xref: /openbmc/linux/fs/ufs/dir.c (revision 22246614)
1 /*
2  *  linux/fs/ufs/ufs_dir.c
3  *
4  * Copyright (C) 1996
5  * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
6  * Laboratory for Computer Science Research Computing Facility
7  * Rutgers, The State University of New Jersey
8  *
9  * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
10  *
11  * 4.4BSD (FreeBSD) support added on February 1st 1998 by
12  * Niels Kristian Bech Jensen <nkbj@image.dk> partially based
13  * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
14  *
15  * Migration to usage of "page cache" on May 2006 by
16  * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
17  */
18 
19 #include <linux/time.h>
20 #include <linux/fs.h>
21 #include <linux/swap.h>
22 
23 #include "ufs_fs.h"
24 #include "ufs.h"
25 #include "swab.h"
26 #include "util.h"
27 
28 /*
29  * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
30  *
31  * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
32  */
33 static inline int ufs_match(struct super_block *sb, int len,
34 		const char * const name, struct ufs_dir_entry * de)
35 {
36 	if (len != ufs_get_de_namlen(sb, de))
37 		return 0;
38 	if (!de->d_ino)
39 		return 0;
40 	return !memcmp(name, de->d_name, len);
41 }
42 
43 static int ufs_commit_chunk(struct page *page, loff_t pos, unsigned len)
44 {
45 	struct address_space *mapping = page->mapping;
46 	struct inode *dir = mapping->host;
47 	int err = 0;
48 
49 	dir->i_version++;
50 	block_write_end(NULL, mapping, pos, len, len, page, NULL);
51 	if (pos+len > dir->i_size) {
52 		i_size_write(dir, pos+len);
53 		mark_inode_dirty(dir);
54 	}
55 	if (IS_DIRSYNC(dir))
56 		err = write_one_page(page, 1);
57 	else
58 		unlock_page(page);
59 	return err;
60 }
61 
62 static inline void ufs_put_page(struct page *page)
63 {
64 	kunmap(page);
65 	page_cache_release(page);
66 }
67 
68 static inline unsigned long ufs_dir_pages(struct inode *inode)
69 {
70 	return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
71 }
72 
73 ino_t ufs_inode_by_name(struct inode *dir, struct dentry *dentry)
74 {
75 	ino_t res = 0;
76 	struct ufs_dir_entry *de;
77 	struct page *page;
78 
79 	de = ufs_find_entry(dir, dentry, &page);
80 	if (de) {
81 		res = fs32_to_cpu(dir->i_sb, de->d_ino);
82 		ufs_put_page(page);
83 	}
84 	return res;
85 }
86 
87 
88 /* Releases the page */
89 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
90 		  struct page *page, struct inode *inode)
91 {
92 	loff_t pos = page_offset(page) +
93 			(char *) de - (char *) page_address(page);
94 	unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
95 	int err;
96 
97 	lock_page(page);
98 	err = __ufs_write_begin(NULL, page->mapping, pos, len,
99 				AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
100 	BUG_ON(err);
101 
102 	de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
103 	ufs_set_de_type(dir->i_sb, de, inode->i_mode);
104 
105 	err = ufs_commit_chunk(page, pos, len);
106 	ufs_put_page(page);
107 	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
108 	mark_inode_dirty(dir);
109 }
110 
111 
112 static void ufs_check_page(struct page *page)
113 {
114 	struct inode *dir = page->mapping->host;
115 	struct super_block *sb = dir->i_sb;
116 	char *kaddr = page_address(page);
117 	unsigned offs, rec_len;
118 	unsigned limit = PAGE_CACHE_SIZE;
119 	const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
120 	struct ufs_dir_entry *p;
121 	char *error;
122 
123 	if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
124 		limit = dir->i_size & ~PAGE_CACHE_MASK;
125 		if (limit & chunk_mask)
126 			goto Ebadsize;
127 		if (!limit)
128 			goto out;
129 	}
130 	for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
131 		p = (struct ufs_dir_entry *)(kaddr + offs);
132 		rec_len = fs16_to_cpu(sb, p->d_reclen);
133 
134 		if (rec_len < UFS_DIR_REC_LEN(1))
135 			goto Eshort;
136 		if (rec_len & 3)
137 			goto Ealign;
138 		if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
139 			goto Enamelen;
140 		if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
141 			goto Espan;
142 		if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
143 						  UFS_SB(sb)->s_uspi->s_ncg))
144 			goto Einumber;
145 	}
