linux/fs/jffs2/nodemgmt.c
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   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
  38static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
  39                                  uint32_t *len, uint32_t sumsize);
  40
  41int 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        D1(printk(KERN_DEBUG "jffs2_reserve_space(): Requested 0x%x bytes\n", minsize));
  50        mutex_lock(&c->alloc_sem);
  51
  52        D1(printk(KERN_DEBUG "jffs2_reserve_space(): alloc sem got\n"));
  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                                        D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on dirty space to GC, but it's a deletion. Allowing...\n"));
  77                                        break;
  78                                }
  79                                D1(printk(KERN_DEBUG "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
  80                                          dirty, c->unchecked_size, c->sector_size));
  81
  82                                spin_unlock(&c->erase_completion_lock);
  83                                mutex_unlock(&c->alloc_sem);
  84                                return -ENOSPC;
  85                        }
  86
  87                        /* Calc possibly available space. Possibly available means that we
  88                         * don't know, if unchecked size contains obsoleted nodes, which could give us some
  89                         * more usable space. This will affect the sum only once, as gc first finishes checking
  90                         * of nodes.
  91                         + Return -ENOSPC, if the maximum possibly available space is less or equal than
  92                         * blocksneeded * sector_size.
  93                         * This blocks endless gc looping on a filesystem, which is nearly full, even if
  94                         * the check above passes.
  95                         */
  96                        avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
  97                        if ( (avail / c->sector_size) <= blocksneeded) {
  98                                if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
  99                                        D1(printk(KERN_NOTICE "jffs2_reserve_space(): Low on possibly available space, but it's a deletion. Allowing...\n"));
 100                                        break;
 101                                }
 102
 103                                D1(printk(KERN_DEBUG "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
 104                                          avail, blocksneeded * c->sector_size));
 105                                spin_unlock(&c->erase_completion_lock);
 106                                mutex_unlock(&c->alloc_sem);
 107                                return -ENOSPC;
 108                        }
 109
 110                        mutex_unlock(&c->alloc_sem);
 111
 112                        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",
 113                                  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,
 114                                  c->free_size + c->dirty_size + c->wasted_size + c->used_size + c->erasing_size + c->bad_size, c->flash_size));
 115                        spin_unlock(&c->erase_completion_lock);
 116
 117                        ret = jffs2_garbage_collect_pass(c);
 118
 119                        if (ret == -EAGAIN) {
 120                                spin_lock(&c->erase_completion_lock);
 121                                if (c->nr_erasing_blocks &&
 122                                    list_empty(&c->erase_pending_list) &&
 123                                    list_empty(&c->erase_complete_list)) {
 124                                        DECLARE_WAITQUEUE(wait, current);
 125                                        set_current_state(TASK_UNINTERRUPTIBLE);
 126                                        add_wait_queue(&c->erase_wait, &wait);
 127                                        D1(printk(KERN_DEBUG "%s waiting for erase to complete\n", __func__));
 128                                        spin_unlock(&c->erase_completion_lock);
 129
 130                                        schedule();
 131                                } else
 132                                        spin_unlock(&c->erase_completion_lock);
 133                        } else if (ret)
 134                                return ret;
 135
 136                        cond_resched();
 137
 138                        if (signal_pending(current))
 139                                return -EINTR;
 140
 141                        mutex_lock(&c->alloc_sem);
