Quelle  delayed-refs-tests.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
#include <linux/sizes.h>
#include "btrfs-tests.h"
#include "../transaction.h"
#include "../delayed-ref.h"
#include "../extent-tree.h"

#define FAKE_ROOT_OBJECTID 256
#define FAKE_BYTENR 0
#define FAKE_LEVEL 1
#define FAKE_INO 256
#define FAKE_FILE_OFFSET 0
#define FAKE_PARENT SZ_1M

struct ref_head_check {
 u64 bytenr;
 u64 num_bytes;
 int ref_mod;
 int total_ref_mod;
 int must_insert;
};

struct ref_node_check {
 u64 bytenr;
 u64 num_bytes;
 int ref_mod;
 enum btrfs_delayed_ref_action action;
 u8 type;
 u64 parent;
 u64 root;
 u64 owner;
 u64 offset;
};

static enum btrfs_ref_type ref_type_from_disk_ref_type(u8 type)
{
 if ((type == BTRFS_TREE_BLOCK_REF_KEY) ||
     (type == BTRFS_SHARED_BLOCK_REF_KEY))
  return BTRFS_REF_METADATA;
 return BTRFS_REF_DATA;
}

static void delete_delayed_ref_head(struct btrfs_trans_handle *trans,
        struct btrfs_delayed_ref_head *head)
{
 struct btrfs_fs_info *fs_info = trans->fs_info;
 struct btrfs_delayed_ref_root *delayed_refs =
  &trans->transaction->delayed_refs;

 spin_lock(&delayed_refs->lock);
 spin_lock(&head->lock);
 btrfs_delete_ref_head(fs_info, delayed_refs, head);
 spin_unlock(&head->lock);
 spin_unlock(&delayed_refs->lock);

 btrfs_delayed_ref_unlock(head);
 btrfs_put_delayed_ref_head(head);
}

static void delete_delayed_ref_node(struct btrfs_delayed_ref_head *head,
        struct btrfs_delayed_ref_node *node)
{
 rb_erase_cached(&node->ref_node, &head->ref_tree);
 RB_CLEAR_NODE(&node->ref_node);
 if (!list_empty(&node->add_list))
  list_del_init(&node->add_list);
 btrfs_put_delayed_ref(node);
}

static int validate_ref_head(struct btrfs_delayed_ref_head *head,
        struct ref_head_check *check)
{
 if (head->bytenr != check->bytenr) {
  test_err("invalid bytenr have: %llu want: %llu", head->bytenr,
    check->bytenr);
  return -EINVAL;
 }

 if (head->num_bytes != check->num_bytes) {
  test_err("invalid num_bytes have: %llu want: %llu",
    head->num_bytes, check->num_bytes);
  return -EINVAL;
 }

 if (head->ref_mod != check->ref_mod) {
  test_err("invalid ref_mod have: %d want: %d", head->ref_mod,
    check->ref_mod);
  return -EINVAL;
 }

 if (head->total_ref_mod != check->total_ref_mod) {
  test_err("invalid total_ref_mod have: %d want: %d",
    head->total_ref_mod, check->total_ref_mod);
  return -EINVAL;
 }

 if (head->must_insert_reserved != check->must_insert) {
  test_err("invalid must_insert have: %d want: %d",
    head->must_insert_reserved, check->must_insert);
  return -EINVAL;
 }

 return 0;
}

static int validate_ref_node(struct btrfs_delayed_ref_node *node,
        struct ref_node_check *check)
{
 if (node->bytenr != check->bytenr) {
  test_err("invalid bytenr have: %llu want: %llu", node->bytenr,
    check->bytenr);
  return -EINVAL;
 }

 if (node->num_bytes != check->num_bytes) {
  test_err("invalid num_bytes have: %llu want: %llu",
    node->num_bytes, check->num_bytes);
  return -EINVAL;
 }

 if (node->ref_mod != check->ref_mod) {
  test_err("invalid ref_mod have: %d want: %d", node->ref_mod,
    check->ref_mod);
  return -EINVAL;
 }

 if (node->action != check->action) {
  test_err("invalid action have: %d want: %d", node->action,
    check->action);
  return -EINVAL;
 }

 if (node->parent != check->parent) {
  test_err("invalid parent have: %llu want: %llu", node->parent,
    check->parent);
  return -EINVAL;
 }

 if (node->ref_root != check->root) {
  test_err("invalid root have: %llu want: %llu", node->ref_root,
    check->root);
  return -EINVAL;
 }

