Merge with rsync://fileserver/linux
[linux-2.6] / fs / jffs2 / readinode.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright (C) 2001-2003 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  * $Id: readinode.c,v 1.125 2005/07/10 13:13:55 dedekind Exp $
11  *
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/fs.h>
17 #include <linux/crc32.h>
18 #include <linux/pagemap.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/compiler.h>
21 #include "nodelist.h"
22
23 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *list, struct jffs2_node_frag *newfrag);
24
25 #if CONFIG_JFFS2_FS_DEBUG >= 2
26 static void jffs2_print_fragtree(struct rb_root *list, int permitbug)
27 {
28         struct jffs2_node_frag *this = frag_first(list);
29         uint32_t lastofs = 0;
30         int buggy = 0;
31
32         while(this) {
33                 if (this->node)
34                         printk(KERN_DEBUG "frag %04x-%04x: 0x%08x(%d) on flash (*%p). left (%p), right (%p), parent (%p)\n",
35                                this->ofs, this->ofs+this->size, ref_offset(this->node->raw), ref_flags(this->node->raw),
36                                this, frag_left(this), frag_right(this), frag_parent(this));
37                 else 
38                         printk(KERN_DEBUG "frag %04x-%04x: hole (*%p). left (%p} right (%p), parent (%p)\n", this->ofs, 
39                                this->ofs+this->size, this, frag_left(this), frag_right(this), frag_parent(this));
40                 if (this->ofs != lastofs)
41                         buggy = 1;
42                 lastofs = this->ofs+this->size;
43                 this = frag_next(this);
44         }
45         if (buggy && !permitbug) {
46                 printk(KERN_CRIT "Frag tree got a hole in it\n");
47                 BUG();
48         }
49 }
50
51 void jffs2_print_frag_list(struct jffs2_inode_info *f)
52 {
53         jffs2_print_fragtree(&f->fragtree, 0);
54
55         if (f->metadata) {
56                 printk(KERN_DEBUG "metadata at 0x%08x\n", ref_offset(f->metadata->raw));
57         }
58 }
59 #endif
60
61 #if CONFIG_JFFS2_FS_DEBUG >= 1
62 static int jffs2_sanitycheck_fragtree(struct jffs2_inode_info *f)
63 {
64         struct jffs2_node_frag *frag;
65         int bitched = 0;
66
67         for (frag = frag_first(&f->fragtree); frag; frag = frag_next(frag)) {
68
69                 struct jffs2_full_dnode *fn = frag->node;
70                 if (!fn || !fn->raw)
71                         continue;
72
73                 if (ref_flags(fn->raw) == REF_PRISTINE) {
74
75                         if (fn->frags > 1) {
76                                 printk(KERN_WARNING "REF_PRISTINE node at 0x%08x had %d frags. Tell dwmw2\n", ref_offset(fn->raw), fn->frags);
77                                 bitched = 1;
78                         }
79                         /* A hole node which isn't multi-page should be garbage-collected
80                            and merged anyway, so we just check for the frag size here,
81                            rather than mucking around with actually reading the node
82                            and checking the compression type, which is the real way
83                            to tell a hole node. */
84                         if (frag->ofs & (PAGE_CACHE_SIZE-1) && frag_prev(frag) && frag_prev(frag)->size < PAGE_CACHE_SIZE && frag_prev(frag)->node) {
85                                 printk(KERN_WARNING "REF_PRISTINE node at 0x%08x had a previous non-hole frag in the same page. Tell dwmw2\n",
86                                        ref_offset(fn->raw));
87                                 bitched = 1;
88                         }
89
90                         if ((frag->ofs+frag->size) & (PAGE_CACHE_SIZE-1) && frag_next(frag) && frag_next(frag)->size < PAGE_CACHE_SIZE && frag_next(frag)->node) {
91                                 printk(KERN_WARNING "REF_PRISTINE node at 0x%08x (%08x-%08x) had a following non-hole frag in the same page. Tell dwmw2\n",
92                                        ref_offset(fn->raw), frag->ofs, frag->ofs+frag->size);
93                                 bitched = 1;
94                         }
95                 }
96         }
97         
98         if (bitched) {
99                 struct jffs2_node_frag *thisfrag;
100
101                 printk(KERN_WARNING "Inode is #%u\n", f->inocache->ino);
102                 thisfrag = frag_first(&f->fragtree);
103                 while (thisfrag) {
104                         if (!thisfrag->node) {
105                                 printk("Frag @0x%x-0x%x; node-less hole\n",
106                                        thisfrag->ofs, thisfrag->size + thisfrag->ofs);
107                         } else if (!thisfrag->node->raw) {
108                                 printk("Frag @0x%x-0x%x; raw-less hole\n",
109                                        thisfrag->ofs, thisfrag->size + thisfrag->ofs);
110                         } else {
