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1/* inode.c: /proc/openprom handling routines
2 *
3 * Copyright (C) 1996-1999 Jakub Jelinek (jakub@redhat.com)
4 * Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
5 */
6
7#include <linux/module.h>
8#include <linux/types.h>
9#include <linux/string.h>
10#include <linux/fs.h>
11#include <linux/init.h>
12#include <linux/slab.h>
13#include <linux/seq_file.h>
14#include <linux/magic.h>
15
16#include <asm/openprom.h>
17#include <asm/oplib.h>
18#include <asm/prom.h>
19#include <asm/uaccess.h>
20
21static DEFINE_MUTEX(op_mutex);
22
23#define OPENPROM_ROOT_INO 0
24
25enum op_inode_type {
26 op_inode_node,
27 op_inode_prop,
28};
29
30union op_inode_data {
31 struct device_node *node;
32 struct property *prop;
33};
34
35struct op_inode_info {
36 struct inode vfs_inode;
37 enum op_inode_type type;
38 union op_inode_data u;
39};
40
41static struct inode *openprom_iget(struct super_block *sb, ino_t ino);
42
43static inline struct op_inode_info *OP_I(struct inode *inode)
44{
45 return container_of(inode, struct op_inode_info, vfs_inode);
46}
47
48static int is_string(unsigned char *p, int len)
49{
50 int i;
51
52 for (i = 0; i < len; i++) {
53 unsigned char val = p[i];
54
55 if ((i && !val) ||
56 (val >= ' ' && val <= '~'))
57 continue;
58
59 return 0;
60 }
61
62 return 1;
63}
64
65static int property_show(struct seq_file *f, void *v)
66{
67 struct property *prop = f->private;
68 void *pval;
69 int len;
70
71 len = prop->length;
72 pval = prop->value;
73
74 if (is_string(pval, len)) {
75 while (len > 0) {
76 int n = strlen(pval);
77
78 seq_printf(f, "%s", (char *) pval);
79
80 /* Skip over the NULL byte too. */
81 pval += n + 1;
82 len -= n + 1;
83
84 if (len > 0)
85 seq_printf(f, " + ");
86 }
87 } else {
88 if (len & 3) {
89 while (len) {
90 len--;
91 if (len)
92 seq_printf(f, "%02x.",
93 *(unsigned char *) pval);
94 else
95 seq_printf(f, "%02x",
96 *(unsigned char *) pval);
97 pval++;
98 }
99 } else {
100 while (len >= 4) {
101 len -= 4;
102
103 if (len)
104 seq_printf(f, "%08x.",
105 *(unsigned int *) pval);
106 else
107 seq_printf(f, "%08x",
108 *(unsigned int *) pval);
109 pval += 4;
110 }
111 }
112 }
113 seq_printf(f, "\n");
114
115 return 0;
116}
117
118static void *property_start(struct seq_file *f, loff_t *pos)
119{
120 if (*pos == 0)
121 return pos;
122 return NULL;
123}
124
125static void *property_next(struct seq_file *f, void *v, loff_t *pos)
126{
127 (*pos)++;
128 return NULL;
129}
130
131static void property_stop(struct seq_file *f, void *v)
132{
133 /* Nothing to do */
134}
135
136static const struct seq_operations property_op = {
137 .start = property_start,
138 .next = property_next,
139 .stop = property_stop,
140 .show = property_show
141};
142
143static int property_open(struct inode *inode, struct file *file)
144{
145 struct op_inode_info *oi = OP_I(inode);
146 int ret;
147
148 BUG_ON(oi->type != op_inode_prop);
149
150 ret = seq_open(file, &property_op);
151 if (!ret) {
152 struct seq_file *m = file->private_data;
153 m->private = oi->u.prop;
154 }
155 return ret;
156}
157
158static const struct file_operations openpromfs_prop_ops = {
159 .open = property_open,
