root/lib/test_objagg.c
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/objagg.h>

struct tokey {
        unsigned int id;
};

#define NUM_KEYS 32

static int key_id_index(unsigned int key_id)
{
        if (key_id >= NUM_KEYS) {
                WARN_ON(1);
                return 0;
        }
        return key_id;
}

#define BUF_LEN 128

struct world {
        unsigned int root_count;
        unsigned int delta_count;
        char next_root_buf[BUF_LEN];
        struct objagg_obj *objagg_objs[NUM_KEYS];
        unsigned int key_refs[NUM_KEYS];
};

struct root {
        struct tokey key;
        char buf[BUF_LEN];
};

struct delta {
        unsigned int key_id_diff;
};

static struct objagg_obj *world_obj_get(struct world *world,
                                        struct objagg *objagg,
                                        unsigned int key_id)
{
        struct objagg_obj *objagg_obj;
        struct tokey key;
        int err;

        key.id = key_id;
        objagg_obj = objagg_obj_get(objagg, &key);
        if (IS_ERR(objagg_obj)) {
                pr_err("Key %u: Failed to get object.\n", key_id);
                return objagg_obj;
        }
        if (!world->key_refs[key_id_index(key_id)]) {
                world->objagg_objs[key_id_index(key_id)] = objagg_obj;
        } else if (world->objagg_objs[key_id_index(key_id)] != objagg_obj) {
                pr_err("Key %u: Got another object for the same key.\n",
                       key_id);
                err = -EINVAL;
                goto err_key_id_check;
        }
        world->key_refs[key_id_index(key_id)]++;
        return objagg_obj;

err_key_id_check:
        objagg_obj_put(objagg, objagg_obj);
        return ERR_PTR(err);
}

static void world_obj_put(struct world *world, struct objagg *objagg,
                          unsigned int key_id)
{
        struct objagg_obj *objagg_obj;

        if (!world->key_refs[key_id_index(key_id)])
                return;
        objagg_obj = world->objagg_objs[key_id_index(key_id)];
        objagg_obj_put(objagg, objagg_obj);
        world->key_refs[key_id_index(key_id)]--;
}

#define MAX_KEY_ID_DIFF 5

static bool delta_check(void *priv, const void *parent_obj, const void *obj)
{
        const struct tokey *parent_key = parent_obj;
        const struct tokey *key = obj;
        int diff = key->id - parent_key->id;

        return diff >= 0 && diff <= MAX_KEY_ID_DIFF;
}

static void *delta_create(void *priv, void *parent_obj, void *obj)
{
        struct tokey *parent_key = parent_obj;
        struct world *world = priv;
        struct tokey *key = obj;
        int diff = key->id - parent_key->id;
        struct delta *delta;

        if (!delta_check(priv, parent_obj, obj))
                return ERR_PTR(-EINVAL);

        delta = kzalloc_obj(*delta);
        if (!delta)
                return ERR_PTR(-ENOMEM);
        delta->key_id_diff = diff;
        world->delta_count++;
        return delta;
}

static void delta_destroy(void *priv, void *delta_priv)
{
        struct delta *delta = delta_priv;
        struct world *world = priv;

        world->delta_count--;
        kfree(delta);
}

static void *root_create(void *priv, void *obj, unsigned int id)
{
        struct world *world = priv;
        struct tokey *key = obj;
        struct root *root;

        root = kzalloc_obj(*root);
        if (!root)
                return ERR_PTR(-ENOMEM);
        memcpy(&root->key, key, sizeof(root->key));
        memcpy(root->buf, world->next_root_buf, sizeof(root->buf));
        world->root_count++;
        return root;
}

static void root_destroy(void *priv, void *root_priv)
{
        struct root *root = root_priv;
        struct world *world = priv;

        world->root_count--;
        kfree(root);
}

static int test_nodelta_obj_get(struct world *world, struct objagg *objagg,
                                unsigned int key_id, bool should_create_root)
{
        unsigned int orig_root_count = world->root_count;
        struct objagg_obj *objagg_obj;
        const struct root *root;
        int err;

        if (should_create_root)
                get_random_bytes(world->next_root_buf,
                              sizeof(world->next_root_buf));

