2 * linux/fs/isofs/rock.c
4 * (C) 1992, 1993 Eric Youngdale
6 * Rock Ridge Extensions to iso9660
9 #include <linux/slab.h>
10 #include <linux/pagemap.h>
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
24 #define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
37 * This is a way of ensuring that we have something in the system
38 * use fields that is compatible with Rock Ridge. Return zero on success.
41 static int check_sp(struct rock_ridge
*rr
, struct inode
*inode
)
43 if (rr
->u
.SP
.magic
[0] != 0xbe)
45 if (rr
->u
.SP
.magic
[1] != 0xef)
47 ISOFS_SB(inode
->i_sb
)->s_rock_offset
= rr
->u
.SP
.skip
;
51 static void setup_rock_ridge(struct iso_directory_record
*de
,
52 struct inode
*inode
, struct rock_state
*rs
)
54 rs
->len
= sizeof(struct iso_directory_record
) + de
->name_len
[0];
57 rs
->chr
= (unsigned char *)de
+ rs
->len
;
58 rs
->len
= *((unsigned char *)de
) - rs
->len
;
62 if (ISOFS_SB(inode
->i_sb
)->s_rock_offset
!= -1) {
63 rs
->len
-= ISOFS_SB(inode
->i_sb
)->s_rock_offset
;
64 rs
->chr
+= ISOFS_SB(inode
->i_sb
)->s_rock_offset
;
70 static void init_rock_state(struct rock_state
*rs
, struct inode
*inode
)
72 memset(rs
, 0, sizeof(*rs
));
77 * Returns 0 if the caller should continue scanning, 1 if the scan must end
80 static int rock_continue(struct rock_state
*rs
)
83 int blocksize
= 1 << rs
->inode
->i_blkbits
;
84 const int min_de_size
= offsetof(struct rock_ridge
, u
);
89 if ((unsigned)rs
->cont_offset
> blocksize
- min_de_size
||
90 (unsigned)rs
->cont_size
> blocksize
||
91 (unsigned)(rs
->cont_offset
+ rs
->cont_size
) > blocksize
) {
92 printk(KERN_NOTICE
"rock: corrupted directory entry. "
93 "extent=%d, offset=%d, size=%d\n",
94 rs
->cont_extent
, rs
->cont_offset
, rs
->cont_size
);
99 if (rs
->cont_extent
) {
100 struct buffer_head
*bh
;
102 rs
->buffer
= kmalloc(rs
->cont_size
, GFP_KERNEL
);
108 bh
= sb_bread(rs
->inode
->i_sb
, rs
->cont_extent
);
110 memcpy(rs
->buffer
, bh
->b_data
+ rs
->cont_offset
,
113 rs
->chr
= rs
->buffer
;
114 rs
->len
= rs
->cont_size
;
120 printk("Unable to read rock-ridge attributes\n");
129 * We think there's a record of type `sig' at rs->chr. Parse the signature
130 * and make sure that there's really room for a record of that type.
