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Stop using radix trees to record pending allocations

master
Chris Mason 2007-10-15 16:25:04 -04:00 committed by David Woodhouse
parent f12d799856
commit 08c66b7738
8 changed files with 822 additions and 97 deletions
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2
Makefile
View File

@ -2,7 +2,7 @@ CC=gcc
CFLAGS = -g -Wall -fno-strict-aliasing -Werror
objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
root-tree.o dir-item.o hash.o file-item.o inode-item.o \
inode-map.o crc32c.o\
inode-map.o crc32c.o rbtree.o pending-extent.o \
#
CHECKFLAGS=-D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise \
-Wuninitialized -Wshadow -Wundef

9
ctree.h
View File

@ -21,6 +21,7 @@
#include "list.h"
#include "kerncompat.h"
#include "pending-extent.h"
struct btrfs_trans_handle;
@ -280,11 +281,12 @@ struct btrfs_fs_info {
struct btrfs_root *fs_root;
struct btrfs_root *extent_root;
struct btrfs_root *tree_root;
struct btrfs_key current_insert;
struct btrfs_key last_insert;
struct radix_tree_root cache_radix;
struct radix_tree_root pinned_radix;
struct radix_tree_root block_group_radix;
struct pending_tree pending_tree;
struct pending_tree pinned_tree;
struct pending_tree del_pending;
struct list_head trans;
struct list_head cache;
u64 last_inode_alloc;
@ -298,8 +300,7 @@ struct btrfs_fs_info {
/*
* in ram representation of the tree. extent_root is used for all allocations
* and for the extent tree extent_root root. current_insert is used
* only for the extent tree.
* and for the extent tree extent_root root.
*/
struct btrfs_root {
struct btrfs_buffer *node;

5
disk-io.c
View File

@ -343,10 +343,12 @@ struct btrfs_root *open_ctree_fd(int fp, struct btrfs_super_block *super)
int ret;
INIT_RADIX_TREE(&fs_info->cache_radix, GFP_KERNEL);
INIT_RADIX_TREE(&fs_info->pinned_radix, GFP_KERNEL);
INIT_RADIX_TREE(&fs_info->block_group_radix, GFP_KERNEL);
INIT_LIST_HEAD(&fs_info->trans);
INIT_LIST_HEAD(&fs_info->cache);
pending_tree_init(&fs_info->pending_tree);
pending_tree_init(&fs_info->pinned_tree);
pending_tree_init(&fs_info->del_pending);
fs_info->cache_size = 0;
fs_info->fp = fp;
fs_info->running_transaction = NULL;
@ -356,7 +358,6 @@ struct btrfs_root *open_ctree_fd(int fp, struct btrfs_super_block *super)
fs_info->last_inode_alloc = 0;
fs_info->last_inode_alloc_dirid = 0;
fs_info->disk_super = super;
memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
ret = pread(fp, super, sizeof(struct btrfs_super_block),