111                                 printk("Frag @0x%x-0x%x; raw at 0x%08x(%d) (0x%x-0x%x)\n",
112                                        thisfrag->ofs, thisfrag->size + thisfrag->ofs,
113                                        ref_offset(thisfrag->node->raw), ref_flags(thisfrag->node->raw),
114                                        thisfrag->node->ofs, thisfrag->node->ofs+thisfrag->node->size);
115                         }
116                         thisfrag = frag_next(thisfrag);
117                 }
118         }
119         return bitched;
120 }
121 #endif /* D1 */
122
123 static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c, struct jffs2_node_frag *this)
124 {
125         if (this->node) {
126                 this->node->frags--;
127                 if (!this->node->frags) {
128                         /* The node has no valid frags left. It's totally obsoleted */
129                         D2(printk(KERN_DEBUG "Marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
130                                   ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size));
131                         jffs2_mark_node_obsolete(c, this->node->raw);
132                         jffs2_free_full_dnode(this->node);
133                 } else {
134                         D2(printk(KERN_DEBUG "Marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
135                                   ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size,
136                                   this->node->frags));
137                         mark_ref_normal(this->node->raw);
138                 }
139                 
140         }
141         jffs2_free_node_frag(this);
142 }
143
144 /* Given an inode, probably with existing list of fragments, add the new node
145  * to the fragment list.
146  */
147 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
148 {
149         int ret;
150         struct jffs2_node_frag *newfrag;
151
152         D1(printk(KERN_DEBUG "jffs2_add_full_dnode_to_inode(ino #%u, f %p, fn %p)\n", f->inocache->ino, f, fn));
153
154         if (unlikely(!fn->size))
155                 return 0;
156
157         newfrag = jffs2_alloc_node_frag();
158         if (unlikely(!newfrag))
159                 return -ENOMEM;
160
161         D2(printk(KERN_DEBUG "adding node %04x-%04x @0x%08x on flash, newfrag *%p\n",
162                   fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag));
163         
164         newfrag->ofs = fn->ofs;
165         newfrag->size = fn->size;
166         newfrag->node = fn;
167         newfrag->node->frags = 1;
168
169         ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
170         if (ret)
171                 return ret;
172
173         /* If we now share a page with other nodes, mark either previous
174            or next node REF_NORMAL, as appropriate.  */
175         if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
176                 struct jffs2_node_frag *prev = frag_prev(newfrag);
177
178                 mark_ref_normal(fn->raw);
179                 /* If we don't start at zero there's _always_ a previous */     
180                 if (prev->node)
181                         mark_ref_normal(prev->node->raw);
182         }
183
184         if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
185                 struct jffs2_node_frag *next = frag_next(newfrag);
186                 
187                 if (next) {
188                         mark_ref_normal(fn->raw);
189                         if (next->node)
190                                 mark_ref_normal(next->node->raw);
191                 }
192         }
193         D2(if (jffs2_sanitycheck_fragtree(f)) {
194                    printk(KERN_WARNING "Just added node %04x-%04x @0x%08x on flash, newfrag *%p\n",
195                           fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
196                    return 0;
197            })
198         D2(jffs2_print_frag_list(f));
199         return 0;
200 }
201
202 /* Doesn't set inode->i_size */
203 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *list, struct jffs2_node_frag *newfrag)
204 {
205         struct jffs2_node_frag *this;
206         uint32_t lastend;
207
208         /* Skip all the nodes which are completed before this one starts */
209         this = jffs2_lookup_node_frag(list, newfrag->node->ofs);
210
211         if (this) {
212                 D2(printk(KERN_DEBUG "j_a_f_d_t_f: Lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
213                           this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this));
214                 lastend = this->ofs + this->size;
215         } else {
216                 D2(printk(KERN_DEBUG "j_a_f_d_t_f: Lookup gave no frag\n"));
217                 lastend = 0;
218         }
219                           
220         /* See if we ran off the end of the list */
221         if (lastend <= newfrag->ofs) {
222                 /* We did */
223
224                 /* Check if 'this' node was on the same page as the new node.