132 static int rock_check_overflow(struct rock_state
*rs
, int sig
)
138 len
= sizeof(struct SU_SP_s
);
141 len
= sizeof(struct SU_CE_s
);
144 len
= sizeof(struct SU_ER_s
);
147 len
= sizeof(struct RR_RR_s
);
150 len
= sizeof(struct RR_PX_s
);
153 len
= sizeof(struct RR_PN_s
);
156 len
= sizeof(struct RR_SL_s
);
159 len
= sizeof(struct RR_NM_s
);
162 len
= sizeof(struct RR_CL_s
);
165 len
= sizeof(struct RR_PL_s
);
168 len
= sizeof(struct RR_TF_s
);
171 len
= sizeof(struct RR_ZF_s
);
177 len
+= offsetof(struct rock_ridge
, u
);
179 printk(KERN_NOTICE
"rock: directory entry would overflow "
181 printk(KERN_NOTICE
"rock: sig=0x%02x, size=%d, remaining=%d\n",
189 * return length of name field; 0: not found, -1: to be ignored
191 int get_rock_ridge_filename(struct iso_directory_record
*de
,
192 char *retname
, struct inode
*inode
)
194 struct rock_state rs
;
195 struct rock_ridge
*rr
;
201 if (!ISOFS_SB(inode
->i_sb
)->s_rock
)
205 init_rock_state(&rs
, inode
);
206 setup_rock_ridge(de
, inode
, &rs
);
209 while (rs
.len
> 2) { /* There may be one byte for padding somewhere */
210 rr
= (struct rock_ridge
*)rs
.chr
;
212 * Ignore rock ridge info if rr->len is out of range, but
213 * don't return -EIO because that would make the file
217 goto out
; /* Something got screwed up here */
218 sig
= isonum_721(rs
.chr
);
219 if (rock_check_overflow(&rs
, sig
))
224 * As above, just ignore the rock ridge info if rr->len
228 goto out
; /* Something got screwed up here */
232 if ((rr
->u
.RR
.flags
[0] & RR_NM
) == 0)
236 if (check_sp(rr
, inode
))
240 rs
.cont_extent
= isonum_733(rr
->u
.CE
.extent
);
241 rs
.cont_offset
= isonum_733(rr
->u
.CE
.offset
);
242 rs
.cont_size
= isonum_733(rr
->u
.CE
.size
);
250 * If the flags are 2 or 4, this indicates '.' or '..'.
251 * We don't want to do anything with this, because it
252 * screws up the code that calls us. We don't really
253 * care anyways, since we can just use the non-RR
256 if (rr
->u
.NM
.flags
& 6)
259 if (rr
->u
.NM
.flags
& ~1) {
260 printk("Unsupported NM flag settings (%d)\n",
264 if ((strlen(retname
) + rr
->len
- 5) >= 254) {
268 strncat(retname
, rr
->u
.NM
.name
, rr
->len
- 5);
269 retnamlen
+= rr
->len
- 5;
278 ret
= rock_continue(&rs
);
282 return retnamlen
; /* If 0, this file did not have a NM field */
292 parse_rock_ridge_inode_internal(struct iso_directory_record
*de
,
293 struct inode
*inode
, int regard_xa
)
298 struct rock_ridge
*rr
;
300 struct rock_state rs
;
303 if (!ISOFS_SB(inode
->i_sb
)->s_rock
)
306 init_rock_state(&rs
, inode
);
307 setup_rock_ridge(de
, inode
, &rs
);
316 while (rs
.len
> 2) { /* There may be one byte for padding somewhere */
317 rr
= (struct rock_ridge
*)rs
.chr
;
319 * Ignore rock ridge info if rr->len is out of range, but
320 * don't return -EIO because that would make the file
324 goto out
; /* Something got screwed up here */
325 sig
= isonum_721(rs
.chr
);
326 if (rock_check_overflow(&rs
, sig
))
331 * As above, just ignore the rock ridge info if rr->len
335 goto out
; /* Something got screwed up here */
338 #ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
340 if ((rr
->u
.RR
.flags
[0] &
341 (RR_PX
| RR_TF
| RR_SL
| RR_CL
)) == 0)
346 if (check_sp(rr
, inode
))
350 rs
.cont_extent
= isonum_733(rr
->u
.CE
.extent
);
351 rs
.cont_offset
= isonum_733(rr
->u
.CE
.offset
);
352 rs
.cont_size
= isonum_733(rr
->u
.CE
.size
);
355 ISOFS_SB(inode
->i_sb
)->s_rock
= 1;
356 printk(KERN_DEBUG
"ISO 9660 Extensions: ");
359 for (p
= 0; p
< rr
->u
.ER
.len_id
; p
++)
360 printk("%c", rr
->u
.ER
.data
[p
]);
365 inode
->i_mode
= isonum_733(rr
->u
.PX
.mode
);
366 inode
->i_nlink
= isonum_733(rr
->u
.PX
.n_links
);
367 inode
->i_uid
= isonum_733(rr
->u
.PX
.uid
);
368 inode
->i_gid
= isonum_733(rr
->u
.PX
.gid
);
373 high
= isonum_733(rr
->u
.PN
.dev_high
);
374 low
= isonum_733(rr
->u
.PN
.dev_low
);
376 * The Rock Ridge standard specifies that if
377 * sizeof(dev_t) <= 4, then the high field is
378 * unused, and the device number is completely
379 * stored in the low field. Some writers may
380 * ignore this subtlety,
381 * and as a result we test to see if the entire
383 * stored in the low field, and use that.
