Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / fs / jffs2 / nodelist.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: nodelist.c,v 1.115 2005/11/07 11:14:40 gleixner Exp $
11  *
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/sched.h>
16 #include <linux/fs.h>
17 #include <linux/mtd/mtd.h>
18 #include <linux/rbtree.h>
19 #include <linux/crc32.h>
20 #include <linux/slab.h>
21 #include <linux/pagemap.h>
22 #include "nodelist.h"
23
24 void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list)
25 {
26         struct jffs2_full_dirent **prev = list;
27
28         dbg_dentlist("add dirent \"%s\", ino #%u\n", new->name, new->ino);
29
30         while ((*prev) && (*prev)->nhash <= new->nhash) {
31                 if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) {
32                         /* Duplicate. Free one */
33                         if (new->version < (*prev)->version) {
34                                 dbg_dentlist("Eep! Marking new dirent node is obsolete, old is \"%s\", ino #%u\n",
35                                         (*prev)->name, (*prev)->ino);
36                                 jffs2_mark_node_obsolete(c, new->raw);
37                                 jffs2_free_full_dirent(new);
38                         } else {
39                                 dbg_dentlist("marking old dirent \"%s\", ino #%u bsolete\n",
40                                         (*prev)->name, (*prev)->ino);
41                                 new->next = (*prev)->next;
42                                 jffs2_mark_node_obsolete(c, ((*prev)->raw));
43                                 jffs2_free_full_dirent(*prev);
44                                 *prev = new;
45                         }
46                         return;
47                 }
48                 prev = &((*prev)->next);
49         }
50         new->next = *prev;
51         *prev = new;
52 }
53
54 void jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
55 {
56         struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
57
58         dbg_fragtree("truncating fragtree to 0x%08x bytes\n", size);
59
60         /* We know frag->ofs <= size. That's what lookup does for us */
61         if (frag && frag->ofs != size) {
62                 if (frag->ofs+frag->size > size) {
63                         frag->size = size - frag->ofs;
64                 }
65                 frag = frag_next(frag);
66         }
67         while (frag && frag->ofs >= size) {
68                 struct jffs2_node_frag *next = frag_next(frag);
69
70                 frag_erase(frag, list);
71                 jffs2_obsolete_node_frag(c, frag);
72                 frag = next;
73         }
74
75         if (size == 0)
76                 return;
77
78         /*
79          * If the last fragment starts at the RAM page boundary, it is
80          * REF_PRISTINE irrespective of its size.
81          */
82         frag = frag_last(list);
83         if (frag->node && (frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
84                 dbg_fragtree2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
85                         frag->ofs, frag->ofs + frag->size);
86                 frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
87         }
88 }
89
90 void jffs2_obsolete_node_frag(struct jffs2_sb_info *c, struct jffs2_node_frag *this)
91 {
92         if (this->node) {
93                 this->node->frags--;
94                 if (!this->node->frags) {
95                         /* The node has no valid frags left. It's totally obsoleted */
96                         dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
97                                 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size);
98                         jffs2_mark_node_obsolete(c, this->node->raw);
99                         jffs2_free_full_dnode(this->node);
100                 } else {
101                         dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
102                                 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags);
103                         mark_ref_normal(this->node->raw);
104                 }
105
106         }
107         jffs2_free_node_frag(this);
108 }
109
110 static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
111 {
112         struct rb_node *parent = &base->rb;
113         struct rb_node **link = &parent;
114
115         dbg_fragtree2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);
116
117         while (*link) {
118                 parent = *link;
119                 base = rb_entry(parent, struct jffs2_node_frag, rb);
120
121                 if (newfrag->ofs > base->ofs)
122                         link = &base->rb.rb_right;
123                 else if (newfrag->ofs < base->ofs)
124                         link = &base->rb.rb_left;
125                 else {
126                         JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
127                         BUG();
128                 }
129         }
130
131         rb_link_node(&newfrag->rb, &base->rb, link);
132 }
133
134 /*
135  * Allocate and initializes a new fragment.
136  */
137 static inline struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
138 {
139         struct jffs2_node_frag *newfrag;
140
141         newfrag = jffs2_alloc_node_frag();
142         if (likely(newfrag)) {
143                 newfrag->ofs = ofs;
144                 newfrag->size = size;
145                 newfrag->node = fn;
146         } else {
147                 JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
148         }
149
150         return newfrag;
151 }
152
153 /*
154  * Called when there is no overlapping fragment exist. Inserts a hole before the new
155  * fragment and inserts the new fragment to the fragtree.
