1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * namei.c - NILFS pathname lookup operations. 4 * 5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 6 * 7 * Modified for NILFS by Amagai Yoshiji and Ryusuke Konishi. 8 */ 9 /* 10 * linux/fs/ext2/namei.c 11 * 12 * Copyright (C) 1992, 1993, 1994, 1995 13 * Remy Card (card@masi.ibp.fr) 14 * Laboratoire MASI - Institut Blaise Pascal 15 * Universite Pierre et Marie Curie (Paris VI) 16 * 17 * from 18 * 19 * linux/fs/minix/namei.c 20 * 21 * Copyright (C) 1991, 1992 Linus Torvalds 22 * 23 * Big-endian to little-endian byte-swapping/bitmaps by 24 * David S. Miller (davem@caip.rutgers.edu), 1995 25 */ 26 27 #include <linux/pagemap.h> 28 #include "nilfs.h" 29 #include "export.h" 30 31 #define NILFS_FID_SIZE_NON_CONNECTABLE \ 32 (offsetof(struct nilfs_fid, parent_gen) / 4) 33 #define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4) 34 35 static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode) 36 { 37 int err = nilfs_add_link(dentry, inode); 38 39 if (!err) { 40 d_instantiate_new(dentry, inode); 41 return 0; 42 } 43 inode_dec_link_count(inode); 44 unlock_new_inode(inode); 45 iput(inode); 46 return err; 47 } 48 49 /* 50 * Methods themselves. 51 */ 52 53 static struct dentry * 54 nilfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 55 { 56 struct inode *inode; 57 ino_t ino; 58 59 if (dentry->d_name.len > NILFS_NAME_LEN) 60 return ERR_PTR(-ENAMETOOLONG); 61 62 ino = nilfs_inode_by_name(dir, &dentry->d_name); 63 inode = ino ? nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino) : NULL; 64 return d_splice_alias(inode, dentry); 65 } 66 67 /* 68 * By the time this is called, we already have created 69 * the directory cache entry for the new file, but it 70 * is so far negative - it has no inode. 71 * 72 * If the create succeeds, we fill in the inode information 73 * with d_instantiate(). 74 */ 75 static int nilfs_create(struct user_namespace *mnt_userns, struct inode *dir, 76 struct dentry *dentry, umode_t mode, bool excl) 77 { 78 struct inode *inode; 79 struct nilfs_transaction_info ti; 80 int err; 81 82 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 83 if (err) 84 return err; 85 inode = nilfs_new_inode(dir, mode); 86 err = PTR_ERR(inode); 87 if (!IS_ERR(inode)) { 88 inode->i_op = &nilfs_file_inode_operations; 89 inode->i_fop = &nilfs_file_operations; 90 inode->i_mapping->a_ops = &nilfs_aops; 91 nilfs_mark_inode_dirty(inode); 92 err = nilfs_add_nondir(dentry, inode); 93 } 94 if (!err) 95 err = nilfs_transaction_commit(dir->i_sb); 96 else 97 nilfs_transaction_abort(dir->i_sb); 98 99 return err; 100 } 101 102 static int 103 nilfs_mknod(struct user_namespace *mnt_userns, struct inode *dir, 104 struct dentry *dentry, umode_t mode, dev_t rdev) 105 { 106 struct inode *inode; 107 struct nilfs_transaction_info ti; 108 int err; 109 110 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 111 if (err) 112 return err; 113 inode = nilfs_new_inode(dir, mode); 114 err = PTR_ERR(inode); 115 if (!IS_ERR(inode)) { 116 init_special_inode(inode, inode->i_mode, rdev); 117 nilfs_mark_inode_dirty(inode); 118 err = nilfs_add_nondir(dentry, inode); 119 } 120 if (!err) 121 err = nilfs_transaction_commit(dir->i_sb); 122 else 123 nilfs_transaction_abort(dir->i_sb); 124 125 return err; 126 } 127 128 static int nilfs_symlink(struct user_namespace *mnt_userns, struct inode *dir, 129 struct dentry *dentry, const char *symname) 130 { 131 struct nilfs_transaction_info ti; 132 struct super_block *sb = dir->i_sb; 133 unsigned int l = strlen(symname) + 1; 134 struct inode *inode; 