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.
19 #include <linux/module.h>
22 #include "transaction.h"
23 #include "print-tree.h"
25 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
26 sizeof(struct btrfs_item) * 2) / \
27 BTRFS_CRC32_SIZE) - 1))
28 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
29 struct btrfs_root *root,
30 u64 objectid, u64 pos,
31 u64 offset, u64 disk_num_blocks,
35 struct btrfs_file_extent_item *item;
36 struct btrfs_key file_key;
37 struct btrfs_path *path;
39 path = btrfs_alloc_path();
41 file_key.objectid = objectid;
42 file_key.offset = pos;
44 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
46 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
49 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
50 struct btrfs_file_extent_item);
51 btrfs_set_file_extent_disk_blocknr(item, offset);
52 btrfs_set_file_extent_disk_num_blocks(item, disk_num_blocks);
53 btrfs_set_file_extent_offset(item, 0);
54 btrfs_set_file_extent_num_blocks(item, num_blocks);
55 btrfs_set_file_extent_generation(item, trans->transid);
56 btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
57 btrfs_mark_buffer_dirty(path->nodes[0]);
59 btrfs_release_path(root, path);
60 btrfs_free_path(path);
64 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
65 struct btrfs_root *root,
66 struct btrfs_path *path,
67 u64 objectid, u64 offset,
71 struct btrfs_key file_key;
72 struct btrfs_key found_key;
73 struct btrfs_csum_item *item;
74 struct btrfs_leaf *leaf;
78 file_key.objectid = objectid;
79 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 = btrfs_buffer_leaf(path->nodes[0]);
88 if (path->slots[0] == 0)
91 btrfs_disk_key_to_cpu(&found_key,
92 &leaf->items[path->slots[0]].key);
93 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
94 found_key.objectid != objectid) {
97 csum_offset = (offset - found_key.offset) >>
98 root->fs_info->sb->s_blocksize_bits;
99 csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
100 csums_in_item /= BTRFS_CRC32_SIZE;
102 if (csum_offset >= csums_in_item) {
107 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
108 item = (struct btrfs_csum_item *)((unsigned char *)item +
109 csum_offset * BTRFS_CRC32_SIZE);
118 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
119 struct btrfs_root *root,
120 struct btrfs_path *path, u64 objectid,
124 struct btrfs_key file_key;
125 int ins_len = mod < 0 ? -1 : 0;
128 file_key.objectid = objectid;
129 file_key.offset = offset;
131 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
132 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
136 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
137 struct btrfs_root *root,
138 u64 objectid, u64 offset,
139 char *data, size_t len)
142 struct btrfs_key file_key;
143 struct btrfs_key found_key;
144 struct btrfs_path *path;
145 struct btrfs_csum_item *item;
146 struct btrfs_leaf *leaf;
149 path = btrfs_alloc_path();
152 file_key.objectid = objectid;
153 file_key.offset = offset;
155 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
157 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
163 /* we found one, but it isn't big enough yet */
164 leaf = btrfs_buffer_leaf(path->nodes[0]);
165 item_size = btrfs_item_size(leaf->items + path->slots[0]);
166 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
167 /* already at max size, make a new one */
171 /* we didn't find a csum item, insert one */
176 * at this point, we know the tree has an item, but it isn't big
177 * enough yet to put our csum in. Grow it
179 btrfs_release_path(root, path);
180 ret = btrfs_search_slot(trans, root, &file_key, path,
181 BTRFS_CRC32_SIZE, 1);
187 if (path->slots[0] == 0) {
191 leaf = btrfs_buffer_leaf(path->nodes[0]);
192 btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
193 csum_offset = (offset - found_key.offset) >>
194 root->fs_info->sb->s_blocksize_bits;
195 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
196 found_key.objectid != objectid ||
197 csum_offset >= MAX_CSUM_ITEMS(root)) {
200 if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
202 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
203 diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
204 if (diff != BTRFS_CRC32_SIZE)
206 ret = btrfs_extend_item(trans, root, path, diff);
212 btrfs_release_path(root, path);
214 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
221 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
222 struct btrfs_csum_item);
224 item = (struct btrfs_csum_item *)((unsigned char *)item +
225 csum_offset * BTRFS_CRC32_SIZE);
227 btrfs_check_bounds(&item->csum, BTRFS_CRC32_SIZE,
228 path->nodes[0]->b_data,
229 root->fs_info->sb->s_blocksize);
230 ret = btrfs_csum_data(root, data, len, &item->csum);
231 // printk("file %lu offset %llu csum %X\n", objectid, (unsigned long long)offset, *(int *)(&item->csum));
232 btrfs_mark_buffer_dirty(path->nodes[0]);
234 btrfs_release_path(root, path);
235 btrfs_free_path(path);
239 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
240 struct btrfs_root *root, struct btrfs_path *path,
243 struct btrfs_key key;
244 struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[0]);
245 int slot = path->slots[0];
251 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
252 if (isize <= key.offset)
254 new_item_span = isize - key.offset;
255 blocks = (new_item_span + root->blocksize - 1) >>
256 root->fs_info->sb->s_blocksize_bits;
257 new_item_size = blocks * BTRFS_CRC32_SIZE;
258 if (new_item_size >= btrfs_item_size(leaf->items + slot))
260 ret = btrfs_truncate_item(trans, root, path, new_item_size);
265 int btrfs_csum_verify_file_block(struct btrfs_root *root,
266 u64 objectid, u64 offset,
267 char *data, size_t len)
270 struct btrfs_key file_key;
271 struct btrfs_path *path;
272 struct btrfs_csum_item *item;
273 char result[BTRFS_CRC32_SIZE];
275 path = btrfs_alloc_path();
277 file_key.objectid = objectid;
278 file_key.offset = offset;
280 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
281 mutex_lock(&root->fs_info->fs_mutex);
283 item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
286 /* a csum that isn't present is a preallocated region. */
287 if (ret == -ENOENT || ret == -EFBIG)
292 ret = btrfs_csum_data(root, data, len, result);
294 if (memcmp(result, &item->csum, BTRFS_CRC32_SIZE))
297 btrfs_release_path(root, path);
298 btrfs_free_path(path);
299 mutex_unlock(&root->fs_info->fs_mutex);