1 /* * This file is part of UBIFS. 2 * 3 * Copyright (C) 2006-2008 Nokia Corporation. 4 * Copyright (C) 2006, 2007 University of Szeged, Hungary 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 51 17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 * Authors: Artem Bityutskiy (Битюцкий Артём) 20 * Adrian Hunter 21 * Zoltan Sogor 22 */ 23 24 /* 25 * This file implements directory operations. 26 * 27 * All FS operations in this file allocate budget before writing anything to the 28 * media. If they fail to allocate it, the error is returned. The only 29 * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even 30 * if they unable to allocate the budget, because deletion %-ENOSPC failure is 31 * not what users are usually ready to get. UBIFS budgeting subsystem has some 32 * space reserved for these purposes. 33 * 34 * All operations in this file write all inodes which they change straight 35 * away, instead of marking them dirty. For example, 'ubifs_link()' changes 36 * @i_size of the parent inode and writes the parent inode together with the 37 * target inode. This was done to simplify file-system recovery which would 38 * otherwise be very difficult to do. The only exception is rename which marks 39 * the re-named inode dirty (because its @i_ctime is updated) but does not 40 * write it, but just marks it as dirty. 41 */ 42 43 #include "ubifs.h" 44 45 /** 46 * inherit_flags - inherit flags of the parent inode. 47 * @dir: parent inode 48 * @mode: new inode mode flags 49 * 50 * This is a helper function for 'ubifs_new_inode()' which inherits flag of the 51 * parent directory inode @dir. UBIFS inodes inherit the following flags: 52 * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on 53 * sub-directory basis; 54 * o %UBIFS_SYNC_FL - useful for the same reasons; 55 * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories. 56 * 57 * This function returns the inherited flags. 58 */ 59 static int inherit_flags(const struct inode *dir, int mode) 60 { 61 int flags; 62 const struct ubifs_inode *ui = ubifs_inode(dir); 63 64 if (!S_ISDIR(dir->i_mode)) 65 /* 66 * The parent is not a directory, which means that an extended 67 * attribute inode is being created. No flags. 68 */ 69 return 0; 70 71 flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL); 72 if (!S_ISDIR(mode)) 73 /* The "DIRSYNC" flag only applies to directories */ 74 flags &= ~UBIFS_DIRSYNC_FL; 75 return flags; 76 } 77 78 /** 79 * ubifs_new_inode - allocate new UBIFS inode object. 80 * @c: UBIFS file-system description object 81 * @dir: parent directory inode 82 * @mode: inode mode flags 83 * 84 * This function finds an unused inode number, allocates new inode and 85 * initializes it. Returns new inode in case of success and an error code in 86 * case of failure. 87 */ 88 struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir, 89 int mode) 90 { 91 struct inode *inode; 92 struct ubifs_inode *ui; 93 94 inode = new_inode(c->vfs_sb); 95 ui = ubifs_inode(inode); 96 if (!inode) 97 return ERR_PTR(-ENOMEM); 98 99 /* 100 * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and 101 * marking them dirty in file write path (see 'file_update_time()'). 102 * UBIFS has to fully control "clean <-> dirty" transitions of inodes 103 * to make budgeting work. 104 */ 105 inode->i_flags |= (S_NOCMTIME); 106 107 inode->i_uid = current->fsuid; 108 if (dir->i_mode & S_ISGID) { 109 inode->i_gid = dir->i_gid; 110 if (S_ISDIR(mode)) 111 mode |= S_ISGID; 112 } else 113 inode->i_gid = current->fsgid; 114 inode->i_mode = mode; 115 inode->i_mtime = inode->i_atime = inode->i_ctime = 116 ubifs_current_time(inode); 117 inode->i_mapping->nrpages = 0; 118 /* Disable readahead */ 119 inode->i_mapping->backing_dev_info = &c->bdi; 120 121 switch (mode & S_IFMT) { 122 case S_IFREG: 123 inode->i_mapping->a_ops = &ubifs_file_address_operations; 124 inode->i_op = &ubifs_file_inode_operations; 125 inode->i_fop = &ubifs_file_operations; 126 break; 127 case S_IFDIR: 128 inode->i_op = &ubifs_dir_inode_operations; 129 inode->i_fop = &ubifs_dir_operations; 130 inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ; 131 break; 132 case S_IFLNK: 133 inode->i_op = &ubifs_symlink_inode_operations; 134 break; 135 case S_IFSOCK: 136 case S_IFIFO: 137 case S_IFBLK: 138 case S_IFCHR: 139 inode->i_op = &ubifs_file_inode_operations; 140 break; 141 default: 142 BUG(); 143 } 144 145 ui->flags = inherit_flags(dir, mode); 146 ubifs_set_inode_flags(inode); 