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 * Modified for NILFS by Amagai Yoshiji and Ryusuke Konishi. 17 */ 18 /* 19 * linux/fs/ext2/namei.c 20 * 21 * Copyright (C) 1992, 1993, 1994, 1995 22 * Remy Card (card@masi.ibp.fr) 23 * Laboratoire MASI - Institut Blaise Pascal 24 * Universite Pierre et Marie Curie (Paris VI) 25 * 26 * from 27 * 28 * linux/fs/minix/namei.c 29 * 30 * Copyright (C) 1991, 1992 Linus Torvalds 31 * 32 * Big-endian to little-endian byte-swapping/bitmaps by 33 * David S. Miller (davem@caip.rutgers.edu), 1995 34 */ 35 36 #include <linux/pagemap.h> 37 #include "nilfs.h" 38 #include "export.h" 39 40 #define NILFS_FID_SIZE_NON_CONNECTABLE \ 41 (offsetof(struct nilfs_fid, parent_gen) / 4) 42 #define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4) 43 44 static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode) 45 { 46 int err = nilfs_add_link(dentry, inode); 47 48 if (!err) { 49 d_instantiate(dentry, inode); 50 unlock_new_inode(inode); 51 return 0; 52 } 53 inode_dec_link_count(inode); 54 unlock_new_inode(inode); 55 iput(inode); 56 return err; 57 } 58 59 /* 60 * Methods themselves. 61 */ 62 63 static struct dentry * 64 nilfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 65 { 66 struct inode *inode; 67 ino_t ino; 68 69 if (dentry->d_name.len > NILFS_NAME_LEN) 70 return ERR_PTR(-ENAMETOOLONG); 71 72 ino = nilfs_inode_by_name(dir, &dentry->d_name); 73 inode = ino ? nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino) : NULL; 74 return d_splice_alias(inode, dentry); 75 } 76 77 /* 78 * By the time this is called, we already have created 79 * the directory cache entry for the new file, but it 80 * is so far negative - it has no inode. 81 * 82 * If the create succeeds, we fill in the inode information 83 * with d_instantiate(). 84 */ 85 static int nilfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, 86 bool excl) 87 { 88 struct inode *inode; 89 struct nilfs_transaction_info ti; 90 int err; 91 92 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 93 if (err) 94 return err; 95 inode = nilfs_new_inode(dir, mode); 96 err = PTR_ERR(inode); 97 if (!IS_ERR(inode)) { 98 inode->i_op = &nilfs_file_inode_operations; 99 inode->i_fop = &nilfs_file_operations; 100 inode->i_mapping->a_ops = &nilfs_aops; 101 nilfs_mark_inode_dirty(inode); 102 err = nilfs_add_nondir(dentry, inode); 103 } 104 if (!err) 105 err = nilfs_transaction_commit(dir->i_sb); 106 else 107 nilfs_transaction_abort(dir->i_sb); 108 109 return err; 110 } 111 112 static int 113 nilfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) 114 { 115 struct inode *inode; 116 struct nilfs_transaction_info ti; 117 int err; 118 119 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 120 if (err) 121 return err; 122 inode = nilfs_new_inode(dir, mode); 123 err = PTR_ERR(inode); 124 if (!IS_ERR(inode)) { 125 init_special_inode(inode, inode->i_mode, rdev); 126 nilfs_mark_inode_dirty(inode); 127 err = nilfs_add_nondir(dentry, inode); 128 } 129 if (!err) 130 err = nilfs_transaction_commit(dir->i_sb); 131 else 132 nilfs_transaction_abort(dir->i_sb); 133 134 return err; 135 } 136 137 static int nilfs_symlink(struct inode *dir, struct dentry *dentry, 138 const char *symname) 139 { 140 struct nilfs_transaction_info ti; 141 struct super_block *sb = dir->i_sb; 142 unsigned int l = strlen(symname) + 1; 143 struct inode *inode; 144 int err; 145 146 if (l > sb->s_blocksize) 147 return -ENAMETOOLONG; 148 149 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 150 if (err) 151 return err; 152 153 inode = nilfs_new_inode(dir, S_IFLNK | S_IRWXUGO); 154 err = PTR_ERR(inode); 155 if (IS_ERR(inode)) 156 goto out; 157 158 /* slow symlink */ 159 inode->i_op = &nilfs_symlink_inode_operations; 160 inode_nohighmem(inode); 161 inode->i_mapping->a_ops = &nilfs_aops; 162 err = page_symlink(inode, symname, l); 163 if (err) 164 goto out_fail; 165 166 /* mark_inode_dirty(inode); */ 167 /* page_symlink() do this */ 168 169 err = nilfs_add_nondir(dentry, inode); 170 out: 171 if (!err) 172 err = nilfs_transaction_commit(dir->i_sb); 173 else 174 nilfs_transaction_abort(dir->i_sb); 175 176 return err; 177 178 out_fail: 179 drop_nlink(inode); 180 nilfs_mark_inode_dirty(inode); 181 unlock_new_inode(inode); 182 iput(inode); 183 goto out; 184 } 185 186 static int nilfs_link(struct dentry *old_dentry, struct inode *dir, 187 struct dentry *dentry) 188 { 189 struct inode *inode = d_inode(old_dentry); 190 struct