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   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: nodemgmt.c,v 1.125 2005/09/07 08:34:54 havasi Exp $
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/slab.h>
  16 #include <linux/mtd/mtd.h>
  17 #include <linux/compiler.h>
  18 #include <linux/sched.h> /* For cond_resched() */
  19 #include "nodelist.h"
  20 #include "debug.h"
  21
  22 /**
  23  *      jffs2_reserve_space - request physical space to write nodes to flash
  24  *      @c: superblock info
  25  *      @minsize: Minimum acceptable size of allocation
  26  *      @ofs: Returned value of node offset
  27  *      @len: Returned value of allocation length
  28  *      @prio: Allocation type - ALLOC_{NORMAL,DELETION}
  29  *
  30  *      Requests a block of physical space on the flash. Returns zero for success
  31  *      and puts 'ofs' and 'len' into the appriopriate place, or returns -ENOSPC
  32  *      or other error if appropriate.
  33  *
  34  *      If it returns zero, jffs2_reserve_space() also downs the per-filesystem
  35  *      allocation semaphore, to prevent more than one allocation from being
  36  *      active at any time. The semaphore is later released by jffs2_commit_allocation()
  37  *
  38  *      jffs2_reserve_space() may trigger garbage collection in order to make room
  39  *      for the requested allocation.
  40  */
  41
  42 static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
  43                                         uint32_t *ofs, uint32_t *len, uint32_t sumsize);
  44
  45 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *ofs,
  46                         uint32_t *len, int prio, uint32_t sumsize)
  47 {
  48         int ret = -EAGAIN;
  49         int blocksneeded = c->resv_blocks_write;
  50         /* align it */
  51         minsize = PAD(minsize);
  52
  53         D1(printk(KERN_DEBUG "jffs2_reserve_space(): Requested 0x%x bytes\n", minsize));
  54         down(&c->alloc_sem);
  55
  56         D1(printk(KERN_DEBUG "jffs2_reserve_space(): alloc sem got\n"));
  57
  58         spin_lock(&c->erase_completion_lock);
  59
  60         /* this needs a little more thought (true <tglx> :)) */
  61         while(ret == -EAGAIN) {
  62                 while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
  63                         int ret;
  64                         uint32_t dirty, avail;
  65
  66                         /* calculate real dirty size
  67                          * dirty_size contains blocks on erase_pending_list
  68                          * those blocks are counted in c->nr_erasing_blocks.
  69                          * If one block is actually erased, it is not longer counted as dirty_space
  70                          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
  71                          * with c->nr_erasing_blocks * c->sector_size again.
  72                          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
  73                          * This helps us to force gc and pick eventually a clean block to spread the load.
  74                          * We add unchecked_size here, as we hopefully will find some space to use.
  75                          * This will affect the sum only once, as gc first finishes checking
  76                          * of nodes.
  77                          */
  78                         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
  79                         if (dirty < c->nospc_dirty_size) {
  80                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
  81                                         D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion. Allowing...\n"));
  82                                         break;
  83                                 }
  84                                 D1(printk(KERN_DEBUG "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
  85                                           dirty, c->unchecked_size, c->sector_size));
  86
  87                                 spin_unlock(&c->erase_completion_lock);
  88                                 up(&c->alloc_sem);
  89                                 return -ENOSPC;
  90                         }
  91
  92                         /* Calc possibly available space. Possibly available means that we
  93                          * don't know, if unchecked size contains obsoleted nodes, which could give us some
  94                          * more usable space. This will affect the sum only once, as gc first finishes checking
  95                          * of nodes.
  96                          + Return -ENOSPC, if the maximum possibly available space is less or equal than
  97                          * blocksneeded * sector_size.
  98                          * This blocks endless gc looping on a filesystem, which is nearly full, even if
  99                          * the check above passes.
