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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 page_cache_release(page);
66}
67
68static inline unsigned long ufs_dir_pages(struct inode *inode)
69{
70 return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
71}
72
73ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
74{
75 ino_t res = 0;
76 struct ufs_dir_entry *de;
77 struct page *page;
78
79 de = ufs_find_entry(dir, qstr, &page);
80 if (de) {
81 res = fs32_to_cpu(dir->i_sb, de->d_ino);
82 ufs_put_page(page);
83 }
84 return res;
85}
86
87
88
89void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
90 struct page *page, struct inode *inode)
91{
92 loff_t pos = page_offset(page) +
93 (char *) de - (char *) page_address(page);
94 unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
95 int err;
96
97 lock_page(page);
98 err = ufs_prepare_chunk(page, pos, len);
99 BUG_ON(err);
100
101 de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
102 ufs_set_de_type(dir->i_sb, de, inode->i_mode);
103
104 err = ufs_commit_chunk(page, pos, len);
105 ufs_put_page(page);
106 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
107 mark_inode_dirty(dir);
108}
109
110
111static void ufs_check_page(struct page *page)
112{
113 struct inode *dir = page->mapping->host;
114 struct super_block *sb = dir->i_sb;
115 char *kaddr = page_address(page);
116 unsigned offs, rec_len;
117 unsigned limit = PAGE_CACHE_SIZE;
118 const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
119 struct ufs_dir_entry *p;
120 char *error;
121
122 if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
123 limit = dir->i_size & ~PAGE_CACHE_MASK;
124 if (limit & chunk_mask)
125 goto Ebadsize;
126 if (!limit)
127 goto out;
128 }
129 for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
130 p = (struct ufs_dir_entry *)(kaddr + offs);
131 rec_len = fs16_to_cpu(sb, p->d_reclen);
132
133 if (rec_len < UFS_DIR_REC_LEN(1))
134 goto Eshort;
135 if (rec_len & 3)
136 goto Ealign;
137 if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
138 goto Enamelen;
139 if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
140 goto Espan;
141 if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
142 UFS_SB(sb)->s_uspi->s_ncg))
143 goto Einumber;
144 }
145 if (offs != limit)
146 goto Eend;
147out:
148 SetPageChecked(page);
149 return;
150
151
152
153Ebadsize:
154 ufs_error(sb, "ufs_check_page",
155 "size of directory #%lu is not a multiple of chunk size",
156 dir->i_ino
157 );
158 goto fail;
159Eshort:
160 error = "rec_len is smaller than minimal";
161 goto bad_entry;
162Ealign:
163 error = "unaligned directory entry";
164 goto bad_entry;
165Enamelen:
166 error = "rec_len is too small for name_len";
167 goto bad_entry;
168Espan:
169 error = "directory entry across blocks";
170 goto bad_entry;
171Einumber:
172 error = "inode out of bounds";
173bad_entry:
174 ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
175 "offset=%lu, rec_len=%d, name_len=%d",
176 dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
177 rec_len, ufs_get_de_namlen(sb, p));
178 goto fail;
179Eend:
180 p = (struct ufs_dir_entry *)(kaddr + offs);
181 ufs_error(sb, __func__,
182 "entry in directory #%lu spans the page boundary"
183 "offset=%lu",
184 dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs);
185fail:
186 SetPageChecked(page);
187 SetPageError(page);
188}
189
190static struct page *ufs_get_page(struct inode *dir, unsigned long n)
191{
192 struct address_space *mapping = dir->i_mapping;
193 struct page *page = read_mapping_page(mapping, n, NULL);
194 if (!IS_ERR(page)) {
195 kmap(page);
196 if (!PageChecked(page))
197 ufs_check_page(page);
198 if (PageError(page))
199 goto fail;
200 }
201 return page;
202
203fail:
204 ufs_put_page(page);
205 return ERR_PTR(-EIO);
