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_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 #ifdef CONFIG_UBIFS_FS_DEBUG 174 175 static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm) 176 { 177 if (!(ubifs_chk_flags & UBIFS_CHK_GEN)) 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 #else 187 188 #define dbg_check_name(dent, nm) 0 189 190 #endif 191 192 static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry, 193 struct nameidata *nd) 194 { 195 int err; 196 union ubifs_key key; 197 struct inode *inode = NULL; 198 struct ubifs_dent_node *dent; 199 struct ubifs_info *c = dir->i_sb->s_fs_info; 200 201 dbg_gen("'%.*s' in dir ino %lu", 202 dentry->d_name.len, dentry->d_name.name, dir->i_ino); 203 204 if (dentry->d_name.len > UBIFS_MAX_NLEN) 205 return ERR_PTR(-ENAMETOOLONG); 206 207 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); 208 if (!dent) 209 return ERR_PTR(-ENOMEM); 210 211 dent_key_init(c, &key, dir->i_ino, &dentry->d_name); 212 213 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name); 214 if (err) { 215 if (err == -ENOENT) { 216 dbg_gen("not found"); 217 goto done; 218 } 219 goto out; 220 } 221 222 if (dbg_check_name(dent, &dentry->d_name)) { 223 err = -EINVAL; 224 goto out; 225 } 226 227 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum)); 228 if (IS_ERR(inode)) { 229 /* 230 * This should not happen. Probably the file-system needs 231 * checking. 232 */ 233 err = PTR_ERR(inode); 234 ubifs_err("dead directory entry '%.*s', error %d", 235 dentry->d_name.len, dentry->d_name.name, err); 236 ubifs_ro_mode(c, err); 237 goto out; 238 } 239 240 done: 241 kfree(dent); 242 /* 243 * Note, d_splice_alias() would be required instead if we supported 244 * NFS. 245 */ 246 d_add(dentry, inode); 247 return NULL; 248 249 out: 250 kfree(dent); 251 return ERR_PTR(err); 252 } 253 254 static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode, 255 struct nameidata *nd) 256 { 257 struct inode *inode; 258 struct ubifs_info *c = dir->i_sb->s_fs_info; 259 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 260 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 261 .dirtied_ino = 1 }; 262 struct ubifs_inode *dir_ui = ubifs_inode(dir); 263 264 /* 265 * Budget request settings: new inode, new direntry, changing the 266 * parent directory inode. 267 */ 268 269 dbg_gen("dent '%.*s', mode %#x in dir ino %lu", 270 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino); 271 272 err = ubifs_budget_space(c, &req); 273 if (err) 274 return err; 275 276 inode = ubifs_new_inode(c, dir, mode); 277 if (IS_ERR(inode)) { 278 err = PTR_ERR(inode); 279 goto out_budg; 280 } 281 282 mutex_lock(&dir_ui->ui_mutex); 283 dir->i_size += sz_change; 284 dir_ui->ui_size = dir->i_size; 285 dir->i_mtime = dir->i_ctime = inode->i_ctime; 286 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 287 if (err) 288 goto out_cancel; 289 mutex_unlock(&dir_ui->ui_mutex); 290 291 ubifs_release_budget(c, &req); 292 insert_inode_hash(inode); 293 d_instantiate(dentry, inode); 294 return 0; 295 296 out_cancel: 297 dir->i_size -= sz_change; 298 dir_ui->ui_size = dir->i_size; 299 mutex_unlock(&dir_ui->ui_mutex); 300 make_bad_inode(inode); 301 iput(inode); 302 out_budg: 303 ubifs_release_budget(c, &req); 304 ubifs_err("cannot create regular file, error %d", err); 305 return err; 306 } 307 308 /** 309 * vfs_dent_type - get VFS directory entry type. 310 * @type: UBIFS directory entry type 311 * 312 * This function converts UBIFS directory entry type into VFS directory entry 313 * type. 314 */ 315 static unsigned int vfs_dent_type(uint8_t type) 316 { 317 switch (type) { 318 case UBIFS_ITYPE_REG: 319 return DT_REG; 320 case UBIFS_ITYPE_DIR: 321 return DT_DIR; 322 case