135 int err; 136 137 if (l > sb->s_blocksize) 138 return -ENAMETOOLONG; 139 140 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 141 if (err) 142 return err; 143 144 inode = nilfs_new_inode(dir, S_IFLNK | 0777); 145 err = PTR_ERR(inode); 146 if (IS_ERR(inode)) 147 goto out; 148 149 /* slow symlink */ 150 inode->i_op = &nilfs_symlink_inode_operations; 151 inode_nohighmem(inode); 152 inode->i_mapping->a_ops = &nilfs_aops; 153 err = page_symlink(inode, symname, l); 154 if (err) 155 goto out_fail; 156 157 /* mark_inode_dirty(inode); */ 158 /* page_symlink() do this */ 159 160 err = nilfs_add_nondir(dentry, inode); 161 out: 162 if (!err) 163 err = nilfs_transaction_commit(dir->i_sb); 164 else 165 nilfs_transaction_abort(dir->i_sb); 166 167 return err; 168 169 out_fail: 170 drop_nlink(inode); 171 nilfs_mark_inode_dirty(inode); 172 unlock_new_inode(inode); 173 iput(inode); 174 goto out; 175 } 176 177 static int nilfs_link(struct dentry *old_dentry, struct inode *dir, 178 struct dentry *dentry) 179 { 180 struct inode *inode = d_inode(old_dentry); 181 struct nilfs_transaction_info ti; 182 int err; 183 184 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 185 if (err) 186 return err; 187 188 inode->i_ctime = current_time(inode); 189 inode_inc_link_count(inode); 190 ihold(inode); 191 192 err = nilfs_add_link(dentry, inode); 193 if (!err) { 194 d_instantiate(dentry, inode); 195 err = nilfs_transaction_commit(dir->i_sb); 196 } else { 197 inode_dec_link_count(inode); 198 iput(inode); 199 nilfs_transaction_abort(dir->i_sb); 200 } 201 202 return err; 203 } 204 205 static int nilfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir, 206 struct dentry *dentry, umode_t mode) 207 { 208 struct inode *inode; 209 struct nilfs_transaction_info ti; 210 int err; 211 212 err = nilfs_transaction_begin(dir->i_sb, &ti, 1); 213 if (err) 214 return err; 215 216 inc_nlink(dir); 217 218 inode = nilfs_new_inode(dir, S_IFDIR | mode); 219 err = PTR_ERR(inode); 220 if (IS_ERR(inode)) 221 goto out_dir; 222 223 inode->i_op = &nilfs_dir_inode_operations; 224 inode->i_fop = &nilfs_dir_operations; 225 inode->i_mapping->a_ops = &nilfs_aops; 226 227 inc_nlink(inode); 228 229 err = nilfs_make_empty(inode, dir); 230 if (err) 231 goto out_fail; 232 233 err = nilfs_add_link(dentry, inode); 234 if (err) 235 goto out_fail; 236 237 nilfs_mark_inode_dirty(inode); 238 d_instantiate_new(dentry, inode); 239 out: 240 if (!err) 241 err = nilfs_transaction_commit(dir->i_sb); 242 else 243 nilfs_transaction_abort(dir->i_sb); 244 245 return err; 246 247 out_fail: 248 drop_nlink(inode); 249 drop_nlink(inode); 250 nilfs_mark_inode_dirty(inode); 251 unlock_new_inode(inode); 252 iput(inode); 253 out_dir: 254 drop_nlink(dir); 255 nilfs_mark_inode_dirty(dir); 256 goto out; 257 } 258 259 static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry) 260 { 261 struct inode *inode; 262 struct nilfs_dir_entry *de; 263 struct page *page; 264 int err; 265 266 err = -ENOENT; 267 de = nilfs_find_entry(dir, &dentry->d_name, &page); 268 if (!de) 269 goto out; 270 271 inode = d_inode(dentry); 272 err = -EIO; 273 if (le64_to_cpu(de->inode) != inode->i_ino) 274 goto out; 275 276 if (!inode->i_nlink) { 277 nilfs_warn(inode->i_sb, 278 "deleting nonexistent file (ino=%lu), %d", 279 inode->i_ino, inode->i_nlink); 280 set_nlink(inode, 1); 281 } 282 err = nilfs_delete_entry(de, page); 283 if (err) 284 goto out; 285 286 inode->i_ctime = dir->i_ctime; 287 drop_nlink(inode); 288 err = 0; 289 out: 290 return err; 291 } 292 293 static int nilfs_unlink(struct inode *dir, struct dentry *dentry) 