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   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright (C) 2001-2003 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  * $Id: scan.c,v 1.125 2005/09/30 13:59:13 dedekind Exp $
  11  *
  12  */
  13 #include <linux/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/slab.h>
  16 #include <linux/mtd/mtd.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/crc32.h>
  19 #include <linux/compiler.h>
  20 #include "nodelist.h"
  21 #include "summary.h"
  22 #include "debug.h"
  23
  24 #define DEFAULT_EMPTY_SCAN_SIZE 1024
  25
  26 #define noisy_printk(noise, args...) do { \
  27         if (*(noise)) { \
  28                 printk(KERN_NOTICE args); \
  29                  (*(noise))--; \
  30                  if (!(*(noise))) { \
  31                          printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \
  32                  } \
  33         } \
  34 } while(0)
  35
  36 static uint32_t pseudo_random;
  37
  38 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  39                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
  40
  41 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
  42  * Returning an error will abort the mount - bad checksums etc. should just mark the space
  43  * as dirty.
  44  */
  45 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  46                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
  47 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  48                                  struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
  49
  50 static inline int min_free(struct jffs2_sb_info *c)
  51 {
  52         uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
  53 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
  54         if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
  55                 return c->wbuf_pagesize;
  56 #endif
  57         return min;
  58
  59 }
  60
  61 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
  62         if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
  63                 return sector_size;
  64         else
  65                 return DEFAULT_EMPTY_SCAN_SIZE;
  66 }
  67
  68 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
  69 {
  70         int ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size);
  71         if (ret)
  72                 return ret;
  73         /* Turned wasted size into dirty, since we apparently
  74            think it's recoverable now. */
  75         jeb->dirty_size += jeb->wasted_size;
  76         c->dirty_size += jeb->wasted_size;
  77         c->wasted_size -= jeb->wasted_size;
  78         jeb->wasted_size = 0;
  79         if (VERYDIRTY(c, jeb->dirty_size)) {
  80                 list_add(&jeb->list, &c->very_dirty_list);
  81         } else {
  82                 list_add(&jeb->list, &c->dirty_list);
  83         }
  84         return 0;
  85 }
  86
  87 int jffs2_scan_medium(struct jffs2_sb_info *c)
  88 {
  89         int i, ret;
  90         uint32_t empty_blocks = 0, bad_blocks = 0;
  91         unsigned char *flashbuf = NULL;
  92         uint32_t buf_size = 0;
  93         struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
  94 #ifndef __ECOS
  95         size_t pointlen;
  96
  97         if (c->mtd->point) {
  98                 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
  99                 if (!ret && pointlen < c->mtd->size) {
 100                         /* Don't muck about if it won't let us point to the whole flash */
 101                         D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
 102                         c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
 103                         flashbuf = NULL;
 104                 }
 105                 if (ret)
 106                         D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
 107         }
 108 #endif
 109         if (!flashbuf) {
 110                 /* For NAND it's quicker to read a whole eraseblock at a time,
 111                    apparently */
 112                 if (jffs2_cleanmarker_oob(c))
 113                         buf_size = c->sector_size;
 114                 else
 115                         buf_size = PAGE_SIZE;
 116
 117                 /* Respect kmalloc limitations */
 118                 if (buf_size > 128*1024)
 119                         buf_size = 128*1024;
 120
 121                 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
 122                 flashbuf = kmalloc(buf_size, GFP_KERNEL);
 123                 if (!flashbuf)
 124                         return -ENOMEM;
 125         }
 126
 127         if (jffs2_sum_active()) {
 128                 s = kmalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
 129                 if (!s) {
 130                         JFFS2_WARNING("Can't allocate memory for summary\n");
 131                         return -ENOMEM;
 132                 }
 133                 memset(s, 0, sizeof(struct jffs2_summary));
 134         }
 135
 136         for (i=0; i<c->nr_blocks; i++) {
 137                 struct jffs2_eraseblock *jeb = &c->blocks[i];
 138
 139                 /* reset summary info for next eraseblock scan */
 140                 jffs2_sum_reset_collected(s);
 141
 142                 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
 143                                                 buf_size, s);
 144
 145                 if (ret < 0)
 146                         goto out;
 147
 148                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 149
 150                 /* Now decide which list to put it on */
 151                 switch(ret) {
 152                 case BLK_STATE_ALLFF:
 153                         /*
 154                          * Empty block.   Since we can't be sure it
 155                          * was entirely erased, we just queue it for erase
 156                          * again.  It will be marked as such when the erase
 157                          * is complete.  Meanwhile we still count it as empty
 158                          * for later checks.