 if (node->type != check->type) {
  test_err("invalid type have: %d want: %d", node->type,
    check->type);
  return -EINVAL;
 }

 if (btrfs_delayed_ref_owner(node) != check->owner) {
  test_err("invalid owner have: %llu want: %llu",
    btrfs_delayed_ref_owner(node), check->owner);
  return -EINVAL;
 }

 if (btrfs_delayed_ref_offset(node) != check->offset) {
  test_err("invalid offset have: %llu want: %llu",
    btrfs_delayed_ref_offset(node), check->offset);
  return -EINVAL;
 }

 return 0;
}

static int simple_test(struct btrfs_trans_handle *trans,
         struct ref_head_check *head_check,
         struct ref_node_check *node_check)
{
 struct btrfs_delayed_ref_root *delayed_refs =
  &trans->transaction->delayed_refs;
 struct btrfs_fs_info *fs_info = trans->fs_info;
 struct btrfs_delayed_ref_head *head;
 struct btrfs_delayed_ref_node *node;
 struct btrfs_ref ref = {
  .type = ref_type_from_disk_ref_type(node_check->type),
  .action = node_check->action,
  .parent = node_check->parent,
  .ref_root = node_check->root,
  .bytenr = node_check->bytenr,
  .num_bytes = fs_info->nodesize,
 };
 int ret;

 if (ref.type == BTRFS_REF_METADATA)
  btrfs_init_tree_ref(&ref, node_check->owner, node_check->root,
        false);
 else
  btrfs_init_data_ref(&ref, node_check->owner, node_check->offset,
        node_check->root, true);

 if (ref.type == BTRFS_REF_METADATA)
  ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 else
  ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
 if (ret) {
  test_err("failed ref action %d", ret);
  return ret;
 }

 head = btrfs_select_ref_head(fs_info, delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  return -EINVAL;
 }

 ret = -EINVAL;
 if (validate_ref_head(head, head_check))
  goto out;

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 if (validate_ref_node(node, node_check))
  goto out;
 ret = 0;
out:
 btrfs_unselect_ref_head(delayed_refs, head);
 btrfs_destroy_delayed_refs(trans->transaction);
 return ret;
}

/*
 * These are simple tests, make sure that our btrfs_ref's get turned into the
 * appropriate btrfs_delayed_ref_node based on their settings and action.
 */
static int simple_tests(struct btrfs_trans_handle *trans)
{
 struct btrfs_fs_info *fs_info = trans->fs_info;
 struct ref_head_check head_check = {
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
  .ref_mod = 1,
  .total_ref_mod = 1,
 };
 struct ref_node_check node_check = {
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
  .ref_mod = 1,
  .action = BTRFS_ADD_DELAYED_REF,
  .type = BTRFS_TREE_BLOCK_REF_KEY,
  .parent = 0,
  .root = FAKE_ROOT_OBJECTID,
  .owner = FAKE_LEVEL,
  .offset = 0,
 };

 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single add tree block failed");
  return -EINVAL;
 }

 node_check.type = BTRFS_EXTENT_DATA_REF_KEY;
 node_check.owner = FAKE_INO;
 node_check.offset = FAKE_FILE_OFFSET;

 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single add extent data failed");
  return -EINVAL;
 }

 node_check.parent = FAKE_PARENT;
 node_check.type = BTRFS_SHARED_BLOCK_REF_KEY;
 node_check.owner = FAKE_LEVEL;
 node_check.offset = 0;

 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single add shared block failed");
  return -EINVAL;
 }

 node_check.type = BTRFS_SHARED_DATA_REF_KEY;
 node_check.owner = FAKE_INO;
 node_check.offset = FAKE_FILE_OFFSET;

 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single add shared data failed");
  return -EINVAL;
 }

 head_check.ref_mod = -1;
 head_check.total_ref_mod = -1;
 node_check.action = BTRFS_DROP_DELAYED_REF;
 node_check.type = BTRFS_TREE_BLOCK_REF_KEY;
 node_check.owner = FAKE_LEVEL;
 node_check.offset = 0;
 node_check.parent = 0;

 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single drop tree block failed");
  return -EINVAL;
 }

 node_check.type = BTRFS_EXTENT_DATA_REF_KEY;
 node_check.owner = FAKE_INO;
 node_check.offset = FAKE_FILE_OFFSET;

