Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 919 insertions, 0 deletions

diff --git a/fs/bcachefs/tests.c b/fs/bcachefs/tests.c
new file mode 100644
index 0000000000..2fc9e60c75
--- /dev/null
+++ b/fs/bcachefs/tests.c
@@ -0,0 +1,919 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifdef CONFIG_BCACHEFS_TESTS
+
+#include "bcachefs.h"
+#include "btree_update.h"
+#include "journal_reclaim.h"
+#include "snapshot.h"
+#include "tests.h"
+
+#include "linux/kthread.h"
+#include "linux/random.h"
+
+static void delete_test_keys(struct bch_fs *c)
+{
+	int ret;
+
+	ret = bch2_btree_delete_range(c, BTREE_ID_extents,
+				      SPOS(0, 0, U32_MAX),
+				      POS(0, U64_MAX),
+				      0, NULL);
+	BUG_ON(ret);
+
+	ret = bch2_btree_delete_range(c, BTREE_ID_xattrs,
+				      SPOS(0, 0, U32_MAX),
+				      POS(0, U64_MAX),
+				      0, NULL);
+	BUG_ON(ret);
+}
+
+/* unit tests */
+
+static int test_delete(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_i_cookie k;
+	int ret;
+
+	bkey_cookie_init(&k.k_i);
+	k.k.p.snapshot = U32_MAX;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs, k.k.p,
+			     BTREE_ITER_INTENT);
+
+	ret = commit_do(trans, NULL, NULL, 0,
+		bch2_btree_iter_traverse(&iter) ?:
+		bch2_trans_update(trans, &iter, &k.k_i, 0));
+	bch_err_msg(c, ret, "update error");
+	if (ret)
+		goto err;
+
+	pr_info("deleting once");
+	ret = commit_do(trans, NULL, NULL, 0,
+		bch2_btree_iter_traverse(&iter) ?:
+		bch2_btree_delete_at(trans, &iter, 0));
+	bch_err_msg(c, ret, "delete error (first)");
+	if (ret)
+		goto err;
+
+	pr_info("deleting twice");
+	ret = commit_do(trans, NULL, NULL, 0,
+		bch2_btree_iter_traverse(&iter) ?:
+		bch2_btree_delete_at(trans, &iter, 0));
+	bch_err_msg(c, ret, "delete error (second)");
+	if (ret)
+		goto err;
+err:
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int test_delete_written(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_i_cookie k;
+	int ret;
+
+	bkey_cookie_init(&k.k_i);
+	k.k.p.snapshot = U32_MAX;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs, k.k.p,
+			     BTREE_ITER_INTENT);
+
+	ret = commit_do(trans, NULL, NULL, 0,
+		bch2_btree_iter_traverse(&iter) ?:
+		bch2_trans_update(trans, &iter, &k.k_i, 0));
+	bch_err_msg(c, ret, "update error");
+	if (ret)
+		goto err;
+
+	bch2_trans_unlock(trans);
+	bch2_journal_flush_all_pins(&c->journal);
+
+	ret = commit_do(trans, NULL, NULL, 0,
+		bch2_btree_iter_traverse(&iter) ?:
+		bch2_btree_delete_at(trans, &iter, 0));
+	bch_err_msg(c, ret, "delete error");
+	if (ret)
+		goto err;
+err:
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int test_iterate(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter = { NULL };
+	struct bkey_s_c k;
+	u64 i;
+	int ret = 0;
+
+	delete_test_keys(c);
+
+	pr_info("inserting test keys");
+
+	for (i = 0; i < nr; i++) {
+		struct bkey_i_cookie ck;
+
+		bkey_cookie_init(&ck.k_i);
+		ck.k.p.offset = i;
+		ck.k.p.snapshot = U32_MAX;
+
+		ret = bch2_btree_insert(c, BTREE_ID_xattrs, &ck.k_i, NULL, 0);
+		bch_err_msg(c, ret, "insert error");
+		if (ret)
+			goto err;
+	}
+
+	pr_info("iterating forwards");
+
+	i = 0;
+
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_xattrs,
+				  SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
+				  0, k, ({
+		BUG_ON(k.k->p.offset != i++);
+		0;
+	}));
+	bch_err_msg(c, ret, "error iterating forwards");
