[IRDA]: Avoid a label defined but not used warning in irda_init()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ufs / dir.c
blob154452172f433f8a44c4965065b900ba6f2f699b
1 /*
2 * linux/fs/ufs/ufs_dir.c
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
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>.
15 * Migration to usage of "page cache" on May 2006 by
16 * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
19 #include <linux/time.h>
20 #include <linux/fs.h>
21 #include <linux/ufs_fs.h>
23 #include "swab.h"
24 #include "util.h"
27 * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
29 * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
31 static inline int ufs_match(struct super_block *sb, int len,
32 const char * const name, struct ufs_dir_entry * de)
34 if (len != ufs_get_de_namlen(sb, de))
35 return 0;
36 if (!de->d_ino)
37 return 0;
38 return !memcmp(name, de->d_name, len);
41 static int ufs_commit_chunk(struct page *page, unsigned from, unsigned to)
43 struct inode *dir = page->mapping->host;
44 int err = 0;
45 dir->i_version++;
46 page->mapping->a_ops->commit_write(NULL, page, from, to);
47 if (IS_DIRSYNC(dir))
48 err = write_one_page(page, 1);
49 else
50 unlock_page(page);
51 return err;
54 static inline void ufs_put_page(struct page *page)
56 kunmap(page);
57 page_cache_release(page);
60 static inline unsigned long ufs_dir_pages(struct inode *inode)
62 return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
65 ino_t ufs_inode_by_name(struct inode *dir, struct dentry *dentry)
67 ino_t res = 0;
68 struct ufs_dir_entry *de;
69 struct page *page;
71 de = ufs_find_entry(dir, dentry, &page);
72 if (de) {
73 res = fs32_to_cpu(dir->i_sb, de->d_ino);
74 ufs_put_page(page);
76 return res;
80 /* Releases the page */
81 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
82 struct page *page, struct inode *inode)
84 unsigned from = (char *) de - (char *) page_address(page);
85 unsigned to = from + fs16_to_cpu(dir->i_sb, de->d_reclen);
86 int err;
88 lock_page(page);
89 err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
90 BUG_ON(err);
91 de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
92 ufs_set_de_type(dir->i_sb, de, inode->i_mode);
93 err = ufs_commit_chunk(page, from, to);
94 ufs_put_page(page);
95 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
96 mark_inode_dirty(dir);
100 static void ufs_check_page(struct page *page)
102 struct inode *dir = page->mapping->host;
103 struct super_block *sb = dir->i_sb;
104 char *kaddr = page_address(page);
105 unsigned offs, rec_len;
106 unsigned limit = PAGE_CACHE_SIZE;
107 const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
108 struct ufs_dir_entry *p;
109 char *error;
111 if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
112 limit = dir->i_size & ~PAGE_CACHE_MASK;
113 if (limit & chunk_mask)
114 goto Ebadsize;
115 if (!limit)
116 goto out;
118 for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
119 p = (struct ufs_dir_entry *)(kaddr + offs);
120 rec_len = fs16_to_cpu(sb, p->d_reclen);
122 if (rec_len < UFS_DIR_REC_LEN(1))
123 goto Eshort;
124 if (rec_len & 3)
125 goto Ealign;
126 if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
127 goto Enamelen;
128 if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
129 goto Espan;
130 if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
131 UFS_SB(sb)->s_uspi->s_ncg))
132 goto Einumber;
134 if (offs != limit)
135 goto Eend;
136 out:
137 SetPageChecked(page);
138 return;
140 /* Too bad, we had an error */
142 Ebadsize:
143 ufs_error(sb, "ufs_check_page",
144 "size of directory #%lu is not a multiple of chunk size",
145 dir->i_ino
147 goto fail;
148 Eshort:
149 error = "rec_len is smaller than minimal";
150 goto bad_entry;
151 Ealign:
152 error = "unaligned directory entry";
153 goto bad_entry;
154 Enamelen:
155 error = "rec_len is too small for name_len";
156 goto bad_entry;
157 Espan:
158 error = "directory entry across blocks";
159 goto bad_entry;
160 Einumber:
161 error = "inode out of bounds";
162 bad_entry:
163 ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
164 "offset=%lu, rec_len=%d, name_len=%d",
165 dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
166 rec_len, ufs_get_de_namlen(sb, p));
167 goto fail;
168 Eend:
169 p = (struct ufs_dir_entry *)(kaddr + offs);
170 ufs_error (sb, "ext2_check_page",
171 "entry in directory #%lu spans the page boundary"
172 "offset=%lu",
173 dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs);
174 fail:
175 SetPageChecked(page);
176 SetPageError(page);
179 static struct page *ufs_get_page(struct inode *dir, unsigned long n)
181 struct address_space *mapping = dir->i_mapping;
182 struct page *page = read_mapping_page(mapping, n, NULL);
183 if (!IS_ERR(page)) {
184 kmap(page);
185 if (!PageChecked(page))
186 ufs_check_page(page);
187 if (PageError(page))
188 goto fail;
190 return page;
192 fail:
193 ufs_put_page(page);
194 return ERR_PTR(-EIO);
198 * Return the offset into page `page_nr' of the last valid
199 * byte in that page, plus one.
