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#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 * Check whether the user is allowed to write.
  23 */
  24static int jffs2_rp_can_write(struct jffs2_sb_info *c)
  25{
  26        uint32_t avail;
  27        struct jffs2_mount_opts *opts = &c->mount_opts;
  28
  29        avail = c->dirty_size + c->free_size + c->unchecked_size +
  30                c->erasing_size - c->resv_blocks_write * c->sector_size
  31                - c->nospc_dirty_size;
  32
  33        if (avail < 2 * opts->rp_size)
  34                jffs2_dbg(1, "rpsize %u, dirty_size %u, free_size %u, "
  35                          "erasing_size %u, unchecked_size %u, "
  36                          "nr_erasing_blocks %u, avail %u, resrv %u\n",
  37                          opts->rp_size, c->dirty_size, c->free_size,
  38                          c->erasing_size, c->unchecked_size,
  39                          c->nr_erasing_blocks, avail, c->nospc_dirty_size);
  40
  41        if (avail > opts->rp_size)
  42                return 1;
  43
  44        /* Always allow root */
  45        if (capable(CAP_SYS_RESOURCE))
  46                return 1;
  47
  48        jffs2_dbg(1, "forbid writing\n");
  49        return 0;
  50}
  51
  52/**
  53 *      jffs2_reserve_space - request physical space to write nodes to flash
  54 *      @c: superblock info
  55 *      @minsize: Minimum acceptable size of allocation
  56 *      @len: Returned value of allocation length
  57 *      @prio: Allocation type - ALLOC_{NORMAL,DELETION}
  58 *
  59 *      Requests a block of physical space on the flash. Returns zero for success
  60 *      and puts 'len' into the appropriate place, or returns -ENOSPC or other 
  61 *      error if appropriate. Doesn't return len since that's 
  62 *
  63 *      If it returns zero, jffs2_reserve_space() also downs the per-filesystem
  64 *      allocation semaphore, to prevent more than one allocation from being
  65 *      active at any time. The semaphore is later released by jffs2_commit_allocation()
  66 *
  67 *      jffs2_reserve_space() may trigger garbage collection in order to make room
  68 *      for the requested allocation.
  69 */
  70
  71static int jffs2_do_reserve_space(struct jffs2_sb_info *c,  uint32_t minsize,
  72                                  uint32_t *len, uint32_t sumsize);
  73
  74int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
  75                        uint32_t *len, int prio, uint32_t sumsize)
  76{
  77        int ret = -EAGAIN;
  78        int blocksneeded = c->resv_blocks_write;
  79        /* align it */
  80        minsize = PAD(minsize);
  81
  82        jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
  83        mutex_lock(&c->alloc_sem);
  84
  85        jffs2_dbg(1, "%s(): alloc sem got\n", __func__);
  86
  87        spin_lock(&c->erase_completion_lock);
  88
  89        /*
  90         * Check if the free space is greater then size of the reserved pool.
  91         * If not, only allow root to proceed with writing.
  92         */
  93        if (prio != ALLOC_DELETION && !jffs2_rp_can_write(c)) {
  94                ret = -ENOSPC;
  95                goto out;
  96        }
  97
  98        /* this needs a little more thought (true <tglx> :)) */
  99        while(ret == -EAGAIN) {
 100                while(c->nr_free_blocks + c->nr_erasing_blocks < blocksneeded) {
 101                        uint32_t dirty, avail;
 102
 103                        /* calculate real dirty size
 104                         * dirty_size contains blocks on erase_pending_list
 105                         * those blocks are counted in c->nr_erasing_blocks.
 106                         * If one block is actually erased, it is not longer counted as dirty_space
 107                         * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 108                         * with c->nr_erasing_blocks * c->sector_size again.
 109                         * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 110                         * This helps us to force gc and pick eventually a clean block to spread the load.
 111                         * We add unchecked_size here, as we hopefully will find some space to use.
 112                         * This will affect the sum only once, as gc first finishes checking
 113                         * of nodes.
