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1/*
2 * linux/fs/ufs/ufs_dir.c
3 *
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
8 *
9 * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
10 *
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>.
14 *
15 * Migration to usage of "page cache" on May 2006 by
16 * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
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 * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
30 *
31 * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
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/* Releases the page */
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(dir);
104 mark_inode_dirty(dir);
105}
106
107
108static bool 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 true;
147
148 /* Too bad, we had an error */
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 SetPageError(page);
184 return false;
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 (unlikely(!PageChecked(page))) {
194 if (PageError(page) || !ufs_check_page(page))
195 goto fail;
196 }
197 }
198 return page;
199
200fail:
201 ufs_put_page(page);
202 return ERR_PTR(-EIO);
203}
204
205/*
206 * Return the offset into page `page_nr' of the last valid
207 * byte in that page, plus one.
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 * ufs_find_entry()
242 *
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.
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 /* OFFSET_CACHE */
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 (ufs_match(sb, namelen, name, de))
283 goto found;
284 de = ufs_next_entry(sb, de);
285 }
286 ufs_put_page(page);
287 }
288 if (++n >= npages)
289 n = 0;
290 } while (n != start);
291out:
292 return NULL;
293
294found:
295 *res_page = page;
296 ui->i_dir_start_lookup = n;
297 return de;
298}
299
300/*
301 * Parent is locked.
302 */
303int ufs_add_link(struct dentry *dentry, struct inode *inode)
304{
305 struct inode *dir = d_inode(dentry->d_parent);
306 const unsigned char *name = dentry->d_name.name;
307 int namelen = dentry->d_name.len;
308 struct super_block *sb = dir->i_sb;
309 unsigned reclen = UFS_DIR_REC_LEN(namelen);
310 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
311 unsigned short rec_len, name_len;
312 struct page *page = NULL;
313 struct ufs_dir_entry *de;
314 unsigned long npages = dir_pages(dir);
315 unsigned long n;
316 char *kaddr;
317 loff_t pos;
318 int err;
319
320 UFSD("ENTER, name %s, namelen %u\n", name, namelen);
321
322 /*
323 * We take care of directory expansion in the same loop.
324 * This code plays outside i_size, so it locks the page
325 * to protect that region.
326 */
327 for (n = 0; n <= npages; n++) {
328 char *dir_end;
329
330 page = ufs_get_page(dir, n);
331 err = PTR_ERR(page);
332 if (IS_ERR(page))
333 goto out;
334 lock_page(page);
335 kaddr = page_address(page);
336 dir_end = kaddr + ufs_last_byte(dir, n);
337 de = (struct ufs_dir_entry *)kaddr;
338 kaddr += PAGE_SIZE - reclen;
339 while ((char *)de <= kaddr) {
340 if ((char *)de == dir_end) {
341 /* We hit i_size */
342 name_len = 0;
343 rec_len = chunk_size;
344 de->d_reclen = cpu_to_fs16(sb, chunk_size);
345 de->d_ino = 0;
346 goto got_it;
347 }
348 if (de->d_reclen == 0) {
349 ufs_error(dir->i_sb, __func__,
350 "zero-length directory entry");
351 err = -EIO;
352 goto out_unlock;
353 }
354 err = -EEXIST;
355 if (ufs_match(sb, namelen, name, de))
356 goto out_unlock;
357 name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
358 rec_len = fs16_to_cpu(sb, de->d_reclen);
