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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/adfs/dir.c
3 *
4 * Copyright (C) 1999-2000 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Common directory handling for ADFS
11 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/errno.h>
13#include <linux/fs.h>
14#include <linux/adfs_fs.h>
15#include <linux/time.h>
16#include <linux/stat.h>
17#include <linux/spinlock.h>
18#include <linux/smp_lock.h>
19#include <linux/buffer_head.h> /* for file_fsync() */
20
21#include "adfs.h"
22
23/*
24 * For future. This should probably be per-directory.
25 */
26static DEFINE_RWLOCK(adfs_dir_lock);
27
28static int
29adfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
30{
Josef Sipek514653e2006-12-08 02:36:50 -080031 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 struct super_block *sb = inode->i_sb;
33 struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
34 struct object_info obj;
35 struct adfs_dir dir;
36 int ret = 0;
37
38 lock_kernel();
39
40 if (filp->f_pos >> 32)
41 goto out;
42
43 ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
44 if (ret)
45 goto out;
46
47 switch ((unsigned long)filp->f_pos) {
48 case 0:
49 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
50 goto free_out;
51 filp->f_pos += 1;
52
53 case 1:
54 if (filldir(dirent, "..", 2, 1, dir.parent_id, DT_DIR) < 0)
55 goto free_out;
56 filp->f_pos += 1;
57
58 default:
59 break;
60 }
61
62 read_lock(&adfs_dir_lock);
63
64 ret = ops->setpos(&dir, filp->f_pos - 2);
65 if (ret)
66 goto unlock_out;
67 while (ops->getnext(&dir, &obj) == 0) {
68 if (filldir(dirent, obj.name, obj.name_len,
69 filp->f_pos, obj.file_id, DT_UNKNOWN) < 0)
70 goto unlock_out;
71 filp->f_pos += 1;
72 }
73
74unlock_out:
75 read_unlock(&adfs_dir_lock);
76
77free_out:
78 ops->free(&dir);
79
80out:
81 unlock_kernel();
82 return ret;
83}
84
85int
86adfs_dir_update(struct super_block *sb, struct object_info *obj)
87{
88 int ret = -EINVAL;
89#ifdef CONFIG_ADFS_FS_RW
90 struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
91 struct adfs_dir dir;
92
93 printk(KERN_INFO "adfs_dir_update: object %06X in dir %06X\n",
94 obj->file_id, obj->parent_id);
95
96 if (!ops->update) {
97 ret = -EINVAL;
98 goto out;
99 }
100
101 ret = ops->read(sb, obj->parent_id, 0, &dir);
102 if (ret)
103 goto out;
104
105 write_lock(&adfs_dir_lock);
106 ret = ops->update(&dir, obj);
107 write_unlock(&adfs_dir_lock);
108
109 ops->free(&dir);
110out:
111#endif
112 return ret;
113}
114
115static int
116adfs_match(struct qstr *name, struct object_info *obj)
117{
118 int i;
119
120 if (name->len != obj->name_len)
121 return 0;
122
123 for (i = 0; i < name->len; i++) {
124 char c1, c2;
125
126 c1 = name->name[i];
127 c2 = obj->name[i];
128
129 if (c1 >= 'A' && c1 <= 'Z')
130 c1 += 'a' - 'A';
131 if (c2 >= 'A' && c2 <= 'Z')
132 c2 += 'a' - 'A';
133
134 if (c1 != c2)
135 return 0;
136 }
137 return 1;
138}
139
140static int
141adfs_dir_lookup_byname(struct inode *inode, struct qstr *name, struct object_info *obj)
142{
143 struct super_block *sb = inode->i_sb;
144 struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
145 struct adfs_dir dir;
146 int ret;
147
148 ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
149 if (ret)
150 goto out;
151
152 if (ADFS_I(inode)->parent_id != dir.parent_id) {
153 adfs_error(sb, "parent directory changed under me! (%lx but got %lx)\n",
154 ADFS_I(inode)->parent_id, dir.parent_id);
155 ret = -EIO;
156 goto free_out;
157 }
158
159 obj->parent_id = inode->i_ino;
160
161 /*
162 * '.' is handled by reserved_lookup() in fs/namei.c
163 */
164 if (name->len == 2 && name->name[0] == '.' && name->name[1] == '.') {
165 /*
166 * Currently unable to fill in the rest of 'obj',
167 * but this is better than nothing. We need to
168 * ascend one level to find it's parent.
