git.oblomov.eu Git - linux-2.6/blob - fs/jffs2/nodelist.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2001-2003 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  * $Id: nodelist.c,v 1.115 2005/11/07 11:14:40 gleixner Exp $
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/sched.h>
  16 #include <linux/fs.h>
  17 #include <linux/mtd/mtd.h>
  18 #include <linux/rbtree.h>
  19 #include <linux/crc32.h>
  20 #include <linux/slab.h>
  21 #include <linux/pagemap.h>
  22 #include "nodelist.h"
  23
  24 void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list)
  25 {
  26         struct jffs2_full_dirent **prev = list;
  27
  28         dbg_dentlist("add dirent \"%s\", ino #%u\n", new->name, new->ino);
  29
  30         while ((*prev) && (*prev)->nhash <= new->nhash) {
  31                 if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) {
  32                         /* Duplicate. Free one */
  33                         if (new->version < (*prev)->version) {
  34                                 dbg_dentlist("Eep! Marking new dirent node is obsolete, old is \"%s\", ino #%u\n",
  35                                         (*prev)->name, (*prev)->ino);
  36                                 jffs2_mark_node_obsolete(c, new->raw);
  37                                 jffs2_free_full_dirent(new);
  38                         } else {
  39                                 dbg_dentlist("marking old dirent \"%s\", ino #%u bsolete\n",
  40                                         (*prev)->name, (*prev)->ino);
  41                                 new->next = (*prev)->next;
  42                                 jffs2_mark_node_obsolete(c, ((*prev)->raw));
  43                                 jffs2_free_full_dirent(*prev);
  44                                 *prev = new;
  45                         }
  46                         return;
  47                 }
  48                 prev = &((*prev)->next);
  49         }
  50         new->next = *prev;
  51         *prev = new;
  52 }
  53
  54 void jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
  55 {
  56         struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
  57
  58         dbg_fragtree("truncating fragtree to 0x%08x bytes\n", size);
  59
  60         /* We know frag->ofs <= size. That's what lookup does for us */
  61         if (frag && frag->ofs != size) {
  62                 if (frag->ofs+frag->size > size) {
  63                         frag->size = size - frag->ofs;
  64                 }
  65                 frag = frag_next(frag);
  66         }
  67         while (frag && frag->ofs >= size) {
  68                 struct jffs2_node_frag *next = frag_next(frag);
  69
  70                 frag_erase(frag, list);
  71                 jffs2_obsolete_node_frag(c, frag);
  72                 frag = next;
  73         }
  74
  75         if (size == 0)
  76                 return;
  77
  78         /*
  79          * If the last fragment starts at the RAM page boundary, it is
  80          * REF_PRISTINE irrespective of its size.
  81          */
  82         frag = frag_last(list);
  83         if (frag->node && (frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
  84                 dbg_fragtree2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
  85                         frag->ofs, frag->ofs + frag->size);
  86                 frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
  87         }
  88 }
  89
  90 void jffs2_obsolete_node_frag(struct jffs2_sb_info *c, struct jffs2_node_frag *this)
  91 {
  92         if (this->node) {
  93                 this->node->frags--;
  94                 if (!this->node->frags) {
  95                         /* The node has no valid frags left. It's totally obsoleted */
  96                         dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
  97                                 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size);
  98                         jffs2_mark_node_obsolete(c, this->node->raw);
  99                         jffs2_free_full_dnode(this->node);
 100                 } else {
 101                         dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
 102                                 ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags);
 103                         mark_ref_normal(this->node->raw);
 104                 }
 105
 106         }
 107         jffs2_free_node_frag(this);
 108 }
 109
 110 static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
 111 {
 112         struct rb_node *parent = &base->rb;
 113         struct rb_node **link = &parent;
 114
 115         dbg_fragtree2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);
 116
 117         while (*link) {
 118                 parent = *link;
 119                 base = rb_entry(parent, struct jffs2_node_frag, rb);
 120
 121                 if (newfrag->ofs > base->ofs)
 122                         link = &base->rb.rb_right;
 123                 else if (newfrag->ofs < base->ofs)
 124                         link = &base->rb.rb_left;
 125                 else {
 126                         JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
 127                         BUG();
 128                 }
 129         }
 130
 131         rb_link_node(&newfrag->rb, &base->rb, link);
 132 }
 133
 134 /*
 135  * Allocate and initializes a new fragment.
 136  */
 137 static struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
 138 {
 139         struct jffs2_node_frag *newfrag;
 140
 141         newfrag = jffs2_alloc_node_frag();
 142         if (likely(newfrag)) {
 143                 newfrag->ofs = ofs;
 144                 newfrag->size = size;
 145                 newfrag->node = fn;
 146         } else {
 147                 JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
 148         }
 149
 150         return newfrag;
 151 }
 152
 153 /*
 154  * Called when there is no overlapping fragment exist. Inserts a hole before the new
 155  * fragment and inserts the new fragment to the fragtree.