359 if (!de->d_ino && rec_len >= reclen)
360 goto got_it;
361 if (rec_len >= name_len + reclen)
362 goto got_it;
363 de = (struct ufs_dir_entry *) ((char *) de + rec_len);
364 }
365 unlock_page(page);
366 ufs_put_page(page);
367 }
368 BUG();
369 return -EINVAL;
370
371got_it:
372 pos = page_offset(page) +
373 (char*)de - (char*)page_address(page);
374 err = ufs_prepare_chunk(page, pos, rec_len);
375 if (err)
376 goto out_unlock;
377 if (de->d_ino) {
378 struct ufs_dir_entry *de1 =
379 (struct ufs_dir_entry *) ((char *) de + name_len);
380 de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
381 de->d_reclen = cpu_to_fs16(sb, name_len);
382
383 de = de1;
384 }
385
386 ufs_set_de_namlen(sb, de, namelen);
387 memcpy(de->d_name, name, namelen + 1);
388 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
389 ufs_set_de_type(sb, de, inode->i_mode);
390
391 err = ufs_commit_chunk(page, pos, rec_len);
392 dir->i_mtime = dir->i_ctime = current_time(dir);
393
394 mark_inode_dirty(dir);
395 /* OFFSET_CACHE */
396out_put:
397 ufs_put_page(page);
398out:
399 return err;
400out_unlock:
401 unlock_page(page);
402 goto out_put;
403}
404
405static inline unsigned
406ufs_validate_entry(struct super_block *sb, char *base,
407 unsigned offset, unsigned mask)
408{
409 struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
410 struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
411 while ((char*)p < (char*)de)
412 p = ufs_next_entry(sb, p);
413 return (char *)p - base;
414}
415
416
417/*
418 * This is blatantly stolen from ext2fs
419 */
420static int
421ufs_readdir(struct file *file, struct dir_context *ctx)
422{
423 loff_t pos = ctx->pos;
424 struct inode *inode = file_inode(file);
425 struct super_block *sb = inode->i_sb;
426 unsigned int offset = pos & ~PAGE_MASK;
427 unsigned long n = pos >> PAGE_SHIFT;
428 unsigned long npages = dir_pages(inode);
429 unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
430 int need_revalidate = file->f_version != inode->i_version;
431 unsigned flags = UFS_SB(sb)->s_flags;
432
433 UFSD("BEGIN\n");
434
435 if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
436 return 0;
437
438 for ( ; n < npages; n++, offset = 0) {
439 char *kaddr, *limit;
440 struct ufs_dir_entry *de;
441
442 struct page *page = ufs_get_page(inode, n);
443
444 if (IS_ERR(page)) {
445 ufs_error(sb, __func__,
446 "bad page in #%lu",
447 inode->i_ino);
448 ctx->pos += PAGE_SIZE - offset;
449 return -EIO;
450 }
451 kaddr = page_address(page);
452 if (unlikely(need_revalidate)) {
453 if (offset) {
454 offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
455 ctx->pos = (n<<PAGE_SHIFT) + offset;
456 }
457 file->f_version = inode->i_version;
458 need_revalidate = 0;
459 }
460 de = (struct ufs_dir_entry *)(kaddr+offset);
461 limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
462 for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
463 if (de->d_ino) {
464 unsigned char d_type = DT_UNKNOWN;
465
466 UFSD("filldir(%s,%u)\n", de->d_name,
467 fs32_to_cpu(sb, de->d_ino));
468 UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
469
470 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
471 d_type = de->d_u.d_44.d_type;
472
473 if (!dir_emit(ctx, de->d_name,
474 ufs_get_de_namlen(sb, de),
475 fs32_to_cpu(sb, de->d_ino),
476 d_type)) {
477 ufs_put_page(page);
478 return 0;
479 }
480 }
481 ctx->pos += fs16_to_cpu(sb, de->d_reclen);
482 }
483 ufs_put_page(page);
484 }
485 return 0;
486}
487
488
489/*
490 * ufs_delete_entry deletes a directory entry by merging it with the
491 * previous entry.
