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/time.h>
18 #include <linux/ufs_fs.h>
19 #include <linux/smp_lock.h>
20 #include <linux/buffer_head.h>
21 #include <linux/sched.h>
29 #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
37 * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
39 * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
41 static inline int ufs_match(struct super_block *sb, int len,
42 const char * const name, struct ufs_dir_entry * de)
44 if (len != ufs_get_de_namlen(sb, de))
48 return !memcmp(name, de->d_name, len);
52 * This is blatantly stolen from ext2fs
55 ufs_readdir (struct file * filp, void * dirent, filldir_t filldir)
57 struct inode *inode = filp->f_dentry->d_inode;
59 unsigned long offset, lblk;
61 struct buffer_head * bh;
62 struct ufs_dir_entry * de;
63 struct super_block * sb;
71 flags = UFS_SB(sb)->s_flags;
73 UFSD(("ENTER, ino %lu f_pos %lu\n", inode->i_ino, (unsigned long) filp->f_pos))
77 offset = filp->f_pos & (sb->s_blocksize - 1);
79 while (!error && !stored && filp->f_pos < inode->i_size) {
80 lblk = (filp->f_pos) >> sb->s_blocksize_bits;
81 blk = ufs_frag_map(inode, lblk);
82 if (!blk || !(bh = sb_bread(sb, blk))) {
83 /* XXX - error - skip to the next block */
84 printk("ufs_readdir: "
85 "dir inode %lu has a hole at offset %lu\n",
86 inode->i_ino, (unsigned long int)filp->f_pos);
87 filp->f_pos += sb->s_blocksize - offset;
92 /* If the dir block has changed since the last call to
93 * readdir(2), then we might be pointing to an invalid
94 * dirent right now. Scan from the start of the block
96 if (filp->f_version != inode->i_version) {
97 for (i = 0; i < sb->s_blocksize && i < offset; ) {
98 de = (struct ufs_dir_entry *)(bh->b_data + i);
99 /* It's too expensive to do a full
100 * dirent test each time round this
101 * loop, but we do have to test at
102 * least that it is non-zero. A
103 * failure will be detected in the
104 * dirent test below. */
105 de_reclen = fs16_to_cpu(sb, de->d_reclen);
111 filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
113 filp->f_version = inode->i_version;
116 while (!error && filp->f_pos < inode->i_size
117 && offset < sb->s_blocksize) {
118 de = (struct ufs_dir_entry *) (bh->b_data + offset);
119 /* XXX - put in a real ufs_check_dir_entry() */
120 if ((de->d_reclen == 0) || (ufs_get_de_namlen(sb, de) == 0)) {
121 filp->f_pos = (filp->f_pos &
122 (sb->s_blocksize - 1)) +
128 if (!ufs_check_dir_entry ("ufs_readdir", inode, de,
130 /* On error, skip the f_pos to the
132 filp->f_pos = (filp->f_pos |
133 (sb->s_blocksize - 1)) +
139 offset += fs16_to_cpu(sb, de->d_reclen);
141 /* We might block in the next section
142 * if the data destination is
143 * currently swapped out. So, use a
144 * version stamp to detect whether or
145 * not the directory has been modified
146 * during the copy operation. */
147 unsigned long version = filp->f_version;
148 unsigned char d_type = DT_UNKNOWN;
150 UFSD(("filldir(%s,%u)\n", de->d_name,
151 fs32_to_cpu(sb, de->d_ino)))
152 UFSD(("namlen %u\n", ufs_get_de_namlen(sb, de)))
154 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
155 d_type = de->d_u.d_44.d_type;
156 error = filldir(dirent, de->d_name,
157 ufs_get_de_namlen(sb, de), filp->f_pos,
158 fs32_to_cpu(sb, de->d_ino), d_type);
161 if (version != filp->f_version)
165 filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
175 * define how far ahead to read directories while searching them.
177 #define NAMEI_RA_CHUNKS 2
178 #define NAMEI_RA_BLOCKS 4
179 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
180 #define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
185 * finds an entry in the specified directory with the wanted name. It
186 * returns the cache buffer in which the entry was found, and the entry
187 * itself (as a parameter - res_bh). It does NOT read the inode of the
188 * entry - you'll have to do that yourself if you want to.
