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   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 1.104 2005/08/01 12:05:19 dedekind 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         JFFS2_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                                 JFFS2_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 Marking new dirent node is obsolete, old is \"%s\", ino #%u\n",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                                 JFFS2_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         JFFS2_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                         JFFS2_DBG_FRAGTREE2("truncating frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size);
  64                         frag->size = size - frag->ofs;
  65                 }
  66                 frag = frag_next(frag);
  67         }
  68         while (frag && frag->ofs >= size) {
  69                 struct jffs2_node_frag *next = frag_next(frag);
  70
  71                 JFFS2_DBG_FRAGTREE("removing frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size);
  72                 frag_erase(frag, list);
  73                 jffs2_obsolete_node_frag(c, frag);
  74                 frag = next;
  75         }
  76
  77         if (size == 0)
  78                 return;
  79
  80         /*
  81          * If the last fragment starts at the RAM page boundary, it is
  82          * REF_PRISTINE irrespective of its size.
  83          */
  84         frag = frag_last(list);
  85         if ((frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
  86                 JFFS2_DBG_FRAGTREE2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
  87                         frag->ofs, frag->ofs + frag->size);
  88                 frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
  89         }
  90 }
  91
  92 void jffs2_obsolete_node_frag(struct jffs2_sb_info *c, struct jffs2_node_frag *this)
  93 {
  94         if (this->node) {
  95                 this->node->frags--;
  96                 if (!this->node->frags) {
  97                         /* The node has no valid frags left. It's totally obsoleted */
  98                         JFFS2_DBG_FRAGTREE2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
  99                                 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size);
 100                         jffs2_mark_node_obsolete(c, this->node->raw);
 101                         jffs2_free_full_dnode(this->node);
 102                 } else {
 103                         JFFS2_DBG_FRAGTREE2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
 104                                 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags);
 105                         mark_ref_normal(this->node->raw);
 106                 }
 107
 108         }
 109         jffs2_free_node_frag(this);
 110 }
 111
 112 static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
 113 {
 114         struct rb_node *parent = &base->rb;
 115         struct rb_node **link = &parent;
 116
 117         JFFS2_DBG_FRAGTREE2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);
 118
 119         while (*link) {
 120                 parent = *link;
 121                 base = rb_entry(parent, struct jffs2_node_frag, rb);
 122
 123                 JFFS2_DBG_FRAGTREE2("considering frag at 0x%08x\n", base->ofs);
 124                 if (newfrag->ofs > base->ofs)
 125                         link = &base->rb.rb_right;
 126                 else if (newfrag->ofs < base->ofs)
 127                         link = &base->rb.rb_left;
 128                 else {
 129                         JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
 130                         BUG();
 131                 }
 132         }
 133
 134         rb_link_node(&newfrag->rb, &base->rb, link);
 135 }
 136
 137 /*
 138  * Allocate and initializes a new fragment.
 139  */
 140 static inline struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
 141 {
 142         struct jffs2_node_frag *newfrag;
 143
 144         newfrag = jffs2_alloc_node_frag();
 145         if (likely(newfrag)) {
 146                 newfrag->ofs = ofs;
 147                 newfrag->size = size;
 148                 newfrag->node = fn;
 149         } else {
 150                 JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
 151         }
 152
 153         return newfrag;
 154 }
 155
 156 /*
 157  * Called when there is no overlapping fragment exist. Inserts a hole before the new
 158  * fragment and inserts the new fragment to the fragtree.
 159  */
 160 static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
 161                                struct jffs2_node_frag *newfrag,
 162                                struct jffs2_node_frag *this, uint32_t lastend)
 163 {
 164         if (lastend < newfrag->node->ofs) {
 165                 /* put a hole in before the new fragment */
 166                 struct jffs2_node_frag *holefrag;
 167
 168                 holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
 169                 if (unlikely(!holefrag)) {
 170                         jffs2_free_node_frag(newfrag);
 171                         return -ENOMEM;
 172                 }
 173
 174                 if (this) {
 175                         /* By definition, the 'this' node has no right-hand child,
 176                            because there are no frags with offset greater than it.
