linux/fs/jffs2/scan.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/sched.h>
  16#include <linux/slab.h>
  17#include <linux/mtd/mtd.h>
  18#include <linux/pagemap.h>
  19#include <linux/crc32.h>
  20#include <linux/compiler.h>
  21#include "nodelist.h"
  22#include "summary.h"
  23#include "debug.h"
  24
  25#define DEFAULT_EMPTY_SCAN_SIZE 256
  26
  27#define noisy_printk(noise, fmt, ...)                                   \
  28do {                                                                    \
  29        if (*(noise)) {                                                 \
  30                pr_notice(fmt, ##__VA_ARGS__);                          \
  31                (*(noise))--;                                           \
  32                if (!(*(noise)))                                        \
  33                        pr_notice("Further such events for this erase block will not be printed\n"); \
  34        }                                                               \
  35} while (0)
  36
  37static uint32_t pseudo_random;
  38
  39static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  40                                  unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
  41
  42/* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
  43 * Returning an error will abort the mount - bad checksums etc. should just mark the space
  44 * as dirty.
  45 */
  46static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  47                                 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
  48static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  49                                 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
  50
  51static inline int min_free(struct jffs2_sb_info *c)
  52{
  53        uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
  54#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
  55        if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
  56                return c->wbuf_pagesize;
  57#endif
  58        return min;
  59
  60}
  61
  62static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
  63        if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
  64                return sector_size;
  65        else
  66                return DEFAULT_EMPTY_SCAN_SIZE;
  67}
  68
  69static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
  70{
  71        int ret;
  72
  73        if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
  74                return ret;
  75        if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
  76                return ret;
  77        /* Turned wasted size into dirty, since we apparently 
  78           think it's recoverable now. */
  79        jeb->dirty_size += jeb->wasted_size;
  80        c->dirty_size += jeb->wasted_size;
  81        c->wasted_size -= jeb->wasted_size;
  82        jeb->wasted_size = 0;
  83        if (VERYDIRTY(c, jeb->dirty_size)) {
  84                list_add(&jeb->list, &c->very_dirty_list);
  85        } else {
  86                list_add(&jeb->list, &c->dirty_list);
  87        }
  88        return 0;
  89}
  90
  91int jffs2_scan_medium(struct jffs2_sb_info *c)
  92{
  93        int i, ret;
  94        uint32_t empty_blocks = 0, bad_blocks = 0;
  95        unsigned char *flashbuf = NULL;
  96        uint32_t buf_size = 0;
  97        struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
  98#ifndef __ECOS
  99        size_t pointlen, try_size;
 100
 101        ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen,
 102                        (void **)&flashbuf, NULL);
 103        if (!ret && pointlen < c->mtd->size) {
 104                /* Don't muck about if it won't let us point to the whole flash */
 105                jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
 106                          pointlen);
 107                mtd_unpoint(c->mtd, 0, pointlen);
 108                flashbuf = NULL;
 109        }
 110        if (ret && ret != -EOPNOTSUPP)
 111                jffs2_dbg(1, "MTD point failed %d\n", ret);
 112#endif
 113        if (!flashbuf) {
 114                /* For NAND it's quicker to read a whole eraseblock at a time,
 115                   apparently */
 116                if (jffs2_cleanmarker_oob(c))
 117                        try_size = c->sector_size;
 118                else
 119                        try_size = PAGE_SIZE;
 120
 121                jffs2_dbg(1, "Trying to allocate readbuf of %zu "
 122                          "bytes\n", try_size);
 123
 124                flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
 125                if (!flashbuf)
 126                        return -ENOMEM;
 127
 128                jffs2_dbg(1, "Allocated readbuf of %zu bytes\n",
 129                          try_size);
 130
 131                buf_size = (uint32_t)try_size;
 132        }
 133
 134        if (jffs2_sum_active()) {
 135                s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
 136                if (!s) {
 137                        JFFS2_WARNING("Can't allocate memory for summary\n");
 138                        ret = -ENOMEM;
 139                        goto out;
 140                }
 141        }
 142
 143        for (i=0; i<c->nr_blocks; i++) {
 144                struct jffs2_eraseblock *jeb = &c->blocks[i];
 145
 146                cond_resched();
 147
 148                /* reset summary info for next eraseblock scan */
 149                jffs2_sum_reset_collected(s);
 150
 151                ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
 152                                                buf_size, s);
 153
 154                if (ret < 0)
 155                        goto out;
 156
 157                jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 158
 159                /* Now decide which list to put it on */
 160                switch(ret) {
 161                case BLK_STATE_ALLFF:
 162                        /*
 163                         * Empty block.   Since we can't be sure it
 164                         * was entirely erased, we just queue it for erase
 165                         * again.  It will be marked as such when the erase
 166                         * is complete.  Meanwhile we still count it as empty
 167                         * for later checks.
