linux/fs/jffs2/nodelist.c
<<
>>
Prefs
   1/*
   2 * JFFS2 -- Journalling Flash File System, Version 2.
   3 *
   4 * Copyright © 2001-2007 Red Hat, Inc.
   5 *
   6 * Created by David Woodhouse <dwmw2@infradead.org>
   7 *
   8 * For licensing information, see the file 'LICENCE' in this directory.
   9 *
  10 */
  11
  12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14#include <linux/kernel.h>
  15#include <linux/sched.h>
  16#include <linux/fs.h>
  17#include <linux/mtd/mtd.h>
  18#include <linux/rbtree.h>
  19#include <linux/crc32.h>
  20#include <linux/pagemap.h>
  21#include "nodelist.h"
  22
  23static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
  24                                     struct jffs2_node_frag *this);
  25
  26void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list)
  27{
  28        struct jffs2_full_dirent **prev = list;
  29
  30        dbg_dentlist("add dirent \"%s\", ino #%u\n", new->name, new->ino);
  31
  32        while ((*prev) && (*prev)->nhash <= new->nhash) {
  33                if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) {
  34                        /* Duplicate. Free one */
  35                        if (new->version < (*prev)->version) {
  36                                dbg_dentlist("Eep! Marking new dirent node obsolete, old is \"%s\", ino #%u\n",
  37                                        (*prev)->name, (*prev)->ino);
  38                                jffs2_mark_node_obsolete(c, new->raw);
  39                                jffs2_free_full_dirent(new);
  40                        } else {
  41                                dbg_dentlist("marking old dirent \"%s\", ino #%u obsolete\n",
  42                                        (*prev)->name, (*prev)->ino);
  43                                new->next = (*prev)->next;
  44                                /* It may have been a 'placeholder' deletion dirent, 
  45                                   if jffs2_can_mark_obsolete() (see jffs2_do_unlink()) */
  46                                if ((*prev)->raw)
  47                                        jffs2_mark_node_obsolete(c, ((*prev)->raw));
  48                                jffs2_free_full_dirent(*prev);
  49                                *prev = new;
  50                        }
  51                        return;
  52                }
  53                prev = &((*prev)->next);
  54        }
  55        new->next = *prev;
  56        *prev = new;
  57}
  58
  59uint32_t jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
  60{
  61        struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
  62
  63        dbg_fragtree("truncating fragtree to 0x%08x bytes\n", size);
  64
  65        /* We know frag->ofs <= size. That's what lookup does for us */
  66        if (frag && frag->ofs != size) {
  67                if (frag->ofs+frag->size > size) {
  68                        frag->size = size - frag->ofs;
  69                }
  70                frag = frag_next(frag);
  71        }
  72        while (frag && frag->ofs >= size) {
  73                struct jffs2_node_frag *next = frag_next(frag);
  74
  75                frag_erase(frag, list);
  76                jffs2_obsolete_node_frag(c, frag);
  77                frag = next;
  78        }
  79
  80        if (size == 0)
  81                return 0;
  82
  83        frag = frag_last(list);
  84
  85        /* Sanity check for truncation to longer than we started with... */
  86        if (!frag)
  87                return 0;
  88        if (frag->ofs + frag->size < size)
  89                return frag->ofs + frag->size;
  90
  91        /* If the last fragment starts at the RAM page boundary, it is
  92         * REF_PRISTINE irrespective of its size. */
  93        if (frag->node && (frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
  94                dbg_fragtree2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
  95                        frag->ofs, frag->ofs + frag->size);
  96                frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
  97        }
  98        return size;
  99}
 100
 101static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
 102                                     struct jffs2_node_frag *this)
 103{
 104        if (this->node) {
 105                this->node->frags--;
 106                if (!this->node->frags) {
 107                        /* The node has no valid frags left. It's totally obsoleted */
 108                        dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
 109                                ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size);
 110                        jffs2_mark_node_obsolete(c, this->node->raw);
 111                        jffs2_free_full_dnode(this->node);
 112                } else {
 113                        dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
 114                                ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags);
 115                        mark_ref_normal(this->node->raw);
 116                }
 117
 118        }
 119        jffs2_free_node_frag(this);
 120}
 121
 122static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
 123{
 124        struct rb_node *parent = &base->rb;
 125        struct rb_node **link = &parent;
 126
 127        dbg_fragtree2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);
 128
 129        while (*link) {
 130                parent = *link;
 131                base = rb_entry(parent, struct jffs2_node_frag, rb);
 132
 133                if (newfrag->ofs > base->ofs)
 134                        link = &base->rb.rb_right;
 135                else if (newfrag->ofs < base->ofs)
 136                        link = &base->rb.rb_left;
 137                else {
 138                        JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
 139                        BUG();
 140                }
 141        }
 142
 143        rb_link_node(&newfrag->rb, &base->rb, link);
 144}
 145
 146/*
 147 * Allocate and initializes a new fragment.
