[JFFS2][XATTR] rid unnecessary writing of delete marker.
[linux-2.6.git] / fs / jffs2 / scan.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright (C) 2001-2003 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  * $Id: scan.c,v 1.125 2005/09/30 13:59:13 dedekind Exp $
11  *
12  */
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/pagemap.h>
18 #include <linux/crc32.h>
19 #include <linux/compiler.h>
20 #include "nodelist.h"
21 #include "summary.h"
22 #include "debug.h"
23
24 #define DEFAULT_EMPTY_SCAN_SIZE 1024
25
26 #define noisy_printk(noise, args...) do { \
27         if (*(noise)) { \
28                 printk(KERN_NOTICE args); \
29                  (*(noise))--; \
30                  if (!(*(noise))) { \
31                          printk(KERN_NOTICE "Further such events for this erase block will not be printed\n"); \
32                  } \
33         } \
34 } while(0)
35
36 static uint32_t pseudo_random;
37
38 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
39                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
40
41 /* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
42  * Returning an error will abort the mount - bad checksums etc. should just mark the space
43  * as dirty.
44  */
45 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
46                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
47 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
48                                  struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
49
50 static inline int min_free(struct jffs2_sb_info *c)
51 {
52         uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
53 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
54         if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
55                 return c->wbuf_pagesize;
56 #endif
57         return min;
58
59 }
60
61 static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
62         if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
63                 return sector_size;
64         else
65                 return DEFAULT_EMPTY_SCAN_SIZE;
66 }
67
68 static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
69 {
70         int ret;
71
72         if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
73                 return ret;
74         if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
75                 return ret;
76         /* Turned wasted size into dirty, since we apparently 
77            think it's recoverable now. */
78         jeb->dirty_size += jeb->wasted_size;
79         c->dirty_size += jeb->wasted_size;
80         c->wasted_size -= jeb->wasted_size;
81         jeb->wasted_size = 0;
82         if (VERYDIRTY(c, jeb->dirty_size)) {
83                 list_add(&jeb->list, &c->very_dirty_list);
84         } else {
85                 list_add(&jeb->list, &c->dirty_list);
86         }
87         return 0;
88 }
89
90 int jffs2_scan_medium(struct jffs2_sb_info *c)
91 {
92         int i, ret;
93         uint32_t empty_blocks = 0, bad_blocks = 0;
94         unsigned char *flashbuf = NULL;
95         uint32_t buf_size = 0;
96         struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
97 #ifndef __ECOS
98         size_t pointlen;
99
100         if (c->mtd->point) {
101                 ret = c->mtd->point (c->mtd, 0, c->mtd->size, &pointlen, &flashbuf);
102                 if (!ret && pointlen < c->mtd->size) {
103                         /* Don't muck about if it won't let us point to the whole flash */
104                         D1(printk(KERN_DEBUG "MTD point returned len too short: 0x%zx\n", pointlen));
105                         c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
106                         flashbuf = NULL;
107                 }
108                 if (ret)
109                         D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
110         }
111 #endif
112         if (!flashbuf) {
113                 /* For NAND it's quicker to read a whole eraseblock at a time,
114                    apparently */
115                 if (jffs2_cleanmarker_oob(c))
116                         buf_size = c->sector_size;
117                 else
118                         buf_size = PAGE_SIZE;
119
120                 /* Respect kmalloc limitations */
121                 if (buf_size > 128*1024)
122                         buf_size = 128*1024;
123
124                 D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
125                 flashbuf = kmalloc(buf_size, GFP_KERNEL);
126                 if (!flashbuf)
127                         return -ENOMEM;
128         }
129
130         if (jffs2_sum_active()) {
131                 s = kmalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
132                 if (!s) {
133                         JFFS2_WARNING("Can't allocate memory for summary\n");
134                         return -ENOMEM;
135                 }
136                 memset(s, 0, sizeof(struct jffs2_summary));
137         }
138
139         for (i=0; i<c->nr_blocks; i++) {
140                 struct jffs2_eraseblock *jeb = &c->blocks[i];
141
142                 /* reset summary info for next eraseblock scan */
143                 jffs2_sum_reset_collected(s);
144
145                 ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
146                                                 buf_size, s);
147
148                 if (ret < 0)
149                         goto out;
150
151                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
152
153                 /* Now decide which list to put it on */
154                 switch(ret) {
155                 case BLK_STATE_ALLFF:
156                         /*
157                          * Empty block.   Since we can't be sure it
158                          * was entirely erased, we just queue it for erase
159                          * again.  It will be marked as such when the erase
160                          * is complete.  Meanwhile we still count it as empty
161                          * for later checks.
