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d2500652
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1/*
2 * namei.c - NILFS pathname lookup operations.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Modified for NILFS by Amagai Yoshiji <amagai@osrg.net>,
21 * Ryusuke Konishi <ryusuke@osrg.net>
22 */
23/*
24 * linux/fs/ext2/namei.c
25 *
26 * Copyright (C) 1992, 1993, 1994, 1995
27 * Remy Card (card@masi.ibp.fr)
28 * Laboratoire MASI - Institut Blaise Pascal
29 * Universite Pierre et Marie Curie (Paris VI)
30 *
31 * from
32 *
33 * linux/fs/minix/namei.c
34 *
35 * Copyright (C) 1991, 1992 Linus Torvalds
36 *
37 * Big-endian to little-endian byte-swapping/bitmaps by
38 * David S. Miller (davem@caip.rutgers.edu), 1995
39 */
40
41#include <linux/pagemap.h>
42#include "nilfs.h"
8e656fd5 43#include "export.h"
d2500652 44
8e656fd5
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45#define NILFS_FID_SIZE_NON_CONNECTABLE \
46 (offsetof(struct nilfs_fid, parent_gen) / 4)
47#define NILFS_FID_SIZE_CONNECTABLE (sizeof(struct nilfs_fid) / 4)
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48
49static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode)
50{
51 int err = nilfs_add_link(dentry, inode);
52 if (!err) {
53 d_instantiate(dentry, inode);
54 return 0;
55 }
56 inode_dec_link_count(inode);
57 iput(inode);
58 return err;
59}
60
61/*
62 * Methods themselves.
63 */
64
65static struct dentry *
66nilfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
67{
68 struct inode *inode;
69 ino_t ino;
70
71 if (dentry->d_name.len > NILFS_NAME_LEN)
72 return ERR_PTR(-ENAMETOOLONG);
73
0319003d 74 ino = nilfs_inode_by_name(dir, &dentry->d_name);
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75 inode = NULL;
76 if (ino) {
4d8d9293 77 inode = nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino);
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78 if (IS_ERR(inode))
79 return ERR_CAST(inode);
80 }
81 return d_splice_alias(inode, dentry);
82}
83
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84/*
85 * By the time this is called, we already have created
86 * the directory cache entry for the new file, but it
87 * is so far negative - it has no inode.
88 *
89 * If the create succeeds, we fill in the inode information
90 * with d_instantiate().
91 */
92static int nilfs_create(struct inode *dir, struct dentry *dentry, int mode,
93 struct nameidata *nd)
94{
95 struct inode *inode;
96 struct nilfs_transaction_info ti;
47420c79 97 int err;
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98
99 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
100 if (err)
101 return err;
102 inode = nilfs_new_inode(dir, mode);
103 err = PTR_ERR(inode);
104 if (!IS_ERR(inode)) {
105 inode->i_op = &nilfs_file_inode_operations;
106 inode->i_fop = &nilfs_file_operations;
107 inode->i_mapping->a_ops = &nilfs_aops;
abdb318b 108 nilfs_mark_inode_dirty(inode);
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109 err = nilfs_add_nondir(dentry, inode);
110 }
47420c79
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111 if (!err)
112 err = nilfs_transaction_commit(dir->i_sb);
113 else
114 nilfs_transaction_abort(dir->i_sb);
115
116 return err;
d2500652
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117}
118
119static int
120nilfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
121{
122 struct inode *inode;
123 struct nilfs_transaction_info ti;
47420c79 124 int err;
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125
126 if (!new_valid_dev(rdev))
127 return -EINVAL;
128
129 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
130 if (err)
131 return err;
132 inode = nilfs_new_inode(dir, mode);
133 err = PTR_ERR(inode);
134 if (!IS_ERR(inode)) {
135 init_special_inode(inode, inode->i_mode, rdev);
abdb318b 136 nilfs_mark_inode_dirty(inode);
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137 err = nilfs_add_nondir(dentry, inode);
138 }
47420c79
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139 if (!err)
140 err = nilfs_transaction_commit(dir->i_sb);
141 else
142 nilfs_transaction_abort(dir->i_sb);
143
144 return err;
d2500652
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145}
146
147static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
148 const char *symname)
149{
150 struct nilfs_transaction_info ti;
151 struct super_block *sb = dir->i_sb;
