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