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 loff_t pos = file->f_pos; 353 struct qstr nm; 354 union ubifs_key key; 355 struct ubifs_dent_node *dent; 356 struct inode *dir = file_inode(file); 357 struct ubifs_info *c = dir->i_sb->s_fs_info; 358 359 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, pos); 360 361 if (pos > UBIFS_S_KEY_HASH_MASK || pos == 2) 362 /* 363 * The directory was seek'ed to a senseless position or there 364 * are no more entries. 365 */ 366 return 0; 367 368 if (file->f_version == 0) { 369 /* 370 * The file was seek'ed, which means that @file->private_data 371 * is now invalid. This may also be just the first 372 * 'ubifs_readdir()' invocation, in which case 373 * @file->private_data is NULL, and the below code is 374 * basically a no-op. 375 */ 376 kfree(file->private_data); 377 file->private_data = NULL; 378 } 379 380 /* 381 * 'generic_file_llseek()' unconditionally sets @file->f_version to 382 * zero, and we use this for detecting whether the file was seek'ed. 383 */ 384 file->f_version = 1; 385 386 /* File positions 0 and 1 correspond to "." and ".." */ 387 if (pos == 0) { 388 ubifs_assert(!file->private_data); 389 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR); 390 if (over) 391 return 0; 392 file->f_pos = pos = 1; 393 } 394 395 if (pos == 1) { 396 ubifs_assert(!file->private_data); 397 over = filldir(dirent, "..", 2, 1, 398 parent_ino(file->f_path.dentry), DT_DIR); 399 if (over) 400 return 0; 401 402 /* Find the first entry in TNC and save it */ 403 lowest_dent_key(c, &key, dir->i_ino); 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 } 410 411 file->f_pos = pos = key_hash_flash(c, &dent->key); 412 file->private_data = dent; 413 } 414 415 dent = file->private_data; 416 if (!dent) { 417 /* 418 * The directory was seek'ed to and is now readdir'ed. 419 * Find the entry corresponding to @pos or the closest one. 420 */ 421 dent_key_init_hash(c, &key, dir->i_ino, pos); 422 nm.name = NULL; 423 dent = ubifs_tnc_next_ent(c, &key, &nm); 424 if (IS_ERR(dent)) { 425 err = PTR_ERR(dent); 426 goto out; 427 } 428 file->f_pos = pos = key_hash_flash(c, &dent->key); 429 file->private_data = dent; 430 } 431 432 while (1) { 433 dbg_gen("feed '%s', ino %llu, new f_pos %#x", 434 dent->name, (unsigned long long)le64_to_cpu(dent->inum), 435 key_hash_flash(c, &dent->key)); 436 ubifs_assert(le64_to_cpu(dent->ch.sqnum) > 437 ubifs_inode(dir)->creat_sqnum); 438 439 nm.len = le16_to_cpu(dent->nlen); 440 over = filldir(dirent, dent->name, nm.len, pos, 441 le64_to_cpu(dent->inum), 442 vfs_dent_type(dent->type)); 443 if (over) 444 return 0; 445 446 /* Switch to the next entry */ 447 key_read(c, &dent->key, &key); 448 nm.name = dent->name; 449 dent = ubifs_tnc_next_ent(c, &key, &nm); 450 if (IS_ERR(dent)) { 451 err = PTR_ERR(dent); 452 goto out; 453 } 454 455 kfree(file->private_data); 456 file->f_pos = pos = key_hash_flash(c, &dent->key); 457 file->private_data = dent; 458 cond_resched(); 459 460 if (file->f_version == 0) 461 /* 462 * The file was seek'ed meanwhile, lets return and start 463 * reading direntries from the new position on the next 464 * invocation. 465 */ 466 return 0; 467 } 468 469 out: 470 if (err != -ENOENT) { 471 ubifs_err("cannot find next direntry, error %d", err); 472 return err; 473 } 474 475 kfree(file->private_data); 476 file->private_data = NULL; 477 /* 2 is a special value indicating that there are no more direntries */ 478 file->f_pos = 2; 479 return 0; 480 } 481 482 static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int whence) 483 { 484 return generic_file_llseek(file, offset, whence); 485 } 486 487 /* Free saved readdir() state when the directory is closed */ 488 static int ubifs_dir_release(struct inode *dir, struct file *file) 489 { 490 kfree(file->private_data); 491 file->private_data = NULL; 492 return 0; 493 } 494 495 /** 496 * lock_2_inodes - a wrapper for locking two UBIFS inodes. 