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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/mtd/mtd.h>
  16 #include <linux/compiler.h>
  17 #include <linux/sched.h> /* For cond_resched() */
  18 #include "nodelist.h"
  19 #include "debug.h"
  20
  21 /**
  22  *      jffs2_reserve_space - request physical space to write nodes to flash
  23  *      @c: superblock info
  24  *      @minsize: Minimum acceptable size of allocation
  25  *      @len: Returned value of allocation length
  26  *      @prio: Allocation type - ALLOC_{NORMAL,DELETION}
  27  *
  28  *      Requests a block of physical space on the flash. Returns zero for success
  29  *      and puts 'len' into the appropriate place, or returns -ENOSPC or other
  30  *      error if appropriate. Doesn't return len since that's
  31  *
  32  *      If it returns zero, jffs2_reserve_space() also downs the per-filesystem
  33  *      allocation semaphore, to prevent more than one allocation from being
  34  *      active at any time. The semaphore is later released by jffs2_commit_allocation()
  35  *
  36  *      jffs2_reserve_space() may trigger garbage collection in order to make room
  37  *      for the requested allocation.
  38  */
  39
  40 static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
  41                                   uint32_t *len, uint32_t sumsize);
  42
  43 int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
  44                         uint32_t *len, int prio, uint32_t sumsize)
  45 {
  46         int ret = -EAGAIN;
  47         int blocksneeded = c->resv_blocks_write;
  48         /* align it */
  49         minsize = PAD(minsize);
  50
  51         jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
  52         mutex_lock(&c->alloc_sem);
  53
  54         jffs2_dbg(1, "%s(): alloc sem got\n", __func__);
  55
  56         spin_lock(&c->erase_completion_lock);
  57
  58         /* this needs a little more thought (true <tglx> :)) */
  59         while(ret == -EAGAIN) {
  60                 while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
  61                         uint32_t dirty, avail;
  62
  63                         /* calculate real dirty size
  64                          * dirty_size contains blocks on erase_pending_list
  65                          * those blocks are counted in c->nr_erasing_blocks.
  66                          * If one block is actually erased, it is not longer counted as dirty_space
  67                          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
  68                          * with c->nr_erasing_blocks * c->sector_size again.
  69                          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
  70                          * This helps us to force gc and pick eventually a clean block to spread the load.
  71                          * We add unchecked_size here, as we hopefully will find some space to use.
  72                          * This will affect the sum only once, as gc first finishes checking
  73                          * of nodes.
  74                          */
  75                         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
  76                         if (dirty < c->nospc_dirty_size) {
  77                                 if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
  78                                         jffs2_dbg(1, "%s(): Low on dirty space to GC, but it's a deletion. Allowing...\n",
  79                                                   __func__);
  80                                         break;
  81                                 }
  82                                 jffs2_dbg(1, "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
  83                                           dirty, c->unchecked_size,
  84                                           c->sector_size);
  85
  86                                 spin_unlock(&c->erase_completion_lock);
  87                                 mutex_unlock(&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                                         jffs2_dbg(1, "%s(): Low on possibly available space, but it's a deletion. Allowing...\n",
 104                                                   __func__);
 105                                         break;
 106                                 }
 107
 108                                 jffs2_dbg(1, "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                                 mutex_unlock(&c->alloc_sem);
 112                                 return -ENOSPC;
 113                         }
 114
 115                         mutex_unlock(&c->alloc_sem);
 116
 117                         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",
 118                                   c->nr_free_blocks, c->nr_erasing_blocks,
 119                                   c->free_size, c->dirty_size, c->wasted_size,
 120                                   c->used_size, c->erasing_size, c->bad_size,
 121                                   c->free_size + c->dirty_size +
 122                                   c->wasted_size + c->used_size +
 123                                   c->erasing_size + c->bad_size,
 124                                   c->flash_size);
 125                         spin_unlock(&c->erase_completion_lock);
 126
 127                         ret = jffs2_garbage_collect_pass(c);
 128
 129                         if (ret == -EAGAIN) {
 130                                 spin_lock(&c->erase_completion_lock);
 131                                 if (c->nr_erasing_blocks &&
 132                                     list_empty(&c->erase_pending_list) &&
 133                                     list_empty(&c->erase_complete_list)) {
 134                                         DECLARE_WAITQUEUE(wait, current);