151
extent-tree.c
View File

@ -25,9 +25,6 @@
#include "print-tree.h"
#include "transaction.h"
static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
*orig_root, u64 num_blocks, u64 search_start, u64
search_end, struct btrfs_key *ins);
static int finish_current_insert(struct btrfs_trans_handle *trans, struct
btrfs_root *extent_root);
static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
@ -40,7 +37,6 @@ static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
* other allocations are done. The pending tag is also used in the same
* manner for deletes.
*/
#define CTREE_EXTENT_PENDING_DEL 0
static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 blocknr)
@ -50,11 +46,8 @@ static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
struct btrfs_key key;
struct btrfs_leaf *l;
struct btrfs_extent_item *item;
struct btrfs_key ins;
u32 refs;
find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1,
&ins);
btrfs_init_path(&path);
key.objectid = blocknr;
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
@ -126,11 +119,7 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
int pending_ret;
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_block_group_item *bi;
struct btrfs_key ins;
ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
if (ret)
return ret;
ret = btrfs_search_slot(trans, root->fs_info->extent_root,
&cache->key, path, 0, 1);
BUG_ON(ret);
@ -220,23 +209,18 @@ static int update_block_group(struct btrfs_trans_handle *trans,
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct
btrfs_root *root)
{
unsigned long gang[8];
u64 first = 0;
int ret;
int i;
struct pending_extent *pe;
struct pending_extent *next;
while(1) {
ret = radix_tree_gang_lookup(&root->fs_info->pinned_radix,
(void *)gang, 0,
ARRAY_SIZE(gang));
if (!ret)
break;
if (!first)
first = gang[0];
for (i = 0; i < ret; i++) {
radix_tree_delete(&root->fs_info->pinned_radix,
gang[i]);
}
pe = find_first_pending_extent(&root->fs_info->pinned_tree, 0);
if (pe)
first = pe->start;
while(pe) {
next = next_pending_extent(pe);
remove_pending_extent(&root->fs_info->pinned_tree, pe);
free_pending_extent(pe);
pe = next;
}
root->fs_info->last_insert.objectid = first;
root->fs_info->last_insert.offset = 0;
@ -248,19 +232,31 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
{
struct btrfs_key ins;
struct btrfs_extent_item extent_item;
int i;
int ret;
u64 super_blocks_used, root_blocks_used;
struct btrfs_fs_info *info = extent_root->fs_info;
struct pending_extent *pe;
struct pending_extent *next;
struct pending_tree *pending_tree = &info->pending_tree;
btrfs_set_extent_refs(&extent_item, 1);
btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid);
ins.offset = 1;
btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
pe = find_first_pending_extent(pending_tree, 0);
while(pe) {
ins.offset = pe->size;
ins.objectid = pe->start;
remove_pending_extent(pending_tree, pe);
next = next_pending_extent(pe);
if (!next)
next = find_first_pending_extent(pending_tree, 0);
free_pending_extent(pe);
pe = next;
for (i = 0; i < extent_root->fs_info->current_insert.type; i++) {
ins.objectid = extent_root->fs_info->current_insert.objectid +
i;
super_blocks_used = btrfs_super_blocks_used(info->disk_super);
btrfs_set_super_blocks_used(info->disk_super,
super_blocks_used + 1);
@ -274,7 +270,6 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
}
BUG_ON(ret);
}
extent_root->fs_info->current_insert.offset = 0;
return 0;
}
@ -290,7 +285,6 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
struct btrfs_root *extent_root = info->extent_root;
int ret;
struct btrfs_extent_item *ei;
struct btrfs_key ins;
u32 refs;
BUG_ON(pin && num_blocks != 1);
@ -298,7 +292,6 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
key.offset = num_blocks;
find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
btrfs_init_path(&path);
ret = btrfs_search_slot(trans, extent_root, &key, &path, -1, 1);
if (ret) {
@ -316,12 +309,9 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
u64 super_blocks_used, root_blocks_used;
if (pin) {
int err;
unsigned long bl = blocknr;
radix_tree_preload(GFP_KERNEL);
err = radix_tree_insert(&info->pinned_radix,
blocknr, (void *)bl);
err = insert_pending_extent(&info->pinned_tree,
blocknr, 1);
BUG_ON(err);
radix_tree_preload_end();
}
super_blocks_used = btrfs_super_blocks_used(info->disk_super);
btrfs_set_super_blocks_used(info->disk_super,
@ -352,25 +342,21 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
btrfs_root *extent_root)
