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 1.112 2005/08/22 09:07:09 dedekind Exp $
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/sched.h>
  16 #include <linux/fs.h>
  17 #include <linux/mtd/mtd.h>
  18 #include <linux/rbtree.h>
  19 #include <linux/crc32.h>
  20 #include <linux/slab.h>
  21 #include <linux/pagemap.h>
  22 #include "nodelist.h"
  23
  24 void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list)
  25 {
  26         struct jffs2_full_dirent **prev = list;
  27
  28         JFFS2_DBG_DENTLIST("add dirent \"%s\", ino #%u\n", new->name, new->ino);
  29
  30         while ((*prev) && (*prev)->nhash <= new->nhash) {
  31                 if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) {
  32                         /* Duplicate. Free one */
  33                         if (new->version < (*prev)->version) {
  34                                 JFFS2_DBG_DENTLIST("Eep! Marking new dirent node is obsolete, old is \"%s\", ino #%u\n",
  35                                         (*prev)->name, (*prev)->ino);
  36                                 jffs2_mark_node_obsolete(c, new->raw);
  37                                 jffs2_free_full_dirent(new);
  38                         } else {
  39                                 JFFS2_DBG_DENTLIST("marking old dirent \"%s\", ino #%u bsolete\n",
  40                                         (*prev)->name, (*prev)->ino);
  41                                 new->next = (*prev)->next;
  42                                 jffs2_mark_node_obsolete(c, ((*prev)->raw));
  43                                 jffs2_free_full_dirent(*prev);
  44                                 *prev = new;
  45                         }
  46                         return;
  47                 }
  48                 prev = &((*prev)->next);
  49         }
  50         new->next = *prev;
  51         *prev = new;
  52 }
  53
  54 void jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
  55 {
  56         struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
  57
  58         JFFS2_DBG_FRAGTREE("truncating fragtree to 0x%08x bytes\n", size);
  59
  60         /* We know frag->ofs <= size. That's what lookup does for us */
  61         if (frag && frag->ofs != size) {
  62                 if (frag->ofs+frag->size > size) {
  63                         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                 JFFS2_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                         JFFS2_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                         JFFS2_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         JFFS2_DBG_FRAGTREE2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);
 116
 117         while (*link) {
 118                 parent = *link;
 119                 base = rb_entry(parent, struct jffs2_node_frag, rb);
 120
 121                 if (newfrag->ofs > base->ofs)
 122                         link = &base->rb.rb_right;
 123                 else if (newfrag->ofs < base->ofs)
 124                         link = &base->rb.rb_left;
 125                 else {
 126                         JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
 127                         BUG();
 128                 }
 129         }
 130
 131         rb_link_node(&newfrag->rb, &base->rb, link);
 132 }
 133
 134 /*
 135  * Allocate and initializes a new fragment.
 136  */
 137 static inline struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
 138 {
 139         struct jffs2_node_frag *newfrag;
 140
 141         newfrag = jffs2_alloc_node_frag();
 142         if (likely(newfrag)) {
 143                 newfrag->ofs = ofs;
 144                 newfrag->size = size;
 145                 newfrag->node = fn;
 146         } else {
 147                 JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
 148         }
 149
 150         return newfrag;
 151 }
 152
 153 /*
 154  * Called when there is no overlapping fragment exist. Inserts a hole before the new
 155  * fragment and inserts the new fragment to the fragtree.
 156  */
 157 static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
 158                                struct jffs2_node_frag *newfrag,
 159                                struct jffs2_node_frag *this, uint32_t lastend)
 160 {
 161         if (lastend < newfrag->node->ofs) {
 162                 /* put a hole in before the new fragment */
 163                 struct jffs2_node_frag *holefrag;
 164
 165                 holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
 166                 if (unlikely(!holefrag)) {
 167                         jffs2_free_node_frag(newfrag);
 168                         return -ENOMEM;
 169                 }
 170
 171                 if (this) {
 172                         /* By definition, the 'this' node has no right-hand child,
 173                            because there are no frags with offset greater than it.