 156  */
 157 static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
 158                                struct jffs2_node_frag *newfrag,
 159                                struct jffs2_node_frag *this, uint32_t lastend)
 160 {
 161         if (lastend < newfrag->node->ofs) {
 162                 /* put a hole in before the new fragment */
 163                 struct jffs2_node_frag *holefrag;
 164
 165                 holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
 166                 if (unlikely(!holefrag)) {
 167                         jffs2_free_node_frag(newfrag);
 168                         return -ENOMEM;
 169                 }
 170
 171                 if (this) {
 172                         /* By definition, the 'this' node has no right-hand child,
 173                            because there are no frags with offset greater than it.
 174                            So that's where we want to put the hole */
 175                         dbg_fragtree2("add hole frag %#04x-%#04x on the right of the new frag.\n",
 176                                 holefrag->ofs, holefrag->ofs + holefrag->size);
 177                         rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
 178                 } else {
 179                         dbg_fragtree2("Add hole frag %#04x-%#04x to the root of the tree.\n",
 180                                 holefrag->ofs, holefrag->ofs + holefrag->size);
 181                         rb_link_node(&holefrag->rb, NULL, &root->rb_node);
 182                 }
 183                 rb_insert_color(&holefrag->rb, root);
 184                 this = holefrag;
 185         }
 186
 187         if (this) {
 188                 /* By definition, the 'this' node has no right-hand child,
 189                    because there are no frags with offset greater than it.
 190                    So that's where we want to put new fragment */
 191                 dbg_fragtree2("add the new node at the right\n");
 192                 rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
 193         } else {
 194                 dbg_fragtree2("insert the new node at the root of the tree\n");
 195                 rb_link_node(&newfrag->rb, NULL, &root->rb_node);
 196         }
 197         rb_insert_color(&newfrag->rb, root);
 198
 199         return 0;
 200 }
 201
 202 /* Doesn't set inode->i_size */
 203 static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *root, struct jffs2_node_frag *newfrag)
 204 {
 205         struct jffs2_node_frag *this;
 206         uint32_t lastend;
 207
 208         /* Skip all the nodes which are completed before this one starts */
 209         this = jffs2_lookup_node_frag(root, newfrag->node->ofs);
 210
 211         if (this) {
 212                 dbg_fragtree2("lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
 213                           this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this);
 214                 lastend = this->ofs + this->size;
 215         } else {
 216                 dbg_fragtree2("lookup gave no frag\n");
 217                 lastend = 0;
 218         }
 219
 220         /* See if we ran off the end of the fragtree */
 221         if (lastend <= newfrag->ofs) {
 222                 /* We did */
 223
 224                 /* Check if 'this' node was on the same page as the new node.
 225                    If so, both 'this' and the new node get marked REF_NORMAL so
 226                    the GC can take a look.
 227                 */
 228                 if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
 229                         if (this->node)
 230                                 mark_ref_normal(this->node->raw);
 231                         mark_ref_normal(newfrag->node->raw);
 232                 }
 233
 234                 return no_overlapping_node(c, root, newfrag, this, lastend);
 235         }
 236
 237         if (this->node)
 238                 dbg_fragtree2("dealing with frag %u-%u, phys %#08x(%d).\n",
 239                 this->ofs, this->ofs + this->size,
 240                 ref_offset(this->node->raw), ref_flags(this->node->raw));
 241         else
 242                 dbg_fragtree2("dealing with hole frag %u-%u.\n",
 243                 this->ofs, this->ofs + this->size);
 244
 245         /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
 246          * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
 247          */
 248         if (newfrag->ofs > this->ofs) {
 249                 /* This node isn't completely obsoleted. The start of it remains valid */
 250
 251                 /* Mark the new node and the partially covered node REF_NORMAL -- let
 252                    the GC take a look at them */
 253                 mark_ref_normal(newfrag->node->raw);
 254                 if (this->node)
 255                         mark_ref_normal(this->node->raw);
 256
 257                 if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
 258                         /* The new node splits 'this' frag into two */
 259                         struct jffs2_node_frag *newfrag2;
 260
 261                         if (this->node)
 262                                 dbg_fragtree2("split old frag 0x%04x-0x%04x, phys 0x%08x\n",
 263                                         this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
 264                         else
 265                                 dbg_fragtree2("split old hole frag 0x%04x-0x%04x\n",
 266                                         this->ofs, this->ofs+this->size);
 267
 268                         /* New second frag pointing to this's node */
 269                         newfrag2 = new_fragment(this->node, newfrag->ofs + newfrag->size,
 270                                                 this->ofs + this->size - newfrag->ofs - newfrag->size);
