bio.h: Declare the arguments of the bio iteration functions const

This change makes it possible to pass 'const struct bio *' arguments to
these functions.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

include/linux/bio.h

@@ -70,7 +70,7 @@ static inline bool bio_has_data(struct bio *bio)
 	return false;
 }
 
-static inline bool bio_no_advance_iter(struct bio *bio)
+static inline bool bio_no_advance_iter(const struct bio *bio)
 {
 	return bio_op(bio) == REQ_OP_DISCARD ||
 	       bio_op(bio) == REQ_OP_SECURE_ERASE ||
@@ -138,8 +138,8 @@ static inline bool bio_next_segment(const struct bio *bio,
 #define bio_for_each_segment_all(bvl, bio, iter) \
 	for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
 
-static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
-				    unsigned bytes)
+static inline void bio_advance_iter(const struct bio *bio,
+				    struct bvec_iter *iter, unsigned int bytes)
 {
 	iter->bi_sector += bytes >> 9;