Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
[linux-2.6] / fs / isofs / rock.c
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 #include <linux/smp_lock.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
27 struct 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         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
42 static 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
52 static 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
71 static 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 /*
78  * Returns 0 if the caller should continue scanning, 1 if the scan must end
79  * and -ve on error.
80  */
81 static int rock_continue(struct rock_state *rs)
82 {
83         int ret = 1;
84         int blocksize = 1 << rs->inode->i_blkbits;
85         const int min_de_size = offsetof(struct rock_ridge, u);
86
87         kfree(rs->buffer);
88         rs->buffer = NULL;
89
90         if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
91             (unsigned)rs->cont_size > blocksize ||
92             (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
93                 printk(KERN_NOTICE "rock: corrupted directory entry. "
94                         "extent=%d, offset=%d, size=%d\n",
95                         rs->cont_extent, rs->cont_offset, rs->cont_size);
96                 ret = -EIO;
97                 goto out;
98         }
99
100         if (rs->cont_extent) {
101                 struct buffer_head *bh;
102
103                 rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
104                 if (!rs->buffer) {
105                         ret = -ENOMEM;
106                         goto out;
107                 }
108                 ret = -EIO;
109                 bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
110                 if (bh) {
111                         memcpy(rs->buffer, bh->b_data + rs->cont_offset,
112                                         rs->cont_size);
113                         put_bh(bh);
114                         rs->chr = rs->buffer;
115                         rs->len = rs->cont_size;
116                         rs->cont_extent = 0;
117                         rs->cont_size = 0;
118                         rs->cont_offset = 0;
119                         return 0;
120                 }
121                 printk("Unable to read rock-ridge attributes\n");
122         }
123 out:
124         kfree(rs->buffer);
125         rs->buffer = NULL;
126         return ret;
127 }
128
129 /*
130  * We think there's a record of type `sig' at rs->chr.  Parse the signature
131  * and make sure that there's really room for a record of that type.
132  */
133 static int rock_check_overflow(struct rock_state *rs, int sig)
134 {
135         int len;
136
137         switch (sig) {
138         case SIG('S', 'P'):
139                 len = sizeof(struct SU_SP_s);
140                 break;
141         case SIG('C', 'E'):
142                 len = sizeof(struct SU_CE_s);
143                 break;
144         case SIG('E', 'R'):
145                 len = sizeof(struct SU_ER_s);
146                 break;
147         case SIG('R', 'R'):
148                 len = sizeof(struct RR_RR_s);
149                 break;
150         case SIG('P', 'X'):
151                 len = sizeof(struct RR_PX_s);
152                 break;
153         case SIG('P', 'N'):
154                 len = sizeof(struct RR_PN_s);
155                 break;
156         case SIG('S', 'L'):
157                 len = sizeof(struct RR_SL_s);
158                 break;
159         case SIG('N', 'M'):
160                 len = sizeof(struct RR_NM_s);
161                 break;
162         case SIG('C', 'L'):
163                 len = sizeof(struct RR_CL_s);
164                 break;
165         case SIG('P', 'L'):
166                 len = sizeof(struct RR_PL_s);
167                 break;
168         case SIG('T', 'F'):
169                 len = sizeof(struct RR_TF_s);
170                 break;
171         case SIG('Z', 'F'):
172                 len = sizeof(struct RR_ZF_s);
173                 break;
174         default:
175                 len = 0;
176                 break;
177         }
178         len += offsetof(struct rock_ridge, u);
179         if (len > rs->len) {
180                 printk(KERN_NOTICE "rock: directory entry would overflow "
181                                 "storage\n");
182                 printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
183                                 sig, len, rs->len);
184                 return -EIO;
185         }
186         return 0;
187 }
188
189 /*
190  * return length of name field; 0: not found, -1: to be ignored
191  */
192 int get_rock_ridge_filename(struct iso_directory_record *de,
193                             char *retname, struct inode *inode)
194 {
195         struct rock_state rs;
196         struct rock_ridge *rr;
197         int sig;
198         int retnamlen = 0;
199         int truncate = 0;
200         int ret = 0;
201
202         if (!ISOFS_SB(inode->i_sb)->s_rock)
203                 return 0;
204         *retname = 0;
205
206         init_rock_state(&rs, inode);
207         setup_rock_ridge(de, inode, &rs);
208 repeat:
209
210         while (rs.len > 2) { /* There may be one byte for padding somewhere */
211                 rr = (struct rock_ridge *)rs.chr;
212                 if (rr->len < 3)
213                         goto out;       /* Something got screwed up here */
214                 sig = isonum_721(rs.chr);
215                 if (rock_check_overflow(&rs, sig))
216                         goto eio;
217                 rs.chr += rr->len;
218                 rs.len -= rr->len;
219                 if (rs.len < 0)
220                         goto eio;       /* corrupted isofs */
221
222                 switch (sig) {
223                 case SIG('R', 'R'):
224                         if ((rr->u.RR.flags[0] & RR_NM) == 0)
225                                 goto out;
226                         break;
227                 case SIG('S', 'P'):
228                         if (check_sp(rr, inode))
229                                 goto out;
230                         break;
231                 case SIG('C', 'E'):
232                         rs.cont_extent = isonum_733(rr->u.CE.extent);
233                         rs.cont_offset = isonum_733(rr->u.CE.offset);
234                         rs.cont_size = isonum_733(rr->u.CE.size);
235                         break;
236                 case SIG('N', 'M'):
237                         if (truncate)
238                                 break;
239                         if (rr->len < 5)
240                                 break;
241                         /*
242                          * If the flags are 2 or 4, this indicates '.' or '..'.
