1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19#include <linux/time.h>
20#include <linux/fs.h>
21#include <linux/swap.h>
22
23#include "ufs_fs.h"
24#include "ufs.h"
25#include "swab.h"
26#include "util.h"
27
28
29
30
31
32
33static inline int ufs_match(struct super_block *sb, int len,
34 const unsigned char *name, struct ufs_dir_entry *de)
35{
36 if (len != ufs_get_de_namlen(sb, de))
37 return 0;
38 if (!de->d_ino)
39 return 0;
40 return !memcmp(name, de->d_name, len);
41}
42
43static int ufs_commit_chunk(struct page *page, loff_t pos, unsigned len)
44{
45 struct address_space *mapping = page->mapping;
46 struct inode *dir = mapping->host;
47 int err = 0;
48
49 dir->i_version++;
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);
54 }
55 if (IS_DIRSYNC(dir))
56 err = write_one_page(page, 1);
57 else
58 unlock_page(page);
59 return err;
60}
61
62static inline void ufs_put_page(struct page *page)
63{
64 kunmap(page);
65 put_page(page);
66}
67
68ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
69{
70 ino_t res = 0;
71 struct ufs_dir_entry *de;
72 struct page *page;
73
74 de = ufs_find_entry(dir, qstr, &page);
75 if (de) {
76 res = fs32_to_cpu(dir->i_sb, de->d_ino);
77 ufs_put_page(page);
78 }
79 return res;
80}
81
82
83
84void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
85 struct page *page, struct inode *inode,
86 bool update_times)
87{
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);
91 int err;
92
93 lock_page(page);
94 err = ufs_prepare_chunk(page, pos, len);
95 BUG_ON(err);
96
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);
99
100 err = ufs_commit_chunk(page, pos, len);
101 ufs_put_page(page);
102 if (update_times)
103 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
104 mark_inode_dirty(dir);
105}
106
107
108static void ufs_check_page(struct page *page)
109{
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_SIZE;
115 const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
116 struct ufs_dir_entry *p;
117 char *error;
118
119 if ((dir->i_size >> PAGE_SHIFT) == page->index) {
120 limit = dir->i_size & ~PAGE_MASK;
121 if (limit & chunk_mask)
122 goto Ebadsize;
123 if (!limit)
124 goto out;
125 }
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);
129
130 if (rec_len < UFS_DIR_REC_LEN(1))
131 goto Eshort;
132 if (rec_len & 3)
133 goto Ealign;
134 if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
135 goto Enamelen;
136 if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
137 goto Espan;
138 if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
139 UFS_SB(sb)->s_uspi->s_ncg))
140 goto Einumber;
141 }
142 if (offs != limit)
143 goto Eend;
144out:
145 SetPageChecked(page);
146 return;
147
148
149
150Ebadsize:
151 ufs_error(sb, "ufs_check_page",
152 "size of directory #%lu is not a multiple of chunk size",
153 dir->i_ino
154 );
155 goto fail;
156Eshort:
157 error = "rec_len is smaller than minimal";
158 goto bad_entry;
159Ealign:
160 error = "unaligned directory entry";
161 goto bad_entry;
162Enamelen:
163 error = "rec_len is too small for name_len";
164 goto bad_entry;
165Espan:
166 error = "directory entry across blocks";
167 goto bad_entry;
168Einumber:
169 error = "inode out of bounds";
170bad_entry:
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_SHIFT)+offs,
174 rec_len, ufs_get_de_namlen(sb, p));
175 goto fail;
176Eend:
177 p = (struct ufs_dir_entry *)(kaddr + offs);
178 ufs_error(sb, __func__,
179 "entry in directory #%lu spans the page boundary"
180 "offset=%lu",
181 dir->i_ino, (page->index<<PAGE_SHIFT)+offs);
182fail:
183 SetPageChecked(page);
184 SetPageError(page);
185}
186
187static struct page *ufs_get_page(struct inode *dir, unsigned long n)
188{
189 struct address_space *mapping = dir->i_mapping;
190 struct page *page = read_mapping_page(mapping, n, NULL);
191 if (!IS_ERR(page)) {
192 kmap(page);
193 if (!PageChecked(page))
194 ufs_check_page(page);
195 if (PageError(page))
196 goto fail;
197 }
198 return page;
199
200fail:
201 ufs_put_page(page);
202 return ERR_PTR(-EIO);
203}
204
205
206
207
208
209static unsigned