162                          */
163                         empty_blocks++;
164                         list_add(&jeb->list, &c->erase_pending_list);
165                         c->nr_erasing_blocks++;
166                         break;
167
168                 case BLK_STATE_CLEANMARKER:
169                         /* Only a CLEANMARKER node is valid */
170                         if (!jeb->dirty_size) {
171                                 /* It's actually free */
172                                 list_add(&jeb->list, &c->free_list);
173                                 c->nr_free_blocks++;
174                         } else {
175                                 /* Dirt */
176                                 D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
177                                 list_add(&jeb->list, &c->erase_pending_list);
178                                 c->nr_erasing_blocks++;
179                         }
180                         break;
181
182                 case BLK_STATE_CLEAN:
183                         /* Full (or almost full) of clean data. Clean list */
184                         list_add(&jeb->list, &c->clean_list);
185                         break;
186
187                 case BLK_STATE_PARTDIRTY:
188                         /* Some data, but not full. Dirty list. */
189                         /* We want to remember the block with most free space
190                         and stick it in the 'nextblock' position to start writing to it. */
191                         if (jeb->free_size > min_free(c) &&
192                                         (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
193                                 /* Better candidate for the next writes to go to */
194                                 if (c->nextblock) {
195                                         ret = file_dirty(c, c->nextblock);
196                                         if (ret)
197                                                 return ret;
198                                         /* deleting summary information of the old nextblock */
199                                         jffs2_sum_reset_collected(c->summary);
200                                 }
201                                 /* update collected summary information for the current nextblock */
202                                 jffs2_sum_move_collected(c, s);
203                                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): new nextblock = 0x%08x\n", jeb->offset));
204                                 c->nextblock = jeb;
205                         } else {
206                                 ret = file_dirty(c, jeb);
207                                 if (ret)
208                                         return ret;
209                         }
210                         break;
211
212                 case BLK_STATE_ALLDIRTY:
213                         /* Nothing valid - not even a clean marker. Needs erasing. */
214                         /* For now we just put it on the erasing list. We'll start the erases later */
215                         D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
216                         list_add(&jeb->list, &c->erase_pending_list);
217                         c->nr_erasing_blocks++;
218                         break;
219
220                 case BLK_STATE_BADBLOCK:
221                         D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
222                         list_add(&jeb->list, &c->bad_list);
223                         c->bad_size += c->sector_size;
224                         c->free_size -= c->sector_size;
225                         bad_blocks++;
226                         break;
227                 default:
228                         printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
229                         BUG();
230                 }
231         }
232
233         /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
234         if (c->nextblock && (c->nextblock->dirty_size)) {
235                 c->nextblock->wasted_size += c->nextblock->dirty_size;
236                 c->wasted_size += c->nextblock->dirty_size;
237                 c->dirty_size -= c->nextblock->dirty_size;
238                 c->nextblock->dirty_size = 0;
239         }
240 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
241         if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
242                 /* If we're going to start writing into a block which already
243                    contains data, and the end of the data isn't page-aligned,
244                    skip a little and align it. */
245
246                 uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
247
248                 D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
249                           skip));
250                 jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
251                 jffs2_scan_dirty_space(c, c->nextblock, skip);
252         }
253 #endif
254         if (c->nr_erasing_blocks) {
255                 if ( !c->used_size && ((c->nr_free_blocks+empty_blocks+bad_blocks)!= c->nr_blocks || bad_blocks == c->nr_blocks) ) {
256                         printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
257                         printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",empty_blocks,bad_blocks,c->nr_blocks);
258                         ret = -EIO;
259                         goto out;
260                 }
261                 jffs2_erase_pending_trigger(c);
262         }
263         ret = 0;
264  out:
265         if (buf_size)
266                 kfree(flashbuf);
267 #ifndef __ECOS
268         else
269                 c->mtd->unpoint(c->mtd, flashbuf, 0, c->mtd->size);
270 #endif
271         if (s)
272                 kfree(s);
273
274         return ret;
275 }
276
277 int jffs2_fill_scan_buf (struct jffs2_sb_info *c, void *buf,
278                                 uint32_t ofs, uint32_t len)
279 {
280         int ret;
281         size_t retlen;
282
283         ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
284         if (ret) {
285                 D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
286                 return ret;
287         }
288         if (retlen < len) {
289                 D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
290                 return -EIO;
291         }
292         return 0;
293 }
294
295 int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
296 {
297         if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
298             && (!jeb->first_node || !ref_next(jeb->first_node)) )
299                 return BLK_STATE_CLEANMARKER;
300
301         /* move blocks with max 4 byte dirty space to cleanlist */
302         else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
303                 c->dirty_size -= jeb->dirty_size;
304                 c->wasted_size += jeb->dirty_size;
305                 jeb->wasted_size += jeb->dirty_size;
306                 jeb->dirty_size = 0;
307                 return BLK_STATE_CLEAN;
308         } else if (jeb->used_size || jeb->unchecked_size)
309                 return BLK_STATE_PARTDIRTY;
310         else
311                 return BLK_STATE_ALLDIRTY;
312 }
313
314 #ifdef CONFIG_JFFS2_FS_XATTR
315 static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
316                                  struct jffs2_raw_xattr *rx, uint32_t ofs,
317                                  struct jffs2_summary *s)
318 {
319         struct jffs2_xattr_datum *xd;
320         uint32_t xid, version, totlen, crc;
321         int err;
322
323         crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
324         if (crc != je32_to_cpu(rx->node_crc)) {
325                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
326                               ofs, je32_to_cpu(rx->node_crc), crc);
327                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
328                         return err;
329                 return 0;
330         }
331
332         xid = je32_to_cpu(rx->xid);
333         version = je32_to_cpu(rx->version);
334
335         totlen = PAD(sizeof(struct jffs2_raw_xattr)
336                         + rx->name_len + 1 + je16_to_cpu(rx->value_len));
337         if (totlen != je32_to_cpu(rx->totlen)) {
338                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
339                               ofs, je32_to_cpu(rx->totlen), totlen);
340                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
341                         return err;
342                 return 0;
343         }
344
345         xd = jffs2_setup_xattr_datum(c, xid, version);
346         if (IS_ERR(xd))
347                 return PTR_ERR(xd);
348
349         if (xd->version > version) {
350                 struct jffs2_raw_node_ref *raw
351                         = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
352                 raw->next_in_ino = xd->node->next_in_ino;
353                 xd->node->next_in_ino = raw;
354         } else {
355                 xd->version = version;
356                 xd->xprefix = rx->xprefix;
357                 xd->name_len = rx->name_len;
358                 xd->value_len = je16_to_cpu(rx->value_len);
359                 xd->data_crc = je32_to_cpu(rx->data_crc);
360
361                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
362         }
363
364         if (jffs2_sum_active())
365                 jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
366         dbg_xattr("scaning xdatum at %#08x (xid=%u, version=%u)\n",
367                   ofs, xd->xid, xd->version);
368         return 0;
369 }
370
371 static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
372                                 struct jffs2_raw_xref *rr, uint32_t ofs,
373                                 struct jffs2_summary *s)
374 {
375         struct jffs2_xattr_ref *ref;
376         uint32_t crc;
377         int err;
378
379         crc = crc32(0, rr, sizeof(*rr) - 4);
380         if (crc != je32_to_cpu(rr->node_crc)) {
381                 JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
382                               ofs, je32_to_cpu(rr->node_crc), crc);
383                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
384                         return err;
385                 return 0;
386         }
387
388         if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
389                 JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
390                               ofs, je32_to_cpu(rr->totlen),
391                               PAD(sizeof(struct jffs2_raw_xref)));
392                 if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
393                         return err;
394                 return 0;
395         }
396
397         ref = jffs2_alloc_xattr_ref();
398         if (!ref)
399                 return -ENOMEM;
400
401         /* BEFORE jffs2_build_xattr_subsystem() called, 
402          * and AFTER xattr_ref is marked as a dead xref,
403          * ref->xid is used to store 32bit xid, xd is not used
404          * ref->ino is used to store 32bit inode-number, ic is not used
405          * Thoes variables are declared as union, thus using those
406          * are exclusive. In a similar way, ref->next is temporarily
407          * used to chain all xattr_ref object. It's re-chained to
408          * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