 148 */
 149static struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
 150{
 151        struct jffs2_node_frag *newfrag;
 152
 153        newfrag = jffs2_alloc_node_frag();
 154        if (likely(newfrag)) {
 155                newfrag->ofs = ofs;
 156                newfrag->size = size;
 157                newfrag->node = fn;
 158        } else {
 159                JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
 160        }
 161
 162        return newfrag;
 163}
 164
 165/*
 166 * Called when there is no overlapping fragment exist. Inserts a hole before the new
 167 * fragment and inserts the new fragment to the fragtree.
 168 */
 169static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
 170                               struct jffs2_node_frag *newfrag,
 171                               struct jffs2_node_frag *this, uint32_t lastend)
 172{
 173        if (lastend < newfrag->node->ofs) {
 174                /* put a hole in before the new fragment */
 175                struct jffs2_node_frag *holefrag;
 176
 177                holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
 178                if (unlikely(!holefrag)) {
 179                        jffs2_free_node_frag(newfrag);
 180                        return -ENOMEM;
 181                }
 182
 183                if (this) {
 184                        /* By definition, the 'this' node has no right-hand child,
 185                           because there are no frags with offset greater than it.
 186                           So that's where we want to put the hole */
 187                        dbg_fragtree2("add hole frag %#04x-%#04x on the right of the new frag.\n",
 188                                holefrag->ofs, holefrag->ofs + holefrag->size);
 189                        rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
 190                } else {
 191                        dbg_fragtree2("Add hole frag %#04x-%#04x to the root of the tree.\n",
 192                                holefrag->ofs, holefrag->ofs + holefrag->size);
 193                        rb_link_node(&holefrag->rb, NULL, &root->rb_node);
 194                }
 195                rb_insert_color(&holefrag->rb, root);
 196                this = holefrag;
 197        }
 198
 199        if (this) {
 200                /* By definition, the 'this' node has no right-hand child,
 201                   because there are no frags with offset greater than it.
 202                   So that's where we want to put new fragment */
 203                dbg_fragtree2("add the new node at the right\n");
 204                rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
 205        } else {
 206                dbg_fragtree2("insert the new node at the root of the tree\n");
 207                rb_link_node(&newfrag->rb, NULL, &root->rb_node);
 208        }
 209        rb_insert_color(&newfrag->rb, root);
 210
 211        return 0;
 212}
 213
 214/* Doesn't set inode->i_size */
 215static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *root, struct jffs2_node_frag *newfrag)
 216{
 217        struct jffs2_node_frag *this;
 218        uint32_t lastend;
 219
 220        /* Skip all the nodes which are completed before this one starts */
 221        this = jffs2_lookup_node_frag(root, newfrag->node->ofs);
 222
 223        if (this) {
 224                dbg_fragtree2("lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
 225                          this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this);
 226                lastend = this->ofs + this->size;
 227        } else {
 228                dbg_fragtree2("lookup gave no frag\n");
 229                lastend = 0;
 230        }
 231
 232        /* See if we ran off the end of the fragtree */
 233        if (lastend <= newfrag->ofs) {
 234                /* We did */
 235
 236                /* Check if 'this' node was on the same page as the new node.
