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>
11 #include <linux/smp_lock.h>
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
25 #define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
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.
42 static int check_sp(struct rock_ridge
*rr
, struct inode
*inode
)
44 if (rr
->u
.SP
.magic
[0] != 0xbe)
46 if (rr
->u
.SP
.magic
[1] != 0xef)
48 ISOFS_SB(inode
->i_sb
)->s_rock_offset
= rr
->u
.SP
.skip
;
52 static void setup_rock_ridge(struct iso_directory_record
*de
,
53 struct inode
*inode
, struct rock_state
*rs
)
55 rs
->len
= sizeof(struct iso_directory_record
) + de
->name_len
[0];
58 rs
->chr
= (unsigned char *)de
+ rs
->len
;
59 rs
->len
= *((unsigned char *)de
) - rs
->len
;
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
;
71 static void init_rock_state(struct rock_state
*rs
, struct inode
*inode
)
73 memset(rs
, 0, sizeof(*rs
));
78 * Returns 0 if the caller should continue scanning, 1 if the scan must end
81 static int rock_continue(struct rock_state
*rs
)
87 if (rs
->cont_extent
) {
88 struct buffer_head
*bh
;
90 rs
->buffer
= kmalloc(rs
->cont_size
, GFP_KERNEL
);
96 bh
= sb_bread(rs
->inode
->i_sb
, rs
->cont_extent
);
98 memcpy(rs
->buffer
, bh
->b_data
+ rs
->cont_offset
,
101 rs
->chr
= rs
->buffer
;
102 rs
->len
= rs
->cont_size
;
108 printk("Unable to read rock-ridge attributes\n");
117 * return length of name field; 0: not found, -1: to be ignored
119 int get_rock_ridge_filename(struct iso_directory_record
*de
,
120 char *retname
, struct inode
*inode
)
122 struct rock_state rs
;
123 struct rock_ridge
*rr
;
129 if (!ISOFS_SB(inode
->i_sb
)->s_rock
)
133 init_rock_state(&rs
, inode
);
134 setup_rock_ridge(de
, inode
, &rs
);
137 while (rs
.len
> 2) { /* There may be one byte for padding somewhere */
138 rr
= (struct rock_ridge
*)rs
.chr
;
140 goto out
; /* Something got screwed up here */
141 sig
= isonum_721(rs
.chr
);
145 goto out
; /* corrupted isofs */
149 if ((rr
->u
.RR
.flags
[0] & RR_NM
) == 0)
153 if (check_sp(rr
, inode
))
157 rs
.cont_extent
= isonum_733(rr
->u
.CE
.extent
);
158 rs
.cont_offset
= isonum_733(rr
->u
.CE
.offset
);
159 rs
.cont_size
= isonum_733(rr
->u
.CE
.size
);
167 * If the flags are 2 or 4, this indicates '.' or '..'.
168 * We don't want to do anything with this, because it
169 * screws up the code that calls us. We don't really
170 * care anyways, since we can just use the non-RR
173 if (rr
->u
.NM
.flags
& 6)
176 if (rr
->u
.NM
.flags
& ~1) {
177 printk("Unsupported NM flag settings (%d)\n",
181 if ((strlen(retname
) + rr
->len
- 5) >= 254) {
185 strncat(retname
, rr
->u
.NM
.name
, rr
->len
- 5);
186 retnamlen
+= rr
->len
- 5;
195 ret
= rock_continue(&rs
);
199 return retnamlen
; /* If 0, this file did not have a NM field */
206 parse_rock_ridge_inode_internal(struct iso_directory_record
*de
,
207 struct inode
*inode
, int regard_xa
)
212 struct rock_ridge
*rr
;
214 struct rock_state rs
;
217 if (!ISOFS_SB(inode
->i_sb
)->s_rock
)
220 init_rock_state(&rs
, inode
);
221 setup_rock_ridge(de
, inode
, &rs
);
230 while (rs
.len
> 2) { /* There may be one byte for padding somewhere */
231 rr
= (struct rock_ridge
*)rs
.chr
;
233 goto out
; /* Something got screwed up here */
234 sig
= isonum_721(rs
.chr
);
238 goto out
; /* corrupted isofs */
241 #ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
243 if ((rr
->u
.RR
.flags
[0] &
244 (RR_PX
| RR_TF
| RR_SL
| RR_CL
)) == 0)
249 if (check_sp(rr
, inode
))
253 rs
.cont_extent
= isonum_733(rr
->u
.CE
.extent
);
254 rs
.cont_offset
= isonum_733(rr
->u
.CE
.offset
);
255 rs
.cont_size
= isonum_733(rr
->u
.CE
.size
);
258 ISOFS_SB(inode
->i_sb
)->s_rock
= 1;
259 printk(KERN_DEBUG
"ISO 9660 Extensions: ");
262 for (p
= 0; p
< rr
->u
.ER
.len_id
; p
++)
263 printk("%c", rr
->u
.ER
.data
[p
]);
268 inode
->i_mode
= isonum_733(rr
->u
.PX
.mode
);
269 inode
->i_nlink
= isonum_733(rr
->u
.PX
.n_links
);
270 inode
->i_uid
= isonum_733(rr
->u
.PX
.uid
);
271 inode
->i_gid
= isonum_733(rr
->u
.PX
.gid
);
276 high
= isonum_733(rr
->u
.PN
.dev_high
);
277 low
= isonum_733(rr
->u
.PN
.dev_low
);
279 * The Rock Ridge standard specifies that if
280 * sizeof(dev_t) <= 4, then the high field is
281 * unused, and the device number is completely
282 * stored in the low field. Some writers may
283 * ignore this subtlety,
284 * and as a result we test to see if the entire
286 * stored in the low field, and use that.
