2016-12-27 16:01:46

by Ming Lei

[permalink] [raw]
Subject: [PATCH v1 19/54] block: bounce: avoid direct access to bvec table

We will support multipage bvecs in the future, so change to
iterator way for getting bv_page of bvec from original bio.

Signed-off-by: Ming Lei <[email protected]>
---
block/bounce.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/block/bounce.c b/block/bounce.c
index 1cb5dd3a5da1..babd3f224ca0 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -126,21 +126,23 @@ static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
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;
+ orig_vec = bio_iter_iovec(bio_orig, orig_iter);
+ if (bvec->bv_page == orig_vec.bv_page)
+ goto next;

dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
mempool_free(bvec->bv_page, pool);
+ next:
+ bio_advance_iter(bio_orig, &orig_iter, orig_vec.bv_len);
}

bio_orig->bi_error = bio->bi_error;
--
2.7.4