 168                         */
 169                        empty_blocks++;
 170                        list_add(&jeb->list, &c->erase_pending_list);
 171                        c->nr_erasing_blocks++;
 172                        break;
 173
 174                case BLK_STATE_CLEANMARKER:
 175                        /* Only a CLEANMARKER node is valid */
 176                        if (!jeb->dirty_size) {
 177                                /* It's actually free */
 178                                list_add(&jeb->list, &c->free_list);
 179                                c->nr_free_blocks++;
 180                        } else {
 181                                /* Dirt */
 182                                jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n",
 183                                          jeb->offset);
 184                                list_add(&jeb->list, &c->erase_pending_list);
 185                                c->nr_erasing_blocks++;
 186                        }
 187                        break;
 188
 189                case BLK_STATE_CLEAN:
 190                        /* Full (or almost full) of clean data. Clean list */
 191                        list_add(&jeb->list, &c->clean_list);
 192                        break;
 193
 194                case BLK_STATE_PARTDIRTY:
 195                        /* Some data, but not full. Dirty list. */
 196                        /* We want to remember the block with most free space
 197                        and stick it in the 'nextblock' position to start writing to it. */
 198                        if (jeb->free_size > min_free(c) &&
 199                                        (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
 200                                /* Better candidate for the next writes to go to */
 201                                if (c->nextblock) {
 202                                        ret = file_dirty(c, c->nextblock);
 203                                        if (ret)
 204                                                goto out;
 205                                        /* deleting summary information of the old nextblock */
 206                                        jffs2_sum_reset_collected(c->summary);
 207                                }
 208                                /* update collected summary information for the current nextblock */
 209                                jffs2_sum_move_collected(c, s);
 210                                jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
 211                                          __func__, jeb->offset);
 212                                c->nextblock = jeb;
 213                        } else {
 214                                ret = file_dirty(c, jeb);
 215                                if (ret)
 216                                        goto out;
 217                        }
 218                        break;
 219
 220                case BLK_STATE_ALLDIRTY:
 221                        /* Nothing valid - not even a clean marker. Needs erasing. */
 222                        /* For now we just put it on the erasing list. We'll start the erases later */
 223                        jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n",
 224                                  jeb->offset);
 225                        list_add(&jeb->list, &c->erase_pending_list);
 226                        c->nr_erasing_blocks++;
 227                        break;
 228
 229                case BLK_STATE_BADBLOCK:
 230                        jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset);
 231                        list_add(&jeb->list, &c->bad_list);
 232                        c->bad_size += c->sector_size;
 233                        c->free_size -= c->sector_size;
 234                        bad_blocks++;
 235                        break;
 236                default:
 237                        pr_warn("%s(): unknown block state\n", __func__);
 238                        BUG();
 239                }
 240        }
 241
 242        /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
 243        if (c->nextblock && (c->nextblock->dirty_size)) {
 244                c->nextblock->wasted_size += c->nextblock->dirty_size;
 245                c->wasted_size += c->nextblock->dirty_size;
 246                c->dirty_size -= c->nextblock->dirty_size;
 247                c->nextblock->dirty_size = 0;
 248        }
 249#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 250        if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
 251                /* If we're going to start writing into a block which already
 252                   contains data, and the end of the data isn't page-aligned,
 253                   skip a little and align it. */
 254
 255                uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
 256
 257                jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n",
 258                          __func__, skip);
 259                jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 260                jffs2_scan_dirty_space(c, c->nextblock, skip);
 261        }
 262#endif
 263        if (c->nr_erasing_blocks) {
 264                if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
 265                        pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
 266                        pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",
 267                                  empty_blocks, bad_blocks, c->nr_blocks);
 268                        ret = -EIO;
 269                        goto out;
 270                }
 271                spin_lock(&c->erase_completion_lock);
 272                jffs2_garbage_collect_trigger(c);
 273                spin_unlock(&c->erase_completion_lock);
 274        }
 275        ret = 0;
 276 out:
 277        if (buf_size)