146 	if (offs != limit)
147 		goto Eend;
148 out:
149 	SetPageChecked(page);
150 	return;
151 
152 	/* Too bad, we had an error */
153 
154 Ebadsize:
155 	ufs_error(sb, "ufs_check_page",
156 		  "size of directory #%lu is not a multiple of chunk size",
157 		  dir->i_ino
158 	);
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 	goto bad_entry;
172 Einumber:
173 	error = "inode out of bounds";
174 bad_entry:
175 	ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
176 		   "offset=%lu, rec_len=%d, name_len=%d",
177 		   dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
178 		   rec_len, ufs_get_de_namlen(sb, p));
179 	goto fail;
180 Eend:
181 	p = (struct ufs_dir_entry *)(kaddr + offs);
182 	ufs_error(sb, __func__,
183 		   "entry in directory #%lu spans the page boundary"
184 		   "offset=%lu",
185 		   dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs);
186 fail:
187 	SetPageChecked(page);
188 	SetPageError(page);
189 }
190 
191 static struct page *ufs_get_page(struct inode *dir, unsigned long n)
192 {
193 	struct address_space *mapping = dir->i_mapping;
194 	struct page *page = read_mapping_page(mapping, n, NULL);
195 	if (!IS_ERR(page)) {
196 		kmap(page);
197 		if (!PageChecked(page))
198 			ufs_check_page(page);
199 		if (PageError(page))
200 			goto fail;
201 	}
202 	return page;
203 
204 fail:
205 	ufs_put_page(page);
206 	return ERR_PTR(-EIO);
207 }
208 
209 /*
210  * Return the offset into page `page_nr' of the last valid
211  * byte in that page, plus one.
212  */
213 static unsigned
214 ufs_last_byte(struct inode *inode, unsigned long page_nr)
215 {
216 	unsigned last_byte = inode->i_size;
217 
218 	last_byte -= page_nr << PAGE_CACHE_SHIFT;
219 	if (last_byte > PAGE_CACHE_SIZE)
220 		last_byte = PAGE_CACHE_SIZE;
221 	return last_byte;
222 }
223 
224 static inline struct ufs_dir_entry *
225 ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
226 {
227 	return (struct ufs_dir_entry *)((char *)p +
228 					fs16_to_cpu(sb, p->d_reclen));
229 }
230 
231 struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
232 {
233 	struct page *page = ufs_get_page(dir, 0);
234 	struct ufs_dir_entry *de = NULL;
235 
236 	if (!IS_ERR(page)) {
237 		de = ufs_next_entry(dir->i_sb,
238 				    (struct ufs_dir_entry *)page_address(page));
239 		*p = page;
240 	}
241 	return de;
242 }
243 
244 /*
245  *	ufs_find_entry()
246  *
247  * finds an entry in the specified directory with the wanted name. It
248  * returns the page in which the entry was found, and the entry itself
249  * (as a parameter - res_dir). Page is returned mapped and unlocked.
250  * Entry is guaranteed to be valid.
251  */
252 struct ufs_dir_entry *ufs_find_entry(struct inode *dir, struct dentry *dentry,
253 				     struct page **res_page)
254 {
255 	struct super_block *sb = dir->i_sb;
256 	const char *name = dentry->d_name.name;
257 	int namelen = dentry->d_name.len;
258 	unsigned reclen = UFS_DIR_REC_LEN(namelen);
259 	unsigned long start, n;
260 	unsigned long npages = ufs_dir_pages(dir);
261 	struct page *page = NULL;
262 	struct ufs_inode_info *ui = UFS_I(dir);
263 	struct ufs_dir_entry *de;
264 
265 	UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
266 
267 	if (npages == 0 || namelen > UFS_MAXNAMLEN)
268 		goto out;
269 
270 	/* OFFSET_CACHE */
271 	*res_page = NULL;
272 
273 	start = ui->i_dir_start_lookup;
274 
275 	if (start >= npages)
276 		start = 0;
277 	n = start;
278 	do {
279 		char *kaddr;
280 		page = ufs_get_page(dir, n);
281 		if (!IS_ERR(page)) {
282 			kaddr = page_address(page);
283 			de = (struct ufs_dir_entry *) kaddr;
284 			kaddr += ufs_last_byte(dir, n) - reclen;
285 			while ((char *) de <= kaddr) {
286 				if (de->d_reclen == 0) {
287 					ufs_error(dir->i_sb, __func__,
288 						  "zero-length directory entry");
289 					ufs_put_page(page);
290 					goto out;
291 				}
292 				if (ufs_match(sb, namelen, name, de))
293 					goto found;
294 				de = ufs_next_entry(sb, de);
295 			}
296 			ufs_put_page(page);
297 		}
298 		if (++n >= npages)
299 			n = 0;
300 	} while (n != start);
301 out:
302 	return NULL;
303 
304 found:
305 	*res_page = page;
306 	ui->i_dir_start_lookup = n;
307 	return de;
308 }
309 
310 /*
311  *	Parent is locked.