409          */
410         ref->ino = je32_to_cpu(rr->ino);
411         ref->xid = je32_to_cpu(rr->xid);
412         ref->xseqno = je32_to_cpu(rr->xseqno);
413         if (ref->xseqno > c->highest_xseqno)
414                 c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
415         ref->next = c->xref_temp;
416         c->xref_temp = ref;
417
418         jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
419
420         if (jffs2_sum_active())
421                 jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
422         dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
423                   ofs, ref->xid, ref->ino);
424         return 0;
425 }
426 #endif
427
428 /* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
429    the flash, XIP-style */
430 static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
431                                   unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
432         struct jffs2_unknown_node *node;
433         struct jffs2_unknown_node crcnode;
434         uint32_t ofs, prevofs;
435         uint32_t hdr_crc, buf_ofs, buf_len;
436         int err;
437         int noise = 0;
438
439
440 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
441         int cleanmarkerfound = 0;
442 #endif
443
444         ofs = jeb->offset;
445         prevofs = jeb->offset - 1;
446
447         D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));
448
449 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
450         if (jffs2_cleanmarker_oob(c)) {
451                 int ret = jffs2_check_nand_cleanmarker(c, jeb);
452                 D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n",ret));
453                 /* Even if it's not found, we still scan to see
454                    if the block is empty. We use this information
455                    to decide whether to erase it or not. */
456                 switch (ret) {
457                 case 0:         cleanmarkerfound = 1; break;
458                 case 1:         break;
459                 case 2:         return BLK_STATE_BADBLOCK;
460                 case 3:         return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */
461                 default:        return ret;
462                 }
463         }
464 #endif
465
466         if (jffs2_sum_active()) {
467                 struct jffs2_sum_marker *sm;
468                 void *sumptr = NULL;
469                 uint32_t sumlen;
470               
471                 if (!buf_size) {
472                         /* XIP case. Just look, point at the summary if it's there */
473                         sm = (void *)buf + c->sector_size - sizeof(*sm);
474                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
475                                 sumptr = buf + je32_to_cpu(sm->offset);
476                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
477                         }
478                 } else {
479                         /* If NAND flash, read a whole page of it. Else just the end */
480                         if (c->wbuf_pagesize)
481                                 buf_len = c->wbuf_pagesize;
482                         else
483                                 buf_len = sizeof(*sm);
484
485                         /* Read as much as we want into the _end_ of the preallocated buffer */
486                         err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len, 
487                                                   jeb->offset + c->sector_size - buf_len,
488                                                   buf_len);                             
489                         if (err)
490                                 return err;
491
492                         sm = (void *)buf + buf_size - sizeof(*sm);
493                         if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
494                                 sumlen = c->sector_size - je32_to_cpu(sm->offset);
495                                 sumptr = buf + buf_size - sumlen;
496
497                                 /* Now, make sure the summary itself is available */
498                                 if (sumlen > buf_size) {
499                                         /* Need to kmalloc for this. */
500                                         sumptr = kmalloc(sumlen, GFP_KERNEL);
501                                         if (!sumptr)
502                                                 return -ENOMEM;
503                                         memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
504                                 }
505                                 if (buf_len < sumlen) {
506                                         /* Need to read more so that the entire summary node is present */
507                                         err = jffs2_fill_scan_buf(c, sumptr, 
508                                                                   jeb->offset + c->sector_size - sumlen,
509                                                                   sumlen - buf_len);                            
510                                         if (err)
511                                                 return err;
512                                 }
513                         }
514
515                 }
516
517                 if (sumptr) {
518                         err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
519
520                         if (buf_size && sumlen > buf_size)
521                                 kfree(sumptr);
522                         /* If it returns with a real error, bail. 
523                            If it returns positive, that's a block classification
524                            (i.e. BLK_STATE_xxx) so return that too.
