[PATCH 2/9] block: optionally mark pages dirty in bio_release_pages

Christoph Hellwig
2019-06-26T13:49:37Z

A lot of callers of bio_release_pages also want to mark the released
pages as dirty. Add a mark_dirty parameter to avoid a second
relatively expensive bio_for_each_segment_all loop.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/bio.c | 12 +++++++-----
include/linux/bio.h | 2 +-
2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 9bc7d28ae997..7f3920b6baca 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -845,7 +845,7 @@ static void bio_get_pages(struct bio *bio)
get_page(bvec->bv_page);
}

-void bio_release_pages(struct bio *bio)
+void bio_release_pages(struct bio *bio, bool mark_dirty)
{
struct bvec_iter_all iter_all;
struct bio_vec *bvec;
@@ -853,8 +853,11 @@ void bio_release_pages(struct bio *bio)
if (bio_flagged(bio, BIO_NO_PAGE_REF))
return;

- bio_for_each_segment_all(bvec, bio, iter_all)
+ bio_for_each_segment_all(bvec, bio, iter_all) {
+ if (mark_dirty && !PageCompound(bvec->bv_page))
+ set_page_dirty_lock(bvec->bv_page);
put_page(bvec->bv_page);
+ }
}

static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter)
@@ -1683,8 +1686,7 @@ static void bio_dirty_fn(struct work_struct *work)
while ((bio = next) != NULL) {
next = bio->bi_private;

- bio_set_pages_dirty(bio);
- bio_release_pages(bio);
+ bio_release_pages(bio, true);
bio_put(bio);
}
}
@@ -1700,7 +1702,7 @@ void bio_check_pages_dirty(struct bio *bio)
goto defer;
}

- bio_release_pages(bio);
+ bio_release_pages(bio, false);
bio_put(bio);
return;
defer:
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 87e6c8637bce..9dca313d948a 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -426,7 +426,7 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page,
void __bio_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int off);
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
-void bio_release_pages(struct bio *bio);
+void bio_release_pages(struct bio *bio, bool mark_dirty);
struct rq_map_data;
extern struct bio *bio_map_user_iov(struct request_queue *,
struct iov_iter *, gfp_t);
--
2.20.1