        objagg_obj = world_obj_get(world, objagg, key_id);
        if (IS_ERR(objagg_obj)) {
                pr_err("Key %u: Failed to get object.\n", key_id);
                return PTR_ERR(objagg_obj);
        }
        if (should_create_root) {
                if (world->root_count != orig_root_count + 1) {
                        pr_err("Key %u: Root was not created\n", key_id);
                        err = -EINVAL;
                        goto err_check_root_count;
                }
        } else {
                if (world->root_count != orig_root_count) {
                        pr_err("Key %u: Root was incorrectly created\n",
                               key_id);
                        err = -EINVAL;
                        goto err_check_root_count;
                }
        }
        root = objagg_obj_root_priv(objagg_obj);
        if (root->key.id != key_id) {
                pr_err("Key %u: Root has unexpected key id\n", key_id);
                err = -EINVAL;
                goto err_check_key_id;
        }
        if (should_create_root &&
            memcmp(world->next_root_buf, root->buf, sizeof(root->buf))) {
                pr_err("Key %u: Buffer does not match the expected content\n",
                       key_id);
                err = -EINVAL;
                goto err_check_buf;
        }
        return 0;

err_check_buf:
err_check_key_id:
err_check_root_count:
        objagg_obj_put(objagg, objagg_obj);
        return err;
}

static int test_nodelta_obj_put(struct world *world, struct objagg *objagg,
                                unsigned int key_id, bool should_destroy_root)
{
        unsigned int orig_root_count = world->root_count;

        world_obj_put(world, objagg, key_id);

        if (should_destroy_root) {
                if (world->root_count != orig_root_count - 1) {
                        pr_err("Key %u: Root was not destroyed\n", key_id);
                        return -EINVAL;
                }
        } else {
                if (world->root_count != orig_root_count) {
                        pr_err("Key %u: Root was incorrectly destroyed\n",
                               key_id);
                        return -EINVAL;
                }
        }
        return 0;
}

static int check_stats_zero(struct objagg *objagg)
{
        const struct objagg_stats *stats;
        int err = 0;

        stats = objagg_stats_get(objagg);
        if (IS_ERR(stats))
                return PTR_ERR(stats);

        if (stats->stats_info_count != 0) {
                pr_err("Stats: Object count is not zero while it should be\n");
                err = -EINVAL;
        }

        objagg_stats_put(stats);
        return err;
}

static int check_stats_nodelta(struct objagg *objagg)
{
        const struct objagg_stats *stats;
        int i;
        int err;

        stats = objagg_stats_get(objagg);
        if (IS_ERR(stats))
                return PTR_ERR(stats);

        if (stats->stats_info_count != NUM_KEYS) {
                pr_err("Stats: Unexpected object count (%u expected, %u returned)\n",
                       NUM_KEYS, stats->stats_info_count);
                err = -EINVAL;
                goto stats_put;
        }

        for (i = 0; i < stats->stats_info_count; i++) {
                if (stats->stats_info[i].stats.user_count != 2) {
                        pr_err("Stats: incorrect user count\n");
                        err = -EINVAL;
                        goto stats_put;
                }
                if (stats->stats_info[i].stats.delta_user_count != 2) {
                        pr_err("Stats: incorrect delta user count\n");
                        err = -EINVAL;
                        goto stats_put;
                }
        }
        err = 0;

stats_put:
        objagg_stats_put(stats);
        return err;
}

static bool delta_check_dummy(void *priv, const void *parent_obj,
                              const void *obj)
{
        return false;
}

static void *delta_create_dummy(void *priv, void *parent_obj, void *obj)
{
        return ERR_PTR(-EOPNOTSUPP);
}

static void delta_destroy_dummy(void *priv, void *delta_priv)
{
}

static const struct objagg_ops nodelta_ops = {
        .obj_size = sizeof(struct tokey),
        .delta_check = delta_check_dummy,
        .delta_create = delta_create_dummy,
        .delta_destroy = delta_destroy_dummy,
        .root_create = root_create,
        .root_destroy = root_destroy,
};

static int test_nodelta(void)
{
        struct world world = {};
        struct objagg *objagg;
        int i;
        int err;

        objagg = objagg_create(&nodelta_ops, NULL, &world);
        if (IS_ERR(objagg))
                return PTR_ERR(objagg);

        err = check_stats_zero(objagg);
        if (err)
                goto err_stats_first_zero;

