block: remove the __bio_add_pc_page export

The same page optimization is a rather odd corner case, which is not
used outside bio.c and which really should not be used outside of bio.c
either - we have better highlevel helpers like the rq/bio mapping
helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bio.c

@@ -709,7 +709,7 @@ static bool can_add_page_to_seg(struct request_queue *q,
  *
  *	This should only be used by passthrough bios.
  */
-int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
+static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
 		struct page *page, unsigned int len, unsigned int offset,
 		bool put_same_page)
 {
@@ -776,7 +776,6 @@ int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
 	bio_set_flag(bio, BIO_SEG_VALID);
 	return len;
 }
-EXPORT_SYMBOL(__bio_add_pc_page);
 
 int bio_add_pc_page(struct request_queue *q, struct bio *bio,
 		struct page *page, unsigned int len, unsigned int offset)

include/linux/bio.h

@@ -435,9 +435,6 @@ void bio_chain(struct bio *, struct bio *);
 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 			   unsigned int, unsigned int);
-extern int __bio_add_pc_page(struct request_queue *, struct bio *,
-			     struct page *, unsigned int, unsigned int,
-			     bool);
 bool __bio_try_merge_page(struct bio *bio, struct page *page,
 		unsigned int len, unsigned int off, bool same_page);
 void __bio_add_page(struct bio *bio, struct page *page,