bcachefs: bch2_extent_atomic_end() now traverses iter

This fixes a bug in io.c bch2_write_index_default() - it was missing the
traverse call, but bch2_extent_atomic_end returns an error now and can
just call it itself.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/extents.c

@@ -1010,13 +1010,19 @@ int bch2_extent_atomic_end(struct btree_iter *iter,
 			   struct bpos *end)
 {
 	struct btree_trans *trans = iter->trans;
-	struct btree *b = iter->l[0].b;
-	struct btree_node_iter	node_iter = iter->l[0].iter;
+	struct btree *b;
+	struct btree_node_iter	node_iter;
 	struct bkey_packed	*_k;
 	unsigned		nr_iters = 0;
 	int ret;
 
-	BUG_ON(iter->uptodate > BTREE_ITER_NEED_PEEK);
+	ret = bch2_btree_iter_traverse(iter);
+	if (ret)
+		return ret;
+
+	b = iter->l[0].b;
+	node_iter = iter->l[0].iter;
+
 	BUG_ON(bkey_cmp(bkey_start_pos(&insert->k), b->data->min_key) < 0);
 
 	*end = bpos_min(insert->k.p, b->key.k.p);

fs/bcachefs/fs-io.c

@@ -297,10 +297,6 @@ int bch2_extent_update(struct btree_trans *trans,
 	s64 i_sectors_delta;
 	int ret;
 
-	ret = bch2_btree_iter_traverse(extent_iter);
-	if (ret)
-		return ret;
-
 	ret = bch2_extent_trim_atomic(k, extent_iter);
 	if (ret)
 		return ret;
@@ -2695,10 +2691,6 @@ static long bch2_fcollapse_finsert(struct bch_inode_info *inode,
 		copy.k.k.p.offset += shift >> 9;
 		bch2_btree_iter_set_pos(dst, bkey_start_pos(&copy.k.k));
 
-		ret = bch2_btree_iter_traverse(dst);
-		if (ret)
-			goto bkey_err;
-
 		ret = bch2_extent_atomic_end(dst, &copy.k, &atomic_end);
 		if (ret)
 			goto bkey_err;

fs/bcachefs/recovery.c

@@ -268,7 +268,7 @@ static int bch2_extent_replay_key(struct bch_fs *c, enum btree_id btree_id,
 				   BTREE_ITER_INTENT);
 
 	do {
-		ret = bch2_btree_iter_traverse(iter);
+		ret = bch2_extent_atomic_end(iter, k, &atomic_end);
 		if (ret)
 			goto err;
 
@@ -282,10 +282,6 @@ static int bch2_extent_replay_key(struct bch_fs *c, enum btree_id btree_id,
 		if (ret)
 			goto err;
 
-		ret = bch2_extent_atomic_end(split_iter, k, &atomic_end);
-		if (ret)
-			goto err;
-
 		if (!remark &&
 		    remark_if_split &&
 		    bkey_cmp(atomic_end, k->k.p) < 0) {