190 struct ufs_dir_entry * ufs_find_entry (struct dentry *dentry,
191 struct buffer_head ** res_bh)
193 struct super_block * sb;
194 struct buffer_head * bh_use[NAMEI_RA_SIZE];
195 struct buffer_head * bh_read[NAMEI_RA_SIZE];
196 unsigned long offset;
197 int block, toread, i, err;
198 struct inode *dir = dentry->d_parent->d_inode;
199 const char *name = dentry->d_name.name;
200 int namelen = dentry->d_name.len;
202 UFSD(("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen))
208 if (namelen > UFS_MAXNAMLEN)
211 memset (bh_use, 0, sizeof (bh_use));
213 for (block = 0; block < NAMEI_RA_SIZE; ++block) {
214 struct buffer_head * bh;
216 if ((block << sb->s_blocksize_bits) >= dir->i_size)
218 bh = ufs_getfrag (dir, block, 0, &err);
220 if (bh && !buffer_uptodate(bh))
221 bh_read[toread++] = bh;
224 for (block = 0, offset = 0; offset < dir->i_size; block++) {
225 struct buffer_head * bh;
226 struct ufs_dir_entry * de;
229 if ((block % NAMEI_RA_BLOCKS) == 0 && toread) {
230 ll_rw_block (READ, toread, bh_read);
233 bh = bh_use[block % NAMEI_RA_SIZE];
235 ufs_error (sb, "ufs_find_entry",
236 "directory #%lu contains a hole at offset %lu",
238 offset += sb->s_blocksize;
242 if (!buffer_uptodate(bh)) {
244 * read error: all bets are off
249 de = (struct ufs_dir_entry *) bh->b_data;
250 dlimit = bh->b_data + sb->s_blocksize;
251 while ((char *) de < dlimit && offset < dir->i_size) {
252 /* this code is executed quadratically often */
253 /* do minimal checking by hand */
256 if ((char *) de + namelen <= dlimit &&
257 ufs_match(sb, namelen, name, de)) {
259 just to be sure, do a full check */
260 if (!ufs_check_dir_entry("ufs_find_entry",
261 dir, de, bh, offset))
263 for (i = 0; i < NAMEI_RA_SIZE; ++i) {
270 /* prevent looping on a bad block */
271 de_len = fs16_to_cpu(sb, de->d_reclen);
275 de = (struct ufs_dir_entry *) ((char *) de + de_len);
279 if (((block + NAMEI_RA_SIZE) << sb->s_blocksize_bits ) >=
283 bh = ufs_getfrag (dir, block + NAMEI_RA_SIZE, 0, &err);
284 bh_use[block % NAMEI_RA_SIZE] = bh;
285 if (bh && !buffer_uptodate(bh))
286 bh_read[toread++] = bh;
290 for (i = 0; i < NAMEI_RA_SIZE; ++i) brelse (bh_use[i]);
295 int ufs_check_dir_entry (const char * function, struct inode * dir,
296 struct ufs_dir_entry * de, struct buffer_head * bh,
297 unsigned long offset)
299 struct super_block *sb = dir->i_sb;
300 const char *error_msg = NULL;
301 int rlen = fs16_to_cpu(sb, de->d_reclen);
303 if (rlen < UFS_DIR_REC_LEN(1))
304 error_msg = "reclen is smaller than minimal";
305 else if (rlen % 4 != 0)
306 error_msg = "reclen % 4 != 0";
307 else if (rlen < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)))
308 error_msg = "reclen is too small for namlen";
309 else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
310 error_msg = "directory entry across blocks";
311 else if (fs32_to_cpu(sb, de->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
312 UFS_SB(sb)->s_uspi->s_ncg))
313 error_msg = "inode out of bounds";
315 if (error_msg != NULL)
316 ufs_error (sb, function, "bad entry in directory #%lu, size %Lu: %s - "
317 "offset=%lu, inode=%lu, reclen=%d, namlen=%d",
318 dir->i_ino, dir->i_size, error_msg, offset,
319 (unsigned long)fs32_to_cpu(sb, de->d_ino),
320 rlen, ufs_get_de_namlen(sb, de));
322 return (error_msg == NULL ? 1 : 0);
325 struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct buffer_head **p)
328 struct buffer_head *bh = ufs_bread (dir, 0, 0, &err);
329 struct ufs_dir_entry *res = NULL;
332 res = (struct ufs_dir_entry *) bh->b_data;
333 res = (struct ufs_dir_entry *)((char *)res +
334 fs16_to_cpu(dir->i_sb, res->d_reclen));
339 ino_t ufs_inode_by_name(struct inode * dir, struct dentry *dentry)
342 struct ufs_dir_entry * de;
343 struct buffer_head *bh;
345 de = ufs_find_entry (dentry, &bh);
347 res = fs32_to_cpu(dir->i_sb, de->d_ino);
353 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
354 struct buffer_head *bh, struct inode *inode)
357 de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
358 mark_buffer_dirty(bh);
360 sync_dirty_buffer(bh);
367 * adds a file entry to the specified directory, using the same
368 * semantics as ufs_find_entry(). It returns NULL if it failed.