 278                kfree(flashbuf);
 279#ifndef __ECOS
 280        else
 281                mtd_unpoint(c->mtd, 0, c->mtd->size);
 282#endif
 283        kfree(s);
 284        return ret;
 285}
 286
 287static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
 288                               uint32_t ofs, uint32_t len)
 289{
 290        int ret;
 291        size_t retlen;
 292
 293        ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
 294        if (ret) {
 295                jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n",
 296                          len, ofs, ret);
 297                return ret;
 298        }
 299        if (retlen < len) {
 300                jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n",
 301                          ofs, retlen);
 302                return -EIO;
 303        }
 304        return 0;
 305}
 306
 307int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 308{
 309        if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
 310            && (!jeb->first_node || !ref_next(jeb->first_node)) )
 311                return BLK_STATE_CLEANMARKER;
 312
 313        /* move blocks with max 4 byte dirty space to cleanlist */
 314        else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
 315                c->dirty_size -= jeb->dirty_size;
 316                c->wasted_size += jeb->dirty_size;
 317                jeb->wasted_size += jeb->dirty_size;
 318                jeb->dirty_size = 0;
 319                return BLK_STATE_CLEAN;
 320        } else if (jeb->used_size || jeb->unchecked_size)
 321                return BLK_STATE_PARTDIRTY;
 322        else
 323                return BLK_STATE_ALLDIRTY;
 324}
 325
 326#ifdef CONFIG_JFFS2_FS_XATTR
 327static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 328                                 struct jffs2_raw_xattr *rx, uint32_t ofs,
 329                                 struct jffs2_summary *s)
 330{
 331        struct jffs2_xattr_datum *xd;
 332        uint32_t xid, version, totlen, crc;
 333        int err;
 334
 335        crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
 336        if (crc != je32_to_cpu(rx->node_crc)) {
 337                JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 338                              ofs, je32_to_cpu(rx->node_crc), crc);
 339                if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
 340                        return err;
 341                return 0;
 342        }
 343
 344        xid = je32_to_cpu(rx->xid);
 345        version = je32_to_cpu(rx->version);
 346
 347        totlen = PAD(sizeof(struct jffs2_raw_xattr)
 348                        + rx->name_len + 1 + je16_to_cpu(rx->value_len));
 349        if (totlen != je32_to_cpu(rx->totlen)) {
 350                JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
 351                              ofs, je32_to_cpu(rx->totlen), totlen);
 352                if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
 353                        return err;
 354                return 0;
 355        }
 356
 357        xd = jffs2_setup_xattr_datum(c, xid, version);
 358        if (IS_ERR(xd))
 359                return PTR_ERR(xd);
 360
 361        if (xd->version > version) {
 362                struct jffs2_raw_node_ref *raw
 363                        = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
 364                raw->next_in_ino = xd->node->next_in_ino;
 365                xd->node->next_in_ino = raw;
 366        } else {
 367                xd->version = version;
 368                xd->xprefix = rx->xprefix;
 369                xd->name_len = rx->name_len;
 370                xd->value_len = je16_to_cpu(rx->value_len);
 371                xd->data_crc = je32_to_cpu(rx->data_crc);
 372
 373                jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
 374        }
 375
 376        if (jffs2_sum_active())
 377                jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
 378        dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n",
 379                  ofs, xd->xid, xd->version);
 380        return 0;
 381}
 382
 383static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 384                                struct jffs2_raw_xref *rr, uint32_t ofs,
 385                                struct jffs2_summary *s)
 386{
 387        struct jffs2_xattr_ref *ref;
 388        uint32_t crc;
 389        int err;
 390
 391        crc = crc32(0, rr, sizeof(*rr) - 4);
 392        if (crc != je32_to_cpu(rr->node_crc)) {
 393                JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 394                              ofs, je32_to_cpu(rr->node_crc), crc);
 395                if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
 396                        return err;
 397                return 0;
 398        }
 399
 400        if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
 401                JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
 402                              ofs, je32_to_cpu(rr->totlen),
 403                              PAD(sizeof(struct jffs2_raw_xref)));
 404                if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
 405                        return err;
 406                return 0;
 407        }
 408
 409        ref = jffs2_alloc_xattr_ref();
 410        if (!ref)
 411                return -ENOMEM;
 412
 413        /* BEFORE jffs2_build_xattr_subsystem() called, 
 414         * and AFTER xattr_ref is marked as a dead xref,
 415         * ref->xid is used to store 32bit xid, xd is not used
 416         * ref->ino is used to store 32bit inode-number, ic is not used
 417         * Thoes variables are declared as union, thus using those
 418         * are exclusive. In a similar way, ref->next is temporarily
 419         * used to chain all xattr_ref object. It's re-chained to