 159                          */
 160                         empty_blocks++;
 161                         list_add(&jeb->list, &c->erase_pending_list);
 162                         c->nr_erasing_blocks++;
 163                         break;
 164
 165                 case BLK_STATE_CLEANMARKER:
 166                         /* Only a CLEANMARKER node is valid */
 167                         if (!jeb->dirty_size) {
 168                                 /* It's actually free */
 169                                 list_add(&jeb->list, &c->free_list);
 170                                 c->nr_free_blocks++;
 171                         } else {
 172                                 /* Dirt */
 173                                 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
 174                                 list_add(&jeb->list, &c->erase_pending_list);
 175                                 c->nr_erasing_blocks++;
 176                         }
 177                         break;
 178
 179                 case BLK_STATE_CLEAN:
 180                         /* Full (or almost full) of clean data. Clean list */
 181                         list_add(&jeb->list, &c->clean_list);
 182                         break;
 183
 184                 case BLK_STATE_PARTDIRTY:
 185                         /* Some data, but not full. Dirty list. */
 186                         /* We want to remember the block with most free space
 187                         and stick it in the 'nextblock' position to start writing to it. */
 188                         if (jeb->free_size > min_free(c) &&
 189                                         (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
 190                                 /* Better candidate for the next writes to go to */
 191                                 if (c->nextblock) {
 192                                         ret = file_dirty(c, c->nextblock);
 193                                         if (ret)
 194                                                 return ret;
 195                                         /* deleting summary information of the old nextblock */
 196                                         jffs2_sum_reset_collected(c->summary);
 197                                 }
 198                                 /* update collected summary information for the current nextblock */
 199                                 jffs2_sum_move_collected(c, s);
 200                                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
 201                                 c->nextblock = jeb;
 202                         } else {
 203                                 ret = file_dirty(c, jeb);
 204                                 if (ret)
 205                                         return ret;
 206                         }
 207                         break;
 208
 209                 case BLK_STATE_ALLDIRTY:
 210                         /* Nothing valid - not even a clean marker. Needs erasing. */
 211                         /* For now we just put it on the erasing list. We'll start the erases later */
 212                         D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
 213                         list_add(&jeb->list, &c->erase_pending_list);
 214                         c->nr_erasing_blocks++;
 215                         break;
 216
 217                 case BLK_STATE_BADBLOCK:
 218                         D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
 219                         list_add(&jeb->list, &c->bad_list);
 220                         c->bad_size += c->sector_size;
 221                         c->free_size -= c->sector_size;
 222                         bad_blocks++;
 223                         break;
 224                 default:
 225                         printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
 226                         BUG();
 227                 }
 228         }
 229
 230         /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
 231         if (c->nextblock && (c->nextblock->dirty_size)) {
 232                 c->nextblock->wasted_size += c->nextblock->dirty_size;
 233                 c->wasted_size += c->nextblock->dirty_size;
 234                 c->dirty_size -= c->nextblock->dirty_size;
 235                 c->nextblock->dirty_size = 0;
 236         }
 237 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 238         if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
 239                 /* If we're going to start writing into a block which already
 240                    contains data, and the end of the data isn't page-aligned,
 241                    skip a little and align it. */
 242
 243                 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
 244
 245                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
 246                           skip));
 247                 c->nextblock->wasted_size += skip;
 248                 c->wasted_size += skip;
 249
 250                 c->nextblock->free_size -= skip;
 251                 c->free_size -= skip;
 252         }
 253 #endif
 254         if (c->nr_erasing_blocks) {
 255                 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
 256                         printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
 257                         printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
 258                         ret = -EIO;
 259                         goto out;
 260                 }
 261                 jffs2_erase_pending_trigger(c);
 262         }
 263         ret = 0;
 264  out:
 265         if (buf_size)
