scan.c

   1/*
   2 * JFFS2 -- Journalling Flash File System, Version 2.
   3 *
   4 * Copyright © 2001-2007 Red Hat, Inc.
   5 *
   6 * Created by David Woodhouse <dwmw2@infradead.org>
   7 *
   8 * For licensing information, see the file 'LICENCE' in this directory.
   9 *
  10 */
  11
  12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14#include <linux/kernel.h>
  15#include <linux/sched.h>
  16#include <linux/slab.h>
  17#include <linux/mtd/mtd.h>
  18#include <linux/pagemap.h>
  19#include <linux/crc32.h>
  20#include <linux/compiler.h>
  21#include "nodelist.h"
  22#include "summary.h"
  23#include "debug.h"
  24
  25#define DEFAULT_EMPTY_SCAN_SIZE 256
  26
  27#define noisy_printk(noise, fmt, ...)					\
  28do {									\
  29	if (*(noise)) {							\
  30		pr_notice(fmt, ##__VA_ARGS__);				\
  31		(*(noise))--;						\
  32		if (!(*(noise)))					\
  33			pr_notice("Further such events for this erase block will not be printed\n"); \
  34	}								\
  35} while (0)
  36
  37static uint32_t pseudo_random;
  38
  39static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  40				  unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
  41
  42/* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
  43 * Returning an error will abort the mount - bad checksums etc. should just mark the space
  44 * as dirty.
  45 */
  46static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  47				 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
  48static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
  49				 struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
  50
  51static inline int min_free(struct jffs2_sb_info *c)
  52{
  53	uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
  54#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
  55	if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
  56		return c->wbuf_pagesize;
  57#endif
  58	return min;
  59
  60}
  61
  62static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
  63	if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
  64		return sector_size;
  65	else
  66		return DEFAULT_EMPTY_SCAN_SIZE;
  67}
  68
  69static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
  70{
  71	int ret;
  72
  73	if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
  74		return ret;
  75	if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
  76		return ret;
  77	/* Turned wasted size into dirty, since we apparently 
  78	   think it's recoverable now. */
  79	jeb->dirty_size += jeb->wasted_size;
  80	c->dirty_size += jeb->wasted_size;
  81	c->wasted_size -= jeb->wasted_size;
  82	jeb->wasted_size = 0;
  83	if (VERYDIRTY(c, jeb->dirty_size)) {
  84		list_add(&jeb->list, &c->very_dirty_list);
  85	} else {
  86		list_add(&jeb->list, &c->dirty_list);
  87	}
  88	return 0;
  89}
  90
  91int jffs2_scan_medium(struct jffs2_sb_info *c)
  92{
  93	int i, ret;
  94	uint32_t empty_blocks = 0, bad_blocks = 0;
  95	unsigned char *flashbuf = NULL;
  96	uint32_t buf_size = 0;
  97	struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
  98#ifndef __ECOS
  99	size_t pointlen, try_size;
 100
 101	ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen,
 102			(void **)&flashbuf, NULL);
 103	if (!ret && pointlen < c->mtd->size) {
 104		/* Don't muck about if it won't let us point to the whole flash */
 105		jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
 106			  pointlen);
 107		mtd_unpoint(c->mtd, 0, pointlen);
 108		flashbuf = NULL;
 109	}
 110	if (ret && ret != -EOPNOTSUPP)
 111		jffs2_dbg(1, "MTD point failed %d\n", ret);
 112#endif
 113	if (!flashbuf) {
 114		/* For NAND it's quicker to read a whole eraseblock at a time,
 115		   apparently */
 116		if (jffs2_cleanmarker_oob(c))
 117			try_size = c->sector_size;
 118		else
 119			try_size = PAGE_SIZE;
 120
 121		jffs2_dbg(1, "Trying to allocate readbuf of %zu "
 122			  "bytes\n", try_size);
 123
 124		flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
 125		if (!flashbuf)
 126			return -ENOMEM;
 127
 128		jffs2_dbg(1, "Allocated readbuf of %zu bytes\n",
 129			  try_size);
 130
 131		buf_size = (uint32_t)try_size;
 132	}
 133
 134	if (jffs2_sum_active()) {
 135		s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
 136		if (!s) {
 137			JFFS2_WARNING("Can't allocate memory for summary\n");
 138			ret = -ENOMEM;
 139			goto out_buf;
 140		}
 141	}
 142
 143	for (i=0; i<c->nr_blocks; i++) {
 144		struct jffs2_eraseblock *jeb = &c->blocks[i];
 145
 146		cond_resched();
 147
 148		/* reset summary info for next eraseblock scan */
 149		jffs2_sum_reset_collected(s);
 150
 151		ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
 152						buf_size, s);
 153
 154		if (ret < 0)
 155			goto out;
 156
 157		jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 158
 159		/* Now decide which list to put it on */
 160		switch(ret) {
 161		case BLK_STATE_ALLFF:
 162			/*
 163			 * Empty block.   Since we can't be sure it
 164			 * was entirely erased, we just queue it for erase
 165			 * again.  It will be marked as such when the erase
 166			 * is complete.  Meanwhile we still count it as empty
 167			 * for later checks.
