Btrfs: byte offsets for file keys

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 09de270..5230a44 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -26,6 +26,7 @@
 
 	ret = btrfs_insert_empty_item(trans, root, &path, &file_key,
 				      sizeof(*item));
+	BUG_ON(ret);
 	item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
 			      struct btrfs_file_extent_item);
 	btrfs_set_file_extent_disk_blocknr(item, ins.objectid);
@@ -42,7 +43,7 @@
 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path, u64 objectid,
-			     u64 blocknr, u64 num_blocks, int mod)
+			     u64 offset, int mod)
 {
 	int ret;
 	struct btrfs_key file_key;
@@ -50,7 +51,7 @@
 	int cow = mod != 0;
 
 	file_key.objectid = objectid;
-	file_key.offset = blocknr;
+	file_key.offset = offset;
 	file_key.flags = 0;
 	btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
 	ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);