 142                        spin_lock(&c->erase_completion_lock);
 143                }
 144
 145                ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 146                if (ret) {
 147                        D1(printk(KERN_DEBUG "jffs2_reserve_space: ret is %d\n", ret));
 148                }
 149        }
 150        spin_unlock(&c->erase_completion_lock);
 151        if (!ret)
 152                ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 153        if (ret)
 154                mutex_unlock(&c->alloc_sem);
 155        return ret;
 156}
 157
 158int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
 159                           uint32_t *len, uint32_t sumsize)
 160{
 161        int ret = -EAGAIN;
 162        minsize = PAD(minsize);
 163
 164        D1(printk(KERN_DEBUG "jffs2_reserve_space_gc(): Requested 0x%x bytes\n", minsize));
 165
 166        spin_lock(&c->erase_completion_lock);
 167        while(ret == -EAGAIN) {
 168                ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 169                if (ret) {
 170                        D1(printk(KERN_DEBUG "jffs2_reserve_space_gc: looping, ret is %d\n", ret));
 171                }
 172        }
 173        spin_unlock(&c->erase_completion_lock);
 174        if (!ret)
 175                ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 176
 177        return ret;
 178}
 179
 180
 181/* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
 182
 183static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 184{
 185
 186        if (c->nextblock == NULL) {
 187                D1(printk(KERN_DEBUG "jffs2_close_nextblock: Erase block at 0x%08x has already been placed in a list\n",
 188                  jeb->offset));
 189                return;
 190        }
 191        /* Check, if we have a dirty block now, or if it was dirty already */
 192        if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
 193                c->dirty_size += jeb->wasted_size;
 194                c->wasted_size -= jeb->wasted_size;
 195                jeb->dirty_size += jeb->wasted_size;
 196                jeb->wasted_size = 0;
 197                if (VERYDIRTY(c, jeb->dirty_size)) {
 198                        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",
 199                          jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 200                        list_add_tail(&jeb->list, &c->very_dirty_list);
 201                } else {
 202                        D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 203                          jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 204                        list_add_tail(&jeb->list, &c->dirty_list);
 205                }
 206        } else {
 207                D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 208                  jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 209                list_add_tail(&jeb->list, &c->clean_list);
 210        }
 211        c->nextblock = NULL;
 212
 213}
 214
 215/* Select a new jeb for nextblock */
 216
 217static int jffs2_find_nextblock(struct jffs2_sb_info *c)
 218{
 219        struct list_head *next;
 220
 221        /* Take the next block off the 'free' list */
 222
 223        if (list_empty(&c->free_list)) {
 224
 225                if (!c->nr_erasing_blocks &&
 226                        !list_empty(&c->erasable_list)) {
 227                        struct jffs2_eraseblock *ejeb;
 228
 229                        ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
 230                        list_move_tail(&ejeb->list, &c->erase_pending_list);
 231                        c->nr_erasing_blocks++;
 232                        jffs2_garbage_collect_trigger(c);
 233                        D1(printk(KERN_DEBUG "jffs2_find_nextblock: Triggering erase of erasable block at 0x%08x\n",
 234                                  ejeb->offset));
 235                }
 236
 237                if (!c->nr_erasing_blocks &&
 238                        !list_empty(&c->erasable_pending_wbuf_list)) {
 239                        D1(printk(KERN_DEBUG "jffs2_find_nextblock: Flushing write buffer\n"));
 240                        /* c->nextblock is NULL, no update to c->nextblock allowed */
 241                        spin_unlock(&c->erase_completion_lock);
 242                        jffs2_flush_wbuf_pad(c);
 243                        spin_lock(&c->erase_completion_lock);
 244                        /* Have another go. It'll be on the erasable_list now */
 245                        return -EAGAIN;
 246                }
 247
 248                if (!c->nr_erasing_blocks) {
 249                        /* Ouch. We're in GC, or we wouldn't have got here.