 168			 */
 169			empty_blocks++;
 170			list_add(&jeb->list, &c->erase_pending_list);
 171			c->nr_erasing_blocks++;
 172			break;
 173
 174		case BLK_STATE_CLEANMARKER:
 175			/* Only a CLEANMARKER node is valid */
 176			if (!jeb->dirty_size) {
 177				/* It's actually free */
 178				list_add(&jeb->list, &c->free_list);
 179				c->nr_free_blocks++;
 180			} else {
 181				/* Dirt */
 182				jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n",
 183					  jeb->offset);
 184				list_add(&jeb->list, &c->erase_pending_list);
 185				c->nr_erasing_blocks++;
 186			}
 187			break;
 188
 189		case BLK_STATE_CLEAN:
 190			/* Full (or almost full) of clean data. Clean list */
 191			list_add(&jeb->list, &c->clean_list);
 192			break;
 193
 194		case BLK_STATE_PARTDIRTY:
 195			/* Some data, but not full. Dirty list. */
 196			/* We want to remember the block with most free space
 197			and stick it in the 'nextblock' position to start writing to it. */
 198			if (jeb->free_size > min_free(c) &&
 199					(!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
 200				/* Better candidate for the next writes to go to */
 201				if (c->nextblock) {
 202					ret = file_dirty(c, c->nextblock);
 203					if (ret)
 204						goto out;
 205					/* deleting summary information of the old nextblock */
 206					jffs2_sum_reset_collected(c->summary);
 207				}
 208				/* update collected summary information for the current nextblock */
 209				jffs2_sum_move_collected(c, s);
 210				jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
 211					  __func__, jeb->offset);
 212				c->nextblock = jeb;
 213			} else {
 214				ret = file_dirty(c, jeb);
 215				if (ret)
 216					goto out;
 217			}
 218			break;
 219
 220		case BLK_STATE_ALLDIRTY:
 221			/* Nothing valid - not even a clean marker. Needs erasing. */
 222			/* For now we just put it on the erasing list. We'll start the erases later */
 223			jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n",
 224				  jeb->offset);
 225			list_add(&jeb->list, &c->erase_pending_list);
 226			c->nr_erasing_blocks++;
 227			break;
 228
 229		case BLK_STATE_BADBLOCK:
 230			jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset);
 231			list_add(&jeb->list, &c->bad_list);
 232			c->bad_size += c->sector_size;
 233			c->free_size -= c->sector_size;
 234			bad_blocks++;
 235			break;
 236		default:
 237			pr_warn("%s(): unknown block state\n", __func__);
 238			BUG();
 239		}
 240	}
 241
 242	/* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
 243	if (c->nextblock && (c->nextblock->dirty_size)) {
 244		c->nextblock->wasted_size += c->nextblock->dirty_size;
 245		c->wasted_size += c->nextblock->dirty_size;
 246		c->dirty_size -= c->nextblock->dirty_size;
 247		c->nextblock->dirty_size = 0;
 248	}
 249#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 250	if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
 251		/* If we're going to start writing into a block which already
 252		   contains data, and the end of the data isn't page-aligned,
 253		   skip a little and align it. */
 254
 255		uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
 256
 257		jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n",
 258			  __func__, skip);
 259		ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
 260		if (ret)
 261			goto out;
 262		jffs2_scan_dirty_space(c, c->nextblock, skip);
 263	}
 264#endif
 265	if (c->nr_erasing_blocks) {
 266		if (!c->used_size && !c->unchecked_size &&
 267			((c->nr_free_blocks+empty_blocks+bad_blocks) != c->nr_blocks || bad_blocks == c->nr_blocks)) {
 268			pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
 269			pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",
 270				  empty_blocks, bad_blocks, c->nr_blocks);
 271			ret = -EIO;
 272			goto out;
 273		}
 274		spin_lock(&c->erase_completion_lock);
 275		jffs2_garbage_collect_trigger(c);
 276		spin_unlock(&c->erase_completion_lock);
 277	}
 278	ret = 0;
 279 out:
 280	jffs2_sum_reset_collected(s);
 281	kfree(s);
 282 out_buf:
 283	if (buf_size)
 284		kfree(flashbuf);
 285#ifndef __ECOS
 286	else
 287		mtd_unpoint(c->mtd, 0, c->mtd->size);
 288#endif
 289	return ret;
 290}
 291
 292static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
 293			       uint32_t ofs, uint32_t len)