 174                            So that's where we want to put the hole */
 175                         JFFS2_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                         JFFS2_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                 JFFS2_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                 JFFS2_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                 JFFS2_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                 JFFS2_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                 JFFS2_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                 JFFS2_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                                 JFFS2_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                                 JFFS2_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                 JFFS2_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                         JFFS2_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                 JFFS2_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         JFFS2_DBG_FRAGTREE("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
 365                   fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
 366
 367         ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
 368         if (unlikely(ret))
 369                 return ret;
 370
 371         /* If we now share a page with other nodes, mark either previous
 372            or next node REF_NORMAL, as appropriate.  */
 373         if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
 374                 struct jffs2_node_frag *prev = frag_prev(newfrag);
 375
 376                 mark_ref_normal(fn->raw);
 377                 /* If we don't start at zero there's _always_ a previous */
 378                 if (prev->node)
 379                         mark_ref_normal(prev->node->raw);
 380         }
 381
 382         if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
 383                 struct jffs2_node_frag *next = frag_next(newfrag);
 384
 385                 if (next) {
 386                         mark_ref_normal(fn->raw);
 387                         if (next->node)
 388                                 mark_ref_normal(next->node->raw);
 389                 }
 390         }
 391         jffs2_dbg_fragtree_paranoia_check_nolock(f);
 392
 393         return 0;
 394 }
 395
 396 /*
 397  * Check the data CRC of the node.
 398  *
 399  * Returns: 0 if the data CRC is correct;
 400  *          1 - if incorrect;
 401  *          error code if an error occured.
 402  */
 403 static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info *tn)
 404 {
 405         struct jffs2_raw_node_ref *ref = tn->fn->raw;
 406         int err = 0, pointed = 0;
 407         struct jffs2_eraseblock *jeb;
 408         unsigned char *buffer;
 409         uint32_t crc, ofs, retlen, len;
 410
 411         BUG_ON(tn->csize == 0);
 412
 413         /* Calculate how many bytes were already checked */
 414         ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);
 415         len = ofs & (c->wbuf_pagesize - 1);
 416         if (likely(len))
 417                 len = c->wbuf_pagesize - len;
 418
 419         if (len >= tn->csize) {
 420                 JFFS2_DBG_READINODE("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",
 421                         ref_offset(ref), tn->csize, ofs);
 422                 goto adj_acc;
 423         }
 424
 425         ofs += len;
 426         len = tn->csize - len;
 427
 428         JFFS2_DBG_READINODE("check node at %#08x, data length %u, partial CRC %#08x, correct CRC %#08x, data starts at %#08x, start checking from %#08x - %u bytes.\n",
 429                 ref_offset(ref), tn->csize, tn->partial_crc, tn->data_crc, ofs - len, ofs, len);
 430
 431 #ifndef __ECOS
 432         /* TODO: instead, incapsulate point() stuff to jffs2_flash_read(),
 433          * adding and jffs2_flash_read_end() interface. */
 434         if (c->mtd->point) {
 435                 err = c->mtd->point(c->mtd, ofs, len, &retlen, &buffer);
 436                 if (!err && retlen < tn->csize) {
 437                         JFFS2_WARNING("MTD point returned len too short: %u instead of %u.\n", retlen, tn->csize);
