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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 | 29 | #include <linux/pagemap.h> |
1da177e4 LT |
30 | #include <linux/buffer_head.h> |
31 | #include "udf_i.h" | |
32 | ||
391e8bbd AV |
33 | static void udf_pc_to_char(struct super_block *sb, unsigned char *from, |
34 | int fromlen, unsigned char *to) | |
1da177e4 LT |
35 | { |
36 | struct pathComponent *pc; | |
37 | int elen = 0; | |
391e8bbd | 38 | unsigned char *p = to; |
1da177e4 | 39 | |
cb00ea35 | 40 | while (elen < fromlen) { |
1da177e4 | 41 | pc = (struct pathComponent *)(from + elen); |
cb00ea35 CG |
42 | switch (pc->componentType) { |
43 | case 1: | |
44 | if (pc->lengthComponentIdent == 0) { | |
45 | p = to; | |
1da177e4 | 46 | *p++ = '/'; |
cb00ea35 CG |
47 | } |
48 | break; | |
49 | case 3: | |
50 | memcpy(p, "../", 3); | |
51 | p += 3; | |
52 | break; | |
53 | case 4: | |
54 | memcpy(p, "./", 2); | |
55 | p += 2; | |
56 | /* that would be . - just ignore */ | |
57 | break; | |
58 | case 5: | |
59 | p += udf_get_filename(sb, pc->componentIdent, p, | |
60 | pc->lengthComponentIdent); | |
61 | *p++ = '/'; | |
62 | break; | |
1da177e4 LT |
63 | } |
64 | elen += sizeof(struct pathComponent) + pc->lengthComponentIdent; | |
65 | } | |
cb00ea35 | 66 | if (p > to + 1) |
1da177e4 LT |
67 | p[-1] = '\0'; |
68 | else | |
69 | p[0] = '\0'; | |
70 | } | |
71 | ||
72 | static int udf_symlink_filler(struct file *file, struct page *page) | |
73 | { | |
74 | struct inode *inode = page->mapping->host; | |
75 | struct buffer_head *bh = NULL; | |
391e8bbd | 76 | unsigned char *symlink; |
1da177e4 | 77 | int err = -EIO; |
391e8bbd | 78 | unsigned char *p = kmap(page); |
48d6d8ff | 79 | struct udf_inode_info *iinfo; |
4d0fb621 | 80 | uint32_t pos; |
1da177e4 | 81 | |
48d6d8ff | 82 | iinfo = UDF_I(inode); |
4d0fb621 AIB |
83 | pos = udf_block_map(inode, 0); |
84 | ||
85 | down_read(&iinfo->i_data_sem); | |
48d6d8ff MS |
86 | if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { |
87 | symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr; | |
28de7948 | 88 | } else { |
4d0fb621 | 89 | bh = sb_bread(inode->i_sb, pos); |
1da177e4 LT |
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 | 99 | |
4d0fb621 | 100 | up_read(&iinfo->i_data_sem); |
1da177e4 LT |
101 | SetPageUptodate(page); |
102 | kunmap(page); | |
103 | unlock_page(page); | |
104 | return 0; | |
28de7948 CG |
105 | |
106 | out: | |
4d0fb621 | 107 | up_read(&iinfo->i_data_sem); |
1da177e4 LT |
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 | }; |