 271                         if (unlikely(!newfrag2))
 272                                 return -ENOMEM;
 273                         if (this->node)
 274                                 this->node->frags++;
 275
 276                         /* Adjust size of original 'this' */
 277                         this->size = newfrag->ofs - this->ofs;
 278
 279                         /* Now, we know there's no node with offset
 280                            greater than this->ofs but smaller than
 281                            newfrag2->ofs or newfrag->ofs, for obvious
 282                            reasons. So we can do a tree insert from
 283                            'this' to insert newfrag, and a tree insert
 284                            from newfrag to insert newfrag2. */
 285                         jffs2_fragtree_insert(newfrag, this);
 286                         rb_insert_color(&newfrag->rb, root);
 287
 288                         jffs2_fragtree_insert(newfrag2, newfrag);
 289                         rb_insert_color(&newfrag2->rb, root);
 290
 291                         return 0;
 292                 }
 293                 /* New node just reduces 'this' frag in size, doesn't split it */
 294                 this->size = newfrag->ofs - this->ofs;
 295
 296                 /* Again, we know it lives down here in the tree */
 297                 jffs2_fragtree_insert(newfrag, this);
 298                 rb_insert_color(&newfrag->rb, root);
 299         } else {
 300                 /* New frag starts at the same point as 'this' used to. Replace
 301                    it in the tree without doing a delete and insertion */
 302                 dbg_fragtree2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
 303                           newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size);
 304
 305                 rb_replace_node(&this->rb, &newfrag->rb, root);
 306
 307                 if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
 308                         dbg_fragtree2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size);
 309                         jffs2_obsolete_node_frag(c, this);
 310                 } else {
 311                         this->ofs += newfrag->size;
 312                         this->size -= newfrag->size;
 313
 314                         jffs2_fragtree_insert(this, newfrag);
 315                         rb_insert_color(&this->rb, root);
 316                         return 0;
 317                 }
 318         }
 319         /* OK, now we have newfrag added in the correct place in the tree, but
 320            frag_next(newfrag) may be a fragment which is overlapped by it
 321         */
 322         while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
 323                 /* 'this' frag is obsoleted completely. */
 324                 dbg_fragtree2("obsoleting node frag %p (%x-%x) and removing from tree\n",
 325                         this, this->ofs, this->ofs+this->size);
 326                 rb_erase(&this->rb, root);
 327                 jffs2_obsolete_node_frag(c, this);
 328         }
 329         /* Now we're pointing at the first frag which isn't totally obsoleted by
 330            the new frag */
 331
 332         if (!this || newfrag->ofs + newfrag->size == this->ofs)
 333                 return 0;
 334
 335         /* Still some overlap but we don't need to move it in the tree */
 336         this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
 337         this->ofs = newfrag->ofs + newfrag->size;
 338
 339         /* And mark them REF_NORMAL so the GC takes a look at them */
 340         if (this->node)
 341                 mark_ref_normal(this->node->raw);
 342         mark_ref_normal(newfrag->node->raw);
 343
 344         return 0;
 345 }
 346
 347 /*
 348  * Given an inode, probably with existing tree of fragments, add the new node
 349  * to the fragment tree.
 350  */
 351 int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
 352 {
 353         int ret;
 354         struct jffs2_node_frag *newfrag;
 355
 356         if (unlikely(!fn->size))
 357                 return 0;
 358
 359         newfrag = new_fragment(fn, fn->ofs, fn->size);
 360         if (unlikely(!newfrag))
 361                 return -ENOMEM;
 362         newfrag->node->frags = 1;
 363
 364         dbg_fragtree("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
 365                   fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
 366
 367         ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
 368         if (unlikely(ret))
 369                 return ret;
 370
 371         /* If we now share a page with other nodes, mark either previous
 372            or next node REF_NORMAL, as appropriate.  */
 373         if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
 374                 struct jffs2_node_frag *prev = frag_prev(newfrag);
 375
 376                 mark_ref_normal(fn->raw);
 377                 /* If we don't start at zero there's _always_ a previous */
 378                 if (prev->node)
 379                         mark_ref_normal(prev->node->raw);
 380         }
 381
 382         if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
 383                 struct jffs2_node_frag *next = frag_next(newfrag);
 384
 385                 if (next) {
 386                         mark_ref_normal(fn->raw);
 387                         if (next->node)
 388                                 mark_ref_normal(next->node->raw);
 389                 }
 390         }
 391         jffs2_dbg_fragtree_paranoia_check_nolock(f);
 392
 393         return 0;
 394 }
 395
 396 /*
 397  * Check the data CRC of the node.
 398  *
 399  * Returns: 0 if the data CRC is correct;
 400  *          1 - if incorrect;
 401  *          error code if an error occured.