+	if (ret)
+		goto err;
+
+	BUG_ON(i != nr);
+
+	pr_info("iterating backwards");
+
+	ret = for_each_btree_key_reverse(trans, iter, BTREE_ID_xattrs,
+					 SPOS(0, U64_MAX, U32_MAX), 0, k,
+		({
+			BUG_ON(k.k->p.offset != --i);
+			0;
+		}));
+	bch_err_msg(c, ret, "error iterating backwards");
+	if (ret)
+		goto err;
+
+	BUG_ON(i);
+err:
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int test_iterate_extents(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter = { NULL };
+	struct bkey_s_c k;
+	u64 i;
+	int ret = 0;
+
+	delete_test_keys(c);
+
+	pr_info("inserting test extents");
+
+	for (i = 0; i < nr; i += 8) {
+		struct bkey_i_cookie ck;
+
+		bkey_cookie_init(&ck.k_i);
+		ck.k.p.offset = i + 8;
+		ck.k.p.snapshot = U32_MAX;
+		ck.k.size = 8;
+
+		ret = bch2_btree_insert(c, BTREE_ID_extents, &ck.k_i, NULL, 0);
+		bch_err_msg(c, ret, "insert error");
+		if (ret)
+			goto err;
+	}
+
+	pr_info("iterating forwards");
+
+	i = 0;
+
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_extents,
+				  SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
+				  0, k, ({
+		BUG_ON(bkey_start_offset(k.k) != i);
+		i = k.k->p.offset;
+		0;
+	}));
+	bch_err_msg(c, ret, "error iterating forwards");
+	if (ret)
+		goto err;
+
+	BUG_ON(i != nr);
+
+	pr_info("iterating backwards");
+
+	ret = for_each_btree_key_reverse(trans, iter, BTREE_ID_extents,
+					 SPOS(0, U64_MAX, U32_MAX), 0, k,
+		({
+			BUG_ON(k.k->p.offset != i);
+			i = bkey_start_offset(k.k);
+			0;
+		}));
+	bch_err_msg(c, ret, "error iterating backwards");
+	if (ret)
+		goto err;
+
+	BUG_ON(i);
+err:
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int test_iterate_slots(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter = { NULL };
+	struct bkey_s_c k;
+	u64 i;
+	int ret = 0;
+
+	delete_test_keys(c);
+
+	pr_info("inserting test keys");
+
+	for (i = 0; i < nr; i++) {
+		struct bkey_i_cookie ck;
+
+		bkey_cookie_init(&ck.k_i);
+		ck.k.p.offset = i * 2;
+		ck.k.p.snapshot = U32_MAX;
+
+		ret = bch2_btree_insert(c, BTREE_ID_xattrs, &ck.k_i, NULL, 0);
+		bch_err_msg(c, ret, "insert error");
+		if (ret)
+			goto err;
+	}
+
+	pr_info("iterating forwards");
+
+	i = 0;
+
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_xattrs,
+				  SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
+				  0, k, ({
+		BUG_ON(k.k->p.offset != i);
+		i += 2;
+		0;
+	}));
+	bch_err_msg(c, ret, "error iterating forwards");
+	if (ret)
+		goto err;
+
+	BUG_ON(i != nr * 2);
+
+	pr_info("iterating forwards by slots");
+
+	i = 0;
+
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_xattrs,
+				  SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
+				  BTREE_ITER_SLOTS, k, ({
+		if (i >= nr * 2)
+			break;
+
+		BUG_ON(k.k->p.offset != i);
+		BUG_ON(bkey_deleted(k.k) != (i & 1));
+
+		i++;
+		0;
+	}));
+	if (ret < 0) {
+		bch_err_msg(c, ret, "error iterating forwards by slots");
+		goto err;
+	}
+	ret = 0;
+err:
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int test_iterate_slots_extents(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter = { NULL };
+	struct bkey_s_c k;
+	u64 i;
+	int ret = 0;
+
+	delete_test_keys(c);
+
+	pr_info("inserting test keys");
+
+	for (i = 0; i < nr; i += 16) {
+		struct bkey_i_cookie ck;
+
+		bkey_cookie_init(&ck.k_i);
+		ck.k.p.offset = i + 16;
+		ck.k.p.snapshot = U32_MAX;
+		ck.k.size = 8;
+
