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 | |
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 | */ |
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(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 | |
102 | static int |
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(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 | |
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(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); |
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(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 | |
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(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); |
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(inode: dir); |
255 | nilfs_mark_inode_dirty(inode: 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 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; |
290 | out: |
291 | return err; |
292 | } |
293 | |
294 | static 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 | |
315 | static 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 | |
344 | static 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 | |
428 | out_dir: |
429 | if (dir_de) |
430 | folio_release_kmap(folio: dir_folio, addr: dir_de); |
431 | out_old: |
432 | folio_release_kmap(folio: old_folio, addr: old_de); |
433 | out: |
434 | nilfs_transaction_abort(old_dir->i_sb); |
435 | return err; |
436 | } |
437 | |
438 | /* |
439 | * Export operations |
440 | */ |
441 | static 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 | |
455 | static 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 | |
480 | static 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 | |
493 | static 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 | |
505 | static 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 | |
538 | const 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 | |
555 | const struct inode_operations nilfs_special_inode_operations = { |
556 | .setattr = nilfs_setattr, |
557 | .permission = nilfs_permission, |
558 | }; |
559 | |
560 | const struct inode_operations nilfs_symlink_inode_operations = { |
561 | .get_link = page_get_link, |
562 | .permission = nilfs_permission, |
563 | }; |
564 | |
565 | const 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 | |