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_mark_buffer_dirty(path->nodes[0]);
39 btrfs_release_path(root, path);
40 btrfs_free_path(path);
44 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
45 struct btrfs_root *root,
46 struct btrfs_path *path,
47 u64 objectid, u64 offset,
51 struct btrfs_key file_key;
52 struct btrfs_key found_key;
53 struct btrfs_csum_item *item;
54 struct btrfs_leaf *leaf;
58 file_key.objectid = objectid;
59 file_key.offset = offset;
61 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
62 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
65 leaf = btrfs_buffer_leaf(path->nodes[0]);
68 if (path->slots[0] == 0)
71 btrfs_disk_key_to_cpu(&found_key,
72 &leaf->items[path->slots[0]].key);
73 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
74 found_key.objectid != objectid) {
77 csum_offset = (offset - found_key.offset) >>
78 root->fs_info->sb->s_blocksize_bits;
79 csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
80 csums_in_item /= sizeof(struct btrfs_csum_item);
82 if (csum_offset >= csums_in_item) {
87 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
97 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
98 struct btrfs_root *root,
99 struct btrfs_path *path, u64 objectid,
103 struct btrfs_key file_key;
104 int ins_len = mod < 0 ? -1 : 0;
107 file_key.objectid = objectid;
108 file_key.offset = offset;
110 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
111 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
115 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
116 struct btrfs_root *root,
117 u64 objectid, u64 offset,
118 char *data, size_t len)
121 struct btrfs_key file_key;
122 struct btrfs_key found_key;
123 struct btrfs_path *path;
124 struct btrfs_csum_item *item;
125 struct btrfs_leaf *leaf;
128 path = btrfs_alloc_path();
131 file_key.objectid = objectid;
132 file_key.offset = offset;
134 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
136 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
142 /* we found one, but it isn't big enough yet */
143 leaf = btrfs_buffer_leaf(path->nodes[0]);
144 item_size = btrfs_item_size(leaf->items + path->slots[0]);
145 if ((item_size / sizeof(struct btrfs_csum_item)) >=
146 MAX_CSUM_ITEMS(root)) {
147 /* already at max size, make a new one */
151 /* we didn't find a csum item, insert one */
156 * at this point, we know the tree has an item, but it isn't big
157 * enough yet to put our csum in. Grow it
159 btrfs_release_path(root, path);
160 ret = btrfs_search_slot(trans, root, &file_key, path,
161 sizeof(struct btrfs_csum_item), 1);
167 if (path->slots[0] == 0) {
171 leaf = btrfs_buffer_leaf(path->nodes[0]);
172 btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
173 csum_offset = (offset - found_key.offset) >>
174 root->fs_info->sb->s_blocksize_bits;
175 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
176 found_key.objectid != objectid ||
177 csum_offset >= MAX_CSUM_ITEMS(root)) {
181 if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
182 sizeof(struct btrfs_csum_item)) {
183 u32 diff = (csum_offset + 1) * sizeof(struct btrfs_csum_item);
184 diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
185 WARN_ON(diff != sizeof(struct btrfs_csum_item));
186 ret = btrfs_extend_item(trans, root, path, diff);
192 btrfs_release_path(root, path);
194 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
195 sizeof(struct btrfs_csum_item));
197 printk("at insert for %Lu %u %Lu ret is %d\n", file_key.objectid, file_key.flags, file_key.offset, ret);
202 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
203 struct btrfs_csum_item);
207 btrfs_check_bounds(item->csum, BTRFS_CSUM_SIZE, path->nodes[0]->b_data, root->fs_info->sb->s_blocksize);
208 ret = btrfs_csum_data(root, data, len, item->csum);
209 btrfs_mark_buffer_dirty(path->nodes[0]);
211 btrfs_release_path(root, path);
212 btrfs_free_path(path);
216 int btrfs_csum_verify_file_block(struct btrfs_root *root,
217 u64 objectid, u64 offset,
218 char *data, size_t len)
221 struct btrfs_key file_key;
222 struct btrfs_path *path;
223 struct btrfs_csum_item *item;
224 char result[BTRFS_CSUM_SIZE];
226 path = btrfs_alloc_path();
228 btrfs_init_path(path);
229 file_key.objectid = objectid;
230 file_key.offset = offset;
232 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
233 mutex_lock(&root->fs_info->fs_mutex);
235 item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
238 /* a csum that isn't present is a preallocated region. */
239 if (ret == -ENOENT || ret == -EFBIG)
244 ret = btrfs_csum_data(root, data, len, result);
246 if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
249 btrfs_release_path(root, path);
250 btrfs_free_path(path);
251 mutex_unlock(&root->fs_info->fs_mutex);