// SPDX-License-Identifier: GPL-2.0 /* * f2fs extent cache support * * Copyright (c) 2015 Motorola Mobility * Copyright (c) 2015 Samsung Electronics * Authors: Jaegeuk Kim * Chao Yu */ #include #include #include "f2fs.h" #include "node.h" #include 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 simplify 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 = f2fs_kmem_cache_alloc(extent_node_slab, GFP_ATOMIC, false, sbi); 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, true, NULL); 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; if (!et) return false; 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. invalidate 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); } #ifdef CONFIG_F2FS_FS_COMPRESSION void f2fs_update_extent_tree_range_compressed(struct inode *inode, pgoff_t fofs, block_t blkaddr, unsigned int llen, unsigned int c_len) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct extent_tree *et = F2FS_I(inode)->extent_tree; struct extent_node *en = NULL; struct extent_node *prev_en = NULL, *next_en = NULL; struct extent_info ei; struct rb_node **insert_p = NULL, *insert_parent = NULL; bool leftmost = false; trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, llen); /* it is safe here to check FI_NO_EXTENT w/o et->lock in ro image */ if (is_inode_flag_set(inode, FI_NO_EXTENT)) return; write_lock(&et->lock); 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) goto unlock_out; set_extent_info(&ei, fofs, blkaddr, llen); ei.c_len = c_len; if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en)) __insert_extent_tree(sbi, et, &ei, insert_p, insert_parent, leftmost); unlock_out: write_unlock(&et->lock); } #endif 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; write_lock(&et->lock); set_inode_flag(inode, FI_NO_EXTENT); __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); }