492 */
493int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
494 struct page * page)
495{
496 struct super_block *sb = inode->i_sb;
497 char *kaddr = page_address(page);
498 unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
499 unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
500 loff_t pos;
501 struct ufs_dir_entry *pde = NULL;
502 struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
503 int err;
504
505 UFSD("ENTER\n");
506
507 UFSD("ino %u, reclen %u, namlen %u, name %s\n",
508 fs32_to_cpu(sb, de->d_ino),
509 fs16_to_cpu(sb, de->d_reclen),
510 ufs_get_de_namlen(sb, de), de->d_name);
511
512 while ((char*)de < (char*)dir) {
513 if (de->d_reclen == 0) {
514 ufs_error(inode->i_sb, __func__,
515 "zero-length directory entry");
516 err = -EIO;
517 goto out;
518 }
519 pde = de;
520 de = ufs_next_entry(sb, de);
521 }
522 if (pde)
523 from = (char*)pde - (char*)page_address(page);
524
525 pos = page_offset(page) + from;
526 lock_page(page);
527 err = ufs_prepare_chunk(page, pos, to - from);
528 BUG_ON(err);
529 if (pde)
530 pde->d_reclen = cpu_to_fs16(sb, to - from);
531 dir->d_ino = 0;
532 err = ufs_commit_chunk(page, pos, to - from);
533 inode->i_ctime = inode->i_mtime = current_time(inode);
534 mark_inode_dirty(inode);
535out:
536 ufs_put_page(page);
537 UFSD("EXIT\n");
538 return err;
539}
540
541int ufs_make_empty(struct inode * inode, struct inode *dir)
542{
543 struct super_block * sb = dir->i_sb;
544 struct address_space *mapping = inode->i_mapping;
545 struct page *page = grab_cache_page(mapping, 0);
546 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
547 struct ufs_dir_entry * de;
548 char *base;
549 int err;
550
551 if (!page)
552 return -ENOMEM;
553
554 err = ufs_prepare_chunk(page, 0, chunk_size);
555 if (err) {
556 unlock_page(page);
557 goto fail;
558 }
559
560 kmap(page);
561 base = (char*)page_address(page);
562 memset(base, 0, PAGE_SIZE);
563
564 de = (struct ufs_dir_entry *) base;
565
566 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
567 ufs_set_de_type(sb, de, inode->i_mode);
568 ufs_set_de_namlen(sb, de, 1);
569 de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
570 strcpy (de->d_name, ".");
571 de = (struct ufs_dir_entry *)
572 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
573 de->d_ino = cpu_to_fs32(sb, dir->i_ino);
574 ufs_set_de_type(sb, de, dir->i_mode);
575 de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
576 ufs_set_de_namlen(sb, de, 2);
577 strcpy (de->d_name, "..");
578 kunmap(page);
579
580 err = ufs_commit_chunk(page, 0, chunk_size);
581fail:
582 put_page(page);
583 return err;
584}
585
586/*
587 * routine to check that the specified directory is empty (for rmdir)
588 */
589int ufs_empty_dir(struct inode * inode)
590{
591 struct super_block *sb = inode->i_sb;
592 struct page *page = NULL;
593 unsigned long i, npages = dir_pages(inode);
594
595 for (i = 0; i < npages; i++) {
596 char *kaddr;
597 struct ufs_dir_entry *de;
598 page = ufs_get_page(inode, i);
599
600 if (IS_ERR(page))
601 continue;
602
603 kaddr = page_address(page);
604 de = (struct ufs_dir_entry *)kaddr;
605 kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
606
607 while ((char *)de <= kaddr) {
608 if (de->d_reclen == 0) {
609 ufs_error(inode->i_sb, __func__,
610 "zero-length directory entry: "
611 "kaddr=%p, de=%p\n", kaddr, de);
612 goto not_empty;
613 }
614 if (de->d_ino) {
615 u16 namelen=ufs_get_de_namlen(sb, de);
616 /* check for . and .. */
617 if (de->d_name[0] != '.')
618 goto not_empty;
619 if (namelen > 2)
620 goto not_empty;
621 if (namelen < 2) {
622 if (inode->i_ino !=
623 fs32_to_cpu(sb, de->d_ino))
624 goto not_empty;
625 } else if (de->d_name[1] != '.')
