// SPDX-License-Identifier: GPL-2.0
/*
 * f2fs extent cache support
 *
 * Copyright (c) 2015 Motorola Mobility
 * Copyright (c) 2015 Samsung Electronics
 * Authors: Jaegeuk Kim <jaegeuk@kernel.org>
 *          Chao Yu <chao2.yu@samsung.com>
 */

#include <linux/fs.h>
#include <linux/f2fs_fs.h>

#include "f2fs.h"
#include "node.h"
#include <trace/events/f2fs.h>

static struct rb_entry *__lookup_rb_tree_fast(struct rb_entry *cached_re,
                                                        unsigned int ofs)
{
        if (cached_re) {
                if (cached_re->ofs <= ofs &&
                                cached_re->ofs + cached_re->len > ofs) {
                        return cached_re;
                }
        }
        return NULL;
}

static struct rb_entry *__lookup_rb_tree_slow(struct rb_root_cached *root,
                                                        unsigned int ofs)
{
        struct rb_node *node = root->rb_root.rb_node;
        struct rb_entry *re;

        while (node) {
                re = rb_entry(node, struct rb_entry, rb_node);

                if (ofs < re->ofs)
                        node = node->rb_left;
                else if (ofs >= re->ofs + re->len)
                        node = node->rb_right;
                else
                        return re;
        }
        return NULL;
}

struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root,
                                struct rb_entry *cached_re, unsigned int ofs)
{
        struct rb_entry *re;

        re = __lookup_rb_tree_fast(cached_re, ofs);
        if (!re)
                return __lookup_rb_tree_slow(root, ofs);

        return re;
}

struct rb_node **f2fs_lookup_rb_tree_ext(struct f2fs_sb_info *sbi,
                                        struct rb_root_cached *root,
                                        struct rb_node **parent,
                                        unsigned long long key, bool *leftmost)
{
        struct rb_node **p = &root->rb_root.rb_node;
        struct rb_entry *re;

        while (*p) {
                *parent = *p;
                re = rb_entry(*parent, struct rb_entry, rb_node);

                if (key < re->key) {
                        p = &(*p)->rb_left;
                } else {
                        p = &(*p)->rb_right;
                        *leftmost = false;
                }
        }

        return p;
}

struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
                                struct rb_root_cached *root,
                                struct rb_node **parent,
                                unsigned int ofs, bool *leftmost)
{
        struct rb_node **p = &root->rb_root.rb_node;
        struct rb_entry *re;

        while (*p) {
                *parent = *p;
                re = rb_entry(*parent, struct rb_entry, rb_node);

                if (ofs < re->ofs) {
                        p = &(*p)->rb_left;
                } else if (ofs >= re->ofs + re->len) {
                        p = &(*p)->rb_right;
                        *leftmost = false;
                } else {
                        f2fs_bug_on(sbi, 1);
                }
        }

        return p;
}

/*
 * lookup rb entry in position of @ofs in rb-tree,
 * if hit, return the entry, otherwise, return NULL
 * @prev_ex: extent before ofs
 * @next_ex: extent after ofs
 * @insert_p: insert point for new extent at ofs
 * in order to simpfy the insertion after.
 * tree must stay unchanged between lookup and insertion.
 */
struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root,
                                struct rb_entry *cached_re,
                                unsigned int ofs,
                                struct rb_entry **prev_entry,
                                struct rb_entry **next_entry,
                                struct rb_node ***insert_p,
                                struct rb_node **insert_parent,
                                bool force, bool *leftmost)
{
        struct rb_node **pnode = &root->rb_root.rb_node;
        struct rb_node *parent = NULL, *tmp_node;
        struct rb_entry *re = cached_re;

        *insert_p = NULL;
        *insert_parent = NULL;
        *prev_entry = NULL;
        *next_entry = NULL;

        if (RB_EMPTY_ROOT(&root->rb_root))
                return NULL;

        if (re) {
                if (re->ofs <= ofs && re->ofs + re->len > ofs)
                        goto lookup_neighbors;
        }

        if (leftmost)
                *leftmost = true;

        while (*pnode) {
                parent = *pnode;
                re = rb_entry(*pnode, struct rb_entry, rb_node);

                if (ofs < re->ofs) {
                        pnode = &(*pnode)->rb_left;
                } else if (ofs >= re->ofs + re->len) {
                        pnode = &(*pnode)->rb_right;
                        if (leftmost)
                                *leftmost = false;
                } else {
                        goto lookup_neighbors;
                }
        }

