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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/isofs/rock.c
4 *
5 * (C) 1992, 1993 Eric Youngdale
6 *
7 * Rock Ridge Extensions to iso9660
8 */
9
10#include <linux/slab.h>
11#include <linux/pagemap.h>
12
13#include "isofs.h"
14#include "rock.h"
15
16/*
17 * These functions are designed to read the system areas of a directory record
18 * and extract relevant information. There are different functions provided
19 * depending upon what information we need at the time. One function fills
20 * out an inode structure, a second one extracts a filename, a third one
21 * returns a symbolic link name, and a fourth one returns the extent number
22 * for the file.
23 */
24
25#define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
26
27struct rock_state {
28 void *buffer;
29 unsigned char *chr;
30 int len;
31 int cont_size;
32 int cont_extent;
33 int cont_offset;
34 int cont_loops;
35 struct inode *inode;
36};
37
38/*
39 * This is a way of ensuring that we have something in the system
40 * use fields that is compatible with Rock Ridge. Return zero on success.
41 */
42
43static int check_sp(struct rock_ridge *rr, struct inode *inode)
44{
45 if (rr->u.SP.magic[0] != 0xbe)
46 return -1;
47 if (rr->u.SP.magic[1] != 0xef)
48 return -1;
49 ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip;
50 return 0;
51}
52
53static void setup_rock_ridge(struct iso_directory_record *de,
54 struct inode *inode, struct rock_state *rs)
55{
56 rs->len = sizeof(struct iso_directory_record) + de->name_len[0];
57 if (rs->len & 1)
58 (rs->len)++;
59 rs->chr = (unsigned char *)de + rs->len;
60 rs->len = *((unsigned char *)de) - rs->len;
61 if (rs->len < 0)
62 rs->len = 0;
63
64 if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
65 rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset;
66 rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset;
67 if (rs->len < 0)
68 rs->len = 0;
69 }
70}
71
72static void init_rock_state(struct rock_state *rs, struct inode *inode)
73{
74 memset(rs, 0, sizeof(*rs));
75 rs->inode = inode;
76}
77
78/* Maximum number of Rock Ridge continuation entries */
79#define RR_MAX_CE_ENTRIES 32
80
81/*
82 * Returns 0 if the caller should continue scanning, 1 if the scan must end
83 * and -ve on error.
84 */
85static int rock_continue(struct rock_state *rs)
86{
87 int ret = 1;
88 int blocksize = 1 << rs->inode->i_blkbits;
89 const int min_de_size = offsetof(struct rock_ridge, u);
90
91 kfree(rs->buffer);
92 rs->buffer = NULL;
93
94 if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
95 (unsigned)rs->cont_size > blocksize ||
96 (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
97 printk(KERN_NOTICE "rock: corrupted directory entry. "
98 "extent=%d, offset=%d, size=%d\n",
99 rs->cont_extent, rs->cont_offset, rs->cont_size);
100 ret = -EIO;
101 goto out;
102 }
103
104 if (rs->cont_extent) {
105 struct buffer_head *bh;
106
107 rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
108 if (!rs->buffer) {
109 ret = -ENOMEM;
110 goto out;
111 }
112 ret = -EIO;
113 if (++rs->cont_loops >= RR_MAX_CE_ENTRIES)
114 goto out;
115 bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
116 if (bh) {
117 memcpy(rs->buffer, bh->b_data + rs->cont_offset,
118 rs->cont_size);
119 put_bh(bh);
120 rs->chr = rs->buffer;
121 rs->len = rs->cont_size;
122 rs->cont_extent = 0;
123 rs->cont_size = 0;
124 rs->cont_offset = 0;
125 return 0;
126 }
127 printk("Unable to read rock-ridge attributes\n");
128 }
129out:
130 kfree(rs->buffer);
131 rs->buffer = NULL;
132 return ret;
133}
134
135/*
136 * We think there's a record of type `sig' at rs->chr. Parse the signature
137 * and make sure that there's really room for a record of that type.
138 */
139static int rock_check_overflow(struct rock_state *rs, int sig)
140{
141 int len;
142
143 switch (sig) {
144 case SIG('S', 'P'):
145 len = sizeof(struct SU_SP_s);
146 break;
147 case SIG('C', 'E'):
148 len = sizeof(struct SU_CE_s);
149 break;
150 case SIG('E', 'R'):
151 len = sizeof(struct SU_ER_s);
152 break;
153 case SIG('R', 'R'):
154 len = sizeof(struct RR_RR_s);
155 break;
156 case SIG('P', 'X'):
157 len = sizeof(struct RR_PX_s);
158 break;
159 case SIG('P', 'N'):
160 len = sizeof(struct RR_PN_s);
161 break;
162 case SIG('S', 'L'):
163 len = sizeof(struct RR_SL_s);
164 break;
165 case SIG('N', 'M'):
166 len = sizeof(struct RR_NM_s);
167 break;
168 case SIG('C', 'L'):
169 len = sizeof(struct RR_CL_s);
170 break;
171 case SIG('P', 'L'):
172 len = sizeof(struct RR_PL_s);
173 break;
174 case SIG('T', 'F'):
175 len = sizeof(struct RR_TF_s);
176 break;
177 case SIG('Z', 'F'):
178 len = sizeof(struct RR_ZF_s);
179 break;
180 default:
181 len = 0;
182 break;
183 }
184 len += offsetof(struct rock_ridge, u);
185 if (len > rs->len) {
186 printk(KERN_NOTICE "rock: directory entry would overflow "
187 "storage\n");
188 printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
189 sig, len, rs->len);
190 return -EIO;
191 }
192 return 0;
193}
194
195/*
196 * return length of name field; 0: not found, -1: to be ignored
197 */
198int get_rock_ridge_filename(struct iso_directory_record *de,
199 char *retname, struct inode *inode)
200{
201 struct rock_state rs;
202 struct rock_ridge *rr;
203 int sig;
204 int retnamlen = 0;
205 int truncate = 0;
206 int ret = 0;
207 char *p;
208 int len;
209
210 if (!ISOFS_SB(inode->i_sb)->s_rock)
211 return 0;
212 *retname = 0;
213
214 init_rock_state(&rs, inode);
215 setup_rock_ridge(de, inode, &rs);
216repeat:
217
218 while (rs.len > 2) { /* There may be one byte for padding somewhere */
219 rr = (struct rock_ridge *)rs.chr;
220 /*
221 * Ignore rock ridge info if rr->len is out of range, but
222 * don't return -EIO because that would make the file
223 * invisible.