 438                         c->mtd->unpoint(c->mtd, buffer, ofs, len);
 439                 } else if (err)
 440                         JFFS2_WARNING("MTD point failed: error code %d.\n", err);
 441                 else
 442                         pointed = 1; /* succefully pointed to device */
 443         }
 444 #endif
 445
 446         if (!pointed) {
 447                 buffer = kmalloc(len, GFP_KERNEL);
 448                 if (unlikely(!buffer))
 449                         return -ENOMEM;
 450
 451                 /* TODO: this is very frequent pattern, make it a separate
 452                  * routine */
 453                 err = jffs2_flash_read(c, ofs, len, &retlen, buffer);
 454                 if (err) {
 455                         JFFS2_ERROR("can not read %d bytes from 0x%08x, error code: %d.\n", len, ofs, err);
 456                         goto free_out;
 457                 }
 458
 459                 if (retlen != len) {
 460                         JFFS2_ERROR("short read at %#08x: %d instead of %d.\n", ofs, retlen, len);
 461                         err = -EIO;
 462                         goto free_out;
 463                 }
 464         }
 465
 466         /* Continue calculating CRC */
 467         crc = crc32(tn->partial_crc, buffer, len);
 468         if(!pointed)
 469                 kfree(buffer);
 470 #ifndef __ECOS
 471         else
 472                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
 473 #endif
 474
 475         if (crc != tn->data_crc) {
 476                 JFFS2_NOTICE("wrong data CRC in data node at 0x%08x: read %#08x, calculated %#08x.\n",
 477                         ofs, tn->data_crc, crc);
 478                 return 1;
 479         }
 480
 481 adj_acc:
 482         jeb = &c->blocks[ref->flash_offset / c->sector_size];
 483         len = ref_totlen(c, jeb, ref);
 484
 485         /*
 486          * Mark the node as having been checked and fix the
 487          * accounting accordingly.
 488          */
 489         spin_lock(&c->erase_completion_lock);
 490         jeb->used_size += len;
 491         jeb->unchecked_size -= len;
 492         c->used_size += len;
 493         c->unchecked_size -= len;
 494         spin_unlock(&c->erase_completion_lock);
 495
 496         return 0;
 497
 498 free_out:
 499         if(!pointed)
 500                 kfree(buffer);
 501 #ifndef __ECOS
 502         else
 503                 c->mtd->unpoint(c->mtd, buffer, ofs, len);
 504 #endif
 505         return err;
 506 }
 507
 508 /*
 509  * Helper function for jffs2_add_older_frag_to_fragtree().
 510  *
 511  * Checks the node if we are in the checking stage.
 512  */
 513 static inline int check_node(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_tmp_dnode_info *tn)
 514 {
 515         int ret;
 516
 517         BUG_ON(ref_obsolete(tn->fn->raw));
 518
 519         /* We only check the data CRC of unchecked nodes */
 520         if (ref_flags(tn->fn->raw) != REF_UNCHECKED)
 521                 return 0;
 522
 523         JFFS2_DBG_FRAGTREE2("check node %#04x-%#04x, phys offs %#08x.\n",
 524                 tn->fn->ofs, tn->fn->ofs + tn->fn->size, ref_offset(tn->fn->raw));
 525
 526         ret = check_node_data(c, tn);
 527         if (unlikely(ret < 0)) {
 528                 JFFS2_ERROR("check_node_data() returned error: %d.\n",
 529                         ret);
 530         } else if (unlikely(ret > 0)) {
 531                 JFFS2_DBG_FRAGTREE2("CRC error, mark it obsolete.\n");
 532                 jffs2_mark_node_obsolete(c, tn->fn->raw);
 533         }
 534
 535         return ret;
 536 }
 537
 538 /*
 539  * Helper function for jffs2_add_older_frag_to_fragtree().
 540  *
 541  * Called when the new fragment that is being inserted
 542  * splits a hole fragment.
 543  */
 544 static int split_hole(struct jffs2_sb_info *c, struct rb_root *root,
 545                       struct jffs2_node_frag *newfrag, struct jffs2_node_frag *hole)
 546 {
 547         JFFS2_DBG_FRAGTREE2("fragment %#04x-%#04x splits the hole %#04x-%#04x\n",
 548                 newfrag->ofs, newfrag->ofs + newfrag->size, hole->ofs, hole->ofs + hole->size);
 549
 550         if (hole->ofs == newfrag->ofs) {
 551                 /*
 552                  * Well, the new fragment actually starts at the same offset as
 553                  * the hole.