 237                   If so, both 'this' and the new node get marked REF_NORMAL so
 238                   the GC can take a look.
 239                */
 240                if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
 241                        if (this->node)
 242                                mark_ref_normal(this->node->raw);
 243                        mark_ref_normal(newfrag->node->raw);
 244                }
 245
 246                return no_overlapping_node(c, root, newfrag, this, lastend);
 247        }
 248
 249        if (this->node)
 250                dbg_fragtree2("dealing with frag %u-%u, phys %#08x(%d).\n",
 251                this->ofs, this->ofs + this->size,
 252                ref_offset(this->node->raw), ref_flags(this->node->raw));
 253        else
 254                dbg_fragtree2("dealing with hole frag %u-%u.\n",
 255                this->ofs, this->ofs + this->size);
 256
 257        /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
 258         * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
 259         */
 260        if (newfrag->ofs > this->ofs) {
 261                /* This node isn't completely obsoleted. The start of it remains valid */
 262
 263                /* Mark the new node and the partially covered node REF_NORMAL -- let
 264                   the GC take a look at them */
 265                mark_ref_normal(newfrag->node->raw);
 266                if (this->node)
 267                        mark_ref_normal(this->node->raw);
 268
 269                if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
 270                        /* The new node splits 'this' frag into two */
 271                        struct jffs2_node_frag *newfrag2;
 272
 273                        if (this->node)
 274                                dbg_fragtree2("split old frag 0x%04x-0x%04x, phys 0x%08x\n",
 275                                        this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
 276                        else
 277                                dbg_fragtree2("split old hole frag 0x%04x-0x%04x\n",
 278                                        this->ofs, this->ofs+this->size);
 279
 280                        /* New second frag pointing to this's node */
 281                        newfrag2 = new_fragment(this->node, newfrag->ofs + newfrag->size,
 282                                                this->ofs + this->size - newfrag->ofs - newfrag->size);
 283                        if (unlikely(!newfrag2))
 284                                return -ENOMEM;
 285                        if (this->node)
 286                                this->node->frags++;
 287
 288                        /* Adjust size of original 'this' */
 289                        this->size = newfrag->ofs - this->ofs;
 290
 291                        /* Now, we know there's no node with offset
 292                           greater than this->ofs but smaller than
 293                           newfrag2->ofs or newfrag->ofs, for obvious
 294                           reasons. So we can do a tree insert from
 295                           'this' to insert newfrag, and a tree insert
 296                           from newfrag to insert newfrag2. */
 297                        jffs2_fragtree_insert(newfrag, this);
 298                        rb_insert_color(&newfrag->rb, root);
 299
 300                        jffs2_fragtree_insert(newfrag2, newfrag);
 301                        rb_insert_color(&newfrag2->rb, root);
 302
 303                        return 0;
 304                }
 305                /* New node just reduces 'this' frag in size, doesn't split it */
 306                this->size = newfrag->ofs - this->ofs;
 307
 308                /* Again, we know it lives down here in the tree */
 309                jffs2_fragtree_insert(newfrag, this);
 310                rb_insert_color(&newfrag->rb, root);
 311        } else {
 312                /* New frag starts at the same point as 'this' used to. Replace
 313                   it in the tree without doing a delete and insertion */
 314                dbg_fragtree2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
