[PATCH] VFS: Permit filesystem to override root dentry on mount
[linux-2.6.git] / fs / openpromfs / inode.c
1 /* $Id: inode.c,v 1.15 2001/11/12 09:43:39 davem Exp $
2  * openpromfs.c: /proc/openprom handling routines
3  *
4  * Copyright (C) 1996-1999 Jakub Jelinek  (jakub@redhat.com)
5  * Copyright (C) 1998      Eddie C. Dost  (ecd@skynet.be)
6  */
7
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/string.h>
11 #include <linux/fs.h>
12 #include <linux/openprom_fs.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/smp_lock.h>
16
17 #include <asm/openprom.h>
18 #include <asm/oplib.h>
19 #include <asm/uaccess.h>
20
21 #define ALIASES_NNODES 64
22
23 typedef struct {
24         u16     parent;
25         u16     next;
26         u16     child;
27         u16     first_prop;
28         u32     node;
29 } openpromfs_node;
30
31 typedef struct {
32 #define OPP_STRING      0x10
33 #define OPP_STRINGLIST  0x20
34 #define OPP_BINARY      0x40
35 #define OPP_HEXSTRING   0x80
36 #define OPP_DIRTY       0x01
37 #define OPP_QUOTED      0x02
38 #define OPP_NOTQUOTED   0x04
39 #define OPP_ASCIIZ      0x08
40         u32     flag;
41         u32     alloclen;
42         u32     len;
43         char    *value;
44         char    name[8];
45 } openprom_property;
46
47 static openpromfs_node *nodes;
48 static int alloced;
49 static u16 last_node;
50 static u16 first_prop;
51 static u16 options = 0xffff;
52 static u16 aliases = 0xffff;
53 static int aliases_nodes;
54 static char *alias_names [ALIASES_NNODES];
55
56 #define OPENPROM_ROOT_INO       16
57 #define OPENPROM_FIRST_INO      OPENPROM_ROOT_INO
58 #define NODE(ino) nodes[ino - OPENPROM_FIRST_INO]
59 #define NODE2INO(node) (node + OPENPROM_FIRST_INO)
60 #define NODEP2INO(no) (no + OPENPROM_FIRST_INO + last_node)
61
62 static int openpromfs_create (struct inode *, struct dentry *, int, struct nameidata *);
63 static int openpromfs_readdir(struct file *, void *, filldir_t);
64 static struct dentry *openpromfs_lookup(struct inode *, struct dentry *dentry, struct nameidata *nd);
65 static int openpromfs_unlink (struct inode *, struct dentry *dentry);
66
67 static ssize_t nodenum_read(struct file *file, char __user *buf,
68                             size_t count, loff_t *ppos)
69 {
70         struct inode *inode = file->f_dentry->d_inode;
71         char buffer[10];
72         
73         if (count < 0 || !inode->u.generic_ip)
74                 return -EINVAL;
75         sprintf (buffer, "%8.8x\n", (u32)(long)(inode->u.generic_ip));
76         if (file->f_pos >= 9)
77                 return 0;
78         if (count > 9 - file->f_pos)
79                 count = 9 - file->f_pos;
80         if (copy_to_user(buf, buffer + file->f_pos, count))
81                 return -EFAULT;
82         *ppos += count;
83         return count;
84 }
85
86 static ssize_t property_read(struct file *filp, char __user *buf,
87                              size_t count, loff_t *ppos)
88 {
89         struct inode *inode = filp->f_dentry->d_inode;
90         int i, j, k;
91         u32 node;
92         char *p, *s;
93         u32 *q;
94         openprom_property *op;
95         char buffer[64];
96         
97         if (!filp->private_data) {
98                 node = nodes[(u16)((long)inode->u.generic_ip)].node;
99                 i = ((u32)(long)inode->u.generic_ip) >> 16;
100                 if ((u16)((long)inode->u.generic_ip) == aliases) {
101                         if (i >= aliases_nodes)
102                                 p = NULL;
103                         else
104                                 p = alias_names [i];
105                 } else
106                         for (p = prom_firstprop (node, buffer);
107                              i && p && *p;
108                              p = prom_nextprop (node, p, buffer), i--)
109                                 /* nothing */ ;
110                 if (!p || !*p)
111                         return -EIO;
112                 i = prom_getproplen (node, p);
113                 if (i < 0) {
114                         if ((u16)((long)inode->u.generic_ip) == aliases)
115                                 i = 0;
116                         else
117                                 return -EIO;
118                 }
119                 k = i;
120                 if (i < 64) i = 64;
121                 filp->private_data = kmalloc (sizeof (openprom_property)
122                                               + (j = strlen (p)) + 2 * i,
123                                               GFP_KERNEL);
124                 if (!filp->private_data)
125                         return -ENOMEM;
126                 op = (openprom_property *)filp->private_data;
127                 op->flag = 0;
128                 op->alloclen = 2 * i;
129                 strcpy (op->name, p);
130                 op->value = (char *)(((unsigned long)(op->name + j + 4)) & ~3);
131                 op->len = k;
132                 if (k && prom_getproperty (node, p, op->value, i) < 0)
133                         return -EIO;
134                 op->value [k] = 0;
135                 if (k) {
136                         for (s = NULL, p = op->value; p < op->value + k; p++) {
137                                 if ((*p >= ' ' && *p <= '~') || *p == '\n') {
138                                         op->flag |= OPP_STRING;
139                                         s = p;
140                                         continue;
141                                 }
142                                 if (p > op->value && !*p && s == p - 1) {
143                                         if (p < op->value + k - 1)
144                                                 op->flag |= OPP_STRINGLIST;
145                                         else
146                                                 op->flag |= OPP_ASCIIZ;