 250                           And there's no space left. At all. */
 251                        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",
 252                                   c->nr_erasing_blocks, c->nr_free_blocks, list_empty(&c->erasable_list)?"yes":"no",
 253                                   list_empty(&c->erasing_list)?"yes":"no", list_empty(&c->erase_pending_list)?"yes":"no");
 254                        return -ENOSPC;
 255                }
 256
 257                spin_unlock(&c->erase_completion_lock);
 258                /* Don't wait for it; just erase one right now */
 259                jffs2_erase_pending_blocks(c, 1);
 260                spin_lock(&c->erase_completion_lock);
 261
 262                /* An erase may have failed, decreasing the
 263                   amount of free space available. So we must
 264                   restart from the beginning */
 265                return -EAGAIN;
 266        }
 267
 268        next = c->free_list.next;
 269        list_del(next);
 270        c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
 271        c->nr_free_blocks--;
 272
 273        jffs2_sum_reset_collected(c->summary); /* reset collected summary */
 274
 275#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 276        /* adjust write buffer offset, else we get a non contiguous write bug */
 277        if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
 278                c->wbuf_ofs = 0xffffffff;
 279#endif
 280
 281        D1(printk(KERN_DEBUG "jffs2_find_nextblock(): new nextblock = 0x%08x\n", c->nextblock->offset));
 282
 283        return 0;
 284}
 285
 286/* Called with alloc sem _and_ erase_completion_lock */
 287static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 288                                  uint32_t *len, uint32_t sumsize)
 289{
 290        struct jffs2_eraseblock *jeb = c->nextblock;
 291        uint32_t reserved_size;                         /* for summary information at the end of the jeb */
 292        int ret;
 293
 294 restart:
 295        reserved_size = 0;
 296
 297        if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
 298                                                        /* NOSUM_SIZE means not to generate summary */
 299
 300                if (jeb) {
 301                        reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 302                        dbg_summary("minsize=%d , jeb->free=%d ,"
 303                                                "summary->size=%d , sumsize=%d\n",
 304                                                minsize, jeb->free_size,
 305                                                c->summary->sum_size, sumsize);
 306                }
 307
 308                /* Is there enough space for writing out the current node, or we have to
 309                   write out summary information now, close this jeb and select new nextblock? */
 310                if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
 311                                        JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
 312
 313                        /* Has summary been disabled for this jeb? */
 314                        if (jffs2_sum_is_disabled(c->summary)) {
 315                                sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 316                                goto restart;
 317                        }
 318
 319                        /* Writing out the collected summary information */
 320                        dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
 321                        ret = jffs2_sum_write_sumnode(c);
 322
 323                        if (ret)
 324                                return ret;
 325
 326                        if (jffs2_sum_is_disabled(c->summary)) {
 327                                /* jffs2_write_sumnode() couldn't write out the summary information
 328                                   diabling summary for this jeb and free the collected information
 329                                 */
 330                                sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 331                                goto restart;
 332                        }
 333
 334                        jffs2_close_nextblock(c, jeb);
 335                        jeb = NULL;
 336                        /* keep always valid value in reserved_size */
 337                        reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 338                }
 339        } else {
 340                if (jeb && minsize > jeb->free_size) {
 341                        uint32_t waste;
 342
 343                        /* Skip the end of this block and file it as having some dirty space */
 344                        /* If there's a pending write to it, flush now */
 345
 346                        if (jffs2_wbuf_dirty(c)) {
 347                                spin_unlock(&c->erase_completion_lock);
 348                                D1(printk(KERN_DEBUG "jffs2_do_reserve_space: Flushing write buffer\n"));
 349                                jffs2_flush_wbuf_pad(c);
 350                                spin_lock(&c->erase_completion_lock);
 351                                jeb = c->nextblock;
 352                                goto restart;
 353                        }
 354
 355                        spin_unlock(&c->erase_completion_lock);
 356
 357                        ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
 358                        if (ret)
 359                                return ret;
 360                        /* Just lock it again and continue. Nothing much can change because
 361                           we hold c->alloc_sem anyway. In fact, it's not entirely clear why
 362                           we hold c->erase_completion_lock in the majority of this function...