 114                         */
 115                        dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size + c->unchecked_size;
 116                        if (dirty < c->nospc_dirty_size) {
 117                                if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
 118                                        jffs2_dbg(1, "%s(): Low on dirty space to GC, but it's a deletion. Allowing...\n",
 119                                                  __func__);
 120                                        break;
 121                                }
 122                                jffs2_dbg(1, "dirty size 0x%08x + unchecked_size 0x%08x < nospc_dirty_size 0x%08x, returning -ENOSPC\n",
 123                                          dirty, c->unchecked_size,
 124                                          c->sector_size);
 125
 126                                spin_unlock(&c->erase_completion_lock);
 127                                mutex_unlock(&c->alloc_sem);
 128                                return -ENOSPC;
 129                        }
 130
 131                        /* Calc possibly available space. Possibly available means that we
 132                         * don't know, if unchecked size contains obsoleted nodes, which could give us some
 133                         * more usable space. This will affect the sum only once, as gc first finishes checking
 134                         * of nodes.
 135                         + Return -ENOSPC, if the maximum possibly available space is less or equal than
 136                         * blocksneeded * sector_size.
 137                         * This blocks endless gc looping on a filesystem, which is nearly full, even if
 138                         * the check above passes.
 139                         */
 140                        avail = c->free_size + c->dirty_size + c->erasing_size + c->unchecked_size;
 141                        if ( (avail / c->sector_size) <= blocksneeded) {
 142                                if (prio == ALLOC_DELETION && c->nr_free_blocks + c->nr_erasing_blocks >= c->resv_blocks_deletion) {
 143                                        jffs2_dbg(1, "%s(): Low on possibly available space, but it's a deletion. Allowing...\n",
 144                                                  __func__);
 145                                        break;
 146                                }
 147
 148                                jffs2_dbg(1, "max. available size 0x%08x  < blocksneeded * sector_size 0x%08x, returning -ENOSPC\n",
 149                                          avail, blocksneeded * c->sector_size);
 150                                spin_unlock(&c->erase_completion_lock);
 151                                mutex_unlock(&c->alloc_sem);
 152                                return -ENOSPC;
 153                        }
 154
 155                        mutex_unlock(&c->alloc_sem);
 156
 157                        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",
 158                                  c->nr_free_blocks, c->nr_erasing_blocks,
 159                                  c->free_size, c->dirty_size, c->wasted_size,
 160                                  c->used_size, c->erasing_size, c->bad_size,
 161                                  c->free_size + c->dirty_size +
 162                                  c->wasted_size + c->used_size +
 163                                  c->erasing_size + c->bad_size,
 164                                  c->flash_size);
 165                        spin_unlock(&c->erase_completion_lock);
 166
 167                        ret = jffs2_garbage_collect_pass(c);
 168
 169                        if (ret == -EAGAIN) {
 170                                spin_lock(&c->erase_completion_lock);
 171                                if (c->nr_erasing_blocks &&
 172                                    list_empty(&c->erase_pending_list) &&
 173                                    list_empty(&c->erase_complete_list)) {
 174                                        DECLARE_WAITQUEUE(wait, current);
 175                                        set_current_state(TASK_UNINTERRUPTIBLE);
 176                                        add_wait_queue(&c->erase_wait, &wait);
 177                                        jffs2_dbg(1, "%s waiting for erase to complete\n",
 178                                                  __func__);
 179                                        spin_unlock(&c->erase_completion_lock);
 180
 181                                        schedule();
 182                                } else
 183                                        spin_unlock(&c->erase_completion_lock);
 184                        } else if (ret)
 185                                return ret;
 186
 187                        cond_resched();
 188
 189                        if (signal_pending(current))
 190                                return -EINTR;
 191
 192                        mutex_lock(&c->alloc_sem);
 193                        spin_lock(&c->erase_completion_lock);
