ACPI: Introduce acpi_get_pci_dev()
[linux-2.6/linux-acpi-2.6.git] / fs / isofs / namei.c
blob8299889a835ea5c9b95c7d71afcabdb4610310c1
1 /*
2 * linux/fs/isofs/namei.c
4 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
6 * (C) 1991 Linus Torvalds - minix filesystem
7 */
9 #include <linux/smp_lock.h>
10 #include "isofs.h"
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.
17 static int
18 isofs_cmp(struct dentry *dentry, const char *compare, int dlen)
20 struct qstr qstr;
22 if (!compare)
23 return 1;
25 /* check special "." and ".." files */
26 if (dlen == 1) {
27 /* "." */
28 if (compare[0] == 0) {
29 if (!dentry->d_name.len)
30 return 0;
31 compare = ".";
32 } else if (compare[0] == 1) {
33 compare = "..";
34 dlen = 2;
38 qstr.name = compare;
39 qstr.len = dlen;
40 return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr);
44 * isofs_find_entry()
46 * finds an entry in the specified directory with the wanted name. It
47 * returns the inode number of the found entry, or 0 on error.
49 static unsigned long
50 isofs_find_entry(struct inode *dir, struct dentry *dentry,
51 unsigned long *block_rv, unsigned long *offset_rv,
52 char *tmpname, struct iso_directory_record *tmpde)
54 unsigned long bufsize = ISOFS_BUFFER_SIZE(dir);
55 unsigned char bufbits = ISOFS_BUFFER_BITS(dir);
56 unsigned long block, f_pos, offset, block_saved, offset_saved;
57 struct buffer_head *bh = NULL;
58 struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb);
60 if (!ISOFS_I(dir)->i_first_extent)
61 return 0;
63 f_pos = 0;
64 offset = 0;
65 block = 0;
67 while (f_pos < dir->i_size) {
68 struct iso_directory_record *de;
69 int de_len, match, i, dlen;
70 char *dpnt;
72 if (!bh) {
73 bh = isofs_bread(dir, block);
74 if (!bh)
75 return 0;
78 de = (struct iso_directory_record *) (bh->b_data + offset);
80 de_len = *(unsigned char *) de;
81 if (!de_len) {
82 brelse(bh);
83 bh = NULL;
84 f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
85 block = f_pos >> bufbits;
86 offset = 0;
87 continue;
90 block_saved = bh->b_blocknr;
91 offset_saved = offset;
92 offset += de_len;
93 f_pos += de_len;
95 /* Make sure we have a full directory entry */
96 if (offset >= bufsize) {
97 int slop = bufsize - offset + de_len;
98 memcpy(tmpde, de, slop);
99 offset &= bufsize - 1;
100 block++;
101 brelse(bh);
102 bh = NULL;
103 if (offset) {
104 bh = isofs_bread(dir, block);
105 if (!bh)
106 return 0;
107 memcpy((void *) tmpde + slop, bh->b_data, offset);
109 de = tmpde;
112 dlen = de->name_len[0];
113 dpnt = de->name;
114 /* Basic sanity check, whether name doesn't exceed dir entry */
115 if (de_len < dlen + sizeof(struct iso_directory_record)) {
116 printk(KERN_NOTICE "iso9660: Corrupted directory entry"
117 " in block %lu of inode %lu\n", block,
118 dir->i_ino);
119 return 0;
122 if (sbi->s_rock &&
123 ((i = get_rock_ridge_filename(de, tmpname, dir)))) {
124 dlen = i; /* possibly -1 */
125 dpnt = tmpname;
126 #ifdef CONFIG_JOLIET
127 } else if (sbi->s_joliet_level) {
128 dlen = get_joliet_filename(de, tmpname, dir);
129 dpnt = tmpname;
130 #endif
131 } else if (sbi->s_mapping == 'a') {
132 dlen = get_acorn_filename(de, tmpname, dir);
133 dpnt = tmpname;
134 } else if (sbi->s_mapping == 'n') {
135 dlen = isofs_name_translate(de, tmpname, dir);
136 dpnt = tmpname;
140 * Skip hidden or associated files unless hide or showassoc,
141 * respectively, is set
143 match = 0;
144 if (dlen > 0 &&
145 (sbi->s_hide =='n' ||
146 (!(de->flags[-sbi->s_high_sierra] & 1))) &&
147 (sbi->s_showassoc =='y' ||
148 (!(de->flags[-sbi->s_high_sierra] & 4)))) {
149 match = (isofs_cmp(dentry, dpnt, dlen) == 0);
151 if (match) {
152 isofs_normalize_block_and_offset(de,
153 &block_saved,
154 &offset_saved);
155 *block_rv = block_saved;
156 *offset_rv = offset_saved;
157 brelse(bh);
158 return 1;
161 brelse(bh);
162 return 0;
165 struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
167 int found;
168 unsigned long uninitialized_var(block);
169 unsigned long uninitialized_var(offset);
170 struct inode *inode;
171 struct page *page;
173 dentry->d_op = dir->i_sb->s_root->d_op;
175 page = alloc_page(GFP_USER);
176 if (!page)
177 return ERR_PTR(-ENOMEM);
179 lock_kernel();
180 found = isofs_find_entry(dir, dentry,
181 &block, &offset,
182 page_address(page),
183 1024 + page_address(page));
184 __free_page(page);
186 inode = NULL;
187 if (found) {
188 inode = isofs_iget(dir->i_sb, block, offset);
189 if (IS_ERR(inode)) {
190 unlock_kernel();
191 return ERR_CAST(inode);
194 unlock_kernel();
195 return d_splice_alias(inode, dentry);