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> | |
26 | #include <linux/udf_fs.h> | |
27 | #include <linux/time.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/stat.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/pagemap.h> | |
32 | #include <linux/smp_lock.h> | |
33 | #include <linux/buffer_head.h> | |
34 | #include "udf_i.h" | |
35 | ||
4b11111a MS |
36 | static void udf_pc_to_char(struct super_block *sb, char *from, int fromlen, |
37 | char *to) | |
1da177e4 LT |
38 | { |
39 | struct pathComponent *pc; | |
40 | int elen = 0; | |
41 | char *p = to; | |
42 | ||
cb00ea35 | 43 | while (elen < fromlen) { |
1da177e4 | 44 | pc = (struct pathComponent *)(from + elen); |
cb00ea35 CG |
45 | switch (pc->componentType) { |
46 | case 1: | |
47 | if (pc->lengthComponentIdent == 0) { | |
48 | p = to; | |
1da177e4 | 49 | *p++ = '/'; |
cb00ea35 CG |
50 | } |
51 | break; | |
52 | case 3: | |
53 | memcpy(p, "../", 3); | |
54 | p += 3; | |
55 | break; | |
56 | case 4: | |
57 | memcpy(p, "./", 2); | |
58 | p += 2; | |
59 | /* that would be . - just ignore */ | |
60 | break; | |
61 | case 5: | |
62 | p += udf_get_filename(sb, pc->componentIdent, p, | |
63 | pc->lengthComponentIdent); | |
64 | *p++ = '/'; | |
65 | break; | |
1da177e4 LT |
66 | } |
67 | elen += sizeof(struct pathComponent) + pc->lengthComponentIdent; | |
68 | } | |
cb00ea35 | 69 | if (p > to + 1) |
1da177e4 LT |
70 | p[-1] = '\0'; |
71 | else | |
72 | p[0] = '\0'; | |
73 | } | |
74 | ||
75 | static int udf_symlink_filler(struct file *file, struct page *page) | |
76 | { | |
77 | struct inode *inode = page->mapping->host; | |
78 | struct buffer_head *bh = NULL; | |
79 | char *symlink; | |
80 | int err = -EIO; | |
81 | char *p = kmap(page); | |
48d6d8ff | 82 | struct udf_inode_info *iinfo; |
1da177e4 LT |
83 | |
84 | lock_kernel(); | |
48d6d8ff MS |
85 | iinfo = UDF_I(inode); |
86 | if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { | |
87 | symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr; | |
28de7948 | 88 | } else { |
1da177e4 LT |
89 | bh = sb_bread(inode->i_sb, udf_block_map(inode, 0)); |
90 | ||
91 | if (!bh) | |
92 | goto out; | |
93 | ||
94 | symlink = bh->b_data; | |
95 | } | |
96 | ||
97 | udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p); | |
3bf25cb4 | 98 | brelse(bh); |
1da177e4 LT |
99 | |
100 | unlock_kernel(); | |
101 | SetPageUptodate(page); | |
102 | kunmap(page); | |
103 | unlock_page(page); | |
104 | return 0; | |
28de7948 CG |
105 | |
106 | out: | |
1da177e4 LT |
107 | unlock_kernel(); |
108 | SetPageError(page); | |
109 | kunmap(page); | |
110 | unlock_page(page); | |
111 | return err; | |
112 | } | |
113 | ||
114 | /* | |
115 | * symlinks can't do much... | |
116 | */ | |
f5e54d6e | 117 | const struct address_space_operations udf_symlink_aops = { |
28de7948 | 118 | .readpage = udf_symlink_filler, |
1da177e4 | 119 | }; |