+		ret = bch2_btree_insert(c, BTREE_ID_extents, &ck.k_i, NULL, 0);
+		bch_err_msg(c, ret, "insert error");
+		if (ret)
+			goto err;
+	}
+
+	pr_info("iterating forwards");
+
+	i = 0;
+
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_extents,
+				  SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
+				  0, k, ({
+		BUG_ON(bkey_start_offset(k.k) != i + 8);
+		BUG_ON(k.k->size != 8);
+		i += 16;
+		0;
+	}));
+	bch_err_msg(c, ret, "error iterating forwards");
+	if (ret)
+		goto err;
+
+	BUG_ON(i != nr);
+
+	pr_info("iterating forwards by slots");
+
+	i = 0;
+
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_extents,
+				 SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
+				 BTREE_ITER_SLOTS, k, ({
+		if (i == nr)
+			break;
+		BUG_ON(bkey_deleted(k.k) != !(i % 16));
+
+		BUG_ON(bkey_start_offset(k.k) != i);
+		BUG_ON(k.k->size != 8);
+		i = k.k->p.offset;
+		0;
+	}));
+	bch_err_msg(c, ret, "error iterating forwards by slots");
+	if (ret)
+		goto err;
+	ret = 0;
+err:
+	bch2_trans_put(trans);
+	return 0;
+}
+
+/*
+ * XXX: we really want to make sure we've got a btree with depth > 0 for these
+ * tests
+ */
+static int test_peek_end(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_s_c k;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs,
+			     SPOS(0, 0, U32_MAX), 0);
+
+	lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_upto(&iter, POS(0, U64_MAX))));
+	BUG_ON(k.k);
+
+	lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_upto(&iter, POS(0, U64_MAX))));
+	BUG_ON(k.k);
+
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return 0;
+}
+
+static int test_peek_end_extents(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_s_c k;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
+			     SPOS(0, 0, U32_MAX), 0);
+
+	lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_upto(&iter, POS(0, U64_MAX))));
+	BUG_ON(k.k);
+
+	lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_upto(&iter, POS(0, U64_MAX))));
+	BUG_ON(k.k);
+
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return 0;
+}
+
+/* extent unit tests */
+
+static u64 test_version;
+
+static int insert_test_extent(struct bch_fs *c,
+			      u64 start, u64 end)
+{
+	struct bkey_i_cookie k;
+	int ret;
+
+	bkey_cookie_init(&k.k_i);
+	k.k_i.k.p.offset = end;
+	k.k_i.k.p.snapshot = U32_MAX;
+	k.k_i.k.size = end - start;
+	k.k_i.k.version.lo = test_version++;
+
+	ret = bch2_btree_insert(c, BTREE_ID_extents, &k.k_i, NULL, 0);
+	bch_err_fn(c, ret);
+	return ret;
+}
+
+static int __test_extent_overwrite(struct bch_fs *c,
+				    u64 e1_start, u64 e1_end,
+				    u64 e2_start, u64 e2_end)
+{
+	int ret;
+
+	ret   = insert_test_extent(c, e1_start, e1_end) ?:
+		insert_test_extent(c, e2_start, e2_end);
+
+	delete_test_keys(c);
+	return ret;
+}
+
+static int test_extent_overwrite_front(struct bch_fs *c, u64 nr)
+{
+	return  __test_extent_overwrite(c, 0, 64, 0, 32) ?:
+		__test_extent_overwrite(c, 8, 64, 0, 32);
+}
+
+static int test_extent_overwrite_back(struct bch_fs *c, u64 nr)
+{
+	return  __test_extent_overwrite(c, 0, 64, 32, 64) ?:
+		__test_extent_overwrite(c, 0, 64, 32, 72);
+}
+
+static int test_extent_overwrite_middle(struct bch_fs *c, u64 nr)
+{
+	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);
+}
+
+static int insert_test_overlapping_extent(struct bch_fs *c, u64 inum, u64 start, u32 len, u32 snapid)
+{