206}
207
208
209
210
211
212static unsigned
213ufs_last_byte(struct inode *inode, unsigned long page_nr)
214{
215 unsigned last_byte = inode->i_size;
216
217 last_byte -= page_nr << PAGE_CACHE_SHIFT;
218 if (last_byte > PAGE_CACHE_SIZE)
219 last_byte = PAGE_CACHE_SIZE;
220 return last_byte;
221}
222
223static inline struct ufs_dir_entry *
224ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
225{
226 return (struct ufs_dir_entry *)((char *)p +
227 fs16_to_cpu(sb, p->d_reclen));
228}
229
230struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
231{
232 struct page *page = ufs_get_page(dir, 0);
233 struct ufs_dir_entry *de = NULL;
234
235 if (!IS_ERR(page)) {
236 de = ufs_next_entry(dir->i_sb,
237 (struct ufs_dir_entry *)page_address(page));
238 *p = page;
239 }
240 return de;
241}
242
243
244
245
246
247
248
249
250
251struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr,
252 struct page **res_page)
253{
254 struct super_block *sb = dir->i_sb;
255 const unsigned char *name = qstr->name;
256 int namelen = qstr->len;
257 unsigned reclen = UFS_DIR_REC_LEN(namelen);
258 unsigned long start, n;
259 unsigned long npages = ufs_dir_pages(dir);
260 struct page *page = NULL;
261 struct ufs_inode_info *ui = UFS_I(dir);
262 struct ufs_dir_entry *de;
263
264 UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
265
266 if (npages == 0 || namelen > UFS_MAXNAMLEN)
267 goto out;
268
269
270 *res_page = NULL;
271
272 start = ui->i_dir_start_lookup;
273
274 if (start >= npages)
275 start = 0;
276 n = start;
277 do {
278 char *kaddr;
279 page = ufs_get_page(dir, n);
280 if (!IS_ERR(page)) {
281 kaddr = page_address(page);
282 de = (struct ufs_dir_entry *) kaddr;
283 kaddr += ufs_last_byte(dir, n) - reclen;
284 while ((char *) de <= kaddr) {
285 if (de->d_reclen == 0) {
286 ufs_error(dir->i_sb, __func__,
287 "zero-length directory entry");
288 ufs_put_page(page);
289 goto out;
290 }
291 if (ufs_match(sb, namelen, name, de))
292 goto found;
293 de = ufs_next_entry(sb, de);
294 }
295 ufs_put_page(page);
296 }
297 if (++n >= npages)
298 n = 0;
299 } while (n != start);
300out:
301 return NULL;
302
303found:
304 *res_page = page;
305 ui->i_dir_start_lookup = n;
306 return de;
307}
308
309
310
311
312int ufs_add_link(struct dentry *dentry, struct inode *inode)
313{
314 struct inode *dir = dentry->d_parent->d_inode;
315 const unsigned char *name = dentry->d_name.name;
316 int namelen = dentry->d_name.len;
317 struct super_block *sb = dir->i_sb;
318 unsigned reclen = UFS_DIR_REC_LEN(namelen);
319 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
320 unsigned short rec_len, name_len;
321 struct page *page = NULL;
322 struct ufs_dir_entry *de;
323 unsigned long npages = ufs_dir_pages(dir);
324 unsigned long n;
325 char *kaddr;
326 loff_t pos;
327 int err;
328
329 UFSD("ENTER, name %s, namelen %u\n", name, namelen);
330
331
332
333
334
335
336 for (n = 0; n <= npages; n++) {
337 char *dir_end;
338
339 page = ufs_get_page(dir, n);
340 err = PTR_ERR(page);
341 if (IS_ERR(page))
342 goto out;
343 lock_page(page);
344 kaddr = page_address(page);
345 dir_end = kaddr + ufs_last_byte(dir, n);
346 de = (struct ufs_dir_entry *)kaddr;
347 kaddr += PAGE_CACHE_SIZE - reclen;
348 while ((char *)de <= kaddr) {
349 if ((char *)de == dir_end) {
350
351 name_len = 0;
352 rec_len = chunk_size;
353 de->d_reclen = cpu_to_fs16(sb, chunk_size);
354 de->d_ino = 0;
355 goto got_it;
356 }
357 if (de->d_reclen == 0) {
358 ufs_error(dir->i_sb, __func__,
359 "zero-length directory entry");
360 err = -EIO;
361 goto out_unlock;
362 }
363 err = -EEXIST;
364 if (ufs_match(sb, namelen, name, de))
365 goto out_unlock;
366 name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
367 rec_len = fs16_to_cpu(sb, de->d_reclen);
368 if (!de->d_ino && rec_len >= reclen)