 402  */
 403 static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
 404 {
 405         struct jffs2_raw_node_ref *ref = tn->fn->raw;
 406         int err = 0, pointed = 0;
 407         struct jffs2_eraseblock *jeb;
 408         unsigned char *buffer;
 409         uint32_t crc, ofs, len;
 410         size_t retlen;
 411
 412         BUG_ON(tn->csize == 0);
 413
 414         if (!jffs2_is_writebuffered(c))
 415                 goto adj_acc;
 416
 417         /* Calculate how many bytes were already checked */
 418         ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);
 419         len = ofs % c->wbuf_pagesize;
 420         if (likely(len))
 421                 len = c->wbuf_pagesize - len;
 422
 423         if (len >= tn->csize) {
 424                 dbg_readinode("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",
 425                         ref_offset(ref), tn->csize, ofs);
 426                 goto adj_acc;
 427         }
 428
 429         ofs += len;
 430         len = tn->csize - len;
 431
 432         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",
 433                 ref_offset(ref), tn->csize, tn->partial_crc, tn->data_crc, ofs - len, ofs, len);
 434
 435 #ifndef __ECOS
 436         /* TODO: instead, incapsulate point() stuff to jffs2_flash_read(),
 437          * adding and jffs2_flash_read_end() interface. */
 438         if (c->mtd->point) {
 439                 err = c->mtd->point(c->mtd, ofs, len, &retlen, &buffer);
 440                 if (!err && retlen < tn->csize) {
 441                         JFFS2_WARNING("MTD point returned len too short: %zu "
 442                                         "instead of %u.\n", retlen, tn->csize);
 443                         c->mtd->unpoint(c->mtd, buffer, ofs, len);
 444                 } else if (err)
 445                         JFFS2_WARNING("MTD point failed: error code %d.\n", err);
 446                 else
 447                         pointed = 1; /* succefully pointed to device */
 448         }
 449 #endif
 450
 451         if (!pointed) {
 452                 buffer = kmalloc(len, GFP_KERNEL);
 453                 if (unlikely(!buffer))
 454                         return -ENOMEM;
 455
 456                 /* TODO: this is very frequent pattern, make it a separate
 457                  * routine */
 458                 err = jffs2_flash_read(c, ofs, len, &retlen, buffer);
 459                 if (err) {
 460                         JFFS2_ERROR("can not read %d bytes from 0x%08x, error code: %d.\n", len, ofs, err);
 461                         goto free_out;
 462                 }
 463
 464                 if (retlen != len) {
 465                         JFFS2_ERROR("short read at %#08x: %zd instead of %d.\n",
 466                                         ofs, retlen, len);
 467                         err = -EIO;
 468                         goto free_out;
 469                 }
 470         }
 471
 472         /* Continue calculating CRC */
 473         crc = crc32(tn->partial_crc, buffer, len);
 474         if(!pointed)
 475                 kfree(buffer);
 476 #ifndef __ECOS
 477         else
 478                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
 479 #endif
 480
 481         if (crc != tn->data_crc) {
 482                 JFFS2_NOTICE("wrong data CRC in data node at 0x%08x: read %#08x, calculated %#08x.\n",
 483                         ofs, tn->data_crc, crc);
 484                 return 1;
 485         }
 486
 487 adj_acc:
 488         jeb = &c->blocks[ref->flash_offset / c->sector_size];
 489         len = ref_totlen(c, jeb, ref);
 490
 491         /*
 492          * Mark the node as having been checked and fix the
 493          * accounting accordingly.
 494          */
 495         spin_lock(&c->erase_completion_lock);
 496         jeb->used_size += len;
 497         jeb->unchecked_size -= len;
 498         c->used_size += len;
 499         c->unchecked_size -= len;
 500         spin_unlock(&c->erase_completion_lock);
 501
 502         return 0;
 503
 504 free_out:
 505         if(!pointed)
 506                 kfree(buffer);
 507 #ifndef __ECOS
 508         else
 509                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
 510 #endif
 511         return err;
 512 }
 513
 514 /*
 515  * Helper function for jffs2_add_older_frag_to_fragtree().
 516  *
 517  * Checks the node if we are in the checking stage.
 518  */
 519 static int check_node(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_tmp_dnode_info *tn)
 520 {
 521         int ret;
 522
 523         BUG_ON(ref_obsolete(tn->fn->raw));
 524
 525         /* We only check the data CRC of unchecked nodes */
 526         if (ref_flags(tn->fn->raw) != REF_UNCHECKED)
 527                 return 0;
 528
 529         dbg_fragtree2("check node %#04x-%#04x, phys offs %#08x.\n",
 530                 tn->fn->ofs, tn->fn->ofs + tn->fn->size, ref_offset(tn->fn->raw));
 531
 532         ret = check_node_data(c, tn);
 533         if (unlikely(ret < 0)) {
 534                 JFFS2_ERROR("check_node_data() returned error: %d.\n",
 535                         ret);
 536         } else if (unlikely(ret > 0)) {
 537                 dbg_fragtree2("CRC error, mark it obsolete.\n");
 538                 jffs2_mark_node_obsolete(c, tn->fn->raw);
 539         }
 540
 541         return ret;
 542 }
 543
 544 /*
 545  * Helper function for jffs2_add_older_frag_to_fragtree().