160 .read = seq_read,
161 .llseek = seq_lseek,
162 .release = seq_release,
163};
164
165static int openpromfs_readdir(struct file *, void *, filldir_t);
166
167static const struct file_operations openprom_operations = {
168 .read = generic_read_dir,
169 .readdir = openpromfs_readdir,
170 .llseek = generic_file_llseek,
171};
172
173static struct dentry *openpromfs_lookup(struct inode *, struct dentry *, struct nameidata *);
174
175static const struct inode_operations openprom_inode_operations = {
176 .lookup = openpromfs_lookup,
177};
178
179static struct dentry *openpromfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
180{
181 struct op_inode_info *ent_oi, *oi = OP_I(dir);
182 struct device_node *dp, *child;
183 struct property *prop;
184 enum op_inode_type ent_type;
185 union op_inode_data ent_data;
186 const char *name;
187 struct inode *inode;
188 unsigned int ino;
189 int len;
190
191 BUG_ON(oi->type != op_inode_node);
192
193 dp = oi->u.node;
194
195 name = dentry->d_name.name;
196 len = dentry->d_name.len;
197
198 mutex_lock(&op_mutex);
199
200 child = dp->child;
201 while (child) {
202 int n = strlen(child->path_component_name);
203
204 if (len == n &&
205 !strncmp(child->path_component_name, name, len)) {
206 ent_type = op_inode_node;
207 ent_data.node = child;
208 ino = child->unique_id;
209 goto found;
210 }
211 child = child->sibling;
212 }
213
214 prop = dp->properties;
215 while (prop) {
216 int n = strlen(prop->name);
217
218 if (len == n && !strncmp(prop->name, name, len)) {
219 ent_type = op_inode_prop;
220 ent_data.prop = prop;
221 ino = prop->unique_id;
222 goto found;
223 }
224
225 prop = prop->next;
226 }
227
228 mutex_unlock(&op_mutex);
229 return ERR_PTR(-ENOENT);
230
231found:
232 inode = openprom_iget(dir->i_sb, ino);
233 mutex_unlock(&op_mutex);
234 if (IS_ERR(inode))
235 return ERR_CAST(inode);
236 ent_oi = OP_I(inode);
237 ent_oi->type = ent_type;
238 ent_oi->u = ent_data;
239
240 switch (ent_type) {
241 case op_inode_node:
242 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
243 inode->i_op = &openprom_inode_operations;
244 inode->i_fop = &openprom_operations;
245 set_nlink(inode, 2);
246 break;
247 case op_inode_prop:
248 if (!strcmp(dp->name, "options") && (len == 17) &&
249 !strncmp (name, "security-password", 17))
250 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
251 else
252 inode->i_mode = S_IFREG | S_IRUGO;
253 inode->i_fop = &openpromfs_prop_ops;
254 set_nlink(inode, 1);
255 inode->i_size = ent_oi->u.prop->length;
256 break;
257 }
258
259 d_add(dentry, inode);
260 return NULL;
261}
262
263static int openpromfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
264{
265 struct inode *inode = filp->f_path.dentry->d_inode;
266 struct op_inode_info *oi = OP_I(inode);
267 struct device_node *dp = oi->u.node;
268 struct device_node *child;
269 struct property *prop;
270 unsigned int ino;
271 int i;
272
273 mutex_lock(&op_mutex);
274
275 ino = inode->i_ino;
276 i = filp->f_pos;
277 switch (i) {
278 case 0:
279 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
280 goto out;
281 i++;
282 filp->f_pos++;
283 /* fall thru */
284 case 1:
285 if (filldir(dirent, "..", 2, i,
286 (dp->parent == NULL ?
