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 sizeof(struct btrfs_csum_item)) - 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 num_blocks)
15 struct btrfs_file_extent_item *item;
16 struct btrfs_key file_key;
17 struct btrfs_path *path;
19 path = btrfs_alloc_path();
21 btrfs_init_path(path);
22 file_key.objectid = objectid;
23 file_key.offset = pos;
25 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
27 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
30 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
31 struct btrfs_file_extent_item);
32 btrfs_set_file_extent_disk_blocknr(item, offset);
33 btrfs_set_file_extent_disk_num_blocks(item, num_blocks);
34 btrfs_set_file_extent_offset(item, 0);
35 btrfs_set_file_extent_num_blocks(item, num_blocks);
36 btrfs_set_file_extent_generation(item, trans->transid);
37 btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
38 btrfs_mark_buffer_dirty(path->nodes[0]);
40 btrfs_release_path(root, path);
41 btrfs_free_path(path);
45 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
46 struct btrfs_root *root,
47 struct btrfs_path *path,
48 u64 objectid, u64 offset,
52 struct btrfs_key file_key;
53 struct btrfs_key found_key;
54 struct btrfs_csum_item *item;
55 struct btrfs_leaf *leaf;
59 file_key.objectid = objectid;
60 file_key.offset = offset;
62 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
63 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
66 leaf = btrfs_buffer_leaf(path->nodes[0]);
69 if (path->slots[0] == 0)
72 btrfs_disk_key_to_cpu(&found_key,
73 &leaf->items[path->slots[0]].key);
74 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
75 found_key.objectid != objectid) {
78 csum_offset = (offset - found_key.offset) >>
79 root->fs_info->sb->s_blocksize_bits;
80 csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
81 csums_in_item /= sizeof(struct btrfs_csum_item);
83 if (csum_offset >= csums_in_item) {
88 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
98 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
99 struct btrfs_root *root,
100 struct btrfs_path *path, u64 objectid,
104 struct btrfs_key file_key;
105 int ins_len = mod < 0 ? -1 : 0;
108 file_key.objectid = objectid;
109 file_key.offset = offset;
111 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
112 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
116 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
117 struct btrfs_root *root,
118 u64 objectid, u64 offset,
119 char *data, size_t len)
122 struct btrfs_key file_key;
123 struct btrfs_key found_key;
124 struct btrfs_path *path;
125 struct btrfs_csum_item *item;
126 struct btrfs_leaf *leaf;
129 path = btrfs_alloc_path();
132 file_key.objectid = objectid;
133 file_key.offset = offset;
135 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
137 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
143 /* we found one, but it isn't big enough yet */
144 leaf = btrfs_buffer_leaf(path->nodes[0]);
145 item_size = btrfs_item_size(leaf->items + path->slots[0]);
146 if ((item_size / sizeof(struct btrfs_csum_item)) >=
147 MAX_CSUM_ITEMS(root)) {
148 /* already at max size, make a new one */
152 /* we didn't find a csum item, insert one */
157 * at this point, we know the tree has an item, but it isn't big
158 * enough yet to put our csum in. Grow it
160 btrfs_release_path(root, path);
161 ret = btrfs_search_slot(trans, root, &file_key, path,
162 sizeof(struct btrfs_csum_item), 1);
168 if (path->slots[0] == 0) {
172 leaf = btrfs_buffer_leaf(path->nodes[0]);
173 btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
174 csum_offset = (offset - found_key.offset) >>
175 root->fs_info->sb->s_blocksize_bits;
176 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
177 found_key.objectid != objectid ||
178 csum_offset >= MAX_CSUM_ITEMS(root)) {
182 if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
183 sizeof(struct btrfs_csum_item)) {
184 u32 diff = (csum_offset + 1) * sizeof(struct btrfs_csum_item);
185 diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
186 WARN_ON(diff != sizeof(struct btrfs_csum_item));
187 ret = btrfs_extend_item(trans, root, path, diff);
193 btrfs_release_path(root, path);
195 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
196 sizeof(struct btrfs_csum_item));
198 printk("at insert for %Lu %u %Lu ret is %d\n", file_key.objectid, file_key.flags, file_key.offset, ret);
203 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
204 struct btrfs_csum_item);
208 btrfs_check_bounds(item->csum, BTRFS_CSUM_SIZE, path->nodes[0]->b_data, root->fs_info->sb->s_blocksize);
209 ret = btrfs_csum_data(root, data, len, item->csum);
210 btrfs_mark_buffer_dirty(path->nodes[0]);
212 btrfs_release_path(root, path);
213 btrfs_free_path(path);
217 int btrfs_csum_verify_file_block(struct btrfs_root *root,
218 u64 objectid, u64 offset,
219 char *data, size_t len)
222 struct btrfs_key file_key;
223 struct btrfs_path *path;
224 struct btrfs_csum_item *item;
225 char result[BTRFS_CSUM_SIZE];
227 path = btrfs_alloc_path();
229 btrfs_init_path(path);
230 file_key.objectid = objectid;
231 file_key.offset = offset;
233 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
234 mutex_lock(&root->fs_info->fs_mutex);
236 item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
239 /* a csum that isn't present is a preallocated region. */
240 if (ret == -ENOENT || ret == -EFBIG)
245 ret = btrfs_csum_data(root, data, len, result);
247 if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
250 btrfs_release_path(root, path);
251 btrfs_free_path(path);
252 mutex_unlock(&root->fs_info->fs_mutex);