1 #include <linux/module.h>
4 #include "transaction.h"
5 #include "print-tree.h"
7 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
8 sizeof(struct btrfs_item) * 2) / \
9 BTRFS_CRC32_SIZE) - 1))
10 int btrfs_insert_file_extent(struct btrfs_trans_handle
*trans
,
11 struct btrfs_root
*root
,
12 u64 objectid
, u64 pos
,
13 u64 offset
, u64 disk_num_blocks
,
17 struct btrfs_file_extent_item
*item
;
18 struct btrfs_key file_key
;
19 struct btrfs_path
*path
;
21 path
= btrfs_alloc_path();
23 btrfs_init_path(path
);
24 file_key
.objectid
= objectid
;
25 file_key
.offset
= pos
;
27 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
29 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
32 printk("failed to insert %Lu %Lu ret %d\n", objectid
, pos
, ret
);
33 btrfs_print_leaf(root
, btrfs_buffer_leaf(path
->nodes
[0]));
36 item
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]), path
->slots
[0],
37 struct btrfs_file_extent_item
);
38 btrfs_set_file_extent_disk_blocknr(item
, offset
);
39 btrfs_set_file_extent_disk_num_blocks(item
, disk_num_blocks
);
40 btrfs_set_file_extent_offset(item
, 0);
41 btrfs_set_file_extent_num_blocks(item
, num_blocks
);
42 btrfs_set_file_extent_generation(item
, trans
->transid
);
43 btrfs_set_file_extent_type(item
, BTRFS_FILE_EXTENT_REG
);
44 btrfs_mark_buffer_dirty(path
->nodes
[0]);
46 btrfs_release_path(root
, path
);
47 btrfs_free_path(path
);
51 struct btrfs_csum_item
*btrfs_lookup_csum(struct btrfs_trans_handle
*trans
,
52 struct btrfs_root
*root
,
53 struct btrfs_path
*path
,
54 u64 objectid
, u64 offset
,
58 struct btrfs_key file_key
;
59 struct btrfs_key found_key
;
60 struct btrfs_csum_item
*item
;
61 struct btrfs_leaf
*leaf
;
65 file_key
.objectid
= objectid
;
66 file_key
.offset
= offset
;
68 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
69 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, 0, cow
);
72 leaf
= btrfs_buffer_leaf(path
->nodes
[0]);
75 if (path
->slots
[0] == 0)
78 btrfs_disk_key_to_cpu(&found_key
,
79 &leaf
->items
[path
->slots
[0]].key
);
80 if (btrfs_key_type(&found_key
) != BTRFS_CSUM_ITEM_KEY
||
81 found_key
.objectid
!= objectid
) {
84 csum_offset
= (offset
- found_key
.offset
) >>
85 root
->fs_info
->sb
->s_blocksize_bits
;
86 csums_in_item
= btrfs_item_size(leaf
->items
+ path
->slots
[0]);
87 csums_in_item
/= BTRFS_CRC32_SIZE
;
89 if (csum_offset
>= csums_in_item
) {
94 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
95 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
96 csum_offset
* BTRFS_CRC32_SIZE
);
105 int btrfs_lookup_file_extent(struct btrfs_trans_handle
*trans
,
106 struct btrfs_root
*root
,
107 struct btrfs_path
*path
, u64 objectid
,
111 struct btrfs_key file_key
;
112 int ins_len
= mod
< 0 ? -1 : 0;
115 file_key
.objectid
= objectid
;
116 file_key
.offset
= offset
;
118 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
119 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, ins_len
, cow
);
123 int btrfs_csum_file_block(struct btrfs_trans_handle
*trans
,
124 struct btrfs_root
*root
,
125 u64 objectid
, u64 offset
,
126 char *data
, size_t len
)
129 struct btrfs_key file_key
;
130 struct btrfs_key found_key
;
131 struct btrfs_path
*path
;
132 struct btrfs_csum_item
*item
;
133 struct btrfs_leaf
*leaf
;
136 path
= btrfs_alloc_path();
139 file_key
.objectid
= objectid
;
140 file_key
.offset
= offset
;
142 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
144 item
= btrfs_lookup_csum(trans
, root
, path
, objectid
, offset
, 1);
150 /* we found one, but it isn't big enough yet */
