2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
21 #include "transaction.h"
22 #include "print-tree.h"
24 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
25 sizeof(struct btrfs_item) * 2) / \
26 BTRFS_CRC32_SIZE) - 1))
27 int btrfs_insert_file_extent(struct btrfs_trans_handle
*trans
,
28 struct btrfs_root
*root
,
29 u64 objectid
, u64 pos
,
30 u64 offset
, u64 disk_num_bytes
,
34 struct btrfs_file_extent_item
*item
;
35 struct btrfs_key file_key
;
36 struct btrfs_path
*path
;
37 struct extent_buffer
*leaf
;
39 path
= btrfs_alloc_path();
41 file_key
.objectid
= objectid
;
42 file_key
.offset
= pos
;
43 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
45 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
50 leaf
= path
->nodes
[0];
51 item
= btrfs_item_ptr(leaf
, path
->slots
[0],
52 struct btrfs_file_extent_item
);
53 btrfs_set_file_extent_disk_bytenr(leaf
, item
, offset
);
54 btrfs_set_file_extent_disk_num_bytes(leaf
, item
, disk_num_bytes
);
55 btrfs_set_file_extent_offset(leaf
, item
, 0);
56 btrfs_set_file_extent_num_bytes(leaf
, item
, num_bytes
);
57 btrfs_set_file_extent_generation(leaf
, item
, trans
->transid
);
58 btrfs_set_file_extent_type(leaf
, item
, BTRFS_FILE_EXTENT_REG
);
59 btrfs_mark_buffer_dirty(leaf
);
61 btrfs_free_path(path
);
65 struct btrfs_csum_item
*btrfs_lookup_csum(struct btrfs_trans_handle
*trans
,
66 struct btrfs_root
*root
,
67 struct btrfs_path
*path
,
68 u64 objectid
, u64 offset
,
72 struct btrfs_key file_key
;
73 struct btrfs_key found_key
;
74 struct btrfs_csum_item
*item
;
75 struct extent_buffer
*leaf
;
79 file_key
.objectid
= objectid
;
80 file_key
.offset
= offset
;
81 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
82 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, 0, cow
);
85 leaf
= path
->nodes
[0];
88 if (path
->slots
[0] == 0)
91 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
92 if (btrfs_key_type(&found_key
) != BTRFS_CSUM_ITEM_KEY
||
93 found_key
.objectid
!= objectid
) {
96 csum_offset
= (offset
- found_key
.offset
) >>
97 root
->fs_info
->sb
->s_blocksize_bits
;
98 csums_in_item
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
99 csums_in_item
/= BTRFS_CRC32_SIZE
;
101 if (csum_offset
>= csums_in_item
) {
106 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
107 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
108 csum_offset
* BTRFS_CRC32_SIZE
);
117 int btrfs_lookup_file_extent(struct btrfs_trans_handle
*trans
,
118 struct btrfs_root
*root
,
119 struct btrfs_path
*path
, u64 objectid
,
123 struct btrfs_key file_key
;
124 int ins_len
= mod
< 0 ? -1 : 0;
127 file_key
.objectid
= objectid
;
128 file_key
.offset
= offset
;
129 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
130 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, ins_len
, cow
);
134 int btrfs_csum_file_block(struct btrfs_trans_handle
*trans
,
135 struct btrfs_root
*root
,
137 u64 objectid
, u64 offset
,
138 char *data
, size_t len
)
141 struct btrfs_key file_key
;
142 struct btrfs_key found_key
;
143 u64 next_offset
= (u64
)-1;
145 struct btrfs_path
*path
;
146 struct btrfs_csum_item
*item
;
147 struct extent_buffer
*leaf
= NULL
;
149 u32 csum_result
= ~(u32
)0;
153 path
= btrfs_alloc_path();
156 file_key
.objectid
= objectid
;
157 file_key
.offset
= offset
;