287 OPENPROM_ROOT_INO :
288 dp->parent->unique_id), DT_DIR) < 0)
289 goto out;
290 i++;
291 filp->f_pos++;
292 /* fall thru */
293 default:
294 i -= 2;
295
296 /* First, the children nodes as directories. */
297 child = dp->child;
298 while (i && child) {
299 child = child->sibling;
300 i--;
301 }
302 while (child) {
303 if (filldir(dirent,
304 child->path_component_name,
305 strlen(child->path_component_name),
306 filp->f_pos, child->unique_id, DT_DIR) < 0)
307 goto out;
308
309 filp->f_pos++;
310 child = child->sibling;
311 }
312
313 /* Next, the properties as files. */
314 prop = dp->properties;
315 while (i && prop) {
316 prop = prop->next;
317 i--;
318 }
319 while (prop) {
320 if (filldir(dirent, prop->name, strlen(prop->name),
321 filp->f_pos, prop->unique_id, DT_REG) < 0)
322 goto out;
323
324 filp->f_pos++;
325 prop = prop->next;
326 }
327 }
328out:
329 mutex_unlock(&op_mutex);
330 return 0;
331}
332
333static struct kmem_cache *op_inode_cachep;
334
335static struct inode *openprom_alloc_inode(struct super_block *sb)
336{
337 struct op_inode_info *oi;
338
339 oi = kmem_cache_alloc(op_inode_cachep, GFP_KERNEL);
340 if (!oi)
341 return NULL;
342
343 return &oi->vfs_inode;
344}
345
346static void openprom_i_callback(struct rcu_head *head)
347{
348 struct inode *inode = container_of(head, struct inode, i_rcu);
349 kmem_cache_free(op_inode_cachep, OP_I(inode));
350}
351
352static void openprom_destroy_inode(struct inode *inode)
353{
354 call_rcu(&inode->i_rcu, openprom_i_callback);
355}
356
357static struct inode *openprom_iget(struct super_block *sb, ino_t ino)
358{
359 struct inode *inode;
360
361 inode = iget_locked(sb, ino);
362 if (!inode)
363 return ERR_PTR(-ENOMEM);
364 if (inode->i_state & I_NEW) {
365 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
366 if (inode->i_ino == OPENPROM_ROOT_INO) {
367 inode->i_op = &openprom_inode_operations;
368 inode->i_fop = &openprom_operations;
369 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
370 }
371 unlock_new_inode(inode);
372 }
373 return inode;
374}
375
376static int openprom_remount(struct super_block *sb, int *flags, char *data)
377{
378 *flags |= MS_NOATIME;
379 return 0;
380}
381
382static const struct super_operations openprom_sops = {
383 .alloc_inode = openprom_alloc_inode,
384 .destroy_inode = openprom_destroy_inode,
385 .statfs = simple_statfs,
386 .remount_fs = openprom_remount,
387};
388
389static int openprom_fill_super(struct super_block *s, void *data, int silent)
390{
391 struct inode *root_inode;
392 struct op_inode_info *oi;
393 int ret;
394
395 s->s_flags |= MS_NOATIME;
396 s->s_blocksize = 1024;
397 s->s_blocksize_bits = 10;
398 s->s_magic = OPENPROM_SUPER_MAGIC;
399 s->s_op = &openprom_sops;
400 s->s_time_gran = 1;
401 root_inode = openprom_iget(s, OPENPROM_ROOT_INO);
402 if (IS_ERR(root_inode)) {
403 ret = PTR_ERR(root_inode);
404 goto out_no_root;
405 }
406
407 oi = OP_I(root_inode);
408 oi->type = op_inode_node;
409 oi->u.node = of_find_node_by_path("/");
410
411 s->s_root = d_make_root(root_inode);
412 if (!s->s_root)
413 goto out_no_root_dentry;
414 return 0;
415
416out_no_root_dentry:
417 ret = -ENOMEM;
418out_no_root:
419 printk("openprom_fill_super: get root inode failed\n");
420 return ret;
421}
422
423static struct dentry *openprom_mount(struct file_system_type *fs_type,
424 int flags, const char *dev_name, void *data)
425{
426 return mount_single(fs_type, flags, data, openprom_fill_super);
427}
428
429static struct file_system_type openprom_fs_type = {
430 .owner = THIS_MODULE,
431 .name = "openpromfs",
432 .mount = openprom_mount,
433 .kill_sb = kill_anon_super,
434};
435
436static void op_inode_init_once(void *data)
437{
438 struct op_inode_info *oi = (struct op_inode_info *) data;
439
440 inode_init_once(&oi->vfs_inode);
441}
442
443static int __init init_openprom_fs(void)
444{
445 int err;
446
447 op_inode_cachep = kmem_cache_create("op_inode_cache",
448 sizeof(struct op_inode_info),
449 0,
450 (SLAB_RECLAIM_ACCOUNT |
451 SLAB_MEM_SPREAD),
452 op_inode_init_once);
453 if (!op_inode_cachep)
454 return -ENOMEM;
455
456 err = register_filesystem(&openprom_fs_type);
457 if (err)
458 kmem_cache_destroy(op_inode_cachep);
459
460 return err;
461}
462
463static void __exit exit_openprom_fs(void)
464{
465 unregister_filesystem(&openprom_fs_type);
466 kmem_cache_destroy(op_inode_cachep);
467}
468
469module_init(init_openprom_fs)
470module_exit(exit_openprom_fs)
471MODULE_LICENSE("GPL");