Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * symlink.c | |
3 | * | |
4 | * PURPOSE | |
5 | * Symlink handling routines for the OSTA-UDF(tm) filesystem. | |
6 | * | |
1da177e4 LT |
7 | * 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 | |
28de7948 | 14 | * (C) 1999 Stelias Computing Inc |
1da177e4 LT |
15 | * |
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> | |
1da177e4 LT |
26 | #include <linux/time.h> |
27 | #include <linux/mm.h> | |
28 | #include <linux/stat.h> | |
1da177e4 LT |
29 | #include <linux/pagemap.h> |
30 | #include <linux/smp_lock.h> | |
31 | #include <linux/buffer_head.h> | |
32 | #include "udf_i.h" | |
33 | ||
391e8bbd AV |
34 | static void udf_pc_to_char(struct super_block *sb, unsigned char *from, |
35 | int fromlen, unsigned char *to) | |
1da177e4 LT |
36 | { |
37 | struct pathComponent *pc; | |
38 | int elen = 0; | |
391e8bbd | 39 | unsigned char *p = to; |
1da177e4 | 40 | |
cb00ea35 | 41 | while (elen < fromlen) { |
1da177e4 | 42 | pc = (struct pathComponent *)(from + elen); |
cb00ea35 CG |
43 | switch (pc->componentType) { |
44 | case 1: | |
45 | if (pc->lengthComponentIdent == 0) { | |
46 | p = to; | |
1da177e4 | 47 | *p++ = '/'; |
cb00ea35 CG |
48 | } |
49 | break; | |
50 | case 3: | |
51 | memcpy(p, "../", 3); | |
52 | p += 3; | |
53 | break; | |
54 | case 4: | |
55 | memcpy(p, "./", 2); | |
56 | p += 2; | |
57 | /* that would be . - just ignore */ | |
58 | break; | |
59 | case 5: | |
60 | p += udf_get_filename(sb, pc->componentIdent, p, | |
61 | pc->lengthComponentIdent); | |
62 | *p++ = '/'; | |
63 | break; | |
1da177e4 LT |
64 | } |
65 | elen += sizeof(struct pathComponent) + pc->lengthComponentIdent; | |
66 | } | |
cb00ea35 | 67 | if (p > to + 1) |
1da177e4 LT |
68 | p[-1] = '\0'; |
69 | else | |
70 | p[0] = '\0'; | |
71 | } | |
72 | ||
73 | static int udf_symlink_filler(struct file *file, struct page *page) | |
74 | { | |
75 | struct inode *inode = page->mapping->host; | |
76 | struct buffer_head *bh = NULL; | |
391e8bbd | 77 | unsigned char *symlink; |
1da177e4 | 78 | int err = -EIO; |
391e8bbd | 79 | unsigned char *p = kmap(page); |
48d6d8ff | 80 | struct udf_inode_info *iinfo; |
1da177e4 LT |
81 | |
82 | lock_kernel(); | |
48d6d8ff MS |
83 | iinfo = UDF_I(inode); |
84 | if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { | |
85 | symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr; | |
28de7948 | 86 | } else { |
1da177e4 LT |
87 | bh = sb_bread(inode->i_sb, udf_block_map(inode, 0)); |
88 | ||
89 | if (!bh) | |
90 | goto out; | |
91 | ||
92 | symlink = bh->b_data; | |
93 | } | |
94 | ||
95 | udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p); | |
3bf25cb4 | 96 | brelse(bh); |
1da177e4 LT |
97 | |
98 | unlock_kernel(); | |
99 | SetPageUptodate(page); | |
100 | kunmap(page); | |
101 | unlock_page(page); | |
102 | return 0; | |
28de7948 CG |
103 | |
104 | out: | |
1da177e4 LT |
105 | unlock_kernel(); |
106 | SetPageError(page); | |
107 | kunmap(page); | |
108 | unlock_page(page); | |
109 | return err; | |
110 | } | |
111 | ||
112 | /* | |
113 | * symlinks can't do much... | |
114 | */ | |
f5e54d6e | 115 | const struct address_space_operations udf_symlink_aops = { |
28de7948 | 116 | .readpage = udf_symlink_filler, |
1da177e4 | 117 | }; |