 546  *
 547  * Called when the new fragment that is being inserted
 548  * splits a hole fragment.
 549  */
 550 static int split_hole(struct jffs2_sb_info *c, struct rb_root *root,
 551                       struct jffs2_node_frag *newfrag, struct jffs2_node_frag *hole)
 552 {
 553         dbg_fragtree2("fragment %#04x-%#04x splits the hole %#04x-%#04x\n",
 554                 newfrag->ofs, newfrag->ofs + newfrag->size, hole->ofs, hole->ofs + hole->size);
 555
 556         if (hole->ofs == newfrag->ofs) {
 557                 /*
 558                  * Well, the new fragment actually starts at the same offset as
 559                  * the hole.
 560                  */
 561                 if (hole->ofs + hole->size > newfrag->ofs + newfrag->size) {
 562                         /*
 563                          * We replace the overlapped left part of the hole by
 564                          * the new node.
 565                          */
 566
 567                         dbg_fragtree2("insert fragment %#04x-%#04x and cut the left part of the hole\n",
 568                                 newfrag->ofs, newfrag->ofs + newfrag->size);
 569                         rb_replace_node(&hole->rb, &newfrag->rb, root);
 570
 571                         hole->ofs += newfrag->size;
 572                         hole->size -= newfrag->size;
 573
 574                         /*
 575                          * We know that 'hole' should be the right hand
 576                          * fragment.
 577                          */
 578                         jffs2_fragtree_insert(hole, newfrag);
 579                         rb_insert_color(&hole->rb, root);
 580                 } else {
 581                         /*
 582                          * Ah, the new fragment is of the same size as the hole.
 583                          * Relace the hole by it.
 584                          */
 585                         dbg_fragtree2("insert fragment %#04x-%#04x and overwrite hole\n",
 586                                 newfrag->ofs, newfrag->ofs + newfrag->size);
 587                         rb_replace_node(&hole->rb, &newfrag->rb, root);
 588                         jffs2_free_node_frag(hole);
 589                 }
 590         } else {
 591                 /* The new fragment lefts some hole space at the left */
 592
 593                 struct jffs2_node_frag * newfrag2 = NULL;
 594
 595                 if (hole->ofs + hole->size > newfrag->ofs + newfrag->size) {
 596                         /* The new frag also lefts some space at the right */
 597                         newfrag2 = new_fragment(NULL, newfrag->ofs +
 598                                 newfrag->size, hole->ofs + hole->size
 599                                 - newfrag->ofs - newfrag->size);
 600                         if (unlikely(!newfrag2)) {
 601                                 jffs2_free_node_frag(newfrag);
 602                                 return -ENOMEM;
 603                         }
 604                 }
 605
 606                 hole->size = newfrag->ofs - hole->ofs;
 607                 dbg_fragtree2("left the hole %#04x-%#04x at the left and inserd fragment %#04x-%#04x\n",
 608                         hole->ofs, hole->ofs + hole->size, newfrag->ofs, newfrag->ofs + newfrag->size);
 609
 610                 jffs2_fragtree_insert(newfrag, hole);
 611                 rb_insert_color(&newfrag->rb, root);
 612
 613                 if (newfrag2) {
 614                         dbg_fragtree2("left the hole %#04x-%#04x at the right\n",
 615                                 newfrag2->ofs, newfrag2->ofs + newfrag2->size);
 616                         jffs2_fragtree_insert(newfrag2, newfrag);
 617                         rb_insert_color(&newfrag2->rb, root);
 618                 }
 619         }
 620
 621         return 0;
 622 }
 623
 624 /*
 625  * This function is used when we build inode. It expects the nodes are passed
 626  * in the decreasing version order. The whole point of this is to improve the
 627  * inodes checking on NAND: we check the nodes' data CRC only when they are not
 628  * obsoleted. Previously, add_frag_to_fragtree() function was used and
 629  * nodes were passed to it in the increasing version ordes and CRCs of all
 630  * nodes were checked.
 631  *
 632  * Note: tn->fn->size shouldn't be zero.