201 static unsigned
202 ufs_last_byte(struct inode *inode, unsigned long page_nr)
204 unsigned last_byte = inode->i_size;
206 last_byte -= page_nr << PAGE_CACHE_SHIFT;
207 if (last_byte > PAGE_CACHE_SIZE)
208 last_byte = PAGE_CACHE_SIZE;
209 return last_byte;
212 static inline struct ufs_dir_entry *
213 ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
215 return (struct ufs_dir_entry *)((char *)p +
216 fs16_to_cpu(sb, p->d_reclen));
219 struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
221 struct page *page = ufs_get_page(dir, 0);
222 struct ufs_dir_entry *de = NULL;
224 if (!IS_ERR(page)) {
225 de = ufs_next_entry(dir->i_sb,
226 (struct ufs_dir_entry *)page_address(page));
227 *p = page;
229 return de;
233 * ufs_find_entry()
235 * finds an entry in the specified directory with the wanted name. It
236 * returns the page in which the entry was found, and the entry itself
237 * (as a parameter - res_dir). Page is returned mapped and unlocked.
238 * Entry is guaranteed to be valid.
240 struct ufs_dir_entry *ufs_find_entry(struct inode *dir, struct dentry *dentry,
241 struct page **res_page)
243 struct super_block *sb = dir->i_sb;
244 const char *name = dentry->d_name.name;
245 int namelen = dentry->d_name.len;
246 unsigned reclen = UFS_DIR_REC_LEN(namelen);
247 unsigned long start, n;
248 unsigned long npages = ufs_dir_pages(dir);
249 struct page *page = NULL;
250 struct ufs_inode_info *ui = UFS_I(dir);
251 struct ufs_dir_entry *de;
253 UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
255 if (npages == 0 || namelen > UFS_MAXNAMLEN)
256 goto out;
258 /* OFFSET_CACHE */
259 *res_page = NULL;
261 start = ui->i_dir_start_lookup;
263 if (start >= npages)
264 start = 0;
265 n = start;
266 do {
267 char *kaddr;
268 page = ufs_get_page(dir, n);
269 if (!IS_ERR(page)) {
270 kaddr = page_address(page);
271 de = (struct ufs_dir_entry *) kaddr;
272 kaddr += ufs_last_byte(dir, n) - reclen;
273 while ((char *) de <= kaddr) {
274 if (de->d_reclen == 0) {
275 ufs_error(dir->i_sb, __FUNCTION__,
276 "zero-length directory entry");
277 ufs_put_page(page);
278 goto out;
280 if (ufs_match(sb, namelen, name, de))
281 goto found;
282 de = ufs_next_entry(sb, de);
284 ufs_put_page(page);
286 if (++n >= npages)
287 n = 0;
288 } while (n != start);
289 out:
290 return NULL;
292 found:
293 *res_page = page;
294 ui->i_dir_start_lookup = n;
295 return de;
299 * Parent is locked.
301 int ufs_add_link(struct dentry *dentry, struct inode *inode)
303 struct inode *dir = dentry->d_parent->d_inode;
304 const char *name = dentry->d_name.name;
305 int namelen = dentry->d_name.len;
306 struct super_block *sb = dir->i_sb;
307 unsigned reclen = UFS_DIR_REC_LEN(namelen);
308 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
309 unsigned short rec_len, name_len;
310 struct page *page = NULL;
311 struct ufs_dir_entry *de;
312 unsigned long npages = ufs_dir_pages(dir);
313 unsigned long n;
314 char *kaddr;
315 unsigned from, to;
316 int err;
318 UFSD("ENTER, name %s, namelen %u\n", name, namelen);
321 * We take care of directory expansion in the same loop.
322 * This code plays outside i_size, so it locks the page
323 * to protect that region.