497 * @inode1: first inode 498 * @inode2: second inode 499 * 500 * We do not implement any tricks to guarantee strict lock ordering, because 501 * VFS has already done it for us on the @i_mutex. So this is just a simple 502 * wrapper function. 503 */ 504 static void lock_2_inodes(struct inode *inode1, struct inode *inode2) 505 { 506 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); 507 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); 508 } 509 510 /** 511 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. 512 * @inode1: first inode 513 * @inode2: second inode 514 */ 515 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) 516 { 517 mutex_unlock(&ubifs_inode(inode2)->ui_mutex); 518 mutex_unlock(&ubifs_inode(inode1)->ui_mutex); 519 } 520 521 static int ubifs_link(struct dentry *old_dentry, struct inode *dir, 522 struct dentry *dentry) 523 { 524 struct ubifs_info *c = dir->i_sb->s_fs_info; 525 struct inode *inode = old_dentry->d_inode; 526 struct ubifs_inode *ui = ubifs_inode(inode); 527 struct ubifs_inode *dir_ui = ubifs_inode(dir); 528 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 529 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2, 530 .dirtied_ino_d = ALIGN(ui->data_len, 8) }; 531 532 /* 533 * Budget request settings: new direntry, changing the target inode, 534 * changing the parent inode. 535 */ 536 537 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu", 538 dentry->d_name.len, dentry->d_name.name, inode->i_ino, 539 inode->i_nlink, dir->i_ino); 540 ubifs_assert(mutex_is_locked(&dir->i_mutex)); 541 ubifs_assert(mutex_is_locked(&inode->i_mutex)); 542 543 err = dbg_check_synced_i_size(c, inode); 544 if (err) 545 return err; 546 547 err = ubifs_budget_space(c, &req); 548 if (err) 549 return err; 550 551 lock_2_inodes(dir, inode); 552 inc_nlink(inode); 553 ihold(inode); 554 inode->i_ctime = ubifs_current_time(inode); 555 dir->i_size += sz_change; 556 dir_ui->ui_size = dir->i_size; 557 dir->i_mtime = dir->i_ctime = inode->i_ctime; 558 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 559 if (err) 560 goto out_cancel; 561 unlock_2_inodes(dir, inode); 562 563 ubifs_release_budget(c, &req); 564 d_instantiate(dentry, inode); 565 return 0; 566 567 out_cancel: 568 dir->i_size -= sz_change; 569 dir_ui->ui_size = dir->i_size; 570 drop_nlink(inode); 571 unlock_2_inodes(dir, inode); 572 ubifs_release_budget(c, &req); 573 iput(inode); 574 return err; 575 } 576 577 static int ubifs_unlink(struct inode *dir, struct dentry *dentry) 578 { 579 struct ubifs_info *c = dir->i_sb->s_fs_info; 580 struct inode *inode = dentry->d_inode; 581 struct ubifs_inode *dir_ui = ubifs_inode(dir); 582 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 583 int err, budgeted = 1; 584 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; 585 unsigned int saved_nlink = inode->i_nlink; 586 587 /* 588 * Budget request settings: deletion direntry, deletion inode (+1 for 589 * @dirtied_ino), changing the parent directory inode. If budgeting 590 * fails, go ahead anyway because we have extra space reserved for 591 * deletions. 