 315                          newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size);
 316
 317                rb_replace_node(&this->rb, &newfrag->rb, root);
 318
 319                if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
 320                        dbg_fragtree2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size);
 321                        jffs2_obsolete_node_frag(c, this);
 322                } else {
 323                        this->ofs += newfrag->size;
 324                        this->size -= newfrag->size;
 325
 326                        jffs2_fragtree_insert(this, newfrag);
 327                        rb_insert_color(&this->rb, root);
 328                        return 0;
 329                }
 330        }
 331        /* OK, now we have newfrag added in the correct place in the tree, but
 332           frag_next(newfrag) may be a fragment which is overlapped by it
 333        */
 334        while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
 335                /* 'this' frag is obsoleted completely. */
 336                dbg_fragtree2("obsoleting node frag %p (%x-%x) and removing from tree\n",
 337                        this, this->ofs, this->ofs+this->size);
 338                rb_erase(&this->rb, root);
 339                jffs2_obsolete_node_frag(c, this);
 340        }
 341        /* Now we're pointing at the first frag which isn't totally obsoleted by
 342           the new frag */
 343
 344        if (!this || newfrag->ofs + newfrag->size == this->ofs)
 345                return 0;
 346
 347        /* Still some overlap but we don't need to move it in the tree */
 348        this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
 349        this->ofs = newfrag->ofs + newfrag->size;
 350
 351        /* And mark them REF_NORMAL so the GC takes a look at them */
 352        if (this->node)
 353                mark_ref_normal(this->node->raw);
 354        mark_ref_normal(newfrag->node->raw);
 355
 356        return 0;
 357}
 358
 359/*
 360 * Given an inode, probably with existing tree of fragments, add the new node
 361 * to the fragment tree.
 362 */
 363int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
 364{
 365        int ret;
 366        struct jffs2_node_frag *newfrag;
 367
 368        if (unlikely(!fn->size))
 369                return 0;
 370
 371        newfrag = new_fragment(fn, fn->ofs, fn->size);
 372        if (unlikely(!newfrag))
 373                return -ENOMEM;
 374        newfrag->node->frags = 1;
 375
 376        dbg_fragtree("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
 377                  fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);
 378
 379        ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
 380        if (unlikely(ret))
 381                return ret;
 382
 383        /* If we now share a page with other nodes, mark either previous
 384           or next node REF_NORMAL, as appropriate.  */
 385        if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
 386                struct jffs2_node_frag *prev = frag_prev(newfrag);
 387
 388                mark_ref_normal(fn->raw);
 389                /* If we don't start at zero there's _always_ a previous */
 390                if (prev->node)
 391                        mark_ref_normal(prev->node->raw);
 392        }
 393
 394        if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
 395                struct jffs2_node_frag *next = frag_next(newfrag);
 396
 397                if (next) {
 398                        mark_ref_normal(fn->raw);
 399                        if (next->node)
 400                                mark_ref_normal(next->node->raw);
 401                }
 402        }
 403        jffs2_dbg_fragtree_paranoia_check_nolock(f);
 404
 405        return 0;
 406}
 407
 408void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
 409{
 410        spin_lock(&c->inocache_lock);
 411        ic->state = state;
 412        wake_up(&c->inocache_wq);
 413        spin_unlock(&c->inocache_lock);
 414}
 415
 416/* During mount, this needs no locking. During normal operation, its
 417   callers want to do other stuff while still holding the inocache_lock.