 633  *
 634  * Returns 0 if the node was inserted
 635  *         1 if it wasn't inserted (since it is obsolete)
 636  *         < 0 an if error occured
 637  */
 638 int jffs2_add_older_frag_to_fragtree(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 639                                      struct jffs2_tmp_dnode_info *tn)
 640 {
 641         struct jffs2_node_frag *this, *newfrag;
 642         uint32_t lastend;
 643         struct jffs2_full_dnode *fn = tn->fn;
 644         struct rb_root *root = &f->fragtree;
 645         uint32_t fn_size = fn->size, fn_ofs = fn->ofs;
 646         int err, checked = 0;
 647         int ref_flag;
 648
 649         dbg_fragtree("insert fragment %#04x-%#04x, ver %u\n", fn_ofs, fn_ofs + fn_size, tn->version);
 650
 651         /* Skip all the nodes which are completed before this one starts */
 652         this = jffs2_lookup_node_frag(root, fn_ofs);
 653         if (this)
 654                 dbg_fragtree2("'this' found %#04x-%#04x (%s)\n", this->ofs, this->ofs + this->size, this->node ? "data" : "hole");
 655
 656         if (this)
 657                 lastend = this->ofs + this->size;
 658         else
 659                 lastend = 0;
 660
 661         /* Detect the preliminary type of node */
 662         if (fn->size >= PAGE_CACHE_SIZE)
 663                 ref_flag = REF_PRISTINE;
 664         else
 665                 ref_flag = REF_NORMAL;
 666
 667         /* See if we ran off the end of the root */
 668         if (lastend <= fn_ofs) {
 669                 /* We did */
 670
 671                 /*
 672                  * We are going to insert the new node into the
 673                  * fragment tree, so check it.
 674                  */
 675                 err = check_node(c, f, tn);
 676                 if (err != 0)
 677                         return err;
 678
 679                 fn->frags = 1;
 680
 681                 newfrag = new_fragment(fn, fn_ofs, fn_size);
 682                 if (unlikely(!newfrag))
 683                         return -ENOMEM;
 684
 685                 err = no_overlapping_node(c, root, newfrag, this, lastend);
 686                 if (unlikely(err != 0)) {
 687                         jffs2_free_node_frag(newfrag);
 688                         return err;
 689                 }
 690
 691                 goto out_ok;
 692         }
 693
 694         fn->frags = 0;
 695
 696         while (1) {
 697                 /*
 698                  * Here we have:
 699                  * fn_ofs < this->ofs + this->size && fn_ofs >= this->ofs.
 700                  *
 701                  * Remember, 'this' has higher version, any non-hole node
 702                  * which is already in the fragtree is newer then the newly
 703                  * inserted.
 704                  */
 705                 if (!this->node) {
 706                         /*
 707                          * 'this' is the hole fragment, so at least the
 708                          * beginning of the new fragment is valid.
 709                          */
 710
 711                         /*
 712                          * We are going to insert the new node into the
 713                          * fragment tree, so check it.
 714                          */
 715                         if (!checked) {
 716                                 err = check_node(c, f, tn);
 717                                 if (unlikely(err != 0))
 718                                         return err;
 719                                 checked = 1;
 720                         }
 721
 722                         if (this->ofs + this->size >= fn_ofs + fn_size) {
 723                                 /* We split the hole on two parts */
 724
 725                                 fn->frags += 1;
 726                                 newfrag = new_fragment(fn, fn_ofs, fn_size);
 727                                 if (unlikely(!newfrag))
 728                                         return -ENOMEM;
 729
 730                                 err = split_hole(c, root, newfrag, this);
 731                                 if (unlikely(err))
 732                                         return err;
 733                                 goto out_ok;
 734                         }
 735
 736                         /*
 737                          * The beginning of the new fragment is valid since it
 738                          * overlaps the hole node.
 739                          */
 740
 741                         ref_flag = REF_NORMAL;
 742
 743                         fn->frags += 1;
 744                         newfrag = new_fragment(fn, fn_ofs,
 745                                         this->ofs + this->size - fn_ofs);
 746                         if (unlikely(!newfrag))
 747                                 return -ENOMEM;
 748
 749                         if (fn_ofs == this->ofs) {
 750                                 /*
 751                                  * The new node starts at the same offset as
 752                                  * the hole and supersieds the hole.
 753                                  */
 754                                 dbg_fragtree2("add the new fragment instead of hole %#04x-%#04x, refcnt %d\n",
 755                                         fn_ofs, fn_ofs + this->ofs + this->size - fn_ofs, fn->frags);
 756
 757                                 rb_replace_node(&this->rb, &newfrag->rb, root);
 758                                 jffs2_free_node_frag(this);
 759                         } else {
 760                                 /*
 761                                  * The hole becomes shorter as its right part
 762                                  * is supersieded by the new fragment.
 763                                  */
 764                                 dbg_fragtree2("reduce size of hole %#04x-%#04x to %#04x-%#04x\n",
 765                                         this->ofs, this->ofs + this->size, this->ofs, this->ofs + this->size - newfrag->size);
 766
 767                                 dbg_fragtree2("add new fragment %#04x-%#04x, refcnt %d\n", fn_ofs,
 768                                         fn_ofs + this->ofs + this->size - fn_ofs, fn->frags);
 769
 770                                 this->size -= newfrag->size;
 771                                 jffs2_fragtree_insert(newfrag, this);
 772                                 rb_insert_color(&newfrag->rb, root);
 773                         }
 774
 775                         fn_ofs += newfrag->size;
 776                         fn_size -= newfrag->size;
 777                         this = rb_entry(rb_next(&newfrag->rb),
 778                                         struct jffs2_node_frag, rb);
 779
 780                         dbg_fragtree2("switch to the next 'this' fragment: %#04x-%#04x %s\n",
 781                                 this->ofs, this->ofs + this->size, this->node ? "(data)" : "(hole)");
 782                 }
 783
 784                 /*
 785                  * 'This' node is not the hole so it obsoletes the new fragment
 786                  * either fully or partially.