 294{
 295	int ret;
 296	size_t retlen;
 297
 298	ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
 299	if (ret) {
 300		jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n",
 301			  len, ofs, ret);
 302		return ret;
 303	}
 304	if (retlen < len) {
 305		jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n",
 306			  ofs, retlen);
 307		return -EIO;
 308	}
 309	return 0;
 310}
 311
 312int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
 313{
 314	if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
 315	    && (!jeb->first_node || !ref_next(jeb->first_node)) )
 316		return BLK_STATE_CLEANMARKER;
 317
 318	/* move blocks with max 4 byte dirty space to cleanlist */
 319	else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
 320		c->dirty_size -= jeb->dirty_size;
 321		c->wasted_size += jeb->dirty_size;
 322		jeb->wasted_size += jeb->dirty_size;
 323		jeb->dirty_size = 0;
 324		return BLK_STATE_CLEAN;
 325	} else if (jeb->used_size || jeb->unchecked_size)
 326		return BLK_STATE_PARTDIRTY;
 327	else
 328		return BLK_STATE_ALLDIRTY;
 329}
 330
 331#ifdef CONFIG_JFFS2_FS_XATTR
 332static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 333				 struct jffs2_raw_xattr *rx, uint32_t ofs,
 334				 struct jffs2_summary *s)
 335{
 336	struct jffs2_xattr_datum *xd;
 337	uint32_t xid, version, totlen, crc;
 338	int err;
 339
 340	crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
 341	if (crc != je32_to_cpu(rx->node_crc)) {
 342		JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 343			      ofs, je32_to_cpu(rx->node_crc), crc);
 344		if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
 345			return err;
 346		return 0;
 347	}
 348
 349	xid = je32_to_cpu(rx->xid);
 350	version = je32_to_cpu(rx->version);
 351
 352	totlen = PAD(sizeof(struct jffs2_raw_xattr)
 353			+ rx->name_len + 1 + je16_to_cpu(rx->value_len));
 354	if (totlen != je32_to_cpu(rx->totlen)) {
 355		JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
 356			      ofs, je32_to_cpu(rx->totlen), totlen);
 357		if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
 358			return err;
 359		return 0;
 360	}
 361
 362	xd = jffs2_setup_xattr_datum(c, xid, version);
 363	if (IS_ERR(xd))
 364		return PTR_ERR(xd);
 365
 366	if (xd->version > version) {
 367		struct jffs2_raw_node_ref *raw
 368			= jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
 369		raw->next_in_ino = xd->node->next_in_ino;
 370		xd->node->next_in_ino = raw;
 371	} else {
 372		xd->version = version;
 373		xd->xprefix = rx->xprefix;
 374		xd->name_len = rx->name_len;
 375		xd->value_len = je16_to_cpu(rx->value_len);
 376		xd->data_crc = je32_to_cpu(rx->data_crc);
 377
 378		jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
 379	}
 380
 381	if (jffs2_sum_active())
 382		jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
 383	dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n",
 384		  ofs, xd->xid, xd->version);
 385	return 0;
 386}
 387
 388static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 389				struct jffs2_raw_xref *rr, uint32_t ofs,
 390				struct jffs2_summary *s)
 391{
 392	struct jffs2_xattr_ref *ref;
 393	uint32_t crc;
 394	int err;
 395
 396	crc = crc32(0, rr, sizeof(*rr) - 4);
 397	if (crc != je32_to_cpu(rr->node_crc)) {
 398		JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
 399			      ofs, je32_to_cpu(rr->node_crc), crc);
 400		if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
 401			return err;
 402		return 0;
 403	}
 404
 405	if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
 406		JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
 407			      ofs, je32_to_cpu(rr->totlen),
 408			      PAD(sizeof(struct jffs2_raw_xref)));
 409		if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
 410			return err;
 411		return 0;
 412	}
 413
 414	ref = jffs2_alloc_xattr_ref();
 415	if (!ref)
 416		return -ENOMEM;
 417
 418	/* BEFORE jffs2_build_xattr_subsystem() called, 
 419	 * and AFTER xattr_ref is marked as a dead xref,
 420	 * ref->xid is used to store 32bit xid, xd is not used
 421	 * ref->ino is used to store 32bit inode-number, ic is not used
 422	 * Thoes variables are declared as union, thus using those
 423	 * are exclusive. In a similar way, ref->next is temporarily