224 */
225 if (rr->len < 3)
226 goto out; /* Something got screwed up here */
227 sig = isonum_721(rs.chr);
228 if (rock_check_overflow(&rs, sig))
229 goto eio;
230 rs.chr += rr->len;
231 rs.len -= rr->len;
232 /*
233 * As above, just ignore the rock ridge info if rr->len
234 * is bogus.
235 */
236 if (rs.len < 0)
237 goto out; /* Something got screwed up here */
238
239 switch (sig) {
240 case SIG('R', 'R'):
241 if ((rr->u.RR.flags[0] & RR_NM) == 0)
242 goto out;
243 break;
244 case SIG('S', 'P'):
245 if (check_sp(rr, inode))
246 goto out;
247 break;
248 case SIG('C', 'E'):
249 rs.cont_extent = isonum_733(rr->u.CE.extent);
250 rs.cont_offset = isonum_733(rr->u.CE.offset);
251 rs.cont_size = isonum_733(rr->u.CE.size);
252 break;
253 case SIG('N', 'M'):
254 if (truncate)
255 break;
256 if (rr->len < 5)
257 break;
258 /*
259 * If the flags are 2 or 4, this indicates '.' or '..'.
260 * We don't want to do anything with this, because it
261 * screws up the code that calls us. We don't really
262 * care anyways, since we can just use the non-RR
263 * name.
264 */
265 if (rr->u.NM.flags & 6)
266 break;
267
268 if (rr->u.NM.flags & ~1) {
269 printk("Unsupported NM flag settings (%d)\n",
270 rr->u.NM.flags);
271 break;
272 }
273 len = rr->len - 5;
274 if (retnamlen + len >= 254) {
275 truncate = 1;
276 break;
277 }
278 p = memchr(rr->u.NM.name, '\0', len);
279 if (unlikely(p))
280 len = p - rr->u.NM.name;
281 memcpy(retname + retnamlen, rr->u.NM.name, len);
282 retnamlen += len;
283 retname[retnamlen] = '\0';
284 break;
285 case SIG('R', 'E'):
286 kfree(rs.buffer);
287 return -1;
288 default:
289 break;
290 }
291 }
292 ret = rock_continue(&rs);
293 if (ret == 0)
294 goto repeat;
295 if (ret == 1)
296 return retnamlen; /* If 0, this file did not have a NM field */
297out:
298 kfree(rs.buffer);
299 return ret;
300eio:
301 ret = -EIO;
302 goto out;
303}
304
305#define RR_REGARD_XA 1
306#define RR_RELOC_DE 2
307
308static int
309parse_rock_ridge_inode_internal(struct iso_directory_record *de,
310 struct inode *inode, int flags)
311{
312 int symlink_len = 0;
313 int cnt, sig;
314 unsigned int reloc_block;
315 struct inode *reloc;
316 struct rock_ridge *rr;
317 int rootflag;
318 struct rock_state rs;
319 int ret = 0;
320
321 if (!ISOFS_SB(inode->i_sb)->s_rock)
322 return 0;
323
324 init_rock_state(&rs, inode);
325 setup_rock_ridge(de, inode, &rs);
326 if (flags & RR_REGARD_XA) {
327 rs.chr += 14;
328 rs.len -= 14;
329 if (rs.len < 0)
330 rs.len = 0;
331 }
332
333repeat:
334 while (rs.len > 2) { /* There may be one byte for padding somewhere */
335 rr = (struct rock_ridge *)rs.chr;
336 /*
337 * Ignore rock ridge info if rr->len is out of range, but
338 * don't return -EIO because that would make the file
339 * invisible.
340 */
341 if (rr->len < 3)
342 goto out; /* Something got screwed up here */
343 sig = isonum_721(rs.chr);
344 if (rock_check_overflow(&rs, sig))
345 goto eio;
346 rs.chr += rr->len;
347 rs.len -= rr->len;
348 /*
349 * As above, just ignore the rock ridge info if rr->len
350 * is bogus.
351 */
352 if (rs.len < 0)
353 goto out; /* Something got screwed up here */
354
355 switch (sig) {
356#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
357 case SIG('R', 'R'):
358 if ((rr->u.RR.flags[0] &
359 (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
360 goto out;
361 break;
362#endif
363 case SIG('S', 'P'):
364 if (check_sp(rr, inode))
365 goto out;
366 break;
367 case SIG('C', 'E'):
368 rs.cont_extent = isonum_733(rr->u.CE.extent);
369 rs.cont_offset = isonum_733(rr->u.CE.offset);
370 rs.cont_size = isonum_733(rr->u.CE.size);
371 break;
372 case SIG('E', 'R'):
373 /* Invalid length of ER tag id? */
374 if (rr->u.ER.len_id + offsetof(struct rock_ridge, u.ER.data) > rr->len)
375 goto out;
376 ISOFS_SB(inode->i_sb)->s_rock = 1;
377 printk(KERN_DEBUG "ISO 9660 Extensions: ");
378 {
379 int p;
380 for (p = 0; p < rr->u.ER.len_id; p++)
381 printk(KERN_CONT "%c", rr->u.ER.data[p]);
382 }
383 printk(KERN_CONT "\n");
384 break;
385 case SIG('P', 'X'):
386 inode->i_mode = isonum_733(rr->u.PX.mode);
387 set_nlink(inode, isonum_733(rr->u.PX.n_links));
388 i_uid_write(inode, isonum_733(rr->u.PX.uid));
389 i_gid_write(inode, isonum_733(rr->u.PX.gid));
390 break;
391 case SIG('P', 'N'):
392 {
393 int high, low;
394 high = isonum_733(rr->u.PN.dev_high);
395 low = isonum_733(rr->u.PN.dev_low);
396 /*
397 * The Rock Ridge standard specifies that if
398 * sizeof(dev_t) <= 4, then the high field is
399 * unused, and the device number is completely
400 * stored in the low field. Some writers may
401 * ignore this subtlety,
402 * and as a result we test to see if the entire
403 * device number is
404 * stored in the low field, and use that.
