f2fs: extract rb-tree operation infrastructure
rb-tree lookup/update functions are deeply coupled into extent cache codes, it's very hard to reuse these basic functions, this patch extracts common rb-tree operation infrastructure for latter reusing. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu
Jaegeuk Kim
parent
8fd5a37efa
commit
54c2258cd6
@ -18,6 +18,146 @@
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#include "node.h"
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#include <trace/events/f2fs.h>
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static struct rb_entry *__lookup_rb_tree_fast(struct rb_entry *cached_re,
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unsigned int ofs)
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{
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if (cached_re) {
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if (cached_re->ofs <= ofs &&
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cached_re->ofs + cached_re->len > ofs) {
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return cached_re;
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}
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}
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return NULL;
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}
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static struct rb_entry *__lookup_rb_tree_slow(struct rb_root *root,
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unsigned int ofs)
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{
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struct rb_node *node = root->rb_node;
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struct rb_entry *re;
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while (node) {
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re = rb_entry(node, struct rb_entry, rb_node);
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if (ofs < re->ofs)
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node = node->rb_left;
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else if (ofs >= re->ofs + re->len)
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node = node->rb_right;
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else
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return re;
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}
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return NULL;
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}
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static struct rb_entry *__lookup_rb_tree(struct rb_root *root,
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struct rb_entry *cached_re, unsigned int ofs)
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{
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struct rb_entry *re;
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re = __lookup_rb_tree_fast(cached_re, ofs);
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if (!re)
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return __lookup_rb_tree_slow(root, ofs);
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return re;
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}
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static struct rb_node **__lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
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struct rb_root *root, struct rb_node **parent,
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unsigned int ofs)
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{
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struct rb_node **p = &root->rb_node;
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struct rb_entry *re;
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while (*p) {
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*parent = *p;
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re = rb_entry(*parent, struct rb_entry, rb_node);
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if (ofs < re->ofs)
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p = &(*p)->rb_left;
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else if (ofs >= re->ofs + re->len)
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p = &(*p)->rb_right;
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else
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f2fs_bug_on(sbi, 1);
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}
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return p;
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}
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/*
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* lookup rb entry in position of @ofs in rb-tree,
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* if hit, return the entry, otherwise, return NULL
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* @prev_ex: extent before ofs
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* @next_ex: extent after ofs
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* @insert_p: insert point for new extent at ofs
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* in order to simpfy the insertion after.
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* tree must stay unchanged between lookup and insertion.
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*/
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static struct rb_entry *__lookup_rb_tree_ret(struct rb_root *root,
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struct rb_entry *cached_re,
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unsigned int ofs,
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struct rb_entry **prev_entry,
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struct rb_entry **next_entry,
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struct rb_node ***insert_p,
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struct rb_node **insert_parent)
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{
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struct rb_node **pnode = &root->rb_node;
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struct rb_node *parent = NULL, *tmp_node;
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struct rb_entry *re = cached_re;
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*insert_p = NULL;
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*insert_parent = NULL;
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*prev_entry = NULL;
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*next_entry = NULL;
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if (RB_EMPTY_ROOT(root))
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return NULL;
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if (re) {
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if (re->ofs <= ofs && re->ofs + re->len > ofs)
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goto lookup_neighbors;
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}
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while (*pnode) {
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parent = *pnode;
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re = rb_entry(*pnode, struct rb_entry, rb_node);
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if (ofs < re->ofs)
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pnode = &(*pnode)->rb_left;
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else if (ofs >= re->ofs + re->len)
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pnode = &(*pnode)->rb_right;
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else
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goto lookup_neighbors;
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}
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*insert_p = pnode;
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*insert_parent = parent;