158 btrfs_set_key_type(&file_key
, BTRFS_CSUM_ITEM_KEY
);
160 item
= btrfs_lookup_csum(trans
, root
, path
, objectid
, offset
, 1);
162 leaf
= path
->nodes
[0];
168 /* we found one, but it isn't big enough yet */
169 leaf
= path
->nodes
[0];
170 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
171 if ((item_size
/ BTRFS_CRC32_SIZE
) >= MAX_CSUM_ITEMS(root
)) {
172 /* already at max size, make a new one */
176 int slot
= path
->slots
[0] + 1;
177 /* we didn't find a csum item, insert one */
178 nritems
= btrfs_header_nritems(path
->nodes
[0]);
179 if (path
->slots
[0] >= nritems
- 1) {
180 ret
= btrfs_next_leaf(root
, path
);
183 } else if (ret
== 0) {
189 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, slot
);
190 if (found_key
.objectid
!= objectid
||
191 found_key
.type
!= BTRFS_CSUM_ITEM_KEY
) {
195 next_offset
= found_key
.offset
;
201 * at this point, we know the tree has an item, but it isn't big
202 * enough yet to put our csum in. Grow it
204 btrfs_release_path(root
, path
);
205 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
,
206 BTRFS_CRC32_SIZE
, 1);
212 if (path
->slots
[0] == 0) {
216 leaf
= path
->nodes
[0];
217 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
218 csum_offset
= (offset
- found_key
.offset
) >>
219 root
->fs_info
->sb
->s_blocksize_bits
;
220 if (btrfs_key_type(&found_key
) != BTRFS_CSUM_ITEM_KEY
||
221 found_key
.objectid
!= objectid
||
222 csum_offset
>= MAX_CSUM_ITEMS(root
)) {
225 if (csum_offset
>= btrfs_item_size_nr(leaf
, path
->slots
[0]) /
227 u32 diff
= (csum_offset
+ 1) * BTRFS_CRC32_SIZE
;
228 diff
= diff
- btrfs_item_size_nr(leaf
, path
->slots
[0]);
229 if (diff
!= BTRFS_CRC32_SIZE
)
231 ret
= btrfs_extend_item(trans
, root
, path
, diff
);
237 btrfs_release_path(root
, path
);
240 u64 tmp
= min((u64
)i_size_read(inode
), next_offset
);
241 tmp
-= offset
+ root
->sectorsize
- 1;
242 tmp
>>= root
->fs_info
->sb
->s_blocksize_bits
;
243 tmp
= max((u64
)1, tmp
);
244 tmp
= min(tmp
, (u64
)MAX_CSUM_ITEMS(root
));
245 ins_size
= BTRFS_CRC32_SIZE
* tmp
;
247 ins_size
= BTRFS_CRC32_SIZE
;
249 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
258 leaf
= path
->nodes
[0];
259 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
261 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
262 csum_offset
* BTRFS_CRC32_SIZE
);
264 csum_result
= btrfs_csum_data(root
, data
, csum_result
, len
);
265 btrfs_csum_final(csum_result
, (char *)&csum_result
);
266 write_extent_buffer(leaf
, &csum_result
, (unsigned long)item
,
268 btrfs_mark_buffer_dirty(path
->nodes
[0]);
270 btrfs_release_path(root
, path
);
271 btrfs_free_path(path
);
275 int btrfs_csum_truncate(struct btrfs_trans_handle
*trans
,
276 struct btrfs_root
*root
, struct btrfs_path
*path
,
279 struct btrfs_key key
;
280 struct extent_buffer
*leaf
= path
->nodes
[0];
281 int slot
= path
->slots
[0];
287 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
288 if (isize
<= key
.offset
)
290 new_item_span
= isize
- key
.offset
;
291 blocks
= (new_item_span
+ root
->sectorsize
- 1) >>
292 root
->fs_info
->sb
->s_blocksize_bits
;
293 new_item_size
= blocks
* BTRFS_CRC32_SIZE
;
294 if (new_item_size
>= btrfs_item_size_nr(leaf
, slot
))
296 ret
= btrfs_truncate_item(trans
, root
, path
, new_item_size
);
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