[PATCH v4 2/3] block: prohibit calls to bio_chain_endio

[zhangshida]

From: Shida Zhang <zhangshida@xxxxxxxxxx>

Now that all potential callers of bio_chain_endio have been
eliminated, completely prohibit any future calls to this function.

Suggested-by: Ming Lei <ming.lei@xxxxxxxxxx>
Suggested-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Shida Zhang <zhangshida@xxxxxxxxxx>
---
 block/bio.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block/bio.c b/block/bio.c
index b3a79285c27..1b5e4577f4c 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -320,9 +320,13 @@ static struct bio *__bio_chain_endio(struct bio *bio)
 	return parent;
 }
 
+/**
+ * This function should only be used as a flag and must never be called.
+ * If execution reaches here, it indicates a serious programming error.
+ */
 static void bio_chain_endio(struct bio *bio)
 {
-	bio_endio(__bio_chain_endio(bio));
+	BUG_ON(1);
 }
 
 /**
-- 
2.34.1