+	struct bkey_i_cookie k;
+	int ret;
+
+	bkey_cookie_init(&k.k_i);
+	k.k_i.k.p.inode	= inum;
+	k.k_i.k.p.offset = start + len;
+	k.k_i.k.p.snapshot = snapid;
+	k.k_i.k.size = len;
+
+	ret = bch2_trans_do(c, NULL, NULL, 0,
+		bch2_btree_insert_nonextent(trans, BTREE_ID_extents, &k.k_i,
+					    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE));
+	bch_err_fn(c, ret);
+	return ret;
+}
+
+static int test_extent_create_overlapping(struct bch_fs *c, u64 inum)
+{
+	return  insert_test_overlapping_extent(c, inum,  0, 16, U32_MAX - 2) ?: /* overwrite entire */
+		insert_test_overlapping_extent(c, inum,  2,  8, U32_MAX - 2) ?:
+		insert_test_overlapping_extent(c, inum,  4,  4, U32_MAX) ?:
+		insert_test_overlapping_extent(c, inum, 32,  8, U32_MAX - 2) ?: /* overwrite front/back */
+		insert_test_overlapping_extent(c, inum, 36,  8, U32_MAX) ?:
+		insert_test_overlapping_extent(c, inum, 60,  8, U32_MAX - 2) ?:
+		insert_test_overlapping_extent(c, inum, 64,  8, U32_MAX);
+}
+
+/* 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, 0);
+	if (ret)
+		return ret;
+
+	trans = bch2_trans_get(c);
+	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_put(trans);
+	return ret;
+}
+
+static int test_snapshots(struct bch_fs *c, u64 nr)
+{
+	struct bkey_i_cookie cookie;
+	u32 snapids[2];
+	u32 snapid_subvols[2] = { 1, 1 };
+	int ret;
+
+	bkey_cookie_init(&cookie.k_i);
+	cookie.k.p.snapshot = U32_MAX;
+	ret = bch2_btree_insert(c, BTREE_ID_xattrs, &cookie.k_i, NULL, 0);
+	if (ret)
+		return ret;
+
+	ret = bch2_trans_do(c, NULL, NULL, 0,
+		      bch2_snapshot_node_create(trans, U32_MAX,
+						snapids,
+						snapid_subvols,
+						2));
+	if (ret)
+		return ret;
+
+	if (snapids[0] > snapids[1])
+		swap(snapids[0], snapids[1]);
+
+	ret = test_snapshot_filter(c, snapids[0], snapids[1]);
+	bch_err_msg(c, ret, "from test_snapshot_filter");
+	return ret;
+}
+
+/* perf tests */
+
+static u64 test_rand(void)
+{
+	u64 v;
+
+	get_random_bytes(&v, sizeof(v));
+	return v;
+}
+
+static int rand_insert(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct bkey_i_cookie k;
+	int ret = 0;
+	u64 i;
+
+	for (i = 0; i < nr; i++) {
+		bkey_cookie_init(&k.k_i);
+		k.k.p.offset = test_rand();
+		k.k.p.snapshot = U32_MAX;
+
+		ret = commit_do(trans, NULL, NULL, 0,
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k.k_i, 0));
+		if (ret)
+			break;
+	}
+
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int rand_insert_multi(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct bkey_i_cookie k[8];
+	int ret = 0;
+	unsigned j;
+	u64 i;
+
+	for (i = 0; i < nr; i += ARRAY_SIZE(k)) {
+		for (j = 0; j < ARRAY_SIZE(k); j++) {
+			bkey_cookie_init(&k[j].k_i);
+			k[j].k.p.offset = test_rand();
+			k[j].k.p.snapshot = U32_MAX;
+		}
+
+		ret = commit_do(trans, NULL, NULL, 0,
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[0].k_i, 0) ?:
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[1].k_i, 0) ?:
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[2].k_i, 0) ?:
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[3].k_i, 0) ?:
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[4].k_i, 0) ?:
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[5].k_i, 0) ?:
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[6].k_i, 0) ?:
+			bch2_btree_insert_trans(trans, BTREE_ID_xattrs, &k[7].k_i, 0));
+		if (ret)
+			break;
+	}
+