225                    If so, both 'this' and the new node get marked REF_NORMAL so
226                    the GC can take a look.
227                 */
228                 if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
229                         if (this->node)
230                                 mark_ref_normal(this->node->raw);
231                         mark_ref_normal(newfrag->node->raw);
232                 }
233
234                 if (lastend < newfrag->node->ofs) {
235                         /* ... and we need to put a hole in before the new node */
236                         struct jffs2_node_frag *holefrag = jffs2_alloc_node_frag();
237                         if (!holefrag) {
238                                 jffs2_free_node_frag(newfrag);
239                                 return -ENOMEM;
240                         }
241                         holefrag->ofs = lastend;
242                         holefrag->size = newfrag->node->ofs - lastend;
243                         holefrag->node = NULL;
244                         if (this) {
245                                 /* By definition, the 'this' node has no right-hand child, 
246                                    because there are no frags with offset greater than it.
247                                    So that's where we want to put the hole */
248                                 D2(printk(KERN_DEBUG "Adding hole frag (%p) on right of node at (%p)\n", holefrag, this));
249                                 rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
250                         } else {
251                                 D2(printk(KERN_DEBUG "Adding hole frag (%p) at root of tree\n", holefrag));
252                                 rb_link_node(&holefrag->rb, NULL, &list->rb_node);
253                         }
254                         rb_insert_color(&holefrag->rb, list);
255                         this = holefrag;
256                 }
257                 if (this) {
258                         /* By definition, the 'this' node has no right-hand child, 
259                            because there are no frags with offset greater than it.
260                            So that's where we want to put the hole */
261                         D2(printk(KERN_DEBUG "Adding new frag (%p) on right of node at (%p)\n", newfrag, this));
262                         rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);                      
263                 } else {
264                         D2(printk(KERN_DEBUG "Adding new frag (%p) at root of tree\n", newfrag));
265                         rb_link_node(&newfrag->rb, NULL, &list->rb_node);
266                 }
267                 rb_insert_color(&newfrag->rb, list);
268                 return 0;
269         }
270
271         D2(printk(KERN_DEBUG "j_a_f_d_t_f: dealing with frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n", 
272                   this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this));
273
274         /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
275          * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs  
276          */
277         if (newfrag->ofs > this->ofs) {
278                 /* This node isn't completely obsoleted. The start of it remains valid */
279
280                 /* Mark the new node and the partially covered node REF_NORMAL -- let
281                    the GC take a look at them */
282                 mark_ref_normal(newfrag->node->raw);
283                 if (this->node)
284                         mark_ref_normal(this->node->raw);
285
286                 if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
287                         /* The new node splits 'this' frag into two */
288                         struct jffs2_node_frag *newfrag2 = jffs2_alloc_node_frag();
289                         if (!newfrag2) {
290                                 jffs2_free_node_frag(newfrag);
291                                 return -ENOMEM;
292                         }
293                         D2(printk(KERN_DEBUG "split old frag 0x%04x-0x%04x -->", this->ofs, this->ofs+this->size);
294                         if (this->node)
295                                 printk("phys 0x%08x\n", ref_offset(this->node->raw));
296                         else 
297                                 printk("hole\n");
298                            )
