5 * Symlink handling routines for the OSTA-UDF(tm) filesystem.
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.
13 * (C) 1998-2001 Ben Fennema
14 * (C) 1999 Stelias Computing Inc
18 * 04/16/99 blf Created.
23 #include <linux/uaccess.h>
24 #include <linux/errno.h>
26 #include <linux/time.h>
28 #include <linux/stat.h>
29 #include <linux/pagemap.h>
32 static int udf_pc_to_char(struct super_block *sb, unsigned char *from,
33 int fromlen, unsigned char *to, int tolen)
35 struct pathComponent *pc;
38 unsigned char *p = to;
40 /* Reserve one byte for terminating \0 */
42 while (elen < fromlen) {
43 pc = (struct pathComponent *)(from + elen);
44 elen += sizeof(struct pathComponent);
45 switch (pc->componentType) {
48 * Symlink points to some place which should be agreed
49 * upon between originator and receiver of the media. Ignore.
51 if (pc->lengthComponentIdent > 0) {
52 elen += pc->lengthComponentIdent;
76 /* that would be . - just ignore */
79 elen += pc->lengthComponentIdent;
82 comp_len = udf_get_filename(sb, pc->componentIdent,
83 pc->lengthComponentIdent,
101 static int udf_symlink_filler(struct file *file, struct page *page)
103 struct inode *inode = page->mapping->host;
104 struct buffer_head *bh = NULL;
105 unsigned char *symlink;
107 unsigned char *p = kmap(page);
108 struct udf_inode_info *iinfo;
111 /* We don't support symlinks longer than one block */
112 if (inode->i_size > inode->i_sb->s_blocksize) {
117 iinfo = UDF_I(inode);
118 pos = udf_block_map(inode, 0);
120 down_read(&iinfo->i_data_sem);
121 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
122 symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
124 bh = sb_bread(inode->i_sb, pos);
128 goto out_unlock_inode;
131 symlink = bh->b_data;
134 err = udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p, PAGE_SIZE);
137 goto out_unlock_inode;
139 up_read(&iinfo->i_data_sem);
140 SetPageUptodate(page);
146 up_read(&iinfo->i_data_sem);
155 * symlinks can't do much...
157 const struct address_space_operations udf_symlink_aops = {
158 .readpage = udf_symlink_filler,