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 
16 #include <linux/sched.h>
17 #include <linux/locks.h>
18 #include <linux/fs.h>
19 #include <linux/ufs_fs.h>
20 
21 #include "swab.h"
22 #include "util.h"
23 
24 #undef UFS_DIR_DEBUG
25 
26 #ifdef UFS_DIR_DEBUG
27 #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
28 #else
29 #define UFSD(x)
30 #endif
31 
32 
33 
34 /*
35  * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
36  *
37  * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
38  */
ufs_match(struct super_block * sb,int len,const char * const name,struct ufs_dir_entry * de)39 static inline int ufs_match(struct super_block *sb, int len,
40 		const char * const name, struct ufs_dir_entry * de)
41 {
42 	if (len != ufs_get_de_namlen(sb, de))
43 		return 0;
44 	if (!de->d_ino)
45 		return 0;
46 	return !memcmp(name, de->d_name, len);
47 }
48 
49 /*
50  * This is blatantly stolen from ext2fs
51  */
52 static int
ufs_readdir(struct file * filp,void * dirent,filldir_t filldir)53 ufs_readdir (struct file * filp, void * dirent, filldir_t filldir)
54 {
55 	struct inode *inode = filp->f_dentry->d_inode;
56 	int error = 0;
57 	unsigned long offset, lblk, blk;
58 	int i, stored;
59 	struct buffer_head * bh;
60 	struct ufs_dir_entry * de;
61 	struct super_block * sb;
62 	int de_reclen;
63 	unsigned flags;
64 
65 	sb = inode->i_sb;
66 	flags = sb->u.ufs_sb.s_flags;
67 
68 	UFSD(("ENTER, ino %lu  f_pos %lu\n", inode->i_ino, (unsigned long) filp->f_pos))
69 
70 	stored = 0;
71 	bh = NULL;
72 	offset = filp->f_pos & (sb->s_blocksize - 1);
73 
74 	while (!error && !stored && filp->f_pos < inode->i_size) {
75 		lblk = (filp->f_pos) >> sb->s_blocksize_bits;
76 		blk = ufs_frag_map(inode, lblk);
77 		if (!blk || !(bh = sb_bread(sb, blk))) {
78 			/* XXX - error - skip to the next block */
79 			printk("ufs_readdir: "
80 			       "dir inode %lu has a hole at offset %lu\n",
81 			       inode->i_ino, (unsigned long int)filp->f_pos);
82 			filp->f_pos += sb->s_blocksize - offset;
83 			continue;
84 		}
85 
86 revalidate:
87 		/* If the dir block has changed since the last call to
88 		 * readdir(2), then we might be pointing to an invalid
89 		 * dirent right now.  Scan from the start of the block
90 		 * to make sure. */
91 		if (filp->f_version != inode->i_version) {
92 			for (i = 0; i < sb->s_blocksize && i < offset; ) {
93 				de = (struct ufs_dir_entry *)(bh->b_data + i);
94 				/* It's too expensive to do a full
95 				 * dirent test each time round this
96 				 * loop, but we do have to test at
97 				 * least that it is non-zero.  A
98 				 * failure will be detected in the
99 				 * dirent test below. */
100 				de_reclen = fs16_to_cpu(sb, de->d_reclen);
101 				if (de_reclen < 1)
102 					break;
103 				i += de_reclen;
104 			}
105 			offset = i;
106 			filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
107 				| offset;
108 			filp->f_version = inode->i_version;
109 		}
110 
111 		while (!error && filp->f_pos < inode->i_size
112 		       && offset < sb->s_blocksize) {
113 			de = (struct ufs_dir_entry *) (bh->b_data + offset);
114 			/* XXX - put in a real ufs_check_dir_entry() */
115 			if ((de->d_reclen == 0) || (ufs_get_de_namlen(sb, de) == 0)) {
116 				filp->f_pos = (filp->f_pos &
