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                        if (ret)
 421                                return ret;
 422                        /* Just lock it again and continue. Nothing much can change because
 423                           we hold c->alloc_sem anyway. In fact, it's not entirely clear why
 424                           we hold c->erase_completion_lock in the majority of this function...
 425                           but that's a question for another (more caffeine-rich) day. */
 426                        spin_lock(&c->erase_completion_lock);
 427
 428                        waste = jeb->free_size;
 429                        jffs2_link_node_ref(c, jeb,
 430                                            (jeb->offset + c->sector_size - waste) | REF_OBSOLETE,
 431                                            waste, NULL);
 432                        /* FIXME: that made it count as dirty. Convert to wasted */
 433                        jeb->dirty_size -= waste;
 434                        c->dirty_size -= waste;
 435                        jeb->wasted_size += waste;
 436                        c->wasted_size += waste;
 437
 438                        jffs2_close_nextblock(c, jeb);
 439                        jeb = NULL;
 440                }
 441        }
 442
 443        if (!jeb) {
 444
 445                ret = jffs2_find_nextblock(c);
 446                if (ret)
 447                        return ret;
 448
 449                jeb = c->nextblock;
 450
 451                if (jeb->free_size != c->sector_size - c->cleanmarker_size) {
 452                        pr_warn("Eep. Block 0x%08x taken from free_list had free_size of 0x%08x!!\n",
 453                                jeb->offset, jeb->free_size);
 454                        goto restart;
 455                }
 456        }
 457        /* OK, jeb (==c->nextblock) is now pointing at a block which definitely has
 458           enough space */
 459        *len = jeb->free_size - reserved_size;
 460
 461        if (c->cleanmarker_size && jeb->used_size == c->cleanmarker_size &&
 462            !jeb->first_node->next_in_ino) {
 463                /* Only node in it beforehand was a CLEANMARKER node (we think).
 464                   So mark it obsolete now that there's going to be another node
 465                   in the block. This will reduce used_size to zero but We've
 466                   already set c->nextblock so that jffs2_mark_node_obsolete()
 467                   won't try to refile it to the dirty_list.
 468                */
 469                spin_unlock(&c->erase_completion_lock);
 470                jffs2_mark_node_obsolete(c, jeb->first_node);
 471                spin_lock(&c->erase_completion_lock);
 472        }
 473
 474        jffs2_dbg(1, "%s(): Giving 0x%x bytes at 0x%x\n",
 475                  __func__,
 476                  *len, jeb->offset + (c->sector_size - jeb->free_size));
 477        return 0;
 478}
 479
 480/**
 481 *      jffs2_add_physical_node_ref - add a physical node reference to the list
 482 *      @c: superblock info
 483 *      @new: new node reference to add
 484 *      @len: length of this physical node
 485 *
 486 *      Should only be used to report nodes for which space has been allocated
 487 *      by jffs2_reserve_space.
 488 *
 489 *      Must be called with the alloc_sem held.
 490 */
 491
 492struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
 493                                                       uint32_t ofs, uint32_t len,
 494                                                       struct jffs2_inode_cache *ic)
 495{
 496        struct jffs2_eraseblock *jeb;
 497        struct jffs2_raw_node_ref *new;
 498
 499        jeb = &c->blocks[ofs / c->sector_size];
 500
 501        jffs2_dbg(1, "%s(): Node at 0x%x(%d), size 0x%x\n",
 502                  __func__, ofs & ~3, ofs & 3, len);
 503#if 1
 504        /* Allow non-obsolete nodes only to be added at the end of c->nextblock, 
 505           if c->nextblock is set. Note that wbuf.c will file obsolete nodes
 506           even after refiling c->nextblock */
 507        if ((c->nextblock || ((ofs & 3) != REF_OBSOLETE))
 508            && (jeb != c->nextblock || (ofs & ~3) != jeb->offset + (c->sector_size - jeb->free_size))) {
 509                pr_warn("argh. node added in wrong place at 0x%08x(%d)\n",
 510                        ofs & ~3, ofs & 3);
 511                if (c->nextblock)
 512                        pr_warn("nextblock 0x%08x", c->nextblock->offset);
 513                else
 514                        pr_warn("No nextblock");