 194                }
 195
 196                ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 197                if (ret) {
 198                        jffs2_dbg(1, "%s(): ret is %d\n", __func__, ret);
 199                }
 200        }
 201
 202out:
 203        spin_unlock(&c->erase_completion_lock);
 204        if (!ret)
 205                ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 206        if (ret)
 207                mutex_unlock(&c->alloc_sem);
 208        return ret;
 209}
 210
 211int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
 212                           uint32_t *len, uint32_t sumsize)
 213{
 214        int ret = -EAGAIN;
 215        minsize = PAD(minsize);
 216
 217        jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize);
 218
 219        spin_lock(&c->erase_completion_lock);
 220        while(ret == -EAGAIN) {
 221                ret = jffs2_do_reserve_space(c, minsize, len, sumsize);
 222                if (ret) {
 223                        jffs2_dbg(1, "%s(): looping, ret is %d\n",
 224                                  __func__, ret);
 225                }
 226        }
 227        spin_unlock(&c->erase_completion_lock);
 228        if (!ret)
 229                ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 230
 231        return ret;
 232}
 233
 234
 235/* Classify nextblock (clean, dirty of verydirty) and force to select an other one */
 236
 237static void jffs2_close_nextblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 238{
 239
 240        if (c->nextblock == NULL) {
 241                jffs2_dbg(1, "%s(): Erase block at 0x%08x has already been placed in a list\n",
 242                          __func__, jeb->offset);
 243                return;
 244        }
 245        /* Check, if we have a dirty block now, or if it was dirty already */
 246        if (ISDIRTY (jeb->wasted_size + jeb->dirty_size)) {
 247                c->dirty_size += jeb->wasted_size;
 248                c->wasted_size -= jeb->wasted_size;
 249                jeb->dirty_size += jeb->wasted_size;
 250                jeb->wasted_size = 0;
 251                if (VERYDIRTY(c, jeb->dirty_size)) {
 252                        jffs2_dbg(1, "Adding full erase block at 0x%08x to very_dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 253                                  jeb->offset, jeb->free_size, jeb->dirty_size,
 254                                  jeb->used_size);
 255                        list_add_tail(&jeb->list, &c->very_dirty_list);
 256                } else {
 257                        jffs2_dbg(1, "Adding full erase block at 0x%08x to dirty_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 258                                  jeb->offset, jeb->free_size, jeb->dirty_size,
 259                                  jeb->used_size);
 260                        list_add_tail(&jeb->list, &c->dirty_list);
 261                }
 262        } else {
 263                jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 264                          jeb->offset, jeb->free_size, jeb->dirty_size,
 265                          jeb->used_size);
 266                list_add_tail(&jeb->list, &c->clean_list);
 267        }
 268        c->nextblock = NULL;
 269
 270}
 271
 272/* Select a new jeb for nextblock */
 273
 274static int jffs2_find_nextblock(struct jffs2_sb_info *c)
 275{
 276        struct list_head *next;
 277
 278        /* Take the next block off the 'free' list */
 279
 280        if (list_empty(&c->free_list)) {
 281
 282                if (!c->nr_erasing_blocks &&
 283                        !list_empty(&c->erasable_list)) {
 284                        struct jffs2_eraseblock *ejeb;
 285
 286                        ejeb = list_entry(c->erasable_list.next, struct jffs2_eraseblock, list);
 287                        list_move_tail(&ejeb->list, &c->erase_pending_list);
 288                        c->nr_erasing_blocks++;
 289                        jffs2_garbage_collect_trigger(c);
 290                        jffs2_dbg(1, "%s(): Triggering erase of erasable block at 0x%08x\n",
 291                                  __func__, ejeb->offset);
 292                }
 293
 294                if (!c->nr_erasing_blocks &&
 295                        !list_empty(&c->erasable_pending_wbuf_list)) {
 296                        jffs2_dbg(1, "%s(): Flushing write buffer\n",
 297                                  __func__);
 298                        /* c->nextblock is NULL, no update to c->nextblock allowed */
 299                        spin_unlock(&c->erase_completion_lock);
 300                        jffs2_flush_wbuf_pad(c);
 301                        spin_lock(&c->erase_completion_lock);
 302                        /* Have another go. It'll be on the erasable_list now */
 303                        return -EAGAIN;
 304                }
 305
 306                if (!c->nr_erasing_blocks) {
 307                        /* Ouch. We're in GC, or we wouldn't have got here.