243                          * We don't want to do anything with this, because it
244                          * screws up the code that calls us.  We don't really
245                          * care anyways, since we can just use the non-RR
246                          * name.
247                          */
248                         if (rr->u.NM.flags & 6)
249                                 break;
250
251                         if (rr->u.NM.flags & ~1) {
252                                 printk("Unsupported NM flag settings (%d)\n",
253                                         rr->u.NM.flags);
254                                 break;
255                         }
256                         if ((strlen(retname) + rr->len - 5) >= 254) {
257                                 truncate = 1;
258                                 break;
259                         }
260                         strncat(retname, rr->u.NM.name, rr->len - 5);
261                         retnamlen += rr->len - 5;
262                         break;
263                 case SIG('R', 'E'):
264                         kfree(rs.buffer);
265                         return -1;
266                 default:
267                         break;
268                 }
269         }
270         ret = rock_continue(&rs);
271         if (ret == 0)
272                 goto repeat;
273         if (ret == 1)
274                 return retnamlen; /* If 0, this file did not have a NM field */
275 out:
276         kfree(rs.buffer);
277         return ret;
278 eio:
279         ret = -EIO;
280         goto out;
281 }
282
283 static int
284 parse_rock_ridge_inode_internal(struct iso_directory_record *de,
285                                 struct inode *inode, int regard_xa)
286 {
287         int symlink_len = 0;
288         int cnt, sig;
289         struct inode *reloc;
290         struct rock_ridge *rr;
291         int rootflag;
292         struct rock_state rs;
293         int ret = 0;
294
295         if (!ISOFS_SB(inode->i_sb)->s_rock)
296                 return 0;
297
298         init_rock_state(&rs, inode);
299         setup_rock_ridge(de, inode, &rs);
300         if (regard_xa) {
301                 rs.chr += 14;
302                 rs.len -= 14;
303                 if (rs.len < 0)
304                         rs.len = 0;
305         }
306
307 repeat:
308         while (rs.len > 2) { /* There may be one byte for padding somewhere */
309                 rr = (struct rock_ridge *)rs.chr;
310                 if (rr->len < 3)
311                         goto out;       /* Something got screwed up here */
312                 sig = isonum_721(rs.chr);
313                 if (rock_check_overflow(&rs, sig))
314                         goto eio;
315                 rs.chr += rr->len;
316                 rs.len -= rr->len;
317                 if (rs.len < 0)
318                         goto eio;       /* corrupted isofs */
319
320                 switch (sig) {
321 #ifndef CONFIG_ZISOFS           /* No flag for SF or ZF */
322                 case SIG('R', 'R'):
323                         if ((rr->u.RR.flags[0] &
324                              (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
325                                 goto out;
326                         break;
327 #endif
328                 case SIG('S', 'P'):
329                         if (check_sp(rr, inode))
330                                 goto out;
331                         break;
332                 case SIG('C', 'E'):
333                         rs.cont_extent = isonum_733(rr->u.CE.extent);
334                         rs.cont_offset = isonum_733(rr->u.CE.offset);
335                         rs.cont_size = isonum_733(rr->u.CE.size);
336                         break;
337                 case SIG('E', 'R'):
338                         ISOFS_SB(inode->i_sb)->s_rock = 1;
339                         printk(KERN_DEBUG "ISO 9660 Extensions: ");
340                         {
341                                 int p;
342                                 for (p = 0; p < rr->u.ER.len_id; p++)
343                                         printk("%c", rr->u.ER.data[p]);
344                         }
345                         printk("\n");
346                         break;
347                 case SIG('P', 'X'):
348                         inode->i_mode = isonum_733(rr->u.PX.mode);
349                         inode->i_nlink = isonum_733(rr->u.PX.n_links);
350                         inode->i_uid = isonum_733(rr->u.PX.uid);
351                         inode->i_gid = isonum_733(rr->u.PX.gid);
352                         break;
353                 case SIG('P', 'N'):
354                         {
355                                 int high, low;
356                                 high = isonum_733(rr->u.PN.dev_high);
357                                 low = isonum_733(rr->u.PN.dev_low);
358                                 /*
359                                  * The Rock Ridge standard specifies that if
360                                  * sizeof(dev_t) <= 4, then the high field is
361                                  * unused, and the device number is completely
362                                  * stored in the low field.  Some writers may
363                                  * ignore this subtlety,
364                                  * and as a result we test to see if the entire
365                                  * device number is
366                                  * stored in the low field, and use that.
