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
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 */
nilfs_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)75 static 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(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
nilfs_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)103 nilfs_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(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
nilfs_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)128 static 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(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
nilfs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)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
nilfs_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)205 static 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(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
nilfs_do_unlink(struct inode * dir,struct dentry * dentry)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
nilfs_unlink(struct inode * dir,struct dentry * dentry)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
nilfs_rmdir(struct inode * dir,struct dentry * dentry)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
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)343 static int nilfs_rename(struct mnt_idmap *idmap,
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 */
nilfs_get_parent(struct dentry * child)439 static struct dentry *nilfs_get_parent(struct dentry *child)
440 {
441 unsigned long ino;
442 struct inode *inode;
443 struct nilfs_root *root;
444
445 ino = nilfs_inode_by_name(d_inode(child), &dotdot_name);
446 if (!ino)
447 return ERR_PTR(-ENOENT);
448
449 root = NILFS_I(d_inode(child))->i_root;
450
451 inode = nilfs_iget(child->d_sb, root, ino);
452 if (IS_ERR(inode))
453 return ERR_CAST(inode);
454
455 return d_obtain_alias(inode);
456 }
457
nilfs_get_dentry(struct super_block * sb,u64 cno,u64 ino,u32 gen)458 static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
459 u64 ino, u32 gen)
460 {
461 struct nilfs_root *root;
462 struct inode *inode;
463
464 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
465 return ERR_PTR(-ESTALE);
466
467 root = nilfs_lookup_root(sb->s_fs_info, cno);
468 if (!root)
469 return ERR_PTR(-ESTALE);
470
471 inode = nilfs_iget(sb, root, ino);
472 nilfs_put_root(root);
473
474 if (IS_ERR(inode))
475 return ERR_CAST(inode);
476 if (gen && inode->i_generation != gen) {
477 iput(inode);
478 return ERR_PTR(-ESTALE);
479 }
480 return d_obtain_alias(inode);
481 }
482
nilfs_fh_to_dentry(struct super_block * sb,struct fid * fh,int fh_len,int fh_type)483 static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
484 int fh_len, int fh_type)
485 {
486 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
487
488 if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE ||
489 (fh_type != FILEID_NILFS_WITH_PARENT &&
490 fh_type != FILEID_NILFS_WITHOUT_PARENT))
491 return NULL;
492
493 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);
494 }
495
nilfs_fh_to_parent(struct super_block * sb,struct fid * fh,int fh_len,int fh_type)496 static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
497 int fh_len, int fh_type)
498 {
499 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
500
501 if (fh_len < NILFS_FID_SIZE_CONNECTABLE ||
502 fh_type != FILEID_NILFS_WITH_PARENT)
503 return NULL;
504
505 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);
506 }
507
nilfs_encode_fh(struct inode * inode,__u32 * fh,int * lenp,struct inode * parent)508 static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
509 struct inode *parent)
510 {
511 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
512 struct nilfs_root *root = NILFS_I(inode)->i_root;
513 int type;
514
515 if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) {
516 *lenp = NILFS_FID_SIZE_CONNECTABLE;
517 return FILEID_INVALID;
518 }
519 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) {
520 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
521 return FILEID_INVALID;
522 }
523
524 fid->cno = root->cno;
525 fid->ino = inode->i_ino;
526 fid->gen = inode->i_generation;
527
528 if (parent) {
529 fid->parent_ino = parent->i_ino;
530 fid->parent_gen = parent->i_generation;
531 type = FILEID_NILFS_WITH_PARENT;
532 *lenp = NILFS_FID_SIZE_CONNECTABLE;
533 } else {
534 type = FILEID_NILFS_WITHOUT_PARENT;
535 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
536 }
537
538 return type;
539 }
540
541 const struct inode_operations nilfs_dir_inode_operations = {
542 .create = nilfs_create,
543 .lookup = nilfs_lookup,
544 .link = nilfs_link,
545 .unlink = nilfs_unlink,
546 .symlink = nilfs_symlink,
547 .mkdir = nilfs_mkdir,
548 .rmdir = nilfs_rmdir,
549 .mknod = nilfs_mknod,
550 .rename = nilfs_rename,
551 .setattr = nilfs_setattr,
552 .permission = nilfs_permission,
553 .fiemap = nilfs_fiemap,
554 .fileattr_get = nilfs_fileattr_get,
555 .fileattr_set = nilfs_fileattr_set,
556 };
557
558 const struct inode_operations nilfs_special_inode_operations = {
559 .setattr = nilfs_setattr,
560 .permission = nilfs_permission,
561 };
562
563 const struct inode_operations nilfs_symlink_inode_operations = {
564 .get_link = page_get_link,
565 .permission = nilfs_permission,
566 };
567
568 const struct export_operations nilfs_export_ops = {
569 .encode_fh = nilfs_encode_fh,
570 .fh_to_dentry = nilfs_fh_to_dentry,
571 .fh_to_parent = nilfs_fh_to_parent,
572 .get_parent = nilfs_get_parent,
573 };
574