626 goto not_empty;
627 }
628 de = ufs_next_entry(sb, de);
629 }
630 ufs_put_page(page);
631 }
632 return 1;
633
634not_empty:
635 ufs_put_page(page);
636 return 0;
637}
638
639const struct file_operations ufs_dir_operations = {
640 .read = generic_read_dir,
641 .iterate_shared = ufs_readdir,
642 .fsync = generic_file_fsync,
643 .llseek = generic_file_llseek,
644};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ufs/ufs_dir.c
4 *
5 * Copyright (C) 1996
6 * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
7 * Laboratory for Computer Science Research Computing Facility
8 * Rutgers, The State University of New Jersey
9 *
10 * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
11 *
12 * 4.4BSD (FreeBSD) support added on February 1st 1998 by
13 * Niels Kristian Bech Jensen <nkbj@image.dk> partially based
14 * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
15 *
16 * Migration to usage of "page cache" on May 2006 by
17 * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
18 */
19
20#include <linux/time.h>
21#include <linux/fs.h>
22#include <linux/swap.h>
23#include <linux/iversion.h>
24
25#include "ufs_fs.h"
26#include "ufs.h"
27#include "swab.h"
28#include "util.h"
29
30/*
31 * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
32 *
33 * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
34 */
35static inline int ufs_match(struct super_block *sb, int len,
36 const unsigned char *name, struct ufs_dir_entry *de)
37{
38 if (len != ufs_get_de_namlen(sb, de))
39 return 0;
40 if (!de->d_ino)
41 return 0;
42 return !memcmp(name, de->d_name, len);
43}
44
45static void ufs_commit_chunk(struct folio *folio, loff_t pos, unsigned len)
46{
47 struct address_space *mapping = folio->mapping;
48 struct inode *dir = mapping->host;
49
50 inode_inc_iversion(dir);
51 block_write_end(NULL, mapping, pos, len, len, folio, NULL);
52 if (pos+len > dir->i_size) {
53 i_size_write(dir, pos+len);
54 mark_inode_dirty(dir);
55 }
56 folio_unlock(folio);
57}
58
59static int ufs_handle_dirsync(struct inode *dir)
60{
61 int err;
62
63 err = filemap_write_and_wait(dir->i_mapping);
64 if (!err)
65 err = sync_inode_metadata(dir, 1);
66 return err;
67}
68
69ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
70{
71 ino_t res = 0;
72 struct ufs_dir_entry *de;
73 struct folio *folio;
74
75 de = ufs_find_entry(dir, qstr, &folio);
76 if (de) {
77 res = fs32_to_cpu(dir->i_sb, de->d_ino);
78 folio_release_kmap(folio, de);
79 }
80 return res;
81}
82
83
84int ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
85 struct folio *folio, struct inode *inode,
86 bool update_times)
87{
88 loff_t pos = folio_pos(folio) + offset_in_folio(folio, de);
89 unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
90 int err;
91
92 folio_lock(folio);
93 err = ufs_prepare_chunk(folio, pos, len);
94 if (unlikely(err)) {
95 folio_unlock(folio);
96 return err;
97 }
98
99 de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
100 ufs_set_de_type(dir->i_sb, de, inode->i_mode);
101
102 ufs_commit_chunk(folio, pos, len);
103 if (update_times)
104 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
105 mark_inode_dirty(dir);
106 return ufs_handle_dirsync(dir);
107}
108
109static bool ufs_check_folio(struct folio *folio, char *kaddr)
110{
111 struct inode *dir = folio->mapping->host;
112 struct super_block *sb = dir->i_sb;
113 unsigned offs, rec_len;
114 unsigned limit = folio_size(folio);
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 < folio_pos(folio) + limit) {
120 limit = offset_in_folio(folio, dir->i_size);
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 folio_set_checked(folio);
146 return true;
147
148 /* Too bad, we had an error */
149
150Ebadsize:
151 ufs_error(sb, __func__,
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, __func__, "bad entry in directory #%lu: %s - "
172 "offset=%llu, rec_len=%d, name_len=%d",
173 dir->i_ino, error, folio_pos(folio) + 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=%llu",
181 dir->i_ino, folio_pos(folio) + offs);
182fail:
183 return false;
184}
185
186static void *ufs_get_folio(struct inode *dir, unsigned long n,
187 struct folio **foliop)
188{
189 struct address_space *mapping = dir->i_mapping;
190 struct folio *folio = read_mapping_folio(mapping, n, NULL);
191 void *kaddr;
192
193 if (IS_ERR(folio))
194 return ERR_CAST(folio);
195 kaddr = kmap_local_folio(folio, 0);
196 if (unlikely(!folio_test_checked(folio))) {
197 if (!ufs_check_folio(folio, kaddr))
198 goto fail;
199 }
200 *foliop = folio;
201 return kaddr;
202
203fail:
204 folio_release_kmap(folio, kaddr);
205 return ERR_PTR(-EIO);
206}
207
208/*
209 * Return the offset into page `page_nr' of the last valid
210 * byte in that page, plus one.
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_SHIFT;
218 if (last_byte > PAGE_SIZE)
219 last_byte = PAGE_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 folio **foliop)
231{
232 struct ufs_dir_entry *de = ufs_get_folio(dir, 0, foliop);
233
234 if (!IS_ERR(de))
235 return ufs_next_entry(dir->i_sb, de);
236
237 return NULL;
238}
239
240/*
241 * ufs_find_entry()
242 *
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.