 308                           And there's no space left. At all. */
 309                        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",
 310                                c->nr_erasing_blocks, c->nr_free_blocks,
 311                                list_empty(&c->erasable_list) ? "yes" : "no",
 312                                list_empty(&c->erasing_list) ? "yes" : "no",
 313                                list_empty(&c->erase_pending_list) ? "yes" : "no");
 314                        return -ENOSPC;
 315                }
 316
 317                spin_unlock(&c->erase_completion_lock);
 318                /* Don't wait for it; just erase one right now */
 319                jffs2_erase_pending_blocks(c, 1);
 320                spin_lock(&c->erase_completion_lock);
 321
 322                /* An erase may have failed, decreasing the
 323                   amount of free space available. So we must
 324                   restart from the beginning */
 325                return -EAGAIN;
 326        }
 327
 328        next = c->free_list.next;
 329        list_del(next);
 330        c->nextblock = list_entry(next, struct jffs2_eraseblock, list);
 331        c->nr_free_blocks--;
 332
 333        jffs2_sum_reset_collected(c->summary); /* reset collected summary */
 334
 335#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 336        /* adjust write buffer offset, else we get a non contiguous write bug */
 337        if (!(c->wbuf_ofs % c->sector_size) && !c->wbuf_len)
 338                c->wbuf_ofs = 0xffffffff;
 339#endif
 340
 341        jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
 342                  __func__, c->nextblock->offset);
 343
 344        return 0;
 345}
 346
 347/* Called with alloc sem _and_ erase_completion_lock */
 348static int jffs2_do_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 349                                  uint32_t *len, uint32_t sumsize)
 350{
 351        struct jffs2_eraseblock *jeb = c->nextblock;
 352        uint32_t reserved_size;                         /* for summary information at the end of the jeb */
 353        int ret;
 354
 355 restart:
 356        reserved_size = 0;
 357
 358        if (jffs2_sum_active() && (sumsize != JFFS2_SUMMARY_NOSUM_SIZE)) {
 359                                                        /* NOSUM_SIZE means not to generate summary */
 360
 361                if (jeb) {
 362                        reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 363                        dbg_summary("minsize=%d , jeb->free=%d ,"
 364                                                "summary->size=%d , sumsize=%d\n",
 365                                                minsize, jeb->free_size,
 366                                                c->summary->sum_size, sumsize);
 367                }
 368
 369                /* Is there enough space for writing out the current node, or we have to
 370                   write out summary information now, close this jeb and select new nextblock? */
 371                if (jeb && (PAD(minsize) + PAD(c->summary->sum_size + sumsize +
 372                                        JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size)) {
 373
 374                        /* Has summary been disabled for this jeb? */
 375                        if (jffs2_sum_is_disabled(c->summary)) {
 376                                sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 377                                goto restart;
 378                        }
 379
 380                        /* Writing out the collected summary information */
 381                        dbg_summary("generating summary for 0x%08x.\n", jeb->offset);
 382                        ret = jffs2_sum_write_sumnode(c);
 383
 384                        if (ret)
 385                                return ret;
 386
 387                        if (jffs2_sum_is_disabled(c->summary)) {
 388                                /* jffs2_write_sumnode() couldn't write out the summary information
 389                                   diabling summary for this jeb and free the collected information
 390                                 */
 391                                sumsize = JFFS2_SUMMARY_NOSUM_SIZE;
 392                                goto restart;
 393                        }
 394
 395                        jffs2_close_nextblock(c, jeb);
 396                        jeb = NULL;
 397                        /* keep always valid value in reserved_size */
 398                        reserved_size = PAD(sumsize + c->summary->sum_size + JFFS2_SUMMARY_FRAME_SIZE);
 399                }
 400        } else {
 401                if (jeb && minsize > jeb->free_size) {
 402                        uint32_t waste;
 403
 404                        /* Skip the end of this block and file it as having some dirty space */
 405                        /* If there's a pending write to it, flush now */
 406
 407                        if (jffs2_wbuf_dirty(c)) {
 408                                spin_unlock(&c->erase_completion_lock);
 409                                jffs2_dbg(1, "%s(): Flushing write buffer\n",
 410                                          __func__);
 411                                jffs2_flush_wbuf_pad(c);
 412                                spin_lock(&c->erase_completion_lock);
 413                                jeb = c->nextblock;
 414                                goto restart;
 415                        }
 416
 417                        spin_unlock(&c->erase_completion_lock);
 418
 419                        ret = jffs2_prealloc_raw_node_refs(c, jeb, 1);
 420
 421                        /* Just lock it again and continue. Nothing much can change because
 422                           we hold c->alloc_sem anyway. In fact, it's not entirely clear why
 423                           we hold c->erase_completion_lock in the majority of this function...