147                                         continue;
148                                 }
149                                 if (k == 1 && !*p) {
150                                         op->flag |= (OPP_STRING|OPP_ASCIIZ);
151                                         break;
152                                 }
153                                 op->flag &= ~(OPP_STRING|OPP_STRINGLIST);
154                                 if (k & 3)
155                                         op->flag |= OPP_HEXSTRING;
156                                 else
157                                         op->flag |= OPP_BINARY;
158                                 break;
159                         }
160                         if (op->flag & OPP_STRINGLIST)
161                                 op->flag &= ~(OPP_STRING);
162                         if (op->flag & OPP_ASCIIZ)
163                                 op->len--;
164                 }
165         } else
166                 op = (openprom_property *)filp->private_data;
167         if (!count || !(op->len || (op->flag & OPP_ASCIIZ)))
168                 return 0;
169         if (*ppos >= 0xffffff || count >= 0xffffff)
170                 return -EINVAL;
171         if (op->flag & OPP_STRINGLIST) {
172                 for (k = 0, p = op->value; p < op->value + op->len; p++)
173                         if (!*p)
174                                 k++;
175                 i = op->len + 4 * k + 3;
176         } else if (op->flag & OPP_STRING) {
177                 i = op->len + 3;
178         } else if (op->flag & OPP_BINARY) {
179                 i = (op->len * 9) >> 2;
180         } else {
181                 i = (op->len << 1) + 1;
182         }
183         k = *ppos;
184         if (k >= i) return 0;
185         if (count > i - k) count = i - k;
186         if (op->flag & OPP_STRING) {
187                 if (!k) {
188                         if (put_user('\'', buf))
189                                 return -EFAULT;
190                         k++;
191                         count--;
192                 }
193
194                 if (k + count >= i - 2)
195                         j = i - 2 - k;
196                 else
197                         j = count;
198
199                 if (j >= 0) {
200                         if (copy_to_user(buf + k - *ppos,
201                                          op->value + k - 1, j))
202                                 return -EFAULT;
203                         count -= j;
204                         k += j;
205                 }
206
207                 if (count) {
208                         if (put_user('\'', &buf [k++ - *ppos]))
209                                 return -EFAULT;
210                 }
211                 if (count > 1) {
212                         if (put_user('\n', &buf [k++ - *ppos]))
213                                 return -EFAULT;
214                 }
215         } else if (op->flag & OPP_STRINGLIST) {
216                 char *tmp;
217
218                 tmp = kmalloc (i, GFP_KERNEL);
219                 if (!tmp)
220                         return -ENOMEM;
221
222                 s = tmp;
223                 *s++ = '\'';
224                 for (p = op->value; p < op->value + op->len; p++) {
225                         if (!*p) {
226                                 strcpy(s, "' + '");
227                                 s += 5;
228                                 continue;
229                         }
230                         *s++ = *p;
231                 }
232                 strcpy(s, "'\n");
233
234                 if (copy_to_user(buf, tmp + k, count))
235                         return -EFAULT;
236
237                 kfree(tmp);
238                 k += count;
239
240         } else if (op->flag & OPP_BINARY) {
241                 char buffer[10];
242                 u32 *first, *last;
243                 int first_off, last_cnt;
244
245                 first = ((u32 *)op->value) + k / 9;
246                 first_off = k % 9;
247                 last = ((u32 *)op->value) + (k + count - 1) / 9;
248                 last_cnt = (k + count) % 9;
249                 if (!last_cnt) last_cnt = 9;
250
251                 if (first == last) {
252                         sprintf (buffer, "%08x.", *first);
253                         if (copy_to_user(buf, buffer + first_off,
254                                          last_cnt - first_off))
255                                 return -EFAULT;
256                         buf += last_cnt - first_off;
257                 } else {                
258                         for (q = first; q <= last; q++) {
259                                 sprintf (buffer, "%08x.", *q);
260                                 if (q == first) {
261                                         if (copy_to_user(buf, buffer + first_off,
262                                                          9 - first_off))
263                                                 return -EFAULT;
264                                         buf += 9 - first_off;
265                                 } else if (q == last) {
266                                         if (copy_to_user(buf, buffer, last_cnt))
267                                                 return -EFAULT;
268                                         buf += last_cnt;
269                                 } else {
270                                         if (copy_to_user(buf, buffer, 9))
271                                                 return -EFAULT;
272                                         buf += 9;
273                                 }
274                         }
275                 }
276
277                 if (last == (u32 *)(op->value + op->len - 4) && last_cnt == 9) {
278                         if (put_user('\n', (buf - 1)))
279                                 return -EFAULT;