405 */
406 if ((low & ~0xff) && high == 0) {
407 inode->i_rdev =
408 MKDEV(low >> 8, low & 0xff);
409 } else {
410 inode->i_rdev =
411 MKDEV(high, low);
412 }
413 }
414 break;
415 case SIG('T', 'F'):
416 /*
417 * Some RRIP writers incorrectly place ctime in the
418 * TF_CREATE field. Try to handle this correctly for
419 * either case.
420 */
421 /* Rock ridge never appears on a High Sierra disk */
422 cnt = 0;
423 if (rr->u.TF.flags & TF_CREATE) {
424 inode_set_ctime(inode,
425 iso_date(rr->u.TF.times[cnt++].time, 0),
426 0);
427 }
428 if (rr->u.TF.flags & TF_MODIFY) {
429 inode_set_mtime(inode,
430 iso_date(rr->u.TF.times[cnt++].time, 0),
431 0);
432 }
433 if (rr->u.TF.flags & TF_ACCESS) {
434 inode_set_atime(inode,
435 iso_date(rr->u.TF.times[cnt++].time, 0),
436 0);
437 }
438 if (rr->u.TF.flags & TF_ATTRIBUTES) {
439 inode_set_ctime(inode,
440 iso_date(rr->u.TF.times[cnt++].time, 0),
441 0);
442 }
443 break;
444 case SIG('S', 'L'):
445 {
446 int slen;
447 struct SL_component *slp;
448 struct SL_component *oldslp;
449 slen = rr->len - 5;
450 slp = &rr->u.SL.link;
451 inode->i_size = symlink_len;
452 while (slen > 1) {
453 rootflag = 0;
454 switch (slp->flags & ~1) {
455 case 0:
456 inode->i_size +=
457 slp->len;
458 break;
459 case 2:
460 inode->i_size += 1;
461 break;
462 case 4:
463 inode->i_size += 2;
464 break;
465 case 8:
466 rootflag = 1;
467 inode->i_size += 1;
468 break;
469 default:
470 printk("Symlink component flag "
471 "not implemented\n");
472 }
473 slen -= slp->len + 2;
474 oldslp = slp;
475 slp = (struct SL_component *)
476 (((char *)slp) + slp->len + 2);
477
478 if (slen < 2) {
479 if (((rr->u.SL.
480 flags & 1) != 0)
481 &&
482 ((oldslp->
483 flags & 1) == 0))
484 inode->i_size +=
485 1;
486 break;
487 }
488
489 /*
490 * If this component record isn't
491 * continued, then append a '/'.
492 */
493 if (!rootflag
494 && (oldslp->flags & 1) == 0)
495 inode->i_size += 1;
496 }
497 }
498 symlink_len = inode->i_size;
499 break;
500 case SIG('R', 'E'):
501 printk(KERN_WARNING "Attempt to read inode for "
502 "relocated directory\n");
503 goto out;
504 case SIG('C', 'L'):
505 if (flags & RR_RELOC_DE) {
506 printk(KERN_ERR
507 "ISOFS: Recursive directory relocation "
508 "is not supported\n");
509 goto eio;
510 }
511 reloc_block = isonum_733(rr->u.CL.location);
512 if (reloc_block == ISOFS_I(inode)->i_iget5_block &&
513 ISOFS_I(inode)->i_iget5_offset == 0) {
514 printk(KERN_ERR
515 "ISOFS: Directory relocation points to "
516 "itself\n");
517 goto eio;
518 }
519 ISOFS_I(inode)->i_first_extent = reloc_block;
520 reloc = isofs_iget_reloc(inode->i_sb, reloc_block, 0);
521 if (IS_ERR(reloc)) {
522 ret = PTR_ERR(reloc);
523 goto out;
524 }
525 inode->i_mode = reloc->i_mode;
526 set_nlink(inode, reloc->i_nlink);
527 inode->i_uid = reloc->i_uid;
528 inode->i_gid = reloc->i_gid;
529 inode->i_rdev = reloc->i_rdev;
530 inode->i_size = reloc->i_size;
531 inode->i_blocks = reloc->i_blocks;
532 inode_set_atime_to_ts(inode, inode_get_atime(reloc));
533 inode_set_ctime_to_ts(inode, inode_get_ctime(reloc));
534 inode_set_mtime_to_ts(inode, inode_get_mtime(reloc));
535 iput(reloc);
536 break;
537#ifdef CONFIG_ZISOFS
538 case SIG('Z', 'F'): {
539 int algo;
540
541 if (ISOFS_SB(inode->i_sb)->s_nocompress)
542 break;
543 algo = isonum_721(rr->u.ZF.algorithm);
544 if (algo == SIG('p', 'z')) {
545 int block_shift =
546 isonum_711(&rr->u.ZF.parms[1]);
547 if (block_shift > 17) {
548 printk(KERN_WARNING "isofs: "
549 "Can't handle ZF block "
550 "size of 2^%d\n",
551 block_shift);
552 } else {
553 /*
554 * Note: we don't change
555 * i_blocks here
556 */
557 ISOFS_I(inode)->i_file_format =
558 isofs_file_compressed;
559 /*
560 * Parameters to compression
561 * algorithm (header size,
562 * block size)
563 */
564 ISOFS_I(inode)->i_format_parm[0] =
565 isonum_711(&rr->u.ZF.parms[0]);
566 ISOFS_I(inode)->i_format_parm[1] =
567 isonum_711(&rr->u.ZF.parms[1]);
568 inode->i_size =
569 isonum_733(rr->u.ZF.
