1 #include <linux/module.h> 2 #include "ctree.h" 3 #include "disk-io.h" 4 #include "transaction.h" 5 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) 13 { 14 int ret = 0; 15 struct btrfs_file_extent_item *item; 16 struct btrfs_key file_key; 17 struct btrfs_path *path; 18 19 path = btrfs_alloc_path(); 20 BUG_ON(!path); 21 btrfs_init_path(path); 22 /* 23 ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block, 24 (u64)-1, &ins); 25 */ 26 BUG_ON(ret); 27 file_key.objectid = objectid; 28 file_key.offset = pos; 29 file_key.flags = 0; 30 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); 31 32 ret = btrfs_insert_empty_item(trans, root, path, &file_key, 33 sizeof(*item)); 34 BUG_ON(ret); 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); 45 return 0; 46 } 47 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, 52 int cow) 53 { 54 int ret; 55 struct btrfs_key file_key; 56 struct btrfs_key found_key; 57 struct btrfs_csum_item *item; 58 struct btrfs_leaf *leaf; 59 u64 csum_offset = 0; 60 61 file_key.objectid = objectid; 62 file_key.offset = offset; 63 file_key.flags = 0; 64 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY); 65 printk("__lookup for %Lu\n", offset); 66 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow); 67 if (ret < 0) 68 goto fail; 69 leaf = btrfs_buffer_leaf(path->nodes[0]); 70 if (ret > 0) { 71 ret = 1; 72 if (path->slots[0] == 0) { 73 printk("fail1\n"); 74 goto fail; 75 } 76 path->slots[0]--; 77 btrfs_disk_key_to_cpu(&found_key, 78 &leaf->items[path->slots[0]].key); 79 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY || 80 found_key.objectid != objectid) { 81 printk("fail2 type %u %Lu %Lu\n", btrfs_key_type(&found_key), found_key.objectid, objectid); 82 goto fail; 83 } 84 csum_offset = (offset - found_key.offset) >> 85 root->fs_info->sb->s_blocksize_bits; 86 if (csum_offset >= 87 btrfs_item_size(leaf->items + path->slots[0]) / 88 sizeof(struct btrfs_csum_item)) { 89 printk("fail3, csum offset %lu size %u\n", csum_offset, btrfs_item_size(leaf->items + path->slots[0]) / sizeof(struct btrfs_csum_item)); 90 goto fail; 91 } 92 } 93 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); 94 item += csum_offset; 95 return item; 96 fail: 97 if (ret > 0) 98 ret = -ENOENT; 99 return ERR_PTR(ret); 100 } 101 102 103 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, 104 struct btrfs_root *root, 105 struct btrfs_path *path, u64 objectid, 106 u64 offset, int mod) 107 { 108 int ret; 109 struct btrfs_key file_key; 110 int ins_len = mod < 0 ? -1 : 0; 111 int cow = mod != 0; 112 struct btrfs_csum_item *csum_item; 113 114 csum_item = btrfs_lookup_csum(trans, root, path, objectid, offset, 0); 115 if (IS_ERR(csum_item)) 116 return PTR_ERR(csum_item); 117 file_key.objectid = objectid; 118 file_key.offset = btrfs_csum_extent_offset(csum_item); 119 file_key.flags = 0; 120 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); 121 btrfs_release_path(root, path); 122 printk("lookup file extent searches for %Lu\n", file_key.offset); 123 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); 124 printk("ret is %d\n", ret); 125 return ret; 126 } 127 128 int btrfs_csum_file_block(struct btrfs_trans_handle *trans, 129 struct btrfs_root *root, 130 u64 objectid, u64 offset, 131 u64 extent_offset, 132 char *data, size_t len) 133 { 134 int ret; 135 struct btrfs_key file_key; 136 struct btrfs_key found_key; 137 struct btrfs_path *path; 138 struct btrfs_csum_item *item; 139 struct btrfs_leaf *leaf; 140 u64 csum_offset; 141 142 path = btrfs_alloc_path(); 143 BUG_ON(!path); 144 btrfs_init_path(path); 145 146 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 0); 147 if (!IS_ERR(item)) 148 goto found; 149 btrfs_release_path(root, path); 150 file_key.objectid = objectid; 151 file_key.offset = offset; 152 file_key.flags = 0; 153 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY); 154 printk("searching for csum %Lu %Lu\n", objectid, offset); 155 ret = btrfs_search_slot(trans, root, &file_key, path, 156 sizeof(struct btrfs_csum_item), 1); 157 printk("ret %d\n", ret); 158 if (ret < 0) 159 goto fail; 160 if (ret == 0) { 161 BUG(); 162 } 163 if (path->slots[0] == 0) { 164 btrfs_release_path(root, path); 165 goto insert; 166 } 167 path->slots[0]--; 168 leaf = btrfs_buffer_leaf(path->nodes[0]); 169 btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key); 170 printk("found key %Lu %Lu %u\n", found_key.objectid, found_key.offset, found_key.flags); 171 csum_offset = (offset - found_key.offset) >> 172 root->fs_info->sb->s_blocksize_bits; 173 printk("csum_offset %Lu\n", csum_offset); 174 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY || 175 found_key.objectid != objectid || 176 csum_offset >= MAX_CSUM_ITEMS(root)) { 177 btrfs_release_path(root, path); 178 printk("insert1\n"); 179 goto insert; 180 } 181 if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) / 182 sizeof(struct btrfs_csum_item)) { 183 ret = btrfs_extend_item(trans, root, path, 184 sizeof(struct btrfs_csum_item)); 185 BUG_ON(ret); 186 printk("item extended\n"); 187 goto csum; 188 } 189 190 insert: 191 csum_offset = 0; 192 printk("inserting item %Lu %Lu %u\n", file_key.objectid, file_key.offset, file_key.flags); 193 ret = btrfs_insert_empty_item(trans, root, path, &file_key, 194 sizeof(struct btrfs_csum_item)); 195 if (ret != 0 && ret != -EEXIST) 196 goto fail; 197 csum: 198 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0], 199 struct btrfs_csum_item); 200 ret = 0; 201 item += csum_offset; 202 found: 203 ret = btrfs_csum_data(root, data, len, item->csum); 204 btrfs_set_csum_extent_offset(item, extent_offset); 205 btrfs_mark_buffer_dirty(path->nodes[0]); 206 fail: 207 btrfs_release_path(root, path); 208 btrfs_free_path(path); 209 printk("return ret %d\n", ret); 210 return ret; 211 } 212 213 int btrfs_csum_verify_file_block(struct btrfs_root *root, 214 u64 objectid, u64 offset, 215 char *data, size_t len) 216 { 217 int ret; 218 struct btrfs_key file_key; 219 struct btrfs_path *path; 220 struct btrfs_csum_item *item; 221 char result[BTRFS_CSUM_SIZE]; 222 223 path = btrfs_alloc_path(); 224 BUG_ON(!path); 225 btrfs_init_path(path); 226 file_key.objectid = objectid; 227 file_key.offset = offset; 228 file_key.flags = 0; 229 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY); 230 mutex_lock(&root->fs_info->fs_mutex); 231 232 item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0); 233 if (IS_ERR(item)) { 234 ret = PTR_ERR(item); 235 goto fail; 236 } 237 238 ret = btrfs_csum_data(root, data, len, result); 239 WARN_ON(ret); 240 if (memcmp(result, item->csum, BTRFS_CSUM_SIZE)) 241 ret = 1; 242 fail: 243 btrfs_release_path(root, path); 244 btrfs_free_path(path); 245 mutex_unlock(&root->fs_info->fs_mutex); 246 return ret; 247 } 248 249