 100                          */
 101                         avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
 102                         if ( (avail / c->sector_size) <= blocksneeded) {
 103                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
 104                                         D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on possibly available space, but it's a deletion. Allowing...\n"));
 105                                         break;
 106                                 }
 107
 108                                 D1(printk(KERN_DEBUG "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
 109                                           avail, blocksneeded * c->sector_size));
 110                                 spin_unlock(&c->erase_completion_lock);
 111                                 up(&c->alloc_sem);
 112                                 return -ENOSPC;
 113                         }
 114
 115                         up(&c->alloc_sem);
 116
 117                         D1(printk(KERN_DEBUG "Triggering GC pass. nr_free_blocks %d, nr_erasing_blocks %d, free_size 0x%08x, dirty_size 0x%08x, wasted_size 0x%08x, used_size 0x%08x, erasing_size 0x%08x, bad_size 0x%08x (total 0x%08x of 0x%08x)\n",
 118                                   c->nr_free_blocks, c->nr_erasing_blocks, c->free_size, c->dirty_size, c->wasted_size, c->used_size, c->erasing_size, c->bad_size,
 119                                   c->free_size + c->dirty_size + c->wasted_size + c->used_size + c->erasing_size + c->bad_size, c->flash_size));
 120                         spin_unlock(&c->erase_completion_lock);
 121
 122                         ret = jffs2_garbage_collect_pass(c);
 123                         if (ret)
 124                                 return ret;
 125
 126                         cond_resched();
 127
 128                         if (signal_pending(current))
 129                                 return -EINTR;
 130
 131                         down(&c->alloc_sem);
 132                         spin_lock(&c->erase_completion_lock);
 133                 }
 134
 135                 ret = jffs2_do_reserve_space(c, minsize, ofs, len, sumsize);
 136                 if (ret) {
 137                         D1(printk(KERN_DEBUG "jffs2_reserve_space: ret is %d\n", ret));
 138                 }
 139         }
 140         spin_unlock(&c->erase_completion_lock);
 141         if (ret)
 142                 up(&c->alloc_sem);
 143         return ret;
 144 }
 145
 146 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *ofs,
 147                         uint32_t *len, uint32_t sumsize)
 148 {
 149         int ret = -EAGAIN;
 150         minsize = PAD(minsize);
 151
 152         D1(printk(KERN_DEBUG "jffs2_reserve_space_gc(): Requested 0x%x bytes\n", minsize));
 153
 154         spin_lock(&c->erase_completion_lock);
 155         while(ret == -EAGAIN) {
 156                 ret = jffs2_do_reserve_space(c, minsize, ofs, len, sumsize);
 157                 if (ret) {
 158                         D1(printk(KERN_DEBUG "jffs2_reserve_space_gc: looping, ret is %d\n", ret));
 159                 }
 160         }
 161         spin_unlock(&c->erase_completion_lock);
 162         return ret;
 163 }
 164
 165
 166 /* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
 167
 168 static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 169 {
 170
 171         /* Check, if we have a dirty block now, or if it was dirty already */
 172         if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
 173                 c->dirty_size += jeb->wasted_size;
 174                 c->wasted_size -= jeb->wasted_size;
 175                 jeb->dirty_size += jeb->wasted_size;
 176                 jeb->wasted_size = 0;
 177                 if (VERYDIRTY(c, jeb->dirty_size)) {
 178                         D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 179                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 180                         list_add_tail(&jeb->list, &c->very_dirty_list);
 181                 } else {
 182                         D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 183                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 184                         list_add_tail(&jeb->list, &c->dirty_list);
 185                 }
 186         } else {
 187                 D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 188                   jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 189                 list_add_tail(&jeb->list, &c->clean_list);
 190         }
 191         c->nextblock = NULL;
 192
 193 }
 194
 195 /* Select a new jeb for nextblock */
 196
 197 static int jffs2_find_nextblock(struct jffs2_sb_info *c)
 198 {
 199         struct list_head *next;
 200
 201         /* Take the next block off the 'free' list */
 202
 203         if (list_empty(&c->free_list)) {
 204
 205                 if (!c->nr_erasing_blocks &&
 206                         !list_empty(&c->erasable_list)) {
 207                         struct jffs2_eraseblock *ejeb;
 208
 209                         ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
 210                         list_del(&ejeb->list);
 211                         list_add_tail(&ejeb->list, &c->erase_pending_list);
 212                         c->nr_erasing_blocks++;
 213                         jffs2_erase_pending_trigger(c);
 214                         D1(printk(KERN_DEBUG "jffs2_find_nextblock: Triggering erase of erasable block at 0x%08x\n",
 215                                   ejeb->offset));
 216                 }
 217
 218                 if (!c->nr_erasing_blocks &&
 219                         !list_empty(&c->erasable_pending_wbuf_list)) {
 220                         D1(printk(KERN_DEBUG "jffs2_find_nextblock: Flushing write buffer\n"));
 221                         /* c->nextblock is NULL, no update to c->nextblock allowed */
 222                         spin_unlock(&c->erase_completion_lock);
 223                         jffs2_flush_wbuf_pad(c);
 224                         spin_lock(&c->erase_completion_lock);
 225                         /* Have another go. It'll be on the erasable_list now */
 226                         return -EAGAIN;
 227                 }
 228
 229                 if (!c->nr_erasing_blocks) {
 230                         /* Ouch. We're in GC, or we wouldn't have got here.