        *insert_p = pnode;
        *insert_parent = parent;

        re = rb_entry(parent, struct rb_entry, rb_node);
        tmp_node = parent;
        if (parent && ofs > re->ofs)
                tmp_node = rb_next(parent);
        *next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);

        tmp_node = parent;
        if (parent && ofs < re->ofs)
                tmp_node = rb_prev(parent);
        *prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
        return NULL;

lookup_neighbors:
        if (ofs == re->ofs || force) {
                /* lookup prev node for merging backward later */
                tmp_node = rb_prev(&re->rb_node);
                *prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
        }
        if (ofs == re->ofs + re->len - 1 || force) {
                /* lookup next node for merging frontward later */
                tmp_node = rb_next(&re->rb_node);
                *next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
        }
        return re;
}

bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
                                struct rb_root_cached *root, bool check_key)
{
#ifdef CONFIG_F2FS_CHECK_FS
        struct rb_node *cur = rb_first_cached(root), *next;
        struct rb_entry *cur_re, *next_re;

        if (!cur)
                return true;

        while (cur) {
                next = rb_next(cur);
                if (!next)
                        return true;

                cur_re = rb_entry(cur, struct rb_entry, rb_node);
                next_re = rb_entry(next, struct rb_entry, rb_node);

                if (check_key) {
                        if (cur_re->key > next_re->key) {
                                f2fs_info(sbi, "inconsistent rbtree, "
                                        "cur(%llu) next(%llu)",
                                        cur_re->key, next_re->key);
                                return false;
                        }
                        goto next;
                }

                if (cur_re->ofs + cur_re->len > next_re->ofs) {
                        f2fs_info(sbi, "inconsistent rbtree, cur(%u, %u) next(%u, %u)",
                                  cur_re->ofs, cur_re->len,
                                  next_re->ofs, next_re->len);
                        return false;
                }
next:
                cur = next;
        }
#endif
        return true;
}

static struct kmem_cache *extent_tree_slab;
static struct kmem_cache *extent_node_slab;

static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
                                struct extent_tree *et, struct extent_info *ei,
                                struct rb_node *parent, struct rb_node **p,
                                bool leftmost)
{
        struct extent_node *en;

        en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
        if (!en)
                return NULL;

        en->ei = *ei;
        INIT_LIST_HEAD(&en->list);
        en->et = et;

        rb_link_node(&en->rb_node, parent, p);
        rb_insert_color_cached(&en->rb_node, &et->root, leftmost);
        atomic_inc(&et->node_cnt);
        atomic_inc(&sbi->total_ext_node);
        return en;
}

static void __detach_extent_node(struct f2fs_sb_info *sbi,
                                struct extent_tree *et, struct extent_node *en)
{
        rb_erase_cached(&en->rb_node, &et->root);
        atomic_dec(&et->node_cnt);
        atomic_dec(&sbi->total_ext_node);

        if (et->cached_en == en)
                et->cached_en = NULL;
        kmem_cache_free(extent_node_slab, en);
}

/*
 * Flow to release an extent_node:
 * 1. list_del_init
 * 2. __detach_extent_node
 * 3. kmem_cache_free.
 */
static void __release_extent_node(struct f2fs_sb_info *sbi,
                        struct extent_tree *et, struct extent_node *en)
{
        spin_lock(&sbi->extent_lock);
        f2fs_bug_on(sbi, list_empty(&en->list));
        list_del_init(&en->list);
        spin_unlock(&sbi->extent_lock);

