Pileus Git - ~andy/linux/blob - fs/jffs2/nodemgmt.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright © 2001-2007 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/mtd/mtd.h>
  14 #include <linux/compiler.h>
  15 #include <linux/sched.h> /* For cond_resched() */
  16 #include "nodelist.h"
  17 #include "debug.h"
  18
  19 /**
  20  *      jffs2_reserve_space - request physical space to write nodes to flash
  21  *      @c: superblock info
  22  *      @minsize: Minimum acceptable size of allocation
  23  *      @len: Returned value of allocation length
  24  *      @prio: Allocation type - ALLOC_{NORMAL,DELETION}
  25  *
  26  *      Requests a block of physical space on the flash. Returns zero for success
  27  *      and puts 'len' into the appropriate place, or returns -ENOSPC or other
  28  *      error if appropriate. Doesn't return len since that's
  29  *
  30  *      If it returns zero, jffs2_reserve_space() also downs the per-filesystem
  31  *      allocation semaphore, to prevent more than one allocation from being
  32  *      active at any time. The semaphore is later released by jffs2_commit_allocation()
  33  *
  34  *      jffs2_reserve_space() may trigger garbage collection in order to make room
  35  *      for the requested allocation.
  36  */
  37
  38 static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
  39                                   uint32_t *len, uint32_t sumsize);
  40
  41 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
  42                         uint32_t *len, int prio, uint32_t sumsize)
  43 {
  44         int ret = -EAGAIN;
  45         int blocksneeded = c->resv_blocks_write;
  46         /* align it */
  47         minsize = PAD(minsize);
  48
  49         jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
  50         mutex_lock(&c->alloc_sem);
  51
  52         jffs2_dbg(1, "%s(): alloc sem got\n", __func__);
  53
  54         spin_lock(&c->erase_completion_lock);
  55
  56         /* this needs a little more thought (true <tglx> :)) */
  57         while(ret == -EAGAIN) {
  58                 while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
  59                         uint32_t dirty, avail;
  60
  61                         /* calculate real dirty size
  62                          * dirty_size contains blocks on erase_pending_list
  63                          * those blocks are counted in c->nr_erasing_blocks.
  64                          * If one block is actually erased, it is not longer counted as dirty_space
  65                          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
  66                          * with c->nr_erasing_blocks * c->sector_size again.
  67                          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
  68                          * This helps us to force gc and pick eventually a clean block to spread the load.
  69                          * We add unchecked_size here, as we hopefully will find some space to use.
  70                          * This will affect the sum only once, as gc first finishes checking
  71                          * of nodes.
  72                          */
  73                         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
  74                         if (dirty < c->nospc_dirty_size) {
  75                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
  76                                         jffs2_dbg(1, "%s(): Low on dirty space to GC, but it's a deletion. Allowing...\n",
  77                                                   __func__);
  78                                         break;
  79                                 }
  80                                 jffs2_dbg(1, "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
  81                                           dirty, c->unchecked_size,
  82                                           c->sector_size);
  83
  84                                 spin_unlock(&c->erase_completion_lock);
  85                                 mutex_unlock(&c->alloc_sem);
  86                                 return -ENOSPC;
  87                         }
  88
  89                         /* Calc possibly available space. Possibly available means that we
  90                          * don't know, if unchecked size contains obsoleted nodes, which could give us some
  91                          * more usable space. This will affect the sum only once, as gc first finishes checking
  92                          * of nodes.
  93                          + Return -ENOSPC, if the maximum possibly available space is less or equal than
  94                          * blocksneeded * sector_size.
  95                          * This blocks endless gc looping on a filesystem, which is nearly full, even if
  96                          * the check above passes.