 418   Rather than introducing special case get_ino_cache functions or
 419   callbacks, we just let the caller do the locking itself. */
 420
 421struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
 422{
 423        struct jffs2_inode_cache *ret;
 424
 425        ret = c->inocache_list[ino % c->inocache_hashsize];
 426        while (ret && ret->ino < ino) {
 427                ret = ret->next;
 428        }
 429
 430        if (ret && ret->ino != ino)
 431                ret = NULL;
 432
 433        return ret;
 434}
 435
 436void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
 437{
 438        struct jffs2_inode_cache **prev;
 439
 440        spin_lock(&c->inocache_lock);
 441        if (!new->ino)
 442                new->ino = ++c->highest_ino;
 443
 444        dbg_inocache("add %p (ino #%u)\n", new, new->ino);
 445
 446        prev = &c->inocache_list[new->ino % c->inocache_hashsize];
 447
 448        while ((*prev) && (*prev)->ino < new->ino) {
 449                prev = &(*prev)->next;
 450        }
 451        new->next = *prev;
 452        *prev = new;
 453
 454        spin_unlock(&c->inocache_lock);
 455}
 456
 457void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
 458{
 459        struct jffs2_inode_cache **prev;
 460
 461#ifdef CONFIG_JFFS2_FS_XATTR
 462        BUG_ON(old->xref);
 463#endif
 464        dbg_inocache("del %p (ino #%u)\n", old, old->ino);
 465        spin_lock(&c->inocache_lock);
 466
 467        prev = &c->inocache_list[old->ino % c->inocache_hashsize];
 468
 469        while ((*prev) && (*prev)->ino < old->ino) {
 470                prev = &(*prev)->next;
 471        }
 472        if ((*prev) == old) {
 473                *prev = old->next;
 474        }
 475
 476        /* Free it now unless it's in READING or CLEARING state, which
 477           are the transitions upon read_inode() and clear_inode(). The
 478           rest of the time we know nobody else is looking at it, and
 479           if it's held by read_inode() or clear_inode() they'll free it
 480           for themselves. */
 481        if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
 482                jffs2_free_inode_cache(old);
 483
 484        spin_unlock(&c->inocache_lock);
 485}
 486
 487void jffs2_free_ino_caches(struct jffs2_sb_info *c)
 488{
 489        int i;
 490        struct jffs2_inode_cache *this, *next;
 491
 492        for (i=0; i < c->inocache_hashsize; i++) {
 493                this = c->inocache_list[i];
 494                while (this) {
 495                        next = this->next;
 496                        jffs2_xattr_free_inode(c, this);
 497                        jffs2_free_inode_cache(this);
 498                        this = next;
 499                }
 500                c->inocache_list[i] = NULL;
 501        }
 502}
 503
 504void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
 505{
 506        int i;
 507        struct jffs2_raw_node_ref *this, *next;
 508
 509        for (i=0; i<c->nr_blocks; i++) {
 510                this = c->blocks[i].first_node;
 511                while (this) {
 512                        if (this[REFS_PER_BLOCK].flash_offset == REF_LINK_NODE)
 513                                next = this[REFS_PER_BLOCK].next_in_ino;
 514                        else
 515                                next = NULL;
 516
 517                        jffs2_free_refblock(this);
 518                        this = next;
 519                }
 520                c->blocks[i].first_node = c->blocks[i].last_node = NULL;
 521        }
 522}
 523
 524struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
 525{
 526        /* The common case in lookup is that there will be a node
 527           which precisely matches. So we go looking for that first */
 528        struct rb_node *next;
 529        struct jffs2_node_frag *prev = NULL;
 530        struct jffs2_node_frag *frag = NULL;
 531
 532        dbg_fragtree2("root %p, offset %d\n", fragtree, offset);
 533
 534        next = fragtree->rb_node;
 535
 536        while(next) {
 537                frag = rb_entry(next, struct jffs2_node_frag, rb);
 538
 539                if (frag->ofs + frag->size <= offset) {
 540                        /* Remember the closest smaller match on the way down */
 541                        if (!prev || frag->ofs > prev->ofs)
 542                                prev = frag;
 543                        next = frag->rb.rb_right;
 544                } else if (frag->ofs > offset) {
