1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * dir.c - NILFS directory entry operations
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Modified for NILFS by Amagai Yoshiji.
8 */
9 /*
10 * linux/fs/ext2/dir.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/dir.c
20 *
21 * Copyright (C) 1991, 1992 Linus Torvalds
22 *
23 * ext2 directory handling functions
24 *
25 * Big-endian to little-endian byte-swapping/bitmaps by
26 * David S. Miller (davem@caip.rutgers.edu), 1995
27 *
28 * All code that works with directory layout had been switched to pagecache
29 * and moved here. AV
30 */
31
32 #include <linux/pagemap.h>
33 #include "nilfs.h"
34 #include "page.h"
35
nilfs_rec_len_from_disk(__le16 dlen)36 static inline unsigned int nilfs_rec_len_from_disk(__le16 dlen)
37 {
38 unsigned int len = le16_to_cpu(dlen);
39
40 #if (PAGE_SIZE >= 65536)
41 if (len == NILFS_MAX_REC_LEN)
42 return 1 << 16;
43 #endif
44 return len;
45 }
46
nilfs_rec_len_to_disk(unsigned int len)47 static inline __le16 nilfs_rec_len_to_disk(unsigned int len)
48 {
49 #if (PAGE_SIZE >= 65536)
50 if (len == (1 << 16))
51 return cpu_to_le16(NILFS_MAX_REC_LEN);
52
53 BUG_ON(len > (1 << 16));
54 #endif
55 return cpu_to_le16(len);
56 }
57
58 /*
59 * nilfs uses block-sized chunks. Arguably, sector-sized ones would be
60 * more robust, but we have what we have
61 */
nilfs_chunk_size(struct inode * inode)62 static inline unsigned int nilfs_chunk_size(struct inode *inode)
63 {
64 return inode->i_sb->s_blocksize;
65 }
66
nilfs_put_page(struct page * page)67 static inline void nilfs_put_page(struct page *page)
68 {
69 kunmap(page);
70 put_page(page);
71 }
72
73 /*
74 * Return the offset into page `page_nr' of the last valid
75 * byte in that page, plus one.
76 */
nilfs_last_byte(struct inode * inode,unsigned long page_nr)77 static unsigned int nilfs_last_byte(struct inode *inode, unsigned long page_nr)
78 {
79 unsigned int last_byte = inode->i_size;
80
81 last_byte -= page_nr << PAGE_SHIFT;
82 if (last_byte > PAGE_SIZE)
83 last_byte = PAGE_SIZE;
84 return last_byte;
85 }
86
nilfs_prepare_chunk(struct page * page,unsigned int from,unsigned int to)87 static int nilfs_prepare_chunk(struct page *page, unsigned int from,
88 unsigned int to)
89 {
90 loff_t pos = page_offset(page) + from;
91
92 return __block_write_begin(page, pos, to - from, nilfs_get_block);
93 }
94
nilfs_commit_chunk(struct page * page,struct address_space * mapping,unsigned int from,unsigned int to)95 static void nilfs_commit_chunk(struct page *page,
96 struct address_space *mapping,
97 unsigned int from, unsigned int to)
98 {
99 struct inode *dir = mapping->host;
100 loff_t pos = page_offset(page) + from;
101 unsigned int len = to - from;
102 unsigned int nr_dirty, copied;
103 int err;
104
105 nr_dirty = nilfs_page_count_clean_buffers(page, from, to);
106 copied = block_write_end(NULL, mapping, pos, len, len, page, NULL);
107 if (pos + copied > dir->i_size)
108 i_size_write(dir, pos + copied);