{
int ret;
struct btrfs_buffer *gang[4];
int i;
struct pending_extent *pe;
struct pending_extent *next;
struct pending_tree *del_pending = &extent_root->fs_info->del_pending;
while(1) {
ret = radix_tree_gang_lookup_tag(
&extent_root->fs_info->cache_radix,
(void *)gang, 0,
ARRAY_SIZE(gang),
CTREE_EXTENT_PENDING_DEL);
if (!ret)
break;
for (i = 0; i < ret; i++) {
ret = __free_extent(trans, extent_root,
gang[i]->blocknr, 1, 1);
radix_tree_tag_clear(&extent_root->fs_info->cache_radix,
gang[i]->blocknr,
CTREE_EXTENT_PENDING_DEL);
btrfs_block_release(extent_root, gang[i]);
}
pe = find_first_pending_extent(del_pending, 0);
while(pe) {
remove_pending_extent(del_pending, pe);
ret = __free_extent(trans, extent_root,
pe->start, 1, 1);
BUG_ON(ret);
next = next_pending_extent(pe);
if (!next)
next = find_first_pending_extent(del_pending, 0);
free_pending_extent(pe);
pe = next;
}
return 0;
}
@ -378,9 +364,7 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
static int run_pending(struct btrfs_trans_handle *trans, struct btrfs_root
*extent_root)
{
while(radix_tree_tagged(&extent_root->fs_info->cache_radix,
CTREE_EXTENT_PENDING_DEL))
del_pending_extents(trans, extent_root);
del_pending_extents(trans, extent_root);
return 0;
}
@ -392,14 +376,13 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
*root, u64 blocknr, u64 num_blocks, int pin)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_buffer *t;
int pending_ret;
int ret;
if (root == extent_root) {
t = find_tree_block(root, blocknr);
radix_tree_tag_set(&root->fs_info->cache_radix, blocknr,
CTREE_EXTENT_PENDING_DEL);
ret = insert_pending_extent(&root->fs_info->del_pending,
blocknr, num_blocks);
BUG_ON(ret);
return 0;
}
ret = __free_extent(trans, root, blocknr, num_blocks, pin);
@ -425,13 +408,11 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
u64 hole_size = 0;
int slot = 0;
u64 last_block = 0;
u64 test_block;
int start_found;
struct btrfs_leaf *l;
struct btrfs_root * root = orig_root->fs_info->extent_root;
int total_needed = num_blocks;
total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3;
if (root->fs_info->last_insert.objectid > search_start)
search_start = root->fs_info->last_insert.objectid;
@ -496,18 +477,16 @@ check_pending:
*/
btrfs_release_path(root, &path);
BUG_ON(ins->objectid < search_start);
for (test_block = ins->objectid;
test_block < ins->objectid + total_needed; test_block++) {
if (radix_tree_lookup(&root->fs_info->pinned_radix,
test_block)) {
search_start = test_block + 1;
goto check_failed;
}
if (find_pending_extent(&root->fs_info->pinned_tree,
ins->objectid, total_needed)) {
search_start = ins->objectid + total_needed;
goto check_failed;
}
if (find_pending_extent(&root->fs_info->pending_tree,
ins->objectid, total_needed)) {
search_start = ins->objectid + total_needed;
goto check_failed;
}
BUG_ON(root->fs_info->current_insert.offset);
root->fs_info->current_insert.offset = total_needed - num_blocks;
root->fs_info->current_insert.objectid = ins->objectid + num_blocks;
root->fs_info->current_insert.type = 0;
root->fs_info->last_insert.objectid = ins->objectid;
ins->offset = num_blocks;
return 0;
@ -537,21 +516,17 @@ static int alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root
btrfs_set_extent_refs(&extent_item, 1);
btrfs_set_extent_owner(&extent_item, owner);
if (root == extent_root) {
BUG_ON(extent_root->fs_info->current_insert.offset == 0);
BUG_ON(num_blocks != 1);
BUG_ON(extent_root->fs_info->current_insert.type ==
extent_root->fs_info->current_insert.offset);
ins->offset = 1;
ins->objectid = extent_root->fs_info->current_insert.objectid +
extent_root->fs_info->current_insert.type++;
return 0;
}
ret = find_free_extent(trans, root, num_blocks, search_start,
search_end, ins);
if (ret)
return ret;
if (root == extent_root) {
ret = insert_pending_extent(&root->fs_info->pending_tree,
ins->objectid, ins->offset);
BUG_ON(ret);
return 0;
}
super_blocks_used = btrfs_super_blocks_used(info->disk_super);
btrfs_set_super_blocks_used(info->disk_super, super_blocks_used +
num_blocks);
@ -803,14 +778,10 @@ int btrfs_insert_block_group(struct btrfs_trans_handle *trans,
struct btrfs_key *key,
struct btrfs_block_group_item *bi)
{
struct btrfs_key ins;
int ret;
int pending_ret;
root = root->fs_info->extent_root;
ret = find_free_extent(trans, root, 0, 0, (u64)-1, &ins);
if (ret)
return ret;
ret = btrfs_insert_item(trans, root, key, bi, sizeof(*bi));
finish_current_insert(trans, root);
pending_ret = run_pending(trans, root);

