2 * linux/fs/ufs/ufs_dir.c
5 * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
6 * Laboratory for Computer Science Research Computing Facility
7 * Rutgers, The State University of New Jersey
9 * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
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>.
16 #include <linux/sched.h>
17 #include <linux/locks.h>
19 #include <linux/ufs_fs.h>
27 #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
35 * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
37 * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
39 static inline int ufs_match(struct super_block *sb, int len,
40 const char * const name, struct ufs_dir_entry * de)
42 if (len != ufs_get_de_namlen(sb, de))
46 return !memcmp(name, de->d_name, len);
50 * This is blatantly stolen from ext2fs
53 ufs_readdir (struct file * filp, void * dirent, filldir_t filldir)
55 struct inode *inode = filp->f_dentry->d_inode;
57 unsigned long offset, lblk, blk;
59 struct buffer_head * bh;
60 struct ufs_dir_entry * de;
61 struct super_block * sb;
66 flags = sb->u.ufs_sb.s_flags;
68 UFSD(("ENTER, ino %lu f_pos %lu\n", inode->i_ino, (unsigned long) filp->f_pos))
72 offset = filp->f_pos & (sb->s_blocksize - 1);
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;
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
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);
106 filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
108 filp->f_version = inode->i_version;
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)) +
122 if (!ufs_check_dir_entry ("ufs_readdir", inode, de,
124 /* On error, skip the f_pos to the
126 filp->f_pos = (filp->f_pos |
127 (sb->s_blocksize - 1)) +
132 offset += fs16_to_cpu(sb, de->d_reclen);
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;
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)))
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);
154 if (version != filp->f_version)
158 filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
168 * define how far ahead to read directories while searching them.
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))
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.
183 struct ufs_dir_entry * ufs_find_entry (struct dentry *dentry,
184 struct buffer_head ** res_bh)
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;
195 UFSD(("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen))
201 if (namelen > UFS_MAXNAMLEN)
204 memset (bh_use, 0, sizeof (bh_use));
206 for (block = 0; block < NAMEI_RA_SIZE; ++block) {
207 struct buffer_head * bh;
209 if ((block << sb->s_blocksize_bits) >= dir->i_size)
211 bh = ufs_getfrag (dir, block, 0, &err);
213 if (bh && !buffer_uptodate(bh))
214 bh_read[toread++] = bh;
217 for (block = 0, offset = 0; offset < dir->i_size; block++) {
218 struct buffer_head * bh;
219 struct ufs_dir_entry * de;
222 if ((block % NAMEI_RA_BLOCKS) == 0 && toread) {
223 ll_rw_block (READ, toread, bh_read);
226 bh = bh_use[block % NAMEI_RA_SIZE];
228 ufs_error (sb, "ufs_find_entry",
229 "directory #%lu contains a hole at offset %lu",
231 offset += sb->s_blocksize;
235 if (!buffer_uptodate(bh)) {
237 * read error: all bets are off
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 */
249 if ((char *) de + namelen <= dlimit &&
250 ufs_match(sb, namelen, name, de)) {
252 just to be sure, do a full check */
253 if (!ufs_check_dir_entry("ufs_find_entry",
254 dir, de, bh, offset))
256 for (i = 0; i < NAMEI_RA_SIZE; ++i) {
263 /* prevent looping on a bad block */
264 de_len = fs16_to_cpu(sb, de->d_reclen);
268 de = (struct ufs_dir_entry *) ((char *) de + de_len);
272 if (((block + NAMEI_RA_SIZE) << sb->s_blocksize_bits ) >=
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;
283 for (i = 0; i < NAMEI_RA_SIZE; ++i) brelse (bh_use[i]);
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)
292 struct super_block *sb = dir->i_sb;
293 const char *error_msg = NULL;
294 int rlen = fs16_to_cpu(sb, de->d_reclen);
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";
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));
315 return (error_msg == NULL ? 1 : 0);
318 struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct buffer_head **p)
321 struct buffer_head *bh = ufs_bread (dir, 0, 0, &err);
322 struct ufs_dir_entry *res = NULL;
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));
332 ino_t ufs_inode_by_name(struct inode * dir, struct dentry *dentry)
335 struct ufs_dir_entry * de;
336 struct buffer_head *bh;
338 de = ufs_find_entry (dentry, &bh);
340 res = fs32_to_cpu(dir->i_sb, de->d_ino);
346 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
347 struct buffer_head *bh, struct inode *inode)
349 dir->i_version = ++event;
350 de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
351 mark_buffer_dirty(bh);
353 ll_rw_block (WRITE, 1, &bh);
362 * adds a file entry to the specified directory, using the same
363 * semantics as ufs_find_entry(). It returns NULL if it failed.