 515                pr_cont(", expected at %08x\n",
 516                        jeb->offset + (c->sector_size - jeb->free_size));
 517                return ERR_PTR(-EINVAL);
 518        }
 519#endif
 520        spin_lock(&c->erase_completion_lock);
 521
 522        new = jffs2_link_node_ref(c, jeb, ofs, len, ic);
 523
 524        if (!jeb->free_size && !jeb->dirty_size && !ISDIRTY(jeb->wasted_size)) {
 525                /* If it lives on the dirty_list, jffs2_reserve_space will put it there */
 526                jffs2_dbg(1, "Adding full erase block at 0x%08x to clean_list (free 0x%08x, dirty 0x%08x, used 0x%08x\n",
 527                          jeb->offset, jeb->free_size, jeb->dirty_size,
 528                          jeb->used_size);
 529                if (jffs2_wbuf_dirty(c)) {
 530                        /* Flush the last write in the block if it's outstanding */
 531                        spin_unlock(&c->erase_completion_lock);
 532                        jffs2_flush_wbuf_pad(c);
 533                        spin_lock(&c->erase_completion_lock);
 534                }
 535
 536                list_add_tail(&jeb->list, &c->clean_list);
 537                c->nextblock = NULL;
 538        }
 539        jffs2_dbg_acct_sanity_check_nolock(c,jeb);
 540        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 541
 542        spin_unlock(&c->erase_completion_lock);
 543
 544        return new;
 545}
 546
 547
 548void jffs2_complete_reservation(struct jffs2_sb_info *c)
 549{
 550        jffs2_dbg(1, "jffs2_complete_reservation()\n");
 551        spin_lock(&c->erase_completion_lock);
 552        jffs2_garbage_collect_trigger(c);
 553        spin_unlock(&c->erase_completion_lock);
 554        mutex_unlock(&c->alloc_sem);
 555}
 556
 557static inline int on_list(struct list_head *obj, struct list_head *head)
 558{
 559        struct list_head *this;
 560
 561        list_for_each(this, head) {
 562                if (this == obj) {
 563                        jffs2_dbg(1, "%p is on list at %p\n", obj, head);
 564                        return 1;
 565
 566                }
 567        }
 568        return 0;
 569}
 570
 571void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *ref)
 572{
 573        struct jffs2_eraseblock *jeb;
 574        int blocknr;
 575        struct jffs2_unknown_node n;
 576        int ret, addedsize;
 577        size_t retlen;
 578        uint32_t freed_len;
 579
 580        if(unlikely(!ref)) {
 581                pr_notice("EEEEEK. jffs2_mark_node_obsolete called with NULL node\n");
 582                return;
 583        }
 584        if (ref_obsolete(ref)) {
 585                jffs2_dbg(1, "%s(): called with already obsolete node at 0x%08x\n",
 586                          __func__, ref_offset(ref));
 587                return;
 588        }
 589        blocknr = ref->flash_offset / c->sector_size;
 590        if (blocknr >= c->nr_blocks) {
 591                pr_notice("raw node at 0x%08x is off the end of device!\n",
 592                          ref->flash_offset);
 593                BUG();
 594        }
 595        jeb = &c->blocks[blocknr];
 596
 597        if (jffs2_can_mark_obsolete(c) && !jffs2_is_readonly(c) &&
 598            !(c->flags & (JFFS2_SB_FLAG_SCANNING | JFFS2_SB_FLAG_BUILDING))) {
 599                /* Hm. This may confuse static lock analysis. If any of the above
 600                   three conditions is false, we're going to return from this
 601                   function without actually obliterating any nodes or freeing
 602                   any jffs2_raw_node_refs. So we don't need to stop erases from
 603                   happening, or protect against people holding an obsolete
 604                   jffs2_raw_node_ref without the erase_completion_lock. */
 605                mutex_lock(&c->erase_free_sem);
 606        }
 607
 608        spin_lock(&c->erase_completion_lock);
 609
 610        freed_len = ref_totlen(c, jeb, ref);
 611
 612        if (ref_flags(ref) == REF_UNCHECKED) {
 613                D1(if (unlikely(jeb->unchecked_size < freed_len)) {
 614                                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",
 615                                          freed_len, blocknr,
 616                                          ref->flash_offset, jeb->used_size);
 617                        BUG();
 618                })
 619                        jffs2_dbg(1, "Obsoleting previously unchecked node at 0x%08x of len %x\n",
 620                                  ref_offset(ref), freed_len);
 621                jeb->unchecked_size -= freed_len;
