blk_queue_bounce(request_queue_t *q, struct bio **bio_orig)