365 int ufs_add_link(struct dentry *dentry, struct inode *inode)
367 struct super_block * sb;
368 struct ufs_sb_private_info * uspi;
369 unsigned long offset;
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;
379 UFSD(("ENTER, name %s, namelen %u\n", name, namelen))
382 uspi = sb->u.ufs_sb.s_uspi;
386 bh = ufs_bread (dir, 0, 0, &err);
389 rec_len = UFS_DIR_REC_LEN(namelen);
391 de = (struct ufs_dir_entry *) bh->b_data;
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);
400 bh = ufs_bread (dir, offset >> sb->s_blocksize_bits, 1, &err);
404 if (dir->i_size <= offset) {
405 if (dir->i_size == 0) {
409 de = (struct ufs_dir_entry *) (bh->b_data + fragoff);
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);
416 de = (struct ufs_dir_entry *) bh->b_data;
419 if (!ufs_check_dir_entry ("ufs_add_entry", dir, de, bh, offset)) {
423 if (ufs_match(sb, namelen, name, de)) {
427 if (de->d_ino == 0 && fs16_to_cpu(sb, de->d_reclen) >= rec_len)
430 if (fs16_to_cpu(sb, de->d_reclen) >=
431 UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)) + rec_len)
433 offset += fs16_to_cpu(sb, de->d_reclen);
434 de = (struct ufs_dir_entry *) ((char *) de + fs16_to_cpu(sb, de->d_reclen));
438 de1 = (struct ufs_dir_entry *) ((char *) de +
439 UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
441 cpu_to_fs16(sb, fs16_to_cpu(sb, de->d_reclen) -
442 UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
444 cpu_to_fs16(sb, UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
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);
454 ll_rw_block (WRITE, 1, &bh);
458 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
459 dir->i_version = ++event;
460 mark_inode_dirty(dir);
467 * ufs_delete_entry deletes a directory entry by merging it with the
470 int ufs_delete_entry (struct inode * inode, struct ufs_dir_entry * dir,
471 struct buffer_head * bh )
474 struct super_block * sb;
475 struct ufs_dir_entry * de, * pde;
483 de = (struct ufs_dir_entry *) bh->b_data;
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))
490 while (i < bh->b_size) {
491 if (!ufs_check_dir_entry ("ufs_delete_entry", inode, de, bh, i)) {
497 fs16_add(sb, &pde->d_reclen,
498 fs16_to_cpu(sb, dir->d_reclen));
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);
512 i += fs16_to_cpu(sb, de->d_reclen);
513 if (i == UFS_SECTOR_SIZE) pde = NULL;
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)
525 int ufs_make_empty(struct inode * inode, struct inode *dir)
527 struct super_block * sb = dir->i_sb;
528 struct buffer_head * dir_block;
529 struct ufs_dir_entry * de;
532 dir_block = ufs_bread (inode, 0, 1, &err);
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);
552 mark_inode_dirty(inode);
557 * routine to check that the specified directory is empty (for rmdir)
559 int ufs_empty_dir (struct inode * inode)
561 struct super_block * sb;
562 unsigned long offset;
563 struct buffer_head * bh;
564 struct ufs_dir_entry * de, * de1;
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",
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 `..'",
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)) {
592 bh = ufs_bread (inode, offset >> sb->s_blocksize_bits, 1, &err);
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;
600 de = (struct ufs_dir_entry *) bh->b_data;
602 if (!ufs_check_dir_entry ("empty_dir", inode, de, bh, offset)) {
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));
618 struct file_operations ufs_dir_operations = {
619 read: generic_read_dir,
620 readdir: ufs_readdir,