 135                                         set_current_state(TASK_UNINTERRUPTIBLE);
 136                                         add_wait_queue(&c->erase_wait, &wait);
 137                                         jffs2_dbg(1, "%s waiting for erase to complete\n",
 138                                                   __func__);
 139                                         spin_unlock(&c->erase_completion_lock);
 140
 141                                         schedule();
 142                                 } else
 143                                         spin_unlock(&c->erase_completion_lock);
 144                         } else if (ret)
 145                                 return ret;
 146
 147                         cond_resched();
 148
 149                         if (signal_pending(current))
 150                                 return -EINTR;
 151
 152                         mutex_lock(&c->alloc_sem);
 153                         spin_lock(&c->erase_completion_lock);
 154                 }
 155
 156                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 157                 if (ret) {
 158                         jffs2_dbg(1, "%s(): ret is %d\n", __func__, ret);
 159                 }
 160         }
 161         spin_unlock(&c->erase_completion_lock);
 162         if (!ret)
 163                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 164         if (ret)
 165                 mutex_unlock(&c->alloc_sem);
 166         return ret;
 167 }
 168
 169 int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
 170                            uint32_t *len, uint32_t sumsize)
 171 {
 172         int ret = -EAGAIN;
 173         minsize = PAD(minsize);
 174
 175         jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
 176
 177         spin_lock(&c->erase_completion_lock);
 178         while(ret == -EAGAIN) {
 179                 ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 180                 if (ret) {
 181                         jffs2_dbg(1, "%s(): looping, ret is %d\n",
 182                                   __func__, ret);
 183                 }
 184         }
 185         spin_unlock(&c->erase_completion_lock);
 186         if (!ret)
 187                 ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 188
 189         return ret;
 190 }
 191
 192
 193 /* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
 194
 195 static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 196 {
 197
 198         if (c->nextblock == NULL) {
 199                 jffs2_dbg(1, "%s(): Erase block at 0x%08x has already been placed in a list\n",
 200                           __func__, jeb->offset);
 201                 return;
 202         }
 203         /* Check, if we have a dirty block now, or if it was dirty already */
 204         if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
 205                 c->dirty_size += jeb->wasted_size;
 206                 c->wasted_size -= jeb->wasted_size;
 207                 jeb->dirty_size += jeb->wasted_size;
 208                 jeb->wasted_size = 0;
 209                 if (VERYDIRTY(c, jeb->dirty_size)) {
 210                         jffs2_dbg(1, "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 211                                   jeb->offset, jeb->free_size, jeb->dirty_size,
 212                                   jeb->used_size);
 213                         list_add_tail(&jeb->list, &c->very_dirty_list);
 214                 } else {
 215                         jffs2_dbg(1, "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 216                                   jeb->offset, jeb->free_size, jeb->dirty_size,
 217                                   jeb->used_size);
 218                         list_add_tail(&jeb->list, &c->dirty_list);
 219                 }
 220         } else {
 221                 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 222                           jeb->offset, jeb->free_size, jeb->dirty_size,
 223                           jeb->used_size);
 224                 list_add_tail(&jeb->list, &c->clean_list);
 225         }
 226         c->nextblock = NULL;
 227
 228 }
 229
 230 /* Select a new jeb for nextblock */
 231
 232 static int jffs2_find_nextblock(struct jffs2_sb_info *c)
 233 {
 234         struct list_head *next;
 235
 236         /* Take the next block off the 'free' list */
 237
 238         if (list_empty(&c->free_list)) {
 239
 240                 if (!c->nr_erasing_blocks &&
 241                         !list_empty(&c->erasable_list)) {
 242                         struct jffs2_eraseblock *ejeb;
 243
 244                         ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
 245                         list_move_tail(&ejeb->list, &c->erase_pending_list);
 246                         c->nr_erasing_blocks++;
 247                         jffs2_garbage_collect_trigger(c);
 248                         jffs2_dbg(1, "%s(): Triggering erase of erasable block at 0x%08x\n",
 249                                   __func__, ejeb->offset);
 250                 }
 251
 252                 if (!c->nr_erasing_blocks &&
 253                         !list_empty(&c->erasable_pending_wbuf_list)) {
 254                         jffs2_dbg(1, "%s(): Flushing write buffer\n",
 255                                   __func__);
 256                         /* c->nextblock is NULL, no update to c->nextblock allowed */
 257                         spin_unlock(&c->erase_completion_lock);
 258                         jffs2_flush_wbuf_pad(c);
 259                         spin_lock(&c->erase_completion_lock);
 260                         /* Have another go. It'll be on the erasable_list now */
 261                         return -EAGAIN;
 262                 }
 263
 264                 if (!c->nr_erasing_blocks) {
 265                         /* Ouch. We're in GC, or we wouldn't have got here.