312  */
313 int ufs_add_link(struct dentry *dentry, struct inode *inode)
314 {
315 	struct inode *dir = dentry->d_parent->d_inode;
316 	const char *name = dentry->d_name.name;
317 	int namelen = dentry->d_name.len;
318 	struct super_block *sb = dir->i_sb;
319 	unsigned reclen = UFS_DIR_REC_LEN(namelen);
320 	const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
321 	unsigned short rec_len, name_len;
322 	struct page *page = NULL;
323 	struct ufs_dir_entry *de;
324 	unsigned long npages = ufs_dir_pages(dir);
325 	unsigned long n;
326 	char *kaddr;
327 	loff_t pos;
328 	int err;
329 
330 	UFSD("ENTER, name %s, namelen %u\n", name, namelen);
331 
332 	/*
333 	 * We take care of directory expansion in the same loop.
334 	 * This code plays outside i_size, so it locks the page
335 	 * to protect that region.
336 	 */
337 	for (n = 0; n <= npages; n++) {
338 		char *dir_end;
339 
340 		page = ufs_get_page(dir, n);
341 		err = PTR_ERR(page);
342 		if (IS_ERR(page))
343 			goto out;
344 		lock_page(page);
345 		kaddr = page_address(page);
346 		dir_end = kaddr + ufs_last_byte(dir, n);
347 		de = (struct ufs_dir_entry *)kaddr;
348 		kaddr += PAGE_CACHE_SIZE - reclen;
349 		while ((char *)de <= kaddr) {
350 			if ((char *)de == dir_end) {
351 				/* We hit i_size */
352 				name_len = 0;
353 				rec_len = chunk_size;
354 				de->d_reclen = cpu_to_fs16(sb, chunk_size);
355 				de->d_ino = 0;
356 				goto got_it;
357 			}
358 			if (de->d_reclen == 0) {
359 				ufs_error(dir->i_sb, __func__,
360 					  "zero-length directory entry");
361 				err = -EIO;
362 				goto out_unlock;
363 			}
364 			err = -EEXIST;
365 			if (ufs_match(sb, namelen, name, de))
366 				goto out_unlock;
367 			name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
368 			rec_len = fs16_to_cpu(sb, de->d_reclen);
369 			if (!de->d_ino && rec_len >= reclen)
370 				goto got_it;
371 			if (rec_len >= name_len + reclen)
372 				goto got_it;
373 			de = (struct ufs_dir_entry *) ((char *) de + rec_len);
374 		}
375 		unlock_page(page);
376 		ufs_put_page(page);
377 	}
378 	BUG();
379 	return -EINVAL;
380 
381 got_it:
382 	pos = page_offset(page) +
383 			(char*)de - (char*)page_address(page);
384 	err = __ufs_write_begin(NULL, page->mapping, pos, rec_len,
385 				AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
386 	if (err)
387 		goto out_unlock;
388 	if (de->d_ino) {
389 		struct ufs_dir_entry *de1 =
390 			(struct ufs_dir_entry *) ((char *) de + name_len);
391 		de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
392 		de->d_reclen = cpu_to_fs16(sb, name_len);
393 
394 		de = de1;
395 	}
396 
397 	ufs_set_de_namlen(sb, de, namelen);
398 	memcpy(de->d_name, name, namelen + 1);
399 	de->d_ino = cpu_to_fs32(sb, inode->i_ino);
400 	ufs_set_de_type(sb, de, inode->i_mode);
401 
402 	err = ufs_commit_chunk(page, pos, rec_len);
403 	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
404 
405 	mark_inode_dirty(dir);
406 	/* OFFSET_CACHE */
407 out_put:
408 	ufs_put_page(page);
409 out:
410 	return err;
411 out_unlock:
412 	unlock_page(page);
