1 /* 2 * namei.c - NILFS pathname lookup operations. 3 * 4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 * 20 * Modified for NILFS by Amagai Yoshiji <amagai@osrg.net>, 21 * Ryusuke Konishi <ryusuke@osrg.net> 22 */ 23 /* 24 * linux/fs/ext2/namei.c 25 * 26 * Copyright (C) 1992, 1993, 1994, 1995 27 * Remy Card (card@masi.ibp.fr) 28 * Laboratoire MASI - Institut Blaise Pascal 29 * Universite Pierre et Marie Curie (Paris VI) 30 * 31 * from 32 * 33 * linux/fs/minix/namei.c 34 * 35 * Copyright (C) 1991, 1992 Linus Torvalds 36 * 37 * Big-endian to little-endian byte-swapping/bitmaps by 38 * David S. Miller (davem@caip.rutgers.edu), 1995 39 */ 40 41 #include <linux/pagemap.h> 42 #include "nilfs.h" 43 #include "export.h" 44 45 #define NILFS_FID_SIZE_NON_CONNECTABLE \ 46 (offsetof(struct nilfs_fid, parent_gen) / 4) 47 #define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4) 48 49 static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode) 50 { 51 int err = nilfs_add_link(dentry, inode); 52 if (!err) { 53 d_instantiate(dentry, inode); 54 unlock_new_inode(inode); 55 return 0; 56 } 57 inode_dec_link_count(inode); 58 unlock_new_inode(inode); 59 iput(inode); 60 return err; 61 } 62 63 /* 64 * Methods themselves. 65 */ 66 67 static struct dentry * 68 nilfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 69 { 70 struct inode *inode; 71 ino_t ino; 72 73 if (dentry->d_name.len > NILFS_NAME_LEN) 74 return ERR_PTR(-ENAMETOOLONG); 75 76 ino = nilfs_inode_by_name(dir, &dentry->d_name); 77 inode = ino ? nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino) : NULL; 78 return d_splice_alias(inode, dentry); 79 } 80 81 /* 82 * By the time this is called, we already have created 83 * the directory cache entry for the new file, but it 84 * is so far negative - it has no inode. 85 * 86 * If the create succeeds, we fill in the inode information 87 * with d_instantiate(). 88 */ 89 static int nilfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, 90 bool excl) 91 { 92 struct inode *inode; 93 struct nilfs_transaction_info ti; 94 int err; 95 96 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 97 if (err) 98 return err; 99 inode = nilfs_new_inode(dir, mode); 100 err = PTR_ERR(inode); 101 if (!IS_ERR(inode)) { 102 inode->i_op = &nilfs_file_inode_operations; 103 inode->i_fop = &nilfs_file_operations; 104 inode->i_mapping->a_ops = &nilfs_aops; 105 nilfs_mark_inode_dirty(inode); 106 err = nilfs_add_nondir(dentry, inode); 107 } 108 if (!err) 109 err = nilfs_transaction_commit(dir->i_sb); 110 else 111 nilfs_transaction_abort(dir->i_sb); 112 113 return err; 114 } 115 116 static int 117 nilfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) 118 { 119 struct inode *inode; 120 struct nilfs_transaction_info ti; 121 int err; 122 123 if (!new_valid_dev(rdev)) 124 return -EINVAL; 125 126 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 127 if (err) 128 return err; 129 inode = nilfs_new_inode(dir, mode); 130 err = PTR_ERR(inode); 131 if (!IS_ERR(inode)) { 132 init_special_inode(inode, inode->i_mode, rdev); 133 nilfs_mark_inode_dirty(inode); 134 err = nilfs_add_nondir(dentry, inode); 135 } 136 if (!err) 137 err = nilfs_transaction_commit(dir->i_sb); 138 else 139 nilfs_transaction_abort(dir->i_sb); 140 141 return err; 142 } 143 144 static int nilfs_symlink(struct inode *dir, struct dentry *dentry, 145 const char *symname) 146 { 147 struct nilfs_transaction_info ti; 148 struct super_block *sb = dir->i_sb; 149 unsigned l = strlen(symname)+1; 150 struct inode *inode; 151 int err; 152 153 if (l > sb->s_blocksize) 154 return -ENAMETOOLONG; 155 156 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 157 if (err) 158 return err; 159 160 inode = nilfs_new_inode(dir, S_IFLNK | S_IRWXUGO); 161 err = PTR_ERR(inode); 162 if (IS_ERR(inode)) 163 goto out; 164 165 /* slow symlink */ 166 inode->i_op = &nilfs_symlink_inode_operations; 167 inode->i_mapping->a_ops = &nilfs_aops; 168 err = page_symlink(inode, symname, l); 169 if (err) 170 goto out_fail; 171 172 /* mark_inode_dirty(inode); */ 173 /* page_symlink() do this */ 174 175 err = nilfs_add_nondir(dentry, inode); 176 out: 177 if (!err) 178 err = nilfs_transaction_commit(dir->i_sb); 179 else 180 nilfs_transaction_abort(dir->i_sb); 181 182 return err; 183 184 out_fail: 185 drop_nlink(inode); 186 nilfs_mark_inode_dirty(inode); 187 unlock_new_inode(inode); 188 iput(inode); 189 goto out; 190 } 191 192 static int nilfs_link(struct dentry *old_dentry, struct inode *dir, 193 struct dentry *dentry) 194 { 195 struct inode *inode = old_dentry->d_inode; 196 struct nilfs_transaction_info ti; 197 int err; 198 199 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 200 if (err) 201 return err; 202 203 inode->i_ctime = CURRENT_TIME; 204 inode_inc_link_count(inode); 205 ihold(inode); 206 207 err = nilfs_add_link(dentry, inode); 208 if (!err) { 209 d_instantiate(dentry, inode); 210 err = nilfs_transaction_commit(dir->i_sb); 211 } else { 212 inode_dec_link_count(inode); 213 iput(inode); 214 nilfs_transaction_abort(dir->i_sb); 215 } 216 217 return err; 218 } 219 220 static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 221 { 222 struct inode *inode; 223 struct nilfs_transaction_info ti; 224 int err; 225 226 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 227 if (err) 228 return err; 229 230 inc_nlink(dir); 231 232 inode = nilfs_new_inode(dir, S_IFDIR | mode); 233 err = PTR_ERR(inode); 234 if (IS_ERR(inode)) 235 goto out_dir; 236 237 inode->i_op = &nilfs_dir_inode_operations; 238 inode->i_fop = &nilfs_dir_operations; 239 inode->i_mapping->a_ops = &nilfs_aops; 240 241 inc_nlink(inode); 242 243 err = nilfs_make_empty(inode, dir); 244 if (err) 245 goto out_fail; 246 247 err = nilfs_add_link(dentry, inode); 248 if (err) 249 goto out_fail; 250 251 nilfs_mark_inode_dirty(inode); 252 d_instantiate(dentry, inode); 253 unlock_new_inode(inode); 254 out: 255 if (!err) 256 err = nilfs_transaction_commit(dir->i_sb); 257 else 258 nilfs_transaction_abort(dir->i_sb); 259 260 return err; 261 262 out_fail: 263 drop_nlink(inode); 264 drop_nlink(inode); 265 nilfs_mark_inode_dirty(inode); 266 unlock_new_inode(inode); 267 iput(inode); 268 out_dir: 269 drop_nlink(dir); 270 nilfs_mark_inode_dirty(dir); 271 goto out; 272 } 273 274 static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry) 275 { 276 struct inode *inode; 277 struct nilfs_dir_entry *de; 278 struct page *page; 279 int err; 280 281 err = -ENOENT; 282 de = nilfs_find_entry(dir, &dentry->d_name, &page); 283 if (!de) 284 goto out; 285 286 inode = dentry->d_inode; 287 err = -EIO; 288 if (le64_to_cpu(de->inode) != inode->i_ino) 289 goto out; 290 291 if (!inode->i_nlink) { 292 nilfs_warning(inode->i_sb, __func__, 293 "deleting nonexistent file (%lu), %d\n", 294 inode->i_ino, inode->i_nlink); 295 set_nlink(inode, 1); 296 } 297 err = nilfs_delete_entry(de, page); 298 if (err) 299 goto out; 300 301 inode->i_ctime = dir->i_ctime; 302 drop_nlink(inode); 303 err = 0; 304 out: 305 return err; 306 } 307 308 static int nilfs_unlink(struct inode *dir, struct dentry *dentry) 309 { 310 struct nilfs_transaction_info ti; 311 int