| Message ID | 1482854250-13481-8-git-send-email-tom.leiming@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <tom.leiming@gmail.com> > --- > 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 <colyli@suse.de> -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
Looks all are safe after multipage bvec is supported. Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- drivers/md/bcache/btree.c | 1 + drivers/md/bcache/super.c | 6 ++++++ drivers/md/bcache/util.c | 7 +++++++ 3 files changed, 14 insertions(+)