  97                          */
  98                         avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
  99                         if ( (avail / c->sector_size) <= blocksneeded) {
 100                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
 101                                         jffs2_dbg(1, "%s(): Low on possibly available space, but it's a deletion. Allowing...\n",
 102                                                   __func__);
 103                                         break;
 104                                 }
 105
 106                                 jffs2_dbg(1, "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
 107                                           avail, blocksneeded * c->sector_size);
 108                                 spin_unlock(&c->erase_completion_lock);
 109                                 mutex_unlock(&c->alloc_sem);
 110                                 return -ENOSPC;
 111                         }
 112
 113                         mutex_unlock(&c->alloc_sem);
 114
 115                         jffs2_dbg(1, "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",
 116                                   c->nr_free_blocks, c->nr_erasing_blocks,
 117                                   c->free_size, c->dirty_size, c->wasted_size,
 118                                   c->used_size, c->erasing_size, c->bad_size,
 119                                   c->free_size + c->dirty_size +
 120                                   c->wasted_size + c->used_size +
 121                                   c->erasing_size + c->bad_size,
 122                                   c->flash_size);
 123                         spin_unlock(&c->erase_completion_lock);
 124
 125                         ret = jffs2_garbage_collect_pass(c);
 126
 127                         if (ret == -EAGAIN) {
 128                                 spin_lock(&c->erase_completion_lock);
 129                                 if (c->nr_erasing_blocks &&
 130                                     list_empty(&c->erase_pending_list) &&
 131                                     list_empty(&c->erase_complete_list)) {
 132                                         DECLARE_WAITQUEUE(wait, current);
 133                                         set_current_state(TASK_UNINTERRUPTIBLE);
 134                                         add_wait_queue(&c->erase_wait, &wait);
 135                                         jffs2_dbg(1, "%s waiting for erase to complete\n",
 136                                                   __func__);
 137                                         spin_unlock(&c->erase_completion_lock);
 138
 139                                         schedule();
 140                                 } else
 141                                         spin_unlock(&c->erase_completion_lock);
 142                         } else if (ret)
 143                                 return ret;
 144
 145                         cond_resched();
 146
 147                         if (signal_pending(current))
 148                                 return -EINTR;
 149
 150                         mutex_lock(&c->alloc_sem);
 151                         spin_lock(&c->erase_completion_lock);
 152                 }
 153
 154                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 155                 if (ret) {
 156                         jffs2_dbg(1, "%s(): ret is %d\n", __func__, ret);
 157                 }
 158         }
 159         spin_unlock(&c->erase_completion_lock);
 160         if (!ret)
 161                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 162         if (ret)
 163                 mutex_unlock(&c->alloc_sem);
 164         return ret;
 165 }
 166
 167 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
 168                            uint32_t *len, uint32_t sumsize)
 169 {
 170         int ret = -EAGAIN;
 171         minsize = PAD(minsize);
 172
 173         jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
 174
 175         spin_lock(&c->erase_completion_lock);
 176         while(ret == -EAGAIN) {
 177                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 178                 if (ret) {
 179                         jffs2_dbg(1, "%s(): looping, ret is %d\n",
 180                                   __func__, ret);
 181                 }
 182         }
 183         spin_unlock(&c->erase_completion_lock);
 184         if (!ret)
 185                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 186
 187         return ret;
 188 }
 189
 190
 191 /* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
 192
 193 static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 194 {
 195
 196         if (c->nextblock == NULL) {
 197                 jffs2_dbg(1, "%s(): Erase block at 0x%08x has already been placed in a list\n",
 198                           __func__, jeb->offset);
 199                 return;
 200         }
 201         /* Check, if we have a dirty block now, or if it was dirty already */
 202         if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
 203                 c->dirty_size += jeb->wasted_size;
 204                 c->wasted_size -= jeb->wasted_size;
 205                 jeb->dirty_size += jeb->wasted_size;
 206                 jeb->wasted_size = 0;
 207                 if (VERYDIRTY(c, jeb->dirty_size)) {
 208                         jffs2_dbg(1, "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 209                                   jeb->offset, jeb->free_size, jeb->dirty_size,
 210                                   jeb->used_size);
 211                         list_add_tail(&jeb->list, &c->very_dirty_list);
 212                 } else {
 213                         jffs2_dbg(1, "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 214                                   jeb->offset, jeb->free_size, jeb->dirty_size,
 215                                   jeb->used_size);
 216                         list_add_tail(&jeb->list, &c->dirty_list);
 217                 }
 218         } else {
 219                 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 220                           jeb->offset, jeb->free_size, jeb->dirty_size,
 221                           jeb->used_size);
 222                 list_add_tail(&jeb->list, &c->clean_list);
 223         }
 224         c->nextblock = NULL;
 225
 226 }
 227
 228 /* Select a new jeb for nextblock */
 229
 230 static int jffs2_find_nextblock(struct jffs2_sb_info *c)
 231 {
 232         struct list_head *next;
 233
 234         /* Take the next block off the 'free' list */
 235
 236         if (list_empty(&c->free_list)) {
 237
 238                 if (!c->nr_erasing_blocks &&
 239                         !list_empty(&c->erasable_list)) {
 240                         struct jffs2_eraseblock *ejeb;
 241
 242                         ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
 243                         list_move_tail(&ejeb->list, &c->erase_pending_list);
 244                         c->nr_erasing_blocks++;