 266                            And there's no space left. At all. */
 267                         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",
 268                                 c->nr_erasing_blocks, c->nr_free_blocks,
 269                                 list_empty(&c->erasable_list) ? "yes" : "no",
 270                                 list_empty(&c->erasing_list) ? "yes" : "no",
 271                                 list_empty(&c->erase_pending_list) ? "yes" : "no");
 272                         return -ENOSPC;
 273                 }
 274
 275                 spin_unlock(&c->erase_completion_lock);
 276                 /* Don't wait for it; just erase one right now */
 277                 jffs2_erase_pending_blocks(c, 1);
 278                 spin_lock(&c->erase_completion_lock);
 279
 280                 /* An erase may have failed, decreasing the
 281                    amount of free space available. So we must
 282                    restart from the beginning */
 283                 return -EAGAIN;
 284         }
 285
 286         next = c->free_list.next;
 287         list_del(next);
 288         c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
 289         c->nr_free_blocks--;
 290
 291         jffs2_sum_reset_collected(c->summary); /* reset collected summary */
 292
 293 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 294         /* adjust write buffer offset, else we get a non contiguous write bug */
 295         if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
 296                 c->wbuf_ofs = 0xffffffff;
 297 #endif
 298
 299         jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
 300                   __func__, c->nextblock->offset);
 301
 302         return 0;
 303 }
 304
 305 /* Called with alloc sem _and_ erase_completion_lock */
 306 static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 307                                   uint32_t *len, uint32_t sumsize)
 308 {
 309         struct jffs2_eraseblock *jeb = c->nextblock;
 310         uint32_t reserved_size;                         /* for summary information at the end of the jeb */
 311         int ret;
 312
 313  restart:
 314         reserved_size = 0;
 315
 316         if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
 317                                                         /* NOSUM_SIZE means not to generate summary */
 318
 319                 if (jeb) {
 320                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 321                         dbg_summary("minsize=%d , jeb->free=%d ,"
 322                                                 "summary->size=%d , sumsize=%d\n",
 323                                                 minsize, jeb->free_size,
 324                                                 c->summary->sum_size, sumsize);
 325                 }
 326
 327                 /* Is there enough space for writing out the current node, or we have to
 328                    write out summary information now, close this jeb and select new nextblock? */
 329                 if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
 330                                         JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
 331
 332                         /* Has summary been disabled for this jeb? */
 333                         if (jffs2_sum_is_disabled(c->summary)) {
 334                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 335                                 goto restart;
 336                         }
 337
 338                         /* Writing out the collected summary information */
 339                         dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
 340                         ret = jffs2_sum_write_sumnode(c);
 341
 342                         if (ret)
 343                                 return ret;
 344
 345                         if (jffs2_sum_is_disabled(c->summary)) {
 346                                 /* jffs2_write_sumnode() couldn't write out the summary information
 347                                    diabling summary for this jeb and free the collected information
 348                                  */
 349                                 sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 350                                 goto restart;
 351                         }
 352
 353                         jffs2_close_nextblock(c, jeb);
 354                         jeb = NULL;
 355                         /* keep always valid value in reserved_size */
 356                         reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 357                 }
 358         } else {
 359                 if (jeb && minsize > jeb->free_size) {
 360                         uint32_t waste;
 361
 362                         /* Skip the end of this block and file it as having some dirty space */
 363                         /* If there's a pending write to it, flush now */
 364
 365                         if (jffs2_wbuf_dirty(c)) {
 366                                 spin_unlock(&c->erase_completion_lock);
 367                                 jffs2_dbg(1, "%s(): Flushing write buffer\n",
 368                                           __func__);
 369                                 jffs2_flush_wbuf_pad(c);
 370                                 spin_lock(&c->erase_completion_lock);
 371                                 jeb = c->nextblock;
 372                                 goto restart;
 373                         }
 374
 375                         spin_unlock(&c->erase_completion_lock);
 376
 377                         ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
 378                         if (ret)
 379                                 return ret;
 380                         /* Just lock it again and continue. Nothing much can change because
 381                            we hold c->alloc_sem anyway. In fact, it's not entirely clear why
 382                            we hold c->erase_completion_lock in the majority of this function...