 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single drop extent data failed");
  return -EINVAL;
 }

 node_check.parent = FAKE_PARENT;
 node_check.type = BTRFS_SHARED_BLOCK_REF_KEY;
 node_check.owner = FAKE_LEVEL;
 node_check.offset = 0;
 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single drop shared block failed");
  return -EINVAL;
 }

 node_check.type = BTRFS_SHARED_DATA_REF_KEY;
 node_check.owner = FAKE_INO;
 node_check.offset = FAKE_FILE_OFFSET;
 if (simple_test(trans, &head_check, &node_check)) {
  test_err("single drop shared data failed");
  return -EINVAL;
 }

 return 0;
}

/*
 * Merge tests, validate that we do delayed ref merging properly, the ref counts
 * all end up properly, and delayed refs are deleted once they're no longer
 * needed.
 */
static int merge_tests(struct btrfs_trans_handle *trans,
         enum btrfs_ref_type type)
{
 struct btrfs_fs_info *fs_info = trans->fs_info;
 struct btrfs_delayed_ref_head *head = NULL;
 struct btrfs_delayed_ref_node *node;
 struct btrfs_ref ref = {
  .type = type,
  .action = BTRFS_ADD_DELAYED_REF,
  .parent = 0,
  .ref_root = FAKE_ROOT_OBJECTID,
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
 };
 struct ref_head_check head_check = {
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
  .ref_mod = 0,
  .total_ref_mod = 0,
 };
 struct ref_node_check node_check = {
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
  .ref_mod = 2,
  .action = BTRFS_ADD_DELAYED_REF,
  .parent = 0,
  .root = FAKE_ROOT_OBJECTID,
 };
 int ret;

 /*
 * First add a ref and then drop it, make sure we get a head ref with a
 * 0 total ref mod and no nodes.
 */
 if (type == BTRFS_REF_METADATA) {
  node_check.type = BTRFS_TREE_BLOCK_REF_KEY;
  node_check.owner = FAKE_LEVEL;
  btrfs_init_tree_ref(&ref, FAKE_LEVEL, FAKE_ROOT_OBJECTID, false);
 } else {
  node_check.type = BTRFS_EXTENT_DATA_REF_KEY;
  node_check.owner = FAKE_INO;
  node_check.offset = FAKE_FILE_OFFSET;
  btrfs_init_data_ref(&ref, FAKE_INO, FAKE_FILE_OFFSET,
        FAKE_ROOT_OBJECTID, true);
 }

 if (type == BTRFS_REF_METADATA)
  ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 else
  ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
 if (ret) {
  test_err("failed ref action %d", ret);
  return ret;
 }

 ref.action = BTRFS_DROP_DELAYED_REF;
 if (type == BTRFS_REF_METADATA)
  ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 else
  ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  goto out;
 }

 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("single add and drop failed");
  goto out;
 }

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (node) {
  test_err("found node when none should exist");
  goto out;
 }

 delete_delayed_ref_head(trans, head);
 head = NULL;

 /*
 * Add a ref, then add another ref, make sure we get a head ref with a
 * 2 total ref mod and 1 node.
 */
 ref.action = BTRFS_ADD_DELAYED_REF;
 if (type == BTRFS_REF_METADATA)
  ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 else
  ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 if (type == BTRFS_REF_METADATA)
  ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 else
  ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  goto out;
 }

 head_check.ref_mod = 2;
 head_check.total_ref_mod = 2;
 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("double add failed");
  goto out;
 }

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }

 delete_delayed_ref_node(head, node);

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (node) {
  test_err("found node when none should exist");
  goto out;
 }
 delete_delayed_ref_head(trans, head);
 head = NULL;

 /* Add two drop refs, make sure they are merged properly. */
 ref.action = BTRFS_DROP_DELAYED_REF;
 if (type == BTRFS_REF_METADATA)
  ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 else
  ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 if (type == BTRFS_REF_METADATA)
  ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 else
  ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  goto out;
 }

 head_check.ref_mod = -2;
 head_check.total_ref_mod = -2;
 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("double drop failed");
  goto out;
 }

 node_check.action = BTRFS_DROP_DELAYED_REF;
 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }

 delete_delayed_ref_node(head, node);

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (node) {
  test_err("found node when none should exist");
  goto out;
 }
 delete_delayed_ref_head(trans, head);
 head = NULL;

 /* Add multiple refs, then drop until we go negative again. */
 ref.action = BTRFS_ADD_DELAYED_REF;
 for (int i = 0; i < 10; i++) {
  if (type == BTRFS_REF_METADATA)
   ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
  else
   ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
  if (ret) {
   test_err("failed ref action %d", ret);
   goto out;
  }
 }

 ref.action = BTRFS_DROP_DELAYED_REF;
 for (int i = 0; i < 12; i++) {
  if (type == BTRFS_REF_METADATA)
   ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
  else
   ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
  if (ret) {
   test_err("failed ref action %d", ret);
   goto out;
  }
 }

 head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  ret = -EINVAL;
  goto out;
 }

 head_check.ref_mod = -2;
 head_check.total_ref_mod = -2;
 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("double drop failed");
  goto out;
 }