 245                         jffs2_garbage_collect_trigger(c);
 246                         jffs2_dbg(1, "%s(): Triggering erase of erasable block at 0x%08x\n",
 247                                   __func__, ejeb->offset);
 248                 }
 249
 250                 if (!c->nr_erasing_blocks &&
 251                         !list_empty(&c->erasable_pending_wbuf_list)) {
 252                         jffs2_dbg(1, "%s(): Flushing write buffer\n",
 253                                   __func__);
 254                         /* c->nextblock is NULL, no update to c->nextblock allowed */
 255                         spin_unlock(&c->erase_completion_lock);
 256                         jffs2_flush_wbuf_pad(c);
 257                         spin_lock(&c->erase_completion_lock);
 258                         /* Have another go. It'll be on the erasable_list now */
 259                         return -EAGAIN;
 260                 }
 261
 262                 if (!c->nr_erasing_blocks) {
 263                         /* Ouch. We're in GC, or we wouldn't have got here.
 264                            And there's no space left. At all. */
 265                         pr_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",
 266                                 c->nr_erasing_blocks, c->nr_free_blocks,
 267                                 list_empty(&c->erasable_list) ? "yes" : "no",
 268                                 list_empty(&c->erasing_list) ? "yes" : "no",
 269                                 list_empty(&c->erase_pending_list) ? "yes" : "no");
 270                         return -ENOSPC;
 271                 }
 272
 273                 spin_unlock(&c->erase_completion_lock);
 274                 /* Don't wait for it; just erase one right now */
 275                 jffs2_erase_pending_blocks(c, 1);
 276                 spin_lock(&c->erase_completion_lock);
 277
 278                 /* An erase may have failed, decreasing the
 279                    amount of free space available. So we must
 280                    restart from the beginning */
 281                 return -EAGAIN;
 282         }
 283
 284         next = c->free_list.next;
 285         list_del(next);
 286         c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
 287         c->nr_free_blocks--;
 288
 289         jffs2_sum_reset_collected(c->summary); /* reset collected summary */
 290
 291 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 292         /* adjust write buffer offset, else we get a non contiguous write bug */
 293         if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
 294                 c->wbuf_ofs = 0xffffffff;
 295 #endif
 296
 297         jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
 298                   __func__, c->nextblock->offset);
 299
 300         return 0;
 301 }
 302
 303 /* Called with alloc sem _and_ erase_completion_lock */
 304 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 305                                   uint32_t *len, uint32_t sumsize)
 306 {
 307         struct jffs2_eraseblock *jeb = c->nextblock;
 308         uint32_t reserved_size;                         /* for summary information at the end of the jeb */
 309         int ret;
 310
 311  restart:
 312         reserved_size = 0;
 313
 314         if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
 315                                                         /* NOSUM_SIZE means not to generate summary */
 316
 317                 if (jeb) {
 318                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 319                         dbg_summary("minsize=%d , jeb->free=%d ,"
 320                                                 "summary->size=%d , sumsize=%d\n",
 321                                                 minsize, jeb->free_size,
 322                                                 c->summary->sum_size, sumsize);
 323                 }
 324
 325                 /* Is there enough space for writing out the current node, or we have to
 326                    write out summary information now, close this jeb and select new nextblock? */
 327                 if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
 328                                         JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
 329
 330                         /* Has summary been disabled for this jeb? */
 331                         if (jffs2_sum_is_disabled(c->summary)) {
 332                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 333                                 goto restart;
 334                         }
 335
 336                         /* Writing out the collected summary information */
 337                         dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
 338                         ret = jffs2_sum_write_sumnode(c);
 339
 340                         if (ret)
 341                                 return ret;
 342
 343                         if (jffs2_sum_is_disabled(c->summary)) {
 344                                 /* jffs2_write_sumnode() couldn't write out the summary information
 345                                    diabling summary for this jeb and free the collected information
 346                                  */
 347                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 348                                 goto restart;
 349                         }
 350
 351                         jffs2_close_nextblock(c, jeb);
 352                         jeb = NULL;
 353                         /* keep always valid value in reserved_size */
 354                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 355                 }
 356         } else {
 357                 if (jeb && minsize > jeb->free_size) {
 358                         uint32_t waste;
 359
 360                         /* Skip the end of this block and file it as having some dirty space */
 361                         /* If there's a pending write to it, flush now */
 362
 363                         if (jffs2_wbuf_dirty(c)) {
 364                                 spin_unlock(&c->erase_completion_lock);
 365                                 jffs2_dbg(1, "%s(): Flushing write buffer\n",
 366                                           __func__);
 367                                 jffs2_flush_wbuf_pad(c);
 368                                 spin_lock(&c->erase_completion_lock);
 369                                 jeb = c->nextblock;
 370                                 goto restart;
 371                         }
 372
 373                         spin_unlock(&c->erase_completion_lock);
 374
 375                         ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
 376                         if (ret)
 377                                 return ret;
 378                         /* Just lock it again and continue. Nothing much can change because
 379                            we hold c->alloc_sem anyway. In fact, it's not entirely clear why
 380                            we hold c->erase_completion_lock in the majority of this function...
