Fix to properly access bio_vecs in read-modify-write code path

Introduced usage of bi_iter to loop through bio_vecs properly.
Replaced direct accesses to bi_io_vec with appropriate macros.

diff --git a/drivers/md/dm-dedup-rw.c b/drivers/md/dm-dedup-rw.c
index 5981ff20b43d3c2d791672abc7e4e2096a43444a..a311d89cc6571bced0d22a597cda1b91a367b790 100644 (file)
--- a/drivers/md/dm-dedup-rw.c
+++ b/drivers/md/dm-dedup-rw.c
@@ -55,24 +55,29 @@ static int merge_data(struct dedup_config *dc, struct page *page,
        sector_t bi_sector = bio->bi_iter.bi_sector;
        void *src_page_vaddr, *dest_page_vaddr;
        int position, err = 0;
+       struct bvec_iter iter;
+       struct bio_vec bvec;
 
        /* Relative offset in terms of sector size */
        position = sector_div(bi_sector, dc->sectors_per_block);
 
-       if (!page || !bio->bi_io_vec->bv_page) {
+       if (!page || !bio_page(bio)) {
                err = -EINVAL;
                goto out;
        }
 
-       src_page_vaddr = page_address(bio->bi_io_vec->bv_page);
-       dest_page_vaddr = page_address(page);
-
-       src_page_vaddr = src_page_vaddr + bio->bi_io_vec->bv_offset;
        /* Locating the right sector to merge */
-       dest_page_vaddr = dest_page_vaddr + (to_bytes(position));
+       dest_page_vaddr = page_address(page) + to_bytes(position);
+       
+       bio_for_each_segment(bvec, bio, iter) {
+               src_page_vaddr = page_address(bio_iter_page(bio, iter)) + bio_iter_offset(bio, iter);
+
+               /* Merging Data */
+               memmove(dest_page_vaddr, src_page_vaddr, bio_iter_len(bio, iter));
 
-       /* Merging Data */
-       memmove(dest_page_vaddr, src_page_vaddr, bio->bi_io_vec->bv_len);
+               /* Updating destinaion address */
+               dest_page_vaddr += bio_iter_len(bio, iter);
+       }
 out:
        return err;
 }
@@ -82,7 +87,7 @@ static void copy_pages(struct page *src, struct bio *clone)
        void *src_page_vaddr, *dest_page_vaddr;
 
        src_page_vaddr = page_address(src);
-       dest_page_vaddr = page_address(clone->bi_io_vec->bv_page);
+       dest_page_vaddr = page_address(bio_page(clone));
 
        memmove(dest_page_vaddr, src_page_vaddr, DMD_IO_SIZE);
 }
@@ -204,7 +209,7 @@ static struct bio *prepare_bio_without_pbn(struct dedup_config *dc,
 
        zero_fill_bio(clone);
 
-       r = merge_data(dc, clone->bi_io_vec->bv_page, bio);
+       r = merge_data(dc, bio_page(clone), bio);
        if (r < 0)
                return ERR_PTR(r);
 out: