2 * linux/fs/ufs/ufs_dir.c
6 * Laboratory for Computer Science Research Computing Facility
7 * Rutgers, The State University of New Jersey
11 * 4.4BSD (FreeBSD) support added on February 1st 1998 by
15 * Migration to usage of "page cache" on May 2006 by
19 #include <linux/time.h>
21 #include <linux/swap.h>
29 * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
31 * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
33 static inline int ufs_match(struct super_block *sb, int len,
34 const unsigned char *name, struct ufs_dir_entry *de)
36 if (len != ufs_get_de_namlen(sb, de))
40 return !memcmp(name, de->d_name, len);
43 static int ufs_commit_chunk(struct page *page, loff_t pos, unsigned len)
45 struct address_space *mapping = page->mapping;
46 struct inode *dir = mapping->host;
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);
56 err = write_one_page(page, 1);
62 static inline void ufs_put_page(struct page *page)
65 page_cache_release(page);
68 ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
71 struct ufs_dir_entry *de;
74 de = ufs_find_entry(dir, qstr, &page);
76 res = fs32_to_cpu(dir->i_sb, de->d_ino);
83 /* Releases the page */
84 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
85 struct page *page, struct inode *inode,
88 loff_t pos = page_offset(page) +
89 (char *) de - (char *) page_address(page);
90 unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
94 err = ufs_prepare_chunk(page, pos, len);
97 de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
98 ufs_set_de_type(dir->i_sb, de, inode->i_mode);
100 err = ufs_commit_chunk(page, pos, len);
103 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
104 mark_inode_dirty(dir);
108 static void ufs_check_page(struct page *page)
110 struct inode *dir = page->mapping->host;
111 struct super_block *sb = dir->i_sb;
112 char *kaddr = page_address(page);
113 unsigned offs, rec_len;
114 unsigned limit = PAGE_CACHE_SIZE;
115 const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
116 struct ufs_dir_entry *p;
119 if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
120 limit = dir->i_size & ~PAGE_CACHE_MASK;
121 if (limit & chunk_mask)
126 for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
127 p = (struct ufs_dir_entry *)(kaddr + offs);
128 rec_len = fs16_to_cpu(sb, p->d_reclen);
130 if (rec_len < UFS_DIR_REC_LEN(1))
134 if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
136 if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
138 if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
139 UFS_SB(sb)->s_uspi->s_ncg))
145 SetPageChecked(page);
148 /* Too bad, we had an error */
151 ufs_error(sb, "ufs_check_page",
152 "size of directory #%lu is not a multiple of chunk size",
157 error = "rec_len is smaller than minimal";
160 error = "unaligned directory entry";
163 error = "rec_len is too small for name_len";
166 error = "directory entry across blocks";
169 error = "inode out of bounds";
171 ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
172 "offset=%lu, rec_len=%d, name_len=%d",
173 dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
174 rec_len, ufs_get_de_namlen(sb, p));
177 p = (struct ufs_dir_entry *)(kaddr + offs);
178 ufs_error(sb, __func__,
179 "entry in directory #%lu spans the page boundary"
181 dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs);
183 SetPageChecked(page);
187 static struct page *ufs_get_page(struct inode *dir, unsigned long n)
189 struct address_space *mapping = dir->i_mapping;
190 struct page *page = read_mapping_page(mapping, n, NULL);
193 if (!PageChecked(page))
194 ufs_check_page(page);
202 return ERR_PTR(-EIO);
206 * Return the offset into page `page_nr' of the last valid
207 * byte in that page, plus one.
210 ufs_last_byte(struct inode *inode, unsigned long page_nr)
212 unsigned last_byte = inode->i_size;
214 last_byte -= page_nr << PAGE_CACHE_SHIFT;
215 if (last_byte > PAGE_CACHE_SIZE)
216 last_byte = PAGE_CACHE_SIZE;
220 static inline struct ufs_dir_entry *
221 ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
223 return (struct ufs_dir_entry *)((char *)p +
224 fs16_to_cpu(sb, p->d_reclen));
227 struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
229 struct page *page = ufs_get_page(dir, 0);
230 struct ufs_dir_entry *de = NULL;
233 de = ufs_next_entry(dir->i_sb,
234 (struct ufs_dir_entry *)page_address(page));
243 * finds an entry in the specified directory with the wanted name. It
244 * returns the page in which the entry was found, and the entry itself
245 * (as a parameter - res_dir). Page is returned mapped and unlocked.
246 * Entry is guaranteed to be valid.
248 struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr,
249 struct page **res_page)
251 struct super_block *sb = dir->i_sb;
252 const unsigned char *name = qstr->name;
253 int namelen = qstr->len;
254 unsigned reclen = UFS_DIR_REC_LEN(namelen);
255 unsigned long start, n;
256 unsigned long npages = dir_pages(dir);
257 struct page *page = NULL;
258 struct ufs_inode_info *ui = UFS_I(dir);
259 struct ufs_dir_entry *de;
261 UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
263 if (npages == 0 || namelen > UFS_MAXNAMLEN)
269 start = ui->i_dir_start_lookup;
276 page = ufs_get_page(dir, n);
278 kaddr = page_address(page);
279 de = (struct ufs_dir_entry *) kaddr;
280 kaddr += ufs_last_byte(dir, n) - reclen;
281 while ((char *) de <= kaddr) {
282 if (de->d_reclen == 0) {
283 ufs_error(dir->i_sb, __func__,
284 "zero-length directory entry");
288 if (ufs_match(sb, namelen, name, de))
290 de = ufs_next_entry(sb, de);
296 } while (n != start);
302 ui->i_dir_start_lookup = n;
309 int ufs_add_link(struct dentry *dentry, struct inode *inode)
311 struct inode *dir = d_inode(dentry->d_parent);
312 const unsigned char *name = dentry->d_name.name;
313 int namelen = dentry->d_name.len;
314 struct super_block *sb = dir->i_sb;
315 unsigned reclen = UFS_DIR_REC_LEN(namelen);
316 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
317 unsigned short rec_len, name_len;
318 struct page *page = NULL;
319 struct ufs_dir_entry *de;
320 unsigned long npages = dir_pages(dir);
326 UFSD("ENTER, name %s, namelen %u\n", name, namelen);
329 * We take care of directory expansion in the same loop.
330 * This code plays outside i_size, so it locks the page
331 * to protect that region.
333 for (n = 0; n <= npages; n++) {
336 page = ufs_get_page(dir, n);
341 kaddr = page_address(page);
342 dir_end = kaddr + ufs_last_byte(dir, n);
343 de = (struct ufs_dir_entry *)kaddr;
344 kaddr += PAGE_CACHE_SIZE - reclen;
345 while ((char *)de <= kaddr) {
346 if ((char *)de == dir_end) {
349 rec_len = chunk_size;
350 de->d_reclen = cpu_to_fs16(sb, chunk_size);
354 if (de->d_reclen == 0) {
355 ufs_error(dir->i_sb, __func__,
356 "zero-length directory entry");
361 if (ufs_match(sb, namelen, name, de))
363 name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
364 rec_len = fs16_to_cpu(sb, de->d_reclen);
365 if (!de->d_ino && rec_len >= reclen)
367 if (rec_len >= name_len + reclen)
369 de = (struct ufs_dir_entry *) ((char *) de + rec_len);
378 pos = page_offset(page) +
379 (char*)de - (char*)page_address(page);
380 err = ufs_prepare_chunk(page, pos, rec_len);
384 struct ufs_dir_entry *de1 =
385 (struct ufs_dir_entry *) ((char *) de + name_len);
386 de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
387 de->d_reclen = cpu_to_fs16(sb, name_len);
392 ufs_set_de_namlen(sb, de, namelen);
393 memcpy(de->d_name, name, namelen + 1);
394 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
395 ufs_set_de_type(sb, de, inode->i_mode);
397 err = ufs_commit_chunk(page, pos, rec_len);
398 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
400 mark_inode_dirty(dir);
411 static inline unsigned
412 ufs_validate_entry(struct super_block *sb, char *base,
413 unsigned offset, unsigned mask)
415 struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
416 struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
417 while ((char*)p < (char*)de) {
418 if (p->d_reclen == 0)
420 p = ufs_next_entry(sb, p);
422 return (char *)p - base;
427 * This is blatantly stolen from ext2fs
430 ufs_readdir(struct file *file, struct dir_context *ctx)
432 loff_t pos = ctx->pos;
433 struct inode *inode = file_inode(file);
434 struct super_block *sb = inode->i_sb;
435 unsigned int offset = pos & ~PAGE_CACHE_MASK;
436 unsigned long n = pos >> PAGE_CACHE_SHIFT;
437 unsigned long npages = dir_pages(inode);
438 unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
439 int need_revalidate = file->f_version != inode->i_version;
440 unsigned flags = UFS_SB(sb)->s_flags;
444 if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
447 for ( ; n < npages; n++, offset = 0) {
449 struct ufs_dir_entry *de;
451 struct page *page = ufs_get_page(inode, n);
454 ufs_error(sb, __func__,
457 ctx->pos += PAGE_CACHE_SIZE - offset;
460 kaddr = page_address(page);
461 if (unlikely(need_revalidate)) {
463 offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
464 ctx->pos = (n<<PAGE_CACHE_SHIFT) + offset;
466 file->f_version = inode->i_version;
469 de = (struct ufs_dir_entry *)(kaddr+offset);
470 limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
471 for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
472 if (de->d_reclen == 0) {
473 ufs_error(sb, __func__,
474 "zero-length directory entry");
479 unsigned char d_type = DT_UNKNOWN;
481 UFSD("filldir(%s,%u)\n", de->d_name,
482 fs32_to_cpu(sb, de->d_ino));
483 UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
485 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
486 d_type = de->d_u.d_44.d_type;
488 if (!dir_emit(ctx, de->d_name,
489 ufs_get_de_namlen(sb, de),
490 fs32_to_cpu(sb, de->d_ino),
496 ctx->pos += fs16_to_cpu(sb, de->d_reclen);
505 * ufs_delete_entry deletes a directory entry by merging it with the
508 int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
511 struct super_block *sb = inode->i_sb;
512 char *kaddr = page_address(page);
513 unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
514 unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
516 struct ufs_dir_entry *pde = NULL;
517 struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
522 UFSD("ino %u, reclen %u, namlen %u, name %s\n",
523 fs32_to_cpu(sb, de->d_ino),
524 fs16_to_cpu(sb, de->d_reclen),
525 ufs_get_de_namlen(sb, de), de->d_name);
527 while ((char*)de < (char*)dir) {
528 if (de->d_reclen == 0) {
529 ufs_error(inode->i_sb, __func__,
530 "zero-length directory entry");
535 de = ufs_next_entry(sb, de);
538 from = (char*)pde - (char*)page_address(page);
540 pos = page_offset(page) + from;
542 err = ufs_prepare_chunk(page, pos, to - from);
545 pde->d_reclen = cpu_to_fs16(sb, to - from);
547 err = ufs_commit_chunk(page, pos, to - from);
548 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
549 mark_inode_dirty(inode);
556 int ufs_make_empty(struct inode * inode, struct inode *dir)
558 struct super_block * sb = dir->i_sb;
559 struct address_space *mapping = inode->i_mapping;
560 struct page *page = grab_cache_page(mapping, 0);
561 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
562 struct ufs_dir_entry * de;
569 err = ufs_prepare_chunk(page, 0, chunk_size);
576 base = (char*)page_address(page);
577 memset(base, 0, PAGE_CACHE_SIZE);
579 de = (struct ufs_dir_entry *) base;
581 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
582 ufs_set_de_type(sb, de, inode->i_mode);
583 ufs_set_de_namlen(sb, de, 1);
584 de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
585 strcpy (de->d_name, ".");
586 de = (struct ufs_dir_entry *)
587 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
588 de->d_ino = cpu_to_fs32(sb, dir->i_ino);
589 ufs_set_de_type(sb, de, dir->i_mode);
590 de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
591 ufs_set_de_namlen(sb, de, 2);
592 strcpy (de->d_name, "..");
595 err = ufs_commit_chunk(page, 0, chunk_size);
597 page_cache_release(page);
602 * routine to check that the specified directory is empty (for rmdir)
604 int ufs_empty_dir(struct inode * inode)
606 struct super_block *sb = inode->i_sb;
607 struct page *page = NULL;
608 unsigned long i, npages = dir_pages(inode);
610 for (i = 0; i < npages; i++) {
612 struct ufs_dir_entry *de;
613 page = ufs_get_page(inode, i);
618 kaddr = page_address(page);
619 de = (struct ufs_dir_entry *)kaddr;
620 kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
622 while ((char *)de <= kaddr) {
623 if (de->d_reclen == 0) {
624 ufs_error(inode->i_sb, __func__,
625 "zero-length directory entry: "
626 "kaddr=%p, de=%p\n", kaddr, de);
630 u16 namelen=ufs_get_de_namlen(sb, de);
631 /* check for . and .. */
632 if (de->d_name[0] != '.')
638 fs32_to_cpu(sb, de->d_ino))
640 } else if (de->d_name[1] != '.')
643 de = ufs_next_entry(sb, de);
654 const struct file_operations ufs_dir_operations = {
655 .read = generic_read_dir,
656 .iterate = ufs_readdir,
657 .fsync = generic_file_fsync,
658 .llseek = generic_file_llseek,