156  */
157 static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
158                                struct jffs2_node_frag *newfrag,
159                                struct jffs2_node_frag *this, uint32_t lastend)
160 {
161         if (lastend < newfrag->node->ofs) {
162                 /* put a hole in before the new fragment */
163                 struct jffs2_node_frag *holefrag;
164
165                 holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
166                 if (unlikely(!holefrag)) {
167                         jffs2_free_node_frag(newfrag);
168                         return -ENOMEM;
169                 }
170
171                 if (this) {
172                         /* By definition, the 'this' node has no right-hand child,
173                            because there are no frags with offset greater than it.
174                            So that's where we want to put the hole */
175                         dbg_fragtree2("add hole frag %#04x-%#04x on the right of the new frag.\n",
176                                 holefrag->ofs, holefrag->ofs + holefrag->size);
177                         rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
178                 } else {
179                         dbg_fragtree2("Add hole frag %#04x-%#04x to the root of the tree.\n",
180                                 holefrag->ofs, holefrag->ofs + holefrag->size);
181                         rb_link_node(&holefrag->rb, NULL, &root->rb_node);
182                 }
183                 rb_insert_color(&holefrag->rb, root);
184                 this = holefrag;
185         }
186
187         if (this) {
188                 /* By definition, the 'this' node has no right-hand child,
189                    because there are no frags with offset greater than it.
190                    So that's where we want to put new fragment */
191                 dbg_fragtree2("add the new node at the right\n");
192                 rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
193         } else {
194                 dbg_fragtree2("insert the new node at the root of the tree\n");
195                 rb_link_node(&newfrag->rb, NULL, &root->rb_node);
196         }
197         rb_insert_color(&newfrag->rb, root);
198
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 *root, 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(root, newfrag->node->ofs);
210
211         if (this) {
212                 dbg_fragtree2("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                 dbg_fragtree2("lookup gave no frag\n");
217                 lastend = 0;
218         }
219
220         /* See if we ran off the end of the fragtree */
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                 return no_overlapping_node(c, root, newfrag, this, lastend);
235         }
236
237         if (this->node)
238                 dbg_fragtree2("dealing with frag %u-%u, phys %#08x(%d).\n",
239                 this->ofs, this->ofs + this->size,
240                 ref_offset(this->node->raw), ref_flags(this->node->raw));
241         else
242                 dbg_fragtree2("dealing with hole frag %u-%u.\n",
243                 this->ofs, this->ofs + this->size);
244
245         /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
246          * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
247          */
248         if (newfrag->ofs > this->ofs) {
249                 /* This node isn't completely obsoleted. The start of it remains valid */
250
251                 /* Mark the new node and the partially covered node REF_NORMAL -- let
252                    the GC take a look at them */
253                 mark_ref_normal(newfrag->node->raw);
254                 if (this->node)
255                         mark_ref_normal(this->node->raw);
256
257                 if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
258                         /* The new node splits 'this' frag into two */
259                         struct jffs2_node_frag *newfrag2;
260
261                         if (this->node)
262                                 dbg_fragtree2("split old frag 0x%04x-0x%04x, phys 0x%08x\n",
263                                         this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
264                         else
265                                 dbg_fragtree2("split old hole frag 0x%04x-0x%04x\n",
266                                         this->ofs, this->ofs+this->size);
267
268                         /* New second frag pointing to this's node */
269                         newfrag2 = new_fragment(this->node, newfrag->ofs + newfrag->size,
270                                                 this->ofs + this->size - newfrag->ofs - newfrag->size);
271                         if (unlikely(!newfrag2))
272                                 return -ENOMEM;
273                         if (this->node)
274                                 this->node->frags++;
275
276                         /* Adjust size of original 'this' */
277                         this->size = newfrag->ofs - this->ofs;
278
279                         /* Now, we know there's no node with offset
280                            greater than this->ofs but smaller than