369 goto got_it;
370 if (rec_len >= name_len + reclen)
371 goto got_it;
372 de = (struct ufs_dir_entry *) ((char *) de + rec_len);
373 }
374 unlock_page(page);
375 ufs_put_page(page);
376 }
377 BUG();
378 return -EINVAL;
379
380got_it:
381 pos = page_offset(page) +
382 (char*)de - (char*)page_address(page);
383 err = ufs_prepare_chunk(page, pos, rec_len);
384 if (err)
385 goto out_unlock;
386 if (de->d_ino) {
387 struct ufs_dir_entry *de1 =
388 (struct ufs_dir_entry *) ((char *) de + name_len);
389 de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
390 de->d_reclen = cpu_to_fs16(sb, name_len);
391
392 de = de1;
393 }
394
395 ufs_set_de_namlen(sb, de, namelen);
396 memcpy(de->d_name, name, namelen + 1);
397 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
398 ufs_set_de_type(sb, de, inode->i_mode);
399
400 err = ufs_commit_chunk(page, pos, rec_len);
401 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
402
403 mark_inode_dirty(dir);
404
405out_put:
406 ufs_put_page(page);
407out:
408 return err;
409out_unlock:
410 unlock_page(page);
411 goto out_put;
412}
413
414static inline unsigned
415ufs_validate_entry(struct super_block *sb, char *base,
416 unsigned offset, unsigned mask)
417{
418 struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
419 struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
420 while ((char*)p < (char*)de) {
421 if (p->d_reclen == 0)
422 break;
423 p = ufs_next_entry(sb, p);
424 }
425 return (char *)p - base;
426}
427
428
429
430
431
432static int
433ufs_readdir(struct file *file, struct dir_context *ctx)
434{
435 loff_t pos = ctx->pos;
436 struct inode *inode = file_inode(file);
437 struct super_block *sb = inode->i_sb;
438 unsigned int offset = pos & ~PAGE_CACHE_MASK;
439 unsigned long n = pos >> PAGE_CACHE_SHIFT;
440 unsigned long npages = ufs_dir_pages(inode);
441 unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
442 int need_revalidate = file->f_version != inode->i_version;
443 unsigned flags = UFS_SB(sb)->s_flags;
444
445 UFSD("BEGIN\n");
446
447 if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
448 return 0;
449
450 for ( ; n < npages; n++, offset = 0) {
451 char *kaddr, *limit;
452 struct ufs_dir_entry *de;
453
454 struct page *page = ufs_get_page(inode, n);
455
456 if (IS_ERR(page)) {
457 ufs_error(sb, __func__,
458 "bad page in #%lu",
459 inode->i_ino);
460 ctx->pos += PAGE_CACHE_SIZE - offset;
461 return -EIO;
462 }
463 kaddr = page_address(page);
464 if (unlikely(need_revalidate)) {
465 if (offset) {
466 offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
467 ctx->pos = (n<<PAGE_CACHE_SHIFT) + offset;
468 }
469 file->f_version = inode->i_version;
470 need_revalidate = 0;
471 }
472 de = (struct ufs_dir_entry *)(kaddr+offset);
473 limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
474 for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
475 if (de->d_reclen == 0) {
476 ufs_error(sb, __func__,
477 "zero-length directory entry");
478 ufs_put_page(page);
479 return -EIO;
480 }
481 if (de->d_ino) {
482 unsigned char d_type = DT_UNKNOWN;
483
484 UFSD("filldir(%s,%u)\n", de->d_name,
485 fs32_to_cpu(sb, de->d_ino));
486 UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
487
488 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
489 d_type = de->d_u.d_44.d_type;
490
491 if (!dir_emit(ctx, de->d_name,
492 ufs_get_de_namlen(sb, de),
493 fs32_to_cpu(sb, de->d_ino),
494 d_type)) {
495 ufs_put_page(page);
496 return 0;
497 }
498 }
499 ctx->pos += fs16_to_cpu(sb, de->d_reclen);
500 }
501 ufs_put_page(page);
502 }
503 return 0;
504}
505
506
507
508
509
510
511int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
512 struct page * page)
513{
514 struct super_block *sb = inode->i_sb;
515 char *kaddr = page_address(page);