280                 }
281
282                 k += count;
283
284         } else if (op->flag & OPP_HEXSTRING) {
285                 char buffer[3];
286
287                 if ((k < i - 1) && (k & 1)) {
288                         sprintf (buffer, "%02x",
289                                  (unsigned char) *(op->value + (k >> 1)) & 0xff);
290                         if (put_user(buffer[1], &buf[k++ - *ppos]))
291                                 return -EFAULT;
292                         count--;
293                 }
294
295                 for (; (count > 1) && (k < i - 1); k += 2) {
296                         sprintf (buffer, "%02x",
297                                  (unsigned char) *(op->value + (k >> 1)) & 0xff);
298                         if (copy_to_user(buf + k - *ppos, buffer, 2))
299                                 return -EFAULT;
300                         count -= 2;
301                 }
302
303                 if (count && (k < i - 1)) {
304                         sprintf (buffer, "%02x",
305                                  (unsigned char) *(op->value + (k >> 1)) & 0xff);
306                         if (put_user(buffer[0], &buf[k++ - *ppos]))
307                                 return -EFAULT;
308                         count--;
309                 }
310
311                 if (count) {
312                         if (put_user('\n', &buf [k++ - *ppos]))
313                                 return -EFAULT;
314                 }
315         }
316         count = k - *ppos;
317         *ppos = k;
318         return count;
319 }
320
321 static ssize_t property_write(struct file *filp, const char __user *buf,
322                               size_t count, loff_t *ppos)
323 {
324         int i, j, k;
325         char *p;
326         u32 *q;
327         void *b;
328         openprom_property *op;
329         
330         if (*ppos >= 0xffffff || count >= 0xffffff)
331                 return -EINVAL;
332         if (!filp->private_data) {
333                 i = property_read (filp, NULL, 0, NULL);
334                 if (i)
335                         return i;
336         }
337         k = *ppos;
338         op = (openprom_property *)filp->private_data;
339         if (!(op->flag & OPP_STRING)) {
340                 u32 *first, *last;
341                 int first_off, last_cnt;
342                 u32 mask, mask2;
343                 char tmp [9];
344                 int forcelen = 0;
345                 
346                 j = k % 9;
347                 for (i = 0; i < count; i++, j++) {
348                         if (j == 9) j = 0;
349                         if (!j) {
350                                 char ctmp;
351                                 if (get_user(ctmp, &buf[i]))
352                                         return -EFAULT;
353                                 if (ctmp != '.') {
354                                         if (ctmp != '\n') {
355                                                 if (op->flag & OPP_BINARY)
356                                                         return -EINVAL;
357                                                 else
358                                                         goto write_try_string;
359                                         } else {
360                                                 count = i + 1;
361                                                 forcelen = 1;
362                                                 break;
363                                         }
364                                 }
365                         } else {
366                                 char ctmp;
367                                 if (get_user(ctmp, &buf[i]))
368                                         return -EFAULT;
369                                 if (ctmp < '0' || 
370                                     (ctmp > '9' && ctmp < 'A') ||
371                                     (ctmp > 'F' && ctmp < 'a') ||
372                                     ctmp > 'f') {
373                                         if (op->flag & OPP_BINARY)
374                                                 return -EINVAL;
375                                         else
376                                                 goto write_try_string;
377                                 }
378                         }
379                 }
380                 op->flag |= OPP_BINARY;
381                 tmp [8] = 0;
382                 i = ((count + k + 8) / 9) << 2;
383                 if (op->alloclen <= i) {
384                         b = kmalloc (sizeof (openprom_property) + 2 * i,
385                                      GFP_KERNEL);
386                         if (!b)
387                                 return -ENOMEM;
388                         memcpy (b, filp->private_data,
389                                 sizeof (openprom_property)
390                                 + strlen (op->name) + op->alloclen);
391                         memset (((char *)b) + sizeof (openprom_property)
392                                 + strlen (op->name) + op->alloclen, 
393                                 0, 2 * i - op->alloclen);
394                         op = (openprom_property *)b;
395                         op->alloclen = 2*i;
396                         b = filp->private_data;
397                         filp->private_data = (void *)op;
398                         kfree (b);
399                 }
400                 first = ((u32 *)op->value) + (k / 9);
401                 first_off = k % 9;
402                 last = (u32 *)(op->value + i);
403                 last_cnt = (k + count) % 9;
404                 if (first + 1 == last) {
405                         memset (tmp, '0', 8);
406                         if (copy_from_user(tmp + first_off, buf,
407                                            (count + first_off > 8) ?