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re = rb_entry(parent, struct rb_entry, rb_node);
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tmp_node = parent;
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if (parent && ofs > re->ofs)
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tmp_node = rb_next(parent);
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*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
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tmp_node = parent;
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if (parent && ofs < re->ofs)
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tmp_node = rb_prev(parent);
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*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
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return NULL;
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lookup_neighbors:
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if (ofs == re->ofs) {
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/* lookup prev node for merging backward later */
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tmp_node = rb_prev(&re->rb_node);
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*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
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}
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if (ofs == re->ofs + re->len - 1) {
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/* lookup next node for merging frontward later */
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tmp_node = rb_next(&re->rb_node);
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*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
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}
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return re;
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}
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static struct kmem_cache *extent_tree_slab;
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static struct kmem_cache *extent_node_slab;
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@ -102,36 +242,6 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode)
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return et;
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}
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static struct extent_node *__lookup_extent_tree(struct f2fs_sb_info *sbi,
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struct extent_tree *et, unsigned int fofs)
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{
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struct rb_node *node = et->root.rb_node;
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struct extent_node *en = et->cached_en;
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if (en) {
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struct extent_info *cei = &en->ei;
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if (cei->fofs <= fofs && cei->fofs + cei->len > fofs) {
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stat_inc_cached_node_hit(sbi);
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return en;
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}
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}
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while (node) {
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en = rb_entry(node, struct extent_node, rb_node);
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if (fofs < en->ei.fofs) {
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node = node->rb_left;
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} else if (fofs >= en->ei.fofs + en->ei.len) {
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node = node->rb_right;
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} else {
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stat_inc_rbtree_node_hit(sbi);
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return en;
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}
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}
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return NULL;
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}
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static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
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struct extent_tree *et, struct extent_info *ei)
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{
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@ -237,17 +347,24 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
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goto out;
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}
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en = __lookup_extent_tree(sbi, et, pgofs);
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if (en) {
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*ei = en->ei;
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spin_lock(&sbi->extent_lock);
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if (!list_empty(&en->list)) {
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list_move_tail(&en->list, &sbi->extent_list);
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et->cached_en = en;
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}
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spin_unlock(&sbi->extent_lock);
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ret = true;
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en = (struct extent_node *)__lookup_rb_tree(&et->root,
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(struct rb_entry *)et->cached_en, pgofs);
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if (!en)
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goto out;
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if (en == et->cached_en)
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stat_inc_cached_node_hit(sbi);
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else
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stat_inc_rbtree_node_hit(sbi);
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*ei = en->ei;
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spin_lock(&sbi->extent_lock);
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if (!list_empty(&en->list)) {
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list_move_tail(&en->list, &sbi->extent_list);
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et->cached_en = en;
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}
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spin_unlock(&sbi->extent_lock);
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ret = true;
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out:
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stat_inc_total_hit(sbi);
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read_unlock(&et->lock);
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@ -256,83 +373,6 @@ out:
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return ret;
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}
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/*
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* lookup extent at @fofs, if hit, return the extent
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* if not, return NULL and
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* @prev_ex: extent before fofs
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* @next_ex: extent after fofs
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* @insert_p: insert point for new extent at fofs
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* in order to simpfy the insertion after.
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* tree must stay unchanged between lookup and insertion.
