fs/jffs2/nodemgmt.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: nodemgmt.c,v 1.127 2005/09/20 15:49:12 dedekind 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                         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                         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                         /* keep always valid value in reserved_size */
 311                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 312                 }
 313         } else {
 314                 if (jeb && minsize > jeb->free_size) {
 315                         /* Skip the end of this block and file it as having some dirty space */
 316                         /* If there's a pending write to it, flush now */
 317
 318                         if (jffs2_wbuf_dirty(c)) {
 319                                 spin_unlock(&c->erase_completion_lock);
 320                                 D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
 321                                 jffs2_flush_wbuf_pad(c);
 322                                 spin_lock(&c->erase_completion_lock);
 323                                 jeb = c->nextblock;
 324                                 goto restart;
 325                         }
 326
 327                         c->wasted_size += jeb->free_size;
 328                         c->free_size -= jeb->free_size;
 329                         jeb->wasted_size += jeb->free_size;
 330                         jeb->free_size = 0;
 331
 332                         jffs2_close_nextblock(c, jeb);
 333                         jeb = NULL;
 334                 }
 335         }
 336
 337         if (!jeb) {
 338
 339                 ret = jffs2_find_nextblock(c);
 340                 if (ret)
 341                         return ret;
 342
 343                 jeb = c->nextblock;
 344
 345                 if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 346                         printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
 347                         goto restart;
 348                 }
 349         }
 350         /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 351            enough space */
 352         *ofs = jeb->offset + (c->sector_size - jeb->free_size);
 353         *len = jeb->free_size - reserved_size;
 354
 355         if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 356             !jeb->first_node->next_in_ino) {
 357                 /* Only node in it beforehand was a CLEANMARKER node (we think).
 358                    So mark it obsolete now that there's going to be another node
 359                    in the block. This will reduce used_size to zero but We've
 360                    already set c->nextblock so that jffs2_mark_node_obsolete()
 361                    won't try to refile it to the dirty_list.
 362                 */
 363                 spin_unlock(&c->erase_completion_lock);
 364                 jffs2_mark_node_obsolete(c, jeb->first_node);
 365                 spin_lock(&c->erase_completion_lock);
 366         }
 367
 368         D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n", *len, *ofs));
 369         return 0;
 370 }
 371
 372 /**
 373  *      jffs2_add_physical_node_ref - add a physical node reference to the list
 374  *      @c: superblock info
 375  *      @new: new node reference to add
 376  *      @len: length of this physical node
 377  *
 378  *      Should only be used to report nodes for which space has been allocated
 379  *      by jffs2_reserve_space.
 380  *
 381  *      Must be called with the alloc_sem held.
 382  */
 383
 384 int jffs2_add_physical_node_ref(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *new, uint32_t len)
 385 {
 386         struct jffs2_eraseblock *jeb;
 387
 388         jeb = &c->blocks[new->flash_offset / c->sector_size];
 389 #ifdef TEST_TOTLEN
 390         new->__totlen = len;
 391 #endif
 392
 393         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));
 394 #if 1
 395         /* we could get some obsolete nodes after nextblock was refiled
 396            in wbuf.c */
 397         if ((c->nextblock || !ref_obsolete(new))
 398             &&(jeb != c->nextblock || ref_offset(new) != jeb->offset + (c->sector_size - jeb->free_size))) {
 399                 printk(KERN_WARNING "argh. node added in wrong place\n");
 400                 jffs2_free_raw_node_ref(new);
 401                 return -EINVAL;
 402         }
 403 #endif
 404         spin_lock(&c->erase_completion_lock);
 405
 406         jffs2_link_node_ref(c, jeb, new, len);
 407
 408         if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 409                 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 410                 D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 411                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 412                 if (jffs2_wbuf_dirty(c)) {
 413                         /* Flush the last write in the block if it's outstanding */
 414                         spin_unlock(&c->erase_completion_lock);
 415                         jffs2_flush_wbuf_pad(c);
 416                         spin_lock(&c->erase_completion_lock);
 417                 }
 418
 419                 list_add_tail(&jeb->list, &c->clean_list);
 420                 c->nextblock = NULL;
 421         }
 422         jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 423         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 424
 425         spin_unlock(&c->erase_completion_lock);
 426
 427         return 0;
 428 }
 429
 430
 431 void jffs2_complete_reservation(struct jffs2_sb_info *c)
 432 {
 433         D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
 434         jffs2_garbage_collect_trigger(c);
 435         up(&c->alloc_sem);
 436 }
 437
 438 static inline int on_list(struct list_head *obj, struct list_head *head)
 439 {
 440         struct list_head *this;
 441
 442         list_for_each(this, head) {
 443                 if (this == obj) {
 444                         D1(printk("%p is on list at %p\n", obj, head));
 445                         return 1;
 446
 447                 }
 448         }
 449         return 0;
 450 }
 451
 452 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 453 {
 454         struct jffs2_eraseblock *jeb;
 455         int blocknr;
 456         struct jffs2_unknown_node n;
 457         int ret, addedsize;
 458         size_t retlen;
 459         uint32_t freed_len;
 460
 461         if(!ref) {
 462                 printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 463                 return;
 464         }
 465         if (ref_obsolete(ref)) {
 466                 D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
 467                 return;
 468         }
 469         blocknr = ref->flash_offset / c->sector_size;
 470         if (blocknr >= c->nr_blocks) {
 471                 printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
 472                 BUG();
 473         }
 474         jeb = &c->blocks[blocknr];
 475
 476         if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 477             !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 478                 /* Hm. This may confuse static lock analysis. If any of the above
 479                    three conditions is false, we're going to return from this
 480                    function without actually obliterating any nodes or freeing
 481                    any jffs2_raw_node_refs. So we don't need to stop erases from
 482                    happening, or protect against people holding an obsolete
 483                    jffs2_raw_node_ref without the erase_completion_lock. */
 484                 down(&c->erase_free_sem);
 485         }
 486
 487         spin_lock(&c->erase_completion_lock);
 488
 489         freed_len = ref_totlen(c, jeb, ref);
 490
 491         if (ref_flags(ref) == REF_UNCHECKED) {
 492                 D1(if (unlikely(jeb->unchecked_size < freed_len)) {
 493                         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",
 494                                freed_len, blocknr, ref->flash_offset, jeb->used_size);
 495                         BUG();
 496                 })
