1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * 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 int res;
59
60 if (dentry->d_name.len > NILFS_NAME_LEN)
61 return ERR_PTR(-ENAMETOOLONG);
62
63 res = nilfs_inode_by_name(dir, &dentry->d_name, &ino);
64 if (res) {
65 if (res != -ENOENT)
66 return ERR_PTR(res);
67 inode = NULL;
68 } else {
69 inode = nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino);
70 }
71
72 return d_splice_alias(inode, dentry);
73 }
74
75 /*
76 * By the time this is called, we already have created
77 * the directory cache entry for the new file, but it
78 * is so far negative - it has no inode.
79 *
80 * If the create succeeds, we fill in the inode information
81 * with d_instantiate().
82 */
83 static int nilfs_create(struct mnt_idmap *idmap, struct inode *dir,
84 struct dentry *dentry, umode_t mode, bool excl)
85 {
86 struct inode *inode;
87 struct nilfs_transaction_info ti;
88 int err;
89
90 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
91 if (err)
92 return err;
93 inode = nilfs_new_inode(dir, mode);
94 err = PTR_ERR(inode);
95 if (!IS_ERR(inode)) {
96 inode->i_op = &nilfs_file_inode_operations;
97 inode->i_fop = &nilfs_file_operations;
98 inode->i_mapping->a_ops = &nilfs_aops;
99 nilfs_mark_inode_dirty(inode);
100 err = nilfs_add_nondir(dentry, inode);
101 }
102 if (!err)
103 err = nilfs_transaction_commit(dir->i_sb);
104 else
105 nilfs_transaction_abort(dir->i_sb);
106
107 return err;
108 }
109
110 static int
111 nilfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
112 struct dentry *dentry, umode_t mode, dev_t rdev)
113 {
114 struct inode *inode;
115 struct nilfs_transaction_info ti;
116 int err;
117
118 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
119 if (err)
120 return err;
121 inode = nilfs_new_inode(dir, mode);
122 err = PTR_ERR(inode);
123 if (!IS_ERR(inode)) {
124 init_special_inode(inode, inode->i_mode, rdev);
125 nilfs_mark_inode_dirty(inode);
126 err = nilfs_add_nondir(dentry, inode);
127 }
128 if (!err)
129 err = nilfs_transaction_commit(dir->i_sb);
130 else
131 nilfs_transaction_abort(dir->i_sb);
132
133 return err;
134 }
135
136 static int nilfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
137 struct dentry *dentry, const char *symname)
138 {
139 struct nilfs_transaction_info ti;
140 struct super_block *sb = dir->i_sb;
141 unsigned int l = strlen(symname) + 1;
142 struct inode *inode;
143 int err;
144
145 if (l > sb->s_blocksize)
146 return -ENAMETOOLONG;
147
148 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
149 if (err)
150 return err;
151
152 inode = nilfs_new_inode(dir, S_IFLNK | 0777);
153 err = PTR_ERR(inode);
154 if (IS_ERR(inode))
155 goto out;
156
157 /* slow symlink */
158 inode->i_op = &nilfs_symlink_inode_operations;
159 inode_nohighmem(inode);
160 inode->i_mapping->a_ops = &nilfs_aops;
161 err = page_symlink(inode, symname, l);
162 if (err)
163 goto out_fail;
164
165 /* mark_inode_dirty(inode); */
166 /* page_symlink() do this */
167
168 err = nilfs_add_nondir(dentry, inode);
169 out:
170 if (!err)
171 err = nilfs_transaction_commit(dir->i_sb);
172 else
173 nilfs_transaction_abort(dir->i_sb);
174
175 return err;
176
177 out_fail:
178 drop_nlink(inode);
179 nilfs_mark_inode_dirty(inode);
180 unlock_new_inode(inode);
181 iput(inode);
182 goto out;
183 }
184
185 static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
186 struct dentry *dentry)
187 {
188 struct inode *inode = d_inode(old_dentry);
189 struct nilfs_transaction_info ti;
190 int err;
191
192 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
193 if (err)
194 return err;
195
196 inode_set_ctime_current(inode);
197 inode_inc_link_count(inode);
198 ihold(inode);
199
200 err = nilfs_add_link(dentry, inode);
201 if (!err) {
202 d_instantiate(dentry, inode);
203 err = nilfs_transaction_commit(dir->i_sb);
204 } else {
205 inode_dec_link_count(inode);
206 iput(inode);
207 nilfs_transaction_abort(dir->i_sb);
208 }
209
210 return err;
211 }
212
213 static int nilfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