281                            newfrag2->ofs or newfrag->ofs, for obvious
282                            reasons. So we can do a tree insert from
283                            'this' to insert newfrag, and a tree insert
284                            from newfrag to insert newfrag2. */
285                         jffs2_fragtree_insert(newfrag, this);
286                         rb_insert_color(&newfrag->rb, root);
287
288                         jffs2_fragtree_insert(newfrag2, newfrag);
289                         rb_insert_color(&newfrag2->rb, root);
290
291                         return 0;
292                 }
293                 /* New node just reduces 'this' frag in size, doesn't split it */
294                 this->size = newfrag->ofs - this->ofs;
295
296                 /* Again, we know it lives down here in the tree */
297                 jffs2_fragtree_insert(newfrag, this);
298                 rb_insert_color(&newfrag->rb, root);
299         } else {
300                 /* New frag starts at the same point as 'this' used to. Replace
301                    it in the tree without doing a delete and insertion */
302                 dbg_fragtree2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
303                           newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size);
304
305                 rb_replace_node(&this->rb, &newfrag->rb, root);
306
307                 if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
308                         dbg_fragtree2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size);
309                         jffs2_obsolete_node_frag(c, this);
310                 } else {
311                         this->ofs += newfrag->size;
312                         this->size -= newfrag->size;
313
314                         jffs2_fragtree_insert(this, newfrag);
315                         rb_insert_color(&this->rb, root);
316                         return 0;
317                 }
318         }
319         /* OK, now we have newfrag added in the correct place in the tree, but
320            frag_next(newfrag) may be a fragment which is overlapped by it
321         */
322         while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
323                 /* 'this' frag is obsoleted completely. */
324                 dbg_fragtree2("obsoleting node frag %p (%x-%x) and removing from tree\n",
325                         this, this->ofs, this->ofs+this->size);
326                 rb_erase(&this->rb, root);
327                 jffs2_obsolete_node_frag(c, this);
328         }
329         /* Now we're pointing at the first frag which isn't totally obsoleted by
330            the new frag */
331
332         if (!this || newfrag->ofs + newfrag->size == this->ofs)
333                 return 0;
334
335         /* Still some overlap but we don't need to move it in the tree */
336         this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
337         this->ofs = newfrag->ofs + newfrag->size;
338
339         /* And mark them REF_NORMAL so the GC takes a look at them */
340         if (this->node)
341                 mark_ref_normal(this->node->raw);
342         mark_ref_normal(newfrag->node->raw);
343
344         return 0;
345 }
346
347 /*
348  * Given an inode, probably with existing tree of fragments, add the new node
349  * to the fragment tree.
350  */
351 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
352 {
353         int ret;
354         struct jffs2_node_frag *newfrag;
355
356         if (unlikely(!fn->size))
357                 return 0;
358
359         newfrag = new_fragment(fn, fn->ofs, fn->size);
360         if (unlikely(!newfrag))
361                 return -ENOMEM;
362         newfrag->node->frags = 1;
363
364         dbg_fragtree("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
365                   fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
366
367         ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
368         if (unlikely(ret))
369                 return ret;
370
371         /* If we now share a page with other nodes, mark either previous
372            or next node REF_NORMAL, as appropriate.  */
373         if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
374                 struct jffs2_node_frag *prev = frag_prev(newfrag);
375
376                 mark_ref_normal(fn->raw);
377                 /* If we don't start at zero there's _always_ a previous */
378                 if (prev->node)
379                         mark_ref_normal(prev->node->raw);
380         }
381
382         if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
383                 struct jffs2_node_frag *next = frag_next(newfrag);
384
385                 if (next) {
386                         mark_ref_normal(fn->raw);
387                         if (next->node)
388                                 mark_ref_normal(next->node->raw);
389                 }
390         }
391         jffs2_dbg_fragtree_paranoia_check_nolock(f);
392
393         return 0;
394 }
395
396 /*
397  * Check the data CRC of the node.
398  *
399  * Returns: 0 if the data CRC is correct;
400  *          1 - if incorrect;
401  *          error code if an error occured.