 554                  */
 555                 if (hole->ofs + hole->size > newfrag->ofs + newfrag->size) {
 556                         /*
 557                          * We replace the overlapped left part of the hole by
 558                          * the new node.
 559                          */
 560
 561                         JFFS2_DBG_FRAGTREE2("insert fragment %#04x-%#04x and cut the left part of the hole\n",
 562                                 newfrag->ofs, newfrag->ofs + newfrag->size);
 563                         rb_replace_node(&hole->rb, &newfrag->rb, root);
 564
 565                         hole->ofs += newfrag->size;
 566                         hole->size -= newfrag->size;
 567
 568                         /*
 569                          * We know that 'hole' should be the right hand
 570                          * fragment.
 571                          */
 572                         jffs2_fragtree_insert(hole, newfrag);
 573                         rb_insert_color(&hole->rb, root);
 574                 } else {
 575                         /*
 576                          * Ah, the new fragment is of the same size as the hole.
 577                          * Relace the hole by it.
 578                          */
 579                         JFFS2_DBG_FRAGTREE2("insert fragment %#04x-%#04x and overwrite hole\n",
 580                                 newfrag->ofs, newfrag->ofs + newfrag->size);
 581                         rb_replace_node(&hole->rb, &newfrag->rb, root);
 582                         jffs2_free_node_frag(hole);
 583                 }
 584         } else {
 585                 /* The new fragment lefts some hole space at the left */
 586
 587                 struct jffs2_node_frag * newfrag2 = NULL;
 588
 589                 if (hole->ofs + hole->size > newfrag->ofs + newfrag->size) {
 590                         /* The new frag also lefts some space at the right */
 591                         newfrag2 = new_fragment(NULL, newfrag->ofs +
 592                                 newfrag->size, hole->ofs + hole->size
 593                                 - newfrag->ofs - newfrag->size);
 594                         if (unlikely(!newfrag2)) {
 595                                 jffs2_free_node_frag(newfrag);
 596                                 return -ENOMEM;
 597                         }
 598                 }
 599
 600                 hole->size = newfrag->ofs - hole->ofs;
 601                 JFFS2_DBG_FRAGTREE2("left the hole %#04x-%#04x at the left and inserd fragment %#04x-%#04x\n",
 602                         hole->ofs, hole->ofs + hole->size, newfrag->ofs, newfrag->ofs + newfrag->size);
 603
 604                 jffs2_fragtree_insert(newfrag, hole);
 605                 rb_insert_color(&newfrag->rb, root);
 606
 607                 if (newfrag2) {
 608                         JFFS2_DBG_FRAGTREE2("left the hole %#04x-%#04x at the right\n",
 609                                 newfrag2->ofs, newfrag2->ofs + newfrag2->size);
 610                         jffs2_fragtree_insert(newfrag2, newfrag);
 611                         rb_insert_color(&newfrag2->rb, root);
 612                 }
 613         }
 614
 615         return 0;
 616 }
 617
 618 /*
 619  * This function is used when we build inode. It expects the nodes are passed
 620  * in the decreasing version order. The whole point of this is to improve the
 621  * inodes checking on NAND: we check the nodes' data CRC only when they are not
 622  * obsoleted. Previously, add_frag_to_fragtree() function was used and
 623  * nodes were passed to it in the increasing version ordes and CRCs of all
 624  * nodes were checked.
 625  *
 626  * Note: tn->fn->size shouldn't be zero.
