Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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 | |
Dmitry Monakhov | abf5d08 | 2010-03-04 17:32:21 +0300 | [diff] [blame] | 107 | inode_init_owner(inode, dir, mode); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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)", |
Artem Bityutskiy | e84461a | 2008-10-29 12:08:43 +0200 | [diff] [blame] | 157 | (unsigned long)c->highest_inum, INUM_WATERMARK); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 158 | } |
| 159 | |
| 160 | inode->i_ino = ++c->highest_inum; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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) { |
Artem Bityutskiy | 720b499 | 2008-08-13 16:16:31 +0300 | [diff] [blame] | 215 | if (err == -ENOENT) { |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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", |
Alexander Beregalov | 7424bac | 2008-09-17 22:09:41 +0400 | [diff] [blame] | 422 | dent->name, (unsigned long long)le64_to_cpu(dent->inum), |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 423 | key_hash_flash(c, &dent->key)); |
Harvey Harrison | 0ecb952 | 2008-10-24 10:52:57 -0700 | [diff] [blame] | 424 | ubifs_assert(le64_to_cpu(dent->ch.sqnum) > |
| 425 | ubifs_inode(dir)->creat_sqnum); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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 | /** |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 478 | * lock_2_inodes - a wrapper for locking two UBIFS inodes. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 479 | * @inode1: first inode |
| 480 | * @inode2: second inode |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 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. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 485 | */ |
| 486 | static void lock_2_inodes(struct inode *inode1, struct inode *inode2) |
| 487 | { |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 488 | mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); |
| 489 | mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 490 | } |
| 491 | |
| 492 | /** |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 493 | * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 494 | * @inode1: first inode |
| 495 | * @inode2: second inode |
| 496 | */ |
| 497 | static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) |
| 498 | { |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 499 | mutex_unlock(&ubifs_inode(inode2)->ui_mutex); |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 500 | mutex_unlock(&ubifs_inode(inode1)->ui_mutex); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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, |
Artem Bityutskiy | dab4b4d | 2008-07-24 14:52:45 +0300 | [diff] [blame] | 512 | .dirtied_ino_d = ALIGN(ui->data_len, 8) }; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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); |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 522 | ubifs_assert(mutex_is_locked(&dir->i_mutex)); |
| 523 | ubifs_assert(mutex_is_locked(&inode->i_mutex)); |
Hunter Adrian | 8b3884a | 2009-05-14 06:32:30 +0200 | [diff] [blame] | 524 | |
| 525 | /* |
| 526 | * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing |
| 527 | * otherwise has the potential to corrupt the orphan inode list. |
| 528 | * |
| 529 | * Indeed, consider a scenario when 'vfs_link(dirA/fileA)' and |
| 530 | * 'vfs_unlink(dirA/fileA, dirB/fileB)' race. 'vfs_link()' does not |
| 531 | * lock 'dirA->i_mutex', so this is possible. Both of the functions |
| 532 | * lock 'fileA->i_mutex' though. Suppose 'vfs_unlink()' wins, and takes |
| 533 | * 'fileA->i_mutex' mutex first. Suppose 'fileA->i_nlink' is 1. In this |
| 534 | * case 'ubifs_unlink()' will drop the last reference, and put 'inodeA' |
| 535 | * to the list of orphans. After this, 'vfs_link()' will link |
| 536 | * 'dirB/fileB' to 'inodeA'. This is a problem because, for example, |