247 */
248struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr,
249 struct folio **foliop)
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 ufs_inode_info *ui = UFS_I(dir);
258 struct ufs_dir_entry *de;
259
260 UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
261
262 if (npages == 0 || namelen > UFS_MAXNAMLEN)
263 goto out;
264
265 start = ui->i_dir_start_lookup;
266
267 if (start >= npages)
268 start = 0;
269 n = start;
270 do {
271 char *kaddr = ufs_get_folio(dir, n, foliop);
272
273 if (!IS_ERR(kaddr)) {
274 de = (struct ufs_dir_entry *)kaddr;
275 kaddr += ufs_last_byte(dir, n) - reclen;
276 while ((char *) de <= kaddr) {
277 if (ufs_match(sb, namelen, name, de))
278 goto found;
279 de = ufs_next_entry(sb, de);
280 }
281 folio_release_kmap(*foliop, kaddr);
282 }
283 if (++n >= npages)
284 n = 0;
285 } while (n != start);
286out:
287 return NULL;
288
289found:
290 ui->i_dir_start_lookup = n;
291 return de;
292}
293
294/*
295 * Parent is locked.
296 */
297int ufs_add_link(struct dentry *dentry, struct inode *inode)
298{
299 struct inode *dir = d_inode(dentry->d_parent);
300 const unsigned char *name = dentry->d_name.name;
301 int namelen = dentry->d_name.len;
302 struct super_block *sb = dir->i_sb;
303 unsigned reclen = UFS_DIR_REC_LEN(namelen);
304 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
305 unsigned short rec_len, name_len;
306 struct folio *folio = NULL;
307 struct ufs_dir_entry *de;
308 unsigned long npages = dir_pages(dir);
309 unsigned long n;
310 loff_t pos;
311 int err;
312
313 UFSD("ENTER, name %s, namelen %u\n", name, namelen);
314
315 /*
316 * We take care of directory expansion in the same loop.
317 * This code plays outside i_size, so it locks the folio
318 * to protect that region.
319 */
320 for (n = 0; n <= npages; n++) {
321 char *kaddr = ufs_get_folio(dir, n, &folio);
322 char *dir_end;
323
324 if (IS_ERR(kaddr))
325 return PTR_ERR(kaddr);
326 folio_lock(folio);
327 dir_end = kaddr + ufs_last_byte(dir, n);
328 de = (struct ufs_dir_entry *)kaddr;
329 kaddr += folio_size(folio) - reclen;
330 while ((char *)de <= kaddr) {
331 if ((char *)de == dir_end) {
332 /* We hit i_size */
333 name_len = 0;
334 rec_len = chunk_size;
335 de->d_reclen = cpu_to_fs16(sb, chunk_size);
336 de->d_ino = 0;
337 goto got_it;
338 }
339 if (de->d_reclen == 0) {
340 ufs_error(dir->i_sb, __func__,
341 "zero-length directory entry");
342 err = -EIO;
343 goto out_unlock;
344 }
345 err = -EEXIST;
346 if (ufs_match(sb, namelen, name, de))
347 goto out_unlock;
348 name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
349 rec_len = fs16_to_cpu(sb, de->d_reclen);
350 if (!de->d_ino && rec_len >= reclen)
351 goto got_it;
352 if (rec_len >= name_len + reclen)
353 goto got_it;
354 de = (struct ufs_dir_entry *) ((char *) de + rec_len);
355 }
356 folio_unlock(folio);
357 folio_release_kmap(folio, kaddr);
358 }
359 BUG();
360 return -EINVAL;
361
362got_it:
363 pos = folio_pos(folio) + offset_in_folio(folio, de);
364 err = ufs_prepare_chunk(folio, pos, rec_len);
365 if (err)
366 goto out_unlock;
367 if (de->d_ino) {
368 struct ufs_dir_entry *de1 =
369 (struct ufs_dir_entry *) ((char *) de + name_len);
370 de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
371 de->d_reclen = cpu_to_fs16(sb, name_len);
372
373 de = de1;
374 }
375
376 ufs_set_de_namlen(sb, de, namelen);
377 memcpy(de->d_name, name, namelen + 1);
378 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
379 ufs_set_de_type(sb, de, inode->i_mode);
380
381 ufs_commit_chunk(folio, pos, rec_len);
382 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
383
384 mark_inode_dirty(dir);
385 err = ufs_handle_dirsync(dir);
386 /* OFFSET_CACHE */