570 real_size);
571 }
572 } else {
573 printk(KERN_WARNING
574 "isofs: Unknown ZF compression "
575 "algorithm: %c%c\n",
576 rr->u.ZF.algorithm[0],
577 rr->u.ZF.algorithm[1]);
578 }
579 break;
580 }
581#endif
582 default:
583 break;
584 }
585 }
586 ret = rock_continue(&rs);
587 if (ret == 0)
588 goto repeat;
589 if (ret == 1)
590 ret = 0;
591out:
592 kfree(rs.buffer);
593 return ret;
594eio:
595 ret = -EIO;
596 goto out;
597}
598
599static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
600{
601 int slen;
602 int rootflag;
603 struct SL_component *oldslp;
604 struct SL_component *slp;
605 slen = rr->len - 5;
606 slp = &rr->u.SL.link;
607 while (slen > 1) {
608 rootflag = 0;
609 switch (slp->flags & ~1) {
610 case 0:
611 if (slp->len > plimit - rpnt)
612 return NULL;
613 memcpy(rpnt, slp->text, slp->len);
614 rpnt += slp->len;
615 break;
616 case 2:
617 if (rpnt >= plimit)
618 return NULL;
619 *rpnt++ = '.';
620 break;
621 case 4:
622 if (2 > plimit - rpnt)
623 return NULL;
624 *rpnt++ = '.';
625 *rpnt++ = '.';
626 break;
627 case 8:
628 if (rpnt >= plimit)
629 return NULL;
630 rootflag = 1;
631 *rpnt++ = '/';
632 break;
633 default:
634 printk("Symlink component flag not implemented (%d)\n",
635 slp->flags);
636 }
637 slen -= slp->len + 2;
638 oldslp = slp;
639 slp = (struct SL_component *)((char *)slp + slp->len + 2);
640
641 if (slen < 2) {
642 /*
643 * If there is another SL record, and this component
644 * record isn't continued, then add a slash.
645 */
646 if ((!rootflag) && (rr->u.SL.flags & 1) &&
647 !(oldslp->flags & 1)) {
648 if (rpnt >= plimit)
649 return NULL;
650 *rpnt++ = '/';
651 }
652 break;
653 }
654
655 /*
656 * If this component record isn't continued, then append a '/'.
657 */
658 if (!rootflag && !(oldslp->flags & 1)) {
659 if (rpnt >= plimit)
660 return NULL;
661 *rpnt++ = '/';
662 }
663 }
664 return rpnt;
665}
666
667int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode,
668 int relocated)
669{
670 int flags = relocated ? RR_RELOC_DE : 0;
671 int result = parse_rock_ridge_inode_internal(de, inode, flags);
672
673 /*
674 * if rockridge flag was reset and we didn't look for attributes
675 * behind eventual XA attributes, have a look there
676 */
677 if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
678 && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
679 result = parse_rock_ridge_inode_internal(de, inode,
680 flags | RR_REGARD_XA);
681 }
682 return result;
683}
684
685/*
686 * read_folio() for symlinks: reads symlink contents into the folio and either
687 * makes it uptodate and returns 0 or returns error (-EIO)
688 */
689static int rock_ridge_symlink_read_folio(struct file *file, struct folio *folio)
690{
691 struct page *page = &folio->page;
692 struct inode *inode = page->mapping->host;
693 struct iso_inode_info *ei = ISOFS_I(inode);
694 struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
695 char *link = page_address(page);
696 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
697 struct buffer_head *bh;
698 char *rpnt = link;
699 unsigned char *pnt;
700 struct iso_directory_record *raw_de;
701 unsigned long block, offset;
702 int sig;
703 struct rock_ridge *rr;
704 struct rock_state rs;
705 int ret;
706
707 if (!sbi->s_rock)
708 goto error;
709
710 init_rock_state(&rs, inode);
711 block = ei->i_iget5_block;
712 bh = sb_bread(inode->i_sb, block);
713 if (!bh)
714 goto out_noread;
715
716 offset = ei->i_iget5_offset;
717 pnt = (unsigned char *)bh->b_data + offset;
718
719 raw_de = (struct iso_directory_record *)pnt;
720
721 /*
722 * If we go past the end of the buffer, there is some sort of error.
723 */
724 if (offset + *pnt > bufsize)
725 goto out_bad_span;
726
727 /*
728 * Now test for possible Rock Ridge extensions which will override
729 * some of these numbers in the inode structure.
730 */
731
732 setup_rock_ridge(raw_de, inode, &rs);
733
734repeat:
735 while (rs.len > 2) { /* There may be one byte for padding somewhere */
736 rr = (struct rock_ridge *)rs.chr;
737 if (rr->len < 3)
738 goto out; /* Something got screwed up here */
739 sig = isonum_721(rs.chr);
740 if (rock_check_overflow(&rs, sig))
741 goto out;
742 rs.chr += rr->len;
743 rs.len -= rr->len;
744 if (rs.len < 0)
745 goto out; /* corrupted isofs */
746
747 switch (sig) {
748 case SIG('R', 'R'):
749 if ((rr->u.RR.flags[0] & RR_SL) == 0)
750 goto out;
751 break;
752 case SIG('S', 'P'):
753 if (check_sp(rr, inode))
754 goto out;
755 break;
756 case SIG('S', 'L'):
757 rpnt = get_symlink_chunk(rpnt, rr,
758 link + (PAGE_SIZE - 1));
759 if (rpnt == NULL)
760 goto out;
761 break;
762 case SIG('C', 'E'):
763 /* This tells is if there is a continuation record */
764 rs.cont_extent = isonum_733(rr->u.CE.extent);
765 rs.cont_offset = isonum_733(rr->u.CE.offset);
766 rs.cont_size = isonum_733(rr->u.CE.size);
767 break;
768 default:
769 break;
770 }
771 }
772 ret = rock_continue(&rs);
773 if (ret == 0)
774 goto repeat;
775 if (ret < 0)
776 goto fail;
777
778 if (rpnt == link)
779 goto fail;
780 brelse(bh);
781 *rpnt = '\0';
782 SetPageUptodate(page);
783 unlock_page(page);
784 return 0;
785
786 /* error exit from macro */
787out:
788 kfree(rs.buffer);
789 goto fail;
790out_noread:
791 printk("unable to read i-node block");
792 goto fail;
793out_bad_span:
794 printk("symlink spans iso9660 blocks\n");
795fail:
796 brelse(bh);
797error:
798 SetPageError(page);
799 unlock_page(page);
800 return -EIO;
801}
802
803const struct address_space_operations isofs_symlink_aops = {
804 .read_folio = rock_ridge_symlink_read_folio
805};
1/*
2 * linux/fs/isofs/rock.c
3 *
4 * (C) 1992, 1993 Eric Youngdale
5 *
6 * Rock Ridge Extensions to iso9660
7 */
8
9#include <linux/slab.h>
10#include <linux/pagemap.h>
11
12#include "isofs.h"
13#include "rock.h"
14
15/*
16 * These functions are designed to read the system areas of a directory record
17 * and extract relevant information. There are different functions provided
18 * depending upon what information we need at the time. One function fills
19 * out an inode structure, a second one extracts a filename, a third one
20 * returns a symbolic link name, and a fourth one returns the extent number
21 * for the file.