 787                  */
 788                 if (this->ofs + this->size >= fn_ofs + fn_size) {
 789                         /* The new node is obsolete, drop it */
 790                         if (fn->frags == 0) {
 791                                 dbg_fragtree2("%#04x-%#04x is obsolete, mark it obsolete\n", fn_ofs, fn_ofs + fn_size);
 792                                 ref_flag = REF_OBSOLETE;
 793                         }
 794                         goto out_ok;
 795                 } else {
 796                         struct jffs2_node_frag *new_this;
 797
 798                         /* 'This' node obsoletes the beginning of the new node */
 799                         dbg_fragtree2("the beginning %#04x-%#04x is obsolete\n", fn_ofs, this->ofs + this->size);
 800
 801                         ref_flag = REF_NORMAL;
 802
 803                         fn_size -= this->ofs + this->size - fn_ofs;
 804                         fn_ofs = this->ofs + this->size;
 805                         dbg_fragtree2("now considering %#04x-%#04x\n", fn_ofs, fn_ofs + fn_size);
 806
 807                         new_this = rb_entry(rb_next(&this->rb), struct jffs2_node_frag, rb);
 808                         if (!new_this) {
 809                                 /*
 810                                  * There is no next fragment. Add the rest of
 811                                  * the new node as the right-hand child.
 812                                  */
 813                                 if (!checked) {
 814                                         err = check_node(c, f, tn);
 815                                         if (unlikely(err != 0))
 816                                                 return err;
 817                                         checked = 1;
 818                                 }
 819
 820                                 fn->frags += 1;
 821                                 newfrag = new_fragment(fn, fn_ofs, fn_size);
 822                                 if (unlikely(!newfrag))
 823                                         return -ENOMEM;
 824
 825                                 dbg_fragtree2("there are no more fragments, insert %#04x-%#04x\n",
 826                                         newfrag->ofs, newfrag->ofs + newfrag->size);
 827                                 rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
 828                                 rb_insert_color(&newfrag->rb, root);
 829                                 goto out_ok;
 830                         } else {
 831                                 this = new_this;
 832                                 dbg_fragtree2("switch to the next 'this' fragment: %#04x-%#04x %s\n",
 833                                         this->ofs, this->ofs + this->size, this->node ? "(data)" : "(hole)");
 834                         }
 835                 }
 836         }
 837
 838 out_ok:
 839         BUG_ON(fn->size < PAGE_CACHE_SIZE && ref_flag == REF_PRISTINE);
 840
 841         if (ref_flag == REF_OBSOLETE) {
 842                 dbg_fragtree2("the node is obsolete now\n");
 843                 /* jffs2_mark_node_obsolete() will adjust space accounting */
 844                 jffs2_mark_node_obsolete(c, fn->raw);
 845                 return 1;
 846         }
 847
 848         dbg_fragtree2("the node is \"%s\" now\n", ref_flag == REF_NORMAL ? "REF_NORMAL" : "REF_PRISTINE");
 849
 850         /* Space accounting was adjusted at check_node_data() */
 851         spin_lock(&c->erase_completion_lock);
 852         fn->raw->flash_offset = ref_offset(fn->raw) | ref_flag;
 853         spin_unlock(&c->erase_completion_lock);
 854
 855         return 0;
 856 }
 857
 858 void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
 859 {
 860         spin_lock(&c->inocache_lock);
 861         ic->state = state;
 862         wake_up(&c->inocache_wq);
 863         spin_unlock(&c->inocache_lock);
 864 }
 865
 866 /* During mount, this needs no locking. During normal operation, its
 867    callers want to do other stuff while still holding the inocache_lock.