UBIFS_ITYPE_LNK: 323 return DT_LNK; 324 case UBIFS_ITYPE_BLK: 325 return DT_BLK; 326 case UBIFS_ITYPE_CHR: 327 return DT_CHR; 328 case UBIFS_ITYPE_FIFO: 329 return DT_FIFO; 330 case UBIFS_ITYPE_SOCK: 331 return DT_SOCK; 332 default: 333 BUG(); 334 } 335 return 0; 336 } 337 338 /* 339 * The classical Unix view for directory is that it is a linear array of 340 * (name, inode number) entries. Linux/VFS assumes this model as well. 341 * Particularly, 'readdir()' call wants us to return a directory entry offset 342 * which later may be used to continue 'readdir()'ing the directory or to 343 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this 344 * model because directory entries are identified by keys, which may collide. 345 * 346 * UBIFS uses directory entry hash value for directory offsets, so 347 * 'seekdir()'/'telldir()' may not always work because of possible key 348 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work 349 * properly by means of saving full directory entry name in the private field 350 * of the file description object. 351 * 352 * This means that UBIFS cannot support NFS which requires full 353 * 'seekdir()'/'telldir()' support. 354 */ 355 static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir) 356 { 357 int err, over = 0; 358 struct qstr nm; 359 union ubifs_key key; 360 struct ubifs_dent_node *dent; 361 struct inode *dir = file->f_path.dentry->d_inode; 362 struct ubifs_info *c = dir->i_sb->s_fs_info; 363 364 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos); 365 366 if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2) 367 /* 368 * The directory was seek'ed to a senseless position or there 369 * are no more entries. 370 */ 371 return 0; 372 373 /* File positions 0 and 1 correspond to "." and ".." */ 374 if (file->f_pos == 0) { 375 ubifs_assert(!file->private_data); 376 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR); 377 if (over) 378 return 0; 379 file->f_pos = 1; 380 } 381 382 if (file->f_pos == 1) { 383 ubifs_assert(!file->private_data); 384 over = filldir(dirent, "..", 2, 1, 385 parent_ino(file->f_path.dentry), DT_DIR); 386 if (over) 387 return 0; 388 389 /* Find the first entry in TNC and save it */ 390 lowest_dent_key(c, &key, dir->i_ino); 391 nm.name = NULL; 392 dent = ubifs_tnc_next_ent(c, &key, &nm); 393 if (IS_ERR(dent)) { 394 err = PTR_ERR(dent); 395 goto out; 396 } 397 398 file->f_pos = key_hash_flash(c, &dent->key); 399 file->private_data = dent; 400 } 401 402 dent = file->private_data; 403 if (!dent) { 404 /* 405 * The directory was seek'ed to and is now readdir'ed. 406 * Find the entry corresponding to @file->f_pos or the 407 * closest one. 408 */ 409 dent_key_init_hash(c, &key, dir->i_ino, file->f_pos); 410 nm.name = NULL; 411 dent = ubifs_tnc_next_ent(c, &key, &nm); 412 if (IS_ERR(dent)) { 413 err = PTR_ERR(dent); 414 goto out; 415 } 416 file->f_pos = key_hash_flash(c, &dent->key); 417 file->private_data = dent; 418 } 419 420 while (1) { 421 dbg_gen("feed '%s', ino %llu, new f_pos %#x", 422 dent->name, (unsigned long long)le64_to_cpu(dent->inum), 423 key_hash_flash(c, &dent->key)); 424 ubifs_assert(le64_to_cpu(dent->ch.sqnum) > 425 ubifs_inode(dir)->creat_sqnum); 426 427 nm.len = le16_to_cpu(dent->nlen); 428 over = filldir(dirent, dent->name, nm.len, file->f_pos, 429 le64_to_cpu(dent->inum), 430 vfs_dent_type(dent->type)); 431 if (over) 432 return 0; 433 434 /* Switch to the next entry */ 435 key_read(c, &dent->key, &key); 436 nm.name = dent->name; 437 dent = ubifs_tnc_next_ent(c, &key, &nm); 438 if (IS_ERR(dent)) { 439 err = PTR_ERR(dent); 440 goto out; 441 } 442 443 kfree(file->private_data); 444 file->f_pos = key_hash_flash(c, &dent->key); 445 file->private_data = dent; 446 cond_resched(); 