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int rand_lookup(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int ret = 0;
+	u64 i;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs,
+			     SPOS(0, 0, U32_MAX), 0);
+
+	for (i = 0; i < nr; i++) {
+		bch2_btree_iter_set_pos(&iter, SPOS(0, test_rand(), U32_MAX));
+
+		lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek(&iter)));
+		ret = bkey_err(k);
+		if (ret)
+			break;
+	}
+
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int rand_mixed_trans(struct btree_trans *trans,
+			    struct btree_iter *iter,
+			    struct bkey_i_cookie *cookie,
+			    u64 i, u64 pos)
+{
+	struct bkey_s_c k;
+	int ret;
+
+	bch2_btree_iter_set_pos(iter, SPOS(0, pos, U32_MAX));
+
+	k = bch2_btree_iter_peek(iter);
+	ret = bkey_err(k);
+	bch_err_msg(trans->c, ret, "lookup error");
+	if (ret)
+		return ret;
+
+	if (!(i & 3) && k.k) {
+		bkey_cookie_init(&cookie->k_i);
+		cookie->k.p = iter->pos;
+		ret = bch2_trans_update(trans, iter, &cookie->k_i, 0);
+	}
+
+	return ret;
+}
+
+static int rand_mixed(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_i_cookie cookie;
+	int ret = 0;
+	u64 i, rand;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs,
+			     SPOS(0, 0, U32_MAX), 0);
+
+	for (i = 0; i < nr; i++) {
+		rand = test_rand();
+		ret = commit_do(trans, NULL, NULL, 0,
+			rand_mixed_trans(trans, &iter, &cookie, i, rand));
+		if (ret)
+			break;
+	}
+
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int __do_delete(struct btree_trans *trans, struct bpos pos)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int ret = 0;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs, pos,
+			     BTREE_ITER_INTENT);
+	k = bch2_btree_iter_peek(&iter);
+	ret = bkey_err(k);
+	if (ret)
+		goto err;
+
+	if (!k.k)
+		goto err;
+
+	ret = bch2_btree_delete_at(trans, &iter, 0);
+err:
+	bch2_trans_iter_exit(trans, &iter);
+	return ret;
+}
+
+static int rand_delete(struct bch_fs *c, u64 nr)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	int ret = 0;
+	u64 i;
+
+	for (i = 0; i < nr; i++) {
+		struct bpos pos = SPOS(0, test_rand(), U32_MAX);
+
+		ret = commit_do(trans, NULL, NULL, 0,
+			__do_delete(trans, pos));
+		if (ret)
+			break;
+	}
+
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int seq_insert(struct bch_fs *c, u64 nr)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	struct bkey_i_cookie insert;
+
+	bkey_cookie_init(&insert.k_i);
+
+	return bch2_trans_run(c,
+		for_each_btree_key_commit(trans, iter, BTREE_ID_xattrs,
+					SPOS(0, 0, U32_MAX),
+					BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k,
+					NULL, NULL, 0, ({
+			if (iter.pos.offset >= nr)
+				break;
+			insert.k.p = iter.pos;
+			bch2_trans_update(trans, &iter, &insert.k_i, 0);
+		})));
+}
+
+static int seq_lookup(struct bch_fs *c, u64 nr)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+
+	return bch2_trans_run(c,
+		for_each_btree_key2_upto(trans, iter, BTREE_ID_xattrs,
+				  SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
+				  0, k,
+		0));
+}
+
+static int seq_overwrite(struct bch_fs *c, u64 nr)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+
+	return bch2_trans_run(c,
+		for_each_btree_key_commit(trans, iter, BTREE_ID_xattrs,
+					SPOS(0, 0, U32_MAX),
+					BTREE_ITER_INTENT, k,
+					NULL, NULL, 0, ({
+			struct bkey_i_cookie u;
+