525                            If it returns zero, fall through to full scan. */
526                         if (err)
527                                 return err;
528                 }
529         }
530
531         buf_ofs = jeb->offset;
532
533         if (!buf_size) {
534                 /* This is the XIP case -- we're reading _directly_ from the flash chip */
535                 buf_len = c->sector_size;
536         } else {
537                 buf_len = EMPTY_SCAN_SIZE(c->sector_size);
538                 err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
539                 if (err)
540                         return err;
541         }
542
543         /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
544         ofs = 0;
545
546         /* Scan only 4KiB of 0xFF before declaring it's empty */
547         while(ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
548                 ofs += 4;
549
550         if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
551 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
552                 if (jffs2_cleanmarker_oob(c)) {
553                         /* scan oob, take care of cleanmarker */
554                         int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
555                         D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n",ret));
556                         switch (ret) {
557                         case 0:         return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
558                         case 1:         return BLK_STATE_ALLDIRTY;
559                         default:        return ret;
560                         }
561                 }
562 #endif
563                 D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
564                 if (c->cleanmarker_size == 0)
565                         return BLK_STATE_CLEANMARKER;   /* don't bother with re-erase */
566                 else
567                         return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
568         }
569         if (ofs) {
570                 D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
571                           jeb->offset + ofs));
572                 if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
573                         return err;
574                 if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
575                         return err;
576         }
577
578         /* Now ofs is a complete physical flash offset as it always was... */
579         ofs += jeb->offset;
580
581         noise = 10;
582
583         dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
584
585 scan_more:
586         while(ofs < jeb->offset + c->sector_size) {
587
588                 jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
589
590                 /* Make sure there are node refs available for use */
591                 err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
592                 if (err)
593                         return err;
594
595                 cond_resched();
596
597                 if (ofs & 3) {
598                         printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
599                         ofs = PAD(ofs);
600                         continue;
601                 }
602                 if (ofs == prevofs) {
603                         printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
604                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
605                                 return err;
606                         ofs += 4;
607                         continue;
608                 }
609                 prevofs = ofs;
610
611                 if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
612                         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),
613                                   jeb->offset, c->sector_size, ofs, sizeof(*node)));
614                         if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
615                                 return err;
616                         break;
617                 }
618
619                 if (buf_ofs + buf_len < ofs + sizeof(*node)) {
620                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
621                         D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
622                                   sizeof(struct jffs2_unknown_node), buf_len, ofs));
623                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
624                         if (err)
625                                 return err;
626                         buf_ofs = ofs;
627                 }
628
629                 node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
630
631                 if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
632                         uint32_t inbuf_ofs;
633                         uint32_t empty_start;
634
635                         empty_start = ofs;
636                         ofs += 4;
637
638                         D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
639                 more_empty:
640                         inbuf_ofs = ofs - buf_ofs;
641                         while (inbuf_ofs < buf_len) {
642                                 if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) {
643                                         printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
644                                                empty_start, ofs);
645                                         if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
646                                                 return err;
647                                         goto scan_more;
648                                 }
649
650                                 inbuf_ofs+=4;
651                                 ofs += 4;
652                         }
653                         /* Ran off end. */
654                         D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));
655
656                         /* If we're only checking the beginning of a block with a cleanmarker,
657                            bail now */
658                         if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
659                             c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
660                                 D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
661                                 return BLK_STATE_CLEANMARKER;
662                         }
663
664                         /* See how much more there is to read in this eraseblock... */
665                         buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
666                         if (!buf_len) {
667                                 /* No more to read. Break out of main loop without marking
668                                    this range of empty space as dirty (because it's not) */
669                                 D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
670                                           empty_start));
671                                 break;
672                         }
673                         D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
