| 1 | /* |
| 2 | * Copyright (C) 2007 Oracle. All rights reserved. |
| 3 | * |
| 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. |
| 7 | * |
| 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. |
| 12 | * |
| 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. |
| 17 | */ |
| 18 | |
| 19 | #include "ctree.h" |
| 20 | #include "disk-io.h" |
| 21 | #include "hash.h" |
| 22 | #include "transaction.h" |
| 23 | |
| 24 | /* |
| 25 | * insert a name into a directory, doing overflow properly if there is a hash |
| 26 | * collision. data_size indicates how big the item inserted should be. On |
| 27 | * success a struct btrfs_dir_item pointer is returned, otherwise it is |
| 28 | * an ERR_PTR. |
| 29 | * |
| 30 | * The name is not copied into the dir item, you have to do that yourself. |
| 31 | */ |
| 32 | static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle |
| 33 | *trans, |
| 34 | struct btrfs_root *root, |
| 35 | struct btrfs_path *path, |
| 36 | struct btrfs_key *cpu_key, |
| 37 | u32 data_size, |
| 38 | const char *name, |
| 39 | int name_len) |
| 40 | { |
| 41 | int ret; |
| 42 | char *ptr; |
| 43 | struct btrfs_item *item; |
| 44 | struct extent_buffer *leaf; |
| 45 | |
| 46 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
| 47 | if (ret == -EEXIST) { |
| 48 | struct btrfs_dir_item *di; |
| 49 | di = btrfs_match_dir_item_name(root, path, name, name_len); |
| 50 | if (di) |
| 51 | return ERR_PTR(-EEXIST); |
| 52 | btrfs_extend_item(root, path, data_size); |
| 53 | } else if (ret < 0) |
| 54 | return ERR_PTR(ret); |
| 55 | WARN_ON(ret > 0); |
| 56 | leaf = path->nodes[0]; |
| 57 | item = btrfs_item_nr(path->slots[0]); |
| 58 | ptr = btrfs_item_ptr(leaf, path->slots[0], char); |
| 59 | BUG_ON(data_size > btrfs_item_size(leaf, item)); |
| 60 | ptr += btrfs_item_size(leaf, item) - data_size; |
| 61 | return (struct btrfs_dir_item *)ptr; |
| 62 | } |
| 63 | |
| 64 | /* |
| 65 | * xattrs work a lot like directories, this inserts an xattr item |
| 66 | * into the tree |
| 67 | */ |
| 68 | int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans, |
| 69 | struct btrfs_root *root, |
| 70 | struct btrfs_path *path, u64 objectid, |
| 71 | const char *name, u16 name_len, |
| 72 | const void *data, u16 data_len) |
| 73 | { |
| 74 | int ret = 0; |
| 75 | struct btrfs_dir_item *dir_item; |
| 76 | unsigned long name_ptr, data_ptr; |
| 77 | struct btrfs_key key, location; |
| 78 | struct btrfs_disk_key disk_key; |
| 79 | struct extent_buffer *leaf; |
| 80 | u32 data_size; |
| 81 | |
| 82 | BUG_ON(name_len + data_len > BTRFS_MAX_XATTR_SIZE(root)); |
| 83 | |
| 84 | key.objectid = objectid; |
| 85 | key.type = BTRFS_XATTR_ITEM_KEY; |
| 86 | key.offset = btrfs_name_hash(name, name_len); |
| 87 | |
| 88 | data_size = sizeof(*dir_item) + name_len + data_len; |
| 89 | dir_item = insert_with_overflow(trans, root, path, &key, data_size, |
| 90 | name, name_len); |
| 91 | if (IS_ERR(dir_item)) |
| 92 | return PTR_ERR(dir_item); |
| 93 | memset(&location, 0, sizeof(location)); |
| 94 | |
| 95 | leaf = path->nodes[0]; |
| 96 | btrfs_cpu_key_to_disk(&disk_key, &location); |
| 97 | btrfs_set_dir_item_key(leaf, dir_item, &disk_key); |
| 98 | btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR); |
