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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 1.127 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  *      @len: Returned value of allocation length
  27  *      @prio: Allocation type - ALLOC_{NORMAL,DELETION}
  28  *
  29  *      Requests a block of physical space on the flash. Returns zero for success
  30  *      and puts 'len' into the appropriate place, or returns -ENOSPC or other
  31  *      error if appropriate. Doesn't return len since that's
  32  *
  33  *      If it returns zero, jffs2_reserve_space() also downs the per-filesystem
  34  *      allocation semaphore, to prevent more than one allocation from being
  35  *      active at any time. The semaphore is later released by jffs2_commit_allocation()
  36  *
  37  *      jffs2_reserve_space() may trigger garbage collection in order to make room
  38  *      for the requested allocation.
  39  */
  40
  41 static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
  42                                   uint32_t *len, uint32_t sumsize);
  43
  44 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
  45                         uint32_t *len, int prio, uint32_t sumsize)
  46 {
  47         int ret = -EAGAIN;
  48         int blocksneeded = c->resv_blocks_write;
  49         /* align it */
  50         minsize = PAD(minsize);
  51
  52         D1(printk(KERN_DEBUG "jffs2_reserve_space(): Requested 0x%x bytes\n", minsize));
  53         down(&c->alloc_sem);
  54
  55         D1(printk(KERN_DEBUG "jffs2_reserve_space(): alloc sem got\n"));
  56
  57         spin_lock(&c->erase_completion_lock);
  58
  59         /* this needs a little more thought (true <tglx> :)) */
  60         while(ret == -EAGAIN) {
  61                 while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
  62                         int ret;
  63                         uint32_t dirty, avail;
  64
  65                         /* calculate real dirty size
  66                          * dirty_size contains blocks on erase_pending_list
  67                          * those blocks are counted in c->nr_erasing_blocks.
  68                          * If one block is actually erased, it is not longer counted as dirty_space
  69                          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
  70                          * with c->nr_erasing_blocks * c->sector_size again.
  71                          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
  72                          * This helps us to force gc and pick eventually a clean block to spread the load.
  73                          * We add unchecked_size here, as we hopefully will find some space to use.
  74                          * This will affect the sum only once, as gc first finishes checking
  75                          * of nodes.
  76                          */
  77                         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
  78                         if (dirty < c->nospc_dirty_size) {
  79                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
  80                                         D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion. Allowing...\n"));
  81                                         break;
  82                                 }
  83                                 D1(printk(KERN_DEBUG "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
  84                                           dirty, c->unchecked_size, c->sector_size));
  85
  86                                 spin_unlock(&c->erase_completion_lock);
  87                                 up(&c->alloc_sem);
  88                                 return -ENOSPC;
  89                         }
  90
  91                         /* Calc possibly available space. Possibly available means that we
  92                          * don't know, if unchecked size contains obsoleted nodes, which could give us some
  93                          * more usable space. This will affect the sum only once, as gc first finishes checking
  94                          * of nodes.
  95                          + Return -ENOSPC, if the maximum possibly available space is less or equal than
  96                          * blocksneeded * sector_size.
  97                          * This blocks endless gc looping on a filesystem, which is nearly full, even if
  98                          * the check above passes.