147 if (S_ISREG(mode)) 148 ui->compr_type = c->default_compr; 149 else 150 ui->compr_type = UBIFS_COMPR_NONE; 151 ui->synced_i_size = 0; 152 153 spin_lock(&c->cnt_lock); 154 /* Inode number overflow is currently not supported */ 155 if (c->highest_inum >= INUM_WARN_WATERMARK) { 156 if (c->highest_inum >= INUM_WATERMARK) { 157 spin_unlock(&c->cnt_lock); 158 ubifs_err("out of inode numbers"); 159 make_bad_inode(inode); 160 iput(inode); 161 return ERR_PTR(-EINVAL); 162 } 163 ubifs_warn("running out of inode numbers (current %lu, max %d)", 164 c->highest_inum, INUM_WATERMARK); 165 } 166 167 inode->i_ino = ++c->highest_inum; 168 inode->i_generation = ++c->vfs_gen; 169 /* 170 * The creation sequence number remains with this inode for its 171 * lifetime. All nodes for this inode have a greater sequence number, 172 * and so it is possible to distinguish obsolete nodes belonging to a 173 * previous incarnation of the same inode number - for example, for the 174 * purpose of rebuilding the index. 175 */ 176 ui->creat_sqnum = ++c->max_sqnum; 177 spin_unlock(&c->cnt_lock); 178 return inode; 179 } 180 181 #ifdef CONFIG_UBIFS_FS_DEBUG 182 183 static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm) 184 { 185 if (!(ubifs_chk_flags & UBIFS_CHK_GEN)) 186 return 0; 187 if (le16_to_cpu(dent->nlen) != nm->len) 188 return -EINVAL; 189 if (memcmp(dent->name, nm->name, nm->len)) 190 return -EINVAL; 191 return 0; 192 } 193 194 #else 195 196 #define dbg_check_name(dent, nm) 0 197 198 #endif 199 200 static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry, 201 struct nameidata *nd) 202 { 203 int err; 204 union ubifs_key key; 205 struct inode *inode = NULL; 206 struct ubifs_dent_node *dent; 207 struct ubifs_info *c = dir->i_sb->s_fs_info; 208 209 dbg_gen("'%.*s' in dir ino %lu", 210 dentry->d_name.len, dentry->d_name.name, dir->i_ino); 211 212 if (dentry->d_name.len > UBIFS_MAX_NLEN) 213 return ERR_PTR(-ENAMETOOLONG); 214 215 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); 216 if (!dent) 217 return ERR_PTR(-ENOMEM); 218 219 dent_key_init(c, &key, dir->i_ino, &dentry->d_name); 220 221 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name); 222 if (err) { 223 /* 224 * Do not hash the direntry if parent 'i_nlink' is zero, because 225 * this has side-effects - '->delete_inode()' call will not be 226 * called for the parent orphan inode, because 'd_count' of its 227 * direntry will stay 1 (it'll be negative direntry I guess) 228 * and prevent 'iput_final()' until the dentry is destroyed due 229 * to unmount or memory pressure. 230 */ 231 if (err == -ENOENT && dir->i_nlink != 0) { 232 dbg_gen("not found"); 233 goto done; 234 } 235 goto out; 236 } 237 238 if (dbg_check_name(dent, &dentry->d_name)) { 239 err = -EINVAL; 240 goto out; 241 } 242 243 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum)); 244 if (IS_ERR(inode)) { 245 /* 246 * This should not happen. Probably the file-system needs 247 * checking. 248 */ 249 err = PTR_ERR(inode); 250 ubifs_err("dead directory entry '%.*s', error %d", 251 dentry->d_name.len, dentry->d_name.name, err); 252 ubifs_ro_mode(c, err); 253 goto out; 254 } 255 256 done: 257 kfree(dent); 258 /* 259 * Note, d_splice_alias() would be required instead if we supported 260 * NFS. 261 */ 262 d_add(dentry, inode); 263 return NULL; 264 265 out: 266 kfree(dent); 267 return ERR_PTR(err); 268 } 269 270 static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode, 271 struct nameidata *nd) 272 { 273 struct inode *inode; 274 struct ubifs_info *c = dir->i_sb->s_fs_info; 275 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 276 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 277 .dirtied_ino = 1 }; 278 struct ubifs_inode *dir_ui = ubifs_inode(dir); 279 280 /* 281 * Budget request settings: new inode, new direntry, changing the 282 * parent directory inode. 283 */ 284 285 dbg_gen("dent '%.