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
nilfs_add_nondir(struct dentry * dentry,struct inode * inode)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 *
nilfs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)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 if (inode == ERR_PTR(-ESTALE)) {
71 nilfs_error(dir->i_sb,
72 "deleted inode referenced: %lu", ino);
73 return ERR_PTR(-EIO);
74 }
75 }
76
77 return d_splice_alias(inode, dentry);
78 }
79
80 /*
81 * By the time this is called, we already have created
82 * the directory cache entry for the new file, but it
83 * is so far negative - it has no inode.
84 *
85 * If the create succeeds, we fill in the inode information
86 * with d_instantiate().
87 */
nilfs_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)88 static int nilfs_create(struct mnt_idmap *idmap, struct inode *dir,
89 struct dentry *dentry, umode_t mode, bool excl)
90 {
91 struct inode *inode;
92 struct nilfs_transaction_info ti;
93 int err;
94
95 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
96 if (err)
97 return err;
98 inode = nilfs_new_inode(dir, mode);
99 err = PTR_ERR(inode);
100 if (!IS_ERR(inode)) {
101 inode->i_op = &nilfs_file_inode_operations;
102 inode->i_fop = &nilfs_file_operations;
103 inode->i_mapping->a_ops = &nilfs_aops;
104 nilfs_mark_inode_dirty(inode);
105 err = nilfs_add_nondir(dentry, inode);
106 }
107 if (!err)
108 err = nilfs_transaction_commit(dir->i_sb);
109 else
110 nilfs_transaction_abort(dir->i_sb);
111
112 return err;
113 }
114
115 static int
nilfs_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)116 nilfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
117 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
nilfs_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)141 static int nilfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
142 struct dentry *dentry, const char *symname)
143 {
144 struct nilfs_transaction_info ti;
145 struct super_block *sb = dir->i_sb;
146 unsigned int 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 | 0777);
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 mapping_set_gfp_mask(inode->i_mapping,
166 mapping_gfp_constraint(inode->i_mapping,
167 ~__GFP_FS));
168 inode->i_mapping->a_ops = &nilfs_aops;
169 err = page_symlink(inode, symname, l);
170 if (err)
171 goto out_fail;
172
173 /* mark_inode_dirty(inode); */
174 /* page_symlink() do this */
175
176 err = nilfs_add_nondir(dentry, inode);
177 out:
178 if (!err)
179 err = nilfs_transaction_commit(dir->i_sb);
180 else
181 nilfs_transaction_abort(dir->i_sb);
182
183 return err;
184
185 out_fail:
186 drop_nlink(inode);
187 nilfs_mark_inode_dirty(inode);
188 unlock_new_inode(inode);
189 iput(inode);
190 goto out;
191 }
192
nilfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)193 static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
194 struct dentry *dentry)
195 {
196 struct inode *inode = d_inode(old_dentry);
197 struct nilfs_transaction_info ti;
198 int err;
199
200 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
201 if (err)
202 return err;
203
204 inode_set_ctime_current(inode);
205 inode_inc_link_count(inode);
206 ihold(inode);
207
208 err = nilfs_add_link(dentry, inode);
209 if (!err) {
210 d_instantiate(dentry, inode);
211 err = nilfs_transaction_commit(dir->i_sb);
212 } else {
213 inode_dec_link_count(inode);
214 iput(inode);
215 nilfs_transaction_abort(dir->i_sb);
216 }
217
218 return err;
219 }
220
nilfs_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)221 static int nilfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
222 struct dentry *dentry, umode_t mode)
223 {
224 struct inode *inode;
225 struct nilfs_transaction_info ti;
226 int err;
227
228 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
229 if (err)
230 return err;
231
232 inc_nlink(dir);
233
234 inode = nilfs_new_inode(dir, S_IFDIR | mode);
235 err = PTR_ERR(inode);
236 if (IS_ERR(inode))
237 goto out_dir;
238
239 inode->i_op = &nilfs_dir_inode_operations;
240 inode->i_fop = &nilfs_dir_operations;
241 inode->i_mapping->a_ops = &nilfs_aops;
242
243 inc_nlink(inode);
244
245 err = nilfs_make_empty(inode, dir);
246 if (err)
247 goto out_fail;
248
249 err = nilfs_add_link(dentry, inode);
250 if (err)
251 goto out_fail;
252
253 nilfs_mark_inode_dirty(inode);
254 d_instantiate_new(dentry, inode);
255 out:
256 if (!err)