| 537 | * the subsequent 'vfs_unlink(dirB/fileB)' will add the same inode |
| 538 | * to the list of orphans. |
| 539 | */ |
| 540 | if (inode->i_nlink == 0) |
| 541 | return -ENOENT; |
| 542 | |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 543 | err = dbg_check_synced_i_size(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); |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame^] | 553 | ihold(inode); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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 | |
| 586 | /* |
| 587 | * Budget request settings: deletion direntry, deletion inode (+1 for |
| 588 | * @dirtied_ino), changing the parent directory inode. If budgeting |
| 589 | * fails, go ahead anyway because we have extra space reserved for |
| 590 | * deletions. |
| 591 | */ |
| 592 | |
| 593 | dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu", |
| 594 | dentry->d_name.len, dentry->d_name.name, inode->i_ino, |
| 595 | inode->i_nlink, dir->i_ino); |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 596 | ubifs_assert(mutex_is_locked(&dir->i_mutex)); |
| 597 | ubifs_assert(mutex_is_locked(&inode->i_mutex)); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 598 | err = dbg_check_synced_i_size(inode); |
| 599 | if (err) |
| 600 | return err; |
| 601 | |
| 602 | err = ubifs_budget_space(c, &req); |
| 603 | if (err) { |
| 604 | if (err != -ENOSPC) |
| 605 | return err; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 606 | budgeted = 0; |
| 607 | } |
| 608 | |
| 609 | lock_2_inodes(dir, inode); |
| 610 | inode->i_ctime = ubifs_current_time(dir); |
| 611 | drop_nlink(inode); |
| 612 | dir->i_size -= sz_change; |
| 613 | dir_ui->ui_size = dir->i_size; |
| 614 | dir->i_mtime = dir->i_ctime = inode->i_ctime; |
| 615 | err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); |
| 616 | if (err) |
| 617 | goto out_cancel; |
| 618 | unlock_2_inodes(dir, inode); |
| 619 | |
| 620 | if (budgeted) |
| 621 | ubifs_release_budget(c, &req); |
| 622 | else { |
| 623 | /* We've deleted something - clean the "no space" flags */ |
| 624 | c->nospace = c->nospace_rp = 0; |
| 625 | smp_wmb(); |
| 626 | } |
| 627 | return 0; |
| 628 | |
| 629 | out_cancel: |
| 630 | dir->i_size += sz_change; |
| 631 | dir_ui->ui_size = dir->i_size; |
| 632 | inc_nlink(inode); |
| 633 | unlock_2_inodes(dir, inode); |
| 634 | if (budgeted) |
| 635 | ubifs_release_budget(c, &req); |
| 636 | return err; |
| 637 | } |
| 638 | |
| 639 | /** |
| 640 | * check_dir_empty - check if a directory is empty or not. |
| 641 | * @c: UBIFS file-system description object |
| 642 | * @dir: VFS inode object of the directory to check |
| 643 | * |
| 644 | * This function checks if directory @dir is empty. Returns zero if the |
| 645 | * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes |
| 646 | * in case of of errors. |
| 647 | */ |
| 648 | static int check_dir_empty(struct ubifs_info *c, struct inode *dir) |
| 649 | { |
| 650 | struct qstr nm = { .name = NULL }; |
| 651 | struct ubifs_dent_node *dent; |
| 652 | union ubifs_key key; |
| 653 | int err; |
| 654 | |
| 655 | lowest_dent_key(c, &key, dir->i_ino); |
| 656 | dent = ubifs_tnc_next_ent(c, &key, &nm); |
| 657 | if (IS_ERR(dent)) { |
| 658 | err = PTR_ERR(dent); |
| 659 | if (err == -ENOENT) |
| 660 | err = 0; |
| 661 | } else { |
| 662 | kfree(dent); |
| 663 | err = -ENOTEMPTY; |
| 664 | } |
| 665 | return err; |
| 666 | } |
| 667 | |
| 668 | static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) |
| 669 | { |
| 670 | struct ubifs_info *c = dir->i_sb->s_fs_info; |
| 671 | struct inode *inode = dentry->d_inode; |
| 672 | int sz_change = CALC_DENT_SIZE(dentry->d_name.len); |
| 673 | int err, budgeted = 1; |
| 674 | struct ubifs_inode *dir_ui = ubifs_inode(dir); |
| 675 | struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; |
| 676 | |
| 677 | /* |
| 678 | * Budget request settings: deletion direntry, deletion inode and |
| 679 | * changing the parent inode. If budgeting fails, go ahead anyway |
