blob: 7b543e6b6526dc8ceebe9bd09aaa07e2d7045236 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/isofs/namei.c
3 *
4 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
5 *
6 * (C) 1991 Linus Torvalds - minix filesystem
7 */
8
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/gfp.h>
Al Viro94f2f7152005-04-25 18:32:12 -070010#include "isofs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070011
12/*
13 * ok, we cannot use strncmp, as the name is not in our data space.
14 * Thus we'll have to use isofs_match. No big problem. Match also makes
15 * some sanity tests.
16 */
17static int
Dave Jonesc3ed85a2007-07-15 23:40:03 -070018isofs_cmp(struct dentry *dentry, const char *compare, int dlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -070019{
20 struct qstr qstr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 qstr.name = compare;
22 qstr.len = dlen;
Al Virob0afd8e2014-10-28 18:40:11 -040023 if (likely(!dentry->d_op))
24 return dentry->d_name.len != dlen || memcmp(dentry->d_name.name, compare, dlen);
Linus Torvaldsda53be12013-05-21 15:22:44 -070025 return dentry->d_op->d_compare(NULL, NULL, dentry->d_name.len, dentry->d_name.name, &qstr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070026}
27
28/*
29 * isofs_find_entry()
30 *
31 * finds an entry in the specified directory with the wanted name. It
32 * returns the inode number of the found entry, or 0 on error.
33 */
34static unsigned long
35isofs_find_entry(struct inode *dir, struct dentry *dentry,
Dave Jonesc3ed85a2007-07-15 23:40:03 -070036 unsigned long *block_rv, unsigned long *offset_rv,
37 char *tmpname, struct iso_directory_record *tmpde)
Linus Torvalds1da177e2005-04-16 15:20:36 -070038{
39 unsigned long bufsize = ISOFS_BUFFER_SIZE(dir);
40 unsigned char bufbits = ISOFS_BUFFER_BITS(dir);
41 unsigned long block, f_pos, offset, block_saved, offset_saved;
Dave Jonesc3ed85a2007-07-15 23:40:03 -070042 struct buffer_head *bh = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb);
44
45 if (!ISOFS_I(dir)->i_first_extent)
46 return 0;
Dave Jonesc3ed85a2007-07-15 23:40:03 -070047
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 f_pos = 0;
49 offset = 0;
50 block = 0;
51
52 while (f_pos < dir->i_size) {
Dave Jonesc3ed85a2007-07-15 23:40:03 -070053 struct iso_directory_record *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 int de_len, match, i, dlen;
55 char *dpnt;
56
57 if (!bh) {
58 bh = isofs_bread(dir, block);
59 if (!bh)
60 return 0;
61 }
62
63 de = (struct iso_directory_record *) (bh->b_data + offset);
64
65 de_len = *(unsigned char *) de;
66 if (!de_len) {
67 brelse(bh);
68 bh = NULL;
69 f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
70 block = f_pos >> bufbits;
71 offset = 0;
72 continue;
73 }
74
75 block_saved = bh->b_blocknr;
76 offset_saved = offset;
77 offset += de_len;
78 f_pos += de_len;
79
80 /* Make sure we have a full directory entry */
81 if (offset >= bufsize) {
82 int slop = bufsize - offset + de_len;
83 memcpy(tmpde, de, slop);
84 offset &= bufsize - 1;
85 block++;
86 brelse(bh);
87 bh = NULL;
88 if (offset) {
89 bh = isofs_bread(dir, block);
90 if (!bh)
91 return 0;
92 memcpy((void *) tmpde + slop, bh->b_data, offset);
93 }
94 de = tmpde;
95 }
96
97 dlen = de->name_len[0];
98 dpnt = de->name;
Jan Kara2deb1ac2008-04-30 00:52:33 -070099 /* Basic sanity check, whether name doesn't exceed dir entry */
100 if (de_len < dlen + sizeof(struct iso_directory_record)) {
101 printk(KERN_NOTICE "iso9660: Corrupted directory entry"
102 " in block %lu of inode %lu\n", block,
103 dir->i_ino);
104 return 0;
105 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107 if (sbi->s_rock &&
108 ((i = get_rock_ridge_filename(de, tmpname, dir)))) {
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700109 dlen = i; /* possibly -1 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 dpnt = tmpname;
111#ifdef CONFIG_JOLIET
112 } else if (sbi->s_joliet_level) {
113 dlen = get_joliet_filename(de, tmpname, dir);
114 dpnt = tmpname;
115#endif
116 } else if (sbi->s_mapping == 'a') {
117 dlen = get_acorn_filename(de, tmpname, dir);
118 dpnt = tmpname;
119 } else if (sbi->s_mapping == 'n') {
120 dlen = isofs_name_translate(de, tmpname, dir);
121 dpnt = tmpname;
122 }
123
124 /*
Jeremy White9769f4e2005-06-21 17:16:53 -0700125 * Skip hidden or associated files unless hide or showassoc,
126 * respectively, is set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 */
128 match = 0;
129 if (dlen > 0 &&
Jan Kara5404ac82009-06-17 16:26:27 -0700130 (!sbi->s_hide ||
Jeremy White9769f4e2005-06-21 17:16:53 -0700131 (!(de->flags[-sbi->s_high_sierra] & 1))) &&
Jan Kara5404ac82009-06-17 16:26:27 -0700132 (sbi->s_showassoc ||
Jeremy White9769f4e2005-06-21 17:16:53 -0700133 (!(de->flags[-sbi->s_high_sierra] & 4)))) {
Al Virof643ff52014-10-28 18:37:40 -0400134 if (dpnt && (dlen > 1 || dpnt[0] > 1))
135 match = (isofs_cmp(dentry, dpnt, dlen) == 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 }
137 if (match) {
138 isofs_normalize_block_and_offset(de,
139 &block_saved,
140 &offset_saved);
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700141 *block_rv = block_saved;
142 *offset_rv = offset_saved;
Jeremy White9769f4e2005-06-21 17:16:53 -0700143 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 return 1;
145 }
146 }
Jeremy White9769f4e2005-06-21 17:16:53 -0700147 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 return 0;
149}
150
Al Viro00cd8dd2012-06-10 17:13:09 -0400151struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152{
153 int found;
Borislav Petkovcd215232007-10-16 23:30:05 -0700154 unsigned long uninitialized_var(block);
155 unsigned long uninitialized_var(offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 struct inode *inode;
157 struct page *page;
158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 page = alloc_page(GFP_USER);
160 if (!page)
161 return ERR_PTR(-ENOMEM);
162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 found = isofs_find_entry(dir, dentry,
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700164 &block, &offset,
165 page_address(page),
166 1024 + page_address(page));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 __free_page(page);
168
Al Viroa9049372011-07-08 21:20:11 -0400169 inode = found ? isofs_iget(dir->i_sb, block, offset) : NULL;
170
Pekka Enberg2ff6b1c2006-01-14 13:21:09 -0800171 return d_splice_alias(inode, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172}