413 	goto out_put;
414 }
415 
416 static inline unsigned
417 ufs_validate_entry(struct super_block *sb, char *base,
418 		   unsigned offset, unsigned mask)
419 {
420 	struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
421 	struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
422 	while ((char*)p < (char*)de) {
423 		if (p->d_reclen == 0)
424 			break;
425 		p = ufs_next_entry(sb, p);
426 	}
427 	return (char *)p - base;
428 }
429 
430 
431 /*
432  * This is blatantly stolen from ext2fs
433  */
434 static int
435 ufs_readdir(struct file *filp, void *dirent, filldir_t filldir)
436 {
437 	loff_t pos = filp->f_pos;
438 	struct inode *inode = filp->f_path.dentry->d_inode;
439 	struct super_block *sb = inode->i_sb;
440 	unsigned int offset = pos & ~PAGE_CACHE_MASK;
441 	unsigned long n = pos >> PAGE_CACHE_SHIFT;
442 	unsigned long npages = ufs_dir_pages(inode);
443 	unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
444 	int need_revalidate = filp->f_version != inode->i_version;
445 	unsigned flags = UFS_SB(sb)->s_flags;
446 
447 	UFSD("BEGIN\n");
448 
449 	if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
450 		return 0;
451 
452 	for ( ; n < npages; n++, offset = 0) {
453 		char *kaddr, *limit;
454 		struct ufs_dir_entry *de;
455 
456 		struct page *page = ufs_get_page(inode, n);
457 
458 		if (IS_ERR(page)) {
459 			ufs_error(sb, __func__,
460 				  "bad page in #%lu",
461 				  inode->i_ino);
462 			filp->f_pos += PAGE_CACHE_SIZE - offset;
463 			return -EIO;
464 		}
465 		kaddr = page_address(page);
466 		if (unlikely(need_revalidate)) {
467 			if (offset) {
468 				offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
469 				filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset;
470 			}
471 			filp->f_version = inode->i_version;
472 			need_revalidate = 0;
473 		}
474 		de = (struct ufs_dir_entry *)(kaddr+offset);
475 		limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
476 		for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
477 			if (de->d_reclen == 0) {
478 				ufs_error(sb, __func__,
479 					"zero-length directory entry");
480 				ufs_put_page(page);
481 				return -EIO;
482 			}
483 			if (de->d_ino) {
484 				int over;
485 				unsigned char d_type = DT_UNKNOWN;
486 
487 				offset = (char *)de - kaddr;
488 
489 				UFSD("filldir(%s,%u)\n", de->d_name,
490 				      fs32_to_cpu(sb, de->d_ino));
491 				UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
492 
493 				if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
494 					d_type = de->d_u.d_44.d_type;
495 
496 				over = filldir(dirent, de->d_name,
497 					       ufs_get_de_namlen(sb, de),
498 						(n<<PAGE_CACHE_SHIFT) | offset,
499 					       fs32_to_cpu(sb, de->d_ino), d_type);
500 				if (over) {
501 					ufs_put_page(page);
502 					return 0;
503 				}
504 			}
505 			filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
506 		}
507 		ufs_put_page(page);
508 	}
509 	return 0;
510 }
511 
512 
513 /*
514  * ufs_delete_entry deletes a directory entry by merging it with the
515  * previous entry.