| 680 | * because we have extra space reserved for deletions. |
| 681 | */ |
| 682 | |
| 683 | dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len, |
| 684 | dentry->d_name.name, inode->i_ino, dir->i_ino); |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 685 | ubifs_assert(mutex_is_locked(&dir->i_mutex)); |
| 686 | ubifs_assert(mutex_is_locked(&inode->i_mutex)); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 687 | err = check_dir_empty(c, dentry->d_inode); |
| 688 | if (err) |
| 689 | return err; |
| 690 | |
| 691 | err = ubifs_budget_space(c, &req); |
| 692 | if (err) { |
| 693 | if (err != -ENOSPC) |
| 694 | return err; |
| 695 | budgeted = 0; |
| 696 | } |
| 697 | |
| 698 | lock_2_inodes(dir, inode); |
| 699 | inode->i_ctime = ubifs_current_time(dir); |
| 700 | clear_nlink(inode); |
| 701 | drop_nlink(dir); |
| 702 | dir->i_size -= sz_change; |
| 703 | dir_ui->ui_size = dir->i_size; |
| 704 | dir->i_mtime = dir->i_ctime = inode->i_ctime; |
| 705 | err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0); |
| 706 | if (err) |
| 707 | goto out_cancel; |
| 708 | unlock_2_inodes(dir, inode); |
| 709 | |
| 710 | if (budgeted) |
| 711 | ubifs_release_budget(c, &req); |
| 712 | else { |
| 713 | /* We've deleted something - clean the "no space" flags */ |
| 714 | c->nospace = c->nospace_rp = 0; |
| 715 | smp_wmb(); |
| 716 | } |
| 717 | return 0; |
| 718 | |
| 719 | out_cancel: |
| 720 | dir->i_size += sz_change; |
| 721 | dir_ui->ui_size = dir->i_size; |
| 722 | inc_nlink(dir); |
| 723 | inc_nlink(inode); |
| 724 | inc_nlink(inode); |
| 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, int 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); |
Artem Bityutskiy | 182854b | 2008-07-18 18:54:29 +0300 | [diff] [blame] | 737 | struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 }; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 738 | |
| 739 | /* |
| 740 | * Budget request settings: new inode, new direntry and changing parent |
| 741 | * directory inode. |
| 742 | */ |
| 743 | |
| 744 | dbg_gen("dent '%.*s', mode %#x 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 | int 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, |
Artem Bityutskiy | dab4b4d | 2008-07-24 14:52:45 +0300 | [diff] [blame] | 798 | .new_ino_d = ALIGN(devlen, 8), |
| 799 | .dirtied_ino = 1 }; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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, |
Artem Bityutskiy | dab4b4d | 2008-07-24 14:52:45 +0300 | [diff] [blame] | 873 | .new_ino_d = ALIGN(len, 8), |
| 874 | .dirtied_ino = 1 }; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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 | /** |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 941 | * lock_3_inodes - a wrapper for locking three UBIFS inodes. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 942 | * @inode1: first inode |
| 943 | * @inode2: second inode |
| 944 | * @inode3: third inode |
| 945 | * |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 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. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 952 | */ |
| 953 | static void lock_3_inodes(struct inode *inode1, struct inode *inode2, |
| 954 | struct inode *inode3) |
| 955 | { |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 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); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 961 | } |
| 962 | |
| 963 | /** |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 964 | * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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 | { |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 972 | if (inode3) |
| 973 | mutex_unlock(&ubifs_inode(inode3)->ui_mutex); |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 974 | if (inode1 != inode2) |
| 975 | mutex_unlock(&ubifs_inode(inode2)->ui_mutex); |
| 976 | mutex_unlock(&ubifs_inode(inode1)->ui_mutex); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 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, |