 627  *
 628  * Returns 0 if the node was inserted
 629  *         1 if it wasn't inserted (since it is obsolete)
 630  *         < 0 an if error occured
 631  */
 632 int jffs2_add_older_frag_to_fragtree(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
 633                                      struct jffs2_tmp_dnode_info *tn)
 634 {
 635         struct jffs2_node_frag *this, *newfrag;
 636         uint32_t lastend;
 637         struct jffs2_full_dnode *fn = tn->fn;
 638         struct rb_root *root = &f->fragtree;
 639         uint32_t fn_size = fn->size, fn_ofs = fn->ofs;
 640         int err, checked = 0;
 641         int ref_flag;
 642
 643         JFFS2_DBG_FRAGTREE("insert fragment %#04x-%#04x, ver %u\n", fn_ofs, fn_ofs + fn_size, tn->version);
 644
 645         /* Skip all the nodes which are completed before this one starts */
 646         this = jffs2_lookup_node_frag(root, fn_ofs);
 647         if (this)
 648                 JFFS2_DBG_FRAGTREE2("'this' found %#04x-%#04x (%s)\n", this->ofs, this->ofs + this->size, this->node ? "data" : "hole");
 649
 650         if (this)
 651                 lastend = this->ofs + this->size;
 652         else
 653                 lastend = 0;
 654
 655         /* Detect the preliminary type of node */
 656         if (fn->size >= PAGE_CACHE_SIZE)
 657                 ref_flag = REF_PRISTINE;
 658         else
 659                 ref_flag = REF_NORMAL;
 660
 661         /* See if we ran off the end of the root */
 662         if (lastend <= fn_ofs) {
 663                 /* We did */
 664
 665                 /*
 666                  * We are going to insert the new node into the
 667                  * fragment tree, so check it.
 668                  */
 669                 err = check_node(c, f, tn);
 670                 if (err != 0)
 671                         return err;
 672
 673                 fn->frags = 1;
 674
 675                 newfrag = new_fragment(fn, fn_ofs, fn_size);
 676                 if (unlikely(!newfrag))
 677                         return -ENOMEM;
 678
 679                 err = no_overlapping_node(c, root, newfrag, this, lastend);
 680                 if (unlikely(err != 0)) {
 681                         jffs2_free_node_frag(newfrag);
 682                         return err;
 683                 }
 684
 685                 goto out_ok;
 686         }
 687
 688         fn->frags = 0;
 689
 690         while (1) {
 691                 /*
 692                  * Here we have:
 693                  * fn_ofs < this->ofs + this->size && fn_ofs >= this->ofs.
 694                  *
 695                  * Remember, 'this' has higher version, any non-hole node
 696                  * which is already in the fragtree is newer then the newly
 697                  * inserted.
 698                  */
 699                 if (!this->node) {
 700                         /*
 701                          * 'this' is the hole fragment, so at least the
 702                          * beginning of the new fragment is valid.
 703                          */
 704
 705                         /*
 706                          * We are going to insert the new node into the
 707                          * fragment tree, so check it.
 708                          */
 709                         if (!checked) {
 710                                 err = check_node(c, f, tn);
 711                                 if (unlikely(err != 0))
 712                                         return err;
 713                                 checked = 1;
 714                         }
 715
 716                         if (this->ofs + this->size >= fn_ofs + fn_size) {
 717                                 /* We split the hole on two parts */
 718
 719                                 fn->frags += 1;
 720                                 newfrag = new_fragment(fn, fn_ofs, fn_size);
 721                                 if (unlikely(!newfrag))
 722                                         return -ENOMEM;
 723
 724                                 err = split_hole(c, root, newfrag, this);
 725                                 if (unlikely(err))
 726                                         return err;
 727                                 goto out_ok;
 728                         }
 729
 730                         /*
 731                          * The beginning of the new fragment is valid since it
 732                          * overlaps the hole node.
 733                          */
 734
 735                         ref_flag = REF_NORMAL;
 736
 737                         fn->frags += 1;
 738                         newfrag = new_fragment(fn, fn_ofs,
 739                                         this->ofs + this->size - fn_ofs);
 740                         if (unlikely(!newfrag))
 741                                 return -ENOMEM;
 742
 743                         if (fn_ofs == this->ofs) {
 744                                 /*
 745                                  * The new node starts at the same offset as
 746                                  * the hole and supersieds the hole.