 231                            And there's no space left. At all. */
 232                         printk(KERN_CRIT "Argh. No free space left for GC. nr_erasing_blocks is %d. nr_free_blocks is %d. (erasableempty: %s, erasingempty: %s, erasependingempty: %s)\n",
 233                                    c->nr_erasing_blocks, c->nr_free_blocks, list_empty(&c->erasable_list)?"yes":"no",
 234                                    list_empty(&c->erasing_list)?"yes":"no", list_empty(&c->erase_pending_list)?"yes":"no");
 235                         return -ENOSPC;
 236                 }
 237
 238                 spin_unlock(&c->erase_completion_lock);
 239                 /* Don't wait for it; just erase one right now */
 240                 jffs2_erase_pending_blocks(c, 1);
 241                 spin_lock(&c->erase_completion_lock);
 242
 243                 /* An erase may have failed, decreasing the
 244                    amount of free space available. So we must
 245                    restart from the beginning */
 246                 return -EAGAIN;
 247         }
 248
 249         next = c->free_list.next;
 250         list_del(next);
 251         c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
 252         c->nr_free_blocks--;
 253
 254         jffs2_sum_reset_collected(c->summary); /* reset collected summary */
 255
 256         D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));
 257
 258         return 0;
 259 }
 260
 261 /* Called with alloc sem _and_ erase_completion_lock */
 262 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *ofs, uint32_t *len, uint32_t sumsize)
 263 {
 264         struct jffs2_eraseblock *jeb = c->nextblock;
 265         uint32_t reserved_size;                         /* for summary information at the end of the jeb */
 266         int ret;
 267
 268  restart:
 269         reserved_size = 0;
 270
 271         if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
 272                                                         /* NOSUM_SIZE means not to generate summary */
 273
 274                 if (jeb) {
 275                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 276                         JFFS2_DBG_SUMMARY("minsize=%d , jeb->free=%d ,"
 277                                                 "summary->size=%d , sumsize=%d\n",
 278                                                 minsize, jeb->free_size,
 279                                                 c->summary->sum_size, sumsize);
 280                 }
 281
 282                 /* Is there enough space for writing out the current node, or we have to
 283                    write out summary information now, close this jeb and select new nextblock? */
 284                 if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
 285                                         JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
 286
 287                         /* Has summary been disabled for this jeb? */
 288                         if (jffs2_sum_is_disabled(c->summary)) {
 289                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 290                                 goto restart;
 291                         }
 292
 293                         /* Writing out the collected summary information */
 294                         JFFS2_DBG_SUMMARY("generating summary for 0x%08x.\n", jeb->offset);
 295                         ret = jffs2_sum_write_sumnode(c);
 296
 297                         if (ret)
 298                                 return ret;
 299
 300                         if (jffs2_sum_is_disabled(c->summary)) {
 301                                 /* jffs2_write_sumnode() couldn't write out the summary information
 302                                    diabling summary for this jeb and free the collected information
 303                                  */
 304                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 305                                 goto restart;
 306                         }
 307
 308                         jffs2_close_nextblock(c, jeb);
 309                         jeb = NULL;
 310                 }
 311         } else {
 312                 if (jeb && minsize > jeb->free_size) {
 313                         /* Skip the end of this block and file it as having some dirty space */
 314                         /* If there's a pending write to it, flush now */
 315
 316                         if (jffs2_wbuf_dirty(c)) {
 317                                 spin_unlock(&c->erase_completion_lock);
 318                                 D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
 319                                 jffs2_flush_wbuf_pad(c);
 320                                 spin_lock(&c->erase_completion_lock);
 321                                 jeb = c->nextblock;
 322                                 goto restart;
 323                         }
 324
 325                         c->wasted_size += jeb->free_size;
 326                         c->free_size -= jeb->free_size;
 327                         jeb->wasted_size += jeb->free_size;
 328                         jeb->free_size = 0;
 329
 330                         jffs2_close_nextblock(c, jeb);
 331                         jeb = NULL;