592 */ 593 594 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu", 595 dentry->d_name.len, dentry->d_name.name, inode->i_ino, 596 inode->i_nlink, dir->i_ino); 597 ubifs_assert(mutex_is_locked(&dir->i_mutex)); 598 ubifs_assert(mutex_is_locked(&inode->i_mutex)); 599 err = dbg_check_synced_i_size(c, inode); 600 if (err) 601 return err; 602 603 err = ubifs_budget_space(c, &req); 604 if (err) { 605 if (err != -ENOSPC) 606 return err; 607 budgeted = 0; 608 } 609 610 lock_2_inodes(dir, inode); 611 inode->i_ctime = ubifs_current_time(dir); 612 drop_nlink(inode); 613 dir->i_size -= sz_change; 614 dir_ui->ui_size = dir->i_size; 615 dir->i_mtime = dir->i_ctime = inode->i_ctime; 616 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); 617 if (err) 618 goto out_cancel; 619 unlock_2_inodes(dir, inode); 620 621 if (budgeted) 622 ubifs_release_budget(c, &req); 623 else { 624 /* We've deleted something - clean the "no space" flags */ 625 c->bi.nospace = c->bi.nospace_rp = 0; 626 smp_wmb(); 627 } 628 return 0; 629 630 out_cancel: 631 dir->i_size += sz_change; 632 dir_ui->ui_size = dir->i_size; 633 set_nlink(inode, saved_nlink); 634 unlock_2_inodes(dir, inode); 635 if (budgeted) 636 ubifs_release_budget(c, &req); 637 return err; 638 } 639 640 /** 641 * check_dir_empty - check if a directory is empty or not. 642 * @c: UBIFS file-system description object 643 * @dir: VFS inode object of the directory to check 644 * 645 * This function checks if directory @dir is empty. Returns zero if the 646 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes 647 * in case of of errors. 648 */ 649 static int check_dir_empty(struct ubifs_info *c, struct inode *dir) 650 { 651 struct qstr nm = { .name = NULL }; 652 struct ubifs_dent_node *dent; 653 union ubifs_key key; 654 int err; 655 656 lowest_dent_key(c, &key, dir->i_ino); 657 dent = ubifs_tnc_next_ent(c, &key, &nm); 658 if (IS_ERR(dent)) { 659 err = PTR_ERR(dent); 660 if (err == -ENOENT) 661 err = 0; 662 } else { 663 kfree(dent); 664 err = -ENOTEMPTY; 665 } 666 return err; 667 } 668 669 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) 670 { 671 struct ubifs_info *c = dir->i_sb->s_fs_info; 672 struct inode *inode = dentry->d_inode; 673 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 674 int err, budgeted = 1; 675 struct ubifs_inode *dir_ui = ubifs_inode(dir); 676 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; 677 678 /* 679 * Budget request settings: deletion direntry, deletion inode and 680 * changing the parent inode. If budgeting fails, go ahead anyway 681 * because we have extra space reserved for deletions. 682 */ 683 684 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len, 685 dentry->d_name.name, inode->i_ino, dir->i_ino); 686 ubifs_assert(mutex_is_locked(&dir->i_mutex)); 687 ubifs_assert(mutex_is_locked(&inode->i_mutex)); 688 err = check_dir_empty(c, dentry->d_inode); 689 if (err) 690 return err; 691 692 err = ubifs_budget_space(c, &req); 693 if (err) { 694 if (err != -ENOSPC) 695 return err; 696 budgeted = 0; 697 } 698 699 lock_2_inodes(dir, inode); 700 inode->i_ctime = ubifs_current_time(dir); 701 clear_nlink(inode); 702 drop_nlink(dir); 703 dir->i_size -= sz_change; 704 dir_ui->ui_size = dir->i_size; 705 dir->i_mtime = dir->i_ctime = inode->i_ctime; 706 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); 707 if (err) 708 goto out_cancel; 709 unlock_2_inodes(dir, inode); 710 711 if (budgeted) 712 ubifs_release_budget(c, &req); 713 else { 714 /* We've deleted something - clean the "no space" flags */ 715 c->bi.nospace = c->bi.nospace_rp = 0; 716 smp_wmb(); 717 } 718 return 0; 719 720 out_cancel: 721 dir->i_size += sz_change; 722 dir_ui->ui_size = dir->i_size; 723 inc_nlink(dir); 724 set_nlink(inode, 2); 725 unlock_2_inodes(dir, inode); 726 if (budgeted) 727 ubifs_release_budget(c, &req); 728 return err; 729 } 730 731 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 732 { 733 struct inode *inode; 734 struct ubifs_inode *dir_ui = ubifs_inode(dir); 735 struct ubifs_info *c = dir->i_sb->s_fs_info; 736 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 737 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 }; 738 739 /* 740 * Budget request settings: new inode, new direntry and changing parent 741 * directory inode. 