constify blk_rq_map_user_iov() and friends

sg_iovec array passed to it can be const

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 11 insertions, 10 deletions

diff --git a/block/blk-map.c b/block/blk-map.c
index ae4ae1047fd9..86d93779c066 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -188,7 +188,7 @@ EXPORT_SYMBOL(blk_rq_map_user);
  *    unmapping.
  */
 int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
-                        struct rq_map_data *map_data, struct sg_iovec *iov,
+                        struct rq_map_data *map_data, const struct sg_iovec *iov,
                         int iov_count, unsigned int len, gfp_t gfp_mask)
 {
         struct bio *bio;
diff --git a/fs/bio.c b/fs/bio.c
index 8754e7b6eb49..7065837ae9f3 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1003,7 +1003,7 @@ struct bio_map_data {
 };
 
 static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
-                             struct sg_iovec *iov, int iov_count,
+                             const struct sg_iovec *iov, int iov_count,
                              int is_our_pages)
 {
         memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
@@ -1023,7 +1023,7 @@ static struct bio_map_data *bio_alloc_map_data(int nr_segs,
                        sizeof(struct sg_iovec) * iov_count, gfp_mask);
 }
 
-static int __bio_copy_iov(struct bio *bio, struct sg_iovec *iov, int iov_count,
+static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_count,
                           int to_user, int from_user, int do_free_page)
 {
         int ret = 0, i;
@@ -1121,7 +1121,7 @@ EXPORT_SYMBOL(bio_uncopy_user);
  */
 struct bio *bio_copy_user_iov(struct request_queue *q,
                               struct rq_map_data *map_data,
-                              struct sg_iovec *iov, int iov_count,
+                              const struct sg_iovec *iov, int iov_count,
                               int write_to_vm, gfp_t gfp_mask)
 {
         struct bio_map_data *bmd;
@@ -1260,7 +1260,7 @@ EXPORT_SYMBOL(bio_copy_user);
 
 static struct bio *__bio_map_user_iov(struct request_queue *q,
                                       struct block_device *bdev,
-                                      struct sg_iovec *iov, int iov_count,
+                                      const struct sg_iovec *iov, int iov_count,
                                       int write_to_vm, gfp_t gfp_mask)
 {
         int i, j;
@@ -1408,7 +1408,7 @@ EXPORT_SYMBOL(bio_map_user);
  *      device. Returns an error pointer in case of error.
  */
 struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
-                             struct sg_iovec *iov, int iov_count,
+                             const struct sg_iovec *iov, int iov_count,
                              int write_to_vm, gfp_t gfp_mask)
 {
         struct bio *bio;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 5a4d39b4686b..21e27208316c 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -388,7 +388,7 @@ struct sg_iovec;
 struct rq_map_data;
 extern struct bio *bio_map_user_iov(struct request_queue *,
                                     struct block_device *,
-                                    struct sg_iovec *, int, int, gfp_t);
+                                    const struct sg_iovec *, int, int, gfp_t);
 extern void bio_unmap_user(struct bio *);
 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
                                 gfp_t);
@@ -414,7 +414,8 @@ extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
                                  unsigned long, unsigned int, int, gfp_t);
 extern struct bio *bio_copy_user_iov(struct request_queue *,
-                                     struct rq_map_data *, struct sg_iovec *,
+                                     struct rq_map_data *,
+                                     const struct sg_iovec *,
                                      int, int, gfp_t);
 extern int bio_uncopy_user(struct bio *);
 void zero_fill_bio(struct bio *bio);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4afa4f8f6090..a639fd8a6d7b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -823,8 +823,8 @@ extern int blk_rq_map_user(struct request_queue *, struct request *,
 extern int blk_rq_unmap_user(struct bio *);
 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
-                               struct rq_map_data *, struct sg_iovec *, int,
-                               unsigned int, gfp_t);
+                               struct rq_map_data *, const struct sg_iovec *,
+                               int, unsigned int, gfp_t);
 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
                           struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,