  99                          */
 100                         avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
 101                         if ( (avail / c->sector_size) <= blocksneeded) {
 102                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
 103                                         D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on possibly available space, but it's a deletion. Allowing...\n"));
 104                                         break;
 105                                 }
 106
 107                                 D1(printk(KERN_DEBUG "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
 108                                           avail, blocksneeded * c->sector_size));
 109                                 spin_unlock(&c->erase_completion_lock);
 110                                 up(&c->alloc_sem);
 111                                 return -ENOSPC;
 112                         }
 113
 114                         up(&c->alloc_sem);
 115
 116                         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",
 117                                   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,
 118                                   c->free_size + c->dirty_size + c->wasted_size + c->used_size + c->erasing_size + c->bad_size, c->flash_size));
 119                         spin_unlock(&c->erase_completion_lock);
 120
 121                         ret = jffs2_garbage_collect_pass(c);
 122                         if (ret)
 123                                 return ret;
 124
 125                         cond_resched();
 126
 127                         if (signal_pending(current))
 128                                 return -EINTR;
 129
 130                         down(&c->alloc_sem);
 131                         spin_lock(&c->erase_completion_lock);
 132                 }
 133
 134                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 135                 if (ret) {
 136                         D1(printk(KERN_DEBUG "jffs2_reserve_space: ret is %d\n", ret));
 137                 }
 138         }
 139         spin_unlock(&c->erase_completion_lock);
 140         if (!ret)
 141                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 142         if (ret)
 143                 up(&c->alloc_sem);
 144         return ret;
 145 }
 146
 147 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
 148                            uint32_t *len, uint32_t sumsize)
 149 {
 150         int ret = -EAGAIN;
 151         minsize = PAD(minsize);
 152
 153         D1(printk(KERN_DEBUG "jffs2_reserve_space_gc(): Requested 0x%x bytes\n", minsize));
 154
 155         spin_lock(&c->erase_completion_lock);
 156         while(ret == -EAGAIN) {
 157                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 158                 if (ret) {
 159                         D1(printk(KERN_DEBUG "jffs2_reserve_space_gc: looping, ret is %d\n", ret));
 160                 }
 161         }
 162         spin_unlock(&c->erase_completion_lock);
 163         if (!ret)
 164                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 165
 166         return ret;
 167 }
 168
 169
 170 /* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
 171
 172 static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 173 {
 174
 175         /* Check, if we have a dirty block now, or if it was dirty already */
 176         if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
 177                 c->dirty_size += jeb->wasted_size;
 178                 c->wasted_size -= jeb->wasted_size;
 179                 jeb->dirty_size += jeb->wasted_size;
 180                 jeb->wasted_size = 0;
 181                 if (VERYDIRTY(c, jeb->dirty_size)) {
 182                         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",
 183                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 184                         list_add_tail(&jeb->list, &c->very_dirty_list);
 185                 } else {
 186                         D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 187                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 188                         list_add_tail(&jeb->list, &c->dirty_list);
 189                 }
 190         } else {
 191                 D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 192                   jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 193                 list_add_tail(&jeb->list, &c->clean_list);
 194         }
 195         c->nextblock = NULL;
 196
 197 }
 198
 199 /* Select a new jeb for nextblock */
 200
 201 static int jffs2_find_nextblock(struct jffs2_sb_info *c)
 202 {
 203         struct list_head *next;
 204
 205         /* Take the next block off the 'free' list */
 206
 207         if (list_empty(&c->free_list)) {
 208
 209                 if (!c->nr_erasing_blocks &&
 210                         !list_empty(&c->erasable_list)) {
 211                         struct jffs2_eraseblock *ejeb;
 212
 213                         ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
 214                         list_del(&ejeb->list);
 215                         list_add_tail(&ejeb->list, &c->erase_pending_list);
 216                         c->nr_erasing_blocks++;
 217                         jffs2_erase_pending_trigger(c);
 218                         D1(printk(KERN_DEBUG "jffs2_find_nextblock: Triggering erase of erasable block at 0x%08x\n",
 219                                   ejeb->offset));
 220                 }
 221
 222                 if (!c->nr_erasing_blocks &&
 223                         !list_empty(&c->erasable_pending_wbuf_list)) {
 224                         D1(printk(KERN_DEBUG "jffs2_find_nextblock: Flushing write buffer\n"));
 225                         /* c->nextblock is NULL, no update to c->nextblock allowed */
 226                         spin_unlock(&c->erase_completion_lock);
 227                         jffs2_flush_wbuf_pad(c);
 228                         spin_lock(&c->erase_completion_lock);
 229                         /* Have another go. It'll be on the erasable_list now */
 230                         return -EAGAIN;
 231                 }
 232
 233                 if (!c->nr_erasing_blocks) {
 234                         /* Ouch. We're in GC, or we wouldn't have got here.