447 } 448 449 out: 450 if (err != -ENOENT) { 451 ubifs_err("cannot find next direntry, error %d", err); 452 return err; 453 } 454 455 kfree(file->private_data); 456 file->private_data = NULL; 457 file->f_pos = 2; 458 return 0; 459 } 460 461 /* If a directory is seeked, we have to free saved readdir() state */ 462 static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin) 463 { 464 kfree(file->private_data); 465 file->private_data = NULL; 466 return generic_file_llseek(file, offset, origin); 467 } 468 469 /* Free saved readdir() state when the directory is closed */ 470 static int ubifs_dir_release(struct inode *dir, struct file *file) 471 { 472 kfree(file->private_data); 473 file->private_data = NULL; 474 return 0; 475 } 476 477 /** 478 * lock_2_inodes - a wrapper for locking two UBIFS inodes. 479 * @inode1: first inode 480 * @inode2: second inode 481 * 482 * We do not implement any tricks to guarantee strict lock ordering, because 483 * VFS has already done it for us on the @i_mutex. So this is just a simple 484 * wrapper function. 485 */ 486 static void lock_2_inodes(struct inode *inode1, struct inode *inode2) 487 { 488 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); 489 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); 490 } 491 492 /** 493 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. 494 * @inode1: first inode 495 * @inode2: second inode 496 */ 497 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) 498 { 499 mutex_unlock(&ubifs_inode(inode2)->ui_mutex); 500 mutex_unlock(&ubifs_inode(inode1)->ui_mutex); 501 } 502 503 static int ubifs_link(struct dentry *old_dentry, struct inode *dir, 504 struct dentry *dentry) 505 { 506 struct ubifs_info *c = dir->i_sb->s_fs_info; 507 struct inode *inode = old_dentry->d_inode; 508 struct ubifs_inode *ui = ubifs_inode(inode); 509 struct ubifs_inode *dir_ui = ubifs_inode(dir); 510 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 511 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2, 512 .dirtied_ino_d = ALIGN(ui->data_len, 8) }; 513 514 /* 515 * Budget request settings: new direntry, changing the target inode, 516 * changing the parent inode. 517 */ 518 519 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu", 520 dentry->d_name.len, dentry->d_name.name, inode->i_ino, 521 inode->i_nlink, dir->i_ino); 522 ubifs_assert(mutex_is_locked(&dir->i_mutex)); 523 ubifs_assert(mutex_is_locked(&inode->i_mutex)); 524 525 err = dbg_check_synced_i_size(inode); 526 if (err) 527 return err; 528 529 err = ubifs_budget_space(c, &req); 530 if (err) 531 return err; 532 533 lock_2_inodes(dir, inode); 534 inc_nlink(inode); 535 ihold(inode); 536 inode->i_ctime = ubifs_current_time(inode); 537 dir->i_size += sz_change; 538 dir_ui->ui_size = dir->i_size; 539 dir->i_mtime = dir->i_ctime = inode->i_ctime; 540 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 541 if (err) 542 goto out_cancel; 543 unlock_2_inodes(dir, inode); 544 545 ubifs_release_budget(c, &req); 546 d_instantiate(dentry, inode); 547 return 0; 548 549 out_cancel: 550 dir->i_size -= sz_change; 551 dir_ui->ui_size = dir->i_size; 552 drop_nlink(inode); 553 unlock_2_inodes(dir, inode); 554 ubifs_release_budget(c, &req); 555 iput(inode); 556 return err; 557 } 558 559 static int ubifs_unlink(struct inode *dir, struct dentry *dentry) 560 { 561 struct ubifs_info *c = dir->i_sb->s_fs_info; 562 struct inode *inode = dentry->d_inode; 563 struct ubifs_inode *dir_ui = ubifs_inode(dir); 564 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 565 int err, budgeted = 1; 566 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; 567 568 /* 569 * Budget request settings: deletion direntry, deletion inode (+1 for 570 * @dirtied_ino), changing the parent directory inode. If budgeting 571 * fails, go ahead anyway because we have extra space reserved for 572 * deletions. 