nilfs_transaction_info ti; 191 int err; 192 193 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 194 if (err) 195 return err; 196 197 inode->i_ctime = current_time(inode); 198 inode_inc_link_count(inode); 199 ihold(inode); 200 201 err = nilfs_add_link(dentry, inode); 202 if (!err) { 203 d_instantiate(dentry, inode); 204 err = nilfs_transaction_commit(dir->i_sb); 205 } else { 206 inode_dec_link_count(inode); 207 iput(inode); 208 nilfs_transaction_abort(dir->i_sb); 209 } 210 211 return err; 212 } 213 214 static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 215 { 216 struct inode *inode; 217 struct nilfs_transaction_info ti; 218 int err; 219 220 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 221 if (err) 222 return err; 223 224 inc_nlink(dir); 225 226 inode = nilfs_new_inode(dir, S_IFDIR | mode); 227 err = PTR_ERR(inode); 228 if (IS_ERR(inode)) 229 goto out_dir; 230 231 inode->i_op = &nilfs_dir_inode_operations; 232 inode->i_fop = &nilfs_dir_operations; 233 inode->i_mapping->a_ops = &nilfs_aops; 234 235 inc_nlink(inode); 236 237 err = nilfs_make_empty(inode, dir); 238 if (err) 239 goto out_fail; 240 241 err = nilfs_add_link(dentry, inode); 242 if (err) 243 goto out_fail; 244 245 nilfs_mark_inode_dirty(inode); 246 d_instantiate(dentry, inode); 247 unlock_new_inode(inode); 248 out: 249 if (!err) 250 err = nilfs_transaction_commit(dir->i_sb); 251 else 252 nilfs_transaction_abort(dir->i_sb); 253 254 return err; 255 256 out_fail: 257 drop_nlink(inode); 258 drop_nlink(inode); 259 nilfs_mark_inode_dirty(inode); 260 unlock_new_inode(inode); 261 iput(inode); 262 out_dir: 263 drop_nlink(dir); 264 nilfs_mark_inode_dirty(dir); 265 goto out; 266 } 267 268 static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry) 269 { 270 struct inode *inode; 271 struct nilfs_dir_entry *de; 272 struct page *page; 273 int err; 274 275 err = -ENOENT; 276 de = nilfs_find_entry(dir, &dentry->d_name, &page); 277 if (!de) 278 goto out; 279 280 inode = d_inode(dentry); 281 err = -EIO; 282 if (le64_to_cpu(de->inode) != inode->i_ino) 283 goto out; 284 285 if (!inode->i_nlink) { 286 nilfs_msg(inode->i_sb, KERN_WARNING, 287 "deleting nonexistent file (ino=%lu), %d", 288 inode->i_ino, inode->i_nlink); 289 set_nlink(inode, 1); 290 } 291 err = nilfs_delete_entry(de, page); 292 if (err) 293 goto out; 294 295 inode->i_ctime = dir->i_ctime; 296 drop_nlink(inode); 297 err = 0; 298 out: 299 return err; 300 } 301 302 static int nilfs_unlink(struct inode *dir, struct dentry *dentry) 303 { 304 struct nilfs_transaction_info ti; 305 int err; 306 307 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 308 if (err) 309 return err; 310 311 err = nilfs_do_unlink(dir, dentry); 312 313 if (!err) { 314 nilfs_mark_inode_dirty(dir); 315 nilfs_mark_inode_dirty(d_inode(dentry)); 316 err = nilfs_transaction_commit(dir->i_sb); 317 } else 318 nilfs_transaction_abort(dir->i_sb); 319 320 return err; 321 } 322 323 static int nilfs_rmdir(struct inode *dir, struct dentry *dentry) 324 { 325 struct inode *inode = d_inode(dentry); 326 struct nilfs_transaction_info ti; 327 int err; 328 329 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 330 if (err) 331 return err; 332 333 err = -ENOTEMPTY; 334 if (nilfs_empty_dir(inode)) { 335 err = nilfs_do_unlink(dir, dentry); 336 if (!err) { 337 inode->i_size = 0; 338 drop_nlink(inode); 339 nilfs_mark_inode_dirty(inode); 340 drop_nlink(dir); 341 nilfs_mark_inode_dirty(dir); 342 } 343 } 344 if (!err) 345 err = nilfs_transaction_commit(dir->i_sb); 346 else 347 nilfs_transaction_abort(dir->i_sb); 348 349 return err; 350 } 351 352 static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry, 353 struct inode *new_dir, struct dentry *new_dentry, 354 unsigned int flags) 355 { 356 struct inode *old_inode = d_inode(old_dentry); 357 struct inode *new_inode = d_inode(new_dentry); 358 struct page *dir_page = NULL; 359 struct nilfs_dir_entry *dir_de = NULL; 360 struct page *old_page; 361 struct nilfs_dir_entry *old_de; 362 struct nilfs_transaction_info ti; 363 int err; 364 365 if (flags & ~RENAME_NOREPLACE) 366 return -EINVAL; 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(new_inode); 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(old_inode); 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 put_page(dir_page); 435 } 436 out_old: 437 kunmap(old_page); 438 put_page(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(child->d_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