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 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; 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_warning(inode->i_sb, __func__, 287 "deleting nonexistent file (%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 { 355 struct inode *old_inode = d_inode(old_dentry); 356 struct inode *new_inode = d_inode(new_dentry); 357 struct page *dir_page = NULL; 358 struct nilfs_dir_entry *dir_de = NULL; 359 struct page *old_page; 360 struct nilfs_dir_entry *old_de; 361 struct nilfs_transaction_info ti; 362 int err; 363 364 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1); 365 if (unlikely(err)) 366 return err; 367 368 err = -ENOENT; 369 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_page); 370 if (!old_de) 371 goto out; 372 373 if (S_ISDIR(old_inode->i_mode)) { 374 err = -EIO; 375 dir_de = nilfs_dotdot(old_inode, &dir_page); 376 if (!dir_de) 377 goto out_old; 378 } 379 380 if (new_inode) { 381 struct page *new_page; 382 struct nilfs_dir_entry *new_de; 383 384 err = -ENOTEMPTY; 385 if (dir_de && !nilfs_empty_dir(new_inode)) 386 goto out_dir; 387 388 err = -ENOENT; 389 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page); 390 if (!new_de) 391 goto out_dir; 392 nilfs_set_link(new_dir, new_de, new_page, old_inode); 393 nilfs_mark_inode_dirty(new_dir); 394 new_inode->i_ctime = CURRENT_TIME; 395 if (dir_de) 396 drop_nlink(new_inode); 397 drop_nlink(new_inode); 398 nilfs_mark_inode_dirty(new_inode); 399 } else { 400 err = nilfs_add_link(new_dentry, old_inode); 401 if (err) 402 goto out_dir; 403 if (dir_de) { 404 inc_nlink(new_dir); 405 nilfs_mark_inode_dirty(new_dir); 406 } 407 } 408 409 /* 410 * Like most other Unix systems, set the ctime for inodes on a 411 * rename. 412 */ 413 old_inode->i_ctime = CURRENT_TIME; 414 415 nilfs_delete_entry(old_de, old_page); 416 417 if (dir_de) { 418 nilfs_set_link(old_inode, dir_de, dir_page, new_dir); 419 drop_nlink(old_dir); 420 } 421 nilfs_mark_inode_dirty(old_dir); 422 nilfs_mark_inode_dirty(old_inode); 423 424 err = nilfs_transaction_commit(old_dir->i_sb); 425 return err; 426 427 out_dir: 428 if (dir_de) { 429 kunmap(dir_page); 430 put_page(dir_page); 431 } 432 out_old: 433 kunmap(old_page); 434 put_page(old_page); 435 out: 436 nilfs_transaction_abort(old_dir->i_sb); 437 return err; 438 } 439 440 /* 441 * Export operations 442 */ 443 static struct dentry *nilfs_get_parent(struct dentry *child) 444 { 445 unsigned long ino; 446 struct inode *inode; 447 struct qstr dotdot = QSTR_INIT("..", 2); 448 struct nilfs_root *root; 449 450 ino = nilfs_inode_by_name(d_inode(child), &dotdot); 451 if (!ino) 452 return ERR_PTR(-ENOENT); 453 454 root = NILFS_I(d_inode(child))->i_root; 455 456 inode = nilfs_iget(child->d_sb, root, ino); 457 if (IS_ERR(inode)) 458 return ERR_CAST(inode); 459 460 return d_obtain_alias(inode); 461 } 462 463 static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno, 464 u64 ino, u32 gen) 465 { 466 struct nilfs_root *root; 467 struct inode *inode; 468 469 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO) 470 return ERR_PTR(-ESTALE); 471 472 root = nilfs_lookup_root(sb->s_fs_info, cno); 473 if (!root) 474 return ERR_PTR(-ESTALE); 475 476 inode = nilfs_iget(sb, root, ino); 477 nilfs_put_root(root); 478 479 if (IS_ERR(inode)) 480 return ERR_CAST(inode); 481 if (gen && inode->i_generation != gen) { 482 iput(inode); 483 return ERR_PTR(-ESTALE); 484 } 485 return d_obtain_alias(inode); 486 } 487 488 static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh, 489 int fh_len, int fh_type) 490 { 491 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 492 493 if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE || 494 (fh_type != FILEID_NILFS_WITH_PARENT && 495 fh_type != FILEID_NILFS_WITHOUT_PARENT)) 496 return NULL; 497 498 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen); 499 } 500 501 static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh, 502 int fh_len, int fh_type) 503 { 504 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 505 506 if (fh_len < NILFS_FID_SIZE_CONNECTABLE || 507 fh_type != FILEID_NILFS_WITH_PARENT) 508 return NULL; 509 510 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen); 511 } 512 513 static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp, 514 struct inode *parent) 515 { 516 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 517 struct nilfs_root *root = NILFS_I(inode)->i_root; 518 int type; 519 520 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) { 521 *lenp = NILFS_FID_SIZE_CONNECTABLE; 522 return FILEID_INVALID; 523 } 524 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) { 525 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 526 return FILEID_INVALID; 527 } 528 529 fid->cno = root->cno; 530 fid->ino = inode->i_ino; 531 fid->gen = inode->i_generation; 532 533 if (parent) { 534 fid->parent_ino = parent->i_ino; 535 fid->parent_gen = parent->i_generation; 536 type = FILEID_NILFS_WITH_PARENT; 537 *lenp = NILFS_FID_SIZE_CONNECTABLE; 538 } else { 539 type = FILEID_NILFS_WITHOUT_PARENT; 540 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 541 } 542 543 return type; 544 } 545 546 const struct inode_operations nilfs_dir_inode_operations = { 547 .create = nilfs_create, 548 .lookup = nilfs_lookup, 549 .link = nilfs_link, 550 .unlink = nilfs_unlink, 551 .symlink = nilfs_symlink, 552 .mkdir = nilfs_mkdir, 553 .rmdir = nilfs_rmdir, 554 .mknod = nilfs_mknod, 555 .rename = nilfs_rename, 556 .setattr = nilfs_setattr, 557 .permission = nilfs_permission, 558 .fiemap = nilfs_fiemap, 559 }; 560 561 const struct inode_operations nilfs_special_inode_operations = { 562 .setattr = nilfs_setattr, 563 .permission = nilfs_permission, 564 }; 565 566 const struct inode_operations nilfs_symlink_inode_operations = { 567 .readlink = generic_readlink, 568 .get_link = page_get_link, 569 .permission = nilfs_permission, 570 }; 571 572 const struct export_operations nilfs_export_ops = { 573 .encode_fh = nilfs_encode_fh, 574 .fh_to_dentry = nilfs_fh_to_dentry, 575 .fh_to_parent = nilfs_fh_to_parent, 576 .get_parent = nilfs_get_parent, 577 }; 578