block: turn the nr_iovecs argument to bio_alloc* into an unsigned short

The bi_max_vecs and bi_vcnt fields are defined as unsigned short, so don't allow passing larger values in. Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
fracktal · Feb 8, 2021 · 0f2e6ab · 0f2e6ab
1 parent de76fd8
commit 0f2e6ab
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Showing 2 changed files with 6 additions and 5 deletions.
diff --git a/block/bio.c b/block/bio.c
@@ -407,7 +407,7 @@ static void punt_bios_to_rescuer(struct bio_set *bs)
  *
  * Returns: Pointer to new bio on success, NULL on failure.
  */
-struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
+struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned short nr_iovecs,
 			     struct bio_set *bs)
 {
 	gfp_t saved_gfp = gfp_mask;
@@ -493,7 +493,7 @@ EXPORT_SYMBOL(bio_alloc_bioset);
  *
  * Returns: Pointer to new bio on success, NULL on failure.
  */
-struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
+struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs)
 {
 	struct bio *bio;
 

diff --git a/include/linux/bio.h b/include/linux/bio.h
@@ -407,16 +407,17 @@ extern void bioset_exit(struct bio_set *);
 extern int biovec_init_pool(mempool_t *pool, int pool_entries);
 extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
 
-extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
-struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs);
+struct bio *bio_alloc_bioset(gfp_t gfp, unsigned short nr_iovecs,
+		struct bio_set *bs);
+struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs);
 extern void bio_put(struct bio *);
 
 extern void __bio_clone_fast(struct bio *, struct bio *);
 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
 
 extern struct bio_set fs_bio_set;
 
-static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
+static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned short nr_iovecs)
 {
 	return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
 }