 177                            So that's where we want to put the hole */
 178                         JFFS2_DBG_FRAGTREE2("add hole frag %u-%u on the right of the new frag.\n",
 179                                 holefrag->ofs, holefrag->ofs + holefrag->size);
 180                         rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
 181                 } else {
 182                         JFFS2_DBG_FRAGTREE2("Add hole frag %u-%u to the root of the tree.\n",
 183                                 holefrag->ofs, holefrag->ofs + holefrag->size);
 184                         rb_link_node(&holefrag->rb, NULL, &root->rb_node);
 185                 }
 186                 rb_insert_color(&holefrag->rb, root);
 187                 this = holefrag;
 188         }
 189
 190         if (this) {
 191                 /* By definition, the 'this' node has no right-hand child,
 192                    because there are no frags with offset greater than it.
 193                    So that's where we want to put new fragment */
 194                 JFFS2_DBG_FRAGTREE2("add the new node at the right\n");
 195                 rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
 196         } else {
 197                 JFFS2_DBG_FRAGTREE2("insert the new node at the root of the tree\n");
 198                 rb_link_node(&newfrag->rb, NULL, &root->rb_node);
 199         }
 200         rb_insert_color(&newfrag->rb, root);
 201
 202         return 0;
 203 }
 204
 205 /* Doesn't set inode->i_size */
 206 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *root, struct jffs2_node_frag *newfrag)
 207 {
 208         struct jffs2_node_frag *this;
 209         uint32_t lastend;
 210
 211         /* Skip all the nodes which are completed before this one starts */
 212         this = jffs2_lookup_node_frag(root, newfrag->node->ofs);
 213
 214         if (this) {
 215                 JFFS2_DBG_FRAGTREE2("lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
 216                           this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this);
 217                 lastend = this->ofs + this->size;
 218         } else {
 219                 JFFS2_DBG_FRAGTREE2("lookup gave no frag\n");
 220                 lastend = 0;
 221         }
 222
 223         /* See if we ran off the end of the fragtree */
 224         if (lastend <= newfrag->ofs) {
 225                 /* We did */
 226
 227                 /* Check if 'this' node was on the same page as the new node.
 228                    If so, both 'this' and the new node get marked REF_NORMAL so
 229                    the GC can take a look.
 230                 */
 231                 if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
 232                         if (this->node)
 233                                 mark_ref_normal(this->node->raw);
 234                         mark_ref_normal(newfrag->node->raw);
 235                 }
 236
 237                 return no_overlapping_node(c, root, newfrag, this, lastend);
 238         }
 239
 240         if (this->node)
 241                 JFFS2_DBG_FRAGTREE2("dealing with frag %u-%u, phys %#08x(%d).\n",
 242                 this->ofs, this->ofs + this->size,
 243                 ref_offset(this->node->raw), ref_flags(this->node->raw));
 244         else
 245                 JFFS2_DBG_FRAGTREE2("dealing with hole frag %u-%u.\n",
 246                 this->ofs, this->ofs + this->size);
 247
 248         /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
 249          * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
 250          */
 251         if (newfrag->ofs > this->ofs) {
 252                 /* This node isn't completely obsoleted. The start of it remains valid */
 253
 254                 /* Mark the new node and the partially covered node REF_NORMAL -- let
 255                    the GC take a look at them */
 256                 mark_ref_normal(newfrag->node->raw);
 257                 if (this->node)
 258                         mark_ref_normal(this->node->raw);
 259
 260                 if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
 261                         /* The new node splits 'this' frag into two */
 262                         struct jffs2_node_frag *newfrag2;
 263
 264                         if (this->node)
 265                                 JFFS2_DBG_FRAGTREE2("split old frag 0x%04x-0x%04x, phys 0x%08x\n",
 266                                         this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
 267                         else
 268                                 JFFS2_DBG_FRAGTREE2("split old hole frag 0x%04x-0x%04x\n",
 269                                         this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
 270
 271                         /* New second frag pointing to this's node */
 272                         newfrag2 = new_fragment(this->node, newfrag->ofs + newfrag->size,
 273                                                 this->ofs + this->size - newfrag->ofs - newfrag->size);
 274                         if (unlikely(!newfrag2))
 275                                 return -ENOMEM;
 276                         if (this->node)
 277                                 this->node->frags++;
 278
 279                         /* Adjust size of original 'this' */
 280                         this->size = newfrag->ofs - this->ofs;
 281
 282                         /* Now, we know there's no node with offset