*s', mode %#x in dir ino %lu", 286 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino); 287 288 err = ubifs_budget_space(c, &req); 289 if (err) 290 return err; 291 292 inode = ubifs_new_inode(c, dir, mode); 293 if (IS_ERR(inode)) { 294 err = PTR_ERR(inode); 295 goto out_budg; 296 } 297 298 mutex_lock(&dir_ui->ui_mutex); 299 dir->i_size += sz_change; 300 dir_ui->ui_size = dir->i_size; 301 dir->i_mtime = dir->i_ctime = inode->i_ctime; 302 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 303 if (err) 304 goto out_cancel; 305 mutex_unlock(&dir_ui->ui_mutex); 306 307 ubifs_release_budget(c, &req); 308 insert_inode_hash(inode); 309 d_instantiate(dentry, inode); 310 return 0; 311 312 out_cancel: 313 dir->i_size -= sz_change; 314 dir_ui->ui_size = dir->i_size; 315 mutex_unlock(&dir_ui->ui_mutex); 316 make_bad_inode(inode); 317 iput(inode); 318 out_budg: 319 ubifs_release_budget(c, &req); 320 ubifs_err("cannot create regular file, error %d", err); 321 return err; 322 } 323 324 /** 325 * vfs_dent_type - get VFS directory entry type. 326 * @type: UBIFS directory entry type 327 * 328 * This function converts UBIFS directory entry type into VFS directory entry 329 * type. 330 */ 331 static unsigned int vfs_dent_type(uint8_t type) 332 { 333 switch (type) { 334 case UBIFS_ITYPE_REG: 335 return DT_REG; 336 case UBIFS_ITYPE_DIR: 337 return DT_DIR; 338 case UBIFS_ITYPE_LNK: 339 return DT_LNK; 340 case UBIFS_ITYPE_BLK: 341 return DT_BLK; 342 case UBIFS_ITYPE_CHR: 343 return DT_CHR; 344 case UBIFS_ITYPE_FIFO: 345 return DT_FIFO; 346 case UBIFS_ITYPE_SOCK: 347 return DT_SOCK; 348 default: 349 BUG(); 350 } 351 return 0; 352 } 353 354 /* 355 * The classical Unix view for directory is that it is a linear array of 356 * (name, inode number) entries. Linux/VFS assumes this model as well. 357 * Particularly, 'readdir()' call wants us to return a directory entry offset 358 * which later may be used to continue 'readdir()'ing the directory or to 359 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this 360 * model because directory entries are identified by keys, which may collide. 361 * 362 * UBIFS uses directory entry hash value for directory offsets, so 363 * 'seekdir()'/'telldir()' may not always work because of possible key 364 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work 365 * properly by means of saving full directory entry name in the private field 366 * of the file description object. 367 * 368 * This means that UBIFS cannot support NFS which requires full 369 * 'seekdir()'/'telldir()' support. 370 */ 371 static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir) 372 { 373 int err, over = 0; 374 struct qstr nm; 375 union ubifs_key key; 376 struct ubifs_dent_node *dent; 377 struct inode *dir = file->f_path.dentry->d_inode; 378 struct ubifs_info *c = dir->i_sb->s_fs_info; 379 380 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos); 381 382 if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2) 383 /* 384 * The directory was seek'ed to a senseless position or there 385 * are no more entries. 386 */ 387 return 0; 388 389 /* File positions 0 and 1 correspond to "." and ".." */ 390 if (file->f_pos == 0) { 391 ubifs_assert(!file->private_data); 392 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR); 393 if (over) 394 return 0; 395 file->f_pos = 1; 396 } 397 398 if (file->f_pos == 1) { 399 ubifs_assert(!file->private_data); 400 over = filldir(dirent, "..", 2, 1, 401 parent_ino(file->f_path.dentry), DT_DIR); 402 if (over) 403 return 0; 404 405 /* Find the first entry in TNC and save it */ 406 lowest_dent_key(c, &key, dir->i_ino); 407 nm.name = NULL; 408 dent = ubifs_tnc_next_ent(c, &key, &nm); 409 if (IS_ERR(dent)) { 410 err = PTR_ERR(dent); 411 goto out; 412 } 413 414 file->f_pos = key_hash_flash(c, &dent->key); 415 file->private_data = dent; 416 } 417 418 dent = file->private_data; 419 if (!dent) { 420 /* 421 * The directory was seek'ed to and is now readdir'ed. 422 * Find the entry corresponding to @file->f_pos or the 423 * closest one. 424 */ 425 dent_key_init_hash(c, &key, dir->i_ino, file->f_pos); 426 nm.name = NULL; 427 dent = ubifs_tnc_next_ent(c, &key, &nm); 428 if (IS_ERR(dent)) { 429 err = PTR_ERR(dent); 430 goto out; 431 } 432 file->f_pos = key_hash_flash(c, &dent->key); 433 file->private_data = dent; 434 } 435 436 while (1) { 437 dbg_gen("feed '%s', ino %llu, new f_pos %#x", 438 dent->name, le64_to_cpu(dent->inum), 439 key_hash_flash(c, &dent->key)); 440 ubifs_assert(dent->ch.sqnum > ubifs_inode(dir)->creat_sqnum); 441 442 nm.len = le16_to_cpu(dent->nlen); 443 over = filldir(dirent, dent->name, nm.len, file->f_pos, 444 le64_to_cpu(dent->inum), 445 vfs_dent_type(dent->type)); 446 if (over) 447 return 0; 448 449 /* Switch to the next entry */ 450 key_read(c, &dent->key, &key); 451 nm.name = dent->name; 452 dent = ubifs_tnc_next_ent(c, &key, &nm); 453 if (IS_ERR(dent)) { 454 err = PTR_ERR(dent); 455 goto out; 456 } 457 458 kfree(file->private_data); 459 file->f_pos = key_hash_flash(c, &dent->key); 460 file->private_data = dent; 461 cond_resched(); 462 } 463 464 out: 465 if (err != -ENOENT) { 466 ubifs_err("cannot find next direntry, error %d", err); 467 return err; 468 } 469 470 kfree(file->private_data); 471 file->private_data = NULL; 472 file->f_pos = 2; 473 return 0; 474 } 475 476 /* If a directory is seeked, we have to free saved readdir() state */ 477 static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin) 478 { 479 kfree(file->private_data); 480 file->private_data = NULL; 481 return generic_file_llseek(file, offset, origin); 482 } 483 484 /* Free saved readdir() state when the directory is closed */ 485 static int ubifs_dir_release(struct inode *dir, struct file *file) 486 { 487 kfree(file->private_data); 488 file->private_data = NULL; 489 return 0; 490 } 491 492 /** 493 * lock_2_inodes - lock two UBIFS inodes. 494 * @inode1: first inode 495 * @inode2: second inode 496 */ 497 static void lock_2_inodes(struct inode *inode1, struct inode *inode2) 498 { 499 if (inode1->i_ino < inode2->i_ino) { 500 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_2); 501 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_3); 502 } else { 503 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); 504 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_3); 505 } 506 } 507 508 /** 509 * unlock_2_inodes - unlock two UBIFS inodes inodes. 510 * @inode1: first inode 511 * @inode2: second inode 512 */ 513 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) 514 { 515 mutex_unlock(&ubifs_inode(inode1)->ui_mutex); 516 mutex_unlock(&ubifs_inode(inode2)->ui_mutex); 517 } 518 519 static int ubifs_link(struct dentry *old_dentry, struct inode *dir, 520 struct dentry *dentry) 521 { 522 struct ubifs_info *c = dir->i_sb->s_fs_info; 523 struct inode *inode = old_dentry->d_inode; 524 struct ubifs_inode *ui = ubifs_inode(inode); 525 struct ubifs_inode *dir_ui = ubifs_inode(dir); 526 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 527 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2, 528 .dirtied_ino_d = ui->data_len }; 529 530 /* 531 * Budget request settings: new direntry, changing the target inode, 532 * changing the parent inode. 533 */ 534 535 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu", 536 dentry->d_name.len, dentry->d_name.name, inode->i_ino, 537 inode->i_nlink, dir->i_ino); 538 err = dbg_check_synced_i_size(inode); 539 if (err) 540 return err; 541 542 err = ubifs_budget_space(c, &req); 543 if (err) 544 return err; 545 546 lock_2_inodes(dir, inode); 547 inc_nlink(inode); 548 atomic_inc(&inode->i_count); 549 inode->i_ctime = ubifs_current_time(inode); 550 dir->i_size += sz_change; 551 dir_ui->ui_size = dir->i_size; 552 dir->i_mtime = dir->i_ctime = inode->i_ctime; 553 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 554 if (err) 555 goto out_cancel; 556 unlock_2_inodes(dir, inode); 557 558 ubifs_release_budget(c, &req); 559 d_instantiate(dentry, inode); 560 return 0; 561 562 out_cancel: 563 dir->i_size -= sz_change; 564 dir_ui->ui_size = dir->i_size; 565 drop_nlink(inode); 566 unlock_2_inodes(dir, inode); 567 ubifs_release_budget(c, &req); 568 iput(inode); 569 return err; 570 } 571 572 static int ubifs_unlink(struct inode *dir, struct dentry *dentry) 573 { 574 struct ubifs_info *c = dir->i_sb->s_fs_info; 575 struct inode *inode = dentry->d_inode; 576 struct ubifs_inode *dir_ui = ubifs_inode(dir); 577 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 578 int err, budgeted = 1; 579 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; 580 581 /* 582 * Budget request settings: deletion direntry, deletion inode (+1 for 583 * @dirtied_ino), changing the parent directory inode. If budgeting 584 * fails, go ahead anyway because we have extra space reserved for 585 * deletions. 