 424	 * used to chain all xattr_ref object. It's re-chained to
 425	 * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
 426	 */
 427	ref->ino = je32_to_cpu(rr->ino);
 428	ref->xid = je32_to_cpu(rr->xid);
 429	ref->xseqno = je32_to_cpu(rr->xseqno);
 430	if (ref->xseqno > c->highest_xseqno)
 431		c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
 432	ref->next = c->xref_temp;
 433	c->xref_temp = ref;
 434
 435	jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
 436
 437	if (jffs2_sum_active())
 438		jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
 439	dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
 440		  ofs, ref->xid, ref->ino);
 441	return 0;
 442}
 443#endif
 444
 445/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
 446   the flash, XIP-style */
 447static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 448				  unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
 449	struct jffs2_unknown_node *node;
 450	struct jffs2_unknown_node crcnode;
 451	uint32_t ofs, prevofs, max_ofs;
 452	uint32_t hdr_crc, buf_ofs, buf_len;
 453	int err;
 454	int noise = 0;
 455
 456
 457#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 458	int cleanmarkerfound = 0;
 459#endif
 460
 461	ofs = jeb->offset;
 462	prevofs = jeb->offset - 1;
 463
 464	jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs);
 465
 466#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 467	if (jffs2_cleanmarker_oob(c)) {
 468		int ret;
 469
 470		if (mtd_block_isbad(c->mtd, jeb->offset))
 471			return BLK_STATE_BADBLOCK;
 472
 473		ret = jffs2_check_nand_cleanmarker(c, jeb);
 474		jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret);
 475
 476		/* Even if it's not found, we still scan to see
 477		   if the block is empty. We use this information
 478		   to decide whether to erase it or not. */
 479		switch (ret) {
 480		case 0:		cleanmarkerfound = 1; break;
 481		case 1: 	break;
 482		default: 	return ret;
 483		}
 484	}
 485#endif
 486
 487	if (jffs2_sum_active()) {
 488		struct jffs2_sum_marker *sm;
 489		void *sumptr = NULL;
 490		uint32_t sumlen;
 491	      
 492		if (!buf_size) {
 493			/* XIP case. Just look, point at the summary if it's there */
 494			sm = (void *)buf + c->sector_size - sizeof(*sm);
 495			if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
 496				sumptr = buf + je32_to_cpu(sm->offset);
 497				sumlen = c->sector_size - je32_to_cpu(sm->offset);
 498			}
 499		} else {
 500			/* If NAND flash, read a whole page of it. Else just the end */
 501			if (c->wbuf_pagesize)
 502				buf_len = c->wbuf_pagesize;
 503			else
 504				buf_len = sizeof(*sm);
 505
 506			/* Read as much as we want into the _end_ of the preallocated buffer */
 507			err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
 508						  jeb->offset + c->sector_size - buf_len,
 509						  buf_len);				
 510			if (err)
 511				return err;
 512
 513			sm = (void *)buf + buf_size - sizeof(*sm);
 514			if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
 515				sumlen = c->sector_size - je32_to_cpu(sm->offset);
 516				sumptr = buf + buf_size - sumlen;
 517
 518				/* sm->offset maybe wrong but MAGIC maybe right */
 519				if (sumlen > c->sector_size)
 520					goto full_scan;
 521
 522				/* Now, make sure the summary itself is available */
 523				if (sumlen > buf_size) {
 524					/* Need to kmalloc for this. */
 525					sumptr = kmalloc(sumlen, GFP_KERNEL);
 526					if (!sumptr)
 527						return -ENOMEM;
 528					memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
 529				}
 530				if (buf_len < sumlen) {
 531					/* Need to read more so that the entire summary node is present */
 532					err = jffs2_fill_scan_buf(c, sumptr, 
 533								  jeb->offset + c->sector_size - sumlen,
 534								  sumlen - buf_len);				
 535					if (err) {
 536						if (sumlen > buf_size)
 537							kfree(sumptr);
 538						return err;
 539					}
 540				}
 541			}
 542
 543		}
 544
 545		if (sumptr) {
 546			err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
 547
 548			if (buf_size && sumlen > buf_size)
 549				kfree(sumptr);
 550			/* If it returns with a real error, bail. 
 551			   If it returns positive, that's a block classification
 552			   (i.e. BLK_STATE_xxx) so return that too.
 553			   If it returns zero, fall through to full scan. */
 554			if (err)
 555				return err;
 556		}
 557	}
 558
 559full_scan:
 560	buf_ofs = jeb->offset;
 561
 562	if (!buf_size) {
 563		/* This is the XIP case -- we're reading _directly_ from the flash chip */
 564		buf_len = c->sector_size;
 565	} else {
 566		buf_len = EMPTY_SCAN_SIZE(c->sector_size);
 567		err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
 568		if (err)
 569			return err;
 570	}
 571
 572	/* We temporarily use 'ofs' as a pointer into the buffer/jeb */
 573	ofs = 0;
 574	max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
 575	/* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
 576	while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
 577		ofs += 4;
 578
 579	if (ofs == max_ofs) {
 580#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 581		if (jffs2_cleanmarker_oob(c)) {
 582			/* scan oob, take care of cleanmarker */
 583			int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
 584			jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n",
 585				  ret);
 586			switch (ret) {
 587			case 0:		return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
 588			case 1: 	return BLK_STATE_ALLDIRTY;
 589			default: 	return ret;
 590			}
 591		}
 592#endif
 593		jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n",
 594			  jeb->offset);
 595		if (c->cleanmarker_size == 0)
 596			return BLK_STATE_CLEANMARKER;	/* don't bother with re-erase */
 597		else
 598			return BLK_STATE_ALLFF;	/* OK to erase if all blocks are like this */
 599	}
 600	if (ofs) {
 601		jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset,
 602			  jeb->offset + ofs);
 603		if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
 604			return err;
 605		if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
 606			return err;
 607	}
 608
 609	/* Now ofs is a complete physical flash offset as it always was... */
 610	ofs += jeb->offset;
 611
 612	noise = 10;
 613
 614	dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
 615
 616scan_more:
 617	while(ofs < jeb->offset + c->sector_size) {
 618
 619		jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 620
 621		/* Make sure there are node refs available for use */
 622		err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
 623		if (err)
 624			return err;
 625
 626		cond_resched();
 627
 628		if (ofs & 3) {
 629			pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs);
 630			ofs = PAD(ofs);
 631			continue;
 632		}
 633		if (ofs == prevofs) {
 634			pr_warn("ofs 0x%08x has already been seen. Skipping\n",
 635				ofs);
 636			if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 637				return err;
 638			ofs += 4;
 639			continue;
 640		}
 641		prevofs = ofs;
 642
 643		if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
 644			jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n",
 645				  sizeof(struct jffs2_unknown_node),
 646				  jeb->offset, c->sector_size, ofs,
 647				  sizeof(*node));
 648			if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
 649				return err;
 650			break;
 651		}
 652
 653		if (buf_ofs + buf_len < ofs + sizeof(*node)) {
 654			buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 655			jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
 656				  sizeof(struct jffs2_unknown_node),
 657				  buf_len, ofs);
 658			err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 659			if (err)
 660				return err;
 661			buf_ofs = ofs;
 662		}
 663
 664		node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
 665
 666		if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
 667			uint32_t inbuf_ofs;
 668			uint32_t empty_start, scan_end;
 669
 670			empty_start = ofs;
 671			ofs += 4;
 672			scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
 673
 674			jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs);
 675		more_empty:
 676			inbuf_ofs = ofs - buf_ofs;
 677			while (inbuf_ofs < scan_end) {
 678				if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
 679					pr_warn("Empty flash at 0x%08x ends at 0x%08x\n",
 680						empty_start, ofs);
 681					if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
 682						return err;
 683					goto scan_more;
 684				}
 685
 686				inbuf_ofs+=4;
 687				ofs += 4;
 688			}
 689			/* Ran off end. */
 690			jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n",
 691				  ofs);
 692
 693			/* If we're only checking the beginning of a block with a cleanmarker,
 694			   bail now */
 695			if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
 696			    c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
 697				jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n",
 698					  EMPTY_SCAN_SIZE(c->sector_size));
 699				return BLK_STATE_CLEANMARKER;
 700			}
 701			if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
 702				scan_end = buf_len;
 703				goto more_empty;
 704			}
 705			
 706			/* See how much more there is to read in this eraseblock... */
 707			buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 708			if (!buf_len) {
 709				/* No more to read. Break out of main loop without marking
 710				   this range of empty space as dirty (because it's not) */
 711				jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n",
 712					  empty_start);
 713				break;
 714			}
 715			/* point never reaches here */
 716			scan_end = buf_len;
