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 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 124 if (err) 125 return err; 126 inode = nilfs_new_inode(dir, mode); 127 err = PTR_ERR(inode); 128 if (!IS_ERR(inode)) { 129 init_special_inode(inode, inode->i_mode, rdev); 130 nilfs_mark_inode_dirty(inode); 131 err = nilfs_add_nondir(dentry, inode); 132 } 133 if (!err) 134 err = nilfs_transaction_commit(dir->i_sb); 135 else 136 nilfs_transaction_abort(dir->i_sb); 137 138 return err; 139 } 140 141 static int nilfs_symlink(struct inode *dir, struct dentry *dentry, 142 const char *symname) 143 { 144 struct nilfs_transaction_info ti; 145 struct super_block *sb = dir->i_sb; 146 unsigned l = strlen(symname)+1; 147 struct inode *inode; 148 int err; 149 150 if (l > sb->s_blocksize) 151 return -ENAMETOOLONG; 152 153 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 154 if (err) 155 return err; 156 157 inode = nilfs_new_inode(dir, S_IFLNK | S_IRWXUGO); 158 err = PTR_ERR(inode); 159 if (IS_ERR(inode)) 160 goto out; 161 162 /* slow symlink */ 163 inode->i_op = &nilfs_symlink_inode_operations; 164 inode_nohighmem(inode); 165 inode->i_mapping->a_ops = &nilfs_aops; 166 err = page_symlink(inode, symname, l); 167 if (err) 168 goto out_fail; 169 170 /* mark_inode_dirty(inode); */ 171 /* page_symlink() do this */ 172 173 err = nilfs_add_nondir(dentry, inode); 174 out: 175 if (!err) 176 err = nilfs_transaction_commit(dir->i_sb); 177 else 178 nilfs_transaction_abort(dir->i_sb); 179 180 return err; 181 182 out_fail: 183 drop_nlink(inode); 184 nilfs_mark_inode_dirty(inode); 185 unlock_new_inode(inode); 186 iput(inode); 187 goto out; 188 } 189 190 static int nilfs_link(struct dentry *old_dentry, struct inode *dir, 191 struct dentry *dentry) 192 { 193 struct inode *inode = d_inode(old_dentry); 194 struct nilfs_transaction_info ti; 195 int err; 196 197 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 198 if (err) 199 return err; 200 201 inode->i_ctime = CURRENT_TIME; 202 inode_inc_link_count(inode); 203 ihold(inode); 204 205 err = nilfs_add_link(dentry, inode); 206 if (!err) { 207 d_instantiate(dentry, inode); 208 err = nilfs_transaction_commit(dir->i_sb); 209 } else { 210 inode_dec_link_count(inode); 211 iput(inode); 212 nilfs_transaction_abort(dir->i_sb); 213 } 214 215 return err; 216 } 217 218 static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 219 { 220 struct inode *inode; 221 struct nilfs_transaction_info ti; 222 int err; 223 224 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 225 if (err) 226 return err; 227 228 inc_nlink(dir); 229 230 inode = nilfs_new_inode(dir, S_IFDIR | mode); 231 err = PTR_ERR(inode); 232 if (IS_ERR(inode)) 233 goto out_dir; 234 235 inode->i_op = &nilfs_dir_inode_operations; 236 inode->i_fop = &nilfs_dir_operations; 237 inode->i_mapping->a_ops = &nilfs_aops; 238 239 inc_nlink(inode); 240 241 err = nilfs_make_empty(inode, dir); 242 if (err) 243 goto out_fail; 244 245 err = nilfs_add_link(dentry, inode); 246 if (err) 247 goto out_fail; 248 249 nilfs_mark_inode_dirty(inode); 250 d_instantiate(dentry, inode); 251 unlock_new_inode(inode); 252 out: 253 if (!err) 254 err = nilfs_transaction_commit(dir->i_sb); 255 else 256 nilfs_transaction_abort(dir->i_sb); 257 258 return err; 259 260 out_fail: 261 drop_nlink(inode); 262 drop_nlink(inode); 263 nilfs_mark_inode_dirty(inode); 264 unlock_new_inode(inode); 265 iput(inode); 266 out_dir: 267 drop_nlink(dir); 268 nilfs_mark_inode_dirty(dir); 269 goto out; 270 } 271 272 static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry) 273 { 274 struct inode *inode; 275 struct nilfs_dir_entry *de; 276 struct page *page; 277 int err; 278 279 err = -ENOENT; 280 de = nilfs_find_entry(dir, &dentry->d_name, &page); 281 if (!de) 282 goto out; 283 284 inode = d_inode(dentry); 