btrfs: use btrfs_ordered_update_i_size in clone_finish_inode_update

We were using btrfs_i_size_write(), which unconditionally jacks up
inode->disk_i_size.  However since clone can operate on ranges we could
have pending ordered extents for a range prior to the start of our clone
operation and thus increase disk_i_size too far and have a hole with no
file extent.

Fix this by using the btrfs_ordered_update_i_size helper which will do
the right thing in the face of pending ordered extents outside of our
clone range.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ioctl.c

@@ -3321,8 +3321,10 @@ static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
 	 */
 	if (endoff > destoff + olen)
 		endoff = destoff + olen;
-	if (endoff > inode->i_size)
-		btrfs_i_size_write(BTRFS_I(inode), endoff);
+	if (endoff > inode->i_size) {
+		i_size_write(inode, endoff);
+		btrfs_ordered_update_i_size(inode, endoff, NULL);
+	}
 
 	ret = btrfs_update_inode(trans, root, inode);
 	if (ret) {