Looks all are safe after multipage bvec is supported.
Signed-off-by: Ming Lei <[email protected]>
---
drivers/md/bcache/btree.c | 1 +
drivers/md/bcache/super.c | 6 ++++++
drivers/md/bcache/util.c | 7 +++++++
3 files changed, 14 insertions(+)
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index a43eedd5804d..fc35cfb4d0f1 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -428,6 +428,7 @@ static void do_btree_node_write(struct btree *b)
continue_at(cl, btree_node_write_done, NULL);
} else {
+ /* No harm for multipage bvec since the new is just allocated */
b->bio->bi_vcnt = 0;
bch_bio_map(b->bio, i);
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 3a19cbc8b230..607b022259dc 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -208,6 +208,7 @@ static void write_bdev_super_endio(struct bio *bio)
static void __write_super(struct cache_sb *sb, struct bio *bio)
{
+ /* single page bio, safe for multipage bvec */
struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page);
unsigned i;
@@ -1156,6 +1157,8 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
dc->bdev->bd_holder = dc;
bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1);
+
+ /* single page bio, safe for multipage bvec */
dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
get_page(sb_page);
@@ -1799,6 +1802,7 @@ void bch_cache_release(struct kobject *kobj)
for (i = 0; i < RESERVE_NR; i++)
free_fifo(&ca->free[i]);
+ /* single page bio, safe for multipage bvec */
if (ca->sb_bio.bi_inline_vecs[0].bv_page)
put_page(ca->sb_bio.bi_io_vec[0].bv_page);
@@ -1854,6 +1858,8 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
ca->bdev->bd_holder = ca;
bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1);
+
+ /* single page bio, safe for multipage bvec */
ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
get_page(sb_page);
diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
index dde6172f3f10..5cc0b49a65fb 100644
--- a/drivers/md/bcache/util.c
+++ b/drivers/md/bcache/util.c
@@ -222,6 +222,13 @@ uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
: 0;
}
+/*
+ * Generally it isn't good to access .bi_io_vec and .bi_vcnt
+ * directly, the preferred way is bio_add_page, but in
+ * this case, bch_bio_map() supposes that the bvec table
+ * is empty, so it is safe to access .bi_vcnt & .bi_io_vec
+ * in this way even after multipage bvec is supported.
+ */
void bch_bio_map(struct bio *bio, void *base)
{
size_t size = bio->bi_iter.bi_size;
--
2.7.4
On 2016/12/27 下午11:55, Ming Lei wrote:
> Looks all are safe after multipage bvec is supported.
>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> drivers/md/bcache/btree.c | 1 +
> drivers/md/bcache/super.c | 6 ++++++
> drivers/md/bcache/util.c | 7 +++++++
> 3 files changed, 14 insertions(+)
>
> diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
> index a43eedd5804d..fc35cfb4d0f1 100644
> --- a/drivers/md/bcache/btree.c
> +++ b/drivers/md/bcache/btree.c
> @@ -428,6 +428,7 @@ static void do_btree_node_write(struct btree *b)
>
> continue_at(cl, btree_node_write_done, NULL);
> } else {
> + /* No harm for multipage bvec since the new is just allocated */
> b->bio->bi_vcnt = 0;
> bch_bio_map(b->bio, i);
>
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index 3a19cbc8b230..607b022259dc 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -208,6 +208,7 @@ static void write_bdev_super_endio(struct bio *bio)
>
> static void __write_super(struct cache_sb *sb, struct bio *bio)
> {
> + /* single page bio, safe for multipage bvec */
> struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page);
> unsigned i;
>
> @@ -1156,6 +1157,8 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
> dc->bdev->bd_holder = dc;
>
> bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1);
> +
> + /* single page bio, safe for multipage bvec */
> dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
> get_page(sb_page);
>
> @@ -1799,6 +1802,7 @@ void bch_cache_release(struct kobject *kobj)
> for (i = 0; i < RESERVE_NR; i++)
> free_fifo(&ca->free[i]);
>
> + /* single page bio, safe for multipage bvec */
> if (ca->sb_bio.bi_inline_vecs[0].bv_page)
> put_page(ca->sb_bio.bi_io_vec[0].bv_page);
>
> @@ -1854,6 +1858,8 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
> ca->bdev->bd_holder = ca;
>
> bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1);
> +
> + /* single page bio, safe for multipage bvec */
> ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
> get_page(sb_page);
>
> diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
> index dde6172f3f10..5cc0b49a65fb 100644
> --- a/drivers/md/bcache/util.c
> +++ b/drivers/md/bcache/util.c
> @@ -222,6 +222,13 @@ uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
> : 0;
> }
>
> +/*
> + * Generally it isn't good to access .bi_io_vec and .bi_vcnt
> + * directly, the preferred way is bio_add_page, but in
> + * this case, bch_bio_map() supposes that the bvec table
> + * is empty, so it is safe to access .bi_vcnt & .bi_io_vec
> + * in this way even after multipage bvec is supported.
> + */
> void bch_bio_map(struct bio *bio, void *base)
> {
> size_t size = bio->bi_iter.bi_size;
>
Acked-by: Coly Li <[email protected]>