408                                            8 - first_off : count))
409                                 return -EFAULT;
410                         mask = 0xffffffff;
411                         mask2 = 0xffffffff;
412                         for (j = 0; j < first_off; j++)
413                                 mask >>= 1;
414                         for (j = 8 - count - first_off; j > 0; j--)
415                                 mask2 <<= 1;
416                         mask &= mask2;
417                         if (mask) {
418                                 *first &= ~mask;
419                                 *first |= simple_strtoul (tmp, NULL, 16);
420                                 op->flag |= OPP_DIRTY;
421                         }
422                 } else {
423                         op->flag |= OPP_DIRTY;
424                         for (q = first; q < last; q++) {
425                                 if (q == first) {
426                                         if (first_off < 8) {
427                                                 memset (tmp, '0', 8);
428                                                 if (copy_from_user(tmp + first_off,
429                                                                    buf,
430                                                                    8 - first_off))
431                                                         return -EFAULT;
432                                                 mask = 0xffffffff;
433                                                 for (j = 0; j < first_off; j++)
434                                                         mask >>= 1;
435                                                 *q &= ~mask;
436                                                 *q |= simple_strtoul (tmp,NULL,16);
437                                         }
438                                         buf += 9;
439                                 } else if ((q == last - 1) && last_cnt
440                                            && (last_cnt < 8)) {
441                                         memset (tmp, '0', 8);
442                                         if (copy_from_user(tmp, buf, last_cnt))
443                                                 return -EFAULT;
444                                         mask = 0xffffffff;
445                                         for (j = 0; j < 8 - last_cnt; j++)
446                                                 mask <<= 1;
447                                         *q &= ~mask;
448                                         *q |= simple_strtoul (tmp, NULL, 16);
449                                         buf += last_cnt;
450                                 } else {
451                                         char tchars[17]; /* XXX yuck... */
452
453                                         if (copy_from_user(tchars, buf, 16))
454                                                 return -EFAULT;
455                                         *q = simple_strtoul (tchars, NULL, 16);
456                                         buf += 9;
457                                 }
458                         }
459                 }
460                 if (!forcelen) {
461                         if (op->len < i)
462                                 op->len = i;
463                 } else
464                         op->len = i;
465                 *ppos += count;
466         }
467 write_try_string:
468         if (!(op->flag & OPP_BINARY)) {
469                 if (!(op->flag & (OPP_QUOTED | OPP_NOTQUOTED))) {
470                         char ctmp;
471
472                         /* No way, if somebody starts writing from the middle, 
473                          * we don't know whether he uses quotes around or not 
474                          */
475                         if (k > 0)
476                                 return -EINVAL;
477                         if (get_user(ctmp, buf))
478                                 return -EFAULT;
479                         if (ctmp == '\'') {
480                                 op->flag |= OPP_QUOTED;
481                                 buf++;
482                                 count--;
483                                 (*ppos)++;
484                                 if (!count) {
485                                         op->flag |= OPP_STRING;
486                                         return 1;
487                                 }
488                         } else
489                                 op->flag |= OPP_NOTQUOTED;
490                 }
491                 op->flag |= OPP_STRING;
492                 if (op->alloclen <= count + *ppos) {
493                         b = kmalloc (sizeof (openprom_property)
494                                      + 2 * (count + *ppos), GFP_KERNEL);
495                         if (!b)
496                                 return -ENOMEM;
497                         memcpy (b, filp->private_data,
498                                 sizeof (openprom_property)
499                                 + strlen (op->name) + op->alloclen);
500                         memset (((char *)b) + sizeof (openprom_property)
501                                 + strlen (op->name) + op->alloclen, 
502                                 0, 2*(count - *ppos) - op->alloclen);
503                         op = (openprom_property *)b;
504                         op->alloclen = 2*(count + *ppos);
505                         b = filp->private_data;
506                         filp->private_data = (void *)op;
507                         kfree (b);
508                 }
509                 p = op->value + *ppos - ((op->flag & OPP_QUOTED) ? 1 : 0);
510                 if (copy_from_user(p, buf, count))
511                         return -EFAULT;
512                 op->flag |= OPP_DIRTY;
513                 for (i = 0; i < count; i++, p++)
514                         if (*p == '\n') {
515                                 *p = 0;
516                                 break;
517                         }