| 99 | btrfs_set_dir_name_len(leaf, dir_item, name_len); |
| 100 | btrfs_set_dir_transid(leaf, dir_item, trans->transid); |
| 101 | btrfs_set_dir_data_len(leaf, dir_item, data_len); |
| 102 | name_ptr = (unsigned long)(dir_item + 1); |
| 103 | data_ptr = (unsigned long)((char *)name_ptr + name_len); |
| 104 | |
| 105 | write_extent_buffer(leaf, name, name_ptr, name_len); |
| 106 | write_extent_buffer(leaf, data, data_ptr, data_len); |
| 107 | btrfs_mark_buffer_dirty(path->nodes[0]); |
| 108 | |
| 109 | return ret; |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * insert a directory item in the tree, doing all the magic for |
| 114 | * both indexes. 'dir' indicates which objectid to insert it into, |
| 115 | * 'location' is the key to stuff into the directory item, 'type' is the |
| 116 | * type of the inode we're pointing to, and 'index' is the sequence number |
| 117 | * to use for the second index (if one is created). |
| 118 | * Will return 0 or -ENOMEM |
| 119 | */ |
| 120 | int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root |
| 121 | *root, const char *name, int name_len, |
| 122 | struct inode *dir, struct btrfs_key *location, |
| 123 | u8 type, u64 index) |
| 124 | { |
| 125 | int ret = 0; |
| 126 | int ret2 = 0; |
| 127 | struct btrfs_path *path; |
| 128 | struct btrfs_dir_item *dir_item; |
| 129 | struct extent_buffer *leaf; |
| 130 | unsigned long name_ptr; |
| 131 | struct btrfs_key key; |
| 132 | struct btrfs_disk_key disk_key; |
| 133 | u32 data_size; |
| 134 | |
| 135 | key.objectid = btrfs_ino(dir); |
| 136 | key.type = BTRFS_DIR_ITEM_KEY; |
| 137 | key.offset = btrfs_name_hash(name, name_len); |
| 138 | |
| 139 | path = btrfs_alloc_path(); |
| 140 | if (!path) |
| 141 | return -ENOMEM; |
| 142 | path->leave_spinning = 1; |
| 143 | |
| 144 | btrfs_cpu_key_to_disk(&disk_key, location); |
| 145 | |
| 146 | data_size = sizeof(*dir_item) + name_len; |
| 147 | dir_item = insert_with_overflow(trans, root, path, &key, data_size, |
| 148 | name, name_len); |
| 149 | if (IS_ERR(dir_item)) { |
| 150 | ret = PTR_ERR(dir_item); |
| 151 | if (ret == -EEXIST) |
| 152 | goto second_insert; |
| 153 | goto out_free; |
| 154 | } |
| 155 | |
| 156 | leaf = path->nodes[0]; |
| 157 | btrfs_set_dir_item_key(leaf, dir_item, &disk_key); |
| 158 | btrfs_set_dir_type(leaf, dir_item, type); |
| 159 | btrfs_set_dir_data_len(leaf, dir_item, 0); |
| 160 | btrfs_set_dir_name_len(leaf, dir_item, name_len); |
| 161 | btrfs_set_dir_transid(leaf, dir_item, trans->transid); |
| 162 | name_ptr = (unsigned long)(dir_item + 1); |
| 163 | |
| 164 | write_extent_buffer(leaf, name, name_ptr, name_len); |
| 165 | btrfs_mark_buffer_dirty(leaf); |
| 166 | |
| 167 | second_insert: |
| 168 | /* FIXME, use some real flag for selecting the extra index */ |
| 169 | if (root == root->fs_info->tree_root) { |
| 170 | ret = 0; |
| 171 | goto out_free; |
| 172 | } |
| 173 | btrfs_release_path(path); |
| 174 | |
| 175 | ret2 = btrfs_insert_delayed_dir_index(trans, root, name, name_len, dir, |
| 176 | &disk_key, type, index); |
| 177 | out_free: |
| 178 | btrfs_free_path(path); |
| 179 | if (ret) |
| 180 | return ret; |
| 181 | if (ret2) |
| 182 | return ret2; |
| 183 | return 0; |
| 184 | } |
| 185 | |
| 186 | /* |