586 */ 587 588 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu", 589 dentry->d_name.len, dentry->d_name.name, inode->i_ino, 590 inode->i_nlink, dir->i_ino); 591 err = dbg_check_synced_i_size(inode); 592 if (err) 593 return err; 594 595 err = ubifs_budget_space(c, &req); 596 if (err) { 597 if (err != -ENOSPC) 598 return err; 599 err = 0; 600 budgeted = 0; 601 } 602 603 lock_2_inodes(dir, inode); 604 inode->i_ctime = ubifs_current_time(dir); 605 drop_nlink(inode); 606 dir->i_size -= sz_change; 607 dir_ui->ui_size = dir->i_size; 608 dir->i_mtime = dir->i_ctime = inode->i_ctime; 609 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); 610 if (err) 611 goto out_cancel; 612 unlock_2_inodes(dir, inode); 613 614 if (budgeted) 615 ubifs_release_budget(c, &req); 616 else { 617 /* We've deleted something - clean the "no space" flags */ 618 c->nospace = c->nospace_rp = 0; 619 smp_wmb(); 620 } 621 return 0; 622 623 out_cancel: 624 dir->i_size += sz_change; 625 dir_ui->ui_size = dir->i_size; 626 inc_nlink(inode); 627 unlock_2_inodes(dir, inode); 628 if (budgeted) 629 ubifs_release_budget(c, &req); 630 return err; 631 } 632 633 /** 634 * check_dir_empty - check if a directory is empty or not. 635 * @c: UBIFS file-system description object 636 * @dir: VFS inode object of the directory to check 637 * 638 * This function checks if directory @dir is empty. Returns zero if the 639 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes 640 * in case of of errors. 641 */ 642 static int check_dir_empty(struct ubifs_info *c, struct inode *dir) 643 { 644 struct qstr nm = { .name = NULL }; 645 struct ubifs_dent_node *dent; 646 union ubifs_key key; 647 int err; 648 649 lowest_dent_key(c, &key, dir->i_ino); 650 dent = ubifs_tnc_next_ent(c, &key, &nm); 651 if (IS_ERR(dent)) { 652 err = PTR_ERR(dent); 653 if (err == -ENOENT) 654 err = 0; 655 } else { 656 kfree(dent); 657 err = -ENOTEMPTY; 658 } 659 return err; 660 } 661 662 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) 663 { 664 struct ubifs_info *c = dir->i_sb->s_fs_info; 665 struct inode *inode = dentry->d_inode; 666 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 667 int err, budgeted = 1; 668 struct ubifs_inode *dir_ui = ubifs_inode(dir); 669 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; 670 671 /* 672 * Budget request settings: deletion direntry, deletion inode and 673 * changing the parent inode. If budgeting fails, go ahead anyway 674 * because we have extra space reserved for deletions. 675 */ 676 677 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len, 678 dentry->d_name.name, inode->i_ino, dir->i_ino); 679 680 err = check_dir_empty(c, dentry->d_inode); 681 if (err) 682 return err; 683 684 err = ubifs_budget_space(c, &req); 685 if (err) { 686 if (err != -ENOSPC) 687 return err; 688 budgeted = 0; 689 } 690 691 lock_2_inodes(dir, inode); 692 inode->i_ctime = ubifs_current_time(dir); 693 clear_nlink(inode); 694 drop_nlink(dir); 695 dir->i_size -= sz_change; 696 dir_ui->ui_size = dir->i_size; 697 dir->i_mtime = dir->i_ctime = inode->i_ctime; 698 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); 699 if (err) 700 goto out_cancel; 701 unlock_2_inodes(dir, inode); 702 703 if (budgeted) 704 ubifs_release_budget(c, &req); 705 else { 706 /* We've deleted something - clean the "no space" flags */ 707 c->nospace = c->nospace_rp = 0; 708 smp_wmb(); 709 } 710 return 0; 711 712 out_cancel: 713 dir->i_size += sz_change; 714 dir_ui->ui_size = dir->i_size; 715 inc_nlink(dir); 716 inc_nlink(inode); 717 inc_nlink(inode); 718 unlock_2_inodes(dir, inode); 719 if (budgeted) 720 ubifs_release_budget(c, &req); 721 return err; 722 } 723 724 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 725 { 726 struct inode *inode; 727 struct ubifs_inode *dir_ui = ubifs_inode(dir); 728 struct ubifs_info *c = dir->i_sb->s_fs_info; 729 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 730 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 731 .dirtied_ino_d = 1 }; 732 733 /* 734 * Budget request settings: new inode, new direntry and changing parent 735 * directory inode. 736 */ 737 738 dbg_gen("dent '%.*s', mode %#x in dir ino %lu", 739 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino); 740 741 err = ubifs_budget_space(c, &req); 742 if (err) 743 return err; 744 745 inode = ubifs_new_inode(c, dir, S_IFDIR | mode); 746 if (IS_ERR(inode)) { 747 err = PTR_ERR(inode); 748 goto out_budg; 749 } 750 751 mutex_lock(&dir_ui->ui_mutex); 752 insert_inode_hash(inode); 753 inc_nlink(inode); 754 inc_nlink(dir); 755 dir->i_size += sz_change; 756 dir_ui->ui_size = dir->i_size; 757 dir->i_mtime = dir->i_ctime = inode->i_ctime; 758 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 759 if (err) { 760 ubifs_err("cannot create directory, error %d", err); 761 goto out_cancel; 762 } 763 mutex_unlock(&dir_ui->ui_mutex); 764 765 ubifs_release_budget(c, &req); 766 d_instantiate(dentry, inode); 767 return 0; 768 769 out_cancel: 770 dir->i_size -= sz_change; 771 dir_ui->ui_size = dir->i_size; 772 drop_nlink(dir); 773 mutex_unlock(&dir_ui->ui_mutex); 774 make_bad_inode(inode); 