518                 if (i < count) {
519                         op->len = p - op->value;
520                         *ppos += i + 1;
521                         if ((p > op->value) && (op->flag & OPP_QUOTED)
522                             && (*(p - 1) == '\''))
523                                 op->len--;
524                 } else {
525                         if (p - op->value > op->len)
526                                 op->len = p - op->value;
527                         *ppos += count;
528                 }
529         }
530         return *ppos - k;
531 }
532
533 int property_release (struct inode *inode, struct file *filp)
534 {
535         openprom_property *op = (openprom_property *)filp->private_data;
536         int error;
537         u32 node;
538         
539         if (!op)
540                 return 0;
541         lock_kernel();
542         node = nodes[(u16)((long)inode->u.generic_ip)].node;
543         if ((u16)((long)inode->u.generic_ip) == aliases) {
544                 if ((op->flag & OPP_DIRTY) && (op->flag & OPP_STRING)) {
545                         char *p = op->name;
546                         int i = (op->value - op->name) - strlen (op->name) - 1;
547                         op->value [op->len] = 0;
548                         *(op->value - 1) = ' ';
549                         if (i) {
550                                 for (p = op->value - i - 2; p >= op->name; p--)
551                                         p[i] = *p;
552                                 p = op->name + i;
553                         }
554                         memcpy (p - 8, "nvalias ", 8);
555                         prom_feval (p - 8);
556                 }
557         } else if (op->flag & OPP_DIRTY) {
558                 if (op->flag & OPP_STRING) {
559                         op->value [op->len] = 0;
560                         error = prom_setprop (node, op->name,
561                                               op->value, op->len + 1);
562                         if (error <= 0)
563                                 printk (KERN_WARNING "openpromfs: "
564                                         "Couldn't write property %s\n",
565                                         op->name);
566                 } else if ((op->flag & OPP_BINARY) || !op->len) {
567                         error = prom_setprop (node, op->name,
568                                               op->value, op->len);
569                         if (error <= 0)
570                                 printk (KERN_WARNING "openpromfs: "
571                                         "Couldn't write property %s\n",
572                                         op->name);
573                 } else {
574                         printk (KERN_WARNING "openpromfs: "
575                                 "Unknown property type of %s\n",
576                                 op->name);
577                 }
578         }
579         unlock_kernel();
580         kfree (filp->private_data);
581         return 0;
582 }
583
584 static const struct file_operations openpromfs_prop_ops = {
585         .read           = property_read,
586         .write          = property_write,
587         .release        = property_release,
588 };
589
590 static const struct file_operations openpromfs_nodenum_ops = {
591         .read           = nodenum_read,
592 };
593
594 static const struct file_operations openprom_operations = {
595         .read           = generic_read_dir,
596         .readdir        = openpromfs_readdir,
597 };
598
599 static struct inode_operations openprom_alias_inode_operations = {
600         .create         = openpromfs_create,
601         .lookup         = openpromfs_lookup,
602         .unlink         = openpromfs_unlink,
603 };
604
605 static struct inode_operations openprom_inode_operations = {
606         .lookup         = openpromfs_lookup,
607 };
608
609 static int lookup_children(u16 n, const char * name, int len)
610 {
611         int ret;
612         u16 node;
613         for (; n != 0xffff; n = nodes[n].next) {
614                 node = nodes[n].child;
615                 if (node != 0xffff) {
616                         char buffer[128];
617                         int i;
618                         char *p;
619                         
620                         while (node != 0xffff) {
621                                 if (prom_getname (nodes[node].node,
622                                                   buffer, 128) >= 0) {
623                                         i = strlen (buffer);
624                                         if ((len == i)
625                                             && !strncmp (buffer, name, len))
626                                                 return NODE2INO(node);
627                                         p = strchr (buffer, '@');
628                                         if (p && (len == p - buffer)
629                                             && !strncmp (buffer, name, len))
630                                                 return NODE2INO(node);
631                                 }
632                                 node = nodes[node].next;
633                         }
634                 } else
635                         continue;
636                 ret = lookup_children (nodes[n].child, name, len);
637                 if (ret) return ret;
638         }
639         return 0;
640 }
641
642 static struct dentry *openpromfs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
643 {
644         int ino = 0;
645 #define OPFSL_DIR       0
646 #define OPFSL_PROPERTY  1
647 #define OPFSL_NODENUM   2
648         int type = 0;
649         char buffer[128];
650         char *p;
651         const char *name;
652         u32 n;
653         u16 dirnode;
654         unsigned int len;
655         int i;
656         struct inode *inode;
657         char buffer2[64];
658         
659         inode = NULL;
660         name = dentry->d_name.name;
661         len = dentry->d_name.len;