299                         
300                         /* New second frag pointing to this's node */
301                         newfrag2->ofs = newfrag->ofs + newfrag->size;
302                         newfrag2->size = (this->ofs+this->size) - newfrag2->ofs;
303                         newfrag2->node = this->node;
304                         if (this->node)
305                                 this->node->frags++;
306
307                         /* Adjust size of original 'this' */
308                         this->size = newfrag->ofs - this->ofs;
309
310                         /* Now, we know there's no node with offset
311                            greater than this->ofs but smaller than
312                            newfrag2->ofs or newfrag->ofs, for obvious
313                            reasons. So we can do a tree insert from
314                            'this' to insert newfrag, and a tree insert
315                            from newfrag to insert newfrag2. */
316                         jffs2_fragtree_insert(newfrag, this);
317                         rb_insert_color(&newfrag->rb, list);
318                         
319                         jffs2_fragtree_insert(newfrag2, newfrag);
320                         rb_insert_color(&newfrag2->rb, list);
321                         
322                         return 0;
323                 }
324                 /* New node just reduces 'this' frag in size, doesn't split it */
325                 this->size = newfrag->ofs - this->ofs;
326
327                 /* Again, we know it lives down here in the tree */
328                 jffs2_fragtree_insert(newfrag, this);
329                 rb_insert_color(&newfrag->rb, list);
330         } else {
331                 /* New frag starts at the same point as 'this' used to. Replace 
332                    it in the tree without doing a delete and insertion */
333                 D2(printk(KERN_DEBUG "Inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
334                           newfrag, newfrag->ofs, newfrag->ofs+newfrag->size,
335                           this, this->ofs, this->ofs+this->size));
336         
337                 rb_replace_node(&this->rb, &newfrag->rb, list);
338                 
339                 if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
340                         D2(printk(KERN_DEBUG "Obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size));
341                         jffs2_obsolete_node_frag(c, this);
342                 } else {
343                         this->ofs += newfrag->size;
344                         this->size -= newfrag->size;
345
346                         jffs2_fragtree_insert(this, newfrag);
347                         rb_insert_color(&this->rb, list);
348                         return 0;
349                 }
350         }
351         /* OK, now we have newfrag added in the correct place in the tree, but
352            frag_next(newfrag) may be a fragment which is overlapped by it 
353         */
354         while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
355                 /* 'this' frag is obsoleted completely. */
356                 D2(printk(KERN_DEBUG "Obsoleting node frag %p (%x-%x) and removing from tree\n", this, this->ofs, this->ofs+this->size));
357                 rb_erase(&this->rb, list);
358                 jffs2_obsolete_node_frag(c, this);
359         }
360         /* Now we're pointing at the first frag which isn't totally obsoleted by 
361            the new frag */
362
363         if (!this || newfrag->ofs + newfrag->size == this->ofs) {
364                 return 0;
365         }
366         /* Still some overlap but we don't need to move it in the tree */
367         this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
368         this->ofs = newfrag->ofs + newfrag->size;
369
370         /* And mark them REF_NORMAL so the GC takes a look at them */
371         if (this->node)
372                 mark_ref_normal(this->node->raw);
373         mark_ref_normal(newfrag->node->raw);
374
375         return 0;
376 }
377
378 void jffs2_truncate_fraglist (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
379 {
380         struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
381
382         D1(printk(KERN_DEBUG "Truncating fraglist to 0x%08x bytes\n", size));
383
384         /* We know frag->ofs <= size. That's what lookup does for us */
385         if (frag && frag->ofs != size) {
386                 if (frag->ofs+frag->size >= size) {
387                         D1(printk(KERN_DEBUG "Truncating frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
388                         frag->size = size - frag->ofs;
389                 }
390                 frag = frag_next(frag);
391         }
392         while (frag && frag->ofs >= size) {
393                 struct jffs2_node_frag *next = frag_next(frag);
394
395                 D1(printk(KERN_DEBUG "Removing frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
396                 frag_erase(frag, list);
397                 jffs2_obsolete_node_frag(c, frag);
398                 frag = next;
399         }
400 }
401
402 /* Scan the list of all nodes present for this ino, build map of versions, etc. */
403
404 static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
405                                         struct jffs2_inode_info *f,
406                                         struct jffs2_raw_inode *latest_node);
407
408 int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 
409                         uint32_t ino, struct jffs2_raw_inode *latest_node)
410 {
411         D2(printk(KERN_DEBUG "jffs2_do_read_inode(): getting inocache\n"));
412
413  retry_inocache:
414         spin_lock(&c->inocache_lock);
415         f->inocache = jffs2_get_ino_cache(c, ino);
416
417         D2(printk(KERN_DEBUG "jffs2_do_read_inode(): Got inocache at %p\n", f->inocache));
418
419         if (f->inocache) {
420                 /* Check its state. We may need to wait before we can use it */
421                 switch(f->inocache->state) {
422                 case INO_STATE_UNCHECKED:
423                 case INO_STATE_CHECKEDABSENT:
424                         f->inocache->state = INO_STATE_READING;
425                         break;
426                         
427                 case INO_STATE_CHECKING:
428                 case INO_STATE_GC:
429                         /* If it's in either of these states, we need
430                            to wait for whoever's got it to finish and
431                            put it back. */
432                         D1(printk(KERN_DEBUG "jffs2_get_ino_cache_read waiting for ino #%u in state %d\n",
433                                   ino, f->inocache->state));
434                         sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
435                         goto retry_inocache;
436
437                 case INO_STATE_READING:
438                 case INO_STATE_PRESENT:
439                         /* Eep. This should never happen. It can
440                         happen if Linux calls read_inode() again
441                         before clear_inode() has finished though. */
442                         printk(KERN_WARNING "Eep. Trying to read_inode #%u when it's already in state %d!\n", ino, f->inocache->state);
443                         /* Fail. That's probably better than allowing it to succeed */
444                         f->inocache = NULL;
445                         break;
446
447                 default:
448                         BUG();
449                 }
450         }
451         spin_unlock(&c->inocache_lock);
452
453         if (!f->inocache && ino == 1) {
454                 /* Special case - no root inode on medium */
455                 f->inocache = jffs2_alloc_inode_cache();
456                 if (!f->inocache) {
457                         printk(KERN_CRIT "jffs2_do_read_inode(): Cannot allocate inocache for root inode\n");
458                         return -ENOMEM;
459                 }
460                 D1(printk(KERN_DEBUG "jffs2_do_read_inode(): Creating inocache for root inode\n"));
461                 memset(f->inocache, 0, sizeof(struct jffs2_inode_cache));
462                 f->inocache->ino = f->inocache->nlink = 1;
463                 f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
464                 f->inocache->state = INO_STATE_READING;
465                 jffs2_add_ino_cache(c, f->inocache);
466         }
467         if (!f->inocache) {
468                 printk(KERN_WARNING "jffs2_do_read_inode() on nonexistent ino %u\n", ino);
469                 return -ENOENT;
470         }
471
472         return jffs2_do_read_inode_internal(c, f, latest_node);
473 }
474
475 int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