117 				              (sb->s_blocksize - 1)) +
118 				               sb->s_blocksize;
119 				brelse(bh);
120 				return stored;
121 			}
122 			if (!ufs_check_dir_entry ("ufs_readdir", inode, de,
123 						   bh, offset)) {
124 				/* On error, skip the f_pos to the
125 				   next block. */
126 				filp->f_pos = (filp->f_pos |
127 				              (sb->s_blocksize - 1)) +
128 					       1;
129 				brelse (bh);
130 				return stored;
131 			}
132 			offset += fs16_to_cpu(sb, de->d_reclen);
133 			if (de->d_ino) {
134 				/* We might block in the next section
135 				 * if the data destination is
136 				 * currently swapped out.  So, use a
137 				 * version stamp to detect whether or
138 				 * not the directory has been modified
139 				 * during the copy operation. */
140 				unsigned long version = filp->f_version;
141 				unsigned char d_type = DT_UNKNOWN;
142 
143 				UFSD(("filldir(%s,%u)\n", de->d_name,
144 							fs32_to_cpu(sb, de->d_ino)))
145 				UFSD(("namlen %u\n", ufs_get_de_namlen(sb, de)))
146 
147 				if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
148 					d_type = de->d_u.d_44.d_type;
149 				error = filldir(dirent, de->d_name,
150 						ufs_get_de_namlen(sb, de), filp->f_pos,
151 						fs32_to_cpu(sb, de->d_ino), d_type);
152 				if (error)
153 					break;
154 				if (version != filp->f_version)
155 					goto revalidate;
156 				stored ++;
157 			}
158 			filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
159 		}
160 		offset = 0;
161 		brelse (bh);
162 	}
163 	UPDATE_ATIME(inode);
164 	return 0;
165 }
166 
167 /*
168  * define how far ahead to read directories while searching them.
169  */
170 #define NAMEI_RA_CHUNKS  2
171 #define NAMEI_RA_BLOCKS  4
172 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
173 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
174 
175 /*
176  *	ufs_find_entry()
177  *
178  * finds an entry in the specified directory with the wanted name. It
179  * returns the cache buffer in which the entry was found, and the entry
180  * itself (as a parameter - res_bh). It does NOT read the inode of the
181  * entry - you'll have to do that yourself if you want to.
182  */
ufs_find_entry(struct dentry * dentry,struct buffer_head ** res_bh)183 struct ufs_dir_entry * ufs_find_entry (struct dentry *dentry,
184 	struct buffer_head ** res_bh)
185 {
186 	struct super_block * sb;
187 	struct buffer_head * bh_use[NAMEI_RA_SIZE];
188 	struct buffer_head * bh_read[NAMEI_RA_SIZE];
189 	unsigned long offset;
190 	int block, toread, i, err;
191 	struct inode *dir = dentry->d_parent->d_inode;
192 	const char *name = dentry->d_name.name;
193 	int namelen = dentry->d_name.len;
194 
195 	UFSD(("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen))
196 
197 	*res_bh = NULL;
198 
199 	sb = dir->i_sb;
200 
201 	if (namelen > UFS_MAXNAMLEN)
202 		return NULL;
203 
204 	memset (bh_use, 0, sizeof (bh_use));
205 	toread = 0;
206 	for (block = 0; block < NAMEI_RA_SIZE; ++block) {
207 		struct buffer_head * bh;
208 
209 		if ((block << sb->s_blocksize_bits) >= dir->i_size)
210 			break;
211 		bh = ufs_getfrag (dir, block, 0, &err);
212 		bh_use[block] = bh;
213 		if (bh && !buffer_uptodate(bh))
214 			bh_read[toread++] = bh;
215 	}
216 
217 	for (block = 0, offset = 0; offset < dir->i_size; block++) {