 420         * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
 421         */
 422        ref->ino = je32_to_cpu(rr->ino);
 423        ref->xid = je32_to_cpu(rr->xid);
 424        ref->xseqno = je32_to_cpu(rr->xseqno);
 425        if (ref->xseqno > c->highest_xseqno)
 426                c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 427        ref->next = c->xref_temp;
 428        c->xref_temp = ref;
 429
 430        jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
 431
 432        if (jffs2_sum_active())
 433                jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
 434        dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
 435                  ofs, ref->xid, ref->ino);
 436        return 0;
 437}
 438#endif
 439
 440/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
 441   the flash, XIP-style */
 442static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 443                                  unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
 444        struct jffs2_unknown_node *node;
 445        struct jffs2_unknown_node crcnode;
 446        uint32_t ofs, prevofs, max_ofs;
 447        uint32_t hdr_crc, buf_ofs, buf_len;
 448        int err;
 449        int noise = 0;
 450
 451
 452#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 453        int cleanmarkerfound = 0;
 454#endif
 455
 456        ofs = jeb->offset;
 457        prevofs = jeb->offset - 1;
 458
 459        jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs);
 460
 461#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 462        if (jffs2_cleanmarker_oob(c)) {
 463                int ret;
 464
 465                if (mtd_block_isbad(c->mtd, jeb->offset))
 466                        return BLK_STATE_BADBLOCK;
 467
 468                ret = jffs2_check_nand_cleanmarker(c, jeb);
 469                jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret);
 470
 471                /* Even if it's not found, we still scan to see
 472                   if the block is empty. We use this information
 473                   to decide whether to erase it or not. */
 474                switch (ret) {
 475                case 0:         cleanmarkerfound = 1; break;
 476                case 1:         break;
 477                default:        return ret;
 478                }
 479        }
 480#endif
 481
 482        if (jffs2_sum_active()) {
 483                struct jffs2_sum_marker *sm;
 484                void *sumptr = NULL;
 485                uint32_t sumlen;
 486              
 487                if (!buf_size) {
 488                        /* XIP case. Just look, point at the summary if it's there */
 489                        sm = (void *)buf + c->sector_size - sizeof(*sm);
 490                        if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
 491                                sumptr = buf + je32_to_cpu(sm->offset);
 492                                sumlen = c->sector_size - je32_to_cpu(sm->offset);
 493                        }
 494                } else {
 495                        /* If NAND flash, read a whole page of it. Else just the end */
 496                        if (c->wbuf_pagesize)
 497                                buf_len = c->wbuf_pagesize;
 498                        else
 499                                buf_len = sizeof(*sm);
 500
 501                        /* Read as much as we want into the _end_ of the preallocated buffer */
 502                        err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
 503                                                  jeb->offset + c->sector_size - buf_len,
 504                                                  buf_len);                             
 505                        if (err)
 506                                return err;
 507
 508                        sm = (void *)buf + buf_size - sizeof(*sm);
 509                        if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
 510                                sumlen = c->sector_size - je32_to_cpu(sm->offset);
 511                                sumptr = buf + buf_size - sumlen;
 512
 513                                /* Now, make sure the summary itself is available */
 514                                if (sumlen > buf_size) {
 515                                        /* Need to kmalloc for this. */
 516                                        sumptr = kmalloc(sumlen, GFP_KERNEL);
 517                                        if (!sumptr)
 518                                                return -ENOMEM;
 519                                        memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
 520                                }
 521                                if (buf_len < sumlen) {
 522                                        /* Need to read more so that the entire summary node is present */
 523                                        err = jffs2_fill_scan_buf(c, sumptr, 
 524                                                                  jeb->offset + c->sector_size - sumlen,
 525                                                                  sumlen - buf_len);                            
 526                                        if (err)
 527                                                return err;
 528                                }
 529                        }
 530
 531                }
 532
 533                if (sumptr) {
 534                        err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
 535
 536                        if (buf_size && sumlen > buf_size)
 537                                kfree(sumptr);
 538                        /* If it returns with a real error, bail. 
 539                           If it returns positive, that's a block classification
 540                           (i.e. BLK_STATE_xxx) so return that too.