 747                                  */
 748                                 JFFS2_DBG_FRAGTREE2("add the new fragment instead of hole %#04x-%#04x, refcnt %d\n",
 749                                         fn_ofs, fn_ofs + this->ofs + this->size - fn_ofs, fn->frags);
 750
 751                                 rb_replace_node(&this->rb, &newfrag->rb, root);
 752                                 jffs2_free_node_frag(this);
 753                         } else {
 754                                 /*
 755                                  * The hole becomes shorter as its right part
 756                                  * is supersieded by the new fragment.
 757                                  */
 758                                 JFFS2_DBG_FRAGTREE2("reduce size of hole %#04x-%#04x to %#04x-%#04x\n",
 759                                         this->ofs, this->ofs + this->size, this->ofs, this->ofs + this->size - newfrag->size);
 760
 761                                 JFFS2_DBG_FRAGTREE2("add new fragment %#04x-%#04x, refcnt %d\n", fn_ofs,
 762                                         fn_ofs + this->ofs + this->size - fn_ofs, fn->frags);
 763
 764                                 this->size -= newfrag->size;
 765                                 jffs2_fragtree_insert(newfrag, this);
 766                                 rb_insert_color(&newfrag->rb, root);
 767                         }
 768
 769                         fn_ofs += newfrag->size;
 770                         fn_size -= newfrag->size;
 771                         this = rb_entry(rb_next(&newfrag->rb),
 772                                         struct jffs2_node_frag, rb);
 773
 774                         JFFS2_DBG_FRAGTREE2("switch to the next 'this' fragment: %#04x-%#04x %s\n",
 775                                 this->ofs, this->ofs + this->size, this->node ? "(data)" : "(hole)");
 776                 }
 777
 778                 /*
 779                  * 'This' node is not the hole so it obsoletes the new fragment
 780                  * either fully or partially.
 781                  */
 782                 if (this->ofs + this->size >= fn_ofs + fn_size) {
 783                         /* The new node is obsolete, drop it */
 784                         if (fn->frags == 0) {
 785                                 JFFS2_DBG_FRAGTREE2("%#04x-%#04x is obsolete, mark it obsolete\n", fn_ofs, fn_ofs + fn_size);
 786                                 ref_flag = REF_OBSOLETE;
 787                         }
 788                         goto out_ok;
 789                 } else {
 790                         struct jffs2_node_frag *new_this;
 791
 792                         /* 'This' node obsoletes the beginning of the new node */
 793                         JFFS2_DBG_FRAGTREE2("the beginning %#04x-%#04x is obsolete\n", fn_ofs, this->ofs + this->size);
 794
 795                         ref_flag = REF_NORMAL;
 796
 797                         fn_size -= this->ofs + this->size - fn_ofs;
 798                         fn_ofs = this->ofs + this->size;
 799                         JFFS2_DBG_FRAGTREE2("now considering %#04x-%#04x\n", fn_ofs, fn_ofs + fn_size);
 800
 801                         new_this = rb_entry(rb_next(&this->rb), struct jffs2_node_frag, rb);
 802                         if (!new_this) {
 803                                 /*
 804                                  * There is no next fragment. Add the rest of
 805                                  * the new node as the right-hand child.