 266                 kfree(flashbuf);
 267 #ifndef __ECOS
 268         else
 269                 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
 270 #endif
 271         if (s)
 272                 kfree(s);
 273
 274         return ret;
 275 }
 276
 277 int jffs2_fill_scan_buf (struct jffs2_sb_info *c, void *buf,
 278                                 uint32_t ofs, uint32_t len)
 279 {
 280         int ret;
 281         size_t retlen;
 282
 283         ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
 284         if (ret) {
 285                 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
 286                 return ret;
 287         }
 288         if (retlen < len) {
 289                 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
 290                 return -EIO;
 291         }
 292         return 0;
 293 }
 294
 295 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 296 {
 297         if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
 298                 && (!jeb->first_node || !jeb->first_node->next_phys) )
 299                 return BLK_STATE_CLEANMARKER;
 300
 301         /* move blocks with max 4 byte dirty space to cleanlist */
 302         else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
 303                 c->dirty_size -= jeb->dirty_size;
 304                 c->wasted_size += jeb->dirty_size;
 305                 jeb->wasted_size += jeb->dirty_size;
 306                 jeb->dirty_size = 0;
 307                 return BLK_STATE_CLEAN;
 308         } else if (jeb->used_size || jeb->unchecked_size)
 309                 return BLK_STATE_PARTDIRTY;
 310         else
 311                 return BLK_STATE_ALLDIRTY;
 312 }
 313
 314 #ifdef CONFIG_JFFS2_FS_XATTR
 315 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 316                                  struct jffs2_raw_xattr *rx, uint32_t ofs,
 317                                  struct jffs2_summary *s)
 318 {
 319         struct jffs2_xattr_datum *xd;
 320         struct jffs2_raw_node_ref *raw;
 321         uint32_t totlen, crc;
 322         int err;
 323
 324         crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
 325         if (crc != je32_to_cpu(rx->node_crc)) {
 326                 if (je32_to_cpu(rx->node_crc) != 0xffffffff)
 327                         JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 328                                       ofs, je32_to_cpu(rx->node_crc), crc);
 329                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
 330                         return err;
 331                 return 0;
 332         }
 333
 334         totlen = PAD(sizeof(*rx) + rx->name_len + 1 + je16_to_cpu(rx->value_len));
 335         if (totlen != je32_to_cpu(rx->totlen)) {
 336                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
 337                               ofs, je32_to_cpu(rx->totlen), totlen);
 338                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
 339                         return err;
 340                 return 0;
 341         }
 342
 343         raw =  jffs2_alloc_raw_node_ref();
 344         if (!raw)
 345                 return -ENOMEM;
 346
 347         xd = jffs2_setup_xattr_datum(c, je32_to_cpu(rx->xid), je32_to_cpu(rx->version));
 348         if (IS_ERR(xd)) {
 349                 jffs2_free_raw_node_ref(raw);
 350                 if (PTR_ERR(xd) == -EEXIST) {
 351                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rx->totlen)))))
 352                                 return err;
 353                         return 0;
 354                 }
 355                 return PTR_ERR(xd);
 356         }
 357         xd->xprefix = rx->xprefix;
 358         xd->name_len = rx->name_len;
 359         xd->value_len = je16_to_cpu(rx->value_len);
 360         xd->data_crc = je32_to_cpu(rx->data_crc);
 361         xd->node = raw;
 362
 363         raw->flash_offset = ofs | REF_PRISTINE;
 364         raw->next_in_ino = (void *)xd;
 365
 366         jffs2_link_node_ref(c, jeb, raw, totlen);
 367
 368         if (jffs2_sum_active())
 369                 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
 370         dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
 371                   ofs, xd->xid, xd->version);
 372         return 0;
 373 }
 374
 375 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 376                                 struct jffs2_raw_xref *rr, uint32_t ofs,
 377                                 struct jffs2_summary *s)
 378 {
 379         struct jffs2_xattr_ref *ref;
 380         struct jffs2_raw_node_ref *raw;
 381         uint32_t crc;
 382         int err;
 383
 384         crc = crc32(0, rr, sizeof(*rr) - 4);
 385         if (crc != je32_to_cpu(rr->node_crc)) {
 386                 if (je32_to_cpu(rr->node_crc) != 0xffffffff)
 387                         JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 388                                       ofs, je32_to_cpu(rr->node_crc), crc);
 389                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
 390                         return err;
 391                 return 0;
 392         }
 393
 394         if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
 395                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
 396                               ofs, je32_to_cpu(rr->totlen),
 397                               PAD(sizeof(struct jffs2_raw_xref)));
 398                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
 399                         return err;
 400                 return 0;
 401         }
 402