214 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_new(dentry, inode);
247 out:
248 if (!err)
249 err = nilfs_transaction_commit(dir->i_sb);
250 else
251 nilfs_transaction_abort(dir->i_sb);
252
253 return err;
254
255 out_fail:
256 drop_nlink(inode);
257 drop_nlink(inode);
258 nilfs_mark_inode_dirty(inode);
259 unlock_new_inode(inode);
260 iput(inode);
261 out_dir:
262 drop_nlink(dir);
263 nilfs_mark_inode_dirty(dir);
264 goto out;
265 }
266
267 static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry)
268 {
269 struct inode *inode;
270 struct nilfs_dir_entry *de;
271 struct folio *folio;
272 int err;
273
274 de = nilfs_find_entry(dir, &dentry->d_name, &folio);
275 if (IS_ERR(de)) {
276 err = PTR_ERR(de);
277 goto out;
278 }
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_warn(inode->i_sb,
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, folio);
292 folio_release_kmap(folio, de);
293 if (err)
294 goto out;
295
296 inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
297 drop_nlink(inode);
298 err = 0;
299 out:
300 return err;
301 }
302
303 static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
304 {
305 struct nilfs_transaction_info ti;
306 int err;
307
308 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
309 if (err)
310 return err;
311
312 err = nilfs_do_unlink(dir, dentry);
313
314 if (!err) {
315 nilfs_mark_inode_dirty(dir);
316 nilfs_mark_inode_dirty(d_inode(dentry));
317 err = nilfs_transaction_commit(dir->i_sb);
318 } else
319 nilfs_transaction_abort(dir->i_sb);
320
321 return err;
322 }
323
324 static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
325 {
326 struct inode *inode = d_inode(dentry);
327 struct nilfs_transaction_info ti;
328 int err;
329
330 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
331 if (err)
332 return err;
333
334 err = -ENOTEMPTY;
335 if (nilfs_empty_dir(inode)) {
336 err = nilfs_do_unlink(dir, dentry);
337 if (!err) {
338 inode->i_size = 0;
339 drop_nlink(inode);
340 nilfs_mark_inode_dirty(inode);
341 drop_nlink(dir);
342 nilfs_mark_inode_dirty(dir);
343 }
344 }
345 if (!err)
346 err = nilfs_transaction_commit(dir->i_sb);
347 else
348 nilfs_transaction_abort(dir->i_sb);
349
350 return err;
351 }
352
353 static int nilfs_rename(struct mnt_idmap *idmap,
354 struct inode *old_dir, struct dentry *old_dentry,
355 struct inode *new_dir, struct dentry *new_dentry,
356 unsigned int flags)
357 {
358 struct inode *old_inode = d_inode(old_dentry);
359 struct inode *new_inode = d_inode(new_dentry);
360 struct folio *dir_folio = NULL;
361 struct nilfs_dir_entry *dir_de = NULL;
362 struct folio *old_folio;
363 struct nilfs_dir_entry *old_de;
364 struct nilfs_transaction_info ti;
365 int err;
366
367 if (flags & ~RENAME_NOREPLACE)
368 return -EINVAL;
369
370 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
371 if (unlikely(err))
372 return err;
373
374 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_folio);
375 if (IS_ERR(old_de)) {
376 err = PTR_ERR(old_de);
377 goto out;
378 }
379
380 if (S_ISDIR(old_inode->i_mode)) {
381 err = -EIO;
382 dir_de = nilfs_dotdot(old_inode, &dir_folio);
383 if (!dir_de)
384 goto out_old;
385 }
386
387 if (new_inode) {
388 struct folio *new_folio;
389 struct nilfs_dir_entry *new_de;
390
391 err = -ENOTEMPTY;
392 if (dir_de && !nilfs_empty_dir(new_inode))
393 goto out_dir;
394
395 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name,
396 &new_folio);
397 if (IS_ERR(new_de)) {
398 err = PTR_ERR(new_de);
399 goto out_dir;
400 }
401 nilfs_set_link(new_dir, new_de, new_folio, old_inode);
402 folio_release_kmap(new_folio, new_de);
403 nilfs_mark_inode_dirty(new_dir);
404 inode_set_ctime_current(new_inode);
405 if (dir_de)
406 drop_nlink(new_inode);
407 drop_nlink(new_inode);
408 nilfs_mark_inode_dirty(new_inode);
409 } else {
410 err = nilfs_add_link(new_dentry, old_inode);
411 if (err)
412 goto out_dir;
413 if (dir_de) {
414 inc_nlink(new_dir);
415 nilfs_mark_inode_dirty(new_dir);
416 }
417 }
418
419 /*
420 * Like most other Unix systems, set the ctime for inodes on a
421 * rename.