 363                           but that's a question for another (more caffeine-rich) day. */
 364                        spin_lock(&c->erase_completion_lock);
 365
 366                        waste = jeb->free_size;
 367                        jffs2_link_node_ref(c, jeb,
 368                                            (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
 369                                            waste, NULL);
 370                        /* FIXME: that made it count as dirty. Convert to wasted */
 371                        jeb->dirty_size -= waste;
 372                        c->dirty_size -= waste;
 373                        jeb->wasted_size += waste;
 374                        c->wasted_size += waste;
 375
 376                        jffs2_close_nextblock(c, jeb);
 377                        jeb = NULL;
 378                }
 379        }
 380
 381        if (!jeb) {
 382
 383                ret = jffs2_find_nextblock(c);
 384                if (ret)
 385                        return ret;
 386
 387                jeb = c->nextblock;
 388
 389                if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 390                        printk(KERN_WARNING "Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n", jeb->offset, jeb->free_size);
 391                        goto restart;
 392                }
 393        }
 394        /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 395           enough space */
 396        *len = jeb->free_size - reserved_size;
 397
 398        if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 399            !jeb->first_node->next_in_ino) {
 400                /* Only node in it beforehand was a CLEANMARKER node (we think).
 401                   So mark it obsolete now that there's going to be another node
 402                   in the block. This will reduce used_size to zero but We've
 403                   already set c->nextblock so that jffs2_mark_node_obsolete()
 404                   won't try to refile it to the dirty_list.
 405                */
 406                spin_unlock(&c->erase_completion_lock);
 407                jffs2_mark_node_obsolete(c, jeb->first_node);
 408                spin_lock(&c->erase_completion_lock);
 409        }
 410
 411        D1(printk(KERN_DEBUG "jffs2_do_reserve_space(): Giving 0x%x bytes at 0x%x\n",
 412                  *len, jeb->offset + (c->sector_size - jeb->free_size)));
 413        return 0;
 414}
 415
 416/**
 417 *      jffs2_add_physical_node_ref - add a physical node reference to the list
 418 *      @c: superblock info
 419 *      @new: new node reference to add
 420 *      @len: length of this physical node
 421 *
 422 *      Should only be used to report nodes for which space has been allocated
 423 *      by jffs2_reserve_space.
 424 *
 425 *      Must be called with the alloc_sem held.
 426 */
 427
 428struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
 429                                                       uint32_t ofs, uint32_t len,
 430                                                       struct jffs2_inode_cache *ic)
 431{
 432        struct jffs2_eraseblock *jeb;
 433        struct jffs2_raw_node_ref *new;
 434
 435        jeb = &c->blocks[ofs / c->sector_size];
 436
 437        D1(printk(KERN_DEBUG "jffs2_add_physical_node_ref(): Node at 0x%x(%d), size 0x%x\n",
 438                  ofs & ~3, ofs & 3, len));
 439#if 1
 440        /* Allow non-obsolete nodes only to be added at the end of c->nextblock, 
 441           if c->nextblock is set. Note that wbuf.c will file obsolete nodes
 442           even after refiling c->nextblock */
 443        if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
 444            && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
 445                printk(KERN_WARNING "argh. node added in wrong place at 0x%08x(%d)\n", ofs & ~3, ofs & 3);
 446                if (c->nextblock)
 447                        printk(KERN_WARNING "nextblock 0x%08x", c->nextblock->offset);
 448                else
 449                        printk(KERN_WARNING "No nextblock");
 450                printk(", expected at %08x\n", jeb->offset + (c->sector_size - jeb->free_size));
 451                return ERR_PTR(-EINVAL);
 452        }
 453#endif
 454        spin_lock(&c->erase_completion_lock);
 455
 456        new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
 457
 458        if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 459                /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 460                D1(printk(KERN_DEBUG "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 461                          jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 462                if (jffs2_wbuf_dirty(c)) {
 463                        /* Flush the last write in the block if it's outstanding */
 464                        spin_unlock(&c->erase_completion_lock);
 465                        jffs2_flush_wbuf_pad(c);
 466                        spin_lock(&c->erase_completion_lock);
 467                }
 468
 469                list_add_tail(&jeb->list, &c->clean_list);
 470                c->nextblock = NULL;
 471        }
 472        jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 473        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 474
 475        spin_unlock(&c->erase_completion_lock);
 476
 477        return new;
 478}
 479
 480
 481void jffs2_complete_reservation(struct jffs2_sb_info *c)
 482{
 483        D1(printk(KERN_DEBUG "jffs2_complete_reservation()\n"));
 484        spin_lock(&c->erase_completion_lock);
 485        jffs2_garbage_collect_trigger(c);