        /* First round of gets, the root objects should be created */
        for (i = 0; i < NUM_KEYS; i++) {
                err = test_nodelta_obj_get(&world, objagg, i, true);
                if (err)
                        goto err_obj_first_get;
        }

        /* Do the second round of gets, all roots are already created,
         * make sure that no new root is created
         */
        for (i = 0; i < NUM_KEYS; i++) {
                err = test_nodelta_obj_get(&world, objagg, i, false);
                if (err)
                        goto err_obj_second_get;
        }

        err = check_stats_nodelta(objagg);
        if (err)
                goto err_stats_nodelta;

        for (i = NUM_KEYS - 1; i >= 0; i--) {
                err = test_nodelta_obj_put(&world, objagg, i, false);
                if (err)
                        goto err_obj_first_put;
        }
        for (i = NUM_KEYS - 1; i >= 0; i--) {
                err = test_nodelta_obj_put(&world, objagg, i, true);
                if (err)
                        goto err_obj_second_put;
        }

        err = check_stats_zero(objagg);
        if (err)
                goto err_stats_second_zero;

        objagg_destroy(objagg);
        return 0;

err_stats_nodelta:
err_obj_first_put:
err_obj_second_get:
        for (i--; i >= 0; i--)
                world_obj_put(&world, objagg, i);

        i = NUM_KEYS;
err_obj_first_get:
err_obj_second_put:
        for (i--; i >= 0; i--)
                world_obj_put(&world, objagg, i);
err_stats_first_zero:
err_stats_second_zero:
        objagg_destroy(objagg);
        return err;
}

static const struct objagg_ops delta_ops = {
        .obj_size = sizeof(struct tokey),
        .delta_check = delta_check,
        .delta_create = delta_create,
        .delta_destroy = delta_destroy,
        .root_create = root_create,
        .root_destroy = root_destroy,
};

enum action {
        ACTION_GET,
        ACTION_PUT,
};

enum expect_delta {
        EXPECT_DELTA_SAME,
        EXPECT_DELTA_INC,
        EXPECT_DELTA_DEC,
};

enum expect_root {
        EXPECT_ROOT_SAME,
        EXPECT_ROOT_INC,
        EXPECT_ROOT_DEC,
};

struct expect_stats_info {
        struct objagg_obj_stats stats;
        bool is_root;
        unsigned int key_id;
};

struct expect_stats {
        unsigned int info_count;
        struct expect_stats_info info[NUM_KEYS];
};

struct action_item {
        unsigned int key_id;
        enum action action;
        enum expect_delta expect_delta;
        enum expect_root expect_root;
        struct expect_stats expect_stats;
};

#define EXPECT_STATS(count, ...)                \
{                                               \
        .info_count = count,                    \
        .info = { __VA_ARGS__ }                 \
}

#define ROOT(key_id, user_count, delta_user_count)      \
        {{user_count, delta_user_count}, true, key_id}

#define DELTA(key_id, user_count)                       \
        {{user_count, user_count}, false, key_id}