109 if (IS_DIRSYNC(dir))
110 nilfs_set_transaction_flag(NILFS_TI_SYNC);
111 err = nilfs_set_file_dirty(dir, nr_dirty);
112 WARN_ON(err); /* do not happen */
113 unlock_page(page);
114 }
115
nilfs_check_page(struct page * page)116 static bool nilfs_check_page(struct page *page)
117 {
118 struct inode *dir = page->mapping->host;
119 struct super_block *sb = dir->i_sb;
120 unsigned int chunk_size = nilfs_chunk_size(dir);
121 char *kaddr = page_address(page);
122 unsigned int offs, rec_len;
123 unsigned int limit = PAGE_SIZE;
124 struct nilfs_dir_entry *p;
125 char *error;
126
127 if ((dir->i_size >> PAGE_SHIFT) == page->index) {
128 limit = dir->i_size & ~PAGE_MASK;
129 if (limit & (chunk_size - 1))
130 goto Ebadsize;
131 if (!limit)
132 goto out;
133 }
134 for (offs = 0; offs <= limit - NILFS_DIR_REC_LEN(1); offs += rec_len) {
135 p = (struct nilfs_dir_entry *)(kaddr + offs);
136 rec_len = nilfs_rec_len_from_disk(p->rec_len);
137
138 if (rec_len < NILFS_DIR_REC_LEN(1))
139 goto Eshort;
140 if (rec_len & 3)
141 goto Ealign;
142 if (rec_len < NILFS_DIR_REC_LEN(p->name_len))
143 goto Enamelen;
144 if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))
145 goto Espan;
146 }
147 if (offs != limit)
148 goto Eend;
149 out:
150 SetPageChecked(page);
151 return true;
152
153 /* Too bad, we had an error */
154
155 Ebadsize:
156 nilfs_error(sb,
157 "size of directory #%lu is not a multiple of chunk size",
158 dir->i_ino);
159 goto fail;
160 Eshort:
161 error = "rec_len is smaller than minimal";
162 goto bad_entry;
163 Ealign:
164 error = "unaligned directory entry";
165 goto bad_entry;
166 Enamelen:
167 error = "rec_len is too small for name_len";
168 goto bad_entry;
169 Espan:
170 error = "directory entry across blocks";
171 bad_entry:
172 nilfs_error(sb,
173 "bad entry in directory #%lu: %s - offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
174 dir->i_ino, error, (page->index << PAGE_SHIFT) + offs,
175 (unsigned long)le64_to_cpu(p->inode),
176 rec_len, p->name_len);
177 goto fail;
178 Eend:
179 p = (struct nilfs_dir_entry *)(kaddr + offs);
180 nilfs_error(sb,
181 "entry in directory #%lu spans the page boundary offset=%lu, inode=%lu",
182 dir->i_ino, (page->index << PAGE_SHIFT) + offs,
183 (unsigned long)le64_to_cpu(p->inode));
184 fail:
185 SetPageError(page);
186 return false;
187 }
188
nilfs_get_page(struct inode * dir,unsigned long n)189 static struct page *nilfs_get_page(struct inode *dir, unsigned long n)
190 {
191 struct address_space *mapping = dir->i_mapping;
192 struct page *page = read_mapping_page(mapping, n, NULL);
193
194 if (!IS_ERR(page)) {
195 kmap(page);
196 if (unlikely(!PageChecked(page))) {
197 if (PageError(page) || !nilfs_check_page(page))
198 goto fail;
199 }
200 }
201 return page;
202
203 fail:
204 nilfs_put_page(page);
205 return ERR_PTR(-EIO);
206 }
207
208 /*
209 * NOTE! unlike strncmp, nilfs_match returns 1 for success, 0 for failure.
210 *
211 * len <= NILFS_NAME_LEN and de != NULL are guaranteed by caller.