 403         ref = jffs2_alloc_xattr_ref();
 404         if (!ref)
 405                 return -ENOMEM;
 406
 407         raw =  jffs2_alloc_raw_node_ref();
 408         if (!raw) {
 409                 jffs2_free_xattr_ref(ref);
 410                 return -ENOMEM;
 411         }
 412
 413         /* BEFORE jffs2_build_xattr_subsystem() called,
 414          * ref->xid is used to store 32bit xid, xd is not used
 415          * ref->ino is used to store 32bit inode-number, ic is not used
 416          * Thoes variables are declared as union, thus using those
 417          * are exclusive. In a similar way, ref->next is temporarily
 418          * used to chain all xattr_ref object. It's re-chained to
 419          * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
 420          */
 421         ref->node = raw;
 422         ref->ino = je32_to_cpu(rr->ino);
 423         ref->xid = je32_to_cpu(rr->xid);
 424         ref->next = c->xref_temp;
 425         c->xref_temp = ref;
 426
 427         raw->flash_offset = ofs | REF_PRISTINE;
 428         raw->next_in_ino = (void *)ref;
 429
 430         jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(rr->totlen)));
 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 */
 442 static 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;
 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         D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
 460
 461 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 462         if (jffs2_cleanmarker_oob(c)) {
 463                 int ret = jffs2_check_nand_cleanmarker(c, jeb);
 464                 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
 465                 /* Even if it's not found, we still scan to see
 466                    if the block is empty. We use this information
 467                    to decide whether to erase it or not. */
 468                 switch (ret) {
 469                 case 0:         cleanmarkerfound = 1; break;
 470                 case 1:         break;
 471                 case 2:         return BLK_STATE_BADBLOCK;
 472                 case 3:         return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */
 473                 default:        return ret;
 474                 }
 475         }
 476 #endif
 477
 478         if (jffs2_sum_active()) {
 479                 struct jffs2_sum_marker *sm;
 480                 void *sumptr = NULL;
 481                 uint32_t sumlen;
 482
 483                 if (!buf_size) {
 484                         /* XIP case. Just look, point at the summary if it's there */
 485                         sm = (void *)buf + jeb->offset - sizeof(*sm);
 486                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
 487                                 sumptr = buf + je32_to_cpu(sm->offset);
 488                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
 489                         }
 490                 } else {
 491                         /* If NAND flash, read a whole page of it. Else just the end */
 492                         if (c->wbuf_pagesize)
 493                                 buf_len = c->wbuf_pagesize;
 494                         else
 495                                 buf_len = sizeof(*sm);
 496
 497                         /* Read as much as we want into the _end_ of the preallocated buffer */
 498                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
 499                                                   jeb->offset + c->sector_size - buf_len,
 500                                                   buf_len);
 501                         if (err)
 502                                 return err;
 503
 504                         sm = (void *)buf + buf_size - sizeof(*sm);
 505                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
 506                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
 507                                 sumptr = buf + buf_size - sumlen;
 508
 509                                 /* Now, make sure the summary itself is available */
 510                                 if (sumlen > buf_size) {
 511                                         /* Need to kmalloc for this. */
 512                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
 513                                         if (!sumptr)
 514                                                 return -ENOMEM;
 515                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
 516                                 }
 517                                 if (buf_len < sumlen) {
 518                                         /* Need to read more so that the entire summary node is present */
 519                                         err = jffs2_fill_scan_buf(c, sumptr,
 520                                                                   jeb->offset + c->sector_size - sumlen,
 521                                                                   sumlen - buf_len);
 522                                         if (err)
 523                                                 return err;
 524                                 }
 525                         }
 526
 527                 }
 528
 529                 if (sumptr) {
 530                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
 531
 532                         if (buf_size && sumlen > buf_size)
 533                                 kfree(sumptr);
 534                         /* If it returns with a real error, bail.
 535                            If it returns positive, that's a block classification
 536                            (i.e. BLK_STATE_xxx) so return that too.