 424                           but that's a question for another (more caffeine-rich) day. */
 425                        spin_lock(&c->erase_completion_lock);
 426
 427                        if (ret)
 428                                return ret;
 429
 430                        waste = jeb->free_size;
 431                        jffs2_link_node_ref(c, jeb,
 432                                            (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
 433                                            waste, NULL);
 434                        /* FIXME: that made it count as dirty. Convert to wasted */
 435                        jeb->dirty_size -= waste;
 436                        c->dirty_size -= waste;
 437                        jeb->wasted_size += waste;
 438                        c->wasted_size += waste;
 439
 440                        jffs2_close_nextblock(c, jeb);
 441                        jeb = NULL;
 442                }
 443        }
 444
 445        if (!jeb) {
 446
 447                ret = jffs2_find_nextblock(c);
 448                if (ret)
 449                        return ret;
 450
 451                jeb = c->nextblock;
 452
 453                if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 454                        pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n",
 455                                jeb->offset, jeb->free_size);
 456                        goto restart;
 457                }
 458        }
 459        /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 460           enough space */
 461        *len = jeb->free_size - reserved_size;
 462
 463        if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 464            !jeb->first_node->next_in_ino) {
 465                /* Only node in it beforehand was a CLEANMARKER node (we think).
 466                   So mark it obsolete now that there's going to be another node
 467                   in the block. This will reduce used_size to zero but We've
 468                   already set c->nextblock so that jffs2_mark_node_obsolete()
 469                   won't try to refile it to the dirty_list.
 470                */
 471                spin_unlock(&c->erase_completion_lock);
 472                jffs2_mark_node_obsolete(c, jeb->first_node);
 473                spin_lock(&c->erase_completion_lock);
 474        }
 475
 476        jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n",
 477                  __func__,
 478                  *len, jeb->offset + (c->sector_size - jeb->free_size));
 479        return 0;
 480}
 481
 482/**
 483 *      jffs2_add_physical_node_ref - add a physical node reference to the list
 484 *      @c: superblock info
 485 *      @new: new node reference to add
 486 *      @len: length of this physical node
 487 *
 488 *      Should only be used to report nodes for which space has been allocated
 489 *      by jffs2_reserve_space.
 490 *
 491 *      Must be called with the alloc_sem held.