674                         err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
675                         if (err)
676                                 return err;
677                         buf_ofs = ofs;
678                         goto more_empty;
679                 }
680
681                 if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
682                         printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
683                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
684                                 return err;
685                         ofs += 4;
686                         continue;
687                 }
688                 if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
689                         D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
690                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
691                                 return err;
692                         ofs += 4;
693                         continue;
694                 }
695                 if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
696                         printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
697                         printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
698                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
699                                 return err;
700                         ofs += 4;
701                         continue;
702                 }
703                 if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
704                         /* OK. We're out of possibilities. Whinge and move on */
705                         noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
706                                      JFFS2_MAGIC_BITMASK, ofs,
707                                      je16_to_cpu(node->magic));
708                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
709                                 return err;
710                         ofs += 4;
711                         continue;
712                 }
713                 /* We seem to have a node of sorts. Check the CRC */
714                 crcnode.magic = node->magic;
715                 crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
716                 crcnode.totlen = node->totlen;
717                 hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
718
719                 if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
720                         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",
721                                      ofs, je16_to_cpu(node->magic),
722                                      je16_to_cpu(node->nodetype),
723                                      je32_to_cpu(node->totlen),
724                                      je32_to_cpu(node->hdr_crc),
725                                      hdr_crc);
726                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
727                                 return err;
728                         ofs += 4;
729                         continue;
730                 }
731
732                 if (ofs + je32_to_cpu(node->totlen) >
733                     jeb->offset + c->sector_size) {
734                         /* Eep. Node goes over the end of the erase block. */
735                         printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
736                                ofs, je32_to_cpu(node->totlen));
737                         printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
738                         if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
739                                 return err;
740                         ofs += 4;
741                         continue;
742                 }
743
744                 if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
745                         /* Wheee. This is an obsoleted node */
746                         D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
747                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
748                                 return err;
749                         ofs += PAD(je32_to_cpu(node->totlen));
750                         continue;
751                 }
752
753                 switch(je16_to_cpu(node->nodetype)) {
754                 case JFFS2_NODETYPE_INODE:
755                         if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
756                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
757                                 D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
758                                           sizeof(struct jffs2_raw_inode), buf_len, ofs));
759                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
760                                 if (err)
761                                         return err;
762                                 buf_ofs = ofs;
763                                 node = (void *)buf;
764                         }
765                         err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
766                         if (err) return err;
767                         ofs += PAD(je32_to_cpu(node->totlen));
768                         break;
769
770                 case JFFS2_NODETYPE_DIRENT:
771                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
772                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
773                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
774                                           je32_to_cpu(node->totlen), buf_len, ofs));
775                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
776                                 if (err)
777                                         return err;
778                                 buf_ofs = ofs;
779                                 node = (void *)buf;
780                         }
781                         err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
782                         if (err) return err;
783                         ofs += PAD(je32_to_cpu(node->totlen));
784                         break;
785
786 #ifdef CONFIG_JFFS2_FS_XATTR
787                 case JFFS2_NODETYPE_XATTR:
788                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
789                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
790                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xattr node)"
791                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
792                                           je32_to_cpu(node->totlen), buf_len, ofs));
793                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
794                                 if (err)
795                                         return err;
796                                 buf_ofs = ofs;
797                                 node = (void *)buf;
798                         }
799                         err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
800                         if (err)
801                                 return err;
802                         ofs += PAD(je32_to_cpu(node->totlen));
803                         break;
804                 case JFFS2_NODETYPE_XREF:
805                         if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
806                                 buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
807                                 D1(printk(KERN_DEBUG "Fewer than %d bytes (xref node)"
808                                           " left to end of buf. Reading 0x%x at 0x%08x\n",
809                                           je32_to_cpu(node->totlen), buf_len, ofs));
810                                 err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
811                                 if (err)
812                                         return err;
813                                 buf_ofs = ofs;
814                                 node = (void *)buf;
815                         }
816                         err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
817                         if (err)
818                                 return err;
819                         ofs += PAD(je32_to_cpu(node->totlen));
820                         break;
821 #endif  /* CONFIG_JFFS2_FS_XATTR */
822
823                 case JFFS2_NODETYPE_CLEANMARKER:
824                         D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
825                         if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
826                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
827                                        ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
828                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
829                                         return err;
830                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
831                         } else if (jeb->first_node) {
832                                 printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
833                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
834                                         return err;
835                                 ofs += PAD(sizeof(struct jffs2_unknown_node));
836                         } else {
837                                 jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
838
839                                 ofs += PAD(c->cleanmarker_size);
840                         }
841                         break;
842
843                 case JFFS2_NODETYPE_PADDING:
844                         if (jffs2_sum_active())
845                                 jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
846                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
847                                 return err;
848                         ofs += PAD(je32_to_cpu(node->totlen));
849                         break;
850
851                 default:
852                         switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
853                         case JFFS2_FEATURE_ROCOMPAT:
854                                 printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
855                                 c->flags |= JFFS2_SB_FLAG_RO;
856                                 if (!(jffs2_is_readonly(c)))
857                                         return -EROFS;
858                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
859                                         return err;
860                                 ofs += PAD(je32_to_cpu(node->totlen));
861                                 break;
862
863                         case JFFS2_FEATURE_INCOMPAT:
864                                 printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
865                                 return -EINVAL;
866
867                         case JFFS2_FEATURE_RWCOMPAT_DELETE:
868                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
869                                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
870                                         return err;
871                                 ofs += PAD(je32_to_cpu(node->totlen));
872                                 break;
873
874                         case JFFS2_FEATURE_RWCOMPAT_COPY: {
875                                 D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
876
877                                 jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
878
879                                 /* We can't summarise nodes we don't grok */
880                                 jffs2_sum_disable_collecting(s);
881                                 ofs += PAD(je32_to_cpu(node->totlen));
882                                 break;
883                                 }
884                         }
885                 }
886         }
887
888         if (jffs2_sum_active()) {
889                 if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
890                         dbg_summary("There is not enough space for "
891                                 "summary information, disabling for this jeb!\n");
892                         jffs2_sum_disable_collecting(s);
893                 }
894         }
895
896         D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
897                   jeb->offset,jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size, jeb->wasted_size));
898         
899         /* mark_node_obsolete can add to wasted !! */
900         if (jeb->wasted_size) {
901                 jeb->dirty_size += jeb->wasted_size;
902                 c->dirty_size += jeb->wasted_size;
903                 c->wasted_size -= jeb->wasted_size;
904                 jeb->wasted_size = 0;
905         }
906
907         return jffs2_scan_classify_jeb(c, jeb);
908 }
909
910 struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
911 {
912         struct jffs2_inode_cache *ic;
913
914         ic = jffs2_get_ino_cache(c, ino);
915         if (ic)
916                 return ic;
917
918         if (ino > c->highest_ino)
919                 c->highest_ino = ino;
920
921         ic = jffs2_alloc_inode_cache();
922         if (!ic) {
923                 printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
924                 return NULL;
925         }
926         memset(ic, 0, sizeof(*ic));
927
928         ic->ino = ino;
929         ic->nodes = (void *)ic;
930         jffs2_add_ino_cache(c, ic);
931         if (ino == 1)
932                 ic->nlink = 1;
933         return ic;
934 }
935
936 static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
937                                  struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
938 {
939         struct jffs2_inode_cache *ic;
940         uint32_t ino = je32_to_cpu(ri->ino);
941         int err;
942
943         D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));
944
945         /* We do very little here now. Just check the ino# to which we should attribute
946            this node; we can do all the CRC checking etc. later. There's a tradeoff here --
947            we used to scan the flash once only, reading everything we want from it into
948            memory, then building all our in-core data structures and freeing the extra
949            information. Now we allow the first part of the mount to complete a lot quicker,
950            but we have to go _back_ to the flash in order to finish the CRC checking, etc.