 381                            but that's a question for another (more caffeine-rich) day. */
 382                         spin_lock(&c->erase_completion_lock);
 383
 384                         waste = jeb->free_size;
 385                         jffs2_link_node_ref(c, jeb,
 386                                             (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
 387                                             waste, NULL);
 388                         /* FIXME: that made it count as dirty. Convert to wasted */
 389                         jeb->dirty_size -= waste;
 390                         c->dirty_size -= waste;
 391                         jeb->wasted_size += waste;
 392                         c->wasted_size += waste;
 393
 394                         jffs2_close_nextblock(c, jeb);
 395                         jeb = NULL;
 396                 }
 397         }
 398
 399         if (!jeb) {
 400
 401                 ret = jffs2_find_nextblock(c);
 402                 if (ret)
 403                         return ret;
 404
 405                 jeb = c->nextblock;
 406
 407                 if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 408                         pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n",
 409                                 jeb->offset, jeb->free_size);
 410                         goto restart;
 411                 }
 412         }
 413         /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 414            enough space */
 415         *len = jeb->free_size - reserved_size;
 416
 417         if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 418             !jeb->first_node->next_in_ino) {
 419                 /* Only node in it beforehand was a CLEANMARKER node (we think).
 420                    So mark it obsolete now that there's going to be another node
 421                    in the block. This will reduce used_size to zero but We've
 422                    already set c->nextblock so that jffs2_mark_node_obsolete()
 423                    won't try to refile it to the dirty_list.
 424                 */
 425                 spin_unlock(&c->erase_completion_lock);
 426                 jffs2_mark_node_obsolete(c, jeb->first_node);
 427                 spin_lock(&c->erase_completion_lock);
 428         }
 429
 430         jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n",
 431                   __func__,
 432                   *len, jeb->offset + (c->sector_size - jeb->free_size));
 433         return 0;
 434 }
 435
 436 /**
 437  *      jffs2_add_physical_node_ref - add a physical node reference to the list
 438  *      @c: superblock info
 439  *      @new: new node reference to add
 440  *      @len: length of this physical node
 441  *
 442  *      Should only be used to report nodes for which space has been allocated
 443  *      by jffs2_reserve_space.
 444  *
 445  *      Must be called with the alloc_sem held.