 332                 }
 333         }
 334
 335         if (!jeb) {
 336
 337                 ret = jffs2_find_nextblock(c);
 338                 if (ret)
 339                         return ret;
 340
 341                 jeb = c->nextblock;
 342
 343                 if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 344                         printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
 345                         goto restart;
 346                 }
 347         }
 348         /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 349            enough space */
 350         *ofs = jeb->offset + (c->sector_size - jeb->free_size);
 351         *len = jeb->free_size - reserved_size;
 352
 353         if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 354             !jeb->first_node->next_in_ino) {
 355                 /* Only node in it beforehand was a CLEANMARKER node (we think).
 356                    So mark it obsolete now that there's going to be another node
 357                    in the block. This will reduce used_size to zero but We've
 358                    already set c->nextblock so that jffs2_mark_node_obsolete()
 359                    won't try to refile it to the dirty_list.
 360                 */
 361                 spin_unlock(&c->erase_completion_lock);
 362                 jffs2_mark_node_obsolete(c, jeb->first_node);
 363                 spin_lock(&c->erase_completion_lock);
 364         }
 365
 366         D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n", *len, *ofs));
 367         return 0;
 368 }
 369
 370 /**
 371  *      jffs2_add_physical_node_ref - add a physical node reference to the list
 372  *      @c: superblock info
 373  *      @new: new node reference to add
 374  *      @len: length of this physical node
 375  *      @dirty: dirty flag for new node
 376  *
 377  *      Should only be used to report nodes for which space has been allocated
 378  *      by jffs2_reserve_space.
 379  *
 380  *      Must be called with the alloc_sem held.
 381  */
 382
 383 int jffs2_add_physical_node_ref(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *new)
 384 {
 385         struct jffs2_eraseblock *jeb;
 386         uint32_t len;
 387
 388         jeb = &c->blocks[new->flash_offset / c->sector_size];
 389         len = ref_totlen(c, jeb, new);
 390
 391         D1(printk(KERN_DEBUG "jffs2_add_physical_node_ref(): Node at 0x%x(%d), size 0x%x\n", ref_offset(new), ref_flags(new), len));
 392 #if 1
 393         /* we could get some obsolete nodes after nextblock was refiled
 394            in wbuf.c */
 395         if ((c->nextblock || !ref_obsolete(new))
 396             &&(jeb != c->nextblock || ref_offset(new) != jeb->offset + (c->sector_size - jeb->free_size))) {
 397                 printk(KERN_WARNING "argh. node added in wrong place\n");
 398                 jffs2_free_raw_node_ref(new);
 399                 return -EINVAL;
 400         }
 401 #endif
 402         spin_lock(&c->erase_completion_lock);
 403
 404         if (!jeb->first_node)
 405                 jeb->first_node = new;
 406         if (jeb->last_node)
 407                 jeb->last_node->next_phys = new;
 408         jeb->last_node = new;
 409
 410         jeb->free_size -= len;
 411         c->free_size -= len;
 412         if (ref_obsolete(new)) {
 413                 jeb->dirty_size += len;
 414                 c->dirty_size += len;
 415         } else {
 416                 jeb->used_size += len;
 417                 c->used_size += len;
 418         }
 419
 420         if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 421                 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 422                 D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 423                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 424                 if (jffs2_wbuf_dirty(c)) {
 425                         /* Flush the last write in the block if it's outstanding */
 426                         spin_unlock(&c->erase_completion_lock);
 427                         jffs2_flush_wbuf_pad(c);
 428                         spin_lock(&c->erase_completion_lock);
 429                 }
 430
 431                 list_add_tail(&jeb->list, &c->clean_list);
 432                 c->nextblock = NULL;
 433         }
 434         jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 435         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 436
 437         spin_unlock(&c->erase_completion_lock);
 438
 439         return 0;
 440 }
 441
 442
 443 void jffs2_complete_reservation(struct jffs2_sb_info *c)
 444 {
 445         D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
 446         jffs2_garbage_collect_trigger(c);
 447         up(&c->alloc_sem);
 448 }
 449
 450 static inline int on_list(struct list_head *obj, struct list_head *head)
 451 {
 452         struct list_head *this;
 453
 454         list_for_each(this, head) {
 455                 if (this == obj) {
 456                         D1(printk("%p is on list at %p\n", obj, head));
 457                         return 1;
 458
 459                 }
 460         }
 461         return 0;
 462 }
 463
 464 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 465 {