static const struct action_item action_items[] = {
        {
                1, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_INC,
                EXPECT_STATS(1, ROOT(1, 1, 1)),
        },      /* r: 1                 d: */
        {
                7, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_INC,
                EXPECT_STATS(2, ROOT(1, 1, 1), ROOT(7, 1, 1)),
        },      /* r: 1, 7              d: */
        {
                3, ACTION_GET, EXPECT_DELTA_INC, EXPECT_ROOT_SAME,
                EXPECT_STATS(3, ROOT(1, 1, 2), ROOT(7, 1, 1),
                                DELTA(3, 1)),
        },      /* r: 1, 7              d: 3^1 */
        {
                5, ACTION_GET, EXPECT_DELTA_INC, EXPECT_ROOT_SAME,
                EXPECT_STATS(4, ROOT(1, 1, 3), ROOT(7, 1, 1),
                                DELTA(3, 1), DELTA(5, 1)),
        },      /* r: 1, 7              d: 3^1, 5^1 */
        {
                3, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(4, ROOT(1, 1, 4), ROOT(7, 1, 1),
                                DELTA(3, 2), DELTA(5, 1)),
        },      /* r: 1, 7              d: 3^1, 3^1, 5^1 */
        {
                1, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(4, ROOT(1, 2, 5), ROOT(7, 1, 1),
                                DELTA(3, 2), DELTA(5, 1)),
        },      /* r: 1, 1, 7           d: 3^1, 3^1, 5^1 */
        {
                30, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_INC,
                EXPECT_STATS(5, ROOT(1, 2, 5), ROOT(7, 1, 1), ROOT(30, 1, 1),
                                DELTA(3, 2), DELTA(5, 1)),
        },      /* r: 1, 1, 7, 30       d: 3^1, 3^1, 5^1 */
        {
                8, ACTION_GET, EXPECT_DELTA_INC, EXPECT_ROOT_SAME,
                EXPECT_STATS(6, ROOT(1, 2, 5), ROOT(7, 1, 2), ROOT(30, 1, 1),
                                DELTA(3, 2), DELTA(5, 1), DELTA(8, 1)),
        },      /* r: 1, 1, 7, 30       d: 3^1, 3^1, 5^1, 8^7 */
        {
                8, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(6, ROOT(1, 2, 5), ROOT(7, 1, 3), ROOT(30, 1, 1),
                                DELTA(3, 2), DELTA(8, 2), DELTA(5, 1)),
        },      /* r: 1, 1, 7, 30       d: 3^1, 3^1, 5^1, 8^7, 8^7 */
        {
                3, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(6, ROOT(1, 2, 4), ROOT(7, 1, 3), ROOT(30, 1, 1),
                                DELTA(8, 2), DELTA(3, 1), DELTA(5, 1)),
        },      /* r: 1, 1, 7, 30       d: 3^1, 5^1, 8^7, 8^7 */
        {
                3, ACTION_PUT, EXPECT_DELTA_DEC, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(1, 2, 3), ROOT(7, 1, 3), ROOT(30, 1, 1),
                                DELTA(8, 2), DELTA(5, 1)),
        },      /* r: 1, 1, 7, 30       d: 5^1, 8^7, 8^7 */
        {
                1, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(7, 1, 3), ROOT(1, 1, 2), ROOT(30, 1, 1),
                                DELTA(8, 2), DELTA(5, 1)),
        },      /* r: 1, 7, 30          d: 5^1, 8^7, 8^7 */
        {
                1, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(7, 1, 3), ROOT(30, 1, 1), ROOT(1, 0, 1),
                                DELTA(8, 2), DELTA(5, 1)),
        },      /* r: 7, 30             d: 5^1, 8^7, 8^7 */
        {
                5, ACTION_PUT, EXPECT_DELTA_DEC, EXPECT_ROOT_DEC,
                EXPECT_STATS(3, ROOT(7, 1, 3), ROOT(30, 1, 1),
                                DELTA(8, 2)),
        },      /* r: 7, 30             d: 8^7, 8^7 */
        {
                5, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_INC,
                EXPECT_STATS(4, ROOT(7, 1, 3), ROOT(30, 1, 1), ROOT(5, 1, 1),
                                DELTA(8, 2)),
        },      /* r: 7, 30, 5          d: 8^7, 8^7 */
        {
                6, ACTION_GET, EXPECT_DELTA_INC, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(7, 1, 3), ROOT(5, 1, 2), ROOT(30, 1, 1),
                                DELTA(8, 2), DELTA(6, 1)),
        },      /* r: 7, 30, 5          d: 8^7, 8^7, 6^5 */
        {
                8, ACTION_GET, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(7, 1, 4), ROOT(5, 1, 2), ROOT(30, 1, 1),
                                DELTA(8, 3), DELTA(6, 1)),
        },      /* r: 7, 30, 5          d: 8^7, 8^7, 8^7, 6^5 */
        {
                8, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(7, 1, 3), ROOT(5, 1, 2), ROOT(30, 1, 1),
                                DELTA(8, 2), DELTA(6, 1)),
        },      /* r: 7, 30, 5          d: 8^7, 8^7, 6^5 */
        {
                8, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(7, 1, 2), ROOT(5, 1, 2), ROOT(30, 1, 1),
                                DELTA(8, 1), DELTA(6, 1)),
        },      /* r: 7, 30, 5          d: 8^7, 6^5 */
        {
                8, ACTION_PUT, EXPECT_DELTA_DEC, EXPECT_ROOT_SAME,
                EXPECT_STATS(4, ROOT(5, 1, 2), ROOT(7, 1, 1), ROOT(30, 1, 1),
                                DELTA(6, 1)),
        },      /* r: 7, 30, 5          d: 6^5 */
        {
                8, ACTION_GET, EXPECT_DELTA_INC, EXPECT_ROOT_SAME,
                EXPECT_STATS(5, ROOT(5, 1, 3), ROOT(7, 1, 1), ROOT(30, 1, 1),
                                DELTA(6, 1), DELTA(8, 1)),
        },      /* r: 7, 30, 5          d: 6^5, 8^5 */
        {
                7, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_DEC,
                EXPECT_STATS(4, ROOT(5, 1, 3), ROOT(30, 1, 1),
                                DELTA(6, 1), DELTA(8, 1)),
        },      /* r: 30, 5             d: 6^5, 8^5 */
        {
                30, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_DEC,
                EXPECT_STATS(3, ROOT(5, 1, 3),
                                DELTA(6, 1), DELTA(8, 1)),
        },      /* r: 5                 d: 6^5, 8^5 */
        {
                5, ACTION_PUT, EXPECT_DELTA_SAME, EXPECT_ROOT_SAME,
                EXPECT_STATS(3, ROOT(5, 0, 2),
                                DELTA(6, 1), DELTA(8, 1)),
        },      /* r:                   d: 6^5, 8^5 */
        {
                6, ACTION_PUT, EXPECT_DELTA_DEC, EXPECT_ROOT_SAME,
                EXPECT_STATS(2, ROOT(5, 0, 1),
                                DELTA(8, 1)),
        },      /* r:                   d: 6^5 */
        {
                8, ACTION_PUT, EXPECT_DELTA_DEC, EXPECT_ROOT_DEC,
                EXPECT_STATS(0, ),
        },      /* r:                   d: */
};