662         lock_kernel();
663         if (name [0] == '.' && len == 5 && !strncmp (name + 1, "node", 4)) {
664                 ino = NODEP2INO(NODE(dir->i_ino).first_prop);
665                 type = OPFSL_NODENUM;
666         }
667         if (!ino) {
668                 u16 node = NODE(dir->i_ino).child;
669                 while (node != 0xffff) {
670                         if (prom_getname (nodes[node].node, buffer, 128) >= 0) {
671                                 i = strlen (buffer);
672                                 if (len == i && !strncmp (buffer, name, len)) {
673                                         ino = NODE2INO(node);
674                                         type = OPFSL_DIR;
675                                         break;
676                                 }
677                                 p = strchr (buffer, '@');
678                                 if (p && (len == p - buffer)
679                                     && !strncmp (buffer, name, len)) {
680                                         ino = NODE2INO(node);
681                                         type = OPFSL_DIR;
682                                         break;
683                                 }
684                         }
685                         node = nodes[node].next;
686                 }
687         }
688         n = NODE(dir->i_ino).node;
689         dirnode = dir->i_ino - OPENPROM_FIRST_INO;
690         if (!ino) {
691                 int j = NODEP2INO(NODE(dir->i_ino).first_prop);
692                 if (dirnode != aliases) {
693                         for (p = prom_firstprop (n, buffer2);
694                              p && *p;
695                              p = prom_nextprop (n, p, buffer2)) {
696                                 j++;
697                                 if ((len == strlen (p))
698                                     && !strncmp (p, name, len)) {
699                                         ino = j;
700                                         type = OPFSL_PROPERTY;
701                                         break;
702                                 }
703                         }
704                 } else {
705                         int k;
706                         for (k = 0; k < aliases_nodes; k++) {
707                                 j++;
708                                 if (alias_names [k]
709                                     && (len == strlen (alias_names [k]))
710                                     && !strncmp (alias_names [k], name, len)) {
711                                         ino = j;
712                                         type = OPFSL_PROPERTY;
713                                         break;
714                                 }
715                         }
716                 }
717         }
718         if (!ino) {
719                 ino = lookup_children (NODE(dir->i_ino).child, name, len);
720                 if (ino)
721                         type = OPFSL_DIR;
722                 else {
723                         unlock_kernel();
724                         return ERR_PTR(-ENOENT);
725                 }
726         }
727         inode = iget (dir->i_sb, ino);
728         unlock_kernel();
729         if (!inode)
730                 return ERR_PTR(-EINVAL);
731         switch (type) {
732         case OPFSL_DIR:
733                 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
734                 if (ino == OPENPROM_FIRST_INO + aliases) {
735                         inode->i_mode |= S_IWUSR;
736                         inode->i_op = &openprom_alias_inode_operations;
737                 } else
738                         inode->i_op = &openprom_inode_operations;
739                 inode->i_fop = &openprom_operations;
740                 inode->i_nlink = 2;
741                 break;
742         case OPFSL_NODENUM:
743                 inode->i_mode = S_IFREG | S_IRUGO;
744                 inode->i_fop = &openpromfs_nodenum_ops;
745                 inode->i_nlink = 1;
746                 inode->u.generic_ip = (void *)(long)(n);
747                 break;
748         case OPFSL_PROPERTY:
749                 if ((dirnode == options) && (len == 17)
750                     && !strncmp (name, "security-password", 17))
751                         inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
752                 else {
753                         inode->i_mode = S_IFREG | S_IRUGO;
754                         if (dirnode == options || dirnode == aliases) {
755                                 if (len != 4 || strncmp (name, "name", 4))
756                                         inode->i_mode |= S_IWUSR;
757                         }
758                 }
759                 inode->i_fop = &openpromfs_prop_ops;
760                 inode->i_nlink = 1;
761                 if (inode->i_size < 0)
762                         inode->i_size = 0;
763                 inode->u.generic_ip = (void *)(long)(((u16)dirnode) | 
764                         (((u16)(ino - NODEP2INO(NODE(dir->i_ino).first_prop) - 1)) << 16));
765                 break;
766         }
767
768         inode->i_gid = 0;
769         inode->i_uid = 0;
770
771         d_add(dentry, inode);
772         return NULL;
773 }
774
775 static int openpromfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
776 {
777         struct inode *inode = filp->f_dentry->d_inode;
778         unsigned int ino;
779         u32 n;
780         int i, j;
781         char buffer[128];
782         u16 node;
783         char *p;
784         char buffer2[64];
785
786         lock_kernel();
787         
788         ino = inode->i_ino;
789         i = filp->f_pos;
790         switch (i) {
791         case 0:
792                 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) goto out;
793                 i++;
794                 filp->f_pos++;
795                 /* fall thru */
796         case 1:
797                 if (filldir(dirent, "..", 2, i, 
798                         (NODE(ino).parent == 0xffff) ? 