387out_put:
388 folio_release_kmap(folio, de);
389 return err;
390out_unlock:
391 folio_unlock(folio);
392 goto out_put;
393}
394
395static inline unsigned
396ufs_validate_entry(struct super_block *sb, char *base,
397 unsigned offset, unsigned mask)
398{
399 struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
400 struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
401 while ((char*)p < (char*)de)
402 p = ufs_next_entry(sb, p);
403 return (char *)p - base;
404}
405
406
407/*
408 * This is blatantly stolen from ext2fs
409 */
410static int
411ufs_readdir(struct file *file, struct dir_context *ctx)
412{
413 loff_t pos = ctx->pos;
414 struct inode *inode = file_inode(file);
415 struct super_block *sb = inode->i_sb;
416 unsigned int offset = pos & ~PAGE_MASK;
417 unsigned long n = pos >> PAGE_SHIFT;
418 unsigned long npages = dir_pages(inode);
419 unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
420 bool need_revalidate = !inode_eq_iversion(inode, *(u64 *)file->private_data);
421 unsigned flags = UFS_SB(sb)->s_flags;
422
423 UFSD("BEGIN\n");
424
425 if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
426 return 0;
427
428 for ( ; n < npages; n++, offset = 0) {
429 struct ufs_dir_entry *de;
430 struct folio *folio;
431 char *kaddr = ufs_get_folio(inode, n, &folio);
432 char *limit;
433
434 if (IS_ERR(kaddr)) {
435 ufs_error(sb, __func__,
436 "bad page in #%lu",
437 inode->i_ino);
438 ctx->pos += PAGE_SIZE - offset;
439 return PTR_ERR(kaddr);
440 }
441 if (unlikely(need_revalidate)) {
442 if (offset) {
443 offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
444 ctx->pos = (n<<PAGE_SHIFT) + offset;
445 }
446 *(u64 *)file->private_data = inode_query_iversion(inode);
447 need_revalidate = false;
448 }
449 de = (struct ufs_dir_entry *)(kaddr+offset);
450 limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
451 for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
452 if (de->d_ino) {
453 unsigned char d_type = DT_UNKNOWN;
454
455 UFSD("filldir(%s,%u)\n", de->d_name,
456 fs32_to_cpu(sb, de->d_ino));
457 UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
458
459 if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
460 d_type = de->d_u.d_44.d_type;
461
462 if (!dir_emit(ctx, de->d_name,
463 ufs_get_de_namlen(sb, de),
464 fs32_to_cpu(sb, de->d_ino),
465 d_type)) {
466 folio_release_kmap(folio, de);
467 return 0;
468 }
469 }
470 ctx->pos += fs16_to_cpu(sb, de->d_reclen);
471 }
472 folio_release_kmap(folio, kaddr);
473 }
474 return 0;
475}
476
477
478/*
479 * ufs_delete_entry deletes a directory entry by merging it with the
480 * previous entry.
481 */
482int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
483 struct folio *folio)
484{
485 struct super_block *sb = inode->i_sb;
486 size_t from, to;
487 char *kaddr;
488 loff_t pos;
489 struct ufs_dir_entry *de, *pde = NULL;
490 int err;
491
492 UFSD("ENTER\n");
493
494 from = offset_in_folio(folio, dir);
495 to = from + fs16_to_cpu(sb, dir->d_reclen);
496 kaddr = (char *)dir - from;
497 from &= ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
498 de = (struct ufs_dir_entry *) (kaddr + from);
499
500 UFSD("ino %u, reclen %u, namlen %u, name %s\n",
501 fs32_to_cpu(sb, de->d_ino),
502 fs16_to_cpu(sb, de->d_reclen),
503 ufs_get_de_namlen(sb, de), de->d_name);
504
505 while ((char*)de < (char*)dir) {
506 if (de->d_reclen == 0) {
507 ufs_error(inode->i_sb, __func__,
508 "zero-length directory entry");
509 return -EIO;
510 }
511 pde = de;
512 de = ufs_next_entry(sb, de);
513 }
514 if (pde)
515 from = offset_in_folio(folio, pde);
516 pos = folio_pos(folio) + from;
517 folio_lock(folio);
518 err = ufs_prepare_chunk(folio, pos, to - from);
