1 files changed, 19 insertions, 14 deletions

diff --git a/block/bounce.c b/block/bounce.c
index 1d05c422c932..6a3e68292273 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -113,45 +113,50 @@ int init_emergency_isa_pool(void)
 static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
 {
 	unsigned char *vfrom;
-	struct bio_vec tovec, *fromvec = from->bi_io_vec;
+	struct bio_vec tovec, fromvec;
 	struct bvec_iter iter;
+	/*
+	 * The bio of @from is created by bounce, so we can iterate
+	 * its bvec from start to end, but the @from->bi_iter can't be
+	 * trusted because it might be changed by splitting.
+	 */
+	struct bvec_iter from_iter = BVEC_ITER_ALL_INIT;
 
 	bio_for_each_segment(tovec, to, iter) {
-		if (tovec.bv_page != fromvec->bv_page) {
+		fromvec = bio_iter_iovec(from, from_iter);
+		if (tovec.bv_page != fromvec.bv_page) {
 			/*
 			 * fromvec->bv_offset and fromvec->bv_len might have
 			 * been modified by the block layer, so use the original
 			 * copy, bounce_copy_vec already uses tovec->bv_len
 			 */
-			vfrom = page_address(fromvec->bv_page) +
+			vfrom = page_address(fromvec.bv_page) +
 				tovec.bv_offset;
 
 			bounce_copy_vec(&tovec, vfrom);
 			flush_dcache_page(tovec.bv_page);
 		}
-
-		fromvec++;
+		bio_advance_iter(from, &from_iter, tovec.bv_len);
 	}
 }
 
 static void bounce_end_io(struct bio *bio, mempool_t *pool)
 {
 	struct bio *bio_orig = bio->bi_private;
-	struct bio_vec *bvec, *org_vec;
+	struct bio_vec *bvec, orig_vec;
 	int i;
-	int start = bio_orig->bi_iter.bi_idx;
+	struct bvec_iter orig_iter = bio_orig->bi_iter;
 
 	/*
 	 * free up bounce indirect pages used
 	 */
 	bio_for_each_segment_all(bvec, bio, i) {
-		org_vec = bio_orig->bi_io_vec + i + start;
-
-		if (bvec->bv_page == org_vec->bv_page)
-			continue;
-
-		dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
-		mempool_free(bvec->bv_page, pool);
+		orig_vec = bio_iter_iovec(bio_orig, orig_iter);
+		if (bvec->bv_page != orig_vec.bv_page) {
+			dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
+			mempool_free(bvec->bv_page, pool);
+		}
+		bio_advance_iter(bio_orig, &orig_iter, orig_vec.bv_len);
 	}
 
 	bio_orig->bi_status = bio->bi_status;