 466         struct jffs2_eraseblock *jeb;
 467         int blocknr;
 468         struct jffs2_unknown_node n;
 469         int ret, addedsize;
 470         size_t retlen;
 471
 472         if(!ref) {
 473                 printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 474                 return;
 475         }
 476         if (ref_obsolete(ref)) {
 477                 D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
 478                 return;
 479         }
 480         blocknr = ref->flash_offset / c->sector_size;
 481         if (blocknr >= c->nr_blocks) {
 482                 printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
 483                 BUG();
 484         }
 485         jeb = &c->blocks[blocknr];
 486
 487         if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 488             !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 489                 /* Hm. This may confuse static lock analysis. If any of the above
 490                    three conditions is false, we're going to return from this
 491                    function without actually obliterating any nodes or freeing
 492                    any jffs2_raw_node_refs. So we don't need to stop erases from
 493                    happening, or protect against people holding an obsolete
 494                    jffs2_raw_node_ref without the erase_completion_lock. */
 495                 down(&c->erase_free_sem);
 496         }
 497
 498         spin_lock(&c->erase_completion_lock);
 499
 500         if (ref_flags(ref) == REF_UNCHECKED) {
 501                 D1(if (unlikely(jeb->unchecked_size < ref_totlen(c, jeb, ref))) {
 502                         printk(KERN_NOTICE "raw unchecked node of size 0x%08x freed from erase block %d at 0x%08x, but unchecked_size was already 0x%08x\n",
 503                                ref_totlen(c, jeb, ref), blocknr, ref->flash_offset, jeb->used_size);
 504                         BUG();
 505                 })
 506                 D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), ref_totlen(c, jeb, ref)));
 507                 jeb->unchecked_size -= ref_totlen(c, jeb, ref);
 508                 c->unchecked_size -= ref_totlen(c, jeb, ref);
 509         } else {
 510                 D1(if (unlikely(jeb->used_size < ref_totlen(c, jeb, ref))) {
 511                         printk(KERN_NOTICE "raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
 512                                ref_totlen(c, jeb, ref), blocknr, ref->flash_offset, jeb->used_size);
 513                         BUG();
 514                 })
 515                 D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), ref_totlen(c, jeb, ref)));
 516                 jeb->used_size -= ref_totlen(c, jeb, ref);
 517                 c->used_size -= ref_totlen(c, jeb, ref);
 518         }
 519
 520         // Take care, that wasted size is taken into concern
 521         if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + ref_totlen(c, jeb, ref))) && jeb != c->nextblock) {
 522                 D1(printk(KERN_DEBUG "Dirtying\n"));
 523                 addedsize = ref_totlen(c, jeb, ref);
 524                 jeb->dirty_size += ref_totlen(c, jeb, ref);
 525                 c->dirty_size += ref_totlen(c, jeb, ref);
 526
 527                 /* Convert wasted space to dirty, if not a bad block */
 528                 if (jeb->wasted_size) {
 529                         if (on_list(&jeb->list, &c->bad_used_list)) {
 530                                 D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
 531                                           jeb->offset));
 532                                 addedsize = 0; /* To fool the refiling code later */
 533                         } else {
 534                                 D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
 535                                           jeb->wasted_size, jeb->offset));
 536                                 addedsize += jeb->wasted_size;
 537                                 jeb->dirty_size += jeb->wasted_size;
 538                                 c->dirty_size += jeb->wasted_size;
 539                                 c->wasted_size -= jeb->wasted_size;
 540                                 jeb->wasted_size = 0;
 541                         }
 542                 }
 543         } else {
 544                 D1(printk(KERN_DEBUG "Wasting\n"));
 545                 addedsize = 0;
 546                 jeb->wasted_size += ref_totlen(c, jeb, ref);
 547                 c->wasted_size += ref_totlen(c, jeb, ref);
 548         }
 549         ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 550
 551         jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 552         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 553
 554         if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 555                 /* Flash scanning is in progress. Don't muck about with the block
 556                    lists because they're not ready yet, and don't actually
 557                    obliterate nodes that look obsolete. If they weren't
 558                    marked obsolete on the flash at the time they _became_
 559                    obsolete, there was probably a reason for that. */