 492 */
 493
 494struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
 495                                                       uint32_t ofs, uint32_t len,
 496                                                       struct jffs2_inode_cache *ic)
 497{
 498        struct jffs2_eraseblock *jeb;
 499        struct jffs2_raw_node_ref *new;
 500
 501        jeb = &c->blocks[ofs / c->sector_size];
 502
 503        jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n",
 504                  __func__, ofs & ~3, ofs & 3, len);
 505#if 1
 506        /* Allow non-obsolete nodes only to be added at the end of c->nextblock, 
 507           if c->nextblock is set. Note that wbuf.c will file obsolete nodes
 508           even after refiling c->nextblock */
 509        if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
 510            && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
 511                pr_warn("argh. node added in wrong place at 0x%08x(%d)\n",
 512                        ofs & ~3, ofs & 3);
 513                if (c->nextblock)
 514                        pr_warn("nextblock 0x%08x", c->nextblock->offset);
 515                else
 516                        pr_warn("No nextblock");
 517                pr_cont(", expected at %08x\n",
 518                        jeb->offset + (c->sector_size - jeb->free_size));
 519                return ERR_PTR(-EINVAL);
 520        }
 521#endif
 522        spin_lock(&c->erase_completion_lock);
 523
 524        new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
 525
 526        if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 527                /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 528                jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 529                          jeb->offset, jeb->free_size, jeb->dirty_size,
 530                          jeb->used_size);
 531                if (jffs2_wbuf_dirty(c)) {
 532                        /* Flush the last write in the block if it's outstanding */
 533                        spin_unlock(&c->erase_completion_lock);
 534                        jffs2_flush_wbuf_pad(c);
 535                        spin_lock(&c->erase_completion_lock);
 536                }
 537
 538                list_add_tail(&jeb->list, &c->clean_list);
 539                c->nextblock = NULL;
 540        }
 541        jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 542        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 543
 544        spin_unlock(&c->erase_completion_lock);
 545
 546        return new;
 547}
 548
 549
 550void jffs2_complete_reservation(struct jffs2_sb_info *c)
 551{
 552        jffs2_dbg(1, "jffs2_complete_reservation()\n");
 553        spin_lock(&c->erase_completion_lock);
 554        jffs2_garbage_collect_trigger(c);
 555        spin_unlock(&c->erase_completion_lock);
 556        mutex_unlock(&c->alloc_sem);
 557}
 558
 559static inline int on_list(struct list_head *obj, struct list_head *head)
 560{
 561        struct list_head *this;
 562
 563        list_for_each(this, head) {
 564                if (this == obj) {
 565                        jffs2_dbg(1, "%p is on list at %p\n", obj, head);
 566                        return 1;
 567
 568                }
 569        }
 570        return 0;
 571}
 572
 573void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 574{
 575        struct jffs2_eraseblock *jeb;
 576        int blocknr;
 577        struct jffs2_unknown_node n;
 578        int ret, addedsize;
 579        size_t retlen;
 580        uint32_t freed_len;
 581
 582        if(unlikely(!ref)) {
 583                pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 584                return;
 585        }
 586        if (ref_obsolete(ref)) {
 587                jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n",
 588                          __func__, ref_offset(ref));
 589                return;
 590        }
 591        blocknr = ref->flash_offset / c->sector_size;
 592        if (blocknr >= c->nr_blocks) {
 593                pr_notice("raw node at 0x%08x is off the end of device!\n",
 594                          ref->flash_offset);
 595                BUG();
 596        }
 597        jeb = &c->blocks[blocknr];
 598
 599        if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 600            !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 601                /* Hm. This may confuse static lock analysis. If any of the above
 602                   three conditions is false, we're going to return from this
 603                   function without actually obliterating any nodes or freeing
 604                   any jffs2_raw_node_refs. So we don't need to stop erases from
 605                   happening, or protect against people holding an obsolete
 606                   jffs2_raw_node_ref without the erase_completion_lock. */
 607                mutex_lock(&c->erase_free_sem);
 608        }
 609
 610        spin_lock(&c->erase_completion_lock);
 611
 612        freed_len = ref_totlen(c, jeb, ref);
 613
 614        if (ref_flags(ref) == REF_UNCHECKED) {
 615                D1(if (unlikely(jeb->unchecked_size < freed_len)) {
 616                                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",
 617                                          freed_len, blocknr,
 618                                          ref->flash_offset, jeb->used_size);
 619                        BUG();
 620                })
 621                        jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n",
 622                                  ref_offset(ref), freed_len);
 623                jeb->unchecked_size -= freed_len;
 624                c->unchecked_size -= freed_len;
 625        } else {
 626                D1(if (unlikely(jeb->used_size < freed_len)) {
 627                                pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
 628                                          freed_len, blocknr,
 629                                          ref->flash_offset, jeb->used_size);
 630                        BUG();
 631                })
 632                        jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ",
 633                                  ref_offset(ref), freed_len);
 634                jeb->used_size -= freed_len;
 635                c->used_size -= freed_len;
 636        }
 637
 638        // Take care, that wasted size is taken into concern
 639        if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
 640                jffs2_dbg(1, "Dirtying\n");
 641                addedsize = freed_len;
 642                jeb->dirty_size += freed_len;
 643                c->dirty_size += freed_len;
 644
 645                /* Convert wasted space to dirty, if not a bad block */
 646                if (jeb->wasted_size) {
 647                        if (on_list(&jeb->list, &c->bad_used_list)) {
 648                                jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n",
 649                                          jeb->offset);
 650                                addedsize = 0; /* To fool the refiling code later */
 651                        } else {