        __detach_extent_node(sbi, et, en);
}

static struct extent_tree *__grab_extent_tree(struct inode *inode)
{
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct extent_tree *et;
        nid_t ino = inode->i_ino;

        mutex_lock(&sbi->extent_tree_lock);
        et = radix_tree_lookup(&sbi->extent_tree_root, ino);
        if (!et) {
                et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
                f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
                memset(et, 0, sizeof(struct extent_tree));
                et->ino = ino;
                et->root = RB_ROOT_CACHED;
                et->cached_en = NULL;
                rwlock_init(&et->lock);
                INIT_LIST_HEAD(&et->list);
                atomic_set(&et->node_cnt, 0);
                atomic_inc(&sbi->total_ext_tree);
        } else {
                atomic_dec(&sbi->total_zombie_tree);
                list_del_init(&et->list);
        }
        mutex_unlock(&sbi->extent_tree_lock);

        /* never died until evict_inode */
        F2FS_I(inode)->extent_tree = et;

        return et;
}

static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
                                struct extent_tree *et, struct extent_info *ei)
{
        struct rb_node **p = &et->root.rb_root.rb_node;
        struct extent_node *en;

        en = __attach_extent_node(sbi, et, ei, NULL, p, true);
        if (!en)
                return NULL;

        et->largest = en->ei;
        et->cached_en = en;
        return en;
}

static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
                                        struct extent_tree *et)
{
        struct rb_node *node, *next;
        struct extent_node *en;
        unsigned int count = atomic_read(&et->node_cnt);

        node = rb_first_cached(&et->root);
        while (node) {
                next = rb_next(node);
                en = rb_entry(node, struct extent_node, rb_node);
                __release_extent_node(sbi, et, en);
                node = next;
        }

        return count - atomic_read(&et->node_cnt);
}

static void __drop_largest_extent(struct extent_tree *et,
                                        pgoff_t fofs, unsigned int len)
{
        if (fofs < et->largest.fofs + et->largest.len &&
                        fofs + len > et->largest.fofs) {
                et->largest.len = 0;
                et->largest_updated = true;
        }
}

/* return true, if inode page is changed */
static void __f2fs_init_extent_tree(struct inode *inode, struct page *ipage)
{
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct f2fs_extent *i_ext = ipage ? &F2FS_INODE(ipage)->i_ext : NULL;
        struct extent_tree *et;
        struct extent_node *en;
        struct extent_info ei;

        if (!f2fs_may_extent_tree(inode)) {
                /* drop largest extent */
                if (i_ext && i_ext->len) {
                        f2fs_wait_on_page_writeback(ipage, NODE, true, true);
                        i_ext->len = 0;
                        set_page_dirty(ipage);
                        return;
                }
                return;
        }

        et = __grab_extent_tree(inode);

        if (!i_ext || !i_ext->len)
                return;

        get_extent_info(&ei, i_ext);

        write_lock(&et->lock);
        if (atomic_read(&et->node_cnt))
                goto out;

        en = __init_extent_tree(sbi, et, &ei);
        if (en) {
                spin_lock(&sbi->extent_lock);
                list_add_tail(&en->list, &sbi->extent_list);
                spin_unlock(&sbi->extent_lock);
        }
out:
        write_unlock(&et->lock);
}

void f2fs_init_extent_tree(struct inode *inode, struct page *ipage)
{
        __f2fs_init_extent_tree(inode, ipage);

        if (!F2FS_I(inode)->extent_tree)
                set_inode_flag(inode, FI_NO_EXTENT);
}

static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
                                                        struct extent_info *ei)
{
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct extent_tree *et = F2FS_I(inode)->extent_tree;
        struct extent_node *en;
        bool ret = false;

        f2fs_bug_on(sbi, !et);

        trace_f2fs_lookup_extent_tree_start(inode, pgofs);

        read_lock(&et->lock);

        if (et->largest.fofs <= pgofs &&
                        et->largest.fofs + et->largest.len > pgofs) {
                *ei = et->largest;
                ret = true;
                stat_inc_largest_node_hit(sbi);
                goto out;
        }

        en = (struct extent_node *)f2fs_lookup_rb_tree(&et->root,
                                (struct rb_entry *)et->cached_en, pgofs);
        if (!en)
                goto out;

        if (en == et->cached_en)
                stat_inc_cached_node_hit(sbi);
        else
                stat_inc_rbtree_node_hit(sbi);

