linux/fs/jffs2/nodelist.c
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   1/*
   2 * JFFS2 -- Journalling Flash File System, Version 2.
   3 *
   4 * Copyright © 2001-2007 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 */
  11
  12#include <linux/kernel.h>
  13#include <linux/sched.h>
  14#include <linux/fs.h>
  15#include <linux/mtd/mtd.h>
  16#include <linux/rbtree.h>
  17#include <linux/crc32.h>
  18#include <linux/slab.h>
  19#include <linux/pagemap.h>
  20#include "nodelist.h"
  21
  22static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
  23                                     struct jffs2_node_frag *this);
  24
  25void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list)
  26{
  27        struct jffs2_full_dirent **prev = list;
  28
  29        dbg_dentlist("add dirent \"%s\", ino #%u\n", new->name, new->ino);
  30
  31        while ((*prev) && (*prev)->nhash <= new->nhash) {
  32                if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) {
  33                        /* Duplicate. Free one */
  34                        if (new->version < (*prev)->version) {
  35                                dbg_dentlist("Eep! Marking new dirent node obsolete, old is \"%s\", ino #%u\n",
  36                                        (*prev)->name, (*prev)->ino);
  37                                jffs2_mark_node_obsolete(c, new->raw);
  38                                jffs2_free_full_dirent(new);
  39                        } else {
  40                                dbg_dentlist("marking old dirent \"%s\", ino #%u obsolete\n",
  41                                        (*prev)->name, (*prev)->ino);
  42                                new->next = (*prev)->next;
  43                                /* It may have been a 'placeholder' deletion dirent, 
  44                                   if jffs2_can_mark_obsolete() (see jffs2_do_unlink()) */
  45                                if ((*prev)->raw)
  46                                        jffs2_mark_node_obsolete(c, ((*prev)->raw));
  47                                jffs2_free_full_dirent(*prev);
  48                                *prev = new;
  49                        }
  50                        return;
  51                }
  52                prev = &((*prev)->next);
  53        }
  54        new->next = *prev;
  55        *prev = new;
  56}
  57
  58uint32_t jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
  59{
  60        struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
  61
  62        dbg_fragtree("truncating fragtree to 0x%08x bytes\n", size);
  63
  64        /* We know frag->ofs <= size. That's what lookup does for us */
  65        if (frag && frag->ofs != size) {
  66                if (frag->ofs+frag->size > size) {
  67                        frag->size = size - frag->ofs;
  68                }
  69                frag = frag_next(frag);
  70        }
  71        while (frag && frag->ofs >= size) {
  72                struct jffs2_node_frag *next = frag_next(frag);
  73
  74                frag_erase(frag, list);
  75                jffs2_obsolete_node_frag(c, frag);
  76                frag = next;
  77        }
  78
  79        if (size == 0)
  80                return 0;
  81
  82        frag = frag_last(list);
  83
  84        /* Sanity check for truncation to longer than we started with... */
  85        if (!frag)
  86                return 0;
  87        if (frag->ofs + frag->size < size)
  88                return frag->ofs + frag->size;
  89
  90        /* If the last fragment starts at the RAM page boundary, it is
  91         * REF_PRISTINE irrespective of its size. */
  92        if (frag->node && (frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
  93                dbg_fragtree2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
  94                        frag->ofs, frag->ofs + frag->size);
  95                frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
  96        }
  97        return size;
  98}
  99
 100static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
 101                                     struct jffs2_node_frag *this)
 102{
 103        if (this->node) {
 104                this->node->frags--;
 105                if (!this->node->frags) {
 106                        /* The node has no valid frags left. It's totally obsoleted */
 107                        dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
 108                                ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size);
 109                        jffs2_mark_node_obsolete(c, this->node->raw);
 110                        jffs2_free_full_dnode(this->node);
 111                } else {
 112                        dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
 113                                ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags);
 114                        mark_ref_normal(this->node->raw);
 115                }
 116
 117        }
 118        jffs2_free_node_frag(this);
 119}
 120
 121static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
 122{
 123        struct rb_node *parent = &base->rb;
 124        struct rb_node **link = &parent;
 125
 126        dbg_fragtree2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);
 127
 128        while (*link) {
 129                parent = *link;
 130                base = rb_entry(parent, struct jffs2_node_frag, rb);
 131
 132                if (newfrag->ofs > base->ofs)
 133                        link = &base->rb.rb_right;
 134                else if (newfrag->ofs < base->ofs)
 135                        link = &base->rb.rb_left;
 136                else {
 137                        JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
 138                        BUG();
 139                }
 140        }
 141
 142        rb_link_node(&newfrag->rb, &base->rb, link);
 143}
 144
 145/*
 146 * Allocate and initializes a new fragment.