742 */ 743 744 dbg_gen("dent '%.*s', mode %#hx in dir ino %lu", 745 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino); 746 747 err = ubifs_budget_space(c, &req); 748 if (err) 749 return err; 750 751 inode = ubifs_new_inode(c, dir, S_IFDIR | mode); 752 if (IS_ERR(inode)) { 753 err = PTR_ERR(inode); 754 goto out_budg; 755 } 756 757 mutex_lock(&dir_ui->ui_mutex); 758 insert_inode_hash(inode); 759 inc_nlink(inode); 760 inc_nlink(dir); 761 dir->i_size += sz_change; 762 dir_ui->ui_size = dir->i_size; 763 dir->i_mtime = dir->i_ctime = inode->i_ctime; 764 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 765 if (err) { 766 ubifs_err("cannot create directory, error %d", err); 767 goto out_cancel; 768 } 769 mutex_unlock(&dir_ui->ui_mutex); 770 771 ubifs_release_budget(c, &req); 772 d_instantiate(dentry, inode); 773 return 0; 774 775 out_cancel: 776 dir->i_size -= sz_change; 777 dir_ui->ui_size = dir->i_size; 778 drop_nlink(dir); 779 mutex_unlock(&dir_ui->ui_mutex); 780 make_bad_inode(inode); 781 iput(inode); 782 out_budg: 783 ubifs_release_budget(c, &req); 784 return err; 785 } 786 787 static int ubifs_mknod(struct inode *dir, struct dentry *dentry, 788 umode_t mode, dev_t rdev) 789 { 790 struct inode *inode; 791 struct ubifs_inode *ui; 792 struct ubifs_inode *dir_ui = ubifs_inode(dir); 793 struct ubifs_info *c = dir->i_sb->s_fs_info; 794 union ubifs_dev_desc *dev = NULL; 795 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 796 int err, devlen = 0; 797 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 798 .new_ino_d = ALIGN(devlen, 8), 799 .dirtied_ino = 1 }; 800 801 /* 802 * Budget request settings: new inode, new direntry and changing parent 803 * directory inode. 804 */ 805 806 dbg_gen("dent '%.*s' in dir ino %lu", 807 dentry->d_name.len, dentry->d_name.name, dir->i_ino); 808 809 if (!new_valid_dev(rdev)) 810 return -EINVAL; 811 812 if (S_ISBLK(mode) || S_ISCHR(mode)) { 813 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); 814 if (!dev) 815 return -ENOMEM; 816 devlen = ubifs_encode_dev(dev, rdev); 817 } 818 819 err = ubifs_budget_space(c, &req); 820 if (err) { 821 kfree(dev); 822 return err; 823 } 824 825 inode = ubifs_new_inode(c, dir, mode); 826 if (IS_ERR(inode)) { 827 kfree(dev); 828 err = PTR_ERR(inode); 829 goto out_budg; 830 } 831 832 init_special_inode(inode, inode->i_mode, rdev); 833 inode->i_size = ubifs_inode(inode)->ui_size = devlen; 834 ui = ubifs_inode(inode); 835 ui->data = dev; 836 ui->data_len = devlen; 837 838 mutex_lock(&dir_ui->ui_mutex); 839 dir->i_size += sz_change; 840 dir_ui->ui_size = dir->i_size; 841 dir->i_mtime = dir->i_ctime = inode->i_ctime; 842 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 843 if (err) 844 goto out_cancel; 845 mutex_unlock(&dir_ui->ui_mutex); 846 847 ubifs_release_budget(c, &req); 848 insert_inode_hash(inode); 849 d_instantiate(dentry, inode); 850 return 0; 851 852 out_cancel: 853 dir->i_size -= sz_change; 854 dir_ui->ui_size = dir->i_size; 855 mutex_unlock(&dir_ui->ui_mutex); 856 make_bad_inode(inode); 857 iput(inode); 858 out_budg: 859 ubifs_release_budget(c, &req); 860 return err; 861 } 862 863 static