151 leaf
= btrfs_buffer_leaf(path
->nodes
[0]);
152 item_size
= btrfs_item_size(leaf
->items
+ path
->slots
[0]);
153 if ((item_size
/ BTRFS_CRC32_SIZE
) >= MAX_CSUM_ITEMS(root
)) {
154 /* already at max size, make a new one */
158 /* we didn't find a csum item, insert one */
163 * at this point, we know the tree has an item, but it isn't big
164 * enough yet to put our csum in. Grow it
166 btrfs_release_path(root
, path
);
167 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
,
168 BTRFS_CRC32_SIZE
, 1);
174 if (path
->slots
[0] == 0) {
178 leaf
= btrfs_buffer_leaf(path
->nodes
[0]);
179 btrfs_disk_key_to_cpu(&found_key
, &leaf
->items
[path
->slots
[0]].key
);
180 csum_offset
= (offset
- found_key
.offset
) >>
181 root
->fs_info
->sb
->s_blocksize_bits
;
182 if (btrfs_key_type(&found_key
) != BTRFS_CSUM_ITEM_KEY
||
183 found_key
.objectid
!= objectid
||
184 csum_offset
>= MAX_CSUM_ITEMS(root
)) {
187 if (csum_offset
>= btrfs_item_size(leaf
->items
+ path
->slots
[0]) /
189 u32 diff
= (csum_offset
+ 1) * BTRFS_CRC32_SIZE
;
190 diff
= diff
- btrfs_item_size(leaf
->items
+ path
->slots
[0]);
191 if (diff
!= BTRFS_CRC32_SIZE
)
193 ret
= btrfs_extend_item(trans
, root
, path
, diff
);
199 btrfs_release_path(root
, path
);
201 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
204 printk("at insert for %Lu %u %Lu ret is %d\n", file_key
.objectid
, file_key
.flags
, file_key
.offset
, ret
);
209 item
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]), path
->slots
[0],
210 struct btrfs_csum_item
);
212 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
213 csum_offset
* BTRFS_CRC32_SIZE
);
215 btrfs_check_bounds(&item
->csum
, BTRFS_CRC32_SIZE
,
216 path
->nodes
[0]->b_data
,
217 root
->fs_info
->sb
->s_blocksize
);
218 ret
= btrfs_csum_data(root
, data
, len
, &item
->csum
);
219 btrfs_mark_buffer_dirty(path
->nodes
[0]);
221 btrfs_release_path(root
, path
);
222 btrfs_free_path(path
);
226 int btrfs_csum_truncate(struct btrfs_trans_handle
*trans
,
227 struct btrfs_root
*root
, struct btrfs_path
*path
,
230 struct btrfs_key key
;
231 struct btrfs_leaf
*leaf
= btrfs_buffer_leaf(path
->nodes
[0]);
232 int slot
= path
->slots
[0];
238 btrfs_disk_key_to_cpu(&key
, &leaf
->items
[slot
].key
);
239 if (isize
<= key
.offset
)
241 new_item_span
= isize
- key
.offset
;
242 blocks
= (new_item_span
+ root
->blocksize
- 1) / root
->blocksize
;
243 new_item_size
= blocks
* BTRFS_CRC32_SIZE
;
244 if (new_item_size
>= btrfs_item_size(leaf
->items
+ slot
))
246 ret
= btrfs_truncate_item(trans
, root
, path
, new_item_size
);
251 int btrfs_csum_verify_file_block(struct btrfs_root
*root
,
252 u64 objectid
, u64 offset
,
253 char *data
, size_t len
)
256 struct btrfs_key file_key
;
257 struct btrfs_path
*path
;
258 struct btrfs_csum_item
*item
;
259 char result
[BTRFS_CRC32_SIZE
];
261 path
= btrfs_alloc_path();
263 btrfs_init_path(path
);
264 file_key
.objectid
= objectid
;
265 file_key
.offset
= offset
;
267 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
268 mutex_lock(&root
->fs_info
->fs_mutex
);
270 item
= btrfs_lookup_csum(NULL
, root
, path
, objectid
, offset
, 0);
273 /* a csum that isn't present is a preallocated region. */
274 if (ret
== -ENOENT
|| ret
== -EFBIG
)
279 ret
= btrfs_csum_data(root
, data
, len
, result
);
281 if (memcmp(result
, &item
->csum
, BTRFS_CRC32_SIZE
))
284 btrfs_release_path(root
, path
);
285 btrfs_free_path(path
);
286 mutex_unlock(&root
->fs_info
->fs_mutex
);
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