 446  */
 447
 448 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
 449                                                        uint32_t ofs, uint32_t len,
 450                                                        struct jffs2_inode_cache *ic)
 451 {
 452         struct jffs2_eraseblock *jeb;
 453         struct jffs2_raw_node_ref *new;
 454
 455         jeb = &c->blocks[ofs / c->sector_size];
 456
 457         jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n",
 458                   __func__, ofs & ~3, ofs & 3, len);
 459 #if 1
 460         /* Allow non-obsolete nodes only to be added at the end of c->nextblock,
 461            if c->nextblock is set. Note that wbuf.c will file obsolete nodes
 462            even after refiling c->nextblock */
 463         if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
 464             && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
 465                 pr_warn("argh. node added in wrong place at 0x%08x(%d)\n",
 466                         ofs & ~3, ofs & 3);
 467                 if (c->nextblock)
 468                         pr_warn("nextblock 0x%08x", c->nextblock->offset);
 469                 else
 470                         pr_warn("No nextblock");
 471                 pr_cont(", expected at %08x\n",
 472                         jeb->offset + (c->sector_size - jeb->free_size));
 473                 return ERR_PTR(-EINVAL);
 474         }
 475 #endif
 476         spin_lock(&c->erase_completion_lock);
 477
 478         new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
 479
 480         if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 481                 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 482                 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 483                           jeb->offset, jeb->free_size, jeb->dirty_size,
 484                           jeb->used_size);
 485                 if (jffs2_wbuf_dirty(c)) {
 486                         /* Flush the last write in the block if it's outstanding */
 487                         spin_unlock(&c->erase_completion_lock);
 488                         jffs2_flush_wbuf_pad(c);
 489                         spin_lock(&c->erase_completion_lock);
 490                 }
 491
 492                 list_add_tail(&jeb->list, &c->clean_list);
 493                 c->nextblock = NULL;
 494         }
 495         jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 496         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 497
 498         spin_unlock(&c->erase_completion_lock);
 499
 500         return new;
 501 }
 502
 503
 504 void jffs2_complete_reservation(struct jffs2_sb_info *c)
 505 {
 506         jffs2_dbg(1, "jffs2_complete_reservation()\n");
 507         spin_lock(&c->erase_completion_lock);
 508         jffs2_garbage_collect_trigger(c);
 509         spin_unlock(&c->erase_completion_lock);
 510         mutex_unlock(&c->alloc_sem);
 511 }
 512
 513 static inline int on_list(struct list_head *obj, struct list_head *head)
 514 {
 515         struct list_head *this;
 516
 517         list_for_each(this, head) {
 518                 if (this == obj) {
 519                         jffs2_dbg(1, "%p is on list at %p\n", obj, head);
 520                         return 1;
 521
 522                 }
 523         }
 524         return 0;
 525 }
 526
 527 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 528 {
 529         struct jffs2_eraseblock *jeb;
 530         int blocknr;
 531         struct jffs2_unknown_node n;
 532         int ret, addedsize;
 533         size_t retlen;
 534         uint32_t freed_len;
 535
 536         if(unlikely(!ref)) {
 537                 pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 538                 return;
 539         }
 540         if (ref_obsolete(ref)) {
 541                 jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n",
 542                           __func__, ref_offset(ref));
 543                 return;
 544         }
 545         blocknr = ref->flash_offset / c->sector_size;
 546         if (blocknr >= c->nr_blocks) {
 547                 pr_notice("raw node at 0x%08x is off the end of device!\n",
 548                           ref->flash_offset);
 549                 BUG();
 550         }
 551         jeb = &c->blocks[blocknr];
 552
 553         if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 554             !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 555                 /* Hm. This may confuse static lock analysis. If any of the above
 556                    three conditions is false, we're going to return from this
 557                    function without actually obliterating any nodes or freeing
 558                    any jffs2_raw_node_refs. So we don't need to stop erases from
 559                    happening, or protect against people holding an obsolete
 560                    jffs2_raw_node_ref without the erase_completion_lock. */
 561                 mutex_lock(&c->erase_free_sem);
 562         }
 563
 564         spin_lock(&c->erase_completion_lock);
 565
 566         freed_len = ref_totlen(c, jeb, ref);
 567
 568         if (ref_flags(ref) == REF_UNCHECKED) {
 569                 D1(if (unlikely(jeb->unchecked_size < freed_len)) {
 570                                 pr_notice("raw unchecked node of size 0x%08x freed from erase block %d at 0x%08x, but unchecked_size was already 0x%08x\n",
 571                                           freed_len, blocknr,
 572                                           ref->flash_offset, jeb->used_size);
 573                         BUG();
 574                 })
 575                         jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n",
 576                                   ref_offset(ref), freed_len);
 577                 jeb->unchecked_size -= freed_len;
 578                 c->unchecked_size -= freed_len;
 579         } else {
 580                 D1(if (unlikely(jeb->used_size < freed_len)) {
 581                                 pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
 582                                           freed_len, blocknr,
 583                                           ref->flash_offset, jeb->used_size);