int ubifs_symlink(struct inode *dir, struct dentry *dentry, 864 const char *symname) 865 { 866 struct inode *inode; 867 struct ubifs_inode *ui; 868 struct ubifs_inode *dir_ui = ubifs_inode(dir); 869 struct ubifs_info *c = dir->i_sb->s_fs_info; 870 int err, len = strlen(symname); 871 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 872 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 873 .new_ino_d = ALIGN(len, 8), 874 .dirtied_ino = 1 }; 875 876 /* 877 * Budget request settings: new inode, new direntry and changing parent 878 * directory inode. 879 */ 880 881 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len, 882 dentry->d_name.name, symname, dir->i_ino); 883 884 if (len > UBIFS_MAX_INO_DATA) 885 return -ENAMETOOLONG; 886 887 err = ubifs_budget_space(c, &req); 888 if (err) 889 return err; 890 891 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO); 892 if (IS_ERR(inode)) { 893 err = PTR_ERR(inode); 894 goto out_budg; 895 } 896 897 ui = ubifs_inode(inode); 898 ui->data = kmalloc(len + 1, GFP_NOFS); 899 if (!ui->data) { 900 err = -ENOMEM; 901 goto out_inode; 902 } 903 904 memcpy(ui->data, symname, len); 905 ((char *)ui->data)[len] = '\0'; 906 /* 907 * The terminating zero byte is not written to the flash media and it 908 * is put just to make later in-memory string processing simpler. Thus, 909 * data length is @len, not @len + %1. 910 */ 911 ui->data_len = len; 912 inode->i_size = ubifs_inode(inode)->ui_size = len; 913 914 mutex_lock(&dir_ui->ui_mutex); 915 dir->i_size += sz_change; 916 dir_ui->ui_size = dir->i_size; 917 dir->i_mtime = dir->i_ctime = inode->i_ctime; 918 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 919 if (err) 920 goto out_cancel; 921 mutex_unlock(&dir_ui->ui_mutex); 922 923 ubifs_release_budget(c, &req); 924 insert_inode_hash(inode); 925 d_instantiate(dentry, inode); 926 return 0; 927 928 out_cancel: 929 dir->i_size -= sz_change; 930 dir_ui->ui_size = dir->i_size; 931 mutex_unlock(&dir_ui->ui_mutex); 932 out_inode: 933 make_bad_inode(inode); 934 iput(inode); 935 out_budg: 936 ubifs_release_budget(c, &req); 937 return err; 938 } 939 940 /** 941 * lock_3_inodes - a wrapper for locking three UBIFS inodes. 942 * @inode1: first inode 943 * @inode2: second inode 944 * @inode3: third inode 945 * 946 * This function is used for 'ubifs_rename()' and @inode1 may be the same as 947 * @inode2 whereas @inode3 may be %NULL. 948 * 949 * We do not implement any tricks to guarantee strict lock ordering, because 950 * VFS has already done it for us on the @i_mutex. So this is just a simple 951 * wrapper function. 952 */ 953 static void lock_3_inodes(struct inode *inode1, struct inode *inode2, 954 struct inode *inode3) 955 { 956 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); 957 if (inode2 != inode1) 958 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); 959 if (inode3) 960 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3); 961 } 962 963 /** 964 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename. 965 * @inode1: first inode 966 * @inode2: second inode 967 * @inode3: third inode 968 */ 969 static void unlock_3_inodes(struct inode *inode1, struct inode *inode2, 970 struct inode *inode3) 971 { 972 if (inode3) 973 mutex_unlock(&ubifs_inode(inode3)->ui_mutex); 974 if (inode1 != inode2) 975 mutex_unlock(&ubifs_inode(inode2)->ui_mutex); 976 mutex_unlock(&ubifs_inode(inode1)->ui_mutex); 977 } 978 979 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, 980 struct inode *new_dir, struct dentry *new_dentry) 981 { 982 struct ubifs_info *c = old_dir->i_sb->s_fs_info; 983 struct inode *old_inode = old_dentry->d_inode; 984 struct inode *new_inode = new_dentry->d_inode; 985 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode); 986 int err, release, sync = 0, move = (new_dir != old_dir); 987 int is_dir = S_ISDIR(old_inode->i_mode); 988 int unlink = !!new_inode; 989 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len); 990 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len); 991 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1, 992 .dirtied_ino = 3 }; 993 struct ubifs_budget_req ino_req = { .dirtied_ino = 1, 994 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; 995 struct timespec time; 996 unsigned int uninitialized_var(saved_nlink); 997 998 /* 999 * Budget request settings: deletion direntry, new direntry, removing 1000 * the old inode, and changing old and new parent directory inodes. 1001 * 1002 * However, this operation also marks the target inode as dirty and 1003 * does not write it, so we allocate budget for the target inode 1004 * separately. 1005 */ 1006 1007 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in dir ino %lu", 1008 old_dentry->d_name.len, old_dentry->d_name.name, 1009 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len, 1010 new_dentry->d_name.name, new_dir->i_ino); 1011 ubifs_assert(mutex_is_locked(&old_dir->i_mutex)); 1012 ubifs_assert(mutex_is_locked(&new_dir->i_mutex)); 1013 if (unlink) 1014 ubifs_assert(mutex_is_locked(&new_inode->i_mutex)); 1015 1016 1017 if (unlink && is_dir) { 1018 err = check_dir_empty(c, new_inode); 1019 if (err) 1020 return err; 1021 } 1022 1023 err = ubifs_budget_space(c, &req); 1024 if (err) 1025 return err; 1026 err = ubifs_budget_space(c, &ino_req); 1027 if (err) { 1028 ubifs_release_budget(c, &req); 1029 return err; 1030 } 1031 1032 lock_3_inodes(old_dir, new_dir, new_inode); 1033 1034 /* 1035 * Like most other Unix systems, set the @i_ctime for inodes on a 1036 * rename. 1037 */ 1038 time = ubifs_current_time(old_dir); 1039 old_inode->i_ctime = time; 1040 1041 /* We must adjust parent link count when renaming directories */ 1042 if (is_dir) { 1043 if (move) { 1044 /* 1045 * @old_dir loses a link because we are moving 1046 * @old_inode to a different directory. 1047 */ 1048 drop_nlink(old_dir); 1049 /* 1050 * @new_dir only gains a link if we are not also 1051 * overwriting an existing directory. 1052 */ 1053 if (!unlink) 1054 inc_nlink(new_dir); 1055 } else { 1056 /* 1057 * @old_inode is not moving to a different directory, 1058 * but @old_dir still loses a link if we are 1059 * overwriting an existing directory. 1060 */ 1061 if (unlink) 1062 drop_nlink(old_dir); 1063 } 1064 } 1065 1066 old_dir->i_size -= old_sz; 1067 ubifs_inode(old_dir)->ui_size = old_dir->i_size; 1068 old_dir->i_mtime = old_dir->i_ctime = time; 1069 new_dir->i_mtime = new_dir->i_ctime = time; 1070 1071 /* 1072 * And finally, if we unlinked a direntry which happened to have the 1073 * same name as the moved direntry, we have to decrement @i_nlink of 1074 * the unlinked inode and change its ctime. 1075 */ 1076 if (unlink) { 1077 /* 1078 * Directories cannot have hard-links, so if this is a 1079 * directory, just clear @i_nlink. 1080 */ 1081 saved_nlink = new_inode->i_nlink; 1082 if (is_dir) 1083 clear_nlink(new_inode); 1084 else 1085 drop_nlink(new_inode); 1086 new_inode->i_ctime = time; 1087 } else { 1088 new_dir->i_size += new_sz; 1089 ubifs_inode(new_dir)->ui_size = new_dir->i_size; 1090 } 1091 1092 /* 1093 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode 1094 * is dirty, because this will be done later on at the end of 1095 * 'ubifs_rename()'. 