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
35static 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
53static struct dentry *
54nilfs_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(error: -ENAMETOOLONG);
61
62 ino = nilfs_inode_by_name(dir, &dentry->d_name);
63 inode = ino ? nilfs_iget(sb: dir->i_sb, root: NILFS_I(inode: 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 */
75static int nilfs_create(struct mnt_idmap *idmap, 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(ptr: inode);
87 if (!IS_ERR(ptr: 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
102static int
103nilfs_mknod(struct mnt_idmap *idmap, 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(ptr: inode);
115 if (!IS_ERR(ptr: 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
128static int nilfs_symlink(struct mnt_idmap *idmap, 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(ptr: inode);
146 if (IS_ERR(ptr: 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, len: 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);
161out:
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
169out_fail:
170 drop_nlink(inode);
171 nilfs_mark_inode_dirty(inode);
172 unlock_new_inode(inode);
173 iput(inode);
174 goto out;
175}
176
177static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
178 struct dentry *dentry)
179{
180 struct inode *inode = d_inode(dentry: 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_set_ctime_current(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
205static int nilfs_mkdir(struct mnt_idmap *idmap, 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(inode: dir);
217
218 inode = nilfs_new_inode(dir, S_IFDIR | mode);
219 err = PTR_ERR(ptr: inode);
220 if (IS_ERR(ptr: 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);
239out:
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
247out_fail:
248 drop_nlink(inode);
249 drop_nlink(inode);
250 nilfs_mark_inode_dirty(inode);
251 unlock_new_inode(inode);
252 iput(inode);
253out_dir:
254 drop_nlink(inode: dir);
255 nilfs_mark_inode_dirty(inode: dir);
256 goto out;
257}
258
259static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry)
260{
261 struct inode *inode;
262 struct nilfs_dir_entry *de;
263 struct folio *folio;
264 int err;
265
266 err = -ENOENT;
267 de = nilfs_find_entry(dir, &dentry->d_name, &folio);
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, nlink: 1);
281 }
282 err = nilfs_delete_entry(de, folio);
283 folio_release_kmap(folio, addr: de);
284 if (err)
285 goto out;
286
287 inode_set_ctime_to_ts(inode, ts: inode_get_ctime(inode: dir));
288 drop_nlink(inode);
289 err = 0;
290out:
291 return err;
292}
293
294static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
295{
296 struct nilfs_transaction_info ti;
297 int err;
298
299 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
300 if (err)
301 return err;
302
303 err = nilfs_do_unlink(dir, dentry);
304
305 if (!err) {
306 nilfs_mark_inode_dirty(inode: dir);
307 nilfs_mark_inode_dirty(inode: d_inode(dentry));
308 err = nilfs_transaction_commit(dir->i_sb);
309 } else
310 nilfs_transaction_abort(dir->i_sb);
311
312 return err;
313}
314
315static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
316{
317 struct inode *inode = d_inode(dentry);
318 struct nilfs_transaction_info ti;
319 int err;
320
321 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
322 if (err)
323 return err;
324
325 err = -ENOTEMPTY;
326 if (nilfs_empty_dir(inode)) {
327 err = nilfs_do_unlink(dir, dentry);
328 if (!err) {
329 inode->i_size = 0;
330 drop_nlink(inode);
331 nilfs_mark_inode_dirty(inode);
332 drop_nlink(inode: dir);
333 nilfs_mark_inode_dirty(inode: dir);
334 }
335 }
336 if (!err)
337 err = nilfs_transaction_commit(dir->i_sb);
338 else
339 nilfs_transaction_abort(dir->i_sb);
340
341 return err;
342}
343
344static int nilfs_rename(struct mnt_idmap *idmap,
345 struct inode *old_dir, struct dentry *old_dentry,
346 struct inode *new_dir, struct dentry *new_dentry,
347 unsigned int flags)
348{
349 struct inode *old_inode = d_inode(dentry: old_dentry);
350 struct inode *new_inode = d_inode(dentry: new_dentry);
351 struct folio *dir_folio = NULL;
352 struct nilfs_dir_entry *dir_de = NULL;
353 struct folio *old_folio;
354 struct nilfs_dir_entry *old_de;
355 struct nilfs_transaction_info ti;
356 int err;
357
358 if (flags & ~RENAME_NOREPLACE)
359 return -EINVAL;
360
361 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
362 if (unlikely(err))
363 return err;
364
365 err = -ENOENT;
366 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_folio);
367 if (!old_de)
368 goto out;
369
370 if (S_ISDIR(old_inode->i_mode)) {
371 err = -EIO;
372 dir_de = nilfs_dotdot(old_inode, &dir_folio);
373 if (!dir_de)
374 goto out_old;
375 }
376
377 if (new_inode) {
378 struct folio *new_folio;
379 struct nilfs_dir_entry *new_de;
380
381 err = -ENOTEMPTY;
382 if (dir_de && !nilfs_empty_dir(new_inode))
383 goto out_dir;
384
385 err = -ENOENT;
386 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_folio);
387 if (!new_de)
388 goto out_dir;
389 nilfs_set_link(new_dir, new_de, new_folio, old_inode);
390 folio_release_kmap(folio: new_folio, addr: new_de);
391 nilfs_mark_inode_dirty(inode: new_dir);
392 inode_set_ctime_current(inode: new_inode);
393 if (dir_de)
394 drop_nlink(inode: new_inode);
395 drop_nlink(inode: new_inode);
396 nilfs_mark_inode_dirty(inode: new_inode);
397 } else {
398 err = nilfs_add_link(new_dentry, old_inode);
399 if (err)
400 goto out_dir;
401 if (dir_de) {
402 inc_nlink(inode: new_dir);
403 nilfs_mark_inode_dirty(inode: new_dir);
404 }
405 }
406
407 /*
408 * Like most other Unix systems, set the ctime for inodes on a
409 * rename.