 147 */
 148static struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
 149{
 150        struct jffs2_node_frag *newfrag;
 151
 152        newfrag = jffs2_alloc_node_frag();
 153        if (likely(newfrag)) {
 154                newfrag->ofs = ofs;
 155                newfrag->size = size;
 156                newfrag->node = fn;
 157        } else {
 158                JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
 159        }
 160
 161        return newfrag;
 162}
 163
 164/*
 165 * Called when there is no overlapping fragment exist. Inserts a hole before the new
 166 * fragment and inserts the new fragment to the fragtree.
 167 */
 168static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
 169                               struct jffs2_node_frag *newfrag,
 170                               struct jffs2_node_frag *this, uint32_t lastend)
 171{
 172        if (lastend < newfrag->node->ofs) {
 173                /* put a hole in before the new fragment */
 174                struct jffs2_node_frag *holefrag;
 175
 176                holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
 177                if (unlikely(!holefrag)) {
 178                        jffs2_free_node_frag(newfrag);
 179                        return -ENOMEM;
 180                }
 181
 182                if (this) {
 183                        /* By definition, the 'this' node has no right-hand child,
 184                           because there are no frags with offset greater than it.
 185                           So that's where we want to put the hole */
 186                        dbg_fragtree2("add hole frag %#04x-%#04x on the right of the new frag.\n",
 187                                holefrag->ofs, holefrag->ofs + holefrag->size);
 188                        rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
 189                } else {
 190                        dbg_fragtree2("Add hole frag %#04x-%#04x to the root of the tree.\n",
 191                                holefrag->ofs, holefrag->ofs + holefrag->size);
 192                        rb_link_node(&holefrag->rb, NULL, &root->rb_node);
 193                }
 194                rb_insert_color(&holefrag->rb, root);
 195                this = holefrag;
 196        }
 197
 198        if (this) {
 199                /* By definition, the 'this' node has no right-hand child,
 200                   because there are no frags with offset greater than it.
 201                   So that's where we want to put new fragment */
 202                dbg_fragtree2("add the new node at the right\n");
 203                rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
 204        } else {
 205                dbg_fragtree2("insert the new node at the root of the tree\n");
 206                rb_link_node(&newfrag->rb, NULL, &root->rb_node);
 207        }
 208        rb_insert_color(&newfrag->rb, root);
 209
 210        return 0;
 211}
 212
 213/* Doesn't set inode->i_size */
 214static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *root, struct jffs2_node_frag *newfrag)
 215{
 216        struct jffs2_node_frag *this;
 217        uint32_t lastend;
 218
 219        /* Skip all the nodes which are completed before this one starts */
 220        this = jffs2_lookup_node_frag(root, newfrag->node->ofs);
 221
 222        if (this) {
 223                dbg_fragtree2("lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
 224                          this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this);
 225                lastend = this->ofs + this->size;
 226        } else {
 227                dbg_fragtree2("lookup gave no frag\n");
 228                lastend = 0;
 229        }
 230
 231        /* See if we ran off the end of the fragtree */
 232        if (lastend <= newfrag->ofs) {
 233                /* We did */
 234
 235                /* Check if 'this' node was on the same page as the new node.
