blob: 852e91845688f24be5b1fa464b70a4d65a044b2a [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>
29#include <linux/slab.h>
30#include <linux/pagemap.h>
31#include <linux/smp_lock.h>
32#include <linux/buffer_head.h>
33#include "udf_i.h"
34
Al Viro391e8bb2010-01-31 21:28:48 -050035static void udf_pc_to_char(struct super_block *sb, unsigned char *from,
36 int fromlen, unsigned char *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
38 struct pathComponent *pc;
39 int elen = 0;
Al Viro391e8bb2010-01-31 21:28:48 -050040 unsigned char *p = to;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070042 while (elen < fromlen) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 pc = (struct pathComponent *)(from + elen);
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070044 switch (pc->componentType) {
45 case 1:
46 if (pc->lengthComponentIdent == 0) {
47 p = to;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 *p++ = '/';
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070049 }
50 break;
51 case 3:
52 memcpy(p, "../", 3);
53 p += 3;
54 break;
55 case 4:
56 memcpy(p, "./", 2);
57 p += 2;
58 /* that would be . - just ignore */
59 break;
60 case 5:
61 p += udf_get_filename(sb, pc->componentIdent, p,
62 pc->lengthComponentIdent);
63 *p++ = '/';
64 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 }
66 elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
67 }
Cyrill Gorcunovcb00ea32007-07-19 01:47:43 -070068 if (p > to + 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 p[-1] = '\0';
70 else
71 p[0] = '\0';
72}
73
74static int udf_symlink_filler(struct file *file, struct page *page)
75{
76 struct inode *inode = page->mapping->host;
77 struct buffer_head *bh = NULL;
Al Viro391e8bb2010-01-31 21:28:48 -050078 unsigned char *symlink;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 int err = -EIO;
Al Viro391e8bb2010-01-31 21:28:48 -050080 unsigned char *p = kmap(page);
Marcin Slusarz48d6d8f2008-02-08 04:20:44 -080081 struct udf_inode_info *iinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83 lock_kernel();
Marcin Slusarz48d6d8f2008-02-08 04:20:44 -080084 iinfo = UDF_I(inode);
85 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
86 symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
Cyrill Gorcunov28de7942007-07-21 04:37:18 -070087 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
89
90 if (!bh)
91 goto out;
92
93 symlink = bh->b_data;
94 }
95
96 udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
Jan Kara3bf25cb2007-05-08 00:35:16 -070097 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 unlock_kernel();
100 SetPageUptodate(page);
101 kunmap(page);
102 unlock_page(page);
103 return 0;
Cyrill Gorcunov28de7942007-07-21 04:37:18 -0700104
105out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 unlock_kernel();
107 SetPageError(page);
108 kunmap(page);
109 unlock_page(page);
110 return err;
111}
112
113/*
114 * symlinks can't do much...
115 */
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700116const struct address_space_operations udf_symlink_aops = {
Cyrill Gorcunov28de7942007-07-21 04:37:18 -0700117 .readpage = udf_symlink_filler,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118};