325 for (n = 0; n <= npages; n++) {
326 char *dir_end;
328 page = ufs_get_page(dir, n);
329 err = PTR_ERR(page);
330 if (IS_ERR(page))
331 goto out;
332 lock_page(page);
333 kaddr = page_address(page);
334 dir_end = kaddr + ufs_last_byte(dir, n);
335 de = (struct ufs_dir_entry *)kaddr;
336 kaddr += PAGE_CACHE_SIZE - reclen;
337 while ((char *)de <= kaddr) {
338 if ((char *)de == dir_end) {
339 /* We hit i_size */
340 name_len = 0;
341 rec_len = chunk_size;
342 de->d_reclen = cpu_to_fs16(sb, chunk_size);
343 de->d_ino = 0;
344 goto got_it;
346 if (de->d_reclen == 0) {
347 ufs_error(dir->i_sb, __FUNCTION__,
348 "zero-length directory entry");
349 err = -EIO;
350 goto out_unlock;
352 err = -EEXIST;
353 if (ufs_match(sb, namelen, name, de))
354 goto out_unlock;
355 name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
356 rec_len = fs16_to_cpu(sb, de->d_reclen);
357 if (!de->d_ino && rec_len >= reclen)
358 goto got_it;
359 if (rec_len >= name_len + reclen)
360 goto got_it;
361 de = (struct ufs_dir_entry *) ((char *) de + rec_len);
363 unlock_page(page);
364 ufs_put_page(page);
366 BUG();
367 return -EINVAL;
369 got_it:
370 from = (char*)de - (char*)page_address(page);
371 to = from + rec_len;
372 err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
373 if (err)
374 goto out_unlock;
375 if (de->d_ino) {
376 struct ufs_dir_entry *de1 =
377 (struct ufs_dir_entry *) ((char *) de + name_len);
378 de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
379 de->d_reclen = cpu_to_fs16(sb, name_len);
381 de = de1;
384 ufs_set_de_namlen(sb, de, namelen);
385 memcpy(de->d_name, name, namelen + 1);
386 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
387 ufs_set_de_type(sb, de, inode->i_mode);
389 err = ufs_commit_chunk(page, from, to);
390 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
392 mark_inode_dirty(dir);
393 /* OFFSET_CACHE */
394 out_put:
395 ufs_put_page(page);
396 out:
397 return err;
398 out_unlock:
399 unlock_page(page);
400 goto out_put;
403 static inline unsigned
404 ufs_validate_entry(struct super_block *sb, char *base,
405 unsigned offset, unsigned mask)
407 struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
408 struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
409 while ((char*)p < (char*)de) {
410 if (p->d_reclen == 0)
411 break;
412 p = ufs_next_entry(sb, p);
414 return (char *)p - base;
419 * This is blatantly stolen from ext2fs
421 static int
422 ufs_readdir(struct file *filp, void *dirent, filldir_t filldir)
424 loff_t pos = filp->f_pos;
425 struct inode *inode = filp->f_path.dentry->d_inode;
426 struct super_block *sb = inode->i_sb;
427 unsigned int offset = pos & ~PAGE_CACHE_MASK;
428 unsigned long n = pos >> PAGE_CACHE_SHIFT;
429 unsigned long npages = ufs_dir_pages(inode);
430 unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
431 int need_revalidate = filp->f_version != inode->i_version;
432 unsigned flags = UFS_SB(sb)->s_flags;
434 UFSD("BEGIN\n");
436 if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
437 return 0;
439 for ( ; n < npages; n++, offset = 0) {
440 char *kaddr, *limit;
441 struct ufs_dir_entry *de;
443 struct page *page = ufs_get_page(inode, n);
445 if (IS_ERR(page)) {
446 ufs_error(sb, __FUNCTION__,
447 "bad page in #%lu",
448 inode->i_ino);
449 filp->f_pos += PAGE_CACHE_SIZE - offset;
450 return -EIO;
452 kaddr = page_address(page);
453 if (unlikely(need_revalidate)) {
454 if (offset) {
455 offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
456 filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset;
458 filp->f_version = inode->i_version;
459 need_revalidate = 0;
461 de = (struct ufs_dir_entry *)(kaddr+offset);
462 limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
463 for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
464 if (de->d_reclen == 0) {
465 ufs_error(sb, __FUNCTION__,
466 "zero-length directory entry");
467 ufs_put_page(page);
468 return -EIO;
470 if (de->d_ino) {
471 int over;
472 unsigned char d_type = DT_UNKNOWN;
474 offset = (char *)de - kaddr;
476 UFSD("filldir(%s,%u)\n", de->d_name,
477 fs32_to_cpu(sb, de->d_ino));
478 UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
480 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
481 d_type = de->d_u.d_44.d_type;
483 over = filldir(dirent, de->d_name,
484 ufs_get_de_namlen(sb, de),
485 (n<<PAGE_CACHE_SHIFT) | offset,
486 fs32_to_cpu(sb, de->d_ino), d_type);
487 if (over) {
488 ufs_put_page(page);
489 return 0;
492 filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
494 ufs_put_page(page);
496 return 0;
501 * ufs_delete_entry deletes a directory entry by merging it with the
502 * previous entry.