 486        spin_unlock(&c->erase_completion_lock);
 487        mutex_unlock(&c->alloc_sem);
 488}
 489
 490static inline int on_list(struct list_head *obj, struct list_head *head)
 491{
 492        struct list_head *this;
 493
 494        list_for_each(this, head) {
 495                if (this == obj) {
 496                        D1(printk("%p is on list at %p\n", obj, head));
 497                        return 1;
 498
 499                }
 500        }
 501        return 0;
 502}
 503
 504void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 505{
 506        struct jffs2_eraseblock *jeb;
 507        int blocknr;
 508        struct jffs2_unknown_node n;
 509        int ret, addedsize;
 510        size_t retlen;
 511        uint32_t freed_len;
 512
 513        if(unlikely(!ref)) {
 514                printk(KERN_NOTICE "EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 515                return;
 516        }
 517        if (ref_obsolete(ref)) {
 518                D1(printk(KERN_DEBUG "jffs2_mark_node_obsolete called with already obsolete node at 0x%08x\n", ref_offset(ref)));
 519                return;
 520        }
 521        blocknr = ref->flash_offset / c->sector_size;
 522        if (blocknr >= c->nr_blocks) {
 523                printk(KERN_NOTICE "raw node at 0x%08x is off the end of device!\n", ref->flash_offset);
 524                BUG();
 525        }
 526        jeb = &c->blocks[blocknr];
 527
 528        if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 529            !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 530                /* Hm. This may confuse static lock analysis. If any of the above
 531                   three conditions is false, we're going to return from this
 532                   function without actually obliterating any nodes or freeing
 533                   any jffs2_raw_node_refs. So we don't need to stop erases from
 534                   happening, or protect against people holding an obsolete
 535                   jffs2_raw_node_ref without the erase_completion_lock. */
 536                mutex_lock(&c->erase_free_sem);
 537        }
 538
 539        spin_lock(&c->erase_completion_lock);
 540
 541        freed_len = ref_totlen(c, jeb, ref);
 542
 543        if (ref_flags(ref) == REF_UNCHECKED) {
 544                D1(if (unlikely(jeb->unchecked_size < freed_len)) {
 545                        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",
 546                               freed_len, blocknr, ref->flash_offset, jeb->used_size);
 547                        BUG();
 548                })
 549                D1(printk(KERN_DEBUG "Obsoleting previously unchecked node at 0x%08x of len %x: ", ref_offset(ref), freed_len));
 550                jeb->unchecked_size -= freed_len;
 551                c->unchecked_size -= freed_len;
 552        } else {
 553                D1(if (unlikely(jeb->used_size < freed_len)) {
 554                        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",
 555                               freed_len, blocknr, ref->flash_offset, jeb->used_size);
 556                        BUG();
 557                })
 558                D1(printk(KERN_DEBUG "Obsoleting node at 0x%08x of len %#x: ", ref_offset(ref), freed_len));
 559                jeb->used_size -= freed_len;
 560                c->used_size -= freed_len;
 561        }
 562
 563        // Take care, that wasted size is taken into concern
 564        if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
 565                D1(printk("Dirtying\n"));
 566                addedsize = freed_len;
 567                jeb->dirty_size += freed_len;
 568                c->dirty_size += freed_len;
 569
 570                /* Convert wasted space to dirty, if not a bad block */
 571                if (jeb->wasted_size) {
 572                        if (on_list(&jeb->list, &c->bad_used_list)) {
 573                                D1(printk(KERN_DEBUG "Leaving block at %08x on the bad_used_list\n",
 574                                          jeb->offset));
 575                                addedsize = 0; /* To fool the refiling code later */
 576                        } else {
 577                                D1(printk(KERN_DEBUG "Converting %d bytes of wasted space to dirty in block at %08x\n",
 578                                          jeb->wasted_size, jeb->offset));
 579                                addedsize += jeb->wasted_size;
 580                                jeb->dirty_size += jeb->wasted_size;
 581                                c->dirty_size += jeb->wasted_size;
 582                                c->wasted_size -= jeb->wasted_size;
 583                                jeb->wasted_size = 0;
 584                        }
 585                }
 586        } else {
 587                D1(printk("Wasting\n"));
 588                addedsize = 0;
 589                jeb->wasted_size += freed_len;
 590                c->wasted_size += freed_len;
 591        }
 592        ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 593
 594        jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 595        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 596
 597        if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 598                /* Flash scanning is in progress. Don't muck about with the block
 599                   lists because they're not ready yet, and don't actually
 600                   obliterate nodes that look obsolete. If they weren't
 601                   marked obsolete on the flash at the time they _became_
 602                   obsolete, there was probably a reason for that. */