212 */
213 static int
nilfs_match(int len,const unsigned char * name,struct nilfs_dir_entry * de)214 nilfs_match(int len, const unsigned char *name, struct nilfs_dir_entry *de)
215 {
216 if (len != de->name_len)
217 return 0;
218 if (!de->inode)
219 return 0;
220 return !memcmp(name, de->name, len);
221 }
222
223 /*
224 * p is at least 6 bytes before the end of page
225 */
nilfs_next_entry(struct nilfs_dir_entry * p)226 static struct nilfs_dir_entry *nilfs_next_entry(struct nilfs_dir_entry *p)
227 {
228 return (struct nilfs_dir_entry *)((char *)p +
229 nilfs_rec_len_from_disk(p->rec_len));
230 }
231
232 static unsigned char
233 nilfs_filetype_table[NILFS_FT_MAX] = {
234 [NILFS_FT_UNKNOWN] = DT_UNKNOWN,
235 [NILFS_FT_REG_FILE] = DT_REG,
236 [NILFS_FT_DIR] = DT_DIR,
237 [NILFS_FT_CHRDEV] = DT_CHR,
238 [NILFS_FT_BLKDEV] = DT_BLK,
239 [NILFS_FT_FIFO] = DT_FIFO,
240 [NILFS_FT_SOCK] = DT_SOCK,
241 [NILFS_FT_SYMLINK] = DT_LNK,
242 };
243
244 #define S_SHIFT 12
245 static unsigned char
246 nilfs_type_by_mode[S_IFMT >> S_SHIFT] = {
247 [S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE,
248 [S_IFDIR >> S_SHIFT] = NILFS_FT_DIR,
249 [S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV,
250 [S_IFBLK >> S_SHIFT] = NILFS_FT_BLKDEV,
251 [S_IFIFO >> S_SHIFT] = NILFS_FT_FIFO,
252 [S_IFSOCK >> S_SHIFT] = NILFS_FT_SOCK,
253 [S_IFLNK >> S_SHIFT] = NILFS_FT_SYMLINK,
254 };
255
nilfs_set_de_type(struct nilfs_dir_entry * de,struct inode * inode)256 static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode)
257 {
258 umode_t mode = inode->i_mode;
259
260 de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
261 }
262
nilfs_readdir(struct file * file,struct dir_context * ctx)263 static int nilfs_readdir(struct file *file, struct dir_context *ctx)
264 {
265 loff_t pos = ctx->pos;
266 struct inode *inode = file_inode(file);
267 struct super_block *sb = inode->i_sb;
268 unsigned int offset = pos & ~PAGE_MASK;
269 unsigned long n = pos >> PAGE_SHIFT;
270 unsigned long npages = dir_pages(inode);
271
272 if (pos > inode->i_size - NILFS_DIR_REC_LEN(1))
273 return 0;
274
275 for ( ; n < npages; n++, offset = 0) {
276 char *kaddr, *limit;
277 struct nilfs_dir_entry *de;
278 struct page *page = nilfs_get_page(inode, n);
279
280 if (IS_ERR(page)) {
281 nilfs_error(sb, "bad page in #%lu", inode->i_ino);
282 ctx->pos += PAGE_SIZE - offset;
283 return -EIO;
284 }
285 kaddr = page_address(page);
286 de = (struct nilfs_dir_entry *)(kaddr + offset);
287 limit = kaddr + nilfs_last_byte(inode, n) -
288 NILFS_DIR_REC_LEN(1);
289 for ( ; (char *)de <= limit; de = nilfs_next_entry(de)) {
290 if (de->rec_len == 0) {
291 nilfs_error(sb, "zero-length directory entry");
292 nilfs_put_page(page);
293 return -EIO;
294 }
295 if (de->inode) {
296 unsigned char t;
297
298 if (de->file_type < NILFS_FT_MAX)
299 t = nilfs_filetype_table[de->file_type];
300 else
301 t = DT_UNKNOWN;
302
303 if (!dir_emit(ctx, de->name, de->name_len,
304 le64_to_cpu(de->inode), t)) {
305 nilfs_put_page(page);
306 return 0;
307 }
308 }
309 ctx->pos += nilfs_rec_len_from_disk(de->rec_len);
310 }
311 nilfs_put_page(page);
312 }
313 return 0;
314 }
315
316 /*
317 * nilfs_find_entry()
318 *
319 * finds an entry in the specified directory with the wanted name. It
320 * returns the page in which the entry was found, and the entry itself
321 * (as a parameter - res_dir). Page is returned mapped and unlocked.
322 * Entry is guaranteed to be valid.
