7990b574211452597df13618e54e9550b4a4905c
1 #include <linux/module.h>
4 #include "transaction.h"
6 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
7 sizeof(struct btrfs_item) * 2) / \
8 BTRFS_CRC32_SIZE) - 1))
9 int btrfs_insert_file_extent(struct btrfs_trans_handle
*trans
,
10 struct btrfs_root
*root
,
11 u64 objectid
, u64 pos
,
12 u64 offset
, u64 disk_num_blocks
,
16 struct btrfs_file_extent_item
*item
;
17 struct btrfs_key file_key
;
18 struct btrfs_path
*path
;
20 path
= btrfs_alloc_path();
22 btrfs_init_path(path
);
23 file_key
.objectid
= objectid
;
24 file_key
.offset
= pos
;
26 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
28 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
31 item
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]), path
->slots
[0],
32 struct btrfs_file_extent_item
);
33 btrfs_set_file_extent_disk_blocknr(item
, offset
);
34 btrfs_set_file_extent_disk_num_blocks(item
, disk_num_blocks
);
35 btrfs_set_file_extent_offset(item
, 0);
36 btrfs_set_file_extent_num_blocks(item
, num_blocks
);
37 btrfs_set_file_extent_generation(item
, trans
->transid
);
38 btrfs_set_file_extent_type(item
, BTRFS_FILE_EXTENT_REG
);
39 btrfs_mark_buffer_dirty(path
->nodes
[0]);
41 btrfs_release_path(root
, path
);
42 btrfs_free_path(path
);
46 struct btrfs_csum_item
*btrfs_lookup_csum(struct btrfs_trans_handle
*trans
,
47 struct btrfs_root
*root
,
48 struct btrfs_path
*path
,
49 u64 objectid
, u64 offset
,
53 struct btrfs_key file_key
;
54 struct btrfs_key found_key
;
55 struct btrfs_csum_item
*item
;
56 struct btrfs_leaf
*leaf
;
60 file_key
.objectid
= objectid
;
61 file_key
.offset
= offset
;
63 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
64 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, 0, cow
);
67 leaf
= btrfs_buffer_leaf(path
->nodes
[0]);
70 if (path
->slots
[0] == 0)
73 btrfs_disk_key_to_cpu(&found_key
,
74 &leaf
->items
[path
->slots
[0]].key
);
75 if (btrfs_key_type(&found_key
) != BTRFS_CSUM_ITEM_KEY
||
76 found_key
.objectid
!= objectid
) {
79 csum_offset
= (offset
- found_key
.offset
) >>
80 root
->fs_info
->sb
->s_blocksize_bits
;
81 csums_in_item
= btrfs_item_size(leaf
->items
+ path
->slots
[0]);
82 csums_in_item
/= BTRFS_CRC32_SIZE
;
84 if (csum_offset
>= csums_in_item
) {
89 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
90 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
91 csum_offset
* BTRFS_CRC32_SIZE
);
100 int btrfs_lookup_file_extent(struct btrfs_trans_handle
*trans
,
101 struct btrfs_root
*root
,
102 struct btrfs_path
*path
, u64 objectid
,
106 struct btrfs_key file_key
;
107 int ins_len
= mod
< 0 ? -1 : 0;
110 file_key
.objectid
= objectid
;
111 file_key
.offset
= offset
;
113 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
114 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, ins_len
, cow
);
118 int btrfs_csum_file_block(struct btrfs_trans_handle
*trans
,
119 struct btrfs_root
*root
,
120 u64 objectid
, u64 offset
,
121 char *data
, size_t len
)
124 struct btrfs_key file_key
;
125 struct btrfs_key found_key
;
126 struct btrfs_path
*path
;
127 struct btrfs_csum_item
*item
;
128 struct btrfs_leaf
*leaf
;
131 path
= btrfs_alloc_path();
134 file_key
.objectid
= objectid
;
135 file_key
.offset
= offset
;
137 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
139 item
= btrfs_lookup_csum(trans
, root
, path
, objectid
, offset
, 1);
145 /* we found one, but it isn't big enough yet */
146 leaf
= btrfs_buffer_leaf(path
->nodes
[0]);
147 item_size
= btrfs_item_size(leaf
->items
+ path
->slots
[0]);
148 if ((item_size
/ BTRFS_CRC32_SIZE
) >= MAX_CSUM_ITEMS(root
)) {
149 /* already at max size, make a new one */
153 /* we didn't find a csum item, insert one */
158 * at this point, we know the tree has an item, but it isn't big
159 * enough yet to put our csum in. Grow it
161 btrfs_release_path(root
, path
);
162 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
,
163 BTRFS_CRC32_SIZE
, 1);
169 if (path
->slots
[0] == 0) {
173 leaf
= btrfs_buffer_leaf(path
->nodes
[0]);
174 btrfs_disk_key_to_cpu(&found_key
, &leaf
->items
[path
->slots
[0]].key
);
175 csum_offset
= (offset
- found_key
.offset
) >>
176 root
->fs_info
->sb
->s_blocksize_bits
;
177 if (btrfs_key_type(&found_key
) != BTRFS_CSUM_ITEM_KEY
||
178 found_key
.objectid
!= objectid
||
179 csum_offset
>= MAX_CSUM_ITEMS(root
)) {
182 if (csum_offset
>= btrfs_item_size(leaf
->items
+ path
->slots
[0]) /
184 u32 diff
= (csum_offset
+ 1) * BTRFS_CRC32_SIZE
;
185 diff
= diff
- btrfs_item_size(leaf
->items
+ path
->slots
[0]);
186 if (diff
!= BTRFS_CRC32_SIZE
)
188 ret
= btrfs_extend_item(trans
, root
, path
, diff
);
194 btrfs_release_path(root
, path
);
196 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
199 printk("at insert for %Lu %u %Lu ret is %d\n", file_key
.objectid
, file_key
.flags
, file_key
.offset
, ret
);
204 item
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]), path
->slots
[0],
205 struct btrfs_csum_item
);
207 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
208 csum_offset
* BTRFS_CRC32_SIZE
);
210 btrfs_check_bounds(&item
->csum
, BTRFS_CRC32_SIZE
,
211 path
->nodes
[0]->b_data
,
212 root
->fs_info
->sb
->s_blocksize
);
213 ret
= btrfs_csum_data(root
, data
, len
, &item
->csum
);
214 btrfs_mark_buffer_dirty(path
->nodes
[0]);
216 btrfs_release_path(root
, path
);
217 btrfs_free_path(path
);
221 int btrfs_csum_verify_file_block(struct btrfs_root
*root
,
222 u64 objectid
, u64 offset
,
223 char *data
, size_t len
)
226 struct btrfs_key file_key
;
227 struct btrfs_path
*path
;
228 struct btrfs_csum_item
*item
;
229 char result
[BTRFS_CRC32_SIZE
];
231 path
= btrfs_alloc_path();
233 btrfs_init_path(path
);
234 file_key
.objectid
= objectid
;
235 file_key
.offset
= offset
;
237 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
238 mutex_lock(&root
->fs_info
->fs_mutex
);
240 item
= btrfs_lookup_csum(NULL
, root
, path
, objectid
, offset
, 0);
243 /* a csum that isn't present is a preallocated region. */
244 if (ret
== -ENOENT
|| ret
== -EFBIG
)
249 ret
= btrfs_csum_data(root
, data
, len
, result
);
251 if (memcmp(result
, &item
->csum
, BTRFS_CRC32_SIZE
))
254 btrfs_release_path(root
, path
);
255 btrfs_free_path(path
);
256 mutex_unlock(&root
->fs_info
->fs_mutex
);
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