152
pending-extent.c 100644
View File

@ -0,0 +1,152 @@
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include "kerncompat.h"
#include "pending-extent.h"
void pending_tree_init(struct pending_tree *tree)
{
tree->root.rb_node = NULL;
}
static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
u64 size, struct rb_node *node)
{
struct rb_node ** p = &root->rb_node;
struct rb_node * parent = NULL;
struct pending_extent *entry;
while(*p) {
parent = *p;
entry = rb_entry(parent, struct pending_extent, rb_node);
if (offset + size <= entry->start)
p = &(*p)->rb_left;
else if (offset >= entry->start + entry->size)
p = &(*p)->rb_right;
else
return parent;
}
entry = rb_entry(parent, struct pending_extent, rb_node);
rb_link_node(node, parent, p);
rb_insert_color(node, root);
return NULL;
}
static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
u64 size, struct rb_node **prev_ret)
{
struct rb_node * n = root->rb_node;
struct rb_node *prev = NULL;
struct pending_extent *entry;
struct pending_extent *prev_entry = NULL;
while(n) {
entry = rb_entry(n, struct pending_extent, rb_node);
prev = n;
prev_entry = entry;
if (offset + size <= entry->start)
n = n->rb_left;
else if (offset >= entry->start + entry->size)
n = n->rb_right;
else
return n;
}
if (!prev_ret)
return NULL;
while(prev && offset >= prev_entry->start + prev_entry->size) {
prev = rb_next(prev);
prev_entry = rb_entry(prev, struct pending_extent, rb_node);
}
*prev_ret = prev;
return NULL;
}
struct pending_extent *alloc_pending_extent(u64 start, u64 size)
{
struct pending_extent *pe = malloc(sizeof(*pe));
if (!pe)
return pe;
pe->start = start;
pe->size = size;
return pe;
}
int insert_pending_extent(struct pending_tree *tree, u64 start, u64 size)
{
struct pending_extent *pe = alloc_pending_extent(start, size);
struct rb_node *found;
found = tree_insert(&tree->root, start, size, &pe->rb_node);
if (found)
return -EEXIST;
return 0;
}
struct pending_extent *find_pending_extent(struct pending_tree *tree,
u64 start, u64 size)
{
struct rb_node *prev;
struct rb_node *ret;
struct pending_extent *entry;
ret = __tree_search(&tree->root, start, size, &prev);
if (!ret)
return NULL;
entry = rb_entry(ret, struct pending_extent, rb_node);
return entry;
}
struct pending_extent *find_first_pending_extent(struct pending_tree *tree,
u64 start)
{
struct rb_node *prev;
struct rb_node *ret;
struct pending_extent *entry;
ret = __tree_search(&tree->root, start, 1, &prev);
if (!ret)
ret = prev;
if (!ret)
return NULL;
entry = rb_entry(ret, struct pending_extent, rb_node);
return entry;
}
struct pending_extent *next_pending_extent(struct pending_extent *pe)
{
struct rb_node *node = rb_next(&pe->rb_node);
if (!node)
return NULL;
return rb_entry(node, struct pending_extent, rb_node);
}
void remove_pending_extent(struct pending_tree *tree,
struct pending_extent *pe)
{
rb_erase(&pe->rb_node, &tree->root);
}

51
pending-extent.h 100644
View File

@ -0,0 +1,51 @@
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef __PENDING_EXTENT__
#define __PENDING_EXTENT__
#include "kerncompat.h"
#include "rbtree.h"
struct pending_tree {
struct rb_root root;
};
struct pending_extent {
struct rb_node rb_node;
u64 start;
u64 size;
};
void pending_tree_init(struct pending_tree *tree);
void remove_pending_extent(struct pending_tree *tree,
struct pending_extent *pe);
struct pending_extent *find_first_pending_extent(struct pending_tree *tree,
u64 start);
struct pending_extent *next_pending_extent(struct pending_extent *pe);
struct pending_extent *find_pending_extent(struct pending_tree *tree,
u64 start, u64 size);
int insert_pending_extent(struct pending_tree *tree, u64 start, u64 size);
static inline void free_pending_extent(struct pending_extent *pe)
{
free(pe);
}
struct pending_extent *alloc_pending_extent(u64 start, u64 size);
#endif