 545                        next = frag->rb.rb_left;
 546                } else {
 547                        return frag;
 548                }
 549        }
 550
 551        /* Exact match not found. Go back up looking at each parent,
 552           and return the closest smaller one */
 553
 554        if (prev)
 555                dbg_fragtree2("no match. Returning frag %#04x-%#04x, closest previous\n",
 556                          prev->ofs, prev->ofs+prev->size);
 557        else
 558                dbg_fragtree2("returning NULL, empty fragtree\n");
 559
 560        return prev;
 561}
 562
 563/* Pass 'c' argument to indicate that nodes should be marked obsolete as
 564   they're killed. */
 565void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
 566{
 567        struct jffs2_node_frag *frag;
 568        struct jffs2_node_frag *parent;
 569
 570        if (!root->rb_node)
 571                return;
 572
 573        dbg_fragtree("killing\n");
 574
 575        frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
 576        while(frag) {
 577                if (frag->rb.rb_left) {
 578                        frag = frag_left(frag);
 579                        continue;
 580                }
 581                if (frag->rb.rb_right) {
 582                        frag = frag_right(frag);
 583                        continue;
 584                }
 585
 586                if (frag->node && !(--frag->node->frags)) {
 587                        /* Not a hole, and it's the final remaining frag
 588                           of this node. Free the node */
 589                        if (c)
 590                                jffs2_mark_node_obsolete(c, frag->node->raw);
 591
 592                        jffs2_free_full_dnode(frag->node);
 593                }
 594                parent = frag_parent(frag);
 595                if (parent) {
 596                        if (frag_left(parent) == frag)
 597                                parent->rb.rb_left = NULL;
 598                        else
 599                                parent->rb.rb_right = NULL;
 600                }
 601
 602                jffs2_free_node_frag(frag);
 603                frag = parent;
 604
 605                cond_resched();
 606        }
 607}
 608
 609struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
 610                                               struct jffs2_eraseblock *jeb,
 611                                               uint32_t ofs, uint32_t len,
 612                                               struct jffs2_inode_cache *ic)
 613{
 614        struct jffs2_raw_node_ref *ref;
 615
 616        BUG_ON(!jeb->allocated_refs);
 617        jeb->allocated_refs--;
 618
 619        ref = jeb->last_node;
 620
 621        dbg_noderef("Last node at %p is (%08x,%p)\n", ref, ref->flash_offset,
 622                    ref->next_in_ino);
 623
 624        while (ref->flash_offset != REF_EMPTY_NODE) {
 625                if (ref->flash_offset == REF_LINK_NODE)
 626                        ref = ref->next_in_ino;
 627                else
 628                        ref++;
 629        }
 630
 631        dbg_noderef("New ref is %p (%08x becomes %08x,%p) len 0x%x\n", ref, 
 632                    ref->flash_offset, ofs, ref->next_in_ino, len);
 633
 634        ref->flash_offset = ofs;
 635
 636        if (!jeb->first_node) {
 637                jeb->first_node = ref;
 638                BUG_ON(ref_offset(ref) != jeb->offset);
 639        } else if (unlikely(ref_offset(ref) != jeb->offset + c->sector_size - jeb->free_size)) {
 640                uint32_t last_len = ref_totlen(c, jeb, jeb->last_node);
 641
 642                JFFS2_ERROR("Adding new ref %p at (0x%08x-0x%08x) not immediately after previous (0x%08x-0x%08x)\n",
 643                            ref, ref_offset(ref), ref_offset(ref)+len,
 644                            ref_offset(jeb->last_node), 
 645                            ref_offset(jeb->last_node)+last_len);
 646                BUG();
 647        }
 648        jeb->last_node = ref;
 649
 650        if (ic) {
 651                ref->next_in_ino = ic->nodes;
 652                ic->nodes = ref;
 653        } else {
 654                ref->next_in_ino = NULL;
 655        }
 656
 657        switch(ref_flags(ref)) {
 658        case REF_UNCHECKED:
 659                c->unchecked_size += len;
 660                jeb->unchecked_size += len;
 661                break;
 662
 663        case REF_NORMAL:
 664        case REF_PRISTINE:
 665                c->used_size += len;