210ufs_last_byte(struct inode *inode, unsigned long page_nr)
211{
212 unsigned last_byte = inode->i_size;
213
214 last_byte -= page_nr << PAGE_SHIFT;
215 if (last_byte > PAGE_SIZE)
216 last_byte = PAGE_SIZE;
217 return last_byte;
218}
219
220static inline struct ufs_dir_entry *
221ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
222{
223 return (struct ufs_dir_entry *)((char *)p +
224 fs16_to_cpu(sb, p->d_reclen));
225}
226
227struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
228{
229 struct page *page = ufs_get_page(dir, 0);
230 struct ufs_dir_entry *de = NULL;
231
232 if (!IS_ERR(page)) {
233 de = ufs_next_entry(dir->i_sb,
234 (struct ufs_dir_entry *)page_address(page));
235 *p = page;
236 }
237 return de;
238}
239
240
241
242
243
244
245
246
247
248struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr,
249 struct page **res_page)
250{
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;
260
261 UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
262
263 if (npages == 0 || namelen > UFS_MAXNAMLEN)
264 goto out;
265
266
267 *res_page = NULL;
268
269 start = ui->i_dir_start_lookup;
270
271 if (start >= npages)
272 start = 0;
273 n = start;
274 do {
275 char *kaddr;
276 page = ufs_get_page(dir, n);
277 if (!IS_ERR(page)) {
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");
285 ufs_put_page(page);
286 goto out;
287 }
288 if (ufs_match(sb, namelen, name, de))
289 goto found;
290 de = ufs_next_entry(sb, de);
291 }
292 ufs_put_page(page);
293 }
294 if (++n >= npages)
295 n = 0;
296 } while (n != start);
297out:
298 return NULL;
299
300found:
301 *res_page = page;
302 ui->i_dir_start_lookup = n;
303 return de;
304}
305
306
307
308
309int ufs_add_link(struct dentry *dentry, struct inode *inode)
310{
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);
321 unsigned long n;
322 char *kaddr;
323 loff_t pos;
324 int err;
325
326 UFSD("ENTER, name %s, namelen %u\n", name, namelen);
327
328
329
330
331
332
333 for (n = 0; n <= npages; n++) {
334 char *dir_end;
335
336 page = ufs_get_page(dir, n);
337 err = PTR_ERR(page);
338 if (IS_ERR(page))
339 goto out;
340 lock_page(page);
341 kaddr = page_address(page);
342 dir_end = kaddr + ufs_last_byte(dir, n);
343 de = (struct ufs_dir_entry *)kaddr;
344 kaddr += PAGE_SIZE - reclen;
345 while ((char *)de <= kaddr) {
346 if ((char *)de == dir_end) {
347
348 name_len = 0;
349 rec_len = chunk_size;
350 de->d_reclen = cpu_to_fs16(sb, chunk_size);
351 de->d_ino = 0;
352 goto got_it;
353 }
354 if (de->d_reclen == 0) {
355 ufs_error(dir->i_sb, __func__,
356 "zero-length directory entry");
357 err = -EIO;
358 goto out_unlock;
359 }
360 err = -EEXIST;
361 if (ufs_match(sb, namelen, name, de))
362 goto out_unlock;
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)
366 goto got_it;
367 if (rec_len >= name_len + reclen)
368 goto got_it;
369 de = (struct ufs_dir_entry *) ((char *) de + rec_len);
370 }
371 unlock_page(page);
372 ufs_put_page(page);
373 }
374 BUG();
375 return -EINVAL;
376
377got_it:
378 pos = page_offset(page) +
379 (char*)de - (char*)page_address(page);
380 err = ufs_prepare_chunk(page, pos, rec_len);
381 if (err)
382 goto out_unlock;
383 if (de->d_ino) {
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);
388
389 de = de1;
390 }
391
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);
396
397 err = ufs_commit_chunk(page, pos, rec_len);
398 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
399
400 mark_inode_dirty(dir);
401
402out_put:
403 ufs_put_page(page);
404out:
405 return err;
406out_unlock:
407 unlock_page(page);
408 goto out_put;
409}
410
411static inline unsigned
412ufs_validate_entry(struct super_block *sb, char *base,
413 unsigned offset, unsigned mask)
414{
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)
419 break;
420 p = ufs_next_entry(sb, p);
421 }
422 return (char *)p - base;
423}
424
425
426
427
428
429static int
430ufs_readdir(struct file *file, struct dir_context *ctx)
431{
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_MASK;
436 unsigned long n = pos >> PAGE_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;
441