static int check_expect(struct world *world,
                        const struct action_item *action_item,
                        unsigned int orig_delta_count,
                        unsigned int orig_root_count)
{
        unsigned int key_id = action_item->key_id;

        switch (action_item->expect_delta) {
        case EXPECT_DELTA_SAME:
                if (orig_delta_count != world->delta_count) {
                        pr_err("Key %u: Delta count changed while expected to remain the same.\n",
                               key_id);
                        return -EINVAL;
                }
                break;
        case EXPECT_DELTA_INC:
                if (WARN_ON(action_item->action == ACTION_PUT))
                        return -EINVAL;
                if (orig_delta_count + 1 != world->delta_count) {
                        pr_err("Key %u: Delta count was not incremented.\n",
                               key_id);
                        return -EINVAL;
                }
                break;
        case EXPECT_DELTA_DEC:
                if (WARN_ON(action_item->action == ACTION_GET))
                        return -EINVAL;
                if (orig_delta_count - 1 != world->delta_count) {
                        pr_err("Key %u: Delta count was not decremented.\n",
                               key_id);
                        return -EINVAL;
                }
                break;
        }

        switch (action_item->expect_root) {
        case EXPECT_ROOT_SAME:
                if (orig_root_count != world->root_count) {
                        pr_err("Key %u: Root count changed while expected to remain the same.\n",
                               key_id);
                        return -EINVAL;
                }
                break;
        case EXPECT_ROOT_INC:
                if (WARN_ON(action_item->action == ACTION_PUT))
                        return -EINVAL;
                if (orig_root_count + 1 != world->root_count) {
                        pr_err("Key %u: Root count was not incremented.\n",
                               key_id);
                        return -EINVAL;
                }
                break;
        case EXPECT_ROOT_DEC:
                if (WARN_ON(action_item->action == ACTION_GET))
                        return -EINVAL;
                if (orig_root_count - 1 != world->root_count) {
                        pr_err("Key %u: Root count was not decremented.\n",
                               key_id);
                        return -EINVAL;
                }
        }