        *ei = en->ei;
        spin_lock(&sbi->extent_lock);
        if (!list_empty(&en->list)) {
                list_move_tail(&en->list, &sbi->extent_list);
                et->cached_en = en;
        }
        spin_unlock(&sbi->extent_lock);
        ret = true;
out:
        stat_inc_total_hit(sbi);
        read_unlock(&et->lock);

        trace_f2fs_lookup_extent_tree_end(inode, pgofs, ei);
        return ret;
}

static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
                                struct extent_tree *et, struct extent_info *ei,
                                struct extent_node *prev_ex,
                                struct extent_node *next_ex)
{
        struct extent_node *en = NULL;

        if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
                prev_ex->ei.len += ei->len;
                ei = &prev_ex->ei;
                en = prev_ex;
        }

        if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
                next_ex->ei.fofs = ei->fofs;
                next_ex->ei.blk = ei->blk;
                next_ex->ei.len += ei->len;
                if (en)
                        __release_extent_node(sbi, et, prev_ex);

                en = next_ex;
        }

        if (!en)
                return NULL;

        __try_update_largest_extent(et, en);

        spin_lock(&sbi->extent_lock);
        if (!list_empty(&en->list)) {
                list_move_tail(&en->list, &sbi->extent_list);
                et->cached_en = en;
        }
        spin_unlock(&sbi->extent_lock);
        return en;
}

static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
                                struct extent_tree *et, struct extent_info *ei,
                                struct rb_node **insert_p,
                                struct rb_node *insert_parent,
                                bool leftmost)
{
        struct rb_node **p;
        struct rb_node *parent = NULL;
        struct extent_node *en = NULL;

        if (insert_p && insert_parent) {
                parent = insert_parent;
                p = insert_p;
                goto do_insert;
        }

        leftmost = true;

        p = f2fs_lookup_rb_tree_for_insert(sbi, &et->root, &parent,
                                                ei->fofs, &leftmost);
do_insert:
        en = __attach_extent_node(sbi, et, ei, parent, p, leftmost);
        if (!en)
                return NULL;

        __try_update_largest_extent(et, en);

        /* update in global extent list */
        spin_lock(&sbi->extent_lock);
        list_add_tail(&en->list, &sbi->extent_list);
        et->cached_en = en;
        spin_unlock(&sbi->extent_lock);
        return en;
}

static void f2fs_update_extent_tree_range(struct inode *inode,
                                pgoff_t fofs, block_t blkaddr, unsigned int len)
{
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct extent_tree *et = F2FS_I(inode)->extent_tree;
        struct extent_node *en = NULL, *en1 = NULL;
        struct extent_node *prev_en = NULL, *next_en = NULL;
        struct extent_info ei, dei, prev;
        struct rb_node **insert_p = NULL, *insert_parent = NULL;
        unsigned int end = fofs + len;
        unsigned int pos = (unsigned int)fofs;
        bool updated = false;
        bool leftmost = false;

        if (!et)
                return;

        trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, len);

        write_lock(&et->lock);

        if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
                write_unlock(&et->lock);
                return;
        }

        prev = et->largest;
        dei.len = 0;

        /*
         * drop largest extent before lookup, in case it's already
         * been shrunk from extent tree
         */
        __drop_largest_extent(et, fofs, len);

        /* 1. lookup first extent node in range [fofs, fofs + len - 1] */
        en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
                                        (struct rb_entry *)et->cached_en, fofs,
                                        (struct rb_entry **)&prev_en,
                                        (struct rb_entry **)&next_en,
                                        &insert_p, &insert_parent, false,
                                        &leftmost);
        if (!en)
                en = next_en;