 383                            but that's a question for another (more caffeine-rich) day. */
 384                         spin_lock(&c->erase_completion_lock);
 385
 386                         waste = jeb->free_size;
 387                         jffs2_link_node_ref(c, jeb,
 388                                             (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
 389                                             waste, NULL);
 390                         /* FIXME: that made it count as dirty. Convert to wasted */
 391                         jeb->dirty_size -= waste;
 392                         c->dirty_size -= waste;
 393                         jeb->wasted_size += waste;
 394                         c->wasted_size += waste;
 395
 396                         jffs2_close_nextblock(c, jeb);
 397                         jeb = NULL;
 398                 }
 399         }
 400
 401         if (!jeb) {
 402
 403                 ret = jffs2_find_nextblock(c);
 404                 if (ret)
 405                         return ret;
 406
 407                 jeb = c->nextblock;
 408
 409                 if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 410                         pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n",
 411                                 jeb->offset, jeb->free_size);
 412                         goto restart;
 413                 }
 414         }
 415         /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 416            enough space */
 417         *len = jeb->free_size - reserved_size;
 418
 419         if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 420             !jeb->first_node->next_in_ino) {
 421                 /* Only node in it beforehand was a CLEANMARKER node (we think).
 422                    So mark it obsolete now that there's going to be another node
 423                    in the block. This will reduce used_size to zero but We've
 424                    already set c->nextblock so that jffs2_mark_node_obsolete()
 425                    won't try to refile it to the dirty_list.
 426                 */
 427                 spin_unlock(&c->erase_completion_lock);
 428                 jffs2_mark_node_obsolete(c, jeb->first_node);
 429                 spin_lock(&c->erase_completion_lock);
 430         }
 431
 432         jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n",
 433                   __func__,
 434                   *len, jeb->offset + (c->sector_size - jeb->free_size));
 435         return 0;
 436 }
 437
 438 /**
 439  *      jffs2_add_physical_node_ref - add a physical node reference to the list
 440  *      @c: superblock info
 441  *      @new: new node reference to add
 442  *      @len: length of this physical node
 443  *
 444  *      Should only be used to report nodes for which space has been allocated
 445  *      by jffs2_reserve_space.
 446  *
 447  *      Must be called with the alloc_sem held.