        return 0;
}

static unsigned int obj_to_key_id(struct objagg_obj *objagg_obj)
{
        const struct tokey *root_key;
        const struct delta *delta;
        unsigned int key_id;

        root_key = objagg_obj_root_priv(objagg_obj);
        key_id = root_key->id;
        delta = objagg_obj_delta_priv(objagg_obj);
        if (delta)
                key_id += delta->key_id_diff;
        return key_id;
}

static int
check_expect_stats_nums(const struct objagg_obj_stats_info *stats_info,
                        const struct expect_stats_info *expect_stats_info,
                        const char **errmsg)
{
        if (stats_info->is_root != expect_stats_info->is_root) {
                if (errmsg)
                        *errmsg = "Incorrect root/delta indication";
                return -EINVAL;
        }
        if (stats_info->stats.user_count !=
            expect_stats_info->stats.user_count) {
                if (errmsg)
                        *errmsg = "Incorrect user count";
                return -EINVAL;
        }
        if (stats_info->stats.delta_user_count !=
            expect_stats_info->stats.delta_user_count) {
                if (errmsg)
                        *errmsg = "Incorrect delta user count";
                return -EINVAL;
        }
        return 0;
}

static int
check_expect_stats_key_id(const struct objagg_obj_stats_info *stats_info,
                          const struct expect_stats_info *expect_stats_info,
                          const char **errmsg)
{
        if (obj_to_key_id(stats_info->objagg_obj) !=
            expect_stats_info->key_id) {
                if (errmsg)
                        *errmsg = "incorrect key id";
                return -EINVAL;
        }
        return 0;
}

static int check_expect_stats_neigh(const struct objagg_stats *stats,
                                    const struct expect_stats *expect_stats,
                                    int pos)
{
        int i;
        int err;

        for (i = pos - 1; i >= 0; i--) {
                err = check_expect_stats_nums(&stats->stats_info[i],
                                              &expect_stats->info[pos], NULL);
                if (err)
                        break;
                err = check_expect_stats_key_id(&stats->stats_info[i],
                                                &expect_stats->info[pos], NULL);
                if (!err)
                        return 0;
        }
        for (i = pos + 1; i < stats->stats_info_count; i++) {
                err = check_expect_stats_nums(&stats->stats_info[i],
                                              &expect_stats->info[pos], NULL);
                if (err)
                        break;
                err = check_expect_stats_key_id(&stats->stats_info[i],
                                                &expect_stats->info[pos], NULL);
                if (!err)
                        return 0;
        }
        return -EINVAL;
}

static int __check_expect_stats(const struct objagg_stats *stats,
                                const struct expect_stats *expect_stats,
                                const char **errmsg)
{
        int i;
        int err;

        if (stats->stats_info_count != expect_stats->info_count) {
                *errmsg = "Unexpected object count";
                return -EINVAL;
        }

        for (i = 0; i < stats->stats_info_count; i++) {
                err = check_expect_stats_nums(&stats->stats_info[i],
                                              &expect_stats->info[i], errmsg);
                if (err)
                        return err;
                err = check_expect_stats_key_id(&stats->stats_info[i],
                                                &expect_stats->info[i], errmsg);
                if (err) {
                        /* It is possible that one of the neighbor stats with
                         * same numbers have the correct key id, so check it
                         */
                        err = check_expect_stats_neigh(stats, expect_stats, i);
                        if (err)
                                return err;
                }
        }
        return 0;
}

static int check_expect_stats(struct objagg *objagg,
                              const struct expect_stats *expect_stats,
                              const char **errmsg)
{
        const struct objagg_stats *stats;
        int err;

        stats = objagg_stats_get(objagg);
        if (IS_ERR(stats)) {
                *errmsg = "objagg_stats_get() failed.";
                return PTR_ERR(stats);
        }
        err = __check_expect_stats(stats, expect_stats, errmsg);
        objagg_stats_put(stats);
        return err;
}