        /* 2. invlidate all extent nodes in range [fofs, fofs + len - 1] */
        while (en && en->ei.fofs < end) {
                unsigned int org_end;
                int parts = 0;  /* # of parts current extent split into */

                next_en = en1 = NULL;

                dei = en->ei;
                org_end = dei.fofs + dei.len;
                f2fs_bug_on(sbi, pos >= org_end);

                if (pos > dei.fofs &&   pos - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
                        en->ei.len = pos - en->ei.fofs;
                        prev_en = en;
                        parts = 1;
                }

                if (end < org_end && org_end - end >= F2FS_MIN_EXTENT_LEN) {
                        if (parts) {
                                set_extent_info(&ei, end,
                                                end - dei.fofs + dei.blk,
                                                org_end - end);
                                en1 = __insert_extent_tree(sbi, et, &ei,
                                                        NULL, NULL, true);
                                next_en = en1;
                        } else {
                                en->ei.fofs = end;
                                en->ei.blk += end - dei.fofs;
                                en->ei.len -= end - dei.fofs;
                                next_en = en;
                        }
                        parts++;
                }

                if (!next_en) {
                        struct rb_node *node = rb_next(&en->rb_node);

                        next_en = rb_entry_safe(node, struct extent_node,
                                                rb_node);
                }

                if (parts)
                        __try_update_largest_extent(et, en);
                else
                        __release_extent_node(sbi, et, en);

                /*
                 * if original extent is split into zero or two parts, extent
                 * tree has been altered by deletion or insertion, therefore
                 * invalidate pointers regard to tree.
                 */
                if (parts != 1) {
                        insert_p = NULL;
                        insert_parent = NULL;
                }
                en = next_en;
        }

        /* 3. update extent in extent cache */
        if (blkaddr) {

                set_extent_info(&ei, fofs, blkaddr, len);
                if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
                        __insert_extent_tree(sbi, et, &ei,
                                        insert_p, insert_parent, leftmost);

                /* give up extent_cache, if split and small updates happen */
                if (dei.len >= 1 &&
                                prev.len < F2FS_MIN_EXTENT_LEN &&
                                et->largest.len < F2FS_MIN_EXTENT_LEN) {
                        et->largest.len = 0;
                        et->largest_updated = true;
                        set_inode_flag(inode, FI_NO_EXTENT);
                }
        }

        if (is_inode_flag_set(inode, FI_NO_EXTENT))
                __free_extent_tree(sbi, et);

        if (et->largest_updated) {
                et->largest_updated = false;
                updated = true;
        }

        write_unlock(&et->lock);

        if (updated)
                f2fs_mark_inode_dirty_sync(inode, true);
}

unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
{
        struct extent_tree *et, *next;
        struct extent_node *en;
        unsigned int node_cnt = 0, tree_cnt = 0;
        int remained;

        if (!test_opt(sbi, EXTENT_CACHE))
                return 0;

        if (!atomic_read(&sbi->total_zombie_tree))
                goto free_node;

        if (!mutex_trylock(&sbi->extent_tree_lock))
                goto out;

        /* 1. remove unreferenced extent tree */
        list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
                if (atomic_read(&et->node_cnt)) {
                        write_lock(&et->lock);
                        node_cnt += __free_extent_tree(sbi, et);
                        write_unlock(&et->lock);
                }
                f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
                list_del_init(&et->list);
                radix_tree_delete(&sbi->extent_tree_root, et->ino);
                kmem_cache_free(extent_tree_slab, et);
                atomic_dec(&sbi->total_ext_tree);
                atomic_dec(&sbi->total_zombie_tree);
                tree_cnt++;

                if (node_cnt + tree_cnt >= nr_shrink)
                        goto unlock_out;
                cond_resched();
        }
        mutex_unlock(&sbi->extent_tree_lock);

free_node:
        /* 2. remove LRU extent entries */
        if (!mutex_trylock(&sbi->extent_tree_lock))
                goto out;

        remained = nr_shrink - (node_cnt + tree_cnt);

        spin_lock(&sbi->extent_lock);
        for (; remained > 0; remained--) {
                if (list_empty(&sbi->extent_list))
                        break;
                en = list_first_entry(&sbi->extent_list,
                                        struct extent_node, list);
                et = en->et;
                if (!write_trylock(&et->lock)) {
                        /* refresh this extent node's position in extent list */
                        list_move_tail(&en->list, &sbi->extent_list);
                        continue;
                }

                list_del_init(&en->list);
                spin_unlock(&sbi->extent_lock);