410 */
411 inode_set_ctime_current(inode: old_inode);
412
413 nilfs_delete_entry(old_de, old_folio);
414
415 if (dir_de) {
416 nilfs_set_link(old_inode, dir_de, dir_folio, new_dir);
417 folio_release_kmap(folio: dir_folio, addr: dir_de);
418 drop_nlink(inode: old_dir);
419 }
420 folio_release_kmap(folio: old_folio, addr: old_de);
421
422 nilfs_mark_inode_dirty(inode: old_dir);
423 nilfs_mark_inode_dirty(inode: old_inode);
424
425 err = nilfs_transaction_commit(old_dir->i_sb);
426 return err;
427
428out_dir:
429 if (dir_de)
430 folio_release_kmap(folio: dir_folio, addr: dir_de);
431out_old:
432 folio_release_kmap(folio: old_folio, addr: old_de);
433out:
434 nilfs_transaction_abort(old_dir->i_sb);
435 return err;
436}
437
438/*
439 * Export operations
440 */
441static struct dentry *nilfs_get_parent(struct dentry *child)
442{
443 unsigned long ino;
444 struct nilfs_root *root;
445
446 ino = nilfs_inode_by_name(d_inode(dentry: child), &dotdot_name);
447 if (!ino)
448 return ERR_PTR(error: -ENOENT);
449
450 root = NILFS_I(inode: d_inode(dentry: child))->i_root;
451
452 return d_obtain_alias(nilfs_iget(sb: child->d_sb, root, ino));
453}
454
455static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
456 u64 ino, u32 gen)
457{
458 struct nilfs_root *root;
459 struct inode *inode;
460
461 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
462 return ERR_PTR(error: -ESTALE);
463
464 root = nilfs_lookup_root(nilfs: sb->s_fs_info, cno);
465 if (!root)
466 return ERR_PTR(error: -ESTALE);
467
468 inode = nilfs_iget(sb, root, ino);
469 nilfs_put_root(root);
470
471 if (IS_ERR(ptr: inode))
472 return ERR_CAST(ptr: inode);
473 if (gen && inode->i_generation != gen) {
474 iput(inode);
475 return ERR_PTR(error: -ESTALE);
476 }
477 return d_obtain_alias(inode);
478}
479
480static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
481 int fh_len, int fh_type)
482{
483 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
484
485 if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE ||
486 (fh_type != FILEID_NILFS_WITH_PARENT &&
487 fh_type != FILEID_NILFS_WITHOUT_PARENT))
488 return NULL;
489
490 return nilfs_get_dentry(sb, cno: fid->cno, ino: fid->ino, gen: fid->gen);
491}
492
493static struct dentry *nilfs_fh_to_parent(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_CONNECTABLE ||
499 fh_type != FILEID_NILFS_WITH_PARENT)
500 return NULL;
501
502 return nilfs_get_dentry(sb, cno: fid->cno, ino: fid->parent_ino, gen: fid->parent_gen);
503}
504
505static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
506 struct inode *parent)
507{
508 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
509 struct nilfs_root *root = NILFS_I(inode)->i_root;
510 int type;
511
512 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) {
513 *lenp = NILFS_FID_SIZE_CONNECTABLE;
514 return FILEID_INVALID;
515 }
516 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) {
517 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
518 return FILEID_INVALID;
519 }
520
521 fid->cno = root->cno;
522 fid->ino = inode->i_ino;
523 fid->gen = inode->i_generation;
524
525 if (parent) {
526 fid->parent_ino = parent->i_ino;
527 fid->parent_gen = parent->i_generation;
528 type = FILEID_NILFS_WITH_PARENT;
529 *lenp = NILFS_FID_SIZE_CONNECTABLE;
530 } else {
531 type = FILEID_NILFS_WITHOUT_PARENT;
532 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
533 }
534
535 return type;
536}
537
538const struct inode_operations nilfs_dir_inode_operations = {
539 .create = nilfs_create,
540 .lookup = nilfs_lookup,
541 .link = nilfs_link,
542 .unlink = nilfs_unlink,
543 .symlink = nilfs_symlink,
544 .mkdir = nilfs_mkdir,
545 .rmdir = nilfs_rmdir,
546 .mknod = nilfs_mknod,
547 .rename = nilfs_rename,
548 .setattr = nilfs_setattr,
549 .permission = nilfs_permission,
550 .fiemap = nilfs_fiemap,
551 .fileattr_get = nilfs_fileattr_get,
552 .fileattr_set = nilfs_fileattr_set,
553};
554
555const struct inode_operations nilfs_special_inode_operations = {
556 .setattr = nilfs_setattr,
557 .permission = nilfs_permission,
558};
559
560const struct inode_operations nilfs_symlink_inode_operations = {
561 .get_link = page_get_link,
562 .permission = nilfs_permission,
563};
564
565const struct export_operations nilfs_export_ops = {
566 .encode_fh = nilfs_encode_fh,
567 .fh_to_dentry = nilfs_fh_to_dentry,
568 .fh_to_parent = nilfs_fh_to_parent,
569 .get_parent = nilfs_get_parent,
570};
571

source code of linux/fs/nilfs2/namei.c