799                         OPENPROM_ROOT_INO : NODE2INO(NODE(ino).parent), DT_DIR) < 0) 
800                         goto out;
801                 i++;
802                 filp->f_pos++;
803                 /* fall thru */
804         default:
805                 i -= 2;
806                 node = NODE(ino).child;
807                 while (i && node != 0xffff) {
808                         node = nodes[node].next;
809                         i--;
810                 }
811                 while (node != 0xffff) {
812                         if (prom_getname (nodes[node].node, buffer, 128) < 0)
813                                 goto out;
814                         if (filldir(dirent, buffer, strlen(buffer),
815                                     filp->f_pos, NODE2INO(node), DT_DIR) < 0)
816                                 goto out;
817                         filp->f_pos++;
818                         node = nodes[node].next;
819                 }
820                 j = NODEP2INO(NODE(ino).first_prop);
821                 if (!i) {
822                         if (filldir(dirent, ".node", 5, filp->f_pos, j, DT_REG) < 0)
823                                 goto out;
824                         filp->f_pos++;
825                 } else
826                         i--;
827                 n = NODE(ino).node;
828                 if (ino == OPENPROM_FIRST_INO + aliases) {
829                         for (j++; i < aliases_nodes; i++, j++) {
830                                 if (alias_names [i]) {
831                                         if (filldir (dirent, alias_names [i], 
832                                                 strlen (alias_names [i]), 
833                                                 filp->f_pos, j, DT_REG) < 0) goto out; 
834                                         filp->f_pos++;
835                                 }
836                         }
837                 } else {
838                         for (p = prom_firstprop (n, buffer2);
839                              p && *p;
840                              p = prom_nextprop (n, p, buffer2)) {
841                                 j++;
842                                 if (i) i--;
843                                 else {
844                                         if (filldir(dirent, p, strlen(p),
845                                                     filp->f_pos, j, DT_REG) < 0)
846                                                 goto out;
847                                         filp->f_pos++;
848                                 }
849                         }
850                 }
851         }
852 out:
853         unlock_kernel();
854         return 0;
855 }
856
857 static int openpromfs_create (struct inode *dir, struct dentry *dentry, int mode,
858                 struct nameidata *nd)
859 {
860         char *p;
861         struct inode *inode;
862         
863         if (!dir)
864                 return -ENOENT;
865         if (dentry->d_name.len > 256)
866                 return -EINVAL;
867         p = kmalloc (dentry->d_name.len + 1, GFP_KERNEL);
868         if (!p)
869                 return -ENOMEM;
870         strncpy (p, dentry->d_name.name, dentry->d_name.len);
871         p [dentry->d_name.len] = 0;
872         lock_kernel();
873         if (aliases_nodes == ALIASES_NNODES) {
874                 kfree(p);
875                 unlock_kernel();
876                 return -EIO;
877         }
878         alias_names [aliases_nodes++] = p;
879         inode = iget (dir->i_sb,
880                         NODEP2INO(NODE(dir->i_ino).first_prop) + aliases_nodes);
881         if (!inode) {
882                 unlock_kernel();
883                 return -EINVAL;
884         }
885         inode->i_mode = S_IFREG | S_IRUGO | S_IWUSR;
886         inode->i_fop = &openpromfs_prop_ops;
887         inode->i_nlink = 1;
888         if (inode->i_size < 0) inode->i_size = 0;
889         inode->u.generic_ip = (void *)(long)(((u16)aliases) | 
890                         (((u16)(aliases_nodes - 1)) << 16));
891         unlock_kernel();
892         d_instantiate(dentry, inode);
893         return 0;
894 }
895
896 static int openpromfs_unlink (struct inode *dir, struct dentry *dentry)
897 {
898         unsigned int len;
899         char *p;
900         const char *name;
901         int i;
902         
903         name = dentry->d_name.name;
904         len = dentry->d_name.len;
905         lock_kernel();
906         for (i = 0; i < aliases_nodes; i++)
907                 if ((strlen (alias_names [i]) == len)
908                     && !strncmp (name, alias_names[i], len)) {
909                         char buffer[512];
910                         
911                         p = alias_names [i];
912                         alias_names [i] = NULL;
913                         kfree (p);
914                         strcpy (buffer, "nvunalias ");
915                         memcpy (buffer + 10, name, len);
916                         buffer [10 + len] = 0;
917                         prom_feval (buffer);
918                 }
919         unlock_kernel();
920         return 0;
921 }
922
923 /* {{{ init section */
924 static int __init check_space (u16 n)
925 {
926         unsigned long pages;
927
928         if ((1 << alloced) * PAGE_SIZE < (n + 2) * sizeof(openpromfs_node)) {
929                 pages = __get_free_pages (GFP_KERNEL, alloced + 1);
930                 if (!pages)
931                         return -1;
932
933                 if (nodes) {
934                         memcpy ((char *)pages, (char *)nodes,
935                                 (1 << alloced) * PAGE_SIZE);
936                         free_pages ((unsigned long)nodes, alloced);
937                 }
938                 alloced++;
939                 nodes = (openpromfs_node *)pages;
940         }