402  */
403 static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
404 {
405         struct jffs2_raw_node_ref *ref = tn->fn->raw;
406         int err = 0, pointed = 0;
407         struct jffs2_eraseblock *jeb;
408         unsigned char *buffer;
409         uint32_t crc, ofs, retlen, len;
410
411         BUG_ON(tn->csize == 0);
412
413         if (!jffs2_is_writebuffered(c))
414                 goto adj_acc;
415
416         /* Calculate how many bytes were already checked */
417         ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);
418         len = ofs % c->wbuf_pagesize;
419         if (likely(len))
420                 len = c->wbuf_pagesize - len;
421
422         if (len >= tn->csize) {
423                 dbg_readinode("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",
424                         ref_offset(ref), tn->csize, ofs);
425                 goto adj_acc;
426         }
427
428         ofs += len;
429         len = tn->csize - len;
430
431         dbg_readinode("check node at %#08x, data length %u, partial CRC %#08x, correct CRC %#08x, data starts at %#08x, start checking from %#08x - %u bytes.\n",
432                 ref_offset(ref), tn->csize, tn->partial_crc, tn->data_crc, ofs - len, ofs, len);
433
434 #ifndef __ECOS
435         /* TODO: instead, incapsulate point() stuff to jffs2_flash_read(),
436          * adding and jffs2_flash_read_end() interface. */
437         if (c->mtd->point) {
438                 err = c->mtd->point(c->mtd, ofs, len, &retlen, &buffer);
439                 if (!err && retlen < tn->csize) {
440                         JFFS2_WARNING("MTD point returned len too short: %u instead of %u.\n", retlen, tn->csize);
441                         c->mtd->unpoint(c->mtd, buffer, ofs, len);
442                 } else if (err)
443                         JFFS2_WARNING("MTD point failed: error code %d.\n", err);
444                 else
445                         pointed = 1; /* succefully pointed to device */
446         }
447 #endif
448
449         if (!pointed) {
450                 buffer = kmalloc(len, GFP_KERNEL);
451                 if (unlikely(!buffer))
452                         return -ENOMEM;
453
454                 /* TODO: this is very frequent pattern, make it a separate
455                  * routine */
456                 err = jffs2_flash_read(c, ofs, len, &retlen, buffer);
457                 if (err) {
458                         JFFS2_ERROR("can not read %d bytes from 0x%08x, error code: %d.\n", len, ofs, err);
459                         goto free_out;
460                 }
461
462                 if (retlen != len) {
463                         JFFS2_ERROR("short read at %#08x: %d instead of %d.\n", ofs, retlen, len);
464                         err = -EIO;
465                         goto free_out;
466                 }
467         }
468
469         /* Continue calculating CRC */
470         crc = crc32(tn->partial_crc, buffer, len);
471         if(!pointed)
472                 kfree(buffer);
473 #ifndef __ECOS
474         else
475                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
476 #endif
477
478         if (crc != tn->data_crc) {
479                 JFFS2_NOTICE("wrong data CRC in data node at 0x%08x: read %#08x, calculated %#08x.\n",
480                         ofs, tn->data_crc, crc);
481                 return 1;
482         }
483
484 adj_acc:
485         jeb = &c->blocks[ref->flash_offset / c->sector_size];
486         len = ref_totlen(c, jeb, ref);
487
488         /*
489          * Mark the node as having been checked and fix the
490          * accounting accordingly.
491          */
492         spin_lock(&c->erase_completion_lock);
493         jeb->used_size += len;
494         jeb->unchecked_size -= len;
495         c->used_size += len;
496         c->unchecked_size -= len;
497         spin_unlock(&c->erase_completion_lock);
498
499         return 0;
500
501 free_out:
502         if(!pointed)
503                 kfree(buffer);
504 #ifndef __ECOS
505         else
506                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
507 #endif
508         return err;
509 }
510
511 /*
512  * Helper function for jffs2_add_older_frag_to_fragtree().
513  *
514  * Checks the node if we are in the checking stage.
515  */
516 static inline int check_node(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_tmp_dnode_info *tn)
517 {
518         int ret;
519
520         BUG_ON(ref_obsolete(tn->fn->raw));
521
522         /* We only check the data CRC of unchecked nodes */
523         if (ref_flags(tn->fn->raw) != REF_UNCHECKED)
524                 return 0;
525
526         dbg_fragtree2("check node %#04x-%#04x, phys offs %#08x.\n",
527                 tn->fn->ofs, tn->fn->ofs + tn->fn->size, ref_offset(tn->fn->raw));
528
529         ret = check_node_data(c, tn);
530         if (unlikely(ret < 0)) {
531                 JFFS2_ERROR("check_node_data() returned error: %d.\n",
532                         ret);
533         } else if (unlikely(ret > 0)) {
534                 dbg_fragtree2("CRC error, mark it obsolete.\n");
535                 jffs2_mark_node_obsolete(c, tn->fn->raw);
536         }
537
538         return ret;
539 }
540
541 /*
542  * Helper function for jffs2_add_older_frag_to_fragtree().
543  *
544  * Called when the new fragment that is being inserted
545  * splits a hole fragment.
546  */
547 static int split_hole(struct jffs2_sb_info *c, struct rb_root *root,
548                       struct jffs2_node_frag *newfrag, struct jffs2_node_frag *hole)
549 {
550         dbg_fragtree2("fragment %#04x-%#04x splits the hole %#04x-%#04x\n",
551                 newfrag->ofs, newfrag->ofs + newfrag->size, hole->ofs, hole->ofs + hole->size);
552
553         if (hole->ofs == newfrag->ofs) {
554                 /*
555                  * Well, the new fragment actually starts at the same offset as
556                  * the hole.