 652                                jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n",
 653                                          jeb->wasted_size, jeb->offset);
 654                                addedsize += jeb->wasted_size;
 655                                jeb->dirty_size += jeb->wasted_size;
 656                                c->dirty_size += jeb->wasted_size;
 657                                c->wasted_size -= jeb->wasted_size;
 658                                jeb->wasted_size = 0;
 659                        }
 660                }
 661        } else {
 662                jffs2_dbg(1, "Wasting\n");
 663                addedsize = 0;
 664                jeb->wasted_size += freed_len;
 665                c->wasted_size += freed_len;
 666        }
 667        ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 668
 669        jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 670        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 671
 672        if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 673                /* Flash scanning is in progress. Don't muck about with the block
 674                   lists because they're not ready yet, and don't actually
 675                   obliterate nodes that look obsolete. If they weren't
 676                   marked obsolete on the flash at the time they _became_
 677                   obsolete, there was probably a reason for that. */
 678                spin_unlock(&c->erase_completion_lock);
 679                /* We didn't lock the erase_free_sem */
 680                return;
 681        }
 682
 683        if (jeb == c->nextblock) {
 684                jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n",
 685                          jeb->offset);
 686        } else if (!jeb->used_size && !jeb->unchecked_size) {
 687                if (jeb == c->gcblock) {
 688                        jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n",
 689                                  jeb->offset);
 690                        c->gcblock = NULL;
 691                } else {
 692                        jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n",
 693                                  jeb->offset);
 694                        list_del(&jeb->list);
 695                }
 696                if (jffs2_wbuf_dirty(c)) {
 697                        jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n");
 698                        list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 699                } else {
 700                        if (jiffies & 127) {
 701                                /* Most of the time, we just erase it immediately. Otherwise we
 702                                   spend ages scanning it on mount, etc. */
 703                                jffs2_dbg(1, "...and adding to erase_pending_list\n");
 704                                list_add_tail(&jeb->list, &c->erase_pending_list);
 705                                c->nr_erasing_blocks++;
 706                                jffs2_garbage_collect_trigger(c);
 707                        } else {
 708                                /* Sometimes, however, we leave it elsewhere so it doesn't get
 709                                   immediately reused, and we spread the load a bit. */
 710                                jffs2_dbg(1, "...and adding to erasable_list\n");
 711                                list_add_tail(&jeb->list, &c->erasable_list);
 712                        }
 713                }
 714                jffs2_dbg(1, "Done OK\n");
 715        } else if (jeb == c->gcblock) {
 716                jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n",
 717                          jeb->offset);
 718        } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 719                jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n",
 720                          jeb->offset);
 721                list_del(&jeb->list);
 722                jffs2_dbg(1, "...and adding to dirty_list\n");
 723                list_add_tail(&jeb->list, &c->dirty_list);
 724        } else if (VERYDIRTY(c, jeb->dirty_size) &&
 725                   !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 726                jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n",
 727                          jeb->offset);
 728                list_del(&jeb->list);
 729                jffs2_dbg(1, "...and adding to very_dirty_list\n");
 730                list_add_tail(&jeb->list, &c->very_dirty_list);
 731        } else {
 732                jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 733                          jeb->offset, jeb->free_size, jeb->dirty_size,
 734                          jeb->used_size);
 735        }
 736
 737        spin_unlock(&c->erase_completion_lock);
 738
 739        if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 740                (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 741                /* We didn't lock the erase_free_sem */
 742                return;
 743        }
 744
 745        /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 746           and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 747           the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 748           by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
 749
 750        jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n",
 751                  ref_offset(ref));
 752        ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 753        if (ret) {
 754                pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n",
 755                        ref_offset(ref), ret);
 756                goto out_erase_sem;
 757        }
 758        if (retlen != sizeof(n)) {
 759                pr_warn("Short read from obsoleted node at 0x%08x: %zd\n",
 760                        ref_offset(ref), retlen);
 761                goto out_erase_sem;
 762        }
 763        if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
 764                pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n",
 765                        je32_to_cpu(n.totlen), freed_len);
 766                goto out_erase_sem;
 767        }
 768        if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 769                jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n",
 770                          ref_offset(ref), je16_to_cpu(n.nodetype));
 771                goto out_erase_sem;
 772        }
 773        /* XXX FIXME: This is ugly now */
 774        n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 775        ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 776        if (ret) {
 777                pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n",
 778                        ref_offset(ref), ret);
 779                goto out_erase_sem;
 780        }
 781        if (retlen != sizeof(n)) {
 782                pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n",
 783                        ref_offset(ref), retlen);
 784                goto out_erase_sem;
 785        }
 786
 787        /* Nodes which have been marked obsolete no longer need to be
 788           associated with any inode. Remove them from the per-inode list.