Artem Bityutskiy | dab4b4d | 2008-07-24 14:52:45 +0300 | [diff] [blame] | 994 | .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 995 | struct timespec time; |
| 996 | |
| 997 | /* |
| 998 | * Budget request settings: deletion direntry, new direntry, removing |
| 999 | * the old inode, and changing old and new parent directory inodes. |
| 1000 | * |
| 1001 | * However, this operation also marks the target inode as dirty and |
| 1002 | * does not write it, so we allocate budget for the target inode |
| 1003 | * separately. |
| 1004 | */ |
| 1005 | |
| 1006 | dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in " |
| 1007 | "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name, |
| 1008 | old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len, |
| 1009 | new_dentry->d_name.name, new_dir->i_ino); |
Artem Bityutskiy | 82c1593 | 2009-01-20 16:46:02 +0200 | [diff] [blame] | 1010 | ubifs_assert(mutex_is_locked(&old_dir->i_mutex)); |
| 1011 | ubifs_assert(mutex_is_locked(&new_dir->i_mutex)); |
| 1012 | if (unlink) |
| 1013 | ubifs_assert(mutex_is_locked(&new_inode->i_mutex)); |
| 1014 | |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 1015 | |
| 1016 | if (unlink && is_dir) { |
| 1017 | err = check_dir_empty(c, new_inode); |
| 1018 | if (err) |
| 1019 | return err; |
| 1020 | } |
| 1021 | |
| 1022 | err = ubifs_budget_space(c, &req); |
| 1023 | if (err) |
| 1024 | return err; |
| 1025 | err = ubifs_budget_space(c, &ino_req); |
| 1026 | if (err) { |
| 1027 | ubifs_release_budget(c, &req); |
| 1028 | return err; |
| 1029 | } |
| 1030 | |
| 1031 | lock_3_inodes(old_dir, new_dir, new_inode); |
| 1032 | |
| 1033 | /* |
| 1034 | * Like most other Unix systems, set the @i_ctime for inodes on a |
| 1035 | * rename. |
| 1036 | */ |
| 1037 | time = ubifs_current_time(old_dir); |
| 1038 | old_inode->i_ctime = time; |
| 1039 | |
| 1040 | /* We must adjust parent link count when renaming directories */ |
| 1041 | if (is_dir) { |
| 1042 | if (move) { |
| 1043 | /* |
| 1044 | * @old_dir loses a link because we are moving |
| 1045 | * @old_inode to a different directory. |
| 1046 | */ |
| 1047 | drop_nlink(old_dir); |
| 1048 | /* |
| 1049 | * @new_dir only gains a link if we are not also |
| 1050 | * overwriting an existing directory. |
| 1051 | */ |
| 1052 | if (!unlink) |
| 1053 | inc_nlink(new_dir); |
| 1054 | } else { |
| 1055 | /* |
| 1056 | * @old_inode is not moving to a different directory, |
| 1057 | * but @old_dir still loses a link if we are |
| 1058 | * overwriting an existing directory. |
| 1059 | */ |
| 1060 | if (unlink) |
| 1061 | drop_nlink(old_dir); |
| 1062 | } |
| 1063 | } |
| 1064 | |
| 1065 | old_dir->i_size -= old_sz; |
| 1066 | ubifs_inode(old_dir)->ui_size = old_dir->i_size; |
| 1067 | old_dir->i_mtime = old_dir->i_ctime = time; |
| 1068 | new_dir->i_mtime = new_dir->i_ctime = time; |
| 1069 | |
| 1070 | /* |
| 1071 | * And finally, if we unlinked a direntry which happened to have the |
| 1072 | * same name as the moved direntry, we have to decrement @i_nlink of |
| 1073 | * the unlinked inode and change its ctime. |
| 1074 | */ |
| 1075 | if (unlink) { |
| 1076 | /* |
| 1077 | * Directories cannot have hard-links, so if this is a |
| 1078 | * directory, decrement its @i_nlink twice because an empty |
| 1079 | * directory has @i_nlink 2. |
| 1080 | */ |
| 1081 | if (is_dir) |
| 1082 | drop_nlink(new_inode); |
| 1083 | new_inode->i_ctime = time; |
| 1084 | drop_nlink(new_inode); |
| 1085 | } else { |
| 1086 | new_dir->i_size += new_sz; |
| 1087 | ubifs_inode(new_dir)->ui_size = new_dir->i_size; |
| 1088 | } |
| 1089 | |
| 1090 | /* |
| 1091 | * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode |
| 1092 | * is dirty, because this will be done later on at the end of |
| 1093 | * 'ubifs_rename()'. |
| 1094 | */ |
| 1095 | if (IS_SYNC(old_inode)) { |
| 1096 | sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); |
| 1097 | if (unlink && IS_SYNC(new_inode)) |