 584                         BUG();
 585                 })
 586                         jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ",
 587                                   ref_offset(ref), freed_len);
 588                 jeb->used_size -= freed_len;
 589                 c->used_size -= freed_len;
 590         }
 591
 592         // Take care, that wasted size is taken into concern
 593         if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
 594                 jffs2_dbg(1, "Dirtying\n");
 595                 addedsize = freed_len;
 596                 jeb->dirty_size += freed_len;
 597                 c->dirty_size += freed_len;
 598
 599                 /* Convert wasted space to dirty, if not a bad block */
 600                 if (jeb->wasted_size) {
 601                         if (on_list(&jeb->list, &c->bad_used_list)) {
 602                                 jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n",
 603                                           jeb->offset);
 604                                 addedsize = 0; /* To fool the refiling code later */
 605                         } else {
 606                                 jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n",
 607                                           jeb->wasted_size, jeb->offset);
 608                                 addedsize += jeb->wasted_size;
 609                                 jeb->dirty_size += jeb->wasted_size;
 610                                 c->dirty_size += jeb->wasted_size;
 611                                 c->wasted_size -= jeb->wasted_size;
 612                                 jeb->wasted_size = 0;
 613                         }
 614                 }
 615         } else {
 616                 jffs2_dbg(1, "Wasting\n");
 617                 addedsize = 0;
 618                 jeb->wasted_size += freed_len;
 619                 c->wasted_size += freed_len;
 620         }
 621         ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 622
 623         jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 624         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 625
 626         if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 627                 /* Flash scanning is in progress. Don't muck about with the block
 628                    lists because they're not ready yet, and don't actually
 629                    obliterate nodes that look obsolete. If they weren't
 630                    marked obsolete on the flash at the time they _became_
 631                    obsolete, there was probably a reason for that. */
 632                 spin_unlock(&c->erase_completion_lock);
 633                 /* We didn't lock the erase_free_sem */
 634                 return;
 635         }
 636
 637         if (jeb == c->nextblock) {
 638                 jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n",
 639                           jeb->offset);
 640         } else if (!jeb->used_size && !jeb->unchecked_size) {
 641                 if (jeb == c->gcblock) {
 642                         jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n",
 643                                   jeb->offset);
 644                         c->gcblock = NULL;
 645                 } else {
 646                         jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n",
 647                                   jeb->offset);
 648                         list_del(&jeb->list);
 649                 }
 650                 if (jffs2_wbuf_dirty(c)) {
 651                         jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n");
 652                         list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 653                 } else {
 654                         if (jiffies & 127) {
 655                                 /* Most of the time, we just erase it immediately. Otherwise we
 656                                    spend ages scanning it on mount, etc. */
 657                                 jffs2_dbg(1, "...and adding to erase_pending_list\n");
 658                                 list_add_tail(&jeb->list, &c->erase_pending_list);
 659                                 c->nr_erasing_blocks++;
 660                                 jffs2_garbage_collect_trigger(c);
 661                         } else {
 662                                 /* Sometimes, however, we leave it elsewhere so it doesn't get
 663                                    immediately reused, and we spread the load a bit. */
 664                                 jffs2_dbg(1, "...and adding to erasable_list\n");
 665                                 list_add_tail(&jeb->list, &c->erasable_list);
 666                         }
 667                 }
 668                 jffs2_dbg(1, "Done OK\n");
 669         } else if (jeb == c->gcblock) {
 670                 jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n",
 671                           jeb->offset);
 672         } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 673                 jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n",
 674                           jeb->offset);
 675                 list_del(&jeb->list);
 676                 jffs2_dbg(1, "...and adding to dirty_list\n");
 677                 list_add_tail(&jeb->list, &c->dirty_list);
 678         } else if (VERYDIRTY(c, jeb->dirty_size) &&
 679                    !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 680                 jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n",
 681                           jeb->offset);
 682                 list_del(&jeb->list);
 683                 jffs2_dbg(1, "...and adding to very_dirty_list\n");
 684                 list_add_tail(&jeb->list, &c->very_dirty_list);
 685         } else {
 686                 jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 687                           jeb->offset, jeb->free_size, jeb->dirty_size,
 688                           jeb->used_size);
 689         }
 690
 691         spin_unlock(&c->erase_completion_lock);
 692
 693         if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 694                 (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 695                 /* We didn't lock the erase_free_sem */