 537                            If it returns zero, fall through to full scan. */
 538                         if (err)
 539                                 return err;
 540                 }
 541         }
 542
 543         buf_ofs = jeb->offset;
 544
 545         if (!buf_size) {
 546                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
 547                 buf_len = c->sector_size;
 548         } else {
 549                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
 550                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
 551                 if (err)
 552                         return err;
 553         }
 554
 555         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
 556         ofs = 0;
 557
 558         /* Scan only 4KiB of 0xFF before declaring it's empty */
 559         while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
 560                 ofs += 4;
 561
 562         if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
 563 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 564                 if (jffs2_cleanmarker_oob(c)) {
 565                         /* scan oob, take care of cleanmarker */
 566                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
 567                         D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
 568                         switch (ret) {
 569                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
 570                         case 1:         return BLK_STATE_ALLDIRTY;
 571                         default:        return ret;
 572                         }
 573                 }
 574 #endif
 575                 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
 576                 if (c->cleanmarker_size == 0)
 577                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
 578                 else
 579                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
 580         }
 581         if (ofs) {
 582                 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
 583                           jeb->offset + ofs));
 584                 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
 585                         return err;
 586         }
 587
 588         /* Now ofs is a complete physical flash offset as it always was... */
 589         ofs += jeb->offset;
 590
 591         noise = 10;
 592
 593         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
 594
 595 scan_more:
 596         while(ofs < jeb->offset + c->sector_size) {
 597
 598                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 599
 600                 cond_resched();
 601
 602                 if (ofs & 3) {
 603                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
 604                         ofs = PAD(ofs);
 605                         continue;
 606                 }
 607                 if (ofs == prevofs) {
 608                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
 609                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 610                                 return err;
 611                         ofs += 4;
 612                         continue;
 613                 }
 614                 prevofs = ofs;
 615
 616                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
 617                         D1(printk(KERN_DEBUG "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", sizeof(struct jffs2_unknown_node),
 618                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
 619                         if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
 620                                 return err;
 621                         break;
 622                 }
 623
 624                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
 625                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 626                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
 627                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
 628                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 629                         if (err)
 630                                 return err;
 631                         buf_ofs = ofs;
 632                 }
 633
 634                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
 635
 636                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
 637                         uint32_t inbuf_ofs;
 638                         uint32_t empty_start;
 639
 640                         empty_start = ofs;
 641                         ofs += 4;
 642
 643                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
 644                 more_empty:
 645                         inbuf_ofs = ofs - buf_ofs;
 646                         while (inbuf_ofs < buf_len) {
 647                                 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
 648                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
 649                                                empty_start, ofs);
 650                                         if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
 651                                                 return err;
 652                                         goto scan_more;
 653                                 }
 654
 655                                 inbuf_ofs+=4;
 656                                 ofs += 4;
 657                         }
 658                         /* Ran off end. */
 659                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
 660
 661                         /* If we're only checking the beginning of a block with a cleanmarker,
 662                            bail now */
 663                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
 664                             c->cleanmarker_size && !jeb->dirty_size && !jeb->first_node->next_phys) {
 665                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
 666                                 return BLK_STATE_CLEANMARKER;
 667                         }
 668
 669                         /* See how much more there is to read in this eraseblock... */
 670                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 671                         if (!buf_len) {
 672                                 /* No more to read. Break out of main loop without marking
 673                                    this range of empty space as dirty (because it's not) */
 674                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
 675                                           empty_start));
 676                                 break;
 677                         }
 678                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
 679                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 680                         if (err)
 681                                 return err;
 682                         buf_ofs = ofs;
 683                         goto more_empty;
 684                 }
 685
 686                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
 687                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
 688                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 689                                 return err;
 690                         ofs += 4;