| 1098 | sync = 1; |
| 1099 | } |
| 1100 | err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry, |
| 1101 | sync); |
| 1102 | if (err) |
| 1103 | goto out_cancel; |
| 1104 | |
| 1105 | unlock_3_inodes(old_dir, new_dir, new_inode); |
| 1106 | ubifs_release_budget(c, &req); |
| 1107 | |
| 1108 | mutex_lock(&old_inode_ui->ui_mutex); |
| 1109 | release = old_inode_ui->dirty; |
| 1110 | mark_inode_dirty_sync(old_inode); |
| 1111 | mutex_unlock(&old_inode_ui->ui_mutex); |
| 1112 | |
| 1113 | if (release) |
| 1114 | ubifs_release_budget(c, &ino_req); |
| 1115 | if (IS_SYNC(old_inode)) |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 1116 | err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 1117 | return err; |
| 1118 | |
| 1119 | out_cancel: |
| 1120 | if (unlink) { |
| 1121 | if (is_dir) |
| 1122 | inc_nlink(new_inode); |
| 1123 | inc_nlink(new_inode); |
| 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 | stat->dev = inode->i_sb->s_dev; |
| 1155 | stat->ino = inode->i_ino; |
| 1156 | stat->mode = inode->i_mode; |
| 1157 | stat->nlink = inode->i_nlink; |
| 1158 | stat->uid = inode->i_uid; |
| 1159 | stat->gid = inode->i_gid; |
| 1160 | stat->rdev = inode->i_rdev; |
| 1161 | stat->atime = inode->i_atime; |
| 1162 | stat->mtime = inode->i_mtime; |
| 1163 | stat->ctime = inode->i_ctime; |
| 1164 | stat->blksize = UBIFS_BLOCK_SIZE; |
| 1165 | stat->size = ui->ui_size; |
| 1166 | |
| 1167 | /* |
| 1168 | * Unfortunately, the 'stat()' system call was designed for block |
| 1169 | * device based file systems, and it is not appropriate for UBIFS, |
| 1170 | * because UBIFS does not have notion of "block". For example, it is |
| 1171 | * difficult to tell how many block a directory takes - it actually |
| 1172 | * takes less than 300 bytes, but we have to round it to block size, |
| 1173 | * which introduces large mistake. This makes utilities like 'du' to |
| 1174 | * report completely senseless numbers. This is the reason why UBIFS |
| 1175 | * goes the same way as JFFS2 - it reports zero blocks for everything |
| 1176 | * but regular files, which makes more sense than reporting completely |
| 1177 | * wrong sizes. |
| 1178 | */ |
| 1179 | if (S_ISREG(inode->i_mode)) { |
| 1180 | size = ui->xattr_size; |
| 1181 | size += stat->size; |
| 1182 | size = ALIGN(size, UBIFS_BLOCK_SIZE); |
| 1183 | /* |
| 1184 | * Note, user-space expects 512-byte blocks count irrespectively |
| 1185 | * of what was reported in @stat->size. |
| 1186 | */ |
| 1187 | stat->blocks = size >> 9; |
| 1188 | } else |
| 1189 | stat->blocks = 0; |
| 1190 | mutex_unlock(&ui->ui_mutex); |
| 1191 | return 0; |
| 1192 | } |
| 1193 | |
Artem Bityutskiy | e8b8156 | 2009-01-15 17:43:23 +0200 | [diff] [blame] | 1194 | const struct inode_operations ubifs_dir_inode_operations = { |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 1195 | .lookup = ubifs_lookup, |
| 1196 | .create = ubifs_create, |
| 1197 | .link = ubifs_link, |
| 1198 | .symlink = ubifs_symlink, |
| 1199 | .unlink = ubifs_unlink, |
| 1200 | .mkdir = ubifs_mkdir, |
| 1201 | .rmdir = ubifs_rmdir, |
| 1202 | .mknod = ubifs_mknod, |
| 1203 | .rename = ubifs_rename, |
| 1204 | .setattr = ubifs_setattr, |
| 1205 | .getattr = ubifs_getattr, |
| 1206 | #ifdef CONFIG_UBIFS_FS_XATTR |
| 1207 | .setxattr = ubifs_setxattr, |
| 1208 | .getxattr = ubifs_getxattr, |
| 1209 | .listxattr = ubifs_listxattr, |
| 1210 | .removexattr = ubifs_removexattr, |
| 1211 | #endif |
| 1212 | }; |
| 1213 | |
Artem Bityutskiy | e8b8156 | 2009-01-15 17:43:23 +0200 | [diff] [blame] | 1214 | const struct file_operations ubifs_dir_operations = { |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 1215 | .llseek = ubifs_dir_llseek, |
| 1216 | .release = ubifs_dir_release, |
| 1217 | .read = generic_read_dir, |
| 1218 | .readdir = ubifs_readdir, |
| 1219 | .fsync = ubifs_fsync, |
| 1220 | .unlocked_ioctl = ubifs_ioctl, |
| 1221 | #ifdef CONFIG_COMPAT |
| 1222 | .compat_ioctl = ubifs_compat_ioctl, |
| 1223 | #endif |
| 1224 | }; |