blob: d3c7905b2ddc007decc5084e5a5a6761ac52b43a [file] [log] [blame]
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{
31 struct inode *inode = filp->f_dentry->d_inode;
32 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,
200 .readdir = adfs_readdir,
201 .fsync = file_fsync,
202};
203
204static int
205adfs_hash(struct dentry *parent, struct qstr *qstr)
206{
207 const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
208 const unsigned char *name;
209 unsigned long hash;
210 int i;
211
212 if (qstr->len < name_len)
213 return 0;
214
215 /*
216 * Truncate the name in place, avoids
217 * having to define a compare function.
218 */
219 qstr->len = i = name_len;
220 name = qstr->name;
221 hash = init_name_hash();
222 while (i--) {
223 char c;
224
225 c = *name++;
226 if (c >= 'A' && c <= 'Z')
227 c += 'a' - 'A';
228
229 hash = partial_name_hash(c, hash);
230 }
231 qstr->hash = end_name_hash(hash);
232
233 return 0;
234}
235
236/*
237 * Compare two names, taking note of the name length
238 * requirements of the underlying filesystem.
239 */
240static int
241adfs_compare(struct dentry *parent, struct qstr *entry, struct qstr *name)
242{
243 int i;
244
245 if (entry->len != name->len)
246 return 1;
247
248 for (i = 0; i < name->len; i++) {
249 char a, b;
250
251 a = entry->name[i];
252 b = name->name[i];
253
254 if (a >= 'A' && a <= 'Z')
255 a += 'a' - 'A';
256 if (b >= 'A' && b <= 'Z')
257 b += 'a' - 'A';
258
259 if (a != b)
260 return 1;
261 }
262 return 0;
263}
264
265struct dentry_operations adfs_dentry_operations = {
266 .d_hash = adfs_hash,
267 .d_compare = adfs_compare,
268};
269
270static struct dentry *
271adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
272{
273 struct inode *inode = NULL;
274 struct object_info obj;
275 int error;
276
277 dentry->d_op = &adfs_dentry_operations;
278 lock_kernel();
279 error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
280 if (error == 0) {
281 error = -EACCES;
282 /*
283 * This only returns NULL if get_empty_inode
284 * fails.
285 */
286 inode = adfs_iget(dir->i_sb, &obj);
287 if (inode)
288 error = 0;
289 }
290 unlock_kernel();
291 d_add(dentry, inode);
292 return ERR_PTR(error);
293}
294
295/*
296 * directories can handle most operations...
297 */
298struct inode_operations adfs_dir_inode_operations = {
299 .lookup = adfs_lookup,
300 .setattr = adfs_notify_change,
301};