USB: cdc-wdm: better allocate a buffer that is at least as big as we tell the USB...
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / udf / symlink.c
blobb1d4488b0f14ad3aad14aeb519877bc38f1f209a
1 /*
2 * symlink.c
4 * PURPOSE
5 * Symlink handling routines for the OSTA-UDF(tm) filesystem.
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.
13 * (C) 1998-2001 Ben Fennema
14 * (C) 1999 Stelias Computing Inc
16 * HISTORY
18 * 04/16/99 blf Created.
22 #include "udfdecl.h"
23 #include <asm/uaccess.h>
24 #include <linux/errno.h>
25 #include <linux/fs.h>
26 #include <linux/time.h>
27 #include <linux/mm.h>
28 #include <linux/stat.h>
29 #include <linux/pagemap.h>
30 #include <linux/buffer_head.h>
31 #include "udf_i.h"
33 static void udf_pc_to_char(struct super_block *sb, unsigned char *from,
34 int fromlen, unsigned char *to)
36 struct pathComponent *pc;
37 int elen = 0;
38 unsigned char *p = to;
40 while (elen < fromlen) {
41 pc = (struct pathComponent *)(from + elen);
42 switch (pc->componentType) {
43 case 1:
44 if (pc->lengthComponentIdent == 0) {
45 p = to;
46 *p++ = '/';
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;
64 elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
66 if (p > to + 1)
67 p[-1] = '\0';
68 else
69 p[0] = '\0';
72 static int udf_symlink_filler(struct file *file, struct page *page)
74 struct inode *inode = page->mapping->host;
75 struct buffer_head *bh = NULL;
76 unsigned char *symlink;
77 int err = -EIO;
78 unsigned char *p = kmap(page);
79 struct udf_inode_info *iinfo;
80 uint32_t pos;
82 iinfo = UDF_I(inode);
83 pos = udf_block_map(inode, 0);
85 down_read(&iinfo->i_data_sem);
86 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
87 symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
88 } else {
89 bh = sb_bread(inode->i_sb, pos);
91 if (!bh)
92 goto out;
94 symlink = bh->b_data;
97 udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
98 brelse(bh);
100 up_read(&iinfo->i_data_sem);
101 SetPageUptodate(page);
102 kunmap(page);
103 unlock_page(page);
104 return 0;
106 out:
107 up_read(&iinfo->i_data_sem);
108 SetPageError(page);
109 kunmap(page);
110 unlock_page(page);
111 return err;
115 * symlinks can't do much...
117 const struct address_space_operations udf_symlink_aops = {
118 .readpage = udf_symlink_filler,