 448  */
 449
 450 struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
 451                                                        uint32_t ofs, uint32_t len,
 452                                                        struct jffs2_inode_cache *ic)
 453 {
 454         struct jffs2_eraseblock *jeb;
 455         struct jffs2_raw_node_ref *new;
 456
 457         jeb = &c->blocks[ofs / c->sector_size];
 458
 459         jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n",
 460                   __func__, ofs & ~3, ofs & 3, len);
 461 #if 1
 462         /* Allow non-obsolete nodes only to be added at the end of c->nextblock,
 463            if c->nextblock is set. Note that wbuf.c will file obsolete nodes
 464            even after refiling c->nextblock */
 465         if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
 466             && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
 467                 pr_warn("argh. node added in wrong place at 0x%08x(%d)\n",
 468                         ofs & ~3, ofs & 3);
 469                 if (c->nextblock)
 470                         pr_warn("nextblock 0x%08x", c->nextblock->offset);
 471                 else
 472                         pr_warn("No nextblock");
 473                 pr_cont(", expected at %08x\n",
 474                         jeb->offset + (c->sector_size - jeb->free_size));
 475                 return ERR_PTR(-EINVAL);
 476         }
 477 #endif
 478         spin_lock(&c->erase_completion_lock);
 479
 480         new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
 481
 482         if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 483                 /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 484                 jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 485                           jeb->offset, jeb->free_size, jeb->dirty_size,
 486                           jeb->used_size);
 487                 if (jffs2_wbuf_dirty(c)) {
 488                         /* Flush the last write in the block if it's outstanding */
 489                         spin_unlock(&c->erase_completion_lock);
 490                         jffs2_flush_wbuf_pad(c);
 491                         spin_lock(&c->erase_completion_lock);
 492                 }
 493
 494                 list_add_tail(&jeb->list, &c->clean_list);
 495                 c->nextblock = NULL;
 496         }
 497         jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 498         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 499
 500         spin_unlock(&c->erase_completion_lock);
 501
 502         return new;
 503 }
 504
 505
 506 void jffs2_complete_reservation(struct jffs2_sb_info *c)
 507 {
 508         jffs2_dbg(1, "jffs2_complete_reservation()\n");
 509         spin_lock(&c->erase_completion_lock);
 510         jffs2_garbage_collect_trigger(c);
 511         spin_unlock(&c->erase_completion_lock);
 512         mutex_unlock(&c->alloc_sem);
 513 }
 514
 515 static inline int on_list(struct list_head *obj, struct list_head *head)
 516 {
 517         struct list_head *this;
 518
 519         list_for_each(this, head) {
 520                 if (this == obj) {
 521                         jffs2_dbg(1, "%p is on list at %p\n", obj, head);
 522                         return 1;
 523
 524                 }
 525         }
 526         return 0;
 527 }
 528
 529 void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 530 {
 531         struct jffs2_eraseblock *jeb;
 532         int blocknr;
 533         struct jffs2_unknown_node n;
 534         int ret, addedsize;
 535         size_t retlen;
 536         uint32_t freed_len;
 537
 538         if(unlikely(!ref)) {
 539                 pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 540                 return;
 541         }
 542         if (ref_obsolete(ref)) {
 543                 jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n",
 544                           __func__, ref_offset(ref));
 545                 return;
 546         }
 547         blocknr = ref->flash_offset / c->sector_size;
 548         if (blocknr >= c->nr_blocks) {
 549                 pr_notice("raw node at 0x%08x is off the end of device!\n",
 550                           ref->flash_offset);
 551                 BUG();
 552         }
 553         jeb = &c->blocks[blocknr];
 554
 555         if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 556             !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 557                 /* Hm. This may confuse static lock analysis. If any of the above
 558                    three conditions is false, we're going to return from this
 559                    function without actually obliterating any nodes or freeing
 560                    any jffs2_raw_node_refs. So we don't need to stop erases from
 561                    happening, or protect against people holding an obsolete
 562                    jffs2_raw_node_ref without the erase_completion_lock. */
 563                 mutex_lock(&c->erase_free_sem);
 564         }
 565
 566         spin_lock(&c->erase_completion_lock);
 567
 568         freed_len = ref_totlen(c, jeb, ref);
 569
 570         if (ref_flags(ref) == REF_UNCHECKED) {
 571                 D1(if (unlikely(jeb->unchecked_size < freed_len)) {
 572                                 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",
 573                                           freed_len, blocknr,
 574                                           ref->flash_offset, jeb->used_size);
 575                         BUG();
 576                 })
 577                         jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n",
 578                                   ref_offset(ref), freed_len);
 579                 jeb->unchecked_size -= freed_len;
 580                 c->unchecked_size -= freed_len;
 581         } else {
 582                 D1(if (unlikely(jeb->used_size < freed_len)) {
 583                                 pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
 584                                           freed_len, blocknr,
 585                                           ref->flash_offset, jeb->used_size);
 586                         BUG();
 587                 })
 588                         jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ",
 589                                   ref_offset(ref), freed_len);
 590                 jeb->used_size -= freed_len;
 591                 c->used_size -= freed_len;
 592         }
 593
 594         // Take care, that wasted size is taken into concern
 595         if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
 596                 jffs2_dbg(1, "Dirtying\n");
 597                 addedsize = freed_len;
 598                 jeb->dirty_size += freed_len;
 599                 c->dirty_size += freed_len;
 600
 601                 /* Convert wasted space to dirty, if not a bad block */
 602                 if (jeb->wasted_size) {
 603                         if (on_list(&jeb->list, &c->bad_used_list)) {
 604                                 jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n",
 605                                           jeb->offset);
 606                                 addedsize = 0; /* To fool the refiling code later */
 607                         } else {