 560                 spin_unlock(&c->erase_completion_lock);
 561                 /* We didn't lock the erase_free_sem */
 562                 return;
 563         }
 564
 565         if (jeb == c->nextblock) {
 566                 D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
 567         } else if (!jeb->used_size && !jeb->unchecked_size) {
 568                 if (jeb == c->gcblock) {
 569                         D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
 570                         c->gcblock = NULL;
 571                 } else {
 572                         D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
 573                         list_del(&jeb->list);
 574                 }
 575                 if (jffs2_wbuf_dirty(c)) {
 576                         D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
 577                         list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 578                 } else {
 579                         if (jiffies & 127) {
 580                                 /* Most of the time, we just erase it immediately. Otherwise we
 581                                    spend ages scanning it on mount, etc. */
 582                                 D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
 583                                 list_add_tail(&jeb->list, &c->erase_pending_list);
 584                                 c->nr_erasing_blocks++;
 585                                 jffs2_erase_pending_trigger(c);
 586                         } else {
 587                                 /* Sometimes, however, we leave it elsewhere so it doesn't get
 588                                    immediately reused, and we spread the load a bit. */
 589                                 D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
 590                                 list_add_tail(&jeb->list, &c->erasable_list);
 591                         }
 592                 }
 593                 D1(printk(KERN_DEBUG "Done OK\n"));
 594         } else if (jeb == c->gcblock) {
 595                 D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
 596         } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 597                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
 598                 list_del(&jeb->list);
 599                 D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
 600                 list_add_tail(&jeb->list, &c->dirty_list);
 601         } else if (VERYDIRTY(c, jeb->dirty_size) &&
 602                    !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 603                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
 604                 list_del(&jeb->list);
 605                 D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
 606                 list_add_tail(&jeb->list, &c->very_dirty_list);
 607         } else {
 608                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 609                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 610         }
 611
 612         spin_unlock(&c->erase_completion_lock);
 613
 614         if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 615                 (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 616                 /* We didn't lock the erase_free_sem */
 617                 return;
 618         }
 619
 620         /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 621            and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 622            the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 623            by jffs2_free_all_node_refs() in erase.c. Which is nice. */
 624
 625         D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
 626         ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 627         if (ret) {
 628                 printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 629                 goto out_erase_sem;
 630         }
 631         if (retlen != sizeof(n)) {
 632                 printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 633                 goto out_erase_sem;
 634         }
 635         if (PAD(je32_to_cpu(n.totlen)) != PAD(ref_totlen(c, jeb, ref))) {
 636                 printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), ref_totlen(c, jeb, ref));
 637                 goto out_erase_sem;
 638         }
 639         if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 640                 D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
 641                 goto out_erase_sem;
 642         }
 643         /* XXX FIXME: This is ugly now */
 644         n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 645         ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 646         if (ret) {
 647                 printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 648                 goto out_erase_sem;
 649         }
 650         if (retlen != sizeof(n)) {
 651                 printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 652                 goto out_erase_sem;
 653         }
 654
 655         /* Nodes which have been marked obsolete no longer need to be
 656            associated with any inode. Remove them from the per-inode list.