 541                           If it returns zero, fall through to full scan. */
 542                        if (err)
 543                                return err;
 544                }
 545        }
 546
 547        buf_ofs = jeb->offset;
 548
 549        if (!buf_size) {
 550                /* This is the XIP case -- we're reading _directly_ from the flash chip */
 551                buf_len = c->sector_size;
 552        } else {
 553                buf_len = EMPTY_SCAN_SIZE(c->sector_size);
 554                err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
 555                if (err)
 556                        return err;
 557        }
 558
 559        /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
 560        ofs = 0;
 561        max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
 562        /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
 563        while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
 564                ofs += 4;
 565
 566        if (ofs == max_ofs) {
 567#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 568                if (jffs2_cleanmarker_oob(c)) {
 569                        /* scan oob, take care of cleanmarker */
 570                        int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
 571                        jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n",
 572                                  ret);
 573                        switch (ret) {
 574                        case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
 575                        case 1:         return BLK_STATE_ALLDIRTY;
 576                        default:        return ret;
 577                        }
 578                }
 579#endif
 580                jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n",
 581                          jeb->offset);
 582                if (c->cleanmarker_size == 0)
 583                        return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
 584                else
 585                        return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
 586        }
 587        if (ofs) {
 588                jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset,
 589                          jeb->offset + ofs);
 590                if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
 591                        return err;
 592                if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
 593                        return err;
 594        }
 595
 596        /* Now ofs is a complete physical flash offset as it always was... */
 597        ofs += jeb->offset;
 598
 599        noise = 10;
 600
 601        dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
 602
 603scan_more:
 604        while(ofs < jeb->offset + c->sector_size) {
 605
 606                jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 607
 608                /* Make sure there are node refs available for use */
 609                err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
 610                if (err)
 611                        return err;
 612
 613                cond_resched();
 614
 615                if (ofs & 3) {
 616                        pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs);
 617                        ofs = PAD(ofs);
 618                        continue;
 619                }
 620                if (ofs == prevofs) {
 621                        pr_warn("ofs 0x%08x has already been seen. Skipping\n",
 622                                ofs);
 623                        if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 624                                return err;
 625                        ofs += 4;
 626                        continue;
 627                }
 628                prevofs = ofs;
 629
 630                if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
 631                        jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n",
 632                                  sizeof(struct jffs2_unknown_node),
 633                                  jeb->offset, c->sector_size, ofs,
 634                                  sizeof(*node));
 635                        if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
 636                                return err;
 637                        break;
 638                }
 639
 640                if (buf_ofs + buf_len < ofs + sizeof(*node)) {
 641                        buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 642                        jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
 643                                  sizeof(struct jffs2_unknown_node),
 644                                  buf_len, ofs);
 645                        err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 646                        if (err)
 647                                return err;
 648                        buf_ofs = ofs;
 649                }
 650
 651                node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
 652
 653                if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
 654                        uint32_t inbuf_ofs;
 655                        uint32_t empty_start, scan_end;
 656
 657                        empty_start = ofs;
 658                        ofs += 4;
 659                        scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
 660
 661                        jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs);
 662                more_empty:
 663                        inbuf_ofs = ofs - buf_ofs;
 664                        while (inbuf_ofs < scan_end) {
 665                                if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
 666                                        pr_warn("Empty flash at 0x%08x ends at 0x%08x\n",
 667                                                empty_start, ofs);
 668                                        if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
 669                                                return err;
 670                                        goto scan_more;
 671                                }
 672
 673                                inbuf_ofs+=4;
 674                                ofs += 4;
 675                        }
 676                        /* Ran off end. */
 677                        jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n",
 678                                  ofs);
 679
 680                        /* If we're only checking the beginning of a block with a cleanmarker,
 681                           bail now */
 682                        if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
 683                            c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
 684                                jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n",
 685                                          EMPTY_SCAN_SIZE(c->sector_size));
 686                                return BLK_STATE_CLEANMARKER;
 687                        }
 688                        if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
 689                                scan_end = buf_len;
 690                                goto more_empty;
 691                        }
 692                        
 693                        /* See how much more there is to read in this eraseblock... */
 694                        buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 695                        if (!buf_len) {
 696                                /* No more to read. Break out of main loop without marking
 697                                   this range of empty space as dirty (because it's not) */
 698                                jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n",
 699                                          empty_start);
 700                                break;
 701                        }
 702                        /* point never reaches here */
 703                        scan_end = buf_len;
 704                        jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n",
