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/*
* 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 "extent-cache.h"
void cache_tree_init(struct cache_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 cache_extent *entry;
while(*p) {
parent = *p;
entry = rb_entry(parent, struct cache_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 cache_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 cache_extent *entry;
struct cache_extent *prev_entry = NULL;
while(n) {
entry = rb_entry(n, struct cache_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 cache_extent, rb_node);
}
*prev_ret = prev;
return NULL;
}
struct cache_extent *alloc_cache_extent(u64 start, u64 size)
{
struct cache_extent *pe = malloc(sizeof(*pe));
if (!pe)
return pe;
pe->start = start;
pe->size = size;
return pe;
}
int insert_existing_cache_extent(struct cache_tree *tree,
struct cache_extent *pe)
{
struct rb_node *found;
found = tree_insert(&tree->root, pe->start, pe->size, &pe->rb_node);
if (found)
return -EEXIST;
return 0;
}
int insert_cache_extent(struct cache_tree *tree, u64 start, u64 size)
{
struct cache_extent *pe = alloc_cache_extent(start, size);
int ret;
ret = insert_existing_cache_extent(tree, pe);
if (ret)
free(pe);
return ret;
}
struct cache_extent *find_cache_extent(struct cache_tree *tree,
u64 start, u64 size)
{
struct rb_node *prev;
struct rb_node *ret;
struct cache_extent *entry;
ret = __tree_search(&tree->root, start, size, &prev);
if (!ret)
return NULL;
entry = rb_entry(ret, struct cache_extent, rb_node);
return entry;
}
struct cache_extent *find_first_cache_extent(struct cache_tree *tree,
u64 start)
{
struct rb_node *prev;
struct rb_node *ret;
struct cache_extent *entry;
ret = __tree_search(&tree->root, start, 1, &prev);
if (!ret)
ret = prev;
if (!ret)
return NULL;
entry = rb_entry(ret, struct cache_extent, rb_node);
return entry;
}
struct cache_extent *prev_cache_extent(struct cache_extent *pe)
{
struct rb_node *node = rb_prev(&pe->rb_node);
if (!node)
return NULL;
return rb_entry(node, struct cache_extent, rb_node);
}
struct cache_extent *next_cache_extent(struct cache_extent *pe)
{
struct rb_node *node = rb_next(&pe->rb_node);
if (!node)
return NULL;
return rb_entry(node, struct cache_extent, rb_node);
}
void remove_cache_extent(struct cache_tree *tree,
struct cache_extent *pe)
{
rb_erase(&pe->rb_node, &tree->root);
}
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