22 */
23
24#define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
25
26struct rock_state {
27 void *buffer;
28 unsigned char *chr;
29 int len;
30 int cont_size;
31 int cont_extent;
32 int cont_offset;
33 int cont_loops;
34 struct inode *inode;
35};
36
37/*
38 * This is a way of ensuring that we have something in the system
39 * use fields that is compatible with Rock Ridge. Return zero on success.
40 */
41
42static int check_sp(struct rock_ridge *rr, struct inode *inode)
43{
44 if (rr->u.SP.magic[0] != 0xbe)
45 return -1;
46 if (rr->u.SP.magic[1] != 0xef)
47 return -1;
48 ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip;
49 return 0;
50}
51
52static void setup_rock_ridge(struct iso_directory_record *de,
53 struct inode *inode, struct rock_state *rs)
54{
55 rs->len = sizeof(struct iso_directory_record) + de->name_len[0];
56 if (rs->len & 1)
57 (rs->len)++;
58 rs->chr = (unsigned char *)de + rs->len;
59 rs->len = *((unsigned char *)de) - rs->len;
60 if (rs->len < 0)
61 rs->len = 0;
62
63 if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
64 rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset;
65 rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset;
66 if (rs->len < 0)
67 rs->len = 0;
68 }
69}
70
71static void init_rock_state(struct rock_state *rs, struct inode *inode)
72{
73 memset(rs, 0, sizeof(*rs));
74 rs->inode = inode;
75}
76
77/* Maximum number of Rock Ridge continuation entries */
78#define RR_MAX_CE_ENTRIES 32
79
80/*
81 * Returns 0 if the caller should continue scanning, 1 if the scan must end
82 * and -ve on error.
83 */
84static int rock_continue(struct rock_state *rs)
85{
86 int ret = 1;
87 int blocksize = 1 << rs->inode->i_blkbits;
88 const int min_de_size = offsetof(struct rock_ridge, u);
89
90 kfree(rs->buffer);
91 rs->buffer = NULL;
92
93 if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
94 (unsigned)rs->cont_size > blocksize ||
95 (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
96 printk(KERN_NOTICE "rock: corrupted directory entry. "
97 "extent=%d, offset=%d, size=%d\n",
98 rs->cont_extent, rs->cont_offset, rs->cont_size);
99 ret = -EIO;
100 goto out;
101 }
102
103 if (rs->cont_extent) {
104 struct buffer_head *bh;
105
106 rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
107 if (!rs->buffer) {
108 ret = -ENOMEM;
109 goto out;
110 }
111 ret = -EIO;
112 if (++rs->cont_loops >= RR_MAX_CE_ENTRIES)
113 goto out;
114 bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
115 if (bh) {
116 memcpy(rs->buffer, bh->b_data + rs->cont_offset,
117 rs->cont_size);
118 put_bh(bh);
119 rs->chr = rs->buffer;
120 rs->len = rs->cont_size;
121 rs->cont_extent = 0;
122 rs->cont_size = 0;
123 rs->cont_offset = 0;
124 return 0;
125 }
126 printk("Unable to read rock-ridge attributes\n");
127 }
128out:
129 kfree(rs->buffer);
130 rs->buffer = NULL;
131 return ret;
132}
133
134/*
135 * We think there's a record of type `sig' at rs->chr. Parse the signature
136 * and make sure that there's really room for a record of that type.
137 */
138static int rock_check_overflow(struct rock_state *rs, int sig)
139{
140 int len;
141
142 switch (sig) {
143 case SIG('S', 'P'):
144 len = sizeof(struct SU_SP_s);
145 break;
146 case SIG('C', 'E'):
147 len = sizeof(struct SU_CE_s);
148 break;
149 case SIG('E', 'R'):
150 len = sizeof(struct SU_ER_s);
151 break;
152 case SIG('R', 'R'):
153 len = sizeof(struct RR_RR_s);
154 break;
155 case SIG('P', 'X'):
156 len = sizeof(struct RR_PX_s);
157 break;
158 case SIG('P', 'N'):
159 len = sizeof(struct RR_PN_s);
160 break;
161 case SIG('S', 'L'):
162 len = sizeof(struct RR_SL_s);
163 break;
164 case SIG('N', 'M'):
165 len = sizeof(struct RR_NM_s);
166 break;
167 case SIG('C', 'L'):
168 len = sizeof(struct RR_CL_s);
169 break;
170 case SIG('P', 'L'):
171 len = sizeof(struct RR_PL_s);
172 break;
173 case SIG('T', 'F'):
174 len = sizeof(struct RR_TF_s);
175 break;
176 case SIG('Z', 'F'):
177 len = sizeof(struct RR_ZF_s);
178 break;
179 default:
180 len = 0;
181 break;
182 }
183 len += offsetof(struct rock_ridge, u);
184 if (len > rs->len) {
185 printk(KERN_NOTICE "rock: directory entry would overflow "
186 "storage\n");
187 printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
188 sig, len, rs->len);
189 return -EIO;
190 }
191 return 0;
192}
193
194/*
195 * return length of name field; 0: not found, -1: to be ignored
196 */
197int get_rock_ridge_filename(struct iso_directory_record *de,
198 char *retname, struct inode *inode)
199{
200 struct rock_state rs;
201 struct rock_ridge *rr;
202 int sig;
203 int retnamlen = 0;
204 int truncate = 0;
205 int ret = 0;
206 char *p;
207 int len;
208
209 if (!ISOFS_SB(inode->i_sb)->s_rock)
210 return 0;
211 *retname = 0;
212
213 init_rock_state(&rs, inode);
214 setup_rock_ridge(de, inode, &rs);
215repeat:
216
217 while (rs.len > 2) { /* There may be one byte for padding somewhere */
218 rr = (struct rock_ridge *)rs.chr;
219 /*
220 * Ignore rock ridge info if rr->len is out of range, but
221 * don't return -EIO because that would make the file
222 * invisible.