389
rbtree.c 100644
View File

@ -0,0 +1,389 @@
/*
Red Black Trees
(C) 1999 Andrea Arcangeli <andrea@suse.de>
(C) 2002 David Woodhouse <dwmw2@infradead.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
linux/lib/rbtree.c
*/
#include "rbtree.h"
static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
{
struct rb_node *right = node->rb_right;
struct rb_node *parent = rb_parent(node);
if ((node->rb_right = right->rb_left))
rb_set_parent(right->rb_left, node);
right->rb_left = node;
rb_set_parent(right, parent);
if (parent)
{
if (node == parent->rb_left)
parent->rb_left = right;
else
parent->rb_right = right;
}
else
root->rb_node = right;
rb_set_parent(node, right);
}
static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
{
struct rb_node *left = node->rb_left;
struct rb_node *parent = rb_parent(node);
if ((node->rb_left = left->rb_right))
rb_set_parent(left->rb_right, node);
left->rb_right = node;
rb_set_parent(left, parent);
if (parent)
{
if (node == parent->rb_right)
parent->rb_right = left;
else
parent->rb_left = left;
}
else
root->rb_node = left;
rb_set_parent(node, left);
}
void rb_insert_color(struct rb_node *node, struct rb_root *root)
{
struct rb_node *parent, *gparent;
while ((parent = rb_parent(node)) && rb_is_red(parent))
{
gparent = rb_parent(parent);
if (parent == gparent->rb_left)
{
{
register struct rb_node *uncle = gparent->rb_right;
if (uncle && rb_is_red(uncle))
{
rb_set_black(uncle);
rb_set_black(parent);
rb_set_red(gparent);
node = gparent;
continue;
}
}
if (parent->rb_right == node)
{
register struct rb_node *tmp;
__rb_rotate_left(parent, root);
tmp = parent;
parent = node;
node = tmp;
}
rb_set_black(parent);
rb_set_red(gparent);
__rb_rotate_right(gparent, root);
} else {
{
register struct rb_node *uncle = gparent->rb_left;
if (uncle && rb_is_red(uncle))
{
rb_set_black(uncle);
rb_set_black(parent);
rb_set_red(gparent);
node = gparent;
continue;
}
}
if (parent->rb_left == node)
{
register struct rb_node *tmp;
__rb_rotate_right(parent, root);
tmp = parent;
parent = node;
node = tmp;
}
rb_set_black(parent);
rb_set_red(gparent);
__rb_rotate_left(gparent, root);
}
}
rb_set_black(root->rb_node);
}
static void __rb_erase_color(struct rb_node *node, struct rb_node *parent,
struct rb_root *root)
{
struct rb_node *other;
while ((!node || rb_is_black(node)) && node != root->rb_node)
{
if (parent->rb_left == node)
{
other = parent->rb_right;
if (rb_is_red(other))
{
rb_set_black(other);
rb_set_red(parent);
__rb_rotate_left(parent, root);
other = parent->rb_right;
}
if ((!other->rb_left || rb_is_black(other->rb_left)) &&
(!other->rb_right || rb_is_black(other->rb_right)))
{
rb_set_red(other);
node = parent;
parent = rb_parent(node);
}
else
{
if (!other->rb_right || rb_is_black(other->rb_right))
{
struct rb_node *o_left;
if ((o_left = other->rb_left))
rb_set_black(o_left);
rb_set_red(other);
__rb_rotate_right(other, root);
other = parent->rb_right;
}
rb_set_color(other, rb_color(parent));
rb_set_black(parent);
if (other->rb_right)
rb_set_black(other->rb_right);
__rb_rotate_left(parent, root);
node = root->rb_node;
break;
}
}
else
{
other = parent->rb_left;
if (rb_is_red(other))
{
rb_set_black(other);
rb_set_red(parent);
__rb_rotate_right(parent, root);
other = parent->rb_left;
}
if ((!other->rb_left || rb_is_black(other->rb_left)) &&
(!other->rb_right || rb_is_black(other->rb_right)))
{
rb_set_red(other);
node = parent;
parent = rb_parent(node);
}
else
{
if (!other->rb_left || rb_is_black(other->rb_left))
{
register struct rb_node *o_right;
if ((o_right = other->rb_right))
rb_set_black(o_right);