476 {
477         struct jffs2_raw_inode n;
478         struct jffs2_inode_info *f = kmalloc(sizeof(*f), GFP_KERNEL);
479         int ret;
480
481         if (!f)
482                 return -ENOMEM;
483
484         memset(f, 0, sizeof(*f));
485         init_MUTEX_LOCKED(&f->sem);
486         f->inocache = ic;
487
488         ret = jffs2_do_read_inode_internal(c, f, &n);
489         if (!ret) {
490                 up(&f->sem);
491                 jffs2_do_clear_inode(c, f);
492         }
493         kfree (f);
494         return ret;
495 }
496
497 static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
498                                         struct jffs2_inode_info *f,
499                                         struct jffs2_raw_inode *latest_node)
500 {
501         struct jffs2_tmp_dnode_info *tn = NULL;
502         struct rb_root tn_list;
503         struct rb_node *rb, *repl_rb;
504         struct jffs2_full_dirent *fd_list;
505         struct jffs2_full_dnode *fn = NULL;
506         uint32_t crc;
507         uint32_t latest_mctime, mctime_ver;
508         uint32_t mdata_ver = 0;
509         size_t retlen;
510         int ret;
511
512         D1(printk(KERN_DEBUG "jffs2_do_read_inode_internal(): ino #%u nlink is %d\n", f->inocache->ino, f->inocache->nlink));
513
514         /* Grab all nodes relevant to this ino */
515         ret = jffs2_get_inode_nodes(c, f, &tn_list, &fd_list, &f->highest_version, &latest_mctime, &mctime_ver);
516
517         if (ret) {
518                 printk(KERN_CRIT "jffs2_get_inode_nodes() for ino %u returned %d\n", f->inocache->ino, ret);
519                 if (f->inocache->state == INO_STATE_READING)
520                         jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
521                 return ret;
522         }
523         f->dents = fd_list;
524
525         rb = rb_first(&tn_list);
526
527         while (rb) {
528                 tn = rb_entry(rb, struct jffs2_tmp_dnode_info, rb);
529                 fn = tn->fn;
530
531                 if (f->metadata) {
532                         if (likely(tn->version >= mdata_ver)) {
533                                 D1(printk(KERN_DEBUG "Obsoleting old metadata at 0x%08x\n", ref_offset(f->metadata->raw)));
534                                 jffs2_mark_node_obsolete(c, f->metadata->raw);
535                                 jffs2_free_full_dnode(f->metadata);
536                                 f->metadata = NULL;
537                                 
538                                 mdata_ver = 0;
539                         } else {
540                                 /* This should never happen. */
541                                 printk(KERN_WARNING "Er. New metadata at 0x%08x with ver %d is actually older than previous ver %d at 0x%08x\n",
542                                           ref_offset(fn->raw), tn->version, mdata_ver, ref_offset(f->metadata->raw));
543                                 jffs2_mark_node_obsolete(c, fn->raw);
544                                 jffs2_free_full_dnode(fn);
545                                 /* Fill in latest_node from the metadata, not this one we're about to free... */
546                                 fn = f->metadata;
547                                 goto next_tn;
548                         }
549                 }
550
551                 if (fn->size) {
552                         jffs2_add_full_dnode_to_inode(c, f, fn);
553                 } else {
554                         /* Zero-sized node at end of version list. Just a metadata update */
555                         D1(printk(KERN_DEBUG "metadata @%08x: ver %d\n", ref_offset(fn->raw), tn->version));
556                         f->metadata = fn;
557                         mdata_ver = tn->version;
558                 }
559         next_tn:
560                 BUG_ON(rb->rb_left);
561                 if (rb->rb_parent && rb->rb_parent->rb_left == rb) {
562                         /* We were then left-hand child of our parent. We need
563                            to move our own right-hand child into our place. */
564                         repl_rb = rb->rb_right;
565                         if (repl_rb)
566                                 repl_rb->rb_parent = rb->rb_parent;
567                 } else
568                         repl_rb = NULL;
569
570                 rb = rb_next(rb);
571
572                 /* Remove the spent tn from the tree; don't bother rebalancing