1096 */ 1097 if (IS_SYNC(old_inode)) { 1098 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); 1099 if (unlink && IS_SYNC(new_inode)) 1100 sync = 1; 1101 } 1102 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry, 1103 sync); 1104 if (err) 1105 goto out_cancel; 1106 1107 unlock_3_inodes(old_dir, new_dir, new_inode); 1108 ubifs_release_budget(c, &req); 1109 1110 mutex_lock(&old_inode_ui->ui_mutex); 1111 release = old_inode_ui->dirty; 1112 mark_inode_dirty_sync(old_inode); 1113 mutex_unlock(&old_inode_ui->ui_mutex); 1114 1115 if (release) 1116 ubifs_release_budget(c, &ino_req); 1117 if (IS_SYNC(old_inode)) 1118 err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); 1119 return err; 1120 1121 out_cancel: 1122 if (unlink) { 1123 set_nlink(new_inode, saved_nlink); 1124 } else { 1125 new_dir->i_size -= new_sz; 1126 ubifs_inode(new_dir)->ui_size = new_dir->i_size; 1127 } 1128 old_dir->i_size += old_sz; 1129 ubifs_inode(old_dir)->ui_size = old_dir->i_size; 1130 if (is_dir) { 1131 if (move) { 1132 inc_nlink(old_dir); 1133 if (!unlink) 1134 drop_nlink(new_dir); 1135 } else { 1136 if (unlink) 1137 inc_nlink(old_dir); 1138 } 1139 } 1140 unlock_3_inodes(old_dir, new_dir, new_inode); 1141 ubifs_release_budget(c, &ino_req); 1142 ubifs_release_budget(c, &req); 1143 return err; 1144 } 1145 1146 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry, 1147 struct kstat *stat) 1148 { 1149 loff_t size; 1150 struct inode *inode = dentry->d_inode; 1151 struct ubifs_inode *ui = ubifs_inode(inode); 1152 1153 mutex_lock(&ui->ui_mutex); 1154 generic_fillattr(inode, stat); 1155 stat->blksize = UBIFS_BLOCK_SIZE; 1156 stat->size = ui->ui_size; 1157 1158 /* 1159 * Unfortunately, the 'stat()' system call was designed for block 1160 * device based file systems, and it is not appropriate for UBIFS, 1161 * because UBIFS does not have notion of "block". For example, it is 1162 * difficult to tell how many block a directory takes - it actually 1163 * takes less than 300 bytes, but we have to round it to block size, 1164 * which introduces large mistake. This makes utilities like 'du' to 1165 * report completely senseless numbers. This is the reason why UBIFS 1166 * goes the same way as JFFS2 - it reports zero blocks for everything 1167 * but regular files, which makes more sense than reporting completely 1168 * wrong sizes. 1169 */ 1170 if (S_ISREG(inode->i_mode)) { 1171 size = ui->xattr_size; 1172 size += stat->size; 1173 size = ALIGN(size, UBIFS_BLOCK_SIZE); 1174 /* 1175 * Note, user-space expects 512-byte blocks count irrespectively 1176 * of what was reported in @stat->size. 1177 */ 1178 stat->blocks = size >> 9; 1179 } else 1180 stat->blocks = 0; 1181 mutex_unlock(&ui->ui_mutex); 1182 return 0; 1183 } 1184 1185 const struct inode_operations ubifs_dir_inode_operations = { 1186 .lookup = ubifs_lookup, 1187 .create = ubifs_create, 1188 .link = ubifs_link, 1189 .symlink = ubifs_symlink, 1190 .unlink = ubifs_unlink, 1191 .mkdir = ubifs_mkdir, 1192 .rmdir = ubifs_rmdir, 1193 .mknod = ubifs_mknod, 1194 .rename = ubifs_rename, 1195 .setattr = ubifs_setattr, 1196 .getattr = ubifs_getattr, 1197 .setxattr = ubifs_setxattr, 1198 .getxattr = ubifs_getxattr, 1199 .listxattr = ubifs_listxattr, 1200 .removexattr = ubifs_removexattr, 1201 }; 1202 1203 const struct file_operations ubifs_dir_operations = { 1204 .llseek = ubifs_dir_llseek, 1205 .release = ubifs_dir_release, 1206 .read = generic_read_dir, 1207 .readdir = ubifs_readdir, 1208 .fsync = ubifs_fsync, 1209 .unlocked_ioctl = ubifs_ioctl, 1210 #ifdef CONFIG_COMPAT 1211 .compat_ioctl = ubifs_compat_ioctl, 1212 #endif 1213 }; 1214