294 { 295 struct nilfs_transaction_info ti; 296 int err; 297 298 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 299 if (err) 300 return err; 301 302 err = nilfs_do_unlink(dir, dentry); 303 304 if (!err) { 305 nilfs_mark_inode_dirty(dir); 306 nilfs_mark_inode_dirty(d_inode(dentry)); 307 err = nilfs_transaction_commit(dir->i_sb); 308 } else 309 nilfs_transaction_abort(dir->i_sb); 310 311 return err; 312 } 313 314 static int nilfs_rmdir(struct inode *dir, struct dentry *dentry) 315 { 316 struct inode *inode = d_inode(dentry); 317 struct nilfs_transaction_info ti; 318 int err; 319 320 err = nilfs_transaction_begin(dir->i_sb, &ti, 0); 321 if (err) 322 return err; 323 324 err = -ENOTEMPTY; 325 if (nilfs_empty_dir(inode)) { 326 err = nilfs_do_unlink(dir, dentry); 327 if (!err) { 328 inode->i_size = 0; 329 drop_nlink(inode); 330 nilfs_mark_inode_dirty(inode); 331 drop_nlink(dir); 332 nilfs_mark_inode_dirty(dir); 333 } 334 } 335 if (!err) 336 err = nilfs_transaction_commit(dir->i_sb); 337 else 338 nilfs_transaction_abort(dir->i_sb); 339 340 return err; 341 } 342 343 static int nilfs_rename(struct user_namespace *mnt_userns, 344 struct inode *old_dir, struct dentry *old_dentry, 345 struct inode *new_dir, struct dentry *new_dentry, 346 unsigned int flags) 347 { 348 struct inode *old_inode = d_inode(old_dentry); 349 struct inode *new_inode = d_inode(new_dentry); 350 struct page *dir_page = NULL; 351 struct nilfs_dir_entry *dir_de = NULL; 352 struct page *old_page; 353 struct nilfs_dir_entry *old_de; 354 struct nilfs_transaction_info ti; 355 int err; 356 357 if (flags & ~RENAME_NOREPLACE) 358 return -EINVAL; 359 360 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1); 361 if (unlikely(err)) 362 return err; 363 364 err = -ENOENT; 365 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_page); 366 if (!old_de) 367 goto out; 368 369 if (S_ISDIR(old_inode->i_mode)) { 370 err = -EIO; 371 dir_de = nilfs_dotdot(old_inode, &dir_page); 372 if (!dir_de) 373 goto out_old; 374 } 375 376 if (new_inode) { 377 struct page *new_page; 378 struct nilfs_dir_entry *new_de; 379 380 err = -ENOTEMPTY; 381 if (dir_de && !nilfs_empty_dir(new_inode)) 382 goto out_dir; 383 384 err = -ENOENT; 385 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page); 386 if (!new_de) 387 goto out_dir; 388 nilfs_set_link(new_dir, new_de, new_page, old_inode); 389 nilfs_mark_inode_dirty(new_dir); 390 new_inode->i_ctime = current_time(new_inode); 391 if (dir_de) 392 drop_nlink(new_inode); 393 drop_nlink(new_inode); 394 nilfs_mark_inode_dirty(new_inode); 395 } else { 396 err = nilfs_add_link(new_dentry, old_inode); 397 if (err) 398 goto out_dir; 399 if (dir_de) { 400 inc_nlink(new_dir); 401 nilfs_mark_inode_dirty(new_dir); 402 } 403 } 404 405 /* 406 * Like most other Unix systems, set the ctime for inodes on a 407 * rename. 408 */ 409 old_inode->i_ctime = current_time(old_inode); 410 411 nilfs_delete_entry(old_de, old_page); 412 413 if (dir_de) { 414 nilfs_set_link(old_inode, dir_de, dir_page, new_dir); 415 drop_nlink(old_dir); 416 } 417 nilfs_mark_inode_dirty(old_dir); 418 nilfs_mark_inode_dirty(old_inode); 419 420 err = nilfs_transaction_commit(old_dir->i_sb); 421 return err; 422 423 out_dir: 424 if (dir_de) { 425 kunmap(dir_page); 426 put_page(dir_page); 427 } 428 out_old: 429 kunmap(old_page); 430 put_page(old_page); 431 out: 432 nilfs_transaction_abort(old_dir->i_sb); 433 return err; 434 } 435 436 /* 437 * Export operations 438 */ 439 static struct dentry *nilfs_get_parent(struct dentry *child) 440 { 441 unsigned long ino; 442 struct inode *inode; 443 struct