// 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;

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