 691                         continue;
 692                 }
 693                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
 694                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
 695                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 696                                 return err;
 697                         ofs += 4;
 698                         continue;
 699                 }
 700                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
 701                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
 702                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
 703                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 704                                 return err;
 705                         ofs += 4;
 706                         continue;
 707                 }
 708                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
 709                         /* OK. We're out of possibilities. Whinge and move on */
 710                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
 711                                      JFFS2_MAGIC_BITMASK, ofs,
 712                                      je16_to_cpu(node->magic));
 713                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 714                                 return err;
 715                         ofs += 4;
 716                         continue;
 717                 }
 718                 /* We seem to have a node of sorts. Check the CRC */
 719                 crcnode.magic = node->magic;
 720                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
 721                 crcnode.totlen = node->totlen;
 722                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
 723
 724                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
 725                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
 726                                      ofs, je16_to_cpu(node->magic),
 727                                      je16_to_cpu(node->nodetype),
 728                                      je32_to_cpu(node->totlen),
 729                                      je32_to_cpu(node->hdr_crc),
 730                                      hdr_crc);
 731                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 732                                 return err;
 733                         ofs += 4;
 734                         continue;
 735                 }
 736
 737                 if (ofs + je32_to_cpu(node->totlen) >
 738                     jeb->offset + c->sector_size) {
 739                         /* Eep. Node goes over the end of the erase block. */
 740                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
 741                                ofs, je32_to_cpu(node->totlen));
 742                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
 743                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 744                                 return err;
 745                         ofs += 4;
 746                         continue;
 747                 }
 748
 749                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
 750                         /* Wheee. This is an obsoleted node */
 751                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
 752                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 753                                 return err;
 754                         ofs += PAD(je32_to_cpu(node->totlen));
 755                         continue;
 756                 }
 757
 758                 switch(je16_to_cpu(node->nodetype)) {
 759                 case JFFS2_NODETYPE_INODE:
 760                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
 761                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 762                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
 763                                           sizeof(struct jffs2_raw_inode), buf_len, ofs));
 764                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 765                                 if (err)
 766                                         return err;
 767                                 buf_ofs = ofs;
 768                                 node = (void *)buf;
 769                         }
 770                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
 771                         if (err) return err;
 772                         ofs += PAD(je32_to_cpu(node->totlen));
 773                         break;
 774
 775                 case JFFS2_NODETYPE_DIRENT:
 776                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 777                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 778                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
 779                                           je32_to_cpu(node->totlen), buf_len, ofs));
 780                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 781                                 if (err)
 782                                         return err;
 783                                 buf_ofs = ofs;
 784                                 node = (void *)buf;
 785                         }
 786                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
 787                         if (err) return err;
 788                         ofs += PAD(je32_to_cpu(node->totlen));
 789                         break;
 790
 791 #ifdef CONFIG_JFFS2_FS_XATTR
 792                 case JFFS2_NODETYPE_XATTR:
 793                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 794                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 795                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
 796                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
 797                                           je32_to_cpu(node->totlen), buf_len, ofs));
 798                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 799                                 if (err)
 800                                         return err;
 801                                 buf_ofs = ofs;
 802                                 node = (void *)buf;
 803                         }
 804                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
 805                         if (err)
 806                                 return err;
 807                         ofs += PAD(je32_to_cpu(node->totlen));
 808                         break;
 809                 case JFFS2_NODETYPE_XREF:
 810                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 811                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 812                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
 813                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
 814                                           je32_to_cpu(node->totlen), buf_len, ofs));
 815                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 816                                 if (err)
 817                                         return err;
 818                                 buf_ofs = ofs;
 819                                 node = (void *)buf;
 820                         }
 821                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