323 */
324 struct nilfs_dir_entry *
nilfs_find_entry(struct inode * dir,const struct qstr * qstr,struct page ** res_page)325 nilfs_find_entry(struct inode *dir, const struct qstr *qstr,
326 struct page **res_page)
327 {
328 const unsigned char *name = qstr->name;
329 int namelen = qstr->len;
330 unsigned int reclen = NILFS_DIR_REC_LEN(namelen);
331 unsigned long start, n;
332 unsigned long npages = dir_pages(dir);
333 struct page *page = NULL;
334 struct nilfs_inode_info *ei = NILFS_I(dir);
335 struct nilfs_dir_entry *de;
336
337 if (npages == 0)
338 goto out;
339
340 /* OFFSET_CACHE */
341 *res_page = NULL;
342
343 start = ei->i_dir_start_lookup;
344 if (start >= npages)
345 start = 0;
346 n = start;
347 do {
348 char *kaddr;
349
350 page = nilfs_get_page(dir, n);
351 if (!IS_ERR(page)) {
352 kaddr = page_address(page);
353 de = (struct nilfs_dir_entry *)kaddr;
354 kaddr += nilfs_last_byte(dir, n) - reclen;
355 while ((char *) de <= kaddr) {
356 if (de->rec_len == 0) {
357 nilfs_error(dir->i_sb,
358 "zero-length directory entry");
359 nilfs_put_page(page);
360 goto out;
361 }
362 if (nilfs_match(namelen, name, de))
363 goto found;
364 de = nilfs_next_entry(de);
365 }
366 nilfs_put_page(page);
367 }
368 if (++n >= npages)
369 n = 0;
370 /* next page is past the blocks we've got */
371 if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) {
372 nilfs_error(dir->i_sb,
373 "dir %lu size %lld exceeds block count %llu",
374 dir->i_ino, dir->i_size,
375 (unsigned long long)dir->i_blocks);
376 goto out;
377 }
378 } while (n != start);
379 out:
380 return NULL;
381
382 found:
383 *res_page = page;
384 ei->i_dir_start_lookup = n;
385 return de;
386 }
387
nilfs_dotdot(struct inode * dir,struct page ** p)388 struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct page **p)
389 {
390 struct page *page = nilfs_get_page(dir, 0);
391 struct nilfs_dir_entry *de = NULL;
392
393 if (!IS_ERR(page)) {
394 de = nilfs_next_entry(
395 (struct nilfs_dir_entry *)page_address(page));
396 *p = page;
397 }
398 return de;
399 }
400
nilfs_inode_by_name(struct inode * dir,const struct qstr * qstr)401 ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr)
402 {
403 ino_t res = 0;
404 struct nilfs_dir_entry *de;
405 struct page *page;
406
407 de = nilfs_find_entry(dir, qstr, &page);
408 if (de) {
409 res = le64_to_cpu(de->inode);
410 kunmap(page);
411 put_page(page);
412 }
413 return res;
414 }
415
416 /* Releases the page */
nilfs_set_link(struct inode * dir,struct nilfs_dir_entry * de,struct page * page,struct inode * inode)417 void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de,
418 struct page *page, struct inode *inode)
419 {
420 unsigned int from = (char *)de - (char *)page_address(page);
421 unsigned int to = from + nilfs_rec_len_from_disk(de->rec_len);
422 struct address_space *mapping = page->mapping;
423 int err;
424
425 lock_page(page);
426 err = nilfs_prepare_chunk(page, from, to);
427 BUG_ON(err);
428 de->inode = cpu_to_le64(inode->i_ino);
429 nilfs_set_de_type(de, inode);
430 nilfs_commit_chunk(page, mapping, from, to);
431 nilfs_put_page(page);
432 dir->i_mtime = dir->i_ctime = current_time(dir);
433 }
434
435 /*
436 * Parent is locked.
437 */
nilfs_add_link(struct dentry * dentry,struct inode * inode)438 int nilfs_add_link(struct dentry *dentry, struct inode *inode)
439 {
440 struct inode *dir = d_inode(dentry->d_parent);
441 const unsigned char *name = dentry->d_name.name;
442 int namelen = dentry->d_name.len;
443 unsigned int chunk_size = nilfs_chunk_size(dir);
444 unsigned int reclen = NILFS_DIR_REC_LEN(namelen);
445 unsigned short rec_len, name_len;
446 struct page *page = NULL;
447 struct nilfs_dir_entry *de;
448 unsigned long npages = dir_pages(dir);
449 unsigned long n;
450 char *kaddr;
451 unsigned int from, to;
452 int err;
453
454 /*
455 * We take care of directory expansion in the same loop.