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*/
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static struct extent_node *__lookup_extent_tree_ret(struct extent_tree *et,
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unsigned int fofs,
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struct extent_node **prev_ex,
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struct extent_node **next_ex,
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struct rb_node ***insert_p,
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struct rb_node **insert_parent)
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{
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struct rb_node **pnode = &et->root.rb_node;
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struct rb_node *parent = NULL, *tmp_node;
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struct extent_node *en = et->cached_en;
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*insert_p = NULL;
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*insert_parent = NULL;
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*prev_ex = NULL;
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*next_ex = NULL;
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if (RB_EMPTY_ROOT(&et->root))
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return NULL;
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if (en) {
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struct extent_info *cei = &en->ei;
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if (cei->fofs <= fofs && cei->fofs + cei->len > fofs)
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goto lookup_neighbors;
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}
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while (*pnode) {
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parent = *pnode;
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en = rb_entry(*pnode, struct extent_node, rb_node);
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if (fofs < en->ei.fofs)
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pnode = &(*pnode)->rb_left;
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else if (fofs >= en->ei.fofs + en->ei.len)
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pnode = &(*pnode)->rb_right;
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else
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goto lookup_neighbors;
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}
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*insert_p = pnode;
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*insert_parent = parent;
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en = rb_entry(parent, struct extent_node, rb_node);
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tmp_node = parent;
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if (parent && fofs > en->ei.fofs)
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tmp_node = rb_next(parent);
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*next_ex = rb_entry_safe(tmp_node, struct extent_node, rb_node);
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tmp_node = parent;
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if (parent && fofs < en->ei.fofs)
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tmp_node = rb_prev(parent);
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*prev_ex = rb_entry_safe(tmp_node, struct extent_node, rb_node);
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return NULL;
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lookup_neighbors:
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if (fofs == en->ei.fofs) {
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/* lookup prev node for merging backward later */
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tmp_node = rb_prev(&en->rb_node);
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*prev_ex = rb_entry_safe(tmp_node, struct extent_node, rb_node);
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}
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if (fofs == en->ei.fofs + en->ei.len - 1) {
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/* lookup next node for merging frontward later */
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tmp_node = rb_next(&en->rb_node);
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*next_ex = rb_entry_safe(tmp_node, struct extent_node, rb_node);
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}
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return en;
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}
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static struct extent_node *__try_merge_extent_node(struct inode *inode,
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struct extent_tree *et, struct extent_info *ei,
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struct extent_node *prev_ex,
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@ -387,17 +427,7 @@ static struct extent_node *__insert_extent_tree(struct inode *inode,
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goto do_insert;
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}
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while (*p) {
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parent = *p;
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en = rb_entry(parent, struct extent_node, rb_node);
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if (ei->fofs < en->ei.fofs)
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p = &(*p)->rb_left;
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else if (ei->fofs >= en->ei.fofs + en->ei.len)
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p = &(*p)->rb_right;
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else
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f2fs_bug_on(sbi, 1);
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}
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p = __lookup_rb_tree_for_insert(sbi, &et->root, &parent, ei->fofs);
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do_insert:
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en = __attach_extent_node(sbi, et, ei, parent, p);
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if (!en)
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@ -447,7 +477,10 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
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__drop_largest_extent(inode, fofs, len);
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/* 1. lookup first extent node in range [fofs, fofs + len - 1] */
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en = __lookup_extent_tree_ret(et, fofs, &prev_en, &next_en,
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en = (struct extent_node *)__lookup_rb_tree_ret(&et->root,
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(struct rb_entry *)et->cached_en, fofs,
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(struct rb_entry **)&prev_en,
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(struct rb_entry **)&next_en,
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&insert_p, &insert_parent);
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if (!en)
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en = next_en;
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@ -377,16 +377,30 @@ enum {
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/* number of extent info in extent cache we try to shrink */
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#define EXTENT_CACHE_SHRINK_NUMBER 128
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struct rb_entry {
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struct rb_node rb_node; /* rb node located in rb-tree */
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unsigned int ofs; /* start offset of the entry */
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unsigned int len; /* length of the entry */
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};
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struct extent_info {
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unsigned int fofs; /* start offset in a file */
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u32 blk; /* start block address of the extent */
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unsigned int len; /* length of the extent */
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u32 blk; /* start block address of the extent */
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};
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struct extent_node {
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struct rb_node rb_node; /* rb node located in rb-tree */
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struct rb_node rb_node;
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union {
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struct {
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unsigned int fofs;
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unsigned int len;
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u32 blk;
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};
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struct extent_info ei; /* extent info */
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};
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struct list_head list; /* node in global extent list of sbi */
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struct extent_info ei; /* extent info */
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struct extent_tree *et; /* extent tree pointer */
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};
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