ext4: fix data corruption in data=journal mode

am: 9d636818db

Change-Id: Idc4320c3f0fa867216d8770b5ad186226e61152a

1 files changed, 13 insertions, 10 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 790961e33961..8a08807359b5 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1232,7 +1232,9 @@ errout:
  * set the buffer to be dirty, since in data=journalled mode we need
  * to call ext4_handle_dirty_metadata() instead.
  */
-static void zero_new_buffers(struct page *page, unsigned from, unsigned to)
+static void ext4_journalled_zero_new_buffers(handle_t *handle,
+					    struct page *page,
+					    unsigned from, unsigned to)
 {
 	unsigned int block_start = 0, block_end;
 	struct buffer_head *head, *bh;
@@ -1249,7 +1251,7 @@ static void zero_new_buffers(struct page *page, unsigned from, unsigned to)
 					size = min(to, block_end) - start;
 
 					zero_user(page, start, size);
-					set_buffer_uptodate(bh);
+					write_end_fn(handle, bh);
 				}
 				clear_buffer_new(bh);
 			}
@@ -1282,15 +1284,16 @@ static int ext4_journalled_write_end(struct file *file,
 	if (ext4_has_inline_data(inode))
 		copied = ext4_write_inline_data_end(inode, pos, len,
 						    copied, page);
-	else {
-		if (copied < len) {
-			if (!PageUptodate(page))
-				copied = 0;
-			zero_new_buffers(page, from+copied, to);
-		}
-
+	else if (unlikely(copied < len) && !PageUptodate(page)) {
+		copied = 0;
+		ext4_journalled_zero_new_buffers(handle, page, from, to);
+	} else {
+		if (unlikely(copied < len))
+			ext4_journalled_zero_new_buffers(handle, page,
+							 from + copied, to);
 		ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
-					     to, &partial, write_end_fn);
+					     from + copied, &partial,
+					     write_end_fn);
 		if (!partial)
 			SetPageUptodate(page);
 	}