456 * This code plays outside i_size, so it locks the page
457 * to protect that region.
458 */
459 for (n = 0; n <= npages; n++) {
460 char *dir_end;
461
462 page = nilfs_get_page(dir, n);
463 err = PTR_ERR(page);
464 if (IS_ERR(page))
465 goto out;
466 lock_page(page);
467 kaddr = page_address(page);
468 dir_end = kaddr + nilfs_last_byte(dir, n);
469 de = (struct nilfs_dir_entry *)kaddr;
470 kaddr += PAGE_SIZE - reclen;
471 while ((char *)de <= kaddr) {
472 if ((char *)de == dir_end) {
473 /* We hit i_size */
474 name_len = 0;
475 rec_len = chunk_size;
476 de->rec_len = nilfs_rec_len_to_disk(chunk_size);
477 de->inode = 0;
478 goto got_it;
479 }
480 if (de->rec_len == 0) {
481 nilfs_error(dir->i_sb,
482 "zero-length directory entry");
483 err = -EIO;
484 goto out_unlock;
485 }
486 err = -EEXIST;
487 if (nilfs_match(namelen, name, de))
488 goto out_unlock;
489 name_len = NILFS_DIR_REC_LEN(de->name_len);
490 rec_len = nilfs_rec_len_from_disk(de->rec_len);
491 if (!de->inode && rec_len >= reclen)
492 goto got_it;
493 if (rec_len >= name_len + reclen)
494 goto got_it;
495 de = (struct nilfs_dir_entry *)((char *)de + rec_len);
496 }
497 unlock_page(page);
498 nilfs_put_page(page);
499 }
500 BUG();
501 return -EINVAL;
502
503 got_it:
504 from = (char *)de - (char *)page_address(page);
505 to = from + rec_len;
506 err = nilfs_prepare_chunk(page, from, to);
507 if (err)
508 goto out_unlock;
509 if (de->inode) {
510 struct nilfs_dir_entry *de1;
511
512 de1 = (struct nilfs_dir_entry *)((char *)de + name_len);
513 de1->rec_len = nilfs_rec_len_to_disk(rec_len - name_len);
514 de->rec_len = nilfs_rec_len_to_disk(name_len);
515 de = de1;
516 }
517 de->name_len = namelen;
518 memcpy(de->name, name, namelen);
519 de->inode = cpu_to_le64(inode->i_ino);
520 nilfs_set_de_type(de, inode);
521 nilfs_commit_chunk(page, page->mapping, from, to);
522 dir->i_mtime = dir->i_ctime = current_time(dir);
523 nilfs_mark_inode_dirty(dir);
524 /* OFFSET_CACHE */
525 out_put:
526 nilfs_put_page(page);
527 out:
528 return err;
529 out_unlock:
530 unlock_page(page);
531 goto out_put;
532 }
533
534 /*
535 * nilfs_delete_entry deletes a directory entry by merging it with the
536 * previous entry. Page is up-to-date. Releases the page.
537 */
nilfs_delete_entry(struct nilfs_dir_entry * dir,struct page * page)538 int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct page *page)
539 {
540 struct address_space *mapping = page->mapping;
541 struct inode *inode = mapping->host;
542 char *kaddr = page_address(page);
543 unsigned int from, to;
544 struct nilfs_dir_entry *de, *pde = NULL;
545 int err;
546
547 from = ((char *)dir - kaddr) & ~(nilfs_chunk_size(inode) - 1);
548 to = ((char *)dir - kaddr) + nilfs_rec_len_from_disk(dir->rec_len);
549 de = (struct nilfs_dir_entry *)(kaddr + from);
550
551 while ((char *)de < (char *)dir) {
552 if (de->rec_len == 0) {
553 nilfs_error(inode->i_sb,
554 "zero-length directory entry");
555 err = -EIO;
556 goto out;
557 }
558 pde = de;
559 de = nilfs_next_entry(de);
560 }
561 if (pde)
562 from = (char *)pde - (char *)page_address(page);
563 lock_page(page);
564 err = nilfs_prepare_chunk(page, from, to);
565 BUG_ON(err);
566 if (pde)
567 pde->rec_len = nilfs_rec_len_to_disk(to - from);
568 dir->inode = 0;
569 nilfs_commit_chunk(page, mapping, from, to);
570 inode->i_ctime = inode->i_mtime = current_time(inode);
571 out:
572 nilfs_put_page(page);
573 return err;
574 }
575
576 /*
577 * Set the first fragment of directory.