367                                  */
368                                 if ((low & ~0xff) && high == 0) {
369                                         inode->i_rdev =
370                                             MKDEV(low >> 8, low & 0xff);
371                                 } else {
372                                         inode->i_rdev =
373                                             MKDEV(high, low);
374                                 }
375                         }
376                         break;
377                 case SIG('T', 'F'):
378                         /*
379                          * Some RRIP writers incorrectly place ctime in the
380                          * TF_CREATE field. Try to handle this correctly for
381                          * either case.
382                          */
383                         /* Rock ridge never appears on a High Sierra disk */
384                         cnt = 0;
385                         if (rr->u.TF.flags & TF_CREATE) {
386                                 inode->i_ctime.tv_sec =
387                                     iso_date(rr->u.TF.times[cnt++].time,
388                                              0);
389                                 inode->i_ctime.tv_nsec = 0;
390                         }
391                         if (rr->u.TF.flags & TF_MODIFY) {
392                                 inode->i_mtime.tv_sec =
393                                     iso_date(rr->u.TF.times[cnt++].time,
394                                              0);
395                                 inode->i_mtime.tv_nsec = 0;
396                         }
397                         if (rr->u.TF.flags & TF_ACCESS) {
398                                 inode->i_atime.tv_sec =
399                                     iso_date(rr->u.TF.times[cnt++].time,
400                                              0);
401                                 inode->i_atime.tv_nsec = 0;
402                         }
403                         if (rr->u.TF.flags & TF_ATTRIBUTES) {
404                                 inode->i_ctime.tv_sec =
405                                     iso_date(rr->u.TF.times[cnt++].time,
406                                              0);
407                                 inode->i_ctime.tv_nsec = 0;
408                         }
409                         break;
410                 case SIG('S', 'L'):
411                         {
412                                 int slen;
413                                 struct SL_component *slp;
414                                 struct SL_component *oldslp;
415                                 slen = rr->len - 5;
416                                 slp = &rr->u.SL.link;
417                                 inode->i_size = symlink_len;
418                                 while (slen > 1) {
419                                         rootflag = 0;
420                                         switch (slp->flags & ~1) {
421                                         case 0:
422                                                 inode->i_size +=
423                                                     slp->len;
424                                                 break;
425                                         case 2:
426                                                 inode->i_size += 1;
427                                                 break;
428                                         case 4:
429                                                 inode->i_size += 2;
430                                                 break;
431                                         case 8:
432                                                 rootflag = 1;
433                                                 inode->i_size += 1;
434                                                 break;
435                                         default:
436                                                 printk("Symlink component flag "
437                                                         "not implemented\n");
438                                         }
439                                         slen -= slp->len + 2;
440                                         oldslp = slp;
441                                         slp = (struct SL_component *)
442                                                 (((char *)slp) + slp->len + 2);
443
444                                         if (slen < 2) {
445                                                 if (((rr->u.SL.
446                                                       flags & 1) != 0)
447                                                     &&
448                                                     ((oldslp->
449                                                       flags & 1) == 0))
450                                                         inode->i_size +=
451                                                             1;
452                                                 break;
453                                         }
454
455                                         /*
456                                          * If this component record isn't
457                                          * continued, then append a '/'.