385 if ((low
& ~0xff) && high
== 0) {
387 MKDEV(low
>> 8, low
& 0xff);
396 * Some RRIP writers incorrectly place ctime in the
397 * TF_CREATE field. Try to handle this correctly for
400 /* Rock ridge never appears on a High Sierra disk */
402 if (rr
->u
.TF
.flags
& TF_CREATE
) {
403 inode
->i_ctime
.tv_sec
=
404 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
406 inode
->i_ctime
.tv_nsec
= 0;
408 if (rr
->u
.TF
.flags
& TF_MODIFY
) {
409 inode
->i_mtime
.tv_sec
=
410 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
412 inode
->i_mtime
.tv_nsec
= 0;
414 if (rr
->u
.TF
.flags
& TF_ACCESS
) {
415 inode
->i_atime
.tv_sec
=
416 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
418 inode
->i_atime
.tv_nsec
= 0;
420 if (rr
->u
.TF
.flags
& TF_ATTRIBUTES
) {
421 inode
->i_ctime
.tv_sec
=
422 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
424 inode
->i_ctime
.tv_nsec
= 0;
430 struct SL_component
*slp
;
431 struct SL_component
*oldslp
;
433 slp
= &rr
->u
.SL
.link
;
434 inode
->i_size
= symlink_len
;
437 switch (slp
->flags
& ~1) {
453 printk("Symlink component flag "
454 "not implemented\n");
456 slen
-= slp
->len
+ 2;
458 slp
= (struct SL_component
*)
459 (((char *)slp
) + slp
->len
+ 2);
473 * If this component record isn't
474 * continued, then append a '/'.
477 && (oldslp
->flags
& 1) == 0)
481 symlink_len
= inode
->i_size
;
484 printk(KERN_WARNING
"Attempt to read inode for "
485 "relocated directory\n");
488 ISOFS_I(inode
)->i_first_extent
=
489 isonum_733(rr
->u
.CL
.location
);
491 isofs_iget(inode
->i_sb
,
492 ISOFS_I(inode
)->i_first_extent
,
495 ret
= PTR_ERR(reloc
);
498 inode
->i_mode
= reloc
->i_mode
;
499 inode
->i_nlink
= reloc
->i_nlink
;
500 inode
->i_uid
= reloc
->i_uid
;
501 inode
->i_gid
= reloc
->i_gid
;
502 inode
->i_rdev
= reloc
->i_rdev
;
503 inode
->i_size
= reloc
->i_size
;
504 inode
->i_blocks
= reloc
->i_blocks
;
505 inode
->i_atime
= reloc
->i_atime
;
506 inode
->i_ctime
= reloc
->i_ctime
;
507 inode
->i_mtime
= reloc
->i_mtime
;
511 case SIG('Z', 'F'): {
514 if (ISOFS_SB(inode
->i_sb
)->s_nocompress
)
516 algo
= isonum_721(rr
->u
.ZF
.algorithm
);
517 if (algo
== SIG('p', 'z')) {
519 isonum_711(&rr
->u
.ZF
.parms
[1]);
520 if (block_shift
> 17) {
521 printk(KERN_WARNING
"isofs: "
522 "Can't handle ZF block "
527 * Note: we don't change
530 ISOFS_I(inode
)->i_file_format
=
531 isofs_file_compressed
;
533 * Parameters to compression
534 * algorithm (header size,
537 ISOFS_I(inode
)->i_format_parm
[0] =
538 isonum_711(&rr
->u
.ZF
.parms
[0]);
539 ISOFS_I(inode
)->i_format_parm
[1] =
540 isonum_711(&rr
->u
.ZF
.parms
[1]);
547 "isofs: Unknown ZF compression "
549 rr
->u
.ZF
.algorithm
[0],
550 rr
->u
.ZF
.algorithm
[1]);
559 ret
= rock_continue(&rs
);
572 static char *get_symlink_chunk(char *rpnt
, struct rock_ridge
*rr
, char *plimit
)
576 struct SL_component
*oldslp
;
577 struct SL_component
*slp
;
579 slp
= &rr
->u
.SL
.link
;
582 switch (slp
->flags
& ~1) {
584 if (slp
->len
> plimit
- rpnt
)
586 memcpy(rpnt
, slp
->text
, slp
->len
);
595 if (2 > plimit
- rpnt
)
607 printk("Symlink component flag not implemented (%d)\n",
610 slen
-= slp
->len
+ 2;
612 slp
= (struct SL_component
*)((char *)slp
+ slp
->len
+ 2);
616 * If there is another SL record, and this component
617 * record isn't continued, then add a slash.