 657
 658            Note we can't do this for NAND at the moment because we need
 659            obsolete dirent nodes to stay on the lists, because of the
 660            horridness in jffs2_garbage_collect_deletion_dirent(). Also
 661            because we delete the inocache, and on NAND we need that to
 662            stay around until all the nodes are actually erased, in order
 663            to stop us from giving the same inode number to another newly
 664            created inode. */
 665         if (ref->next_in_ino) {
 666                 struct jffs2_inode_cache *ic;
 667                 struct jffs2_raw_node_ref **p;
 668
 669                 spin_lock(&c->erase_completion_lock);
 670
 671                 ic = jffs2_raw_ref_to_ic(ref);
 672                 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 673                         ;
 674
 675                 *p = ref->next_in_ino;
 676                 ref->next_in_ino = NULL;
 677
 678                 if (ic->nodes == (void *)ic && ic->nlink == 0)
 679                         jffs2_del_ino_cache(c, ic);
 680
 681                 spin_unlock(&c->erase_completion_lock);
 682         }
 683
 684
 685         /* Merge with the next node in the physical list, if there is one
 686            and if it's also obsolete and if it doesn't belong to any inode */
 687         if (ref->next_phys && ref_obsolete(ref->next_phys) &&
 688             !ref->next_phys->next_in_ino) {
 689                 struct jffs2_raw_node_ref *n = ref->next_phys;
 690
 691                 spin_lock(&c->erase_completion_lock);
 692
 693                 ref->__totlen += n->__totlen;
 694                 ref->next_phys = n->next_phys;
 695                 if (jeb->last_node == n) jeb->last_node = ref;
 696                 if (jeb->gc_node == n) {
 697                         /* gc will be happy continuing gc on this node */
 698                         jeb->gc_node=ref;
 699                 }
 700                 spin_unlock(&c->erase_completion_lock);
 701
 702                 jffs2_free_raw_node_ref(n);
 703         }
 704
 705         /* Also merge with the previous node in the list, if there is one
 706            and that one is obsolete */
 707         if (ref != jeb->first_node ) {
 708                 struct jffs2_raw_node_ref *p = jeb->first_node;
 709
 710                 spin_lock(&c->erase_completion_lock);
 711
 712                 while (p->next_phys != ref)
 713                         p = p->next_phys;
 714
 715                 if (ref_obsolete(p) && !ref->next_in_ino) {
 716                         p->__totlen += ref->__totlen;
 717                         if (jeb->last_node == ref) {
 718                                 jeb->last_node = p;
 719                         }
 720                         if (jeb->gc_node == ref) {
 721                                 /* gc will be happy continuing gc on this node */
 722                                 jeb->gc_node=p;
 723                         }
 724                         p->next_phys = ref->next_phys;
 725                         jffs2_free_raw_node_ref(ref);
 726                 }
 727                 spin_unlock(&c->erase_completion_lock);
 728         }
 729  out_erase_sem:
 730         up(&c->erase_free_sem);
 731 }
 732
 733 int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 734 {
 735         int ret = 0;
 736         uint32_t dirty;
 737
 738         if (c->unchecked_size) {
 739                 D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 740                           c->unchecked_size, c->checked_ino));
 741                 return 1;
 742         }
 743
 744         /* dirty_size contains blocks on erase_pending_list
 745          * those blocks are counted in c->nr_erasing_blocks.
 746          * If one block is actually erased, it is not longer counted as dirty_space
 747          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 748          * with c->nr_erasing_blocks * c->sector_size again.
 749          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 750          * This helps us to force gc and pick eventually a clean block to spread the load.
 751          */
 752         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 753
 754         if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 755                         (dirty > c->nospc_dirty_size))
 756                 ret = 1;
 757
 758         D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x: %s\n",
 759                   c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, ret?"yes":"no"));
 760
 761         return ret;
 762 }