rb_set_red(other);
__rb_rotate_left(other, root);
other = parent->rb_left;
}
rb_set_color(other, rb_color(parent));
rb_set_black(parent);
if (other->rb_left)
rb_set_black(other->rb_left);
__rb_rotate_right(parent, root);
node = root->rb_node;
break;
}
}
}
if (node)
rb_set_black(node);
}
void rb_erase(struct rb_node *node, struct rb_root *root)
{
struct rb_node *child, *parent;
int color;
if (!node->rb_left)
child = node->rb_right;
else if (!node->rb_right)
child = node->rb_left;
else
{
struct rb_node *old = node, *left;
node = node->rb_right;
while ((left = node->rb_left) != NULL)
node = left;
child = node->rb_right;
parent = rb_parent(node);
color = rb_color(node);
if (child)
rb_set_parent(child, parent);
if (parent == old) {
parent->rb_right = child;
parent = node;
} else
parent->rb_left = child;
node->rb_parent_color = old->rb_parent_color;
node->rb_right = old->rb_right;
node->rb_left = old->rb_left;
if (rb_parent(old))
{
if (rb_parent(old)->rb_left == old)
rb_parent(old)->rb_left = node;
else
rb_parent(old)->rb_right = node;
} else
root->rb_node = node;
rb_set_parent(old->rb_left, node);
if (old->rb_right)
rb_set_parent(old->rb_right, node);
goto color;
}
parent = rb_parent(node);
color = rb_color(node);
if (child)
rb_set_parent(child, parent);
if (parent)
{
if (parent->rb_left == node)
parent->rb_left = child;
else
parent->rb_right = child;
}
else
root->rb_node = child;
color:
if (color == RB_BLACK)
__rb_erase_color(child, parent, root);
}
/*
* This function returns the first node (in sort order) of the tree.
*/
struct rb_node *rb_first(struct rb_root *root)
{
struct rb_node *n;
n = root->rb_node;
if (!n)
return NULL;
while (n->rb_left)
n = n->rb_left;
return n;
}
struct rb_node *rb_last(struct rb_root *root)
{
struct rb_node *n;
n = root->rb_node;
if (!n)
return NULL;
while (n->rb_right)
n = n->rb_right;
return n;
}
struct rb_node *rb_next(struct rb_node *node)
{
struct rb_node *parent;
if (rb_parent(node) == node)
return NULL;
/* If we have a right-hand child, go down and then left as far
as we can. */
if (node->rb_right) {
node = node->rb_right;
while (node->rb_left)
node=node->rb_left;
return node;
}
/* No right-hand children. Everything down and left is
smaller than us, so any 'next' node must be in the general
direction of our parent. Go up the tree; any time the
ancestor is a right-hand child of its parent, keep going
up. First time it's a left-hand child of its parent, said
parent is our 'next' node. */
while ((parent = rb_parent(node)) && node == parent->rb_right)
node = parent;
return parent;
}
struct rb_node *rb_prev(struct rb_node *node)
{
struct rb_node *parent;
if (rb_parent(node) == node)
return NULL;
/* If we have a left-hand child, go down and then right as far
as we can. */
if (node->rb_left) {
node = node->rb_left;
while (node->rb_right)
node=node->rb_right;
return node;
}
/* No left-hand children. Go up till we find an ancestor which
is a right-hand child of its parent */
while ((parent = rb_parent(node)) && node == parent->rb_left)
node = parent;
return parent;
}
void rb_replace_node(struct rb_node *victim, struct rb_node *new,
struct rb_root *root)
{
struct rb_node *parent = rb_parent(victim);
/* Set the surrounding nodes to point to the replacement */
if (parent) {
if (victim == parent->rb_left)
parent->rb_left = new;
else
parent->rb_right = new;
} else {
root->rb_node = new;
}
if (victim->rb_left)
rb_set_parent(victim->rb_left, new);
if (victim->rb_right)
rb_set_parent(victim->rb_right, new);
/* Copy the pointers/colour from the victim to the replacement */
*new = *victim;
}