 622                c->unchecked_size -= freed_len;
 623        } else {
 624                D1(if (unlikely(jeb->used_size < freed_len)) {
 625                                pr_notice("raw node of size 0x%08x freed from erase block %d at 0x%08x, but used_size was already 0x%08x\n",
 626                                          freed_len, blocknr,
 627                                          ref->flash_offset, jeb->used_size);
 628                        BUG();
 629                })
 630                        jffs2_dbg(1, "Obsoleting node at 0x%08x of len %#x: ",
 631                                  ref_offset(ref), freed_len);
 632                jeb->used_size -= freed_len;
 633                c->used_size -= freed_len;
 634        }
 635
 636        // Take care, that wasted size is taken into concern
 637        if ((jeb->dirty_size || ISDIRTY(jeb->wasted_size + freed_len)) && jeb != c->nextblock) {
 638                jffs2_dbg(1, "Dirtying\n");
 639                addedsize = freed_len;
 640                jeb->dirty_size += freed_len;
 641                c->dirty_size += freed_len;
 642
 643                /* Convert wasted space to dirty, if not a bad block */
 644                if (jeb->wasted_size) {
 645                        if (on_list(&jeb->list, &c->bad_used_list)) {
 646                                jffs2_dbg(1, "Leaving block at %08x on the bad_used_list\n",
 647                                          jeb->offset);
 648                                addedsize = 0; /* To fool the refiling code later */
 649                        } else {
 650                                jffs2_dbg(1, "Converting %d bytes of wasted space to dirty in block at %08x\n",
 651                                          jeb->wasted_size, jeb->offset);
 652                                addedsize += jeb->wasted_size;
 653                                jeb->dirty_size += jeb->wasted_size;
 654                                c->dirty_size += jeb->wasted_size;
 655                                c->wasted_size -= jeb->wasted_size;
 656                                jeb->wasted_size = 0;
 657                        }
 658                }
 659        } else {
 660                jffs2_dbg(1, "Wasting\n");
 661                addedsize = 0;
 662                jeb->wasted_size += freed_len;
 663                c->wasted_size += freed_len;
 664        }
 665        ref->flash_offset = ref_offset(ref) | REF_OBSOLETE;
 666
 667        jffs2_dbg_acct_sanity_check_nolock(c, jeb);
 668        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 669
 670        if (c->flags & JFFS2_SB_FLAG_SCANNING) {
 671                /* Flash scanning is in progress. Don't muck about with the block
 672                   lists because they're not ready yet, and don't actually
 673                   obliterate nodes that look obsolete. If they weren't
 674                   marked obsolete on the flash at the time they _became_
 675                   obsolete, there was probably a reason for that. */
 676                spin_unlock(&c->erase_completion_lock);
 677                /* We didn't lock the erase_free_sem */
 678                return;
 679        }
 680
 681        if (jeb == c->nextblock) {
 682                jffs2_dbg(2, "Not moving nextblock 0x%08x to dirty/erase_pending list\n",
 683                          jeb->offset);
 684        } else if (!jeb->used_size && !jeb->unchecked_size) {
 685                if (jeb == c->gcblock) {
 686                        jffs2_dbg(1, "gcblock at 0x%08x completely dirtied. Clearing gcblock...\n",
 687                                  jeb->offset);
 688                        c->gcblock = NULL;
 689                } else {
 690                        jffs2_dbg(1, "Eraseblock at 0x%08x completely dirtied. Removing from (dirty?) list...\n",
 691                                  jeb->offset);
 692                        list_del(&jeb->list);
 693                }
 694                if (jffs2_wbuf_dirty(c)) {
 695                        jffs2_dbg(1, "...and adding to erasable_pending_wbuf_list\n");
 696                        list_add_tail(&jeb->list, &c->erasable_pending_wbuf_list);
 697                } else {
 698                        if (jiffies & 127) {
 699                                /* Most of the time, we just erase it immediately. Otherwise we
 700                                   spend ages scanning it on mount, etc. */
 701                                jffs2_dbg(1, "...and adding to erase_pending_list\n");
 702                                list_add_tail(&jeb->list, &c->erase_pending_list);