458                                          */
459                                         if (!rootflag
460                                             && (oldslp->flags & 1) == 0)
461                                                 inode->i_size += 1;
462                                 }
463                         }
464                         symlink_len = inode->i_size;
465                         break;
466                 case SIG('R', 'E'):
467                         printk(KERN_WARNING "Attempt to read inode for "
468                                         "relocated directory\n");
469                         goto out;
470                 case SIG('C', 'L'):
471                         ISOFS_I(inode)->i_first_extent =
472                             isonum_733(rr->u.CL.location);
473                         reloc =
474                             isofs_iget(inode->i_sb,
475                                        ISOFS_I(inode)->i_first_extent,
476                                        0);
477                         if (!reloc)
478                                 goto out;
479                         inode->i_mode = reloc->i_mode;
480                         inode->i_nlink = reloc->i_nlink;
481                         inode->i_uid = reloc->i_uid;
482                         inode->i_gid = reloc->i_gid;
483                         inode->i_rdev = reloc->i_rdev;
484                         inode->i_size = reloc->i_size;
485                         inode->i_blocks = reloc->i_blocks;
486                         inode->i_atime = reloc->i_atime;
487                         inode->i_ctime = reloc->i_ctime;
488                         inode->i_mtime = reloc->i_mtime;
489                         iput(reloc);
490                         break;
491 #ifdef CONFIG_ZISOFS
492                 case SIG('Z', 'F'): {
493                         int algo;
494
495                         if (ISOFS_SB(inode->i_sb)->s_nocompress)
496                                 break;
497                         algo = isonum_721(rr->u.ZF.algorithm);
498                         if (algo == SIG('p', 'z')) {
499                                 int block_shift =
500                                         isonum_711(&rr->u.ZF.parms[1]);
501                                 if (block_shift < PAGE_CACHE_SHIFT
502                                                 || block_shift > 17) {
503                                         printk(KERN_WARNING "isofs: "
504                                                 "Can't handle ZF block "
505                                                 "size of 2^%d\n",
506                                                 block_shift);
507                                 } else {
508                                         /*
509                                          * Note: we don't change
510                                          * i_blocks here
511                                          */
512                                         ISOFS_I(inode)->i_file_format =
513                                                 isofs_file_compressed;
514                                         /*
515                                          * Parameters to compression
516                                          * algorithm (header size,
517                                          * block size)
518                                          */
519                                         ISOFS_I(inode)->i_format_parm[0] =
520                                                 isonum_711(&rr->u.ZF.parms[0]);
521                                         ISOFS_I(inode)->i_format_parm[1] =
522                                                 isonum_711(&rr->u.ZF.parms[1]);
523                                         inode->i_size =
524                                             isonum_733(rr->u.ZF.
525                                                        real_size);
526                                 }
527                         } else {
528                                 printk(KERN_WARNING
529                                        "isofs: Unknown ZF compression "
530                                                 "algorithm: %c%c\n",
531                                        rr->u.ZF.algorithm[0],
532                                        rr->u.ZF.algorithm[1]);
533                         }
534                         break;
535                 }
536 #endif
537                 default:
538                         break;
539                 }
540         }
541         ret = rock_continue(&rs);
542         if (ret == 0)
543                 goto repeat;
544         if (ret == 1)
545                 ret = 0;
546 out:
547         kfree(rs.buffer);
548         return ret;
549 eio:
550         ret = -EIO;
551         goto out;
552 }
553
554 static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
555 {
556         int slen;
557         int rootflag;
558         struct SL_component *oldslp;
559         struct SL_component *slp;
560         slen = rr->len - 5;
561         slp = &rr->u.SL.link;
562         while (slen > 1) {
563                 rootflag = 0;
564                 switch (slp->flags & ~1) {
565                 case 0:
566                         if (slp->len > plimit - rpnt)
567                                 return NULL;
568                         memcpy(rpnt, slp->text, slp->len);
569                         rpnt += slp->len;
570                         break;
571                 case 2:
572                         if (rpnt >= plimit)
573                                 return NULL;
574                         *rpnt++ = '.';
575                         break;
576                 case 4:
577                         if (2 > plimit - rpnt)
578                                 return NULL;
579                         *rpnt++ = '.';
580                         *rpnt++ = '.';
581                         break;
582                 case 8:
583                         if (rpnt >= plimit)
584                                 return NULL;
585                         rootflag = 1;
586                         *rpnt++ = '/';
587                         break;
588                 default:
589                         printk("Symlink component flag not implemented (%d)\n",
590                                slp->flags);
591                 }
592                 slen -= slp->len + 2;
593                 oldslp = slp;
594                 slp = (struct SL_component *)((char *)slp + slp->len + 2);
595
596                 if (slen < 2) {
597                         /*
598                          * If there is another SL record, and this component
599                          * record isn't continued, then add a slash.
600                          */
601                         if ((!rootflag) && (rr->u.SL.flags & 1) &&
602                             !(oldslp->flags & 1)) {
603                                 if (rpnt >= plimit)
604                                         return NULL;
605                                 *rpnt++ = '/';
606                         }
607                         break;
608                 }
609
610                 /*
611                  * If this component record isn't continued, then append a '/'.