288 if ((low
& ~0xff) && high
== 0) {
290 MKDEV(low
>> 8, low
& 0xff);
299 * Some RRIP writers incorrectly place ctime in the
300 * TF_CREATE field. Try to handle this correctly for
303 /* Rock ridge never appears on a High Sierra disk */
305 if (rr
->u
.TF
.flags
& TF_CREATE
) {
306 inode
->i_ctime
.tv_sec
=
307 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
309 inode
->i_ctime
.tv_nsec
= 0;
311 if (rr
->u
.TF
.flags
& TF_MODIFY
) {
312 inode
->i_mtime
.tv_sec
=
313 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
315 inode
->i_mtime
.tv_nsec
= 0;
317 if (rr
->u
.TF
.flags
& TF_ACCESS
) {
318 inode
->i_atime
.tv_sec
=
319 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
321 inode
->i_atime
.tv_nsec
= 0;
323 if (rr
->u
.TF
.flags
& TF_ATTRIBUTES
) {
324 inode
->i_ctime
.tv_sec
=
325 iso_date(rr
->u
.TF
.times
[cnt
++].time
,
327 inode
->i_ctime
.tv_nsec
= 0;
333 struct SL_component
*slp
;
334 struct SL_component
*oldslp
;
336 slp
= &rr
->u
.SL
.link
;
337 inode
->i_size
= symlink_len
;
340 switch (slp
->flags
& ~1) {
356 printk("Symlink component flag "
357 "not implemented\n");
359 slen
-= slp
->len
+ 2;
361 slp
= (struct SL_component
*)
362 (((char *)slp
) + slp
->len
+ 2);
376 * If this component record isn't
377 * continued, then append a '/'.
380 && (oldslp
->flags
& 1) == 0)
384 symlink_len
= inode
->i_size
;
387 printk(KERN_WARNING
"Attempt to read inode for "
388 "relocated directory\n");
391 ISOFS_I(inode
)->i_first_extent
=
392 isonum_733(rr
->u
.CL
.location
);
394 isofs_iget(inode
->i_sb
,
395 ISOFS_I(inode
)->i_first_extent
,
399 inode
->i_mode
= reloc
->i_mode
;
400 inode
->i_nlink
= reloc
->i_nlink
;
401 inode
->i_uid
= reloc
->i_uid
;
402 inode
->i_gid
= reloc
->i_gid
;
403 inode
->i_rdev
= reloc
->i_rdev
;
404 inode
->i_size
= reloc
->i_size
;
405 inode
->i_blocks
= reloc
->i_blocks
;
406 inode
->i_atime
= reloc
->i_atime
;
407 inode
->i_ctime
= reloc
->i_ctime
;
408 inode
->i_mtime
= reloc
->i_mtime
;
412 case SIG('Z', 'F'): {
415 if (ISOFS_SB(inode
->i_sb
)->s_nocompress
)
417 algo
= isonum_721(rr
->u
.ZF
.algorithm
);
418 if (algo
== SIG('p', 'z')) {
420 isonum_711(&rr
->u
.ZF
.parms
[1]);
421 if (block_shift
< PAGE_CACHE_SHIFT
422 || block_shift
> 17) {
423 printk(KERN_WARNING
"isofs: "
424 "Can't handle ZF block "
429 * Note: we don't change
432 ISOFS_I(inode
)->i_file_format
=
433 isofs_file_compressed
;
435 * Parameters to compression
436 * algorithm (header size,
439 ISOFS_I(inode
)->i_format_parm
[0] =
440 isonum_711(&rr
->u
.ZF
.parms
[0]);
441 ISOFS_I(inode
)->i_format_parm
[1] =
442 isonum_711(&rr
->u
.ZF
.parms
[1]);
449 "isofs: Unknown ZF compression "
451 rr
->u
.ZF
.algorithm
[0],
452 rr
->u
.ZF
.algorithm
[1]);
461 ret
= rock_continue(&rs
);
471 static char *get_symlink_chunk(char *rpnt
, struct rock_ridge
*rr
, char *plimit
)
475 struct SL_component
*oldslp
;
476 struct SL_component
*slp
;
478 slp
= &rr
->u
.SL
.link
;
481 switch (slp
->flags
& ~1) {
483 if (slp
->len
> plimit
- rpnt
)
485 memcpy(rpnt
, slp
->text
, slp
->len
);
494 if (2 > plimit
- rpnt
)
506 printk("Symlink component flag not implemented (%d)\n",
509 slen
-= slp
->len
+ 2;
511 slp
= (struct SL_component
*)((char *)slp
+ slp
->len
+ 2);
515 * If there is another SL record, and this component
516 * record isn't continued, then add a slash.