 717			jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n",
 718				  buf_len, ofs);
 719			err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 720			if (err)
 721				return err;
 722			buf_ofs = ofs;
 723			goto more_empty;
 724		}
 725
 726		if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
 727			pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n",
 728				ofs);
 729			if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 730				return err;
 731			ofs += 4;
 732			continue;
 733		}
 734		if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
 735			jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs);
 736			if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 737				return err;
 738			ofs += 4;
 739			continue;
 740		}
 741		if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
 742			pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs);
 743			pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n");
 744			if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 745				return err;
 746			ofs += 4;
 747			continue;
 748		}
 749		if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
 750			/* OK. We're out of possibilities. Whinge and move on */
 751			noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
 752				     __func__,
 753				     JFFS2_MAGIC_BITMASK, ofs,
 754				     je16_to_cpu(node->magic));
 755			if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 756				return err;
 757			ofs += 4;
 758			continue;
 759		}
 760		/* We seem to have a node of sorts. Check the CRC */
 761		crcnode.magic = node->magic;
 762		crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
 763		crcnode.totlen = node->totlen;
 764		hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
 765
 766		if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
 767			noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
 768				     __func__,
 769				     ofs, je16_to_cpu(node->magic),
 770				     je16_to_cpu(node->nodetype),
 771				     je32_to_cpu(node->totlen),
 772				     je32_to_cpu(node->hdr_crc),
 773				     hdr_crc);
 774			if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 775				return err;
 776			ofs += 4;
 777			continue;
 778		}
 779
 780		if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
 781			/* Eep. Node goes over the end of the erase block. */
 782			pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
 783				ofs, je32_to_cpu(node->totlen));
 784			pr_warn("Perhaps the file system was created with the wrong erase size?\n");
 785			if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
 786				return err;
 787			ofs += 4;
 788			continue;
 789		}
 790
 791		if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
 792			/* Wheee. This is an obsoleted node */
 793			jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n",
 794				  ofs);
 795			if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 796				return err;
 797			ofs += PAD(je32_to_cpu(node->totlen));
 798			continue;
 799		}
 800
 801		switch(je16_to_cpu(node->nodetype)) {
 802		case JFFS2_NODETYPE_INODE:
 803			if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
 804				buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 805				jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
 806					  sizeof(struct jffs2_raw_inode),
 807					  buf_len, ofs);
 808				err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 809				if (err)
 810					return err;
 811				buf_ofs = ofs;
 812				node = (void *)buf;
 813			}
 814			err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
 815			if (err) return err;
 816			ofs += PAD(je32_to_cpu(node->totlen));
 817			break;
 818
 819		case JFFS2_NODETYPE_DIRENT:
 820			if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 821				buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 822				jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
 823					  je32_to_cpu(node->totlen), buf_len,
 824					  ofs);
 825				err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 826				if (err)
 827					return err;
 828				buf_ofs = ofs;
 829				node = (void *)buf;
 830			}
 831			err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
 832			if (err) return err;
 833			ofs += PAD(je32_to_cpu(node->totlen));
 834			break;
 835
 836#ifdef CONFIG_JFFS2_FS_XATTR
 837		case JFFS2_NODETYPE_XATTR:
 838			if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 839				buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 840				jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n",
 841					  je32_to_cpu(node->totlen), buf_len,
 842					  ofs);
 843				err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 844				if (err)
 845					return err;
 846				buf_ofs = ofs;
 847				node = (void *)buf;
 848			}
 849			err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
 850			if (err)
 851				return err;
 852			ofs += PAD(je32_to_cpu(node->totlen));
 853			break;
 854		case JFFS2_NODETYPE_XREF:
 855			if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
 856				buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
 857				jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n",
 858					  je32_to_cpu(node->totlen), buf_len,
 859					  ofs);
 860				err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
 861				if (err)
 862					return err;
 863				buf_ofs = ofs;
 864				node = (void *)buf;
 865			}