612                  */
613                 if (!rootflag && !(oldslp->flags & 1)) {
614                         if (rpnt >= plimit)
615                                 return NULL;
616                         *rpnt++ = '/';
617                 }
618         }
619         return rpnt;
620 }
621
622 int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode)
623 {
624         int result = parse_rock_ridge_inode_internal(de, inode, 0);
625
626         /*
627          * if rockridge flag was reset and we didn't look for attributes
628          * behind eventual XA attributes, have a look there
629          */
630         if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
631             && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
632                 result = parse_rock_ridge_inode_internal(de, inode, 14);
633         }
634         return result;
635 }
636
637 /*
638  * readpage() for symlinks: reads symlink contents into the page and either
639  * makes it uptodate and returns 0 or returns error (-EIO)
640  */
641 static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
642 {
643         struct inode *inode = page->mapping->host;
644         struct iso_inode_info *ei = ISOFS_I(inode);
645         char *link = kmap(page);
646         unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
647         struct buffer_head *bh;
648         char *rpnt = link;
649         unsigned char *pnt;
650         struct iso_directory_record *raw_de;
651         unsigned long block, offset;
652         int sig;
653         struct rock_ridge *rr;
654         struct rock_state rs;
655         int ret;
656
657         if (!ISOFS_SB(inode->i_sb)->s_rock)
658                 goto error;
659
660         init_rock_state(&rs, inode);
661         block = ei->i_iget5_block;
662         lock_kernel();
663         bh = sb_bread(inode->i_sb, block);
664         if (!bh)
665                 goto out_noread;
666
667         offset = ei->i_iget5_offset;
668         pnt = (unsigned char *)bh->b_data + offset;
669
670         raw_de = (struct iso_directory_record *)pnt;
671
672         /*
673          * If we go past the end of the buffer, there is some sort of error.
674          */
675         if (offset + *pnt > bufsize)
676                 goto out_bad_span;
677
678         /*
679          * Now test for possible Rock Ridge extensions which will override
680          * some of these numbers in the inode structure.
681          */
682
683         setup_rock_ridge(raw_de, inode, &rs);
684
685 repeat:
686         while (rs.len > 2) { /* There may be one byte for padding somewhere */
687                 rr = (struct rock_ridge *)rs.chr;
688                 if (rr->len < 3)
689                         goto out;       /* Something got screwed up here */
690                 sig = isonum_721(rs.chr);
691                 if (rock_check_overflow(&rs, sig))
692                         goto out;
693                 rs.chr += rr->len;
694                 rs.len -= rr->len;
695                 if (rs.len < 0)
696                         goto out;       /* corrupted isofs */
697
698                 switch (sig) {
699                 case SIG('R', 'R'):
700                         if ((rr->u.RR.flags[0] & RR_SL) == 0)
701                                 goto out;
702                         break;
703                 case SIG('S', 'P'):
704                         if (check_sp(rr, inode))
705                                 goto out;
706                         break;
707                 case SIG('S', 'L'):
708                         rpnt = get_symlink_chunk(rpnt, rr,
709                                                  link + (PAGE_SIZE - 1));
710                         if (rpnt == NULL)
711                                 goto out;
712                         break;
713                 case SIG('C', 'E'):
714                         /* This tells is if there is a continuation record */
715                         rs.cont_extent = isonum_733(rr->u.CE.extent);
716                         rs.cont_offset = isonum_733(rr->u.CE.offset);
717                         rs.cont_size = isonum_733(rr->u.CE.size);
718                 default:
719                         break;
720                 }
721         }
722         ret = rock_continue(&rs);
723         if (ret == 0)
724                 goto repeat;
725         if (ret < 0)
726                 goto fail;
727
728         if (rpnt == link)
729                 goto fail;
730         brelse(bh);
731         *rpnt = '\0';
732         unlock_kernel();
733         SetPageUptodate(page);
734         kunmap(page);
735         unlock_page(page);
736         return 0;
737
738         /* error exit from macro */
739 out:
740         kfree(rs.buffer);
741         goto fail;
742 out_noread:
743         printk("unable to read i-node block");
744         goto fail;
745 out_bad_span:
746         printk("symlink spans iso9660 blocks\n");
747 fail:
748         brelse(bh);
749         unlock_kernel();
750 error:
751         SetPageError(page);
752         kunmap(page);
753         unlock_page(page);
754         return -EIO;
755 }
756
757 const struct address_space_operations isofs_symlink_aops = {
758         .readpage = rock_ridge_symlink_readpage
759 };