516  */
517 int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
518 		     struct page * page)
519 {
520 	struct super_block *sb = inode->i_sb;
521 	struct address_space *mapping = page->mapping;
522 	char *kaddr = page_address(page);
523 	unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
524 	unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
525 	loff_t pos;
526 	struct ufs_dir_entry *pde = NULL;
527 	struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
528 	int err;
529 
530 	UFSD("ENTER\n");
531 
532 	UFSD("ino %u, reclen %u, namlen %u, name %s\n",
533 	      fs32_to_cpu(sb, de->d_ino),
534 	      fs16_to_cpu(sb, de->d_reclen),
535 	      ufs_get_de_namlen(sb, de), de->d_name);
536 
537 	while ((char*)de < (char*)dir) {
538 		if (de->d_reclen == 0) {
539 			ufs_error(inode->i_sb, __func__,
540 				  "zero-length directory entry");
541 			err = -EIO;
542 			goto out;
543 		}
544 		pde = de;
545 		de = ufs_next_entry(sb, de);
546 	}
547 	if (pde)
548 		from = (char*)pde - (char*)page_address(page);
549 
550 	pos = page_offset(page) + from;
551 	lock_page(page);
552 	err = __ufs_write_begin(NULL, mapping, pos, to - from,
553 				AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
554 	BUG_ON(err);
555 	if (pde)
556 		pde->d_reclen = cpu_to_fs16(sb, to - from);
557 	dir->d_ino = 0;
558 	err = ufs_commit_chunk(page, pos, to - from);
559 	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
560 	mark_inode_dirty(inode);
561 out:
562 	ufs_put_page(page);
563 	UFSD("EXIT\n");
564 	return err;
565 }
566 
567 int ufs_make_empty(struct inode * inode, struct inode *dir)
568 {
569 	struct super_block * sb = dir->i_sb;
570 	struct address_space *mapping = inode->i_mapping;
571 	struct page *page = grab_cache_page(mapping, 0);
572 	const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
573 	struct ufs_dir_entry * de;
574 	char *base;
575 	int err;
576 
577 	if (!page)
578 		return -ENOMEM;
579 
580 	err = __ufs_write_begin(NULL, mapping, 0, chunk_size,
581 				AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
582 	if (err) {
583 		unlock_page(page);
584 		goto fail;
585 	}
586 
587 	kmap(page);
588 	base = (char*)page_address(page);
589 	memset(base, 0, PAGE_CACHE_SIZE);
590 
591 	de = (struct ufs_dir_entry *) base;
592 
593 	de->d_ino = cpu_to_fs32(sb, inode->i_ino);
594 	ufs_set_de_type(sb, de, inode->i_mode);
595 	ufs_set_de_namlen(sb, de, 1);
596 	de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
597 	strcpy (de->d_name, ".");
598 	de = (struct ufs_dir_entry *)
599 		((char *)de + fs16_to_cpu(sb, de->d_reclen));
600 	de->d_ino = cpu_to_fs32(sb, dir->i_ino);
601 	ufs_set_de_type(sb, de, dir->i_mode);
602 	de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
603 	ufs_set_de_namlen(sb, de, 2);
604 	strcpy (de->d_name, "..");
605 	kunmap(page);
606 
607 	err = ufs_commit_chunk(page, 0, chunk_size);
608 fail:
609 	page_cache_release(page);
610 	return err;
611 }
612 
613 /*
614  * routine to check that the specified directory is empty (for rmdir)
615  */
616 int ufs_empty_dir(struct inode * inode)
617 {
618 	struct super_block *sb = inode->i_sb;
619 	struct page *page = NULL;
620 	unsigned long i, npages = ufs_dir_pages(inode);
621 
622 	for (i = 0; i < npages; i++) {
623 		char *kaddr;
624 		struct ufs_dir_entry *de;
625 		page = ufs_get_page(inode, i);
626 
627 		if (IS_ERR(page))
628 			continue;
629 
630 		kaddr = page_address(page);
631 		de = (struct ufs_dir_entry *)kaddr;
632 		kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
633 
634 		while ((char *)de <= kaddr) {
635 			if (de->d_reclen == 0) {
636 				ufs_error(inode->i_sb, __func__,
637 					"zero-length directory entry: "
638 					"kaddr=%p, de=%p\n", kaddr, de);
639 				goto not_empty;
640 			}
641 			if (de->d_ino) {
642 				u16 namelen=ufs_get_de_namlen(sb, de);
643 				/* check for . and .. */
644 				if (de->d_name[0] != '.')
645 					goto not_empty;
646 				if (namelen > 2)
647 					goto not_empty;
648 				if (namelen < 2) {
649 					if (inode->i_ino !=
650 					    fs32_to_cpu(sb, de->d_ino))
651 						goto not_empty;
652 				} else if (de->d_name[1] != '.')
653 					goto not_empty;
654 			}
655 			de = ufs_next_entry(sb, de);
656 		}
657 		ufs_put_page(page);
658 	}
659 	return 1;
660 
661 not_empty:
662 	ufs_put_page(page);
663 	return 0;
664 }
665 
666 const struct file_operations ufs_dir_operations = {
667 	.read		= generic_read_dir,
668 	.readdir	= ufs_readdir,
669 	.fsync		= file_fsync,
670 };
671