| 187 | * lookup a directory item based on name. 'dir' is the objectid |
| 188 | * we're searching in, and 'mod' tells us if you plan on deleting the |
| 189 | * item (use mod < 0) or changing the options (use mod > 0) |
| 190 | */ |
| 191 | struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, |
| 192 | struct btrfs_root *root, |
| 193 | struct btrfs_path *path, u64 dir, |
| 194 | const char *name, int name_len, |
| 195 | int mod) |
| 196 | { |
| 197 | int ret; |
| 198 | struct btrfs_key key; |
| 199 | int ins_len = mod < 0 ? -1 : 0; |
| 200 | int cow = mod != 0; |
| 201 | |
| 202 | key.objectid = dir; |
| 203 | key.type = BTRFS_DIR_ITEM_KEY; |
| 204 | |
| 205 | key.offset = btrfs_name_hash(name, name_len); |
| 206 | |
| 207 | ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); |
| 208 | if (ret < 0) |
| 209 | return ERR_PTR(ret); |
| 210 | if (ret > 0) |
| 211 | return NULL; |
| 212 | |
| 213 | return btrfs_match_dir_item_name(root, path, name, name_len); |
| 214 | } |
| 215 | |
| 216 | int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir, |
| 217 | const char *name, int name_len) |
| 218 | { |
| 219 | int ret; |
| 220 | struct btrfs_key key; |
| 221 | struct btrfs_dir_item *di; |
| 222 | int data_size; |
| 223 | struct extent_buffer *leaf; |
| 224 | int slot; |
| 225 | struct btrfs_path *path; |
| 226 | |
| 227 | |
| 228 | path = btrfs_alloc_path(); |
| 229 | if (!path) |
| 230 | return -ENOMEM; |
| 231 | |
| 232 | key.objectid = dir; |
| 233 | key.type = BTRFS_DIR_ITEM_KEY; |
| 234 | key.offset = btrfs_name_hash(name, name_len); |
| 235 | |
| 236 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 237 | |
| 238 | /* return back any errors */ |
| 239 | if (ret < 0) |
| 240 | goto out; |
| 241 | |
| 242 | /* nothing found, we're safe */ |
| 243 | if (ret > 0) { |
| 244 | ret = 0; |
| 245 | goto out; |
| 246 | } |
| 247 | |
| 248 | /* we found an item, look for our name in the item */ |
| 249 | di = btrfs_match_dir_item_name(root, path, name, name_len); |
| 250 | if (di) { |
| 251 | /* our exact name was found */ |
| 252 | ret = -EEXIST; |
| 253 | goto out; |
| 254 | } |
| 255 | |
| 256 | /* |
| 257 | * see if there is room in the item to insert this |
| 258 | * name |
| 259 | */ |
| 260 | data_size = sizeof(*di) + name_len; |
| 261 | leaf = path->nodes[0]; |
| 262 | slot = path->slots[0]; |
| 263 | if (data_size + btrfs_item_size_nr(leaf, slot) + |
| 264 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) { |
| 265 | ret = -EOVERFLOW; |
| 266 | } else { |
| 267 | /* plenty of insertion room */ |
| 268 | ret = 0; |
| 269 | } |
| 270 | out: |
| 271 | btrfs_free_path(path); |
| 272 | return ret; |
| 273 | } |
| 274 | |
| 275 | /* |
| 276 | * lookup a directory item based on index. 'dir' is the objectid |
| 277 | * we're searching in, and 'mod' tells us if you plan on deleting the |
| 278 | * item (use mod < 0) or changing the options (use mod > 0) |
| 279 | * |
| 280 | * The name is used to make sure the index really points to the name you were |
| 281 | * looking for. |
| 282 | */ |
| 283 | struct btrfs_dir_item * |
| 284 | btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans, |
| 285 | struct btrfs_root *root, |
| 286 | struct btrfs_path *path, u64 dir, |