err; 312 313 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 314 if (err) 315 return err; 316 317 err = nilfs_do_unlink(dir, dentry); 318 319 if (!err) { 320 nilfs_mark_inode_dirty(dir); 321 nilfs_mark_inode_dirty(dentry->d_inode); 322 err = nilfs_transaction_commit(dir->i_sb); 323 } else 324 nilfs_transaction_abort(dir->i_sb); 325 326 return err; 327 } 328 329 static int nilfs_rmdir(struct inode *dir, struct dentry *dentry) 330 { 331 struct inode *inode = dentry->d_inode; 332 struct nilfs_transaction_info ti; 333 int err; 334 335 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 336 if (err) 337 return err; 338 339 err = -ENOTEMPTY; 340 if (nilfs_empty_dir(inode)) { 341 err = nilfs_do_unlink(dir, dentry); 342 if (!err) { 343 inode->i_size = 0; 344 drop_nlink(inode); 345 nilfs_mark_inode_dirty(inode); 346 drop_nlink(dir); 347 nilfs_mark_inode_dirty(dir); 348 } 349 } 350 if (!err) 351 err = nilfs_transaction_commit(dir->i_sb); 352 else 353 nilfs_transaction_abort(dir->i_sb); 354 355 return err; 356 } 357 358 static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry, 359 struct inode *new_dir, struct dentry *new_dentry) 360 { 361 struct inode *old_inode = old_dentry->d_inode; 362 struct inode *new_inode = new_dentry->d_inode; 363 struct page *dir_page = NULL; 364 struct nilfs_dir_entry *dir_de = NULL; 365 struct page *old_page; 366 struct nilfs_dir_entry *old_de; 367 struct nilfs_transaction_info ti; 368 int err; 369 370 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1); 371 if (unlikely(err)) 372 return err; 373 374 err = -ENOENT; 375 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_page); 376 if (!old_de) 377 goto out; 378 379 if (S_ISDIR(old_inode->i_mode)) { 380 err = -EIO; 381 dir_de = nilfs_dotdot(old_inode, &dir_page); 382 if (!dir_de) 383 goto out_old; 384 } 385 386 if (new_inode) { 387 struct page *new_page; 388 struct nilfs_dir_entry *new_de; 389 390 err = -ENOTEMPTY; 391 if (dir_de && !nilfs_empty_dir(new_inode)) 392 goto out_dir; 393 394 err = -ENOENT; 395 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page); 396 if (!new_de) 397 goto out_dir; 398 nilfs_set_link(new_dir, new_de, new_page, old_inode); 399 nilfs_mark_inode_dirty(new_dir); 400 new_inode->i_ctime = CURRENT_TIME; 401 if (dir_de) 402 drop_nlink(new_inode); 403 drop_nlink(new_inode); 404 nilfs_mark_inode_dirty(new_inode); 405 } else { 406 err = nilfs_add_link(new_dentry, old_inode); 407 if (err) 408 goto out_dir; 409 if (dir_de) { 410 inc_nlink(new_dir); 411 nilfs_mark_inode_dirty(new_dir); 412 } 413 } 414 415 /* 416 * Like most other Unix systems, set the ctime for inodes on a 417 * rename. 418 */ 419 old_inode->i_ctime = CURRENT_TIME; 420 421 nilfs_delete_entry(old_de, old_page); 422 423 if (dir_de) { 424 nilfs_set_link(old_inode, dir_de, dir_page, new_dir); 425 drop_nlink(old_dir); 426 } 427 nilfs_mark_inode_dirty(old_dir); 428 nilfs_mark_inode_dirty(old_inode); 429 430 err = nilfs_transaction_commit(old_dir->i_sb); 431 return err; 432 433 out_dir: 434 if (dir_de) { 435 kunmap(dir_page); 436 page_cache_release(dir_page); 437 } 438 out_old: 439 kunmap(old_page); 440 page_cache_release(old_page); 441 out: 442 nilfs_transaction_abort(old_dir->i_sb); 443 return err; 444 } 445 446 /* 447 * Export operations 448 */ 449 static struct dentry *nilfs_get_parent(struct dentry *child) 450 { 451 unsigned long ino; 452 struct inode *inode; 453 struct qstr dotdot = QSTR_INIT("..", 2); 454 struct nilfs_root *root; 455 456 ino = nilfs_inode_by_name(child->d_inode, &dotdot); 457 if (!ino) 458 return