370 int ufs_add_link(struct dentry *dentry, struct inode *inode)
372 struct super_block * sb;
373 struct ufs_sb_private_info * uspi;
374 unsigned long offset;
376 unsigned short rec_len;
377 struct buffer_head * bh;
378 struct ufs_dir_entry * de, * de1;
379 struct inode *dir = dentry->d_parent->d_inode;
380 const char *name = dentry->d_name.name;
381 int namelen = dentry->d_name.len;
384 UFSD(("ENTER, name %s, namelen %u\n", name, namelen))
387 uspi = UFS_SB(sb)->s_uspi;
391 bh = ufs_bread (dir, 0, 0, &err);
394 rec_len = UFS_DIR_REC_LEN(namelen);
396 de = (struct ufs_dir_entry *) bh->b_data;
398 if ((char *)de >= UFS_SECTOR_SIZE + bh->b_data) {
399 fragoff = offset & ~uspi->s_fmask;
400 if (fragoff != 0 && fragoff != UFS_SECTOR_SIZE)
401 ufs_error (sb, "ufs_add_entry", "internal error"
402 " fragoff %u", fragoff);
405 bh = ufs_bread (dir, offset >> sb->s_blocksize_bits, 1, &err);
409 if (dir->i_size <= offset) {
410 if (dir->i_size == 0) {
414 de = (struct ufs_dir_entry *) (bh->b_data + fragoff);
416 de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE);
417 ufs_set_de_namlen(sb, de, 0);
418 dir->i_size = offset + UFS_SECTOR_SIZE;
419 mark_inode_dirty(dir);
421 de = (struct ufs_dir_entry *) bh->b_data;
424 if (!ufs_check_dir_entry ("ufs_add_entry", dir, de, bh, offset)) {
428 if (ufs_match(sb, namelen, name, de)) {
432 if (de->d_ino == 0 && fs16_to_cpu(sb, de->d_reclen) >= rec_len)
435 if (fs16_to_cpu(sb, de->d_reclen) >=
436 UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)) + rec_len)
438 offset += fs16_to_cpu(sb, de->d_reclen);
439 de = (struct ufs_dir_entry *) ((char *) de + fs16_to_cpu(sb, de->d_reclen));
443 de1 = (struct ufs_dir_entry *) ((char *) de +
444 UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
446 cpu_to_fs16(sb, fs16_to_cpu(sb, de->d_reclen) -
447 UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
449 cpu_to_fs16(sb, UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
453 ufs_set_de_namlen(sb, de, namelen);
454 memcpy (de->d_name, name, namelen + 1);
455 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
456 ufs_set_de_type(sb, de, inode->i_mode);
457 mark_buffer_dirty(bh);
459 sync_dirty_buffer(bh);
461 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
463 mark_inode_dirty(dir);
470 * ufs_delete_entry deletes a directory entry by merging it with the
473 int ufs_delete_entry (struct inode * inode, struct ufs_dir_entry * dir,
474 struct buffer_head * bh )
477 struct super_block * sb;
478 struct ufs_dir_entry * de, * pde;
486 de = (struct ufs_dir_entry *) bh->b_data;
488 UFSD(("ino %u, reclen %u, namlen %u, name %s\n",
489 fs32_to_cpu(sb, de->d_ino),
490 fs16to_cpu(sb, de->d_reclen),
491 ufs_get_de_namlen(sb, de), de->d_name))
493 while (i < bh->b_size) {
494 if (!ufs_check_dir_entry ("ufs_delete_entry", inode, de, bh, i)) {
500 fs16_add(sb, &pde->d_reclen,
501 fs16_to_cpu(sb, dir->d_reclen));
504 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