573 */ 574 575 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu", 576 dentry->d_name.len, dentry->d_name.name, inode->i_ino, 577 inode->i_nlink, dir->i_ino); 578 ubifs_assert(mutex_is_locked(&dir->i_mutex)); 579 ubifs_assert(mutex_is_locked(&inode->i_mutex)); 580 err = dbg_check_synced_i_size(inode); 581 if (err) 582 return err; 583 584 err = ubifs_budget_space(c, &req); 585 if (err) { 586 if (err != -ENOSPC) 587 return err; 588 budgeted = 0; 589 } 590 591 lock_2_inodes(dir, inode); 592 inode->i_ctime = ubifs_current_time(dir); 593 drop_nlink(inode); 594 dir->i_size -= sz_change; 595 dir_ui->ui_size = dir->i_size; 596 dir->i_mtime = dir->i_ctime = inode->i_ctime; 597 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); 598 if (err) 599 goto out_cancel; 600 unlock_2_inodes(dir, inode); 601 602 if (budgeted) 603 ubifs_release_budget(c, &req); 604 else { 605 /* We've deleted something - clean the "no space" flags */ 606 c->nospace = c->nospace_rp = 0; 607 smp_wmb(); 608 } 609 return 0; 610 611 out_cancel: 612 dir->i_size += sz_change; 613 dir_ui->ui_size = dir->i_size; 614 inc_nlink(inode); 615 unlock_2_inodes(dir, inode); 616 if (budgeted) 617 ubifs_release_budget(c, &req); 618 return err; 619 } 620 621 /** 622 * check_dir_empty - check if a directory is empty or not. 623 * @c: UBIFS file-system description object 624 * @dir: VFS inode object of the directory to check 625 * 626 * This function checks if directory @dir is empty. Returns zero if the 627 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes 628 * in case of of errors. 629 */ 630 static int check_dir_empty(struct ubifs_info *c, struct inode *dir) 631 { 632 struct qstr nm = { .name = NULL }; 633 struct ubifs_dent_node *dent; 634 union ubifs_key key; 635 int err; 636 637 lowest_dent_key(c, &key, dir->i_ino); 638 dent = ubifs_tnc_next_ent(c, &key, &nm); 639 if (IS_ERR(dent)) { 640 err = PTR_ERR(dent); 641 if (err == -ENOENT) 642 err = 0; 643 } else { 644 kfree(dent); 645 err = -ENOTEMPTY; 646 } 647 return err; 648 } 649 650 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) 651 { 652 struct ubifs_info *c = dir->i_sb->s_fs_info; 653 struct inode *inode = dentry->d_inode; 654 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 655 int err, budgeted = 1; 656 struct ubifs_inode *dir_ui = ubifs_inode(dir); 657 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; 658 659 /* 660 * Budget request settings: deletion direntry, deletion inode and 661 * changing the parent inode. If budgeting fails, go ahead anyway 662 * because we have extra space reserved for deletions. 663 */ 664 665 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len, 666 dentry->d_name.name, inode->i_ino, dir->i_ino); 667 ubifs_assert(mutex_is_locked(&dir->i_mutex)); 668 ubifs_assert(mutex_is_locked(&inode->i_mutex)); 669 err = check_dir_empty(c, dentry->d_inode); 670 if (err) 671 return err; 672 673 err = ubifs_budget_space(c, &req); 674 if (err) { 675 if (err != -ENOSPC) 676 return err; 677 budgeted = 0; 678 } 679 680 lock_2_inodes(dir, inode); 681 inode->i_ctime = ubifs_current_time(dir); 682 clear_nlink(inode); 683 drop_nlink(dir); 684 dir->i_size -= sz_change; 685 dir_ui->ui_size = dir->i_size; 686 dir->i_mtime = dir->i_ctime = inode->i_ctime; 687 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); 688 if (err) 689 goto out_cancel; 690 unlock_2_inodes(dir, inode); 691 692 if (budgeted) 693 ubifs_release_budget(c, &req); 694 else { 695 /* We've deleted something - clean the "no space" flags */ 696 c->nospace = c->nospace_rp = 0; 697 smp_wmb(); 698 } 699 return 0; 700 701 out_cancel: 702 