static int test_delta_action_item(struct world *world,
                                  struct objagg *objagg,
                                  const struct action_item *action_item,
                                  bool inverse)
{
        unsigned int orig_delta_count = world->delta_count;
        unsigned int orig_root_count = world->root_count;
        unsigned int key_id = action_item->key_id;
        enum action action = action_item->action;
        struct objagg_obj *objagg_obj;
        const char *errmsg;
        int err;

        if (inverse)
                action = action == ACTION_GET ? ACTION_PUT : ACTION_GET;

        switch (action) {
        case ACTION_GET:
                objagg_obj = world_obj_get(world, objagg, key_id);
                if (IS_ERR(objagg_obj))
                        return PTR_ERR(objagg_obj);
                break;
        case ACTION_PUT:
                world_obj_put(world, objagg, key_id);
                break;
        }

        if (inverse)
                return 0;
        err = check_expect(world, action_item,
                           orig_delta_count, orig_root_count);
        if (err)
                goto errout;

        err = check_expect_stats(objagg, &action_item->expect_stats, &errmsg);
        if (err) {
                pr_err("Key %u: Stats: %s\n", action_item->key_id, errmsg);
                goto errout;
        }

        return 0;

errout:
        /* This can only happen when action is not inversed.
         * So in case of an error, cleanup by doing inverse action.
         */
        test_delta_action_item(world, objagg, action_item, true);
        return err;
}

static int test_delta(void)
{
        struct world world = {};
        struct objagg *objagg;
        int i;
        int err;

        objagg = objagg_create(&delta_ops, NULL, &world);
        if (IS_ERR(objagg))
                return PTR_ERR(objagg);

        for (i = 0; i < ARRAY_SIZE(action_items); i++) {
                err = test_delta_action_item(&world, objagg,
                                             &action_items[i], false);
                if (err)
                        goto err_do_action_item;
        }

        objagg_destroy(objagg);
        return 0;

err_do_action_item:
        for (i--; i >= 0; i--)
                test_delta_action_item(&world, objagg, &action_items[i], true);

        objagg_destroy(objagg);
        return err;
}

struct hints_case {
        const unsigned int *key_ids;
        size_t key_ids_count;
        struct expect_stats expect_stats;
        struct expect_stats expect_stats_hints;
};

static const unsigned int hints_case_key_ids[] = {
        1, 7, 3, 5, 3, 1, 30, 8, 8, 5, 6, 8,
};

static const struct hints_case hints_case = {
        .key_ids = hints_case_key_ids,
        .key_ids_count = ARRAY_SIZE(hints_case_key_ids),
        .expect_stats =
                EXPECT_STATS(7, ROOT(1, 2, 7), ROOT(7, 1, 4), ROOT(30, 1, 1),
                                DELTA(8, 3), DELTA(3, 2),
                                DELTA(5, 2), DELTA(6, 1)),
        .expect_stats_hints =
                EXPECT_STATS(7, ROOT(3, 2, 9), ROOT(1, 2, 2), ROOT(30, 1, 1),
                                DELTA(8, 3), DELTA(5, 2),
                                DELTA(6, 1), DELTA(7, 1)),
};

static void __pr_debug_stats(const struct objagg_stats *stats)
{
        int i;

        for (i = 0; i < stats->stats_info_count; i++)
                pr_debug("Stat index %d key %u: u %d, d %d, %s\n", i,
                         obj_to_key_id(stats->stats_info[i].objagg_obj),
                         stats->stats_info[i].stats.user_count,
                         stats->stats_info[i].stats.delta_user_count,
                         stats->stats_info[i].is_root ? "root" : "noroot");
}

static void pr_debug_stats(struct objagg *objagg)
{
        const struct objagg_stats *stats;

        stats = objagg_stats_get(objagg);
        if (IS_ERR(stats))
                return;
        __pr_debug_stats(stats);
        objagg_stats_put(stats);
}

static void pr_debug_hints_stats(struct objagg_hints *objagg_hints)
{
        const struct objagg_stats *stats;

        stats = objagg_hints_stats_get(objagg_hints);
        if (IS_ERR(stats))
                return;
        __pr_debug_stats(stats);
        objagg_stats_put(stats);
}

