[PATCH 4.19 195/361] f2fs: fix to account IO correctly

Greg Kroah-Hartman
2018-11-12T00:02:08Z

From: Chao Yu <yuchao0@huawei.com>

commit 4c58ed076875f36dae0f240da1e25e99e5d4afb8 upstream.

Below race can cause reversed reference on dirty count, fix it by
relocating __submit_bio() and inc_page_count().

Thread A Thread B
- f2fs_inplace_write_data
- f2fs_submit_page_bio
- __submit_bio
- f2fs_write_end_io
- dec_page_count
- inc_page_count

Cc: <stable@vger.kernel.org>
Fixes: d1b3e72d5490 ("f2fs: submit bio of in-place-update pages")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/f2fs/data.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -463,10 +463,10 @@ int f2fs_submit_page_bio(struct f2fs_io_

bio_set_op_attrs(bio, fio->op, fio->op_flags);

- __submit_bio(fio->sbi, bio, fio->type);
-
if (!is_read_io(fio->op))
inc_page_count(fio->sbi, WB_DATA_TYPE(fio->page));
+
+ __submit_bio(fio->sbi, bio, fio->type);
return 0;
}