dir->i_size += sz_change; 703 dir_ui->ui_size = dir->i_size; 704 inc_nlink(dir); 705 inc_nlink(inode); 706 inc_nlink(inode); 707 unlock_2_inodes(dir, inode); 708 if (budgeted) 709 ubifs_release_budget(c, &req); 710 return err; 711 } 712 713 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 714 { 715 struct inode *inode; 716 struct ubifs_inode *dir_ui = ubifs_inode(dir); 717 struct ubifs_info *c = dir->i_sb->s_fs_info; 718 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); 719 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 }; 720 721 /* 722 * Budget request settings: new inode, new direntry and changing parent 723 * directory inode. 724 */ 725 726 dbg_gen("dent '%.*s', mode %#x in dir ino %lu", 727 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino); 728 729 err = ubifs_budget_space(c, &req); 730 if (err) 731 return err; 732 733 inode = ubifs_new_inode(c, dir, S_IFDIR | mode); 734 if (IS_ERR(inode)) { 735 err = PTR_ERR(inode); 736 goto out_budg; 737 } 738 739 mutex_lock(&dir_ui->ui_mutex); 740 insert_inode_hash(inode); 741 inc_nlink(inode); 742 inc_nlink(dir); 743 dir->i_size += sz_change; 744 dir_ui->ui_size = dir->i_size; 745 dir->i_mtime = dir->i_ctime = inode->i_ctime; 746 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 747 if (err) { 748 ubifs_err("cannot create directory, error %d", err); 749 goto out_cancel; 750 } 751 mutex_unlock(&dir_ui->ui_mutex); 752 753 ubifs_release_budget(c, &req); 754 d_instantiate(dentry, inode); 755 return 0; 756 757 out_cancel: 758 dir->i_size -= sz_change; 759 dir_ui->ui_size = dir->i_size; 760 drop_nlink(dir); 761 mutex_unlock(&dir_ui->ui_mutex); 762 make_bad_inode(inode); 763 iput(inode); 764 out_budg: 765 ubifs_release_budget(c, &req); 766 return err; 767 } 768 769 static int ubifs_mknod(struct inode *dir, struct dentry *dentry, 770 int mode, dev_t rdev) 771 { 772 struct inode *inode; 773 struct ubifs_inode *ui; 774 struct ubifs_inode *dir_ui = ubifs_inode(dir); 775 struct ubifs_info *c = dir->i_sb->s_fs_info; 776 union ubifs_dev_desc *dev = NULL; 777 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 778 int err, devlen = 0; 779 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 780 .new_ino_d = ALIGN(devlen, 8), 781 .dirtied_ino = 1 }; 782 783 /* 784 * Budget request settings: new inode, new direntry and changing parent 785 * directory inode. 786 */ 787 788 dbg_gen("dent '%.*s' in dir ino %lu", 789 dentry->d_name.len, dentry->d_name.name, dir->i_ino); 790 791 if (!new_valid_dev(rdev)) 792 return -EINVAL; 793 794 if (S_ISBLK(mode) || S_ISCHR(mode)) { 795 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); 796 if (!dev) 797 return -ENOMEM; 798 devlen = ubifs_encode_dev(dev, rdev); 799 } 800 801 err = ubifs_budget_space(c, &req); 802 if (err) { 803 kfree(dev); 804 return err; 805 } 806 807 inode = ubifs_new_inode(c, dir, mode); 808 if (IS_ERR(inode)) { 809 kfree(dev); 810 err = PTR_ERR(inode); 811 goto out_budg; 812 } 813 814 init_special_inode(inode, inode->i_mode, rdev); 815 inode->i_size = ubifs_inode(inode)->ui_size = devlen; 816 ui = ubifs_inode(inode); 817 ui->data = dev; 818 ui->data_len = devlen; 819 820 mutex_lock(&dir_ui->ui_mutex); 821 dir->i_size += sz_change; 822 dir_ui->ui_size = dir->i_size; 823 dir->i_mtime = dir->i_ctime = inode->i_ctime; 824 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 825 if (err) 826 goto out_cancel; 827 mutex_unlock(&dir_ui->ui_mutex); 828 829 ubifs_release_budget(c, &req); 830 insert_inode_hash(inode); 831 d_instantiate(dentry, inode); 832 return 0; 833 834 out_cancel: 835 dir->i_size -= sz_change; 836 dir_ui->ui_size = dir->i_size; 837 mutex_unlock(&dir_ui->ui_mutex); 838 make_bad_inode(inode); 839 iput(inode); 840 out_budg: 841 