285 err = -EIO; 286 if (le64_to_cpu(de->inode) != inode->i_ino) 287 goto out; 288 289 if (!inode->i_nlink) { 290 nilfs_warning(inode->i_sb, __func__, 291 "deleting nonexistent file (%lu), %d\n", 292 inode->i_ino, inode->i_nlink); 293 set_nlink(inode, 1); 294 } 295 err = nilfs_delete_entry(de, page); 296 if (err) 297 goto out; 298 299 inode->i_ctime = dir->i_ctime; 300 drop_nlink(inode); 301 err = 0; 302 out: 303 return err; 304 } 305 306 static int nilfs_unlink(struct inode *dir, struct dentry *dentry) 307 { 308 struct nilfs_transaction_info ti; 309 int err; 310 311 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 312 if (err) 313 return err; 314 315 err = nilfs_do_unlink(dir, dentry); 316 317 if (!err) { 318 nilfs_mark_inode_dirty(dir); 319 nilfs_mark_inode_dirty(d_inode(dentry)); 320 err = nilfs_transaction_commit(dir->i_sb); 321 } else 322 nilfs_transaction_abort(dir->i_sb); 323 324 return err; 325 } 326 327 static int nilfs_rmdir(struct inode *dir, struct dentry *dentry) 328 { 329 struct inode *inode = d_inode(dentry); 330 struct nilfs_transaction_info ti; 331 int err; 332 333 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 334 if (err) 335 return err; 336 337 err = -ENOTEMPTY; 338 if (nilfs_empty_dir(inode)) { 339 err = nilfs_do_unlink(dir, dentry); 340 if (!err) { 341 inode->i_size = 0; 342 drop_nlink(inode); 343 nilfs_mark_inode_dirty(inode); 344 drop_nlink(dir); 345 nilfs_mark_inode_dirty(dir); 346 } 347 } 348 if (!err) 349 err = nilfs_transaction_commit(dir->i_sb); 350 else 351 nilfs_transaction_abort(dir->i_sb); 352 353 return err; 354 } 355 356 static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry, 357 struct inode *new_dir, struct dentry *new_dentry) 358 { 359 struct inode *old_inode = d_inode(old_dentry); 360 struct inode *new_inode = d_inode(new_dentry); 361 struct page *dir_page = NULL; 362 struct nilfs_dir_entry *dir_de = NULL; 363 struct page *old_page; 364 struct nilfs_dir_entry *old_de; 365 struct nilfs_transaction_info ti; 366 int err; 367 368 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1); 369 if (unlikely(err)) 370 return err; 371 372 err = -ENOENT; 373 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_page); 374 if (!old_de) 375 goto out; 376 377 if (S_ISDIR(old_inode->i_mode)) { 378 err = -EIO; 379 dir_de = nilfs_dotdot(old_inode, &dir_page); 380 if (!dir_de) 381 goto out_old; 382 } 383 384 if (new_inode) { 385 struct page *new_page; 386 struct nilfs_dir_entry *new_de; 387 388 err = -ENOTEMPTY; 389 if (dir_de && !nilfs_empty_dir(new_inode)) 390 goto out_dir; 391 392 err = -ENOENT; 393 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page); 394 if (!new_de) 395 goto out_dir; 396 nilfs_set_link(new_dir, new_de, new_page, old_inode); 397 nilfs_mark_inode_dirty(new_dir); 398 new_inode->i_ctime = CURRENT_TIME; 399 if (dir_de) 400 drop_nlink(new_inode); 401 drop_nlink(new_inode); 402 nilfs_mark_inode_dirty(new_inode); 403 } else { 404 err = nilfs_add_link(new_dentry, old_inode); 405 if (err) 406 goto out_dir; 407 if (dir_de) { 408 inc_nlink(new_dir); 409 nilfs_mark_inode_dirty(new_dir); 410 } 411 } 412 413 /* 414 * Like most other Unix systems, set the ctime for inodes on a 415 * rename. 416 */ 417 old_inode->i_ctime = CURRENT_TIME; 418 419 nilfs_delete_entry(old_de, old_page); 420 421 if (dir_de) { 422 nilfs_set_link(old_inode, dir_de, dir_page, new_dir); 423 drop_nlink(old_dir); 424 } 425 nilfs_mark_inode_dirty(old_dir); 426 nilfs_mark_inode_dirty(old_inode); 427 428 err = nilfs_transaction_commit(old_dir->i_sb); 429 return err; 430 431 out_dir: 432 if (dir_de) { 433 kunmap(dir_page); 434 page_cache_release(dir_page); 435 } 436 out_old: 437 kunmap(old_page); 438 page_cache_release(old_page); 439 out: 440 nilfs_transaction_abort(old_dir->i_sb); 441 return err; 442 } 