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
|
--- trunk/grub2/fs/ext2.c 2008/07/12 15:40:50 1698
+++ trunk/grub2/fs/ext2.c 2008/07/13 01:13:12 1699
@@ -86,6 +86,8 @@
#define EXT3_JOURNAL_FLAG_DELETED 4
#define EXT3_JOURNAL_FLAG_LAST_TAG 8
+#define EXT4_EXTENTS_FLAG 0x80000
+
/* The ext2 superblock. */
struct grub_ext2_sblock
{
@@ -226,6 +228,33 @@
grub_uint32_t start;
};
+#define EXT4_EXT_MAGIC 0xf30a
+
+struct grub_ext4_extent_header
+{
+ grub_uint16_t magic;
+ grub_uint16_t entries;
+ grub_uint16_t max;
+ grub_uint16_t depth;
+ grub_uint32_t generation;
+};
+
+struct grub_ext4_extent
+{
+ grub_uint32_t block;
+ grub_uint16_t len;
+ grub_uint16_t start_hi;
+ grub_uint32_t start;
+};
+
+struct grub_ext4_extent_idx
+{
+ grub_uint32_t block;
+ grub_uint32_t leaf;
+ grub_uint16_t leaf_hi;
+ grub_uint16_t unused;
+};
+
struct grub_fshelp_node
{
struct grub_ext2_data *data;
@@ -262,6 +291,45 @@
sizeof (struct grub_ext2_block_group), (char *) blkgrp);
}
+static struct grub_ext4_extent_header *
+grub_ext4_find_leaf (struct grub_ext2_data *data, char *buf,
+ struct grub_ext4_extent_header *ext_block,
+ grub_uint32_t fileblock)
+{
+ struct grub_ext4_extent_idx *index;
+
+ while (1)
+ {
+ int i;
+ grub_disk_addr_t block;
+
+ index = (struct grub_ext4_extent_idx *) (ext_block + 1);
+
+ if (grub_le_to_cpu16(ext_block->magic) != EXT4_EXT_MAGIC)
+ return 0;
+
+ if (ext_block->depth == 0)
+ return ext_block;
+
+ for (i = 0; i < grub_le_to_cpu16 (ext_block->entries); i++)
+ {
+ if (fileblock < grub_le_to_cpu32(index[i].block))
+ break;
+ }
+
+ if (--i < 0)
+ return 0;
+
+ block = grub_le_to_cpu16 (index[i].leaf_hi);
+ block = (block << 32) + grub_le_to_cpu32 (index[i].leaf);
+ if (grub_disk_read (data->disk,
+ block << LOG2_EXT2_BLOCK_SIZE (data),
+ 0, EXT2_BLOCK_SIZE(data), buf))
+ return 0;
+
+ ext_block = (struct grub_ext4_extent_header *) buf;
+ }
+}
static grub_disk_addr_t
grub_ext2_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
@@ -272,6 +340,50 @@
unsigned int blksz = EXT2_BLOCK_SIZE (data);
int log2_blksz = LOG2_EXT2_BLOCK_SIZE (data);
+ if (inode->flags & EXT4_EXTENTS_FLAG)
+ {
+ char buf[EXT2_BLOCK_SIZE(data)];
+ struct grub_ext4_extent_header *leaf;
+ struct grub_ext4_extent *ext;
+ int i;
+
+ leaf = grub_ext4_find_leaf (data, buf,
+ (struct grub_ext4_extent_header *) inode->blocks.dir_blocks,
+ fileblock);
+ if (! leaf)
+ {
+ grub_error (GRUB_ERR_BAD_FS, "invalid extent");
+ return -1;
+ }
+
+ ext = (struct grub_ext4_extent *) (leaf + 1);
+ for (i = 0; i < grub_le_to_cpu16 (leaf->entries); i++)
+ {
+ if (fileblock < grub_le_to_cpu32 (ext[i].block))
+ break;
+ }
+
+ if (--i >= 0)
+ {
+ fileblock -= grub_le_to_cpu32 (ext[i].block);
+ if (fileblock >= grub_le_to_cpu16 (ext[i].len))
+ return 0;
+ else
+ {
+ grub_disk_addr_t start;
+
+ start = grub_le_to_cpu16 (ext[i].start_hi);
+ start = (start << 32) + grub_le_to_cpu32 (ext[i].start);
+
+ return fileblock + start;
+ }
+ }
+ else
+ {
+ grub_error (GRUB_ERR_BAD_FS, "something wrong with extent");
+ return -1;
+ }
+ }
/* Direct blocks. */
if (fileblock < INDIRECT_BLOCKS)
blknr = grub_le_to_cpu32 (inode->blocks.dir_blocks[fileblock]);
|
GitWeb