519 if (unlikely(err)) {
520 folio_unlock(folio);
521 return err;
522 }
523 if (pde)
524 pde->d_reclen = cpu_to_fs16(sb, to - from);
525 dir->d_ino = 0;
526 ufs_commit_chunk(folio, pos, to - from);
527 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
528 mark_inode_dirty(inode);
529 return ufs_handle_dirsync(inode);
530}
531
532int ufs_make_empty(struct inode * inode, struct inode *dir)
533{
534 struct super_block * sb = dir->i_sb;
535 struct address_space *mapping = inode->i_mapping;
536 struct folio *folio = filemap_grab_folio(mapping, 0);
537 const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
538 struct ufs_dir_entry * de;
539 int err;
540 char *kaddr;
541
542 if (IS_ERR(folio))
543 return PTR_ERR(folio);
544
545 err = ufs_prepare_chunk(folio, 0, chunk_size);
546 if (err) {
547 folio_unlock(folio);
548 goto fail;
549 }
550
551 kaddr = kmap_local_folio(folio, 0);
552 memset(kaddr, 0, folio_size(folio));
553
554 de = (struct ufs_dir_entry *)kaddr;
555
556 de->d_ino = cpu_to_fs32(sb, inode->i_ino);
557 ufs_set_de_type(sb, de, inode->i_mode);
558 ufs_set_de_namlen(sb, de, 1);
559 de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
560 strcpy (de->d_name, ".");
561 de = (struct ufs_dir_entry *)
562 ((char *)de + fs16_to_cpu(sb, de->d_reclen));
563 de->d_ino = cpu_to_fs32(sb, dir->i_ino);
564 ufs_set_de_type(sb, de, dir->i_mode);
565 de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
566 ufs_set_de_namlen(sb, de, 2);
567 strcpy (de->d_name, "..");
568 kunmap_local(kaddr);
569
570 ufs_commit_chunk(folio, 0, chunk_size);
571 err = ufs_handle_dirsync(inode);
572fail:
573 folio_put(folio);
574 return err;
575}
576
577/*
578 * routine to check that the specified directory is empty (for rmdir)
579 */
580int ufs_empty_dir(struct inode * inode)
581{
582 struct super_block *sb = inode->i_sb;
583 struct folio *folio;
584 char *kaddr;
585 unsigned long i, npages = dir_pages(inode);
586
587 for (i = 0; i < npages; i++) {
588 struct ufs_dir_entry *de;
589
590 kaddr = ufs_get_folio(inode, i, &folio);
591 if (IS_ERR(kaddr))
592 continue;
593
594 de = (struct ufs_dir_entry *)kaddr;
595 kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
596
597 while ((char *)de <= kaddr) {
598 if (de->d_reclen == 0) {
599 ufs_error(inode->i_sb, __func__,
600 "zero-length directory entry: "
601 "kaddr=%p, de=%p\n", kaddr, de);
602 goto not_empty;
603 }
604 if (de->d_ino) {
605 u16 namelen=ufs_get_de_namlen(sb, de);
606 /* check for . and .. */
607 if (de->d_name[0] != '.')
608 goto not_empty;
609 if (namelen > 2)
610 goto not_empty;
611 if (namelen < 2) {
612 if (inode->i_ino !=
613 fs32_to_cpu(sb, de->d_ino))
614 goto not_empty;
615 } else if (de->d_name[1] != '.')
616 goto not_empty;
617 }
618 de = ufs_next_entry(sb, de);
619 }
620 folio_release_kmap(folio, kaddr);
621 }
622 return 1;
623
624not_empty:
625 folio_release_kmap(folio, kaddr);
626 return 0;
627}
628
629static int ufs_dir_open(struct inode *inode, struct file *file)
630{
631 file->private_data = kzalloc(sizeof(u64), GFP_KERNEL);
632 if (!file->private_data)
633 return -ENOMEM;
634 return 0;
635}
636
637static int ufs_dir_release(struct inode *inode, struct file *file)
638{
639 kfree(file->private_data);
640 return 0;
641}
642
643static loff_t ufs_dir_llseek(struct file *file, loff_t offset, int whence)
644{
645 return generic_llseek_cookie(file, offset, whence,
646 (u64 *)file->private_data);
647}
648
649const struct file_operations ufs_dir_operations = {
650 .open = ufs_dir_open,
651 .release = ufs_dir_release,
652 .read = generic_read_dir,
653 .iterate_shared = ufs_readdir,
654 .fsync = generic_file_fsync,
655 .llseek = ufs_dir_llseek,
656};