| 287 | u64 objectid, const char *name, int name_len, |
| 288 | int mod) |
| 289 | { |
| 290 | int ret; |
| 291 | struct btrfs_key key; |
| 292 | int ins_len = mod < 0 ? -1 : 0; |
| 293 | int cow = mod != 0; |
| 294 | |
| 295 | key.objectid = dir; |
| 296 | key.type = BTRFS_DIR_INDEX_KEY; |
| 297 | key.offset = objectid; |
| 298 | |
| 299 | ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); |
| 300 | if (ret < 0) |
| 301 | return ERR_PTR(ret); |
| 302 | if (ret > 0) |
| 303 | return ERR_PTR(-ENOENT); |
| 304 | return btrfs_match_dir_item_name(root, path, name, name_len); |
| 305 | } |
| 306 | |
| 307 | struct btrfs_dir_item * |
| 308 | btrfs_search_dir_index_item(struct btrfs_root *root, |
| 309 | struct btrfs_path *path, u64 dirid, |
| 310 | const char *name, int name_len) |
| 311 | { |
| 312 | struct extent_buffer *leaf; |
| 313 | struct btrfs_dir_item *di; |
| 314 | struct btrfs_key key; |
| 315 | u32 nritems; |
| 316 | int ret; |
| 317 | |
| 318 | key.objectid = dirid; |
| 319 | key.type = BTRFS_DIR_INDEX_KEY; |
| 320 | key.offset = 0; |
| 321 | |
| 322 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 323 | if (ret < 0) |
| 324 | return ERR_PTR(ret); |
| 325 | |
| 326 | leaf = path->nodes[0]; |
| 327 | nritems = btrfs_header_nritems(leaf); |
| 328 | |
| 329 | while (1) { |
| 330 | if (path->slots[0] >= nritems) { |
| 331 | ret = btrfs_next_leaf(root, path); |
| 332 | if (ret < 0) |
| 333 | return ERR_PTR(ret); |
| 334 | if (ret > 0) |
| 335 | break; |
| 336 | leaf = path->nodes[0]; |
| 337 | nritems = btrfs_header_nritems(leaf); |
| 338 | continue; |
| 339 | } |
| 340 | |
| 341 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 342 | if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY) |
| 343 | break; |
| 344 | |
| 345 | di = btrfs_match_dir_item_name(root, path, name, name_len); |
| 346 | if (di) |
| 347 | return di; |
| 348 | |
| 349 | path->slots[0]++; |
| 350 | } |
| 351 | return NULL; |
| 352 | } |
| 353 | |
| 354 | struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans, |
| 355 | struct btrfs_root *root, |
| 356 | struct btrfs_path *path, u64 dir, |
| 357 | const char *name, u16 name_len, |
| 358 | int mod) |
| 359 | { |
| 360 | int ret; |
| 361 | struct btrfs_key key; |
| 362 | int ins_len = mod < 0 ? -1 : 0; |
| 363 | int cow = mod != 0; |
| 364 | |
| 365 | key.objectid = dir; |
| 366 | key.type = BTRFS_XATTR_ITEM_KEY; |
| 367 | key.offset = btrfs_name_hash(name, name_len); |
| 368 | ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); |
| 369 | if (ret < 0) |
| 370 | return ERR_PTR(ret); |
| 371 | if (ret > 0) |
| 372 | return NULL; |
| 373 | |
| 374 | return btrfs_match_dir_item_name(root, path, name, name_len); |
| 375 | } |
| 376 | |
| 377 | /* |
| 378 | * helper function to look at the directory item pointed to by 'path' |
| 379 | * this walks through all the entries in a dir item and finds one |
| 380 | * for a specific name. |
| 381 | */ |
| 382 | struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, |
| 383 | struct btrfs_path *path, |
| 384 | const char *name, int name_len) |
| 385 | { |
| 386 | struct btrfs_dir_item *dir_item; |
| 387 | unsigned long name_ptr; |
| 388 | u32 total_len; |
| 389 | u32 cur = 0; |
| 390 | u32 this_len; |
| 391 | struct extent_buffer *leaf; |