775 iput(inode); 776 out_budg: 777 ubifs_release_budget(c, &req); 778 return err; 779 } 780 781 static int ubifs_mknod(struct inode *dir, struct dentry *dentry, 782 int mode, dev_t rdev) 783 { 784 struct inode *inode; 785 struct ubifs_inode *ui; 786 struct ubifs_inode *dir_ui = ubifs_inode(dir); 787 struct ubifs_info *c = dir->i_sb->s_fs_info; 788 union ubifs_dev_desc *dev = NULL; 789 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 790 int err, devlen = 0; 791 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 792 .new_ino_d = devlen, .dirtied_ino = 1 }; 793 794 /* 795 * Budget request settings: new inode, new direntry and changing parent 796 * directory inode. 797 */ 798 799 dbg_gen("dent '%.*s' in dir ino %lu", 800 dentry->d_name.len, dentry->d_name.name, dir->i_ino); 801 802 if (!new_valid_dev(rdev)) 803 return -EINVAL; 804 805 if (S_ISBLK(mode) || S_ISCHR(mode)) { 806 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); 807 if (!dev) 808 return -ENOMEM; 809 devlen = ubifs_encode_dev(dev, rdev); 810 } 811 812 err = ubifs_budget_space(c, &req); 813 if (err) { 814 kfree(dev); 815 return err; 816 } 817 818 inode = ubifs_new_inode(c, dir, mode); 819 if (IS_ERR(inode)) { 820 kfree(dev); 821 err = PTR_ERR(inode); 822 goto out_budg; 823 } 824 825 init_special_inode(inode, inode->i_mode, rdev); 826 inode->i_size = ubifs_inode(inode)->ui_size = devlen; 827 ui = ubifs_inode(inode); 828 ui->data = dev; 829 ui->data_len = devlen; 830 831 mutex_lock(&dir_ui->ui_mutex); 832 dir->i_size += sz_change; 833 dir_ui->ui_size = dir->i_size; 834 dir->i_mtime = dir->i_ctime = inode->i_ctime; 835 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 836 if (err) 837 goto out_cancel; 838 mutex_unlock(&dir_ui->ui_mutex); 839 840 ubifs_release_budget(c, &req); 841 insert_inode_hash(inode); 842 d_instantiate(dentry, inode); 843 return 0; 844 845 out_cancel: 846 dir->i_size -= sz_change; 847 dir_ui->ui_size = dir->i_size; 848 mutex_unlock(&dir_ui->ui_mutex); 849 make_bad_inode(inode); 850 iput(inode); 851 out_budg: 852 ubifs_release_budget(c, &req); 853 return err; 854 } 855 856 static int ubifs_symlink(struct inode *dir, struct dentry *dentry, 857 const char *symname) 858 { 859 struct inode *inode; 860 struct ubifs_inode *ui; 861 struct ubifs_inode *dir_ui = ubifs_inode(dir); 862 struct ubifs_info *c = dir->i_sb->s_fs_info; 863 int err, len = strlen(symname); 864 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 865 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 866 .new_ino_d = len, .dirtied_ino = 1 }; 867 868 /* 869 * Budget request settings: new inode, new direntry and changing parent 870 * directory inode. 871 */ 872 873 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len, 874 dentry->d_name.name, symname, dir->i_ino); 875 876 if (len > UBIFS_MAX_INO_DATA) 877 return -ENAMETOOLONG; 878 879 err = ubifs_budget_space(c, &req); 880 if (err) 881 return err; 882 883 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO); 884 if (IS_ERR(inode)) { 885 err = PTR_ERR(inode); 886 goto out_budg; 887 } 888 889 ui = ubifs_inode(inode); 890 ui->data = kmalloc(len + 1, GFP_NOFS); 891 if (!ui->data) { 892 err = -ENOMEM; 893 goto out_inode; 894 } 895 896 memcpy(ui->data, symname, len); 897 ((char *)ui->data)[len] = '\0'; 898 /* 899 * The terminating zero byte is not written to the flash media and it 900 * is put just to make later in-memory string processing simpler. Thus, 901 * data length is @len, not @len + %1. 902 */ 903 ui->data_len = len; 904 inode->i_size = ubifs_inode(inode)->ui_size = len; 905 906 mutex_lock(&dir_ui->ui_mutex); 907 dir->i_size += sz_change; 908 dir_ui->ui_size = dir->i_size; 909 dir->i_mtime = dir->i_ctime = inode->i_ctime; 910 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 911 if (err) 912 goto out_cancel; 913 mutex_unlock(&dir_ui->ui_mutex); 914 915 ubifs_release_budget(c, &req); 916 insert_inode_hash(inode); 917 d_instantiate(dentry, inode); 918 return 0; 919 920 out_cancel: 921 dir->i_size -= sz_change; 922 dir_ui->ui_size = dir->i_size; 923 mutex_unlock(&dir_ui->ui_mutex); 924 out_inode: 925 make_bad_inode(inode); 926 iput(inode); 927 out_budg: 928 ubifs_release_budget(c, &req); 929 return err; 930 } 931 932 /** 933 * lock_3_inodes - lock three UBIFS inodes for rename. 