578 */
nilfs_make_empty(struct inode * inode,struct inode * parent)579 int nilfs_make_empty(struct inode *inode, struct inode *parent)
580 {
581 struct address_space *mapping = inode->i_mapping;
582 struct page *page = grab_cache_page(mapping, 0);
583 unsigned int chunk_size = nilfs_chunk_size(inode);
584 struct nilfs_dir_entry *de;
585 int err;
586 void *kaddr;
587
588 if (!page)
589 return -ENOMEM;
590
591 err = nilfs_prepare_chunk(page, 0, chunk_size);
592 if (unlikely(err)) {
593 unlock_page(page);
594 goto fail;
595 }
596 kaddr = kmap_atomic(page);
597 memset(kaddr, 0, chunk_size);
598 de = (struct nilfs_dir_entry *)kaddr;
599 de->name_len = 1;
600 de->rec_len = nilfs_rec_len_to_disk(NILFS_DIR_REC_LEN(1));
601 memcpy(de->name, ".\0\0", 4);
602 de->inode = cpu_to_le64(inode->i_ino);
603 nilfs_set_de_type(de, inode);
604
605 de = (struct nilfs_dir_entry *)(kaddr + NILFS_DIR_REC_LEN(1));
606 de->name_len = 2;
607 de->rec_len = nilfs_rec_len_to_disk(chunk_size - NILFS_DIR_REC_LEN(1));
608 de->inode = cpu_to_le64(parent->i_ino);
609 memcpy(de->name, "..\0", 4);
610 nilfs_set_de_type(de, inode);
611 kunmap_atomic(kaddr);
612 nilfs_commit_chunk(page, mapping, 0, chunk_size);
613 fail:
614 put_page(page);
615 return err;
616 }
617
618 /*
619 * routine to check that the specified directory is empty (for rmdir)
620 */
nilfs_empty_dir(struct inode * inode)621 int nilfs_empty_dir(struct inode *inode)
622 {
623 struct page *page = NULL;
624 unsigned long i, npages = dir_pages(inode);
625
626 for (i = 0; i < npages; i++) {
627 char *kaddr;
628 struct nilfs_dir_entry *de;
629
630 page = nilfs_get_page(inode, i);
631 if (IS_ERR(page))
632 continue;
633
634 kaddr = page_address(page);
635 de = (struct nilfs_dir_entry *)kaddr;
636 kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1);
637
638 while ((char *)de <= kaddr) {
639 if (de->rec_len == 0) {
640 nilfs_error(inode->i_sb,
641 "zero-length directory entry (kaddr=%p, de=%p)",
642 kaddr, de);
643 goto not_empty;
644 }
645 if (de->inode != 0) {
646 /* check for . and .. */
647 if (de->name[0] != '.')
648 goto not_empty;
649 if (de->name_len > 2)
650 goto not_empty;
651 if (de->name_len < 2) {
652 if (de->inode !=
653 cpu_to_le64(inode->i_ino))
654 goto not_empty;
655 } else if (de->name[1] != '.')
656 goto not_empty;
657 }
658 de = nilfs_next_entry(de);
659 }
660 nilfs_put_page(page);
661 }
662 return 1;
663
664 not_empty:
665 nilfs_put_page(page);
666 return 0;
667 }
668
669 const struct file_operations nilfs_dir_operations = {
670 .llseek = generic_file_llseek,
671 .read = generic_read_dir,
672 .iterate_shared = nilfs_readdir,
673 .unlocked_ioctl = nilfs_ioctl,
674 #ifdef CONFIG_COMPAT
675 .compat_ioctl = nilfs_compat_ioctl,
676 #endif /* CONFIG_COMPAT */
677 .fsync = nilfs_sync_file,
678
679 };
680