422 */
423 inode_set_ctime_current(old_inode);
424
425 nilfs_delete_entry(old_de, old_folio);
426
427 if (dir_de) {
428 nilfs_set_link(old_inode, dir_de, dir_folio, new_dir);
429 folio_release_kmap(dir_folio, dir_de);
430 drop_nlink(old_dir);
431 }
432 folio_release_kmap(old_folio, old_de);
433
434 nilfs_mark_inode_dirty(old_dir);
435 nilfs_mark_inode_dirty(old_inode);
436
437 err = nilfs_transaction_commit(old_dir->i_sb);
438 return err;
439
440 out_dir:
441 if (dir_de)
442 folio_release_kmap(dir_folio, dir_de);
443 out_old:
444 folio_release_kmap(old_folio, old_de);
445 out:
446 nilfs_transaction_abort(old_dir->i_sb);
447 return err;
448 }
449
450 /*
451 * Export operations
452 */
453 static struct dentry *nilfs_get_parent(struct dentry *child)
454 {
455 ino_t ino;
456 int res;
457 struct nilfs_root *root;
458
459 res = nilfs_inode_by_name(d_inode(child), &dotdot_name, &ino);
460 if (res)
461 return ERR_PTR(res);
462
463 root = NILFS_I(d_inode(child))->i_root;
464
465 return d_obtain_alias(nilfs_iget(child->d_sb, root, ino));
466 }
467
468 static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
469 u64 ino, u32 gen)
470 {
471 struct nilfs_root *root;
472 struct inode *inode;
473
474 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
475 return ERR_PTR(-ESTALE);
476
477 root = nilfs_lookup_root(sb->s_fs_info, cno);
478 if (!root)
479 return ERR_PTR(-ESTALE);
480
481 inode = nilfs_iget(sb, root, ino);
482 nilfs_put_root(root);
483
484 if (IS_ERR(inode))
485 return ERR_CAST(inode);
486 if (gen && inode->i_generation != gen) {
487 iput(inode);
488 return ERR_PTR(-ESTALE);
489 }
490 return d_obtain_alias(inode);
491 }
492
493 static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
494 int fh_len, int fh_type)
495 {
496 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
497
498 if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE ||
499 (fh_type != FILEID_NILFS_WITH_PARENT &&
500 fh_type != FILEID_NILFS_WITHOUT_PARENT))
501 return NULL;
502
503 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);
504 }
505
506 static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
507 int fh_len, int fh_type)
508 {
509 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
510
511 if (fh_len < NILFS_FID_SIZE_CONNECTABLE ||
512 fh_type != FILEID_NILFS_WITH_PARENT)
513 return NULL;
514
515 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);
516 }
517
518 static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
519 struct inode *parent)
520 {
521 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
522 struct nilfs_root *root = NILFS_I(inode)->i_root;
523 int type;
524
525 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) {
526 *lenp = NILFS_FID_SIZE_CONNECTABLE;
527 return FILEID_INVALID;
528 }
529 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) {
530 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
531 return FILEID_INVALID;
532 }
533
534 fid->cno = root->cno;
535 fid->ino = inode->i_ino;
536 fid->gen = inode->i_generation;
537
538 if (parent) {
539 fid->parent_ino = parent->i_ino;
540 fid->parent_gen = parent->i_generation;
541 type = FILEID_NILFS_WITH_PARENT;
542 *lenp = NILFS_FID_SIZE_CONNECTABLE;
543 } else {
544 type = FILEID_NILFS_WITHOUT_PARENT;
545 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
546 }
547
548 return type;
549 }
550
551 const struct inode_operations nilfs_dir_inode_operations = {
552 .create = nilfs_create,
553 .lookup = nilfs_lookup,
554 .link = nilfs_link,
555 .unlink = nilfs_unlink,
556 .symlink = nilfs_symlink,
557 .mkdir = nilfs_mkdir,
558 .rmdir = nilfs_rmdir,
559 .mknod = nilfs_mknod,
560 .rename = nilfs_rename,
561 .setattr = nilfs_setattr,
562 .permission = nilfs_permission,
563 .fiemap = nilfs_fiemap,
564 .fileattr_get = nilfs_fileattr_get,
565 .fileattr_set = nilfs_fileattr_set,
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 .get_link = page_get_link,
575 .permission = nilfs_permission,
576 };
577
578 const struct export_operations nilfs_export_ops = {
579 .encode_fh = nilfs_encode_fh,
580 .fh_to_dentry = nilfs_fh_to_dentry,
581 .fh_to_parent = nilfs_fh_to_parent,
582 .get_parent = nilfs_get_parent,
583 };
584
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