218 		struct buffer_head * bh;
219 		struct ufs_dir_entry * de;
220 		char * dlimit;
221 
222 		if ((block % NAMEI_RA_BLOCKS) == 0 && toread) {
223 			ll_rw_block (READ, toread, bh_read);
224 			toread = 0;
225 		}
226 		bh = bh_use[block % NAMEI_RA_SIZE];
227 		if (!bh) {
228 			ufs_error (sb, "ufs_find_entry",
229 				"directory #%lu contains a hole at offset %lu",
230 				dir->i_ino, offset);
231 			offset += sb->s_blocksize;
232 			continue;
233 		}
234 		wait_on_buffer (bh);
235 		if (!buffer_uptodate(bh)) {
236 			/*
237 			 * read error: all bets are off
238 			 */
239 			break;
240 		}
241 
242 		de = (struct ufs_dir_entry *) bh->b_data;
243 		dlimit = bh->b_data + sb->s_blocksize;
244 		while ((char *) de < dlimit && offset < dir->i_size) {
245 			/* this code is executed quadratically often */
246 			/* do minimal checking by hand */
247 			int de_len;
248 
249 			if ((char *) de + namelen <= dlimit &&
250 			    ufs_match(sb, namelen, name, de)) {
251 				/* found a match -
252 				just to be sure, do a full check */
253 				if (!ufs_check_dir_entry("ufs_find_entry",
254 				    dir, de, bh, offset))
255 					goto failed;
256 				for (i = 0; i < NAMEI_RA_SIZE; ++i) {
257 					if (bh_use[i] != bh)
258 						brelse (bh_use[i]);
259 				}
260 				*res_bh = bh;
261 				return de;
262 			}
263                         /* prevent looping on a bad block */
264 			de_len = fs16_to_cpu(sb, de->d_reclen);
265 			if (de_len <= 0)
266 				goto failed;
267 			offset += de_len;
268 			de = (struct ufs_dir_entry *) ((char *) de + de_len);
269 		}
270 
271 		brelse (bh);
272 		if (((block + NAMEI_RA_SIZE) << sb->s_blocksize_bits ) >=
273 		    dir->i_size)
274 			bh = NULL;
275 		else
276 			bh = ufs_getfrag (dir, block + NAMEI_RA_SIZE, 0, &err);
277 		bh_use[block % NAMEI_RA_SIZE] = bh;
278 		if (bh && !buffer_uptodate(bh))
279 			bh_read[toread++] = bh;
280 	}
281 
282 failed:
283 	for (i = 0; i < NAMEI_RA_SIZE; ++i) brelse (bh_use[i]);
284 	UFSD(("EXIT\n"))
285 	return NULL;
286 }
287 
ufs_check_dir_entry(const char * function,struct inode * dir,struct ufs_dir_entry * de,struct buffer_head * bh,unsigned long offset)288 int ufs_check_dir_entry (const char * function,	struct inode * dir,
289 	struct ufs_dir_entry * de, struct buffer_head * bh,
290 	unsigned long offset)
291 {
292 	struct super_block *sb = dir->i_sb;
293 	const char *error_msg = NULL;
294 	int rlen = fs16_to_cpu(sb, de->d_reclen);
295 
296 	if (rlen < UFS_DIR_REC_LEN(1))
297 		error_msg = "reclen is smaller than minimal";
298 	else if (rlen % 4 != 0)
299 		error_msg = "reclen % 4 != 0";
300 	else if (rlen < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)))
301 		error_msg = "reclen is too small for namlen";
302 	else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
303 		error_msg = "directory entry across blocks";
304 	else if (fs32_to_cpu(sb, de->d_ino) > (sb->u.ufs_sb.s_uspi->s_ipg *
305 				      sb->u.ufs_sb.s_uspi->s_ncg))
306 		error_msg = "inode out of bounds";
307 
308 	if (error_msg != NULL)
309 		ufs_error (sb, function, "bad entry in directory #%lu, size %Lu: %s - "
310 			    "offset=%lu, inode=%lu, reclen=%d, namlen=%d",
311 			    dir->i_ino, dir->i_size, error_msg, offset,
312 			    (unsigned long)fs32_to_cpu(sb, de->d_ino),