619 if ((!rootflag
) && (rr
->u
.SL
.flags
& 1) &&
620 !(oldslp
->flags
& 1)) {
629 * If this component record isn't continued, then append a '/'.
631 if (!rootflag
&& !(oldslp
->flags
& 1)) {
640 int parse_rock_ridge_inode(struct iso_directory_record
*de
, struct inode
*inode
)
642 int result
= parse_rock_ridge_inode_internal(de
, inode
, 0);
645 * if rockridge flag was reset and we didn't look for attributes
646 * behind eventual XA attributes, have a look there
648 if ((ISOFS_SB(inode
->i_sb
)->s_rock_offset
== -1)
649 && (ISOFS_SB(inode
->i_sb
)->s_rock
== 2)) {
650 result
= parse_rock_ridge_inode_internal(de
, inode
, 14);
656 * readpage() for symlinks: reads symlink contents into the page and either
657 * makes it uptodate and returns 0 or returns error (-EIO)
659 static int rock_ridge_symlink_readpage(struct file
*file
, struct page
*page
)
661 struct inode
*inode
= page
->mapping
->host
;
662 struct iso_inode_info
*ei
= ISOFS_I(inode
);
663 struct isofs_sb_info
*sbi
= ISOFS_SB(inode
->i_sb
);
664 char *link
= kmap(page
);
665 unsigned long bufsize
= ISOFS_BUFFER_SIZE(inode
);
666 struct buffer_head
*bh
;
669 struct iso_directory_record
*raw_de
;
670 unsigned long block
, offset
;
672 struct rock_ridge
*rr
;
673 struct rock_state rs
;
679 init_rock_state(&rs
, inode
);
680 block
= ei
->i_iget5_block
;
681 bh
= sb_bread(inode
->i_sb
, block
);
685 offset
= ei
->i_iget5_offset
;
686 pnt
= (unsigned char *)bh
->b_data
+ offset
;
688 raw_de
= (struct iso_directory_record
*)pnt
;
691 * If we go past the end of the buffer, there is some sort of error.
693 if (offset
+ *pnt
> bufsize
)
697 * Now test for possible Rock Ridge extensions which will override
698 * some of these numbers in the inode structure.
701 setup_rock_ridge(raw_de
, inode
, &rs
);
704 while (rs
.len
> 2) { /* There may be one byte for padding somewhere */
705 rr
= (struct rock_ridge
*)rs
.chr
;
707 goto out
; /* Something got screwed up here */
708 sig
= isonum_721(rs
.chr
);
709 if (rock_check_overflow(&rs
, sig
))
714 goto out
; /* corrupted isofs */
718 if ((rr
->u
.RR
.flags
[0] & RR_SL
) == 0)
722 if (check_sp(rr
, inode
))
726 rpnt
= get_symlink_chunk(rpnt
, rr
,
727 link
+ (PAGE_SIZE
- 1));
732 /* This tells is if there is a continuation record */
733 rs
.cont_extent
= isonum_733(rr
->u
.CE
.extent
);
734 rs
.cont_offset
= isonum_733(rr
->u
.CE
.offset
);
735 rs
.cont_size
= isonum_733(rr
->u
.CE
.size
);
740 ret
= rock_continue(&rs
);
750 SetPageUptodate(page
);
755 /* error exit from macro */
760 printk("unable to read i-node block");
763 printk("symlink spans iso9660 blocks\n");
773 const struct address_space_operations isofs_symlink_aops
= {
774 .readpage
= rock_ridge_symlink_readpage