573                    but put our right-hand child in our own place. */
574                 if (tn->rb.rb_parent) {
575                         if (tn->rb.rb_parent->rb_left == &tn->rb)
576                                 tn->rb.rb_parent->rb_left = repl_rb;
577                         else if (tn->rb.rb_parent->rb_right == &tn->rb)
578                                 tn->rb.rb_parent->rb_right = repl_rb;
579                         else BUG();
580                 } else if (tn->rb.rb_right)
581                         tn->rb.rb_right->rb_parent = NULL;
582
583                 jffs2_free_tmp_dnode_info(tn);
584         }
585         D1(jffs2_sanitycheck_fragtree(f));
586
587         if (!fn) {
588                 /* No data nodes for this inode. */
589                 if (f->inocache->ino != 1) {
590                         printk(KERN_WARNING "jffs2_do_read_inode(): No data nodes found for ino #%u\n", f->inocache->ino);
591                         if (!fd_list) {
592                                 if (f->inocache->state == INO_STATE_READING)
593                                         jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
594                                 return -EIO;
595                         }
596                         printk(KERN_WARNING "jffs2_do_read_inode(): But it has children so we fake some modes for it\n");
597                 }
598                 latest_node->mode = cpu_to_jemode(S_IFDIR|S_IRUGO|S_IWUSR|S_IXUGO);
599                 latest_node->version = cpu_to_je32(0);
600                 latest_node->atime = latest_node->ctime = latest_node->mtime = cpu_to_je32(0);
601                 latest_node->isize = cpu_to_je32(0);
602                 latest_node->gid = cpu_to_je16(0);
603                 latest_node->uid = cpu_to_je16(0);
604                 if (f->inocache->state == INO_STATE_READING)
605                         jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
606                 return 0;
607         }
608
609         ret = jffs2_flash_read(c, ref_offset(fn->raw), sizeof(*latest_node), &retlen, (void *)latest_node);
610         if (ret || retlen != sizeof(*latest_node)) {
611                 printk(KERN_NOTICE "MTD read in jffs2_do_read_inode() failed: Returned %d, %zd of %zd bytes read\n",
612                        ret, retlen, sizeof(*latest_node));
613                 /* FIXME: If this fails, there seems to be a memory leak. Find it. */
614                 up(&f->sem);
615                 jffs2_do_clear_inode(c, f);
616                 return ret?ret:-EIO;
617         }
618
619         crc = crc32(0, latest_node, sizeof(*latest_node)-8);
620         if (crc != je32_to_cpu(latest_node->node_crc)) {
621                 printk(KERN_NOTICE "CRC failed for read_inode of inode %u at physical location 0x%x\n", f->inocache->ino, ref_offset(fn->raw));
622                 up(&f->sem);
623                 jffs2_do_clear_inode(c, f);
624                 return -EIO;
625         }
626
627         switch(jemode_to_cpu(latest_node->mode) & S_IFMT) {
628         case S_IFDIR:
629                 if (mctime_ver > je32_to_cpu(latest_node->version)) {
630                         /* The times in the latest_node are actually older than
631                            mctime in the latest dirent. Cheat. */
632                         latest_node->ctime = latest_node->mtime = cpu_to_je32(latest_mctime);
633                 }
634                 break;
635
636                         
637         case S_IFREG:
638                 /* If it was a regular file, truncate it to the latest node's isize */
639                 jffs2_truncate_fraglist(c, &f->fragtree, je32_to_cpu(latest_node->isize));
640                 break;
641
642         case S_IFLNK:
643                 /* Hack to work around broken isize in old symlink code.
644                    Remove this when dwmw2 comes to his senses and stops
645                    symlinks from being an entirely gratuitous special
646                    case. */
647                 if (!je32_to_cpu(latest_node->isize))
648                         latest_node->isize = latest_node->dsize;
649
650                 if (f->inocache->state != INO_STATE_CHECKING) {
651                         /* Symlink's inode data is the target path. Read it and
652                          * keep in RAM to facilitate quick follow symlink operation.