 283                            greater than this->ofs but smaller than
 284                            newfrag2->ofs or newfrag->ofs, for obvious
 285                            reasons. So we can do a tree insert from
 286                            'this' to insert newfrag, and a tree insert
 287                            from newfrag to insert newfrag2. */
 288                         jffs2_fragtree_insert(newfrag, this);
 289                         rb_insert_color(&newfrag->rb, root);
 290
 291                         jffs2_fragtree_insert(newfrag2, newfrag);
 292                         rb_insert_color(&newfrag2->rb, root);
 293
 294                         return 0;
 295                 }
 296                 /* New node just reduces 'this' frag in size, doesn't split it */
 297                 this->size = newfrag->ofs - this->ofs;
 298
 299                 /* Again, we know it lives down here in the tree */
 300                 jffs2_fragtree_insert(newfrag, this);
 301                 rb_insert_color(&newfrag->rb, root);
 302         } else {
 303                 /* New frag starts at the same point as 'this' used to. Replace
 304                    it in the tree without doing a delete and insertion */
 305                 JFFS2_DBG_FRAGTREE2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
 306                           newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size);
 307
 308                 rb_replace_node(&this->rb, &newfrag->rb, root);
 309
 310                 if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
 311                         JFFS2_DBG_FRAGTREE2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size);
 312                         jffs2_obsolete_node_frag(c, this);
 313                 } else {
 314                         this->ofs += newfrag->size;
 315                         this->size -= newfrag->size;
 316
 317                         jffs2_fragtree_insert(this, newfrag);
 318                         rb_insert_color(&this->rb, root);
 319                         return 0;
 320                 }
 321         }
 322         /* OK, now we have newfrag added in the correct place in the tree, but
 323            frag_next(newfrag) may be a fragment which is overlapped by it
 324         */
 325         while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
 326                 /* 'this' frag is obsoleted completely. */
 327                 JFFS2_DBG_FRAGTREE2("obsoleting node frag %p (%x-%x) and removing from tree\n",
 328                         this, this->ofs, this->ofs+this->size);
 329                 rb_erase(&this->rb, root);
 330                 jffs2_obsolete_node_frag(c, this);
 331         }
 332         /* Now we're pointing at the first frag which isn't totally obsoleted by
 333            the new frag */
 334
 335         if (!this || newfrag->ofs + newfrag->size == this->ofs)
 336                 return 0;
 337
 338         /* Still some overlap but we don't need to move it in the tree */
 339         this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
 340         this->ofs = newfrag->ofs + newfrag->size;
 341
 342         /* And mark them REF_NORMAL so the GC takes a look at them */
 343         if (this->node)
 344                 mark_ref_normal(this->node->raw);
 345         mark_ref_normal(newfrag->node->raw);
 346
 347         return 0;
 348 }
 349
 350 /*
 351  * Given an inode, probably with existing tree of fragments, add the new node
 352  * to the fragment tree.
 353  */
 354 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
 355 {
 356         int ret;
 357         struct jffs2_node_frag *newfrag;
 358
 359         if (unlikely(!fn->size))
 360                 return 0;
 361
 362         newfrag = new_fragment(fn, fn->ofs, fn->size);
 363         if (unlikely(!newfrag))
 364                 return -ENOMEM;
 365         newfrag->node->frags = 1;
 366
 367         JFFS2_DBG_FRAGTREE("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
 368                   fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
 369
 370         ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
 371         if (unlikely(ret))
 372                 return ret;
 373
 374         /* If we now share a page with other nodes, mark either previous
 375            or next node REF_NORMAL, as appropriate.  */
 376         if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
 377                 struct jffs2_node_frag *prev = frag_prev(newfrag);
 378
 379                 mark_ref_normal(fn->raw);
 380                 /* If we don't start at zero there's _always_ a previous */
 381                 if (prev->node)
 382                         mark_ref_normal(prev->node->raw);
 383         }
 384
 385         if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
 386                 struct jffs2_node_frag *next = frag_next(newfrag);
 387
 388                 if (next) {
 389                         mark_ref_normal(fn->raw);
 390                         if (next->node)
 391                                 mark_ref_normal(next->node->raw);
 392                 }
 393         }
 394         jffs2_dbg_fragtree_paranoia_check_nolock(f);
 395
 396         return 0;
 397 }
 398
 399 /*
 400  * Check the data CRC of the node.
 401  *
 402  * Returns: 0 if the data CRC is correct;
 403  *          1 - if incorrect;
 404  *          error code if an error occured.