 235                            And there's no space left. At all. */
 236                         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",
 237                                    c->nr_erasing_blocks, c->nr_free_blocks, list_empty(&c->erasable_list)?"yes":"no",
 238                                    list_empty(&c->erasing_list)?"yes":"no", list_empty(&c->erase_pending_list)?"yes":"no");
 239                         return -ENOSPC;
 240                 }
 241
 242                 spin_unlock(&c->erase_completion_lock);
 243                 /* Don't wait for it; just erase one right now */
 244                 jffs2_erase_pending_blocks(c, 1);
 245                 spin_lock(&c->erase_completion_lock);
 246
 247                 /* An erase may have failed, decreasing the
 248                    amount of free space available. So we must
 249                    restart from the beginning */
 250                 return -EAGAIN;
 251         }
 252
 253         next = c->free_list.next;
 254         list_del(next);
 255         c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
 256         c->nr_free_blocks--;
 257
 258         jffs2_sum_reset_collected(c->summary); /* reset collected summary */
 259
 260         D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));
 261
 262         return 0;
 263 }
 264
 265 /* Called with alloc sem _and_ erase_completion_lock */
 266 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 267                                   uint32_t *len, uint32_t sumsize)
 268 {
 269         struct jffs2_eraseblock *jeb = c->nextblock;
 270         uint32_t reserved_size;                         /* for summary information at the end of the jeb */
 271         int ret;
 272
 273  restart:
 274         reserved_size = 0;
 275
 276         if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
 277                                                         /* NOSUM_SIZE means not to generate summary */
 278
 279                 if (jeb) {
 280                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 281                         dbg_summary("minsize=%d , jeb->free=%d ,"
 282                                                 "summary->size=%d , sumsize=%d\n",
 283                                                 minsize, jeb->free_size,
 284                                                 c->summary->sum_size, sumsize);
 285                 }
 286
 287                 /* Is there enough space for writing out the current node, or we have to
 288                    write out summary information now, close this jeb and select new nextblock? */
 289                 if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
 290                                         JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
 291
 292                         /* Has summary been disabled for this jeb? */
 293                         if (jffs2_sum_is_disabled(c->summary)) {
 294                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 295                                 goto restart;
 296                         }
 297
 298                         /* Writing out the collected summary information */
 299                         dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
 300                         ret = jffs2_sum_write_sumnode(c);
 301
 302                         if (ret)
 303                                 return ret;
 304
 305                         if (jffs2_sum_is_disabled(c->summary)) {
 306                                 /* jffs2_write_sumnode() couldn't write out the summary information
 307                                    diabling summary for this jeb and free the collected information
 308                                  */
 309                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 310                                 goto restart;
 311                         }
 312
 313                         jffs2_close_nextblock(c, jeb);
 314                         jeb = NULL;
 315                         /* keep always valid value in reserved_size */
 316                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 317                 }
 318         } else {
 319                 if (jeb && minsize > jeb->free_size) {
 320                         uint32_t waste;
 321
 322                         /* Skip the end of this block and file it as having some dirty space */
 323                         /* If there's a pending write to it, flush now */
 324
 325                         if (jffs2_wbuf_dirty(c)) {
 326                                 spin_unlock(&c->erase_completion_lock);
 327                                 D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
 328                                 jffs2_flush_wbuf_pad(c);
 329                                 spin_lock(&c->erase_completion_lock);
 330                                 jeb = c->nextblock;
 331                                 goto restart;
 332                         }
 333
 334                         spin_unlock(&c->erase_completion_lock);
 335
 336                         ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
 337                         if (ret)
 338                                 return ret;
 339                         /* Just lock it again and continue. Nothing much can change because
 340                            we hold c->alloc_sem anyway. In fact, it's not entirely clear why
 341                            we hold c->erase_completion_lock in the majority of this function...
 342                            but that's a question for another (more caffeine-rich) day. */
 343                         spin_lock(&c->erase_completion_lock);
 344
 345                         waste = jeb->free_size;
 346                         jffs2_link_node_ref(c, jeb,
 347                                             (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
 348                                             waste, NULL);
 349                         /* FIXME: that made it count as dirty. Convert to wasted */
 350                         jeb->dirty_size -= waste;
 351                         c->dirty_size -= waste;
 352                         jeb->wasted_size += waste;
 353                         c->wasted_size += waste;
 354
 355                         jffs2_close_nextblock(c, jeb);
 356                         jeb = NULL;
 357                 }
 358         }
 359
 360         if (!jeb) {
 361
 362                 ret = jffs2_find_nextblock(c);
 363                 if (ret)
 364                         return ret;
 365
 366                 jeb = c->nextblock;
 367
 368                 if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 369                         printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
 370                         goto restart;
 371                 }
 372         }
 373         /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 374            enough space */
 375         *len = jeb->free_size - reserved_size;
 376
 377         if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 378             !jeb->first_node->next_in_ino) {
 379                 /* Only node in it beforehand was a CLEANMARKER node (we think).