934 * @inode1: first inode 935 * @inode2: second inode 936 * @inode3: third inode 937 * 938 * For 'ubifs_rename()', @inode1 may be the same as @inode2 whereas @inode3 may 939 * be null. 940 */ 941 static void lock_3_inodes(struct inode *inode1, struct inode *inode2, 942 struct inode *inode3) 943 { 944 struct inode *i1, *i2, *i3; 945 946 if (!inode3) { 947 if (inode1 != inode2) { 948 lock_2_inodes(inode1, inode2); 949 return; 950 } 951 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); 952 return; 953 } 954 955 if (inode1 == inode2) { 956 lock_2_inodes(inode1, inode3); 957 return; 958 } 959 960 /* 3 different inodes */ 961 if (inode1 < inode2) { 962 i3 = inode2; 963 if (inode1 < inode3) { 964 i1 = inode1; 965 i2 = inode3; 966 } else { 967 i1 = inode3; 968 i2 = inode1; 969 } 970 } else { 971 i3 = inode1; 972 if (inode2 < inode3) { 973 i1 = inode2; 974 i2 = inode3; 975 } else { 976 i1 = inode3; 977 i2 = inode2; 978 } 979 } 980 mutex_lock_nested(&ubifs_inode(i1)->ui_mutex, WB_MUTEX_1); 981 lock_2_inodes(i2, i3); 982 } 983 984 /** 985 * unlock_3_inodes - unlock three UBIFS inodes for rename. 986 * @inode1: first inode 987 * @inode2: second inode 988 * @inode3: third inode 989 */ 990 static void unlock_3_inodes(struct inode *inode1, struct inode *inode2, 991 struct inode *inode3) 992 { 993 mutex_unlock(&ubifs_inode(inode1)->ui_mutex); 994 if (inode1 != inode2) 995 mutex_unlock(&ubifs_inode(inode2)->ui_mutex); 996 if (inode3) 997 mutex_unlock(&ubifs_inode(inode3)->ui_mutex); 998 } 999 1000 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, 1001 struct inode *new_dir, struct dentry *new_dentry) 1002 { 1003 struct ubifs_info *c = old_dir->i_sb->s_fs_info; 1004 struct inode *old_inode = old_dentry->d_inode; 1005 struct inode *new_inode = new_dentry->d_inode; 1006 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode); 1007 int err, release, sync = 0, move = (new_dir != old_dir); 1008 int is_dir = S_ISDIR(old_inode->i_mode); 1009 int unlink = !!new_inode; 1010 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len); 1011 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len); 1012 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1, 1013 .dirtied_ino = 3 }; 1014 struct ubifs_budget_req ino_req = { .dirtied_ino = 1, 1015 .dirtied_ino_d = old_inode_ui->data_len }; 1016 struct timespec time; 1017 1018 /* 1019 * Budget request settings: deletion direntry, new direntry, removing 1020 * the old inode, and changing old and new parent directory inodes. 1021 * 1022 * However, this operation also marks the target inode as dirty and 1023 * does not write it, so we allocate budget for the target inode 1024 * separately. 1025 */ 1026 1027 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in " 1028 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name, 1029 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len, 1030 new_dentry->d_name.name, new_dir->i_ino); 1031 1032 if (unlink && is_dir) { 1033 err = check_dir_empty(c, new_inode); 1034 if (err) 1035 return err; 1036 } 1037 1038 err = ubifs_budget_space(c, &req); 1039 if (err) 1040 return err; 1041 err = ubifs_budget_space(c, &ino_req); 1042 if (err) { 1043 ubifs_release_budget(c, &req); 1044 return err; 1045 } 1046 1047 lock_3_inodes(old_dir, new_dir, new_inode); 1048 1049 /* 1050 * Like most other Unix systems, set the @i_ctime for inodes on a 1051 * rename. 1052 */ 1053 time = ubifs_current_time(old_dir); 1054 old_inode->i_ctime = time; 1055 1056 /* We must adjust parent link count when renaming directories */ 1057 if (is_dir) { 1058 if (move) { 1059 /* 1060 * @old_dir loses a link because we are moving 1061 * @old_inode to a different directory. 1062 */ 1063 drop_nlink(old_dir); 1064 /* 1065 * @new_dir only gains a link if we are not also 1066 * overwriting an existing directory. 1067 */ 1068 if (!unlink) 1069 inc_nlink(new_dir); 1070 } else { 1071 /* 1072 * @old_inode is not moving to a different directory, 1073 * but @old_dir still loses a link if we are 1074 * overwriting an existing directory. 1075 */ 1076 if (unlink) 1077 drop_nlink(old_dir); 1078 } 1079 } 1080 1081 old_dir->i_size -= old_sz; 1082 ubifs_inode(old_dir)->ui_size = old_dir->i_size; 1083 old_dir->i_mtime = old_dir->i_ctime = time; 1084 new_dir->i_mtime = new_dir->i_ctime = time; 1085 1086 /* 1087 * And finally, if we unlinked a direntry which happened to have the 1088 * same name as the moved direntry, we have to decrement @i_nlink of 1089 * the unlinked inode and change its ctime. 1090 */ 1091 if (unlink) { 1092 /* 1093 * Directories cannot have hard-links, so if this is a 1094 * directory, decrement its @i_nlink twice because an empty 1095 * directory has @i_nlink 2. 