257 err = nilfs_transaction_commit(dir->i_sb);
258 else
259 nilfs_transaction_abort(dir->i_sb);
260
261 return err;
262
263 out_fail:
264 drop_nlink(inode);
265 drop_nlink(inode);
266 nilfs_mark_inode_dirty(inode);
267 unlock_new_inode(inode);
268 iput(inode);
269 out_dir:
270 drop_nlink(dir);
271 nilfs_mark_inode_dirty(dir);
272 goto out;
273 }
274
nilfs_do_unlink(struct inode * dir,struct dentry * dentry)275 static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry)
276 {
277 struct inode *inode;
278 struct nilfs_dir_entry *de;
279 struct folio *folio;
280 int err;
281
282 de = nilfs_find_entry(dir, &dentry->d_name, &folio);
283 if (IS_ERR(de)) {
284 err = PTR_ERR(de);
285 goto out;
286 }
287
288 inode = d_inode(dentry);
289 err = -EIO;
290 if (le64_to_cpu(de->inode) != inode->i_ino)
291 goto out;
292
293 if (!inode->i_nlink) {
294 nilfs_warn(inode->i_sb,
295 "deleting nonexistent file (ino=%lu), %d",
296 inode->i_ino, inode->i_nlink);
297 set_nlink(inode, 1);
298 }
299 err = nilfs_delete_entry(de, folio);
300 folio_release_kmap(folio, de);
301 if (err)
302 goto out;
303
304 inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
305 drop_nlink(inode);
306 err = 0;
307 out:
308 return err;
309 }
310
nilfs_unlink(struct inode * dir,struct dentry * dentry)311 static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
312 {
313 struct nilfs_transaction_info ti;
314 int err;
315
316 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
317 if (err)
318 return err;
319
320 err = nilfs_do_unlink(dir, dentry);
321
322 if (!err) {
323 nilfs_mark_inode_dirty(dir);
324 nilfs_mark_inode_dirty(d_inode(dentry));
325 err = nilfs_transaction_commit(dir->i_sb);
326 } else
327 nilfs_transaction_abort(dir->i_sb);
328
329 return err;
330 }
331
nilfs_rmdir(struct inode * dir,struct dentry * dentry)332 static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
333 {
334 struct inode *inode = d_inode(dentry);
335 struct nilfs_transaction_info ti;
336 int err;
337
338 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
339 if (err)
340 return err;
341
342 err = -ENOTEMPTY;
343 if (nilfs_empty_dir(inode)) {
344 err = nilfs_do_unlink(dir, dentry);
345 if (!err) {
346 inode->i_size = 0;
347 drop_nlink(inode);
348 nilfs_mark_inode_dirty(inode);
349 drop_nlink(dir);
350 nilfs_mark_inode_dirty(dir);
351 }
352 }
353 if (!err)
354 err = nilfs_transaction_commit(dir->i_sb);
355 else
356 nilfs_transaction_abort(dir->i_sb);
357
358 return err;
359 }
360
nilfs_rename(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)361 static int nilfs_rename(struct mnt_idmap *idmap,
362 struct inode *old_dir, struct dentry *old_dentry,
363 struct inode *new_dir, struct dentry *new_dentry,
364 unsigned int flags)
365 {
366 struct inode *old_inode = d_inode(old_dentry);
367 struct inode *new_inode = d_inode(new_dentry);
368 struct folio *dir_folio = NULL;
369 struct nilfs_dir_entry *dir_de = NULL;
370 struct folio *old_folio;
371 struct nilfs_dir_entry *old_de;
372 struct nilfs_transaction_info ti;
373 int err;
374
375 if (flags & ~RENAME_NOREPLACE)
376 return -EINVAL;
377
378 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
379 if (unlikely(err))
380 return err;
381
382 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_folio);
383 if (IS_ERR(old_de)) {
384 err = PTR_ERR(old_de);
385 goto out;
386 }
387
388 if (S_ISDIR(old_inode->i_mode)) {
389 err = -EIO;
390 dir_de = nilfs_dotdot(old_inode, &dir_folio);
391 if (!dir_de)
392 goto out_old;
393 }
394
395 if (new_inode) {
396 struct folio *new_folio;
397 struct nilfs_dir_entry *new_de;
398
399 err = -ENOTEMPTY;
400 if (dir_de && !nilfs_empty_dir(new_inode))
401 goto out_dir;
402
403 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name,
404 &new_folio);
405 if (IS_ERR(new_de)) {
406 err = PTR_ERR(new_de);
407 goto out_dir;
408 }
409 nilfs_set_link(new_dir, new_de, new_folio, old_inode);
410 folio_release_kmap(new_folio, new_de);
411 nilfs_mark_inode_dirty(new_dir);
412 inode_set_ctime_current(new_inode);
413 if (dir_de)
414 drop_nlink(new_inode);
415 drop_nlink(new_inode);
416 nilfs_mark_inode_dirty(new_inode);
417 } else {
418 err = nilfs_add_link(new_dentry, old_inode);
419 if (err)
420 goto out_dir;
421 if (dir_de) {
422 inc_nlink(new_dir);
423 nilfs_mark_inode_dirty(new_dir);
424 }
425 }
426
427 /*
428 * Like most other Unix systems, set the ctime for inodes on a
429 * rename.