 608                                 jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n",
 609                                           jeb->wasted_size, jeb->offset);
 610                                 addedsize += jeb->wasted_size;
 611                                 jeb->dirty_size += jeb->wasted_size;
 612                                 c->dirty_size += jeb->wasted_size;
 613                                 c->wasted_size -= jeb->wasted_size;
 614                                 jeb->wasted_size = 0;
 615                         }
 616                 }
 617         } else {
 618                 jffs2_dbg(1, "Wasting\n");
 619                 addedsize = 0;
 620                 jeb->wasted_size += freed_len;
 621                 c->wasted_size += freed_len;
 622         }
 623         ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 624
 625         jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 626         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 627
 628         if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 629                 /* Flash scanning is in progress. Don't muck about with the block
 630                    lists because they're not ready yet, and don't actually
 631                    obliterate nodes that look obsolete. If they weren't
 632                    marked obsolete on the flash at the time they _became_
 633                    obsolete, there was probably a reason for that. */
 634                 spin_unlock(&c->erase_completion_lock);
 635                 /* We didn't lock the erase_free_sem */
 636                 return;
 637         }
 638
 639         if (jeb == c->nextblock) {
 640                 jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n",
 641                           jeb->offset);
 642         } else if (!jeb->used_size && !jeb->unchecked_size) {
 643                 if (jeb == c->gcblock) {
 644                         jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n",
 645                                   jeb->offset);
 646                         c->gcblock = NULL;
 647                 } else {
 648                         jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n",
 649                                   jeb->offset);
 650                         list_del(&jeb->list);
 651                 }
 652                 if (jffs2_wbuf_dirty(c)) {
 653                         jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n");
 654                         list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 655                 } else {
 656                         if (jiffies & 127) {
 657                                 /* Most of the time, we just erase it immediately. Otherwise we
 658                                    spend ages scanning it on mount, etc. */
 659                                 jffs2_dbg(1, "...and adding to erase_pending_list\n");
 660                                 list_add_tail(&jeb->list, &c->erase_pending_list);
 661                                 c->nr_erasing_blocks++;
 662                                 jffs2_garbage_collect_trigger(c);
 663                         } else {
 664                                 /* Sometimes, however, we leave it elsewhere so it doesn't get
 665                                    immediately reused, and we spread the load a bit. */
 666                                 jffs2_dbg(1, "...and adding to erasable_list\n");
 667                                 list_add_tail(&jeb->list, &c->erasable_list);
 668                         }
 669                 }
 670                 jffs2_dbg(1, "Done OK\n");
 671         } else if (jeb == c->gcblock) {
 672                 jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n",
 673                           jeb->offset);
 674         } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 675                 jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n",
 676                           jeb->offset);
 677                 list_del(&jeb->list);
 678                 jffs2_dbg(1, "...and adding to dirty_list\n");
 679                 list_add_tail(&jeb->list, &c->dirty_list);
 680         } else if (VERYDIRTY(c, jeb->dirty_size) &&
 681                    !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 682                 jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n",
 683                           jeb->offset);
 684                 list_del(&jeb->list);
 685                 jffs2_dbg(1, "...and adding to very_dirty_list\n");
 686                 list_add_tail(&jeb->list, &c->very_dirty_list);
 687         } else {
 688                 jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 689                           jeb->offset, jeb->free_size, jeb->dirty_size,
 690                           jeb->used_size);
 691         }
 692
 693         spin_unlock(&c->erase_completion_lock);
 694
 695         if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 696                 (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 697                 /* We didn't lock the erase_free_sem */
 698                 return;
 699         }
 700
 701         /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 702            and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 703            the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 704            by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
 705
 706         jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n",
 707                   ref_offset(ref));
 708         ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 709         if (ret) {
 710                 pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n",
 711                         ref_offset(ref), ret);
 712                 goto out_erase_sem;
 713         }
 714         if (retlen != sizeof(n)) {
 715                 pr_warn("Short read from obsoleted node at 0x%08x: %zd\n",
 716                         ref_offset(ref), retlen);
 717                 goto out_erase_sem;
 718         }
 719         if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
 720                 pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n",
 721                         je32_to_cpu(n.totlen), freed_len);
 722                 goto out_erase_sem;
 723         }
 724         if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 725                 jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n",
 726                           ref_offset(ref), je16_to_cpu(n.nodetype));
 727                 goto out_erase_sem;
 728         }
 729         /* XXX FIXME: This is ugly now */
 730         n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 731         ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 732         if (ret) {
 733                 pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n",
 734                         ref_offset(ref), ret);
 735                 goto out_erase_sem;
 736         }
 737         if (retlen != sizeof(n)) {
 738                 pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n",
 739                         ref_offset(ref), retlen);
 740                 goto out_erase_sem;
 741         }
 742
 743         /* Nodes which have been marked obsolete no longer need to be
 744            associated with any inode. Remove them from the per-inode list.