951            Which means that the _full_ amount of time to get to proper write mode with GC
952            operational may actually be _longer_ than before. Sucks to be me. */
953
954         ic = jffs2_get_ino_cache(c, ino);
955         if (!ic) {
956                 /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
957                    first node we found for this inode. Do a CRC check to protect against the former
958                    case */
959                 uint32_t crc = crc32(0, ri, sizeof(*ri)-8);
960
961                 if (crc != je32_to_cpu(ri->node_crc)) {
962                         printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
963                                ofs, je32_to_cpu(ri->node_crc), crc);
964                         /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
965                         if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(ri->totlen)))))
966                                 return err;
967                         return 0;
968                 }
969                 ic = jffs2_scan_make_ino_cache(c, ino);
970                 if (!ic)
971                         return -ENOMEM;
972         }
973
974         /* Wheee. It worked */
975         jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
976
977         D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
978                   je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
979                   je32_to_cpu(ri->offset),
980                   je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize)));
981
982         pseudo_random += je32_to_cpu(ri->version);
983
984         if (jffs2_sum_active()) {
985                 jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
986         }
987
988         return 0;
989 }
990
991 static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
992                                   struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
993 {
994         struct jffs2_full_dirent *fd;
995         struct jffs2_inode_cache *ic;
996         uint32_t crc;
997         int err;
998
999         D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));
1000
1001         /* We don't get here unless the node is still valid, so we don't have to
1002            mask in the ACCURATE bit any more. */
1003         crc = crc32(0, rd, sizeof(*rd)-8);
1004
1005         if (crc != je32_to_cpu(rd->node_crc)) {
1006                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1007                        ofs, je32_to_cpu(rd->node_crc), crc);
1008                 /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
1009                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1010                         return err;
1011                 return 0;
1012         }
1013
1014         pseudo_random += je32_to_cpu(rd->version);
1015
1016         fd = jffs2_alloc_full_dirent(rd->nsize+1);
1017         if (!fd) {
1018                 return -ENOMEM;
1019         }
1020         memcpy(&fd->name, rd->name, rd->nsize);
1021         fd->name[rd->nsize] = 0;
1022
1023         crc = crc32(0, fd->name, rd->nsize);
1024         if (crc != je32_to_cpu(rd->name_crc)) {
1025                 printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
1026                        ofs, je32_to_cpu(rd->name_crc), crc);
1027                 D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
1028                 jffs2_free_full_dirent(fd);
1029                 /* FIXME: Why do we believe totlen? */
1030                 /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
1031                 if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
1032                         return err;
1033                 return 0;
1034         }
1035         ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
1036         if (!ic) {
1037                 jffs2_free_full_dirent(fd);
1038                 return -ENOMEM;
1039         }
1040
1041         fd->raw = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rd->totlen)), ic);
1042
1043         fd->next = NULL;
1044         fd->version = je32_to_cpu(rd->version);
1045         fd->ino = je32_to_cpu(rd->ino);
1046         fd->nhash = full_name_hash(fd->name, rd->nsize);
1047         fd->type = rd->type;
1048         jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
1049
1050         if (jffs2_sum_active()) {
1051                 jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
1052         }
1053
1054         return 0;
1055 }
1056
1057 static int count_list(struct list_head *l)
1058 {
1059         uint32_t count = 0;
1060         struct list_head *tmp;
1061
1062         list_for_each(tmp, l) {
1063                 count++;
1064         }
1065         return count;
1066 }
1067
1068 /* Note: This breaks if list_empty(head). I don't care. You
1069    might, if you copy this code and use it elsewhere :) */
1070 static void rotate_list(struct list_head *head, uint32_t count)
1071 {
1072         struct list_head *n = head->next;
1073
1074         list_del(head);
1075         while(count--) {
1076                 n = n->next;
1077         }
1078         list_add(head, n);
1079 }
1080
1081 void jffs2_rotate_lists(struct jffs2_sb_info *c)
1082 {
1083         uint32_t x;
1084         uint32_t rotateby;
1085
1086         x = count_list(&c->clean_list);
1087         if (x) {
1088                 rotateby = pseudo_random % x;
1089                 rotate_list((&c->clean_list), rotateby);
1090         }
1091
1092         x = count_list(&c->very_dirty_list);
1093         if (x) {
1094                 rotateby = pseudo_random % x;
1095                 rotate_list((&c->very_dirty_list), rotateby);
1096         }
1097
1098         x = count_list(&c->dirty_list);
1099         if (x) {
1100                 rotateby = pseudo_random % x;
1101                 rotate_list((&c->dirty_list), rotateby);
1102         }
1103
1104         x = count_list(&c->erasable_list);
1105         if (x) {
1106                 rotateby = pseudo_random % x;
1107                 rotate_list((&c->erasable_list), rotateby);
1108         }
1109
1110         if (c->nr_erasing_blocks) {
1111                 rotateby = pseudo_random % c->nr_erasing_blocks;
1112                 rotate_list((&c->erase_pending_list), rotateby);
1113         }
1114
1115         if (c->nr_free_blocks) {
1116                 rotateby = pseudo_random % c->nr_free_blocks;
1117                 rotate_list((&c->free_list), rotateby);
1118         }
1119 }