xref: /linux/fs/nilfs2/dir.c (revision d786bdf2a70545a868cd0b06b5603cd5a5fec011) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * 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 
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 
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  */
62 static inline unsigned int nilfs_chunk_size(struct inode *inode)
63 {
64 	return inode->i_sb->s_blocksize;
65 }
66 
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  */
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 
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 
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 
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 
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
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  */
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 
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 
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 *
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 
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 
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 */
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  */
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  */
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  */
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  */
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