152 unsigned l = strlen(symname)+1;
153 struct inode *inode;
47420c79 154 int err;
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155
156 if (l > sb->s_blocksize)
157 return -ENAMETOOLONG;
158
159 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
160 if (err)
161 return err;
162
163 inode = nilfs_new_inode(dir, S_IFLNK | S_IRWXUGO);
164 err = PTR_ERR(inode);
165 if (IS_ERR(inode))
166 goto out;
167
168 /* slow symlink */
169 inode->i_op = &nilfs_symlink_inode_operations;
170 inode->i_mapping->a_ops = &nilfs_aops;
171 err = page_symlink(inode, symname, l);
172 if (err)
173 goto out_fail;
174
175 /* mark_inode_dirty(inode); */
9ca941d4 176 /* page_symlink() do this */
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177
178 err = nilfs_add_nondir(dentry, inode);
179out:
47420c79
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180 if (!err)
181 err = nilfs_transaction_commit(dir->i_sb);
182 else
183 nilfs_transaction_abort(dir->i_sb);
184
185 return err;
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186
187out_fail:
565de406 188 drop_nlink(inode);
abdb318b 189 nilfs_mark_inode_dirty(inode);
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190 iput(inode);
191 goto out;
192}
193
194static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
195 struct dentry *dentry)
196{
197 struct inode *inode = old_dentry->d_inode;
198 struct nilfs_transaction_info ti;
47420c79 199 int err;
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200
201 if (inode->i_nlink >= NILFS_LINK_MAX)
202 return -EMLINK;
203
204 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
205 if (err)
206 return err;
207
208 inode->i_ctime = CURRENT_TIME;
209 inode_inc_link_count(inode);
7de9c6ee 210 ihold(inode);
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211
212 err = nilfs_add_nondir(dentry, inode);
47420c79
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213 if (!err)
214 err = nilfs_transaction_commit(dir->i_sb);
215 else
216 nilfs_transaction_abort(dir->i_sb);
217
218 return err;
d2500652
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219}
220
221static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
222{
223 struct inode *inode;
224 struct nilfs_transaction_info ti;
47420c79 225 int err;
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226
227 if (dir->i_nlink >= NILFS_LINK_MAX)
228 return -EMLINK;
229
230 err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
231 if (err)
232 return err;
233
565de406 234 inc_nlink(dir);
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235
236 inode = nilfs_new_inode(dir, S_IFDIR | mode);
237 err = PTR_ERR(inode);
238 if (IS_ERR(inode))
239 goto out_dir;
240
241 inode->i_op = &nilfs_dir_inode_operations;
242 inode->i_fop = &nilfs_dir_operations;
243 inode->i_mapping->a_ops = &nilfs_aops;
244
565de406 245 inc_nlink(inode);
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246
247 err = nilfs_make_empty(inode, dir);
248 if (err)
249 goto out_fail;
250
251 err = nilfs_add_link(dentry, inode);
252 if (err)
253 goto out_fail;
254
abdb318b 255 nilfs_mark_inode_dirty(inode);
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256 d_instantiate(dentry, inode);
257out:
47420c79
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258 if (!err)
259 err = nilfs_transaction_commit(dir->i_sb);
260 else
261 nilfs_transaction_abort(dir->i_sb);
262
263 return err;
d2500652
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264
265out_fail:
565de406 266 drop_nlink(inode);
565de406 267 drop_nlink(inode);
abdb318b 268 nilfs_mark_inode_dirty(inode);
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269 iput(inode);
270out_dir:
565de406 271 drop_nlink(dir);
abdb318b 272 nilfs_mark_inode_dirty(dir);
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273 goto out;
274}
275
4cd76c3c 276static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry)
d2500652
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277{
278 struct inode *inode;
279 struct nilfs_dir_entry *de;
280 struct page *page;
47420c79 281 int err;
d2500652 282
d2500652 283 err = -ENOENT;
0319003d 284 de = nilfs_find_entry(dir, &dentry->d_name, &page);
d2500652
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285 if (!de)
286 goto out;
287
288 inode = dentry->d_inode;
289 err = -EIO;
290 if (le64_to_cpu(de->inode) != inode->i_ino)
291 goto out;
292