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }

 delete_delayed_ref_node(head, node);

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (node) {
  test_err("found node when none should exist");
  goto out;
 }

 delete_delayed_ref_head(trans, head);
 head = NULL;

 /* Drop multiple refs, then add until we go positive again. */
 ref.action = BTRFS_DROP_DELAYED_REF;
 for (int i = 0; i < 10; i++) {
  if (type == BTRFS_REF_METADATA)
   ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
  else
   ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
  if (ret) {
   test_err("failed ref action %d", ret);
   goto out;
  }
 }

 ref.action = BTRFS_ADD_DELAYED_REF;
 for (int i = 0; i < 12; i++) {
  if (type == BTRFS_REF_METADATA)
   ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
  else
   ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
  if (ret) {
   test_err("failed ref action %d", ret);
   goto out;
  }
 }

 head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  ret = -EINVAL;
  goto out;
 }

 head_check.ref_mod = 2;
 head_check.total_ref_mod = 2;
 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("add and drop to positive failed");
  goto out;
 }

 node_check.action = BTRFS_ADD_DELAYED_REF;
 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }

 delete_delayed_ref_node(head, node);

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (node) {
  test_err("found node when none should exist");
  goto out;
 }
 delete_delayed_ref_head(trans, head);
 head = NULL;

 /*
 * Add a bunch of refs with different roots and parents, then drop them
 * all, make sure everything is properly merged.
 */
 ref.action = BTRFS_ADD_DELAYED_REF;
 for (int i = 0; i < 50; i++) {
  if (!(i % 2)) {
   ref.parent = 0;
   ref.ref_root = FAKE_ROOT_OBJECTID + i;
  } else {
   ref.parent = FAKE_PARENT + (i * fs_info->nodesize);
  }
  if (type == BTRFS_REF_METADATA)
   ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
  else
   ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
  if (ret) {
   test_err("failed ref action %d", ret);
   goto out;
  }
 }

 ref.action = BTRFS_DROP_DELAYED_REF;
 for (int i = 0; i < 50; i++) {
  if (!(i % 2)) {
   ref.parent = 0;
   ref.ref_root = FAKE_ROOT_OBJECTID + i;
  } else {
   ref.parent = FAKE_PARENT + (i * fs_info->nodesize);
  }
  if (type == BTRFS_REF_METADATA)
   ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
  else
   ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
  if (ret) {
   test_err("failed ref action %d", ret);
   goto out;
  }
 }

 head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  ret = -EINVAL;
  goto out;
 }

 head_check.ref_mod = 0;
 head_check.total_ref_mod = 0;
 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("add and drop multiple failed");
  goto out;
 }

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (node) {
  test_err("found node when none should exist");
  goto out;
 }
 ret = 0;
out:
 if (!IS_ERR_OR_NULL(head))
  btrfs_unselect_ref_head(&trans->transaction->delayed_refs, head);
 btrfs_destroy_delayed_refs(trans->transaction);
 return ret;
}

/*
 * Basic test to validate we always get the add operations first followed by any
 * delete operations.
 */
static int select_delayed_refs_test(struct btrfs_trans_handle *trans)
{
 struct btrfs_delayed_ref_root *delayed_refs =
  &trans->transaction->delayed_refs;
 struct btrfs_fs_info *fs_info = trans->fs_info;
 struct btrfs_delayed_ref_head *head = NULL;
 struct btrfs_delayed_ref_node *node;
 struct btrfs_ref ref = {
  .type = BTRFS_REF_METADATA,
  .action = BTRFS_DROP_DELAYED_REF,
  .parent = 0,
  .ref_root = FAKE_ROOT_OBJECTID,
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
 };
 struct ref_head_check head_check = {
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
  .ref_mod = 0,
  .total_ref_mod = 0,
 };
 struct ref_node_check node_check = {
  .bytenr = FAKE_BYTENR,
  .num_bytes = fs_info->nodesize,
  .ref_mod = 1,
  .action = BTRFS_ADD_DELAYED_REF,
  .type = BTRFS_TREE_BLOCK_REF_KEY,
  .parent = 0,
  .owner = FAKE_LEVEL,
  .offset = 0,
 };
 int ret;