557                  */
558                 if (hole->ofs + hole->size > newfrag->ofs + newfrag->size) {
559                         /*
560                          * We replace the overlapped left part of the hole by
561                          * the new node.
562                          */
563
564                         dbg_fragtree2("insert fragment %#04x-%#04x and cut the left part of the hole\n",
565                                 newfrag->ofs, newfrag->ofs + newfrag->size);
566                         rb_replace_node(&hole->rb, &newfrag->rb, root);
567
568                         hole->ofs += newfrag->size;
569                         hole->size -= newfrag->size;
570
571                         /*
572                          * We know that 'hole' should be the right hand
573                          * fragment.
574                          */
575                         jffs2_fragtree_insert(hole, newfrag);
576                         rb_insert_color(&hole->rb, root);
577                 } else {
578                         /*
579                          * Ah, the new fragment is of the same size as the hole.
580                          * Relace the hole by it.
581                          */
582                         dbg_fragtree2("insert fragment %#04x-%#04x and overwrite hole\n",
583                                 newfrag->ofs, newfrag->ofs + newfrag->size);
584                         rb_replace_node(&hole->rb, &newfrag->rb, root);
585                         jffs2_free_node_frag(hole);
586                 }
587         } else {
588                 /* The new fragment lefts some hole space at the left */
589
590                 struct jffs2_node_frag * newfrag2 = NULL;
591
592                 if (hole->ofs + hole->size > newfrag->ofs + newfrag->size) {
593                         /* The new frag also lefts some space at the right */
594                         newfrag2 = new_fragment(NULL, newfrag->ofs +
595                                 newfrag->size, hole->ofs + hole->size
596                                 - newfrag->ofs - newfrag->size);
597                         if (unlikely(!newfrag2)) {
598                                 jffs2_free_node_frag(newfrag);
599                                 return -ENOMEM;
600                         }
601                 }
602
603                 hole->size = newfrag->ofs - hole->ofs;
604                 dbg_fragtree2("left the hole %#04x-%#04x at the left and inserd fragment %#04x-%#04x\n",
605                         hole->ofs, hole->ofs + hole->size, newfrag->ofs, newfrag->ofs + newfrag->size);
606
607                 jffs2_fragtree_insert(newfrag, hole);
608                 rb_insert_color(&newfrag->rb, root);
609
610                 if (newfrag2) {
611                         dbg_fragtree2("left the hole %#04x-%#04x at the right\n",
612                                 newfrag2->ofs, newfrag2->ofs + newfrag2->size);
613                         jffs2_fragtree_insert(newfrag2, newfrag);
614                         rb_insert_color(&newfrag2->rb, root);
615                 }
616         }
617
618         return 0;
619 }
620
621 /*
622  * This function is used when we build inode. It expects the nodes are passed
623  * in the decreasing version order. The whole point of this is to improve the
624  * inodes checking on NAND: we check the nodes' data CRC only when they are not
625  * obsoleted. Previously, add_frag_to_fragtree() function was used and
626  * nodes were passed to it in the increasing version ordes and CRCs of all
627  * nodes were checked.
628  *
629  * Note: tn->fn->size shouldn't be zero.
630  *
631  * Returns 0 if the node was inserted
632  *         1 if it wasn't inserted (since it is obsolete)
633  *         < 0 an if error occured
634  */
635 int jffs2_add_older_frag_to_fragtree(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
636                                      struct jffs2_tmp_dnode_info *tn)
637 {
638         struct jffs2_node_frag *this, *newfrag;
639         uint32_t lastend;
640         struct jffs2_full_dnode *fn = tn->fn;
641         struct rb_root *root = &f->fragtree;
642         uint32_t fn_size = fn->size, fn_ofs = fn->ofs;
643         int err, checked = 0;
644         int ref_flag;
645
646         dbg_fragtree("insert fragment %#04x-%#04x, ver %u\n", fn_ofs, fn_ofs + fn_size, tn->version);
647
648         /* Skip all the nodes which are completed before this one starts */
649         this = jffs2_lookup_node_frag(root, fn_ofs);
650         if (this)
651                 dbg_fragtree2("'this' found %#04x-%#04x (%s)\n", this->ofs, this->ofs + this->size, this->node ? "data" : "hole");
652
653         if (this)
654                 lastend = this->ofs + this->size;
655         else
656                 lastend = 0;
657
658         /* Detect the preliminary type of node */
659         if (fn->size >= PAGE_CACHE_SIZE)
660                 ref_flag = REF_PRISTINE;
661         else
662                 ref_flag = REF_NORMAL;
663
664         /* See if we ran off the end of the root */
665         if (lastend <= fn_ofs) {
666                 /* We did */
667
668                 /*
669                  * We are going to insert the new node into the
670                  * fragment tree, so check it.