 236                   If so, both 'this' and the new node get marked REF_NORMAL so
 237                   the GC can take a look.
 238                */
 239                if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
 240                        if (this->node)
 241                                mark_ref_normal(this->node->raw);
 242                        mark_ref_normal(newfrag->node->raw);
 243                }
 244
 245                return no_overlapping_node(c, root, newfrag, this, lastend);
 246        }
 247
 248        if (this->node)
 249                dbg_fragtree2("dealing with frag %u-%u, phys %#08x(%d).\n",
 250                this->ofs, this->ofs + this->size,
 251                ref_offset(this->node->raw), ref_flags(this->node->raw));
 252        else
 253                dbg_fragtree2("dealing with hole frag %u-%u.\n",
 254                this->ofs, this->ofs + this->size);
 255
 256        /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
 257         * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
 258         */
 259        if (newfrag->ofs > this->ofs) {
 260                /* This node isn't completely obsoleted. The start of it remains valid */
 261
 262                /* Mark the new node and the partially covered node REF_NORMAL -- let
 263                   the GC take a look at them */
 264                mark_ref_normal(newfrag->node->raw);
 265                if (this->node)
 266                        mark_ref_normal(this->node->raw);
 267
 268                if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
 269                        /* The new node splits 'this' frag into two */
 270                        struct jffs2_node_frag *newfrag2;
 271
 272                        if (this->node)
 273                                dbg_fragtree2("split old frag 0x%04x-0x%04x, phys 0x%08x\n",
 274                                        this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
 275                        else
 276                                dbg_fragtree2("split old hole frag 0x%04x-0x%04x\n",
 277                                        this->ofs, this->ofs+this->size);
 278
 279                        /* New second frag pointing to this's node */
 280                        newfrag2 = new_fragment(this->node, newfrag->ofs + newfrag->size,
 281                                                this->ofs + this->size - newfrag->ofs - newfrag->size);
 282                        if (unlikely(!newfrag2))
 283                                return -ENOMEM;
 284                        if (this->node)
 285                                this->node->frags++;
 286
 287                        /* Adjust size of original 'this' */
 288                        this->size = newfrag->ofs - this->ofs;
 289
 290                        /* Now, we know there's no node with offset
 291                           greater than this->ofs but smaller than
 292                           newfrag2->ofs or newfrag->ofs, for obvious
 293                           reasons. So we can do a tree insert from
 294                           'this' to insert newfrag, and a tree insert
 295                           from newfrag to insert newfrag2. */
 296                        jffs2_fragtree_insert(newfrag, this);
 297                        rb_insert_color(&newfrag->rb, root);
 298
 299                        jffs2_fragtree_insert(newfrag2, newfrag);
 300                        rb_insert_color(&newfrag2->rb, root);
 301
 302                        return 0;
 303                }
 304                /* New node just reduces 'this' frag in size, doesn't split it */
 305                this->size = newfrag->ofs - this->ofs;
 306
 307                /* Again, we know it lives down here in the tree */
 308                jffs2_fragtree_insert(newfrag, this);
 309                rb_insert_color(&newfrag->rb, root);
 310        } else {
 311                /* New frag starts at the same point as 'this' used to. Replace
 312                   it in the tree without doing a delete and insertion */
 313                dbg_fragtree2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
 314                          newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size);
 315
 316                rb_replace_node(&this->rb, &newfrag->rb, root);
 317
 318                if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
 319                        dbg_fragtree2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size);
 320                        jffs2_obsolete_node_frag(c, this);
 321                } else {
 322                        this->ofs += newfrag->size;
 323                        this->size -= newfrag->size;
 324
 325                        jffs2_fragtree_insert(this, newfrag);
 326                        rb_insert_color(&this->rb, root);
 327                        return 0;
 328                }
 329        }
 330        /* OK, now we have newfrag added in the correct place in the tree, but
 331           frag_next(newfrag) may be a fragment which is overlapped by it
 332        */
 333        while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
 334                /* 'this' frag is obsoleted completely. */
 335                dbg_fragtree2("obsoleting node frag %p (%x-%x) and removing from tree\n",
 336                        this, this->ofs, this->ofs+this->size);
 337                rb_erase(&this->rb, root);
 338                jffs2_obsolete_node_frag(c, this);
 339        }
 340        /* Now we're pointing at the first frag which isn't totally obsoleted by
 341           the new frag */
 342
 343        if (!this || newfrag->ofs + newfrag->size == this->ofs)
 344                return 0;
 345
 346        /* Still some overlap but we don't need to move it in the tree */
 347        this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
 348        this->ofs = newfrag->ofs + newfrag->size;
 349
 350        /* And mark them REF_NORMAL so the GC takes a look at them */
 351        if (this->node)
 352                mark_ref_normal(this->node->raw);
 353        mark_ref_normal(newfrag->node->raw);
 354
 355        return 0;
 356}
 357
 358/*
 359 * Given an inode, probably with existing tree of fragments, add the new node
 360 * to the fragment tree.