ubifs_release_budget(c, &req); 842 return err; 843 } 844 845 static int ubifs_symlink(struct inode *dir, struct dentry *dentry, 846 const char *symname) 847 { 848 struct inode *inode; 849 struct ubifs_inode *ui; 850 struct ubifs_inode *dir_ui = ubifs_inode(dir); 851 struct ubifs_info *c = dir->i_sb->s_fs_info; 852 int err, len = strlen(symname); 853 int sz_change = CALC_DENT_SIZE(dentry->d_name.len); 854 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, 855 .new_ino_d = ALIGN(len, 8), 856 .dirtied_ino = 1 }; 857 858 /* 859 * Budget request settings: new inode, new direntry and changing parent 860 * directory inode. 861 */ 862 863 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len, 864 dentry->d_name.name, symname, dir->i_ino); 865 866 if (len > UBIFS_MAX_INO_DATA) 867 return -ENAMETOOLONG; 868 869 err = ubifs_budget_space(c, &req); 870 if (err) 871 return err; 872 873 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO); 874 if (IS_ERR(inode)) { 875 err = PTR_ERR(inode); 876 goto out_budg; 877 } 878 879 ui = ubifs_inode(inode); 880 ui->data = kmalloc(len + 1, GFP_NOFS); 881 if (!ui->data) { 882 err = -ENOMEM; 883 goto out_inode; 884 } 885 886 memcpy(ui->data, symname, len); 887 ((char *)ui->data)[len] = '\0'; 888 /* 889 * The terminating zero byte is not written to the flash media and it 890 * is put just to make later in-memory string processing simpler. Thus, 891 * data length is @len, not @len + %1. 892 */ 893 ui->data_len = len; 894 inode->i_size = ubifs_inode(inode)->ui_size = len; 895 896 mutex_lock(&dir_ui->ui_mutex); 897 dir->i_size += sz_change; 898 dir_ui->ui_size = dir->i_size; 899 dir->i_mtime = dir->i_ctime = inode->i_ctime; 900 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0); 901 if (err) 902 goto out_cancel; 903 mutex_unlock(&dir_ui->ui_mutex); 904 905 ubifs_release_budget(c, &req); 906 insert_inode_hash(inode); 907 d_instantiate(dentry, inode); 908 return 0; 909 910 out_cancel: 911 dir->i_size -= sz_change; 912 dir_ui->ui_size = dir->i_size; 913 mutex_unlock(&dir_ui->ui_mutex); 914 out_inode: 915 make_bad_inode(inode); 916 iput(inode); 917 out_budg: 918 ubifs_release_budget(c, &req); 919 return err; 920 } 921 922 /** 923 * lock_3_inodes - a wrapper for locking three UBIFS inodes. 924 * @inode1: first inode 925 * @inode2: second inode 926 * @inode3: third inode 927 * 928 * This function is used for 'ubifs_rename()' and @inode1 may be the same as 929 * @inode2 whereas @inode3 may be %NULL. 930 * 931 * We do not implement any tricks to guarantee strict lock ordering, because 932 * VFS has already done it for us on the @i_mutex. So this is just a simple 933 * wrapper function. 934 */ 935 static void lock_3_inodes(struct inode *inode1, struct inode *inode2, 936 struct inode *inode3) 937 { 938 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); 939 if (inode2 != inode1) 940 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); 941 if (inode3) 942 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3); 943 } 944 945 /** 946 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename. 947 * @inode1: first inode 948 * @inode2: second inode 949 * @inode3: third inode 950 */ 951 static void unlock_3_inodes(struct inode *inode1, struct inode *inode2, 952 struct inode *inode3) 953 { 954 if (inode3) 955 mutex_unlock(&ubifs_inode(inode3)->ui_mutex); 956 if (inode1 != inode2) 957 mutex_unlock(&ubifs_inode(inode2)->ui_mutex); 958 mutex_unlock(&ubifs_inode(inode1)->ui_mutex); 959 } 960 961 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, 962 struct inode *new_dir, struct dentry *new_dentry) 963 { 964 struct ubifs_info *c = old_dir->i_sb->s_fs_info; 965 struct inode *old_inode = old_dentry->d_inode; 966 struct inode *new_inode = new_dentry->d_inode; 967 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode); 968 int err, release, sync = 0, move = (new_dir != old_dir); 969 int is_dir = S_ISDIR(old_inode->i_mode); 970 int unlink = !!new_inode; 971 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len); 972 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len); 973 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1, 974 .dirtied_ino = 3 }; 975 struct ubifs_budget_req ino_req = { .dirtied_ino = 1, 976 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; 977 struct timespec time; 978 979 /* 980 * Budget request settings: deletion direntry, new direntry, removing 981 * the old inode, and changing old and new parent directory inodes. 982 * 983 * However, this operation also marks the target inode as dirty and 984 * does not write it, so we allocate budget for the target inode 985 * separately. 986 */ 987 988 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in " 989 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name, 990 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len, 991 new_dentry->d_name.name, new_dir->i_ino); 992 ubifs_assert(mutex_is_locked(&old_dir->i_mutex)); 993 ubifs_assert(mutex_is_locked(&new_dir->i_mutex)); 994 if (unlink) 995 ubifs_assert(mutex_is_locked(&new_inode->i_mutex)); 996 997 998 if (unlink && is_dir) { 999 err = check_dir_empty(c, new_inode); 1000 if (err) 1001 return err; 1002 } 1003 1004 err = ubifs_budget_space(c, &req); 1005 if (err) 1006 return err; 1007 err = ubifs_budget_space(c, &ino_req); 1008 if (err) { 1009 ubifs_release_budget(c, &req); 1010 return err; 1011 } 1012 1013 lock_3_inodes(old_dir, new_dir, new_inode); 1014 1015 /* 1016 * Like most other Unix systems, set the @i_ctime for inodes on a 1017 * rename. 1018 */ 1019 time = ubifs_current_time(old_dir); 1020 old_inode->i_ctime = time; 1021 1022 /* We must adjust parent link count when renaming directories */ 1023 if (is_dir) { 1024 if (move) { 1025 /* 1026 * @old_dir loses a link because we are moving 1027 * @old_inode to a different directory. 1028 */ 1029 drop_nlink(old_dir); 1030 /* 1031 * @new_dir only gains a link if we are not also 1032 * overwriting an existing directory. 1033 */ 1034 if (!unlink) 1035 inc_nlink(new_dir); 1036 } else { 1037 /* 1038 * @old_inode is not moving to a different directory, 1039 * but @old_dir still loses a link if we are 1040 * overwriting an existing directory. 1041 */ 1042 if (unlink) 1043 drop_nlink(old_dir); 1044 } 1045 } 1046 1047 old_dir->i_size -= old_sz; 1048 ubifs_inode(old_dir)->ui_size = old_dir->i_size; 1049 old_dir->i_mtime = old_dir->i_ctime = time; 1050 new_dir->i_mtime = new_dir->i_ctime = time; 1051 1052 /* 1053 * And finally, if we unlinked a direntry which happened to have the 1054 * same name as the moved direntry, we have to decrement @i_nlink of 1055 * the unlinked inode and change its ctime. 1056 */ 1057 if (unlink) { 1058 /* 1059 * Directories cannot have hard-links, so if this is a 1060 * directory, decrement its @i_nlink twice because an empty 1061 * directory has @i_nlink 2. 1062 */ 1063 if (is_dir) 1064 drop_nlink(new_inode); 1065 new_inode->i_ctime = time; 1066 drop_nlink(new_inode); 1067 } else { 1068 new_dir->i_size += new_sz; 1069 ubifs_inode(new_dir)->ui_size = new_dir->i_size; 1070 } 1071 1072 /* 1073 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode 1074 * is dirty, because this will be done later on at the end of 1075 * 'ubifs_rename()'. 