 603                spin_unlock(&c->erase_completion_lock);
 604                /* We didn't lock the erase_free_sem */
 605                return;
 606        }
 607
 608        if (jeb == c->nextblock) {
 609                D2(printk(KERN_DEBUG "Not moving nextblock 0x%08x to dirty/erase_pending list\n", jeb->offset));
 610        } else if (!jeb->used_size && !jeb->unchecked_size) {
 611                if (jeb == c->gcblock) {
 612                        D1(printk(KERN_DEBUG "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n", jeb->offset));
 613                        c->gcblock = NULL;
 614                } else {
 615                        D1(printk(KERN_DEBUG "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n", jeb->offset));
 616                        list_del(&jeb->list);
 617                }
 618                if (jffs2_wbuf_dirty(c)) {
 619                        D1(printk(KERN_DEBUG "...and adding to erasable_pending_wbuf_list\n"));
 620                        list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 621                } else {
 622                        if (jiffies & 127) {
 623                                /* Most of the time, we just erase it immediately. Otherwise we
 624                                   spend ages scanning it on mount, etc. */
 625                                D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
 626                                list_add_tail(&jeb->list, &c->erase_pending_list);
 627                                c->nr_erasing_blocks++;
 628                                jffs2_garbage_collect_trigger(c);
 629                        } else {
 630                                /* Sometimes, however, we leave it elsewhere so it doesn't get
 631                                   immediately reused, and we spread the load a bit. */
 632                                D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
 633                                list_add_tail(&jeb->list, &c->erasable_list);
 634                        }
 635                }
 636                D1(printk(KERN_DEBUG "Done OK\n"));
 637        } else if (jeb == c->gcblock) {
 638                D2(printk(KERN_DEBUG "Not moving gcblock 0x%08x to dirty_list\n", jeb->offset));
 639        } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 640                D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n", jeb->offset));
 641                list_del(&jeb->list);
 642                D1(printk(KERN_DEBUG "...and adding to dirty_list\n"));
 643                list_add_tail(&jeb->list, &c->dirty_list);
 644        } else if (VERYDIRTY(c, jeb->dirty_size) &&
 645                   !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 646                D1(printk(KERN_DEBUG "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n", jeb->offset));
 647                list_del(&jeb->list);
 648                D1(printk(KERN_DEBUG "...and adding to very_dirty_list\n"));
 649                list_add_tail(&jeb->list, &c->very_dirty_list);
 650        } else {
 651                D1(printk(KERN_DEBUG "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 652                          jeb->offset, jeb->free_size, jeb->dirty_size, jeb->used_size));
 653        }
 654
 655        spin_unlock(&c->erase_completion_lock);
 656
 657        if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 658                (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 659                /* We didn't lock the erase_free_sem */
 660                return;
 661        }
 662
 663        /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 664           and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 665           the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 666           by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
 667
 668        D1(printk(KERN_DEBUG "obliterating obsoleted node at 0x%08x\n", ref_offset(ref)));
 669        ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 670        if (ret) {
 671                printk(KERN_WARNING "Read error reading from obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 672                goto out_erase_sem;
 673        }
 674        if (retlen != sizeof(n)) {
 675                printk(KERN_WARNING "Short read from obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 676                goto out_erase_sem;
 677        }
 678        if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
 679                printk(KERN_WARNING "Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n", je32_to_cpu(n.totlen), freed_len);
 680                goto out_erase_sem;
 681        }
 682        if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 683                D1(printk(KERN_DEBUG "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n", ref_offset(ref), je16_to_cpu(n.nodetype)));
 684                goto out_erase_sem;
 685        }
 686        /* XXX FIXME: This is ugly now */
 687        n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 688        ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 689        if (ret) {
 690                printk(KERN_WARNING "Write error in obliterating obsoleted node at 0x%08x: %d\n", ref_offset(ref), ret);
 691                goto out_erase_sem;
 692        }
 693        if (retlen != sizeof(n)) {
 694                printk(KERN_WARNING "Short write in obliterating obsoleted node at 0x%08x: %zd\n", ref_offset(ref), retlen);
 695                goto out_erase_sem;
 696        }
 697
 698        /* Nodes which have been marked obsolete no longer need to be
 699           associated with any inode. Remove them from the per-inode list.