 361 */
 362int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
 363{
 364        int ret;
 365        struct jffs2_node_frag *newfrag;
 366
 367        if (unlikely(!fn->size))
 368                return 0;
 369
 370        newfrag = new_fragment(fn, fn->ofs, fn->size);
 371        if (unlikely(!newfrag))
 372                return -ENOMEM;
 373        newfrag->node->frags = 1;
 374
 375        dbg_fragtree("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
 376                  fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
 377
 378        ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
 379        if (unlikely(ret))
 380                return ret;
 381
 382        /* If we now share a page with other nodes, mark either previous
 383           or next node REF_NORMAL, as appropriate.  */
 384        if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
 385                struct jffs2_node_frag *prev = frag_prev(newfrag);
 386
 387                mark_ref_normal(fn->raw);
 388                /* If we don't start at zero there's _always_ a previous */
 389                if (prev->node)
 390                        mark_ref_normal(prev->node->raw);
 391        }
 392
 393        if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
 394                struct jffs2_node_frag *next = frag_next(newfrag);
 395
 396                if (next) {
 397                        mark_ref_normal(fn->raw);
 398                        if (next->node)
 399                                mark_ref_normal(next->node->raw);
 400                }
 401        }
 402        jffs2_dbg_fragtree_paranoia_check_nolock(f);
 403
 404        return 0;
 405}
 406
 407void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
 408{
 409        spin_lock(&c->inocache_lock);
 410        ic->state = state;
 411        wake_up(&c->inocache_wq);
 412        spin_unlock(&c->inocache_lock);
 413}
 414
 415/* During mount, this needs no locking. During normal operation, its
 416   callers want to do other stuff while still holding the inocache_lock.