 806                                  */
 807                                 if (!checked) {
 808                                         err = check_node(c, f, tn);
 809                                         if (unlikely(err != 0))
 810                                                 return err;
 811                                         checked = 1;
 812                                 }
 813
 814                                 fn->frags += 1;
 815                                 newfrag = new_fragment(fn, fn_ofs, fn_size);
 816                                 if (unlikely(!newfrag))
 817                                         return -ENOMEM;
 818
 819                                 JFFS2_DBG_FRAGTREE2("there are no more fragments, insert %#04x-%#04x\n",
 820                                         newfrag->ofs, newfrag->ofs + newfrag->size);
 821                                 rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
 822                                 rb_insert_color(&newfrag->rb, root);
 823                                 goto out_ok;
 824                         } else {
 825                                 this = new_this;
 826                                 JFFS2_DBG_FRAGTREE2("switch to the next 'this' fragment: %#04x-%#04x %s\n",
 827                                         this->ofs, this->ofs + this->size, this->node ? "(data)" : "(hole)");
 828                         }
 829                 }
 830         }
 831
 832 out_ok:
 833         BUG_ON(fn->size < PAGE_CACHE_SIZE && ref_flag == REF_PRISTINE);
 834
 835         if (ref_flag == REF_OBSOLETE) {
 836                 JFFS2_DBG_FRAGTREE2("the node is obsolete now\n");
 837                 /* jffs2_mark_node_obsolete() will adjust space accounting */
 838                 jffs2_mark_node_obsolete(c, fn->raw);
 839                 return 1;
 840         }
 841
 842         JFFS2_DBG_FRAGTREE2("the node is \"%s\" now\n", ref_flag == REF_NORMAL ? "REF_NORMAL" : "REF_PRISTINE");
 843
 844         /* Space accounting was adjusted at check_node_data() */
 845         spin_lock(&c->erase_completion_lock);
 846         fn->raw->flash_offset = ref_offset(fn->raw) | ref_flag;
 847         spin_unlock(&c->erase_completion_lock);
 848
 849         return 0;
 850 }
 851
 852 void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
 853 {
 854         spin_lock(&c->inocache_lock);
 855         ic->state = state;
 856         wake_up(&c->inocache_wq);
 857         spin_unlock(&c->inocache_lock);
 858 }
 859
 860 /* During mount, this needs no locking. During normal operation, its
 861    callers want to do other stuff while still holding the inocache_lock.
 862    Rather than introducing special case get_ino_cache functions or
 863    callbacks, we just let the caller do the locking itself. */
 864
 865 struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
 866 {
 867         struct jffs2_inode_cache *ret;
 868
 869         ret = c->inocache_list[ino % INOCACHE_HASHSIZE];
 870         while (ret && ret->ino < ino) {
 871                 ret = ret->next;
 872         }
 873
 874         if (ret && ret->ino != ino)
 875                 ret = NULL;
 876
 877         return ret;
 878 }
 879
 880 void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
 881 {
 882         struct jffs2_inode_cache **prev;
 883
 884         spin_lock(&c->inocache_lock);
 885         if (!new->ino)
 886                 new->ino = ++c->highest_ino;
 887
 888         JFFS2_DBG_INOCACHE("add %p (ino #%u)\n", new, new->ino);
 889
 890         prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE];
 891
 892         while ((*prev) && (*prev)->ino < new->ino) {
 893                 prev = &(*prev)->next;
 894         }
 895         new->next = *prev;
 896         *prev = new;
 897
 898         spin_unlock(&c->inocache_lock);
 899 }
 900
 901 void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
 902 {
 903         struct jffs2_inode_cache **prev;
 904
 905         JFFS2_DBG_INOCACHE("del %p (ino #%u)\n", old, old->ino);
 906         spin_lock(&c->inocache_lock);
 907
 908         prev = &c->inocache_list[old->ino % INOCACHE_HASHSIZE];
 909
 910         while ((*prev) && (*prev)->ino < old->ino) {
 911                 prev = &(*prev)->next;
 912         }
 913         if ((*prev) == old) {
 914                 *prev = old->next;
 915         }
 916
 917         /* Free it now unless it's in READING or CLEARING state, which
 918            are the transitions upon read_inode() and clear_inode(). The
 919            rest of the time we know nobody else is looking at it, and