 705                                  buf_len, ofs);
 706                        err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 707                        if (err)
 708                                return err;
 709                        buf_ofs = ofs;
 710                        goto more_empty;
 711                }
 712
 713                if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
 714                        pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n",
 715                                ofs);
 716                        if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 717                                return err;
 718                        ofs += 4;
 719                        continue;
 720                }
 721                if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
 722                        jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs);
 723                        if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 724                                return err;
 725                        ofs += 4;
 726                        continue;
 727                }
 728                if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
 729                        pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs);
 730                        pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n");
 731                        if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 732                                return err;
 733                        ofs += 4;
 734                        continue;
 735                }
 736                if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
 737                        /* OK. We're out of possibilities. Whinge and move on */
 738                        noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
 739                                     __func__,
 740                                     JFFS2_MAGIC_BITMASK, ofs,
 741                                     je16_to_cpu(node->magic));
 742                        if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 743                                return err;
 744                        ofs += 4;
 745                        continue;
 746                }
 747                /* We seem to have a node of sorts. Check the CRC */
 748                crcnode.magic = node->magic;
 749                crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
 750                crcnode.totlen = node->totlen;
 751                hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
 752
 753                if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
 754                        noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
 755                                     __func__,
 756                                     ofs, je16_to_cpu(node->magic),
 757                                     je16_to_cpu(node->nodetype),
 758                                     je32_to_cpu(node->totlen),
 759                                     je32_to_cpu(node->hdr_crc),
 760                                     hdr_crc);
 761                        if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 762                                return err;
 763                        ofs += 4;
 764                        continue;
 765                }
 766
 767                if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
 768                        /* Eep. Node goes over the end of the erase block. */
 769                        pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
 770                                ofs, je32_to_cpu(node->totlen));
 771                        pr_warn("Perhaps the file system was created with the wrong erase size?\n");
 772                        if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 773                                return err;
 774                        ofs += 4;
 775                        continue;
 776                }
 777
 778                if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
 779                        /* Wheee. This is an obsoleted node */
 780                        jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n",
 781                                  ofs);
 782                        if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 783                                return err;
 784                        ofs += PAD(je32_to_cpu(node->totlen));
 785                        continue;
 786                }
 787
 788                switch(je16_to_cpu(node->nodetype)) {
 789                case JFFS2_NODETYPE_INODE:
 790                        if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
 791                                buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 792                                jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
 793                                          sizeof(struct jffs2_raw_inode),
 794                                          buf_len, ofs);
 795                                err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 796                                if (err)
 797                                        return err;
 798                                buf_ofs = ofs;
 799                                node = (void *)buf;
 800                        }
 801                        err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
 802                        if (err) return err;
 803                        ofs += PAD(je32_to_cpu(node->totlen));
 804                        break;
 805
 806                case JFFS2_NODETYPE_DIRENT:
 807                        if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 808                                buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 809                                jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
 810                                          je32_to_cpu(node->totlen), buf_len,
 811                                          ofs);
 812                                err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 813                                if (err)
 814                                        return err;
 815                                buf_ofs = ofs;
 816                                node = (void *)buf;
 817                        }
 818                        err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
 819                        if (err) return err;
 820                        ofs += PAD(je32_to_cpu(node->totlen));
 821                        break;
 822
 823#ifdef CONFIG_JFFS2_FS_XATTR
 824                case JFFS2_NODETYPE_XATTR:
 825                        if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 826                                buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 827                                jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n",
 828                                          je32_to_cpu(node->totlen), buf_len,
 829                                          ofs);
 830                                err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 831                                if (err)
 832                                        return err;
 833                                buf_ofs = ofs;
 834                                node = (void *)buf;
 835                        }
 836                        err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
 837                        if (err)
 838                                return err;
 839                        ofs += PAD(je32_to_cpu(node->totlen));
 840                        break;
 841                case JFFS2_NODETYPE_XREF:
 842                        if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 843                                buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 844                                jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n",
 845                                          je32_to_cpu(node->totlen), buf_len,
