btrfs-progs/common/extent-cache.c
David Sterba c3ee6a8a09 btrfs-progs: unify GPL header comments
Add the GPL v2 header to files where it was missing and is not from an
external source, update to the most recent version with the address.

Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07 13:58:44 +02:00

328 lines
7.6 KiB
C

/*
* 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 "common/extent-cache.h"
#include "common/rbtree-utils.h"
struct cache_extent_search_range {
u64 objectid;
u64 start;
u64 size;
};
static int cache_tree_comp_range(struct rb_node *node, void *data)
{
struct cache_extent *entry;
struct cache_extent_search_range *range;
range = (struct cache_extent_search_range *)data;
entry = rb_entry(node, struct cache_extent, rb_node);
if (entry->start + entry->size <= range->start)
return 1;
else if (range->start + range->size <= entry->start)
return -1;
else
return 0;
}
static int cache_tree_comp_nodes(struct rb_node *node1, struct rb_node *node2)
{
struct cache_extent *entry;
struct cache_extent_search_range range;
entry = rb_entry(node2, struct cache_extent, rb_node);
range.start = entry->start;
range.size = entry->size;
return cache_tree_comp_range(node1, (void *)&range);
}
static int cache_tree_comp_range2(struct rb_node *node, void *data)
{
struct cache_extent *entry;
struct cache_extent_search_range *range;
range = (struct cache_extent_search_range *)data;
entry = rb_entry(node, struct cache_extent, rb_node);
if (entry->objectid < range->objectid)
return 1;
else if (entry->objectid > range->objectid)
return -1;
else if (entry->start + entry->size <= range->start)
return 1;
else if (range->start + range->size <= entry->start)
return -1;
else
return 0;
}
static int cache_tree_comp_nodes2(struct rb_node *node1, struct rb_node *node2)
{
struct cache_extent *entry;
struct cache_extent_search_range range;
entry = rb_entry(node2, struct cache_extent, rb_node);
range.objectid = entry->objectid;
range.start = entry->start;
range.size = entry->size;
return cache_tree_comp_range2(node1, (void *)&range);
}
void cache_tree_init(struct cache_tree *tree)
{
tree->root = RB_ROOT;
}
static struct cache_extent *alloc_cache_extent(u64 start, u64 size)
{
struct cache_extent *pe = malloc(sizeof(*pe));
if (!pe)
return pe;
pe->objectid = 0;
pe->start = start;
pe->size = size;
return pe;
}
int add_cache_extent(struct cache_tree *tree, u64 start, u64 size)
{
struct cache_extent *pe = alloc_cache_extent(start, size);
int ret;
if (!pe)
return -ENOMEM;
ret = insert_cache_extent(tree, pe);
if (ret)
free(pe);
return ret;
}
int insert_cache_extent(struct cache_tree *tree, struct cache_extent *pe)
{
return rb_insert(&tree->root, &pe->rb_node, cache_tree_comp_nodes);
}
int insert_cache_extent2(struct cache_tree *tree, struct cache_extent *pe)
{
return rb_insert(&tree->root, &pe->rb_node, cache_tree_comp_nodes2);
}
struct cache_extent *lookup_cache_extent(struct cache_tree *tree,
u64 start, u64 size)
{
struct rb_node *node;
struct cache_extent *entry;
struct cache_extent_search_range range;
range.start = start;
range.size = size;
node = rb_search(&tree->root, &range, cache_tree_comp_range, NULL);
if (!node)
return NULL;
entry = rb_entry(node, struct cache_extent, rb_node);
return entry;
}
struct cache_extent *lookup_cache_extent2(struct cache_tree *tree,
u64 objectid, u64 start, u64 size)
{
struct rb_node *node;
struct cache_extent *entry;
struct cache_extent_search_range range;
range.objectid = objectid;
range.start = start;
range.size = size;
node = rb_search(&tree->root, &range, cache_tree_comp_range2, NULL);
if (!node)
return NULL;
entry = rb_entry(node, struct cache_extent, rb_node);
return entry;
}
struct cache_extent *search_cache_extent(struct cache_tree *tree, u64 start)
{
struct rb_node *next;
struct rb_node *node;
struct cache_extent *entry;
struct cache_extent_search_range range;
range.start = start;
range.size = 1;
node = rb_search(&tree->root, &range, cache_tree_comp_range, &next);
if (!node)
node = next;
if (!node)
return NULL;
entry = rb_entry(node, struct cache_extent, rb_node);
return entry;
}
struct cache_extent *search_cache_extent2(struct cache_tree *tree,
u64 objectid, u64 start)
{
struct rb_node *next;
struct rb_node *node;
struct cache_extent *entry;
struct cache_extent_search_range range;
range.objectid = objectid;
range.start = start;
range.size = 1;
node = rb_search(&tree->root, &range, cache_tree_comp_range2, &next);
if (!node)
node = next;
if (!node)
return NULL;
entry = rb_entry(node, struct cache_extent, rb_node);
return entry;
}
struct cache_extent *first_cache_extent(struct cache_tree *tree)
{
struct rb_node *node = rb_first(&tree->root);
if (!node)
return NULL;
return rb_entry(node, struct cache_extent, rb_node);
}
struct cache_extent *last_cache_extent(struct cache_tree *tree)
{
struct rb_node *node = rb_last(&tree->root);
if (!node)
return NULL;
return rb_entry(node, struct cache_extent, rb_node);
}
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);
}
void cache_tree_free_extents(struct cache_tree *tree,
free_cache_extent free_func)
{
struct cache_extent *ce;
while ((ce = first_cache_extent(tree))) {
remove_cache_extent(tree, ce);
free_func(ce);
}
}
static void free_extent_cache(struct cache_extent *pe)
{
free(pe);
}
void free_extent_cache_tree(struct cache_tree *tree)
{
cache_tree_free_extents(tree, free_extent_cache);
}
int add_merge_cache_extent(struct cache_tree *tree, u64 start, u64 size)
{
struct cache_extent *cache;
struct cache_extent *next = NULL;
struct cache_extent *prev = NULL;
int next_merged = 0;
int prev_merged = 0;
int ret = 0;
if (cache_tree_empty(tree))
goto insert;
cache = search_cache_extent(tree, start);
if (!cache) {
/*
* Either the tree is completely empty, or the no range after
* start.
* Either way, the last cache_extent should be prev.
*/
prev = last_cache_extent(tree);
} else if (start <= cache->start) {
next = cache;
prev = prev_cache_extent(cache);
} else {
prev = cache;
next = next_cache_extent(cache);
}
/*
* Ensure the range to be inserted won't cover with existings
* Or we will need extra loop to do merge
*/
BUG_ON(next && start + size > next->start);
BUG_ON(prev && prev->start + prev->size > start);
if (next && start + size == next->start) {
next_merged = 1;
next->size = next->start + next->size - start;
next->start = start;
}
if (prev && prev->start + prev->size == start) {
prev_merged = 1;
if (next_merged) {
next->size = next->start + next->size - prev->start;
next->start = prev->start;
remove_cache_extent(tree, prev);
free(prev);
} else {
prev->size = start + size - prev->start;
}
}
insert:
if (!prev_merged && !next_merged)
ret = add_cache_extent(tree, start, size);
return ret;
}