static int check_expect_hints_stats(struct objagg_hints *objagg_hints,
                                    const struct expect_stats *expect_stats,
                                    const char **errmsg)
{
        const struct objagg_stats *stats;
        int err;

        stats = objagg_hints_stats_get(objagg_hints);
        if (IS_ERR(stats)) {
                *errmsg = "objagg_hints_stats_get() failed.";
                return PTR_ERR(stats);
        }
        err = __check_expect_stats(stats, expect_stats, errmsg);
        objagg_stats_put(stats);
        return err;
}

static int test_hints_case2(const struct hints_case *hints_case,
                            struct objagg_hints *hints, struct objagg *objagg)
{
        struct objagg_obj *objagg_obj;
        struct world world2 = {};
        struct objagg *objagg2;
        const char *errmsg;
        int i;
        int err;

        pr_debug_hints_stats(hints);
        err = check_expect_hints_stats(hints, &hints_case->expect_stats_hints,
                                       &errmsg);
        if (err) {
                pr_err("Hints stats: %s\n", errmsg);
                return err;
        }

        objagg2 = objagg_create(&delta_ops, hints, &world2);
        if (IS_ERR(objagg2))
                return PTR_ERR(objagg2);

        for (i = 0; i < hints_case->key_ids_count; i++) {
                objagg_obj = world_obj_get(&world2, objagg2,
                                           hints_case->key_ids[i]);
                if (IS_ERR(objagg_obj)) {
                        err = PTR_ERR(objagg_obj);
                        goto err_world2_obj_get;
                }
        }

        pr_debug_stats(objagg2);
        err = check_expect_stats(objagg2, &hints_case->expect_stats_hints,
                                 &errmsg);
        if (err) {
                pr_err("Stats2: %s\n", errmsg);
                goto err_check_expect_stats2;
        }

        err = 0;

err_check_expect_stats2:
err_world2_obj_get:
        for (i--; i >= 0; i--)
                world_obj_put(&world2, objagg, hints_case->key_ids[i]);
        i = hints_case->key_ids_count;
        objagg_destroy(objagg2);

        return err;
}

static int test_hints_case(const struct hints_case *hints_case)
{
        struct objagg_obj *objagg_obj;
        struct objagg_hints *hints;
        struct world world = {};
        struct objagg *objagg;
        const char *errmsg;
        int i;
        int err;

        objagg = objagg_create(&delta_ops, NULL, &world);
        if (IS_ERR(objagg))
                return PTR_ERR(objagg);

        for (i = 0; i < hints_case->key_ids_count; i++) {
                objagg_obj = world_obj_get(&world, objagg,
                                           hints_case->key_ids[i]);
                if (IS_ERR(objagg_obj)) {
                        err = PTR_ERR(objagg_obj);
                        goto err_world_obj_get;
                }
        }

        pr_debug_stats(objagg);
        err = check_expect_stats(objagg, &hints_case->expect_stats, &errmsg);
        if (err) {
                pr_err("Stats: %s\n", errmsg);
                goto err_check_expect_stats;
        }

        hints = objagg_hints_get(objagg, OBJAGG_OPT_ALGO_SIMPLE_GREEDY);
        if (IS_ERR(hints)) {
                err = PTR_ERR(hints);
                goto err_hints_get;
        }

        err = test_hints_case2(hints_case, hints, objagg);

        objagg_hints_put(hints);
err_hints_get:
err_check_expect_stats:
err_world_obj_get:
        for (i--; i >= 0; i--)
                world_obj_put(&world, objagg, hints_case->key_ids[i]);

        objagg_destroy(objagg);
        return err;
}
static int test_hints(void)
{
        return test_hints_case(&hints_case);
}

static int __init test_objagg_init(void)
{
        int err;

        err = test_nodelta();
        if (err)
                return err;
        err = test_delta();
        if (err)
                return err;
        return test_hints();
}

static void __exit test_objagg_exit(void)
{
}

module_init(test_objagg_init);
module_exit(test_objagg_exit);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
MODULE_DESCRIPTION("Test module for objagg");