 866			err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
 867			if (err)
 868				return err;
 869			ofs += PAD(je32_to_cpu(node->totlen));
 870			break;
 871#endif	/* CONFIG_JFFS2_FS_XATTR */
 872
 873		case JFFS2_NODETYPE_CLEANMARKER:
 874			jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs);
 875			if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
 876				pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
 877					  ofs, je32_to_cpu(node->totlen),
 878					  c->cleanmarker_size);
 879				if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
 880					return err;
 881				ofs += PAD(sizeof(struct jffs2_unknown_node));
 882			} else if (jeb->first_node) {
 883				pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n",
 884					  ofs, jeb->offset);
 885				if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
 886					return err;
 887				ofs += PAD(sizeof(struct jffs2_unknown_node));
 888			} else {
 889				jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
 890
 891				ofs += PAD(c->cleanmarker_size);
 892			}
 893			break;
 894
 895		case JFFS2_NODETYPE_PADDING:
 896			if (jffs2_sum_active())
 897				jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
 898			if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 899				return err;
 900			ofs += PAD(je32_to_cpu(node->totlen));
 901			break;
 902
 903		default:
 904			switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
 905			case JFFS2_FEATURE_ROCOMPAT:
 906				pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n",
 907					  je16_to_cpu(node->nodetype), ofs);
 908				c->flags |= JFFS2_SB_FLAG_RO;
 909				if (!(jffs2_is_readonly(c)))
 910					return -EROFS;
 911				if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 912					return err;
 913				ofs += PAD(je32_to_cpu(node->totlen));
 914				break;
 915
 916			case JFFS2_FEATURE_INCOMPAT:
 917				pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n",
 918					  je16_to_cpu(node->nodetype), ofs);
 919				return -EINVAL;
 920
 921			case JFFS2_FEATURE_RWCOMPAT_DELETE:
 922				jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
 923					  je16_to_cpu(node->nodetype), ofs);
 924				if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
 925					return err;
 926				ofs += PAD(je32_to_cpu(node->totlen));
 927				break;
 928
 929			case JFFS2_FEATURE_RWCOMPAT_COPY: {
 930				jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
 931					  je16_to_cpu(node->nodetype), ofs);
 932
 933				jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
 934
 935				/* We can't summarise nodes we don't grok */
 936				jffs2_sum_disable_collecting(s);
 937				ofs += PAD(je32_to_cpu(node->totlen));
 938				break;
 939				}
 940			}
 941		}
 942	}
 943
 944	if (jffs2_sum_active()) {
 945		if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
 946			dbg_summary("There is not enough space for "
 947				"summary information, disabling for this jeb!\n");
 948			jffs2_sum_disable_collecting(s);
 949		}
 950	}
 951
 952	jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
 953		  jeb->offset, jeb->free_size, jeb->dirty_size,
 954		  jeb->unchecked_size, jeb->used_size, jeb->wasted_size);
 955	
 956	/* mark_node_obsolete can add to wasted !! */
 957	if (jeb->wasted_size) {
 958		jeb->dirty_size += jeb->wasted_size;
 959		c->dirty_size += jeb->wasted_size;
 960		c->wasted_size -= jeb->wasted_size;
 961		jeb->wasted_size = 0;
 962	}
 963
 964	return jffs2_scan_classify_jeb(c, jeb);
 965}
 966
 967struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
 968{
 969	struct jffs2_inode_cache *ic;
 970
 971	ic = jffs2_get_ino_cache(c, ino);
 972	if (ic)
 973		return ic;
 974
 975	if (ino > c->highest_ino)
 976		c->highest_ino = ino;
 977
 978	ic = jffs2_alloc_inode_cache();
 979	if (!ic) {
 980		pr_notice("%s(): allocation of inode cache failed\n", __func__);
 981		return NULL;
 982	}
 983	memset(ic, 0, sizeof(*ic));
 984
 985	ic->ino = ino;
 986	ic->nodes = (void *)ic;
 987	jffs2_add_ino_cache(c, ic);
 988	if (ino == 1)
 989		ic->pino_nlink = 1;
 990	return ic;
 991}
 992
 993static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
 994				 struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
 995{
 996	struct jffs2_inode_cache *ic;
 997	uint32_t crc, ino = je32_to_cpu(ri->ino);
 998
 999	jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
1000
1001	/* We do very little here now. Just check the ino# to which we should attribute
1002	   this node; we can do all the CRC checking etc. later. There's a tradeoff here --
1003	   we used to scan the flash once only, reading everything we want from it into
1004	   memory, then building all our in-core data structures and freeing the extra
1005	   information. Now we allow the first part of the mount to complete a lot quicker,
1006	   but we have to go _back_ to the flash in order to finish the CRC checking, etc.
1007	   Which means that the _full_ amount of time to get to proper write mode with GC
1008	   operational may actually be _longer_ than before. Sucks to be me. */
1009
1010	/* Check the node CRC in any case. */
1011	crc = crc32(0, ri, sizeof(*ri)-8);
1012	if (crc != je32_to_cpu(ri->node_crc)) {
1013		pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1014			  __func__, ofs, je32_to_cpu(ri->node_crc), crc);
1015		/*
1016		 * We believe totlen because the CRC on the node
1017		 * _header_ was OK, just the node itself failed.