 380                    So mark it obsolete now that there's going to be another node
 381                    in the block. This will reduce used_size to zero but We've
 382                    already set c->nextblock so that jffs2_mark_node_obsolete()
 383                    won't try to refile it to the dirty_list.
 384                 */
 385                 spin_unlock(&c->erase_completion_lock);
 386                 jffs2_mark_node_obsolete(c, jeb->first_node);
 387                 spin_lock(&c->erase_completion_lock);
 388         }
 389
 390         D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n",
 391                   *len, jeb->offset + (c->sector_size - jeb->free_size)));
 392         return 0;
 393 }
 394
 395 /**
 396  *      jffs2_add_physical_node_ref - add a physical node reference to the list
 397  *      @c: superblock info
 398  *      @new: new node reference to add
 399  *      @len: length of this physical node
 400  *
 401  *      Should only be used to report nodes for which space has been allocated
 402  *      by jffs2_reserve_space.
 403  *
 404  *      Must be called with the alloc_sem held.
 405  */
 406
 407 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
 408                                                        uint32_t ofs, uint32_t len,
 409                                                        struct jffs2_inode_cache *ic)
 410 {
 411         struct jffs2_eraseblock *jeb;
 412         struct jffs2_raw_node_ref *new;
 413
 414         jeb = &c->blocks[ofs / c->sector_size];
 415
 416         D1(printk(KERN_DEBUG "jffs2_add_physical_node_ref(): Node at 0x%x(%d), size 0x%x\n",
 417                   ofs & ~3, ofs & 3, len));
 418 #if 1
 419         /* Allow non-obsolete nodes only to be added at the end of c->nextblock,
 420            if c->nextblock is set. Note that wbuf.c will file obsolete nodes
 421            even after refiling c->nextblock */
 422         if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
 423             && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
 424                 printk(KERN_WARNING "argh. node added in wrong place\n");
 425                 return ERR_PTR(-EINVAL);
 426         }
 427 #endif
 428         spin_lock(&c->erase_completion_lock);
 429
 430         new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
 431
 432         if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 433                 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 434                 D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 435                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 436                 if (jffs2_wbuf_dirty(c)) {
 437                         /* Flush the last write in the block if it's outstanding */
 438                         spin_unlock(&c->erase_completion_lock);
 439                         jffs2_flush_wbuf_pad(c);
 440                         spin_lock(&c->erase_completion_lock);
 441                 }
 442
 443                 list_add_tail(&jeb->list, &c->clean_list);
 444                 c->nextblock = NULL;
 445         }
 446         jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 447         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 448
 449         spin_unlock(&c->erase_completion_lock);
 450
 451         return new;
 452 }
 453
 454
 455 void jffs2_complete_reservation(struct jffs2_sb_info *c)
 456 {
 457         D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
 458         jffs2_garbage_collect_trigger(c);
 459         up(&c->alloc_sem);
 460 }
 461
 462 static inline int on_list(struct list_head *obj, struct list_head *head)
 463 {
 464         struct list_head *this;
 465
 466         list_for_each(this, head) {
 467                 if (this == obj) {
 468                         D1(printk("%p is on list at %p\n", obj, head));
 469                         return 1;
 470
 471                 }
 472         }
 473         return 0;
 474 }
 475
 476 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 477 {
 478         struct jffs2_eraseblock *jeb;
 479         int blocknr;
 480         struct jffs2_unknown_node n;
 481         int ret, addedsize;
 482         size_t retlen;
 483         uint32_t freed_len;
 484
 485         if(unlikely(!ref)) {
 486                 printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 487                 return;
 488         }
 489         if (ref_obsolete(ref)) {
 490                 D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
 491                 return;
 492         }
 493         blocknr = ref->flash_offset / c->sector_size;
 494         if (blocknr >= c->nr_blocks) {
 495                 printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
 496                 BUG();
 497         }
 498         jeb = &c->blocks[blocknr];
 499
 500         if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 501             !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 502                 /* Hm. This may confuse static lock analysis. If any of the above
 503                    three conditions is false, we're going to return from this
 504                    function without actually obliterating any nodes or freeing
 505                    any jffs2_raw_node_refs. So we don't need to stop erases from
 506                    happening, or protect against people holding an obsolete
 507                    jffs2_raw_node_ref without the erase_completion_lock. */
 508                 down(&c->erase_free_sem);
 509         }
 510
 511         spin_lock(&c->erase_completion_lock);
 512
 513         freed_len = ref_totlen(c, jeb, ref);
 514
 515         if (ref_flags(ref) == REF_UNCHECKED) {
 516                 D1(if (unlikely(jeb->unchecked_size < freed_len)) {