 868    Rather than introducing special case get_ino_cache functions or
 869    callbacks, we just let the caller do the locking itself. */
 870
 871 struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
 872 {
 873         struct jffs2_inode_cache *ret;
 874
 875         ret = c->inocache_list[ino % INOCACHE_HASHSIZE];
 876         while (ret && ret->ino < ino) {
 877                 ret = ret->next;
 878         }
 879
 880         if (ret && ret->ino != ino)
 881                 ret = NULL;
 882
 883         return ret;
 884 }
 885
 886 void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
 887 {
 888         struct jffs2_inode_cache **prev;
 889
 890         spin_lock(&c->inocache_lock);
 891         if (!new->ino)
 892                 new->ino = ++c->highest_ino;
 893
 894         dbg_inocache("add %p (ino #%u)\n", new, new->ino);
 895
 896         prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE];
 897
 898         while ((*prev) && (*prev)->ino < new->ino) {
 899                 prev = &(*prev)->next;
 900         }
 901         new->next = *prev;
 902         *prev = new;
 903
 904         spin_unlock(&c->inocache_lock);
 905 }
 906
 907 void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
 908 {
 909         struct jffs2_inode_cache **prev;
 910
 911         dbg_inocache("del %p (ino #%u)\n", old, old->ino);
 912         spin_lock(&c->inocache_lock);
 913
 914         prev = &c->inocache_list[old->ino % INOCACHE_HASHSIZE];
 915
 916         while ((*prev) && (*prev)->ino < old->ino) {
 917                 prev = &(*prev)->next;
 918         }
 919         if ((*prev) == old) {
 920                 *prev = old->next;
 921         }
 922
 923         /* Free it now unless it's in READING or CLEARING state, which
 924            are the transitions upon read_inode() and clear_inode(). The
 925            rest of the time we know nobody else is looking at it, and
 926            if it's held by read_inode() or clear_inode() they'll free it
 927            for themselves. */
 928         if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
 929                 jffs2_free_inode_cache(old);
 930
 931         spin_unlock(&c->inocache_lock);
 932 }
 933
 934 void jffs2_free_ino_caches(struct jffs2_sb_info *c)
 935 {
 936         int i;
 937         struct jffs2_inode_cache *this, *next;
 938
 939         for (i=0; i<INOCACHE_HASHSIZE; i++) {
 940                 this = c->inocache_list[i];
 941                 while (this) {
 942                         next = this->next;
 943                         jffs2_free_inode_cache(this);
 944                         this = next;
 945                 }
 946                 c->inocache_list[i] = NULL;
 947         }
 948 }
 949
 950 void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
 951 {
 952         int i;
 953         struct jffs2_raw_node_ref *this, *next;
 954
 955         for (i=0; i<c->nr_blocks; i++) {
 956                 this = c->blocks[i].first_node;
 957                 while(this) {
 958                         next = this->next_phys;
 959                         jffs2_free_raw_node_ref(this);
 960                         this = next;
 961                 }
 962                 c->blocks[i].first_node = c->blocks[i].last_node = NULL;
 963         }
 964 }
 965
 966 struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
 967 {
 968         /* The common case in lookup is that there will be a node
 969            which precisely matches. So we go looking for that first */
 970         struct rb_node *next;
 971         struct jffs2_node_frag *prev = NULL;
 972         struct jffs2_node_frag *frag = NULL;
 973
 974         dbg_fragtree2("root %p, offset %d\n", fragtree, offset);
 975
 976         next = fragtree->rb_node;
 977
 978         while(next) {
 979                 frag = rb_entry(next, struct jffs2_node_frag, rb);
 980
 981                 if (frag->ofs + frag->size <= offset) {
 982                         /* Remember the closest smaller match on the way down */
 983                         if (!prev || frag->ofs > prev->ofs)
 984                                 prev = frag;
 985                         next = frag->rb.rb_right;
 986                 } else if (frag->ofs > offset) {
 987                         next = frag->rb.rb_left;
 988                 } else {
 989                         return frag;
 990                 }
 991         }
 992
 993         /* Exact match not found. Go back up looking at each parent,
 994            and return the closest smaller one */
 995
 996         if (prev)
 997                 dbg_fragtree2("no match. Returning frag %#04x-%#04x, closest previous\n",
 998                           prev->ofs, prev->ofs+prev->size);
 999         else
1000                 dbg_fragtree2("returning NULL, empty fragtree\n");
1001
1002         return prev;
1003 }
1004
1005 /* Pass 'c' argument to indicate that nodes should be marked obsolete as
1006    they're killed. */
1007 void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
1008 {
1009         struct jffs2_node_frag *frag;
1010         struct jffs2_node_frag *parent;
1011
1012         if (!root->rb_node)
1013                 return;
1014
1015         dbg_fragtree("killing\n");
1016
1017         frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
1018         while(frag) {
1019                 if (frag->rb.rb_left) {
1020                         frag = frag_left(frag);
1021                         continue;
1022                 }
1023                 if (frag->rb.rb_right) {
1024                         frag = frag_right(frag);
1025                         continue;
1026                 }
1027
1028                 if (frag->node && !(--frag->node->frags)) {
1029                         /* Not a hole, and it's the final remaining frag
1030                            of this node. Free the node */
1031                         if (c)
1032                                 jffs2_mark_node_obsolete(c, frag->node->raw);
1033
1034                         jffs2_free_full_dnode(frag->node);
1035                 }
1036                 parent = frag_parent(frag);
1037                 if (parent) {
1038                         if (frag_left(parent) == frag)
1039                                 parent->rb.rb_left = NULL;
1040                         else
1041                                 parent->rb.rb_right = NULL;
1042                 }
1043
1044                 jffs2_free_node_frag(frag);
1045                 frag = parent;
1046
1047                 cond_resched();
1048         }
1049 }