 696                 return;
 697         }
 698
 699         /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 700            and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 701            the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 702            by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
 703
 704         jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n",
 705                   ref_offset(ref));
 706         ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 707         if (ret) {
 708                 pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n",
 709                         ref_offset(ref), ret);
 710                 goto out_erase_sem;
 711         }
 712         if (retlen != sizeof(n)) {
 713                 pr_warn("Short read from obsoleted node at 0x%08x: %zd\n",
 714                         ref_offset(ref), retlen);
 715                 goto out_erase_sem;
 716         }
 717         if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
 718                 pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n",
 719                         je32_to_cpu(n.totlen), freed_len);
 720                 goto out_erase_sem;
 721         }
 722         if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 723                 jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n",
 724                           ref_offset(ref), je16_to_cpu(n.nodetype));
 725                 goto out_erase_sem;
 726         }
 727         /* XXX FIXME: This is ugly now */
 728         n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 729         ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 730         if (ret) {
 731                 pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n",
 732                         ref_offset(ref), ret);
 733                 goto out_erase_sem;
 734         }
 735         if (retlen != sizeof(n)) {
 736                 pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n",
 737                         ref_offset(ref), retlen);
 738                 goto out_erase_sem;
 739         }
 740
 741         /* Nodes which have been marked obsolete no longer need to be
 742            associated with any inode. Remove them from the per-inode list.
 743
 744            Note we can't do this for NAND at the moment because we need
 745            obsolete dirent nodes to stay on the lists, because of the
 746            horridness in jffs2_garbage_collect_deletion_dirent(). Also
 747            because we delete the inocache, and on NAND we need that to
 748            stay around until all the nodes are actually erased, in order
 749            to stop us from giving the same inode number to another newly
 750            created inode. */
 751         if (ref->next_in_ino) {
 752                 struct jffs2_inode_cache *ic;
 753                 struct jffs2_raw_node_ref **p;
 754
 755                 spin_lock(&c->erase_completion_lock);
 756
 757                 ic = jffs2_raw_ref_to_ic(ref);
 758                 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 759                         ;
 760
 761                 *p = ref->next_in_ino;
 762                 ref->next_in_ino = NULL;
 763
 764                 switch (ic->class) {
 765 #ifdef CONFIG_JFFS2_FS_XATTR
 766                         case RAWNODE_CLASS_XATTR_DATUM:
 767                                 jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
 768                                 break;
 769                         case RAWNODE_CLASS_XATTR_REF:
 770                                 jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
 771                                 break;
 772 #endif
 773                         default:
 774                                 if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
 775                                         jffs2_del_ino_cache(c, ic);
 776                                 break;
 777                 }
 778                 spin_unlock(&c->erase_completion_lock);
 779         }
 780
 781  out_erase_sem:
 782         mutex_unlock(&c->erase_free_sem);
 783 }
 784
 785 int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 786 {
 787         int ret = 0;
 788         uint32_t dirty;
 789         int nr_very_dirty = 0;
 790         struct jffs2_eraseblock *jeb;
 791
 792         if (!list_empty(&c->erase_complete_list) ||
 793             !list_empty(&c->erase_pending_list))
 794                 return 1;
 795
 796         if (c->unchecked_size) {
 797                 jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 798                           c->unchecked_size, c->checked_ino);
 799                 return 1;
 800         }
 801
 802         /* dirty_size contains blocks on erase_pending_list
 803          * those blocks are counted in c->nr_erasing_blocks.
 804          * If one block is actually erased, it is not longer counted as dirty_space
 805          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 806          * with c->nr_erasing_blocks * c->sector_size again.
 807          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 808          * This helps us to force gc and pick eventually a clean block to spread the load.
 809          */
 810         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 811
 812         if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 813                         (dirty > c->nospc_dirty_size))
 814                 ret = 1;
 815
 816         list_for_each_entry(jeb, &c->very_dirty_list, list) {
 817                 nr_very_dirty++;
 818                 if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
 819                         ret = 1;
 820                         /* In debug mode, actually go through and count them all */
 821                         D1(continue);
 822                         break;
 823                 }
 824         }
 825
 826         jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n",
 827                   __func__, c->nr_free_blocks, c->nr_erasing_blocks,
 828                   c->dirty_size, nr_very_dirty, ret ? "yes" : "no");
 829
 830         return ret;
 831 }