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