 700
 701           Note we can't do this for NAND at the moment because we need
 702           obsolete dirent nodes to stay on the lists, because of the
 703           horridness in jffs2_garbage_collect_deletion_dirent(). Also
 704           because we delete the inocache, and on NAND we need that to
 705           stay around until all the nodes are actually erased, in order
 706           to stop us from giving the same inode number to another newly
 707           created inode. */
 708        if (ref->next_in_ino) {
 709                struct jffs2_inode_cache *ic;
 710                struct jffs2_raw_node_ref **p;
 711
 712                spin_lock(&c->erase_completion_lock);
 713
 714                ic = jffs2_raw_ref_to_ic(ref);
 715                for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 716                        ;
 717
 718                *p = ref->next_in_ino;
 719                ref->next_in_ino = NULL;
 720
 721                switch (ic->class) {
 722#ifdef CONFIG_JFFS2_FS_XATTR
 723                        case RAWNODE_CLASS_XATTR_DATUM:
 724                                jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
 725                                break;
 726                        case RAWNODE_CLASS_XATTR_REF:
 727                                jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
 728                                break;
 729#endif
 730                        default:
 731                                if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
 732                                        jffs2_del_ino_cache(c, ic);
 733                                break;
 734                }
 735                spin_unlock(&c->erase_completion_lock);
 736        }
 737
 738 out_erase_sem:
 739        mutex_unlock(&c->erase_free_sem);
 740}
 741
 742int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 743{
 744        int ret = 0;
 745        uint32_t dirty;
 746        int nr_very_dirty = 0;
 747        struct jffs2_eraseblock *jeb;
 748
 749        if (!list_empty(&c->erase_complete_list) ||
 750            !list_empty(&c->erase_pending_list))
 751                return 1;
 752
 753        if (c->unchecked_size) {
 754                D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 755                          c->unchecked_size, c->checked_ino));
 756                return 1;
 757        }
 758
 759        /* dirty_size contains blocks on erase_pending_list
 760         * those blocks are counted in c->nr_erasing_blocks.
 761         * If one block is actually erased, it is not longer counted as dirty_space
 762         * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 763         * with c->nr_erasing_blocks * c->sector_size again.
 764         * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 765         * This helps us to force gc and pick eventually a clean block to spread the load.
 766         */
 767        dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 768
 769        if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 770                        (dirty > c->nospc_dirty_size))
 771                ret = 1;
 772
 773        list_for_each_entry(jeb, &c->very_dirty_list, list) {
 774                nr_very_dirty++;
 775                if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
 776                        ret = 1;
 777                        /* In debug mode, actually go through and count them all */
 778                        D1(continue);
 779                        break;
 780                }
 781        }
 782
 783        D1(printk(KERN_DEBUG "jffs2_thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n",
 784                  c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size, nr_very_dirty, ret?"yes":"no"));
 785
 786        return ret;
 787}
 788