443 444 /* 445 * Export operations 446 */ 447 static struct dentry *nilfs_get_parent(struct dentry *child) 448 { 449 unsigned long ino; 450 struct inode *inode; 451 struct qstr dotdot = QSTR_INIT("..", 2); 452 struct nilfs_root *root; 453 454 ino = nilfs_inode_by_name(d_inode(child), &dotdot); 455 if (!ino) 456 return ERR_PTR(-ENOENT); 457 458 root = NILFS_I(d_inode(child))->i_root; 459 460 inode = nilfs_iget(d_inode(child)->i_sb, root, ino); 461 if (IS_ERR(inode)) 462 return ERR_CAST(inode); 463 464 return d_obtain_alias(inode); 465 } 466 467 static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno, 468 u64 ino, u32 gen) 469 { 470 struct nilfs_root *root; 471 struct inode *inode; 472 473 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO) 474 return ERR_PTR(-ESTALE); 475 476 root = nilfs_lookup_root(sb->s_fs_info, cno); 477 if (!root) 478 return ERR_PTR(-ESTALE); 479 480 inode = nilfs_iget(sb, root, ino); 481 nilfs_put_root(root); 482 483 if (IS_ERR(inode)) 484 return ERR_CAST(inode); 485 if (gen && inode->i_generation != gen) { 486 iput(inode); 487 return ERR_PTR(-ESTALE); 488 } 489 return d_obtain_alias(inode); 490 } 491 492 static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh, 493 int fh_len, int fh_type) 494 { 495 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 496 497 if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE || 498 (fh_type != FILEID_NILFS_WITH_PARENT && 499 fh_type != FILEID_NILFS_WITHOUT_PARENT)) 500 return NULL; 501 502 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen); 503 } 504 505 static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh, 506 int fh_len, int fh_type) 507 { 508 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 509 510 if (fh_len < NILFS_FID_SIZE_CONNECTABLE || 511 fh_type != FILEID_NILFS_WITH_PARENT) 512 return NULL; 513 514 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen); 515 } 516 517 static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp, 518 struct inode *parent) 519 { 520 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 521 struct nilfs_root *root = NILFS_I(inode)->i_root; 522 int type; 523 524 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) { 525 *lenp = NILFS_FID_SIZE_CONNECTABLE; 526 return FILEID_INVALID; 527 } 528 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) { 529 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 530 return FILEID_INVALID; 531 } 532 533 fid->cno = root->cno; 534 fid->ino = inode->i_ino; 535 fid->gen = inode->i_generation; 536 537 if (parent) { 538 fid->parent_ino = parent->i_ino; 539 fid->parent_gen = parent->i_generation; 540 type = FILEID_NILFS_WITH_PARENT; 541 *lenp = NILFS_FID_SIZE_CONNECTABLE; 542 } else { 543 type = FILEID_NILFS_WITHOUT_PARENT; 544 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 545 } 546 547 return type; 548 } 549 550 const struct inode_operations nilfs_dir_inode_operations = { 551 .create = nilfs_create, 552 .lookup = nilfs_lookup, 553 .link = nilfs_link, 554 .unlink = nilfs_unlink, 555 .symlink = nilfs_symlink, 556 .mkdir = nilfs_mkdir, 557 .rmdir = nilfs_rmdir, 558 .mknod = nilfs_mknod, 559 .rename = nilfs_rename, 560 .setattr = nilfs_setattr, 561 .permission = nilfs_permission, 562 .fiemap = nilfs_fiemap, 563 }; 564 565 const struct inode_operations nilfs_special_inode_operations = { 566 .setattr = nilfs_setattr, 567 .permission = nilfs_permission, 568 }; 569 570 const struct inode_operations nilfs_symlink_inode_operations = { 571 .readlink = generic_readlink, 572 .get_link = page_get_link, 573 .permission = nilfs_permission, 574 }; 575 576 const struct export_operations nilfs_export_ops = { 577 .encode_fh = nilfs_encode_fh, 578 .fh_to_dentry = nilfs_fh_to_dentry, 579 .fh_to_parent = nilfs_fh_to_parent, 580 .get_parent = nilfs_get_parent, 581 }; 582