1096 */ 1097 if (is_dir) 1098 drop_nlink(new_inode); 1099 new_inode->i_ctime = time; 1100 drop_nlink(new_inode); 1101 } else { 1102 new_dir->i_size += new_sz; 1103 ubifs_inode(new_dir)->ui_size = new_dir->i_size; 1104 } 1105 1106 /* 1107 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode 1108 * is dirty, because this will be done later on at the end of 1109 * 'ubifs_rename()'. 1110 */ 1111 if (IS_SYNC(old_inode)) { 1112 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); 1113 if (unlink && IS_SYNC(new_inode)) 1114 sync = 1; 1115 } 1116 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry, 1117 sync); 1118 if (err) 1119 goto out_cancel; 1120 1121 unlock_3_inodes(old_dir, new_dir, new_inode); 1122 ubifs_release_budget(c, &req); 1123 1124 mutex_lock(&old_inode_ui->ui_mutex); 1125 release = old_inode_ui->dirty; 1126 mark_inode_dirty_sync(old_inode); 1127 mutex_unlock(&old_inode_ui->ui_mutex); 1128 1129 if (release) 1130 ubifs_release_budget(c, &ino_req); 1131 if (IS_SYNC(old_inode)) 1132 err = old_inode->i_sb->s_op->write_inode(old_inode, 1); 1133 return err; 1134 1135 out_cancel: 1136 if (unlink) { 1137 if (is_dir) 1138 inc_nlink(new_inode); 1139 inc_nlink(new_inode); 1140 } else { 1141 new_dir->i_size -= new_sz; 1142 ubifs_inode(new_dir)->ui_size = new_dir->i_size; 1143 } 1144 old_dir->i_size += old_sz; 1145 ubifs_inode(old_dir)->ui_size = old_dir->i_size; 1146 if (is_dir) { 1147 if (move) { 1148 inc_nlink(old_dir); 1149 if (!unlink) 1150 drop_nlink(new_dir); 1151 } else { 1152 if (unlink) 1153 inc_nlink(old_dir); 1154 } 1155 } 1156 unlock_3_inodes(old_dir, new_dir, new_inode); 1157 ubifs_release_budget(c, &ino_req); 1158 ubifs_release_budget(c, &req); 1159 return err; 1160 } 1161 1162 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry, 1163 struct kstat *stat) 1164 { 1165 loff_t size; 1166 struct inode *inode = dentry->d_inode; 1167 struct ubifs_inode *ui = ubifs_inode(inode); 1168 1169 mutex_lock(&ui->ui_mutex); 1170 stat->dev = inode->i_sb->s_dev; 1171 stat->ino = inode->i_ino; 1172 stat->mode = inode->i_mode; 1173 stat->nlink = inode->i_nlink; 1174 stat->uid = inode->i_uid; 1175 stat->gid = inode->i_gid; 1176 stat->rdev = inode->i_rdev; 1177 stat->atime = inode->i_atime; 1178 stat->mtime = inode->i_mtime; 1179 stat->ctime = inode->i_ctime; 1180 stat->blksize = UBIFS_BLOCK_SIZE; 1181 stat->size = ui->ui_size; 1182 1183 /* 1184 * Unfortunately, the 'stat()' system call was designed for block 1185 * device based file systems, and it is not appropriate for UBIFS, 1186 * because UBIFS does not have notion of "block". For example, it is 1187 * difficult to tell how many block a directory takes - it actually 1188 * takes less than 300 bytes, but we have to round it to block size, 1189 * which introduces large mistake. This makes utilities like 'du' to 1190 * report completely senseless numbers. This is the reason why UBIFS 1191 * goes the same way as JFFS2 - it reports zero blocks for everything 1192 * but regular files, which makes more sense than reporting completely 1193 * wrong sizes. 1194 */ 1195 if (S_ISREG(inode->i_mode)) { 1196 size = ui->xattr_size; 1197 size += stat->size; 1198 size = ALIGN(size, UBIFS_BLOCK_SIZE); 1199 /* 1200 * Note, user-space expects 512-byte blocks count irrespectively 1201 * of what was reported in @stat->size. 1202 */ 1203 stat->blocks = size >> 9; 1204 } else 1205 stat->blocks = 0; 1206 mutex_unlock(&ui->ui_mutex); 1207 return 0; 1208 } 1209 1210 struct inode_operations ubifs_dir_inode_operations = { 1211 .lookup = ubifs_lookup, 1212 .create = ubifs_create, 1213 .link = ubifs_link, 1214 .symlink = ubifs_symlink, 1215 .unlink = ubifs_unlink, 1216 .mkdir = ubifs_mkdir, 1217 .rmdir = ubifs_rmdir, 1218 .mknod = ubifs_mknod, 1219 .rename = ubifs_rename, 1220 .setattr = ubifs_setattr, 1221 .getattr = ubifs_getattr, 1222 #ifdef CONFIG_UBIFS_FS_XATTR 1223 .setxattr = ubifs_setxattr, 1224 .getxattr = ubifs_getxattr, 1225 .listxattr = ubifs_listxattr, 1226 .removexattr = ubifs_removexattr, 1227 #endif 1228 }; 1229 1230 struct file_operations ubifs_dir_operations = { 1231 .llseek = ubifs_dir_llseek, 1232 .release = ubifs_dir_release, 1233 .read = generic_read_dir, 1234 .readdir = ubifs_readdir, 1235 .fsync = ubifs_fsync, 1236 .unlocked_ioctl = ubifs_ioctl, 1237 #ifdef CONFIG_COMPAT 1238 .compat_ioctl = ubifs_compat_ioctl, 1239 #endif 1240 }; 1241