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11#include <linux/time.h>
12#include <linux/fs.h>
13#include <linux/namei.h>
14#include <linux/quotaops.h>
15#include <linux/buffer_head.h>
16#include <linux/swap.h>
17#include <linux/pagemap.h>
18#include <linux/blkdev.h>
19#include <linux/slab.h>
20#include "ext4.h"
21
22struct ext4_system_zone {
23 struct rb_node node;
24 ext4_fsblk_t start_blk;
25 unsigned int count;
26};
27
28static struct kmem_cache *ext4_system_zone_cachep;
29
30int __init ext4_init_system_zone(void)
31{
32 ext4_system_zone_cachep = KMEM_CACHE(ext4_system_zone, 0);
33 if (ext4_system_zone_cachep == NULL)
34 return -ENOMEM;
35 return 0;
36}
37
38void ext4_exit_system_zone(void)
39{
40 kmem_cache_destroy(ext4_system_zone_cachep);
41}
42
43static inline int can_merge(struct ext4_system_zone *entry1,
44 struct ext4_system_zone *entry2)
45{
46 if ((entry1->start_blk + entry1->count) == entry2->start_blk)
47 return 1;
48 return 0;
49}
50
51
52
53
54
55
56static int add_system_zone(struct ext4_sb_info *sbi,
57 ext4_fsblk_t start_blk,
58 unsigned int count)
59{
60 struct ext4_system_zone *new_entry = NULL, *entry;
61 struct rb_node **n = &sbi->system_blks.rb_node, *node;
62 struct rb_node *parent = NULL, *new_node = NULL;
63
64 while (*n) {
65 parent = *n;
66 entry = rb_entry(parent, struct ext4_system_zone, node);
67 if (start_blk < entry->start_blk)
68 n = &(*n)->rb_left;
69 else if (start_blk >= (entry->start_blk + entry->count))
70 n = &(*n)->rb_right;
71 else {
72 if (start_blk + count > (entry->start_blk +
73 entry->count))
74 entry->count = (start_blk + count -
75 entry->start_blk);
76 new_node = *n;
77 new_entry = rb_entry(new_node, struct ext4_system_zone,
78 node);
79 break;
80 }
81 }
82
83 if (!new_entry) {
84 new_entry = kmem_cache_alloc(ext4_system_zone_cachep,
85 GFP_KERNEL);
86 if (!new_entry)
87 return -ENOMEM;
88 new_entry->start_blk = start_blk;
89 new_entry->count = count;
90 new_node = &new_entry->node;
91
92 rb_link_node(new_node, parent, n);
93 rb_insert_color(new_node, &sbi->system_blks);
94 }
95
96
97 node = rb_prev(new_node);
98 if (node) {
99 entry = rb_entry(node, struct ext4_system_zone, node);
100 if (can_merge(entry, new_entry)) {
101 new_entry->start_blk = entry->start_blk;
102 new_entry->count += entry->count;
103 rb_erase(node, &sbi->system_blks);
104 kmem_cache_free(ext4_system_zone_cachep, entry);
105 }
106 }
107
108
109 node = rb_next(new_node);
110 if (node) {
111 entry = rb_entry(node, struct ext4_system_zone, node);
112 if (can_merge(new_entry, entry)) {
113 new_entry->count += entry->count;
114 rb_erase(node, &sbi->system_blks);
115 kmem_cache_free(ext4_system_zone_cachep, entry);
116 }
117 }
118 return 0;
119}
120
121static void debug_print_tree(struct ext4_sb_info *sbi)
122{
123 struct rb_node *node;
124 struct ext4_system_zone *entry;
125 int first = 1;
126
127 printk(KERN_INFO "System zones: ");
128 node = rb_first(&sbi->system_blks);
129 while (node) {
130 entry = rb_entry(node, struct ext4_system_zone, node);
131 printk("%s%llu-%llu", first ? "" : ", ",
132 entry->start_blk, entry->start_blk + entry->count - 1);
133 first = 0;
134 node = rb_next(node);
135 }
136 printk("\n");
137}
138
139int ext4_setup_system_zone(struct super_block *sb)
140{
141 ext4_group_t ngroups = ext4_get_groups_count(sb);
142 struct ext4_sb_info *sbi = EXT4_SB(sb);
143 struct ext4_group_desc *gdp;
144 ext4_group_t i;
145 int flex_size = ext4_flex_bg_size(sbi);
146 int ret;
147
148 if (!test_opt(sb, BLOCK_VALIDITY)) {
149 if (EXT4_SB(sb)->system_blks.rb_node)
150 ext4_release_system_zone(sb);
151 return 0;
152 }
153 if (EXT4_SB(sb)->system_blks.rb_node)
154 return 0;
155
156 for (i=0; i < ngroups; i++) {
157 if (ext4_bg_has_super(sb, i) &&
158 ((i < 5) || ((i % flex_size) == 0)))
159 add_system_zone(sbi, ext4_group_first_block_no(sb, i),
160 ext4_bg_num_gdb(sb, i) + 1);
161 gdp = ext4_get_group_desc(sb, i, NULL);
162 ret = add_system_zone(sbi, ext4_block_bitmap(sb, gdp), 1);
163 if (ret)
164 return ret;
165 ret = add_system_zone(sbi, ext4_inode_bitmap(sb, gdp), 1);
166 if (ret)
167 return ret;
168 ret = add_system_zone(sbi, ext4_inode_table(sb, gdp),
169 sbi->s_itb_per_group);
170 if (ret)
171 return ret;
172 }
173
174 if (test_opt(sb, DEBUG))
175 debug_print_tree(EXT4_SB(sb));
176 return 0;
177}
178
179
180void ext4_release_system_zone(struct super_block *sb)
181{
182 struct ext4_system_zone *entry, *n;
183
184 rbtree_postorder_for_each_entry_safe(entry, n,
185 &EXT4_SB(sb)->system_blks, node)
186 kmem_cache_free(ext4_system_zone_cachep, entry);
187
188 EXT4_SB(sb)->system_blks = RB_ROOT;
189}
190
191
192
193
194
195
196int ext4_data_block_valid(struct ext4_sb_info *sbi, ext4_fsblk_t start_blk,
197 unsigned int count)
198{
199 struct ext4_system_zone *entry;
200 struct rb_node *n = sbi->system_blks.rb_node;
201
202 if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
203 (start_blk + count < start_blk) ||
204 (start_blk + count > ext4_blocks_count(sbi->s_es))) {
205 sbi->s_es->s_last_error_block = cpu_to_le64(start_blk);
206 return 0;
207 }
208 while (n) {
209 entry = rb_entry(n, struct ext4_system_zone, node);
210 if (start_blk + count - 1 < entry->start_blk)
211 n = n->rb_left;
212 else if (start_blk >= (entry->start_blk + entry->count))
213 n = n->rb_right;
214 else {
215 sbi->s_es->s_last_error_block = cpu_to_le64(start_blk);
216 return 0;
217 }
218 }
219 return 1;
220}
221
222int ext4_check_blockref(const char *function, unsigned int line,
223 struct inode *inode, __le32 *p, unsigned int max)
224{
225 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
226 __le32 *bref = p;
227 unsigned int blk;
228
229 while (bref < p+max) {
230 blk = le32_to_cpu(*bref++);
231 if (blk &&
232 unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb),
233 blk, 1))) {
234 es->s_last_error_block = cpu_to_le64(blk);
235 ext4_error_inode(inode, function, line, blk,
236 "invalid block");
237 return -EIO;
238 }
239 }
240 return 0;
241}
242
243