 703                                c->nr_erasing_blocks++;
 704                                jffs2_garbage_collect_trigger(c);
 705                        } else {
 706                                /* Sometimes, however, we leave it elsewhere so it doesn't get
 707                                   immediately reused, and we spread the load a bit. */
 708                                jffs2_dbg(1, "...and adding to erasable_list\n");
 709                                list_add_tail(&jeb->list, &c->erasable_list);
 710                        }
 711                }
 712                jffs2_dbg(1, "Done OK\n");
 713        } else if (jeb == c->gcblock) {
 714                jffs2_dbg(2, "Not moving gcblock 0x%08x to dirty_list\n",
 715                          jeb->offset);
 716        } else if (ISDIRTY(jeb->dirty_size) && !ISDIRTY(jeb->dirty_size - addedsize)) {
 717                jffs2_dbg(1, "Eraseblock at 0x%08x is freshly dirtied. Removing from clean list...\n",
 718                          jeb->offset);
 719                list_del(&jeb->list);
 720                jffs2_dbg(1, "...and adding to dirty_list\n");
 721                list_add_tail(&jeb->list, &c->dirty_list);
 722        } else if (VERYDIRTY(c, jeb->dirty_size) &&
 723                   !VERYDIRTY(c, jeb->dirty_size - addedsize)) {
 724                jffs2_dbg(1, "Eraseblock at 0x%08x is now very dirty. Removing from dirty list...\n",
 725                          jeb->offset);
 726                list_del(&jeb->list);
 727                jffs2_dbg(1, "...and adding to very_dirty_list\n");
 728                list_add_tail(&jeb->list, &c->very_dirty_list);
 729        } else {
 730                jffs2_dbg(1, "Eraseblock at 0x%08x not moved anywhere. (free 0x%08x, dirty 0x%08x, used 0x%08x)\n",
 731                          jeb->offset, jeb->free_size, jeb->dirty_size,
 732                          jeb->used_size);
 733        }
 734
 735        spin_unlock(&c->erase_completion_lock);
 736
 737        if (!jffs2_can_mark_obsolete(c) || jffs2_is_readonly(c) ||
 738                (c->flags & JFFS2_SB_FLAG_BUILDING)) {
 739                /* We didn't lock the erase_free_sem */
 740                return;
 741        }
 742
 743        /* The erase_free_sem is locked, and has been since before we marked the node obsolete
 744           and potentially put its eraseblock onto the erase_pending_list. Thus, we know that
 745           the block hasn't _already_ been erased, and that 'ref' itself hasn't been freed yet
 746           by jffs2_free_jeb_node_refs() in erase.c. Which is nice. */
 747
 748        jffs2_dbg(1, "obliterating obsoleted node at 0x%08x\n",
 749                  ref_offset(ref));
 750        ret = jffs2_flash_read(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 751        if (ret) {
 752                pr_warn("Read error reading from obsoleted node at 0x%08x: %d\n",
 753                        ref_offset(ref), ret);
 754                goto out_erase_sem;
 755        }
 756        if (retlen != sizeof(n)) {
 757                pr_warn("Short read from obsoleted node at 0x%08x: %zd\n",
 758                        ref_offset(ref), retlen);
 759                goto out_erase_sem;
 760        }
 761        if (PAD(je32_to_cpu(n.totlen)) != PAD(freed_len)) {
 762                pr_warn("Node totlen on flash (0x%08x) != totlen from node ref (0x%08x)\n",
 763                        je32_to_cpu(n.totlen), freed_len);
 764                goto out_erase_sem;
 765        }
 766        if (!(je16_to_cpu(n.nodetype) & JFFS2_NODE_ACCURATE)) {
 767                jffs2_dbg(1, "Node at 0x%08x was already marked obsolete (nodetype 0x%04x)\n",
 768                          ref_offset(ref), je16_to_cpu(n.nodetype));
 769                goto out_erase_sem;
 770        }
 771        /* XXX FIXME: This is ugly now */
 772        n.nodetype = cpu_to_je16(je16_to_cpu(n.nodetype) & ~JFFS2_NODE_ACCURATE);
 773        ret = jffs2_flash_write(c, ref_offset(ref), sizeof(n), &retlen, (char *)&n);
 774        if (ret) {
 775                pr_warn("Write error in obliterating obsoleted node at 0x%08x: %d\n",
 776                        ref_offset(ref), ret);
 777                goto out_erase_sem;
 778        }
 779        if (retlen != sizeof(n)) {
 780                pr_warn("Short write in obliterating obsoleted node at 0x%08x: %zd\n",
 781                        ref_offset(ref), retlen);
 782                goto out_erase_sem;
 783        }
 784
 785        /* Nodes which have been marked obsolete no longer need to be
 786           associated with any inode. Remove them from the per-inode list.
