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