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