| 392 | |
| 393 | leaf = path->nodes[0]; |
| 394 | dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item); |
| 395 | if (verify_dir_item(root, leaf, dir_item)) |
| 396 | return NULL; |
| 397 | |
| 398 | total_len = btrfs_item_size_nr(leaf, path->slots[0]); |
| 399 | while (cur < total_len) { |
| 400 | this_len = sizeof(*dir_item) + |
| 401 | btrfs_dir_name_len(leaf, dir_item) + |
| 402 | btrfs_dir_data_len(leaf, dir_item); |
| 403 | name_ptr = (unsigned long)(dir_item + 1); |
| 404 | |
| 405 | if (btrfs_dir_name_len(leaf, dir_item) == name_len && |
| 406 | memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) |
| 407 | return dir_item; |
| 408 | |
| 409 | cur += this_len; |
| 410 | dir_item = (struct btrfs_dir_item *)((char *)dir_item + |
| 411 | this_len); |
| 412 | } |
| 413 | return NULL; |
| 414 | } |
| 415 | |
| 416 | /* |
| 417 | * given a pointer into a directory item, delete it. This |
| 418 | * handles items that have more than one entry in them. |
| 419 | */ |
| 420 | int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans, |
| 421 | struct btrfs_root *root, |
| 422 | struct btrfs_path *path, |
| 423 | struct btrfs_dir_item *di) |
| 424 | { |
| 425 | |
| 426 | struct extent_buffer *leaf; |
| 427 | u32 sub_item_len; |
| 428 | u32 item_len; |
| 429 | int ret = 0; |
| 430 | |
| 431 | leaf = path->nodes[0]; |
| 432 | sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) + |
| 433 | btrfs_dir_data_len(leaf, di); |
| 434 | item_len = btrfs_item_size_nr(leaf, path->slots[0]); |
| 435 | if (sub_item_len == item_len) { |
| 436 | ret = btrfs_del_item(trans, root, path); |
| 437 | } else { |
| 438 | /* MARKER */ |
| 439 | unsigned long ptr = (unsigned long)di; |
| 440 | unsigned long start; |
| 441 | |
| 442 | start = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| 443 | memmove_extent_buffer(leaf, ptr, ptr + sub_item_len, |
| 444 | item_len - (ptr + sub_item_len - start)); |
| 445 | btrfs_truncate_item(root, path, item_len - sub_item_len, 1); |
| 446 | } |
| 447 | return ret; |
| 448 | } |
| 449 | |
| 450 | int verify_dir_item(struct btrfs_root *root, |
| 451 | struct extent_buffer *leaf, |
| 452 | struct btrfs_dir_item *dir_item) |
| 453 | { |
| 454 | u16 namelen = BTRFS_NAME_LEN; |
| 455 | u8 type = btrfs_dir_type(leaf, dir_item); |
| 456 | |
| 457 | if (type >= BTRFS_FT_MAX) { |
| 458 | btrfs_crit(root->fs_info, "invalid dir item type: %d", |
| 459 | (int)type); |
| 460 | return 1; |
| 461 | } |
| 462 | |
| 463 | if (type == BTRFS_FT_XATTR) |
| 464 | namelen = XATTR_NAME_MAX; |
| 465 | |
| 466 | if (btrfs_dir_name_len(leaf, dir_item) > namelen) { |
| 467 | btrfs_crit(root->fs_info, "invalid dir item name len: %u", |
| 468 | (unsigned)btrfs_dir_data_len(leaf, dir_item)); |
| 469 | return 1; |
| 470 | } |
| 471 | |
| 472 | /* BTRFS_MAX_XATTR_SIZE is the same for all dir items */ |
| 473 | if ((btrfs_dir_data_len(leaf, dir_item) + |
| 474 | btrfs_dir_name_len(leaf, dir_item)) > BTRFS_MAX_XATTR_SIZE(root)) { |
| 475 | btrfs_crit(root->fs_info, "invalid dir item name + data len: %u + %u", |
| 476 | (unsigned)btrfs_dir_name_len(leaf, dir_item), |
| 477 | (unsigned)btrfs_dir_data_len(leaf, dir_item)); |
| 478 | return 1; |
| 479 | } |
| 480 | |
| 481 | return 0; |
| 482 | } |