 822                         if (err)
 823                                 return err;
 824                         ofs += PAD(je32_to_cpu(node->totlen));
 825                         break;
 826 #endif  /* CONFIG_JFFS2_FS_XATTR */
 827
 828                 case JFFS2_NODETYPE_CLEANMARKER:
 829                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
 830                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
 831                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
 832                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
 833                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
 834                                         return err;
 835                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
 836                         } else if (jeb->first_node) {
 837                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
 838                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
 839                                         return err;
 840                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
 841                         } else {
 842                                 struct jffs2_raw_node_ref *marker_ref = jffs2_alloc_raw_node_ref();
 843                                 if (!marker_ref) {
 844                                         printk(KERN_NOTICE "Failed to allocate node ref for clean marker\n");
 845                                         return -ENOMEM;
 846                                 }
 847                                 marker_ref->next_in_ino = NULL;
 848                                 marker_ref->flash_offset = ofs | REF_NORMAL;
 849
 850                                 jffs2_link_node_ref(c, jeb, marker_ref, c->cleanmarker_size);
 851
 852                                 ofs += PAD(c->cleanmarker_size);
 853                         }
 854                         break;
 855
 856                 case JFFS2_NODETYPE_PADDING:
 857                         if (jffs2_sum_active())
 858                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
 859                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 860                                 return err;
 861                         ofs += PAD(je32_to_cpu(node->totlen));
 862                         break;
 863
 864                 default:
 865                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
 866                         case JFFS2_FEATURE_ROCOMPAT:
 867                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
 868                                 c->flags |= JFFS2_SB_FLAG_RO;
 869                                 if (!(jffs2_is_readonly(c)))
 870                                         return -EROFS;
 871                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 872                                         return err;
 873                                 ofs += PAD(je32_to_cpu(node->totlen));
 874                                 break;
 875
 876                         case JFFS2_FEATURE_INCOMPAT:
 877                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
 878                                 return -EINVAL;
 879
 880                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
 881                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
 882                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 883                                         return err;
 884                                 ofs += PAD(je32_to_cpu(node->totlen));
 885                                 break;
 886
 887                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
 888                                 struct jffs2_raw_node_ref *ref;
 889                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
 890
 891                                 ref = jffs2_alloc_raw_node_ref();
 892                                 if (!ref)
 893                                         return -ENOMEM;
 894                                 ref->flash_offset = ofs | REF_PRISTINE;
 895                                 ref->next_in_ino = 0;
 896                                 jffs2_link_node_ref(c, jeb, ref, PAD(je32_to_cpu(node->totlen)));
 897
 898                                 /* We can't summarise nodes we don't grok */
 899                                 jffs2_sum_disable_collecting(s);
 900                                 ofs += PAD(je32_to_cpu(node->totlen));
 901                                 break;
 902                                 }
 903                         }
 904                 }
 905         }
 906
 907         if (jffs2_sum_active()) {
 908                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
 909                         dbg_summary("There is not enough space for "
 910                                 "summary information, disabling for this jeb!\n");
 911                         jffs2_sum_disable_collecting(s);
 912                 }
 913         }
 914
 915         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x\n", jeb->offset,
 916                   jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size));
 917
 918         /* mark_node_obsolete can add to wasted !! */
 919         if (jeb->wasted_size) {
 920                 jeb->dirty_size += jeb->wasted_size;
 921                 c->dirty_size += jeb->wasted_size;
 922                 c->wasted_size -= jeb->wasted_size;
 923                 jeb->wasted_size = 0;
 924         }
 925
 926         return jffs2_scan_classify_jeb(c, jeb);
 927 }
 928
 929 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
 930 {
 931         struct jffs2_inode_cache *ic;
 932
 933         ic = jffs2_get_ino_cache(c, ino);
 934         if (ic)
 935                 return ic;
 936
 937         if (ino > c->highest_ino)
 938                 c->highest_ino = ino;
 939
 940         ic = jffs2_alloc_inode_cache();
 941         if (!ic) {
 942                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
 943                 return NULL;
 944         }
 945         memset(ic, 0, sizeof(*ic));
 946
 947         ic->ino = ino;
 948         ic->nodes = (void *)ic;
 949         jffs2_add_ino_cache(c, ic);
 950         if (ino == 1)
 951                 ic->nlink = 1;
 952         return ic;
 953 }
 954
 955 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 956                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
 957 {
 958         struct jffs2_raw_node_ref *raw;
 959         struct jffs2_inode_cache *ic;
 960         uint32_t ino = je32_to_cpu(ri->ino);
 961         int err;
 962
 963         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
 964
 965         /* We do very little here now. Just check the ino# to which we should attribute
 966            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
 967            we used to scan the flash once only, reading everything we want from it into
 968            memory, then building all our in-core data structures and freeing the extra
 969            information. Now we allow the first part of the mount to complete a lot quicker,
 970            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
 971            Which means that the _full_ amount of time to get to proper write mode with GC
 972            operational may actually be _longer_ than before. Sucks to be me. */
