f2fs: fix to account IO correctly for cgroup writeback

From: Chao Yu <[email protected]>

Now, we have supported cgroup writeback, it depends on correctly IO account of specified filesystem.

But in commit d1b3e72d5490 ("f2fs: submit bio of in-place-update pages"), we split write paths from f2fs_submit_page_mbio() to two:
- f2fs_submit_page_bio() for IPU path
- f2fs_submit_page_bio() for OPU path

But still we account write IO only in f2fs_submit_page_mbio(), result in incorrect IO account, fix it by adding missing IO account in IPU path.

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

index c6618eee4650..2dea5777597f 100644
@@ -478,6 +478,10 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 		bio_put(bio);
 		return -EFAULT;
 	}
+
+	if (fio->io_wbc && !is_read_io(fio->op))
+		wbc_account_io(fio->io_wbc, page, PAGE_SIZE);
+
 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
 
 	inc_page_count(fio->sbi, is_read_io(fio->op) ?

2.18.0