 789
 790           Note we can't do this for NAND at the moment because we need
 791           obsolete dirent nodes to stay on the lists, because of the
 792           horridness in jffs2_garbage_collect_deletion_dirent(). Also
 793           because we delete the inocache, and on NAND we need that to
 794           stay around until all the nodes are actually erased, in order
 795           to stop us from giving the same inode number to another newly
 796           created inode. */
 797        if (ref->next_in_ino) {
 798                struct jffs2_inode_cache *ic;
 799                struct jffs2_raw_node_ref **p;
 800
 801                spin_lock(&c->erase_completion_lock);
 802
 803                ic = jffs2_raw_ref_to_ic(ref);
 804                for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 805                        ;
 806
 807                *p = ref->next_in_ino;
 808                ref->next_in_ino = NULL;
 809
 810                switch (ic->class) {
 811#ifdef CONFIG_JFFS2_FS_XATTR
 812                        case RAWNODE_CLASS_XATTR_DATUM:
 813                                jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
 814                                break;
 815                        case RAWNODE_CLASS_XATTR_REF:
 816                                jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
 817                                break;
 818#endif
 819                        default:
 820                                if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
 821                                        jffs2_del_ino_cache(c, ic);
 822                                break;
 823                }
 824                spin_unlock(&c->erase_completion_lock);
 825        }
 826
 827 out_erase_sem:
 828        mutex_unlock(&c->erase_free_sem);
 829}
 830
 831int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 832{
 833        int ret = 0;
 834        uint32_t dirty;
 835        int nr_very_dirty = 0;
 836        struct jffs2_eraseblock *jeb;
 837
 838        if (!list_empty(&c->erase_complete_list) ||
 839            !list_empty(&c->erase_pending_list))
 840                return 1;
 841
 842        if (c->unchecked_size) {
 843                jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 844                          c->unchecked_size, c->checked_ino);
 845                return 1;
 846        }
 847
 848        /* dirty_size contains blocks on erase_pending_list
 849         * those blocks are counted in c->nr_erasing_blocks.
 850         * If one block is actually erased, it is not longer counted as dirty_space
 851         * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 852         * with c->nr_erasing_blocks * c->sector_size again.
 853         * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 854         * This helps us to force gc and pick eventually a clean block to spread the load.
 855         */
 856        dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 857
 858        if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 859                        (dirty > c->nospc_dirty_size))
 860                ret = 1;
 861
 862        list_for_each_entry(jeb, &c->very_dirty_list, list) {
 863                nr_very_dirty++;
 864                if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
 865                        ret = 1;
 866                        /* In debug mode, actually go through and count them all */
 867                        D1(continue);
 868                        break;
 869                }
 870        }
 871
 872        jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n",
 873                  __func__, c->nr_free_blocks, c->nr_erasing_blocks,
 874                  c->dirty_size, nr_very_dirty, ret ? "yes" : "no");
 875
 876        return ret;
 877}
 878
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