qstr dotdot = QSTR_INIT("..", 2); 444 struct nilfs_root *root; 445 446 ino = nilfs_inode_by_name(d_inode(child), &dotdot); 447 if (!ino) 448 return ERR_PTR(-ENOENT); 449 450 root = NILFS_I(d_inode(child))->i_root; 451 452 inode = nilfs_iget(child->d_sb, root, ino); 453 if (IS_ERR(inode)) 454 return ERR_CAST(inode); 455 456 return d_obtain_alias(inode); 457 } 458 459 static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno, 460 u64 ino, u32 gen) 461 { 462 struct nilfs_root *root; 463 struct inode *inode; 464 465 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO) 466 return ERR_PTR(-ESTALE); 467 468 root = nilfs_lookup_root(sb->s_fs_info, cno); 469 if (!root) 470 return ERR_PTR(-ESTALE); 471 472 inode = nilfs_iget(sb, root, ino); 473 nilfs_put_root(root); 474 475 if (IS_ERR(inode)) 476 return ERR_CAST(inode); 477 if (gen && inode->i_generation != gen) { 478 iput(inode); 479 return ERR_PTR(-ESTALE); 480 } 481 return d_obtain_alias(inode); 482 } 483 484 static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh, 485 int fh_len, int fh_type) 486 { 487 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 488 489 if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE || 490 (fh_type != FILEID_NILFS_WITH_PARENT && 491 fh_type != FILEID_NILFS_WITHOUT_PARENT)) 492 return NULL; 493 494 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen); 495 } 496 497 static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh, 498 int fh_len, int fh_type) 499 { 500 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 501 502 if (fh_len < NILFS_FID_SIZE_CONNECTABLE || 503 fh_type != FILEID_NILFS_WITH_PARENT) 504 return NULL; 505 506 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen); 507 } 508 509 static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp, 510 struct inode *parent) 511 { 512 struct nilfs_fid *fid = (struct nilfs_fid *)fh; 513 struct nilfs_root *root = NILFS_I(inode)->i_root; 514 int type; 515 516 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) { 517 *lenp = NILFS_FID_SIZE_CONNECTABLE; 518 return FILEID_INVALID; 519 } 520 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) { 521 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 522 return FILEID_INVALID; 523 } 524 525 fid->cno = root->cno; 526 fid->ino = inode->i_ino; 527 fid->gen = inode->i_generation; 528 529 if (parent) { 530 fid->parent_ino = parent->i_ino; 531 fid->parent_gen = parent->i_generation; 532 type = FILEID_NILFS_WITH_PARENT; 533 *lenp = NILFS_FID_SIZE_CONNECTABLE; 534 } else { 535 type = FILEID_NILFS_WITHOUT_PARENT; 536 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE; 537 } 538 539 return type; 540 } 541 542 const struct inode_operations nilfs_dir_inode_operations = { 543 .create = nilfs_create, 544 .lookup = nilfs_lookup, 545 .link = nilfs_link, 546 .unlink = nilfs_unlink, 547 .symlink = nilfs_symlink, 548 .mkdir = nilfs_mkdir, 549 .rmdir = nilfs_rmdir, 550 .mknod = nilfs_mknod, 551 .rename = nilfs_rename, 552 .setattr = nilfs_setattr, 553 .permission = nilfs_permission, 554 .fiemap = nilfs_fiemap, 555 }; 556 557 const struct inode_operations nilfs_special_inode_operations = { 558 .setattr = nilfs_setattr, 559 .permission = nilfs_permission, 560 }; 561 562 const struct inode_operations nilfs_symlink_inode_operations = { 563 .get_link = page_get_link, 564 .permission = nilfs_permission, 565 }; 566 567 const struct export_operations nilfs_export_ops = { 568 .encode_fh = nilfs_encode_fh, 569 .fh_to_dentry = nilfs_fh_to_dentry, 570 .fh_to_parent = nilfs_fh_to_parent, 571 .get_parent = nilfs_get_parent, 572 }; 573