313 			    rlen, ufs_get_de_namlen(sb, de));
314 
315 	return (error_msg == NULL ? 1 : 0);
316 }
317 
ufs_dotdot(struct inode * dir,struct buffer_head ** p)318 struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct buffer_head **p)
319 {
320 	int err;
321 	struct buffer_head *bh = ufs_bread (dir, 0, 0, &err);
322 	struct ufs_dir_entry *res = NULL;
323 
324 	if (bh) {
325 		res = (struct ufs_dir_entry *) bh->b_data;
326 		res = (struct ufs_dir_entry *)((char *)res +
327 			fs16_to_cpu(dir->i_sb, res->d_reclen));
328 	}
329 	*p = bh;
330 	return res;
331 }
ufs_inode_by_name(struct inode * dir,struct dentry * dentry)332 ino_t ufs_inode_by_name(struct inode * dir, struct dentry *dentry)
333 {
334 	ino_t res = 0;
335 	struct ufs_dir_entry * de;
336 	struct buffer_head *bh;
337 
338 	de = ufs_find_entry (dentry, &bh);
339 	if (de) {
340 		res = fs32_to_cpu(dir->i_sb, de->d_ino);
341 		brelse(bh);
342 	}
343 	return res;
344 }
345 
ufs_set_link(struct inode * dir,struct ufs_dir_entry * de,struct buffer_head * bh,struct inode * inode)346 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
347 		struct buffer_head *bh, struct inode *inode)
348 {
349 	dir->i_version = ++event;
350 	de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
351 	mark_buffer_dirty(bh);
352 	if (IS_SYNC(dir)) {
353 		ll_rw_block (WRITE, 1, &bh);
354 		wait_on_buffer(bh);
355 	}
356 	brelse (bh);
357 }
358 
359 /*
360  *	ufs_add_entry()
361  *
362  * adds a file entry to the specified directory, using the same
363  * semantics as ufs_find_entry(). It returns NULL if it failed.
364  */
ufs_add_link(struct dentry * dentry,struct inode * inode)365 int ufs_add_link(struct dentry *dentry, struct inode *inode)
366 {
367 	struct super_block * sb;
368 	struct ufs_sb_private_info * uspi;
369 	unsigned long offset;
370 	unsigned fragoff;
371 	unsigned short rec_len;
372 	struct buffer_head * bh;
373 	struct ufs_dir_entry * de, * de1;
374 	struct inode *dir = dentry->d_parent->d_inode;
375 	const char *name = dentry->d_name.name;
376 	int namelen = dentry->d_name.len;
377 	int err;
378 
379 	UFSD(("ENTER, name %s, namelen %u\n", name, namelen))
380 
381 	sb = dir->i_sb;
382 	uspi = sb->u.ufs_sb.s_uspi;
383 
384 	if (!namelen)
385 		return -EINVAL;
386 	bh = ufs_bread (dir, 0, 0, &err);
387 	if (!bh)
388 		return err;
389 	rec_len = UFS_DIR_REC_LEN(namelen);
390 	offset = 0;
391 	de = (struct ufs_dir_entry *) bh->b_data;
392 	while (1) {
393 		if ((char *)de >= UFS_SECTOR_SIZE + bh->b_data) {
394 			fragoff = offset & ~uspi->s_fmask;
395 			if (fragoff != 0 && fragoff != UFS_SECTOR_SIZE)
396 				ufs_error (sb, "ufs_add_entry", "internal error"
397 					" fragoff %u", fragoff);
398 			if (!fragoff) {
399 				brelse (bh);
400 				bh = ufs_bread (dir, offset >> sb->s_blocksize_bits, 1, &err);
401 				if (!bh)
402 					return err;
403 			}
404 			if (dir->i_size <= offset) {
405 				if (dir->i_size == 0) {
406 					brelse(bh);
407 					return -ENOENT;
408 				}
409 				de = (struct ufs_dir_entry *) (bh->b_data + fragoff);
410 				de->d_ino = 0;
411 				de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE);
412 				ufs_set_de_namlen(sb, de, 0);
413 				dir->i_size = offset + UFS_SECTOR_SIZE;
414 				mark_inode_dirty(dir);
415 			} else {