 846                                          ofs);
 847                                err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 848                                if (err)
 849                                        return err;
 850                                buf_ofs = ofs;
 851                                node = (void *)buf;
 852                        }
 853                        err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
 854                        if (err)
 855                                return err;
 856                        ofs += PAD(je32_to_cpu(node->totlen));
 857                        break;
 858#endif  /* CONFIG_JFFS2_FS_XATTR */
 859
 860                case JFFS2_NODETYPE_CLEANMARKER:
 861                        jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs);
 862                        if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
 863                                pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
 864                                          ofs, je32_to_cpu(node->totlen),
 865                                          c->cleanmarker_size);
 866                                if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
 867                                        return err;
 868                                ofs += PAD(sizeof(struct jffs2_unknown_node));
 869                        } else if (jeb->first_node) {
 870                                pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n",
 871                                          ofs, jeb->offset);
 872                                if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
 873                                        return err;
 874                                ofs += PAD(sizeof(struct jffs2_unknown_node));
 875                        } else {
 876                                jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
 877
 878                                ofs += PAD(c->cleanmarker_size);
 879                        }
 880                        break;
 881
 882                case JFFS2_NODETYPE_PADDING:
 883                        if (jffs2_sum_active())
 884                                jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
 885                        if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 886                                return err;
 887                        ofs += PAD(je32_to_cpu(node->totlen));
 888                        break;
 889
 890                default:
 891                        switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
 892                        case JFFS2_FEATURE_ROCOMPAT:
 893                                pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n",
 894                                          je16_to_cpu(node->nodetype), ofs);
 895                                c->flags |= JFFS2_SB_FLAG_RO;
 896                                if (!(jffs2_is_readonly(c)))
 897                                        return -EROFS;
 898                                if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 899                                        return err;
 900                                ofs += PAD(je32_to_cpu(node->totlen));
 901                                break;
 902
 903                        case JFFS2_FEATURE_INCOMPAT:
 904                                pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n",
 905                                          je16_to_cpu(node->nodetype), ofs);
 906                                return -EINVAL;
 907
 908                        case JFFS2_FEATURE_RWCOMPAT_DELETE:
 909                                jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
 910                                          je16_to_cpu(node->nodetype), ofs);
 911                                if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 912                                        return err;
 913                                ofs += PAD(je32_to_cpu(node->totlen));
 914                                break;
 915
 916                        case JFFS2_FEATURE_RWCOMPAT_COPY: {
 917                                jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
 918                                          je16_to_cpu(node->nodetype), ofs);
 919
 920                                jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
 921
 922                                /* We can't summarise nodes we don't grok */
 923                                jffs2_sum_disable_collecting(s);
 924                                ofs += PAD(je32_to_cpu(node->totlen));
 925                                break;
 926                                }
 927                        }
 928                }
 929        }
 930
 931        if (jffs2_sum_active()) {
 932                if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
 933                        dbg_summary("There is not enough space for "
 934                                "summary information, disabling for this jeb!\n");
 935                        jffs2_sum_disable_collecting(s);
 936                }
 937        }
 938
 939        jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
 940                  jeb->offset, jeb->free_size, jeb->dirty_size,
 941                  jeb->unchecked_size, jeb->used_size, jeb->wasted_size);
 942        
 943        /* mark_node_obsolete can add to wasted !! */
 944        if (jeb->wasted_size) {
 945                jeb->dirty_size += jeb->wasted_size;
 946                c->dirty_size += jeb->wasted_size;
 947                c->wasted_size -= jeb->wasted_size;
 948                jeb->wasted_size = 0;
 949        }
 950
 951        return jffs2_scan_classify_jeb(c, jeb);
 952}
 953
 954struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
 955{
 956        struct jffs2_inode_cache *ic;
 957
 958        ic = jffs2_get_ino_cache(c, ino);
 959        if (ic)
 960                return ic;
 961
 962        if (ino > c->highest_ino)
 963                c->highest_ino = ino;
 964
 965        ic = jffs2_alloc_inode_cache();
 966        if (!ic) {
 967                pr_notice("%s(): allocation of inode cache failed\n", __func__);
 968                return NULL;
 969        }
 970        memset(ic, 0, sizeof(*ic));
 971
 972        ic->ino = ino;
 973        ic->nodes = (void *)ic;
 974        jffs2_add_ino_cache(c, ic);
 975        if (ino == 1)
 976                ic->pino_nlink = 1;
 977        return ic;
 978}
 979
 980static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 981                                 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
 982{
 983        struct jffs2_inode_cache *ic;
 984        uint32_t crc, ino = je32_to_cpu(ri->ino);
 985
 986        jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
 987
 988        /* We do very little here now. Just check the ino# to which we should attribute
 989           this node; we can do all the CRC checking etc. later. There's a tradeoff here --
 990           we used to scan the flash once only, reading everything we want from it into
 991           memory, then building all our in-core data structures and freeing the extra
 992           information. Now we allow the first part of the mount to complete a lot quicker,
 993           but we have to go _back_ to the flash in order to finish the CRC checking, etc.
 994           Which means that the _full_ amount of time to get to proper write mode with GC
 995           operational may actually be _longer_ than before. Sucks to be me. */
 996
 997        /* Check the node CRC in any case. */
 998        crc = crc32(0, ri, sizeof(*ri)-8);
 999        if (crc != je32_to_cpu(ri->node_crc)) {
1000                pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1001                          __func__, ofs, je32_to_cpu(ri->node_crc), crc);
1002                /*
1003                 * We believe totlen because the CRC on the node
1004                 * _header_ was OK, just the node itself failed.
