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)) / \
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);
23 ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
27 file_key.objectid = objectid;
28 file_key.offset = pos;
30 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
32 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
35 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
36 struct btrfs_file_extent_item);
37 btrfs_set_file_extent_disk_blocknr(item, offset);
38 btrfs_set_file_extent_disk_num_blocks(item, num_blocks);
39 btrfs_set_file_extent_offset(item, 0);
40 btrfs_set_file_extent_num_blocks(item, num_blocks);
41 btrfs_set_file_extent_generation(item, trans->transid);
42 btrfs_mark_buffer_dirty(path->nodes[0]);
43 btrfs_release_path(root, path);
44 btrfs_free_path(path);
48 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
49 struct btrfs_root *root,
50 struct btrfs_path *path,
51 u64 objectid, u64 offset,
55 struct btrfs_key file_key;
56 struct btrfs_key found_key;
57 struct btrfs_csum_item *item;
58 struct btrfs_leaf *leaf;
61 file_key.objectid = objectid;
62 file_key.offset = offset;
64 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
65 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
68 leaf = btrfs_buffer_leaf(path->nodes[0]);
71 if (path->slots[0] == 0)
74 btrfs_disk_key_to_cpu(&found_key,
75 &leaf->items[path->slots[0]].key);
76 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
77 found_key.objectid != objectid) {
80 csum_offset = (offset - found_key.offset) >>
81 root->fs_info->sb->s_blocksize_bits;
83 btrfs_item_size(leaf->items + path->slots[0]) /
84 sizeof(struct btrfs_csum_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();
131 btrfs_init_path(path);
133 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 0);
136 btrfs_release_path(root, path);
137 file_key.objectid = objectid;
138 file_key.offset = offset;
140 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
141 ret = btrfs_search_slot(trans, root, &file_key, path,
142 sizeof(struct btrfs_csum_item), 1);
148 if (path->slots[0] == 0) {
149 btrfs_release_path(root, path);
153 leaf = btrfs_buffer_leaf(path->nodes[0]);
154 btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
155 csum_offset = (offset - found_key.offset) >>
156 root->fs_info->sb->s_blocksize_bits;
157 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
158 found_key.objectid != objectid ||
159 csum_offset >= MAX_CSUM_ITEMS(root)) {
160 btrfs_release_path(root, path);
163 if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
164 sizeof(struct btrfs_csum_item)) {
165 ret = btrfs_extend_item(trans, root, path,
166 sizeof(struct btrfs_csum_item));
173 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
174 sizeof(struct btrfs_csum_item));
175 if (ret != 0 && ret != -EEXIST)
178 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
179 struct btrfs_csum_item);
183 ret = btrfs_csum_data(root, data, len, item->csum);
184 btrfs_mark_buffer_dirty(path->nodes[0]);
186 btrfs_release_path(root, path);
187 btrfs_free_path(path);
191 int btrfs_csum_verify_file_block(struct btrfs_root *root,
192 u64 objectid, u64 offset,
193 char *data, size_t len)
196 struct btrfs_key file_key;
197 struct btrfs_path *path;
198 struct btrfs_csum_item *item;
199 char result[BTRFS_CSUM_SIZE];
201 path = btrfs_alloc_path();
203 btrfs_init_path(path);
204 file_key.objectid = objectid;
205 file_key.offset = offset;
207 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
208 mutex_lock(&root->fs_info->fs_mutex);
210 item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
216 ret = btrfs_csum_data(root, data, len, result);
218 if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
221 btrfs_release_path(root, path);
222 btrfs_free_path(path);
223 mutex_unlock(&root->fs_info->fs_mutex);