416 				de = (struct ufs_dir_entry *) bh->b_data;
417 			}
418 		}
419 		if (!ufs_check_dir_entry ("ufs_add_entry", dir, de, bh, offset)) {
420 			brelse (bh);
421 			return -ENOENT;
422 		}
423 		if (ufs_match(sb, namelen, name, de)) {
424 			brelse (bh);
425 			return -EEXIST;
426 		}
427 		if (de->d_ino == 0 && fs16_to_cpu(sb, de->d_reclen) >= rec_len)
428 			break;
429 
430 		if (fs16_to_cpu(sb, de->d_reclen) >=
431 		     UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)) + rec_len)
432 			break;
433 		offset += fs16_to_cpu(sb, de->d_reclen);
434 		de = (struct ufs_dir_entry *) ((char *) de + fs16_to_cpu(sb, de->d_reclen));
435 	}
436 
437 	if (de->d_ino) {
438 		de1 = (struct ufs_dir_entry *) ((char *) de +
439 			UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
440 		de1->d_reclen =
441 			cpu_to_fs16(sb, fs16_to_cpu(sb, de->d_reclen) -
442 				UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
443 		de->d_reclen =
444 			cpu_to_fs16(sb, UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
445 		de = de1;
446 	}
447 	de->d_ino = 0;
448 	ufs_set_de_namlen(sb, de, namelen);
449 	memcpy (de->d_name, name, namelen + 1);
450 	de->d_ino = cpu_to_fs32(sb, inode->i_ino);
451 	ufs_set_de_type(sb, de, inode->i_mode);
452 	mark_buffer_dirty(bh);
453 	if (IS_SYNC(dir)) {
454 		ll_rw_block (WRITE, 1, &bh);
455 		wait_on_buffer (bh);
456 	}
457 	brelse (bh);
458 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
459 	dir->i_version = ++event;
460 	mark_inode_dirty(dir);
461 
462 	UFSD(("EXIT\n"))
463 	return 0;
464 }
465 
466 /*
467  * ufs_delete_entry deletes a directory entry by merging it with the
468  * previous entry.
469  */
ufs_delete_entry(struct inode * inode,struct ufs_dir_entry * dir,struct buffer_head * bh)470 int ufs_delete_entry (struct inode * inode, struct ufs_dir_entry * dir,
471 	struct buffer_head * bh )
472 
473 {
474 	struct super_block * sb;
475 	struct ufs_dir_entry * de, * pde;
476 	unsigned i;
477 
478 	UFSD(("ENTER\n"))
479 
480 	sb = inode->i_sb;
481 	i = 0;
482 	pde = NULL;
483 	de = (struct ufs_dir_entry *) bh->b_data;
484 
485 	UFSD(("ino %u, reclen %u, namlen %u, name %s\n",
486 		fs32_to_cpu(sb, de->d_ino),
487 		fs16to_cpu(sb, de->d_reclen),
488 		ufs_get_de_namlen(sb, de), de->d_name))
489 
490 	while (i < bh->b_size) {
491 		if (!ufs_check_dir_entry ("ufs_delete_entry", inode, de, bh, i)) {
492 			brelse(bh);
493 			return -EIO;
494 		}
495 		if (de == dir)  {
496 			if (pde)
497 				fs16_add(sb, &pde->d_reclen,
498 					fs16_to_cpu(sb, dir->d_reclen));
499 			dir->d_ino = 0;
500 			inode->i_version = ++event;
501 			inode->i_ctime = inode->i_mtime = CURRENT_TIME;
502 			mark_inode_dirty(inode);
503 			mark_buffer_dirty(bh);
504 			if (IS_SYNC(inode)) {
505 				ll_rw_block(WRITE, 1, &bh);
506 				wait_on_buffer(bh);
507 			}
508 			brelse(bh);
509 			UFSD(("EXIT\n"))
510 			return 0;
511 		}
512 		i += fs16_to_cpu(sb, de->d_reclen);
513 		if (i == UFS_SECTOR_SIZE) pde = NULL;
514 		else pde = de;
515 		de = (struct ufs_dir_entry *)
516 		    ((char *) de + fs16_to_cpu(sb, de->d_reclen));
517 		if (i == UFS_SECTOR_SIZE && de->d_reclen == 0)
518 			break;
519 	}
520 	UFSD(("EXIT\n"))
521 	brelse(bh);
522 	return -ENOENT;
523 }
524 
ufs_make_empty(struct inode * inode,struct inode * dir)525 int ufs_make_empty(struct inode * inode, struct inode *dir)