293 if (!inode->i_nlink) {
294 nilfs_warning(inode->i_sb, __func__,
295 "deleting nonexistent file (%lu), %d\n",
296 inode->i_ino, inode->i_nlink);
297 inode->i_nlink = 1;
298 }
299 err = nilfs_delete_entry(de, page);
300 if (err)
301 goto out;
302
303 inode->i_ctime = dir->i_ctime;
565de406 304 drop_nlink(inode);
d2500652
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305 err = 0;
306out:
4cd76c3c
JS
307 return err;
308}
309
310static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
311{
312 struct nilfs_transaction_info ti;
313 int err;
314
315 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
316 if (err)
317 return err;
318
319 err = nilfs_do_unlink(dir, dentry);
320
321 if (!err) {
abdb318b
JS
322 nilfs_mark_inode_dirty(dir);
323 nilfs_mark_inode_dirty(dentry->d_inode);
47420c79 324 err = nilfs_transaction_commit(dir->i_sb);
4cd76c3c 325 } else
47420c79
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326 nilfs_transaction_abort(dir->i_sb);
327
328 return err;
d2500652
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329}
330
331static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
332{
333 struct inode *inode = dentry->d_inode;
334 struct nilfs_transaction_info ti;
47420c79 335 int err;
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336
337 err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
338 if (err)
339 return err;
340
341 err = -ENOTEMPTY;
342 if (nilfs_empty_dir(inode)) {
4cd76c3c 343 err = nilfs_do_unlink(dir, dentry);
d2500652
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344 if (!err) {
345 inode->i_size = 0;
565de406 346 drop_nlink(inode);
abdb318b 347 nilfs_mark_inode_dirty(inode);
565de406 348 drop_nlink(dir);
abdb318b 349 nilfs_mark_inode_dirty(dir);
d2500652
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350 }
351 }
47420c79
RK
352 if (!err)
353 err = nilfs_transaction_commit(dir->i_sb);
354 else
355 nilfs_transaction_abort(dir->i_sb);
356
357 return err;
d2500652
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358}
359
360static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
361 struct inode *new_dir, struct dentry *new_dentry)
362{
363 struct inode *old_inode = old_dentry->d_inode;
364 struct inode *new_inode = new_dentry->d_inode;
365 struct page *dir_page = NULL;
366 struct nilfs_dir_entry *dir_de = NULL;
367 struct page *old_page;
368 struct nilfs_dir_entry *old_de;
369 struct nilfs_transaction_info ti;
370 int err;
371
372 err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
373 if (unlikely(err))
374 return err;
375
376 err = -ENOENT;
0319003d 377 old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_page);
d2500652
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378 if (!old_de)
379 goto out;
380
381 if (S_ISDIR(old_inode->i_mode)) {
382 err = -EIO;
383 dir_de = nilfs_dotdot(old_inode, &dir_page);
384 if (!dir_de)
385 goto out_old;
386 }
387
388 if (new_inode) {
389 struct page *new_page;
390 struct nilfs_dir_entry *new_de;
391
392 err = -ENOTEMPTY;
393 if (dir_de && !nilfs_empty_dir(new_inode))
394 goto out_dir;
395
396 err = -ENOENT;
0319003d 397 new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page);
d2500652
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398 if (!new_de)
399 goto out_dir;
565de406 400 inc_nlink(old_inode);
d2500652 401 nilfs_set_link(new_dir, new_de, new_page, old_inode);
abdb318b 402 nilfs_mark_inode_dirty(new_dir);
d2500652
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403 new_inode->i_ctime = CURRENT_TIME;
404 if (dir_de)
405 drop_nlink(new_inode);
565de406 406 drop_nlink(new_inode);
abdb318b 407 nilfs_mark_inode_dirty(new_inode);
d2500652
RK
408 } else {
409 if (dir_de) {
410 err = -EMLINK;
411 if (new_dir->i_nlink >= NILFS_LINK_MAX)
412 goto out_dir;
413 }
565de406 414 inc_nlink(old_inode);
d2500652
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415 err = nilfs_add_link(new_dentry, old_inode);
416 if (err) {
565de406 417 drop_nlink(old_inode);
abdb318b 418 nilfs_mark_inode_dirty(old_inode);
d2500652
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419 goto out_dir;
420 }
565de406
JS
421 if (dir_de) {
422 inc_nlink(new_dir);
abdb318b 423 nilfs_mark_inode_dirty(new_dir);
565de406 424 }
d2500652
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425 }
426
427 /*
428 * Like most other Unix systems, set the ctime for inodes on a
429 * rename.