 417   Rather than introducing special case get_ino_cache functions or
 418   callbacks, we just let the caller do the locking itself. */
 419
 420struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
 421{
 422        struct jffs2_inode_cache *ret;
 423
 424        ret = c->inocache_list[ino % INOCACHE_HASHSIZE];
 425        while (ret && ret->ino < ino) {
 426                ret = ret->next;
 427        }
 428
 429        if (ret && ret->ino != ino)
 430                ret = NULL;
 431
 432        return ret;
 433}
 434
 435void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
 436{
 437        struct jffs2_inode_cache **prev;
 438
 439        spin_lock(&c->inocache_lock);
 440        if (!new->ino)
 441                new->ino = ++c->highest_ino;
 442
 443        dbg_inocache("add %p (ino #%u)\n", new, new->ino);
 444
 445        prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE];
 446
 447        while ((*prev) && (*prev)->ino < new->ino) {
 448                prev = &(*prev)->next;
 449        }
 450        new->next = *prev;
 451        *prev = new;
 452
 453        spin_unlock(&c->inocache_lock);
 454}
 455
 456void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
 457{
 458        struct jffs2_inode_cache **prev;
 459
 460#ifdef CONFIG_JFFS2_FS_XATTR
 461        BUG_ON(old->xref);
 462#endif
 463        dbg_inocache("del %p (ino #%u)\n", old, old->ino);
 464        spin_lock(&c->inocache_lock);
 465
 466        prev = &c->inocache_list[old->ino % INOCACHE_HASHSIZE];
 467
 468        while ((*prev) && (*prev)->ino < old->ino) {
 469                prev = &(*prev)->next;
 470        }
 471        if ((*prev) == old) {
 472                *prev = old->next;
 473        }
 474
 475        /* Free it now unless it's in READING or CLEARING state, which
 476           are the transitions upon read_inode() and clear_inode(). The
 477           rest of the time we know nobody else is looking at it, and
 478           if it's held by read_inode() or clear_inode() they'll free it
 479           for themselves. */
 480        if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
 481                jffs2_free_inode_cache(old);
 482
 483        spin_unlock(&c->inocache_lock);
 484}
 485
 486void jffs2_free_ino_caches(struct jffs2_sb_info *c)
 487{
 488        int i;
 489        struct jffs2_inode_cache *this, *next;
 490
 491        for (i=0; i<INOCACHE_HASHSIZE; i++) {
 492                this = c->inocache_list[i];
 493                while (this) {
 494                        next = this->next;
 495                        jffs2_xattr_free_inode(c, this);
 496                        jffs2_free_inode_cache(this);
 497                        this = next;
 498                }
 499                c->inocache_list[i] = NULL;
 500        }
 501}
 502
 503void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
 504{
 505        int i;
 506        struct jffs2_raw_node_ref *this, *next;
 507
 508        for (i=0; i<c->nr_blocks; i++) {
 509                this = c->blocks[i].first_node;
 510                while (this) {
 511                        if (this[REFS_PER_BLOCK].flash_offset == REF_LINK_NODE)
 512                                next = this[REFS_PER_BLOCK].next_in_ino;
 513                        else
 514                                next = NULL;
 515
 516                        jffs2_free_refblock(this);
 517                        this = next;
 518                }
 519                c->blocks[i].first_node = c->blocks[i].last_node = NULL;
 520        }
 521}
 522
 523struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
 524{
 525        /* The common case in lookup is that there will be a node
 526           which precisely matches. So we go looking for that first */
 527        struct rb_node *next;
 528        struct jffs2_node_frag *prev = NULL;
 529        struct jffs2_node_frag *frag = NULL;
 530
 531        dbg_fragtree2("root %p, offset %d\n", fragtree, offset);
 532
 533        next = fragtree->rb_node;
 534
 535        while(next) {
 536                frag = rb_entry(next, struct jffs2_node_frag, rb);
 537
 538                if (frag->ofs + frag->size <= offset) {
 539                        /* Remember the closest smaller match on the way down */
 540                        if (!prev || frag->ofs > prev->ofs)
 541                                prev = frag;
 542                        next = frag->rb.rb_right;