                __detach_extent_node(sbi, et, en);

                write_unlock(&et->lock);
                node_cnt++;
                spin_lock(&sbi->extent_lock);
        }
        spin_unlock(&sbi->extent_lock);

unlock_out:
        mutex_unlock(&sbi->extent_tree_lock);
out:
        trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);

        return node_cnt + tree_cnt;
}

unsigned int f2fs_destroy_extent_node(struct inode *inode)
{
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct extent_tree *et = F2FS_I(inode)->extent_tree;
        unsigned int node_cnt = 0;

        if (!et || !atomic_read(&et->node_cnt))
                return 0;

        write_lock(&et->lock);
        node_cnt = __free_extent_tree(sbi, et);
        write_unlock(&et->lock);

        return node_cnt;
}

void f2fs_drop_extent_tree(struct inode *inode)
{
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct extent_tree *et = F2FS_I(inode)->extent_tree;
        bool updated = false;

        if (!f2fs_may_extent_tree(inode))
                return;

        set_inode_flag(inode, FI_NO_EXTENT);

        write_lock(&et->lock);
        __free_extent_tree(sbi, et);
        if (et->largest.len) {
                et->largest.len = 0;
                updated = true;
        }
        write_unlock(&et->lock);
        if (updated)
                f2fs_mark_inode_dirty_sync(inode, true);
}

void f2fs_destroy_extent_tree(struct inode *inode)
{
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct extent_tree *et = F2FS_I(inode)->extent_tree;
        unsigned int node_cnt = 0;

        if (!et)
                return;

        if (inode->i_nlink && !is_bad_inode(inode) &&
                                        atomic_read(&et->node_cnt)) {
                mutex_lock(&sbi->extent_tree_lock);
                list_add_tail(&et->list, &sbi->zombie_list);
                atomic_inc(&sbi->total_zombie_tree);
                mutex_unlock(&sbi->extent_tree_lock);
                return;
        }

        /* free all extent info belong to this extent tree */
        node_cnt = f2fs_destroy_extent_node(inode);

        /* delete extent tree entry in radix tree */
        mutex_lock(&sbi->extent_tree_lock);
        f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
        radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
        kmem_cache_free(extent_tree_slab, et);
        atomic_dec(&sbi->total_ext_tree);
        mutex_unlock(&sbi->extent_tree_lock);

        F2FS_I(inode)->extent_tree = NULL;

        trace_f2fs_destroy_extent_tree(inode, node_cnt);
}

bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
                                        struct extent_info *ei)
{
        if (!f2fs_may_extent_tree(inode))
                return false;

        return f2fs_lookup_extent_tree(inode, pgofs, ei);
}

void f2fs_update_extent_cache(struct dnode_of_data *dn)
{
        pgoff_t fofs;
        block_t blkaddr;

        if (!f2fs_may_extent_tree(dn->inode))
                return;

        if (dn->data_blkaddr == NEW_ADDR)
                blkaddr = NULL_ADDR;
        else
                blkaddr = dn->data_blkaddr;

        fofs = f2fs_start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
                                                                dn->ofs_in_node;
        f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, 1);
}

void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
                                pgoff_t fofs, block_t blkaddr, unsigned int len)

{
        if (!f2fs_may_extent_tree(dn->inode))
                return;

        f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, len);
}

void f2fs_init_extent_cache_info(struct f2fs_sb_info *sbi)
{
        INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
        mutex_init(&sbi->extent_tree_lock);
        INIT_LIST_HEAD(&sbi->extent_list);
        spin_lock_init(&sbi->extent_lock);
        atomic_set(&sbi->total_ext_tree, 0);
        INIT_LIST_HEAD(&sbi->zombie_list);
        atomic_set(&sbi->total_zombie_tree, 0);
        atomic_set(&sbi->total_ext_node, 0);
}

int __init f2fs_create_extent_cache(void)
{
        extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
                        sizeof(struct extent_tree));
        if (!extent_tree_slab)
                return -ENOMEM;
        extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
                        sizeof(struct extent_node));
        if (!extent_node_slab) {
                kmem_cache_destroy(extent_tree_slab);
                return -ENOMEM;
        }
        return 0;
}

void f2fs_destroy_extent_cache(void)
{
        kmem_cache_destroy(extent_node_slab);
        kmem_cache_destroy(extent_tree_slab);
}