jbd: Use offset_in_page() instead of manual calculation
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index 981449c..c9bb7a7 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -711,7 +711,7 @@
J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)),
"Possible IO failure.\n");
page = jh2bh(jh)->b_page;
- offset = ((unsigned long) jh2bh(jh)->b_data) & ~PAGE_MASK;
+ offset = offset_in_page(jh2bh(jh)->b_data);
source = kmap_atomic(page, KM_USER0);
memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size);
kunmap_atomic(source, KM_USER0);