+			bkey_reassemble(&u.k_i, k);
+			bch2_trans_update(trans, &iter, &u.k_i, 0);
+		})));
+}
+
+static int seq_delete(struct bch_fs *c, u64 nr)
+{
+	return bch2_btree_delete_range(c, BTREE_ID_xattrs,
+				      SPOS(0, 0, U32_MAX),
+				      POS(0, U64_MAX),
+				      0, NULL);
+}
+
+typedef int (*perf_test_fn)(struct bch_fs *, u64);
+
+struct test_job {
+	struct bch_fs			*c;
+	u64				nr;
+	unsigned			nr_threads;
+	perf_test_fn			fn;
+
+	atomic_t			ready;
+	wait_queue_head_t		ready_wait;
+
+	atomic_t			done;
+	struct completion		done_completion;
+
+	u64				start;
+	u64				finish;
+	int				ret;
+};
+
+static int btree_perf_test_thread(void *data)
+{
+	struct test_job *j = data;
+	int ret;
+
+	if (atomic_dec_and_test(&j->ready)) {
+		wake_up(&j->ready_wait);
+		j->start = sched_clock();
+	} else {
+		wait_event(j->ready_wait, !atomic_read(&j->ready));
+	}
+
+	ret = j->fn(j->c, div64_u64(j->nr, j->nr_threads));
+	if (ret) {
+		bch_err(j->c, "%ps: error %s", j->fn, bch2_err_str(ret));
+		j->ret = ret;
+	}
+
+	if (atomic_dec_and_test(&j->done)) {
+		j->finish = sched_clock();
+		complete(&j->done_completion);
+	}
+
+	return 0;
+}
+
+int bch2_btree_perf_test(struct bch_fs *c, const char *testname,
+			 u64 nr, unsigned nr_threads)
+{
+	struct test_job j = { .c = c, .nr = nr, .nr_threads = nr_threads };
+	char name_buf[20];
+	struct printbuf nr_buf = PRINTBUF;
+	struct printbuf per_sec_buf = PRINTBUF;
+	unsigned i;
+	u64 time;
+
+	atomic_set(&j.ready, nr_threads);
+	init_waitqueue_head(&j.ready_wait);
+
+	atomic_set(&j.done, nr_threads);
+	init_completion(&j.done_completion);
+
+#define perf_test(_test)				\
+	if (!strcmp(testname, #_test)) j.fn = _test
+
+	perf_test(rand_insert);
+	perf_test(rand_insert_multi);
+	perf_test(rand_lookup);
+	perf_test(rand_mixed);
+	perf_test(rand_delete);
+
+	perf_test(seq_insert);
+	perf_test(seq_lookup);
+	perf_test(seq_overwrite);
+	perf_test(seq_delete);
+
+	/* a unit test, not a perf test: */
+	perf_test(test_delete);
+	perf_test(test_delete_written);
+	perf_test(test_iterate);
+	perf_test(test_iterate_extents);
+	perf_test(test_iterate_slots);
+	perf_test(test_iterate_slots_extents);
+	perf_test(test_peek_end);
+	perf_test(test_peek_end_extents);
+
+	perf_test(test_extent_overwrite_front);
+	perf_test(test_extent_overwrite_back);
+	perf_test(test_extent_overwrite_middle);
+	perf_test(test_extent_overwrite_all);
+	perf_test(test_extent_create_overlapping);
+
+	perf_test(test_snapshots);
+
+	if (!j.fn) {
+		pr_err("unknown test %s", testname);
+		return -EINVAL;
+	}
+
+	//pr_info("running test %s:", testname);
+
+	if (nr_threads == 1)
+		btree_perf_test_thread(&j);
+	else
+		for (i = 0; i < nr_threads; i++)
+			kthread_run(btree_perf_test_thread, &j,
+				    "bcachefs perf test[%u]", i);
+
+	while (wait_for_completion_interruptible(&j.done_completion))
+		;
+
+	time = j.finish - j.start;
+
+	scnprintf(name_buf, sizeof(name_buf), "%s:", testname);
+	prt_human_readable_u64(&nr_buf, nr);
+	prt_human_readable_u64(&per_sec_buf, div64_u64(nr * NSEC_PER_SEC, time));
+	printk(KERN_INFO "%-12s %s with %u threads in %5llu sec, %5llu nsec per iter, %5s per sec\n",
+		name_buf, nr_buf.buf, nr_threads,
+		div_u64(time, NSEC_PER_SEC),
+		div_u64(time * nr_threads, nr),
+		per_sec_buf.buf);
+	printbuf_exit(&per_sec_buf);
+	printbuf_exit(&nr_buf);
+	return j.ret;
+}
+
+#endif /* CONFIG_BCACHEFS_TESTS */