From: Chao Yu <yuchao0@huawei.com>
Date: Mon, 22 Oct 2018 01:12:51 +0000 (+0800)
Subject: f2fs: fix to account IO correctly
X-Git-Tag: v4.20-rc1~138^2~10
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4c58ed076875f36dae0f240da1e25e99e5d4afb8;p=linux.git

f2fs: fix to account IO correctly

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>
---

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 9ef6f1f01eda..83b1983094bd 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -462,10 +462,10 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 	}
 	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;
 }