671                  */
672                 err = check_node(c, f, tn);
673                 if (err != 0)
674                         return err;
675
676                 fn->frags = 1;
677
678                 newfrag = new_fragment(fn, fn_ofs, fn_size);
679                 if (unlikely(!newfrag))
680                         return -ENOMEM;
681
682                 err = no_overlapping_node(c, root, newfrag, this, lastend);
683                 if (unlikely(err != 0)) {
684                         jffs2_free_node_frag(newfrag);
685                         return err;
686                 }
687
688                 goto out_ok;
689         }
690
691         fn->frags = 0;
692
693         while (1) {
694                 /*
695                  * Here we have:
696                  * fn_ofs < this->ofs + this->size && fn_ofs >= this->ofs.
697                  *
698                  * Remember, 'this' has higher version, any non-hole node
699                  * which is already in the fragtree is newer then the newly
700                  * inserted.
701                  */
702                 if (!this->node) {
703                         /*
704                          * 'this' is the hole fragment, so at least the
705                          * beginning of the new fragment is valid.
706                          */
707
708                         /*
709                          * We are going to insert the new node into the
710                          * fragment tree, so check it.
711                          */
712                         if (!checked) {
713                                 err = check_node(c, f, tn);
714                                 if (unlikely(err != 0))
715                                         return err;
716                                 checked = 1;
717                         }
718
719                         if (this->ofs + this->size >= fn_ofs + fn_size) {
720                                 /* We split the hole on two parts */
721
722                                 fn->frags += 1;
723                                 newfrag = new_fragment(fn, fn_ofs, fn_size);
724                                 if (unlikely(!newfrag))
725                                         return -ENOMEM;
726
727                                 err = split_hole(c, root, newfrag, this);
728                                 if (unlikely(err))
729                                         return err;
730                                 goto out_ok;
731                         }
732
733                         /*
734                          * The beginning of the new fragment is valid since it
735                          * overlaps the hole node.
736                          */
737
738                         ref_flag = REF_NORMAL;
739
740                         fn->frags += 1;
741                         newfrag = new_fragment(fn, fn_ofs,
742                                         this->ofs + this->size - fn_ofs);
743                         if (unlikely(!newfrag))
744                                 return -ENOMEM;
745
746                         if (fn_ofs == this->ofs) {
747                                 /*
748                                  * The new node starts at the same offset as
749                                  * the hole and supersieds the hole.
750                                  */
751                                 dbg_fragtree2("add the new fragment instead of hole %#04x-%#04x, refcnt %d\n",
752                                         fn_ofs, fn_ofs + this->ofs + this->size - fn_ofs, fn->frags);
753
754                                 rb_replace_node(&this->rb, &newfrag->rb, root);
755                                 jffs2_free_node_frag(this);
756                         } else {
757                                 /*
758                                  * The hole becomes shorter as its right part
759                                  * is supersieded by the new fragment.
760                                  */
761                                 dbg_fragtree2("reduce size of hole %#04x-%#04x to %#04x-%#04x\n",
762                                         this->ofs, this->ofs + this->size, this->ofs, this->ofs + this->size - newfrag->size);
763
764                                 dbg_fragtree2("add new fragment %#04x-%#04x, refcnt %d\n", fn_ofs,
765                                         fn_ofs + this->ofs + this->size - fn_ofs, fn->frags);
766
767                                 this->size -= newfrag->size;
768                                 jffs2_fragtree_insert(newfrag, this);
769                                 rb_insert_color(&newfrag->rb, root);
770                         }
771
772                         fn_ofs += newfrag->size;
773                         fn_size -= newfrag->size;
774                         this = rb_entry(rb_next(&newfrag->rb),
775                                         struct jffs2_node_frag, rb);
776
777                         dbg_fragtree2("switch to the next 'this' fragment: %#04x-%#04x %s\n",
778                                 this->ofs, this->ofs + this->size, this->node ? "(data)" : "(hole)");
779                 }
780
781                 /*
782                  * 'This' node is not the hole so it obsoletes the new fragment
783                  * either fully or partially.