 543                } else if (frag->ofs > offset) {
 544                        next = frag->rb.rb_left;
 545                } else {
 546                        return frag;
 547                }
 548        }
 549
 550        /* Exact match not found. Go back up looking at each parent,
 551           and return the closest smaller one */
 552
 553        if (prev)
 554                dbg_fragtree2("no match. Returning frag %#04x-%#04x, closest previous\n",
 555                          prev->ofs, prev->ofs+prev->size);
 556        else
 557                dbg_fragtree2("returning NULL, empty fragtree\n");
 558
 559        return prev;
 560}
 561
 562/* Pass 'c' argument to indicate that nodes should be marked obsolete as
 563   they're killed. */
 564void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
 565{
 566        struct jffs2_node_frag *frag;
 567        struct jffs2_node_frag *parent;
 568
 569        if (!root->rb_node)
 570                return;
 571
 572        dbg_fragtree("killing\n");
 573
 574        frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
 575        while(frag) {
 576                if (frag->rb.rb_left) {
 577                        frag = frag_left(frag);
 578                        continue;
 579                }
 580                if (frag->rb.rb_right) {
 581                        frag = frag_right(frag);
 582                        continue;
 583                }
 584
 585                if (frag->node && !(--frag->node->frags)) {
 586                        /* Not a hole, and it's the final remaining frag
 587                           of this node. Free the node */
 588                        if (c)
 589                                jffs2_mark_node_obsolete(c, frag->node->raw);
 590
 591                        jffs2_free_full_dnode(frag->node);
 592                }
 593                parent = frag_parent(frag);
 594                if (parent) {
 595                        if (frag_left(parent) == frag)
 596                                parent->rb.rb_left = NULL;
 597                        else
 598                                parent->rb.rb_right = NULL;
 599                }
 600
 601                jffs2_free_node_frag(frag);
 602                frag = parent;
 603
 604                cond_resched();
 605        }
 606}
 607
 608struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
 609                                               struct jffs2_eraseblock *jeb,
 610                                               uint32_t ofs, uint32_t len,
 611                                               struct jffs2_inode_cache *ic)
 612{
 613        struct jffs2_raw_node_ref *ref;
 614
 615        BUG_ON(!jeb->allocated_refs);
 616        jeb->allocated_refs--;
 617
 618        ref = jeb->last_node;
 619
 620        dbg_noderef("Last node at %p is (%08x,%p)\n", ref, ref->flash_offset,
 621                    ref->next_in_ino);
 622
 623        while (ref->flash_offset != REF_EMPTY_NODE) {
 624                if (ref->flash_offset == REF_LINK_NODE)
 625                        ref = ref->next_in_ino;
 626                else
 627                        ref++;
 628        }
 629
 630        dbg_noderef("New ref is %p (%08x becomes %08x,%p) len 0x%x\n", ref, 
 631                    ref->flash_offset, ofs, ref->next_in_ino, len);
 632
 633        ref->flash_offset = ofs;
 634
 635        if (!jeb->first_node) {
 636                jeb->first_node = ref;
 637                BUG_ON(ref_offset(ref) != jeb->offset);
 638        } else if (unlikely(ref_offset(ref) != jeb->offset + c->sector_size - jeb->free_size)) {
 639                uint32_t last_len = ref_totlen(c, jeb, jeb->last_node);
 640
 641                JFFS2_ERROR("Adding new ref %p at (0x%08x-0x%08x) not immediately after previous (0x%08x-0x%08x)\n",
 642                            ref, ref_offset(ref), ref_offset(ref)+len,
 643                            ref_offset(jeb->last_node), 
 644                            ref_offset(jeb->last_node)+last_len);
 645                BUG();
 646        }
 647        jeb->last_node = ref;
 648
 649        if (ic) {
 650                ref->next_in_ino = ic->nodes;
 651                ic->nodes = ref;
 652        } else {
 653                ref->next_in_ino = NULL;
 654        }
 655
 656        switch(ref_flags(ref)) {
 657        case REF_UNCHECKED:
 658                c->unchecked_size += len;
 659                jeb->unchecked_size += len;