526 {
527 	struct super_block * sb = dir->i_sb;
528 	struct buffer_head * dir_block;
529 	struct ufs_dir_entry * de;
530 	int err;
531 
532 	dir_block = ufs_bread (inode, 0, 1, &err);
533 	if (!dir_block)
534 		return err;
535 
536 	inode->i_blocks = sb->s_blocksize / UFS_SECTOR_SIZE;
537 	de = (struct ufs_dir_entry *) dir_block->b_data;
538 	de->d_ino = cpu_to_fs32(sb, inode->i_ino);
539 	ufs_set_de_type(sb, de, inode->i_mode);
540 	ufs_set_de_namlen(sb, de, 1);
541 	de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
542 	strcpy (de->d_name, ".");
543 	de = (struct ufs_dir_entry *)
544 		((char *)de + fs16_to_cpu(sb, de->d_reclen));
545 	de->d_ino = cpu_to_fs32(sb, dir->i_ino);
546 	ufs_set_de_type(sb, de, dir->i_mode);
547 	de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE - UFS_DIR_REC_LEN(1));
548 	ufs_set_de_namlen(sb, de, 2);
549 	strcpy (de->d_name, "..");
550 	mark_buffer_dirty(dir_block);
551 	brelse (dir_block);
552 	mark_inode_dirty(inode);
553 	return 0;
554 }
555 
556 /*
557  * routine to check that the specified directory is empty (for rmdir)
558  */
ufs_empty_dir(struct inode * inode)559 int ufs_empty_dir (struct inode * inode)
560 {
561 	struct super_block * sb;
562 	unsigned long offset;
563 	struct buffer_head * bh;
564 	struct ufs_dir_entry * de, * de1;
565 	int err;
566 
567 	sb = inode->i_sb;
568 
569 	if (inode->i_size < UFS_DIR_REC_LEN(1) + UFS_DIR_REC_LEN(2) ||
570 	    !(bh = ufs_bread (inode, 0, 0, &err))) {
571 	    	ufs_warning (inode->i_sb, "empty_dir",
572 			      "bad directory (dir #%lu) - no data block",
573 			      inode->i_ino);
574 		return 1;
575 	}
576 	de = (struct ufs_dir_entry *) bh->b_data;
577 	de1 = (struct ufs_dir_entry *)
578 		((char *)de + fs16_to_cpu(sb, de->d_reclen));
579 	if (fs32_to_cpu(sb, de->d_ino) != inode->i_ino || de1->d_ino == 0 ||
580 	     strcmp (".", de->d_name) || strcmp ("..", de1->d_name)) {
581 	    	ufs_warning (inode->i_sb, "empty_dir",
582 			      "bad directory (dir #%lu) - no `.' or `..'",
583 			      inode->i_ino);
584 		return 1;
585 	}
586 	offset = fs16_to_cpu(sb, de->d_reclen) + fs16_to_cpu(sb, de1->d_reclen);
587 	de = (struct ufs_dir_entry *)
588 		((char *)de1 + fs16_to_cpu(sb, de1->d_reclen));
589 	while (offset < inode->i_size ) {
590 		if (!bh || (void *) de >= (void *) (bh->b_data + sb->s_blocksize)) {
591 			brelse (bh);
592 			bh = ufs_bread (inode, offset >> sb->s_blocksize_bits, 1, &err);
593 	 		if (!bh) {
594 				ufs_error (sb, "empty_dir",
595 					    "directory #%lu contains a hole at offset %lu",
596 					    inode->i_ino, offset);
597 				offset += sb->s_blocksize;
598 				continue;
599 			}
600 			de = (struct ufs_dir_entry *) bh->b_data;
601 		}
602 		if (!ufs_check_dir_entry ("empty_dir", inode, de, bh, offset)) {
603 			brelse (bh);
604 			return 1;
605 		}
606 		if (de->d_ino) {
607 			brelse (bh);
608 			return 0;
609 		}
610 		offset += fs16_to_cpu(sb, de->d_reclen);
611 		de = (struct ufs_dir_entry *)
612 			((char *)de + fs16_to_cpu(sb, de->d_reclen));
613 	}
614 	brelse (bh);
615 	return 1;
616 }
617 
618 struct file_operations ufs_dir_operations = {
619 	read:		generic_read_dir,
620 	readdir:	ufs_readdir,
621 	fsync:		file_fsync,
622 };
623