 517                         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",
 518                                freed_len, blocknr, ref->flash_offset, jeb->used_size);
 519                         BUG();
 520                 })
 521                 D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), freed_len));
 522                 jeb->unchecked_size -= freed_len;
 523                 c->unchecked_size -= freed_len;
 524         } else {
 525                 D1(if (unlikely(jeb->used_size < freed_len)) {
 526                         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",
 527                                freed_len, blocknr, ref->flash_offset, jeb->used_size);
 528                         BUG();
 529                 })
 530                 D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), freed_len));
 531                 jeb->used_size -= freed_len;
 532                 c->used_size -= freed_len;
 533         }
 534
 535         // Take care, that wasted size is taken into concern
 536         if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
 537                 D1(printk("Dirtying\n"));
 538                 addedsize = freed_len;
 539                 jeb->dirty_size += freed_len;
 540                 c->dirty_size += freed_len;
 541
 542                 /* Convert wasted space to dirty, if not a bad block */
 543                 if (jeb->wasted_size) {
 544                         if (on_list(&jeb->list, &c->bad_used_list)) {
 545                                 D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
 546                                           jeb->offset));
 547                                 addedsize = 0; /* To fool the refiling code later */
 548                         } else {
 549                                 D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
 550                                           jeb->wasted_size, jeb->offset));
 551                                 addedsize += jeb->wasted_size;
 552                                 jeb->dirty_size += jeb->wasted_size;
 553                                 c->dirty_size += jeb->wasted_size;
 554                                 c->wasted_size -= jeb->wasted_size;
 555                                 jeb->wasted_size = 0;
 556                         }
 557                 }
 558         } else {
 559                 D1(printk("Wasting\n"));
 560                 addedsize = 0;
 561                 jeb->wasted_size += freed_len;
 562                 c->wasted_size += freed_len;
 563         }
 564         ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 565
 566         jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 567         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 568
 569         if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 570                 /* Flash scanning is in progress. Don't muck about with the block
 571                    lists because they're not ready yet, and don't actually
 572                    obliterate nodes that look obsolete. If they weren't
 573                    marked obsolete on the flash at the time they _became_
 574                    obsolete, there was probably a reason for that. */
 575                 spin_unlock(&c->erase_completion_lock);
 576                 /* We didn't lock the erase_free_sem */
 577                 return;
 578         }
 579
 580         if (jeb == c->nextblock) {
 581                 D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
 582         } else if (!jeb->used_size && !jeb->unchecked_size) {
 583                 if (jeb == c->gcblock) {
 584                         D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
 585                         c->gcblock = NULL;
 586                 } else {
 587                         D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
 588                         list_del(&jeb->list);
 589                 }
 590                 if (jffs2_wbuf_dirty(c)) {
 591                         D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
 592                         list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 593                 } else {
 594                         if (jiffies & 127) {
 595                                 /* Most of the time, we just erase it immediately. Otherwise we
 596                                    spend ages scanning it on mount, etc. */
 597                                 D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
 598                                 list_add_tail(&jeb->list, &c->erase_pending_list);
 599                                 c->nr_erasing_blocks++;
 600                                 jffs2_erase_pending_trigger(c);
 601                         } else {
 602                                 /* Sometimes, however, we leave it elsewhere so it doesn't get
 603                                    immediately reused, and we spread the load a bit. */
 604                                 D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
 605                                 list_add_tail(&jeb->list, &c->erasable_list);
 606                         }
 607                 }
 608                 D1(printk(KERN_DEBUG "Done OK\n"));
 609         } else if (jeb == c->gcblock) {
 610                 D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
 611         } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 612                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
 613                 list_del(&jeb->list);
 614                 D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
 615                 list_add_tail(&jeb->list, &c->dirty_list);
 616         } else if (VERYDIRTY(c, jeb->dirty_size) &&