 745
 746            Note we can't do this for NAND at the moment because we need
 747            obsolete dirent nodes to stay on the lists, because of the
 748            horridness in jffs2_garbage_collect_deletion_dirent(). Also
 749            because we delete the inocache, and on NAND we need that to
 750            stay around until all the nodes are actually erased, in order
 751            to stop us from giving the same inode number to another newly
 752            created inode. */
 753         if (ref->next_in_ino) {
 754                 struct jffs2_inode_cache *ic;
 755                 struct jffs2_raw_node_ref **p;
 756
 757                 spin_lock(&c->erase_completion_lock);
 758
 759                 ic = jffs2_raw_ref_to_ic(ref);
 760                 for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 761                         ;
 762
 763                 *p = ref->next_in_ino;
 764                 ref->next_in_ino = NULL;
 765
 766                 switch (ic->class) {
 767 #ifdef CONFIG_JFFS2_FS_XATTR
 768                         case RAWNODE_CLASS_XATTR_DATUM:
 769                                 jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
 770                                 break;
 771                         case RAWNODE_CLASS_XATTR_REF:
 772                                 jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
 773                                 break;
 774 #endif
 775                         default:
 776                                 if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
 777                                         jffs2_del_ino_cache(c, ic);
 778                                 break;
 779                 }
 780                 spin_unlock(&c->erase_completion_lock);
 781         }
 782
 783  out_erase_sem:
 784         mutex_unlock(&c->erase_free_sem);
 785 }
 786
 787 int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 788 {
 789         int ret = 0;
 790         uint32_t dirty;
 791         int nr_very_dirty = 0;
 792         struct jffs2_eraseblock *jeb;
 793
 794         if (!list_empty(&c->erase_complete_list) ||
 795             !list_empty(&c->erase_pending_list))
 796                 return 1;
 797
 798         if (c->unchecked_size) {
 799                 jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 800                           c->unchecked_size, c->checked_ino);
 801                 return 1;
 802         }
 803
 804         /* dirty_size contains blocks on erase_pending_list
 805          * those blocks are counted in c->nr_erasing_blocks.
 806          * If one block is actually erased, it is not longer counted as dirty_space
 807          * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 808          * with c->nr_erasing_blocks * c->sector_size again.
 809          * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 810          * This helps us to force gc and pick eventually a clean block to spread the load.
 811          */
 812         dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 813
 814         if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 815                         (dirty > c->nospc_dirty_size))
 816                 ret = 1;
 817
 818         list_for_each_entry(jeb, &c->very_dirty_list, list) {
 819                 nr_very_dirty++;
 820                 if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
 821                         ret = 1;
 822                         /* In debug mode, actually go through and count them all */
 823                         D1(continue);
 824                         break;
 825                 }
 826         }
 827
 828         jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n",
 829                   __func__, c->nr_free_blocks, c->nr_erasing_blocks,
 830                   c->dirty_size, nr_very_dirty, ret ? "yes" : "no");
 831
 832         return ret;
 833 }