169 */
170 obj->name_len = 0;
171 obj->file_id = obj->parent_id;
172 goto free_out;
173 }
174
175 read_lock(&adfs_dir_lock);
176
177 ret = ops->setpos(&dir, 0);
178 if (ret)
179 goto unlock_out;
180
181 ret = -ENOENT;
182 while (ops->getnext(&dir, obj) == 0) {
183 if (adfs_match(name, obj)) {
184 ret = 0;
185 break;
186 }
187 }
188
189unlock_out:
190 read_unlock(&adfs_dir_lock);
191
192free_out:
193 ops->free(&dir);
194out:
195 return ret;
196}
197
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800198const struct file_operations adfs_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 .read = generic_read_dir,
Al Viro59af1582008-08-24 07:24:41 -0400200 .llseek = generic_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 .readdir = adfs_readdir,
202 .fsync = file_fsync,
203};
204
205static int
206adfs_hash(struct dentry *parent, struct qstr *qstr)
207{
208 const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
209 const unsigned char *name;
210 unsigned long hash;
211 int i;
212
213 if (qstr->len < name_len)
214 return 0;
215
216 /*
217 * Truncate the name in place, avoids
218 * having to define a compare function.
219 */
220 qstr->len = i = name_len;
221 name = qstr->name;
222 hash = init_name_hash();
223 while (i--) {
224 char c;
225
226 c = *name++;
227 if (c >= 'A' && c <= 'Z')
228 c += 'a' - 'A';
229
230 hash = partial_name_hash(c, hash);
231 }
232 qstr->hash = end_name_hash(hash);
233
234 return 0;
235}
236
237/*
238 * Compare two names, taking note of the name length
239 * requirements of the underlying filesystem.
240 */
241static int
242adfs_compare(struct dentry *parent, struct qstr *entry, struct qstr *name)
243{
244 int i;
245
246 if (entry->len != name->len)
247 return 1;
248
249 for (i = 0; i < name->len; i++) {
250 char a, b;
251
252 a = entry->name[i];
253 b = name->name[i];
254
255 if (a >= 'A' && a <= 'Z')
256 a += 'a' - 'A';
257 if (b >= 'A' && b <= 'Z')
258 b += 'a' - 'A';
259
260 if (a != b)
261 return 1;
262 }
263 return 0;
264}
265
Al Viroe16404e2009-02-20 05:55:13 +0000266const struct dentry_operations adfs_dentry_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 .d_hash = adfs_hash,
268 .d_compare = adfs_compare,
269};
270
271static struct dentry *
272adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
273{
274 struct inode *inode = NULL;
275 struct object_info obj;
276 int error;
277
278 dentry->d_op = &adfs_dentry_operations;
279 lock_kernel();
280 error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
281 if (error == 0) {
282 error = -EACCES;
283 /*
284 * This only returns NULL if get_empty_inode
285 * fails.
286 */
287 inode = adfs_iget(dir->i_sb, &obj);
288 if (inode)
289 error = 0;
290 }
291 unlock_kernel();
292 d_add(dentry, inode);
293 return ERR_PTR(error);
294}
295
296/*
297 * directories can handle most operations...
298 */
Arjan van de Ven754661f2007-02-12 00:55:38 -0800299const struct inode_operations adfs_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 .lookup = adfs_lookup,
301 .setattr = adfs_notify_change,
302};