 660                break;
 661
 662        case REF_NORMAL:
 663        case REF_PRISTINE:
 664                c->used_size += len;
 665                jeb->used_size += len;
 666                break;
 667
 668        case REF_OBSOLETE:
 669                c->dirty_size += len;
 670                jeb->dirty_size += len;
 671                break;
 672        }
 673        c->free_size -= len;
 674        jeb->free_size -= len;
 675
 676#ifdef TEST_TOTLEN
 677        /* Set (and test) __totlen field... for now */
 678        ref->__totlen = len;
 679        ref_totlen(c, jeb, ref);
 680#endif
 681        return ref;
 682}
 683
 684/* No locking, no reservation of 'ref'. Do not use on a live file system */
 685int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 686                           uint32_t size)
 687{
 688        if (!size)
 689                return 0;
 690        if (unlikely(size > jeb->free_size)) {
 691                printk(KERN_CRIT "Dirty space 0x%x larger then free_size 0x%x (wasted 0x%x)\n",
 692                       size, jeb->free_size, jeb->wasted_size);
 693                BUG();
 694        }
 695        /* REF_EMPTY_NODE is !obsolete, so that works OK */
 696        if (jeb->last_node && ref_obsolete(jeb->last_node)) {
 697#ifdef TEST_TOTLEN
 698                jeb->last_node->__totlen += size;
 699#endif
 700                c->dirty_size += size;
 701                c->free_size -= size;
 702                jeb->dirty_size += size;
 703                jeb->free_size -= size;
 704        } else {
 705                uint32_t ofs = jeb->offset + c->sector_size - jeb->free_size;
 706                ofs |= REF_OBSOLETE;
 707
 708                jffs2_link_node_ref(c, jeb, ofs, size, NULL);
 709        }
 710
 711        return 0;
 712}
 713
 714/* Calculate totlen from surrounding nodes or eraseblock */
 715static inline uint32_t __ref_totlen(struct jffs2_sb_info *c,
 716                                    struct jffs2_eraseblock *jeb,
 717                                    struct jffs2_raw_node_ref *ref)
 718{
 719        uint32_t ref_end;
 720        struct jffs2_raw_node_ref *next_ref = ref_next(ref);
 721
 722        if (next_ref)
 723                ref_end = ref_offset(next_ref);
 724        else {
 725                if (!jeb)
 726                        jeb = &c->blocks[ref->flash_offset / c->sector_size];
 727
 728                /* Last node in block. Use free_space */
 729                if (unlikely(ref != jeb->last_node)) {
 730                        printk(KERN_CRIT "ref %p @0x%08x is not jeb->last_node (%p @0x%08x)\n",
 731                               ref, ref_offset(ref), jeb->last_node, jeb->last_node?ref_offset(jeb->last_node):0);
 732                        BUG();
 733                }
 734                ref_end = jeb->offset + c->sector_size - jeb->free_size;
 735        }
 736        return ref_end - ref_offset(ref);
 737}
 738
 739uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 740                            struct jffs2_raw_node_ref *ref)
 741{
 742        uint32_t ret;
 743
 744        ret = __ref_totlen(c, jeb, ref);
 745
 746#ifdef TEST_TOTLEN
 747        if (unlikely(ret != ref->__totlen)) {
 748                if (!jeb)
 749                        jeb = &c->blocks[ref->flash_offset / c->sector_size];
 750
 751                printk(KERN_CRIT "Totlen for ref at %p (0x%08x-0x%08x) miscalculated as 0x%x instead of %x\n",
 752                       ref, ref_offset(ref), ref_offset(ref)+ref->__totlen,
 753                       ret, ref->__totlen);
 754                if (ref_next(ref)) {
 755                        printk(KERN_CRIT "next %p (0x%08x-0x%08x)\n", ref_next(ref), ref_offset(ref_next(ref)),
 756                               ref_offset(ref_next(ref))+ref->__totlen);
 757                } else 
 758                        printk(KERN_CRIT "No next ref. jeb->last_node is %p\n", jeb->last_node);
 759
 760                printk(KERN_CRIT "jeb->wasted_size %x, dirty_size %x, used_size %x, free_size %x\n", jeb->wasted_size, jeb->dirty_size, jeb->used_size, jeb->free_size);
 761
 762#if defined(JFFS2_DBG_DUMPS) || defined(JFFS2_DBG_PARANOIA_CHECKS)
 763                __jffs2_dbg_dump_node_refs_nolock(c, jeb);
 764#endif
 765
 766                WARN_ON(1);
 767
 768                ret = ref->__totlen;
 769        }
 770#endif /* TEST_TOTLEN */
 771        return ret;
 772}
 773