784                  */
785                 if (this->ofs + this->size >= fn_ofs + fn_size) {
786                         /* The new node is obsolete, drop it */
787                         if (fn->frags == 0) {
788                                 dbg_fragtree2("%#04x-%#04x is obsolete, mark it obsolete\n", fn_ofs, fn_ofs + fn_size);
789                                 ref_flag = REF_OBSOLETE;
790                         }
791                         goto out_ok;
792                 } else {
793                         struct jffs2_node_frag *new_this;
794
795                         /* 'This' node obsoletes the beginning of the new node */
796                         dbg_fragtree2("the beginning %#04x-%#04x is obsolete\n", fn_ofs, this->ofs + this->size);
797
798                         ref_flag = REF_NORMAL;
799
800                         fn_size -= this->ofs + this->size - fn_ofs;
801                         fn_ofs = this->ofs + this->size;
802                         dbg_fragtree2("now considering %#04x-%#04x\n", fn_ofs, fn_ofs + fn_size);
803
804                         new_this = rb_entry(rb_next(&this->rb), struct jffs2_node_frag, rb);
805                         if (!new_this) {
806                                 /*
807                                  * There is no next fragment. Add the rest of
808                                  * the new node as the right-hand child.
809                                  */
810                                 if (!checked) {
811                                         err = check_node(c, f, tn);
812                                         if (unlikely(err != 0))
813                                                 return err;
814                                         checked = 1;
815                                 }
816
817                                 fn->frags += 1;
818                                 newfrag = new_fragment(fn, fn_ofs, fn_size);
819                                 if (unlikely(!newfrag))
820                                         return -ENOMEM;
821
822                                 dbg_fragtree2("there are no more fragments, insert %#04x-%#04x\n",
823                                         newfrag->ofs, newfrag->ofs + newfrag->size);
824                                 rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
825                                 rb_insert_color(&newfrag->rb, root);
826                                 goto out_ok;
827                         } else {
828                                 this = new_this;
829                                 dbg_fragtree2("switch to the next 'this' fragment: %#04x-%#04x %s\n",
830                                         this->ofs, this->ofs + this->size, this->node ? "(data)" : "(hole)");
831                         }
832                 }
833         }
834
835 out_ok:
836         BUG_ON(fn->size < PAGE_CACHE_SIZE && ref_flag == REF_PRISTINE);
837
838         if (ref_flag == REF_OBSOLETE) {
839                 dbg_fragtree2("the node is obsolete now\n");
840                 /* jffs2_mark_node_obsolete() will adjust space accounting */
841                 jffs2_mark_node_obsolete(c, fn->raw);
842                 return 1;
843         }
844
845         dbg_fragtree2("the node is \"%s\" now\n", ref_flag == REF_NORMAL ? "REF_NORMAL" : "REF_PRISTINE");
846
847         /* Space accounting was adjusted at check_node_data() */
848         spin_lock(&c->erase_completion_lock);
849         fn->raw->flash_offset = ref_offset(fn->raw) | ref_flag;
850         spin_unlock(&c->erase_completion_lock);
851
852         return 0;
853 }
854
855 void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
856 {
857         spin_lock(&c->inocache_lock);
858         ic->state = state;
859         wake_up(&c->inocache_wq);
860         spin_unlock(&c->inocache_lock);
861 }
862
863 /* During mount, this needs no locking. During normal operation, its
864    callers want to do other stuff while still holding the inocache_lock.