 497                 D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), freed_len));
 498                 jeb->unchecked_size -= freed_len;
 499                 c->unchecked_size -= freed_len;
 500         } else {
 501                 D1(if (unlikely(jeb->used_size < freed_len)) {
 502                         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",
 503                                freed_len, blocknr, ref->flash_offset, jeb->used_size);
 504                         BUG();
 505                 })
 506                 D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), freed_len));
 507                 jeb->used_size -= freed_len;
 508                 c->used_size -= freed_len;
 509         }
 510
 511         // Take care, that wasted size is taken into concern
 512         if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
 513                 D1(printk(KERN_DEBUG "Dirtying\n"));
 514                 addedsize = freed_len;
 515                 jeb->dirty_size += freed_len;
 516                 c->dirty_size += freed_len;
 517
 518                 /* Convert wasted space to dirty, if not a bad block */
 519                 if (jeb->wasted_size) {
 520                         if (on_list(&jeb->list, &c->bad_used_list)) {
 521                                 D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
 522                                           jeb->offset));
 523                                 addedsize = 0; /* To fool the refiling code later */
 524                         } else {
 525                                 D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
 526                                           jeb->wasted_size, jeb->offset));
 527                                 addedsize += jeb->wasted_size;
 528                                 jeb->dirty_size += jeb->wasted_size;
 529                                 c->dirty_size += jeb->wasted_size;
 530                                 c->wasted_size -= jeb->wasted_size;
 531                                 jeb->wasted_size = 0;
 532                         }
 533                 }
 534         } else {
 535                 D1(printk(KERN_DEBUG "Wasting\n"));
 536                 addedsize = 0;
 537                 jeb->wasted_size += freed_len;
 538                 c->wasted_size += freed_len;
 539         }
 540         ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 541
 542         jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 543         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 544
 545         if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 546                 /* Flash scanning is in progress. Don't muck about with the block
 547                    lists because they're not ready yet, and don't actually
 548                    obliterate nodes that look obsolete. If they weren't
 549                    marked obsolete on the flash at the time they _became_
 550                    obsolete, there was probably a reason for that. */
 551                 spin_unlock(&c->erase_completion_lock);
 552                 /* We didn't lock the erase_free_sem */
 553                 return;
 554         }
 555
 556         if (jeb == c->nextblock) {
 557                 D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
 558         } else if (!jeb->used_size && !jeb->unchecked_size) {
 559                 if (jeb == c->gcblock) {
 560                         D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
 561                         c->gcblock = NULL;
 562                 } else {
 563                         D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
 564                         list_del(&jeb->list);
 565                 }
 566                 if (jffs2_wbuf_dirty(c)) {
 567                         D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
 568                         list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 569                 } else {
 570                         if (jiffies & 127) {
 571                                 /* Most of the time, we just erase it immediately. Otherwise we
 572                                    spend ages scanning it on mount, etc. */
 573                                 D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
 574                                 list_add_tail(&jeb->list, &c->erase_pending_list);
 575                                 c->nr_erasing_blocks++;
 576                                 jffs2_erase_pending_trigger(c);
 577                         } else {
 578                                 /* Sometimes, however, we leave it elsewhere so it doesn't get
 579                                    immediately reused, and we spread the load a bit. */
 580                                 D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
 581                                 list_add_tail(&jeb->list, &c->erasable_list);
 582                         }
 583                 }
 584                 D1(printk(KERN_DEBUG "Done OK\n"));
 585         } else if (jeb == c->gcblock) {
 586                 D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
 587         } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 588                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
 589                 list_del(&jeb->list);
 590                 D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
 591                 list_add_tail(&jeb->list, &c->dirty_list);
 592         } else if (VERYDIRTY(c, jeb->dirty_size) &&
 593                    !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 594                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
 595                 list_del(&jeb->list);
 596                 D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
 597                 list_add_tail(&jeb->list, &c->very_dirty_list);
 598         } else {
 599                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 600                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 601         }
 602
 603         spin_unlock(&c->erase_completion_lock);
 604
 605         if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 606                 (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 607                 /* We didn't lock the erase_free_sem */
 608                 return;
 609         }
 610
 611         /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 612            and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 613            the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 614            by jffs2_free_all_node_refs() in erase.c. Which is nice. */
 615
 616         D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
 617         ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 618         if (ret) {
 619                 printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 620                 goto out_erase_sem;
 621         }
 622         if (retlen != sizeof(n)) {
 623                 printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 624                 goto out_erase_sem;
 625         }
 626         if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
 627                 printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), freed_len);
 628                 goto out_erase_sem;
 629         }
 630         if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 631                 D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
 632                 goto out_erase_sem;
 633         }
 634         /* XXX FIXME: This is ugly now */
 635         n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 636         ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 637         if (ret) {
 638                 printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 639                 goto out_erase_sem;
 640         }
 641         if (retlen != sizeof(n)) {
 642                 printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 643                 goto out_erase_sem;
 644         }
 645
 646         /* Nodes which have been marked obsolete no longer need to be
 647            associated with any inode. Remove them from the per-inode list.