1076 */ 1077 if (IS_SYNC(old_inode)) { 1078 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); 1079 if (unlink && IS_SYNC(new_inode)) 1080 sync = 1; 1081 } 1082 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry, 1083 sync); 1084 if (err) 1085 goto out_cancel; 1086 1087 unlock_3_inodes(old_dir, new_dir, new_inode); 1088 ubifs_release_budget(c, &req); 1089 1090 mutex_lock(&old_inode_ui->ui_mutex); 1091 release = old_inode_ui->dirty; 1092 mark_inode_dirty_sync(old_inode); 1093 mutex_unlock(&old_inode_ui->ui_mutex); 1094 1095 if (release) 1096 ubifs_release_budget(c, &ino_req); 1097 if (IS_SYNC(old_inode)) 1098 err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); 1099 return err; 1100 1101 out_cancel: 1102 if (unlink) { 1103 if (is_dir) 1104 inc_nlink(new_inode); 1105 inc_nlink(new_inode); 1106 } else { 1107 new_dir->i_size -= new_sz; 1108 ubifs_inode(new_dir)->ui_size = new_dir->i_size; 1109 } 1110 old_dir->i_size += old_sz; 1111 ubifs_inode(old_dir)->ui_size = old_dir->i_size; 1112 if (is_dir) { 1113 if (move) { 1114 inc_nlink(old_dir); 1115 if (!unlink) 1116 drop_nlink(new_dir); 1117 } else { 1118 if (unlink) 1119 inc_nlink(old_dir); 1120 } 1121 } 1122 unlock_3_inodes(old_dir, new_dir, new_inode); 1123 ubifs_release_budget(c, &ino_req); 1124 ubifs_release_budget(c, &req); 1125 return err; 1126 } 1127 1128 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry, 1129 struct kstat *stat) 1130 { 1131 loff_t size; 1132 struct inode *inode = dentry->d_inode; 1133 struct ubifs_inode *ui = ubifs_inode(inode); 1134 1135 mutex_lock(&ui->ui_mutex); 1136 stat->dev = inode->i_sb->s_dev; 1137 stat->ino = inode->i_ino; 1138 stat->mode = inode->i_mode; 1139 stat->nlink = inode->i_nlink; 1140 stat->uid = inode->i_uid; 1141 stat->gid = inode->i_gid; 1142 stat->rdev = inode->i_rdev; 1143 stat->atime = inode->i_atime; 1144 stat->mtime = inode->i_mtime; 1145 stat->ctime = inode->i_ctime; 1146 stat->blksize = UBIFS_BLOCK_SIZE; 1147 stat->size = ui->ui_size; 1148 1149 /* 1150 * Unfortunately, the 'stat()' system call was designed for block 1151 * device based file systems, and it is not appropriate for UBIFS, 1152 * because UBIFS does not have notion of "block". For example, it is 1153 * difficult to tell how many block a directory takes - it actually 1154 * takes less than 300 bytes, but we have to round it to block size, 1155 * which introduces large mistake. This makes utilities like 'du' to 1156 * report completely senseless numbers. This is the reason why UBIFS 1157 * goes the same way as JFFS2 - it reports zero blocks for everything 1158 * but regular files, which makes more sense than reporting completely 1159 * wrong sizes. 1160 */ 1161 if (S_ISREG(inode->i_mode)) { 1162 size = ui->xattr_size; 1163 size += stat->size; 1164 size = ALIGN(size, UBIFS_BLOCK_SIZE); 1165 /* 1166 * Note, user-space expects 512-byte blocks count irrespectively 1167 * of what was reported in @stat->size. 1168 */ 1169 stat->blocks = size >> 9; 1170 } else 1171 stat->blocks = 0; 1172 mutex_unlock(&ui->ui_mutex); 1173 return 0; 1174 } 1175 1176 const struct inode_operations ubifs_dir_inode_operations = { 1177 .lookup = ubifs_lookup, 1178 .create = ubifs_create, 1179 .link = ubifs_link, 1180 .symlink = ubifs_symlink, 1181 .unlink = ubifs_unlink, 1182 .mkdir = ubifs_mkdir, 1183 .rmdir = ubifs_rmdir, 1184 .mknod = ubifs_mknod, 1185 .rename = ubifs_rename, 1186 .setattr = ubifs_setattr, 1187 .getattr = ubifs_getattr, 1188 #ifdef CONFIG_UBIFS_FS_XATTR 1189 .setxattr = ubifs_setxattr, 1190 .getxattr = ubifs_getxattr, 1191 .listxattr = ubifs_listxattr, 1192 .removexattr = ubifs_removexattr, 1193 #endif 1194 }; 1195 1196 const struct file_operations ubifs_dir_operations = { 1197 .llseek = ubifs_dir_llseek, 1198 .release = ubifs_dir_release, 1199 .read = generic_read_dir, 1200 .readdir = ubifs_readdir, 1201 .fsync = ubifs_fsync, 1202 .unlocked_ioctl = ubifs_ioctl, 1203 #ifdef CONFIG_COMPAT 1204 .compat_ioctl = ubifs_compat_ioctl, 1205 #endif 1206 }; 1207