 666                jeb->used_size += len;
 667                break;
 668
 669        case REF_OBSOLETE:
 670                c->dirty_size += len;
 671                jeb->dirty_size += len;
 672                break;
 673        }
 674        c->free_size -= len;
 675        jeb->free_size -= len;
 676
 677#ifdef TEST_TOTLEN
 678        /* Set (and test) __totlen field... for now */
 679        ref->__totlen = len;
 680        ref_totlen(c, jeb, ref);
 681#endif
 682        return ref;
 683}
 684
 685/* No locking, no reservation of 'ref'. Do not use on a live file system */
 686int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 687                           uint32_t size)
 688{
 689        if (!size)
 690                return 0;
 691        if (unlikely(size > jeb->free_size)) {
 692                pr_crit("Dirty space 0x%x larger then free_size 0x%x (wasted 0x%x)\n",
 693                        size, jeb->free_size, jeb->wasted_size);
 694                BUG();
 695        }
 696        /* REF_EMPTY_NODE is !obsolete, so that works OK */
 697        if (jeb->last_node && ref_obsolete(jeb->last_node)) {
 698#ifdef TEST_TOTLEN
 699                jeb->last_node->__totlen += size;
 700#endif
 701                c->dirty_size += size;
 702                c->free_size -= size;
 703                jeb->dirty_size += size;
 704                jeb->free_size -= size;
 705        } else {
 706                uint32_t ofs = jeb->offset + c->sector_size - jeb->free_size;
 707                ofs |= REF_OBSOLETE;
 708
 709                jffs2_link_node_ref(c, jeb, ofs, size, NULL);
 710        }
 711
 712        return 0;
 713}
 714
 715/* Calculate totlen from surrounding nodes or eraseblock */
 716static inline uint32_t __ref_totlen(struct jffs2_sb_info *c,
 717                                    struct jffs2_eraseblock *jeb,
 718                                    struct jffs2_raw_node_ref *ref)
 719{
 720        uint32_t ref_end;
 721        struct jffs2_raw_node_ref *next_ref = ref_next(ref);
 722
 723        if (next_ref)
 724                ref_end = ref_offset(next_ref);
 725        else {
 726                if (!jeb)
 727                        jeb = &c->blocks[ref->flash_offset / c->sector_size];
 728
 729                /* Last node in block. Use free_space */
 730                if (unlikely(ref != jeb->last_node)) {
 731                        pr_crit("ref %p @0x%08x is not jeb->last_node (%p @0x%08x)\n",
 732                                ref, ref_offset(ref), jeb->last_node,
 733                                jeb->last_node ?
 734                                ref_offset(jeb->last_node) : 0);
 735                        BUG();
 736                }
 737                ref_end = jeb->offset + c->sector_size - jeb->free_size;
 738        }
 739        return ref_end - ref_offset(ref);
 740}
 741
 742uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 743                            struct jffs2_raw_node_ref *ref)
 744{
 745        uint32_t ret;
 746
 747        ret = __ref_totlen(c, jeb, ref);
 748
 749#ifdef TEST_TOTLEN
 750        if (unlikely(ret != ref->__totlen)) {
 751                if (!jeb)
 752                        jeb = &c->blocks[ref->flash_offset / c->sector_size];
 753
 754                pr_crit("Totlen for ref at %p (0x%08x-0x%08x) miscalculated as 0x%x instead of %x\n",
 755                        ref, ref_offset(ref), ref_offset(ref) + ref->__totlen,
 756                        ret, ref->__totlen);
 757                if (ref_next(ref)) {
 758                        pr_crit("next %p (0x%08x-0x%08x)\n",
 759                                ref_next(ref), ref_offset(ref_next(ref)),
 760                                ref_offset(ref_next(ref)) + ref->__totlen);
 761                } else 
 762                        pr_crit("No next ref. jeb->last_node is %p\n",
 763                                jeb->last_node);
 764
 765                pr_crit("jeb->wasted_size %x, dirty_size %x, used_size %x, free_size %x\n",
 766                        jeb->wasted_size, jeb->dirty_size, jeb->used_size,
 767                        jeb->free_size);
 768
 769#if defined(JFFS2_DBG_DUMPS) || defined(JFFS2_DBG_PARANOIA_CHECKS)
 770                __jffs2_dbg_dump_node_refs_nolock(c, jeb);
 771#endif
 772
 773                WARN_ON(1);
 774
 775                ret = ref->__totlen;
 776        }
 777#endif /* TEST_TOTLEN */
 778        return ret;
 779}
 780
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.