223 */
224 if (rr->len < 3)
225 goto out; /* Something got screwed up here */
226 sig = isonum_721(rs.chr);
227 if (rock_check_overflow(&rs, sig))
228 goto eio;
229 rs.chr += rr->len;
230 rs.len -= rr->len;
231 /*
232 * As above, just ignore the rock ridge info if rr->len
233 * is bogus.
234 */
235 if (rs.len < 0)
236 goto out; /* Something got screwed up here */
237
238 switch (sig) {
239 case SIG('R', 'R'):
240 if ((rr->u.RR.flags[0] & RR_NM) == 0)
241 goto out;
242 break;
243 case SIG('S', 'P'):
244 if (check_sp(rr, inode))
245 goto out;
246 break;
247 case SIG('C', 'E'):
248 rs.cont_extent = isonum_733(rr->u.CE.extent);
249 rs.cont_offset = isonum_733(rr->u.CE.offset);
250 rs.cont_size = isonum_733(rr->u.CE.size);
251 break;
252 case SIG('N', 'M'):
253 if (truncate)
254 break;
255 if (rr->len < 5)
256 break;
257 /*
258 * If the flags are 2 or 4, this indicates '.' or '..'.
259 * We don't want to do anything with this, because it
260 * screws up the code that calls us. We don't really
261 * care anyways, since we can just use the non-RR
262 * name.
263 */
264 if (rr->u.NM.flags & 6)
265 break;
266
267 if (rr->u.NM.flags & ~1) {
268 printk("Unsupported NM flag settings (%d)\n",
269 rr->u.NM.flags);
270 break;
271 }
272 len = rr->len - 5;
273 if (retnamlen + len >= 254) {
274 truncate = 1;
275 break;
276 }
277 p = memchr(rr->u.NM.name, '\0', len);
278 if (unlikely(p))
279 len = p - rr->u.NM.name;
280 memcpy(retname + retnamlen, rr->u.NM.name, len);
281 retnamlen += len;
282 retname[retnamlen] = '\0';
283 break;
284 case SIG('R', 'E'):
285 kfree(rs.buffer);
286 return -1;
287 default:
288 break;
289 }
290 }
291 ret = rock_continue(&rs);
292 if (ret == 0)
293 goto repeat;
294 if (ret == 1)
295 return retnamlen; /* If 0, this file did not have a NM field */
296out:
297 kfree(rs.buffer);
298 return ret;
299eio:
300 ret = -EIO;
301 goto out;
302}
303
304#define RR_REGARD_XA 1
305#define RR_RELOC_DE 2
306
307static int
308parse_rock_ridge_inode_internal(struct iso_directory_record *de,
309 struct inode *inode, int flags)
310{
311 int symlink_len = 0;
312 int cnt, sig;
313 unsigned int reloc_block;
314 struct inode *reloc;
315 struct rock_ridge *rr;
316 int rootflag;
317 struct rock_state rs;
318 int ret = 0;
319
320 if (!ISOFS_SB(inode->i_sb)->s_rock)
321 return 0;
322
323 init_rock_state(&rs, inode);
324 setup_rock_ridge(de, inode, &rs);
325 if (flags & RR_REGARD_XA) {
326 rs.chr += 14;
327 rs.len -= 14;
328 if (rs.len < 0)
329 rs.len = 0;
330 }
331
332repeat:
333 while (rs.len > 2) { /* There may be one byte for padding somewhere */
334 rr = (struct rock_ridge *)rs.chr;
335 /*
336 * Ignore rock ridge info if rr->len is out of range, but
337 * don't return -EIO because that would make the file
338 * invisible.
339 */
340 if (rr->len < 3)
341 goto out; /* Something got screwed up here */
342 sig = isonum_721(rs.chr);
343 if (rock_check_overflow(&rs, sig))
344 goto eio;
345 rs.chr += rr->len;
346 rs.len -= rr->len;
347 /*
348 * As above, just ignore the rock ridge info if rr->len
349 * is bogus.
350 */
351 if (rs.len < 0)
352 goto out; /* Something got screwed up here */
353
354 switch (sig) {
355#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
356 case SIG('R', 'R'):
357 if ((rr->u.RR.flags[0] &
358 (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
359 goto out;
360 break;
361#endif
362 case SIG('S', 'P'):
363 if (check_sp(rr, inode))
364 goto out;
365 break;
366 case SIG('C', 'E'):
367 rs.cont_extent = isonum_733(rr->u.CE.extent);
368 rs.cont_offset = isonum_733(rr->u.CE.offset);
369 rs.cont_size = isonum_733(rr->u.CE.size);
370 break;
371 case SIG('E', 'R'):
372 /* Invalid length of ER tag id? */
373 if (rr->u.ER.len_id + offsetof(struct rock_ridge, u.ER.data) > rr->len)
374 goto out;
375 ISOFS_SB(inode->i_sb)->s_rock = 1;
376 printk(KERN_DEBUG "ISO 9660 Extensions: ");
377 {
378 int p;
379 for (p = 0; p < rr->u.ER.len_id; p++)
380 printk("%c", rr->u.ER.data[p]);
381 }
382 printk("\n");
383 break;
384 case SIG('P', 'X'):
385 inode->i_mode = isonum_733(rr->u.PX.mode);
386 set_nlink(inode, isonum_733(rr->u.PX.n_links));
387 i_uid_write(inode, isonum_733(rr->u.PX.uid));
388 i_gid_write(inode, isonum_733(rr->u.PX.gid));
389 break;
390 case SIG('P', 'N'):
391 {
392 int high, low;
393 high = isonum_733(rr->u.PN.dev_high);
394 low = isonum_733(rr->u.PN.dev_low);
395 /*
396 * The Rock Ridge standard specifies that if
397 * sizeof(dev_t) <= 4, then the high field is
398 * unused, and the device number is completely
399 * stored in the low field. Some writers may
400 * ignore this subtlety,
401 * and as a result we test to see if the entire
402 * device number is
403 * stored in the low field, and use that.
