1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
/*
* Copyright (C) 2008 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 <linux/sched.h>
#include "ctree.h"
#include "ref-cache.h"
#include "transaction.h"
struct btrfs_leaf_ref *btrfs_alloc_leaf_ref(int nr_extents)
{
struct btrfs_leaf_ref *ref;
ref = kmalloc(btrfs_leaf_ref_size(nr_extents), GFP_NOFS);
if (ref) {
memset(ref, 0, sizeof(*ref));
atomic_set(&ref->usage, 1);
INIT_LIST_HEAD(&ref->list);
}
return ref;
}
void btrfs_free_leaf_ref(struct btrfs_leaf_ref *ref)
{
if (!ref)
return;
WARN_ON(atomic_read(&ref->usage) == 0);
if (atomic_dec_and_test(&ref->usage)) {
BUG_ON(ref->in_tree);
kfree(ref);
}
}
static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
struct rb_node *node)
{
struct rb_node ** p = &root->rb_node;
struct rb_node * parent = NULL;
struct btrfs_leaf_ref *entry;
while(*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_leaf_ref, rb_node);
WARN_ON(!entry->in_tree);
if (bytenr < entry->bytenr)
p = &(*p)->rb_left;
else if (bytenr > entry->bytenr)
p = &(*p)->rb_right;
else
return parent;
}
entry = rb_entry(node, struct btrfs_leaf_ref, rb_node);
entry->in_tree = 1;
rb_link_node(node, parent, p);
rb_insert_color(node, root);
return NULL;
}
static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
{
struct rb_node * n = root->rb_node;
struct btrfs_leaf_ref *entry;
while(n) {
entry = rb_entry(n, struct btrfs_leaf_ref, rb_node);
WARN_ON(!entry->in_tree);
if (bytenr < entry->bytenr)
n = n->rb_left;
else if (bytenr > entry->bytenr)
n = n->rb_right;
else
return n;
}
return NULL;
}
int btrfs_remove_leaf_refs(struct btrfs_root *root)
{
struct rb_node *rb;
struct btrfs_leaf_ref *ref = NULL;
struct btrfs_leaf_ref_tree *tree = root->ref_tree;
if (!tree)
return 0;
spin_lock(&tree->lock);
while(!btrfs_leaf_ref_tree_empty(tree)) {
rb = rb_first(&tree->root);
ref = rb_entry(rb, struct btrfs_leaf_ref, rb_node);
rb_erase(&ref->rb_node, &tree->root);
ref->in_tree = 0;
list_del_init(&ref->list);
spin_unlock(&tree->lock);
btrfs_free_leaf_ref(ref);
cond_resched();
spin_lock(&tree->lock);
}
spin_unlock(&tree->lock);
return 0;
}
struct btrfs_leaf_ref *btrfs_lookup_leaf_ref(struct btrfs_root *root,
u64 bytenr)
{
struct rb_node *rb;
struct btrfs_leaf_ref *ref = NULL;
struct btrfs_leaf_ref_tree *tree = root->ref_tree;
if (!tree)
return NULL;
spin_lock(&tree->lock);
rb = tree_search(&tree->root, bytenr);
if (rb)
ref = rb_entry(rb, struct btrfs_leaf_ref, rb_node);
if (ref)
atomic_inc(&ref->usage);
spin_unlock(&tree->lock);
return ref;
}
int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref)
{
int ret = 0;
struct rb_node *rb;
size_t size = btrfs_leaf_ref_size(ref->nritems);
struct btrfs_leaf_ref_tree *tree = root->ref_tree;
spin_lock(&tree->lock);
rb = tree_insert(&tree->root, ref->bytenr, &ref->rb_node);
if (rb) {
ret = -EEXIST;
} else {
spin_lock(&root->fs_info->ref_cache_lock);
root->fs_info->total_ref_cache_size += size;
spin_unlock(&root->fs_info->ref_cache_lock);
atomic_inc(&ref->usage);
list_add_tail(&ref->list, &tree->list);
}
spin_unlock(&tree->lock);
return ret;
}
int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref)
{
size_t size = btrfs_leaf_ref_size(ref->nritems);
struct btrfs_leaf_ref_tree *tree = root->ref_tree;
BUG_ON(!ref->in_tree);
spin_lock(&tree->lock);
spin_lock(&root->fs_info->ref_cache_lock);
root->fs_info->total_ref_cache_size -= size;
spin_unlock(&root->fs_info->ref_cache_lock);
rb_erase(&ref->rb_node, &tree->root);
ref->in_tree = 0;
list_del_init(&ref->list);
spin_unlock(&tree->lock);
btrfs_free_leaf_ref(ref);
return 0;
}
|