653                          * We use f->dents field to store the target path, which
654                          * is somewhat ugly. */
655                         f->dents = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL);
656                         if (!f->dents) {
657                                 printk(KERN_WARNING "Can't allocate %d bytes of memory "
658                                                 "for the symlink target path cache\n",
659                                                 je32_to_cpu(latest_node->csize));
660                                 up(&f->sem);
661                                 jffs2_do_clear_inode(c, f);
662                                 return -ENOMEM;
663                         }
664                         
665                         ret = jffs2_flash_read(c, ref_offset(fn->raw) + sizeof(*latest_node),
666                                                 je32_to_cpu(latest_node->csize), &retlen, (char *)f->dents);
667                         
668                         if (ret  || retlen != je32_to_cpu(latest_node->csize)) {
669                                 if (retlen != je32_to_cpu(latest_node->csize))
670                                         ret = -EIO;
671                                 kfree(f->dents);
672                                 f->dents = NULL;
673                                 up(&f->sem);
674                                 jffs2_do_clear_inode(c, f);
675                                 return -ret;
676                         }
677
678                         ((char *)f->dents)[je32_to_cpu(latest_node->csize)] = '\0';
679                         D1(printk(KERN_DEBUG "jffs2_do_read_inode(): symlink's target '%s' cached\n",
680                                                 (char *)f->dents));
681                 }
682                 
683                 /* fall through... */
684
685         case S_IFBLK:
686         case S_IFCHR:
687                 /* Certain inode types should have only one data node, and it's
688                    kept as the metadata node */
689                 if (f->metadata) {
690                         printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o had metadata node\n",
691                                f->inocache->ino, jemode_to_cpu(latest_node->mode));
692                         up(&f->sem);
693                         jffs2_do_clear_inode(c, f);
694                         return -EIO;
695                 }
696                 if (!frag_first(&f->fragtree)) {
697                         printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o has no fragments\n",
698                                f->inocache->ino, jemode_to_cpu(latest_node->mode));
699                         up(&f->sem);
700                         jffs2_do_clear_inode(c, f);
701                         return -EIO;
702                 }
703                 /* ASSERT: f->fraglist != NULL */
704                 if (frag_next(frag_first(&f->fragtree))) {
705                         printk(KERN_WARNING "Argh. Special inode #%u with mode 0x%x had more than one node\n",
706                                f->inocache->ino, jemode_to_cpu(latest_node->mode));
707                         /* FIXME: Deal with it - check crc32, check for duplicate node, check times and discard the older one */
708                         up(&f->sem);
709                         jffs2_do_clear_inode(c, f);
710                         return -EIO;
711                 }
712                 /* OK. We're happy */
713                 f->metadata = frag_first(&f->fragtree)->node;
714                 jffs2_free_node_frag(frag_first(&f->fragtree));
715                 f->fragtree = RB_ROOT;
716                 break;
717         }
718         if (f->inocache->state == INO_STATE_READING)
719                 jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
720
721         return 0;
722 }
723
724 void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f)
725 {
726         struct jffs2_full_dirent *fd, *fds;
727         int deleted;
728
729         down(&f->sem);
730         deleted = f->inocache && !f->inocache->nlink;
731
732         if (f->inocache && f->inocache->state != INO_STATE_CHECKING)
733                 jffs2_set_inocache_state(c, f->inocache, INO_STATE_CLEARING);
734
735         if (f->metadata) {
736                 if (deleted)
737                         jffs2_mark_node_obsolete(c, f->metadata->raw);
738                 jffs2_free_full_dnode(f->metadata);
739         }
740
741         jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL);
742
743         /* For symlink inodes we us f->dents to store the target path name */
744         if (S_ISLNK(OFNI_EDONI_2SFFJ(f)->i_mode)) {
745                 if (f->dents) {
746                         kfree(f->dents);
747                         f->dents = NULL;
748                 }
749         } else {
750                 fds = f->dents;
751
752                 while(fds) {
753                         fd = fds;
754                         fds = fd->next;
755                         jffs2_free_full_dirent(fd);
756                 }
757         }
758
759         if (f->inocache && f->inocache->state != INO_STATE_CHECKING) {
760                 jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
761                 if (f->inocache->nodes == (void *)f->inocache)
762                         jffs2_del_ino_cache(c, f->inocache);
763         }
764
765         up(&f->sem);
766 }