/* * 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> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/fs.h> #include <linux/f2fs_fs.h> #include "f2fs.h" #include "node.h" #include <trace/events/f2fs.h> 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) { 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(&en->rb_node, &et->root); 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(&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; down_write(&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; 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); } up_write(&sbi->extent_tree_lock); /* never died until evict_inode */ F2FS_I(inode)->extent_tree = et; return et; } static struct extent_node *__lookup_extent_tree(struct f2fs_sb_info *sbi, struct extent_tree *et, unsigned int fofs) { struct rb_node *node = et->root.rb_node; struct extent_node *en = et->cached_en; if (en) { struct extent_info *cei = &en->ei; if (cei->fofs <= fofs && cei->fofs + cei->len > fofs) { stat_inc_cached_node_hit(sbi); return en; } } while (node) { en = rb_entry(node, struct extent_node, rb_node); if (fofs < en->ei.fofs) { node = node->rb_left; } else if (fofs >= en->ei.fofs + en->ei.len) { node = node->rb_right; } else { stat_inc_rbtree_node_hit(sbi); return en; } } return NULL; } 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_node; struct extent_node *en; en = __attach_extent_node(sbi, et, ei, NULL, p); 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(&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 inode *inode, pgoff_t fofs, unsigned int len) { struct extent_info *largest = &F2FS_I(inode)->extent_tree->largest; if (fofs < largest->fofs + largest->len && fofs + len > largest->fofs) { largest->len = 0; f2fs_mark_inode_dirty_sync(inode); } } /* return true, if inode page is changed */ bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 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) { i_ext->len = 0; return true; } return false; } et = __grab_extent_tree(inode); if (!i_ext || !i_ext->len) return false; 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); return false; } 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 = __lookup_extent_tree(sbi, et, pgofs); if (en) { *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; } /* * lookup extent at @fofs, if hit, return the extent * if not, return NULL and * @prev_ex: extent before fofs * @next_ex: extent after fofs * @insert_p: insert point for new extent at fofs * in order to simpfy the insertion after. * tree must stay unchanged between lookup and insertion. */ static struct extent_node *__lookup_extent_tree_ret(struct extent_tree *et, unsigned int fofs, struct extent_node **prev_ex, struct extent_node **next_ex, struct rb_node ***insert_p, struct rb_node **insert_parent) { struct rb_node **pnode = &et->root.rb_node; struct rb_node *parent = NULL, *tmp_node; struct extent_node *en = et->cached_en; *insert_p = NULL; *insert_parent = NULL; *prev_ex = NULL; *next_ex = NULL; if (RB_EMPTY_ROOT(&et->root)) return NULL; if (en) { struct extent_info *cei = &en->ei; if (cei->fofs <= fofs && cei->fofs + cei->len > fofs) goto lookup_neighbors; } while (*pnode) { parent = *pnode; en = rb_entry(*pnode, struct extent_node, rb_node); if (fofs < en->ei.fofs) pnode = &(*pnode)->rb_left; else if (fofs >= en->ei.fofs + en->ei.len) pnode = &(*pnode)->rb_right; else goto lookup_neighbors; } *insert_p = pnode; *insert_parent = parent; en = rb_entry(parent, struct extent_node, rb_node); tmp_node = parent; if (parent && fofs > en->ei.fofs) tmp_node = rb_next(parent); *next_ex = tmp_node ? rb_entry(tmp_node, struct extent_node, rb_node) : NULL; tmp_node = parent; if (parent && fofs < en->ei.fofs) tmp_node = rb_prev(parent); *prev_ex = tmp_node ? rb_entry(tmp_node, struct extent_node, rb_node) : NULL; return NULL; lookup_neighbors: if (fofs == en->ei.fofs) { /* lookup prev node for merging backward later */ tmp_node = rb_prev(&en->rb_node); *prev_ex = tmp_node ? rb_entry(tmp_node, struct extent_node, rb_node) : NULL; } if (fofs == en->ei.fofs + en->ei.len - 1) { /* lookup next node for merging frontward later */ tmp_node = rb_next(&en->rb_node); *next_ex = tmp_node ? rb_entry(tmp_node, struct extent_node, rb_node) : NULL; } return en; } static struct extent_node *__try_merge_extent_node(struct inode *inode, struct extent_tree *et, struct extent_info *ei, struct extent_node *prev_ex, struct extent_node *next_ex) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 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)) { if (en) __release_extent_node(sbi, et, prev_ex); next_ex->ei.fofs = ei->fofs; next_ex->ei.blk = ei->blk; next_ex->ei.len += ei->len; en = next_ex; } if (!en) return NULL; __try_update_largest_extent(inode, 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 inode *inode, struct extent_tree *et, struct extent_info *ei, struct rb_node **insert_p, struct rb_node *insert_parent) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct rb_node **p = &et->root.rb_node; struct rb_node *parent = NULL; struct extent_node *en = NULL; if (insert_p && insert_parent) { parent = insert_parent; p = insert_p; goto do_insert; } while (*p) { parent = *p; en = rb_entry(parent, struct extent_node, rb_node); if (ei->fofs < en->ei.fofs) p = &(*p)->rb_left; else if (ei->fofs >= en->ei.fofs + en->ei.len) p = &(*p)->rb_right; else f2fs_bug_on(sbi, 1); } do_insert: en = __attach_extent_node(sbi, et, ei, parent, p); if (!en) return NULL; __try_update_largest_extent(inode, 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 unsigned int 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; if (!et) return false; 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 false; } prev = et->largest; dei.len = 0; /* * drop largest extent before lookup, in case it's already * been shrunk from extent tree */ __drop_largest_extent(inode, fofs, len); /* 1. lookup first extent node in range [fofs, fofs + len - 1] */ en = __lookup_extent_tree_ret(et, fofs, &prev_en, &next_en, &insert_p, &insert_parent); 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(inode, et, &ei, NULL, NULL); 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 = node ? rb_entry(node, struct extent_node, rb_node) : NULL; } if (parts) __try_update_largest_extent(inode, 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(inode, et, &ei, prev_en, next_en)) __insert_extent_tree(inode, et, &ei, insert_p, insert_parent); /* 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) { __drop_largest_extent(inode, 0, UINT_MAX); set_inode_flag(inode, FI_NO_EXTENT); } } if (is_inode_flag_set(inode, FI_NO_EXTENT)) __free_extent_tree(sbi, et); write_unlock(&et->lock); return !__is_extent_same(&prev, &et->largest); } 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 (!down_write_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(); } up_write(&sbi->extent_tree_lock); free_node: /* 2. remove LRU extent entries */ if (!down_write_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: up_write(&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; set_inode_flag(inode, FI_NO_EXTENT); write_lock(&et->lock); __free_extent_tree(sbi, et); __drop_largest_extent(inode, 0, UINT_MAX); write_unlock(&et->lock); } 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)) { down_write(&sbi->extent_tree_lock); list_add_tail(&et->list, &sbi->zombie_list); atomic_inc(&sbi->total_zombie_tree); up_write(&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 */ down_write(&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); up_write(&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 = 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 init_extent_cache_info(struct f2fs_sb_info *sbi) { INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO); init_rwsem(&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 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 destroy_extent_cache(void) { kmem_cache_destroy(extent_node_slab); kmem_cache_destroy(extent_tree_slab); }