865    Rather than introducing special case get_ino_cache functions or
866    callbacks, we just let the caller do the locking itself. */
867
868 struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
869 {
870         struct jffs2_inode_cache *ret;
871
872         ret = c->inocache_list[ino % INOCACHE_HASHSIZE];
873         while (ret && ret->ino < ino) {
874                 ret = ret->next;
875         }
876
877         if (ret && ret->ino != ino)
878                 ret = NULL;
879
880         return ret;
881 }
882
883 void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
884 {
885         struct jffs2_inode_cache **prev;
886
887         spin_lock(&c->inocache_lock);
888         if (!new->ino)
889                 new->ino = ++c->highest_ino;
890
891         dbg_inocache("add %p (ino #%u)\n", new, new->ino);
892
893         prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE];
894
895         while ((*prev) && (*prev)->ino < new->ino) {
896                 prev = &(*prev)->next;
897         }
898         new->next = *prev;
899         *prev = new;
900
901         spin_unlock(&c->inocache_lock);
902 }
903
904 void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
905 {
906         struct jffs2_inode_cache **prev;
907
908         dbg_inocache("del %p (ino #%u)\n", old, old->ino);
909         spin_lock(&c->inocache_lock);
910
911         prev = &c->inocache_list[old->ino % INOCACHE_HASHSIZE];
912
913         while ((*prev) && (*prev)->ino < old->ino) {
914                 prev = &(*prev)->next;
915         }
916         if ((*prev) == old) {
917                 *prev = old->next;
918         }
919
920         /* Free it now unless it's in READING or CLEARING state, which
921            are the transitions upon read_inode() and clear_inode(). The
922            rest of the time we know nobody else is looking at it, and
923            if it's held by read_inode() or clear_inode() they'll free it
924            for themselves. */
925         if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
926                 jffs2_free_inode_cache(old);
927
928         spin_unlock(&c->inocache_lock);
929 }
930
931 void jffs2_free_ino_caches(struct jffs2_sb_info *c)
932 {
933         int i;
934         struct jffs2_inode_cache *this, *next;
935
936         for (i=0; i<INOCACHE_HASHSIZE; i++) {
937                 this = c->inocache_list[i];
938                 while (this) {
939                         next = this->next;
940                         jffs2_free_inode_cache(this);
941                         this = next;
942                 }
943                 c->inocache_list[i] = NULL;
944         }
945 }
946
947 void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
948 {
949         int i;
950         struct jffs2_raw_node_ref *this, *next;
951
952         for (i=0; i<c->nr_blocks; i++) {
953                 this = c->blocks[i].first_node;
954                 while(this) {
955                         next = this->next_phys;
956                         jffs2_free_raw_node_ref(this);
957                         this = next;
958                 }
959                 c->blocks[i].first_node = c->blocks[i].last_node = NULL;
960         }
961 }
962
963 struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
964 {
965         /* The common case in lookup is that there will be a node
966            which precisely matches. So we go looking for that first */
967         struct rb_node *next;
968         struct jffs2_node_frag *prev = NULL;
969         struct jffs2_node_frag *frag = NULL;
970
971         dbg_fragtree2("root %p, offset %d\n", fragtree, offset);
972
973         next = fragtree->rb_node;
974
975         while(next) {
976                 frag = rb_entry(next, struct jffs2_node_frag, rb);
977
978                 if (frag->ofs + frag->size <= offset) {
979                         /* Remember the closest smaller match on the way down */
980                         if (!prev || frag->ofs > prev->ofs)
981                                 prev = frag;
982                         next = frag->rb.rb_right;
983                 } else if (frag->ofs > offset) {
984                         next = frag->rb.rb_left;
985                 } else {
986                         return frag;
987                 }
988         }
989
990         /* Exact match not found. Go back up looking at each parent,
991            and return the closest smaller one */
992
993         if (prev)
994                 dbg_fragtree2("no match. Returning frag %#04x-%#04x, closest previous\n",
995                           prev->ofs, prev->ofs+prev->size);
996         else
997                 dbg_fragtree2("returning NULL, empty fragtree\n");
998
999         return prev;
1000 }
1001
1002 /* Pass 'c' argument to indicate that nodes should be marked obsolete as
1003    they're killed. */
1004 void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
1005 {
1006         struct jffs2_node_frag *frag;
1007         struct jffs2_node_frag *parent;
1008
1009         if (!root->rb_node)
1010                 return;
1011
1012         dbg_fragtree("killing\n");
1013
1014         frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
1015         while(frag) {
1016                 if (frag->rb.rb_left) {
1017                         frag = frag_left(frag);
1018                         continue;
1019                 }
1020                 if (frag->rb.rb_right) {
1021                         frag = frag_right(frag);
1022                         continue;
1023                 }
1024
1025                 if (frag->node && !(--frag->node->frags)) {
1026                         /* Not a hole, and it's the final remaining frag
1027                            of this node. Free the node */
1028                         if (c)
1029                                 jffs2_mark_node_obsolete(c, frag->node->raw);
1030
1031                         jffs2_free_full_dnode(frag->node);
1032                 }
1033                 parent = frag_parent(frag);
1034                 if (parent) {
1035                         if (frag_left(parent) == frag)
1036                                 parent->rb.rb_left = NULL;
1037                         else
1038                                 parent->rb.rb_right = NULL;
1039                 }
1040
1041                 jffs2_free_node_frag(frag);
1042                 frag = parent;
1043
1044                 cond_resched();
1045         }
1046 }