 405  */
 406 static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
 407 {
 408         struct jffs2_raw_node_ref *ref = tn->fn->raw;
 409         int err = 0, pointed = 0;
 410         struct jffs2_eraseblock *jeb;
 411         unsigned char *buffer;
 412         uint32_t crc, ofs, retlen, len;
 413
 414         BUG_ON(tn->csize == 0);
 415
 416         /* Calculate how many bytes were already checked */
 417         ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);
 418         len = ofs - (ofs & (PAGE_CACHE_SIZE - 1));
 419         len = c->wbuf_pagesize - len;
 420
 421         if (len >= tn->csize) {
 422                 JFFS2_DBG_READINODE("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",
 423                         ref_offset(ref), tn->csize, ofs);
 424                 goto adj_acc;
 425         }
 426
 427         ofs += len;
 428         len = tn->csize - len;
 429
 430         JFFS2_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",
 431                 ref_offset(ref), tn->csize, tn->partial_crc, tn->data_crc, ofs - len, ofs, len);
 432
 433 #ifndef __ECOS
 434         /* TODO: instead, incapsulate point() stuff to jffs2_flash_read(),
 435          * adding and jffs2_flash_read_end() interface. */
 436         if (c->mtd->point) {
 437                 err = c->mtd->point(c->mtd, ofs, len, &retlen, &buffer);
 438                 if (!err && retlen < tn->csize) {
 439                         JFFS2_WARNING("MTD point returned len too short: %u instead of %u.\n", retlen, tn->csize);
 440                         c->mtd->unpoint(c->mtd, buffer, ofs, len);
 441                 } else if (err)
 442                         JFFS2_WARNING("MTD point failed: error code %d.\n", err);
 443                 else
 444                         pointed = 1; /* succefully pointed to device */
 445         }
 446 #endif
 447
 448         if (!pointed) {
 449                 buffer = kmalloc(len, GFP_KERNEL);
 450                 if (unlikely(!buffer))
 451                         return -ENOMEM;
 452
 453                 /* TODO: this is very frequent pattern, make it a separate
 454                  * routine */
 455                 err = jffs2_flash_read(c, ofs, len, &retlen, buffer);
 456                 if (err) {
 457                         JFFS2_ERROR("can not read %d bytes from 0x%08x, error code: %d.\n", len, ofs, err);
 458                         goto free_out;
 459                 }
 460
 461                 if (retlen != len) {
 462                         JFFS2_ERROR("short read at %#08x: %d instead of %d.\n", ofs, retlen, len);
 463                         err = -EIO;
 464                         goto free_out;
 465                 }
 466         }
 467
 468         /* Continue calculating CRC */
 469         crc = crc32(tn->partial_crc, buffer, len);
 470         if(!pointed)
 471                 kfree(buffer);
 472 #ifndef __ECOS
 473         else
 474                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
 475 #endif
 476
 477         if (crc != tn->data_crc) {
 478                 JFFS2_NOTICE("drong data CRC in data node at 0x%08x: read %#08x, calculated %#08x.\n",
 479                         ofs, tn->data_crc, crc);
 480                 return 1;
 481         }
 482
 483 adj_acc:
 484         jeb = &c->blocks[ref->flash_offset / c->sector_size];
 485         len = ref_totlen(c, jeb, ref);
 486
 487         /*
 488          * Mark the node as having been checked and fix the
 489          * accounting accordingly.
 490          */
 491         spin_lock(&c->erase_completion_lock);
 492         jeb->used_size += len;
 493         jeb->unchecked_size -= len;
 494         c->used_size += len;
 495         c->unchecked_size -= len;
 496         spin_unlock(&c->erase_completion_lock);
 497
 498         return 0;
 499
 500 free_out:
 501         if(!pointed)
 502                 kfree(buffer);
 503 #ifndef __ECOS
 504         else
 505                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
 506 #endif
 507         return err;
 508 }
 509
 510 /*
 511  * Helper function for jffs2_add_older_frag_to_fragtree().
 512  *
 513  * Checks the node if we are in the checking stage.