516 unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
517 unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
518 loff_t pos;
519 struct ufs_dir_entry *pde = NULL;
520 struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
521 int err;
522
523 UFSD("ENTER\n");
524
525 UFSD("ino %u, reclen %u, namlen %u, name %s\n",
526 fs32_to_cpu(sb, de->d_ino),
527 fs16_to_cpu(sb, de->d_reclen),
528 ufs_get_de_namlen(sb, de), de->d_name);
529
530 while ((char*)de < (char*)dir) {
531 if (de->d_reclen == 0) {
532 ufs_error(inode->i_sb, __func__,
533 "zero-length directory entry");
534 err = -EIO;
535 goto out;
536 }
537 pde = de;
538 de = ufs_next_entry(sb, de);
539 }
540 if (pde)
541 from = (char*)pde - (char*)page_address(page);
542
543 pos = page_offset(page) + from;
544 lock_page(page);
545 err = ufs_prepare_chunk(page, pos, to - from);
546 BUG_ON(err);
547 if (pde)
548 pde->d_reclen = cpu_to_fs16(sb, to - from);
549 dir->d_ino = 0;
550 err = ufs_commit_chunk(page, pos, to - from);
551 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
552 mark_inode_dirty(inode);
553out:
554 ufs_put_page(page);
555 UFSD("EXIT\n");
556 return err;
557}
558
559int ufs_make_empty(struct inode * inode, struct inode *dir)
560{
561 struct super_block * sb = dir->i_sb;
562 struct address_space *mapping = inode->i_mapping;
563 struct page *page = grab_cache_page(mapping, 0);
564 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
565 struct ufs_dir_entry * de;
566 char *base;
567 int err;
568
569 if (!page)
570 return -ENOMEM;
571
572 err = ufs_prepare_chunk(page, 0, chunk_size);
573 if (err) {
574 unlock_page(page);
575 goto fail;
576 }
577
578 kmap(page);
579 base = (char*)page_address(page);
580 memset(base, 0, PAGE_CACHE_SIZE);
581
582 de = (struct ufs_dir_entry *) base;
583
584 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
585 ufs_set_de_type(sb, de, inode->i_mode);
586 ufs_set_de_namlen(sb, de, 1);
587 de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
588 strcpy (de->d_name, ".");
589 de = (struct ufs_dir_entry *)
590 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
591 de->d_ino = cpu_to_fs32(sb, dir->i_ino);
592 ufs_set_de_type(sb, de, dir->i_mode);
593 de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
594 ufs_set_de_namlen(sb, de, 2);
595 strcpy (de->d_name, "..");
596 kunmap(page);
597
598 err = ufs_commit_chunk(page, 0, chunk_size);
599fail:
600 page_cache_release(page);
601 return err;
602}
603
604
605
606
607int ufs_empty_dir(struct inode * inode)
608{
609 struct super_block *sb = inode->i_sb;
610 struct page *page = NULL;
611 unsigned long i, npages = ufs_dir_pages(inode);
612
613 for (i = 0; i < npages; i++) {
614 char *kaddr;
615 struct ufs_dir_entry *de;
616 page = ufs_get_page(inode, i);
617
618 if (IS_ERR(page))
619 continue;
620
621 kaddr = page_address(page);
622 de = (struct ufs_dir_entry *)kaddr;
623 kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
624
625 while ((char *)de <= kaddr) {
626 if (de->d_reclen == 0) {
627 ufs_error(inode->i_sb, __func__,
628 "zero-length directory entry: "
629 "kaddr=%p, de=%p\n", kaddr, de);
630 goto not_empty;
631 }
632 if (de->d_ino) {
633 u16 namelen=ufs_get_de_namlen(sb, de);
634
635 if (de->d_name[0] != '.')
636 goto not_empty;
637 if (namelen > 2)
638 goto not_empty;
639 if (namelen < 2) {
640 if (inode->i_ino !=
641 fs32_to_cpu(sb, de->d_ino))
642 goto not_empty;
643 } else if (de->d_name[1] != '.')
644 goto not_empty;
645 }
646 de = ufs_next_entry(sb, de);
647 }
648 ufs_put_page(page);
649 }
650 return 1;
651
652not_empty:
653 ufs_put_page(page);
654 return 0;
655}
656
657const struct file_operations ufs_dir_operations = {
658 .read = generic_read_dir,
659 .iterate = ufs_readdir,
660 .fsync = generic_file_fsync,
661 .llseek = generic_file_llseek,
662};
663