ERR_PTR(-ENOENT); 459 460 root = NILFS_I(child->d_inode)->i_root; 461 462 inode = nilfs_iget(child->d_inode->i_sb, root, ino); 463 if (IS_ERR(inode)) 464 return ERR_CAST(inode); 465 466 return d_obtain_alias(inode); 467 } 468 469 static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno, 470 u64 ino, u32 gen) 471 { 472 struct nilfs_root *root; 473 struct inode *inode; 474 475 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO) 476 return ERR_PTR(-ESTALE); 477 478 root = nilfs_lookup_root(sb->s_fs_info, cno); 479 if (!root) 480 return ERR_PTR(-ESTALE); 481 482 inode = nilfs_iget(sb, root, ino); 483 nilfs_put_root(root); 484 485 if (IS_ERR(inode)) 486 return ERR_CAST(inode); 487 if (gen && inode->i_generation != gen) { 488 iput(inode); 489 return ERR_PTR(-ESTALE); 490 } 491 return d_obtain_alias(inode); 492 } 493 494 static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh, 495 int fh_len, int fh_type) 496 { 497 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 498 499 if ((fh_len != NILFS_FID_SIZE_NON_CONNECTABLE && 500 fh_len != NILFS_FID_SIZE_CONNECTABLE) || 501 (fh_type != FILEID_NILFS_WITH_PARENT && 502 fh_type != FILEID_NILFS_WITHOUT_PARENT)) 503 return NULL; 504 505 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen); 506 } 507 508 static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh, 509 int fh_len, int fh_type) 510 { 511 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 512 513 if (fh_len != NILFS_FID_SIZE_CONNECTABLE || 514 fh_type != FILEID_NILFS_WITH_PARENT) 515 return NULL; 516 517 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen); 518 } 519 520 static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp, 521 struct inode *parent) 522 { 523 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 524 struct nilfs_root *root = NILFS_I(inode)->i_root; 525 int type; 526 527 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) { 528 *lenp = NILFS_FID_SIZE_CONNECTABLE; 529 return FILEID_INVALID; 530 } 531 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) { 532 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 533 return FILEID_INVALID; 534 } 535 536 fid->cno = root->cno; 537 fid->ino = inode->i_ino; 538 fid->gen = inode->i_generation; 539 540 if (parent) { 541 fid->parent_ino = parent->i_ino; 542 fid->parent_gen = parent->i_generation; 543 type = FILEID_NILFS_WITH_PARENT; 544 *lenp = NILFS_FID_SIZE_CONNECTABLE; 545 } else { 546 type = FILEID_NILFS_WITHOUT_PARENT; 547 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 548 } 549 550 return type; 551 } 552 553 const struct inode_operations nilfs_dir_inode_operations = { 554 .create = nilfs_create, 555 .lookup = nilfs_lookup, 556 .link = nilfs_link, 557 .unlink = nilfs_unlink, 558 .symlink = nilfs_symlink, 559 .mkdir = nilfs_mkdir, 560 .rmdir = nilfs_rmdir, 561 .mknod = nilfs_mknod, 562 .rename = nilfs_rename, 563 .setattr = nilfs_setattr, 564 .permission = nilfs_permission, 565 .fiemap = nilfs_fiemap, 566 }; 567 568 const struct inode_operations nilfs_special_inode_operations = { 569 .setattr = nilfs_setattr, 570 .permission = nilfs_permission, 571 }; 572 573 const struct inode_operations nilfs_symlink_inode_operations = { 574 .readlink = generic_readlink, 575 .follow_link = page_follow_link_light, 576 .put_link = page_put_link, 577 .permission = nilfs_permission, 578 }; 579 580 const struct export_operations nilfs_export_ops = { 581 .encode_fh = nilfs_encode_fh, 582 .fh_to_dentry = nilfs_fh_to_dentry, 583 .fh_to_parent = nilfs_fh_to_parent, 584 .get_parent = nilfs_get_parent, 585 }; 586