 787
 788           Note we can't do this for NAND at the moment because we need
 789           obsolete dirent nodes to stay on the lists, because of the
 790           horridness in jffs2_garbage_collect_deletion_dirent(). Also
 791           because we delete the inocache, and on NAND we need that to
 792           stay around until all the nodes are actually erased, in order
 793           to stop us from giving the same inode number to another newly
 794           created inode. */
 795        if (ref->next_in_ino) {
 796                struct jffs2_inode_cache *ic;
 797                struct jffs2_raw_node_ref **p;
 798
 799                spin_lock(&c->erase_completion_lock);
 800
 801                ic = jffs2_raw_ref_to_ic(ref);
 802                for (p = &ic->nodes; (*p) != ref; p = &((*p)->next_in_ino))
 803                        ;
 804
 805                *p = ref->next_in_ino;
 806                ref->next_in_ino = NULL;
 807
 808                switch (ic->class) {
 809#ifdef CONFIG_JFFS2_FS_XATTR
 810                        case RAWNODE_CLASS_XATTR_DATUM:
 811                                jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
 812                                break;
 813                        case RAWNODE_CLASS_XATTR_REF:
 814                                jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
 815                                break;
 816#endif
 817                        default:
 818                                if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
 819                                        jffs2_del_ino_cache(c, ic);
 820                                break;
 821                }
 822                spin_unlock(&c->erase_completion_lock);
 823        }
 824
 825 out_erase_sem:
 826        mutex_unlock(&c->erase_free_sem);
 827}
 828
 829int jffs2_thread_should_wake(struct jffs2_sb_info *c)
 830{
 831        int ret = 0;
 832        uint32_t dirty;
 833        int nr_very_dirty = 0;
 834        struct jffs2_eraseblock *jeb;
 835
 836        if (!list_empty(&c->erase_complete_list) ||
 837            !list_empty(&c->erase_pending_list))
 838                return 1;
 839
 840        if (c->unchecked_size) {
 841                jffs2_dbg(1, "jffs2_thread_should_wake(): unchecked_size %d, checked_ino #%d\n",
 842                          c->unchecked_size, c->checked_ino);
 843                return 1;
 844        }
 845
 846        /* dirty_size contains blocks on erase_pending_list
 847         * those blocks are counted in c->nr_erasing_blocks.
 848         * If one block is actually erased, it is not longer counted as dirty_space
 849         * but it is counted in c->nr_erasing_blocks, so we add it and subtract it
 850         * with c->nr_erasing_blocks * c->sector_size again.
 851         * Blocks on erasable_list are counted as dirty_size, but not in c->nr_erasing_blocks
 852         * This helps us to force gc and pick eventually a clean block to spread the load.
 853         */
 854        dirty = c->dirty_size + c->erasing_size - c->nr_erasing_blocks * c->sector_size;
 855
 856        if (c->nr_free_blocks + c->nr_erasing_blocks < c->resv_blocks_gctrigger &&
 857                        (dirty > c->nospc_dirty_size))
 858                ret = 1;
 859
 860        list_for_each_entry(jeb, &c->very_dirty_list, list) {
 861                nr_very_dirty++;
 862                if (nr_very_dirty == c->vdirty_blocks_gctrigger) {
 863                        ret = 1;
 864                        /* In debug mode, actually go through and count them all */
 865                        D1(continue);
 866                        break;
 867                }
 868        }
 869
 870        jffs2_dbg(1, "%s(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x, vdirty_blocks %d: %s\n",
 871                  __func__, c->nr_free_blocks, c->nr_erasing_blocks,
 872                  c->dirty_size, nr_very_dirty, ret ? "yes" : "no");
 873
 874        return ret;
 875}
 876
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