941         return 0;
942 }
943
944 static u16 __init get_nodes (u16 parent, u32 node)
945 {
946         char *p;
947         u16 n = last_node++, i;
948         char buffer[64];
949
950         if (check_space (n) < 0)
951                 return 0xffff;
952         nodes[n].parent = parent;
953         nodes[n].node = node;
954         nodes[n].next = 0xffff;
955         nodes[n].child = 0xffff;
956         nodes[n].first_prop = first_prop++;
957         if (!parent) {
958                 char buffer[8];
959                 int j;
960                 
961                 if ((j = prom_getproperty (node, "name", buffer, 8)) >= 0) {
962                     buffer[j] = 0;
963                     if (!strcmp (buffer, "options"))
964                         options = n;
965                     else if (!strcmp (buffer, "aliases"))
966                         aliases = n;
967                 }
968         }
969         if (n != aliases)
970                 for (p = prom_firstprop (node, buffer);
971                      p && p != (char *)-1 && *p;
972                      p = prom_nextprop (node, p, buffer))
973                         first_prop++;
974         else {
975                 char *q;
976                 for (p = prom_firstprop (node, buffer);
977                      p && p != (char *)-1 && *p;
978                      p = prom_nextprop (node, p, buffer)) {
979                         if (aliases_nodes == ALIASES_NNODES)
980                                 break;
981                         for (i = 0; i < aliases_nodes; i++)
982                                 if (!strcmp (p, alias_names [i]))
983                                         break;
984                         if (i < aliases_nodes)
985                                 continue;
986                         q = kmalloc (strlen (p) + 1, GFP_KERNEL);
987                         if (!q)
988                                 return 0xffff;
989                         strcpy (q, p);
990                         alias_names [aliases_nodes++] = q;
991                 }
992                 first_prop += ALIASES_NNODES;
993         }
994         node = prom_getchild (node);
995         if (node) {
996                 parent = get_nodes (n, node);
997                 if (parent == 0xffff)
998                         return 0xffff;
999                 nodes[n].child = parent;
1000                 while ((node = prom_getsibling (node)) != 0) {
1001                         i = get_nodes (n, node);
1002                         if (i == 0xffff)
1003                                 return 0xffff;
1004                         nodes[parent].next = i;
1005                         parent = i;
1006                 }
1007         }
1008         return n;
1009 }
1010
1011 static void openprom_read_inode(struct inode * inode)
1012 {
1013         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1014         if (inode->i_ino == OPENPROM_ROOT_INO) {
1015                 inode->i_op = &openprom_inode_operations;
1016                 inode->i_fop = &openprom_operations;
1017                 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
1018         }
1019 }
1020
1021 static int openprom_remount(struct super_block *sb, int *flags, char *data)
1022 {
1023         *flags |= MS_NOATIME;
1024         return 0;
1025 }
1026
1027 static struct super_operations openprom_sops = { 
1028         .read_inode     = openprom_read_inode,
1029         .statfs         = simple_statfs,
1030         .remount_fs     = openprom_remount,
1031 };
1032
1033 static int openprom_fill_super(struct super_block *s, void *data, int silent)
1034 {
1035         struct inode * root_inode;
1036
1037         s->s_flags |= MS_NOATIME;
1038         s->s_blocksize = 1024;
1039         s->s_blocksize_bits = 10;
1040         s->s_magic = OPENPROM_SUPER_MAGIC;
1041         s->s_op = &openprom_sops;
1042         s->s_time_gran = 1;
1043         root_inode = iget(s, OPENPROM_ROOT_INO);
1044         if (!root_inode)
1045                 goto out_no_root;
1046         s->s_root = d_alloc_root(root_inode);
1047         if (!s->s_root)
1048                 goto out_no_root;
1049         return 0;
1050
1051 out_no_root:
1052         printk("openprom_fill_super: get root inode failed\n");
1053         iput(root_inode);
1054         return -ENOMEM;
1055 }
1056
1057 static int openprom_get_sb(struct file_system_type *fs_type,
1058         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1059 {
1060         return get_sb_single(fs_type, flags, data, openprom_fill_super, mnt);
1061 }
1062
1063 static struct file_system_type openprom_fs_type = {
1064         .owner          = THIS_MODULE,
1065         .name           = "openpromfs",
1066         .get_sb         = openprom_get_sb,
1067         .kill_sb        = kill_anon_super,
1068 };
1069
1070 static int __init init_openprom_fs(void)
1071 {
1072         nodes = (openpromfs_node *)__get_free_pages(GFP_KERNEL, 0);
1073         if (!nodes) {
1074                 printk (KERN_WARNING "openpromfs: can't get free page\n");
1075                 return -EIO;
1076         }
1077         if (get_nodes (0xffff, prom_root_node) == 0xffff) {
1078                 printk (KERN_WARNING "openpromfs: couldn't setup tree\n");
1079                 return -EIO;
1080         }
1081         nodes[last_node].first_prop = first_prop;
1082         return register_filesystem(&openprom_fs_type);
1083 }
1084
1085 static void __exit exit_openprom_fs(void)
1086 {
1087         int i;
1088         unregister_filesystem(&openprom_fs_type);
1089         free_pages ((unsigned long)nodes, alloced);
1090         for (i = 0; i < aliases_nodes; i++)
1091                 kfree (alias_names [i]);
1092         nodes = NULL;
1093 }
1094
1095 module_init(init_openprom_fs)
1096 module_exit(exit_openprom_fs)
1097 MODULE_LICENSE("GPL");