blob: d7c6dbe4194bb33bbe37930c63cf23377e5d9343 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * symlink.c
3 *
4 * PURPOSE
5 * Symlink handling routines for the OSTA-UDF(tm) filesystem.
6 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * COPYRIGHT
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.
12 *
13 * (C) 1998-2001 Ben Fennema
Cyrill Gorcunov28de7942007-07-21 04:37:18 -070014 * (C) 1999 Stelias Computing Inc
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 *
16 * HISTORY
17 *
18 * 04/16/99 blf Created.
19 *
20 */
21
22#include "udfdecl.h"
23#include <asm/uaccess.h>
24#include <linux/errno.h>
25#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/time.h>
27#include <linux/mm.h>
28#include <linux/stat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/buffer_head.h>
31#include "udf_i.h"
32
Al Viro391e8bb2010-01-31 21:28:48 -050033static void udf_pc_to_char(struct super_block *sb, unsigned char *from,
34 int fromlen, unsigned char *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035{
36 struct pathComponent *pc;
37 int elen = 0;
Al Viro391e8bb2010-01-31 21:28:48 -050038 unsigned char *p = to;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070040 while (elen < fromlen) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 pc = (struct pathComponent *)(from + elen);
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070042 switch (pc->componentType) {
43 case 1:
Jan Karafef2e9f2011-12-12 15:13:50 +010044 /*
45 * Symlink points to some place which should be agreed
46 * upon between originator and receiver of the media. Ignore.
47 */
48 if (pc->lengthComponentIdent > 0)
49 break;
50 /* Fall through */
51 case 2:
52 p = to;
53 *p++ = '/';
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070054 break;
55 case 3:
56 memcpy(p, "../", 3);
57 p += 3;
58 break;
59 case 4:
60 memcpy(p, "./", 2);
61 p += 2;
62 /* that would be . - just ignore */
63 break;
64 case 5:
65 p += udf_get_filename(sb, pc->componentIdent, p,
66 pc->lengthComponentIdent);
67 *p++ = '/';
68 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 }
70 elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
71 }
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070072 if (p > to + 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 p[-1] = '\0';
74 else
75 p[0] = '\0';
76}
77
78static int udf_symlink_filler(struct file *file, struct page *page)
79{
80 struct inode *inode = page->mapping->host;
81 struct buffer_head *bh = NULL;
Al Viro391e8bb2010-01-31 21:28:48 -050082 unsigned char *symlink;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 int err = -EIO;
Al Viro391e8bb2010-01-31 21:28:48 -050084 unsigned char *p = kmap(page);
Marcin Slusarz48d6d8f2008-02-08 04:20:44 -080085 struct udf_inode_info *iinfo;
Alessio Igor Bogani4d0fb622010-11-16 18:40:47 +010086 uint32_t pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
Marcin Slusarz48d6d8f2008-02-08 04:20:44 -080088 iinfo = UDF_I(inode);
Alessio Igor Bogani4d0fb622010-11-16 18:40:47 +010089 pos = udf_block_map(inode, 0);
90
91 down_read(&iinfo->i_data_sem);
Marcin Slusarz48d6d8f2008-02-08 04:20:44 -080092 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
93 symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
Cyrill Gorcunov28de7942007-07-21 04:37:18 -070094 } else {
Alessio Igor Bogani4d0fb622010-11-16 18:40:47 +010095 bh = sb_bread(inode->i_sb, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97 if (!bh)
98 goto out;
99
100 symlink = bh->b_data;
101 }
102
103 udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
Jan Kara3bf25cb2007-05-08 00:35:16 -0700104 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
Alessio Igor Bogani4d0fb622010-11-16 18:40:47 +0100106 up_read(&iinfo->i_data_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 SetPageUptodate(page);
108 kunmap(page);
109 unlock_page(page);
110 return 0;
Cyrill Gorcunov28de7942007-07-21 04:37:18 -0700111
112out:
Alessio Igor Bogani4d0fb622010-11-16 18:40:47 +0100113 up_read(&iinfo->i_data_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 SetPageError(page);
115 kunmap(page);
116 unlock_page(page);
117 return err;
118}
119
120/*
121 * symlinks can't do much...
122 */
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700123const struct address_space_operations udf_symlink_aops = {
Cyrill Gorcunov28de7942007-07-21 04:37:18 -0700124 .readpage = udf_symlink_filler,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125};