 973
 974         raw = jffs2_alloc_raw_node_ref();
 975         if (!raw) {
 976                 printk(KERN_NOTICE "jffs2_scan_inode_node(): allocation of node reference failed\n");
 977                 return -ENOMEM;
 978         }
 979
 980         ic = jffs2_get_ino_cache(c, ino);
 981         if (!ic) {
 982                 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
 983                    first node we found for this inode. Do a CRC check to protect against the former
 984                    case */
 985                 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
 986
 987                 if (crc != je32_to_cpu(ri->node_crc)) {
 988                         printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
 989                                ofs, je32_to_cpu(ri->node_crc), crc);
 990                         /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
 991                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(ri->totlen)))))
 992                                 return err;
 993                         jffs2_free_raw_node_ref(raw);
 994                         return 0;
 995                 }
 996                 ic = jffs2_scan_make_ino_cache(c, ino);
 997                 if (!ic) {
 998                         jffs2_free_raw_node_ref(raw);
 999                         return -ENOMEM;
1000                 }
1001         }
1002
1003         /* Wheee. It worked */
1004
1005         raw->flash_offset = ofs | REF_UNCHECKED;
1006
1007         raw->next_in_ino = ic->nodes;
1008         ic->nodes = raw;
1009
1010         jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(ri->totlen)));
1011
1012         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1013                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1014                   je32_to_cpu(ri->offset),
1015                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
1016
1017         pseudo_random += je32_to_cpu(ri->version);
1018
1019         if (jffs2_sum_active()) {
1020                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1021         }
1022
1023         return 0;
1024 }
1025
1026 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1027                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1028 {
1029         struct jffs2_raw_node_ref *raw;
1030         struct jffs2_full_dirent *fd;
1031         struct jffs2_inode_cache *ic;
1032         uint32_t crc;
1033         int err;
1034
1035         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1036
1037         /* We don't get here unless the node is still valid, so we don't have to
1038            mask in the ACCURATE bit any more. */
1039         crc = crc32(0, rd, sizeof(*rd)-8);
1040
1041         if (crc != je32_to_cpu(rd->node_crc)) {
1042                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1043                        ofs, je32_to_cpu(rd->node_crc), crc);
1044                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1045                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1046                         return err;
1047                 return 0;
1048         }
1049
1050         pseudo_random += je32_to_cpu(rd->version);
1051
1052         fd = jffs2_alloc_full_dirent(rd->nsize+1);
1053         if (!fd) {
1054                 return -ENOMEM;
1055         }
1056         memcpy(&fd->name, rd->name, rd->nsize);
1057         fd->name[rd->nsize] = 0;
1058
1059         crc = crc32(0, fd->name, rd->nsize);
1060         if (crc != je32_to_cpu(rd->name_crc)) {
1061                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1062                        ofs, je32_to_cpu(rd->name_crc), crc);
1063                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1064                 jffs2_free_full_dirent(fd);
1065                 /* FIXME: Why do we believe totlen? */
1066                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1067                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1068                         return err;
1069                 return 0;
1070         }
1071         raw = jffs2_alloc_raw_node_ref();
1072         if (!raw) {
1073                 jffs2_free_full_dirent(fd);
1074                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): allocation of node reference failed\n");
1075                 return -ENOMEM;
1076         }
1077         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1078         if (!ic) {
1079                 jffs2_free_full_dirent(fd);
1080                 jffs2_free_raw_node_ref(raw);
1081                 return -ENOMEM;
1082         }
1083
1084         raw->flash_offset = ofs | REF_PRISTINE;
1085         raw->next_in_ino = ic->nodes;
1086         ic->nodes = raw;
1087
1088         jffs2_link_node_ref(c, jeb, raw, PAD(je32_to_cpu(rd->totlen)));
1089
1090         fd->raw = raw;
1091         fd->next = NULL;
1092         fd->version = je32_to_cpu(rd->version);
1093         fd->ino = je32_to_cpu(rd->ino);
1094         fd->nhash = full_name_hash(fd->name, rd->nsize);
1095         fd->type = rd->type;
1096         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1097
1098         if (jffs2_sum_active()) {
1099                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1100         }
1101
1102         return 0;
1103 }
1104
1105 static int count_list(struct list_head *l)
1106 {
1107         uint32_t count = 0;
1108         struct list_head *tmp;
1109
1110         list_for_each(tmp, l) {
1111                 count++;
1112         }
1113         return count;
1114 }
1115
1116 /* Note: This breaks if list_empty(head). I don't care. You
1117    might, if you copy this code and use it elsewhere :) */
1118 static void rotate_list(struct list_head *head, uint32_t count)
1119 {
1120         struct list_head *n = head->next;
1121
1122         list_del(head);
1123         while(count--) {
1124                 n = n->next;
1125         }
1126         list_add(head, n);
1127 }
1128
1129 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1130 {
1131         uint32_t x;
1132         uint32_t rotateby;
1133
1134         x = count_list(&c->clean_list);
1135         if (x) {
1136                 rotateby = pseudo_random % x;
1137                 rotate_list((&c->clean_list), rotateby);
1138         }
1139
1140         x = count_list(&c->very_dirty_list);
1141         if (x) {
1142                 rotateby = pseudo_random % x;
1143                 rotate_list((&c->very_dirty_list), rotateby);
1144         }
1145
1146         x = count_list(&c->dirty_list);
1147         if (x) {
1148                 rotateby = pseudo_random % x;
1149                 rotate_list((&c->dirty_list), rotateby);
1150         }
1151
1152         x = count_list(&c->erasable_list);
1153         if (x) {
1154                 rotateby = pseudo_random % x;
1155                 rotate_list((&c->erasable_list), rotateby);
1156         }
1157
1158         if (c->nr_erasing_blocks) {
1159                 rotateby = pseudo_random % c->nr_erasing_blocks;
1160                 rotate_list((&c->erase_pending_list), rotateby);
1161         }
1162
1163         if (c->nr_free_blocks) {
1164                 rotateby = pseudo_random % c->nr_free_blocks;
1165                 rotate_list((&c->free_list), rotateby);
1166         }
1167 }