d2500652
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430 */
431 old_inode->i_ctime = CURRENT_TIME;
432
433 nilfs_delete_entry(old_de, old_page);
43f8bc26 434 drop_nlink(old_inode);
d2500652
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435
436 if (dir_de) {
437 nilfs_set_link(old_inode, dir_de, dir_page, new_dir);
565de406 438 drop_nlink(old_dir);
d2500652 439 }
abdb318b
JS
440 nilfs_mark_inode_dirty(old_dir);
441 nilfs_mark_inode_dirty(old_inode);
d2500652 442
47420c79 443 err = nilfs_transaction_commit(old_dir->i_sb);
d2500652
RK
444 return err;
445
446out_dir:
447 if (dir_de) {
448 kunmap(dir_page);
449 page_cache_release(dir_page);
450 }
451out_old:
452 kunmap(old_page);
453 page_cache_release(old_page);
454out:
47420c79 455 nilfs_transaction_abort(old_dir->i_sb);
d2500652
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456 return err;
457}
458
8e656fd5
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459/*
460 * Export operations
461 */
462static struct dentry *nilfs_get_parent(struct dentry *child)
463{
464 unsigned long ino;
465 struct inode *inode;
466 struct qstr dotdot = {.name = "..", .len = 2};
467 struct nilfs_root *root;
468
469 ino = nilfs_inode_by_name(child->d_inode, &dotdot);
470 if (!ino)
471 return ERR_PTR(-ENOENT);
472
473 root = NILFS_I(child->d_inode)->i_root;
474
475 inode = nilfs_iget(child->d_inode->i_sb, root, ino);
476 if (IS_ERR(inode))
477 return ERR_CAST(inode);
478
479 return d_obtain_alias(inode);
480}
481
482static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
483 u64 ino, u32 gen)
484{
485 struct nilfs_root *root;
486 struct inode *inode;
487
488 if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
489 return ERR_PTR(-ESTALE);
490
491 root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);
492 if (!root)
493 return ERR_PTR(-ESTALE);
494
495 inode = nilfs_iget(sb, root, ino);
496 nilfs_put_root(root);
497
498 if (IS_ERR(inode))
499 return ERR_CAST(inode);
500 if (gen && inode->i_generation != gen) {
501 iput(inode);
502 return ERR_PTR(-ESTALE);
503 }
504 return d_obtain_alias(inode);
505}
506
507static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
508 int fh_len, int fh_type)
509{
510 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
511
512 if ((fh_len != NILFS_FID_SIZE_NON_CONNECTABLE &&
513 fh_len != NILFS_FID_SIZE_CONNECTABLE) ||
514 (fh_type != FILEID_NILFS_WITH_PARENT &&
515 fh_type != FILEID_NILFS_WITHOUT_PARENT))
516 return NULL;
517
518 return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);
519}
520
521static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
522 int fh_len, int fh_type)
523{
524 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
525
526 if (fh_len != NILFS_FID_SIZE_CONNECTABLE ||
527 fh_type != FILEID_NILFS_WITH_PARENT)
528 return NULL;
529
530 return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);
531}
532
533static int nilfs_encode_fh(struct dentry *dentry, __u32 *fh, int *lenp,
534 int connectable)
535{
536 struct nilfs_fid *fid = (struct nilfs_fid *)fh;
537 struct inode *inode = dentry->d_inode;
538 struct nilfs_root *root = NILFS_I(inode)->i_root;
539 int type;
540
541 if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE ||
542 (connectable && *lenp < NILFS_FID_SIZE_CONNECTABLE))
543 return 255;
544
545 fid->cno = root->cno;
546 fid->ino = inode->i_ino;
547 fid->gen = inode->i_generation;
548
549 if (connectable && !S_ISDIR(inode->i_mode)) {
550 struct inode *parent;
551
552 spin_lock(&dentry->d_lock);
553 parent = dentry->d_parent->d_inode;
554 fid->parent_ino = parent->i_ino;
555 fid->parent_gen = parent->i_generation;
556 spin_unlock(&dentry->d_lock);
557
558 type = FILEID_NILFS_WITH_PARENT;
559 *lenp = NILFS_FID_SIZE_CONNECTABLE;
560 } else {
561 type = FILEID_NILFS_WITHOUT_PARENT;
562 *lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
563 }
564
565 return type;
566}
567
6e1d5dcc 568const struct inode_operations nilfs_dir_inode_operations = {
d2500652
RK
569 .create = nilfs_create,
570 .lookup = nilfs_lookup,
571 .link = nilfs_link,
572 .unlink = nilfs_unlink,
573 .symlink = nilfs_symlink,
574 .mkdir = nilfs_mkdir,
575 .rmdir = nilfs_rmdir,
576 .mknod = nilfs_mknod,
577 .rename = nilfs_rename,
578 .setattr = nilfs_setattr,
579 .permission = nilfs_permission,
580};
581
6e1d5dcc 582const struct inode_operations nilfs_special_inode_operations = {
d2500652
RK
583 .setattr = nilfs_setattr,
584 .permission = nilfs_permission,
585};
586
6e1d5dcc 587const struct inode_operations nilfs_symlink_inode_operations = {
d2500652
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588 .readlink = generic_readlink,
589 .follow_link = page_follow_link_light,
590 .put_link = page_put_link,
dc3d3b81 591 .permission = nilfs_permission,
d2500652 592};
8e656fd5
RK
593
594const struct export_operations nilfs_export_ops = {
595 .encode_fh = nilfs_encode_fh,
596 .fh_to_dentry = nilfs_fh_to_dentry,
597 .fh_to_parent = nilfs_fh_to_parent,
598 .get_parent = nilfs_get_parent,
599};