160
rbtree.h 100644
View File

@ -0,0 +1,160 @@
/*
Red Black Trees
(C) 1999 Andrea Arcangeli <andrea@suse.de>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
linux/include/linux/rbtree.h
To use rbtrees you'll have to implement your own insert and search cores.
This will avoid us to use callbacks and to drop drammatically performances.
I know it's not the cleaner way, but in C (not in C++) to get
performances and genericity...
Some example of insert and search follows here. The search is a plain
normal search over an ordered tree. The insert instead must be implemented
int two steps: as first thing the code must insert the element in
order as a red leaf in the tree, then the support library function
rb_insert_color() must be called. Such function will do the
not trivial work to rebalance the rbtree if necessary.
-----------------------------------------------------------------------
static inline struct page * rb_search_page_cache(struct inode * inode,
unsigned long offset)
{
struct rb_node * n = inode->i_rb_page_cache.rb_node;
struct page * page;
while (n)
{
page = rb_entry(n, struct page, rb_page_cache);
if (offset < page->offset)
n = n->rb_left;
else if (offset > page->offset)
n = n->rb_right;
else
return page;
}
return NULL;
}
static inline struct page * __rb_insert_page_cache(struct inode * inode,
unsigned long offset,
struct rb_node * node)
{
struct rb_node ** p = &inode->i_rb_page_cache.rb_node;
struct rb_node * parent = NULL;
struct page * page;
while (*p)
{
parent = *p;
page = rb_entry(parent, struct page, rb_page_cache);
if (offset < page->offset)
p = &(*p)->rb_left;
else if (offset > page->offset)
p = &(*p)->rb_right;
else
return page;
}
rb_link_node(node, parent, p);
return NULL;
}
static inline struct page * rb_insert_page_cache(struct inode * inode,
unsigned long offset,
struct rb_node * node)
{
struct page * ret;
if ((ret = __rb_insert_page_cache(inode, offset, node)))
goto out;
rb_insert_color(node, &inode->i_rb_page_cache);
out:
return ret;
}
-----------------------------------------------------------------------
*/
#ifndef _LINUX_RBTREE_H
#define _LINUX_RBTREE_H
#include "kerncompat.h"
struct rb_node
{
unsigned long rb_parent_color;
#define RB_RED 0
#define RB_BLACK 1
struct rb_node *rb_right;
struct rb_node *rb_left;
} __attribute__((aligned(sizeof(long))));
/* The alignment might seem pointless, but allegedly CRIS needs it */
struct rb_root
{
struct rb_node *rb_node;
void (*rotate_notify)(struct rb_node *old_parent, struct rb_node *node);
};
#define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~3))
#define rb_color(r) ((r)->rb_parent_color & 1)
#define rb_is_red(r) (!rb_color(r))
#define rb_is_black(r) rb_color(r)
#define rb_set_red(r) do { (r)->rb_parent_color &= ~1; } while (0)
#define rb_set_black(r) do { (r)->rb_parent_color |= 1; } while (0)
static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
{
rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
}
static inline void rb_set_color(struct rb_node *rb, int color)
{
rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
}
#define RB_ROOT (struct rb_root) { NULL, }
#define rb_entry(ptr, type, member) container_of(ptr, type, member)
#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
#define RB_EMPTY_NODE(node) (rb_parent(node) == node)
#define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
extern void rb_insert_color(struct rb_node *, struct rb_root *);
extern void rb_erase(struct rb_node *, struct rb_root *);
/* Find logical next and previous nodes in a tree */
extern struct rb_node *rb_next(struct rb_node *);
extern struct rb_node *rb_prev(struct rb_node *);
extern struct rb_node *rb_first(struct rb_root *);
extern struct rb_node *rb_last(struct rb_root *);
/* Fast replacement of a single node without remove/rebalance/add/rebalance */
extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
struct rb_root *root);
static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
struct rb_node ** rb_link)
{
node->rb_parent_color = (unsigned long )parent;
node->rb_left = node->rb_right = NULL;
*rb_link = node;
}
#endif /* _LINUX_RBTREE_H */