404 */
405 if ((low & ~0xff) && high == 0) {
406 inode->i_rdev =
407 MKDEV(low >> 8, low & 0xff);
408 } else {
409 inode->i_rdev =
410 MKDEV(high, low);
411 }
412 }
413 break;
414 case SIG('T', 'F'):
415 /*
416 * Some RRIP writers incorrectly place ctime in the
417 * TF_CREATE field. Try to handle this correctly for
418 * either case.
419 */
420 /* Rock ridge never appears on a High Sierra disk */
421 cnt = 0;
422 if (rr->u.TF.flags & TF_CREATE) {
423 inode->i_ctime.tv_sec =
424 iso_date(rr->u.TF.times[cnt++].time,
425 0);
426 inode->i_ctime.tv_nsec = 0;
427 }
428 if (rr->u.TF.flags & TF_MODIFY) {
429 inode->i_mtime.tv_sec =
430 iso_date(rr->u.TF.times[cnt++].time,
431 0);
432 inode->i_mtime.tv_nsec = 0;
433 }
434 if (rr->u.TF.flags & TF_ACCESS) {
435 inode->i_atime.tv_sec =
436 iso_date(rr->u.TF.times[cnt++].time,
437 0);
438 inode->i_atime.tv_nsec = 0;
439 }
440 if (rr->u.TF.flags & TF_ATTRIBUTES) {
441 inode->i_ctime.tv_sec =
442 iso_date(rr->u.TF.times[cnt++].time,
443 0);
444 inode->i_ctime.tv_nsec = 0;
445 }
446 break;
447 case SIG('S', 'L'):
448 {
449 int slen;
450 struct SL_component *slp;
451 struct SL_component *oldslp;
452 slen = rr->len - 5;
453 slp = &rr->u.SL.link;
454 inode->i_size = symlink_len;
455 while (slen > 1) {
456 rootflag = 0;
457 switch (slp->flags & ~1) {
458 case 0:
459 inode->i_size +=
460 slp->len;
461 break;
462 case 2:
463 inode->i_size += 1;
464 break;
465 case 4:
466 inode->i_size += 2;
467 break;
468 case 8:
469 rootflag = 1;
470 inode->i_size += 1;
471 break;
472 default:
473 printk("Symlink component flag "
474 "not implemented\n");
475 }
476 slen -= slp->len + 2;
477 oldslp = slp;
478 slp = (struct SL_component *)
479 (((char *)slp) + slp->len + 2);
480
481 if (slen < 2) {
482 if (((rr->u.SL.
483 flags & 1) != 0)
484 &&
485 ((oldslp->
486 flags & 1) == 0))
487 inode->i_size +=
488 1;
489 break;
490 }
491
492 /*
493 * If this component record isn't
494 * continued, then append a '/'.
495 */
496 if (!rootflag
497 && (oldslp->flags & 1) == 0)
498 inode->i_size += 1;
499 }
500 }
501 symlink_len = inode->i_size;
502 break;
503 case SIG('R', 'E'):
504 printk(KERN_WARNING "Attempt to read inode for "
505 "relocated directory\n");
506 goto out;
507 case SIG('C', 'L'):
508 if (flags & RR_RELOC_DE) {
509 printk(KERN_ERR
510 "ISOFS: Recursive directory relocation "
511 "is not supported\n");
512 goto eio;
513 }
514 reloc_block = isonum_733(rr->u.CL.location);
515 if (reloc_block == ISOFS_I(inode)->i_iget5_block &&
516 ISOFS_I(inode)->i_iget5_offset == 0) {
517 printk(KERN_ERR
518 "ISOFS: Directory relocation points to "
519 "itself\n");
520 goto eio;
521 }
522 ISOFS_I(inode)->i_first_extent = reloc_block;
523 reloc = isofs_iget_reloc(inode->i_sb, reloc_block, 0);
524 if (IS_ERR(reloc)) {
525 ret = PTR_ERR(reloc);
526 goto out;
527 }
528 inode->i_mode = reloc->i_mode;
529 set_nlink(inode, reloc->i_nlink);
530 inode->i_uid = reloc->i_uid;
531 inode->i_gid = reloc->i_gid;
532 inode->i_rdev = reloc->i_rdev;
533 inode->i_size = reloc->i_size;
534 inode->i_blocks = reloc->i_blocks;
535 inode->i_atime = reloc->i_atime;
536 inode->i_ctime = reloc->i_ctime;
537 inode->i_mtime = reloc->i_mtime;
538 iput(reloc);
539 break;
540#ifdef CONFIG_ZISOFS
541 case SIG('Z', 'F'): {
542 int algo;
543
544 if (ISOFS_SB(inode->i_sb)->s_nocompress)
545 break;
546 algo = isonum_721(rr->u.ZF.algorithm);
547 if (algo == SIG('p', 'z')) {
548 int block_shift =
549 isonum_711(&rr->u.ZF.parms[1]);
550 if (block_shift > 17) {
551 printk(KERN_WARNING "isofs: "
552 "Can't handle ZF block "
553 "size of 2^%d\n",
554 block_shift);
555 } else {
556 /*
557 * Note: we don't change
558 * i_blocks here
559 */
560 ISOFS_I(inode)->i_file_format =
561 isofs_file_compressed;
562 /*
563 * Parameters to compression
564 * algorithm (header size,
565 * block size)
566 */
567 ISOFS_I(inode)->i_format_parm[0] =
568 isonum_711(&rr->u.ZF.parms[0]);
569 ISOFS_I(inode)->i_format_parm[1] =
570 isonum_711(&rr->u.ZF.parms[1]);
571 inode->i_size =
572 isonum_733(rr->u.ZF.
