fs/jffs2/nodelist.c

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