1018		 */
1019		return jffs2_scan_dirty_space(c, jeb,
1020					      PAD(je32_to_cpu(ri->totlen)));
1021	}
1022
1023	ic = jffs2_get_ino_cache(c, ino);
1024	if (!ic) {
1025		ic = jffs2_scan_make_ino_cache(c, ino);
1026		if (!ic)
1027			return -ENOMEM;
1028	}
1029
1030	/* Wheee. It worked */
1031	jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
1032
1033	jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
1034		  je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
1035		  je32_to_cpu(ri->offset),
1036		  je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize));
1037
1038	pseudo_random += je32_to_cpu(ri->version);
1039
1040	if (jffs2_sum_active()) {
1041		jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
1042	}
1043
1044	return 0;
1045}
1046
1047static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
1048				  struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
1049{
1050	struct jffs2_full_dirent *fd;
1051	struct jffs2_inode_cache *ic;
1052	uint32_t checkedlen;
1053	uint32_t crc;
1054	int err;
1055
1056	jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
1057
1058	/* We don't get here unless the node is still valid, so we don't have to
1059	   mask in the ACCURATE bit any more. */
1060	crc = crc32(0, rd, sizeof(*rd)-8);
1061
1062	if (crc != je32_to_cpu(rd->node_crc)) {
1063		pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1064			  __func__, ofs, je32_to_cpu(rd->node_crc), crc);
1065		/* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1066		if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1067			return err;
1068		return 0;
1069	}
1070
1071	pseudo_random += je32_to_cpu(rd->version);
1072
1073	/* Should never happen. Did. (OLPC trac #4184)*/
1074	checkedlen = strnlen(rd->name, rd->nsize);
1075	if (checkedlen < rd->nsize) {
1076		pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n",
1077		       ofs, checkedlen);
1078	}
1079	fd = jffs2_alloc_full_dirent(checkedlen+1);
1080	if (!fd) {
1081		return -ENOMEM;
1082	}
1083	memcpy(&fd->name, rd->name, checkedlen);
1084	fd->name[checkedlen] = 0;
1085
1086	crc = crc32(0, fd->name, checkedlen);
1087	if (crc != je32_to_cpu(rd->name_crc)) {
1088		pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1089			  __func__, ofs, je32_to_cpu(rd->name_crc), crc);
1090		jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n",
1091			  fd->name, je32_to_cpu(rd->ino));
1092		jffs2_free_full_dirent(fd);
1093		/* FIXME: Why do we believe totlen? */
1094		/* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1095		if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1096			return err;
1097		return 0;
1098	}
1099	ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1100	if (!ic) {
1101		jffs2_free_full_dirent(fd);
1102		return -ENOMEM;
1103	}
1104
1105	fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
1106				      PAD(je32_to_cpu(rd->totlen)), ic);
1107
1108	fd->next = NULL;
1109	fd->version = je32_to_cpu(rd->version);
1110	fd->ino = je32_to_cpu(rd->ino);
1111	fd->nhash = full_name_hash(NULL, fd->name, checkedlen);
1112	fd->type = rd->type;
1113	jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1114
1115	if (jffs2_sum_active()) {
1116		jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1117	}
1118
1119	return 0;
1120}
1121
1122static int count_list(struct list_head *l)
1123{
1124	uint32_t count = 0;
1125	struct list_head *tmp;
1126
1127	list_for_each(tmp, l) {
1128		count++;
1129	}
1130	return count;
1131}
1132
1133/* Note: This breaks if list_empty(head). I don't care. You
1134   might, if you copy this code and use it elsewhere :) */
1135static void rotate_list(struct list_head *head, uint32_t count)
1136{
1137	struct list_head *n = head->next;
1138
1139	list_del(head);
1140	while(count--) {
1141		n = n->next;
1142	}
1143	list_add(head, n);
1144}
1145
1146void jffs2_rotate_lists(struct jffs2_sb_info *c)
1147{
1148	uint32_t x;
1149	uint32_t rotateby;
1150
1151	x = count_list(&c->clean_list);
1152	if (x) {
1153		rotateby = pseudo_random % x;
1154		rotate_list((&c->clean_list), rotateby);
1155	}
1156
1157	x = count_list(&c->very_dirty_list);
1158	if (x) {
1159		rotateby = pseudo_random % x;
1160		rotate_list((&c->very_dirty_list), rotateby);
1161	}
1162
1163	x = count_list(&c->dirty_list);
1164	if (x) {
1165		rotateby = pseudo_random % x;
1166		rotate_list((&c->dirty_list), rotateby);
1167	}
1168
1169	x = count_list(&c->erasable_list);
1170	if (x) {
1171		rotateby = pseudo_random % x;
1172		rotate_list((&c->erasable_list), rotateby);
1173	}
1174
1175	if (c->nr_erasing_blocks) {
1176		rotateby = pseudo_random % c->nr_erasing_blocks;
1177		rotate_list((&c->erase_pending_list), rotateby);
1178	}
1179
1180	if (c->nr_free_blocks) {
1181		rotateby = pseudo_random % c->nr_free_blocks;
1182		rotate_list((&c->free_list), rotateby);
1183	}
1184}