1005                 */
1006                return jffs2_scan_dirty_space(c, jeb,
1007                                              PAD(je32_to_cpu(ri->totlen)));
1008        }
1009
1010        ic = jffs2_get_ino_cache(c, ino);
1011        if (!ic) {
1012                ic = jffs2_scan_make_ino_cache(c, ino);
1013                if (!ic)
1014                        return -ENOMEM;
1015        }
1016
1017        /* Wheee. It worked */
1018        jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
1019
1020        jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1021                  je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1022                  je32_to_cpu(ri->offset),
1023                  je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize));
1024
1025        pseudo_random += je32_to_cpu(ri->version);
1026
1027        if (jffs2_sum_active()) {
1028                jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1029        }
1030
1031        return 0;
1032}
1033
1034static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1035                                  struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1036{
1037        struct jffs2_full_dirent *fd;
1038        struct jffs2_inode_cache *ic;
1039        uint32_t checkedlen;
1040        uint32_t crc;
1041        int err;
1042
1043        jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
1044
1045        /* We don't get here unless the node is still valid, so we don't have to
1046           mask in the ACCURATE bit any more. */
1047        crc = crc32(0, rd, sizeof(*rd)-8);
1048
1049        if (crc != je32_to_cpu(rd->node_crc)) {
1050                pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1051                          __func__, ofs, je32_to_cpu(rd->node_crc), crc);
1052                /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1053                if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1054                        return err;
1055                return 0;
1056        }
1057
1058        pseudo_random += je32_to_cpu(rd->version);
1059
1060        /* Should never happen. Did. (OLPC trac #4184)*/
1061        checkedlen = strnlen(rd->name, rd->nsize);
1062        if (checkedlen < rd->nsize) {
1063                pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1064                       ofs, checkedlen);
1065        }
1066        fd = jffs2_alloc_full_dirent(checkedlen+1);
1067        if (!fd) {
1068                return -ENOMEM;
1069        }
1070        memcpy(&fd->name, rd->name, checkedlen);
1071        fd->name[checkedlen] = 0;
1072
1073        crc = crc32(0, fd->name, rd->nsize);
1074        if (crc != je32_to_cpu(rd->name_crc)) {
1075                pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1076                          __func__, ofs, je32_to_cpu(rd->name_crc), crc);
1077                jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n",
1078                          fd->name, je32_to_cpu(rd->ino));
1079                jffs2_free_full_dirent(fd);
1080                /* FIXME: Why do we believe totlen? */
1081                /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1082                if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1083                        return err;
1084                return 0;
1085        }
1086        ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1087        if (!ic) {
1088                jffs2_free_full_dirent(fd);
1089                return -ENOMEM;
1090        }
1091
1092        fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1093                                      PAD(je32_to_cpu(rd->totlen)), ic);
1094
1095        fd->next = NULL;
1096        fd->version = je32_to_cpu(rd->version);
1097        fd->ino = je32_to_cpu(rd->ino);
1098        fd->nhash = full_name_hash(fd->name, checkedlen);
1099        fd->type = rd->type;
1100        jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1101
1102        if (jffs2_sum_active()) {
1103                jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1104        }
1105
1106        return 0;
1107}
1108
1109static int count_list(struct list_head *l)
1110{
1111        uint32_t count = 0;
1112        struct list_head *tmp;
1113
1114        list_for_each(tmp, l) {
1115                count++;
1116        }
1117        return count;
1118}
1119
1120/* Note: This breaks if list_empty(head). I don't care. You
1121   might, if you copy this code and use it elsewhere :) */
1122static void rotate_list(struct list_head *head, uint32_t count)
1123{
1124        struct list_head *n = head->next;
1125
1126        list_del(head);
1127        while(count--) {
1128                n = n->next;
1129        }
1130        list_add(head, n);
1131}
1132
1133void jffs2_rotate_lists(struct jffs2_sb_info *c)
1134{
1135        uint32_t x;
1136        uint32_t rotateby;
1137
1138        x = count_list(&c->clean_list);
1139        if (x) {
1140                rotateby = pseudo_random % x;
1141                rotate_list((&c->clean_list), rotateby);
1142        }
1143
1144        x = count_list(&c->very_dirty_list);
1145        if (x) {
1146                rotateby = pseudo_random % x;
1147                rotate_list((&c->very_dirty_list), rotateby);
1148        }
1149
1150        x = count_list(&c->dirty_list);
1151        if (x) {
1152                rotateby = pseudo_random % x;
1153                rotate_list((&c->dirty_list), rotateby);
1154        }
1155
1156        x = count_list(&c->erasable_list);
1157        if (x) {
1158                rotateby = pseudo_random % x;
1159                rotate_list((&c->erasable_list), rotateby);
1160        }
1161
1162        if (c->nr_erasing_blocks) {
1163                rotateby = pseudo_random % c->nr_erasing_blocks;
1164                rotate_list((&c->erase_pending_list), rotateby);
1165        }
1166
1167        if (c->nr_free_blocks) {
1168                rotateby = pseudo_random % c->nr_free_blocks;
1169                rotate_list((&c->free_list), rotateby);
1170        }
1171}
1172
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