tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * symlink.c
3 *
4 * PURPOSE
5 * Symlink handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * CONTACTS
8 * E-mail regarding any portion of the Linux UDF file system should be
9 * directed to the development team mailing list (run by majordomo):
10 * linux_udf@hpesjro.fc.hp.com
11 *
12 * COPYRIGHT
13 * This file is distributed under the terms of the GNU General Public
14 * License (GPL). Copies of the GPL can be obtained from:
15 * ftp://prep.ai.mit.edu/pub/gnu/GPL
16 * Each contributing author retains all rights to their own work.
17 *
18 * (C) 1998-2001 Ben Fennema
19 * (C) 1999 Stelias Computing Inc
20 *
21 * HISTORY
22 *
23 * 04/16/99 blf Created.
24 *
25 */
26
27#include "udfdecl.h"
28#include <asm/uaccess.h>
29#include <linux/errno.h>
30#include <linux/fs.h>
31#include <linux/udf_fs.h>
32#include <linux/time.h>
33#include <linux/mm.h>
34#include <linux/stat.h>
35#include <linux/slab.h>
36#include <linux/pagemap.h>
37#include <linux/smp_lock.h>
38#include <linux/buffer_head.h>
39#include "udf_i.h"
40
41static void udf_pc_to_char(struct super_block *sb, char *from, int fromlen, char *to)
42{
43 struct pathComponent *pc;
44 int elen = 0;
45 char *p = to;
46
47 while (elen < fromlen)
48 {
49 pc = (struct pathComponent *)(from + elen);
50 switch (pc->componentType)
51 {
52 case 1:
53 if (pc->lengthComponentIdent == 0)
54 {
55 p = to;
56 *p++ = '/';
57 }
58 break;
59 case 3:
60 memcpy(p, "../", 3);
61 p += 3;
62 break;
63 case 4:
64 memcpy(p, "./", 2);
65 p += 2;
66 /* that would be . - just ignore */
67 break;
68 case 5:
69 p += udf_get_filename(sb, pc->componentIdent, p, pc->lengthComponentIdent);
70 *p++ = '/';
71 break;
72 }
73 elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
74 }
75 if (p > to+1)
76 p[-1] = '\0';
77 else
78 p[0] = '\0';
79}
80
81static int udf_symlink_filler(struct file *file, struct page *page)
82{
83 struct inode *inode = page->mapping->host;
84 struct buffer_head *bh = NULL;
85 char *symlink;
86 int err = -EIO;
87 char *p = kmap(page);
88
89 lock_kernel();
90 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
91 symlink = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
92 else
93 {
94 bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
95
96 if (!bh)
97 goto out;
98
99 symlink = bh->b_data;
100 }
101
102 udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
103 udf_release_data(bh);
104
105 unlock_kernel();
106 SetPageUptodate(page);
107 kunmap(page);
108 unlock_page(page);
109 return 0;
110out:
111 unlock_kernel();
112 SetPageError(page);
113 kunmap(page);
114 unlock_page(page);
115 return err;
116}
117
118/*
119 * symlinks can't do much...
120 */
121struct address_space_operations udf_symlink_aops = {
122 .readpage = udf_symlink_filler,
123};