 920            if it's held by read_inode() or clear_inode() they'll free it
 921            for themselves. */
 922         if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
 923                 jffs2_free_inode_cache(old);
 924
 925         spin_unlock(&c->inocache_lock);
 926 }
 927
 928 void jffs2_free_ino_caches(struct jffs2_sb_info *c)
 929 {
 930         int i;
 931         struct jffs2_inode_cache *this, *next;
 932
 933         for (i=0; i<INOCACHE_HASHSIZE; i++) {
 934                 this = c->inocache_list[i];
 935                 while (this) {
 936                         next = this->next;
 937                         jffs2_free_inode_cache(this);
 938                         this = next;
 939                 }
 940                 c->inocache_list[i] = NULL;
 941         }
 942 }
 943
 944 void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
 945 {
 946         int i;
 947         struct jffs2_raw_node_ref *this, *next;
 948
 949         for (i=0; i<c->nr_blocks; i++) {
 950                 this = c->blocks[i].first_node;
 951                 while(this) {
 952                         next = this->next_phys;
 953                         jffs2_free_raw_node_ref(this);
 954                         this = next;
 955                 }
 956                 c->blocks[i].first_node = c->blocks[i].last_node = NULL;
 957         }
 958 }
 959
 960 struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
 961 {
 962         /* The common case in lookup is that there will be a node
 963            which precisely matches. So we go looking for that first */
 964         struct rb_node *next;
 965         struct jffs2_node_frag *prev = NULL;
 966         struct jffs2_node_frag *frag = NULL;
 967
 968         JFFS2_DBG_FRAGTREE2("root %p, offset %d\n", fragtree, offset);
 969
 970         next = fragtree->rb_node;
 971
 972         while(next) {
 973                 frag = rb_entry(next, struct jffs2_node_frag, rb);
 974
 975                 if (frag->ofs + frag->size <= offset) {
 976                         /* Remember the closest smaller match on the way down */
 977                         if (!prev || frag->ofs > prev->ofs)
 978                                 prev = frag;
 979                         next = frag->rb.rb_right;
 980                 } else if (frag->ofs > offset) {
 981                         next = frag->rb.rb_left;
 982                 } else {
 983                         return frag;
 984                 }
 985         }
 986
 987         /* Exact match not found. Go back up looking at each parent,
 988            and return the closest smaller one */
 989
 990         if (prev)
 991                 JFFS2_DBG_FRAGTREE2("no match. Returning frag %#04x-%#04x, closest previous\n",
 992                           prev->ofs, prev->ofs+prev->size);
 993         else
 994                 JFFS2_DBG_FRAGTREE2("returning NULL, empty fragtree\n");
 995
 996         return prev;
 997 }
 998
 999 /* Pass 'c' argument to indicate that nodes should be marked obsolete as
1000    they're killed. */
1001 void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
1002 {
1003         struct jffs2_node_frag *frag;
1004         struct jffs2_node_frag *parent;
1005
1006         if (!root->rb_node)
1007                 return;
1008
1009         JFFS2_DBG_FRAGTREE("killing\n");
1010
1011         frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
1012         while(frag) {
1013                 if (frag->rb.rb_left) {
1014                         frag = frag_left(frag);
1015                         continue;
1016                 }
1017                 if (frag->rb.rb_right) {
1018                         frag = frag_right(frag);
1019                         continue;
1020                 }
1021
1022                 if (frag->node && !(--frag->node->frags)) {
1023                         /* Not a hole, and it's the final remaining frag
1024                            of this node. Free the node */
1025                         if (c)
1026                                 jffs2_mark_node_obsolete(c, frag->node->raw);
1027
1028                         jffs2_free_full_dnode(frag->node);
1029                 }
1030                 parent = frag_parent(frag);
1031                 if (parent) {
1032                         if (frag_left(parent) == frag)
1033                                 parent->rb.rb_left = NULL;
1034                         else
1035                                 parent->rb.rb_right = NULL;
1036                 }
1037
1038                 jffs2_free_node_frag(frag);
1039                 frag = parent;
1040
1041                 cond_resched();
1042         }
1043 }