442 UFSD("BEGIN\n");
443
444 if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
445 return 0;
446
447 for ( ; n < npages; n++, offset = 0) {
448 char *kaddr, *limit;
449 struct ufs_dir_entry *de;
450
451 struct page *page = ufs_get_page(inode, n);
452
453 if (IS_ERR(page)) {
454 ufs_error(sb, __func__,
455 "bad page in #%lu",
456 inode->i_ino);
457 ctx->pos += PAGE_SIZE - offset;
458 return -EIO;
459 }
460 kaddr = page_address(page);
461 if (unlikely(need_revalidate)) {
462 if (offset) {
463 offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
464 ctx->pos = (n<<PAGE_SHIFT) + offset;
465 }
466 file->f_version = inode->i_version;
467 need_revalidate = 0;
468 }
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");
475 ufs_put_page(page);
476 return -EIO;
477 }
478 if (de->d_ino) {
479 unsigned char d_type = DT_UNKNOWN;
480
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));
484
485 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
486 d_type = de->d_u.d_44.d_type;
487
488 if (!dir_emit(ctx, de->d_name,
489 ufs_get_de_namlen(sb, de),
490 fs32_to_cpu(sb, de->d_ino),
491 d_type)) {
492 ufs_put_page(page);
493 return 0;
494 }
495 }
496 ctx->pos += fs16_to_cpu(sb, de->d_reclen);
497 }
498 ufs_put_page(page);
499 }
500 return 0;
501}
502
503
504
505
506
507
508int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
509 struct page * page)
510{
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);
515 loff_t pos;
516 struct ufs_dir_entry *pde = NULL;
517 struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
518 int err;
519
520 UFSD("ENTER\n");
521
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);
526
527 while ((char*)de < (char*)dir) {
528 if (de->d_reclen == 0) {
529 ufs_error(inode->i_sb, __func__,
530 "zero-length directory entry");
531 err = -EIO;
532 goto out;
533 }
534 pde = de;
535 de = ufs_next_entry(sb, de);
536 }
537 if (pde)
538 from = (char*)pde - (char*)page_address(page);
539
540 pos = page_offset(page) + from;
541 lock_page(page);
542 err = ufs_prepare_chunk(page, pos, to - from);
543 BUG_ON(err);
544 if (pde)
545 pde->d_reclen = cpu_to_fs16(sb, to - from);
546 dir->d_ino = 0;
547 err = ufs_commit_chunk(page, pos, to - from);
548 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
549 mark_inode_dirty(inode);
550out:
551 ufs_put_page(page);
552 UFSD("EXIT\n");
553 return err;
554}
555
556int ufs_make_empty(struct inode * inode, struct inode *dir)
557{
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;
563 char *base;
564 int err;
565
566 if (!page)
567 return -ENOMEM;
568
569 err = ufs_prepare_chunk(page, 0, chunk_size);
570 if (err) {
571 unlock_page(page);
572 goto fail;
573 }
574
575 kmap(page);
576 base = (char*)page_address(page);
577 memset(base, 0, PAGE_SIZE);
578
579 de = (struct ufs_dir_entry *) base;
580
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, "..");
593 kunmap(page);
594
595 err = ufs_commit_chunk(page, 0, chunk_size);
596fail:
597 put_page(page);
598 return err;
599}
600
601
602
603
604int ufs_empty_dir(struct inode * inode)
605{
606 struct super_block *sb = inode->i_sb;
607 struct page *page = NULL;
608 unsigned long i, npages = dir_pages(inode);
609
610 for (i = 0; i < npages; i++) {
611 char *kaddr;
612 struct ufs_dir_entry *de;
613 page = ufs_get_page(inode, i);
614
615 if (IS_ERR(page))
616 continue;
617
618 kaddr = page_address(page);
619 de = (struct ufs_dir_entry *)kaddr;
620 kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
621
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);
627 goto not_empty;
628 }
629 if (de->d_ino) {
630 u16 namelen=ufs_get_de_namlen(sb, de);
631
632 if (de->d_name[0] != '.')
633 goto not_empty;
634 if (namelen > 2)
635 goto not_empty;
636 if (namelen < 2) {
637 if (inode->i_ino !=
638 fs32_to_cpu(sb, de->d_ino))
639 goto not_empty;
640 } else if (de->d_name[1] != '.')
641 goto not_empty;
642 }
643 de = ufs_next_entry(sb, de);
644 }
645 ufs_put_page(page);
646 }
647 return 1;
648
649not_empty:
650 ufs_put_page(page);
651 return 0;
652}
653
654const 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,
659};
660