573 real_size);
574 }
575 } else {
576 printk(KERN_WARNING
577 "isofs: Unknown ZF compression "
578 "algorithm: %c%c\n",
579 rr->u.ZF.algorithm[0],
580 rr->u.ZF.algorithm[1]);
581 }
582 break;
583 }
584#endif
585 default:
586 break;
587 }
588 }
589 ret = rock_continue(&rs);
590 if (ret == 0)
591 goto repeat;
592 if (ret == 1)
593 ret = 0;
594out:
595 kfree(rs.buffer);
596 return ret;
597eio:
598 ret = -EIO;
599 goto out;
600}
601
602static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
603{
604 int slen;
605 int rootflag;
606 struct SL_component *oldslp;
607 struct SL_component *slp;
608 slen = rr->len - 5;
609 slp = &rr->u.SL.link;
610 while (slen > 1) {
611 rootflag = 0;
612 switch (slp->flags & ~1) {
613 case 0:
614 if (slp->len > plimit - rpnt)
615 return NULL;
616 memcpy(rpnt, slp->text, slp->len);
617 rpnt += slp->len;
618 break;
619 case 2:
620 if (rpnt >= plimit)
621 return NULL;
622 *rpnt++ = '.';
623 break;
624 case 4:
625 if (2 > plimit - rpnt)
626 return NULL;
627 *rpnt++ = '.';
628 *rpnt++ = '.';
629 break;
630 case 8:
631 if (rpnt >= plimit)
632 return NULL;
633 rootflag = 1;
634 *rpnt++ = '/';
635 break;
636 default:
637 printk("Symlink component flag not implemented (%d)\n",
638 slp->flags);
639 }
640 slen -= slp->len + 2;
641 oldslp = slp;
642 slp = (struct SL_component *)((char *)slp + slp->len + 2);
643
644 if (slen < 2) {
645 /*
646 * If there is another SL record, and this component
647 * record isn't continued, then add a slash.
648 */
649 if ((!rootflag) && (rr->u.SL.flags & 1) &&
650 !(oldslp->flags & 1)) {
651 if (rpnt >= plimit)
652 return NULL;
653 *rpnt++ = '/';
654 }
655 break;
656 }
657
658 /*
659 * If this component record isn't continued, then append a '/'.
660 */
661 if (!rootflag && !(oldslp->flags & 1)) {
662 if (rpnt >= plimit)
663 return NULL;
664 *rpnt++ = '/';
665 }
666 }
667 return rpnt;
668}
669
670int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode,
671 int relocated)
672{
673 int flags = relocated ? RR_RELOC_DE : 0;
674 int result = parse_rock_ridge_inode_internal(de, inode, flags);
675
676 /*
677 * if rockridge flag was reset and we didn't look for attributes
678 * behind eventual XA attributes, have a look there
679 */
680 if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
681 && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
682 result = parse_rock_ridge_inode_internal(de, inode,
683 flags | RR_REGARD_XA);
684 }
685 return result;
686}
687
688/*
689 * readpage() for symlinks: reads symlink contents into the page and either
690 * makes it uptodate and returns 0 or returns error (-EIO)
691 */
692static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
693{
694 struct inode *inode = page->mapping->host;
695 struct iso_inode_info *ei = ISOFS_I(inode);
696 struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
697 char *link = page_address(page);
698 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
699 struct buffer_head *bh;
700 char *rpnt = link;
701 unsigned char *pnt;
702 struct iso_directory_record *raw_de;
703 unsigned long block, offset;
704 int sig;
705 struct rock_ridge *rr;
706 struct rock_state rs;
707 int ret;
708
709 if (!sbi->s_rock)
710 goto error;
711
712 init_rock_state(&rs, inode);
713 block = ei->i_iget5_block;
714 bh = sb_bread(inode->i_sb, block);
715 if (!bh)
716 goto out_noread;
717
718 offset = ei->i_iget5_offset;
719 pnt = (unsigned char *)bh->b_data + offset;
720
721 raw_de = (struct iso_directory_record *)pnt;
722
723 /*
724 * If we go past the end of the buffer, there is some sort of error.
725 */
726 if (offset + *pnt > bufsize)
727 goto out_bad_span;
728
729 /*
730 * Now test for possible Rock Ridge extensions which will override
731 * some of these numbers in the inode structure.
732 */
733
734 setup_rock_ridge(raw_de, inode, &rs);
735
736repeat:
737 while (rs.len > 2) { /* There may be one byte for padding somewhere */
738 rr = (struct rock_ridge *)rs.chr;
739 if (rr->len < 3)
740 goto out; /* Something got screwed up here */
741 sig = isonum_721(rs.chr);
742 if (rock_check_overflow(&rs, sig))
743 goto out;
744 rs.chr += rr->len;
745 rs.len -= rr->len;
746 if (rs.len < 0)
747 goto out; /* corrupted isofs */
748
749 switch (sig) {
750 case SIG('R', 'R'):
751 if ((rr->u.RR.flags[0] & RR_SL) == 0)
752 goto out;
753 break;
754 case SIG('S', 'P'):
755 if (check_sp(rr, inode))
756 goto out;
757 break;
758 case SIG('S', 'L'):
759 rpnt = get_symlink_chunk(rpnt, rr,
760 link + (PAGE_SIZE - 1));
761 if (rpnt == NULL)
762 goto out;
763 break;
764 case SIG('C', 'E'):
765 /* This tells is if there is a continuation record */
766 rs.cont_extent = isonum_733(rr->u.CE.extent);
767 rs.cont_offset = isonum_733(rr->u.CE.offset);
768 rs.cont_size = isonum_733(rr->u.CE.size);
769 default:
770 break;
771 }
772 }
773 ret = rock_continue(&rs);
774 if (ret == 0)
775 goto repeat;
776 if (ret < 0)
777 goto fail;
778
779 if (rpnt == link)
780 goto fail;
781 brelse(bh);
782 *rpnt = '\0';
783 SetPageUptodate(page);
784 unlock_page(page);
785 return 0;
786
787 /* error exit from macro */
788out:
789 kfree(rs.buffer);
790 goto fail;
791out_noread:
792 printk("unable to read i-node block");
793 goto fail;
794out_bad_span:
795 printk("symlink spans iso9660 blocks\n");
796fail:
797 brelse(bh);
798error:
799 SetPageError(page);
800 unlock_page(page);
801 return -EIO;
802}
803
804const struct address_space_operations isofs_symlink_aops = {
805 .readpage = rock_ridge_symlink_readpage
806};