 617                    !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 618                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
 619                 list_del(&jeb->list);
 620                 D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
 621                 list_add_tail(&jeb->list, &c->very_dirty_list);
 622         } else {
 623                 D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 624                           jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 625         }
 626
 627         spin_unlock(&c->erase_completion_lock);
 628
 629         if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 630                 (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 631                 /* We didn't lock the erase_free_sem */
 632                 return;
 633         }
 634
 635         /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 636            and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 637            the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 638            by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
 639
 640         D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
 641         ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 642         if (ret) {
 643                 printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 644                 goto out_erase_sem;
 645         }
 646         if (retlen != sizeof(n)) {
 647                 printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 648                 goto out_erase_sem;
 649         }
 650         if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
 651                 printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), freed_len);
 652                 goto out_erase_sem;
 653         }
 654         if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 655                 D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
 656                 goto out_erase_sem;
 657         }
 658         /* XXX FIXME: This is ugly now */
 659         n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 660         ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 661         if (ret) {
 662                 printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 663                 goto out_erase_sem;
 664         }
 665         if (retlen != sizeof(n)) {
 666                 printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 667                 goto out_erase_sem;
 668         }
 669
 670         /* Nodes which have been marked obsolete no longer need to be
 671            associated with any inode. Remove them from the per-inode list.
 672
 673            Note we can't do this for NAND at the moment because we need
 674            obsolete dirent nodes to stay on the lists, because of the
 675            horridness in jffs2_garbage_collect_deletion_dirent(). Also
 676            because we delete the inocache, and on NAND we need that to
 677            stay around until all the nodes are actually erased, in order
 678            to stop us from giving the same inode number to another newly
 679            created inode. */
 680         if (ref->next_in_ino) {
 681                 struct jffs2_inode_cache *ic;
 682                 struct jffs2_raw_node_ref **p;
 683
 684                 spin_lock(&c->erase_completion_lock);
 685
 686                 ic = jffs2_raw_ref_to_ic(ref);
 687                 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 688                         ;
 689
 690                 *p = ref->next_in_ino;
 691                 ref->next_in_ino = NULL;
 692
 693                 switch (ic->class) {
 694 #ifdef CONFIG_JFFS2_FS_XATTR
 695                         case RAWNODE_CLASS_XATTR_DATUM:
 696                                 jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
 697                                 break;
 698                         case RAWNODE_CLASS_XATTR_REF:
 699                                 jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
 700                                 break;
 701 #endif
 702                         default:
 703                                 if (ic->nodes == (void *)ic && ic->nlink == 0)
 704                                         jffs2_del_ino_cache(c, ic);
 705                                 break;
 706                 }
 707                 spin_unlock(&c->erase_completion_lock);
 708         }
 709
 710  out_erase_sem:
 711         up(&c->erase_free_sem);
 712 }
 713
 714 int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 715 {
 716         int ret = 0;
 717         uint32_t dirty;
 718
 719         if (c->unchecked_size) {
 720                 D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 721                           c->unchecked_size, c->checked_ino));
 722                 return 1;
 723         }
 724
 725         /* dirty_size contains blocks on erase_pending_list
 726          * those blocks are counted in c->nr_erasing_blocks.
 727          * If one block is actually erased, it is not longer counted as dirty_space
 728          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 729          * with c->nr_erasing_blocks * c->sector_size again.
 730          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 731          * This helps us to force gc and pick eventually a clean block to spread the load.
 732          */
 733         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 734
 735         if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 736                         (dirty > c->nospc_dirty_size))
 737                 ret = 1;
 738
 739         D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x: %s\n",
 740                   c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, ret?"yes":"no"));
 741
 742         return ret;
 743 }