 /* Add the drop first. */
 btrfs_init_tree_ref(&ref, FAKE_LEVEL, FAKE_ROOT_OBJECTID, false);
 ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 if (ret) {
  test_err("failed ref action %d", ret);
  return ret;
 }

 /*
 * Now add the add, and make it a different root so it's logically later
 * in the rb tree.
 */
 ref.action = BTRFS_ADD_DELAYED_REF;
 ref.ref_root = FAKE_ROOT_OBJECTID + 1;
 ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 head = btrfs_select_ref_head(fs_info, delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  ret = -EINVAL;
  head = NULL;
  goto out;
 }

 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("head check failed");
  goto out;
 }

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 node_check.root = FAKE_ROOT_OBJECTID + 1;
 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }
 delete_delayed_ref_node(head, node);

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 node_check.action = BTRFS_DROP_DELAYED_REF;
 node_check.root = FAKE_ROOT_OBJECTID;
 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }
 delete_delayed_ref_node(head, node);
 delete_delayed_ref_head(trans, head);
 head = NULL;

 /*
 * Now we're going to do the same thing, but we're going to have an add
 * that gets deleted because of a merge, and make sure we still have
 * another add in place.
 */
 ref.action = BTRFS_DROP_DELAYED_REF;
 ref.ref_root = FAKE_ROOT_OBJECTID;
 ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 ref.action = BTRFS_ADD_DELAYED_REF;
 ref.ref_root = FAKE_ROOT_OBJECTID + 1;
 ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 ref.action = BTRFS_DROP_DELAYED_REF;
 ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 ref.action = BTRFS_ADD_DELAYED_REF;
 ref.ref_root = FAKE_ROOT_OBJECTID + 2;
 ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
 if (ret) {
  test_err("failed ref action %d", ret);
  goto out;
 }

 head = btrfs_select_ref_head(fs_info, delayed_refs);
 if (IS_ERR_OR_NULL(head)) {
  if (IS_ERR(head))
   test_err("failed to select delayed ref head: %ld",
     PTR_ERR(head));
  else
   test_err("failed to find delayed ref head");
  ret = -EINVAL;
  head = NULL;
  goto out;
 }

 ret = -EINVAL;
 if (validate_ref_head(head, &head_check)) {
  test_err("head check failed");
  goto out;
 }

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 node_check.action = BTRFS_ADD_DELAYED_REF;
 node_check.root = FAKE_ROOT_OBJECTID + 2;
 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }
 delete_delayed_ref_node(head, node);

 spin_lock(&head->lock);
 node = btrfs_select_delayed_ref(head);
 spin_unlock(&head->lock);
 if (!node) {
  test_err("failed to select delayed ref");
  goto out;
 }

 node_check.action = BTRFS_DROP_DELAYED_REF;
 node_check.root = FAKE_ROOT_OBJECTID;
 if (validate_ref_node(node, &node_check)) {
  test_err("node check failed");
  goto out;
 }
 delete_delayed_ref_node(head, node);
 ret = 0;
out:
 if (head)
  btrfs_unselect_ref_head(delayed_refs, head);
 btrfs_destroy_delayed_refs(trans->transaction);
 return ret;
}

int btrfs_test_delayed_refs(u32 sectorsize, u32 nodesize)
{
 struct btrfs_transaction *transaction;
 struct btrfs_trans_handle trans;
 struct btrfs_fs_info *fs_info;
 int ret;

 test_msg("running delayed refs tests");

 fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
 if (!fs_info) {
  test_std_err(TEST_ALLOC_FS_INFO);
  return -ENOMEM;
 }
 transaction = kmalloc(sizeof(*transaction), GFP_KERNEL);
 if (!transaction) {
  test_std_err(TEST_ALLOC_TRANSACTION);
  ret = -ENOMEM;
  goto out_free_fs_info;
 }
 btrfs_init_dummy_trans(&trans, fs_info);
 btrfs_init_dummy_transaction(transaction, fs_info);
 trans.transaction = transaction;

 ret = simple_tests(&trans);
 if (!ret) {
  test_msg("running delayed refs merg tests on metadata refs");
  ret = merge_tests(&trans, BTRFS_REF_METADATA);
 }

 if (!ret) {
  test_msg("running delayed refs merg tests on data refs");
  ret = merge_tests(&trans, BTRFS_REF_DATA);
 }

 if (!ret)
  ret = select_delayed_refs_test(&trans);

 kfree(transaction);
out_free_fs_info:
 btrfs_free_dummy_fs_info(fs_info);
 return ret;
}