5 * Symlink handling routines for the OSTA-UDF(tm) filesystem.
8 * This file is distributed under the terms of the GNU General Public
9 * License (GPL). Copies of the GPL can be obtained from:
10 * ftp://prep.ai.mit.edu/pub/gnu/GPL
11 * Each contributing author retains all rights to their own work.
13 * (C) 1998-2001 Ben Fennema
14 * (C) 1999 Stelias Computing Inc
18 * 04/16/99 blf Created.
23 #include <linux/uaccess.h>
24 #include <linux/errno.h>
26 #include <linux/time.h>
28 #include <linux/stat.h>
29 #include <linux/pagemap.h>
32 static int udf_pc_to_char(struct super_block
*sb
, unsigned char *from
,
33 int fromlen
, unsigned char *to
, int tolen
)
35 struct pathComponent
*pc
;
38 unsigned char *p
= to
;
40 /* Reserve one byte for terminating \0 */
42 while (elen
< fromlen
) {
43 pc
= (struct pathComponent
*)(from
+ elen
);
44 elen
+= sizeof(struct pathComponent
);
45 switch (pc
->componentType
) {
48 * Symlink points to some place which should be agreed
49 * upon between originator and receiver of the media. Ignore.
51 if (pc
->lengthComponentIdent
> 0) {
52 elen
+= pc
->lengthComponentIdent
;
76 /* that would be . - just ignore */
79 elen
+= pc
->lengthComponentIdent
;
82 comp_len
= udf_get_filename(sb
, pc
->componentIdent
,
83 pc
->lengthComponentIdent
,
104 static int udf_symlink_filler(struct file
*file
, struct page
*page
)
106 struct inode
*inode
= page
->mapping
->host
;
107 struct buffer_head
*bh
= NULL
;
108 unsigned char *symlink
;
110 unsigned char *p
= page_address(page
);
111 struct udf_inode_info
*iinfo
;
114 /* We don't support symlinks longer than one block */
115 if (inode
->i_size
> inode
->i_sb
->s_blocksize
) {
120 iinfo
= UDF_I(inode
);
121 pos
= udf_block_map(inode
, 0);
123 down_read(&iinfo
->i_data_sem
);
124 if (iinfo
->i_alloc_type
== ICBTAG_FLAG_AD_IN_ICB
) {
125 symlink
= iinfo
->i_ext
.i_data
+ iinfo
->i_lenEAttr
;
127 bh
= sb_bread(inode
->i_sb
, pos
);
131 goto out_unlock_inode
;
134 symlink
= bh
->b_data
;
137 err
= udf_pc_to_char(inode
->i_sb
, symlink
, inode
->i_size
, p
, PAGE_SIZE
);
140 goto out_unlock_inode
;
142 up_read(&iinfo
->i_data_sem
);
143 SetPageUptodate(page
);
148 up_read(&iinfo
->i_data_sem
);
156 * symlinks can't do much...
158 const struct address_space_operations udf_symlink_aops
= {
159 .readpage
= udf_symlink_filler
,