518 if ((!rootflag
) && (rr
->u
.SL
.flags
& 1) &&
519 !(oldslp
->flags
& 1)) {
528 * If this component record isn't continued, then append a '/'.
530 if (!rootflag
&& !(oldslp
->flags
& 1)) {
539 int parse_rock_ridge_inode(struct iso_directory_record
*de
, struct inode
*inode
)
541 int result
= parse_rock_ridge_inode_internal(de
, inode
, 0);
544 * if rockridge flag was reset and we didn't look for attributes
545 * behind eventual XA attributes, have a look there
547 if ((ISOFS_SB(inode
->i_sb
)->s_rock_offset
== -1)
548 && (ISOFS_SB(inode
->i_sb
)->s_rock
== 2)) {
549 result
= parse_rock_ridge_inode_internal(de
, inode
, 14);
555 * readpage() for symlinks: reads symlink contents into the page and either
556 * makes it uptodate and returns 0 or returns error (-EIO)
558 static int rock_ridge_symlink_readpage(struct file
*file
, struct page
*page
)
560 struct inode
*inode
= page
->mapping
->host
;
561 struct iso_inode_info
*ei
= ISOFS_I(inode
);
562 char *link
= kmap(page
);
563 unsigned long bufsize
= ISOFS_BUFFER_SIZE(inode
);
564 struct buffer_head
*bh
;
567 struct iso_directory_record
*raw_de
;
568 unsigned long block
, offset
;
570 struct rock_ridge
*rr
;
571 struct rock_state rs
;
574 if (!ISOFS_SB(inode
->i_sb
)->s_rock
)
577 init_rock_state(&rs
, inode
);
578 block
= ei
->i_iget5_block
;
580 bh
= sb_bread(inode
->i_sb
, block
);
584 offset
= ei
->i_iget5_offset
;
585 pnt
= (unsigned char *)bh
->b_data
+ offset
;
587 raw_de
= (struct iso_directory_record
*)pnt
;
590 * If we go past the end of the buffer, there is some sort of error.
592 if (offset
+ *pnt
> bufsize
)
596 * Now test for possible Rock Ridge extensions which will override
597 * some of these numbers in the inode structure.
600 setup_rock_ridge(raw_de
, inode
, &rs
);
603 while (rs
.len
> 2) { /* There may be one byte for padding somewhere */
604 rr
= (struct rock_ridge
*)rs
.chr
;
606 goto out
; /* Something got screwed up here */
607 sig
= isonum_721(rs
.chr
);
611 goto out
; /* corrupted isofs */
615 if ((rr
->u
.RR
.flags
[0] & RR_SL
) == 0)
619 if (check_sp(rr
, inode
))
623 rpnt
= get_symlink_chunk(rpnt
, rr
,
624 link
+ (PAGE_SIZE
- 1));
629 /* This tells is if there is a continuation record */
630 rs
.cont_extent
= isonum_733(rr
->u
.CE
.extent
);
631 rs
.cont_offset
= isonum_733(rr
->u
.CE
.offset
);
632 rs
.cont_size
= isonum_733(rr
->u
.CE
.size
);
637 ret
= rock_continue(&rs
);
648 SetPageUptodate(page
);
653 /* error exit from macro */
658 printk("unable to read i-node block");
661 printk("symlink spans iso9660 blocks\n");
672 struct address_space_operations isofs_symlink_aops
= {
673 .readpage
= rock_ridge_symlink_readpage