 514  */
 515 static inline int check_node(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_tmp_dnode_info *tn)
 516 {
 517         int ret;
 518
 519         BUG_ON(ref_obsolete(tn->fn->raw));
 520
 521         /* We only check the data CRC of unchecked nodes */
 522         if (ref_flags(tn->fn->raw) != REF_UNCHECKED)
 523                 return 0;
 524
 525         JFFS2_DBG_FRAGTREE2("check node %u-%u, phys offs %#08x.\n",
 526                 tn->fn->ofs, tn->fn->ofs + tn->fn->size,
 527                 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                 JFFS2_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         JFFS2_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                         JFFS2_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                         JFFS2_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                 JFFS2_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                         JFFS2_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         JFFS2_DBG_FRAGTREE("insert fragment %#04x-%#04x\n", fn_ofs, fn_ofs + fn_size);
 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                 JFFS2_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                                 JFFS2_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                                 JFFS2_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                                 JFFS2_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                         JFFS2_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                                 JFFS2_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                         JFFS2_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                         JFFS2_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                                 JFFS2_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                                 JFFS2_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                 JFFS2_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         JFFS2_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         JFFS2_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         JFFS2_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         JFFS2_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                 JFFS2_DBG_FRAGTREE2("considering frag %#04x-%#04x (%p). left %p, right %p\n",
 979                           frag->ofs, frag->ofs+frag->size, frag, frag->rb.rb_left, frag->rb.rb_right);
 980                 if (frag->ofs + frag->size <= offset) {
 981                         JFFS2_DBG_FRAGTREE2("going right from frag %#04x-%#04x, before the region we care about\n",
 982                                   frag->ofs, frag->ofs+frag->size);
 983                         /* Remember the closest smaller match on the way down */
 984                         if (!prev || frag->ofs > prev->ofs)
 985                                 prev = frag;
 986                         next = frag->rb.rb_right;
 987                 } else if (frag->ofs > offset) {
 988                         JFFS2_DBG_FRAGTREE2("going left from frag %#04x-%#04x, after the region we care about\n",
 989                                   frag->ofs, frag->ofs+frag->size);
 990                         next = frag->rb.rb_left;
 991                 } else {
 992                         JFFS2_DBG_FRAGTREE2("returning frag %#04x-%#04x, matched\n",
 993                                   frag->ofs, frag->ofs+frag->size);
 994                         return frag;
 995                 }
 996         }
 997
 998         /* Exact match not found. Go back up looking at each parent,
 999            and return the closest smaller one */
1000
1001         if (prev)
1002                 JFFS2_DBG_FRAGTREE2("no match. Returning frag %#04x-%#04x, closest previous\n",
1003                           prev->ofs, prev->ofs+prev->size);
1004         else
1005                 JFFS2_DBG_FRAGTREE2("returning NULL, empty fragtree\n");
1006
1007         return prev;
1008 }
1009
1010 /* Pass 'c' argument to indicate that nodes should be marked obsolete as
1011    they're killed. */
1012 void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
1013 {
1014         struct jffs2_node_frag *frag;
1015         struct jffs2_node_frag *parent;
1016
1017         if (!root->rb_node)
1018                 return;
1019
1020         JFFS2_DBG_FRAGTREE("killing\n");
1021
1022         frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
1023         while(frag) {
1024                 if (frag->rb.rb_left) {
1025                         JFFS2_DBG_FRAGTREE2("going left from frag (%p) %#04x-%#04x\n",
1026                                 frag, frag->ofs, frag->ofs+frag->size);
1027                         frag = frag_left(frag);
1028                         continue;
1029                 }
1030                 if (frag->rb.rb_right) {
1031                         JFFS2_DBG_FRAGTREE2("going right from frag (%p) %#04x-%#04x\n",
1032                                   frag, frag->ofs, frag->ofs+frag->size);
1033                         frag = frag_right(frag);
1034                         continue;
1035                 }
1036
1037                 JFFS2_DBG_FRAGTREE2("frag %#04x-%#04x: node %p, frags %d\n",
1038                           frag->ofs, frag->ofs+frag->size, frag->node, frag->node?frag->node->frags:0);
1039
1040                 if (frag->node && !(--frag->node->frags)) {
1041                         /* Not a hole, and it's the final remaining frag
1042                            of this node. Free the node */
1043                         if (c)
1044                                 jffs2_mark_node_obsolete(c, frag->node->raw);
1045
1046                         jffs2_free_full_dnode(frag->node);
1047                 }
1048                 parent = frag_parent(frag);
1049                 if (parent) {
1050                         if (frag_left(parent) == frag)
1051                                 parent->rb.rb_left = NULL;
1052                         else
1053                                 parent->rb.rb_right = NULL;
1054                 }
1055
1056                 jffs2_free_node_frag(frag);
1057                 frag = parent;
1058
1059                 cond_resched();
1060         }
1061 }