+ return __test_extent_overwrite(c, 0, 64, 32, 40);
+}
+
+static int test_extent_overwrite_all(struct bch_fs *c, u64 nr)
+{
+ return __test_extent_overwrite(c, 32, 64, 0, 64) ?:
+ __test_extent_overwrite(c, 32, 64, 0, 128) ?:
+ __test_extent_overwrite(c, 32, 64, 32, 64) ?:
+ __test_extent_overwrite(c, 32, 64, 32, 128);
+}
+
+/* snapshot unit tests */
+
+/* Test skipping over keys in unrelated snapshots: */
+static int test_snapshot_filter(struct bch_fs *c, u32 snapid_lo, u32 snapid_hi)
+{
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_i_cookie cookie;
+ int ret;
+
+ bkey_cookie_init(&cookie.k_i);
+ cookie.k.p.snapshot = snapid_hi;
+ ret = bch2_btree_insert(c, BTREE_ID_xattrs, &cookie.k_i,
+ NULL, NULL, 0);
+ if (ret)
+ return ret;
+
+ bch2_trans_init(&trans, c, 0, 0);
+ bch2_trans_iter_init(&trans, &iter, BTREE_ID_xattrs,
+ SPOS(0, 0, snapid_lo), 0);
+ lockrestart_do(&trans, bkey_err(k = bch2_btree_iter_peek_upto(&iter, POS(0, U64_MAX))));
+
+ BUG_ON(k.k->p.snapshot != U32_MAX);
+
+ bch2_trans_iter_exit(&trans, &iter);
+ bch2_trans_exit(&trans);
+ return ret;