505 mark_inode_dirty(inode);
506 mark_buffer_dirty(bh);
507 if (IS_DIRSYNC(inode))
508 sync_dirty_buffer(bh);
513 i += fs16_to_cpu(sb, de->d_reclen);
514 if (i == UFS_SECTOR_SIZE) pde = NULL;
516 de = (struct ufs_dir_entry *)
517 ((char *) de + fs16_to_cpu(sb, de->d_reclen));
518 if (i == UFS_SECTOR_SIZE && de->d_reclen == 0)
526 int ufs_make_empty(struct inode * inode, struct inode *dir)
528 struct super_block * sb = dir->i_sb;
529 struct buffer_head * dir_block;
530 struct ufs_dir_entry * de;
533 dir_block = ufs_bread (inode, 0, 1, &err);
537 inode->i_blocks = sb->s_blocksize / UFS_SECTOR_SIZE;
538 de = (struct ufs_dir_entry *) dir_block->b_data;
539 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
540 ufs_set_de_type(sb, de, inode->i_mode);
541 ufs_set_de_namlen(sb, de, 1);
542 de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
543 strcpy (de->d_name, ".");
544 de = (struct ufs_dir_entry *)
545 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
546 de->d_ino = cpu_to_fs32(sb, dir->i_ino);
547 ufs_set_de_type(sb, de, dir->i_mode);
548 de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE - UFS_DIR_REC_LEN(1));
549 ufs_set_de_namlen(sb, de, 2);
550 strcpy (de->d_name, "..");
551 mark_buffer_dirty(dir_block);
553 mark_inode_dirty(inode);
558 * routine to check that the specified directory is empty (for rmdir)
560 int ufs_empty_dir (struct inode * inode)
562 struct super_block * sb;
563 unsigned long offset;
564 struct buffer_head * bh;
565 struct ufs_dir_entry * de, * de1;
570 if (inode->i_size < UFS_DIR_REC_LEN(1) + UFS_DIR_REC_LEN(2) ||
571 !(bh = ufs_bread (inode, 0, 0, &err))) {
572 ufs_warning (inode->i_sb, "empty_dir",
573 "bad directory (dir #%lu) - no data block",
577 de = (struct ufs_dir_entry *) bh->b_data;
578 de1 = (struct ufs_dir_entry *)
579 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
580 if (fs32_to_cpu(sb, de->d_ino) != inode->i_ino || de1->d_ino == 0 ||
581 strcmp (".", de->d_name) || strcmp ("..", de1->d_name)) {
582 ufs_warning (inode->i_sb, "empty_dir",
583 "bad directory (dir #%lu) - no `.' or `..'",
587 offset = fs16_to_cpu(sb, de->d_reclen) + fs16_to_cpu(sb, de1->d_reclen);
588 de = (struct ufs_dir_entry *)
589 ((char *)de1 + fs16_to_cpu(sb, de1->d_reclen));
590 while (offset < inode->i_size ) {
591 if (!bh || (void *) de >= (void *) (bh->b_data + sb->s_blocksize)) {
593 bh = ufs_bread (inode, offset >> sb->s_blocksize_bits, 1, &err);
595 ufs_error (sb, "empty_dir",
596 "directory #%lu contains a hole at offset %lu",
597 inode->i_ino, offset);
598 offset += sb->s_blocksize;
601 de = (struct ufs_dir_entry *) bh->b_data;
603 if (!ufs_check_dir_entry ("empty_dir", inode, de, bh, offset)) {
611 offset += fs16_to_cpu(sb, de->d_reclen);
612 de = (struct ufs_dir_entry *)
613 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
619 struct file_operations ufs_dir_operations = {
620 .read = generic_read_dir,
621 .readdir = ufs_readdir,