504 int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
505 struct page * page)
507 struct super_block *sb = inode->i_sb;
508 struct address_space *mapping = page->mapping;
509 char *kaddr = page_address(page);
510 unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
511 unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
512 struct ufs_dir_entry *pde = NULL;
513 struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
514 int err;
516 UFSD("ENTER\n");
518 UFSD("ino %u, reclen %u, namlen %u, name %s\n",
519 fs32_to_cpu(sb, de->d_ino),
520 fs16_to_cpu(sb, de->d_reclen),
521 ufs_get_de_namlen(sb, de), de->d_name);
523 while ((char*)de < (char*)dir) {
524 if (de->d_reclen == 0) {
525 ufs_error(inode->i_sb, __FUNCTION__,
526 "zero-length directory entry");
527 err = -EIO;
528 goto out;
530 pde = de;
531 de = ufs_next_entry(sb, de);
533 if (pde)
534 from = (char*)pde - (char*)page_address(page);
535 lock_page(page);
536 err = mapping->a_ops->prepare_write(NULL, page, from, to);
537 BUG_ON(err);
538 if (pde)
539 pde->d_reclen = cpu_to_fs16(sb, to-from);
540 dir->d_ino = 0;
541 err = ufs_commit_chunk(page, from, to);
542 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
543 mark_inode_dirty(inode);
544 out:
545 ufs_put_page(page);
546 UFSD("EXIT\n");
547 return err;
550 int ufs_make_empty(struct inode * inode, struct inode *dir)
552 struct super_block * sb = dir->i_sb;
553 struct address_space *mapping = inode->i_mapping;
554 struct page *page = grab_cache_page(mapping, 0);
555 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
556 struct ufs_dir_entry * de;
557 char *base;
558 int err;
560 if (!page)
561 return -ENOMEM;
562 kmap(page);
563 err = mapping->a_ops->prepare_write(NULL, page, 0, chunk_size);
564 if (err) {
565 unlock_page(page);
566 goto fail;
570 base = (char*)page_address(page);
571 memset(base, 0, PAGE_CACHE_SIZE);
573 de = (struct ufs_dir_entry *) base;
575 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
576 ufs_set_de_type(sb, de, inode->i_mode);
577 ufs_set_de_namlen(sb, de, 1);
578 de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
579 strcpy (de->d_name, ".");
580 de = (struct ufs_dir_entry *)
581 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
582 de->d_ino = cpu_to_fs32(sb, dir->i_ino);
583 ufs_set_de_type(sb, de, dir->i_mode);
584 de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
585 ufs_set_de_namlen(sb, de, 2);
586 strcpy (de->d_name, "..");
588 err = ufs_commit_chunk(page, 0, chunk_size);
589 fail:
590 kunmap(page);
591 page_cache_release(page);
592 return err;
596 * routine to check that the specified directory is empty (for rmdir)
598 int ufs_empty_dir(struct inode * inode)
600 struct super_block *sb = inode->i_sb;
601 struct page *page = NULL;
602 unsigned long i, npages = ufs_dir_pages(inode);
604 for (i = 0; i < npages; i++) {
605 char *kaddr;
606 struct ufs_dir_entry *de;
607 page = ufs_get_page(inode, i);
609 if (IS_ERR(page))
610 continue;
612 kaddr = page_address(page);
613 de = (struct ufs_dir_entry *)kaddr;
614 kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
616 while ((char *)de <= kaddr) {
617 if (de->d_reclen == 0) {
618 ufs_error(inode->i_sb, __FUNCTION__,
619 "zero-length directory entry: "
620 "kaddr=%p, de=%p\n", kaddr, de);
621 goto not_empty;
623 if (de->d_ino) {
624 u16 namelen=ufs_get_de_namlen(sb, de);
625 /* check for . and .. */
626 if (de->d_name[0] != '.')
627 goto not_empty;
628 if (namelen > 2)
629 goto not_empty;
630 if (namelen < 2) {
631 if (inode->i_ino !=
632 fs32_to_cpu(sb, de->d_ino))
633 goto not_empty;
634 } else if (de->d_name[1] != '.')
635 goto not_empty;
637 de = ufs_next_entry(sb, de);
639 ufs_put_page(page);
641 return 1;
643 not_empty:
644 ufs_put_page(page);
645 return 0;
648 const struct file_operations ufs_dir_operations = {
649 .read = generic_read_dir,
650 .readdir = ufs_readdir,
651 .fsync = file_fsync,