430 */
431 inode_set_ctime_current(old_inode);
432
433 nilfs_delete_entry(old_de, old_folio);
434
435 if (dir_de) {
436 nilfs_set_link(old_inode, dir_de, dir_folio, new_dir);
437 folio_release_kmap(dir_folio, dir_de);
438 drop_nlink(old_dir);
439 }
440 folio_release_kmap(old_folio, old_de);
441
442 nilfs_mark_inode_dirty(old_dir);
443 nilfs_mark_inode_dirty(old_inode);
444
445 err = nilfs_transaction_commit(old_dir->i_sb);
446 return err;
447
448 out_dir:
449 if (dir_de)
450 folio_release_kmap(dir_folio, dir_de);
451 out_old:
452 folio_release_kmap(old_folio, old_de);
453 out:
454 nilfs_transaction_abort(old_dir->i_sb);
455 return err;
456 }
457
458 /*
459 * Export operations
460 */
nilfs_get_parent(struct dentry * child)461 static struct dentry *nilfs_get_parent(struct dentry *child)
462 {
463 ino_t ino;
464 int res;
465 struct nilfs_root *root;
466
467 res = nilfs_inode_by_name(d_inode(child), &dotdot_name, &ino);
468 if (res)
469 return ERR_PTR(res);
470
471 root = NILFS_I(d_inode(child))->i_root;
472
473 return d_obtain_alias(nilfs_iget(child->d_sb, root, ino));
474 }
475
nilfs_get_dentry(struct super_block * sb,u64 cno,u64 ino,u32 gen)476 static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
477 u64 ino, u32 gen)
478 {
479 struct nilfs_root *root;
480 struct inode *inode;
481
482 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
483 return ERR_PTR(-ESTALE);
484
485 root = nilfs_lookup_root(sb->s_fs_info, cno);
486 if (!root)
487 return ERR_PTR(-ESTALE);
488
489 inode = nilfs_iget(sb, root, ino);
490 nilfs_put_root(root);
491
492 if (IS_ERR(inode))
493 return ERR_CAST(inode);
494 if (gen && inode->i_generation != gen) {
495 iput(inode);
496 return ERR_PTR(-ESTALE);
497 }
498 return d_obtain_alias(inode);
499 }
500
nilfs_fh_to_dentry(struct super_block * sb,struct fid * fh,int fh_len,int fh_type)501 static struct dentry *nilfs_fh_to_dentry(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_NON_CONNECTABLE ||
507 (fh_type != FILEID_NILFS_WITH_PARENT &&
508 fh_type != FILEID_NILFS_WITHOUT_PARENT))
509 return NULL;
510
511 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);
512 }
513
nilfs_fh_to_parent(struct super_block * sb,struct fid * fh,int fh_len,int fh_type)514 static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
515 int fh_len, int fh_type)
516 {
517 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
518
519 if (fh_len < NILFS_FID_SIZE_CONNECTABLE ||
520 fh_type != FILEID_NILFS_WITH_PARENT)
521 return NULL;
522
523 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);
524 }
525
nilfs_encode_fh(struct inode * inode,__u32 * fh,int * lenp,struct inode * parent)526 static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
527 struct inode *parent)
528 {
529 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
530 struct nilfs_root *root = NILFS_I(inode)->i_root;
531 int type;
532
533 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) {
534 *lenp = NILFS_FID_SIZE_CONNECTABLE;
535 return FILEID_INVALID;
536 }
537 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) {
538 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
539 return FILEID_INVALID;
540 }
541
542 fid->cno = root->cno;
543 fid->ino = inode->i_ino;
544 fid->gen = inode->i_generation;
545
546 if (parent) {
547 fid->parent_ino = parent->i_ino;
548 fid->parent_gen = parent->i_generation;
549 type = FILEID_NILFS_WITH_PARENT;
550 *lenp = NILFS_FID_SIZE_CONNECTABLE;
551 } else {
552 type = FILEID_NILFS_WITHOUT_PARENT;
553 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
554 }
555
556 return type;
557 }
558
559 const struct inode_operations nilfs_dir_inode_operations = {
560 .create = nilfs_create,
561 .lookup = nilfs_lookup,
562 .link = nilfs_link,
563 .unlink = nilfs_unlink,
564 .symlink = nilfs_symlink,
565 .mkdir = nilfs_mkdir,
566 .rmdir = nilfs_rmdir,
567 .mknod = nilfs_mknod,
568 .rename = nilfs_rename,
569 .setattr = nilfs_setattr,
570 .permission = nilfs_permission,
571 .fiemap = nilfs_fiemap,
572 .fileattr_get = nilfs_fileattr_get,
573 .fileattr_set = nilfs_fileattr_set,
574 };
575
576 const struct inode_operations nilfs_special_inode_operations = {
577 .setattr = nilfs_setattr,
578 .permission = nilfs_permission,
579 };
580
581 const struct inode_operations nilfs_symlink_inode_operations = {
582 .get_link = page_get_link,
583 .permission = nilfs_permission,
584 };
585
586 const struct export_operations nilfs_export_ops = {
587 .encode_fh = nilfs_encode_fh,
588 .fh_to_dentry = nilfs_fh_to_dentry,
589 .fh_to_parent = nilfs_fh_to_parent,
590 .get_parent = nilfs_get_parent,
591 };
592