 648
 649            Note we can't do this for NAND at the moment because we need
 650            obsolete dirent nodes to stay on the lists, because of the
 651            horridness in jffs2_garbage_collect_deletion_dirent(). Also
 652            because we delete the inocache, and on NAND we need that to
 653            stay around until all the nodes are actually erased, in order
 654            to stop us from giving the same inode number to another newly
 655            created inode. */
 656         if (ref->next_in_ino) {
 657                 struct jffs2_inode_cache *ic;
 658                 struct jffs2_raw_node_ref **p;
 659
 660                 spin_lock(&c->erase_completion_lock);
 661
 662                 ic = jffs2_raw_ref_to_ic(ref);
 663                 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 664                         ;
 665
 666                 *p = ref->next_in_ino;
 667                 ref->next_in_ino = NULL;
 668
 669                 if (ic->nodes == (void *)ic && ic->nlink == 0)
 670                         jffs2_del_ino_cache(c, ic);
 671
 672                 spin_unlock(&c->erase_completion_lock);
 673         }
 674
 675
 676         /* Merge with the next node in the physical list, if there is one
 677            and if it's also obsolete and if it doesn't belong to any inode */
 678         if (ref->next_phys && ref_obsolete(ref->next_phys) &&
 679             !ref->next_phys->next_in_ino) {
 680                 struct jffs2_raw_node_ref *n = ref->next_phys;
 681
 682                 spin_lock(&c->erase_completion_lock);
 683
 684 #ifdef TEST_TOTLEN
 685                 ref->__totlen += n->__totlen;
 686 #endif
 687                 ref->next_phys = n->next_phys;
 688                 if (jeb->last_node == n) jeb->last_node = ref;
 689                 if (jeb->gc_node == n) {
 690                         /* gc will be happy continuing gc on this node */
 691                         jeb->gc_node=ref;
 692                 }
 693                 spin_unlock(&c->erase_completion_lock);
 694
 695                 jffs2_free_raw_node_ref(n);
 696         }
 697
 698         /* Also merge with the previous node in the list, if there is one
 699            and that one is obsolete */
 700         if (ref != jeb->first_node ) {
 701                 struct jffs2_raw_node_ref *p = jeb->first_node;
 702
 703                 spin_lock(&c->erase_completion_lock);
 704
 705                 while (p->next_phys != ref)
 706                         p = p->next_phys;
 707
 708                 if (ref_obsolete(p) && !ref->next_in_ino) {
 709 #ifdef TEST_TOTLEN
 710                         p->__totlen += ref->__totlen;
 711 #endif
 712                         if (jeb->last_node == ref) {
 713                                 jeb->last_node = p;
 714                         }
 715                         if (jeb->gc_node == ref) {
 716                                 /* gc will be happy continuing gc on this node */
 717                                 jeb->gc_node=p;
 718                         }
 719                         p->next_phys = ref->next_phys;
 720                         jffs2_free_raw_node_ref(ref);
 721                 }
 722                 spin_unlock(&c->erase_completion_lock);
 723         }
 724  out_erase_sem:
 725         up(&c->erase_free_sem);
 726 }
 727
 728 int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 729 {
 730         int ret = 0;
 731         uint32_t dirty;
 732
 733         if (c->unchecked_size) {
 734                 D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 735                           c->unchecked_size, c->checked_ino));
 736                 return 1;
 737         }
 738
 739         /* dirty_size contains blocks on erase_pending_list
 740          * those blocks are counted in c->nr_erasing_blocks.
 741          * If one block is actually erased, it is not longer counted as dirty_space
 742          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 743          * with c->nr_erasing_blocks * c->sector_size again.
 744          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 745          * This helps us to force gc and pick eventually a clean block to spread the load.
 746          */
 747         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 748
 749         if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 750                         (dirty > c->nospc_dirty_size))
 751                 ret = 1;
 752
 753         D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x: %s\n",
 754                   c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, ret?"yes":"no"));
 755
 756         return ret;
 757 }